環境試験器における温湿度制御手法の検討

抄録

Environmental testing apparatuses are widely used in production sites for quality assurance of manufactured products. They can simultaneously control both temperature and humidity inside the apparatus. However, the preinstalled controllers are traditional PID feedback control systems, and they cannot control both physical values, temperature and humidity, effectively because a PID cannot be designed for a MIMO (Multiple-Input Multiple-Output) system. Moreover, when the control input signals for the heater and humidifier reach either the upper or lower limit, the PID controller can no longer control the temperature and humidity effectively, because of the nonlinearity of the saturations. Recently, MPC (Model Predictive Control) is becoming widely used in industrial manufacturing systems because it can take into account the limitation of the control input signal, and can be applied to a MIMO system. Simulation results show the effectiveness of the MPC system which is intended to implement in the PLC (Programmable Logic Controller).