VERSATILE ROBOT CONTROL SYSTEM

• US 20020087232A1
• Filed: 12/28/2000
• Published: 07/04/2002
• Est. Priority Date: 12/28/2000
• Status: Active Grant

• Current Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Original Assignee: Robotic Workspace Technologies, Inc.
• Inventors: Lapham, John R.
• Granted Patent: US 6,442,451 B1
• Time in Patent Office: Days
• US Class Current: 700/245
• CPC Class Codes: A61B 1/00158 using magnetic field
• CPC Class Codes: A61B 1/0055 Constructional details of insertion parts, e.g. vertebral elements
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: A61B 1/31 for the rectum, e.g. proctoscopes, sigmoidoscopes , colonoscopes
• CPC Class Codes: B25J 9/161 Hardware, e.g. neural networks, fuzzy logic, interfaces, processor
• CPC Class Codes: B25J 9/1656 characterised by programming, planning systems for manipulators
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05B 2219/33242 Watchdog for datacommunication, on error switch off supply to bus modules
• CPC Class Codes: G05B 2219/34047 Dsp digital signal processor
• CPC Class Codes: G05B 2219/34261 Windows, microsoft windows
• CPC Class Codes: G05B 2219/39001 Robot, manipulator control
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: Y10S 901/41 Tool
• CPC Class Codes: Y10S 901/42 Welding
• CPC Class Codes: Y10S 901/46 Sensing device
• CPC Class Codes: Y10S 901/47 Optical
• CPC Class Codes: Y10S 901/48 Counterbalance

Abstract

An improved, versatile robot control system comprises a general purpose computer with a general purpose operating system in electronic communication with a real-time computer subsystem. The general purpose computer includes a program execution module to selectively start and stop processing of a program of robot instructions and to generate a plurality of robot move commands. The real-time computer subsystem includes a move command data buffer for storing the plurality of move commands, a robot move module linked to the data buffer for sequentially processing the moves and calculating a required position for a robot mechanical joint. The real-time computer subsystem also includes a dynamic control algorithm in software communication with the move module to repeatedly calculate a required actuator activation signal from a robot joint position feedback signal.

Claims

1. A control system for processing a program of robot instructions for robots having a mechanical joint, a mechanical actuator to move the joint and a position feedback sensor, the mechanical actuator being adapted to receive an activation signal and the feedback sensor providing a position signal, the control system comprising:

a general purpose computer with a general purpose operating system, said general purpose computer including a program execution module to selectively start and stop processing of the program of robot instructions and to generate a plurality of robot move commands; and

a real-time computer subsystem in electronic communication with said general purpose computer and operably linked to the mechanical actuator and the position feedback sensor, a move command data buffer for storing said plurality of move commands, a robot move module linked to said data buffer to sequentially process said plurality of move commands and calculate a required position for the mechanical joint, and a control algorithm in software communication with said robot move module to repeatedly calculate a required activation signal from the feedback signal and said required position for the mechanical joint.

2. The control system according to claim 1 further comprising a watchdog intercommunication between said real-time computer subsystem and said general purpose computer for detecting faults in operation of said general purpose computer.

3. The control system according to claim 2 wherein said watchdog intercommunication includes:

a timer variable for storing an elapsed time indication;

a timer code segment for adjusting said timer variable according to passing time;

an activity software switch having an active position and an unset position;

a status code segment installed in said general purpose computer for repeatedly setting said activity software switch to said active position;

a timer reset code segment installed in said real-time computer subsystem for repeatedly resetting said timer variable to a predetermined amount of time when said activity software switch is in said active position and repeatedly setting said activity software switch to said unset position; and

a fail safe code segment installed in said real-time computer subsystem for repeatedly inspecting said timer variable and setting said activation signal to shut down the robot if said timer variable reaches a predetermined value.

4. The control system according to claim 3 wherein said activity software switch is implemented as an integer software variable with said unset position being represented by zero and said active position being represented by one.

5. The control system according to claim 1 further comprising a data bus for receiving bus cards and wherein said real-time computer subsystem includes a bus card with a central processing unit, said bus card being installed in said data bus.

