Patent ID: 8326510

Claim:
An apparatus for controlling output torque of an electric motor for an electric vehicle in a downhill mode, comprising: a motor controller; an angle sensor configured to determine a tilt angle value (θ), and output the tilt angle value (θ) to the motor controller; a vehicle speed sensor configured to determine a current vehicle speed value (V), and output the current vehicle speed value (V) to the motor controller; an accelerator-pedal position sensor configured to determine a position of an accelerator pedal, and output an accelerator-pedal travel value (Gain) to the motor controller; the motor controller further configured to: determine if the vehicle is in downhill mode based on the tilt angle value (θ), the current vehicle speed value (V), and the accelerator-pedal travel value (Gain); if the vehicle is in a downhill mode, then calculate a downhill slip torque (T 1 ) based on the tilt angle value (θ), obtain a maximum output torque (T 2 ) of the motor based on the current vehicle speed value (V), calculate an output torque (T) of the motor based on the downhill slip torque (T 1 ) and the maximum output torque (T 2 ) and the accelerator-pedal travel value (Gain) and a given vehicle speed delimitative value V ref , and generate a control signal configured to control an output of the motor based on the calculated output torque (T); and if the vehicle is not in a downhill mode, then calculate a maximum output torque (T 2 ) of the motor based on the current vehicle speed value (V), calculate an output torque T of the motor based on the maximum output torque (T 2 ) and the accelerator-pedal travel value (Gain), and generate a control signal configured to control an output of the motor based on the calculated output torque (T).