Work Machine System

Abstract

To simplify the structure of a drive section and a control system by achieving a desired operation by a minimum number of actuators.SOLUTION: A work machine system 10 includes a work machine 100 which is driven by working fluid. The work machine 100 has: a movable mechanism 130 which rotates an end effector 170; a wire 120 which is wound around the movable mechanism 130; and a double rod cylinder 110 which has a piston rod 111 having one end 111a connected to one end 120a of the wire 120 and the other end 111b connected to the other end 120b of the wire 120 and is operated by working fluid.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work machine system. [Background technology]

[0002] Fluid-pressure-driven work machine systems, such as robot systems driven by fluid pressure, can generate higher output than industrial robot systems that use electric motors. Therefore, fluid-pressure-driven work machine systems are widely used in fields that require high output, such as construction work or decommissioning work. However, because fluid-pressure-driven work machine systems use mechanisms that operate through the application of fluid pressure to form the work machine, the overall weight of the work machine increases. As a result, fluid-pressure-driven work machine systems have faced issues such as an increased risk of collision due to large inertial forces and reduced output due to weight compensation.

[0003] In response to this, in recent years, work machine systems that use wire as a power transmission medium have been proposed to reduce the weight of work machines. This type of work machine system achieves weight reduction by configuring the moving part connected to the end effector and the drive part that drives the moving part separately via wire. Furthermore, the moving part of this type of work machine system achieves multiple degrees of freedom by configuring multiple rotational axes, each with one rotational degree of freedom.

[0004] An example of prior art for a work machine system that uses a wire as a power transmission medium is Patent Document 1. Patent Document 1 describes a wire-driven manipulator that controls the three-dimensional position and attitude of an end effector by controlling three wire winding devices, which are drive units provided on a base, and adjusting the amount of each wire that is fed out. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-77577 Summary of the Invention [Problem to be solved by the invention]

[0006] The manipulator described in Patent Document 1 has to control three wire winding devices, which makes the structure of the drive unit and the control system complicated. Therefore, there is a demand for a work machine system that can operate with a smaller number of actuators.

[0007] The present invention has been made in consideration of the above, and aims to provide a work machine system that can simplify the structure of the drive unit and the control system by achieving desired operation with a minimum number of actuators. [Means for solving the problem]

[0008] In order to solve the above problems, the work machine system of the present invention has a work machine driven by a working fluid, and is characterized in that the work machine is equipped with a movable mechanism that rotates an end effector around an axis, a wire wound around the movable mechanism, and a double-rod cylinder that has a piston rod having one end connected to one end of the wire and the other end connected to the other end of the wire, and is operated by the working fluid. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a work machine system that can simplify the structure of the drive unit and the control system by realizing a desired operation with a minimum number of actuators. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall configuration diagram of a work machine system according to a first embodiment. [Figure 2] 1 is a structural diagram of a work machine according to a first embodiment. [Figure 3]Expanded structural diagram of a double-rod cylinder according to the first embodiment. [Figure 4] Functional block diagram of a pressure control device according to the first embodiment. [Figure 5] Diagram showing an example of a command generation model according to the first embodiment. [Figure 6] Fig. 6(a) is a diagram showing the output band of a working machine in the case of C > M / 2 according to the first embodiment, Fig. 6(b) is a diagram showing the output band of a working machine in the case of C = M / 2 according to the first embodiment, and Fig. 6(c) is a diagram showing the output band of a working machine in the case of C < M / 2 according to the first embodiment. [Figure 7] Control flowchart of a pressure control device according to the first embodiment. [Figure 8] Fig. 8(a) is a diagram showing the standby state of a working machine according to the second and third embodiments, Fig. 8(b) is a diagram showing the approach and gripping state to an object according to the second and third embodiments, Fig. 8(c) is a diagram showing the approach to a standby position and the standby state according to the second and third embodiments, and Fig. 8(d) is a diagram showing the approach to a place position and the placing state according to the second and third embodiments. [Figure 9] Fig. 9(a) is a diagram showing the relationship between the output band of a working machine in the relationship of C = M / 2 and the torque required for the working machine to work at a constant speed for each operation sequence, and Fig. 9(b) is a diagram showing the relationship between the output band of a working machine according to the second and third embodiments and the torque required for the working machine to work at a constant speed for each operation sequence.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment, for components denoted by the same reference numerals, unless otherwise specified, they have the same functions in each embodiment, and the description thereof will be omitted.

[0012] [First Embodiment] <Overall Configuration of a Working Machine System> Fig. 1 is an overall configuration diagram of a working machine system 10 according to the first embodiment.

[0013] The work machine system 10 is a system configured to include a work machine 100, a fluid pressure application device 200, a pressure control device 300, and a sensor 400.

[0014] The work machine 100 is a machine that is driven by a working fluid. The work machine 100 is a machine that can perform work that involves gripping and moving objects, such as part assembly work or transportation work. Specifically, the work machine 100 may be a machine that grips and moves objects, such as a robot arm. The work machine 100 may also be a machine that transports objects by equipping a robot arm with crawlers or wheels, etc. Furthermore, the work machine 100 may be a machine that has the function of acquiring images of objects, the work environment, etc. The work machine 100 may also be driven by a combination of a working fluid and an electric motor, etc.

[0015] The sensor 400 is a device that measures the state of the work machine 100 and / or the state of the work environment. For example, the sensor 400 may be a current sensor for a motor provided on an end effector that serves as the gripping part of the work machine 100, or a tactile sensor and inertial sensor that are attached externally to the work machine 100. Furthermore, for example, the sensor 400 may be a temperature sensor that measures the temperature of the work environment in which the work machine 100 is installed. In this way, each sensor measures the state of the work machine 100 and / or the state of the work environment, and transmits a measurement signal according to the measurement content to the pressure control device 300.