6. The control system according to claim 1 wherein said general-purpose computer and said real-time computer subsystem are electronically linked via a standard data bus.

7. The control system according to claim 1 wherein said general-purpose computer and said real-time computer subsystem are electronically linked via an ISA data bus.

8. The control system according to claim 1 further comprising a data bus for receiving bus cards and wherein said real-time computer subsystem includes a first bus card with a central processing unit and said general purpose computer includes a second bus card with a central processing unit, both said first and said second bus cards being installed in said data bus.

9. The control system according to claim 1 wherein said real-time computer subsystem includes a digital signal processor (DSP) based computer.

10. The control system according to claim 1 wherein said general purpose computer is an Intel Pentium®

processor based computer.

11. The control system according to claim 1 wherein said general purpose computer is a DEC/Compaq Alpha®

processor based computer.

12. The control system according to claim 1 wherein said general purpose operating system is a not tied to real-time.

13. The control system according to claim 1 wherein said general purpose operating system is a member of the group consisting of a Windows-NT®

, a Windows 2000®

, a Windows 95®

, a Windows 98®

, an Open VMS®

, a PC/MS DOS, and a Unix.

14. The control system according to claim 1 wherein said general purpose computer is an Intel Pentium®

processor based computer and said general purpose operating system is a Microsoft Windows NT®

.

15. The control system according to claim 1 wherein the mechanical actuator is a servo motor and said control algorithm is a servo control algorithm.

16. The control system according to claim 1 wherein said robot move module includes a kinematics model for calculating a required joint position in response to a move command.

18. The control system according to claim 17 wherein said general-purpose computer and said real-time computer subsystem are electronically linked via a standard data bus.

19. The control system according to claim 17 wherein said first digital processors runs an operator interface module including:

a configuration variable for storing data specifying the electromechanical configuration of the robot;

a first code segment for generating a first operator display according to a first electromechanical configuration;

a second code segment for generating a second operator display according to a second electromechanical configuration; and

a third code segment for selecting said first or second code segment according to said electromechanical configuration.

20. The control system according to claim 19 wherein said first code segment generates an operator display requesting operating limits for a revolute joint.

21. The control system according to claim 19 wherein said second code segment generates an operator display requesting operating limits for a linear joint.

22. The control system of claim 19 wherein said configuration variable is defined to store data specifying a robot joint type.

23. The control system of claim 19 wherein said configuration variable is defined to store data specifying a linear joint type.

24. The control system of claim 19 wherein said configuration variable is defined to store data specifying a revolute joint type.

25. The control system of claim 19 wherein said configuration variable is defined to store data specifying whether a robot joint is windable.

27. The operator interface according to claim 26 wherein said first code segment generates an operator display requesting operating limits for a revolute joint.

28. The operator interface according to claim 26 wherein said second code segment generates an operator display requesting operating limits for a linear joint.

29. The operator interface module of claim 26 wherein said configuration variable is defined to store data specifying a robot joint type.

30. The operator interface module of claim 26 wherein said configuration variable is defined to store data specifying a linear joint type.

31. The operator interface module of claim 26 wherein said configuration variable is configured to store data specifying a revolute joint type.

32. The operator interface module of claim 26 wherein said configuration variable is defined to store data specifying whether a robot joint is windable.

17. A versatile robot control system suitable for controlling robots of different electromechanical configurations, the control system comprising:

a robot-independent computer unit including a video display and a first digital processor running an operator interface module for creating a sequence of robot move commands; and

a robot-specific controller unit operably linked to the robot and including a second digital processor running a real-time tied operating system and a robot move module for executing said robot move commands, said robot specific controller unit being in electronic communication with said robot independent computer unit.

26. An operator interface module for controlling robots of different electromechanical configurations, the operator interface module comprising:

a first code segment for generating a first operator display according to a first electromechanical configuration;

a second code segment for generating a second operator display according to a second electromechanical configuration; and

a third segment for selecting said first or second code segment according to said electromechanical configuration.