Hydraulic work machines

Abstract

To provide a hydraulic work machine capable of causing a power running operation and a non-power running operation to get close to an ideal operation commensurate with an operation amount even when input / output characteristics of a control object vary greatly.SOLUTION: Each of a pump control device 14 and a valve control device 13 includes command calculators 2-7 for calculating a control command for operating a control object 100 using an operation amount of the operation and at least one control parameter, and inputting it to the control object 100, and an ideal output calculator 10 for calculating ideal output, which is ideal output of an actuator 27 related to the operation amount of the operation. The pump control device 14 adjusts at least one pump control parameter so that a difference between the control output and the ideal output becomes small when the operation of a moving part 24 is a power running operation. The valve control device 13 adjusts at least one valve control parameter so that a difference between the control output and the ideal output becomes small when the operation of the moving part 24 is a non-power running operation.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a hydraulic working machine equipped with a control device that controls a controlled object. [Background technology]

[0002] Improving the operability of an operator in a hydraulic work machine such as a hydraulic excavator leads to improved work efficiency at a work site.

[0003] For example, Patent Document 1 discloses a hydraulic actuator control device equipped with a current control means, which supplies a current larger than a target current corresponding to the amount of operation of the operating lever to the electromagnetic proportional flow control valve for a predetermined short period of time when starting the hydraulic actuator from a stopped state in order to reduce the response delay when starting the hydraulic actuator from a stopped state and improve operability.

[0004] Patent Document 2 discloses a construction machine equipped with a control device that outputs a command current for driving an electromagnetic proportional valve in response to an operation signal from an operating device, and this control device has a correction function that corrects the command current so that it is larger than a target current corresponding to the operation amount of the operating device for a predetermined period of time when operation of the operating device starts from the neutral position, in order to ensure different initial responses depending on the hydraulic actuator.

[0005] Patent Document 3 discloses a hydraulic work machine equipped with a control device for improving the initial response of a hydraulic actuator while ensuring energy saving. This control device corrects a pump target flow rate by adding a predetermined correction flow rate that is greater than the minimum pump flow rate of the first hydraulic pump to the pump target flow rate during a period from when a first operating lever is operated from the neutral position until a predetermined correction time has elapsed.

[0006] Patent Document 4 discloses a construction machine equipped with a control means for keeping the relationship between the amount of boom operation and the amount of up and down movement of the attachment tip constant regardless of changes in reach during up and down work performed by moving the tip of the attachment up and down. During boom-raising operation, which is an operation in the load direction, this control means reduces the pump flow rate at long reaches and increases it at short reaches by correcting the pump flow rate determined by the amount of boom-raising operation according to the reach. On the other hand, during boom-lowering, when the attachment's own weight acts, the secondary pressure of the proportional valve provided in the boom-lowering pilot line is corrected according to the reach, thereby reducing the opening of the control valve at long reaches and increasing it at short reaches. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 5-195546 [Patent Document 2] JP 2017-110774 A [Patent Document 3] JP 2019-44933 A [Patent Document 4] JP 2012-225084 A Summary of the Invention [Problem to be solved by the invention]

[0008] Incidentally, the input / output characteristics of the controlled object, which includes a proportional valve to which a command from the control device is input and an actuator that operates a movable part such as a boom, may change significantly due to factors such as replacement of a tip attachment and deterioration of parts in a work machine over time. However, the control devices of Patent Documents 1 to 4 do not take into consideration the change in the input / output characteristics of the controlled object, so when the input / output characteristics of the controlled object change significantly, the control output, which is the output of the actuator, does not become an output that matches the amount of operation. Moreover, the controlled object differs between, for example, a powered operation such as a boom-up operation and a non-powered operation such as a boom-down operation, and the degree of deterioration over time differs for each part that constitutes the controlled object. Therefore, even when the change in the input / output characteristics of the controlled object fluctuates significantly, it is required to make each of the powered operation and non-powered operation of the movable part closer to an ideal operation that matches the amount of operation.

[0009] The present invention has been made to solve the above-mentioned problems, and has an object to provide a hydraulic working machine that can bring both powering operation and non-powering operation closer to ideal operation commensurate with the operating amount, even if the input / output characteristics of the controlled object fluctuate greatly. [Means for solving the problem]

[0010] a control valve interposed between the hydraulic pump and the actuator and operable to open and close so as to change a flow rate of the hydraulic oil supplied to the actuator; an operation device that receives an operation for operating the movable part; an operation determiner that determines whether an operation of the movable part performed in response to the operation received by the operation device is a powering operation in which the movable part operates against a load acting on the movable part or a non-powering operation in which the movable part operates in a direction along a direction of the load acting on the movable part; a pump control device for adjusting the discharge amount of the hydraulic pump; a valve control device for adjusting an opening degree of the control valve; and an output detector that detects a control output which is an output of the actuator, the valve control device comprises: a pump command calculator that calculates a control command for operating a controlled object including the actuator and inputs the control command to the controlled object; an ideal output calculator for pump control that calculates an ideal output which is an ideal output of the actuator associated with an operation amount of the operation; and a pump control parameter adjuster that adjusts the at least one pump control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the powering operation. The valve control device comprises: a valve command calculator that calculates a control command for operating a controlled object including the control valve and the actuator using the operation amount of the operation and at least one valve control parameter and inputs the control command to the controlled object; an ideal output calculator for valve control that calculates an ideal output which is an ideal output of the actuator associated with the operation amount of the operation; and a valve control parameter adjuster that adjusts the at least one valve control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the non-powering operation.

[0011] In this hydraulic working machine, pump control parameters for calculating a control command for the controlled object when powering is performed are adjusted so as to reduce the difference between the control output and the ideal output, and valve control parameters for calculating a control command for the controlled object when non-powering is performed are adjusted so as to reduce the difference between the control output and the ideal output. Therefore, in this hydraulic working machine, even if the input / output characteristics of the controlled object fluctuate greatly, regardless of whether it is powering operation, which requires active driving force from the hydraulic pump, or non-powering operation, which requires flow rate restriction by a control valve, both of these operations can be brought close to an ideal operation commensurate with the operation amount.

[0012] In the hydraulic working machine, it is preferable that the movable part is a boom supported on the support body so as to be able to be raised and lowered, the powered operation is a boom-raising operation that is an operation of the boom such that the tip of the boom leaves the ground, and the non-powered operation is a boom-lowering operation that is an operation of the boom such that the tip of the boom approaches the ground, and the operation determiner determines that the operation of the movable part is the powered operation when the operating device receives a boom-raising operation that is an operation for causing the boom to perform the boom-raising operation, and determines that the operation of the movable part is the non-powered operation when the operating device receives a boom-lowering operation that is an operation for causing the boom to perform the boom-lowering operation. In this configuration, it is possible to appropriately adjust the driving force for performing the boom-raising operation against the weight of the working device including the boom, and to limit the flow rate of hydraulic oil for performing the boom-lowering operation in a direction along the direction of the weight of the working device including the boom, by adjusting a pump control parameter and a valve control parameter, respectively.

[0013] In the hydraulic working machine, it is preferable that the control output of the actuator is an operating speed of the actuator or a physical quantity corresponding thereto, and the output detector is a sensor for detecting the operating speed or the physical quantity. In this configuration, the output detector of the hydraulic working machine can detect the operating speed of the actuator or a physical quantity corresponding thereto as a control output that serves as a base for adjusting a parameter.

[0014] The hydraulic working machine further includes a mode input receiver that receives an input for switching a control mode of the hydraulic working machine between a preset first mode and a preset second mode, the pump control parameter adjuster controls the adjustment of the at least one pump control parameter when the control mode is the first mode and reserves the control of adjusting the at least one pump control parameter when the control mode is the second mode, and the valve control parameter adjuster controls the adjustment of the at least one valve control parameter when the control mode is the first mode and reserves the control of adjusting the at least one valve control parameter when the control mode is the second mode. In this configuration, a person involved in the work, such as an operator or a work manager, can cause the pump control device and the valve control device to control the parameters at any timing that the person involved in the work determines to be necessary. This makes it possible to perform control that respects the will of the operator.

[0015] It is preferable that the hydraulic working machine further includes a working device including the movable part, and a replacement determinator that determines whether at least a part of the working device has been replaced with another part, and the pump control parameter adjuster controls to adjust the at least one pump control parameter when the replacement determinator determines that at least a part of the working device has been replaced with the other part, and the valve control parameter adjuster controls to adjust the at least one valve control parameter when the replacement determinator determines that at least a part of the working device has been replaced with the other part. In this configuration, when the replacement determinator determines that a part or all of the working device has been replaced, the pump control device and the valve control device each control to adjust their control parameters. This makes it possible to automatically perform control to adjust the control parameters when there is a high need to adjust the control parameters, while suppressing the load of computational control.

