提出了一种平面移动式立体车库用的自动对中式汽车回转台，分析了其自动对中的工作原理和液压系统回路;建立了对称阀控非对称液压缸动力机构的模型，推导了液
压缸活塞杆位移和伺服阀阀芯位移的传递函数;在 AMESim 和 Simulink 中分别建立了液压系统模型和输入信号模型，推导了输入信号和活塞杆位移的开环传递函数，论证了此闭环系统的稳定性;应用 AMESim/Simulink 对液压系统回路的动态特性进行联合仿真，得到了不同输入条件下两活塞杆位移曲线以及两活塞杆位移的误差曲线． 仿真结果表明，两活塞杆位移存在一定失真度但属于正常现象，说明该装置可行并有效．

Proposed in this paper is an automatic-centering rotary platform for a kind of planar movable stereo car garage,and its automatic centering principle and hydraulic system circuit are analyzed.Then,a power mechanism model of the asymmetric hydraulic cylinder controlled by the symmetric valve is constructed,and a transfer function between the piston rod displacement of the hydraulic cylinder and the spool displacement of the servo-valve is de- rived.Moreover,a model of the hydraulic system and a model of the input signal are constructed respectively by u- sing AMESim and Simulink,and an open-loop transfer function between the input signal and the piston rod dis- placement is deduced to verify the stability of the closed-loop system.Finally,the dynamic characteristics of the hydraulic system circuit is collaboratively simulated by using AMESim/Simulink,thus achieving the displacement curves and displacement error curves of two piston rods under different input conditions.Simulation results demon- strate that，for the displacement of the two piston rods,there exists a certain distortion,but it is a normal phenome- non,which means that the proposed platform is both feasible and effective.