Fundamental Studies on Biological Process Control by Means of Digital Computer. (V)

Simulation of Humidity Control

Abstract

In this paper, characteristics of the digital computer control of humidity in a growth-cabinet were made clear by simulation. Simulation of humidity control system on modelling of a growth-cabinet was carried out by means of hybrid computer. Sampling PID control was carried out by means of digital computer. Characteristics of K, T_I and T_D in feed-back PID algorithm of humidity were examined with τ-parameter in the simulation.
1) Value of K should be decided upon the relations with manipulating capacity P or τ. Computer control of humidity should be programmed in consideration of proper value of K in steady-state condition or in transient condition.
2) Optimum value of T_I was 200 sec in transient condition. In steady-state condition, optimum value of T_I should be smaller.
3) Values of T_D should be optimum in the next relation; 3 sec≤T_D≤20 sec.
4) Time constant of detecting means was examined with the relation of P and K. In large time constant of detecting means, stability of humidity control could be allowable on the condition of optimum K and P.