Research On Relevant Problems Of Nonlinear Control Method About Hydraulic Press

High accuracy control of hydraulic press based on nonlinear model are thedifficulty and hotspot in recent years.The reason is that there are some key issues arenot solved ideally,and the relevant efficient nonlinear control method is still needed tobe developed.So some research was carried out against the issues around the nonlinearcontrol method of hydraulic press in this paper:1. A control scheme based on Lyapunov’s direct method was proposed for a classof electro-hydraulic servo system.The scheme improve the problems such ascomplex derivation,too many parameters and vague target,and find the appropriateLyapunov function and parameters.The design method ensures the stability of thesystem.2. A adaptive sliding mode controller was designed based on the interferencesupremum for a single cylinder hydraulic press which had a high-level non-canonicalform.This methods was mainly proposed against the problems such as strong loaddisturbance and parameter uncertainty.The specific design method on the gain anduncertain parameter was given to ensure the reaching condition of sliding surface.Theresult proves that the proposed scheme can realize high accuracy track and have abetter robustness.3. By analysis of compositon and principle,a general description ofmulti-cylinder hydraulic press model was given,and a unified standard model wasformed.After that,a specific modeling process for four and five cylinders press wasgiven.4. The redundant control method was investigated deeply against theoveractuated problems of multi-cylinder hydraulic press.A control scheme based oncontrol allocation theory was proposed to solve the force allocation problem,and amulti-level design idea which take the control allocation as a link was formed.Thescheme can deal with multi-point leveling problem.Then a dynamic control allocationmethod for multi-cylinder hydraulic press was explored,the simulation proves that thecylinder can get a more gentle allocation result,and the hydraulic cylinder impactproblem is improved which may be caused by the load force transition.5. The fault tolerant control research for multi-cylinder hydraulic press wasexplored,and a fault tolerant control allocation method which considers the fault information was proposed.By mobilize the actuator output capability of non-failedstate,the original performance of the system was retained intact.In summary research,a series novel control scheme were proposed againstrelevant problems of nonlinear control method about hydraulic press.The design flawsof traditional control scheme was improved,and the problems of force allcation、multi-point leveling、fault tolerant control were solved effectively.The researchachievement can provide a theoretical basis for high-performance control of hydraulicpress,and promote the further research and development of nonlinear control methodabout hydraulic press.