Acceleration control for an electric vehicle

• US 9,096,135 B1
• Filed: 09/26/2014
• Issued: 08/04/2015
• Est. Priority Date: 09/26/2014
• Status: Active Grant

• Current Assignee: Proterra Operating Co., Inc.
• Original Assignee: Proterra AG
• Inventors: Simonini, Matthew
• Primary Examiner(s): Shaawat, Mussa A
• Application Number:
  US14/498,422
• Time in Patent Office: 312 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2200/18 Buses
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/32 by charging in short intervals along the itinerary, e.g. during short stops
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: H02H 7/0833 for electric motors with control arrangements
• CPC Class Codes: H02H 7/0851 for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal
• 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: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

An electric vehicle includes an electric motor configured to provide traction and a control system. The control system may be configured to receive a signal indicative of a requested torque and determine an acceleration limit based on the requested torque. The electric vehicle may also include an inverter operatively coupled to the control system and the electric motor. The inverter may be configured to control the electric motor based at least on (a) a signal indicative of the requested torque, and (b) a signal indicative of the acceleration limit.

Claims

1. An electric vehicle, comprising:

an electric motor configured to provide traction;

a control system configured to receive a signal indicative of a requested torque and determine (i) a first acceleration, the first acceleration being indicative of an acceleration of the electric motor that provides the requested torque, and (ii) a second acceleration, the second acceleration being a threshold acceleration of the electric motor; and

an inverter operatively coupled to the control system and the electric motor, the inverter being configured to control the electric motor to provide a lower value of (a) first acceleration and (b) the second acceleration.

2. The vehicle of claim 1, wherein the control system is configured to determine the first acceleration based at least on a chart of acceleration values at different torque values.

3. The vehicle of claim 1, wherein the second acceleration is a constant value.

4. The vehicle of claim 1, wherein the second acceleration is a dynamic value that varies based on at least one of (i) a state of charge of a battery of the vehicle, (ii) available battery power, and (iii) a temperature of a component of the vehicle.

5. The vehicle of claim 1, wherein the signal indicative of requested torque is a voltage signal that is indicative of a position of an accelerator of the vehicle.

6. The vehicle of claim 5, wherein the control system is configured to convert the voltage signal to a torque request.

7. An electric vehicle, comprising:

a powertrain powered by an electric motor;

a control system configured to (a) receive a signal indicative of a requested torque, (b) determine a requested acceleration based on the requested torque, (c) determine an acceleration limit, and (d) control the electric motor to provide a lower value of the requested acceleration and the acceleration limit.

8. The vehicle of claim 7, wherein the control system is configured to determine the requested acceleration based at least on a chart of acceleration values at different torque values.

9. The vehicle of claim 7, wherein the acceleration limit is a predetermined threshold acceleration value.

10. The vehicle of claim 7, wherein the acceleration limit is a constant value.

11. The vehicle of claim 7, wherein the acceleration limit is a dynamic value that varies based on at least one of (i) a state of charge of a battery of the vehicle, (ii) available battery power, and (iii) a temperature of a component of the vehicle.

12. The vehicle of claim 7, wherein the signal indicative of requested torque is a voltage signal that is indicative of a position of an accelerator of the bus.

13. The vehicle of claim 12, wherein the control system is configured to convert the voltage signal to a torque request.

14. The vehicle of claim 7, wherein the vehicle is a bus.

15. A method of operating an electric motor of an electric vehicle, comprising:

receiving a signal indicative of a requested torque;

determining a requested acceleration based at least on the requested torque;

determining an acceleration limit, the acceleration limit being indicative of a maximum desired acceleration of the electric motor; and

controlling the electric motor to provide a lower of the requested acceleration and the acceleration limit.

16. The method of claim 15, wherein the acceleration limit is a predetermined threshold acceleration value.

17. The method of claim 16, wherein the threshold acceleration value is a constant value.

18. The method of claim 15, wherein the acceleration limit is a dynamic value that varies based on at least one of (i) a state of charge of a battery of the vehicle, (ii) available battery power, and (iii) a temperature of a component of the vehicle.

19. The method of claim 15, wherein receiving a signal indicative of a requested torque includes receiving a voltage signal that is indicative of a position of an accelerator of the vehicle.