Robot control device, robot control method, and robot control program

Abstract

To provide a robot control device, etc., that are able to appropriately increase the movement speed of a movable portion of a robot.SOLUTION: A robot control device 50 includes: a movement path setting unit 51 that sets a movement path for a movable portion of a robot arm 100; a movement speed acquisition unit 52 that acquires a movement speed of the movable portion; and a deviation allowable range setting unit 53 that sets a deviation allowable range of a position of the movable portion from the movement path, the deviation allowable range setting unit 53 expanding the deviation allowable range according to an increase in the movement speed. The deviation allowable range setting unit 53 reduces the deviation allowable range according to a decrease in the movement speed. The movable portion is a conveying portion 18 that conveys a to-be-conveyed object 60 along the movement path.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a robot control device and the like. [Background technology]

[0002] Industrial robots that perform various tasks in place of humans have been introduced in industrial sites such as factories, logistics warehouses, construction sites, and hospitals. Conventional industrial robots are often large and high-powered, and for safety reasons, they have had to be operated in isolated spaces that humans cannot enter. Meanwhile, in recent years, collaborative robots that work together with humans in the same space have also been introduced. Compared to conventional industrial robots, collaborative robots are small and can be installed in narrow spaces, and because they have low power output, they do not require large-scale systems to ensure safety. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-26150 A Summary of the Invention [Problem to be solved by the invention]

[0004] In collaborative robots, the tolerance range for deviation of movable parts such as a robot hand from the intended movement path tends to be set narrowly from the viewpoint of safety, etc. However, when there is no problem with safety or the work accuracy of the robot hand, etc., there is an issue that increasing the movement speed of the movable parts can easily cause deviation from the narrow tolerance range.

[0005] The present disclosure has been made in consideration of these circumstances, and aims to provide a robot control device and the like that can appropriately increase the moving speed of a movable part in a robot. Note that, although a collaborative robot has been exemplified above, the present disclosure is not limited to a collaborative robot and can also be applied to a robot arm or the like as a general industrial robot. [Means for solving the problem]

[0006] In order to solve the above problems, a robot control device according to one aspect of the present disclosure includes a movement path setting unit that sets a movement path for a movable part in the robot, a movement speed acquisition unit that acquires the movement speed of the movable part, and a deviation tolerance range setting unit that sets an acceptable range of deviation of the position of the movable part from the movement path, the deviation tolerance range expanding as the movement speed increases.

[0007] According to this aspect, the allowable deviation range is expanded as the moving speed of the movable part increases, so that the position of the movable part is less likely to deviate from the allowable deviation range.

[0008] Another aspect of the present disclosure is a robot control method, which executes the steps of: setting a movement path of a movable part of a robot; acquiring a movement speed of the movable part; and setting an allowable range of deviation of a position of the movable part from the movement path, and expanding the allowable range as the movement speed increases.

[0009] Any combination of the above components, or any conversion of these components into a method, device, system, recording medium, computer program, or the like, is also encompassed by the present disclosure. Effect of the Invention

[0010] According to the present disclosure, the movement speed of a movable part in a robot can be appropriately increased. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view showing the appearance of a robot arm. [Diagram 2] 1 shows a schematic configuration of a coupling device that constitutes each joint of a robot arm. [Diagram 3] 1 shows a schematic configuration of a coupling device that constitutes each joint of a robot arm. [Figure 4] FIG. 2 is a schematic functional block diagram of a robot control device. [Diagram 5] 1 shows a drive control section including a position control section. [Figure 6] 13 shows a schematic diagram of the movement speed of the transport unit and the allowable deviation range when the transport unit picks up the transported object at the pick position and transports it to the place position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the following, a form for carrying out the present disclosure (hereinafter also referred to as an embodiment) will be described in detail with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc. will be given the same reference numerals, and duplicated descriptions will be omitted. The scale and shape of each part shown in the drawings are set for convenience in order to simplify the description, and are not to be interpreted as being limiting unless otherwise specified. The embodiment is an example, and does not limit the scope of the present disclosure in any way. All features and their combinations presented in the embodiment are not necessarily essential to the present disclosure. The embodiment is presented for convenience, decomposed into components for each function and / or each functional group that realizes it. However, one component in the embodiment may actually be realized by a combination of multiple components as separate entities, and multiple components in the embodiment may actually be realized by one component as an integrated entity.

