JP7683169B2 - Work Machine - Google Patents

Description

The present invention relates to a work machine.

For example, work machines such as shovels are known (see, for example, Patent Document 1).

JP 2013-028962 A

However, when an abnormality occurs in a work machine, operation may be halted. As a result, even if the abnormality is recoverable, it is not possible to perform work during the period from when the abnormality is recovered through recovery work after operation is stopped, until the work machine is restarted and work can be resumed, resulting in reduced work efficiency.

In view of the above problems, the objective is to provide a work machine that can suppress a decrease in work efficiency even when an abnormality occurs.

In order to achieve the above object, in one embodiment of the present invention,
A control device is provided,
When a predetermined abnormality occurs , the control device automatically transitions to a state in which operation of the work machine in response to an operation input is restricted while continuing operation of the work machine , and also attempts to recover from the predetermined abnormality, and as a result of the attempt, if recovery from the predetermined abnormality is successful, releases the operational restriction of the work machine , and if recovery from the predetermined abnormality fails, stops the operation of the work machine .
A work machine is provided.

In another embodiment of the present invention,
A control device is provided,
When a predetermined abnormality occurs , the control device attempts to recover from the predetermined abnormality while continuing operation while restricting the operation of the work machine , and thereafter, when recovery from the predetermined abnormality is successful, the control device releases the operation restriction of the work machine , and when recovery from the predetermined abnormality is unsuccessful, stops the operation of the work machine .
A work machine is provided.

In still another embodiment of the present invention,
A control device is provided,
When a predetermined abnormality occurs , the control device attempts to recover from the predetermined abnormality while continuing normal operation of the work machine , and when the recovery from the predetermined abnormality fails as a result of the attempt, the control device stops the operation of the work machine .
A work machine is provided.

According to the above-described embodiment, it is possible to provide a work machine that can suppress a decrease in work efficiency even when an abnormality occurs.

FIG. FIG. 2 is a block diagram illustrating an example of a configuration of a shovel. FIG. 4 is a sequence diagram showing an example of an operation of a control system of a shovel when an abnormality occurs in a motor generator. FIG. 4 is a sequence diagram showing an example of an operation of a control system of a shovel when an abnormality occurs in a motor generator. FIG. 2 is a front view of the mobile crane. FIG. 2 is a side view of the mobile crane. FIG. 1 is a diagram illustrating an example of a configuration of a mobile crane.

Below, we will explain the form for implementing the invention with reference to the drawings.

[First example of a work machine (shovel)]
First, a shovel will be described as a first example of a work machine according to this embodiment with reference to FIGS. 1 to 3 (FIGS. 3A and 3B).

<Outline of the excavator>
First, with reference to FIG. 1, an overview of a shovel as a first example of a work machine will be described.

Figure 1 is a side view showing a shovel according to this embodiment.

The excavator according to this embodiment includes a lower carrier 1, an upper rotating body 3 mounted on the lower carrier 1 so as to be rotatable via a rotating mechanism 2, a boom 4, an arm 5, and a bucket 6 as working devices, and a cabin 10 in which the operator sits.

The lower traveling body 1 includes, for example, a pair of left and right crawlers, each of which is hydraulically driven by traveling hydraulic motors 1A, 1B (see Figure 2) to enable self-propulsion.

The upper rotating body 3 rotates relative to the lower traveling body 1 by being electrically driven by a rotating electric motor 21 (see FIG. 2) described later.

The boom 4 is pivotally attached to the front center of the upper rotating body 3 so that it can be raised and lowered, and an arm 5 is pivotally attached to the tip of the boom 4 so that it can rotate up and down, and a bucket 6 is pivotally attached to the tip of the arm 5 so that it can rotate up and down. The boom 4, arm 5, and bucket 6 are hydraulically driven by a boom cylinder 7, arm cylinder 8, and bucket cylinder 9, which serve as hydraulic actuators, respectively.

The cabin 10 is mounted on the front left side of the upper rotating body 3, and inside it are a cockpit where the operator sits, an operating device 26 (described below), and other equipment.

<Excavator configuration>
Next, the configuration of the shovel according to this embodiment will be described with reference to FIG. 2 in addition to FIG.

Figure 2 is a block diagram showing an example of the configuration of the excavator, focusing on the drive system, according to this embodiment.

In the diagram, mechanical power lines are indicated by double lines, high-pressure hydraulic lines are indicated by thick solid lines, pilot lines are indicated by dashed lines, and electrical drive and control lines are indicated by thin solid lines.

As described above, the hydraulic drive system of the excavator according to this embodiment includes hydraulic actuators such as the traveling hydraulic motors 1A and 1B, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, which hydraulically drive the lower traveling body 1, the boom 4, the arm 5, and the bucket 6, respectively. The hydraulic drive system according to this embodiment also mainly includes the engine 11, the motor generator 12, the reducer 13, the main pump 14, and the control valve 17.

The motor generator 12 will be described in detail in the section explaining the excavator's electric drive system.

The engine 11 (an example of a power source) is the main power source in the hydraulic drive system, and is mounted at the rear of the upper rotating body 3. The engine 11 rotates at a predetermined target speed under the control of an engine controller (ECM: Engine Control Module) 30C, which will be described later. The engine 11 is, for example, a diesel engine that uses diesel as fuel, and drives a main pump 14 and a pilot pump 15 via a reduction gear 13. The engine 11 also drives a motor generator 12 via the reduction gear 13, and can cause the motor generator 12 to generate electricity.

The reduction gear 13 is mounted, for example, on the rear of the upper rotating body 3, and has two input shafts to which the engine 11 and the motor generator 12 described below are connected, and one output shaft to which the main pump 14 and pilot pump 15 are coaxially connected in series. The reduction gear 13 can transmit the power of the engine 11 and the motor generator 12 to the main pump 14 and the pilot pump 15 at a predetermined reduction ratio. The reduction gear 13 can also distribute and transmit the power of the engine 11 to the motor generator 12, the main pump 14, and the pilot pump 15 at a predetermined reduction ratio.

