转向制动工况下平衡重叉车横向稳定性控制
Lateral Stability Control of Counterbalanced Forklift under Braking and Steering Conditions

为了克服实际叉车转向制动作业工况下质心位置的时变和动态行为不确定性导致整车侧倾，改善该工况下叉车的横向动态稳定性，建立了叉车制动转向工况半车动力学模型，以叉车横摆角速度和横向加速度为反馈控制量，设计了叉车主动后轮转向线性二次型调节器，得到最优输出反馈增益矩阵，对转向制动工况下的叉车横向稳定性进行最优控制并进行仿真计算。仿真结果表明，叉车制动性能保持基本不变的情况下，反映叉车横向稳定性的横向加速度和横摆角速度响应得到明显改善。依据欧洲标准EN16203：2012动态稳定性试验方法和要求进行的实车试验结果表明：叉车横向稳定性的指标量-横向加速度、横摆角速度均方根值分别下降了19.2%和23.29%，叉车的横向稳定性得到了有效控制。
In order to prevent rollover accidents and improve the lateral dynamic stability of the forklift under braking and steering conditions, the dynamic semi-model of forklift was built at first. Secondly the adaptive LQR control strategy is proposed in this paper, and the adaptive LQR controller of the active rear wheel steering system(ARS) is designed by the yaw rate and lateral acceleration as quadratic form indicators in order to overcome the time-varying position of mass center and uncertainties of dynamic behaviors caused by various forklift working conditions. The simulation was carried out in the braking and steering working conditions in MATLAB. The result of simulation shows that the lateral acceleration and yaw rate representing the lateral stability of forklifts are improved obviously in different working conditions and the lateral stability of forklift is also be enhanced significantly. The result of road test also shows that the root mean square values of the lateral acceleration and the yaw rate are reduced by 19.2% and 22.39% respectively, which improved the lateral dynamic stability of the counterbalanced forklift