Development of high performance servo drive/anti drive mechanism for backlash removal
Keywords: 1 Degree of freedom Platform, Backlash Removal, System Modelling. Abstract: In electromechanical drives, there is always a backlash between any pair of gears. Because of this, it is almost impossible to realize a high accuracy and high performance drive. However such drives are crucial in today’s modern electromechanical systems. A high performance drive/anti-drive servo mechanism is developed to eliminate the effect of backlash. The concept utilizes redundant unidirectional drives to assure positive coupling of gear meshes at all times. Based on this concept, a methodology for enumeration of admissible redundant-drive backlash free mechanism has been established. The angular displacement is achieved as a difference of two torques. These torques can be controlled by a high performance control system. A controller model will be designed to move a single degree of freedom platform up to a desired span with a payload.
Discrete Output-Prediction based Proportional Switching controller
This paper introduces a novel control law that is generic in nature and stabilizes linear and a class of non-linear systems. The parameters of the proposed controller give the same flexibility of tuning the transient response of a system as the standard PID does. The superiority of the Output-Prediction based Proportional Switching (OPPS) controller lies in the fact that it addresses the fundamental implementation problems of the PID such as integrator windup, high frequency gain of the derivative term and especially sacrifice of rise-time as system damping is further enhanced using the derivative term. Extensive simulation results are presented implementing OPPS on different linear and non-linear systems that show its generic nature and strength. Finally OPPS is implemented to stabilize a 2-DOF platform stabilization scheme and results are compared with those of a PID.
Zoom-based head tracker in complex environment
In this paper, we establish a nearly real-time surveillance tracking system, which is able to detect any person who intrudes to a prohibited area and lock his head image at the scene center. The entire underlying algorithm consists of a motion detector, an elliptical head tracking algorithm, auto-zooming ability, and a VPDA filter which is modified by probabilistic data association filter (PDA filter). The system operates about 35 ms and actively controls the camera platform pan and tilt motion to track a person in real environment.