Robotic Vehicle with Dynamic Range Actuators

• US 20090145671A1
• Filed: 01/07/2008
• Published: 06/11/2009
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: Flir Detection, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: iRobot Corporation
• Inventors: O`Brien, John P., Couture, Adam P., Filippov, Mikhail
• Granted Patent: US 8,342,271 B2
• Time in Patent Office: Days
• US Class Current: 180/9.420
• CPC Class Codes: B25J 19/005 using batteries, e.g. as a back-up power source
• CPC Class Codes: B25J 5/005 mounted on endless tracks or belts
• CPC Class Codes: B60K 1/00 Arrangement or mounting of electrical propulsion units B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00; electric transmission arrangements B60K17/12; electric equipment or propulsion of electrically-propelled vehicles per se B60L; current-collectors for power supply lines of electrically-propelled vehicles B60L5/00
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B62D 37/00 Stabilising vehicle bodies without controlling suspension arrangements
• CPC Class Codes: B62D 55/075 Tracked vehicles for ascending or descending stairs, steep slopes or vertical surfacesmagnetic or pneumatic ground-engaging parts B62D55/265; chairs or multi-track cycles specially adapted for invalids A61G5/00
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A robotic vehicle including a chassis having front and rear ends, an electric power source supported by the chassis, and multiple drive assemblies supporting the chassis. Each drive assembly including a track trained about a corresponding drive wheel and a drive control module. The drive control module including a drive control housing, a drive motor carried by the drive control housing and operable to drive the track, and a drive motor controller in communication with the drive motor. The drive motor controller including a motor controller logic circuit and an amplifier commutator in communication with the drive motor and the motor controller logic circuit and is capable of delivering both amplified and reduced voltage to the drive motor from the power source. In one instance, the drive control module is separately and independently removable from a receptacle of the chassis as a complete unit.

Claims

1. A robotic vehicle comprising:

a chassis having front and rear ends;

an electric power source supported by the chassis; and

multiple drive assemblies supporting the chassis, each drive assembly comprising;

a track trained about a corresponding drive wheel; and

a drive control module comprising;

a drive control housing;

a drive motor carried by the drive control housing and operable to drive the track; and

a drive motor controller in communication with the drive motor and comprising;

a drive motor controller logic circuit; and

an amplifier commutator in communication with the drive motor and the drive motor controller logic circuit and capable of delivering both amplified and reduced voltage to the drive motor relative to an input voltage from the power source.

2. The robotic vehicle of claim 1, wherein the drive control module further comprises a back-drivable gearbox coupling the motor to the track.

3. The robotic vehicle of claim 1, wherein the drive motor controller further comprises a health monitor capable of monitoring the proper functioning of the drive motor controller logic circuit and the amplifier commutator, the health monitor capable of sending a signal to the amplifier commutator to cease operation of the motor upon detecting a malfunction.

4. The robotic vehicle of claim 1, further comprising a robot controller in communication with each drive control module.

5. The robotic vehicle of claim 1, wherein the amplifier commutator comprises:

a commutator in communication with the drive motor;

a DC/DC converter capable of delivering both amplified and reduced voltage to the commutator; and

a programmable logic circuit in communication with the drive motor controller logic circuit, DC/DC converter, and commutator.

6. The robotic vehicle of claim 5, wherein the drive control module further comprises:

multiple magnetic field sensors mounted radially about to the motor, the magnetic field sensors detecting magnetic pulses;

a velocity sensor connected to the motor; and

a rotary position sensor connected to the motor.

7. The robotic vehicle of claim 6, wherein the drive motor controller logic circuit comprises logic for three cascading control loops comprising motor current, motor voltage, and motor rotor rotation.

8. The robotic vehicle of claim 7, wherein the current control loop of the drive motor controller logic circuit comprises:

reading a current feedback from the commutator;

reading the magnetic field sensors;

computing a pulse-width modulation output;

writing the pulse-width modulation output to a shared structure accessible by the other control loops; and

updating a cycle counter.

9. The robotic vehicle of claim 7, wherein the voltage control loop of the drive motor controller logic circuit comprises:

reading a velocity feedback from the velocity sensor;

reading a voltage feedback from the DC/DC converter;

computing a commanded current based on a current limit, maximum current from a thermal protection model, and a current rate of change limit; and

writing the commanded current to a shared structure accessible by the other control loops.

10. The robotic vehicle of claim 7, wherein the motor rotor rotation control loop of the drive motor controller logic circuit comprises:

reading a rotational position feedback from the rotary position sensor;

computing a commanded velocity based on current and velocity limits; and

writing the commanded velocity to a shared structure accessible by the other control loops.

11. The robotic vehicle of claim 5, wherein the DC/DC converter receives about 42 V from the power source and is capable of delivering between about 0 V and about 150 V.

12. The robotic vehicle of claim 1, wherein the power source comprises three 14 V batteries in series and three 14 V batteries in parallel, providing about 42 V.

13. The robotic vehicle of claim 1, wherein the drive control module is separately and independently removable from a receptacle of the chassis as a complete unit.

14. The robotic vehicle of claim 13, wherein the drive control module is sealed within the receptacle of the chassis from an outside environment and cooled.

