| Electric forklifts have greater advantages than traditional forklifts in terms of environmental protection,energy saving,simple structure and high transmission efficiency.Dual-motor independent drive is also a promising new energy technology solution.This paper studies one of the core technologies of the two-wheel drive electric forklift:electronic differential control technology,and aims to improve the robustness and stability of the control system,and design a robust electronic differential control strategy.Firstly,taking the two rear wheels independently driving the electric forklift as the research object,on the basis of establishing a 7-DOF electric forklift dynamics model,and the expression of the centroid position in the model is improved for the characteristics of the fork moving frequently when the forklift is actually working.After the simulation experiment,the state space model of the controlled object is obtained by analyzing and calculating the dynamic model of the electric forklift;then,the relative slip ratio of the driving wheels on both sides is controlled,according to the input of the electronic throttle opening degree,the wheel torque is controlled directly,and the electronic differential robust controller is designed based on the robust control theory.The torque distribution of the forklift ensures the running stability of the forklift.Then,the sliding mode extreme value search method is used to control the forklift.The optimal slip ratio of driving is used as an evaluation criterion to optimize the robust controller,further the performance of controlleris improved.In this paper,the designed electronic differential robust control system is simulated with Matlab/Simulink software,and experiments are carried out in BanYiTong.The results show that the robust controller optimized by extreme value search can better distribute the torque and control the slip ratio in a more ideal state,thus it is advantageous to guarantee the stability of the forklift. |
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