The main pump 14 (an example of a hydraulic pump) is mounted on the rear of the upper rotating body 3 and supplies hydraulic oil to a control valve 17 through a high-pressure hydraulic line 16. The main pump 14 is driven by the engine 11, or by the engine 11 and a motor generator 12. The main pump 14 is, for example, a variable displacement hydraulic pump, and a regulator (not shown) controls the angle (tilt angle) of the swash plate under the control of a shovel controller 30A (described later). This allows the main pump 14 to adjust the stroke length of the piston and control the discharge flow rate (discharge pressure).

The control valve 17 is mounted in the center of the upper rotating body 3 and is a hydraulic control device that controls the hydraulic drive system in response to an operation input by the operator to the operating device 26. As described above, the control valve 17 is connected to the main pump 14 via the high-pressure hydraulic line 16 and is configured to be able to supply hydraulic oil supplied from the main pump 14 to the traveling hydraulic motors 1A (for the right) and 1B (for the left), the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, which serve as hydraulic actuators. Specifically, the control valve 17 is a valve unit that includes multiple hydraulic control valves (directional control valves) that control the flow rate and direction of the hydraulic oil supplied from the main pump 14 to each of the hydraulic actuators.

The electric drive system of the excavator according to this embodiment includes a motor generator 12, a current sensor 12s1, a voltage sensor 12s2, and an inverter 18A as components that assist the hydraulic drive system. The electric drive system of the excavator according to this embodiment also includes a rotation motor 21, a current sensor 21s, a resolver 22, a mechanical brake 23, a rotation reducer 24, and an inverter 18B as components related to the electric drive of the driven element (specifically, the upper rotating body 3).

The motor generator 12 (an example of a power source and an electric motor) is an assist power source for the hydraulic drive system, and is mounted on the rear of the upper rotating body 3. The motor generator 12 is, for example, an IPM (Interior Permanent Magnet) motor. The motor generator 12 is connected to a power storage system 120 including a capacitor 19 and a swing motor 21 via an inverter 18A. The motor generator 12 runs on three-phase AC power supplied from the capacitor 19 and the swing motor 21 via the inverter 18A, and drives the main pump 14 and the pilot pump 15 via the reduction gear 13 in a manner that assists the engine 11. The motor generator 12 also runs a generating operation by being driven by the engine 11, and can supply the generated power to the capacitor 19 and the swing motor 21. The switching control between the power running operation and the generating operation of the motor generator 12 may be realized by the inverter 18A under the control of a hybrid controller (hereinafter, "HB controller") 30B described later.

The current sensor 12s1 detects the current of each of the three phases (U-phase, V-phase, and W-phase) of the motor generator 12. The current sensor 12s1 is provided, for example, in the power path between the motor generator 12 and the inverter 18A. The detection signal corresponding to the current of each of the three phases of the turning motor 21 detected by the current sensor 12s1 is taken into the inverter 18A through an in-vehicle network such as a one-to-one communication line or a controller area network (CAN). The detection signal may also be taken into the HB controller 30B once through an in-vehicle network such as a one-to-one communication line or a CAN, and input to the inverter 18A via the HB controller 30B. The same applies to the detection signal of the voltage sensor 12s2.

The voltage sensor 12s2 detects the applied voltage of each of the three phases of the motor generator 12. The current sensor 21s is provided, for example, in the power path between the motor generator 12 and the inverter 18A. The detection signal corresponding to the applied voltage of each of the three phases of the turning motor 21 detected by the voltage sensor 12s2 is input to the inverter 18A via a one-to-one communication line or an in-vehicle network such as a CAN.

The inverter 18A drives and controls the motor generator 12 under the control of the HB controller 30B. The inverter 18A includes, for example, a conversion circuit that converts DC power to three-phase AC power and converts three-phase AC power to DC power, a drive circuit that switches and drives the conversion circuit, and a control circuit that outputs a control signal (for example, a PWM (Pulse Width Modulation) signal) that specifies the operation of the drive circuit.

Specifically, the control circuit of the inverter 18A may successively estimate the rotation angle, etc., of the rotating shaft of the motor generator 12 based on the detection signals of the current sensor 12s1 and the voltage sensor 12s2. For example, the control circuit may estimate the rotation angle, rotation speed, etc., of the rotating shaft of the motor generator 12 based on a known extended electromotive force (EEFM) model. The control circuit may then perform drive control of the motor generator 12 (hereinafter, "sensorless control") while grasping the operating state of the motor generator 12 based on the estimated values of the rotation angle and rotation speed that are successively derived. As a result, the motor generator 12 does not need to be provided with a specific sensor (e.g., a rotary encoder, etc.) that detects the rotation angle and rotation position. This makes it possible to reduce the number of mechanical sensors, thereby reducing the cost of the shovel and suppressing detection failures due to sensor dirt, etc.

The control circuit of the inverter 18A may estimate the rotation angle of the rotating shaft of the motor generator 12, etc., using a voltage command value of the motor generator 12 input from the HB controller 30B or generated by the inverter 18A itself during the control process, instead of the detection value of the applied voltage of the motor generator 12 by the voltage sensor 12s2. In this case, the voltage sensor 12s2 may be omitted. The control circuit of the inverter 18A may also control the motor generator 12 based on a detection signal of a sensor that detects the rotation angle of the motor generator 12. In this case, the motor generator 12 is equipped with a sensor that detects the rotation angle of the rotating shaft, such as a rotary encoder or resolver. At least one of the drive circuit and control circuit of the inverter 18A may be provided outside the inverter 18A.

