CN1210570A - Controller of construction machine - Google Patents

Abstract

A controller for a construction machine, such as a hydraulic excavator used for digging, comprises: an angle detection device (20 to 22) for detecting the posture of an articulated arm mechanism with angle information; a conversion device (26) for converting the detected angle information into extension/retraction displacement information of a corresponding cylinder actuator (120 to 122); and a control device (1) for controlling the actuator (120 to 122) to have the required extension/retraction displacement based on the obtained extension/retraction information. Thus, while maintaining low cost, the position and posture of a workpiece (400) can be accurately and stably controlled.

Description

Control equipment for construction machinery

The present invention relates to a construction machine, such as a hydraulic excavator for digging earth, and more particularly to a control device for a construction machine of said type.

A construction machine such as a hydraulic excavator has a structure in which, for example, as shown schematically in FIG. 500A on a lower traveling body 500;

And, according to the extension/contraction displacement information of the boom 200, the rod 300 and the bucket 400 obtained by the stroke sensors 210, 220 and 230, the hydraulic cylinders 120, 121 and 122 can appropriately drive the boom 200, the rod 300 respectively. and bucket 400 to perform excavation operations while keeping the forward direction of the bucket or the posture of bucket 400 fixed, so that the position and posture control of a workpiece such as bucket 400 can be accurately and stably performed.

However, such a conventional hydraulic excavator as described above has a problem in that it requires high cost as a whole because the stroke sensors 210, 220 and 230 is more expensive.

The present invention has been made in view of such a problem as described above, and an object of the present invention is to provide a control device for a construction machine by which the movement of a work piece can be accurately and stably controlled while reducing costs. position and posture.

To this end, a control device for a construction machine according to the invention is characterized in that it comprises: a construction machine body; an articulated arm mechanism, one end of which is mounted on the construction machine body for pivotal movement, And on its other end side, there is a work piece, the articulated arm mechanism includes at least one pair of arms connected to each other with a hinged part placed therebetween; a cylinder type actuator mechanism with a plurality of The cylinder-type actuator of the /shrink operation is used to drive the arm mechanism; the angle detection device is used to detect the posture of the arm mechanism with angle information; the conversion device is used to convert the angle information obtained by the angle detection device into the corresponding position of the cylinder-type actuator expansion/contraction displacement information; and a control device, used to control the cylinder type actuator according to the expansion/contraction information of the cylinder type actuator converted by the conversion device, so that the cylinder type actuator can realize the predetermined expansion/contraction displacement.

The articulated arm mechanism may include: a rotary arm connected at one end to the construction machine body for pivotal movement; and a rod connected to the rotary arm at one end with a hinged portion interposed therebetween; and the work piece It may be formed as a bucket connected at one end to the rod for pivotal movement with a hinged portion interposed therebetween and capable of digging earth at its end and holding earth and sand therein.

The cylinder type actuator mechanism may include: a boom hydraulic cylinder placed between the construction machine body and the boom so as to rotate the boom relative to the construction machine body by telescoping the distance between its ends; a rod hydraulic cylinder placed between the boom and the rod so as to rotate the rod relative to the boom by telescoping the distance between its ends; and a bucket hydraulic cylinder inserted between the rod and the bucket so as to The distance to rotate the bucket relative to the rod.

Also, the angle detection means may include: a first angle sensor for detecting the posture of the boom; a second angle sensor for detecting the posture of the rod; and a third angle sensor for detecting the posture of the bucket.

At the same time, the conversion device may include: a computing device, which is used to determine the expansion/contraction displacement information of the cylinder type actuator corresponding to the angle information through calculation according to the angle information obtained by the angle detection device; or may include: a storage device, which is used to store The cylinder type actuator corresponds to the extension/contraction displacement information of the angle information obtained by the angle detection device.

Also, the conversion device can be constructed so that the angle information obtained by the first angle sensor is converted into the extension/contraction displacement information of the boom hydraulic cylinder, and the angle information obtained by the second angle sensor is converted into the extension/contraction displacement information of the rod hydraulic cylinder. Displacement information, and convert the angle information obtained by the third angle sensor into the extension/contraction displacement information of the bucket hydraulic cylinder.

In the control device for construction machinery of the present invention having such a structure as above, the angle information detected by the above angle detection means is converted by the conversion means into the expansion/contraction displacement information of the cylinder type actuator driving the arm mechanism, And input to the control device, even without the expensive travel sensor used to detect the expansion/contraction displacement of each actuator in the prior art, the control of the expansion/contraction displacement of the actuators used in the conventional control system can be performed. Therefore, it is possible to provide a system that can accurately and stably control the position and orientation of the workpiece while reducing the cost.