[0016] It is preferable that the hydraulic working machine further includes a deterioration determiner that determines deterioration of the hydraulic working machine based on a preset determination condition, and the pump control parameter adjuster performs control to adjust the at least one pump control parameter when the deterioration determiner determines that the hydraulic working machine has deteriorated, and the valve control parameter adjuster performs control to adjust the at least one valve control parameter when the deterioration determiner determines that the hydraulic working machine has deteriorated. In this configuration, when the deterioration determiner determines that the hydraulic working machine has deteriorated, each of the pump control device and the valve control device performs control to adjust the control parameters. This makes it possible to automatically perform control to adjust the control parameters when there is a high need to adjust the control parameters while suppressing the load of computational control.

[0017] In the hydraulic working machine, the pump command calculator may be any one capable of calculating a control command for operating a controlled object including the hydraulic pump and the actuator using the operation amount of the operation and at least one pump control parameter, and is not particularly limited in its specific configuration, but it is preferable that the pump command calculator has, for example, the following configuration. That is, the pump command calculator includes a target setter that sets a target output, which is a target of the control output, in accordance with the operation amount of the operation, and a control input calculator that calculates a control input for making the deviation between the target output and the control output zero, and the pump control device preferably further includes a control input corrector that corrects the control input to compensate for fluctuations in characteristics of the controlled object based on at least one of the control input and the control output and the at least one pump control parameter, and calculates the control command and inputs it to the controlled object. With this configuration, even if the input / output characteristics of the controlled object fluctuate significantly, the powering operation can be made to more accurately approximate an ideal operation corresponding to the operation amount.

[0018] In the hydraulic working machine, it is preferable that the at least one pump control parameter includes a static parameter and a dynamic parameter, and the control input corrector of the pump control device includes a static compensator that calculates a static compensation input for compensating for fluctuations in the static characteristics of the controlled object based on the static parameters and the control input, a dynamic compensator that calculates a dynamic compensation input for compensating for fluctuations in the dynamic characteristics of the controlled object based on the dynamic parameters and the control output, and a combiner that combines the static compensation input and the dynamic compensation input to calculate the control command and inputs it to the controlled object. In this configuration, since the control input is corrected by the dynamic compensation input calculated based on the dynamic parameters and the control output, it is possible to compensate for fluctuations in the dynamic characteristics of the controlled object, such as rise characteristics and damping characteristics. Furthermore, since the control input is corrected by the static compensation input calculated based on the control input and the static parameters, it is possible to compensate for fluctuations in the static characteristics of the controlled object, such as fluctuations in the scale of the control input due to the combination of the dynamic compensation inputs.

[0019] In the hydraulic working machine, it is preferable that the pump control ideal output calculator calculates the ideal output corresponding to the control input using an input / output model that defines an ideal input / output relationship between the control input and the control output. In this configuration, the static parameters and dynamic parameters are adjusted using the ideal output and the control output calculated during operation of the controlled object. Therefore, online adjustment is possible to adjust the static parameters and dynamic parameters during operation without stopping the operation of equipment including the controlled object.

[0020] In the hydraulic working machine, the valve command calculator may be any one capable of calculating a control command for operating a controlled object including the control valve and the actuator using the operation amount of the operation and at least one valve control parameter, and is not particularly limited in its specific configuration, but it is preferable that the valve command calculator includes a target setter that sets a target output that is a target of the control output in accordance with the operation amount of the operation, and a control input calculator that calculates a control input for making the deviation between the target output and the control output zero, and the valve control device preferably further includes a control input corrector that corrects the control input to compensate for fluctuations in characteristics of the controlled object based on at least one of the control input and the control output and the at least one valve control parameter, and calculates the control command and inputs it to the controlled object. With this configuration, even if the input / output characteristics of the controlled object fluctuate greatly, it is possible to more accurately bring the non-powering operation closer to an ideal operation corresponding to the operation amount.

[0021] In the hydraulic working machine, it is preferable that the at least one valve control parameter includes a static parameter and a dynamic parameter, and the control input corrector of the valve control device includes a static compensator that calculates a static compensation input for compensating for fluctuations in the static characteristics of the controlled object based on the static parameters and the control input, a dynamic compensator that calculates a dynamic compensation input for compensating for fluctuations in the dynamic characteristics of the controlled object based on the dynamic parameters and the control output, and a combiner that combines the static compensation input and the dynamic compensation input to calculate the control command and inputs it to the controlled object. In this configuration, since the control input is corrected by the dynamic compensation input calculated based on the dynamic parameters and the control output, it is possible to compensate for fluctuations in the dynamic characteristics of the controlled object, such as rise characteristics and damping characteristics. Furthermore, since the control input is corrected by the static compensation input calculated based on the control input and the static parameters, it is possible to compensate for fluctuations in the static characteristics of the controlled object, such as fluctuations in the scale of the control input due to the combination of the dynamic compensation inputs.

[0022] In the hydraulic working machine, it is preferable that the valve control ideal output calculator calculates the ideal output corresponding to the control input using an input / output model that defines an ideal input / output relationship between the control input and the control output. In this configuration, the static parameters and dynamic parameters are adjusted using the ideal output and the control output calculated during operation of the controlled object. Therefore, online adjustment is possible to adjust the static parameters and dynamic parameters during operation without stopping the operation of equipment including the controlled object.

[0023] It is preferable that the hydraulic working machine further includes a characteristic input receiver that receives an input for changing the settings of the input / output characteristics of the control input and the control output. In this configuration, the input / output characteristics of the control input and the control output can be set in the control device by an operator inputting characteristics according to his / her preference. Effect of the Invention

[0024] According to the present invention, a hydraulic working machine is provided that can bring both powering operation and non-powering operation closer to ideal operation corresponding to the operation amount even if the input / output characteristics of the controlled object fluctuate greatly. [Brief description of the drawings]

[0025] [Figure 1] 1 is a side view showing an example of a hydraulic working machine according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of a hydraulic circuit and a control unit in the hydraulic working machine. [Diagram 3] FIG. 2 is a block diagram showing an example of a control device in the control unit. [Figure 4] 4 is a flowchart illustrating an example of a process performed by the control device. [Diagram 5] 5 is a graph showing an example of a relationship between an operation amount received by an operating device of the hydraulic working machine and time, a relationship between an electrical output and time, and a relationship between a control output and time, respectively. [Figure 6] FIG. 2 is a block diagram showing a feedback system that constitutes a control loop. [Figure 7] 5 is a diagram showing another example of a hydraulic circuit and a control unit of the hydraulic working machine. FIG. [Figure 8] FIG. 4 is a diagram showing still another example of a hydraulic circuit and a control unit of the hydraulic working machine. [Figure 9] 6 is a graph showing other examples of the relationship between the operation amount of the operation received by the operating device of the hydraulic working machine and time, the relationship between the electrical output and time, and the relationship between the control output and time, respectively. [Figure 10] FIG. 4 is a diagram showing still another example of a hydraulic circuit and a control unit of the hydraulic working machine. [Figure 11] 6 is a graph showing still another example of the relationship between the operation amount of the operation device of the hydraulic working machine and time, the relationship between the electrical output and time, and the relationship between the control output and time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view showing a hydraulic excavator 20, which is an example of a hydraulic working machine according to this embodiment. Fig. 2 is a diagram showing an example of a hydraulic circuit and a control unit in the hydraulic excavator 20.

[0027] As shown in Figures 1 and 2, the hydraulic excavator 20 comprises a self-propelled lower running body 21, an upper rotating body 22 rotatably supported on the lower running body 21, a working device 23, a plurality of hydraulic actuators, a plurality of hydraulic pumps, a pilot pump 47, a plurality of control valves, a plurality of operating devices, a plurality of proportional valves, an output detector 12 (see Figure 3), and a control unit 1.

[0028] The upper rotating body 22 includes an upper frame 30 rotatably supported on the lower traveling body 21, a cabin 31 supported on the upper frame 30, and a counterweight 32 disposed behind the cabin 31. The lower traveling body 21 and the upper rotating body 22 are examples of a support body.

[0029] The working device 23 includes a boom 24 supported on the upper frame 30 so as to be able to rise and fall, an arm 25 supported rotatably at the tip of the boom 24, and a bucket 26 supported rotatably at the tip of the arm 25. The boom 24 is an example of a movable part.

[0030] The multiple hydraulic actuators include a boom cylinder 27 , an arm cylinder 28 , a bucket cylinder 29 , and a swing motor 33 .

