JPH04250990A - Control method for movable working vehicle - Google Patents

Abstract

PURPOSE:To offer a control method by which the position of an object to be worked viewed from a movable working vehicle can be accurately grasped and the work using the working device can be performed smoothly and accurately, even when the movable working vehicle is stopped deviated from a prescribed position to be stopped for working, or the stopping posture is deviated from a prescribed posture to be. CONSTITUTION:In this invention, when the main body 1 of a movable working vehicle is stopped, a position deviated quantity between the prescribed position to be stopped and actual stopping position, and a posture deviated quantity between the prescribed posture to be and actual stopping posture, are calculated from the detected result of a magnetic sensor 61 for induction and a magnetic sensor 62 for stop, based on the calculated result the position of a work 14 on absolute coordinates (x, y) is converted onto the working coordinates (xr, yr) of the movable working vehicle, and working is performed based on the position A (xA, yA) on the working coordinates.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling a mobile work vehicle that moves along a travel route and performs various tasks on an object.

0002

[Background Art] In recent years, automation has progressed in various fields.
Mobile work vehicles such as the one proposed in Japanese Patent Application No. 2-14210 by the applicant of the present invention are beginning to be used. This thing is
It is equipped with a movement mechanism driven by a motor and a working device consisting of an articulated robot, which moves on a movement path and performs tasks such as grasping and moving objects placed there.

By the way, a working device such as an articulated robot cannot perform the work smoothly and accurately unless it is accurately positioned with respect to the workpiece. Regarding such positioning, research is being conducted on adding sensing functions such as proximity sense, tactile sense, and pressure sense to the hand part of an articulated robot to sense the position of the work object and perform the work smoothly (Japanese Patent Application Laid-Open No. 2-185385). However, when a sensing function is provided to the hand portion of a robot, the configuration of the hand portion becomes complicated, large-sized, and expensive.

0004

[Problems to be Solved by the Invention] The present invention solves problems in which a mobile work vehicle stops at a position deviated from a predetermined position to perform work, or when the stopped posture deviates from a predetermined position in which it should be stopped. Even in such cases, the position of the workpiece as seen from the mobile work vehicle can be accurately grasped, and work using the work equipment can therefore be carried out smoothly and accurately.Moreover, it is simple in configuration and inexpensive to move. The present invention provides a method for controlling a work vehicle.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides the amount of positional deviation between the predetermined position and the actual stopping position and the posture between the predetermined position and the actual stopping position based on the detection results of the sensor. The amount of deviation is calculated, and based on the calculation result, the position of the work object on the absolute coordinates is converted to the work coordinates of the mobile work vehicle, and work is performed based on the work coordinates.

[0006]

[Operation] When the mobile work vehicle stops, the control device of the mobile work vehicle determines the amount of positional deviation between the predetermined stop position and the actual stop position, the predetermined posture to be taken, and the actual stop position based on the sensor detection results. Calculate the amount of posture deviation from the stopped posture. Then, based on the calculation result, the position of the work object on the absolute coordinates is converted to the work coordinates of the mobile work vehicle, and the work is performed based on the work coordinates.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show an embodiment of the invention. 1 is the main body of the mobile work vehicle, 2 is an articulated robot as a working device provided on the upper part of the main body 1, 3 is a drive device for movement provided in the main body 1, and 4 is driven by the drive device 3. It is the driving wheel. 5 is a rotary encoder that is attached coaxially with the drive wheel 4 and detects its rotation amount, 6 is a magnetic sensor provided on the bottom surface of the main body, and 7 is an articulated robot that refers to information from the magnetic sensor 6 and rotary encoder 5. 2
and a control device that controls the drive device 3.

Reference numeral 11 denotes a magnetic tape for guiding provided on the floor which is the movement route; 12 a magnetic tape for stopping also provided at a stop position on the floor; 13 a table placed on the floor; 14 is a workpiece placed on the table 13 as an object to be worked on.

The magnetic sensor 6 has a magnetic tape 11 for guidance.
A pair of guiding magnetic sensors 61 detect the positional relationship with the magnetic tape 12, and a stopping magnetic sensor 62 detects the positional relationship with the stopping magnetic tape 12.

[0010] Here, absolute coordinates (x, y) that do not change are determined on the floor surface, and the workpiece 14 is placed at a predetermined position A (xa, ya) on the table 13.

On the other hand, near the main body 1 of the mobile work vehicle,
The work coordinates (xr, yr) are determined with the center Or as the center and the direction of movement as xr.

When this mobile work vehicle uses the articulated robot 2 to grasp and transport the workpiece 14, the control when performing the action of grasping the workpiece 14 will be described below. In the following explanation, it is assumed that the predetermined position where the main body 1 is scheduled to perform such an operation is the origin O of the absolute coordinates (x, y), and the predetermined posture that the main body 1 should take at that time is based on the work coordinates (xr, yr). The posture is made to match the absolute coordinates (x, y).