The turning motor 21 is provided in the turning mechanism 2 that connects the lower traveling body 1 and the upper turning body 3, and performs power running operation to drive the upper turning body 3 to turn and regenerative operation to generate regenerative power to brake the upper turning body 3 to turn under the control of the HB controller 30B. The turning motor 21 is connected to the power storage system 120 via the inverter 18B and is driven by three-phase AC power supplied from the capacitor 19 and the motor generator 12 via the inverter 18B. The turning motor 21 also supplies regenerative power to the capacitor 19 and the motor generator 12 via the inverter 18B. This allows the capacitor 19 to be charged and the motor generator 12 to be driven with the regenerative power. The switching control between power running operation and regenerative operation of the turning motor 21 may be realized by the inverter 18B under the control of the HB controller 30B. A resolver 22, a mechanical brake 23, and a rotation reducer 24 are connected to the rotating shaft 21A of the rotation motor 21.

The current sensor 21s detects the current of each of the three phases (U-phase, V-phase, and W-phase) of the turning motor 21. The current sensor 21s is provided, for example, in the power path between the turning motor 21 and the inverter 18B. The detection signals detected by the current sensor 21s and corresponding to the current of each of the three phases of the turning motor 21 are directly input to the inverter 18B via a one-to-one communication line or an in-vehicle network such as a CAN. The detection signals may also be input to the HB controller 30B via a one-to-one communication line or an in-vehicle network such as a CAN, and input to the inverter 18B via the HB controller 30B.

The resolver 22 detects the rotational position (rotational angle) of the turning motor 21. A detection signal corresponding to the rotational angle detected by the resolver 22 is input to the HB controller 30B via a one-to-one communication line or an in-vehicle network such as a CAN, and is input to the inverter 18B via the HB controller 30B. The detection signal may also be directly input to the inverter 18B.

The mechanical brake 23 mechanically generates a braking force on the rotating shaft 21A of the slewing motor 21 under the control of the HB controller 30B. This allows the mechanical brake 23 to brake the slewing of the upper slewing body 3 or to keep the upper slewing body 3 stationary.

The slewing reduction gear 24 is connected to the rotating shaft 21A of the slewing motor 21, and reduces the output (torque) of the slewing motor 21 at a predetermined reduction ratio, thereby increasing the torque and driving the upper slewing body 3 to rotate. That is, during power running, the slewing motor 21 drives the upper slewing body 3 to rotate via the slewing reduction gear 24. The slewing reduction gear 24 also increases the inertial rotational force of the upper slewing body 3 and transmits it to the slewing motor 21 to generate regenerative power. That is, during regenerative operation, the slewing motor 21 generates regenerative power using the inertial rotational force of the upper slewing body 3 transmitted via the slewing reduction gear 24, and brakes the upper slewing body 3 to rotate.

The inverter 18B, under the control of the HB controller 30B, drives and controls the turning electric motor 21. The inverter 18B includes, for example, a conversion circuit that converts DC power into three-phase AC power and converts three-phase AC power into DC power, a drive circuit that switches and drives the conversion circuit, and a control circuit that outputs a control signal (for example, a PWM signal) that defines the operation of the drive circuit.

Specifically, the control circuit of the inverter 18B performs speed feedback control and torque feedback control for the turning motor 21 based on the detection signals of the current sensor 21s and the resolver 22.

The power storage system 120 of the excavator according to this embodiment includes a capacitor 19, a step-up/step-down converter 100, and a DC bus 110. The power storage system 120 is mounted, for example, on the front right side of the upper rotating body 3 together with inverters 18A and 18B of the electric drive system.

The capacitor 19 is an example of a power storage device that supplies power to the motor generator 12 and the swing motor 21, and charges the generated power of the motor generator 12 and the swing motor 21. In addition, a relay (hereinafter, "shutoff relay") is provided to cut off between the capacitor 19 and the load-side main circuit including the step-up/step-down converter 100. As a result, the capacitor 19 is disconnected from the main circuit under the control of the HB controller 30B when the shovel is stopped or when an abnormality occurs in the shovel (for example, when an accident such as a fall occurs). Therefore, it is possible to prevent a situation in which a very large short-circuit current flows through the capacitor 19 due to an abnormality when the operator is absent or when the operator is present. The shutoff relay is provided, for example, in both the positive and negative power paths between the capacitor 19 and the step-up/step-down converter 100.

The step-up/step-down converter 100 steps up the power of the capacitor 19 and outputs it to the DC bus 110, or steps down the power supplied to the DC bus 110 and stores it in the capacitor 19. The step-up/step-down converter 100 switches between step-up and step-down operations so that the voltage value of the DC bus 110 falls within a certain range depending on the operating state of the motor generator 12 and the turning motor 21. The switching control between the step-up and step-down operations of the step-up/step-down converter 100 may be realized by the HB controller 30B based on the voltage detection value of the DC bus 110, the voltage detection value of the capacitor 19, and the current detection value of the capacitor 19.

The DC bus 110 is provided between the inverters 18A, 18B and the step-up/step-down converter 100, and controls the exchange of power between the capacitor 19, the motor generator 12, and the turning motor 21.

The operating system of the excavator in this embodiment also includes a pilot pump 15, an operating device 26, a pressure sensor 29, etc.

The pilot pump 15 is mounted on the rear of the upper rotating body 3 and supplies pilot pressure to the operating device 26 via a pilot line 25. The pilot pump 15 is, for example, a fixed displacement hydraulic pump, and is driven by the engine 11, or by the engine 11 and the motor generator 12.

The operating device 26 includes, for example, levers 26A and 26B and a pedal 26C. The operating device 26 is provided near the cockpit of the cabin 10, and is an operation input means for the operator to operate each driven element (e.g., the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, and the bucket 6, etc.). In other words, the operating device 26 is an operation input means for operating hydraulic actuators (e.g., the traveling hydraulic motors 1A and 1B, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, etc.) and electric actuators (the swing electric motor 21, etc.) that drive each driven element. The operating device 26 (levers 26A, 26B, and pedal 26C) are connected to the control valve 17 via a hydraulic line 27. As a result, a pilot signal (pilot pressure) corresponding to the operating state of the lower traveling body 1, the boom 4, the arm 5, and the bucket 6, etc. in the operating device 26 is input to the control valve 17. Therefore, the control valve 17 can drive each hydraulic actuator according to the operating state of the operating device 26. In addition, the operating device 26 is connected to a pressure sensor 29 via a hydraulic line 28.