[0031] Each of the hydraulic pumps is a hydraulic pump for supplying hydraulic oil to at least one of the hydraulic actuators. The hydraulic pumps include a variable displacement hydraulic pump 41 shown in Fig. 2. The pilot pump 47 is a hydraulic pump for supplying pilot pressure to each of the control valves. Each of the hydraulic pumps and the pilot pump 47 is driven by an engine (not shown).

[0032] 2 representatively illustrates only the circuit for operating the boom cylinder 27, and does not illustrate the circuits for operating the arm cylinder 28, the bucket cylinder 29, and the swing motor 33. Each of the circuits for operating the arm cylinder 28, the bucket cylinder 29, and the swing motor 33 has a similar structure to the circuit for operating the boom cylinder 27 shown in FIG.

[0033] The boom cylinder 27 is a hydraulic cylinder that receives hydraulic oil from a hydraulic pump 41 shown in Fig. 2 and operates to raise and lower the boom 24. As shown in Fig. 1, a base end of a cylinder tube of the boom cylinder 27 is rotatably attached to an upper frame 30 of the upper rotating body 22, and a tip end of a piston rod of the boom cylinder 27 is rotatably attached to the boom 24. As shown in Fig. 2, the boom cylinder 27 has a rod chamber 27R and a head chamber 27H.

[0034] The arm cylinder 28 is a hydraulic cylinder that receives hydraulic oil from any one of a plurality of hydraulic pumps and operates to rotate the arm 25. The bucket cylinder 29 is a hydraulic cylinder that receives hydraulic oil from any one of a plurality of hydraulic pumps and operates to rotate the bucket 26. The swing motor 33 is a hydraulic motor that receives hydraulic oil from any one of a plurality of hydraulic pumps and operates to swing the upper frame 30 of the upper swing body 22 relative to the lower traveling body 21.

[0035] The multiple control valves include a boom control valve 42 shown in Fig. 2, an arm control valve (not shown), a bucket control valve (not shown), and a swing control valve (not shown). Each of the multiple control valves has a spool and a pair of pilot ports that receive pilot pressure from a pilot pump 47.

[0036] The boom control valve 42 is interposed between the hydraulic pump 41 and the boom cylinder 27, and opens and closes to change the direction and flow rate of hydraulic oil supplied to the boom cylinder 27. The arm control valve is interposed between any of the hydraulic pumps and the arm cylinder 28, and opens and closes to change the direction and flow rate of hydraulic oil supplied to the arm cylinder 28. The bucket control valve is interposed between any of the hydraulic pumps and the bucket cylinder 29, and opens and closes to change the direction and flow rate of hydraulic oil supplied to the bucket cylinder 29. The swing control valve is interposed between any of the hydraulic pumps and the swing motor 33, and opens and closes to change the direction and flow rate of hydraulic oil supplied to the swing motor 33.

[0037] The multiple operation devices include a boom operation device 43 (see FIG. 2) that receives an operation for operating the boom 24, an arm operation device (not shown) that receives an operation for operating the arm 25, a bucket operation device (not shown) that receives an operation for operating the bucket 26, and a swing operation device (not shown) for swinging the upper swing body 22 relative to the lower traveling body 21. Each of the multiple operation devices has an operation lever that can be operated by an operator. Each of the multiple operation devices is an electric lever device that outputs a command signal (electrical signal) corresponding to the operation received by the operation lever and the amount of operation. The output command signal is input to the control unit 1.

[0038] Specifically, the boom operation device 43 is configured to be capable of receiving a boom raising operation for making the boom 24 perform a boom raising operation and a boom lowering operation for making the boom 24 perform a boom lowering operation. The boom raising operation is an operation of the boom 24 such that the tip of the boom 24 moves away from the ground, and the boom lowering operation is an operation of the boom 24 such that the tip of the boom 24 moves closer to the ground. The boom raising operation is an operation that requires adjusting the discharge amount of the hydraulic pump 41 in order to displace the working device 23 in a direction against gravity as shown in FIG. 2. The boom raising operation is an example of a powered operation in which the boom 24 operates against a load acting on the working device 23 including the boom 24. The boom lowering operation is an operation that requires adjusting the opening degree of the boom control valve 42 in order to displace the working device 23 at a desired operating speed in a direction along the direction of gravity acting on the working device 23 including the boom 24. The boom lowering operation is an example of a non-powered operation in which the boom 24 operates in a direction along the direction of the load acting on the working device 23 including the boom 24. The boom-raising operation is an example of a powering operation, and the boom-lowering operation is an example of a non-powering operation (regenerative operation).

[0039] When the boom operation device 43 receives a boom-raising operation, it inputs a boom-raising command signal corresponding to the boom-raising operation and the amount of operation to the control unit 1. When the boom operation device 43 receives a boom-lowering operation, it inputs a boom-lowering command signal corresponding to the boom-lowering operation and the amount of operation to the control unit 1. The basic configurations and functions of the arm operation device, bucket operation device and swing operation device are similar to those of the boom operation device 43, so detailed explanations will be omitted.

[0040] Each of the multiple proportional valves reduces the pressure of the pressure oil of the pilot pump 47 and outputs it in response to a control command input from the control unit 1. Each of the multiple proportional valves is configured, for example, by an electromagnetic proportional valve. The multiple proportional valves include a pair of boom proportional valves 44, 45, a pair of arm proportional valves (not shown), a pair of bucket proportional valves (not shown), a pair of swing proportional valves (not shown), and a pump proportional valve 46.

[0041] Specifically, each of the pair of boom proportional valves 44, 45 reduces the pressure oil from the pilot pump 47 in response to a control command (command current) input from the control unit 1, and outputs a pilot pressure corresponding to the control command to the boom control valve 42. The pair of boom proportional valves 44, 45 are respectively provided on a pair of pilot lines connecting the pilot pump 47 and a pair of pilot ports of the boom control valve 42.

[0042] When the boom operation device 43 receives a boom lowering operation, a control command from the control unit 1 is input to the boom proportional valve 44. The boom proportional valve 44 generates a pilot pressure according to the control command, and the generated pilot pressure is supplied to one pilot port of the boom control valve 42 (the left port of the boom control valve 42 in FIG. 2). The spool of the boom control valve 42 shifts by a displacement amount (amount of shift from the neutral position) corresponding to the supplied pilot pressure. As a result, the boom control valve 42 is adjusted to an opening (amount of opening) corresponding to the displacement amount, and allows the hydraulic oil discharged from the hydraulic pump 41 to be supplied to the rod chamber 27R of the boom cylinder 27 at a flow rate corresponding to the displacement amount, and allows the hydraulic oil to be discharged from the head chamber 27H and returned to the tank.

[0043] When the boom operation device 43 receives a boom raising operation, a control command from the control unit 1 is input to the boom proportional valve 45. The control unit 1 outputs, as the control command, for example, a command value corresponding to the operation amount of the boom raising operation. The boom proportional valve 45 generates a pilot pressure corresponding to the control command, and the generated pilot pressure is supplied to the other pilot port of the boom control valve 42 (the right port of the boom control valve 42 in FIG. 2). The spool of the boom control valve 42 shifts by a displacement amount (amount of shift from the neutral position) corresponding to the supplied pilot pressure. As a result, the boom control valve 42 is adjusted to an opening degree (amount of opening) corresponding to the displacement amount, and allows the hydraulic oil discharged from the hydraulic pump 41 to be supplied to the head chamber 27H of the boom cylinder 27 at a flow rate corresponding to the displacement amount, and allows the hydraulic oil to be discharged from the rod chamber 27R and returned to the tank.

[0044] Each of the pair of arm proportional valves reduces the pressure of oil from the pilot pump 47 in response to a control command input from the control unit 1, and outputs a pilot pressure corresponding to the control command to the arm control valve. Each of the pair of bucket proportional valves reduces the pressure of oil from the pilot pump 47 in response to a control command input from the control unit 1, and outputs a pilot pressure corresponding to the control command to the bucket control valve. Each of the pair of swing proportional valves reduces the pressure of oil from the pilot pump 47 in response to a control command input from the control unit 1, and outputs a pilot pressure corresponding to the control command to the swing control valve. The basic configuration and function of each of these proportional valves are similar to those of the boom proportional valves 44, 45, so detailed explanations will be omitted.

[0045] The pump proportional valve 46 reduces the pressure of the hydraulic oil from a hydraulic pump (for example, a pilot pump 47) in response to a control command (command current) output from the control unit 1, and outputs an operating pressure corresponding to the control command to the hydraulic pump 41. The pump proportional valve 46 is provided in a pump line connecting the pilot pump 47 and the hydraulic pump 41. When an operating pressure is input to the hydraulic pump 41, the capacity (tilt angle) of the hydraulic pump 41 is adjusted to a capacity (tilt angle) according to the operating pressure. This adjusts the discharge amount of the hydraulic pump 41.

