Industrial robot with servo

• US 4,973,215 A
• Filed: 02/14/1989
• Issued: 11/27/1990
• Est. Priority Date: 02/18/1986
• Status: Expired due to Term

• Current Assignee: Robotic Research LLC
• Original Assignee: Robotic Research LLC
• Inventors: Eismann, Paul H., Karlen, James P., Damico, David A., Thompson, Jack M. Jr., Kowalski, Keith A.
• Primary Examiner(s): Bucci, David A.
• Assistant Examiner(s): Underwood, Donald W.
• Application Number:
  US07/310,511
• Time in Patent Office: 651 Days
• Field of Search: 414/729, 414/730, 414/732, 414/735, 901/14, 901/15, 901/23, 901/24, 901/27, 901/28, 74/479
• US Class Current: 414/729
• CPC Class Codes: B25J 17/02 Wrist joints
• CPC Class Codes: B25J 17/0241 One-dimensional joints
• CPC Class Codes: B25J 9/04 by rotating at least one arm, excluding the head movement itself, e.g. cylindrical coordinate type or polar coordinate type
• CPC Class Codes: B25J 9/046 Revolute coordinate type
• CPC Class Codes: B25J 9/08 characterised by modular constructions
• CPC Class Codes: B25J 9/1025 Harmonic drives in general: F16H49/001
• CPC Class Codes: B25J 9/1633 compliant, force, torque control, e.g. combined with position control
• CPC Class Codes: B25J 9/1643 redundant control
• CPC Class Codes: G05B 2219/41116 Compensation for instability
• CPC Class Codes: G05B 2219/41203 Lead-phase compensation, lag-phase compensation servo
• CPC Class Codes: G05B 2219/42092 Position and force control loop together
• CPC Class Codes: G05B 2219/49292 Harmonic gear, transmission, strain wave gear
• CPC Class Codes: Y10T 74/20207 Multiple controlling elements for single controlled element

Abstract

A digitally controlled industrial robot comprises a set of unitized and integrated joint drive modules which can be assembled in series to form an arm. The joints are of two basic types, pitch joints and roll joints, with the roll joints providing rotation about the longitudinal axis of the manipulator and the pitch joints providing rotation about axes which are substantially perpendicular to and offset from the roll joint axes. Any number of joints may be assembled to comprise the manipulator, permitting the configuration of a kinematically redundant manipulator. A servocontrol derives feedback from sensing the motive force on a driven member and compensates the drive signal accordingly. More particularly, the torque exerted on each roll and pitch joint is measured and used for feedback to provide stability and optimum bandwidth for the servomechanism.

Claims

1. An articulated manipulator comprising:

a plurality of pitch joints and roll joints connected to one another in alternating relationship to define a manipulator arm having proximal and distal end portions;

each said roll joint having a roll joint axis and each said pitch joint having a pitch joint axis;

said arm being positionable such that all of said roll joint axes extend along a substantially common axis;

each said pitch joint axis extending transversely of said common axis and also being spaced transversely from said common axis; and

,

said pitch joint axes being located progressively closer to said common axis proceeding in a direction along said arm toward said distal end.

2. The manipulator of claim 1 including independent drive means for each said joint.

3. The manipulator of claim 1, means for said joints being readily separable from one another.

4. The manipulator of claim 2, wherein at least one of said pitch and roll drive means includes overload clutch means for providing relative slippage between said drive means and its respective joint under overload conditions.

5. The manipulator of claim 2, means for said joints being readily separable from one another.

6. The manipulator of claim 4, means for said joints being readily separable from one another.

7. An articulated manipulator comprising:

a roll joint rotatable about a roll joint axis;

a pitch joint connected to said roll joint and being rotatable about a pitch joint axis;

said pitch and roll joint axes extending transversely of one another and also being transversely spaced from one another such that said pitch and roll joint axes do not intersect one another;

roll joint drive means for rotating said roll joint;

pitch joint drive means for rotating said pitch joint;

said roll and pitch drive means being completely independent of one another and each being selectively operable independently of the other;

wherein each of said pitch and roll joint drive means includes overload clutch means for providing relative slippage between each said drive means and its respective joint under overload conditions.