As described above, the pressure sensor 29 is connected to the operating device 26 via the hydraulic line 28, and detects the secondary pilot pressure of the operating device 26, i.e., the pilot pressure corresponding to the operating state of each operating element in the operating device 26. The pressure sensor 29 is connected to the shovel controller 30A, and pressure signals (pressure detection values) corresponding to the operating states of the lower traveling body 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc. in the operating device 26 are input to the shovel controller 30A.

The control system of the excavator in this embodiment includes a control device 30, other controlled units 40, and an HMI (Human Machine Interface) 50.

The control device 30 includes a shovel controller 30A, an HB controller 30B, and an engine controller 30C.

The functions of the shovel controller 30A, HB controller 30B, engine controller 30C, etc. may be realized by any hardware or a combination of hardware and software. For example, the shovel controller 30A, HB controller 30B, engine controller 30C, etc. may be configured around a microcomputer including a CPU (Central Processing Unit), a memory device (main storage device) such as a RAM (Random Access Memory), a non-volatile auxiliary storage device such as a ROM (Read Only Memory), an I/O (Input-Output) interface device, etc.

The shovel controller 30A cooperates with various controllers including the HB controller 30B and the engine controller 30C to control the operation of the shovel. For example, the shovel controller 30A may comprehensively control the operation of the entire shovel (various devices mounted on the shovel) based on two-way communication with various controllers such as the HB controller 30B and the engine controller 30C.

The HB controller 30B controls the drive of the electric drive system based on various information (e.g., control commands including the detection value of the pressure sensor 29 corresponding to the operation state of the operating device 26) input from the shovel controller 30A. For example, the HB controller 30B drives the inverter 18A based on the detection value corresponding to the operation state of the operating device 26 detected by the pressure sensor 29, and controls the switching of the operating state (powering operation and generating operation) of the motor generator 12. Also, for example, the HB controller 30B drives the inverter 18B based on the detection value corresponding to the operation state of the operating device 26 detected by the pressure sensor 29, and controls the switching of the operating state (powering operation and regenerative operation) of the swing motor 21. Also, for example, the HB controller 30B drives the step-up/step-down converter 100 based on a detection value corresponding to the operation state of the operating device 26 detected by the pressure sensor 29, and controls the step-up and step-down operation of the step-up/step-down converter 100, in other words, the switching between the discharged state and the charged state of the capacitor 19.

The HB controller 30B may also have a self-diagnosis function for the electric drive system and detect various abnormalities in the electric drive system.

Specifically, the HB controller 30B may detect abnormalities in the motor generator 12 or the inverter 18A, i.e., abnormalities in the motor generator 12. For example, the HB controller 30B may detect temperature abnormalities, current abnormalities (e.g., overcurrent), voltage abnormalities (e.g., overvoltage), etc. by monitoring the temperature, current, voltage, etc. of the motor generator 12 and the inverter 18A. The HB controller 30B may also detect abnormalities in components of the inverter 18A, such as semiconductor switches, resistors, capacitors, diodes, etc.

The engine controller 30C controls the operation of the engine 11 based on various information (e.g., control commands including the set rotation speed of the engine 11 and the operation mode of the shovel corresponding to the set rotation speed of the engine 11) input from the shovel controller 30A. Specifically, the engine controller 30C realizes the operation control of the engine 11 by outputting control commands to actuators such as the starter motor and fuel injection device of the engine 11 to be controlled.

The engine controller 30C may also have a self-diagnosis function for the engine 11 and detect various abnormalities related to the engine 11. For example, the engine controller 30C may detect abnormalities in various actuators such as the fuel injection device of the engine 11, abnormalities in various sensors such as the crank angle sensor, and abnormalities in the exhaust system.

The other controlled units 40 are components that are related to the operation of the excavator and are controlled by the control device 30, other than the components related to the motor generator 12 (specifically, the motor generator 12 and the inverter 18A, etc.). For example, the other controlled units 40 may include the inverter 18B that drives the engine 11 and the swing motor 21. In addition, for example, the other controlled units 40 may include at least one of the main pump 14 of the hydraulic drive system, the control valve 17, and various valves for controlling the control valve 17 (for example, a gate lock valve, a pressure reducing valve that adjusts the secondary pressure of the operating device 26, etc.).

The HMI 50 is provided in the cabin 10 and serves as an interface between the operator and the excavator. The HMI 50 includes notification (display) means (e.g., an instrument panel and display including warning lights, etc.) and operation means (e.g., the operation device 26, the display touch panel, various buttons, switches, toggles, etc. arranged around the operator's seat).

<Excavator operation when an abnormality occurs>
Next, the operation of the shovel when an abnormality occurs will be described with reference to FIG. 3 (FIG. 3A, FIG. 3B).

Figures 3A and 3B are sequence diagrams showing a specific example of the operation of the shovel when a specified abnormality (an abnormality related to the motor generator 12) occurs. Specifically, Figure 3A is a sequence diagram showing a specific example of the operation of the shovel when it can return to normal after the occurrence of a specified abnormality, and Figure 3B is a sequence diagram showing a specific example of the operation of the shovel when it cannot return to normal and stops after the occurrence of a specified abnormality.

Note that steps S102 to S118 are common between FIG. 3A and FIG. 3B, so the process in FIG. 3B that is different from FIG. 3A (steps S130 to S138) will be mainly described. Also, the process by HB controller 30B in FIG. 3A and FIG. 3B may be performed by the control circuit of inverter 18A instead.

As shown in FIG. 3A, in step S102, the HB controller 30B detects an abnormality in the motor generator 12 based on its own diagnostic function.

In step S104, the HB controller 30B starts abnormality processing in response to the occurrence of an abnormality related to the motor generator 12.