[0046] The control unit 1 includes a pump control device 14 for adjusting the discharge volume of the hydraulic pump 41, a valve control device 13 for adjusting the opening degree of the boom control valve 42, and an operation determiner 17 for determining the operation of the boom 24.

[0047] 3 is a block diagram showing an example of a control device in the control unit 1. The control device shown in FIG.

[0048] The output detector 12 shown in FIG. 3 is a detector for detecting a control output y(k) which is an output of the boom cylinder 27. The control output y(k) of the boom cylinder 27 may be, for example, the operating speed of the boom cylinder 27, or a physical quantity corresponding to the operating speed of the boom cylinder 27. The physical quantity corresponding to the operating speed may be, for example, the flow rate of hydraulic oil supplied to the boom cylinder 27, the flow rate of hydraulic oil discharged from the boom cylinder 27, or the operating speed of the boom 24 when the boom 24 performs a hoisting operation. Therefore, the output detector 12 may be a speed sensor that detects the operating speed of the boom cylinder 27, a flow rate sensor that detects the flow rate of hydraulic oil supplied to the boom cylinder 27 or the flow rate of hydraulic oil discharged from the boom cylinder 27, or a speed sensor that detects the operating speed of the boom 24 when the boom 24 performs a hoisting operation.

[0049] 2 determines whether the operation of the boom 24 performed in response to the operation received by the boom operation device 43 is a boom-raising operation or a boom-lowering operation. When the boom operation device 43 receives a boom-raising operation, the boom-raising command signal is input to the control unit 1, and the operation determiner 17 determines that the operation of the boom 24 is a boom-raising operation (powered operation). When the boom operation device 43 receives a boom-lowering operation, the boom-lowering command signal is input to the control unit 1, and the operation determiner 17 determines that the operation of the boom 24 is a boom-lowering operation (non-powered operation).

[0050] 3, each of the pump control device 14 and the valve control device 13 controls a control object 100 that outputs a control output y(k) in response to an actual input up(k) as a control command. In this embodiment, the control object 100 controlled by the pump control device 14 includes a pump proportional valve 46, a pump 41, and a boom cylinder 27, and the control object 100 controlled by the valve control device 13 includes a boom proportional valve 44, a boom control valve 42, and a boom cylinder 27. The k in parentheses next to the reference symbol indicates time.

[0051] 3 shows the configuration of the pump control device 14, and also shows the configuration of the valve control device 13. In this embodiment, the pump control device 14 and the valve control device 13 may have different specific values ​​of parameters, etc., which will be described later, but have the same basic configuration.

[0052] As shown in Fig. 3, each of the pump control device 14 and the valve control device 13 includes a target setter 2, a subtracter 3, a controller 4, a static compensator 5, a dynamic compensator 6, a subtracter 7 (an example of a synthesizer), a parameter adjuster 9, a subtracter 8, an ideal output calculator 10, and a memory 11. The target setter 2, the subtracter 3, the controller 4, the static compensator 5, the dynamic compensator 6, the subtracter 7, the subtracter 8, the parameter adjuster 9, and the ideal output calculator 10 are configured by a processor such as a CPU or an ASIC. The static compensator 5, the dynamic compensator 6, and the subtracter 7 are examples of a control input corrector. The target setter 2, the subtracter 3, the controller 4, the static compensator 5, the dynamic compensator 6, and the subtracter 7 are examples of a command calculator.

[0053] The target setter 2 sets a target output r(k), which is a target of the control output y(k), according to the operation amount of the operation received by the boom operation device 43. Specifically, the target setter 2 in the pump control device 14 sets a target output r(k) according to the operation amount of the boom raising operation based on a preset map showing the relationship between the operation amount of the boom raising operation and the target output r(k). The target setter 2 in the valve control device 13 sets a target output r(k) according to the operation amount of the boom lowering operation based on a preset map showing the relationship between the operation amount of the boom lowering operation and the target output r(k).

[0054] A subtractor 3 calculates a deviation e(k) by subtracting the control output y(k) from the target output r(k).

[0055] A controller 4 (control input calculator) calculates a control input uc(k) for making the deviation e(k) zero based on the control output y(k). The controller 4 corresponds to an upstream controller. In each of the pump control device 14 and the valve control device 13, the control structure is hierarchical, and a downstream control loop 50 that directly controls the controlled object 100 is operated according to instructions from the controller 4, which is the upstream controller. The control loop 50 will be described later.

[0056] The controller 4 may be configured to calculate a control input uc(k) for making the deviation e(k) zero by, for example, PID control. As a formula used for the PID control, for example, formula (17) described below is adopted. Note that the controller 4 may calculate the control input uc(k) by using various feedback controls or feedforward controls such as P control, PD control, and PI control other than PID control.

[0057] The static compensator 5 multiplies the control input uc(k) by a static gain f0 (an example of a static parameter) to calculate a static compensation input that compensates for fluctuations in the static characteristics of the control target 100. The static characteristics are characteristics of the control target 100 that are independent of time. An example of the static characteristics is the scale that the control output y(k) can take. The static gain f0 is a gain for compensating for fluctuations in this static characteristic. For example, if the dynamic compensation input calculated by the dynamic compensator 6 becomes excessively large, the actual input up(k) becomes too small, and the value of the control output y(k) becomes significantly smaller than the expected scale. To avoid such a situation, the static compensator 5 multiplies the control input uc(k) by the static gain f0.

[0058] The dynamic compensator 6 calculates a dynamic compensation input for compensating for fluctuations in the dynamic characteristics of the controlled object 100 based on a dynamic gain (an example of a dynamic parameter) and the control output y(k). The dynamic characteristics are time-dependent characteristics such as the rise characteristics and decay characteristics of the controlled object 100. The dynamic gain is a gain for compensating for such fluctuations in the dynamic characteristics. The dynamic gain includes, for example, a proportional gain Kp and a differential gain K DThe dynamic compensator 6 includes, for example, Kp y(k)+K D Calculate the dynamic compensation input using the formula Δy(k), where Δy(k) represents the derivative of y(k).

[0059] In the pump control device 14 and the valve control device 13, the static gain f0 is individually initialized, and the dynamic gains (proportional gain Kp and differential gain K D ) are individually initialized. Therefore, the static gain f0 initially set in the pump control device 14 and the static gain f0 initially set in the valve control device 13 may be different from each other, and the dynamic gain initially set in the pump control device 14 and the dynamic gain initially set in the valve control device 13 may be different from each other. Each of the static gain f0 and the dynamic gain initially set in the pump control device 14 is an example of a pump control parameter. Each of the static gain f0 and the dynamic gain initially set in the valve control device 13 is an example of a valve control parameter.

[0060] The subtractor 7 calculates an actual input up(k) as a control command by subtracting the dynamic compensation input from the static compensation input, and inputs the actual input up(k) to the controlled object 100. This adjusts the control input uc(k) so that the dynamic characteristics and static characteristics of the controlled object 100 are compensated for. Specifically, the subtractor 7 in the pump control device 14 inputs the calculated actual input up(k) to the pump proportional valve 46 of the controlled object 100 (see FIG. 2). The subtractor 7 in the valve control device 13 inputs the calculated actual input up(k) to the boom proportional valve 44 of the controlled object 100 (see FIG. 2). The actual input up(k) is expressed by, for example, the following equation.

[0061] up(k)=f0·uc(k)-Kp·y(k)-K D Δy(k) The above-mentioned static compensator 5, dynamic compensator 6, subtractor 7, and controlled object 100 constitute a control loop 50. The control loop 50 is a downstream control loop that directly controls the controlled object 100. The control loop 50 outputs a control output y(k) in response to a control input uc(k).

[0062] The ideal output calculator 10 calculates an input / output model Gm(z -1 ) to calculate an ideal output yr(k) corresponding to a control input uc(k). The ideal input / output relationship corresponds to the relationship between the control input uc(k) and the control output y(k) at the time of designing the controller 4. Hereinafter, the relationship between the control input uc(k) and the control output y(k) is referred to as the input / output characteristic of the control loop 50. For example, when the controller 4 is designed based on the input / output characteristic of the initial control loop 50 including the initial control target 100, the input / output model has the input / output characteristic of the initial control loop 50. Therefore, even if the input / output characteristic of the control target 100 changes from the initial characteristic and the input / output characteristic of the control loop 50 changes from the initial input / output characteristic, the ideal output calculator 10 can calculate an ideal output yr(k) according to the input / output characteristic of the initial control loop 50. The input / output model Gm(z -1 ) are expressed, for example, by equations (19), (20), and (21) described below.

