基于UIO的EPS系统状态反馈最优控制  

Optimal State Feedback Control of EPS System Based on UIO

作　　者：郑太雄[1] 周花[1] 李永福[1] 

机构地区：[1]重庆邮电大学自动化学院汽车电子与嵌入式系统工程研究中心,重庆400065

出　　处：《自动化学报》2014年第7期1433-1441,共9页Acta Automatica Sinica

基　　金：国家自然科学基金(61304197);重庆市教委科学技术研究项目(KJ130506);重庆市工程技术研究中心建设项目(cstc2011pt-gc30051);重庆邮电大学青年基金(A2012-78);重庆邮电大学博士启动项目(A2012-26)资助~~

摘　　要：准确地获知电动助力转向(Electric powering steering,EPS)系统阻力矩是提高行车安全的一个重要因素.针对车辆转向过程中,由不同附着路面上EPS系统所需辅助力矩与转向路感之间的差别而可能导致的误操纵问题,本文基于2自由度整车动力学的EPS系统模型,结合轮眙特性,以轮眙侧偏角和理想路面附着系数为输入,通过设计非线性观测器估计当前路面的附着系数,以获取EPS系统阻力矩;进而,根据EPS系统模型,运用未知输入观测器(Unknown input observer,UIO)估算方向盘输入转矩,并基于EPS系统状态反馈以实现对EPS系统的无传感器最优控制.最后,对基于永磁同步电机(Permanent magnet synchronous motor,PMSM)的EPS系统进行仿真实验分析.结果表明:在以电机q轴电流闭环误差最小为指标函数情形下,本设计的方向盘回正残留角从25°降到0°,能有效抑制系统外界干扰,提高了转向时人-车系统的鲁棒性.To obtain the resistance moment of the EPS （Electric powering steering） system accurately is an important factor to improve the traffic safety. Considering that the difference between assist torque and road feel of the EPS system under different kinds of pavenmnt may lead to incorrect manipulation when a vehicle is steering, a nonlinear observer based on the two-degree-freedom vehicle dynamics model and tire characteristics is designed to estimate the adhesion coefficient of the current pavement with the side-slip angle and ideal surface adhesion coefficient as inputs. Consequently, the resistance moment can be obtained. Then, according to the EPS model, the unknown input observer （UIO） is designed to estimate the steering wheel input torque. Therefore, the sensorless optimal control of the EPS system can be conducted in terms of the state feedback. Finally, the corresponding simulations are carried out through the EPS system with PMSM. The results show that in the case of the minimum of the q-axis closed-loop current error of the PMSM, the steering wheel residual angle in this approach can be reduced from 25° to 0°, which can realize disturbance rejection and improve the steering robustness of the human-vehicle system effectively.

关 键 词：电动助力转向 未知输入观测器 状态反馈 阻力距 助力-回正特性 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]