Functioning-distributed robot control system

• US 4,833,624 A
• Filed: 03/17/1988
• Issued: 05/23/1989
• Est. Priority Date: 04/02/1986
• Status: Expired due to Fees

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Matsumoto, Takaharu, Kuwahara, Hajime, Ono, Yutaka
• Primary Examiner(s): MacDonald, Allen
• Application Number:
  US07/170,049
• Time in Patent Office: 432 Days
• Field of Search: 364/513, 364/131, 364/132, 364/133, 364/135, 364/138, 364/139, 364/474, 364/478, 901/9, 901/10, 901/46, 901/47, 901/15, 318/568
• US Class Current: 700/249
• CPC Class Codes: G05B 19/4148 characterised by using several processors for different functions, distributed (real-time) systems G05B19/4141 takes precedence
• CPC Class Codes: G05B 2219/33162 Two bus, high speed and low speed bus, linked or not

Abstract

A robot system comprising a main computer having a robot language incorporated therein and having the functions of preparing, executing and storing programs and a plurality of slave computers connected via a high speed data bus to the main computer. Task programs are prepared by using the robot language and then executed on the main computer. The task programs inherent to the respective functions, such as trajectory control for the manipulator, vision control and feature extraction of objects are executed in each of the slave computers by commands issued from the main computer to the respective slave computers for each operational unit.

Claims

1. A distributed robot control system comprising:

(a) a main computer means for (i) preparing a centralized task program, (ii) executing said centralized task program, and (iii) supplying command signals representing said centralized task program;

(b) at least one manipulator control slave computer means for individually, concurrently, and parallelly controlling parts of a manipulator;

(c) at least one vision control slave computer means for individually, concurrently, and parallelly controlling a vision sensor for supplying images;

(d) a high speed system bus, said bus being connected to each computer means;

(e) wherein said at least one manipulator control slave computer means comprises;

a slave controller means for individually calculating trajectory positions of one or more arms of said manipulator and desired angle positions of one or more joints of said manipulator from the control signals;

a plurality of position controller means for controlling the arm and joint positions of said manipulator in accordance with the trajectory and angle positions calculated by said slave controller means; and

a local command and data bus connected to said slave controller means and said plurality of position controller means; and

(f) wherein said at least one vision control slave computer means comprises;

a slave vision controller means for (i) receiving said command signals and (ii) producing control signals based on said command signals;

an image processing controller means for (i) receiving said control signals, (ii) processing images from said vision sensor, and (iii) recognizing a target in the images in accordance with said control signals; and

a data bus connected to said slave vision controller means and said image processing controller means.

2. The system of claim 1, wherein said main computer comprises means for automatically converting data between each of a plurality of coordinate systems based on an offset of an inherent coordinate system for said manipulator and an offset of an inherent coordinate system for said vision sensor, relative to a world coordinate system.

3. The system of claim 1, further comprising

a servo means for (i) determining the value of the actual angle and trajectory positions of said manipulator and (ii) transmitting the determined values to said plurality of position controller means.

4. The system of claim 3, wherein the servo means comprises:

a magnetic inductor type synchronous motor for driving said manipulator based on a signal from one of said plurality of position controller means, said motor having an outer rotor; and

an optical resolver means for (i) detecting a rotational displacement of said outer rotor, (ii) generating a positional signal from said detected rotational displacement, and (iii) supplying the generated signal to said one of said plurality of position controller means.

5. The system of claim 1, further comprising

a slave monitor computer means, connected to said high speed system bus, for monitoring respective operational states of said main computer means.

6. The system of claim 1, wherein said image processing controller means comprises:

means for digitizing one of said images supplied by said vision sensor into digital values forming a binary image formed by pixels, said one image being an object;

means for compressing the digitized values using a runlength code with X, Y addresses of each left end pixel and the number of horizontally connected pixels of said one image;

means for counting the number of pixels; and

means for calculating the X,Y coordinates of the center of gravity of said object based on said compressing and counting.

7. The system of claim 1, wherein said manipulator control slave computer comprises a plurality of position controllers of a number equal to the number of joints to be controlled in said manipulator, a manual controller for controlling manual operation, and an input/output controller connected to a force sensor and a tactile sensor, said plurality of position controllers and said input/output controller being connected to said local command and data bus.

8. The system of claim 7, further comprising a magnetic inductor type synchronous motor driving a rotor, said optical resolver being connected to said rotor, means for connecting said optical resolver to said plurality of position controllers, and servo amplifier connected to said motor and to said plurality of position controllers so that position feedback signals representing angle of rotation of said optical resolver is applied to said plurality of position controllers.

9. The system of claim 4, wherein said optical resolver comprises a slit plate, means on one side of said slit plate for applying light to said slit plate, a photodiode array on the other side of said slit plate for receiving light from said means for applying light passed through slits formed in said slit plate, and a self running type spatial filter connected to said photodiode array and comprising a plurality of analog switches.