[0063] The subtractor 8 subtracts the ideal output yr(k) from the control output y(k) to calculate a difference A, and inputs the difference A to the parameter adjuster 9.

[0064] The parameter adjuster 9 adjusts the static gain f0 and the dynamic gain (Kp, K D ) are adjusted by the parameter adjuster 9, for example, by the recursive least squares method. D In this case, the static gain f0 and the dynamic gain (Kp, K D ) is adjusted. That is, the static gain f0 and the dynamic gain (Kp, K D ) can be adjusted online. As the recursive least squares method, a method can be adopted in which an evaluation function J shown in equation (9) described later is minimized using equations (10) to (16) described later.

[0065] The memory 11 is composed of, for example, a RAM or a flash memory. The memory 11 stores the control output y(k) and the ideal output yr(k). The memory 11 may store the control output y(k) and the ideal output yr(k) calculated from the time k up to several samples before.

[0066] Next, a description will be given of the processing of the control devices 13 and 14. Fig. 4 is a flow chart showing an example of the processing of the control devices 13 and 14.

[0067] When the boom operation device 43 receives a boom-raising operation, it inputs a boom-raising command signal corresponding to the boom-raising operation and the amount of operation to the control unit 1, and in step S0, the target setter 2 in the pump control device 14 sets a target output r(k) corresponding to the amount of operation of the boom-raising operation based on the preset map. Similarly, when the boom operation device 43 receives a boom-lowering operation, it inputs a boom-lowering command signal corresponding to the boom-lowering operation and the amount of operation to the control unit 1, and in step S0, the target setter 2 in the valve control device 13 sets a target output r(k) corresponding to the amount of operation of the boom-lowering operation based on the preset map.

[0068] In step S1, the subtractor 3 calculates the deviation e(k) by subtracting the control output y(k) from the target output r(k).

[0069] In step S2, the controller 4 inputs the deviation e(k) and the control output y(k) into the equation (17) to calculate the control input uc(k).

[0070] In step S3, the ideal output calculator 10 calculates the control input uc(k) and the input / output model Gm(z -1 ) to calculate the ideal output yr(k).

[0071] In step S4, the detector 12 detects the control output y(k) output from the control loop 50 in response to the control input uc(k).

[0072] In step S5, the subtractor 8 calculates the difference A by subtracting the ideal output yr(k) from the control output y(k) detected by the detector 12.

[0073] In step S6, the parameter adjuster 9 adjusts the static gain f0 and the dynamic gain (Kp, K D When step S6 is completed, the process returns to step S1. This sequentially calculates the static gain f0 and the dynamic gain (Kp, K D ) is adjusted.

[0074] In this way, according to the hydraulic excavator 20, the input / output model Gm(z -1 ) is used to calculate the ideal output yr(k) corresponding to the control input uc(k), and the static gain f0 of the static compensator 5 and the dynamic gain (Kp, K D ) are adjusted. As a result, even if the input / output characteristics of the controlled object 100 vary significantly, the input / output characteristics of the control input uc(k) and the control output y(k) are maintained at the ideal input / output characteristics at the time of designing the controller 4. Therefore, even if the input / output characteristics of the controlled object 100 vary significantly, the controlled object 100 can be appropriately controlled using the controller 4 at the time of design. This makes it easier to design the controller 4, and facilitates the development of the hydraulic excavator 20.

[0075] The upper graph in FIG. 5 shows an example of the relationship between the operation amount (lever operation amount) of the boom operation received by the boom operation device 43 and time. The middle graph in FIG. 5 shows an example of the relationship between the electric output output from the subtractor 7 and time when the boom operation device 43 receives a boom operation (boom raising operation or boom lowering operation) as shown in the upper graph. The electric output output from the subtractor 7 is the actual input up(k) as a control command input from the subtractor 7 to the pump proportional valve 46 or the boom proportional valve 44 in the controlled object 100. This middle graph shows the effect of compensation for the static characteristic fluctuation and compensation for the dynamic characteristic fluctuation by the static compensator 5, the dynamic compensator 6, and the subtractor 7. In the middle graph, the solid line shows an example of the relationship between the electric output and time when compensation for the static characteristic fluctuation and compensation for the dynamic characteristic fluctuation are not performed, and the dashed line shows an example of the relationship between the electric output and time when compensation for the static characteristic fluctuation and compensation for the dynamic characteristic fluctuation are performed in the hydraulic excavator 20 according to this embodiment.

[0076] As shown in the middle graph of FIG. 5, in the hydraulic excavator 20 according to this embodiment, the rise of the electrical output (actual input up(k)) is corrected by compensating for fluctuations in the dynamic characteristics. This suppresses overshooting of the rise and obtains a desired rise gradient, as shown by the dashed line. Moreover, in the hydraulic excavator 20 according to this embodiment, the steady-state characteristics of the electrical output (actual input up(k)) are corrected by compensating for fluctuations in the static characteristics. This obtains a desired steady-state value, as shown by the dashed line.

[0077] The graphs in the lower part of FIG. 5 are graphs showing an example of the relationship between the control output output from the boom cylinder 27 in the controlled object 100 and time. As described above, the control output of the boom cylinder 27 may be the operating speed of the boom cylinder 27, or may be a physical quantity corresponding to the operating speed of the boom cylinder 27. Specifically, the physical quantity may be the flow rate of hydraulic oil supplied to the boom cylinder 27, the flow rate of hydraulic oil discharged from the boom cylinder 27, or the like. The graphs in the lower part show the effect of adjustment of the static parameters and dynamic parameters by the parameter adjuster 9. In the graphs in the lower part, the solid line shows an example of the relationship between the control output and time in the case where the static parameters and dynamic parameters are not adjusted by the parameter adjuster 9, and the dashed line shows an example of the relationship between the control output and time in the case where the static parameters and dynamic parameters are adjusted by the parameter adjuster 9 in the hydraulic excavator 20 according to this embodiment.

[0078] 5, in the hydraulic excavator 20 according to this embodiment, even if the input / output characteristics of the control object 100 fluctuate significantly, the input / output characteristics between the control input uc(k) and the control output y(k) are maintained at ideal input / output characteristics at the time of designing the controller 4, by adjusting the static parameters and dynamic parameters using the parameter adjuster 9. Therefore, even if the input / output characteristics of the control object 100 fluctuate significantly, the control object 100 can be appropriately controlled using the controller 4 at the time of designing.

[0079] Next, a description will be given of a specific example of the design of the control loop 50. Fig. 6 is a block diagram showing a feedback system that constitutes the control loop 50. This feedback system is expressed by the following equation.

[0080]

number

[0081] Here, up(k), y(k), uc(k), and P represent the real input, control output, control input, and control target, respectively. Also, Δ represents the difference operator, and the backward operator z -1 Using Δ=1-z -1 f0(k), Kp(k), K D (k) represent the parameters. The parameter adjuster 9 adjusts f0(k), Kp(k), and K D The parameters of the static compensator 5 and the dynamic compensator 6 are tuned online using the recursive least squares method. The advantage of the recursive least squares method is that it has low calculation costs. The parameter adjuster 9 calculates the parameters of the static compensator 5 and the dynamic compensator 6 from the operation data (actual input up(k), control output y(k)).

[0082] Next, a method for adjusting parameters based on operational data will be described. Assuming that f0(k)=0 is not the case, equation (1) can be modified as follows:

[0083]

number

[0084] In the formula (3), θ1(k), θ2(k), and θ3(k) are expressed by the formula (4).

[0085] In addition, the input / output model Gm(z -1 The response obtained when a control input uc(k) is input to the control system is defined as the ideal output yr(k,θ(k)). In this case, the ideal output yr(k,θ(k)) is expressed by equation (5).

[0086]

number

[0087] The following equation is obtained from the relationship between equations (3) and (5).

[0088]

number

[0089] The evaluation function J is defined as follows:

[0090]

number

[0091] Here, N is the total number of data, and the parameter θ(k) is adjusted so that the control output y(k) follows the ideal output yr(k) by minimizing the evaluation function J. Therefore, by using the optimized parameters, the input / output characteristics and the input / output model Gm(z -1 ) input / output characteristics can be made to match those of the

[0092] Next, the following recursive least squares method is applied to minimize the sum of squares in equation (9):

[0093]

number

[0094] ω is the forgetting factor. θ(k) and ψ(k) are expressed by the following equation.

[0095]

number

[0096] The initial value Γ(0) of the error covariance matrix Γ(k) and the initial value θ(0) of the estimated value θ(k) are determined by the following equations.

[0097]

number

[0098] α is any real number that satisfies α>0. I is a 3x3 unit matrix. θi(0) is any real number. Due to the condition that f0 is not 0, θi(0) is determined to be not 0.