1 is a schematic diagram of a hydraulic excavator on which a control device according to an embodiment of the present invention is installed;

Fig. 2 schematically represents the general configuration (electrical system and hydraulic system) of the control device according to an embodiment of the present invention;

Fig. 3 schematically represents the control system configuration of the control device according to an embodiment of the present invention;

FIG. 4 is a block diagram for explaining a functional configuration of a control device according to an embodiment of the present invention;

5 is a control block diagram of essential parts of a control device according to an embodiment of the present invention;

Fig. 6 is a side view schematically showing the operating portion (articulated arm mechanism and bucket) of the hydraulic excavator according to the present embodiment;

7 is a side view schematically showing a hydraulic excavator in order to explain the operation of the hydraulic excavator according to the present embodiment;

8 is a side view schematically showing a hydraulic excavator in order to explain the operation of the hydraulic excavator according to the present embodiment;

9 is a side view schematically showing a hydraulic excavator in order to explain the operation of the hydraulic excavator according to the present embodiment;

10 is a side view schematically showing a hydraulic excavator in order to explain the operation of the hydraulic excavator according to the present embodiment;

11 is a side view schematically showing a hydraulic excavator in order to explain the operation of the hydraulic excavator according to the present embodiment;

Fig. 12 is a side view schematically showing the general construction of a conventional hydraulic excavator.

As follows, an embodiment of the present invention is described with reference to the drawings.

A hydraulic excavator as a construction machine according to this embodiment includes, for example, as schematically shown in FIG. Swivel movement in the horizontal plane on the lower traveling unit 500 with crawlers 500A on the left and right thereof.

A rotating arm (arm member) 200 whose one end is connected for swinging motion is provided on the upper swivel unit 100, and a rod (arm member) 300 whose one end is connected by a hinge portion for swinging motion is provided on the rotating arm 200.

A bucket (work piece) 400 is provided on the rod 300, one end of which is connected by a hinge portion for swinging motion, and can dig soil with its tip and hold soil and sand therein.

In this way, an articulated type arm mechanism, which includes the rotary arm 200, the rod 300 and the bucket 400, is mounted on the upper swivel unit 100 at one end for rotational movement, and has a A bucket 400, and at least a rotating arm 200 and a rod 300 as a pair of arm members connected to each other by a hinged portion.

Also, a boom cylinder 120, a rod cylinder 121, and a bucket cylinder 122 are provided as cylinder-type actuators (in the following description, the boom cylinder 120 may be referred to as the boom cylinder 120 or simply cylinder 120, rod cylinder 121 may be called rod cylinder 121 or just cylinder 121, and bucket hydraulic cylinder 122 may be called bucket cylinder 122 or just cylinder 122).

Here, the boom hydraulic cylinder 120 is connected at one end thereof to the upper swing unit 100 for swing movement, and the other end thereof is connected to the boom 200 for swing movement, or in other words, the boom hydraulic cylinder 120 is placed on the upper swing unit 100 and the rotating arm 200, so that when the distance between the opposite ends expands or contracts, the rotating arm 200 can swing relative to the upper rotating unit 100.

One end of the rod hydraulic cylinder 121 is connected to the rotating arm 200 for swinging motion, and the other end thereof is connected to the rod 300 for swinging motion, or in other words, the rod hydraulic cylinder 121 is placed between the rotating arm 200 and the rod 300 so that When the distance between the opposite ends is extended or contracted, the rod 300 can swing relative to the rotating arm 200 .

One end of the bucket cylinder 122 is connected to the rod 300 for swinging motion, and the other end thereof is connected to the bucket 400 for swinging motion, or in other words, the bucket cylinder 122 is interposed between the rod 300 and the bucket 400 , so that the bucket 400 can swing relative to the rod 300 when the distance between its opposite ends is extended or contracted. Note that a link 130 is provided at one free end of the bucket hydraulic cylinder 122 .

In this way, a cylinder type actuator mechanism with a plurality of cylinder type actuators that drive the arm mechanism by performing a telescoping operation is composed of the cylinders 120 to 122 described above.

Note that, although not shown in the drawings, hydraulic motors for driving the left and right crawlers 500A and a swing motor for driving the upper swing unit 100 to swing are also provided.

In addition, as shown in FIG. 2, the above-mentioned hydraulic excavator includes a hydraulic circuit for the above-mentioned cylinders 120 to 122, a hydraulic motor and a swing motor, and in addition to a variable displacement type pump driven by an engine E such as a diesel engine 51 and 52, a boom main control valve (control valve) 13, a rod main control valve (control valve) 14, a bucket main control valve (control valve) 15 and the like are arranged in the hydraulic circuit.

Note that the variable displacement type pumps 51 and 52 are each constructed such that their inclination is controlled by an engine pump controller 27 which will be described later, so that the displacement of working oil to the hydraulic circuit can be varied. Also, where each line interconnecting two components is a solid line in Figure 2, it indicates that the line is an electrical system, but where each line interconnecting two components is a dashed line, it indicates that the line is a Hydraulic system.

