旋耕机组对拖拉机半主动座椅非线性振动的影响

Influence of rotary tiller group on nonlinear vibration of tractor semi-active seat

为了解旋耕机组在运输和作业过程中对拖拉机座椅振动的影响,建立了拖拉机系统竖向平面三自由度振动模型,应用Matlab/SIMULINK对东方红MG654型拖拉机悬挂2BYL–4型油菜旋耕机组系统进行振动仿真,以获得座椅加权加速度均方根值最小时空气弹簧气压值和磁流变减振器电流值。仿真结果表明:当旋耕机组处于运输状态时,座椅空气弹簧气压为5 bar、磁流变减振器电流为0.650 A时,座椅加权加速度均方根值最小,为0.629m/s2;当旋耕机组处于作业状态时,座椅空气弹簧气压为5 bar、磁流变减振器电流为0.250 A时,座椅加权加速度均方根值最小,为0.520m/s2;这表明通过改变座椅空气弹簧气压和磁流变减振器电流,减小了座椅加速度均方根值,可改善驾驶员的驾驶感受。在座椅加权加速度均方根值最小时进行试验研究,并将座椅非线性振动试验结果和仿真结果对比,其最大相对误差为6.40%。由此可见,建立的非线性模型比较合理。

In order to comprehend the influence of rotary tiller group on the vibration characteristics of tractor seat in transport and working state,the vibration model of the tractor system with 3 freedom degrees were established in the vertical plane.The vibration simulation of Dongfanghong MG654 tractor suspened 2BYL-4 rapeseed rototiller system was carried out with Matlab/SIMULINK to obtain the minimum air spring pressure value and the current value of Mr Damper when the root mean square of seat weighted acceleration was the smallest.The simulation results show that the smallest value of the seat weighted acceleration root mean square is 0.629 m/s2 when the air pressure is 5 bar and the current is 0.650 A in transport state,and the smallest value of the seat weighted acceleration root mean square is 0.520 m/s2 when the air pressure is 5 bar and the current is 0.250 A in working state.It shows that the root mean square value of the acceleration of the seat could be reduced by changing the air pressure of the seat air spring and the current of the Mr Damper,thus the driver’s driving experience could be effectively improved.The experimental study was carried out when the seat weighted acceleration root-mean-square value was the lowest,and the seat nonlinear vibration test results were compared with the simulation results,and the maximum relative error was 6.40%.It can be seen that the established nonlinear model is reasonable.