Topic
Proportional control
About: Proportional control is a research topic. Over the lifetime, 3756 publications have been published within this topic receiving 49050 citations.
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TL;DR: Dynamic environmental control of the SPAR units, which involves process feedback influenced by random climatic variations, can be obtained using an inexpensive microprocessor-based system and enables researchers to conduct precise experiments involving climatic variables to provide the necessary inputs for crop simula-tion modeling.
Abstract: COMPUTER software has been developed for a microprocessor-based data acquisition and control system to measure 64 transducers and to maintain closed loop environmental control for three sunlit Soil-Plant-Atmosphere Research (SPAR) units at Florence, SC. An assembly language program and a BASIC program were written to run concurrently by using a real-time inter-rupt. The assembly language program performs the data acquisition, real-time control, and time keeping. The BASIC program performs the dynamic signal condition-ing, the computation of control parameters, and the con-version and output of the acquired data in engineering units. Environmental control algorithms were im-plemented in software to control temperature, C02 con-centration, and relative humidity. The BASIC program utilizes the history of the absolute deviation from the control levels to compute the control parameters for the assembly language program to implement. The temperature control algorithm enabled control within ± 0.5 °C for control temperatures ranging from 15 °C to 35 °C with ambient temperatures ranging from 4 °C to 32 °C. A proportional control algorithm written in BASIC enabled C02 control for three SPAR units within ± 10 mg/L under changing radiation load with full canopy closure using one infrared gas analyzer. A C02 control algorithm using light response curves is derived to pro-ject C02 uptake and absolute deviations from the control level to correct the coefficients of light response curves. Dynamic environmental control of the SPAR units, which involves process feedback influenced by random climatic variations, can be obtained using an inexpensive microprocessor-based system. This enables researchers to conduct precise experiments involving climatic variables to provide the necessary inputs for crop simula-tion modeling.
12 citations
12 Dec 2005
TL;DR: In this article, the authors used passive level control for flotation circuits with nonlinear dynamics with soft state contraints and rigourously established the stability of the closed loop system.
Abstract: Level control plays a fundamental role in the economic operation of flotation circuits. This paper shows that Interconnection and Damping Assignment Passivity-Based Control, well-known for electrical and mechanical applications, can be used to design high performance averaging level controllers for flotation circuits units using physically motivated mass-balance principles. Using this method we can deal with multiple tanks described by nonlinear dynamics with soft state contraints and rigourously establish the stability of the closed loop system. Furthermore, the transient behavior can be easily regulated selecting the mass storage function assigned to the system. As far as we know, such performance specifications are unattainable with existing methods. The simulation of a three tank flotation circuit illustrates the main issues raised in this paper.
12 citations
29 Jun 1994
TL;DR: In this paper, the problem of implementing the Miller-Davison (1989) self-tuning integral robust servomechanism for the case of constant references and disturbances is considered and examined using an experimental multi-input multi-output apparatus; cases involving both known and unknown estimates of the steady state gain matrix T are considered.
Abstract: In this paper, the problem of implementing the Miller-Davison (1989) self-tuning integral robust servomechanism for the case of constant references and disturbances is considered and examined using an experimental multi-input multi-output apparatus; cases involving both known and unknown estimates of the steady state gain matrix T are considered. In order to improve the speed of response, proportional feedback has been added in both instances, and this has yielded a superior transient response.
12 citations
01 Jan 2005
TL;DR: In this paper, a simple PID autotuning technique for digitally controlled DC-DC boost converters using the relay feedback technique is proposed, which introduces small perturbations on the output voltage by including a relay in the control feedback and ensuring closed-loop operation during the autOTuning procedure.
Abstract: This paper proposes a simple PID autotuning technique for digitally controlled DC-DC boost converters using the relay feedback technique Controller parameter tuning is obtained introducing small perturbations on the output voltage by including a relay in the control feedback and ensuring closed-loop operation during the autotuning procedure Moreover, including the PID regulator in the relay feedback loop, the controller parameters are directly tuned according to the specified dynamic requirement The proposed algorithm is simple, it requires small tuning times and it is fully compliant with the cost/complexity constraints of integrated digital ICs Simulation results and experimental results confirm the validity and effectiveness of the proposed solution
12 citations
TL;DR: In this article, an electrohydraulic proportional control system was developed to raise the Shanghai Grand Theater as a whole to a height of 26.5 m. The arrangement of the lifting stations, the method for uniform load distribution among the spiral lift strands, the hydraulic system, the synchronization control system and the simulation and test results are presented.
12 citations