Proportional control

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

Design of a Data-Driven PID Controller

Abstract: Since most processes have nonlinearities, controller design schemes to deal with such systems are required. On the other hand, proportional-integral-derivative (PID) controllers have been widely used for process systems. Therefore, in this paper, a new design scheme of PID controllers based on a data-driven (DD) technique is proposed for nonlinear systems. According to the DD technique, a suitable set of PID parameters is automatically generated based on input/output data pairs of the controlled object stored in the database. This scheme can adjust the PID parameters in an online manner even if the system has nonlinear properties and/or time-variant system parameters. Finally, the effectiveness of the newly proposed control scheme is evaluated on some simulation examples, and a pilot-scale temperature control system.

Adaptive control of a stewart platform‐based manipulator

Abstract: A joint-space adaptive control scheme for controlling noncompliant motion of a Stewart platform-based manipulator (SPBM) was implemented in the Hardware Real-Time Emulator at Goddard Space Flight Center. The six-degrees of freedom SPBM uses two platforms and six linear actuators driven by dc motors. The adaptive control scheme is based on proportional-derivative controllers whose gains are adjusted by an adaptation law based on model reference adaptive control and Liapunov direct method. It is concluded that the adaptive control scheme provides superior tracking capability as compared to fixed-gain controllers.

Design and control of Proportional-Resonant controller based Photovoltaic power conditioning system

Abstract: This paper presents a current control technique for a single-phase grid-connected DC/AC inverter which is used in Photovoltaic power conditioning system (PV PCS). A Proportional - Resonant (PR) controller is used for replacing the conventional Proportional - Integral (PI) controller in this system. By comparison with the conventional PI control method, the PR control can introduce an infinite gain at the fundamental frequency and hence can achieve zero steady-state error. A theoretical analysis of the PR controller is presented and verified by experiment. Furthermore, a pseudo synchronous d-q transformation is employed in current control scheme and an all-pass filter based single-phase digital phase-locked loop (PLL) is introduced to detect the phase of grid voltage. Based on the theoretical analysis, the control strategy is implemented on a 32-bit fixed-point TMS320F2812 DSP and tested in a 3kW prototype PV PCS. Simulation and experimental verify the high performance of the implemented control scheme.

PID Control Using Presearched Genetic Algorithms for a MIMO System

Abstract: This correspondence presents a new approach that utilizes evolutionary computation and proportional-integral differential (PID) control to a multi-input multioutput (MIMO) nonlinear system. This approach is demonstrated through a laboratory helicopter called the twin rotor MIMO system (TRMS). The goals of control are to stabilize the TRMS in significant cross-couplings, reach a desired position, and track a specified trajectory efficiently. The proposed control scheme includes four PID controllers with independent input. In order to reduce total error and control energy, all parameters of the controller are obtained by a real-value-type genetic algorithm (RGA) with a system performance index as the fitness function. The system performance index was applied to the integral of time multiplied by the square error criterion to build a suitable fitness function in the RGA. We also investigated a new method for the RGA to solve more than ten parameters in the control scheme. The initial search range of the RGA was obtained by a nonlinear control design (NCD) technique. The NCD provided a narrow initial search range for the RGA. This new method led chromosomes to converge to optimal solutions more quickly in a complicated hyperplane. Computer simulations show that the proposed control scheme conquers system nonlinearities and influence between two rotors successfully.

Design and experience with a fuzzy logic controller for automatic generation control (AGC)

Abstract: This paper describes the design, implementation and operational performance of a fuzzy controller as part of the automatic generation control (AGC) system in Eskom's National Control Centre. The fuzzy controller was implemented in the control ACE (area control error) calculation, which determines the shortfall or surplus generation that has to be corrected. This paper sets out the problems associated with secondary frequency control and AGC. The difficulties associated with optimising the original standard AGC controller, the design, implementation and optimisation of the fuzzy controller and the operational performance of the new controller over two years, are discussed. The fuzzy controller was integrated into the existing off-the-shelf-AGC system with only a few modifications. The operational performance over two years showed an overall improvement of over 50% in the reduction of control compared to the original AGC controller, and an initial improvement of 20% in the quality of control of the optimised original controller.