The Controls team is responsible for taking the state of the car - motion, driver inputs, and the electrical state - and determining how the car should react. In addition to programming the control systems, we have to model the physics of the car and its motors to design our torque vectoring traction control system.


Vehicle Dynamics

One key difference between electric motors and combustion engines is that torque is almost instantly available in electric motors. This means that developing a traction control strategy is essential. Our Electronic Control Unit (ECU) is the center of our control system. The SBG Systems Inertial Measurement Unit (IMU) communicates the current speed and acceleration of the car and the ECU can then determine the available traction at every tire.

Knowing how much traction is available, the ECU then takes the drivers inputs - pedal position and steering angle - and determines what torque to request from the motors to make the car accelerate. Lastly, and the key reason to use an all-wheel-drive architecture, is torque vectoring. Based on driver steering angle and the current car yaw rate, the vehicle's ability to turn can be significantly improved by creating a torque imbalance left-to-right in the car and cause the car to yaw faster than it would based on steering alone.