Since straightness error of linear motor stage is hardly dependent upon machining accuracy and assembling accuracy, there is limit on maximum realizable accuracy. To cope with this limitation, this paper proposed a servo system to compensate straightness error of a linear motor stage. The servo system is mounted on the slider of the linear motor stage and moves in the direction of the straightn...

An adaptive sliding mode controller (ASMC) based on characteristic model is designed to overcome the detrimental effect of large inertia ratio and large-range varying inertia in high accuracy servo systems. The servo system discrete characteristic model is established and adopted for the controller designed instead of using the traditional mechanism model. The recursive least square (RLS) algor...

This paper describes a method for estimating forces applied at the end effector of a robot without the need for force sensors. Servo motor currents and positions are used together with an accurate system model to estimate applied forces. The system model includes inertia, friction and position dependent force components. The signal processing techniques required to extract the force information...

This paper describes the Customizable Coherent Demodulation Algorithm, a servo demodulator which provides dramatically improved performance over the currently used servo demodulation methods for disk drives. The demodulation algorithm proposed here makes better use of knowledge about the readback signal coming from the disk to provide better noise immunity and more immunity to other nonidealiti...

A scale-factor-stabilized fiber-optic gyroscope by deep phase modulation is demonstrated. There are two servo loops included in this system. The first servo loop is used for stabilization of the light intensity output of the fiber-optic gyroscope. The second loop is used to stabilize the phase-modulation index. The third-harmonic frequency of the phase-modulation signal is used for detection of...

As capacity demands for magnetic tape storage systems grow, servo actuator design for tracking data on high density tape media presents new modeling and control design challenges. In this paper a frequency weighted subspace identification algorithm is presented for control relevant model estimation of a tape servo actuator. Common to other subspace identification methods, the proposed algorithm...

The servo control design for a piezo-electric dual-stage instrumented suspension to achieve windage vibration reduction for high track density recording is presented in this paper. The servo design exploits the information available from both the sampled position error signal (PES) and a continuous time instrumented suspension signal (ISS) available from an instrumented suspension. The ISS from...

This paper presents an internal model-based approach for trajectory tracking in the discrete time-varying setting. A newly designed parallel kinematics servo gantry is well suited for high precision contouring at high speed ranges. The discrete time-varying internal model-based control is developed for controlling the servo gantry system to track complicated trajectories generated by linear tim...

The conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put forward. First, the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil volume is analyzed. Then, a scheme using double servo valves to realize flow feedforward compensation is presented, in wh...