Hunan Runshare developed a valve-controlled cylinder electro-hydraulic  positioning closed-loop control system with four-channel actuators through  automatic control principle study,theoretical modeling, simulated analysis and  experiment practice about leveling system. Taking Hunan Runshare Heavy Industry  Co.,Ltd telescopic series aerial work platform as background, mono-direction  supporting level-strategy will be applied to electro-hydraulic automatic control  system for platform of automobile body; the valved-controlled cylinder  electro-hydraulic position closed-loop control system has features of a higher  precision and automatic level acting on the automobile body of Runshare aerial  work Platform.

Firstly, according to the actual require of leveling device,an  electro-hydraulic automatic control system has be finished; a sequence of  actions for level and vertical legs designed; the stability of parking on hill  demonstrated;the automobile body of aerial work platform manually leveled.

Secondly, proceed from optimal computation of drive parameters for  valve-controlled cylinder, a method of hydraulic power system has been used to  match the electro-hydraulic leveling system and select the key components.

Then, electro-hydraulic proportional valve-controlled cylinder system  mathematical model is built according to classical transfer function based on  electro-hydraulic proportional control theory, which starts from hydro-dynamics  flow equation, continuity equation and force equilibrium equation. In virtue of  Matlab software, the system is proven to be stable using frequently analysis. Besides, electro-hydraulic closed-loop control  is built under the condition of Simulink, which makes it dynamic simulation and  analysis come true.

Finally, performance test platform of automobile body of aerial work  vehicle is designed and built for functional test and experimental study.Test  results show that mono-direction supporting level-stralegy is feasible for the  level system of automobile body of Runshare aerial work platform, in which the  leveling precision is within the range of 0.3 degrees,the leveling time is In  less than one minute, and it maintains a stable state more than 8 hours, which  lays a solid foundation for the four-point electro-hydraulic automatic level  control.