Proportional control

About: Proportional control is a research topic. Over the lifetime, 3756 publications have been published within this topic receiving 49050 citations.

Method and circuit arrangement for automatically parameterizing a quick-acting digital speed control loop

Abstract: A filter module inserted into a speed control loop to shorten the rise time of the loop. The filter parameters of the filters provided in the filter module and the controller parameters are calculated in such a way that instances of resonant rise. The amplification factors for the proportional controller branch and the integral controller branch are increased, which leads to a shorter rise time.

Hydraulic circuit for four-position closed-center selector valve controlled by pressure proportional control valve

Abstract: A hydraulic circuit, having a four-position closed-center valve (6) controlled by a proportional control valve (22), can facilitate the vertical position control and operating speed control of a blade with a simple structure, while providing that the floating condition of the blade can be precisely recognized by the position of a control lever (20a). The spool (41) of the four-position selector valve (6) has a "hold" position which is given by the closed-center position. Opposite ends of the spool (41) receive a pilot pressure from the pressure proportional control valve (22), one position being obtained by applying pilot pressure to a first end of the spool (41), and two positions being obtained by applying pilot pressure to the second end of the spool (41). One of the latter two positions is a "floating" position, while the other two positions are the "up" position and the "down" position. The control lever (20a) for the pressure proportional control valve (22) can have a detent device for fixing the control lever at the "floating" position.

Comparison of controllers for a three-phase Phase Locked Loop system under distorted conditions

Abstract: The analysis and design of a three-phase Phase Locked Loop system to synchronize to the electrical grid is presented. The whole phase locked loop model is obtained and a Proportional Integral, a Proportional Integral Derivative and a novel Fractional Proportional Integral controllers in continuous time domain are proposed to solve the phase tracking by improving time response, phase error and overshoot. The performance of the three controllers is analyzed under distorted utility conditions, such as imbalance, harmonics and phase and/or frequency variations. The phase locked loop is totally implemented by software, and tested by simulation via SIMULINK and experimentally via xPCTarget, in a three phase Autoadjustable Synchronous Reference Frame application. A comparison in the dynamic and steady state of the phase locked loop parameters like accurate, robustness and fastness is carried out for the three different controllers.

A multi-rate nonlinear state estimation for hard disk drives

Abstract: In this paper, we propose a new multi-rate state estimator for seeking control of hard disk drives, which has a proportional, integral, and discontinuous error feedback structure to improve robustness. Conventional state estimators do not have enough accuracy under the existence of external disturbances and model uncertainty. With the proposed estimator, the seeking control system of hard disk drives can have better robustness. Our main focus is on the discontinuous action, which alleviates the estimation error caused by, for example, actuator gain variations. Integral action is secondarily introduced not only to cancel out a quasi-constant disturbance and uncertainty, but also to reduce the chattering motion caused by the discontinuous feedback. Simulations and experiments have been carried out to validate our proposed multi-rate state estimator. Finally, an experimental example of seeking control for a single stage actuated hard disk drive is demonstrated.