Method and apparatus for power management of a regenerative braking system

• US 7,029,077 B2
• Filed: 08/20/2003
• Issued: 04/18/2006
• Est. Priority Date: 08/20/2002
• Status: Expired due to Fees

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Anwar, Sohel, Pavlov, Kevin J, Klaes, Carl David
• Primary Examiner(s): NGUYEN, XUAN LAN T
• Application Number:
  US10/644,909
• Publication Number:
  US 20040035656A1
• Time in Patent Office: 972 Days
• Field of Search: 188156-164, 303/20, 303/151, 303/152, 303/155, 701/22, 701/70, 701/93, 180 651- 657
• US Class Current: 303/152
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/461 Speed
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60L 7/28 Eddy-current braking
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• 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

Abstract

A vehicle braking system and method of control is disclosed which includes electromagnetic and friction braking functionality. The electromagnetic braking system includes a generator which supplies power to eddy current devices. Accordingly, the eddy current devices apply a retarding torque on the wheels of the vehicle. In the event the generator produces an amount of power greater than that needed by the electromagnetic braking system, the generator will supply power to a supplemental power source such as a battery.

Claims

1. A braking system for a vehicle having at least one wheel comprising;

at least one battery capable of receiving and supplying power;

a battery switch;

a plurality of eddy current devices that provide a retarding to que to the wheel of the vehicle when energized;

a throttle position sensor for sensing a throttle position of the vehicle;

a brake pedal;

a brake pedal sensor coupled to the brake pedal for generating a brake pedal position signal;

a wheel speed sensor for determining the speed of the wheel and generating a wheel speed sensor signal;

a generator for supplying power to the eddy current devices and the battery for charging when the brake pedal sensor senses that the vehicle operator has placed the brake pedal in a predetermined brake pedal position, the throttle position is less than a predetermined throttle position, and the wheel speed is greater than a predetermined wheel speed threshold; and

a controller having memory storage capability, the controller for storing, a predetermined throttle position threshold, a predetermined brake pedal position, and a predetermined wheel speed threshold in memory and receiving inputs from the brake pedal sensor, the wheel speed sensor, a power nodule and the generator, and the controller for generating signals for the battery switch.

2. A braking system according to claim 1, wherein the eddy current devices are electromagnetic retarders.

3. A braking system according to claim 1, wherein the plurality of eddy current devices equals 4.

4. A braking system according to claim 1, wherein the generator has an operating voltage of about 42 volts.

5. A braking system according to claim 1, wherein the battery has a voltage of 36 volts.

6. A braking system according to claim 1, wherein the predetermined pedal position of the brake pedal is a depressed position.

7. A braking system control method for a vehicle having a generator, a battery, a brake pedal sensor, at least one wheel, and a wheel speed sensor, the method comprising the steps of:

detecting a braking demand based on an input from the brake pedal sensor;

comparing the braking demand to a predetermined brake demand threshold;

decoupling the battery from the generator when the braking demand is greater than the predetermined brake demand threshold;

detecting a wheel speed based on an input from the wheel speed sensor;

comparing the wheel speed to a predetermined wheel speed threshold when the braking demand is less than the predetermined brake demand threshold;

comparing the generator voltage to the battery voltage when the wheel speed is greater than the predetermined wheel speed threshold; and

coupling the generator to the battery when the generator voltage is greater than the battery voltage thereby charging the battery.

8. A braking system control method for a vehicle having a generator, a battery, a brake pedal, and at least one wheel, a wheel speed sensor, the method comprising the steps of:

detecting a throttle position based on inputs from a throttle position sensor;

comparing the throttle position to a predetermined throttle position threshold;

decoupling the battery from the generator when the throttle position is less than the predetermined throttle position threshold;

detecting a braking demand based on inputs from the brake pedal sensor;

comparing the braking demand to a predetermined brake demand threshold when the throttle position is greater than the predetermined throttle position threshold;

decoupling the battery from the generator when the braking demand is greater than the predetermined brake demand threshold;

detecting a wheel speed based on inputs from the wheel speed sensor;

comparing the generator voltage to the battery voltage when the wheel speed is greater than the predetermined wheel speed threshold; and

coupling the generator to the battery if the generator voltage is greater than the battery voltage to thereby charge the battery.

9. A braking system control method according to claim 8, wherein the predetermined throttle position ranges from 5 to 10 degrees from a non-depressed position.

10. A braking system control method for a vehicle having a generator, a battery, a brake pedal capable of generating a brake pedal position signal and at least one wheel, the method comprising the steps of:

determining a throttle position based on inputs from a throttle position sensor;

comparing the throttle position to a predetermined throttle position threshold;

generating a first command signal for a battery switch to decouple the battery from the generator thereby preventing charging of the battery when the throttle position is greater than the predetermined throttle position threshold;

comparing the brake pedal position signal based on the position of a brake pedal to a predetermined brake pedal position when the throttle position is less than the predetermined throttle position threshold;

generating the first command signal for the battery switch to decouple the battery from the generator when the brake pedal position signal is greater than the predetermined brake pedal position and the throttle position is less than the predetermined throttle position threshold;

comparing a wheel speed sensor signal based on the wheel speed to a predetermined wheel speed threshold when the brake pedal position signal is less than the predetermined brake pedal threshold and the throttle position is less than the predetermined throttle position threshold;

generating the first command signal to for the battery switch to decouple the battery from the generator when the wheel speed is less than the predetermined wheel speed threshold, the brake pedal position signal is less than the predetermined brake pedal position, and throttle position is less than the predetermined throttle position threshold; and

generating a second command signal to electrically couple the battery to the generator thereby enabling the generator to charge the battery when the wheel speed is greater than the predetermined wheel speed threshold, the throttle position is less than the predetermined throttle position threshold, and the brake pedal position signal is less than the predetermined brake pedal position.

11. A braking system control method according to claim 10, wherein the predetermined throttle position ranges from 5 to 10 degrees from a non-depressed position.

12. A braking system control method according to claim 10, wherein the predetermined brake pedal position is a depressed position.

13. A braking system control method according to claim 10, wherein the predetermined wheel speed threshold is at least 50 revolutions per minute.