JP2018122399A - Path planning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce failure when moving an object.SOLUTION: A path planning device comprises a truck part on which a pair of drive wheels are provided and which is omnidirectionally movable, and a body part on which an arm for gripping an object is provided and which is so provided on the truck part as to be capable of being revolved. The truck part is moved from an initial position to a gripping position, the arm part grips the object at the gripping position, and the truck part is moved to a target position corresponding to a movement position at which the object is moved from the gripping position, thereby planning a movement path of an omnidirectional robot for moving the object. The path planning device plans a movement path which is the movement path from the initial position to the gripping position so that a line passing axles of the pair of drive wheels of the truck part and a line passing the gripping position and the target position are perpendicular to each other at the gripping position.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a path planning apparatus that plans a moving path of an omnidirectional mobile robot that can move in all directions.

  2. Description of the Related Art An omnidirectional mobile robot having a pair of drive wheels that can move in all directions and a main body that is provided with an arm unit that grips an object and that can be turned on the carriage unit is known. (See Patent Document 1).

JP 09-164968 A

  By the way, in the omnidirectional robot, when the object is moved while being held by the arm unit, the force of the arm unit is not sufficient, and the object may be moved by moving the carriage unit. In this case, depending on the direction of the carriage when the object is gripped, it becomes difficult to move the object, and there is a possibility that the movement of the object may fail.

  This invention is made | formed in view of such a problem, and makes it a main objective to provide the route planning apparatus which can reduce the failure at the time of moving a target object.

In order to achieve the above object, one embodiment of the present invention provides:
A carriage unit provided with a pair of drive wheels and movable in all directions; and an arm unit for gripping an object, and a main body unit rotatably provided on the carriage unit, the carriage unit being an initial stage Moving from a position to a gripping position, the arm unit grips the object at the gripping position, and the carriage unit moves from the gripping position to a target position corresponding to a moving position for moving the object, A path planning device for planning a moving path of an omnidirectional mobile robot that moves the object,
The movement path from the initial position to the gripping position, and at the gripping position, a line passing through an axle of a pair of drive wheels of the carriage unit and a line passing through the gripping position and the target position are Planning the travel path to be vertical,
This is a route planning device characterized by this.

  ADVANTAGE OF THE INVENTION According to this invention, the route planning apparatus which can reduce the failure at the time of moving a target object can be provided.

1 is a perspective view illustrating a schematic configuration of an omnidirectional mobile robot according to an embodiment of the present invention. (A) It is the top view which looked at the omnidirectional mobile robot which concerns on one Embodiment of this invention from upper direction. (B) It is the front view which looked at the omnidirectional mobile robot which concerns on one Embodiment of this invention from the front. (C) It is the side view which looked at the omnidirectional mobile robot which concerns on one Embodiment of this invention from the side. 1 is a block diagram showing a schematic system configuration of an omnidirectional mobile robot according to an embodiment of the present invention. (A) It is a figure which shows the state which an arm part hold | grips the handle of a door and a trolley | bogie part moves to the direction which a door opens. (B) It is a figure which shows the state which an arm part hold | grips the handle of a drawer and a trolley | bogie part moves to the pulling-out direction. It is a figure for demonstrating the calculation method of operating force. It is a figure which shows the relationship between the moving direction of a trolley | bogie part, and operating force. It is a figure which shows the relationship between the line L1 which passes along the axle shaft of a driving wheel, and the line L2 which passes through the holding position P1 and the target position P2. It is a figure which shows an example of the movement path | route planned by the route planning apparatus. It is a figure which shows an example of the movement path | route planned by the route planning apparatus. FIG. 10 is a flowchart showing an exemplary flow of the route planning method according to the present embodiment. It is a figure for demonstrating the calculation method of a movement path | route.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A route planning apparatus according to an embodiment of the present invention plans a moving route of an omnidirectional mobile robot that can move in all directions. The route planning apparatus according to the present embodiment is mounted on, for example, an omnidirectional mobile robot.

  FIG. 1 is a perspective view showing a schematic configuration of an omnidirectional mobile robot according to an embodiment of the present invention. 2A to 2C are schematic views showing a schematic configuration of an omnidirectional mobile robot according to an embodiment of the present invention, and a top view of the omnidirectional mobile robot viewed from above and a front view, respectively. It is the front view seen and the side view seen from the side. 2A to 2C, in order to make each component easy to see, the arm portion 11 is omitted and each component is simply described. The omnidirectional mobile robot 1 according to the embodiment of the present invention is configured as an active caster robot, for example.