[0013] FIG. 1 is a perspective view showing the appearance of a robot arm 100 as an example of a robot such as an industrial robot or a collaborative robot. This robot arm 100 is a vertical multi-joint type robot arm with a serial link mechanism. The robot to which the present disclosure is applicable is not limited to a robot arm in the narrow sense, but may be a robot arm in the broad sense having joints (corresponding to joints in the human body) that connect multiple links (corresponding to bones in the human body) so that they can move relative to one another, or any robot having at least one movable part. In addition, a parallel link mechanism may be used instead of the serial link mechanism, and a horizontal multi-joint type may be used instead of the vertical multi-joint type.

[0014] The robot arm 100 has seven joints or axes, namely, a first joint 11, a second joint 12, a third joint 13, a fourth joint 14, a fifth joint 15, a sixth joint 16, and a seventh joint 17, in order from the side closest to the base 10. Each joint corresponds to a joint of the human body, with the first joint 11 corresponding to the waist, the second joint 12 corresponding to the shoulder, the third joint 13 corresponding to the upper arm (twist), the fourth joint 14 corresponding to the elbow, the fifth joint 15 corresponding to the forearm (twist), the sixth joint 16 corresponding to the wrist, and the seventh joint 17 corresponding to the fingertip (twist). Each of the rotatable joints 11 to 17 and each of the links connected via the joints 11 to 17 constitute a movable part of the robot arm 100.

[0015] The direction of each axis can be designed appropriately depending on the purpose and use of the robot arm 100, but in this embodiment, the base 10 is placed on a horizontal plane, and the first joint 11 may be oriented in the vertical direction (perpendicular to the base 10, which is a horizontal plane), the second joint 12 may be oriented in the horizontal direction (parallel to the base 10, which is a horizontal plane), the third joint 13 may be oriented in a vertical direction relative to the second joint 12, the fourth joint 14 may be oriented in a vertical direction relative to the third joint 13, the fifth joint 15 may be oriented in a vertical direction relative to the fourth joint 14, the sixth joint 16 may be oriented in a vertical direction relative to the fifth joint 15, and the seventh joint 17 may be oriented in a vertical direction relative to the sixth joint 16.

[0016] An end effector or robot hand as a working part having a shape and function according to the purpose of work is attached to the seventh joint 17 at the tip of the robot arm 100. For example, various end effectors such as a grapple shape for grasping an object, a shovel shape for scooping an object, a fork shape for supporting an object from below and transporting it, a hook shape for hanging an object and transporting it, and a crane shape for lifting an object and transporting it can be used. In this embodiment, an example is described in which a holding tool or a gripping tool is used as an end effector as a transport part that holds or grips a transported object as a work target and transports it. In addition, the movable part in the robot arm 100 to which the present disclosure is applicable may be any part (substantially the entire robot arm 100 except for the base 10) that can move (translate and / or rotate), including each of the joints 11 to 17 and each of the links, as described above, but in this embodiment, a holding tool or a gripping tool as a transport part is exemplarily described as a movable part.

[0017] 2 and 3 are schematic diagrams showing the configuration of a connecting device 30 constituting each of the joints 11 to 17 of the robot arm 100. The connecting device 30 in Fig. 2 is applicable to joints that perform a "bending" motion, such as the second joint 12, the fourth joint 14, and the sixth joint 16 in Fig. 1, and the connecting device 30 in Fig. 3 is applicable to joints that perform a "twisting" motion, such as the first joint 11, the third joint 13, the fifth joint 15, and the seventh joint 17 in Fig. 1.

[0018] 2, the connecting device 30 connects a first link 41 as a first member and a second link 42 as a second member so as to be capable of relative movement. The connecting device 30 corresponds to a joint in the human body, and the first link 41 and the second link 42 connected to each other by the connecting device 30 correspond to bones in the human body.

