线控转向系统力反馈的研究

Research on Steer-by-Wire System Force Feedback

线控转向系统取消了转向盘与转向轮的机械连接,所以必须通过电机向驾驶员实时反馈路感,从而使驾驶员感知车辆行驶状态和路面状况。首先建立了包括驾驶员在内的转向盘力反馈模型。提出的路感控制策略包括上层控制策略和下层控制策略。上层控制策略中转向盘回正力矩建模为扭杆弹簧施加的回复力矩,与转向盘转角成线性;下层控制策略对电机电流进行比例积分控制。最后研究了不同驾驶员模型比例系数,积分系数和电流比例积分控制的比例系数,积分系数对转向盘转角跟踪性能的影响。结果表明,遗传算法优化得到的这四个参数,可使得驾驶员较好跟踪转向盘转角,路感电机电流较好跟踪目标电流,实现较好的力反馈。

Steer-by-Wire system cuts off the mechanical link between steering wheel and steered wheels,so it has to feedback road feel real time to the driver through motor to enable the driver to sense vehicle state and road state.First,a steering wheel force feedback model including driver model is built.The prescribed control strategy comprises of both the upper layer control strategy,in which the steering wheel restoring torque is modeled as proportional with steering wheel angles,and the lower layer control strategy,which adopts motor current proportional and integration control.Finally,effects of different proportional coefficients and integration coefficients of driver model and current proportional and integration control on steering wheel angles tracing performance are researched.Results show that the four parameters optimized using genetic algorithm can trace both steering wheel angles and motor currents well and realize good force feedback.