GB2579959A - Vibration control device for rolling stock - Google Patents

Abstract

This control device is configured including a damper control device, which variably controls damping force generated by 1-axle through 4-axle dampers, and an anomaly detection estimation unit, which detects and estimates anomalies in the 1-axle through 4-axle dampers. The anomaly detection estimation unit is provided with a roll data calculation unit (roll data output device), which outputs roll data that changes depending on the roll (leftward and rightward rocking) of a body, and a breakdown assessment device 14, which compares the roll data outputted from the roll data calculation unit with a breakdown assessment value in a prescribed travel condition and assesses whether or not the 1-axle through 4-axle dampers 7A-7D have broken down.

Description

DESCRIPTION

VIBRATION CONTROL DEVICE FOR RAILWAY VEHICLE

TECHNICAL FIELD

[0001] The invention relates to a vibration control device for a railway vehicle, which is suitably used to reduce vibrations, for example, of railway vehicles and the like. BACKGROUND ART [0002] In general, a railway vehicle with a vehicle body that is long in total length is provided with four acceleration sensors and a plurality of damping force variable dampers. The acceleration sensors are arranged away from each other in longitudinal and lateral directions and located close to four corners of the vehicle body. The acceleration sensors detect the sprung acceleration of the vehicle body at their respective locations. The damping force variable dampers generate variably adjustable damping forces. The damping forces generated by the dampers are controlled by a control device on the basis of signals detected by the acceleration sensors (see Patent Literatures 1 and 2, for example).

CITATION LIST

PATENT LITERATURE

[0003] PTL 1: Japanese Unexamined Patent Application Publication (Kokai) No. 20006807 PTL 2: Japanese Patent No. 5650483

SUMMARY OF INVENTION

TECHNICAL PROBLEM

[0004] The technology described in Patent Literature 1 provides acceleration sensors on a plurality of carriages and compares acceleration detection signals outputted from these sensors to determine the presence of an abnormality of the sensors. The technology described in Patent Literature 2 determines the presence of an abnormality of a sensor on the basis of a code outputted from a triaxial acceleration sensor. Basically, the above-mentioned conventional technologies merely determine the presence of abnormalities or -2 -failures in the acceleration sensors and do not make any failure diagnosis (judgment of normality or abnormality) of a plurality of damping force variable dampers (force generating mechanisms).

SOLUTION TO PROBLEM

[0005] An object of the invention is to provide a vibration control device for a railway vehicle, which is capable of making a failure diagnosis of a force generating mechanism and taking quick countermeasures.

[0006] The vibration control device for a railway vehicle according to one embodiment of the invention comprises a force generating mechanism disposed between a carriage on which wheels are mounted and a vehicle body, the force generating mechanism being configured to generate a force that is adjustable in a vertical direction; a control portion configured to control the generated force of the force generating mechanism; and an abnormality detecting and estimating portion configured to detect and estimate an abnormality of the force generating mechanism. The abnormality detecting and estimating portion includes a roll data output device configured to output roll data changed by roll of the vehicle body, and a failure judgment device configured to compare the roll data outputted from the roll data output device with a failure judgment value under a predetermined running condition and thus judge whether the force generating mechanism is failed.

[0007] One embodiment of the invention makes it possible to detect an abnormality of the force generating mechanism and repress to the minimum a deterioration in ride comfort which is attributable to the abnormality.

BRIEF DESCRIPTION OF DRAWINGS

[0008] Fig. 1 is a front elevation view of a railway vehicle applied with a vibration control device for a railway vehicle according to an embodiment of the invention.

Fig. 2 is a plan view of an interior portion of the railway vehicle as viewed from above for explaining a layout of damping force variable dampers and acceleration sensors illustrated in Fig. 1.

Fig. 3 is a block diagram showing control by the control device illustrated in Fig. 2. -3 -

Fig. 4 is a flowchart showing a process of a failure diagnosis of a variable damper according to a first embodiment.

Fig. 5 is a flowchart showing a process of a failure diagnosis of a variable damper according to a second embodiment.

Fig. 6 is a flowchart showing a process of a failure diagnosis of a variable damper according to a third embodiment.

Fig. 7 is a flowchart showing the process of the failure diagnosis of the variable damper, which is continued from the flowchart of Fig. 6.

Fig. 8 is a flowchart showing a process of a failure diagnosis of a variable damper according to a fourth embodiment.

Fig. 9 is a flowchart showing the process of the failure diagnosis of the variable damper, which is continued from the flowchart of Fig. 8.

Fig. 10 is a flowchart showing the process of the failure diagnosis of the variable damper, which is continued from the flowchart of Fig. 9.

DESCRIPTION OF EMBODIMENTS

[0009] A vibration control device for a railway vehicle according to embodiments of the invention will be discussed below in detail with reference to the attached drawings, taking as an example a case in which the vibration control device is installed in a railway vehicle such as a train.

[0010] Figs. 1 to 4 illustrate a first embodiment of the invention. Referring to Fig. 1, a railway vehicle 1 includes a vehicle body 2 boarded, for example, by passengers, crews and the like and front and rear carriages 3 disposed under the vehicle body 2. The carriages 3 are separately arranged on front and rear sides of the vehicle body 2 and each provided with four wheels 4. The railway vehicle 1 is driven to run, for example, in a direction of an arrow A when moving forward along rails 5 by rolling movement (rotation) of the wheels 4 on right and left rails 5, only one of the rails shown.

[0011] Disposed between the vehicle body 2 and each of the carriages 3 are a plurality of suspension springs 6 elastically supporting the vehicle body 2 on the respective carriages 3 -4 -and a plurality of damping force variable dampers 7 (hereinafter, referred to as variable dampers 7) arranged in parallel with the suspension springs 6. The variable dampers 7 are disposed between the carriages 3 and the vehicle body 2. Each of the variable dampers 7 forms a force generating mechanism configured to generate a force that is adjustable in a vertical direction.

[0012] Each of the carriages 3 is provided with two variable dampers 7, and therefore, one vehicle is provided with four variable dampers 7. In Fig. 2, the variable dampers 7 are exemplified as a first axial damper 7A and a second axial damper 7B respectively arranged on left and right sides (FL and FR sides) of the front carriage 3 located on the front side of the vehicle body 2, and a third axial damper 7C and a fourth axial damper 7D respectively arranged on left and right sides (AL and RR sides) of the rear carriage 3 located on the rear side of the vehicle body 2.

[0013] The variable dampers 7 (first to fourth axial dampers 7A to 7D) include cylinder devices (for example, damping force adjustment hydraulic shock absorbers called semi-active dampers) whose damping forces are individually adjustable Each of the variable dampers 7 includes a damping force adjustment valve, not shown, which comprises, for example, a proportional solenoid or the like. The damping force adjustment valve is configured to adjust damping force characteristics to characteristics freely selected in a range between hard characteristics and soft characteristics to reduce vibrations of the vehicle body 2.

[0014] More specifically, the damping forces of the variable dampers 7 are variably controlled according to control signals that are individually outputted from a control device 9 discussed later to individually absorb and reduce rightward and leftward vibrations of the vehicle body 2 relative to the front and rear carriages 3. In this case, the variable dampers 7 may be configured to adjust the damping force characteristics between the hard characteristics and the soft characteristics either in a continuous manner or in two or more steps.