Also, in order to control the main control valves 13, 14 and 15, a pilot hydraulic circuit is provided, and a pilot pump 50 driven by the engine E, electromagnetic proportional valves 3A, 3B and 3C, electromagnetic directional control valves 4A, 4B and 4C, Selector valves 18A, 18B, 18C, etc. are arranged in this pilot hydraulic circuit.

In the hydraulic excavator of the present invention, a controller (control device) 1 is provided to control the main control valves 13, 14 and 15 via the electromagnetic proportional valves 3A, 3B and 3C, so as to control the main control valves 13, 14 and 15 according to a kind of boom 200, The rod 300 and bucket 400 should be controlled so that they have the desired pattern of extension/retraction displacement, controlling the boom 200 , rod 300 and bucket 400 . Note that the controller 1 includes a microprocessor, memories such as ROM and RAM, appropriate input/output interfaces, and the like.

Signals from various sensors (including setting signals) are input to the controller 1, and the controller 1 performs the above-described control based on detection signals from the sensors. Note that such control with the controller 1 is called semi-automatic control, and even during excavation under semi-automatic control (semi-automatic excavation mode), fine adjustment of the bucket angle and target slope height can be achieved manually.

As a kind of above-mentioned semi-automatic control mode (semi-automatic excavation mode), a bucket angle control mode (refer to FIG. ), a leveling mode (refer to FIG. 9 ), a bucket angle automatic return mode (auto return mode) (refer to FIG. 10 ) etc. as a combination of the slope excavation mode and the bucket angle control mode are available.

Here, the bucket angle control mode is a mode in which the angle (bucket angle) of the bucket 400 with respect to the horizontal direction (vertical direction) is always kept constant even if the lever 300 and the boom 200 move, as shown in FIG. 7, and if a bucket angle control switch on a manipulation panel 10 described below is turned on, this mode is executed. Note that when the bucket 400 is manually moved, this mode is canceled, and the bucket angle at the time when the bucket 400 is stopped is stored as a new bucket holding angle.

The ramp digging mode is a mode in which the tip 112 of the bucket 400 (which may sometimes be referred to as the bucket tip 112 ) moves in a straight line, as shown in FIG. 8 . However, bucket cylinder 122 does not move. Also, the bucket angle φ changes as the bucket 400 moves.

The slope excavation mode+bucket angle control mode is a mode in which the tip 112 of the bucket 400 moves linearly and the bucket angle φ is also kept constant during excavation, as shown in FIG. 9 .

The bucket automatic return mode is a mode in which the bucket angle is automatically returned to a preset angle, as shown in FIG. 10 , and the return bucket angle is set by the manipulation panel 10 . This mode is activated when a bucket auto-return activation switch 7 on the boom/bucket control lever 6 is turned on. This mode is canceled when the bucket 400 returns to the preset angle.

Here, when turning on a semi-automatic control switch on the control panel 10, and turning on a slope excavation switch 9 on the lever joystick 8, and making both the lever joystick 8 and the boom/bucket joystick 6 or any When one is in motion, enter the aforementioned slope digging mode and leveling mode. Note that the target slope angle is set by the switch operation on the manipulation panel 10 .

Also, in the slope excavation mode and leveling mode, the operation amount of the lever joystick 8 provides the bucket end movement speed in the direction parallel to the target slope angle, while the operation amount of the boom/bucket joystick 6 provides the vertical direction. Speed of bucket tip movement. Thus, if the lever joystick 8 is moved, the tip 112 of the bucket 400 begins its linear motion along the target slope angle, and during excavation by moving the boom/bucket joystick 6 the target slope height via manual manipulation can be performed. fine-tuning.

In addition, in the slope excavation mode and the leveling mode, by operating the boom/bucket joystick 6, not only the bucket angle during excavation can be fine-tuned, but also the target slope height can be changed.

Note that in the present system, a manual mode is also possible, and in this manual mode, not only operation equivalent to a conventional hydraulic excavator is possible, but also coordinate indication of the tip 112 of the bucket 400 is possible.

A maintenance mode for performing maintenance of the entire semi-automatic system is also prepared, and this maintenance mode is realized by connecting an external terminal 2 to the controller 1 . And, through this maintenance mode, adjustment of control gain, initialization of various sensors, and the like are performed.

In addition, as various sensors connected to the controller 1, as shown in FIG. 24 and so on. And what are connected on the controller 1 are: engine pump controller 27, an on-off switch (the above-mentioned bucket automatic return start switch) 7, another on-off switch (the above-mentioned slope excavation switch) 9, belt There is a manipulation panel (display switch panel) 10 of the target slope angle setting unit. Note that external terminal 2 is connected to controller 1 when controlling gain adjustment, sensor initialization, etc.

