Vehicle movement on an inclined surface

Patent metadata

Field	Value
Publication number	US-10030598-B2
Application number	US-201515120102-A
Country	US
Kind code	B2
Filing date	Feb 18, 2015
Priority date	Feb 18, 2014
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

Aspects of the present invention relate to the pull away from rest of a motor vehicle on a slope. The vehicle includes an automatic transmission and internal combustion engine with an electronic controller. The engine torque response to the accelerator pedal input is modified accounting for the slope to improve consistency of pull away on different slopes and reduce the dead pedal feeling on steep slopes.

First claim

The invention claimed is:

1. A method for accelerating a vehicle from rest on a slope comprising:
determining a gradient of the slope on which the vehicle is positioned,
generating an offset value for an accelerator pedal position signal taking into account the gradient;
combining the offset value with the accelerator pedal position signal to generate a virtual pedal position signal, and;
controlling an engine of the vehicle to produce torque using the virtual pedal position signal,
wherein the offset value is applied whether the accelerator pedal is depressed or is not depressed.

2. The method of claim 1 , comprising:
calculating a desired acceleration of the vehicle taking into account the accelerator pedal position signal;
determining an actual acceleration of the vehicle;
adjusting the offset value to the accelerator pedal position based on the difference between the actual and desired vehicle acceleration, and;
repeating the above steps in a closed loop manner in order that actual acceleration approaches the desired acceleration.

3. The method of claim 1 , comprising:
determining vehicle speed, and;
reducing the offset value as the vehicle speed increases.

4. The method of claim 1 , comprising:
determining vehicle speed, and;
increasing the offset value as the vehicle speed decreases.

5. The method of claim 1 , comprising a removal of the offset value when vehicle brakes are applied.

6. The method of claim 1 wherein the offset value is filtered or blended to achieve a smooth transition.

7. The method of claim 1 , wherein determination of the gradient is achieved taking into account any difference between vehicle acceleration as measured based on wheel speeds and vehicle acceleration as measured by a longitudinal acceleration sensor.

8. The method of claim 1 , comprising calibration of the offset value to enable a creep speed without depression of the accelerator pedal.

9. The method of claim 8 wherein creep speed is enabled upon release of vehicle brakes.

10. The method of claim 8 , comprising a calibrated variance of creep speed with gradient.

11. The method of claim 1 , comprising:
generating a vehicle mass estimate taking into account vehicle acceleration and a tractive effort produced by the engine;
determining an average of the vehicle mass estimate over a period of time, and;
modifying the offset value taking into account the time averaged vehicle mass estimate.

12. The method of claim 11 , comprising a closed loop estimation function responsive to vehicle acceleration in order to modify the vehicle mass estimate.

13. A controller for implementing the method of claim 1 .

14. A vehicle comprising a controller as claimed in claim 13 .

15. A system for controlling movement of a vehicle, comprising:
at least one vehicle sensor to provide an indication of a gradient of a slope the vehicle is at rest on;
an engine controller configured to provide torque at pull away, said torque being dependent on the gradient and on an accelerator pedal position signal.

16. A vehicle comprising:
an engine;
an accelerator pedal sensor configured to provide an indication of a driver intent to accelerate the vehicle;
one or more brake sensors configured to provide an indication of the driver intent to release brakes of the vehicle;
one or more sensors configured to provide an indication of a gradient of a slope the vehicle is at rest on;
a control system configured to control the engine of the vehicle to provide torque to accelerate the vehicle up the slope in response to an indication of a driver intent provided from the accelerator pedal sensor, said torque varying in dependence on the gradient and on an accelerator pedal position signal received from the accelerator pedal sensor.

17. The method of claim 1 , wherein the offset value is non-zero at least while the accelerator pedal is depressed.

Assignees

• Jaguar Land Rover Ltd

Inventors

• Gennard James
• Spooner John

Classifications

• B60W2552/15

  Road slope, i.e. the inclination of a road segment in the longitudinal direction · CPC title

• B60W40/13

  Load or weight · CPC title

• B60W2050/0008

  Feedback, closed loop systems or details of feedback error signal · CPC title

• B60W30/18027 Primary

  Drive off, accelerating from standstill · CPC title

• F02D41/14

  Introducing closed-loop corrections · CPC title