Book excerpt: This book focuses on the control-by-wire system, particularly the steer-by-wire system, as well as its control and optimization issues in chassis integration. The steering stability of the vehicle, handling portability, and overall performance of the chassis system are improved by steer-by-wire technology, which includes stability control, road-feeling control, decoupling control, force and displacement coordinated control, and chassis integration optimization. Furthermore, intelligent control goals such as active collision avoidance and active rollover prevention of the vehicle are realized, and the active safety of the vehicle is increased, due to the integrated control of the steer-by-wire system and chassis system. In this book, different types of steer-by-wire systems are introduced, as well as thorough force and displacement control strategies and their implementation in chassis integrated control, ensuring the intelligent and unmanned driving's control reaction speed and precision.