Method and apparatus for analyzing the feasibility of performing a programmed sequence of motions with a robot

• US 4,360,886 A
• Filed: 10/27/1980
• Issued: 11/23/1982
• Est. Priority Date: 04/04/1980
• Status: Expired due to Term

• Current Assignee: Nordson Corporation
• Original Assignee: Nordson Corporation
• Inventors: Crum, Gerald W., Kostas, Evans, Walker, Jerome F.
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US06/201,221
• Time in Patent Office: 757 Days
• Field of Search: 364/578, 364/513, 364/174, 364/190, 364/193, 318/565, 318/568
• US Class Current: 700/264
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02
• CPC Class Codes: B25J 9/0081 with master teach-in means
• CPC Class Codes: G05B 19/427 Teaching successive positions by tracking the position of a joystick or handle to control the positioning servo of the tool head, master-slave control G05B19/423 takes precedence
• CPC Class Codes: G05B 2219/42309 Excess in speed

Abstract

An apparatus and method for determining the feasibility of performing a programmed sequence of motions with a robot. Included is a work robot at a first location having a plurality of power-driven, signal-controlled, relatively massive links interconnected to permit relative motion in plural degrees of freedom, the work robot having a given mechanical response characteristic. Associated with each link of the work robot is a position transducer which generates a signal representative of the actual position of its associated work robot link. Also included is a portable, relatively lightweight, manually manipulable simulator robot located remote from the work robot. The simulator robot has a plurality of different interconnected links adapted for manual movement in different degrees of freedom for setting a program of desired mechanical responses, with the links and degrees of freedom of the simulator robot simulating those of the work robot. Associated with each link of the simulator robot is a position transducer for generating a signal representative of the position of its associated simulator robot link. A signal recorder is provided at the location of the simulator robot for storing the position signals representative of the program of desired mechanical responses imparted to it by the operator. A work robot controller is provided at the site of the work robot which is responsive to the stored position signals for manipulating the work robot links to perform the movements corresponding to the program of desired mechanical responses limited only by the given mechanical response characteristic of the work robot. An analyzer responsive to the actual and desired position signals of the work robot links is provided for generating error signals correlated to the extent to which the work robot is capable of performing the program of desired mechanical responses manually imparted to the simulator robot. An indicator responsive to the analyzer provides a humanly perceptible indication of the feasibility.

Claims

1. Automation feasibility analyzing apparatus for analyzing the feasibility of performing a sequence of motions with a work robot, comprising:

a work robot at a first location having a plurality of power-driven, signal-controlled links interconnected to permit relative motion therebetween to define plural degrees of freedom, at least some of said links being relatively massive, said work robot having a given mechanical response characteristic for positioning said links in response to position signals input to each link at a rate of N signals per link per second;

a plurality of work robot link position transducers, a different work robot link position transducer being associated with each of said work robot links for generating an actual position signal representative of the actual position of the associated work robot link;

a portable, relatively lightweight, manually manipulable simulator robot at a second location remote from said first location, said simulator robot having a plurality of interconnected links adapted the manual movement in different degrees of freedom for setting a program of desired mechanical responses, said links and degrees of freedom of said simulator robot simulating those of said work robot;

a plurality of simulator robot link position transducers, a different simulator robot link position transducer being associated with each of said simulator robot links for generating a signal representative of the position of its associated simulator robot link;

signal recording means at said second location responsive to said simulator robot link position transducers for storing the signals generated thereby representative of a program of desired mechanical responses;

work robot control means at said first location responsive to said stored position signals generated by said plurality of simulator robot link position transducers for manipulating the work robot links for performing movements corresponding to the program of desired mechanical responses limited only by said given mechanical response characteristic of said work robot;

analyzer means responsive to (a) said actual position signals generated by said plurality of work robot link position transducers when said work robot control means is input with stored position signals and (b) said stored position signals generated by said simulator robot transducers, for generating error signals correlated to the extent to which said work robot is capable of performing the program of desired mechanical responses manually imparted to said simulator robot; and

indicating means responsive to said error signals for providing a humanly perceptible indication of the feasibility of said work robot for performing the program of desired mechanical responses imparted to said simulator robot.

2. The apparatus of claim 1 wherein said analyzer means generates error signals correlated to the difference between the actual position of said work robot links and the desired position imparted to said simulator robot links as recorded on said recorder, and wherein said indicating means displays information correlated to said positional differences between said actual and desired work robot link positions.

3. The apparatus of claim 2 further including:

a switch element associated with said simulator robot manually operable between OFF and ON conditions of a utilization device movable by said work robot;

means to monitor the condition of said switch element and provide switch condition signals correlated to the condition thereof when said simulator robot is manipulated to different positions;

said signal recording means storing said switch condition signals in conjunction with said simulator robot link position transducer output signals; and

wherein said indicating means is responsive to said signal recording means for displaying the monitored condition of said switch element in association with said displayed information correlated to said positional difference between said actual and desired work robot positions, whereby the feasibility of said work robot for performing said program of desired mechanical responses is analyzed in dependence upon the condition of said switch element.

