Modular robotic system

• US 4,990,839 A
• Filed: 12/09/1988
• Issued: 02/05/1991
• Est. Priority Date: 12/09/1988
• Status: Expired due to Term

• Current Assignee: William J. Schonlau
• Original Assignee: William J. Schonlau
• Inventors: Schonlau, William J.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Ip, Paul
• Application Number:
  US07/281,625
• Time in Patent Office: 788 Days
• Field of Search: 901/2, 901/14, 901/15, 901/19, 901/23, 901/24, 901/25, 901/27, 901/28, 901/29, 901/22, 318/560-634, 364/513
• US Class Current: 700/248
• CPC Class Codes: B25J 9/08 characterised by modular constructions
• CPC Class Codes: B25J 9/161 Hardware, e.g. neural networks, fuzzy logic, interfaces, processor
• CPC Class Codes: G05B 19/4141 characterised by a controller or microprocessor per axis
• CPC Class Codes: G05B 2219/33161 Data exchange between controller and processors
• CPC Class Codes: G05B 2219/33254 Serial position feedback, serial to parallel conversion and reverse
• CPC Class Codes: G05B 2219/39335 Independent joint control, decentralised
• CPC Class Codes: G05B 2219/42129 Teach, learn position table, model, for each reference a motor control output
• CPC Class Codes: G05B 2219/49292 Harmonic gear, transmission, strain wave gear

Abstract

A modular robotic system is provided with one or more robotic arm sets constructed from modular components and controlled by a central processor to displace an end effector or tool through a desired movement or movements as a function of time. Each arm set comprises a custom assembled combination of passive and active members of selected sizes and shapes, wherein each active member includes a drive motor for rotating a driven member with one degree of mechanical freedom. The active members of each arm set are connected to the central processor via a common communications cable for receiving position commands in the form of end effector position signals. The active members include individual on-board microprocessors for translating each end effector position signal to obtain individualized displacements of the active members which, in combination, result in the desired end effector displacement.

Claims

1. A modular robotic system for displacing an end effector through a prescribed path of motion, comprising:

an arm set defined by an assembled plurality of modular components including a plurality of active members each having a drive portion and a driven portion movable with respect thereto, said arm set being adapted to carry said end effector;

a control station including means for transmitting an end effector position signal;

cable means coupled between said control station and each of said active members for communicating said end effector position signal to said active members, said cable means being coupled to said active members; and

microprocessor means mounted on-board each of said active members for receiving and interpreting said end effector position signal and for responding thereto to operate said drive portion for displacing said driven portion through an individualized displacement, whereby the combination of individual displacements of said driven portions of said active members displaces said end effector to a prescribed destination point;

said drive portion of each of said active members including a drive motor having an output shaft, and said driven portion of each of said active members comprises a driven sleeve coupled to said output shaft, and further wherein said microprocessor means is responsive to said end effector position signal to operate said drive motor to rotate said output shaft in a selected direction and magnitude.

2. The modular robotic system of claim 1 wherein said control station comprises a central processor of a computer.

3. The modular robotic system of claim 1 wherein said cable is mounted to extend along the assembled components of said arm set for serial connection to said active members.

4. The modular robotic system of claim 1 wherein each of said active members includes first and second terminal sets, and slip ring coupling means connected electrically between said terminal sets, said first and second terminal sets being adapted for series connection to said cable means.

5. The modular robotic system of claim 1 wherein each of said active members further includes speed reduction means coupled between said output shaft and said driven sleeve.

6. The modular robotic system of claim 5 wherein said speed reduction means comprises an harmonic gear drive unit.

7. The modular robotic system of claim 1 wherein each of said active members further includes means for monitoring the actual displacement thereof in response to the end effector position signal, and for comparing said actual displacement with said individualized displacement commanded by said microprocessor means, and for correcting said actual displacement for conformance with said individualized displacement.

8. The modular robotic system of claim 7 wherein said actual displacement monitoring means comprises a position sensor.

9. The modular robotic system of claim 8 wherein said position sensor monitors the rotational position of said output shaft.

10. The modular robotic system of claim 1 wherein said microprocessor means includes means for producing a motor drive signal and for coupling said motor drive signal to a power stage circuit for coupling electrical power to said drive motor, said power stage circuit having a low pass filter including an inductor coupled in series with said motor and a capacitor coupled in parallel with said motor.

11. A modular robotic system for displacing an end effector through a prescribed path of motion, comprising:

at least one arm set defined by an assembled plurality of modular components including a plurality of active members each having a drive portion and a driven portion movable with respect thereto, said arm set being adapted to carry said end effector;

a control station including means for transmitting an end effector position signal;

means for communicating said end effector position signal to said active members; and

microprocessor means mounted on-board each of said active members for receiving and interpreting said end effector position signal and for responding thereto to operate said drive portion for displacing said driven portion through an individual displacement, whereby the combination of individual displacements of said driven portions of said active members displaces said end effector to a prescribed destination point;

said drive portion of each of said active members including a drive motor having an output shaft, and said driven portion of each of said active members comprises a driven sleeve coupled to said output shaft, and further wherein said microprocessor means is responsive to said end effector position signal to operate said drive motor to rotate said output shaft in a selected direction and magnitude.