The engine pump controller 27 receives engine speed information from an engine rotation speed sensor 23, and controls the inclination angles of the above-mentioned engine E and variable displacement type pumps 51 and 52. The engine pump controller 27 can communicate coordinate information with the controller 1 .

The pressure sensor 19 is installed on the pilot line connected to the main control valves 13, 14 and 15 from the joysticks 6 and 8 for the extension/retraction of the rod 300 and the up/down movement of the swing arm 200, and detects the pressure in the pilot line. pilot hydraulic pressure. Since the pilot hydraulic pressures in these pilot lines are changed by the operation amounts of the joysticks 6 and 8, the operation amounts of the joysticks 6 and 8 can be estimated by measuring the hydraulic pressure.

The pressure sensors 28A and 28B detect the extension/contraction states of the boom cylinder 120 and the rod cylinder 121 .

Note that in the semi-automatic control described above, lever joystick 8 is used to determine the speed of movement of the bucket tip in a direction parallel to a set digging slope, while boom/bucket joystick 6 is used to determine the speed of movement of the bucket end relative to a set digging slope. This sets the movement speed of the bucket end in the vertical direction of the slope. Thus, when the lever joystick 8 and the boom/bucket joystick 6 are operated simultaneously, the movement direction and movement speed of the tip 112 of the bucket 400 are determined by a resultant vector in parallel and perpendicular directions with respect to the setting slope.

The pressure switch 16 is installed to the pilot lines of the joysticks 6 and 8 for the boom 200, the rod 300 and the bucket 400, the selector 17 or the like is arranged therebetween, and the pressure switch 16 is used to detect the joystick 6 and 8 are in the middle. Specifically, when the joystick 6 or 8 is in the middle state, the output of the pressure switch 16 is off, and when the joystick 6 or 8 is used, the output of the pressure switch 16 is on. Note that the pressure switch 16 used to detect the intermediate state is also used to detect the abnormal state of the pressure sensor 19 and to switch between manual/semi-automatic modes.

The phase resolver 20 is provided at a rotationally mounted portion (hinge portion) of the boom 200 on the construction machine body 100, where the posture of the boom 200 can be monitored, and the phase resolver 20 serves to detect the posture of the boom 200. A first angle sensor acts. The phase resolver 21 is provided at the rotation mounting portion (hinge portion) of the rod 300 on the pivot arm 200, where the posture of the rod 300 can be monitored, and the phase resolver 21 serves as a second angle sensor for detecting the posture of the rod 300 role. Also, the phase resolver 22 is provided at a link rotation mounting portion where the attitude of the bucket 400 can be monitored, and the phase resolver 22 functions as a third angle sensor for detecting the attitude of the bucket 400 . By these phase splitters 20 to 22, angle detection means for detecting the posture of the arm mechanism with angle information is constituted.

A signal converter (conversion device) 26 converts the angle information obtained by the phase splitter 20 into the extension/contraction displacement information of the boom cylinder 120, and converts the angle information obtained by the phase splitter 21 into the extension/contraction displacement information of the rod cylinder 121. and convert the angle information obtained by the phase splitter 22 into the extension/contraction displacement information of the bucket cylinder 122, that is, convert the angle information obtained by the phase splitter 20 to 22 into the corresponding extension of the cylinders 120 to 122 /shrink displacement information.

For this reason, signal converter 26 comprises: an input interface 26A, is used for receiving signal from phase splitter 20 to 22; A lookup table 26B-1 of the expansion/contraction displacement information of the angle information obtained by 20 to 22; a main operation unit (CPU) 26C, which can calculate the extension of the cylinder 120 to 122 corresponding to the angle information obtained by the phase splitter 20 to 22 /retraction displacement information, and communicate cylinder extension/retraction displacement information with the controller 1; and an output interface 26D for sending cylinder extension/contraction displacement information from the main computing unit (CPU) 26C.

In addition, the expansion/contraction displacement information λbm, λst and λbm, λst and λbk:

λbm=(L _101/102 ² +L _101/111 ² -2L _101/102 ·L _101/111 cos(θbm+Axbm)) ^1/2

…(1)

λst=(L _103/104 ² +L _104/105 ² -2L _103/104 ·L _104/105 cosθst) ^1/2 …(2)

λbk=(L _{106/107 2} +L _107/109 ² -2L _106/107 ·L _107/109 cosθst) ^1/2 …(2)

Here, in the above expressions (1) to (3), L _i/j represents a fixed length, Axbm represents a fixed angle, and the subscript of L has information between nodes i and j. For example, L _101/102 represents the distance between node 101 and node 102. Note that the node 101 is determined as the origin of the xy coordinate system (see FIG. 6 ).

