Patent ID: 7747363

Claim:
An electric vehicle drive system, comprising: a drive system, comprising: an electric motor, said electric motor mechanically coupled to at least one wheel of a first vehicle axle, wherein said electric motor provides propulsion power to said at least one wheel of said first vehicle axle; and a power control module electrically connected to said electric motor, said power control module configured to receive motor torque commands, and said power control module configured to control said electric motor based on said motor torque commands; at least one wheel speed sensor; and a torque control system electrically connected to said power control module and to said at least one wheel speed sensor, wherein said torque control system outputs said motor torque commands to said power control module, wherein said torque control system further comprises: a traction control command generation unit for computing vehicle speed, wheel slip ratios corresponding to said at least one wheel speed sensor, and a slip error corresponding to said first vehicle axle; a torque control unit for computing an optimal motor torque request based on said vehicle speed and a required drive torque request; a traction control unit comprising: a first stage feedback control system for minimizing said slip error; and a torque limiter for transforming said optimal motor torque request into said motor torque command in response to an output from said first stage feedback control system.