具有转矩不确定性的分布式驱动电动汽车横向失稳机理与控制研究

For the unique advantages in dynamic stability controlling, the distributed drive electric vehicle has become an important direction in the development of electric vehicle, but the wheel torque coordination control conundrum is the bottleneck that hinders its development. Especially, when to distribution control the desired yaw moment, the torque uncertainty will lead control mismatch for the control strategy and the controlled object, which will affect control performance in less serious situation, or deteriorate vehicle lateral instability in serious situation. This project first to analysis the lateral instability mechanism of the distributed drive electric vehicle subject to torque uncertainty, and establish multi-dimension unstable boundary model with multi-variable parameters and propose lateral instability warning mechanism. The vehicle nonlinear dynamic inverse model is then established for outputting the wheel torque, so an comprehensive online-estimation method of the multifactor torque uncertainty is proposed. A torque distribution control strategy with torque uncertainty is established, in which the vehicle lateral stability margin is extended when it is integrated with differential braking and torque vector control. In order to provide a complete test method for verifying the validity and reliability of the research results, a hardware in the loop simulation method for distributed drive electric vehicle lateral stability control is finally carry out. The establishment of theory and method for lateral stability control of the distributed driving electric vehicle with torque uncertainty has important significance in the reliability improvement of the torque distribution control, and can perfect the theory and method of the vehicle dynamic stability control.

分布式驱动电动汽车在动力学稳定性控制方面具有独特优点，已成为电动汽车的重要发展方向，但车轮转矩协调控制难题是阻碍其发展的瓶颈。特别是，当进行期望横摆力矩分配控制时，转矩不确定性会导致控制策略与被控对象失配，轻者影响控制性能，重者加剧车辆横向失稳。项目首先分析具有转矩不确定性的分布式驱动电动汽车横向失稳机理，建立多变化参数下的多维失稳边界模型，提出横向失稳预警机制；建立以车轮转矩为输出的车辆非线性动力学逆模型，提出多元转矩不确定性的在线综合估计方法；建立具有转矩不确定性的转矩分配控制策略，并结合差动制动与转矩矢量控制，实现车辆横向稳定裕扩展；为给验证成果有效性和可靠性提供完备的实验法，最后开展分布式驱动电动汽车横向稳定性控制硬件在环仿真方法研究。本项目建立的具有转矩不确定性的分布式驱动电动汽车横向稳定性控制理论和方法，对提高转矩分配控制的可靠性，完善车辆动力学控制理论和方法具有重要意义。

本项目以分布式驱动电动汽车为研究对象，以解决具有转矩不确定性的过驱动车辆横向稳定性控制难题为总目标。揭示转矩不确定性对分布式驱动电动汽车横向失稳影响的机理。提出多元转矩不确定性在线综合估计方法。建立具有转矩不确定性的转矩分配控制策略，在其中结合差动制动和转矩矢量控制，实现横向稳定裕扩展和多动力学目标达成。建立分布式驱动电动汽车横向稳定性控制硬件在环仿真方法。本项目完成预期研究目标：成功建立了基于非线性偏最小二乘回归方法的电机转矩在线估计策略，为转矩不确定性描述和分析提供了基础；提出的结合差动制动和转矩矢量分配控制的转矩分配方法，实现横向稳定性、舒适性、动力性多目标的协同达成；开发了四轮毂电机驱动电动汽车试验样车和分布式驱动电动汽车硬件在环仿真台架，建立了完备的试验方案。本项目的完成能推动分布式驱动电动汽车工程应用，为车辆在极限工况下的安全、舒适、可靠行驶提供理论支持与依据。此外，项目涉及的车辆状态估计、转矩分配控制，对过驱动的智能汽车发展也有实际应用价值。