マイクロコンピュータによるホッパーの重量制御

有限時間整定制御方式の適用; 流動性の良好な粉粒体の場合

抄録

In the present report, the weight control of the hopper was discussed by using a microcomputer as the controller and using sand as granules, due to its good flowability.
For the control algorithm, the so-called “Finite Time Settling Control (F. T. S. C.)” method was used and for the control action, two actions are considered; namely, integral and proportional actions which are inserted into the main loop, respectively. Applying the above F. T. S. C. algorithm, it is usually necessary for all the state variables to be fed back to the set point, but this time, only the weight of the hopper as the control variable was weasured, and the remaining variables were estimated by an “observer” which is realized within the microcomputer by the soft-ware program.
The following results were obtained:
1) The suitable index of controllability was obtained from the responses thrrough the step change of the weight and the external disturbance to the system.
2) The results of he computer simulation and the experimental wave form show good agreement and this fact shows that the simulation is useful for estimating the dynamic states of fhe granules inside the hooper.
3) Applying the F. T. S. C. method, it is more suitable to use P-action than I-action in the main loop for the following reasons.
a) The undesired influence of the saturation characteristics coming from the motion of the actuator is less for P-action than for I-action.
b) The response wave form of P-action is more stable than for I-action both for the step change of the set point value and the external disturbance.
c) In P-action, it was confirmed that there is no “off-set” in the response wave form for the external disturbance, despite of the fact that “off-set” remains for the step change of the set point value.