Recent developments in vehicle steering systems offer new opportunities to measure the steering torque and reliably estimate the vehicle sideslip and the tire-road friction coefficient. This paper presents an approach to vehicle stabilization that leverages these estimates to define state boundaries that exclude unstable vehicle dynamics and utilizes a model predictive envelope controller to bound the vehicle motion within this stable region of the state space. This approach provides a large operating region accessible by the driver and smooth interventions at the stability boundaries. Experimental results obtained with a steer-by-wire vehicle and a proof of envelope invariance demonstrate the efficacy of the envelope controller in controlling the vehicle at the limits of handling.

Model Predictive Control for Vehicle Stabilization at the Limits of Handling

This paper presents a method for electronic stability control (ESC) based on model predictive control (MPC) using the bicycle model with lagged tire force to reflect the lagged characteristics of lateral tire forces on the prediction model of the MPC problem for better description of the vehicle behavior. To avoid the computational burden in finding the optimal solution of the MPC problem using the constrained optimal control theory, the desired states and inputs as references are generated since the solution of the MPC problem can be easily obtained in a closed form without using numeric solvers using these reference values. The suggested method controls the vehicle to follow the generated reference values to maintain the vehicle yaw stability while the vehicle turns as the driver intended. The superiority of the proposed method is verified through comparisons with an ESC method based on ordinary MPC in the simulation environments on both high- and low- μ surfaces using the vehicle dynamics software CarSim.

Model Predictive Control for Vehicle Yaw Stability With Practical Concerns

Modular integrated longitudinal and lateral vehicle stability control for electric vehicles

Integrated stability and traction control for electric vehicles using model predictive control

Model predictive control of vehicle stability using coordinated active steering and differential brakes

LTV-MPC for Yaw Rate Control and Side Slip Control with Dynamically Constrained Differential Braking

In this paper we present the integration of a Linear-Time-Varying Model-Predictive-Control (LTV-MPC), designed to stabilize a vehicle during sudden lane change or excessive speed-entry in curve, with a slip controller that converts the desired longitudinal tire force variation in pressure variation in the brake system. The lateral controller is designed using a three-degrees-of-freedom vehicle model taking into account both yaw rate and side slip angle of vehicle while the slip controller is a nonlinear gain scheduling P with feedforward action. The performances are validated with SIL technique, in particular, the authors use a proprietary simulator calibrated on an oversteering sport commercial car. Simulation results show the benefits of the control methodology used.

A preliminary study to integrate LTV-MPC lateral vehicle dynamics control with a slip control

In this work we present the integration of a Linear-time-varying Model-predictive-control (LTV-MPC), designed to stabilize a vehicle during sudden lane change or excessive entry-speed in curve, with a slip controller that converts the desired longitudinal tire force variation to pressure variation in the brake system. The lateral controller is designed using a 3DOF vehicle model taking into account both yaw rate and side slip angle of vehicle while the slip controller is a gain scheduled proportional controller with feedforward action. The performances are validated through simulation: in particular, the authors use a proprietary simulator calibrated on an oversteering sport commercial car and commercial simulator calibrated on a standard light car. Simulation results show the benefits of the control methodology in that very effective steering manoeuvres can be obtained as a result of this feedback policy while satisfying input constraints and show the importance of the introduction of inputs constraints in the control strategy design.

An Integrated LTV-MPC Lateral Vehicle Dynamics Control: Simulation Results

In this paper a novel vehicle lateral dynamic control approach is presented. A differential braking control law based on vehicle planar motion has been designed using a two-degrees-of-freedom vehicle model. On the basis of the estimate of tire longitudinal forces we estimate the range of lateral forces which the tire can exert. Using this constraints a model predictive control (MPC) based on a two-track model is designed in order to stabilize the vehicle. The performances are estimated comparing the results with standard manoeuvers. Simulation results show the benefits of the control methodology used: in particular we show how very effective distribution of braking torque are obtained as a result of this feedback policy.

Stefano Scala

Papers

LTV-MPC for Yaw Rate Control and Side Slip Control with Dynamically Constrained Differential Braking

A preliminary study to integrate LTV-MPC lateral vehicle dynamics control with a slip control

An Integrated LTV-MPC Lateral Vehicle Dynamics Control: Simulation Results

LTV-MPC for yaw rate control and side slip control with dynamically constrained differential braking