[0016] The fluid pressure application device 200 is a device that applies pressure to a working fluid. Specifically, the fluid pressure application device 200 receives a control command transmitted from the pressure control device 300 as input and applies pressure to the working fluid in the work machine 100 via the fluid piping 160 (see FIG. 2 ). The fluid pressure application device 200 includes a pressure source such as a compressor, and a pressure control valve that controls the pressure of the working fluid in the work machine 100 to a value according to the control command. The fluid pressure application device 200 applies pressure to the working fluid in the work machine 100 by supplying the working fluid pressurized by the pressure source into the work machine 100. The working fluid is, for example, air, water, oil, or other fluid. The fluid pressure application device 200 measures the pressure of the working fluid applied to the work machine 100 and transmits the measured pressure signal to the pressure control device 300.

[0017] The pressure control device 300 is a device that controls the pressure of the working fluid applied by the fluid pressure application device 200. The pressure control device 300 is a device that calculates a control command for controlling the pressure of the working fluid using an operation signal corresponding to an input operation by the operator of the work machine 100, a pressure signal from the fluid pressure application device 200, or a measurement signal from the sensor 400 as input, and transmits the control command to the fluid pressure application device 200. The pressure control device 300 is configured to include a computer that calculates a control command from various inputs based on a control law, an AIO (Analog Input / Output) board for taking inputs from various sensors into the computer, and the like.

[0018] <Work machine configuration> Fig. 2 is a structural diagram of the work machine 100 according to the first embodiment. Fig. 3 is an enlarged structural diagram of the dual rod cylinder 110 according to the first embodiment.

[0019] The work machine 100 includes an end effector 170 , a movable mechanism 130 , a wire 120 , and a double-rod cylinder 110 .

[0020] The end effector 170 is a device that mainly grips objects. Specifically, the end effector 170 is a robot hand that can grip objects. The number of claws that serve as the fingertips of the end effector 170 can be changed as appropriate to suit the target object. The work machine 100 according to this embodiment is equipped with a robot hand as the end effector 170, but the end effector 170 may also be equipped with a camera, various sensors, etc.

[0021] The movable mechanism 130 is a mechanism that rotates the end effector 170 around an axis. The movable mechanism 130 is a mechanism that is movable by the operation of the dual rod cylinder 110 and the wire 120, which will be described later. The movable mechanism 130 is a mechanism that corresponds to a joint in a robot arm.

[0022] Specifically, the movable mechanism 130 may include a pulley and a holder that holds the rotation shaft of the pulley. The movable mechanism 130 according to this embodiment is a rotation mechanism that rotates the connected end effector 170 in a clockwise direction θ1 or a counterclockwise direction θ2 around the rotation shaft of the pulley. Note that the movable mechanism 130 may also be a mechanism that converts the rotation of the pulley into linear motion and linearly moves the end effector 170.

[0023] The middle portion of the wire 120 is wound around the outer periphery of the pulley of the movable mechanism 130. One end 120a and the other end 120b of the wire 120 are connected to the dual rod cylinder 110 and are in a closed state. The wire 120 may be any long, deformable linear or belt-like member, and may be a chain, a belt, or the like.

[0024] The wire 120 moves on the movable mechanism 130 in a clockwise direction θ1 or a counterclockwise direction θ2 as the piston rod 111 of the dual rod cylinder 110 described later moves.

[0025] The double-rod cylinder 110 is a double-acting double-rod cylinder. The double-rod cylinder 110 is connected to the fluid pressure application device 200 via two fluid pipes 160. The two fluid pipes 160 are individually connected to the fluid pressure application device 200. The double rod cylinder 110 will be described in detail below with reference to an enlarged structural view of the double rod cylinder 110 shown in FIG.

[0026] The double rod cylinder 110 includes a cylindrical cylinder tube 112 and a piston rod 111 including a columnar piston 111c that is arranged in the cylinder tube 112 so as to be capable of reciprocating.

[0027] The piston 111 c reciprocates within the cylinder tube 112 due to the pressure of the working fluid within the cylinder tube 112 .

[0028] The piston rod 111 is a rod-shaped member that extends along the central axis of the cylinder tube 112. The piston rod 111 is attached to the piston 111c by passing through the center of the piston 111c. The piston rod 111 is disposed inside the cylinder tube 112 with the piston 111c attached.

[0029] The dual-rod cylinder 110 has one fluid chamber 110a (hereinafter also referred to as the right fluid chamber 110a) and the other fluid chamber 110b (hereinafter also referred to as the left fluid chamber 110b) separated by a piston 111c inside a cylinder tube 112. The volumes of both fluid chambers 110a and 110b vary depending on the position of the piston 111c.

[0030] The right fluid chamber 110a and the left fluid chamber 110b each have an inlet and an outlet that allow the supply and discharge of the working fluid. The inlet and outlet of the right fluid chamber 110a and the left fluid chamber 110b are connected to a fluid pipe 160.

[0031] In the double rod cylinder 110, the pressure difference between the working fluid in each of the fluid chambers 110a, 110b causes the piston 111c to move within the cylinder tube 112. The pressure of the working fluid in each of the fluid chambers 110a, 110b is applied by a fluid pressure application device 200.

[0032] As the piston 111c moves, the piston rod 111 moves within the cylinder tube 112 along the central axis of the cylinder tube 112. Hereinafter, the movement direction L of the piston rod 111 will also be simply referred to as "direction L." The amount of movement of the piston rod 111 is determined according to the pressure difference between the working fluids in both fluid chambers 110a and 110b. The dual rod cylinder 110 moves the wire 120 as the piston rod 111 moves within the cylinder tube 112 along direction L.

[0033] The double-rod cylinder 110 has a piston rod 111, one end 111a of which located on the right fluid chamber 110a side is connected to one end 120a of a wire 120, and the other end 111b of which located on the left fluid chamber 110b side is connected to the other end 120b of the wire 120. In other words, the double-rod cylinder 110 has a piston rod 111, one end 111a of which is connected to one end 120a of the wire 120, and the other end 111b of which is connected to the other end 120b of the wire 120.

