The purpose of this paper is to present a robust strategy in controlling a hydraulically actuated active suspension system. The controller consists of the two controller loops namely inner loop controller for force tracking control of the hydraulic actuator and outer loop controller to reject the effects of road induced disturbances. The outer loop controller utilized a proportional integral sl...

In this paper, the nonlinear optimal control problem is formulated for the position control of an electrohydraulic servo system. The optimal control is given by the solution to the Hamilton-Jacobi-Bellman equation, which in this case cannot be solved explicitly. An alternative method, based upon successive Galerkin approximation, is used to obtain an approximate optimal solution. Preliminary si...

Piezoelectric actuators are widely used in micro manipulation applications. However hysteresis nonlinearity limits accuracy of these actuators. This paper presents a novel approach for utilizing a piezoelectric nano-stage as slave manipulator of a teleoperation system. The Prandtl-Ishlinskii (PI) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. T...

0957-4158/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.mechatronics.2010.09.001 ⇑ Corresponding author. ⇑⇑ Corresponding author. E-mail addresses: [email protected] (J. Park), spark@jn Various electromagnetic based actuation (EMA) methods have been proposed for the actuation of microrobots. The advantage of EMA is that it can generate a wireless driving force for the microrobot, and this i...

In this paper we propose a Fractional Order Controller for an under-actuated system (POAC). This system has two degrees-of-freedom and one control input. The model of the system is derived using Euler Lagrange method and the stabilization is achieved with constraints using Fractional Order Controller. To validate the control law, simulation are performed and compared with Integer Order Controll...

Modern direct-driven and high-speed rotary tables with torque motor are optimally suited for all handling assembly applications that require the shortest indexing times flexible positioning. The following paper is devoted to study, design, optimization of an innovative table clamping system (brake accurate positioning) actuated by pneumatic energy, working at a maximum pressure 6 bar. challenge...

This paper presents a novel RF MEMS (Micro Electromechanical System) fixed-fixed switch for very fast switching. Using the obtained equations, the switching time depends on the stiffness and effective mass of the switch beam so that the switching time will be decreased by higher stiffness (spring constant) and lower effective mass. In new design, the suspension bridge is a three-layer beam so t...

Under-actuated robot manipulator is a kinematic chain wherein total degree of the freedom of the mechanism is more than actuators. Under actuated manipulators are advantageous from the minimalism viewpoint in robotics where a task is performed with less energy consuming actuations. In fact dynamic of the mechanism is exploited instead of fighting it [1][2]. Moreover, studies on under-actuated c...

This chapter focuses on the mobility analysis of spatial parallel manipulators. It first develops an analytical methodology to investigate the instantaneous degree of freedom (DOF) of the end-effector of a parallel manipulator. And then, the instantaneous controllability of the end-effector is discussed from the viewpoint of the possible actuation schemes which will be especially useful for the...