Cylindrical-cam modulation instantaneous angular speed sensor for reciprocating-rotary machine

Abstract

This paper presents the theory and implementation of a novel sensor system for measuring the instantaneous angular speed (IAS) of a shaft with reciprocating rotary motion. The system comprises a laser displacement sensor and an S-shaped cylindrical cam sleeve fixed to the shaft. As the shaft rotates with reciprocating rotary motion, the cylindrical cam modulates the IAS signal of the machine to achieve a change in profile radius. The signal is then demodulated to obtain the IAS of the reciprocating rotary motion. The sensor system is experimentally validated using a vibration-assisted tapping machine. Results show that the IAS readings are consistent with the machine’s set parameters. Furthermore, the novel sensor produces considerably smooth and stable traces of the IAS, demonstrating its high accuracy and reliability in obtaining the IAS of reciprocating rotary motion transients. The frequency error rate of the system is less than 3%, and the highest resolution of the angular amplitude is 4.788″. Finally, a cutting experiment confirmed the feasibility and validity of the proposed sensor system in optimizing the parameters of the vibration-assisted tapping machine.