Novel laser Doppler tachometer

Abstract

In order to improve the accuracy and universality of the rotational speed measurement, an instantaneous rotational speed measurement method based on laser Doppler technology is proposed. The composition and working principle of the new system are discussed in detail. Theoretical and experimental results show that the new rotational speed measurement system belongs to the non-contact method, which eliminates the quantization error of the contact method and greatly improves the applicability and accuracy. Compared to the commonly used method, the measurement accuracy of the new rotational speed measurement system will not be affected by the system's installation angle deviation, and it does not need to measure the radius of the rotating body, so the influence of the radius fluctuation of the rotating body on the measurement accuracy can be avoided while outputting the rotational speed in real time. The relative error of the rotational speed measurement is less than 0.06% (1σ).

Optimization of Electrostatic Sensors for Rotational Speed Measurement of a Metallic Rotor

“…In order to satisfy the minimum requirements for both autocorrelation and crosscorrelation algorithms, it is essential to ensure that at least one complete rotation period is included in the data length for the autocorrelation algorithm, and at least one transit time is included in the data length for the cross-correlation algorithm. It is recommended that the data length should be at least 2 times the maximum T or τ at the minimum speed (RPMmin), i.e., (6) It can be seen that the autocorrelation algorithm requires a longer data length (tauto > tcross). Consequently, tauto should be considered as the lower limit of the data length for the data acquisition system.…”

“…Accurate measurement of rotational speed is thus important in the control and regulation processes of mechanical systems. primarily based on mechanical, optical [5], [6], and electrical [7] principles. Each of these sensing techniques has its own limitations, such as low accuracy, limited rangeability, mechanical wear, susceptibility to harsh environments, high cost, etc.…”

Characterization of Self-Powered Triboelectric Tachometer with Low Friction Force

“…Tachometers are widely needed in mechanical and electrical industries to characterize or monitor the rotation speed of shafts, gears, motors, etc. [18]. Constructing a self-powered tachometer is of huge industrial application interest.…”