[0019] The first link 41 and the second link 42 perform various types of relative movement depending on the manner of connection by the connecting device 30. In this embodiment, an example will be described in which the first link 41 and the second link 42 rotate relatively around a rotation axis A perpendicular to the extension direction of the first link 41 and the second link 42.

[0020] The relative motion of the first link 41 and the second link 42 is not limited to rotational motion, but may be translational motion. For example, the first link 41 and the second link 42 may be configured to relatively translate in a direction perpendicular to the extension direction of the first link 41 and the second link (direction perpendicular to the paper surface in FIG. 2), or the first link 41 and the second link 42 may be configured to relatively translate in a direction parallel to the extension direction of the first link 41 and the second link (up and down direction in FIG. 2).

[0021] The coupling device 30 includes a housing 31, a control board 32, a motor 33, a reducer 34, an elastic member 35, and an output flange 36. The housing 31 has a rotationally symmetric shape about the rotation axis A, and accommodates therein the components 32 to 36 of the coupling device 30. On the outer periphery of the housing 31, a first attachment portion 311 to which the first link 41 is attached, and a second attachment portion 312 to which the second link 42 is attached are provided.

[0022] The first link 41 fixed to the housing 31 at the first attachment portion 311 is rotatable integrally with the housing 31 relative to the second link 42 around the rotation axis A. The second attachment portion 312 is an opening on the bottom side (left side in FIG. 2) that communicates with the internal space of the housing 31 that houses the components 32 to 36. The second link 42 is attached to the connecting device 30 via the output flange 36 provided in this opening.

[0023] The control board 32 controls the coupling device 30 under the control of a central control device (not shown) that controls the entire robot arm 100. For example, the control board 32 generates drive commands for the motor 33, performs adaptive control based on measurement data from an output shaft encoder (not shown), detects torque based on elastic deformation of the elastic member 35, and performs adaptive control based on the detected torque. The motor 33 is an actuator that generates power to rotate the second link 42 around the rotation axis A in response to a drive command from the control board 32. The reducer 34 reduces the rotational speed of the motor 33 using gears or the like, and generates torque proportional to a reduction ratio.

[0024] The elastic member 35 is provided in series between the motor 33 and the reducer 34 as a power source, and the second link 42 as a load that is rotationally driven by the power, and constitutes a series elastic actuator (SEA) in the connecting device 30. Even if the robot arm 100 as a collaborative robot collides with a human working together, the elastic deformation of the elastic member 35 absorbs the impact, improving safety. In addition, the elastic member 35 can store and release the power generated by the motor 33 and the reducer 34 and the external force applied to the second link 42 as elastic energy, thereby realizing efficient movement like human muscles.

[0025] The elastic member 35 is a member that imparts elasticity to the connecting device 30, and is formed of any elastic body such as a spring or rubber. In addition to or instead of the elastic member 35, a resistance imparting member that imparts resistance to the relative rotation of the first link 41 and the second link 42 of the connecting device 30 may be provided. Examples of the resistance imparting member include one that imparts resistance by mechanical friction, and one that imparts resistance by the viscosity of a viscous fluid such as oil or grease. The elasticity of the elastic member 35 and the resistance imparted by the resistance imparting member may be made variable by the control board 32.

[0026] The elastic member 35 also functions as a torque sensor that detects torque due to an external force. That is, torque due to an external force causes elastic deformation of the elastic member 35, and torque can be detected based on the amount of elastic deformation. In order to measure the amount of elastic deformation of the elastic member 35, various displacement sensors such as magnetostrictive sensors, strain gauges, piezoelectric elements, polarizing elements, and electrostatic capacitance sensors may be attached to the surface of the elastic member 35. The amount of elastic deformation measured by the displacement sensor is converted into torque by a computing device or the like mounted on the control board 32. The connecting device 30 may be provided with a force sensor that detects a force applied to the connecting device 30 by the elastic member 35 and / or other members. Hereinafter, the force sensor and the torque sensor are collectively referred to as a force sensor.