[0015] The damping force characteristics of the variable dampers 7 are variably adjusted between a soft mode and a hard mode according to a value of current supplied (carried) from -5 -the control device 9 to the solenoids, not shown, of the variable dampers 7. The variable dampers 7 are so configured as to generate medium damping forces (which means that the damping forces generated by the variable dampers 7 are approximately midway between the hard mode and the soft mode) as discussed later in a state where the current carried to the solenoids is blocked, and the current value is therefore 0 A (zero ampere). When the variable dampers 7 are failed, therefor, the current carried from the control device 9 to the variable dampers 7 is cut off (blocked). The variable dampers 7 are accordingly fixed at medium damping force characteristics.

[0016] As illustrated in Fig. 2, the vehicle body 2 is provided with four acceleration sensors 8A, 8B, SC and 8D arranged close to four corners separated in front, rear, right and left directions. The acceleration sensors 8A, 8B, 8C and 8D detect vertical acceleration of the vehicle body 2 as sprung acceleration at the respective locations. The acceleration sensors SA to 8D are installed at a plurality of different places in the railway vehicle 1 and form a plurality of sensors (behavior sensors) for detecting behavior of the railway vehicle 1. The acceleration sensors 8A to 8D may comprise, for example, analogue acceleration sensors of a piezoelectric type, a piezoresistive type or another like type. It is preferable to use an acceleration sensor that is excellent especially in water and heat resistance.

[0017] The acceleration sensor 8A is arranged close to the first axial damper 7A located at the FL side that is a left front side of the vehicle body 2. The acceleration sensor 8B is arranged close to the second axial damper 7B located at the FR side that is a right front side of the vehicle body 2. The acceleration sensor 8C is arranged close to the third axial damper 7C located at the RL side that is a left rear side of the vehicle body 2. The acceleration sensor 8D is arranged close to the fourth axial damper 7D located at the RR side that is a right rear side of the vehicle body 2. The acceleration sensors 8A to 8D detect accelerations at the respective locations and output detected signals to the later-discussed control device 9 as individual detected signals.

[0018] The acceleration sensors 8A to 8D (collectively referred to as acceleration sensors 8) may be arranged in any manner, instead of being arranged on the left front side, right front -6 -side, left rear side, and right rear side of the vehicle body 2. For example, the acceleration sensors 8 may be arranged at a center on the front side, at a left side of a center portion, at a right side of the center portion, and at a center on the rear side of the vehicle body 2 or arranged in any other way. The number of the acceleration sensors 8 is also not limited to four and may be freely selected depending on intended use such as measurement and control. It is desirable nevertheless to arrange at least two acceleration sensors 8.

[0019] The following discussion will mention the control device 9 functioning as a control portion that variably controls the generated damping forces of the variable dampers 7. The control device 9 is placed at a predetermined position in the railway vehicle 1 (for example, such a position that the control device 9 is located at a substantially center of the vehicle body 2 as illustrated in Fig. 2). The control device 9 comprises, for example, a microcomputer or the like. An input side of the control device 9 is connected to the acceleration sensors 8A to 8D through cables 15A to 15D (collectively referred to as cables 15) discussed later. An output side of the control device 9 is connected to the first axial damper 7A located on the left front (FL) side of the vehicle body 2, the second axial damper 7B located on the right front (FR) side of the vehicle body 2, the third axial damper 7C located on the left rear (RL) side of the vehicle body 2, and the fourth axial damper 7D on the right rear (RR) side through cables 16A to 16D (collectively referred to as cables 16). [0020] The control device 9 is connected to a control device, not shown, of another vehicle body that is jointed (coupled) to the vehicle body 2 illustrated in Fig. 1, for example, through a communication line 10. Furthermore, vehicle information (for example, a running position and running speed of the vehicle, and other like information) of the railway vehicle 1 is inputted/outputted through the communication line 10. One control device 9 is arranged in one vehicle body 2. The control device 9 communicates with a high-order portion of the vehicle through the communication line 10, performs computing inside on the basis of a sensor signal, and carries current based on a damping force command to the variable dampers 7. The control device 9 further, for example, performs a failure diagnosis, abnormality detection and the like with respect to the variable dampers 7. -7 -

[0021] The control device 9 includes a memory 9A functioning as a storage portion comprising, for example, a ROM, a RAM, a non-volatile memory and the like. The memory 9A stores, for example, a program for making a failure diagnosis of the variable dampers 7 as illustrated in Fig. 4, a failure judgment value, and the like. The failure judgment value is a threshold value for determining whether operating states of the variable dampers 7 (first to fourth axial dampers 7A to 7D) are in a normal range. More specifically, the judgment value for making a normality or failure judgment with respect to the variable dampers 7 (namely, failure judgment value) is updatably stored in a roll data storage portion 14C (see Fig. 3) forming a part of the memory 9A. The control device 9 determines whether the roll data obtained from a roll data output device is in a normal range. The roll data output device includes the acceleration sensors 8 mounted on the vehicle body 2, a gyroscope sensor, a vehicle height sensor, not shown, and the like. The control device 9 is thus capable of making the failure diagnosis of the variable dampers 7 (first to fourth axial dampers 7A to 7D).

[0022] As illustrated in Fig. 3, the control device 9 comprises a damper control device 11 finictioning as a control portion that variably controls the generated damping forces of the first to fourth axial dampers 7A to 7D and an abnormality detecting and estimating portion 12 that detects and estimates abnormalities of the force generating mechanisms (first to fourth axial dampers 7A to 7D). The abnormality detecting and estimating portion 12 includes a roll data calculating portion 13 functioning as a roll data output device that outputs roll data changed by roll (right-and-left oscillations) of the vehicle body 2 and a failure judgment device 14 that compares the roll data outputted from the roll data calculating portion 13 (roll data output device) with the failure judgment value under a predetermined running condition (which is stored in the memory 9A) and judges whether the first to fourth axial dampers 7A to 7D are failed.

[0023] In order to reduce vibrations such as the roll (lateral oscillations), pitch (front-andback oscillations), and other like vibrations of the vehicle body 2, the damper control device 11 of the control device 9 reads in the detected signals outputted from the acceleration -8 -sensors 8A to 8D at every sampling time, obtains control signals (current values of a control command) through computing, for example, according to a skyhook theory (skyhook control law), and outputs the obtained control signals individually to the variable dampers 7 (first to fourth axial dampers 7A to 7D), to thereby variably control the damping force characteristics of each of the variable dampers 7. The control law of the variable dampers 7 is not limited to the skyhook control law and may be, for example, LQG control law, Hoo control law or the like.

[0024] The failure judgment device 14 of the control device 9 comprises a vehicle position detecting portion 14A configured to detect a running position of the railway vehicle 1, a vehicle speed detecting portion 14B configured to detect running speed of the railway vehicle 1, the roll data storage portion 14C configured to store the roll data outputted from the roll data calculating portion 13 under the predetermined running condition, and a failure judgment value calculating portion 14D configured to calculate the failure judgment value as the threshold value from the running position, the running speed, and the roll data.