  The omnidirectional mobile robot 1 includes a cart unit 2 that moves and a main body unit 3 that is connected to the upper side of the cart unit 2 so as to be capable of turning. The carriage unit 2 is provided with one auxiliary wheel 21 and a pair of left and right drive wheels 22. The main body 3 rotates relative to the carriage unit 2 around a turning axis (Yaw rotation axis) 4. The drive shaft of the drive wheel 22 and the turning shaft 4 of the main body 3 are offset (do not intersect).

  The omnidirectional mobile robot 1 realizes omnidirectional movement by driving the drive axis and the turning axis 4 independently. The omnidirectional mobile robot 1 realizes omnidirectional movement by, for example, relative rotation of the main body 3 by the turning shaft 4 in addition to the rotation difference of the drive wheel 22 by the drive shaft. The main body 3 is provided with, for example, an articulated arm 11 that can grip an object so as to be rotatable. Accordingly, the object can be easily grasped and moved by operating the arm unit 11 while moving the omnidirectional mobile robot 1 in an arbitrary direction.

  FIG. 3 is a block diagram showing a schematic system configuration of the omnidirectional mobile robot according to the present embodiment. The omnidirectional mobile robot 1 according to this embodiment includes a pair of rotation sensors 5 that detect rotation information (rotation angle, rotation speed, rotation angle acceleration) of the left and right drive wheels 22, and rotation that detects rotation information of the turning shaft 4. The sensor 6, a pair of wheel actuators 7 that drive the pair of driving wheels 22, a turning actuator 8 that drives the turning shaft 4, a rotation sensor 13 that detects rotation information of each joint 12 of the arm portion 11, and the arm portion 11. A joint actuator 14 for driving each joint 12, and a wheel actuator 7, a turning actuator 8, and a control device 9 for controlling each joint actuator 14.

  The control device 9 controls the wheel actuator 7, the turning actuator 8, and the joint actuator 14 based on the rotation information detected by the rotation sensors 5, 6, and 13.

  The control device 9 includes, for example, a CPU (Central Processing Unit) 9a that performs arithmetic processing and the like, a memory 9b that includes a ROM (Read Only Memory) and a RAM (Random Access Memory) in which an arithmetic program executed by the CPU 9a is stored, The hardware configuration is centered on a microcomputer including an interface unit (I / F) 9c for inputting / outputting signals to / from the outside. The CPU 9a, the memory 9b, and the interface unit 9c are connected to each other via a data bus or the like.

  Each rotation sensor 5 is provided, for example, on the drive shafts of the left and right drive wheels 22. Each rotation sensor 5 includes a potentiometer, an encoder, and the like. Each wheel actuator 7 is connected to the drive shafts of the left and right drive wheels 22, for example. Each wheel actuator 7 is constituted by a motor or the like.

  The turning actuator 8 is connected to the turning shaft 4, for example. Each turning actuator 8 is configured by a motor or the like. Each rotation sensor 13 is provided on each drive shaft of each joint 12 (wrist joint, elbow joint, shoulder joint, etc.), for example. Each joint actuator 14 includes a motor or the like. The wheel actuator 7, the turning actuator 8, and the joint actuator 14 are driven to rotate according to a control signal output from the control device 9.

  The route planning apparatus 10 according to the present embodiment plans a movement route of the omnidirectional mobile robot 1 from a set initial position to a gripping position where the arm unit 11 grips an object. The route planning device 10 is connected to the control device 9 and transmits the planned movement route of the omnidirectional mobile robot 1 to the control device 9. The control device 9 stores the movement route of the omnidirectional mobile robot 1 transmitted from the route planning device 10 in the memory 9b or the like.

  The control device 9 controls the wheel actuator 7, the turning actuator 8, and the joint actuator 14 so that the omnidirectional mobile robot 1 travels according to the movement route transmitted from the route planning device 10. In the present embodiment, the route planning device 10 is configured to be mounted on the omnidirectional mobile robot 1, but is not limited thereto. The path planning device 10 may be independent of the omnidirectional mobile robot 1. In this case, the route planning device 10 is connected to the control device 9 of the omnidirectional mobile robot 1 via wired or wireless (network such as Bluetooth (registered trademark), Wi-Fi (registered trademark), the Internet, or LAN). Is done.