[0034] The movement direction L of the piston rod 111 includes the direction from one end 111a to the other end 111b of the piston rod 111 and the direction from the other end 111b to the one end 111a of the piston rod 111. Hereinafter, in the direction L, the direction from the other end 111b to the one end 111a is defined as the positive direction, and the direction from the one end 111a to the other end 111b is defined as the negative direction.

[0035] The operation of the work machine 100 having the above configuration will be described. The operation described below is an example, and the operation of the work machine 100 is not limited to the operation described below.

[0036] For example, when pressure is applied to the working fluid in the right fluid chamber 110a of the dual-rod cylinder 110 and the chamber is pressurized, the piston rod 111 moves in a direction from one end 111a to the other end 111b (the negative direction in direction L) and pulls one end 120a of the wire 120. At this time, the pressure of the working fluid in the left fluid chamber 110b may be reduced as necessary. As the dual-rod cylinder 110 pulls one end 120a of the wire 120, the movable mechanism 130 rotates the end effector 170 in a predetermined direction about its axis, i.e., in a clockwise direction θ1.

[0037] Meanwhile, when pressure is applied to the working fluid in the left fluid chamber 110b of the dual-rod cylinder 110 and the chamber is pressurized, the piston rod 111 moves in a direction from the other end 111b toward the one end 111a (the positive direction in the direction L) and pulls the other end 120b of the wire 120. At this time, the pressure of the working fluid in the right fluid chamber 110a may be reduced as necessary. As the dual-rod cylinder 110 pulls the other end 120b of the wire 120, the movable mechanism 130 rotates the end effector 170 in the opposite direction to the predetermined direction around the axis, i.e., in the counterclockwise direction θ2.

[0038] As described above, the work machine system 10 according to this embodiment has a piston rod 111 with both ends 111a, 111b connected to the wire 120, and the dual-rod cylinder 110, which is operated by a working fluid, pulls the wire 120, and as the wire 120, wound around the movable mechanism 130, is pulled, the movable mechanism 130 rotates the end effector 170 in a predetermined direction θ1 about the axis or in the opposite direction θ2 to the predetermined direction. In other words, with the above configuration, the work machine system 10 according to this embodiment can move the one-degree-of-freedom movable mechanism 130 using a single dual-rod cylinder 110. In other words, the work machine system 10 according to this embodiment can achieve the desired operation with a minimum number of actuators. As a result, this embodiment can provide a work machine system that can simplify the structure of the drive unit and the control system.

[0039] The work machine 100 also includes a base member 140 for fixing the movable mechanism 130 and the dual rod cylinder 110.

[0040] The base member 140 has a base plate 142 which is the foundation of the base member 140 and to which the dual rod cylinder 110 is fixed, a fixed plate 141 to which the movable mechanism 130 is fixed, a support 144 extending upward from the base plate 142, and a beam 145 connected to the support 144. The base member 140 may have wheels. The fixed plate 141 may be disposed above the base plate 142 and in a state parallel to the base plate 142. The fixed plate 141 may be fixed by the support 144 or a wall plate (not shown). The fixed plate 141 may be the top plate portion of the base member 140, and the base plate 142 may be the bottom plate portion of the base member 140.

[0041] The support 144 fixes the dual rod cylinder 110 together with the base plate 142. The beam 145 is connected to the support 144 in an orientation extending along direction L. The beam 145 is disposed between the fixed plate 141 and the dual rod cylinder 110.

[0042] Furthermore, the base member 140 includes pulleys 151 to 154 and a support member 143 .

[0043] The pulleys 151 to 154 are disposed between the double rod cylinder 110 and the movable mechanism 130, and the wire 120 is wound around them. The pulleys 151 to 154 apply tension to the wire 120 and change the direction in which the wire 120 moves.

[0044] The type of pulleys 151 to 154 may be any type that is compatible with the wire 120, and may be, for example, toothed or V-grooved. Alternatively, the pulleys 151 to 154 may be non-rotating components that use a lubricant to guide the wire while sliding it.

[0045] Pulleys 151 to 154 according to this embodiment are configured by pulley 151 and pulley 152 arranged on the side closer to dual rod cylinder 110, and pulley 153 and pulley 154 arranged on the side closer to movable mechanism 130. The number of pulleys is not particularly limited.

[0046] The pulleys 151 and 152 are tension pulleys that mainly serve to apply tension to the wire 120, and the pulleys 153 and 154 are guide pulleys that mainly serve to change the moving direction of the wire 120.

[0047] Pulley 151 according to this embodiment is connected to one end 120a, and changes the extending direction of wire 120, which extends from one end 111b of piston rod 111 toward one end 111a, to a direction from one end 111a toward the other end 111b of piston rod 111. Pulley 152 according to this embodiment is connected to the other end 120b, and changes the extending direction of wire 120, which extends from one end 111a toward the other end 111b of piston rod 111, to a direction from the other end 111b toward one end 111a of piston rod 111. Pulleys 151 and 152 according to this embodiment are supported by a support member 143.

[0048] The pulleys 153 and 154 according to this embodiment are fixed to the beam 145 with a gap between them along the direction L. The gap between the pulleys 153 and 154 according to this embodiment is equal to or less than the diameter of the pulleys that make up the movable mechanism 130. The gap between the pulleys 153 and 154 refers to the shortest distance between the circumference of the pulley 153 and the circumference of the pulley 154 in the direction L.

[0049] The pulley 153 according to this embodiment changes the extending direction of the wire 120, which is wound around the pulley 151 and extends in a direction from one end 111a to the other end 111b of the piston rod 111, to a direction from the dual rod cylinder 110 to the movable mechanism 130. The pulley 154 according to this embodiment changes the extending direction of the wire 120, which is wound around the pulley 152 and extends in a direction from the other end 111b to the one end 111a of the piston rod 111, to a direction from the dual rod cylinder 110 to the movable mechanism 130. In other words, the pulleys 153 and 154 according to this embodiment change the moving direction of the wire 120, which is wound around the pulleys 151 and 152 and moves along direction L, so that the wire 120 moves in a direction from the dual rod cylinder 110 to the movable mechanism 130. As a result, the wire 120 wound around the pulleys 151 and 152 is wound so as to contact more than half of the circumference of the pulleys that constitute the movable mechanism .