[0025] The vehicle position detecting portion 14A and the vehicle speed detecting portion 14B are capable of detecting the running position and the running speed of the railway vehicle 1 moving along a track (rails 5) on the basis of the vehicle information transmitted through the communication line 10. The roll data storage portion 14C comprises, for example, the memory 9A of the control device 9. The failure judgment value calculated by the failure judgment value calculating portion 14D is a judgment value for the failure judgment device 14 to determine (judge) whether the variable dampers 7 (first to fourth axial dampers 7A to 7D) normally operate. The failure judgment value is updatably stored in the roll data storage portion 14C.

[0026] The failure judgment value that is also a normality/abnorniality threshold value is determined in the following fashion. For example, the railway vehicle 1 is repeatedly subjected to a running test while the variable dampers 7 (first to fourth axial dampers 7A to 7D) are in normal conditions, to thereby accumulate in the roll data storage portion 14C the roll data that is sequentially outputted from the roll data calculating portion 13. The failure -9 -judgment value is determined on the basis of the normal-time roll data mentioned above. The failure judgment value calculating portion 14D calculates the failure judgment value as a threshold value on the basis of whether the roll data outputted from the roll data calculating portion 13 falls within a range of the normal roll data under the predetermined running condition (for example, predetermined running position and running speed). It is preferable that a proper evaluation interval and proper evaluation speed be previously determined on the basis of a signal transmitted from the vehicle position detecting portion 14A and a signal transmitted from the vehicle speed detecting portion 14B.

[0027] Specifically, the failure judgment device 14 is capable of making a. correct judgment as to whether each of the variable dampers 7 (first to fourth axial dampers 7A to 7D) operates normally or abnormally by determining whether the roll data of the vehicle body 2 falls within the range of the normal-time roll data when the running speed of the railway vehicle 1 is in a prescribed evaluation speed range while the railway vehicle 1 is running in a predetermined evaluation interval. The failure judgment value calculating portion 14D combines and relates the roll data stored in the roll data storage portion 14C and the signals transmitted from the vehicle position detecting portion 14A and the vehicle speed detecting portion 14B. The failure judgment value calculating portion 14D then calculates from the aforementioned roll data the failure judgment value to be used as the threshold value for determining whether the roll data is in the normal range.

[0028] The failure diagnosis of the variable dampers 7 by the failure judgment device 14 may be made on the basis of a comparison between the roll data of one of a plurality of vehicle bodies 2 coupled together and the roll data of another one of the vehicle bodies 2. When the comparison is made in real-time, the roll data of the vehicle body 2 running in a curved line interval is large, whereas the roll data of the vehicle body 2 running close to an entrance or exit of the curved line interval is low. This might lead to an erroneous detection. To eliminate the possibility of such an erroneous detection, it is preferable that the comparison be made on the basis of information about the position of the railway vehicle 1 running on a predetermined track (rails 5). In addition, vehicle body's weight and the -10 -number of occupants differ from one vehicle body 2 to another. The threshold value for abnormality determination is preferably determined in light of the vehicle body's weight and the number of occupants of each of the vehicle bodies 2.

[0029] The roll data output device comprises a plurality of sensors (acceleration sensors 8) disposed in the vehicle body 2 and configured to detect vehicle body behavior, and the roll data calculating portion 13 configured to calculate the roll data from values that are derived from the acceleration sensors 8. The roll data output device does not necessarily have to be configured in the foregoing manner The roll data output device may comprise, for example, a roll detector of a gyroscope sensor and the like. The plurality of sensors for detecting the vehicle body behavior may comprise, for example, vehicle height sensors or other like sensors.

[0030] As illustrated in Fig. 2, the input side of the control device 9 is connected to the acceleration sensors 8A to 8D through the long-length cables 15A to 15D (collectively referred to as cables 15) functioning as lines. The output side of the control device 9 is connected to the variable dampers 7 (first to fourth axial dampers 7A to 7D) and the like through the cables 16A to 16D (collectively referred to as cables 16).

[0031] The vibration control device for a railway vehicle according to the first embodiment is thus configured. The following will discuss operation of the vibration control device for a railway vehicle according to the first embodiment.

[0032] When vibrations such as roll (lateral oscillations) and pitch (front-and-back oscillations) are generated while the railway vehicle 1 runs along the rails 5 in the direction of arrow A in Figs. 1 and 2, vertical vibrations are detected by the acceleration sensors 8A to 8D. To be more specific, the acceleration sensor 8A detects vibrations on the left front (FL) side of the vehicle body 2. The acceleration sensor 8B detects vibrations on the right front (FR) side of the vehicle body 2. The acceleration sensor 8C detects vibrations on the left rear (RL) side of the vehicle body 2. The acceleration sensor SD detects vibrations on the right rear (RR) side of the vehicle body 2.

[0033] The damper control device 11 of the control device 9 individuates the signals detected by the acceleration sensors 8A to 8D as individual detected signals indicative of accelerations. At the same time, in order to repress the vibrations of the railway vehicle 1, the damper control device 11, for example, computes target damping forces to be generated by the variable dampers 7 (first to fourth axial dampers 7A to 7D) located on the FL, FR, RL, and RR sides. The first to fourth axial dampers 7A to 7D are then variably controlled according to the control signals that are individually outputted from the damper control device 11 so that the generated damping forces of the first to fourth axial dampers 7A to 7D have characteristics corresponding to the respective target damping forces.

[0034] With regard to the railway vehicle 1, the failure diagnosis of the acceleration sensors 8A to 8D and the like has been known. As for the failure diagnosis and abnormality detection of the variable dampers 7 (first to fourth axial dampers 7A to 7D), on the other hand, effective means has not necessarily been provided. To solve this, the first embodiment makes the failure diagnosis of the variable dampers 7, for example, using the failure judgment device 14 of the control device 9 illustrated in Fig. 3 according to process steps in Fig. 4.

[0035] After the process illustrated in Fig. 4 starts, the roll data outputted from the roll data calculating portion 13 is read in at Step 1. Next Step 2 compares the failure judgment value under the predetermined running condition (the value being previously stored, for example, in the roll data storage portion 14C of Fig. 3) with the roll data, to thereby determine whether the roll data falls within the normal range.

[0036] A "YES" determination at Step 2 means that the roll data is in the normal range and that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally. Therefore, roll control over the railway vehicle 1 is judged as stable. The routine then returns to Step 1 and implements the subsequent process. When the determination at Step 2 is "NO", the roll data is out of the normal range and shows an abnormal value.

[0037] Next Step 3 thus judges that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate abnormally and are failed. After Step 3 judges the variable dampers 7 to operate abnormally, the vibration control over each of the vehicle bodies 2 (namely, the -12 -control device 9) may be discontinued, and a fail mode may be used. In a case where only one of the vehicle bodies 2 is judged as abnormal, and this causes a great difference in ride comfort as compared to the other vehicles (vehicle bodies 2), the control over the railway vehicles 1 (the plurality of vehicle bodies 2) coupled together may be suspended. When the variable dampers 7 of the railway vehicle 1 are judged as failed, the current carried to the variable dampers 7 is blocked so that the variable dampers 7 are fixed at medium damping force characteristics. This allows a medium damping action to be ensured.