[0027] In this way, the connecting device 30 may be provided with a force sensor capable of detecting the applied force and / or torque. Based on the force and / or torque applied to the connecting device 30 constituting each joint 11-17, the end effector or robot hand, such as a holding tool or a gripping tool, which is a movable part provided at the tip of the robot arm 100, can calculate the force, torque, and weight of the workpiece received from the workpiece, such as a workpiece to be held, gripped, or worked on, based on the force and / or torque applied to the connecting device 30 constituting each joint 11-17. In other words, the force sensor provided in the connecting device 30 can indirectly detect the force, torque, and weight of the workpiece received by the end effector. In addition to or instead of these force sensors, a force sensor may be provided in the end effector to directly detect the force, torque, and weight of the workpiece received by the end effector.

[0028] In the above configuration, the reducer 34, the elastic member 35, and the resistance imparting member each constitute a flexibility imparting portion that imparts flexibility to the connecting device 30 as a joint. Here, flexibility means the ease with which a joint can bend, and a joint is said to have flexibility when it can bend due to an external force. For example, the reducer 34 generates a torque proportional to the reduction ratio, so that a highly flexible state in which the joint can bend easily due to an external force can be realized by lowering the reduction ratio. In addition, the elastic member 35 and the resistance imparting member can be said to impart flexibility to the joint since they allow the joint to bend while generating elastic force and resistance against an external force. Note that it is sufficient to provide a flexibility imparting portion to at least one joint, and it is not necessary to provide a flexibility imparting portion to all of the seven joints 11 to 17 in FIG. 1.

[0029] The output shaft encoder (not shown) is a rotary encoder that measures the rotational position of the second link 42 about the rotation axis A relative to the first link 41. The output flange 36 transmits the torque generated by the reducer 34 to the second link 42 via the elastic member 35, causing the second link 42 to rotate about the rotation axis A. A bearing 361 that smooths the rotation of the second link 42 relative to the housing 31 is provided around the output flange 36.

[0030] 3, the first link 41 and the second link 42 rotate relatively around a rotation axis B that is parallel to the extension direction of each link. A cutout 37 provided on the second link 42 side of the housing 31 prevents the housing 31 from interfering with the rotation of the second link 42 around the rotation axis B caused by the motor 33.

[0031] FIG. 4 is a schematic functional block diagram of a robot control device 50 according to this embodiment. The robot control device 50 includes a movement path setting unit 51, a movement speed acquisition unit 52, a deviation tolerance setting unit 53, a position control unit 54, and an abnormality detection unit 55. As long as the robot control device 50 can achieve at least a part of the actions and / or effects described below, some of these functional blocks may be omitted. These functional blocks may be realized by the cooperation of hardware resources such as a central processing unit of a computer, a memory, an input device, an output device, and peripheral devices connected to the computer, and software executed using them. Regardless of the type of computer or the installation location, each of the above functional blocks may be realized by the hardware resources of a single computer, or may be realized by combining hardware resources distributed among multiple computers. For example, some or all of the functional blocks of the robot control device 50 may be incorporated into the robot arm 100 as the control target, or may be realized as a configuration outside the robot arm 100 as the control target.

[0032] In the illustrated example, a gripping tool as an end effector or robot hand attached to the robot arm 100 moves as a movable part and conveying part 18. The conveying part 18 holds or grips and conveys a conveyed object 60 of any shape and size. The movement of the conveying part 18 and the conveyed object 60 is realized by a combination of rotations of the above-mentioned joints 11 to 17.

[0033] The movement path setting unit 51 sets a movement path of the conveying unit 18 as a movable unit in the robot arm 100. In the illustrated example, the movement path set by the movement path setting unit 51 is shown by a right-facing arrow. The conveying unit 18 conveys the conveyed object 60 along the movement path set by the movement path setting unit 51 under the control of the position control unit 54 and the like. Note that the movement path set by the movement path setting unit 51 is a planned path, and the position control unit 54 and the like control the conveying unit 18 to move along the planned path. However, in reality, the conveying unit 18 does not necessarily move according to the planned path. That is, a deviation may occur between the actual path (not shown in FIG. 4) along which the conveying unit 18 actually moves and the planned path set by the movement path setting unit 51 (see FIG. 6 described later).