[0050] The support member 143 is disposed perpendicular to the fixed plate 141 and the substrate 142 and the direction L, with its upper and lower bases in contact with the fixed plate 141 and the substrate 142. The support member 143 may be fixed to the fixed plate 141 and the substrate 142 at a desired position with screws. The support member 143 may be provided so as to be movable along the direction L within the base member 140. The support member 143 may be provided so as to be movable by a linear-type electric actuator or the like.

[0051] The support member 143 supports the pulleys 151, 152 on a surface facing the dual rod cylinder 110 in the direction L. The support member 143 can adjust the tension applied to the wire 120 by moving along the direction L while supporting the pulleys 151, 152.

[0052] Two support members 143 according to this embodiment are disposed, one on each end of the double-rod cylinder 110. One of the two support members 143 may be fixed in advance and not move along the direction L, provided that the supporting pulleys 151, 152 can apply tension to the wire 120.

[0053] As described above, the work machine system 10 according to this embodiment is provided with the pulleys 151, 152, which are disposed between the dual rod cylinder 110 and the movable mechanism 130 and around which the wire 120 is wound, and the support member 143, which is provided so as to be movable in direction L while supporting the pulleys 151, 152. This allows the pulleys 151, 152 in the work machine system 10 according to this embodiment to appropriately apply tension to the wire 120. As a result, the work machine system 10 according to this embodiment allows the movable mechanism 130 to efficiently receive power from the wire 120, making it less likely that a decrease in output of the work machine 100 will occur. The provision of the pulleys 151, 152 and the support member 143 is particularly effective as a means of solving the problem of a decrease in output of the work machine 100, which can occur particularly in a work machine system that employs a dual rod cylinder 110 in which the wire 120 and the piston rod 111 are connected in a closed manner.

[0054] Furthermore, the work machine system 10 according to this embodiment is equipped with pulleys 153, 154 that change the direction of movement of the wire 120. As a result, in the work machine system 10 according to this embodiment, the wire 120 is wound around the pulleys that make up the movable mechanism 130 so that the wire 120 abuts on more than half of the circumference of the pulleys. As a result, the work machine system 10 according to this embodiment allows the movable mechanism 130 to receive power from the wire 120 more efficiently, making it even less likely that a drop in output from the work machine 100 will occur.

[0055] <Configuration of pressure control device> FIG. 4 is a functional block diagram of the pressure control device 300 according to the first embodiment.

[0056] The pressure control device 300 is specifically a computer, and includes an input / output unit 310 , a control unit 320 , and a storage unit 330 .

[0057] The input / output unit 310 includes an input unit 311 and an output unit 312. User interface devices such as a display, keyboard, and mouse are connected to the input / output unit 310. The input / output unit 310 includes a communication device and is capable of transmitting and receiving signals to and from at least the fluid pressure application device 200 and the sensor 400. The input unit 311 receives an operation signal in response to an input operation by the operator of the work machine 100, a pressure signal from the fluid pressure application device 200, or a measurement signal from the sensor 400.

[0058] The storage unit 330 includes memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 330 stores a command generation model 331 and a program 332. The program 332 includes a description of a command generation process (see FIG. 7, which will be described later).

[0059] The control unit 320 is configured to include a processor such as a CPU (Central Processing Unit). The control unit 320 executes the functions of an acquisition unit 321 and a command generation unit 322. The acquisition unit 321 reads out, at an appropriate timing, various signals received by the input unit 311 or various pieces of information such as a command generation model 331 and a program 332 stored in the storage unit 330. The acquisition unit 321 processes the various signals or pieces of information read out as necessary.

[0060] The command generating unit 322 uses the command generation model 331 to generate a control command using the various signals or information acquired by the acquiring unit 321 as input. The command generating unit 322 transmits the generated control command to the fluid pressure application device 200 via the output unit 312.

[0061] <Pressure control device: command generation model> 5 is a diagram showing an example of a command generation model 331 according to the first embodiment. In this embodiment, the pressure of the working fluid in the right fluid chamber 110a of the dual-rod cylinder 110 is defined as pr, and the pressure of the working fluid in the left fluid chamber 110b is defined as pl.

[0062] When controlling the pressure of the working fluid in the double-rod cylinder 110, the pressure control device 300 increases or decreases the pressure of the working fluid in one fluid chamber while maintaining the pressure of the working fluid in the other fluid chamber at a predetermined value. The pressure control device 300 according to this embodiment maintains the pressure pr of the working fluid in the right fluid chamber 110a at a predetermined value C. The pressure control device 300 according to this embodiment increases or decreases the operating amount u by setting the pressure pl of the working fluid in the left fluid chamber 110b as the sum of the operating amount u, the gravity compensation term pg, and the predetermined value C.

[0063] The manipulated variable u is a pressure value corresponding to the rotation direction of the movable mechanism 130, with u=0 corresponding to stationary, u>0 corresponding to rightward movement of the rod, and u<0 corresponding to leftward movement of the rod. The gravity compensation term pg is a term for compensating for the gravitational load of the movable mechanism 130, the end effector 170, etc., and depends on the attitude of the movable mechanism 130. If the movable mechanism 130 does not operate when pg=0 and u=0 due to high friction or other reasons, the gravity compensation term pg may be set to 0.

[0064] The predetermined value C must be determined taking into consideration the output band of the work machine 100. FIG. 6 is a diagram showing the output band of the work machine 100 for each magnitude relationship between half the value (M / 2) of the maximum applicable pressure M and the predetermined value C. In the graph shown in FIG. 6, the horizontal axis represents the differential pressure pl-pr, and the vertical axis represents the torque τ of the movable mechanism 130 in the clockwise direction θ1, which is proportional to the differential pressure. For ease of explanation, the graph shown in FIG. 6 sets the gravity compensation term pg to 0. The output band of the work machine 100 refers to the range of torque that can be output by the movable mechanism 130 and the end effector 170. The output band of the work machine 100 is correlated with the range of movement of the piston rod 111, which is the drive source of the movable mechanism 130.

