Method and apparatus for controlling output torque of a motor for an electric vehicle in uphill mode

A computer readable memory or data storage means encoded with data representing a computer program for system for controlling output torque of an electric motor for an electric vehicle in an uphill mode, the computer readable memory or data storage means causing a computer to perform the acts of:

• S1) detecting a tilt angle value (θ), a current vehicle speed value (V), and an accelerator-pedal travel value (Gain) of the vehicle;
• S2) determining if the vehicle is in uphill mode;
• S3) if the vehicle is in an uphill mode, then calculating a minimum torque (T1) required to prevent the vehicle from slipping backward based on the tilt angle value (θ) and the current vehicle speed value (V), obtaining a maximum output torque (T2) of the motor based on the current vehicle speed value (V), calculating an output torque (T) of the motor based on the minimum torque (T1) and the maximum output torque (T2) and the accelerator-pedal travel value (Gain), and controlling an output of the motor based on the calculated output torque (T);
• S4) if the vehicle is not in an uphill mode calculating a maximum output torque (T2) of the motor under the current vehicle speed value (V), calculating an output torque T of the motor based on the maximum output torque (T2) and the accelerator-pedal travel value (Gain), and controlling an output of the motor based on the calculated output torque (T);
• and
• wherein the output torque (T) of the motor is calculated in step S3 according to the equation:
• T=T1+(T2−T1)*Gain, and wherein the output torque (T) of the motor is calculated in step S4 according to the equation:
• T=T2*Gain.

An apparatus for controlling output torque of an electric motor for an electric vehicle in an uphill 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 uphill 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 an uphill mode, then calculate a minimum torque (T1) required to prevent the vehicle from slipping backward based on the tilt angle value (θ) and the current vehicle speed value (V), obtain a maximum output torque (T2) of the motor based on the current vehicle speed value (V), calculate an output torque (T) of the motor based on the minimum torque (T1) and the maximum output torque (T2) 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);
• if the vehicle is not in an uphill mode, then calculate a maximum output torque (T2) of the motor under the current vehicle speed value (V), calculate an output torque T of the motor based on the maximum output torque (T2) 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)
• wherein the motor controller comprises a calculating unit configured to calculate the minimum torque T1 according to the equation:
• T1=−T0, wherein T0=mg*sin(θ)*(r/k), wherein,
• m=total mass of the vehicle;
• g=gravitational constant;
• r=wheel radius;
• k=a variable transmission ratio of a gearbox disposed between the motor and the wheel;
• and
• wherein the calculating unit is configured to calculate the output torque (T) according to the equation:
• T=T1(T2−T1)*(Gain) if the vehicle is in an uphill mode;
• and calculate the output torque (T) according to the equation T=T2*(Gain) if the vehicle is not in an uphill mode.