Motor speed control apparatus

• US 4,555,651 A
• Filed: 08/08/1984
• Issued: 11/26/1985
• Est. Priority Date: 01/05/1983
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Towmotor Corporation (Caterpillar Incorporated)
• Inventors: Pickering, William, Melocik, Grant C.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Ip, Shik Luen Paul
• Application Number:
  US06/638,850
• Time in Patent Office: 475 Days
• Field of Search: 318/138, 318/139, 318/384, 318/385, 318/397, 318/398, 318/301-328, 318/341, 318/345 E, 318/439
• US Class Current: 388/828
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: H02P 5/68 controlling two or more dc dynamo-electric motors H02P5/46, H02P5/60 take precedence
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 388/902 Compensation
• CPC Class Codes: Y10S 388/921 Timer or time delay means

Abstract

Apparatus is provided for controlling increases in the speed of a motor, including a transducer coupled to an accelerator pedal, that generates digital numbers representing motor speed commands, a data processor for receiving the speed commands, generating motor speed limit signals in response to the digital numbers and delivering the limit signals to a controllable circuit for supplying power to the motor. The limit signals are delivered in response to time and the magnitude of the speed commands.

Claims

1. Appparatus (10) for controlling the rate of acceleraton of an electric motor (12) of a vehicle, said vehicle having a power source (48), comprising:

generating means (14) for producing a predetermined plurality of motor speed command signals, each signal having an incrementally different digital value;

processor means (32) for receiving each of said motor speed command signals, producing an accelerator ramp signal in response to receiving said motor speed command signals, said accelerator ramp signal having a predetermined digital value, storing said produced accelerator ramp signal within said processor means (32), producing predetermined successive motor speed limit signals each for a first predetermined period of time in response to said received motor speed command signal having a digital value geater than said stored accelerator ramp signal digital value and to said stored accelerator ramp signal digital value being in a first predetermined range of values, and incrementing said accelerator ramp signal to the next successive value in response to each successive motor speed limit signal being produced for said first predetermined period of time; and

controllable supplying means (30) for receiving said motor speed limit signals and controllably coupling said power source (48) to said motor (12) in response to said received motor speed limit signals.

2. Apparatus (10), as set forth in claim 1, wherein said processor means (32) produces only one motor speed limit signal for a second predetermined period of time greater than said first predetermined period of time, in response to said received motor speed command signal having a digital value greater than said stored accelerator ramp signal digital value and to said stored accelerator ramp signal digital value being in a second predetermined range of values exclusive of said first predetermined range of values, said stored accelerator ramp signal value being periodically incremented to the next successive value in response to said one motor speed limit signal being produced for said first predetermined period of time.

3. Apparatus, as set forth in claim 2, wherein the total number of different values of said first and second predetermined ranges of values is equal to the number of said motor speed command signals.

4. Apparatus (10), as set forth in claim 2, wherein said one produced motor speed limit signal has a value determined by said received motor speed command signal in response to said motor speed command signal digital value being in said second predetermined range of values.

5. Apparatus, as set forth in claim 2, wherein said first predetermined period of time is fixed, and said second predetermined period of time is varied in response to the difference between said received motor speed command signal digital value and said stored accelerator ramp signal digital value.

6. Apparatus, as set forth in claim 2, wherein the absolute number of different motor speed limit signals produced in response to said received motor speed command signal having a digital value greater than said stored accelerator ramp signal digital value is equal to the arithmetic difference between said received motor command signal digital value and said stored accelerator ramp signal digital value.