[0034] The movement speed acquisition unit 52 acquires the movement speed of the conveying unit 18. Here, the movement speed acquisition unit 52 may acquire the movement speed of the conveying unit 18 based on a measurement value obtained from a motion sensor such as a position sensor, a speed sensor, or an acceleration sensor that may be attached to the conveying unit 18 itself or each of the joints 11 to 17. Alternatively, the movement speed acquisition unit 52 may acquire, as the movement speed of the conveying unit 18, a speed command for the conveying unit 18 generated by the position control unit 54 or the like in accordance with the movement path set by the movement path setting unit 51.

[0035] As shown diagrammatically in FIG. 5, the drive control unit 70 including the position control unit 54 includes a speed command generating unit 71, a rotational position differentiator 72, a speed subtractor 73, a speed deviation conversion unit 74, a torque subtractor 75, and a torque deviation conversion unit 76.

[0036] The speed command generating unit 71 generates a speed command for the motor 33 in each of the joints 11 to 17. A collection of the speed commands for each of these joints 11 to 17 becomes a speed command for the transport unit 18. The speed command generating unit 71 generates a speed command that specifies an appropriate movement speed for the transport unit 18 in accordance with the shape and length of the movement path of the transport unit 18 set by the movement path setting unit 51 and the work of the transport unit 18 planned on the movement path (see FIG. 6 described later).

[0037] The rotational position differentiator 72 differentiates the rotational position of the motor 33 measured by a rotational position measuring device 331 called a PG (Position Generator) to calculate the rotational speed of the motor 33. The speed subtractor 73 subtracts the speed command generated by the speed command generation unit 71 and the measured speed of the motor 33 from the rotational position differentiator 72 to calculate a speed deviation. The speed deviation conversion unit 74 converts the speed deviation calculated by the speed subtractor 73 into a torque command for the motor 33.

[0038] The torque subtractor 75 calculates a torque deviation by subtracting the torque command generated by the speed deviation conversion unit 74 and the measured torque of the motor 33 from the force sensor 19 of the elastic member 35, etc. The torque deviation conversion unit 76 converts the torque deviation calculated by the torque subtractor 75 into a current value (current command) to be passed through the motor 33.

[0039] 5, the movement speed acquisition unit 52 preferably acquires, as the movement speed of the conveyance unit 18, a speed command for the conveyance unit 18 generated by a speed command generation unit 71 based on the movement path set by a movement path setting unit 51. Alternatively, the movement speed acquisition unit 52 may acquire the actual movement speed of the conveyance unit 18 calculated by a rotational position differentiator 72 based on the rotational position of the motor 33 measured by a rotational position measurement device 331.

[0040] 4, the force sensor 19 capable of detecting the force or torque that the transport unit 18 receives from the transported object 60, the weight of the transported object 60, and the like, may be attached to the transport unit 18 itself or each of the joints 11 to 17, as described above. The force sensor 19 may also detect the force (gripping force) with which the transport unit 18 grips the transported object 60. This gripping force may indirectly represent, for example, the weight of the transported object 60. Although not shown, various information acquisition units that acquire other information related to the transport of the transported object 60 by the transport unit 18 (for example, the shape, size, and material of the transported object 60) may be provided in addition to or in place of the moving speed acquisition unit 52 and / or the force sensor 19.

[0041] The deviation tolerance setting unit 53 sets a deviation tolerance of the conveying unit 18 from the movement path set by the movement path setting unit 51. As shown in the schematic diagram, the deviation tolerance may be set as a width on both sides (upper and lower sides in FIG. 4) of the movement path set by the movement path setting unit 51.

[0042] The deviation allowable range setting unit 53 may set, as the deviation allowable range, a first deviation allowable range having a relatively small width and a second deviation allowable range having a relatively large width wider than the first deviation allowable range.

