Remote Evaluation of Rotational Velocity Using a Quadrant Photo-Detector and a DSC Algorithm

Abstract

This paper presents an approach to remotely evaluate the rotational velocity of a measured object by using a quadrant photo-detector and a differential subtraction correlation (DSC) algorithm. The rotational velocity of a rotating object is determined by two temporal-delay numbers at the minima of two DSCs that are derived from the four output signals of the quadrant photo-detector, and the sign of the calculated rotational velocity directly represents the rotational direction. The DSC algorithm does not require any multiplication operations. Experimental calculations were performed to confirm the proposed evaluation method. The calculated rotational velocity, including its amplitude and direction, showed good agreement with the given one, which had an amplitude error of ~0.3%, and had over 1100 times the efficiency of the traditional cross-correlation method in the case of data number N > 4800. The confirmations have shown that the remote evaluation of rotational velocity can be done without any circular division disk, and that it has much fewer error sources, making it simple, accurate and effective for remotely evaluating rotational velocity.

An analysis and interpretation of the signals in gamma-absorption measurements of liquid–gas intermittent flow

“…Various statistical methods are used to determine τ 0 . The most popular ones include the cross-correlation function (CCF) and methods based on a modification of CCF, such as differential and complex functions, CCF with Hilbert's transform, conditional averaging, deconvolution and the phase method (Hanus 2003;Mosorov 2006b;Sommerlatt and Andruszkiewicz 2008;Hanus 2009;Kowalczyk et al 2011;Hanus et al 2014;Zych et al 2015;Zeng et al 2016;Arkani et al 2017). The cross-correlation function may be applied to signals whose relation of the signal to noise is unfavourable.…”

Applying Neural Networks in Aerial Vehicle Guidance to Simplify Navigation Systems

“…Equation (19) proposes a law which is chosen to increase range. It adjusts the longitudinal axis of the vehicle (x b ) with a vertical flight plane, orthogonal to ground, parallel to the line joining the gravity center of the vehicle and the destination target and containing the gravity center of the vehicle.…”

“…Consequently, the lateral correction to be applied (ψ dem ) is calculated by the first component of Equation (19), while the correction in the vertical plane (θ dem ) with respect to a constant glide angle trajectory given by C 1 [1] is given by the second component. Note that guidance effectively starts after apogee, which is determined by the pitch angle (θ) and after fuel burn time.…”

“…Laser guidance may be provided by means of Semi Active Laser Kits (SAL). These devices are applied in many designing areas, such as calculating rotational speed of objects and estimating dynamics of laser spots [19,20]. The bonus of these kits is their favorable position during the last periods of the guidance, when they can provide high precision for GNC systems.…”