[0099] Next, a specific example will be given of the configuration of each of the pump control device 14 and the valve control device 13 according to this embodiment. Each of the pump control device 14 and the valve control device 13 is shown in FIG.

[0100] Control loop 50 is a downstream control loop composed of a control system including a combination of a static compensator 5 and a dynamic compensator 6. Controller 4 is an upstream control loop. Controller 4 is composed of a PID (proportional integral derivative) control system with fixed control parameters.

[0101] In the configuration of FIG. 3, the input / output characteristics of the control loop 50 and the input / output model Gm(z -1 The parameters of the static compensator 5 and the dynamic compensator 6 are adjusted so that the input / output characteristics of the input / output model Gm(z -1 ) as the input / output characteristics. As a result, the upstream controller 4 is modeled after the ideal input / output model Gm(z -1 ) can be designed based on this.

[0102] In this embodiment, the controller 4 is configured with a PID control system shown in equation (17).

[0103]

number

[0104] where kc represents the proportional gain, TI represents the integral time [s], and TD represents the differential time [s].

[0105] Next, a simulation will be described in which the pump control device 14 and the valve control device 13 according to this embodiment are each applied to a hydraulic motor control system.

[0106] In this embodiment, the ideal input / output model Gm(z -1 ) was designed as follows:

[0107]

number

[0108] The denominator P(z -1 ) is expressed by the following equation. Coefficients p1 and p2 are expressed by the following equation.

[0109]

number

[0110] Ts represents the sampling time, and σ and δ represent dynamic parameters such as the rise characteristic and the attenuation characteristic of the controlled object 100. These dynamic parameters are arbitrarily set by the designer based on the input / output characteristics of the controlled object 100.

[0111] [Variations] The hydraulic excavator 20, which is an example of a hydraulic work machine according to an embodiment of the present invention, has been described above. However, the present invention is not limited to the above embodiment and includes, for example, the following modified examples.

[0112] (A) Mode input acceptor FIG. 7 is a diagram showing another example of the hydraulic circuit and the control unit 1 in the hydraulic excavator 20. In the modification shown in FIG. 7, the hydraulic excavator 20 further includes a mode input acceptor 61. The mode input acceptor 61 accepts an input for switching the control mode of the hydraulic excavator 20 between a preset first mode and a preset second mode. This input is made by a person involved in the work, such as an operator or a work manager. The mode input acceptor 61 may include a switch provided inside the cabin 31, for example.

[0113] The first mode is a mode in which parameters are adjusted by the parameter adjuster 9, and the second mode is a mode in which parameters are not adjusted by the parameter adjuster 9. Note that in the second mode, compensation for variations in static characteristics and compensation for variations in dynamic characteristics may be performed, or these compensations may not be performed.

[0114] When the control mode is the second mode, the parameter adjusters 9 of the pump control device 14 and the valve control device 13 do not perform control to adjust the static parameters and the dynamic parameters. On the other hand, when the mode input receiver 61 receives an input from a worker involved in the work and the control mode is switched from the second mode to the first mode, the parameter adjusters 9 of the pump control device 14 and the valve control device 13 perform control to adjust the static parameters and the dynamic parameters.

[0115] In this modified example, control can be performed that respects the will of the operator. Specifically, for example, a skilled operator can operate the hydraulic working machine using his or her own skills without relying on automatic control by the hydraulic working machine, and an unskilled person with little experience can improve work efficiency by relying on automatic control by the hydraulic working machine.

[0116] (B) Control based on replacement and deterioration judgments Fig. 8 is a diagram showing yet another example of the hydraulic circuit and the control unit 1 in the hydraulic excavator 20. In the modification shown in Fig. 8, the control unit 1 further includes a determiner 16. The determiner 16 may be, for example, a replacement determiner that determines that at least a part of the working implement 23 has been replaced with another part, or may be a deterioration determiner that determines deterioration of the hydraulic excavator 20. The replacement determiner determines that a part of the working implement 23 has been replaced with another part based on preset determination conditions. The deterioration determiner determines deterioration of the hydraulic excavator 20 based on preset determination conditions.

[0117] Specifically, specific examples of replacing at least a part of the working device 23 with a different part include, for example, when the tip attachment of the working device 23 is replaced with a tip attachment of the same type but with a different weight, when the tip attachment of the working device 23 is replaced with a tip attachment of a different type, etc. Types of tip attachments include, for example, the bucket 26, as well as a grapple, a crusher (crusher), a breaker, and a fork.

[0118] The upper graph in Fig. 9 shows an example of the relationship between time and the operation amount (lever operation amount) of the boom operation received by the boom operation device 43, and the middle graph in Fig. 9 shows an example of the relationship between time and the electrical output output from the subtractor 7 when the boom operation device 43 receives a boom operation (boom raising operation or boom lowering operation) such as the upper graph. The upper and middle graphs in Fig. 9 are similar to the upper and middle graphs in Fig. 5, so a description thereof will be omitted.

[0119] The graphs in the lower part of Fig. 9 are graphs showing an example of the relationship between time and the control output output from the boom cylinder 27 in the control target 100. In the graphs in the lower part of Fig. 9, the solid line shows an example of the relationship between time and the control output when the static parameters and dynamic parameters are not adjusted by the parameter adjuster 9, and the dashed line shows an example of the relationship between time and the control output when the static parameters and dynamic parameters are adjusted by the parameter adjuster 9 in the hydraulic excavator 20 according to this embodiment.

[0120] When the input / output characteristics of the controlled object 100 fluctuate significantly due to replacement of at least a part of the working device 23 with another part, the rising slope s2 of the control output and the steady-state value f2 of the control output shown by the solid lines in the lower graph in FIG. 9 fluctuate significantly from the rising slope s1 of the control output and the steady-state value f1 of the control output that are ideal at the time of designing the controller 4.

[0121] Furthermore, when the input / output characteristics of the controlled object 100 fluctuate significantly due to the progression of deterioration of the hydraulic excavator 20, the rising slope s2 of the control output and the steady-state value f2 of the control output, which are shown by solid lines in the lower graph in FIG. 9, fluctuate significantly from the rising slope s1 of the control output and the steady-state value f1 of the control output that are ideal at the time of designing the controller 4.

[0122] In this modified example, the judgment condition may be, for example, that the rising slope s2 of the control output deviates from the rising slope s1 of the ideal control output by a preset threshold value se or more. The judgment condition may be, for example, that the steady-state value f2 of the control output deviates from the steady-state value f1 of the ideal control output by a preset threshold value fe or more. The judger 16 can calculate the rising slope of the control output and the steady-state value of the control output based on the control output input from the output detector 12 to the control unit 1.

[0123] The parameter adjuster 9 of the pump control device 14 does not perform control to adjust the static parameters and the dynamic parameters when the determiner 16 (the replacement determiner) determines that at least a part of the working device 23 has not been replaced with another part, or when the determiner 16 (the deterioration determiner) determines that the hydraulic excavator 20 has not deteriorated. On the other hand, the parameter adjuster 9 of the pump control device 14 performs control to adjust the static parameters and the dynamic parameters when the determiner 16 (the replacement determiner) determines that at least a part of the working device 23 has been replaced with another part, or when the determiner 16 (the deterioration determiner) determines that the hydraulic excavator 20 has deteriorated.

[0124] Similarly, when the determiner 16 (the replacement determiner) determines that at least a part of the working device 23 has not been replaced with another part, or when the determiner 16 (the deterioration determiner) determines that the hydraulic excavator 20 has not deteriorated, the parameter adjuster 9 of the valve control device 13 does not perform control to adjust the static parameters and the dynamic parameters. On the other hand, when the determiner 16 (the replacement determiner) determines that at least a part of the working device 23 has been replaced with another part, or when the determiner 16 (the deterioration determiner) determines that the hydraulic excavator 20 has deteriorated, the parameter adjuster 9 of the valve control device 13 performs control to adjust the static parameters and the dynamic parameters.

[0125] 8, by adjusting the static parameters and dynamic parameters by the parameter adjuster 9, even if the input / output characteristics of the controlled object 100 vary significantly due to replacement of parts or deterioration of the hydraulic excavator 20, the input / output characteristics of the control input uc(k) and the control output y(k) are maintained at ideal input / output characteristics at the time of designing the controller 4. Therefore, even if the input / output characteristics of the controlled object 100 vary significantly, the controlled object 100 can be appropriately controlled using the controller 4 at the time of design.

