System and method for maintaining the speed of a vehicle

• US 10,099,560 B2
• Filed: 01/26/2011
• Issued: 10/16/2018
• Est. Priority Date: 01/26/2011
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Wippler, Erik Anthony
• Primary Examiner(s): Truong, Minh
• Assistant Examiner(s): Butler, Michael E
• Application Number:
  US13/014,451
• Publication Number:
  US 20120191278A1
• Time in Patent Office: 2,820 Days
• Field of Search: 700 22, 701 22
• CPC Class Codes: B60L 15/2027 whilst maintaining constant speed
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A system for maintaining a selected speed of a vehicle is provided. The vehicle is powered in part by an electric motor and a battery. The electric motor is operable to drive in either a driving state or a charging state. In the charging state the polarity of the electric motor is modified so as to slow the vehicle down and supply power to the battery. A load bank is provided. The load bank is in electrical communication with the electric motor. The controller is further operable to direct power from the electric motor to the load bank when the electric motor is in the charging state.

Claims

1. A cruise control system for maintaining a selected speed of a vehicle, the vehicle having an electric motor and a battery, the battery in electrical communication with the electric motor, the electric motor operable to both drive the vehicle and charge the battery, wherein the electric motor supplies power to the battery, the cruise control system comprising:

a controller operable to actuate the electric motor between the driving state and the charging state;

a first sensor for detecting the state of the battery, the first sensor in communication with the controller;

a load bank electrically connected to the electric motor and in parallel with the battery, the load bank configured to only receive a charge from the electric motor and further configured to either discharge the stored electrical charge or supplement the vehicle'"'"'s electrical load; and

a processor and a second sensor, the second sensor operable to detect a current speed of the vehicle, the processor configured to maintain the selected speed by actuating the electric motor between a driving state and a charring state, wherein in the driving state the processor is configured to signal the controller to actuate the electric motor so as to supply power to the vehicle'"'"'s drive train, in the charging state the processor is configured to signal to the controller to modify the polarity of the electric motor so as to slow the vehicle, the processor further configured to process the selected speed and the current speed of the vehicle and the available store of the battery, wherein the controller is configured to direct power from the electric motor to the load bank only in instance, where the vehicle is operating in cruise control, the vehicle is above the selected speed, the vehicle is in the charging state and the available store of the battery is above a predetermined threshold, such that the cruise control system maintains the speed of the vehicle without excessively charging the battery.

2. The system as set forth in claim 1, wherein the first sensor is operable to detect the available store of the battery.

3. The system as set forth in claim 1, further including an input in communication with the controller, the input operable to provide the selected speed.

4. The system as set forth in claim 1, wherein the load bank is a resistor.

5. The system as set forth in claim 1, wherein the load bank is a capacitor.

6. The system as set forth in claim 1, wherein the predetermined threshold is the amount of force, generated by changing the polarity of the motor, necessary to slow the vehicle down to the selected speed within a desired period of time.

7. A method for maintaining a selected speed of a vehicle having an electric motor and a battery, the battery in electrical communication with the electric motor, the electric motor operable to both drive the vehicle and charge the battery, the electric motor operable in one of either a driving state or a charging state, wherein in the driving state the electric motor supplies power to the vehicle'"'"'s drive train, in the charging state the polarity of the electric motor is modified so as to slow the vehicle and supply power to the battery, the method comprising the steps of:

selecting a speed;

actuating the electric motor between the driving state and the charging state so as to maintain the selected speed;

providing a load bank in electrical communication with the electric motor, the load bank configured to only receive a charge from the electric motor;

providing a first sensor and a controller, the first sensor detecting the state available store of the battery, the controller actuating the electric motor between the driving state and the charging state;

detecting the speed of the vehicle;

actuating the electric motor in the charging state when the speed of the vehicle is above the selected speed so as to slow the vehicle down to the selected speed; and

directing power from the electric motor to the load bank only when; and

speed has been selected, the electric motor is in the charging state, the power in the battery is above a predetermined threshold, and the speed of the vehicle is above the selected speed wherein the load bank is further configured to either discharge the stored electrical charge or supplement the vehicle'"'"'s electrical load.

8. The method as set forth in claim 7, further including the step of providing an input, the input in communication with the controller and operable to provide the selected speed.