[0065] As shown in Fig. 6(b), when C = M / 2, pressure can be applied evenly in the positive and negative directions of torque τ, so the output bands in the positive and negative directions are equal. On the other hand, as shown in Figs. 6(a) and 6(c), when C ≠ M / 2, the pressure applied in the positive and negative directions of torque τ becomes uneven, so a bias occurs in the output band. When high output is required in the clockwise direction θ1 or counterclockwise direction θ2, C > M / 2 or C < M / 2 may be set according to the direction, and when equal output is required, C = M / 2 may be set.

[0066] <Pressure control device: Command generation process> Fig. 7 is a control flowchart of the pressure control device 300 according to the first embodiment. Fig. 7 shows the control flow of the pressure control device 300 at a certain time during the execution of a predetermined operation. A series of operations of the working machine 100 are executed by the pressure control device 300 repeatedly performing the control process shown in Fig. 7 to continuously operate the fluid pressure applying device 200.

[0067] In step S101, the pressure control device 300 receives a movable direction command for the movable mechanism 130 of the working machine 100 at the input unit 311 and reads it out at the acquisition unit 321. The movable direction command may be an operation signal according to the input operation of the operator. Also, the movable direction command may be a signal generated by a movable direction determination program included in the program 332 based on the measurement signal of the sensor 400 that measures the rotation angle of the rotation axis of the movable mechanism 130. The movable direction determination program determines the next movable direction from the difference between the rotation angle of the rotation axis of the movable mechanism 130 obtained by the measurement signal and a predetermined target rotation angle, and generates a signal indicating the determined movable direction.

[0068] In step S102, the pressure control device 300 generates a control command in accordance with the movable direction command acquired in step S101 by referring to the command generation model 331 in the command generation unit 322. Specifically, the pressure control device 300 selectively executes any one of the following steps S103 to S105 in accordance with the acquired movable direction command.

[0069] If the movable direction command indicates stationary (step S102: stationary), the pressure control device 300 proceeds to step S103. If the movable direction command indicates clockwise rotation, i.e., rotation in the direction θ1 (step S102: rotate in θ1), the pressure control device 300 proceeds to step S104. If the movable direction command indicates counterclockwise rotation, i.e., rotation in the direction θ2 (step S102: rotate in θ2), the pressure control device 300 proceeds to step S105.

[0070] In step S103, the pressure control device 300 generates a control command to set the pressure of the working fluid to pr=C and pl=C in accordance with the movable direction command indicating rest.

[0071] In step S104, the pressure control device 300 generates a control command to set the pressure of the working fluid to pr=C, pl=-P+C in accordance with the movable direction command indicating rotation in the direction θ1.

[0072] In step S105, the pressure control device 300 generates a control command to set the pressure of the working fluid to pr=C, pl=P+C in accordance with the movable direction command indicating rotation in the direction θ2.

[0073] In step S106, the pressure control device 300 transmits the control commands generated in steps S103 to S105 to the fluid pressure application device 200 via the output unit 312.

[0074] When the fluid pressure application device 200 receives the control command generated in step S103, it applies pressure to the working fluid in both the right fluid chamber 110a and the left fluid chamber 110b so that the pressures of the working fluid in both the right fluid chamber 110a and the left fluid chamber 110b become equal. This causes the piston rod 111 to come to a standstill, and the moving mechanism 130 to also come to a standstill. With the moving mechanism 130 coming to a standstill, the end effector 170 comes to a standstill.

[0075] When the fluid pressure application device 200 receives the control command generated in step S104, it applies pressure to the working fluid in both fluid chambers 110a and 110b so that the pressure of the working fluid in the right fluid chamber 110a is greater than the pressure of the working fluid in the left fluid chamber 110b. This causes the piston rod 111 to move in a direction from one end 111a to the other end 111b, i.e., in the negative direction in direction L. As a result, the rotation axis of the movable mechanism 130 rotates clockwise, i.e., in direction θ1. As the movable mechanism 130 rotates in direction θ1, the end effector 170 rotates in direction θ1, i.e., in a predetermined direction.

[0076] When the fluid pressure application device 200 receives the control command generated in step S105, it applies pressure to the working fluid in both fluid chambers 110a and 110b so that the pressure of the working fluid in the right fluid chamber 110a is less than the pressure of the working fluid in the left fluid chamber 110b. This causes the piston rod 111 to move in a direction from the other end 111b toward the one end 111a, i.e., in the positive direction in direction L. As a result, the rotation axis of the movable mechanism 130 rotates counterclockwise, i.e., in direction θ2. As the movable mechanism 130 rotates in direction θ2, the end effector 170 rotates in direction θ2, i.e., in the direction opposite to the predetermined direction.

[0077] 7 is a constant value of the manipulated variable u of the command generation model shown in FIG.

[0078] As described above, the pressure control device 300 according to this embodiment moves the piston rod 111 by increasing or decreasing the pressure of the working fluid in one fluid chamber 110b while maintaining the pressure of the working fluid in one fluid chamber 110a at a predetermined value. This eliminates the need for simultaneous control of the pressure of the working fluid in both fluid chambers 110a and 110b of the dual-rod cylinder 110, and enables the work machine 100 to be driven by controlling the pressure of only one of the fluid chambers (the left fluid chamber 110b in this embodiment). Conventionally, highly accurate pressure control of two fluid chambers is required to precisely control the piston rod, which necessitates two expensive pressure control valves in the fluid pressure application device. In contrast, the work machine system 10 according to this embodiment requires one of the two pressure control valves to be capable of highly accurate pressure control, but the other only needs to steadily apply the same pressure, eliminating the need for an expensive pressure control valve. Therefore, the work machine system 10 according to this embodiment can be realized at a relatively low cost compared to conventional systems. Therefore, according to this embodiment, it is possible to provide a work machine system that can further simplify the structure and control system of the drive unit.