Naturally, the above expressions can be calculated by the arithmetic means (eg, CPU 26C) whenever the angle information θbm, θst, and θbk are obtained by the phase splitters 20 to 22. In this example, the CPU 26C forms arithmetic means for calculating expansion/contraction displacement information of the cylinders 120 to 122 corresponding to the angle information based on the angle information obtained from the phase splitters 20 to 22 .

Note that the signal obtained by conversion by the signal converter 26 is used not only for feedback control at the time of semi-automatic control, but also for measuring coordinates for measurement/indication of the position of the bucket tip 112 .

Using a certain point of the hydraulic excavator upper slewing unit 100 as an origin, the position of the bucket tip 112 in the semi-automatic system is calculated (this position may be referred to as the bucket tip position 112 hereinafter). However, when the upper swivel unit 100 is tilted in the forward link direction, it is necessary to rotate the coordinate system used for control calculation by an angle of vehicle tilt. The vehicle tilt angle sensor 24 is used to correct the rotation amount of the coordinate system to the coordinate system.

While the solenoid proportional valves 3A to 3C control the hydraulic pressure supplied from the pilot pump 50 in response to the electric signal from the controller 1, and the controlled hydraulic pressure passes through the control valves 4A to 4C or the selector valves 18A to 18C so as to act on the main Control valves 13, 14 and 15 to control the spool positions of the main control valves 13, 14 and 15, so that the target cylinder speed can be obtained. If the control valves 4A to 4C are set to the manual mode side, the cylinder 120 can be manually controlled. to 122.

Note that a stem manifold control proportional valve 11 adjusts the manifold ratio of the two pumps 51 and 52 so as to obtain the oil quantity corresponding to the target cylinder speed.

Also, the above-mentioned on-off switch (slope excavation switch) 9 is mounted on the lever joystick 8, and when the operator operates the switch 9, the semi-automatic mode is selected or not selected. Then, if the semi-automatic mode is selected, the tip 112 of the bucket 400 can be moved linearly.

In addition, the above-mentioned on-off switch (bucket automatic return start switch) 7 is installed on the boom/bucket joystick 6, and when the operator turns on the switch 7, the bucket 400 can automatically return to a preset angle.

The safety valve 5 is provided to switch the pilot pressure supplied to the electromagnetic proportional valves 3A to 3C, and the pilot pressure is supplied to the electromagnetic proportional valves 3A to 3C only when the safety valve 5 is in an on state. Therefore, when some kind of failure occurs in the semi-automatic control or the like, by switching the safety valve 5 to the OFF state, the automatic control of the connecting rod can be quickly stopped.

The rotational speed of the engine E varies depending on the position of the engine throttle set by the operator [the position is set by operating a throttle dial (not shown)], and, even if the engine throttle is fixed, the engine rotational speed varies with the load. Since the pumps 50, 51 and 52 are directly coupled to the engine E, if the engine rotational speed is changed, the pump discharges are also changed, therefore, even if the spool positions of the main control valves 13, 14 and 15 are fixed, the cylinder speed varies with the engine E. Variations in rotation speed. In order to correct this problem, the engine rotational speed sensor 23 is installed, and when the engine rotational speed is low, the target moving speed of the bucket tip 112 is set low.

The manipulation panel 10 (sometimes simply referred to as "manipulation panel 10") with a target slope angle setting unit not only serves as a setting unit for the target slope angle α (refer to FIGS. 6 and 11 ) and the bucket return angle. , and is used as an indicator for the coordinates of the bucket tip 112, the measured slope angle, or the distance between the measured coordinates of two points. Note that the manipulation panel 10 is provided in the cab 600 together with the joysticks 6 and 8 .

Specifically, in the system according to the present embodiment, the pressure sensor 19 and the pressure switch 16 are included in the conventional pilot hydraulic line to detect the operation amounts of the joysticks 6 and 8, and the phase splitters 20, 21 and 22 realizes feedback control, and at the same time, each of the cylinders 120, 121 and 122 can independently realize multi-degree-of-freedom feedback control. Thus, the need to add oil units such as pressure compensating valves is eliminated. Also, the tilt influence of the upper swing unit 100 is corrected with the vehicle tilt angle sensor 24 , and the electromagnetic proportional valves 3A to 3C are used for driving the cylinders 120 , 121 and 122 with electrical signals from the controller 1 . Note that the operator can manually select a mode using the manual/semi-automatic mode changeover switch 9, and besides that, can set a target slope angle.

As follows, the control operation of the semi-automatic system performed by the controller 1 is described. The control operation of the semi-automatic mode (except the bucket automatic return mode) realized by the controller 1 is basically as shown in FIG. 4 .

