In the general framework of hydraulic servo systems, this paper addresses the problem of position control in the presence of important friction nonlinearities. The accent falls on the variable structure methodology, as we try to use its intrinsic robustness properties. Several friction observers, including the one based on a variable structure approach, were incorporated and tested in an accele...

In this document the design, control and simulation of a hydraulic model for grasping an object is presented. The principal equations that constraint such a system are first investigated through the presentation of the hydraulic components which constitute the model. Their intrinsic characteristics are discussed as well as their interactions with each other. The controller that best fit this ap...

The study researched the orifice flow equation when state of is laminar. Based on novel and expected linear equation, a compensator designed to compensate non-linearity make characteristics linear. characteris-tics experiment result shows that after compensa-tion control close flow, in which pres-sure difference was increased from 0.5MPa 4MPa, error less than 20%. When used as feed forward EHSS...

Linear electro hydraulic servo-drives have been built and used in various industrial equipment for more than sixty years. They are distinguished by the ability to develope extremely large forces with the positioning accuracy of the order of a micrometer, ensuring, at the same time, very good dynamic features. The drives characterised by very slow motion and large force are used, among others, i...

According to the nonlinear and time-varying uncertainty characteristics of direct drive electrohydraulic servo control system, a self-tuning fuzzy PID control method with speed change integral and differential ahead optimizing operator is put forward by combining fuzzy inference and traditional PID control in this paper. The rule of fuzzy logic is designed, the membership function of the fuzzy ...

This paper addresses the experimental identification of a servo actuator which is used in many industrial applications. Because the system consisted of electrical and mechanical components, the behavior of the system was nonlinear. In addition, the under load behavior of this servo was different. The load torque was considered as the input and a two input-one output model was presented for t...