Power control unit

• US 7,520,351 B2
• Filed: 02/08/2006
• Issued: 04/21/2009
• Est. Priority Date: 02/15/2005
• Status: Expired due to Fees

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Ozeki, Takashi, Tsukada, Yoshiaki, Uchisasai, Hiroaki, Kojima, Hiroyuki
• Primary Examiner(s): Ellis; Christopher P
• Assistant Examiner(s): COLLADO, CYNTHIA FRANCISCA
• Application Number:
  US11/349,167
• Publication Number:
  US 20060180363A1
• Time in Patent Office: 1,168 Days
• Field of Search: 701/22, 180/65.2, 180/65.3, 180/65.4
• US Class Current: 180/65.245
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60Y 2200/12 Motorcycles, Trikes; Quads; Scooters
• CPC Class Codes: B62K 2202/00 Motorised scooters
• CPC Class Codes: B62K 2204/00 Adaptations for driving cycles by electric motor for driving electrically assisted bicycles B62M6/00
• CPC Class Codes: B62M 7/12 with the engine beside or within the driven wheel
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A hybrid vehicle includes an engine and a drive motor which adds power to power generated by the engine in a superimposed manner to assist the engine. A power control unit includes: a fourth rotor sensor as a vehicle speed sensor which detects vehicle speed of the hybrid vehicle; an accelerator sensor which detects an amount of accelerator operation; and an ECU having an assist map which determines an output command reference value for the drive motor based on the vehicle speed and the amount of accelerator operation. The ECU outputs, to the drive motor, a corrected output command value which is calculated by adding an additional value corresponding to a rate of change in the amount of accelerator operation, to the output command reference value obtained from the assist map.

Claims

1. A power control unit in a hybrid vehicle comprising:

an engine and a drive motor which generate a driving force for running;

a vehicle speed sensor which detects a vehicle speed;

an accelerator sensor which detects an amount of accelerator operation; and

a control part having a reference value setting part which determines an output command reference value for said drive motor based on said vehicle speed supplied from said vehicle speed sensor and said amount of accelerator operation supplied from said accelerator sensor, characterized in that;

said control part outputs, to said drive motor, a corrected output command value obtained by adding an additional value corresponding to a rate of change in said amount of accelerator operation to said output command reference value obtained from said reference value setting part.

2. The power control unit as described in claim 1, characterized in that said control part adds said additional value to said output command reference value and outputs said corrected output command value when said rate of change in said amount of accelerator operation exceeds a threshold.

3. The power control unit as described in claim 2, characterized in that said control part makes said additional value 0 when said rate of change in said amount of accelerator operation is below said threshold.

4. The power control unit as described in claim 2, characterized in that said control part changes said threshold based on said vehicle speed.

5. The power control unit as described in claim 4, characterized in that said control part increases said threshold as said vehicle speed increases.

6. The power control unit as described in claim 1, characterized in that said the power control unit comprising:

a one-way clutch with an input side connected with said engine and an output side connected with said drive motor;

a throttle valve which regulates the throttle opening degree under the influence of a throttle motor;

an input rotation sensor which detects the input rotation speed of said one-way clutch and supplies it to said control part; and

an output rotation sensor which detects the output rotation speed of said one-way clutch and supplies it to said control part,

wherein said control part reads said amount of accelerator operation from said accelerator sensor, calculates a target opening degree for said throttle opening degree based on said amount of accelerator operation, activates said throttle motor so as to make said throttle opening degree agree with said target opening degree, calculates the speed difference between said input rotation speed and said output rotation speed, and sets said target opening degree to a value lower than a reference value calculated based on said amount of accelerator operation when said speed difference is below a prescribed value.

7. The power control unit as described in claim 6, characterized in that said control part resets said target opening degree to said reference value after a prescribed engagement control time has elapsed.

8. The power control unit as described in claim 6, characterized in that said control part calculates an estimated engagement time for said one-way clutch to engage, based on the rate of change in said speed difference, and controls said throttle opening degree depending on said estimated engagement time.

9. The power control unit as described in claim 6, characterized in that said control part regulates the amount of decrease of said target opening degree with respect to said reference value depending on said rate of change in speed difference.

10. The power control unit as described in claim 9, characterized in that when said rate of change in speed difference is larger, said amount of decrease is set to a larger value.