Vibration suppression of electromagnetic-force-restoration weighing cell using wave control

High-speed and high-precision weighing is required in industrial and medical fields. Recently, medical services have improved rapidly and the demand for medicines have increased. Because improper medication can lead to life-threatening symptoms, precise filling and weighing all medicines are vital processes. On the other hand, there are requirements from suppliers to increase production volume. For this problem, Reduction the time by applying vibration-suppression control for a weighing cell is presented. The weighing cell exhibits oscillating responses as it has vibration mechanism inside. This vibration increases the weighing time and then reflected-wave rejection is introduced to suppress the vibration. Because reflected-wave rejection is a phase-stabilizing method, the controller attains a robustness against modeling errors. As a result, the weighing cell did not vibrate regardless of existence of a load. In addition, lift-up operations of vial bottles with water by the weighing cell were also conducted. The water surface did not fluctuate and immediately settled. Reflected-wave rejection certainly contributes to reducing the time for weighing.