Use the variable frequency motor instead of the original electromagnetic speed-adjustable motor. Redesign of the hydraulic system, add electro-hydraulic proportional valve and one-way throttle valve to ensure the accuracy of automatic control and experimental safety. 使用变频调速电机代替原有的电磁调速电机,对液压系统进行重新设计,添加电液比例阀以及单向节流阀,保证自动控制的精度以及实验安全。