CONTROLLING THE OSCILLATIONS OF A SWINGING BELL BY USING THE DRIVING INDUCTION MOTOR AS A SENSOR

摘要

Swinging bells deliver the best sound quality when the swinging angle is kept to a specific value proper to each system. The aim of our paper is to propose an original method for controlling this swinging angle without any external sensor, by using the driving motor (actually a three-phase induction machine) as a sensor when it is not active as a motor. In the sensor mode, we control the maximum speed of the bell, which is related to the swinging angle by a time-invariant mechanical coefficient specific to each bell system. The main advantage of the proposed solution is that the speed information is practically insensitive to the motor parameters variations. This solution, well adapted to the problem of concern, establishes a close interrelation between the motoring, sensoring and regulating aspects. The pertinence of our solution is deduced from theoretical developments and confirmed both by simulations and experimental observations on a real swinging bell system.