[0126] (C) Mode input acceptor FIG. 10 is a diagram showing yet another example of the hydraulic circuit and the control unit 1 in the hydraulic excavator 20. In the modified example shown in FIG. 10, the hydraulic excavator 20 further includes a characteristic input receiver 62. The characteristic input receiver 62 receives an input for changing the settings of the input / output characteristics of the control input uc(k) and the control output y(k). In this modified example, for example, as shown in the lower graph in FIG. 11, the rising slope of the control output can be changed to a slope preferred by the operator. A person involved in the work, such as an operator, provides the characteristic input receiver 62 with an input for changing the input force characteristics, such as a desired rising slope. The characteristic input receiver 62 outputs a signal corresponding to the input to the control unit 1. The control unit 1 changes the settings of the input / output characteristics of the control input uc(k) and the control output y(k) based on the signal corresponding to the input. Specifically, the control unit 1 changes the settings of the input / output characteristics of the input uc(k) and the control output y(k), for example, based on the input of the person involved in the work. -1 ) setting. This allows the response characteristics (input / output characteristics) such as the slope of the rise of the control output to be changed to the operator's preference.

[0127] (D) About the object of control The controlled object 100 controlled by the pump control device may be a pump proportional valve, a pump, and an arm cylinder, and the controlled object 100 controlled by the valve control device may be an arm proportional valve, an arm control valve, and an arm cylinder. Also, the controlled object 100 controlled by the pump control device may be a pump proportional valve, a pump, and a bucket cylinder, and the controlled object 100 controlled by the valve control device may be a bucket proportional valve, a bucket control valve, and a bucket cylinder. Also, the controlled object 100 controlled by the pump control device may be a pump proportional valve, a pump, and a swing motor, and the controlled object 100 controlled by the valve control device may be a swing proportional valve, a swing control valve, and a swing motor.

[0128] (E) Command calculator In the above-described embodiment, the command calculator of the pump control device 14 and the command calculator of the valve control device 13 are each configured with a target setter 2, a subtractor 3, a controller 4, a static compensator 5, a dynamic compensator 6, and a subtractor 7. However, the command calculator of the pump control device is not limited to the configuration of the above-described embodiment as long as it uses the manipulated variable of the operation and at least one pump control parameter to calculate a control command for operating a controlled object including a hydraulic pump and an actuator, and inputs the control command to the controlled object. The command calculator of the valve control device is not limited to the configuration of the above-described embodiment as long as it uses the manipulated variable of the operation and at least one valve control parameter to calculate a control command for operating a controlled object including a control valve and an actuator, and inputs the control command to the controlled object.

[0129] (F) About the Parameter Adjuster The parameter adjuster 9 uses a database-driven control method to adjust the static gain f0 and the dynamic gain (Kp, K D The database-driven control method is a method for calculating parameters that are suitable for the current state of the controlled object based on previously calculated parameters stored in a database.

[0130] When this method is adopted, each of the control devices 13 and 14 uses the static gain f0 and dynamic gain (Kp, K D The parameter adjuster 9 further includes a database that stores therein a request point indicating the current state of the controlled object 100 from the memory 11. The request point includes, for example, a control output y(k) and an ideal output yr(k) from one sample to several samples before. The parameter adjuster 9 calculates the distance between each of the request points and the parameter sets stored in the database, and extracts k parameter sets in ascending order of distance. The parameter set includes, for example, a set of a static gain f0, a proportional gain Kp, and a differential gain K DThe parameter adjuster 9 calculates a weighting coefficient for each of the k extracted parameter sets so that the weighting coefficient is larger as the distance becomes shorter. The parameter adjuster 9 averages the k parameter sets using the calculated weighting coefficient to calculate a final parameter set, and adjusts the final parameter set as a static gain f0 and a dynamic gain (Kp, K D ) is calculated as follows.

[0131] (G) Other The arithmetic expression used by the dynamic compensator 6 to calculate the dynamic compensation input may include the product of the second-order differential term of the control output y(k) and the second-order differential gain. Furthermore, this arithmetic expression may include the sum of the products of the i-th order differential term of the control output y(k) and the i-th order differential gain from i=1 to i=n (n is a positive integer).

[0132] The hydraulic work machine may be a hybrid type work machine that uses both an engine and an electric motor. The hybrid type work machine is equipped with, for example, a generator motor and a power storage device. The generator motor charges the power storage device with electric power generated by the driving force of the engine, and assists the engine by powering the work machine using the electric power from the power storage device. [Explanation of symbols]

[0133] 2: Goal setter 3: Subtractor 4: Controller (control input calculator) 5: Static compensator 6: Dynamic compensator 7: Subtractor (an example of a synthesizer) 8: Subtractor 9: Pump control device parameter adjuster (pump control parameter adjuster), valve control device parameter adjuster (valve control parameter adjuster) 10: Ideal output calculator for pump control device (ideal output calculator for pump control), ideal output calculator for valve control device (ideal output calculator for valve control) 12: Output detector 13: Valve control device 14: Pump control device 16: Judgement device (replacement judgement device or deterioration judgement device) 17:Operation judger 20: Hydraulic excavator (an example of a hydraulic work machine) 22: Upper rotating body 23: Working equipment 24: Boom 27: Boom cylinder (an example of an actuator and part of the control object) 41: Hydraulic pump (part of the controlled objects) 42: Boom control valve (an example of a control valve and part of the controlled object) 43: Boom operation device (an example of an operation device) 44: Boom proportional valve (part of the control object) 46: Pump proportional valve (part of the controlled object) 61: Mode input acceptor 62: Characteristics input receiver 100: Control target Gm: Input / Output model KD: Differential gain (an example of a dynamic parameter) Kp: Proportional gain (an example of a dynamic parameter) f0:Static gain

Claims

1. A hydraulic work machine, A support; A movable portion that is displaceable relative to the support body; A hydraulic pump that discharges hydraulic oil; an actuator that receives the hydraulic oil and operates to operate the movable part; a control valve that is interposed between the hydraulic pump and the actuator and opens and closes to change the flow rate of the hydraulic oil supplied to the actuator; An operating device that receives an operation for operating the movable part; an operation determiner that determines whether an operation of the movable part performed in response to the operation received by the operating device is a powered operation in which the movable part operates against a load acting on the movable part, or a non-powered operation in which the movable part operates in a direction along a direction of the load acting on the movable part; A pump control device for adjusting a discharge amount of the hydraulic pump; A valve control device for adjusting the opening degree of the control valve; an output detector for detecting a control output which is an output of the actuator; The pump control device includes: a pump command calculator that calculates a control command for operating a controlled object including the hydraulic pump and the actuator by using an operation amount of the operation and at least one pump control parameter, and inputs the control command to the controlled object; an ideal output calculator for controlling a pump that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a pump control parameter adjuster that adjusts the at least one pump control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the powering operation, The valve control device includes: a valve command calculator that calculates a control command for operating a controlled object including the control valve and the actuator by using the manipulated variable of the operation and at least one valve control parameter, and inputs the control command to the controlled object; an ideal output calculator for valve control that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a valve control parameter adjuster that adjusts the at least one valve control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the non-powering operation, The hydraulic working machine further includes a mode input receiver that receives an input for switching a control mode of the hydraulic working machine between a preset first mode and a preset second mode, the pump control parameter adjuster performs control to adjust the at least one pump control parameter when the control mode is the first mode, and reserves performing control to adjust the at least one pump control parameter when the control mode is the second mode; the valve control parameter adjuster performs control to adjust the at least one valve control parameter when the control mode is the first mode, and reserves performing control to adjust the at least one valve control parameter when the control mode is the second mode.

2. A hydraulic work machine, A support; A movable portion that is displaceable relative to the support body; A hydraulic pump that discharges hydraulic oil; an actuator that receives the hydraulic oil and operates to operate the movable part; a control valve that is interposed between the hydraulic pump and the actuator and opens and closes to change the flow rate of the hydraulic oil supplied to the actuator; An operating device that receives an operation for operating the movable part; an operation determiner that determines whether an operation of the movable part performed in response to the operation received by the operating device is a powered operation in which the movable part operates against a load acting on the movable part, or a non-powered operation in which the movable part operates in a direction along a direction of the load acting on the movable part; A pump control device for adjusting a discharge amount of the hydraulic pump; A valve control device for adjusting the opening degree of the control valve; an output detector for detecting a control output which is an output of the actuator; The pump control device includes: a pump command calculator that calculates a control command for operating a controlled object including the hydraulic pump and the actuator by using an operation amount of the operation and at least one pump control parameter, and inputs the control command to the controlled object; an ideal output calculator for controlling a pump that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a pump control parameter adjuster that adjusts the at least one pump control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the powering operation, The valve control device includes: a valve command calculator that calculates a control command for operating a controlled object including the control valve and the actuator by using the manipulated variable of the operation and at least one valve control parameter, and inputs the control command to the controlled object; an ideal output calculator for valve control that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a valve control parameter adjuster that adjusts the at least one valve control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the non-powering operation, The hydraulic working machine includes: A working device including the movable part; A replacement determiner that determines whether at least a part of the working device has been replaced with another part, the pump control parameter adjuster performs control to adjust the at least one pump control parameter when the replacement determiner determines that at least a part of the working device has been replaced with the different part; The valve control parameter adjuster performs control to adjust the at least one valve control parameter when the replacement determiner determines that at least a part of the working device has been replaced with the different part.

