Proportional control

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

Control-structure interaction

Abstract: The feasibility of using conventional proportional-integral-derivative (PID) control and an alternative optimal control to perform the pointing and tracking functions of the Space Station solar dynamic power module is investigated. A very large state model of six rigid body modes and 272 flexible modes is used in conjunction with classical linear-quadratic-Gaussian (LQG) optimal control to produce a full-order controller that satisfies the requirements. The results are compared with a classically designed PID controller that was implemented for a much smaller (six rigid body, 40 flexible modes) model. The conventional control design approach is shown to be very much influenced by the order reduction of the plant model, i.e. the number of retained elastic modes from the full-order model, suggesting that for a complex, large space structure, such as the Space Station Freedom solar dynamic module, application of conventional control system design methods may not be adequate. The use of LQG control is recommended, and method for solving the large matrix. Riccati equation that arises from the optimal formulation is provided. >

A comparative study of servosystems with acceleration feedback

Abstract: Benefits and limitations of the acceleration feedback use in electrical servosystems are researched. The performance of a speed control system with a PI controller and following acceleration feedback-based speed controllers are compared by computer simulation: PI controller extended by inner proportional acceleration controller, proportional controller extended by feedback compensation action for the estimated load torque, and polynomial speed controller. The comparison is carried out for a wide range of characteristic process parameters, assuming measurement of the acceleration by time-differentiation of the measured speed, and taking into account sensitivity of the speed control loop to noise and inner current control loop modeling errors. Comparative experimental results for a positioning servosystem with friction disturbance are also presented.

Improvement in Arterial Oxygen Control using Multiple Model Adaptive Control Procedures

Abstract: A computer-based proportional-integral (PI) controller has been developed to control arterial oxygen levels in mechanically-ventilated animals. Arterial oxygen saturation is monitored using a non-invasive oximeter and control is effected by adjusting inspired oxygen fraction. The performance of the feedback system is sensitive to the open-loop gain so that the desired transient specifications can only be achieved by empirical adjustment of a PI controller. Because the open-loop gain includes the animal's response, it may vary with time and with the administration of positive end-expiratory pressure. Multiple model adaptive control procedures were therefore used to desensitize the system to these gain variables. Computer simulations demonstrated the effectiveness of the algorithm over a wide variation of plant parameters. A comparison with a fixed well-tuned proportional-integral controller showed an improvement in the regulatory response to a step disturbance. Animal experiments reiterated the feasibility of using multiple model adaptive control procedures in arterial oxygen saturation regulation.

Research on PID Control Parameters Tuning Based on Election-Survey Optimization Algorithm

Abstract: According to the tuning rule of PID control parameters, IAE, ISE, ITAE, ITSE performance criteria are chosen to be optimization object, a new optimization method of PID control parameters tuning based on Election-survey Optimization Algorithm is presented, and is applied to design optimally a PID control, and the simulation results show that satisfactory performances are obtained by means of this method developed.

Force controlled contour following on unknown objects with an industrial robot

Abstract: This paper deals with controller features which improve force controlled contour following. This kind of robot force control may by used in surface finishing tasks like polishing, deburring or grinding. The already introduced proportional controller with positive position feedback brought very good results in force control of a position controlled robot in both impact and contact phase. If the characteristics of the environment which should be finished with the robot tool are not constant, unfavorable contact forces may occur which can damage the tool or the workpiece. For the purpose of adapting the current inclination angle between robot end-effector and environment we investigate the insertion of an additional integrator into the force controller. Thereby, it will be possible to reduce static control errors. However, more attention should be paid during its parameterization with respect to the stability boundary of the closed loop control. Another novel feature in this paper is the variation of the end-effector velocity as a function of the force control error. With this idea force peaks can be decreased or the loss of contact between robot end-effector and environment can be avoided, e.g. when the inclination angle of the environment changes. All algorithms proposed in this paper are successfully verified by practical experiments.