8. The manipulator of claim 7, means for said joints being readily separable from one another.

9. An articulated manipulator comprising:

a roll joint rotatable about a roll joint axis;

a pitch joint connected to said roll joint and being rotatable about a pitch joint axis;

said pitch and roll joint axes extending transversely of one another and also being transversely spaced from one another such that said pitch and roll joint axes do not intersect one another;

wherein said joints are separably connected by quick release connecting means comprising clamp bands.

10. The manipulator of claim 9 including independent drive means for each said joint.

11. An articulated manipulator comprising:

a roll joint rotatable about a roll joint axis;

a pitch joint connected to said roll joint and being rotatable about a pitch joint axis;

said pitch and roll joint axes extending transversely of one another and also being transversely spaced from one another such that said pitch and roll joint axes do not intersect one anther;

wherein said roll joint has opposite end portions and including a said pitch joint connected to each of said end portions, each said pitch joint having a pitch joint axis extending transversely spaced from said roll joint axis such that said roll joint axis does not intersect either of said pitch joint axes.

12. The manipulator of claim 11 including independent drive means for each said joint.

13. The manipulator of claim 11, means for said joints being readily separable from one another.

14. The manipulator of claim 12, means for said joints being readily separable from one another.

15. The manipulator of claim 12, wherein at least one of said pitch and roll drive means includes overload clutch means for providing relative slippage between said drive means and its respective joint under load conditions.

16. The manipulator of claim 15, means for said joints being readily separable form one another.

17. The manipulator of claim 16 wherein said joints are separably connected by quick release connecting means.

18. An articulated manipulator comprising:

a roll joint rotatable about a roll joint axis;

a pitch joint connected to said roll joint and being rotatable about a pitch joint axis;

said pitch and roll joint axes extending transversely of one another and also being transversely spaced from one another such that said pitch and roll joint axes do not intersect one another;

wherein said roll joint has opposite end portions and including a said pitch joint connected to each of said end portions, each said pitch joint having a pitch joint axis extending transversely of said roll joint axis and also being transversely spaced from said roll joint axis such that said roll joint axis does not intersect either of said pitch joint axes; and

including independent drive means for each said joint, and means for said joints being readily separable from one another.

19. The manipulator of claim 18 wherein at least one of said pitch and roll drive means includes overload clutch means for providing relative slippage between said drive means and its respective joint under overload conditions.

20. The manipulator of claim 18, wherein said pitch and roll joints comprise an arm having proximal and distal end portions and said pitch joint axes are located progressively closer to said common axis proceeding in a direction along said arm toward said distal end.

21. The manipulator of claim 18, said joints being such that a given joint can be structurally and electrically disconnected form said manipulator for servicing or replacement independently of structural and electrical connections to other joints which may be attached a part of said manipulator.

22. The manipulator of claim 20 wherein at least one of said pitch and roll drive means includes overload clutch means for providing relative slippage between said drive means and its respective joint under overload conditions.

23. The manipulator of claim 19 wherein at least one of said joint drive means is substantially concentric with its joint axis.

24. The manipulator of claim 23 wherein each said joint drive means includes a harmonic drive transmission means.

25. An articulated manipulator comprising:

a roll joint rotatable about a roll joint axis;

a pitch joint connected to said roll joint and being rotatable about a pitch joint axis;

said pitch and roll joint axes extending transversely of one another and also being transversely spaced from one another such that said pitch and roll joint axes do not intersect one another;

wherein said roll joint has opposite end portions and including a said pitch joint connected to each of said end portions, each said pitch joint having a pitch joint axis extending transversely of said roll joint axis and also being transversely spaced from said roll joint axis such that said roll joint axis does not intersect either of said pitch joint axes;

including independent drive means for each said joint which includes a motor and a drive assembly, each said joint including a pair of relatively movable parts, each said motor and drive assembly in each said joint being mounted on one of said parts and being drivingly connected to the other of said parts; and

means for said joints being readily separable from one another.

26. The manipulator of claim 25 wherein at least one of said pitch and roll drive means includes overload clutch means for providing relative slippage between said drive means and its respective joint under overload conditions.

27. The manipulator of claim 26 wherein at least one of said joint drive means is substantially concentric with its joint axis.

28. The manipulator of claim 27 wherein said pair of relatively movable parts of said roll joint comprise relatively rotatable inner and outer shells and said motor and drive assembly being mounted substantially internally of said inner shell.

29. The manipulator of claim 28 wherein said drive assembly comprises a harmonic drive reduction gear assembly.