基于REPS系统的助力曲线设计及性能分析

通过理论推导以及实车测试,证明电动齿条助力转向(REPS)系统相比电动管柱助力转向(CEPS)系统更有优势。在REPS的基础上进行电机助力特性曲线的设计,并对实车转向性能进行实验验证,将结果与同级别CEPS对标车性能进行对比。实验结果表明:采用该REPS方式后,实验车在静止工况和车速为10 km/h工况下的最大方向盘手力绝对值平均值分别为3.313和1.953 N·m,平均方向盘手力绝对值平均值分别为2.473和1.620 N·m,均明显小于同级别CEPS对标车,转向更加轻便;实验车在高速、中速及低速工况下的回正时间分别为0.60、0.30和0.16 s,最终残余橫摆角速度都趋近于0(°)/s,有更好的回正性能;实验车在0.5 Hz频率下的横摆角速度-方向盘转角增益为0.338 s^-1,在1 Hz频率下的横摆角速度滞后时间为0.07 s,转向精准性和转向敏捷性均优于同级别CEPS对标车。

Power-assisted curve design and performance analysis based on REPS system

Through theoretical derivation and actual vehicle testing,it was proved that the Rack Electric Power-assisted Steering(REPS)system has more advantages than the Column Electric Power-assisted Steering(CEPS)system.The power-assisted curve based on REPS was designed and the steering performance by actual vehicle testing was verified,then the results with the benchmarking vehicles was compared.The test results show that after using the REPS mode,the maximum hand torque of the experimental vehicle is 3.313 and 1.953 N·m under the condition of static and the speed of 10 km/h,and the average hand torque is 2.473 and 1.620 N·m,both of which are significantly smaller than the benchmarking vehicles of CEPS,so the steering torque is more lighter.Under the conditions of high speed,medium speed and low speed,the return time of the experimental vehicle is 0.60,0.30 and 0.16 s respectively,and the residual yaw rate is close to 0(°)/s,so the steering returnability is better.The yaw rate-steering wheel angle gain of the experimental vehicle is 0.338 s^-1at 0.5 Hz,and the lag time of the yaw rate is 0.07 s at 1 Hz,showing better accuracy and agility than the benchmarking vehicles of CEPS.