FIG. 1 shows a state in which the main body 1 of the mobile work vehicle is moving toward the origin O(0,0), which is a predetermined position, in order to perform work. In the state shown in FIG. 1, the guiding magnetic sensor 61 is not detecting the guiding magnetic tape 11.
Therefore, it is impossible to calculate the position based on the information from the guiding magnetic sensor 61. At this time, the control device 7 calculates the position on the absolute coordinates by calculating the rotation speed of the drive wheel 4 detected by the rotary encoder 5 and the coordinates of the starting position, and controls the drive device 3 to move toward the target position. do.

When the main body 1 approaches the target position, the guiding magnetic sensor 61 detects the positional relationship with the guiding magnetic tape 11, and the control device 7 uses the detection result to determine the absolute coordinates of the main body 1. Recognize position and posture. and,
Thereafter, the drive device 3 is controlled to move toward the target position based on the detection result of the guidance magnetic sensor 61.

When the main body 1 approaches the target position, the stop magnetic sensor 62 detects the positional relationship with the stop magnetic tape 12, and the control device 7 uses the detection result to determine the absolute coordinates of the main body 1. Recognize the position and posture of Then, the robot is controlled so as to further approach a predetermined position, which is a target, and to take a predetermined posture.

However, normally, the drive device 3 and the control device 7
There is a limit to the ability to control minute quantities, and it is difficult to make the actual stopping position and stopping posture of the mobile work vehicle main body 1 completely match the target predetermined position and predetermined posture. Furthermore, even if it is technically possible, it is not practical in terms of cost.

FIG. 4 schematically shows a state in which the actual stopped position and stopped posture of the mobile work vehicle main body 1 deviate from the target predetermined position and predetermined posture. Now, in the stopped state as described above, the control device 7 of the present invention calculates the amount of positional deviation between the predetermined position that is the target position and the actual stopping position, and the attitude deviation between the predetermined posture that is the target posture and the actual stopping posture. The amount is calculated from the detection results of the guiding magnetic sensor 61 and the stopping magnetic sensor 62. In order to perform an operation of grasping the workpiece 14, the position of the workpiece 14 on the absolute coordinates is converted to the work coordinates of the mobile work vehicle based on the calculation result, and the work is performed based on the work coordinates. In the state shown in FIG. 4, the actual stop position Or is separated from the predetermined position O by (Δx, Δy) and is tilted clockwise by Δθ. In this case, the working coordinates (xr, y
The position A (xA, yA) of the workpiece 14 on r) is calculated by the following equation.

xA=cosΔθ・(xa−Δx)+sinΔθ・
(ya-Δy)yA=-sinΔθ・(xa-Δx)+
In this way, the cosΔθ・(ya−Δy) control device 7 adjusts the position A of the workpiece 14 on the work coordinates (xr, yr).
By calculating (xA, yA), the position where the workpiece 14 is placed as viewed from the mobile work vehicle body 1 can be recognized. The multi-joint robot 2 is then controlled based on the work coordinates to perform operations such as grasping the workpiece 14.

[0019]

As described above, in this invention, when a mobile work vehicle stops, the amount of positional deviation between the predetermined position at which it should stop and the actual stop position, the predetermined posture it should take, and the actual position are determined based on the sensor detection results. Calculate the amount of posture deviation from the stopped posture of
Based on the calculation results, the position of the work object on the absolute coordinates is converted to the work coordinates of the mobile work vehicle, and work is performed based on the work coordinates. Therefore, the mobile work vehicle may deviate from the predetermined stop position for performing work, or stop.
Even if the stopped posture deviates from the predetermined posture that the workpiece should be in, the position of the workpiece as seen from the mobile work vehicle can be accurately grasped, and the work using the work equipment can therefore be carried out smoothly. And it can be done accurately. Furthermore, the configuration is simple and inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a side view showing the mobile work vehicle.

FIG. 3 is a block diagram showing a control circuit.

FIG. 4 is a schematic diagram showing an example of conversion between absolute coordinates and work coordinates.

[Explanation of symbols]

1 Main body 2 Articulated robot 7 Control device 14 Work 61 Induction magnetic sensor 62 Magnetic sensor for stopping

Claims (1)

[Claims] Claim 1: The robot moves while recognizing the position and orientation by detecting the positional relationship with the position index provided on the movement path on absolute coordinates using a sensor, stops at a predetermined position with a predetermined orientation, and moves toward the workpiece. On the other hand, in a mobile work vehicle that performs work using a work device, the amount of positional deviation between the predetermined position and the actual stopping position and the amount of posture deviation between the predetermined posture and the actual stopping posture are calculated from the detection results of the sensor, A method for controlling a mobile work vehicle, characterized in that the position of the work object on absolute coordinates is converted to work coordinates of the mobile work vehicle based on the result, and work is performed based on the work coordinates.