Vehicle speed control system and method employing torque balancing

Abstract

A method for operating a speed control system of a vehicle having a plurality of wheels is provided. The method comprises receiving one or more electrical signals representative of vehicle-related information. The method further comprises determining, based on the one or more electrical signals representative of vehicle-related information, that one or more of the wheels of the vehicle have overcome an obstacle or are about to overcome an obstacle and that therefore a reduction in an applied drive torque to one or more of the wheels of the vehicle by a powertrain subsystem (applied drive torque) will be required to maintain the speed of the vehicle at a target set-speed of the speed control system. The method still further comprises automatically commanding the application of a retarding torque to one or more of the wheels of the vehicle to counteract the effect of an overrun condition in the powertrain subsystem from increasing the speed of the vehicle. A system for controlling the speed of a vehicle comprising an electronic control unit configured to perform the above- described methodology is also provided.

Description

technical field [0001] The present invention relates generally to vehicle speed control and, more particularly, to a method and system for controlling the speed of a vehicle capable of traversing a variety of terrain by employing a torque balancing scheme to counteract engine or powertrain overspeed. Background technique [0002] In known vehicle speed control systems, commonly referred to as cruise control systems, the set speed of the vehicle can be initially set by manually bringing the vehicle to a desired speed and then by manipulating a button such as for example A user selectable user interface device for setting the current vehicle speed as the set speed. When the user subsequently wishes to change the set speed, the same or a different user input device may be manipulated to increase or decrease the set speed. In response to a requested change in set speed or a commanded change in set speed, the speed control system provides feedback to one or more vehicle subsyste...

AI Technical Summary

Problems solved by technology

However, due to the lag in the response of the internal combustion engine to changes in torque demand (i.e., torque output lags torque demand), powertrain or engine overspeed may occur when the vehicle reaches the top of the boulder, causing the vehicle's speed to exceed, at least temporarily, The set speed of the speed control system until the engine or power train is able to reduce the drive torque to an appropriate level

Images