[0043] The first deviation tolerance range is set for position control of the transport unit 18 by the position control unit 54. The position control unit 54 drives each of the joints 11 to 17 so that the position of the transport unit 18 on both sides of the movement path set by the movement path setting unit 51 remains within the first deviation tolerance range. If the transport unit 18 falls outside the first deviation tolerance range, the position control unit 54 drives each of the joints 11 to 17 to return the transport unit 18 to within the first deviation tolerance range.

[0044] The second deviation tolerance range is set for the abnormality detection by the abnormality detection unit 55. The abnormality detection unit 55 detects an abnormality when the position of the transport unit 18 is outside the second deviation tolerance range. For example, when the transport unit 18 deviates significantly from the movement path set by the movement path setting unit 51 and falls outside the second deviation tolerance range, there is a possibility that the transport unit 18 cannot safely continue transporting the transported object 60. The abnormality detection unit 55 may notify an operator of the robot arm 100 or the like of the occurrence of such an abnormality. In addition, when the transport unit 18 falls outside the second deviation tolerance range, the transport of the transported object 60 by the transport unit 18 may be immediately and urgently stopped.

[0045] The deviation tolerance setting unit 53 expands the deviation tolerance range (the first deviation tolerance range and / or the second deviation tolerance range) in response to an increase in the movement speed of the transport unit 18 acquired by the movement speed acquisition unit 52. In this way, the deviation tolerance range is expanded in response to an increase in the movement speed of the transport unit 18, so that even if the transport unit 18 moves fast, it is difficult for the deviation tolerance range to deviate from the deviation tolerance range. Conversely, the deviation tolerance setting unit 53 may reduce the deviation tolerance range (the first deviation tolerance range and / or the second deviation tolerance range) in response to a decrease in the movement speed of the transport unit 18 acquired by the movement speed acquisition unit 52.

[0046] The deviation tolerance setting unit 53 may expand the deviation tolerance range (the first deviation tolerance range and / or the second deviation tolerance range) in response to an increase in the detection value by the force sensor 19 (the force or torque that the conveying unit 18 receives from the conveyed object 60, the weight of the conveyed object 60, etc.). In this way, since the deviation tolerance range is expanded in response to an increase in the detection value by the force sensor 19, the conveying unit 18 is less likely to deviate from the deviation tolerance range even when the force, torque, weight, etc. applied to the conveying unit 18 is large during movement. Conversely, the deviation tolerance setting unit 53 may narrow the deviation tolerance range (the first deviation tolerance range and / or the second deviation tolerance range) in response to a decrease in the detection value by the force sensor 19 (the force or torque that the conveying unit 18 receives from the conveyed object 60, the weight of the conveyed object 60, etc.).

[0047] Furthermore, the deviation tolerance setting unit 53 may expand or reduce the deviation tolerance (the first deviation tolerance and / or the second deviation tolerance) depending on other information (e.g., the shape, size, and material of the transported object 60) related to the transport of the transported object 60 by the transport unit 18 acquired by various information acquisition units (not shown). For example, if the shape, size, and material of the transported object 60 are difficult for the transport unit 18 to hold, it is considered that the transport unit 18 transporting it is likely to deviate from the deviation tolerance, and therefore it is preferable that the deviation tolerance setting unit 53 expands the deviation tolerance.

[0048] 6 shows a schematic diagram of the movement speed of the transport unit 18 acquired by the movement speed acquisition unit 52 and the allowable deviation range (first allowable deviation range and / or second allowable deviation range) set by the allowable deviation range setting unit 53 when the transport unit 18 picks up the transported object 60 at the pick position and transports it to the place position. The dotted line in the figure indicates the movement path of the transport unit 18 set by the movement path setting unit 51.

[0049] When the transport unit 18 holds the transported object 60 near the pick position, precise control of the transport unit 18 is required, so the movement speed (e.g., speed command) of the transport unit 18 is set low, and a correspondingly narrow tolerance range is set by the deviation tolerance range setting unit 53. Similarly, when the transport unit 18 releases the transported object 60 near the place position, precise control of the transport unit 18 is required, so the movement speed (e.g., speed command) of the transport unit 18 is set low, and a correspondingly narrow tolerance range is set by the deviation tolerance range setting unit 53. Therefore, near the pick position and the place position, the transport unit 18 moves faithfully following the set movement path (dotted line).

