Vehicle controller

• US 6,493,611 B2
• Filed: 03/19/2001
• Issued: 12/10/2002
• Est. Priority Date: 04/06/2000
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yoshino, Takahiro, Nakajima, Yuki
• Primary Examiner(s): Nguyen, Tan
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US09/810,578
• Publication Number:
  US 20010034571A1
• Time in Patent Office: 631 Days
• Field of Search: 701/22, 701/54, 290/40.A, 290/40.R, 290/40.B, 290/40.C, 290/40.D, 290/40.F, 290/38.R, 290/45, 290/46, 180/65.2, 180/65.3, 180/65.8, 477/3, 477/5, 477/174, 477/175, 318/8, 318/9, 318/34, 318/51
• US Class Current: 701/22
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• 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 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• 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: 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
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor

Abstract

Torque control of an electrical motor 4 connected to a drive shaft 6 and control of the rotation speed of a generator 2 supplying electrical power to the electrical motor 4 are performed in response to the running conditions of a vehicle. The actual generator output of the generator 2 is estimated at a given time and the drive output of the electrical motor 4 is limited in response to the estimated generator output. The drive output of the electrical motor 4 is limited in response to increases in consumed energy and reductions in the generated output of the generator 2 resulting from increases in the kinetic energy of rotating components of the engine 1 or the generator 2 during acceleration. Thus the difference of the generated output of the generator 2 and the consumed electrical power of the electrical motor 4 can be reduced during acceleration and it is possible to reduce the capacity of the battery supplying auxiliary electrical power.

Claims

1. A controller for a vehicle having an engine, a generator connected to the engine, an electrical motor connected to the vehicle drive shaft and a battery electrically connected to the generator and the electrical motor, comprising,

sensors to detect operational conditions of the vehicle, and a microprocessor programmed to:

calculate a first parameter showing a target output of the electrical motor based on operational conditions of the vehicle;

calculate a second parameter showing a target output of the engine based on the first parameter;

calculate a third parameter showing a target rotation speed of the generator based on the second parameter;

calculate a fourth parameter showing a generated output of the generator based on the second parameter;

calculate a fifth parameter showing a target output of the electrical motor by limiting the first parameter in response to the fourth parameter;

control the operation of the engine based on the second parameter;

control the operation of the generator based on the third parameter; and

control the operation of the electrical motor based on the fifth parameter.

2. The controller as defined in claim 1, wherein the microprocessor is further programmed to:

calculate a sixth parameter showing an actual output of the engine based on the second parameter,

calculate a seventh parameter showing a work ratio corresponding to variation in the kinetic energy of the rotating components of the engine and the generator based on variation in the actual rotation speed of the engine and the generator; and

calculate the fourth parameter based on the difference of the sixth parameter and the seventh parameter.

3. The controller as defined in claim 1, wherein the microprocessor is further programmed to:

set an upper limiting value and a lower limiting value based on the fourth parameter, and

limit the first parameter to a range between the upper limiting value and the lower limiting value in order to calculate a fifth parameter.

4. The controller as defined in claim 3, wherein the microprocessor is further programmed to:

set the upper limiting value and the lower limiting value so that the difference of the limiting values from the fourth parameter respectively decreases as a vehicle speed increases.

5. The controller as defined in claim 3, wherein the microprocessor is further programmed to:

set the upper limiting value and the lower limiting value so that the difference of the limiting values from the fourth parameter respectively decreases as a temperature of the battery decreases.

6. A controller for a vehicle having an engine, a generator connected to the engine, an electrical motor connected to the vehicle drive shaft and a battery electrically connected to the generator and the electrical motor, comprising,

means for detecting operational conditions of the vehicle;

means for calculating a first parameter showing a target output of the electrical motor based on operational conditions of the vehicle;

means for calculating a second parameter showing a target output of the engine based on the first parameter;

means for calculating a third parameter showing a target rotation speed of the generator based on the second parameter;

means for calculating a fourth parameter showing a generated output of the generator based on the second parameter;

means for calculating a fifth parameter showing a target output of the electrical motor by limiting the first parameter in response to the fourth parameter; and

means for controlling the operation of the engine based on the second parameter, the operation of the generator based on the third parameter, and the operation of the electrical motor based on the fifth parameter.

7. A method for controlling the operation of a vehicle having an engine, a generator connected to the engine, and an electrical motor connected to a vehicle drive shaft, comprising the steps of:

calculating a target output of the electrical motor based on operational conditions of the vehicle;

calculating a target output of the engine based on the target output of the electrical motor;

calculating a generated output of the generator based on the target output of the engine; and

limiting the target output of the electrical motor in response to the generated output of the generator.

8. The method of claim 7, further comprising:

calculating a target rotational speed of the generator based on the target output of the engine.

9. The method of claim 8, further comprising:

controlling the operation of the generator based on the target rotational speed of the generator.

10. The method of claim 8, further comprising:

calculating an actual output of the engine;

calculating a work ratio corresponding to variation in the kinetic energy of rotating components of the engine and the generator based on variation in the actual rotational speed of the engine and the generator; and

calculating a difference between the actual output of the engine and the work ratio.

11. The method of claim 7, further comprising:

controlling the operation of the engine based on the target output of the engine.

12. The method of claim 7, further comprising:

setting an upper limiting value and a lower limiting value based on the generated output of the generator; and

limiting the target output of the electrical motor to a range between the upper limiting value and the lower limiting value.

13. The method of claim 12, wherein the step of setting an upper limiting value and a lower limiting value sets the upper limiting value and the lower limiting value so that limiting the target output of the electrical motor in response to the generated output of the generator respectively decreases as a vehicle speed increases.

14. The method of claim 12, wherein the step of setting an upper limiting value and a lower limiting value sets the upper limiting value and the lower limiting value so that limiting the target output of the electrical motor in response to the generated output of the generator respectively decreases as a battery temperature decreases.