[0038] In the aforementioned case, a high-order railway management system may be informed, through a driver's seat (for example, from the control device 9 through the communication line 10), that the variable damper 7 (any of the first to fourth axial dampers 7A to 7D) is failed to cause an abnormality in the damping system. if the high-order portion is thus informed, a swift repair takes place. According to the present embodiment, a proper determination can be made as to an abnormality of the variable dampers 7. After the abnormality of the variable dampers 7 is detected, it is possible to, for example, turn off the control over the variable dampers 7 and provide proper countermeasures including the use of the fail mode (in which the variable dampers 7 are fixed at the medium damping force characteristics).

[0039] The proper evaluation interval for the determination of a roll data abnormality may be extracted from conditions including a running interval and running speed of the vehicle and the track. In the present embodiment, the failure judgment value (threshold value) of the roll data is obtained by the failure judgment value calculating portion 14D, so that the evaluation interval is set, for example, to a large curve interval in which the vehicle runs at high speed. The failure judgment device 14 accordingly performs the failure diagnosis and the abnormality detection only in such a curve interval. In this case, the running interval and the running speed are preferably also taken into account. Basically, a running area and the running speed of the railway vehicle 1 are roughly preset. In this view, the failure diagnosis and the abnormality detection are more effectively achieved if the abnormality determination is made only when the running interval and the running speed fall within a -13 -range of prescribed values.

[0040] The failure judgment device 14 functions as below. The evaluation interval and the running speed are preset, for example, through a plurality of running tests. Running data obtained in abnormality simulation is then analyzed. The obtained running data is updatably stored as the failure judgment value (threshold value) in the memory 9A (roll data storage portion 14C) of the control device 9. Since the evaluation interval and a proper threshold value of the speed are set as described above, when an abnormality occurs, the failure judgment device 14 is capable of performing the abnormality detection (that is, the failure diagnosis of the variable dampers 7) without false detection. In this connection, it is also possible to avoid detecting the abnormalities in the aforementioned evaluation interval if the vehicle runs at different running speed. For example, when a running condition is different, there is a possibility that traveling itself is not properly carried out due to a travel delay, a vehicle failure or the like. On some occasions, the traveling of the vehicle needs to be prioritized over the abnormality detection.

[0041] According to another mode of the invention which is related to the roll data abnormality determination (that is, the failure diagnosis of the variable dampers 7), a comparison may be made between the roll data of one vehicle body 2 and the roll data of another vehicle body 2. For example, the roll data of the vehicle body 2 is compared with the roll data of an adjacent vehicle body 2. If the roll data of the vehicle body 2 subjected to the abnormality determination is larger than the prescribed value, the threshold value for the determination of abnormality of the target vehicle body 2 determines that the roll data is abnormal. Assuming that the comparison is made in real-time, however, for example, if the comparison is made between the vehicle body 2 rolling in the curve interval and another vehicle body 2 located at the entrance of the curve interval, difference in the roll data between the two vehicle bodies 2 is large. This creates a possibility that the variable dampers 7 are determined as abnormal. For that reason, it is preferable to make the comparison on the basis of the running position that is obtained, for example, from vehicle position data or the like.

-14 - [0042] Fig. 5 illustrates a second embodiment of the present invention. In the present embodiment, the same constituent elements as those of the first embodiment are provided with the same reference signs, and description thereof will be omitted. The second embodiment is characterized in that, when variable dampers 7 operate abnormally, and roll data is out of a normal range, a determination is made as to whether a cause for the abnormality is incorrect wiring, or more specifically, incorrect wiring attributable to wrong connection of lines (cables 16A to 16D, for example) connecting the variable dampers 7 (first to fourth axial dampers 7A to 7D) to a control device 9.

[0043] After the process illustrated in Fig. 5 starts, roll data is read in at Step 11 as in Step 1 of Fig. 4 according to the first embodiment. Next Step 12 compares a failure judgment value (stored, for example, in a roll data storage portion 14C of Fig. 3) under a predetermined running condition with the roll data, to thereby determine whether the roll data is within a normal range. A "YES" determination at Step 12 means that variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally. The routine then returns to the process of Step 11 and implements the subsequent process.

[0044] When the determination at Step 12 is "NO," the roll data is out of the normal range and shows an abnormal value. At next Step 13, a. mode is changed to an "abnormality diagnosis mode." The "abnormality diagnosis mode" first interchanges controls over the first and second axial dampers 7A and 7B arranged on left and right (FL and FR) sides of one carriage 3 to inspect the presence of incorrect wiring between the variable dampers 7 (Step 14). This allows the damping force command or current that is outputted from a control device 9 to the first axial damper 7A to be outputted to the second axial damper 7B in an interchanging manner. Likewise, a damping force command or current that is outputted from the control device 9 to the second axial damper 7B is allowed to be outputted to the first axial damper 7A in the interchanging manner.

[0045] In other words, when force generating mechanisms (variable dampers 7) are judged as failed by a failure judgment device 14, the control device 9 interchanges controls over the first and second axial dampers 7A and 7B functioning as the force generating mechanisms at Step 14. This control interchange takes place as reverse action control by which the variable dampers 7 are actuated in an opposite direction to normal time (which is practically fault time).

[0046] At next Step 15, the roll data under a state where controls over the first and second axial dampers 7A and 7B are interchanged is read in from a roll data calculating portion 13 within a predetermined evaluation interval (vehicle running interval). Next Step 16 compares a failure judgment value under a predetermined running condition (the value being previously stored in the roll data storage portion 14C) with the roll data, to thereby determine whether the roll data falls within a. normal range. A "YES" determination at Step 16 means that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally. [0047] Next Step 17 judges that the lines (cables 16A and 16B) of the first and second axial dampers 7A and 7B are interchanged. Next Step 18 interchanges and stores controls over the first and second axial dampers 7A and 7B. This enables the first and second axial dampers 7A and 7B to subsequently continue vibration control over the vehicle body 2 in a state where the incorrect wiring of the cables 16A and 16B is rectified (corrected).

[0048] if determination at Step 16 is "NO," it is determined that the roll data does not return to the normal range. Next Step 19 then restores the controls over the first and second axial dampers 7A and 7B. The damping force command or current that is outputted from the control device 9 to the first axial damper 7A is accordingly outputted and controlled as in a normal state. Similarly, the damping force command or current that is outputted from the control device 9 to the second axial damper 7B is outputted and controlled as in the normal state. Next Step 20 interchanges controls over the third and fourth axial dampers 7C and 7D arranged on left and right (RL and RR) sides of one carriage 3. This allows the damping force command or current outputted from the control device 9 to the third axial damper 7C to be outputted to the fourth axial damper 7D in the interchanging manner. Likewise, the damping force command or current outputted from the control device 9 to the fourth axial damper 7D to be outputted to the third axial damper 7C in the interchanging manner. If it is determined that there is no incorrect wiring between the third and fourth axial dampers 7C and 7D, it is preferable to restore the interchanged controls over the third and fourth axial dampers 7C and 7D.