[0050] On the other hand, in the section between the pick position and the place position, the required control accuracy is relatively low, so the movement speed (e.g., speed command) of the conveying unit 18 is set high (e.g., medium speed or high speed), and the deviation tolerance range is expanded accordingly (e.g., medium range or wide range) by the deviation tolerance range setting unit 53. Since the conveying unit 18 moves fast with the deviation tolerance range expanded, the conveying unit 18 may move off the set movement path (dotted line) (but within the deviation tolerance range).

[0051] As described above, the movement speed and tolerance range of deviation when the conveying unit 18 holds the transported object 60 (near the pick position) and / or releases it (near the place position) is smaller than the movement speed and tolerance range of deviation when the conveying unit 18 is transporting the transported object 60 (in the section between the pick position and the place position).

[0052] In the illustrated example, the allowable deviation range changes continuously according to the movement speed of the conveying unit 18, but the allowable deviation range may change stepwise according to the movement speed of the conveying unit 18. For example, the allowable deviation range may change in three steps according to three ranges of the movement speed of the conveying unit 18 (for example, a low speed range, a medium speed range, and a high speed range).

[0053] The present disclosure has been described above based on the embodiments. Various modifications are possible to the combinations of the components and processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included within the scope of the present disclosure.

[0054] The configuration, action, and function of each device and method described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. For example, a processor, ROM, RAM, and various integrated circuits can be used as hardware resources. For example, programs such as an operating system and applications can be used as software resources. [Explanation of symbols]

[0055] 18 conveying unit, 19 force sensor, 33 motor, 35 elastic member, 50 robot control device, 51 movement path setting unit, 52 movement speed acquisition unit, 53 deviation tolerance range setting unit, 54 position control unit, 55 abnormality detection unit, 60 conveyed object, 70 drive control unit, 100 robot arm.

Claims

1. a movement path setting unit that sets a movement path of a movable part of the robot; A moving speed acquisition unit that acquires a moving speed of the movable part; a deviation tolerance setting unit that sets an allowable deviation range of a position of the movable part from the movement path, the deviation tolerance setting unit expanding the deviation tolerance range in response to an increase in the movement speed; A robot control device comprising:

2. The robot control device according to claim 1 , wherein the allowable deviation range setting unit reduces the allowable deviation range in response to a decrease in the moving speed.

3. The robot control device according to claim 2 , wherein the movable unit is a transport unit that transports an object along the movement path.

4. The robot control device according to claim 3 , wherein the movement speed and the allowable deviation range when the transport unit picks up and / or releases the transported object are smaller than the movement speed and the allowable deviation range when the transport unit is transporting the transported object.

5. The robot control device according to claim 1 , further comprising a position control unit that, when a position of the movable part falls outside the allowable deviation range, returns the position of the movable part to within the allowable deviation range.

6. The robot control device according to claim 1 , further comprising an abnormality detection unit that detects an abnormality when a position of the movable part falls outside the allowable deviation range.

7. the deviation tolerance setting unit sets, as the deviation tolerance, a first deviation tolerance and a second deviation tolerance wider than the first deviation tolerance, a position control unit that returns a position of the movable part to within the first deviation tolerance range when the position of the movable part deviates from the first deviation tolerance range; an abnormality detection unit that detects an abnormality when a position of the movable part falls outside the second deviation allowable range; The robot control device according to claim 1 , further comprising:

8. Setting a movement path of a movable part of a robot; Obtaining a moving speed of the movable part; setting an allowable deviation range of a position of the movable part from the movement path, and expanding the allowable deviation range in response to an increase in the movement speed; A robot control method for performing the above.

9. Setting a movement path of a movable part of a robot; Obtaining a moving speed of the movable part; setting an allowable deviation range of a position of the movable part from the movement path, and expanding the allowable deviation range in response to an increase in the movement speed; A robot control program that causes a computer to execute the above.

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