In step S106, the HB controller 30B sends a notification to the shovel controller 30A indicating that an abnormality has occurred in the motor generator 12 (hereinafter, "abnormality occurrence notification"), and in step S108, stops the motor generator 12 (i.e., the inverter 18A). This stops the transmission of assist power from the motor generator 12 to the main pump 14 and the supply of generated power from the motor generator 12 to the rotation motor. In other words, the shovel transitions to an operating state in which the main pump 14 is driven only by the power of the engine 11, and the rotation motor 21 is driven only by power from the power storage system (capacitor 19).

On the other hand, in step S110, when the shovel controller 30A receives the abnormality occurrence notification from the HB controller 30B, it transmits a notification (hereinafter, "operation restriction notification") indicating that the operation of the other controlled units 40 is to be restricted to the other controlled units 40 and the HMI 50. This is because the transmission of assist power from the motor generator 12 to the main pump 14 and the supply of generated power from the motor generator 12 to the turning motor 21 are stopped, and the response speed and maximum output of the main pump 14 and the turning motor 21 are reduced. At this time, the operation restriction notification from the shovel controller 30A may be transmitted directly to the other controlled units 40 and the HMI 50 through a one-to-one communication line or an in-vehicle network such as a CAN, or may be transmitted to the other controlled units 40 and the HMI 50 via other controllers (for example, the engine controller 30C corresponding to the engine 11 and the HB controller 30B corresponding to the turning motor 21) that directly control the other controlled units 40 and the HMI 50. The same applies to the notifications in steps S124 and S130 described below.

In step S112, the operation of the other controlled units 40 is restricted in response to receiving an operation restriction notification (i.e., a control signal) from the shovel controller 30A. For example, the control valve 17 and various valves that adjust the pilot pressure acting on the control valve 17 may be restricted in operation so that the response and operating speed of the hydraulic actuator to an operation input to the operating device 26 is slower than normal. Also, for example, the inverter 18B may be restricted in operation so that the response and operating speed of the swing motor 21 to an operation input to the operating device 26 is slower than normal.

Furthermore, in step S114, the HMI 50 notifies the operator in the cabin 10 of a warning of the occurrence of an abnormality related to the motor generator 12 by a visual method (display) or an auditory method (sound) in response to receiving an operation restriction notification (i.e., a control signal) from the shovel controller 30A. In other words, the HMI 50 notifies the operator of a warning (hereinafter, "operation restriction warning") indicating that the operation of the shovel is restricted due to the occurrence of the abnormality and is in a restricted operating state.

In addition, in step S114, the HMI 50 may further issue a warning (hereinafter, "operation suppression warning") to urge the operator to suppress operation through the shovel's operating device 26 (e.g., to slow down the operating speed). This makes it possible to suppress the operation itself for operating the other controlled units 40, in addition to restricting the operation of the other controlled units 40. Also, instead of restricting the operation of the other controlled units 40, the operator may only be notified of an operation suppression warning. This makes it possible to suppress the operator's operation of the operating device 26, rather than automatically restricting the operation in the shovel's control system, and achieves the same effect.

After the motor generator 12 is stopped (step S108), in step S116, the HB controller 30B performs a process to attempt to restart the motor generator 12 (hereinafter, "restart process"). Specifically, the HB controller 30B restarts the inverter 18A and performs a process based on the self-diagnosis function for the motor generator 12 (hereinafter, "self-diagnosis process").

In step S118, the HB controller 30B determines whether the restart was successful, that is, whether it has been confirmed through the self-diagnosis process associated with the restart that the abnormality related to the motor generator 12 has been resolved. In this example, the abnormality related to the motor generator 12 has been resolved, and the HB controller 30B determines that the restart was successful.

If the abnormality related to the motor generator 12 has not been resolved, the processing of steps S108 and S116 may be repeated up to a predefined number of times until it is confirmed that the abnormality has been resolved.

In step S120, the HB controller 30B transmits a notification (hereinafter, "successful restart notification") to the excavator controller 30A indicating that the restart of the motor generator 12 has been successful, i.e., that the motor generator 12 has returned to normal.

Then, in step S122, the HB controller 30B controls the inverter 18A to resume normal operation of the motor generator 12, i.e., resumes servo control by the inverter 18A.

Meanwhile, in step S124, in response to receiving the restart success notification from the HB controller 30B, the excavator controller 30A transmits a notification to the other controlled units 40 and the HMI 50 to release the operation restrictions on the other controlled units 40 (hereinafter, "operation restriction release notification").

In step S126, the other controlled units 40 release the operational restrictions in response to receiving an operational restriction release notification (i.e., a control signal) from the shovel controller 30A, and return to normal operation.

Furthermore, in step S128, the HMI 50 cancels the warning that is still being notified to the operator in response to receiving the operation restriction release notification (i.e., the control signal). This enables the HMI 50 to notify the operator that the excavator operation restriction has been released.

3B , in this example, the HB controller 30B determines that the restart has failed in step S118. Therefore, in step S130, the HB controller 30B transmits a notification indicating that the restart has failed (hereinafter, a "restart failure notification") to the shovel controller 30A due to the failure of the restart of the motor generator 12, and in step S132, stops the motor generator 12 (i.e., the inverter 18A).

On the other hand, in step S134, in response to receiving the restart failure notification from the HB controller 30B, the shovel controller 30A transmits a notification indicating that the other controlled units 40 are to be stopped (hereinafter, "operation stop notification") to the other controlled units 40 and the HMI 50.

In step S136, the other controlled units 40 stop in response to receiving an operation stop notification (i.e., a control signal) from the shovel controller 30A. This causes the engine 11, the electric drive system, etc. to all stop, and the shovel stops.

In addition, in step S138, in response to the operation stop notification from the shovel controller 30A, the HMI 50 notifies the operator in the cabin 10 of a warning indicating that the shovel has stopped due to an abnormality related to the motor-generator 12.

In this way, in this example, when an abnormality occurs with the motor generator 12, the control device 30 allows the shovel to continue operating while restricting the operation of the shovel. This allows the shovel to continue operating using the power of the engine 11 and the power of the storage system 120 (capacitor 19), making it possible to suppress a decrease in work efficiency when an abnormality occurs.