[0049] In other words, when the force generating mechanisms (variable dampers 7) are judged as failed by the failure judgment device 14, the control device 9 interchanges controls over the third and fourth axial dampers 7C and 7D functioning as the force generating mechanisms at Step 20. This control interchange takes place as reverse action control by which the variable dampers 7 are actuated in the opposite direction to normal time (which is practically fault time).

[0050] At next Step 21, the roll data under a state where controls over the third and fourth axial dampers 7C and 7D are interchanged is read in from the roll data calculating portion 13. Next Step 22 compares the failure judgment value under the predetermined running condition (the value being previously stored in the roll data storage portion 14C) with the roll data, to thereby determine whether the roll data falls within the normal range. A "YES" determination at Step 22 means that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally.

[0051] Next Step 23 determines that the lines (cables 16C and 16D) of the third and fourth axial dampers 7C and 7D are interchanged. Next Step 24 interchanges and stores controls over the third and fourth axial dampers 7C and 7D. This enables the third and fourth axial dampers 7C and 7D to subsequently continue vibration control over the vehicle body 2 in a state where the incorrect wiring of the cables 16C and 16D is rectified (corrected).

[0052] Next Step 25 determines whether there is a "line interchange" between the first and second axial dampers 7A and 7B or between the third and fourth axial dampers 7C and 7D. A "YES" determination at Step 25 means that the controls over the first and second axial dampers 7A and 7B or over the third and fourth axial dampers 7C and 7D are interchanged. It is therefore determined that the wiring is restored to a proper state. At next Step 26, the mode is changed to a "normal control mode." The process of Step 11 and subsequent steps is then continued.

[0053] If determination at Step 25 is "NO," next Step 27 determines that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate abnormally and are therefore failed. More specifically, Step 27 determines that a cause for the abnormal operation of the variable dampers 7 is not incorrect wiring, that is, the incorrect wiring caused by wrong connection of the lines (cables 16A to 16D, for example) connecting the variable dampers 7 (first to fourth axial dampers 7A to 7D) to the control device 9. Step 27 then, for example, discontinues the damping control of each vehicle body 2 (namely, control device 9) and changes the mode to a fail mode. In such a case, the variable dampers 7 of the railway vehicle 1 are determined as failed. The current carried to the variable dampers 7 is blocked, and the variable dampers 7 are fixed at medium damping force characteristics. This ensures a damping action based on the medium damping force characteristics.

[0054] As described above, the second embodiment thus configured detects the incorrect wiring between the first and second axial dampers 7A and 7B or between the third and fourth axial dampers 7C and 7D. If there is a line interchange, the controls over the first and second axial dampers 7A and 7B or over the third and fourth axial dampers 7C and 7D are interchanged, to thereby detect the incorrect wiring between the variable dampers 7. When an abnormality is detected, the wiring is changed in terms of control so that the damping force command or current is outputted to a correct damper, to thereby ensure proper ride comfort in the railway vehicle 1.

[0055] The second embodiment makes it possible to detect the incorrect wiring between the variable dampers 7 as discussed above. If any incorrect wiring is detected (judged as present), the control interchange of the right and left dampers takes place as reverse action control by which the variable dampers 7 are actuated in the opposite direction to normal time (which is practically fault time), and the incorrect wiring is corrected in terms of control. The vibration control over the vehicle body 2 continues accordingly. It is therefore possible to safely enhance and maintain reliability of travel of the railway vehicle 1.

[0056] The second embodiment has been explained, taking as an example the case in which a determination is first made as to whether any incorrect wiring is present between the first axial damper 7A and the second axial damper 7B by following process steps, illustrated in -18 -Fig. 5. The invention is not limited to the foregoing constitution and may be so configured to first make a determination as to whether any incorrect wiring is present between the third and fourth axial dampers 7C and 7D, and thereafter make a determination as to whether any incorrect wiring is present between the first and second axial dampers 7A and 7B.

[0057] Figs. 6 and 7 illustrate a third embodiment of the invention. 1n the present embodiment, the same constituent elements as those of the first embodiment are provided with the same reference signs, and description thereof will be omitted. The third embodiment is characterized in that, when variable dampers 7 operate abnormally, and roll data is out of a normal range, a failure diagnosis is made to identify which variable damper 7 among first to fourth axial dampers 7A to 7D causes the damper abnormality.

[0058] After the process illustrated in Fig. 6 starts, roll data is read in at Step 31 as in Step 1 of Fig. 4 according to the first embodiment. Next Step 32 compares a failure judgment value (stored, for example, in a roll data storage portion 14C of Fig. 3) under a predetermined running condition with the roll data, to thereby determine whether the roll data falls within the normal range. A "YES" determination at Step 32 means that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally. The routine therefore returns to the process of Step 31 and implements the subsequent process.

[0059] A "NO" determination at Step 32 means that the roll data is out of the normal range and shows an abnormal value. At next Step 33, a mode is changed to an "abnormality diagnosis mode." The "abnormality diagnosis mode" identifies which variable damper 7 among the first to fourth axial dampers 7A to 7D causes the damper abnormality. To that end, first of all, a damping force command to fix all the variable dampers 7 (all the first to fourth axial dampers 7A to 7D) at medium (intermediate) characteristics (that is, zero ampere current value) is outputted from a damper control device 11 of a control device 9 at Step 34. [0060] Accordingly, all the variable dampers 7 of one vehicle are blocked from current carried from the control device 9 and fixed at the medium damping force characteristics. The medium damping force command may be intended, for example, to fix current values supplied to solenoids of the first to fourth axial dampers 7A to 7D at prescribed intermediate values. An interval in which the damping force command to fix the dampers 7 at the medium damping force characteristics is outputted may be limited to a predetermined specific evaluation interval, a previous interval, and a subsequent interval.

[0061] At next Step 35, the roll data under the aforementioned state is read in from a roll data calculating portion 13 within a predetermined evaluation interval (vehicle running interval). At next Step 36, the roll data under the aforementioned state is stored as a temporal "storage value" in the roll data storage portion 14C of a failure judgment device 14. [0062] Next Step 37 outputs the damping force command from the damper control device 11 of the control device 9 to the first axial damper 7A, for example, so that the first axial damper 7A is temporarily fixed at soft damping force characteristics. The other variable dampers 7 (second to fourth axial dampers 7B to 7D) keep being fixed at the medium damping force characteristics. At next Step 38, the roll data under the conditions set at Step 37 is read in from the roll data calculating portion 13 (roll data output device) within the predetermined evaluation interval (vehicle running interval).

[0063] Next Step 39 determines whether the roll data that is read in at Step 38 shows a roll value equivalent to the temporal "storage value." A "YES" determination at Step 39 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers are fixed at the middle damping force characteristics (sec Steps 34 to 36) and that the first axial damper 7A is not adjusted to the soft damping force characteristics in spite of the damping force command outputted from the control device 9. At next Step 40, the first axial damper 7A is evaluated as failed.

[0064] if determination at Step 39 is "NO," at next Step 41, the damping force command is outputted from the damper control device 11 of the control device 9 to the second axial damper 7B, for example, so that the second axial damper 7B is temporarily fixed at the soft damping force characteristics. The other variable dampers 7 (first, third and fourth axial dampers 7A, 7C and 7D) keep being fixed at the medium damping force characteristics. At next Step 42, the roll data under the conditions set at Step 41 is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval).

