随着线控底盘和自动驾驶技术的发展，线控转向成为乘用车关键技术之一。线控转向应用的前提是具备高可靠性，采用双绕组电机作为冗余转向执行器是提高可靠性的有效方案。这种方案具有容错运行能力，且重量、体积较小，满足乘用车的轻量化要求。冗余线控转向系统在提高可靠性的同时，也增加了系统复杂度，为软硬件设计带来了新的挑战。除常规转向控制问题外，冗余线控转向还需要解决双动力系统的协调配合问题、切换控制问题和故障诊断等问题。本课题针对这些问题，从架构设计、控制方法和故障诊断策略等方面开展研究工作。 本文以双绕组电机转向结构为基础，开发出一套具有冗余动力的线控转向系统。其中，下转向机采用全冗余电子控制器，软件架构参考汽车开放系统架构，采用分层和模块化设计方法，便于集成和扩展。双系统信息交互采用热备份逻辑，保证控制模式能够快速切换。 针对双绕组电机的耦合干扰问题，以及故障导致的输出能力下降问题，提出解耦控制和容错控制方法。无故障状态下，解耦控制算法可以减轻双绕组之间的干扰，降低电流谐波和力矩波动。单侧绕组故障时，容错控制方法利用故障绕组补充输出，并采用可变力矩分配方法避免较大的输出波动。容错控制使电机的最大电磁力矩提升了11.1%，从而提高转向执行的可靠性。 针对转向控制中的模型非线性和未知干扰等问题，提出自适应控制策略。所设计的方案使用数据驱动观测器来同步更新模型参数，从而实现控制律的自适应调整。鲁棒控制算法可以在系统参数波动和存在未知干扰的情况下保持收敛，使得转向控制误差降低了28.3%，保证冗余线控转向系统的输出准确可靠。 针对冗余线控转向系统中故障模式复杂、现有诊断策略不够快速准确的问题，提出融合故障诊断策略。该方案将基于信号和基于模型的诊断方法结合，使故障诊断覆盖更全面、结果更快速和准确。然后分析故障状态的转化逻辑，为各种故障模式设计容错控制方法，使得单侧故障后的转向角度误差降低了37.4%，从而保证冗余线控转向系统的可靠运行。

With the development of drive-by-wire and automatic driving technology, steer-by-wire has become one of the key technologies of passenger vehicles. The premise of the application of steer-by-wire system is high reliability, and using dual-winding motors as redundant steering actuators is an effective scheme to improve reliability. This scheme has fault-tolerant operation ability, and the weight and volume are small, which meets the lightweight requirements of passenger vehicles. Redundant steer-by-wire system not only improves reliability, but also increases system complexity, which brings new challenges to software and hardware design. In addition to the conventional steering control problems, the coordination problems, switching control problems and fault diagnosis problems are also need to be solved in the redundant steer-by-wire system. In order to solve these problems, the architecture design, control methods and fault diagnosis strategies are studied in this paper. Based on the steering gear with dual-winding motors, a steer-by-wire system with redundant actuators is developed. Redundant electronic controllers are adopted in the road wheel assembly. The software architecture refers to AutoSar, and hierarchical and modular design methods are adopted, which is convenient for integration and expansion. The hot backup logic is adopted for dual system information interaction, in order to ensure that the control mode can be switched quickly. Aiming at the coupling interference of dual-winding motor and the decline of output capacity caused by faults, the decoupling control and fault-tolerant control methods are proposed. In the fault-free state, the decoupling control algorithm can reduce the interference between the two windings, and reduce the current harmonics and torque fluctuations. When a single winding fails, the fault-tolerant control method uses the faulty winding to supplement the output, and adopts the variable torque distribution method to avoid large output fluctuation. Fault-tolerant control method increases the maximum electromagnetic torque of the motor by 11.1\%, thus improving the reliability of steering execution. Aiming at the problems of model nonlinearity and unknown disturbance in steering control, an adaptive control strategy is proposed. The designed scheme uses data-driven observer to update the model parameters synchronously, so as to realize the adaptive adjustment of the control law. The robust control algorithm can keep convergence under the condition of parameter fluctuation and unknown interference, which reduces the steering control error by 28.3\%, and ensures the output of redundant steer-by-wire system to be accurate and reliable. Aiming at the problems that the fault modes in redundant steer-by-wire system are complex and the existing diagnosis strategies are not fast and accurate enough, a fusion fault diagnosis strategy is proposed. This scheme combines signal-based and model-based diagnosis methods, which makes fault diagnosis more comprehensive, faster and more accurate. Then, the transformation logic of fault states are analyzed, and fault-tolerant control methods are designed for various fault modes, so that the steering angle error after single subsystem fault is reduced by 37.4\%, thus ensuring the reliable operation of the redundant steer-by-wire system.