15. A robotic vehicle comprising:

a chassis having front and rear ends and supported on right and left driven drive tracks, each drive track trained about a corresponding front wheel rotatable about a front wheel axis;

right and left elongated flippers disposed on corresponding sides of the chassis and operable to pivot about the front wheel axis of the chassis, each flipper having a driven flipper track;

a flipper actuator module supported by the chassis and operable to rotate the flippers;

at least one drive module supported by the chassis and operably connected to drive at least one of the drive and flipper tracks;

a payload deck configured to support a payload; and

a linkage connecting the payload deck to the chassis, the linkage having a first end rotatably connected to the chassis at a first pivot, and a second end rotatably connected to the deck at a second pivot, the first and second pivots including respective linkage actuator modules operable to rotatably position their corresponding pivots to control orientation of the payload deck with respect to the chassis;

wherein the track drive modules and actuator modules each comprise;

a module housing;

a motor supported by the module housing; and

a motor controller supported by the module housing and in communication with the motor;

wherein the linkage actuator modules are each separately and independently removable as complete units; and

wherein the track drive modules and the flipper actuator module are each separately and independently removable from respective receptacles of the chassis as complete units.

16. The robotic vehicle of claim 15 wherein the actuator modules are each interchangeable.

17. The robotic vehicle of claim 15 wherein the track drive modules are each interchangeable.

18. The robotic vehicle of claim 15 wherein the track drive modules and the flipper actuator module are each sealed within respective receptacles of the chassis from an outside environment and cooled.

19. The robotic vehicle of claim 15 wherein the track drive modules and actuator modules each communicate with a robot controller.

20. The robotic vehicle of claim 15 wherein the track drive modules and actuator modules each further comprise a back-drivable gearbox supported by the module housing and coupled to the motor.

21. The robotic vehicle of claim 20 wherein the actuator modules further comprise a slip clutch supported by the module housing and coupled to a planetary gearbox.

22. The robotic vehicle of claim 15 wherein the motor of the actuator module provides friction braking for inhibiting actuation upon power loss.

23. The robotic vehicle of claim 15 wherein the motor controller comprises:

a motor controller logic circuit; and

an amplifier commutator in communication with the drive motor and the motor controller logic circuit and capable of delivering both amplified and reduced voltage to the drive motor.

24. The robotic vehicle of claim 15 wherein each module further comprises a power connector disposed on an outer surface of the module housing and configured to mate with a corresponding power bus connector to establish an electric power connection to the module.

25. The robotic vehicle of claim 24 wherein each track drive module establishes an electric power connection with the bus power connector within its respective receptacle as the module is placed within the receptacle.

26. A method of controlling a robotic vehicle, the method comprising:

providing a robotic vehicle comprising;

a chassis having front and rear ends;

at least one electric power source supported by the chassis; and

at least one drive assembly supporting the chassis and driven by a drive control module, the drive control module comprising;

a drive control housing;

a drive motor carried by the drive control housing and operable to drive the drive assembly; and

a drive motor controller in communication with the drive motor and comprising;

a drive motor controller logic circuit; and

an amplifier commutator in communication with the drive motor and the drive motor controller logic circuit; and

providing a robot controller with a power management control logic that recognizes a power source type and monitors an available power level, the robot controller communicating drive commands to the drive motor controller logic circuit of each drive control module based on the power source type and the available power level.

27. The method of claim 26 wherein the power management control logic monitors a power source temperature.

28. The method of claim 27 wherein the robot controller communicates drive commands to the drive motor controller logic circuits of each drive control module based on the power source temperature.

29. The method of claim 26 wherein the drive motor controller logic circuit checks for regenerative braking, wherein upon regenerative braking, the drive motor controller logic circuit checks the available power level of the power source and charges the power source until it detects one of the following:

a charged level is attained or regenerative breaking ends.

30. The method of claim 26 wherein robotic vehicle further comprises:

a payload deck supported by the chassis, the payload deck configured to receive at least one electric power source; and

a payload deck logic circuit supported by the payload deck, the payload deck logic circuit recognizing a power source type, monitoring an available power level, and communicating the power source type and available power level of the at least one electric power source to the robot controller.

31. The method of claim 30 wherein the payload deck logic circuit communicates with the robot controller over a controller area network bus.

32. The method of claim 30 wherein the robotic vehicle further comprises a linkage connecting the payload deck to the chassis, the linkage having a first end rotatably connected to the chassis at a first pivot, and a second end rotatably connected to the deck at a second pivot, the first and second pivots including respective linkage actuator modules operable to rotatably position their corresponding pivots to control orientation of the payload deck with respect to the chassis, wherein the actuator modules each comprise:

an actuator module housing;

an actuator motor supported by the module housing; and

an actuator motor controller supported by the module housing and in communication with the actuator motor and comprising;

a actuator motor controller logic circuit;

an amplifier commutator in communication with the actuator motor and the actuator motor controller logic circuit; and

a slip clutch supported by the module housing and coupling the actuator motor to the respective pivot.

33. The method of claim 32 wherein the actuator motor controller logic circuit checks for regenerative impact absorption, wherein upon regenerative impact absorption, the actuator motor controller logic circuit checks the available power level of the power source and charges the power source until it detects one of the following:

a charged level is attained or regenerative impact absorption ends.

34. The method of claim 26 wherein the amplifier commutator is capable of delivering both amplified and reduced voltage to the drive motor from the power source.