Specifically, the moving speed and direction of the bucket tip 122 are first calculated from the information of the target slope setting angle, pilot hydraulic pressure for controlling the rod cylinder 121 and the boom cylinder 120, the vehicle tilt angle, and the engine rotational speed. Then, target speeds of the hydraulic cylinders 120, 121, and 122 are calculated based on the calculated information (moving speed and moving direction of the bucket tip 112). In this example, information on engine rotational speed is required to determine an upper limit on cylinder speed.

Moreover, the controller 1 includes, as shown in FIGS. 3 and 4 , control sections 1A, 1B, and 1C provided independently of each other for the cylinders 120, 121, and 122, and the control sections are constructed as independent control feedback loops, as shown in FIG. 4 shown so that they do not interfere with each other.

Here, the essential part of the control device of the present embodiment is described. The compensation configuration in the closed-loop control shown in FIG. 4 is in each of the control sections 1A, 1B, and 1C, with a multi-freedom system including a feedback loop and a feedforward loop with respect to displacement and velocity shown in FIG. 5 degree configuration, and includes feedback loop type compensating means 72 with a variable control gain (control parameter), and feedforward loop type compensating means 73 with a variable control gain (control parameter).

Specifically, if a target speed is given, then the process according to the following path is performed by the feedback loop type compensating means 72: a path in which the deviation between the target speed and the speed feedback information is multiplied by a predetermined gain Kvp (reference numeral 62); another path, wherein the target speed is integrated once (referring to the integration link 61 of Fig. 5), and the deviation between the target speed integral information and the displacement feedback information is multiplied by a predetermined gain Kpp (referring to the label 63); and A path, wherein the deviation between the target velocity integral information and the displacement feedback information is multiplied by a predetermined gain Kpi (refer to numeral 64), and is further integrated (refer to numeral 66); and a feedforward loop type compensation device 73 performs a Through the course of a path in which the target speed is multiplied by a predetermined gain Kf (refer to numeral 65).

In the process described above, the feedback loop process is described in more detail. This apparatus includes, as shown in FIG. 5 , an operation information detection device 91 for detecting operation information of the cylinders 120 to 122, and the controller 1 receives the detection information from the operation information detection device 91 and is set as an input by the target value setting device 80 Target operation information (for example, target movement speed) of the information, and set and output control signals so that arm members such as the boom 200 and the bucket (work piece) 400 can assume the target operation state. Moreover, the operation information detection device 91 is specifically the cylinder position detection device 83 capable of detecting the positions of the cylinders 120 to 122, and in this embodiment, the cylinder position detection device 83 is composed of the phase splitters 20 to 22 and the above-mentioned signal converter 26 compositions.

Note that the values of the gains Kvp, Kpp, Kpi and Kf can be changed by a gain programmer 70.

Furthermore, a non-linear removal table 71 is provided to remove the non-linear properties of the electromagnetic proportional valves 3A to 3C, the main control valves 13, 14, and 15, etc., performed at high speed by a computer using a table lookup technique in which non-linear Process to remove Table 71.

When such a slope excavation operation of the target slope angle α shown in FIG. An electro-hydraulic system regulating the resultant movement of the boom 200 and rod 300 enables the semi-automatic control functions described above.

Specifically, a detection signal (including setting information of a target slope angle) is input from each sensor to the controller 1 installed on the hydraulic excavator, and the controller 1 is based on the detection signal from the sensor (including the signal received by the signal converter 26). detection signals of the phase splitters 20 to 22), control the main control valves 13, 14 and 15 through the electromagnetic proportional valves 3A, 3B and 3C to realize such control, so that the boom 200, the rod 300 and the bucket 400 can present The desired extension/retraction displacement is realized to realize the above-mentioned semi-automatic control.

Then, during semi-automatic control, the moving speed and direction of the bucket end 112 are calculated from the information of the target slope setting angle, the pilot hydraulic pressure of the control rod cylinder 121 and the boom cylinder 120, the vehicle tilt angle and the engine rotational speed, and according to This information calculates the target speeds of the cylinders 120 , 121 and 122 . In this example, information on the engine rotational speed is required when determining the upper limit on cylinder speed. Also, the controls are performed as mutually independent feedback loops for the cylinders 120, 121, and 122, and the controls do not interfere with each other.

Note that setting of the target slope angle in the semi-automatic system can be performed by a method based on numerical input using a switch on the manipulation panel 10, a two-point coordinate input method, or an input method using a bucket angle, And similarly, the setting of the bucket return angle in the semi-automatic system is performed by a method based on numerical input using a switch on the manipulation panel 10, or a method based on bucket motion. For all of these, known techniques are used.

Also, the above-described semi-automatic control mode and control method are realized based on cylinder expansion/contraction displacement information obtained by converting the angle information detected by the phase splitters 20 to 22 by the signal converter 26 in the following manner.

First, in the bucket angle control mode, the length of the bucket cylinder 122 is controlled so that the angle (bucket angle) φ defined between the bucket 400 and the x-axis can be fixed at every arbitrary position. In this instance, if the boom cylinder length λbm, the rod cylinder length λst, and the above-mentioned angle φ are determined, the bucket cylinder length λbk is determined.

