Real time capable control design with increased life expectancy for research purposes

Innovative Ideas in Science 2016

Epple, S.^1 ; Jung, R.^1 ; Jalba, K.^2 ; Nasui, V.^3

University of Applied Sciences Kempten, Research Centre, Innovapark 20, Kaufbeuren

87600, Germany^1

University of Applied Sciences Ulm, Production Engineering and Production Economics, Prittwitzstraße 10, Ulm

89075, Germany^2

Technical University of Cluj Napoca, North University Centre of Baia Mare, Faculty of Engineering, Str. Doctor Victor Babe 62A, Baia Mare

430083, Romania^3

关键词: Conventional control;    Electronic component;    Failure in time rates;    Laboratory equipments;    Mean time between failures;    Scalable control systems;    Sensors or actuators;    Thermal solar system;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/200/1/012034/pdf
DOI  :  10.1088/1757-899X/200/1/012034

来源: IOP

【 摘 要 】

A new, freely programmable, scalable control system for academic research purposes was developed. The intention was, to have a control unit capable of handling multiple PT1000 temperature sensors at reasonable accuracy and temperature range, as well as digital input signals and providing more powerful output signals at 230V AC than conventional control units. To take full advantage of the system, control-loops are run in real time. The whole system runs independently of a personal computer. The two on-board RS232 connectors allow to connect further units to use more sensors or actuators or to connect other laboratory equipment, as required. To allow usage for long-time experiments, systematically electronic components with low failure-in-time (FIT) rate have been chosen in order to achieve high life expectancy. This paper describes the third prototype, which now provides stable measurements, and an improvement in accuracy compared to the previous designs. A rough estimation about the expected mean time between failures is given. As test case, a thermal solar system to produce hot tap water and assist heating in a single-family house was implemented. The solar fluid pump was power-controlled and several temperatures at different points in the hydraulic system were measured and used in the control algorithms. The hardware design proved suitable to test several different control strategies and their corresponding algorithms for the thermal solar system.