The control device 30 may perform similar control when an abnormality occurs in the other power source related to the hydraulic drive system, that is, the engine 11. That is, when an abnormality occurs in the engine 11, the control device 30 may continue to operate the shovel with the power of the motor generator 12 while restricting the operation of the shovel. The control device 30 may also perform similar control when an abnormality occurs in the capacitor 19 (electricity storage system 120). That is, when an abnormality occurs in the capacitor 19, the control device 30 may continue to operate the shovel in a manner in which the slewing motor 21 is driven by the power of the motor generator 12 and the motor generator 12 is driven by the regenerative power of the slewing motor 21 while restricting the operation of the shovel.

In addition, in this example, when an abnormality occurs with the motor generator 12, the control device 30 either restricts the operation of the shovel or issues a notification urging the user to suppress operational inputs related to the shovel (i.e., operational inputs to the operating device 26), and continues operating the shovel. In this way, the control device 30 restricts the operation of the shovel in accordance with the reduction in response and output of the main pump 14 and the slewing motor 21 that accompanies an abnormality with the motor generator 12, thereby enabling the mobile crane to continue operating.

In addition, in this example, if an abnormality occurs with the motor generator 12, the control device 30 continues to operate the shovel while restricting the operation of the shovel, and attempts to recover from the abnormality. If recovery from the abnormality is successful, the control device 30 releases the operational restriction. This allows the control device 30 to return the shovel to normal operation from restricted operation while ensuring safety, etc.

[Second example of work machine (mobile crane)]
Next, a mobile crane will be described as a second example of a work machine according to this embodiment with reference to Figures 4 (Figures 4A and 4B) and 5.

<Mobile crane overview>
First, an overview of the mobile crane will be described with reference to Figures 4A and 4B.

Figures 4A and 4B show a front view and a side view, respectively, of an example of a mobile crane according to this embodiment.

As shown in Figures 4A and 4B, the mobile crane according to this embodiment includes a portal frame 140 composed of multiple pillars 141A and girders 141B supported by the multiple pillars 141A, and wheels 142 attached to the lower end of the portal frame 140 (pillars 141A). The mobile crane can move along rails 143 using the wheels 142.

The mobile crane according to this embodiment also includes a trolley 145 mounted on the girder 141, and a winch 146 is mounted on the trolley 145.

The winch 146 uses the power of a winch motor 153 (described later) to winch up and down a hoisting work unit 147 including a wire 147A and a hook 147B attached to the end of the wire 147A.

<Mobile crane configuration>
Next, the configuration of the mobile crane will be described with reference to FIG. 5 in addition to FIG. 4A and FIG. 4B.

The electric drive system of the mobile crane according to this embodiment includes an AC power source 160, a rectifier 163, a power conversion device 165, a power storage system 190 consisting of a power storage device 167 and a power conversion device 168, etc., and a DC bus 170. The electric drive system of the mobile crane according to this embodiment also includes a travel motor 151, a traverse motor 152, a hoisting motor 153, inverters 154-156, and power conversion devices 157-159. The components related to the electric drive system of the mobile crane are each mounted on a portal frame 140.

The AC power supply 160 is connected to the DC bus 170 via a rectifier 163 and a power converter 165, and the power storage device 167 is connected to the DC bus 170 via a power converter 168. The travel motor 151, the traverse motor 152, and the hoisting motor 153 are connected to the DC bus 170 via an inverter 154 and a power converter 157, an inverter 155 and a power converter 158, and an inverter 156 and a power converter 159.

The AC power source 160 includes an engine 161 and a generator 162 (an example of a power source) driven by the engine 161.

The rectifier 163 rectifies the generated power (AC) output from the AC power source 160 and outputs DC power to the power conversion device 165.

Under the control of the controller 180, the power conversion device 165 converts the generated power (DC) of the AC power source 160 supplied via the rectifier 163 into a predetermined target voltage and outputs it to the DC bus 170.

The power storage device 167 (an example of a power source) is connected to the DC bus 70 via the power conversion device 168, and supplies DC power to the DC bus 170, and charges the DC power (regenerated power from the hoist motor 153 or generated power from the AC power source 160) supplied from the DC bus 170. The power storage device 167 is, for example, a lithium-ion battery module.

Under the control of the controller 180, the power conversion device 168 boosts the DC power of the storage device 167 and discharges it to the DC bus 170, or reduces the DC power of the DC bus 170 and charges it to the storage device 167.

The DC bus 170 includes a positive bus 170P and a negative bus 170N, and a smoothing capacitor 172 is provided between the positive bus 170P and the negative bus 170N.

The travel motor 151 (an example of an actuator and an electric actuator) drives the wheels 142 to move the mobile crane forward and backward.

The traverse motor 152 (an example of an actuator and an electric actuator) is mounted on the trolley 145 and moves the trolley 145, i.e., the hoist 146 and the lifting unit 147, in the traverse direction (i.e., left and right direction) along the girder 141B.

The winding motor 153 (an example of an actuator and an electric actuator) winds up and down the lifting work unit 147 (wire 147A).

The inverters 154-156 drive the travel motor 151, the traverse motor 152, and the winding motor 153, respectively, under the control of the controller 180. Specifically, the inverters 154-156 convert the DC power supplied via the power conversion devices 157-159 into AC power, and output it to the travel motor 151, the traverse motor 152, and the winding motor 153, respectively. In addition, the inverter 156 converts the regenerative power (AC) generated by the winding motor 153 during the winding down operation of the winding motor 153 into DC power, and outputs it to the DC bus 170 via the power conversion device 159.

Under the control of the controller 180, the power conversion devices 157 to 159 boost the voltage of the DC bus 170 and output the boosted DC power to the inverters 154 to 156, respectively. In addition, under the control of the controller 180, the power conversion device 159 reduces the voltage of the regenerative power (DC) supplied from the winding motor 153 via the inverter 156 and outputs it to the DC bus 170 during the winding down operation of the winding motor 153.

