Despite many advantages, parallel manipulators are known to possess drive singularities where the control of one or more degrees of freedom is lost. Around these singular configurations, the required actuator forces grow unbounded. Previous efforts in the literature put forward singularity-consistent trajectory planning and singularityrobust modification of the dynamic equations as a solution t...

This Thesis was aimed at studying the effects of time delay in the visual feedback loop of a man-machine system. A one-dimensional, step-type input, pursuit tracking experiment was developed to study these effects with transmission-type delays of zero to ten seconds. Thirty-six subjects participated in a series of tests that covered: seven different delays, two different levels of course comple...

This paper is to study the tracking control of a piezoceramic actuator (PA). Due to the inherent hysteresis nonlinearity, the PA always causes position error in the open-loop system and instability in the closed-loop system. To remedy this problem, a new control method combining the feedforward and feedback controllers is proposed to improve the dynamic performance of the PA. In the feedforward...

As Kalman filter technology has better performance for estimation and prediction of dynamic signal, it is gradually used in GNSS signal tracking. According to the steady-state error, transfer function and equivalent noise bandwidth of Kalman filter and traditional loop in steady status, the tracking performance of these two methods is compared in theory. The theoretical analysis demonstrates th...

End effector tracking control of robot manipulators subject to dynamical uncertainties is the main objective this article. Direct task space that aims minimizing end error directly preferred. In open loop system, vector depends on uncertain terms modeled via a fuzzy logic network and self-adjusting adaptive component designed as part nonlinear proportional derivative based input torque. The sta...

The objective of this paper is to devise a vision-based control scheme for the Khepera-II robot to achieve efficient object tracking using fuzzy logic. The robot is equipped with a K2D video turret. The algorithm was verified in simulation study by the Webots simulator using a colored ball as the sample object. Pattern recognition was not performed hence the algorithm can be used for tracking t...

A wide range of dynamical systems from elds as diverse as mechanics, electrical networks and molecular chemistry can be modeled by invariant systems on matrix Lie groups. This paper extends the concept of approximate tracking in the high-frequency limit to non-nilpotent three-dimensional matrix Lie groups by making use of feedback nilpotentization for the local representations of these systems....

Object tracking by sensor fusion has become an active research area in recent years, but how to fuse various information in an efficient and robust way is still an open problem. This paper presents a new algorithm for tracking speaker based on audio and visual information fusion using particle filter. A closed-loop architecture with reliability of each individual tracker is adopted, and a new m...

In this paper we concentrate on MPSK carrier frequency estmation based on random data modulation. We present a fast, open-loop frequency estimation and tracking techinque, which combines a feedforward estimator stucture and a recursive least square (RLS) predictor. It is suitable for the frequency estimation and large frequency acquisition and tracking required of burst mode satellite modems op...