Theoretical model and application method of periodically fluctuating rotational angular speed with stepping motor

Abstract This paper presents a theoretical model and application method for generating periodically fluctuating rotational speeds using a stepping motor. While speed fluctuation generally degrades rotor performance, it can be advantageous in certain vibration-based machines. This work facilitates research into both the suppression and exploitation of speed fluctuations. A sine function models the fluctuating speed, and the theoretical model is derived via definite integration. Simulations investigate the effects of model parameters on pulse sequence length and speed error. Experimental verification was conducted using a specialized test setup. Six key parameters were individually varied across six experimental groups, each repeated twenty times to mitigate random error. Steady-state performance was evaluated using average results. The proposed model and method are applicable to studying rotor system dynamic stability and simplifying the design of vibration-based machinery.