[0079] Furthermore, the pressure control device 300 according to this embodiment sets the pressure in one fluid chamber 110a to a predetermined value C and sets the pressure in the other fluid chamber 110b to a value less than the predetermined value C, thereby moving the piston rod 111 in a direction from one end 111a to the other end 111b. As a result, the pressure control device 300 according to this embodiment rotates the end effector 170 in a predetermined direction θ1. Furthermore, the pressure control device 300 according to this embodiment sets the pressure in one fluid chamber 110a to a predetermined value C and sets the pressure in the other fluid chamber 110b to a value greater than the predetermined value C, thereby moving the piston rod 111 in a direction from the other end 111b to the one end 111a. As a result, the pressure control device 300 according to this embodiment rotates the end effector 170 in a direction θ2 opposite to the predetermined direction. Furthermore, the pressure control device 300 according to this embodiment sets the pressure in one fluid chamber 110a and the pressure in the other fluid chamber 110b to a predetermined value C, thereby stationarying the piston rod 111. As a result, the pressure control device 300 according to this embodiment keeps the end effector 170 stationary.

[0080] In this way, the work machine system 10 according to this embodiment can realize a series of operations such as rotating the end effector 170 in the direction θ1 or the direction θ2 or stopping it still by controlling the pressure of only one of the fluid chambers of the dual rod cylinder 110. In other words, the work machine system 10 according to this embodiment can realize a series of operations such as rotating the end effector 170 in the direction θ1 or the direction θ2 or stopping it still at a lower cost than conventional methods.

[0081] Next, second and third embodiments of the work machine system 10 of the present invention will be described with reference to Figures 8 and 9. The second and third embodiments are effective in addressing, for example, the problems described below.

[0082] Consider a pick-and-place operation for an object, such as switching an object on a factory line using the work machine system 10. Figure 8 is a diagram showing the flow of the operation in which the work machine 100 picks and places the target object T from position A to position B. The flow of the operation is as follows: (1) to (7) operational sequence. (1) Standby position (2) Rotate counterclockwise and approach the object (approach) (3) Grasping (4) Approach (lift) to standby position (5) Standby position (6) Approach to the place location (approach) (7) Plaything The "standby posture" in the operation sequences (1) and (5) refers to a posture in which the machine is stationary at an angle obtained by adding the maximum rotation angle in direction θ1 and the maximum rotation angle in direction θ2 and dividing the sum by 2. The standby posture of the work machine 100 according to this embodiment refers to a posture in which the machine is stationary at an angle facing vertically upward.

[0083] FIG. 9(a) is a diagram showing the relationship between the power bandwidth of the work machine 100 in the relationship C=M / 2 and the torque required for the work machine 100 to work at a constant speed for each operation sequence when performing the work shown in FIG. 8. In the case of FIG. 9(a), the power bandwidth is constant. The torque required for the work machine 100 for each operation sequence is shown by a solid line in FIG. 9(a). As shown by the dotted lines in FIG. 8(a), the clockwise direction is the positive direction for the torque τ and rotation angle θ. Furthermore, if the mass of the object T is m, the distance from the center of the rotation axis to the center of gravity of the object T is l, and the acceleration due to gravity is g, then the torque required for the work machine 100 to grip the object T is τ=mgl cosθ due to torque balance. Furthermore, the power bandwidth of the work machine 100 is assumed to be W.

[0084] The torque required for the working machine 100 varies depending on the operation sequence, as shown in Fig. 9(a). In particular, the absolute value of the torque required for the working machine 100 during the operation sequences of (3) "Grasping", (4) "Lifting", (6) "Approaching", and (7) "Placing" is significantly greater than that during the operation sequences of (1) "Standby position", (2) "Approaching", and (5) "Standby position". When the maximum pressure M that can be applied due to the performance of the hydraulic pressure applying device and / or the double-rod cylinder is small, there is a risk that the torque required for the working machine 100 during the operation sequences of (3) "Grasping", (4) "Lifting", (6) "Approaching", and (7) "Placing" will exceed the output band W.

[0085] Note that the torque required for the working machine 100 may exceed at least one of the maximum value τmax and the minimum value τmin of the output band W even in the output band W in the relationship of C > M / 2 or C < M / 2.

[0086] Therefore, in the second and third embodiments, even when the maximum pressure M that can be applied due to the performance of the hydraulic pressure applying device and / or the double-rod cylinder is small, the above problem is solved by adopting a method in which the torque required for the working machine 100 does not exceed the output band W.

[0087] [Second Embodiment] Specifically, in the second embodiment, the output band W is adjusted by changing the predetermined value C maintained as the pressure of the working fluid in one of the fluid chambers (right fluid chamber 110a) from the first predetermined value to the second predetermined value. In the second embodiment, the first embodiment is applicable to points not specifically described.

[0088] Fig. 9(b) is a diagram showing the relationship between the output band of the working machine 100 and the torque required for the working machine 100 to work at a constant speed for each operation sequence when the predetermined value C is changed from the first predetermined value to the second predetermined value according to the second embodiment.

[0089] The pressure control device 300 according to the second embodiment sets an initial predetermined value C to a value (first predetermined value) satisfying the relation C>M / 2 in accordance with the torque required for the working machine 100 during the operation sequence of (3) "Gripping". Next, the pressure control device 300 according to the second embodiment changes the predetermined value C to a value (second predetermined value) satisfying the relation C<M / 2 in the operation sequence of (5) "Standby posture" in order to match the torque required for the working machine 100 during the operation sequence of (7) "Placing".

