VEHICLE AND METHOD FOR IMPROVING PERFORMANCE AT LOW BATTERY LIMITS

• US 20140012441A1
• Filed: 07/03/2012
• Published: 01/09/2014
• Est. Priority Date: 07/03/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Wang, Qing, Kuang, Ming Lang, Okubo, Carol Louise
• Granted Patent: US 9,802,601 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2050/0012 Feedforward or open loop systems
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/0677 Engine power
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A hybrid electric vehicle (HEV) includes an internal combustion engine, a traction motor, a generator, and a traction battery. Available electric power in the HEV is based upon the available power in the traction battery. The engine and the motor may both work simultaneously to propel the HEV. While the engine is powering the HEV, a controller is configured to increase a power output of the engine based upon a difference between available battery power and a combination of desired motor power and desired generator power.

Claims

1. A method for controlling a vehicle having an engine, a traction motor, and an electrical energy storage device coupled to the traction motor, comprising:

increasing power output of the engine at a rate that varies in response to available power from the electrical energy storage device when driver demanded power exceeds a corresponding threshold.

2. The method of claim 1, wherein the rate of increasing power output of the engine varies based upon a difference between available power in the electrical energy storage device and a combination of desired motor power and desired generator power.

3. The method of claim 1, further comprising filtering the difference with an adjustable filter.

4. The method of claim 3, wherein the filtering is adjusted based upon a discharge limit of the electrical storage device.

5. The method of claim 4, wherein the filtering includes reducing the filtering based upon a charge level of the electrical energy storage device being below a threshold.

6. The method of claim 1, further comprising preventing further increasing of the power output of the engine based upon the available power in the electrical energy storage device exceeding a charge limit.

7. The method of claim 1, wherein the rate of increasing power output of the engine varies inversely with the available power from the electrical energy storage device.

8. A hybrid electric vehicle, comprising:

an engine;

a generator drivably connected to the engine;

an electrical energy storage device coupled to a traction motor and the generator; and

a controller configured to increase a power output of the engine at different rates while the engine is running, based upon a difference between available power in the electrical energy storage device and a desired power in the motor and the generator.

9. The hybrid electric vehicle of claim 8, wherein the increase of the power output of the engine transmits to the motor, such that the motor has a power output that exceeds the available power in the electrical energy storage device.

10. The hybrid electric vehicle of claim 8, wherein the generator and the motor are one integrated machine.

11. The hybrid electric vehicle of claim 8, wherein the controller adjustably filters the difference based upon a discharge limit of the electrical energy storage device.

12. The hybrid electric vehicle of claim 8, further comprising a transmission that includes a planetary gear set.

13. The hybrid electric vehicle of claim 12, wherein the generator and the motor are one integrated machine, and wherein the engine, the machine, and the transmission are selectively coupled in series by clutches.

14. A computer system for controlling power distribution of an engine in a hybrid electric vehicle comprising a computer having a central processing unit (CPU) for executing machine instructions and a memory for storing the machine instructions, the machine instructions when executed by the CPU:

transmitting power to wheels of the vehicle from both an engine and a traction motor; and

increasing power output of the engine at a rate that varies in response to available power from an electrical energy storage device when driver demanded power exceeds a corresponding threshold.

15. The computer system of claim 14, wherein the increase of the power output of the engine increases a power output of the motor, such that the motor has a power output that exceeds the available power in the electrical energy storage device.

16. The computer system of claim 14, wherein the rate of increasing power output of the engine varies based upon a difference between available power in the electrical energy storage device and a combination of desired motor power and desired generator power.

17. The computer system of claim 14, wherein the rate of increasing the power output of the engine varies inversely with the available power from the electrical energy storage device.