[0065] Next Step 43 determines whether the roll data that is read in at Step 42 shows the roll value equivalent to the temporal "storage value." A "YES" determination at Step 43 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers are fixed at the middle damping force characteristics (see Steps 34 to 36) and that the second axial damper 7B is not adjusted to the soft damping force characteristics in spite of the damping force command outputted from the control device 9. At next Step 44, the second axial damper 7B is evaluated as failed.

[0066] If determination at Step 43 is "NO," at next Step 45 illustrated in Fig. 7, the damping force command is outputted from the damper control device 11 of the control device 9 to the third axial damper 7C, for example, so that the third axial damper 7C is temporarily fixed at the soft damping force characteristics. The other variable dampers 7 (first, second and fourth axial dampers 7A, 7B and 7D) keep being fixed at the medium damping force characteristics. At next Step 46, the roll data under the conditions set at Step 45 is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval).

[0067] Next Step 47 determines whether the roll data that is read in at Step 46 shows the roll value equivalent to the temporal "storage value." A "YES" determination at Step 47 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers are fixed at the middle damping force characteristics (see Steps 34 to 36) and that the third axial damper 7C is not adjusted to the soft damping force characteristics in spite of the damping force command outputted from the control device 9. At next Step 48, the third axial damper 7C is evaluated as failed.

[0068] If determination at Step 47 is "NO," at next Step 49, the damping force command is outputted from the damper control device 11 of the control device 9 to the fourth axial damper 7D, for example, so that the fourth axial damper 7D is temporarily fixed at the soft damping force characteristics. The other variable dampers 7 (first to third axial dampers 7A to 7C) keep being fixed at the medium damping force characteristics. At next Step 50, the roll data under the conditions set at Step 49 is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval).

[0069] Next Step 51 determines whether the roll data that is read in at Step 50 shows the roll value equivalent to the temporal "storage value." A "YES" determination at Step 51 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers are fixed at the middle damping force characteristics (see Steps 34 to 36) and that the fourth axial damper 7D is not adjusted to the soft damping force characteristics in spite of the damping force command outputted from the control device 9. At next Step 52, the fourth axial damper 7D is evaluated as failed.

[0070] If determination at Step 51 is "NO," the routine moves to next Step 53. Step 53 makes a determination with the "abnormality diagnosis mode" used at Step 33 and subsequent steps as to whether any one of the first to fourth axial dampers 7A to 7D is failed. If determination at Step 53 is "YES," next Step 54 judges that at least one of the variable dampers 7 (first to fourth dampers 7A to 7D) operates abnormally and is therefore failed. Step 54 then indicates a need for a prompt dismounting and replacement of the damper that is identified as failed. A "NO" determination at Step 53 means that there is no abnormal damper that is identified as failed. At next Step 55, therefore, the mode is changed to a "normal control mode," and the process of Step 31 and subsequent steps is continued. [0071] According to the third embodiment thus configured, when the variable damper 7 operates abnormally, and the roll data is out of the normal range, a failure diagnosis is made to identify which variable damper 7 among the first to fourth axial dampers 7A to 7D causes the damper abnormality. This simplifies the task for identifying an abnormal damper, which has conventionally required the dismounting of dampers, the check of damping force characteristics and the other like work. A quick replacement of the damper is then possible when an abnormality occurs.

[0072] Figs. 8 to 10 illustrate a fourth embodiment of the present invention. In the present embodiment, the same constituent elements as those of the first embodiment are provided with the same reference signs, and description thereof will be omitted. The fourth embodiment is characterized in that, when variable dampers 7 operate abnormally, and roll -22 -data is out of a normal range, a determination is first made as to whether there is an abnormality related to incorrect wiring between the right and left dampers. If no abnormality is identified, the embodiment identifies which variable damper 7 among first to fourth axial dampers 7A to 7D causes the damper abnormality.

[0073] After the process illustrated in Fig. 8 starts, roll data is read in at Step 61 as in Step 1 illustrated in Fig. 4 according to the first embodiment Next Step 62 compares a failure judgment value (stored, for example, in a roll data storage portion 14C of Fig. 3) under a predetermined running condition with the roll data, to thereby determine whether the roll data is within a normal range. A "YES" determination at Step 62 means that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally. The routine returns to the process of Step 61 and implements subsequent process.

[0074] If determination at Step 62 is "NO," a mode is changed to an "abnormality diagnosis mode" at next Step 63. The "abnormality diagnosis mode" first interchanges controls over the first and second axial dampers 7A and 7B arranged on left and right (FL and FR) sides of one carriage 3 at Step 64 to inspect the presence of incorrect wiring between the variable dampers 7. This allows a damping force command or current that is outputted from a control device 9 to the first axial damper 7A to be outputted to the second axial damper 7B in an interchanging manner. Likewise, a damping force command or current that is outputted from the control device 9 to the second axial damper 7B is allowed to be outputted to the first axial damper 7A in the interchanging manner.

[0075] In other words, when force generating mechanisms (variable dampers 7) are judged as failed by a failure judgment device 14, the control device 9 interchanges controls over the first and second axial dampers 7A and 7B functioning as the force generating mechanisms at Step 64. This control interchange takes place as reverse action control by which the variable dampers 7 arc actuated in an opposite direction to normal time (which is practically fault time).

[0076] At Step 65, the roll data under a state where controls over the first and second axial dampers 7A and 7B are interchanged is read in from a roll data calculating portion 13 within -23 -a predetermined evaluation interval (vehicle running interval). Next Step 66 compares a failure judgment value under a predetermined running condition (the value being previously stored in the roll data storage portion 14C) with the roll data, to thereby determine whether the roll data falls within a normal range. A "YES" determination at Step 66 means that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally.

[0077] Next Step 67 then judges that lines (cables 16A and 16B) of the first and second axial dampers 7A and 7B are interchanged. In Step 68, controls over the first and second axial dampers 7A and 7B are stored in the interchanged state. This allows the first and second axial dampers 7A and 7B to subsequently continue vibration control over the vehicle body 2 in a state where the incorrect wiring of the cables 16A and 16B is rectified (corrected).

[0078] If determination at Step 66 is "NO," it is determined that the roll data does not return to the normal range. Next Step 69 then restores the controls over the first and second axial dampers 7A and 7B. Next Step 70 interchanges the controls over the third and fourth axial dampers 7C and 7D arranged on left and right (RL and RR) sides of one carriage 3. This allows the damping force command or current that is outputted from the control device 9 to the third axial damper 7C to be outputted to the fourth axial damper 7D in an interchanging manner. Likewise, a damping force command or current that is outputted from the control device 9 to the fourth axial damper 7D is allowed to be outputted to the third axial damper 7C in the interchanging manner.

[0079] In other words, when force generating mechanisms (variable dampers 7) are judged as failed by a failure judgment device 14, the control device 9 interchanges the controls over the third and fourth axial dampers 7C and 7D functioning as the force generating mechanisms at Step 70. This control interchange takes place as reverse action control by which the variable dampers 7 are actuated in an opposite direction to normal time (which is practically fault time).

