Proportional control

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

Performance of Optimum Tuned PID Controller with Different Feedback Strategies on Active-Controlled Structures

Abstract: In this study, multi-story structures with different combinations (on each floor and only the first floor) of active tendon control systems driven by a proportional–integral–derivative (PID) controller were actively controlled. The PID parameters, Kp (proportional gain), Td (derivative gain), and Ti (integral gain) for each structure, were optimally tuned by using both the harmony search algorithm (HS) and flower pollination algorithm (FPA), which are metaheuristic algorithms. In two different active-controlled structures, which are formed according to the position of the PID, the structural responses under near-fault records defined in FEMA P-695 are examined to determine the appropriate feedback which was applied for displacement, velocity, acceleration, and total acceleration. The performance of the different feedback strategies on these two active-controlled structures is evaluated. As a result, the acceleration feedback is suitable for all combinations of the active control system with a PID controller. The HS algorithm outperforms the optimum results found according to the FPA.

In-Cycle Closed Loop Control of the Fuel Injection on a 1-Cylinder Heavy Duty CI-Engine

Abstract: The focus of this article is on implementation of real time combustion control by using an FPGA. The feedback used for the controller is the heat release. Due to the desire to avoid using division on the FPGA an alternative way of calculating the polytropic exponent is investigated. When this method is compared against using a constant exponent it shows less fluctuations in regards to cycle to cycle variations when calculating the heat release. A dual injection strategy is used and real time control is implemented on the second fuel injection. The calculated heat release is continuously compared with a reference and then the difference is converted to a duration correction of the filet injection. This is done by a proportional controller which is initiated after the start of the second injection. By adding a perturbation on the first fuel injection the controller is shown to compensate during the second and thereby decreasing the cycle to cycle variations. (Less)

Piezoresistive feedback for improving transient response of MEMS thermal actuators

Abstract: We examine exploiting the inherent piezoresistivity of a polysilicon compliant mechanism to provide feedback sensing of the mechanism displacement. As the piezoresistive compliant mechanism deflects to produce motion its resistance changes producing a usable signal. The goal of this work is to improve the transient response of a thermal actuator through piezoresistive feedback control. Implementing feedback control significantly improves the actuators transient response. The actuator response time to step inputs is reduced from 800μs to 230μs with proportional control alone. The system bandwidth was increased from 500~Hz to 4~kHz with proportional control. The large overshoot in the step response or the resonant peak in the frequency response can be reduce by an appropriately tuned 2~kHz notch prefilter.

Motor speed controller

Abstract: PROBLEM TO BE SOLVED: To provide a speed controller of simple arrangement with excellent ability to suppress disturbance such that the rate of overshooting is low even at high speeds. SOLUTION: A speed control part 13 comprises a speed integration compensating low-pass filter 133 having a transfer function corresponding to the delay of a speed control system; an integration control system 136 including a speed integrator 132 which integrates a speed deviation between a delay speed command obtained by inputting a speed command to the low-pass filter 133 and a speed; a proportional control system 137 which outputs a command proportional to the deviation between the speed command and the speed; and a multiplying means 134 by which an output of the integration control system 136 plus an output of the proportional control system 137 is multiplied by a speed proportional gain and output as a torque command. A torque control part 4 controls the motor speed in accordance with the torque command output from the speed control part 13 so that the motor speed conforms to the speed command. A speed feedback low-pass filter 135 is provided having a transfer function that prevents a ripple resulting from the position detection of an encoder E from appearing in the torque command. COPYRIGHT: (C)2005,JPO&NCIPI

Modeling and control of an airbrake electro-hydraulic smart actuator

Abstract: In this paper, an accurate model of an airbrake electro-hydraulic smart actuator is obtained by physical considerations, and then different control strategies (variable-gain proportional control, PT1 control with switching integrator, and second order sub-optimal sliding mode control) are proposed and analyzed. This application is innovative in the avionic field, and is one of the first attempts to realize a fly-by-wire system for airbrakes, oriented to its immediate employment and installation on current aircraft. The project was carried on with the participation of the Italian Ministry of Defense, and was commissioned to MAG, a leading provider of integrated systems and aviation services for aerospace. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society