  By the way, in the omnidirectional mobile robot 1, when the object is moved while being held by the arm unit 11, the force of the arm unit 11 is not enough, and the driving force of the cart unit 2 is increased by moving the cart unit 2. Use it to apply operating force to the object and move it. In the omnidirectional mobile robot 1 according to the present embodiment, the carriage unit 2 first moves from the initial position to the gripping position, and the arm unit 11 grips the object at the gripping position. And the trolley | bogie part 2 moves a target object by moving to the target position corresponding to the movement position to which a target object is moved from a holding position. Thereby, a big operating force can be given to a target object using the driving force of cart unit 2, and a target object can be moved easily.

  For example, as shown in FIG. 4A, when the heavy door is moved in the opening direction, the carriage unit 2 moves in the door opening direction (lateral direction) while the arm unit 11 grips the door handle. Thereby, a heavy door can be opened easily. As shown in FIG. 4 (b), when the heavy drawer is moved in the pulling direction, the carriage unit 2 moves in the pulling direction (front-rear direction) while the arm unit 11 grips the drawer handle. Thereby, a heavy drawer can be pulled easily.

Further, depending on the angle formed by the line passing through the axle of the pair of drive wheels 22 of the carriage unit 2 and the line of the movement direction of the carriage unit 2, the magnitude of the operating force applied to the object from the movement of the carriage unit 2. Changes.
For example, the operating force (F _x , F _y , T) can be obtained by the following equation, and it can be seen that the operating force changes according to θ _s (FIG. 5).

In the above formula, r is the radius of the drive wheels 22, s is the distance between the axle and the pivot axis of the pair of drive wheels 22, W is the distance between the pair of drive wheels 22, T _R is the driving torque of the right driving wheel 22 , the T _L driving torque of the left driving wheel 22, the T _S is the driving torque of the pivot shaft.

  FIG. 6 is a diagram illustrating a relationship between the moving direction of the carriage unit and the operation force. In FIG. 6, the solid line S indicates the magnitude of the operating force, and the carriage unit 2 outputs a larger operating force in the direction with the larger radius. As shown in FIG. 6, the cart unit 2 can output the maximum operating force in the Y direction in the state of the initial position (1). However, when the carriage unit 2 simply changes direction from the initial position (1) as shown in (2) and (3) and moves to the gripping position (4) in the X direction, the gripping position (4) In this state, the maximum operating force can be output in the X direction, but only a small operating force can be output in the required Y direction.

  For this reason, in the conventional omnidirectional mobile robot, depending on the direction of the carriage unit at the gripping position, the operation force is insufficient, and it becomes difficult to move the object, and there is a possibility that the movement of the object may fail.

  In contrast, the route planning apparatus 10 according to the present embodiment, for example, as shown in FIG. 7, at the gripping position P1, the line L1 passing through the axles of the pair of drive wheels 22 of the carriage unit 2, the gripping position P1, and the target The movement path is planned so that the line L2 passing through the position P2 is vertical. Thereby, the cart unit 2 can output the maximum operating force to the object when moving from the gripping position P1 to the target position P2. Therefore, the failure at the time of moving a target object can be reduced. In FIG. 7, the target position P <b> 2 is set on the rear side of the carriage unit 2, but is not limited thereto, and may be set on the front side.

  For example, as shown in FIG. 8, it is assumed that the carriage unit 2 faces the Y direction at the initial position P0. Then, the carriage unit 2 moves from the initial position P0 in the X direction to the gripping position P1, the arm unit 11 grips the object at the gripping position P1, and the carriage unit 2 moves the object from the gripping position P1. It is assumed that the object is moved in the Y direction by moving to the target position P2 corresponding to the position.

  In this case, for example, the path planning device 10 considers the condition that the shortest distance from the initial position P0 to the gripping position P1 and the obstacle between the initial position P0 and the gripping position P1 are avoided, and the final point Is calculated such that the line L1 passing through the axle of the pair of drive wheels 22 of the carriage unit 2 and the line L2 passing through the gripping position P1 and the target position P2 are perpendicular to each other. .