[0080] At next Step 71, the roll data under a state where controls over the third and fourth axial dampers 7C and 7D are interchanged is read in from the roll data calculating portion 13.

-24 -Next Step 72 compares a failure judgment value under a predetermined running condition (the value being previously stored in the roll data storage portion 14C) with the roll data, to thereby determine whether the roll data is in a normal range. A "YES" determination at Step 72 means that the variable dampers 7 (first to fourth axial dampers 7A to 7D) operate normally.

[0081] Next Step 73 judges that the lines (cables 16C and 16D) of the third and fourth axial dampers 7C and 7D are interchanged. At next Step 74, the controls over the third and fourth axial dampers 7C and 7D are stored in the interchanged state. This allows the third and fourth axial dampers 7C and 7D to subsequently continue vibration control over the vehicle body 2 in a state where the incorrect wiring of the cables 16C and 1613 is rectified (corrected).

[0082] Next Step 75 determines whether there is a "line interchange" between the first axial damper 7A and the second axial damper 7B or between the third axial damper 7C and the fourth axial damper 711 If determination at Step 75 is "YES," it is determined that the wiring is restored to a proper state since the controls over the first and second axial dampers 7A and 7B or over the third and fourth axial dampers 7C and 7D are interchanged. At next Step 76, the mode is changed to a "normal control mode." The process of Step 61 and subsequent steps is then continued.

[0083] If determination at Step 75 is "NO," the variable dampers 7 (first to fourth axial dampers 7A to 71)) are judged to operate abnormally and as failed. Following this judgment, the routine moves to Step 77 illustrated in Fig. 9 to identify which variable damper 7 among the first to fourth axial dampers 7A to 7D causes the damper abnormality. Step 77 first outputs from the damper control device 11 of the control device 9 the damping force command to fix all the variable dampers 7 (all the first to fourth axial dampers 7A to 713) at the medium (intermediate) characteristics (that is, zero ampere current value).

[0084] Consequently, all the variable dampers 7 of one vehicle are blocked from current carried from the control device 9 and fixed at the medium damping force characteristics. * The medium damping force command may be intended, for example, to fix a current value -25 -supplied to solenoids of the first to fourth axial dampers 7A to 7D at a prescribed intermediate value. An interval in which the damping force command to fix the dampers 7 at the medium damping force characteristics is outputted may be limited to a predetermined specific evaluation interval, a previous interval, and a subsequent interval.

[0085] At next Step 78, the roll data under the foregoing state is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval). At next Step 79, the roll data under the foregoing state is stored as a temporal "storage value" in the roll data storage portion 14C of the failure judgment device 14.

[0086] Next Step 80 outputs a damping force command from the damper control device 11 of the control device 9 to the first axial damper 7A, for example, so that the first axial damper 7A is temporarily fixed at the soft damping force characteristics. The other variable dampers 7 (second to fourth axial dampers 7B to 7D) keep being fixed at the medium damping force characteristics. At next Step 81, the roll data under the conditions set at Step 80 is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval).

[0087] Next Step 82 determines whether the roll data that is read in at Step 81 shows a roll value equivalent to the temporal "storage value." A "YES" determination at Step 82 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers are fixed at the middle damping force characteristics (see Steps 77 to 79) and that the first axial damper 7A is not adjusted to the soft damping force characteristics. Next Step 83 then evaluates the first axial damper 7A as failed.

[0088] If determination at Step 82 is "NO," next Step 84 outputs a damping force command from the damper control device 11 of the control device 9 to the second axial damper 7B, for example, so that the second axial damper 7B is temporarily fixed at the soft damping force characteristics. The other variable dampers 7 (first, third and fourth axial dampers 7A, 7C and 7D) keep being fixed at the medium damping force characteristics. At next Step 85, the roll data under the conditions set at Step 84 is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval).

[0089] Next Step 86 determines whether the roll data that is read in at Step 85 shows the roll value equivalent to the temporal "storage value." A "YES" determination at Step 86 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers arc fixed at the middle damping force characteristics (see Steps 77 to 79) and that the second axial damper 7B is not adjusted to the soft damping force characteristics. At next Step 87, the second axial damper 7B is evaluated as failed. [0090] If determination at Step 86 is "NO," next Step 88 illustrated in Fig. 10 outputs a damping force command from the damper control device 11 of the control device 9 to the third axial damper 7C, for example, so that the third axial damper 7C is temporarily fixed at the soft damping force characteristics. The other variable dampers 7 (first, second and fourth axial dampers 7A, 7B and 7D) keep being fixed at the medium damping force characteristics. At next Step 89, the roll data under the conditions set at Step 88 is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval).

[0091] Next Step 90 determines whether the roll data that is read in at Step 89 shows the roll value equivalent to the temporal "storage value." A "YES" determination at Step 90 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers are fixed at the middle damping force characteristics (see Steps 77 to 79) and that the third axial damper 7C is not adjusted to the soft damping force characteristics. At next Step 91, the third axial damper 7C is evaluated as failed. [0092] If determination at Step 90 is "NO," next Step 92 outputs a damping force command from the damper control device 11 of the control device 9 to the fourth axial damper 7D, for example, so that the fourth axial damper 7D is temporarily fixed at the soft damping force characteristics. The other variable dampers 7 (first to third axial dampers 7A to 7C) keep being fixed at the medium damping force characteristics. At next Step 93, the roll data under the conditions set at Step 92 is read in from the roll data calculating portion 13 within the predetermined evaluation interval (vehicle running interval).

[0093] Next Step 94 determines whether the roll data that is read in at Step 93 shows the roll value equivalent to the temporal "storage value." A "YES" determination at Step 94 means that the roll data shows the roll value equivalent to the "storage value" that is stored under the condition that all the dampers are fixed at the middle damping force characteristics (see Steps 77 to 79) and that the fourth axial damper 7D is not adjusted to the soft damping force characteristics. At next Step 95, the fourth axial damper 7D is evaluated as failed. [0094] If determination at Step 94 is "NO," next Step 96 makes a determination with the "abnormality diagnosis mode" used in Step 33 and subsequent steps as to whether any one of the first to fourth axial dampers 7A to 7D is failed. If determination at Step 96 is "YES," next Step 97 judges that at least one of the variable dampers 7 (first to fourth axial dampers 7A to 7D) operates abnormally and is failed. Step 97 then indicates a need for a prompt dismounting and replacement of the damper that is identified as failed. A "NO" determination at Step 96 means that there is no abnormal damper that is identified as failed At next Step 98, therefore, the mode is changed to a "normal control mode," and the process of Step 61 and subsequent steps starts again.

[0095] According to the fourth embodiment thus configured, if the variable damper 7 operates abnormally, and the roll data is out of the normal range, a determination is first made as to whether there is an abnormality related to incorrect wiring between the right and left dampers. If no abnormality is identified, the failure diagnosis is made to identify which variable damper 7 among first to fourth axial dampers 7A to 7D causes the damper abnormality. This makes it possible to carry out the exhaustive identification of the abnormality related to incorrect wiring between the right and left dampers and of an abnormal damper, which enables the damper to be immediately replaced when an abnormality occurs.