3. A hydraulic work machine, A support; A movable portion that is displaceable relative to the support body; A hydraulic pump that discharges hydraulic oil; an actuator that receives the hydraulic oil and operates to operate the movable part; a control valve that is interposed between the hydraulic pump and the actuator and opens and closes to change the flow rate of the hydraulic oil supplied to the actuator; An operating device that receives an operation for operating the movable part; an operation determiner that determines whether an operation of the movable part performed in response to the operation received by the operating device is a powered operation in which the movable part operates against a load acting on the movable part, or a non-powered operation in which the movable part operates in a direction along a direction of the load acting on the movable part; A pump control device for adjusting a discharge amount of the hydraulic pump; A valve control device for adjusting the opening degree of the control valve; an output detector for detecting a control output which is an output of the actuator; The pump control device includes: a pump command calculator that calculates a control command for operating a controlled object including the hydraulic pump and the actuator by using an operation amount of the operation and at least one pump control parameter, and inputs the control command to the controlled object; an ideal output calculator for controlling a pump that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a pump control parameter adjuster that adjusts the at least one pump control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the powering operation, The valve control device includes: a valve command calculator that calculates a control command for operating a controlled object including the control valve and the actuator by using the manipulated variable of the operation and at least one valve control parameter, and inputs the control command to the controlled object; an ideal output calculator for valve control that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a valve control parameter adjuster that adjusts the at least one valve control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the non-powering operation, The hydraulic working machine further includes a deterioration determiner that determines deterioration of the hydraulic working machine based on preset determination conditions, the pump control parameter adjuster performs control to adjust the at least one pump control parameter when the deterioration determiner determines that the hydraulic working machine has deteriorated, The valve control parameter adjuster performs control to adjust the at least one valve control parameter when the deterioration determiner determines that the hydraulic working machine has deteriorated.

4. A hydraulic work machine, A support; A movable portion that is displaceable relative to the support body; A hydraulic pump that discharges hydraulic oil; an actuator that receives the hydraulic oil and operates to operate the movable part; a control valve that is interposed between the hydraulic pump and the actuator and opens and closes to change the flow rate of the hydraulic oil supplied to the actuator; An operating device that receives an operation for operating the movable part; an operation determiner that determines whether an operation of the movable part performed in response to the operation received by the operating device is a powered operation in which the movable part operates against a load acting on the movable part, or a non-powered operation in which the movable part operates in a direction along a direction of the load acting on the movable part; A pump control device for adjusting a discharge amount of the hydraulic pump; A valve control device for adjusting the opening degree of the control valve; an output detector for detecting a control output which is an output of the actuator; The pump control device includes: a pump command calculator that calculates a control command for operating a controlled object including the hydraulic pump and the actuator by using an operation amount of the operation and at least one pump control parameter, and inputs the control command to the controlled object; an ideal output calculator for controlling a pump that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a pump control parameter adjuster that adjusts the at least one pump control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the powering operation, The valve control device includes: a valve command calculator that calculates a control command for operating a controlled object including the control valve and the actuator by using the manipulated variable of the operation and at least one valve control parameter, and inputs the control command to the controlled object; an ideal output calculator for valve control that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a valve control parameter adjuster that adjusts the at least one valve control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the non-powering operation, The pump command calculator a target setter that sets a target output, which is a target of the control output, in accordance with an amount of operation of the operation; a control input calculator for calculating a control input for making a deviation between the target output and the control output zero; the pump control device further includes a control input compensator that corrects the control input so as to compensate for fluctuations in characteristics of the controlled object based on at least one of the control input and the control output and the at least one pump control parameter, calculates the control command, and inputs the control command to the controlled object.

5. A hydraulic working machine according to claim 4, The at least one pump control parameter includes a static parameter and a dynamic parameter; The control input compensator of the pump control device comprises: a static compensator that calculates a static compensation input that compensates for a variation in a static characteristic of the controlled object based on the static parameters and the control input; a dynamic compensator that calculates a dynamic compensation input for compensating for a variation in a dynamic characteristic of the controlled object based on the dynamic parameters and the control output; a synthesizer that synthesizes the static compensation input and the dynamic compensation input to calculate the control command and inputs the control command to the controlled object.

6. A hydraulic working machine according to claim 4 or 5, The pump control ideal output calculator calculates the ideal output corresponding to the control input by using an input / output model that defines an ideal input / output relationship between the control input and the control output.

7. A hydraulic work machine, A support; A movable portion that is displaceable relative to the support body; A hydraulic pump that discharges hydraulic oil; an actuator that receives the hydraulic oil and operates to operate the movable part; a control valve that is interposed between the hydraulic pump and the actuator and opens and closes to change the flow rate of the hydraulic oil supplied to the actuator; An operating device that receives an operation for operating the movable part; an operation determiner that determines whether an operation of the movable part performed in response to the operation received by the operating device is a powered operation in which the movable part operates against a load acting on the movable part, or a non-powered operation in which the movable part operates in a direction along a direction of the load acting on the movable part; A pump control device for adjusting a discharge amount of the hydraulic pump; A valve control device for adjusting the opening degree of the control valve; an output detector for detecting a control output which is an output of the actuator; The pump control device includes: a pump command calculator that calculates a control command for operating a controlled object including the hydraulic pump and the actuator by using an operation amount of the operation and at least one pump control parameter, and inputs the control command to the controlled object; an ideal output calculator for controlling a pump that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a pump control parameter adjuster that adjusts the at least one pump control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the powering operation, The valve control device includes: a valve command calculator that calculates a control command for operating a controlled object including the control valve and the actuator by using the manipulated variable of the operation and at least one valve control parameter, and inputs the control command to the controlled object; an ideal output calculator for valve control that calculates an ideal output, which is an ideal output of the actuator associated with an amount of operation of the operation; a valve control parameter adjuster that adjusts the at least one valve control parameter so that a difference between the control output and the ideal output becomes small when the operation of the movable part is the non-powering operation, The valve command calculator a target setter that sets a target output, which is a target of the control output, in accordance with an amount of operation of the operation; a control input calculator for calculating a control input for making a deviation between the target output and the control output zero; the valve control device further includes a control input compensator that corrects the control input so as to compensate for fluctuations in characteristics of the controlled object based on at least one of the control input and the control output and the at least one valve control parameter, calculates the control command, and inputs the control command to the controlled object.

8. A hydraulic working machine according to claim 7, The at least one valve control parameter includes a static parameter and a dynamic parameter; The control input compensator of the valve control device comprises: a static compensator that calculates a static compensation input that compensates for a variation in a static characteristic of the controlled object based on the static parameters and the control input; a dynamic compensator that calculates a dynamic compensation input for compensating for a variation in a dynamic characteristic of the controlled object based on the dynamic parameters and the control output; a synthesizer that synthesizes the static compensation input and the dynamic compensation input to calculate the control command and inputs the control command to the controlled object.

9. A hydraulic working machine according to claim 7 or 8, The valve control ideal output calculator calculates the ideal output corresponding to the control input by using an input / output model that defines an ideal input / output relationship between the control input and the control output.

10. A hydraulic working machine according to claim 6 or 9, The hydraulic working machine further comprises a characteristic input receiver that receives an input for changing settings of input / output characteristics of the control input and the control output.

11. A hydraulic working machine according to any one of claims 1 to 10, the movable portion is a boom supported on the support body so as to be capable of being raised and lowered, the powered operation is a boom-raising operation which is an operation of the boom such that the tip of the boom leaves the ground, and the non-powered operation is a boom-lowering operation which is an operation of the boom such that the tip of the boom approaches the ground, The operation determiner determines that the operation of the movable part is the powered operation when the operating device receives a boom raising operation, which is an operation for causing the boom to perform the boom raising operation, and determines that the operation of the movable part is the non-powered operation when the operating device receives a boom lowering operation, which is an operation for causing the boom to perform the boom lowering operation.

12. A hydraulic working machine according to any one of claims 1 to 11, the control output of the actuator is an operating speed of the actuator or a physical quantity corresponding thereto; The hydraulic working machine, wherein the output detector is a sensor for detecting the operating speed or the physical quantity.

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