[0090] Along with the above change, when the predetermined value C is the first predetermined value, the moving range of the piston rod 111 is changed so that the relation of the right fluid chamber 110a>left fluid chamber 110b holds. When the predetermined value C is the second predetermined value, the moving range of the piston rod 111 is changed so that the relation of the right fluid chamber 110a<left fluid chamber 110b holds. The output band W that has a correlation with the moving range of the piston rod 111 dynamically changes from the range at the first predetermined value to the range at the second predetermined value as shown in Fig. 9(b).

[0091] As described above, the pressure control device 300 according to the second embodiment changes the moving range of the piston rod 111 by changing the pressure of the working fluid in one fluid chamber 110a from the first predetermined value to the second predetermined value. Thereby, the working machine system 10 according to the second embodiment can dynamically change the output band W. As a result, even when the maximum pressure M that can be applied due to the performance of the fluid pressure applying device and / or the double rod cylinder is small, the working machine system 10 according to the second embodiment embodiment can secure the torque required for the working machine 100 without exceeding the output band W. That is, the working machine system 10 according to the second embodiment can cause the working machine 100 to execute a desired operation even when the fluid pressure applying device 200 and / or the double rod cylinder 110 are relatively inexpensive compared to the first embodiment. Therefore, according to the second embodiment, it is possible to provide a working machine system capable of further simplifying the structure of the drive unit and the control system compared to the first embodiment.

[0092] The pressure control device 300 according to the second embodiment may change the predetermined value C from the first predetermined value to the second predetermined value based on an operation signal corresponding to an input operation by an operator. The pressure control device 300 according to the second embodiment may change the predetermined value C from the first predetermined value to the second predetermined value based on a measurement signal from a sensor 400 that measures the rotation angle of the rotation shaft of the movable mechanism 130.

[0093] Furthermore, in the second embodiment, the pressure of the working fluid in one of the fluid chambers 110a was simply changed from a first predetermined value to a second predetermined value, but the present invention does not prevent the predetermined value from being changed by any amount necessary for the working machine 100 to perform the desired operation.

[0094] As a result, the method of adjusting the output band W according to the second embodiment has the advantage that the predetermined value C, which is the pressure of the working fluid in one of the fluid chambers 110a, can be flexibly changed to match the torque required for the working machine 100 to perform the desired operation.

[0095] [Third embodiment] In the third embodiment, the output band W is adjusted by switching the fluid chamber in which the pressure of the working fluid is maintained at a predetermined value C from one fluid chamber (the right fluid chamber 110a) to the other fluid chamber (the left fluid chamber 110b). Note that the first embodiment is applicable to the third embodiment except for the points not specifically described.

[0096] Figure 9(b) is also a diagram showing the relationship between the output band of the work machine 100 and the torque required for the work machine 100 to work at a constant speed for each operating sequence when the fluid chamber maintained at a predetermined value C is switched from one fluid chamber to the other in the third embodiment.

[0097] In the third embodiment, the predetermined value C satisfies the relationship C≠M / 2. The predetermined value C shown in Fig. 9(b) satisfies the relationship C>M / 2.

[0098] The pressure control device 300 according to the third embodiment initially sets the right fluid chamber 110a as the fluid chamber maintained at a predetermined value C to match the torque required by the work machine 100 during the (3) "grasping" operation sequence. Next, the pressure control device 300 according to the third embodiment switches the fluid chamber maintained at a predetermined value C to the left fluid chamber 110b during the (5) "standby posture" operation sequence in order to match the torque required by the work machine 100 during the (7) "placing" operation sequence.

[0099] As a result of the above switching, when the fluid chamber maintained at the predetermined value C is the right fluid chamber 110a, the movement range of the piston rod 111 is changed so that the relationship is right fluid chamber 110a > left fluid chamber 110b. When the fluid chamber maintained at the predetermined value C is the left fluid chamber 110b, the movement range of the piston rod 111 is changed so that the relationship is right fluid chamber 110a < left fluid chamber 110b. In other words, the movement range of the piston rod 111 switches from the range in which it moves according to the predetermined value C, which is the pressure of the working fluid in one fluid chamber, to the range in which it moves according to the predetermined value C, which is the pressure of the working fluid in the other fluid chamber. As shown in Figure 9(b), the output band W, which is correlated with the movement range of the piston rod 111, dynamically changes as the fluid chamber maintained at the predetermined value C is switched from one fluid chamber to the other.

[0100] As described above, the pressure control device 300 according to the third embodiment changes the movement range of the piston rod 111 by switching the fluid chamber in which the pressure of the working fluid is maintained at the predetermined value C from one fluid chamber 110a to the other fluid chamber 110b. This allows the work machine system 10 according to the third embodiment to dynamically change the output band W. The work machine system 10 according to the third embodiment can ensure the torque required for the work machine 100 without exceeding the output band W, even if the maximum applicable pressure M is small due to the performance of the fluid pressure application device and / or dual-rod cylinder, etc. In other words, the work machine system 10 according to the third embodiment can cause the work machine 100 to perform the desired operation, even if the fluid pressure application device 200 and / or dual-rod cylinder 110 are relatively inexpensive compared to the first embodiment. Therefore, according to the third embodiment, it is possible to provide a work machine system in which the structure of the drive unit and the control system can be further simplified compared to the first embodiment.

[0101] The pressure control device 300 according to the third embodiment may switch the fluid chambers that are maintained at the predetermined value C based on an operation signal corresponding to an input operation by an operator. The pressure control device 300 according to the third embodiment may also switch the fluid chambers that are maintained at the predetermined value C based on a measurement signal from a sensor 400 that measures the rotation angle of the rotation shaft of the movable mechanism 130.

[0102] The method for adjusting the output band W according to the third embodiment is an effective method when the operations before and after a specific timing (for example, the operation sequence of (5) "standby position") are the same, such that the rotation axis of the movable mechanism 130 rotates in accordance with the movement of the piston rod 111.