[0096] The first embodiment is discussed, taking as an example the case in which the force generating mechanisms comprise the variable dampers 7 including the damping force adjustment hydraulic shock absorbers disposed between the vehicle body 2 and each of the carriages 3. The invention is not limited to the aforementioned example. The force generating mechanisms disposed between each of the carriages and the vehicle body and -28 -configured to generate the forces that are adjustable in the vertical direction may comprise, for example, electromagnetic linear actuators, electromagnetic dampers, air suspensions or the like. Same applies to the second to fourth embodiments.

[0097] Vibration control devices for railway vehicles based on the above-discussed embodiments include, for example, the following vibration control devices. In a first mode, a vibration control device for a railway vehicle comprises a force generating mechanism disposed between a carriage on which wheels are mounted and a vehicle body, the force generating mechanism being configured to generate a force that is adjustable in a vertical direction, a control portion configured to control the generated force of the force generating mechanism, and an abnormality detecting and estimating portion configured to detect and estimate an abnormality of the force generating mechanism. The abnormality detecting and estimating portion includes a roll data output device configured to output roll data changed by roll of the vehicle body, and a failure judgment device configured to compare the roll data outputted from the roll data output device with a failure judgment value under a predetermined running condition and thus judge whether the force generating mechanism is failed. This makes it possible to judge a failure of the force generating mechanism.

[0098] According to the vibration control device for a railway vehicle in a second mode according to the first mode, the roll data output device includes at least one sensor disposed in the vehicle body and configured to detect vehicle body behavior, and a roll data calculating portion configured to calculate the roll data from a value derived from the sensor. This makes it possible to achieve a more effective failure diagnosis and abnormality detection. In a third mode according to the first or second mode, the failure judgment device includes a vehicle position detecting portion configured to detect a running position of a vehicle, a vehicle speed detecting portion configured to detect running speed of the vehicle, a roll data storage portion configured to store the roll data outputted from the roll data output device under the predetermined running condition, and a failure judgment value calculating portion configured to calculate the failure judgment value from the running position, the running speed, and the roll data. This makes it possible to detect an abnormality of the force generating mechanism without false detection.

[0099] In a fourth mode according to the third mode, the abnormality detecting and estimating portion is disposed in at least one other vehicle body jointed to the vehicle body, and the failure judgment value calculating portion calculates the failure judgment value from the roll data of the at least one other vehicle body. This makes it possible to detect an abnormality of the force generating mechanism without false detection. In a fifth mode according to any one of the first to fourth modes, when the force generating mechanism is judged as failed by the failure judgment device, the control portion turns off the control over the force generating mechanism. This makes it possible to safely enhance and maintain reliability of travel of the railway vehicle.

In a sixth mode according to any one of the first to fourth modes, when the force generating mechanism is judged as failed by the failure judgment device, the control portion implements reverse action control by which the force generating mechanism is actuated in an opposite direction to normal time. If the failure is attributable to incorrect wiring between dampers, controls over the dampers are interchanged, and the reverse action control is implemented. This reduces to a minimum a deterioration in ride comfort which is attributable to the abnormality.

[0100] In a seventh mode according to any one of the first to fourth modes, when the force generating mechanism is judged as failed by the failure judgment device, the control portion implements medium control of the generated force of the force generating mechanism. This makes it possible to previously identify an abnormal damper when a damper failure occurs and thus reduce total time between the identification of the abnormal damper and replacement of the damper.

[0101] The invention is not limited to the embodiments which have been described and may be modified in various ways. For example, the embodiments are intended to explain the invention to facilitate the understanding of the invention and do not necessarily have to include all the constitutions mentioned above. A part of the constitution of any one of the embodiments may be replaced with the constitution of another embodiment. The constitution of any one of the embodiments may be incorporated into the constitution of another embodiment. It is also possible to incorporate or replace a part of the constitution of any one of the embodiments into or with the constitution of another embodiment, or eliminate a part of the constitution of any one of the embodiments.

[0102] The present patent application claims priority under Japanese Patent Application No. 2017-186283 filed on September 27, 2017. The entire disclosure of Japanese Patent Application No. 2017-186283 filed on September 27, 2017 including the description, claims, drawings and abstract, is incorporated herein by reference in its entirety.

REFERENCE SIGN LIST

[0103] 1 Railway vehicle; 2 Vehicle body; 3 Carriage; 4 Wheel; 5 Rail, 6 Suspension spring; 7 Damping force variable damper (force generating mechanism); 7A First axial damper; 7B Second axial damper; 7C Third axial damper; 7D Fourth axial damper; 8A, 8B, 8C, 8D Acceleration sensor (sensor for detecting vehicle body behavior); 9 Control device (control circuit); 11 Damper control device (control portion); 12 Abnormality detecting and estimating portion; 13 Roll data calculating portion (roll data output device); 14 Failure judgment device; 14A Vehicle position detecting portion; 14B Vehicle speed detecting portion; 14C Roll data storage portion; 14D Failure judgment value calculating portion -31 -

Claims (7)

1. CLAIMS1. A vibration control device for a railway vehicle comprising: a force generating mechanism disposed between a carriage on which wheels are mounted and a vehicle body, the force generating mechanism being configured to generate a force that is adjustable in a vertical direction; a control portion configured to control the generated force of the force generating mechanism; and an abnormality detecting and estimating portion configured to detect and estimate an abnormality of the force generating mechanism, the abnormality detecting and estimating portion including: a roll data output device configured to output roll data changed by roll of the vehicle body, and a failure judgment device configured to compare the roll data outputted from the roll data output device with a failure judgment value under a predetermined running condition and thus judge whether the force generating mechanism is failed.
2. 2. The vibration control device for a railway vehicle according to Claim 1, wherein the roll data output device includes at least one sensor disposed in the vehicle body and configured to detect vehicle body behavior, and a roll data calculating portion configured to calculate the roll data from a value derived from the sensor.
3. 3. The vibration control device for a railway vehicle according to Claim 1 or 2, wherein the failure judgment device includes: a vehicle position detecting portion configured to detect a running position of a vehicle, a vehicle speed detecting portion configured to detect running speed of the vehicle, a roll data storage portion configured to store the roll data outputted from the roll data output device under the predetermined running condition, and a failure judgment value calculating portion configured to calculate the failure -32 -judgment value from the running position, the running speed, and the roll data.
4. 4. The vibration control device for a railway vehicle according to Claim 3, wherein the abnormality detecting and estimating portion is disposed in at least one other vehicle body jointed to the vehicle body, and the failure judgment value calculating portion calculates the failure judgment value from the roll data of the at least one other vehicle body.
5. 5. The vibration control device for a railway vehicle according to any one of Claims 1 to 4, wherein, when the force generating mechanism is judged as failed by the failure judgment device, the control portion turns off the control over the force generating mechanism.
6. 6. The vibration control device for a railway vehicle according to any one of Claims 1 to 4, wherein, when the force generating mechanism is judged as failed by the failure judgment device, the control portion implements reverse action control by which the force generating mechanism is actuated in an opposite direction to normal time.
7. 7. The vibration control device for a railway vehicle according to any one of Claims 1 to 4, wherein, when the force generating mechanism is judged as failed by the failure judgment device, the control portion implements medium control of the generated force of the force generating mechanism.