Design and Implementation of Rotary Inverter for Speed Measurement of Tracked Vehicles

Abstract

Accurate speed measurement and running records are integral to ensure safety and periodic maintenance of vehicles. This paper presents a novel structure of a solid rotary inverter (DAC) sensor for linear speed measurement of vehicles by eliminating reliance on magnets, coils, armatures, and toothed rings. The electromechanical sensor is exited through the vehicle’s DC power from the battery and utilizes a specially designed solid rotary part that is rotated mechanically by the wheel, enabling conversion of the DC into three-phase AC. The frequency of the produced AC voltage is proportional to the rotation speed. The three-phase alternating voltage is then used to run an analog speedometer gauge (a three-phase AC motor) to display the linear speed. The study determines stability analysis and response assessment by modeling a novel electromechanical rotational system and then evaluating its optimal design parameters. Real-time output voltage data from the sensor is acquired using a Rohde & Schwarz RTM 2034 oscilloscope and processed in MATLAB R2022b for frequency analysis. Experimental tests are conducted in a laboratory setting, varying the rotational speed sweep of the sensor from 150 to 450 RPM and translating the results into linear speed. A machine learning regression technique is applied to features such as shaft rotational speed, angular velocity, frequency, and period with linear speed. The obtained results reveal a total harmonic distortion (THD) value of -28.9778 dB (3.557%), meeting the criteria outlined in the IEEE 519-2014 "Recommended Practice and Requirements for Harmonic Control in Electric Power Systems".