Vehicle dynamics control in electric drive vehicles

Abstract

Embodiments of the invention are directed toward a geared traction drive system configured to drive a wheel of a vehicle, comprising: a driveshaft for transmitting power to the wheel; an electric drive motor for driving the driveshaft, the electric drive motor configured to receive signals from a vehicle dynamic control system to command a required speed; a gear reduction component for reducing the speed of the motor by a predetermined factor to a lower speed suitable for driving the wheel; and a drive electronics component that works with the electric drive motor to drive the wheel to the speed commanded by the vehicle dynamic control system.

1 . A vehicle dynamics control system, comprising:
 a first motor electrically coupled to a first drive electronics module,
 the first motor coupled to a first wheel; 
   a second motor electrically coupled to a second electronics module,
 the second motor coupled to a second wheel; and 
   a control processor configured to control the first electrical motor and the second electric motor by transmitting speed commands to the first electronics drive and the second electronics modules,
 the transmitted speed commands determined by causing the control processor to: 
 receive velocity data from at least one sensor, 
 receive driver data from at least one driver input sensor, 
 generate a first wheel speed and a second wheel speed from the driver data and the velocity data, 
 determine a steering condition, 
 calculate in response to the velocity data and driver data, at least one front slip angle and at least one rear slip angle, 
 determine, using the at least one front slip angle and at least one rear slip angle, whether a current steering condition is understeering or oversteering in comparison with the determined steering condition, 
 calculate, in response to determining the current steering condition is understeering, a first calculated Wheel speed and a second calculated wheel speeds, the first calculated wheel speed and the second calculated wheel speed being the speed at which each wheel is driven so as to decrease the at least one front slip angle or increase the at least one rear slip angle to achieve the optimal steering condition.