Thrust vector control (TVC) is a prime example of an aerospace system in which electromechanical actuators (EMAs) can potentially be effective. Researchers at NASA’s Marshall Space Flight Center are currently developing EMAs to replace the hydraulic servo actuators for use on space vehicles with TVC. The current paper focuses on the control of EMAs in TVC applications and on the optimization of...

Výskum vlastností hydrostatickej transmisie regulovanej rôznymi regulátormi In this paper the possibility of a uses control system with a signal processor DSP to control hydrostatic transmission was described. A hydrostatic transmission with pump variable efficiency and engine radial with constant working absorptivity was chosen. The control of the efficiency of pump was realized by using the e...

In this paper, different models of the pressure buildup inside a hydraulic servoaxis are compared. These models are obtained using RBF networks, local linear models and support vector machines (SVMs), with a particular focus on the latter. For SVMs, a reduction method is derived, which allows to reduce the number of support vectors without losing the generalization abilities of the SVM. Experim...

This paper deals with the position control of a hydraulic actuator regulated by a proportional directional control valve. The control algorithms based on the proportional-derivative controller have been applied to a specially designed two-channel electro-hydraulic servo system, which has the capacity to experimentally simulate common circumstances of a typical fluid power circuit. The first sys...

This paper focuses on optimal hydraulic component selection for electrohydraulic systems used in high performance servo tasks. Dynamic models of low complexity are proposed that describe the salient dynamics of basic electrohydraulic equipment. Rigid body equations of motion, the hydraulic dynamics and typical trajectory inputs are used in conjunction with optimization techniques, to yield an o...

This paper examines the effect of friction model on the simulation accuracy of a hydraulic cylinder by using three friction models: a steady-state friction model, the LuGre model, and the new modified LuGre model. Hydraulic cylinder’s behaviors were measured under sinusoidal input to the servo valve. Simulations were conducted under the same conditions as the experiments. The comparisons of sim...

Abstract There are stochastic initial disturbances which lead to unexpected tracking errors of the ammunition manipulator during starting stage. In this paper, a prescribed performance control strategy is proposed for steady constraint coordinator. order keep position coordinator in whole process within range, theory adopted convert system original error into new form that can be restrained thr...