Speed control of symmetrical type three-mass resonant system by PID-controller

In this paper, we deal with a symmetrical type three-mass resonant system like an elevator system. First, the block diagram of the symmetrical type three-mass resonant system is converted into a form with two types of vibration blocks, it is found that there is a vibration which can't be observed from motor speed when the parameters become a certain condition. We employ the PID-controller and attach dampers to simple-rods that is a kind of flexible shafts. We can raise response frequency to anti-resonant frequency and determine arbitrary damping characteristics of the system by the PID-controller. The vibration which can't be observed on the motor side is suppressed by attaching dampers to simple-rods.