The control system of the mobile crane in this embodiment includes a controller 180.

As described above, the controller 180 (an example of a control device) controls the inverters 154-156, the power conversion devices 157-159, the power conversion device 165, and the power conversion device 168 to control the operation of the travel motor 151, the traverse motor 152, and the hoisting motor 153, and to control the charging and discharging of the power storage device 167.

The controller 180 also has a self-diagnosis function for the electric drive system and detects various abnormalities in the electric drive system.

Specifically, the controller 180 may detect an abnormality related to the AC power supply 160, that is, an abnormality related to the generator 162. For example, the controller 180 may detect a temperature abnormality, a current abnormality (e.g., overcurrent), a voltage abnormality (e.g., overvoltage), etc., by monitoring the temperature, current, and voltage of the generator 162. The controller 180 may also detect an abnormality of the engine 161 that drives the generator 162 (e.g., an abnormality of various actuators such as a fuel injection device, an abnormality of various sensors such as a crank angle sensor, an abnormality of the exhaust system, etc.), or an abnormality of the rectifier 163 or the power conversion device 165 (e.g., an abnormality of temperature, an abnormality of current, an abnormality of voltage, an abnormality of components such as semiconductor switches, resistors, capacitors, diodes, etc.).

The controller 180 may also detect an abnormality in the power storage system 190, that is, an abnormality related to the power storage device 167. For example, the controller 180 may detect an internal resistance abnormality, a deterioration abnormality, a temperature abnormality, a current abnormality, a voltage abnormality, etc., by monitoring the temperature, current, and voltage of the power storage device 167. The controller 180 may also detect an abnormality in the power conversion device 168 (for example, a temperature abnormality, a current abnormality, a voltage abnormality, etc., or an abnormality in components such as semiconductor switches, resistors, capacitors, and diodes, etc.).

<Mobile crane operation when an abnormality occurs>
Next, the operation of the mobile crane when an abnormality occurs will be described.

As in the case of the excavator described above, when the controller 180 detects an abnormality in either the generator 162 or the power storage device 167 as multiple power sources, the controller 180 may limit the operation of the machine itself (mobile crane) while allowing the machine itself to continue operating using the power of the other power source. This allows the mobile crane to continue operating using the power of the other power source, which is different from the power source corresponding to the abnormality, and suppresses a decrease in work efficiency when an abnormality occurs.

In addition, similar to the case of the excavator described above, when an abnormality occurs in either the generator 162 or the power storage device 167, the controller 180 either restricts the operation of the mobile crane or issues a notification urging the user to suppress operation inputs related to the mobile crane (i.e., operation inputs related to the travel motor 151, the traverse motor 152, and the hoisting motor 153), thereby continuing operation of the mobile crane. In this way, the controller 180 restricts the operation of the mobile crane in accordance with the reduced response and output of the travel motor 151, the traverse motor 152, and the hoisting motor 153 that accompanies an abnormality in either the generator 162 or the power storage device 167, thereby enabling the mobile crane to continue operating.

Furthermore, if an abnormality occurs with either the generator 162 or the power storage device 167, the controller 180 may continue to operate the mobile crane while restricting its operation, and may also attempt to recover from the abnormality, and may release the operational restriction if recovery from the abnormality is successful. In this way, the controller 180 can return the mobile crane from restricted operation to normal operation while ensuring safety, etc.

[Operation of this embodiment]
Next, the operation of the work machine according to this embodiment will be described.

When a specific abnormality occurs, the work machine according to this embodiment at least performs one of the following: notifying the operator to suppress operation of the machine, and automatically transitioning to a state in which the operation of the machine in response to operational input is restricted, thereby continuing operation of the machine.

As a result, even if a specified abnormality occurs, the work machine can continue to operate while ensuring safety by restricting operation or encouraging the operator to refrain from operating the work machine. Therefore, it is possible to prevent a decrease in the work efficiency of the work machine compared to a case in which the work machine is stopped in response to the occurrence of an abnormality.

The work machine may not only urge the operator to suppress operation of the work machine itself or automatically transition to a state in which operation of the work machine in response to operational input is restricted, but may also issue a notification via the HMI 50 or the like to urge the operator to suspend work (i.e., suspend operation of the operating device 26) and evacuate the work machine to a relatively safe place or a place that will not interfere with other work machines. This can further improve the safety of the work machine and the work site where the work machine is working.

In addition, when a specified abnormality occurs, the work machine according to this embodiment continues to operate while restricting its operation, and then releases the operation restriction.

As a result, even if a specified abnormality occurs, the work machine can continue to operate while restricting its operation and ensuring safety, and ultimately, the operation restriction can be lifted and the machine can return to normal operation. This makes it possible to prevent a decrease in the work efficiency of the work machine compared to a case in which the work machine is stopped in response to the occurrence of an abnormality.

In addition, the work machine according to this embodiment may attempt to recover from a specified abnormality when the specified abnormality occurs, and may release the operational restriction when the recovery from the specified abnormality is successful.

This allows the work machine according to this embodiment to return from restricted operation to normal operation while ensuring safety, etc.

In addition, when a predetermined abnormality occurs, the work machine may continue normal operation and attempt to recover from the predetermined abnormality as long as safety and the like are ensured. Specifically, the work machine may continue normal operation without restricting the operation of components other than the component in which the abnormality occurred (e.g., other control target units 40). In addition, when a predetermined abnormality occurs, the work machine may continue normal operation and thereafter restrict the operation in stages according to the machine's own status. Specifically, the work machine may continue normal operation of components other than the component in which the abnormality occurred and restrict the operation in stages according to the status of the other components or components related to the other components. For example, when an abnormality occurs in the motor generator 12, the work machine (shovel) may continue normal operation of the swing motor 21 when the remaining capacity of the capacitor 19 is equal to or greater than a predetermined threshold, and may restrict the operation of the swing motor 21 when the remaining capacity of the capacitor 19 is equal to or less than a predetermined threshold. Further, the rotation motor 21 may be configured to increase the degree of operation restriction under the control of the inverter 18B in accordance with a decrease in the remaining capacity of the capacitor 19. This makes it possible to prevent a situation in which the remaining capacity of the capacitor 19 becomes zero during the period until recovery from an abnormality related to the motor generator 12, making it impossible to continue the rotation operation of the upper rotating body 3.