4. The apparatus of claim 2 wherein said analyzer means generates error signals correlated to the difference between the actual velocity of said work robot links and the desired velocity imparted to said simulator robot links, and wherein said indicating means displays information correlated to said velocity differences between said actual and desired work robot link velocities, said velocity difference information and positional difference information being displayed in association with each other.

5. The apparatus of claim 4 further including:

a switch element associated with said simulator robot manually operable between OFF and ON conditions of a utilization device movable by said work robot;

means to monitor the condition of said switch element and provide switch condition signals correlated to the condition thereof when said simulator robot is manipulated to different positions;

said signal recording means storing said switch condition signals in conjunction with said simulator robot link position transducer output signals; and

wherein said indicating means is responsive to said signal recording means for displaying said switch condition in association with said displayed information correlated to said positional and velocity differences.

6. The apparatus of claim 1 wherein said analyzer means generates error signals correlated to the difference between the actual velocity of said work robot links and the desired velocity imparted to said simulator robot links, and wherein said indicating means displays information correlated to said velocity differences between said actual and desired work robot link velocities.

7. The apparatus of claim 1 wherein said stored position signals are input to said recorder at a rate of at least N signals per link per second, and said actual position signals are generated at a rate of N signals per link per second, and said work robot control means is input with said stored position signals at a rate of N/M signals per link per second, where N,M is greater than 1, said work robot control means including an interpolator for providing interpolated position signals between said stored position signals input to said control means for controlling said work robot with a combination of stored and interpolated position signals.

8. A method of analyzing at a first location the feasibility of performing a sequence of motions with a work robot having a given mechanical response characteristic located at a second location remote from first location, which work robot has a plurality of different, power-driven, signal-controlled links interconnected to permit relative motion therebetween to define plural degrees of freedom, at least some of said links being relatively massive, said method comprising the steps of:

manually manipulating at the second location a portable, relatively lightweight, simulator robot having links and degrees of freedom simulating those of the work robot, for setting a program of desired mechanical responses;

generating plural signals per link per second with position transducers associated with the simulator robot links representative of the position of the simulator robot links during setting of the program of desired mechanical responses;

storing in a recorder the position signals generated during manipulation of the simulator robot to thereby store the program of desired mechanical responses;

driving the work robot at the second location with the recorded position signals for performing work robot link movements corresponding to the program of desired mechanical responses limited only by the mechanical response characteristics of the work robot;

generating from position transducers associated with the work robot links actual position signals representative of the actual position of the work robot links while driving the work robot with the recorded position signals representative of the program of desired mechanical responses;

deriving from said actual position signals and said recorded simulator robot position signals, error signals correlated to the extent to which the work robot is capable of performing the program of desired mechanical responses manually imparted to the simulator robot; and

deriving, in response to the error signals, a humanly perceptible indication of the feasibility of the work robot for performing the program of desired mechanical responses imparted to the simulator robot.

9. The method of claim 8 wherein:

said error derivation step includes generating error signals correlated to the difference between the actual position of the work robot links and the desired position imparted to the simulator robot links as recorded in the recorder; and

said indicating step includes displaying information correlated to the positional differences between the actual and desired work robot link positions.

10. The method of claim 9 further including the steps of:

monitoring and storing in conjunction with the simulator robot position signals the condition of a switch element associated with the simulator robot, which switch element is operable between OFF and ON conditions of a utilization device movable by the work robot, when the simulator robot is manipulated to different positions; and

displaying the condition of the switch element in association with the displayed positional differences of the simulator and work robot links, to facilitate analysis of the feasibility of the work robot for performing the program of desired mechanical responses in dependence upon the condition of the switch element.

11. The method of claim 10 wherein:

said error derivation step includes generating signals correlated to the difference between the actual velocity of the work robot links and the desired velocity imparted to the simulator robot links; and

said indicating step includes displaying information correlated to the velocity differences between the actual and desired work robot link velocities in association with the positional differences between desired and actual work robot link velocities.

12. The method of claim 9 wherein:

said error derivation step includes generating signals correlated to the difference between the actual velocity of the work robot links and the desired velocity imparted to the simulator robot links; and

said indicating step includes displaying information correlated to the velocity differences between the actual and desired work robot link velocities in association with the positional differences between desired and actual work robot link velocities.

13. The method of claim 8 further including the steps of:

monitoring and storing in conjunction with the simulator robot position signals the condition of a switch element associated with the simulator robot, which switch element is operable between OFF and ON conditions of a utilization device movable by the work robot, when the simulator robot is manipulated to different positions;

said error derivation step includes generating signals correlated to the difference between the actual velocity of the work robot links and the desired velocity imparted to the simulator robot links;

displaying information correlated to the velocity differences between the actual and desired work robot link velocities; and

displaying the condition of the switch element in association with the displayed information correlated to said velocity differences.

14. The method of claim 8 wherein said driving step includes utilizing N/M stored position signals per link per second, where N,M is greater than 1, and generating interpolated position signals between said stored position signals for controlling said work robot with a combination of stored and interpolated position signals.