In grading mode, the bucket end position 112 and node 108 move in parallel as the bucket angle φ remains fixed. First, consider the case where the node 108 moves parallel to the x-axis (horizontal digging).

Specifically, in this example, the coordinates of the node 108 in the link posture when digging is started are represented by (x ₁₀₈ , y ₁₀₈ ), and the boom cylinder 120 and The cylinder length of the rod cylinder 121, and calculate the speed of the boom 200 and the rod 300 so that x ₁₀₈ can move horizontally. Note that the movement speed of the node 108 depends on the operation amount of the joystick 8 .

On the other hand, where parallel motion of node 108 is considered, the coordinates of node 108 are represented by (x ₁₀₈ +Δx,y ₁₀₈ ) after a very short time Δt, Δx being a very small displacement depending on the speed of motion. Thus, by factoring Δx into x ₁₀₈ , the target length of the boom and rod cylinder after Δt can be calculated.

In slope digging mode, controls similar to those in grading mode are available. However, the point of motion changes from the node 108 to the bucket end position 112, and the control takes into account that the bucket cylinder length is fixed.

Also, when the final lean angle is corrected by the vehicle lean angle sensor 24 , the calculation of the front link position is performed on the xy coordinate system whose origin is the node 101 of FIG. 6 . Thus, if the vehicle body is tilted relative to the xy plane, the xy coordinates are rotated and the target tilt angle relative to the ground is changed. In order to correct this problem, the vehicle tilt angle sensor 24 is mounted on the vehicle, and when the vehicle body is detected by the vehicle tilt angle sensor 24 to rotate β with respect to the xy plane, the target tilt angle should be obtained by adding β thereto. value instead of it to correct.

Prevention of deterioration of control accuracy by the engine rotation speed sensor 23 is as follows. Specifically, as far as the correction of the target bucket tip speed is concerned, the target bucket tip speed depends on the positions of the lever joystick 8 and boom/bucket joystick 6 and the engine rotation speed. Meanwhile, since the hydraulic pumps 51 and 52 are directly coupled to the engine E, when the engine rotational speed is low, the pump discharge is small and the cylinder speed is also low. Therefore, the engine rotation speed is detected, and the target bucket tip speed is calculated so as to coincide with the change in the pump discharge amount.

Meanwhile, as for the correction of the maximum value of the target cylinder speed, it is also necessary to consider that the target cylinder speed is changed by the posture of the connecting rod and the inclination angle of the target slope, and when the pump discharge amount decreases as the engine rotational speed decreases. Correct by reducing the maximum cylinder speed. Note that if the target cylinder speed exceeds its maximum cylinder speed, then the target bucket tip speed is reduced so that the target cylinder speed does not exceed the maximum cylinder speed.

Although various control modes and control methods have been described above, they all employ a technique for realizing them based on cylinder expansion/contraction displacement information, and the content of control according to this technique is well known. Specifically, in the system according to the present embodiment, since the angle information is detected by the phase splitters 20 to 22, and then the angle information is converted into cylinder extension/contraction displacement information by the signal converter 26, it is possible for subsequent processing to Use known techniques.

Although in the system according to the present invention, various controls are performed by the controller 1, since the angle information signals detected by the phase splitters 20 to 22 are converted into cylinder displacement information by the signal converter 26, and then input to the controller 1 , so even without using the expensive travel sensor used in the prior art to detect the extension/retraction displacement of each cylinder of the boom 200, the rod 300 and the bucket 400, the cylinder extension/retraction displacement used in the conventional control system can be implemented. shrinkage control. Therefore, a system capable of accurately and stably controlling the position and attitude of the bucket cylinder 400 can be provided although the cost is reduced.

Also, since the feedback control loops for the cylinders 120, 121, and 122 are independent from each other, and the control algorithm is multi-degree-of-freedom control of displacement, velocity, and feedforward, the control system can be simplified. Furthermore, the present system also contributes to an improvement in control accuracy since the nonlinearity of hydraulic equipment can be converted to linearity at high speed by a table lookup technique.

In addition, the present system contributes to more accurate control since the decrease in control accuracy caused by engine throttle position and load variations is corrected by correcting the influence of vehicle tilt by the vehicle tilt angle sensor 24 or reading in the engine rotational speed.

Furthermore, since maintenance such as gain adjustment can be performed using the external terminal 2, there is also an advantage that adjustment and the like are relatively easy. In addition, since the operation amounts of the joysticks 7 and 8 are determined according to changes in pilot pressure using the pressure sensor 19 and the like, and otherwise the conventional open center valve hydraulic system is used as it is, there is no need to add a pressure compensating valve, etc. advantages, and it is also possible to display the bucket end coordinates in real time on the manipulation panel 10 with a target slope angle setting unit. Moreover, due to the construction of the safety valve 5, abnormal system operation when the system is abnormal can also be prevented.