  As shown in FIG. 8, for example, the route planning unit moves the route so that the carriage unit 2 turns slightly outward in the vicinity of the gripping position P1 and is directed in the direction of the line L2 passing through the gripping position P1 and the target position P2. Is calculated. Further, as shown in FIG. 9, the route planning unit first moves to the vicinity of the gripping position P1, then moves away from the gripping position P1 in the direction of the line L2 passing through the gripping position P1 and the target position P2, and again. The movement path may be calculated so as to return to the gripping position P1. In addition, the movement path | route mentioned above is an example, and is not limited to this.

  FIG. 10 is a flowchart showing an exemplary flow of the route planning method according to the present embodiment.

  The path planning device 10 determines whether or not the movement position of the object is determined and the gripping position P1 and the target position P2 are set (step S101). When the path planning device 10 determines that the gripping position P1 and the target position P2 are not set (NO in step S101), the shortest distance from the initial position P0 to the gripping position P1 and the initial position P0 and the gripping position P1. A movement route that avoids the obstacle in the meantime is calculated (step 102), and this process is terminated.

  On the other hand, when the path planning device 10 determines that the gripping position P1 and the target position P2 are set (YES in step S101), the extension of the line L2 passing through the gripping position P1 and the target position P2 as shown in FIG. A temporary gripping position P3 and a temporary gripping region S centered on the temporary gripping position P3 are set on the line (step S103).

  The path planning device 10 calculates the shortest distance from the initial position P0 to the temporary gripping position P3 and the movement path R1 that avoids an obstacle between the initial position P0 and the temporary gripping position P3 (step S104).

  The path planning device 10 uses, for example, a spline interpolation method or the like to calculate an interpolation path R2 that smoothly connects the intersection point P4 where the calculated movement path R1 and the boundary line of the temporary gripping area S intersect with the gripping position P1. Calculate (step S105). The path planning device 10 uses the movement path R1 from the calculated initial position P0 to the intersection point P4 and the interpolation path R2 from the calculated intersection point P4 to the gripping position P1 as a final omnidirectional mobile robot 1. Is calculated as a movement route (step S106).

  As described above, in the gripping position, the route planning device 10 according to the present embodiment is configured such that a line passing through the axle of the pair of drive wheels 22 of the carriage unit 2 and a line passing through the gripping position and the target position are vertical. Plan travel routes. Thereby, when the trolley | bogie part 2 moves to a target position from a holding position, it can output the largest operating force with respect to a target object. Therefore, the failure at the time of moving a target object can be reduced.

Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.
For example, in the above-described embodiment, the path planning device 10 has the line L1 passing through the axle of the pair of drive wheels 22 of the carriage unit 2 and the line passing the gripping position P1 and the target position P2 at the gripping position P1 as described above. The movement route is planned so that L2 is vertical. Furthermore, the route planning device 10 may plan the movement route so that the hand position of the arm unit 11 approaches within a predetermined distance from the object at the gripping position P1.

  Furthermore, the control device 9 causes the center of gravity position of the omnidirectional mobile robot 1 to be lower at the gripping position P1 when the carriage unit 2 moves to the gripping position P1 according to the movement route planned by the route planning device 10. Further, the wheel actuator 7, the turning actuator 8, and the joint actuator 14 may be controlled. Thus, after the carriage unit 2 moves to the gripping position, the omnidirectional mobile robot 1 can be stabilized even when force is applied to the omnidirectional mobile robot 1 when the arm unit 11 grips and moves the object. it can.

  DESCRIPTION OF SYMBOLS 1 Omni-directional mobile robot, 2 trolley | bogie part, 3 main-body part, 4 rotation axis, 5 rotation sensor, 6 rotation sensor, 7 wheel actuator, 8 rotation actuator, 9 control apparatus, 10 path planning apparatus, 11 arm part, 12 joint, 13 rotation sensor, 14 joint actuator, 21 auxiliary wheel, 22 driving wheel

Claims (1)

A carriage unit provided with a pair of drive wheels and movable in all directions; and an arm unit for gripping an object, and a main body unit rotatably provided on the carriage unit, the carriage unit being an initial stage Moving from a position to a gripping position, the arm unit grips the object at the gripping position, and the carriage unit moves from the gripping position to a target position corresponding to a moving position for moving the object, A path planning device for planning a moving path of an omnidirectional mobile robot that moves the object,
The movement path from the initial position to the gripping position, and at the gripping position, a line passing through an axle of a pair of drive wheels of the carriage unit and a line passing through the gripping position and the target position are Planning the travel path to be vertical,
A path planning device characterized by that.

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