[0103] [Third embodiment: Modification] Furthermore, as a modification of the third embodiment, even when the predetermined value C is in the relationship of C < M / 2, the working machine system 10 can perform the same operations as in the third embodiment according to the following procedure. In the description of this modification, the figure showing the output band in FIG. 6 has the differential pressure, which is the value on the horizontal axis, as pr - pl, and the graph itself also has the values on the vertical and horizontal axes inverted. Also, regarding the description of the above command generation model and command generation process, in this modification, the numerical values of pr and pl are interchanged with each other.

[0104] The pressure control device 300 according to this modification, during the operation sequence of (3) "grasping", initially sets the fluid chamber maintained at the predetermined value C as the left fluid chamber 110b in accordance with the torque required for the working machine 100. Next, the pressure control device 300 according to this modification switches the fluid chamber maintained at the predetermined value C to the right fluid chamber 110a during the operation sequence of (5) "standby posture" in order to match the torque required for the working machine 100 during the operation sequence of (7) "placing".

[0105] With the above switching, when the fluid chamber maintained at the predetermined value C is the left fluid chamber 110b, the moving range of the piston rod 111 is changed so that the relationship is right fluid chamber 110a > left fluid chamber 110b. When the fluid chamber maintained at the predetermined value C is the right fluid chamber 110a, the moving range of the piston rod 111 is changed so that the relationship is right fluid chamber 110a < left fluid chamber 110b. As a result, the output band W, which has a correlation with the moving range of the piston rod 111, will change dynamically as in the third embodiment when the fluid chamber maintained at the predetermined value C is switched from one fluid chamber to the other.

[0106] As described above, when the predetermined value C satisfies C < M / 2, the pressure control device 300 according to this modification example changes the moving range of the piston rod 111 by switching the fluid chamber in which the pressure of the working fluid is maintained at the predetermined value C from one fluid chamber 110b to the other fluid chamber 110a. Thereby, the working machine system 10 according to this modification example can dynamically change the output band W. Even when the maximum pressure M that can be applied due to the performance of the fluid pressure applying device and / or the double-rod cylinder is small, the working machine system 10 according to this modification example can secure the torque required for the working machine 100 without exceeding the output band W. That is, similar to the third embodiment, the working machine system 10 according to this modification example can cause the working machine 100 to execute a desired operation even when the fluid pressure applying device 200 and / or the double-rod cylinder 110 are relatively inexpensive compared to the first embodiment. Therefore, also according to this modification example, it is possible to provide a working machine system capable of further simplifying the structure of the drive unit and the control system compared to the first embodiment.

[0107] Here, assume a case where the pressure of the working fluid in the fluid chamber that is not the fluid chamber maintained at the predetermined value C decreases due to damage to the piping or the cylinder. In this modification example, since the relationship C < M / 2 holds for the predetermined value C, the pressure difference between the two fluid chambers is small. As a result, even when the pressure of the working fluid decreases due to damage or the like as described above, the piston rod 111 according to this modification example is less likely to move vigorously toward the fluid chamber side where the pressure has decreased. As a result, in addition to the above advantages, the working machine system 10 according to this modification example has an advantage that it can prevent the double-rod cylinder 110 from suffering a secondary failure.

[0108] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0109] Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be partially or entirely implemented in hardware, for example, by designing them as integrated circuits. The above-described configurations, functions, etc. may also be implemented in software, with a processor interpreting and executing a program that implements each function. Information such as programs, tapes, and files that implement each function can be stored in a storage device such as a memory, a hard disk, or an SSD (solid state drive), or in a storage medium such as an IC card, an SD card, or a DVD.

[0110] In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are interconnected. [Explanation of symbols]

[0111] 10...working machine system, 100...working machine, 110...double-rod cylinder, 110a...right fluid chamber (one fluid chamber), 110b...left fluid chamber (the other fluid chamber), 111...piston rod, 111a...one end, 111b...other end, 120...wire, 120a...one end, 120b...other end, 130...moving mechanism, 143...support member, 151, 152...pulley, 170...end effector, 300...pressure control device, L...moving direction of piston rod, θ1...clockwise direction (predetermined direction), θ2...counterclockwise direction (reverse direction)

Claims

1. A work machine system having a work machine driven by a working fluid and a pressure control device that controls the pressure of the working fluid, The work machine includes: a movable mechanism that rotates the end effector around an axis; a wire wound around the movable mechanism; a double-rod cylinder having a piston rod whose one end is connected to one end of the wire and whose other end is connected to the other end of the wire, and which is actuated by the hydraulic fluid; The pressure control device is Controlling the pressure of the hydraulic fluid in the double-rod cylinder; The piston rod is moved by increasing or decreasing the pressure in one fluid chamber of the dual-rod cylinder while maintaining the pressure in the other fluid chamber of the dual-rod cylinder at a predetermined value. A work machine system comprising:

2. The pressure control device is a pressure in one of the fluid chambers is set to the predetermined value, and a pressure in the other fluid chamber is set to be smaller than the predetermined value, and the piston rod is moved in a direction from the one end toward the other end, thereby rotating the end effector in a predetermined direction; By setting the pressure in one of the fluid chambers to the predetermined value and setting the pressure in the other fluid chamber to be greater than the predetermined value, the piston rod is moved in a direction from the other end toward the one end, thereby rotating the end effector in a direction opposite to the predetermined direction, or The pressure in the one fluid chamber and the pressure in the other fluid chamber are set to the predetermined value, and the piston rod is made stationary, thereby making the end effector stationary.

2. The work machine system according to claim 1.

3. The pressure control device changes the pressure in the one fluid chamber from a first predetermined value to a second predetermined value, thereby changing the movement range of the piston rod.

2. The work machine system according to claim 1.

4. The pressure control device changes the movement range of the piston rod by switching the fluid chamber in which the pressure is maintained at the predetermined value from the one fluid chamber to the other fluid chamber.

2. The work machine system according to claim 1.

5. The work machine includes: a pulley disposed between the dual rod cylinder and the movable mechanism and around which the wire is wound; a support member for supporting the pulley, The support member is provided so as to be movable along the movement direction of the piston rod while supporting the pulley.

2. The work machine system according to claim 1.

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