MPC based Rear Wheel Torque Vectoring Near the Limits of Handling

1. MPC based Rear Wheel Torque Vectoring Near the Limits of Handling EfstathiosSiampis Dr EfstathiosVelenis, Dr Stefano Longo Cranfield University UKACC PhD Presentation Showcase

2. Introduction • Velocity regulation becomes important in terminal understeer cases • Design an active safety system that: • Stabilizes the vehicle using combined velocity, yaw and sideslip control • Accounts for the important in limit handling conditions system constraints UKACC PhD Presentation Showcase

3. Approach to Problem Rear wheel torques Driver Intention - MPCs Driver inputs (using the steering, throttle, and brake pedal) + RWD Vehicle Velocity, sideslip angle and yaw rate UKACC PhD Presentation Showcase

4. Approach to Problem: Target Generation • Steady state cornering analysis of a nonlinear four-wheel vehicle model to derive feasible targets • Then the requested path radius from the driver can be feasible, or not Driver Intention - MPCs + RWD Vehicle UKACC PhD Presentation Showcase

5. Approach to Problem: Controller Design • For the MPC, we linearize the nonlinear four-wheel vehicle model and use the rear wheel slip as inputs • Constraints are set on yaw rate and sideslip angle, but also on the rear wheels’ slip ratios and torques • Then a sliding mode controller calculates the necessary torques on the rear wheels MPC SMC Rear wheel slip ratios Rear wheel torques Driver Intention - MPCs + RWD Vehicle UKACC PhD Presentation Showcase

6. Simulations: U-turn scenario Uncontrolled LQR MPCs UKACC PhD Presentation Showcase

7. Simulations: Double-lane Change Scenario Uncontrolled LQR MPCs UKACC PhD Presentation Showcase

8. Conclusions and Future Work • Conclusions • Lateral control only not enough for terminal understeer mitigation • Accounting for the system constraints can prevent instability • Future Work • Exploration of different vehicle topologies • Controller testing in the HIL facility of the Automotive Department UKACC PhD Presentation Showcase