Note that although the application of the present invention to a hydraulic excavator has been described in the above embodiments, the present invention is not limited thereto. The present invention can be similarly applied to construction machines such as tractors, loaders, or bulldozers, as long as the construction machines have an articulated arm mechanism driven by a cylinder-type actuator, and in any construction machine, the similar effects described above can be obtained .

Also, the present invention is not limited to the above-described embodiments, and can be implemented in various modified forms without departing from the spirit of the invention.

As described above, according to a control apparatus for a construction machine of the present invention, since the control using the expansion/contraction displacement information of the actuator used by the above conventional control system is performed, it is possible to accurately and stably The position and posture of the arm mechanism of the construction machine are controlled, so this control device for the construction machine is very helpful in reducing the cost of equipment investment expenses, shortening the work cycle in a desired workplace such as a construction site, etc., and The practicality of this control device for construction machines is considered to be very high.

Claims (7)

1. control appliance that is used for construction machinery is characterized in that it comprises:

A construction machinery body (100);

An articulated type arm mechanism, one end thereof is installed in described construction machinery body (100) and goes up so that be pivotable, and distolaterally having a work package its another, described articulated type arm mechanism comprises the arm spare (200,300) that at least one pair of connects with a hinge portion that places therebetween each other;

A cylinder type execution device has and a plurality ofly is used for stretching/contract the cylinder type actuator (120 to 122) of operation to drive described arm mechanism;

Angle detection device (20 to 22) is used for detecting with angle information the posture of described arm mechanism;

Conversion equipment (26), be used for the angle information that obtains by described angle detection device (20 to 22) convert to described cylinder type actuator corresponding stretching/information of moving condenses; And

Control device (1), be used for according to by stretching/contract information by the described cylinder type actuator (120 to 122) that is converted to of described conversion equipment (26), control described cylinder type actuator (120 to 122), thus described cylinder type actuator (120 to 122) can realize being scheduled to stretch/condense and move.

2. the control appliance that is used for construction machinery according to claim 1 is characterized in that described articulated type arm mechanism can comprise:

A pivoted arm (200) is connected to described construction machinery body (100) at the one end and goes up so that be pivotable; And

A bar (300) is connected on the described pivoted arm (200) to place described hinge portion therebetween at the one end; And its feature also is:

Described work package (400) can form a bucket (400), and bucket (400) is gone up so that be pivotable to place therebetween a hinge portion to be connected to described bar (300) at the one end, and terminally can cut the earth and can adorn soil and sand therein at it.

3. the control appliance that is used for construction machinery according to claim 2 is characterized in that described cylinder type execution device comprises:

A boom hydraulic cylinder (120) places between described construction machinery body (100) and the described pivoted arm (200), so that rotate described pivoted arm by the distance between flexible its end with respect to described construction machinery body;

A bar hydraulic cylinder (121) places between described pivoted arm (200) and the described bar (300), so that rotate described bar (300) by the distance between flexible its end with respect to described pivoted arm (200); And

A bucket hydraulic cylinder (122) places between described bar (300) and the described bucket (400), so that rotate described bucket (400) by the distance between flexible its end with respect to described bar.

4. the control appliance that is used for construction machinery according to claim 2 is characterized in that described angle detection device can comprise:

One first angular transducer (20) is used for detecting the posture of described pivoted arm (200);

One second angular transducer (21) is used for detecting the posture of described bar (300); And

A third angle degree sensor (22) is used for detecting the posture of described bucket (400).

5. the control appliance that is used for construction machinery according to claim 1 is characterized in that described conversion equipment (26) comprising:

Arithmetic unit (26C) is used for according to the angle information that is obtained by described angle detection device (20 to 22), determines that by calculating described cylinder type actuator (120 to 122) stretches/condense the information of moving corresponding to angle information.

6. the control appliance that is used for construction machinery according to claim 1 is characterized in that described conversion equipment (26) comprising:

Storage device (26B) is used for storing described cylinder type actuator (120 to 122) and stretches/condense the information of moving corresponding to the angle information that is obtained by described angle detection device (20 to 22).

7. the control appliance that is used for construction machinery according to claim 3, it is characterized in that building described conversion equipment (26) so that

Stretch/condense the information of moving to what the angle information that is obtained by described first angular transducer (20) converted described boom hydraulic cylinder (120) to, stretch/condense the information of moving to what the angle information that is obtained by described second angular transducer (21) converted described bar hydraulic cylinder (121) to, and stretch/condense the information of moving to what the angle information that is obtained by described third angle degree sensor (22) converted described bucket hydraulic cylinder (122) to.

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