Development of Decentralized Integrated Chassis Control for Vehicle Stability in Limit Handling

As we move towards the world of autonomous vehicles it becomes increasingly important to integrate several chassis control systems to provide the desired vehicle stability without mutual interference. The principles for integration proposed in existing technical literature are majorly centralized which are not only computationally expensive but does not fit the current supplier based OEM business model. An Automotive OEM brings multiple suppliers on-board for developing the Active Safety systems considering several factors such as cost, quality, time, ease of business etc. When these systems are put together in the vehicle they may interfere with each other’s function. Decoupling their function results in a need of heavy calibration causing performance trade-offs and loss in development time. This puts forward a need for an algorithm which integrates individual control systems supplied by different vendors and enable them to function simultaneously to meet the vehicle dynamics performance criteria. To recreate the above scenario, individual control systems viz. Electronic Stability Control (ESC), Active Front Steer (AFS) and Active Suspensions have been developed and validated independent of each other using Matlab Simulink and CarSim. Further, two integrated chassis control approaches have been proposed. The first approach involves fractionating the output signals of individual control systems based on a vehicle velocity based ‘Relative Gain Array’ approach. The second approach demonstrates a friction circle monitoring approach to operate the tire within friction limits. This paper will present control algorithms of the above proposed approaches. Finally, the proposed approaches are evaluated for their performance and robustness to variations.