The work machine according to this embodiment is equipped with multiple power sources for the actuators that operate the work machine itself. If an abnormality occurs in one of the multiple power sources as a specified abnormality, the work machine according to this embodiment may continue to operate using the remaining power sources of the multiple power sources.

As a result, even if an abnormality occurs in one of the multiple power sources, the work machine can continue to operate using power from the remaining power sources while restricting its operation.

The work machine according to this embodiment also includes a hydraulic pump that supplies hydraulic oil to the hydraulic actuator, and an engine and an electric motor that drive the hydraulic pump as multiple power sources. If a specified abnormality occurs in either the engine or the electric motor, the work machine according to this embodiment may continue to operate using the power of the other.

As a result, if the hydraulic actuator can be driven by the power of both the engine and the electric motor via the hydraulic pump, even if an abnormality occurs in either the engine or the electric motor, the hydraulic pump can be driven by the power of the other, allowing the work machine to continue operating.

The work machine according to this embodiment includes, as multiple power sources, a generator and a power storage device that supply power to the electric actuator. If a specified abnormality occurs in either the generator or the power storage device, the work machine according to this embodiment continues to operate using the power of the other.

As a result, if the work machine is capable of driving the electric actuator with the power (electricity) of both the generator and the power storage device, even if an abnormality occurs in either the generator or the power storage device, the electric actuator can be driven with the power (electricity) of the other device, allowing the work machine to continue operating.

Although the above describes in detail the form for carrying out the present invention, the present invention is not limited to such specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims.

For example, in the above-described embodiment, the work machine may be remotely operated from outside the work machine instead of being operated by an operator in the cabin 10. For example, the work machine may have a communication device capable of communicating with a specified external device, and an operation signal related to remote operation may be received from the external device through the communication device, and the control valve 17 and the inverters 18A, 18B may be controlled in response to the operation signal. In this case, the notification contents (various warnings) of the HMI 50 in the above-described embodiment may be confirmed by the operator performing the remote operation through an HMI (e.g., a display, etc.) installed in the external device.

In addition, in the above-described embodiment and modified examples, the work machine may autonomously perform a predetermined task without relying on operation by an operator in the cabin 10 or remote operation based on operation information from an external device. In this case, for example, if a predetermined abnormality occurs, the work machine autonomously continues the predetermined task while restricting its operation.

1A, 1B Travel hydraulic motor (actuator, hydraulic actuator)
7 Boom cylinder (actuator, hydraulic actuator)
8 Arm cylinder (actuator, hydraulic actuator)
9 Bucket cylinder (actuator, hydraulic actuator)
11 engine 12 motor generator (electric motor)
14 Main pump (hydraulic pump)
30 Control device 30A Shovel controller 30B Hybrid controller 30C Engine controller 151 Travel motor (actuator, electric actuator)
152 Traverse motor (actuator, electric actuator)
153 Winding motor (actuator, electric actuator)
162 Generator 167 Electricity storage device 180 Controller (control device)

Claims (8)

A control device is provided,
When a predetermined abnormality occurs , the control device automatically transitions to a state in which operation of the work machine in response to an operation input is restricted while continuing operation of the work machine , and also attempts to recover from the predetermined abnormality, and as a result of the attempt, if recovery from the predetermined abnormality is successful, releases the operational restriction of the work machine , and if recovery from the predetermined abnormality fails, stops the operation of the work machine .
Working machinery. A control device is provided,
When a predetermined abnormality occurs , the control device attempts to recover from the predetermined abnormality while continuing operation while restricting the operation of the work machine , and thereafter, when recovery from the predetermined abnormality is successful, the control device releases the operation restriction of the work machine , and when recovery from the predetermined abnormality is unsuccessful, stops the operation of the work machine .
Working machinery. When the predetermined abnormality occurs , the control device issues a notice to an operator to suspend operation of the work machine and evacuate to a relatively safe place or a place that does not interfere with other surrounding work machines.
2. The work machine of claim 1. An actuator that operates the work machine ;
a plurality of power sources for the actuators;
when an abnormality occurs in some of the plurality of power sources as the predetermined abnormality , the control device continues operation of the work machine using the remaining power sources of the plurality of power sources.
A work machine according to any one of claims 1 to 3. A hydraulic pump is provided to supply hydraulic oil to the hydraulic actuator as the actuator,
The plurality of power sources include an engine and an electric motor;
the hydraulic pump is driven by the engine and the electric motor;
When an abnormality occurs in either one of the engine or the electric motor as the predetermined abnormality , the control device continues operation of the work machine using the power of the other one.
5. A work machine according to claim 4. the plurality of power sources include a generator and a power storage device that supply electric power to an electric actuator serving as the actuator,
When an abnormality occurs in either one of the generator or the power storage device as the predetermined abnormality , the control device continues operation of the work machine using the power of the other.
5. A work machine according to claim 4. A control device is provided,
When a predetermined abnormality occurs , the control device attempts to recover from the predetermined abnormality while continuing normal operation of the work machine , and when the recovery from the predetermined abnormality fails as a result of the attempt, the control device stops the operation of the work machine .
Working machinery. When the specified abnormality occurs , the control device continues normal operation of the work machine , and then attempts to recover from the specified abnormality while gradually restricting the operation of the work machine according to the state of the work machine , and if the attempt succeeds in recovering from the specified abnormality, releases the restriction on the operation of the work machine , and if the attempt fails to recover from the specified abnormality, stops the operation of the work machine .
8. A work machine according to claim 7.

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