A novel velocity measurement method based on contact image sensor

Abstract

In many industrial fields, the camera is often used to capture the movement of the geometric figure and measure the movement speed of the object through image processing, but the camera is very expensive and has high requirements for the field installation environment. In this paper, a new low-cost velocity measurement method based on CIS (contact image sensor) is proposed. Because CIS is a kind of linear array image sensor, so if the sampling rate is not high enough, it is easy to produce image blur. Therefore, CIS is not suitable for scanning high-speed moving targets. However, the blurring degree just reflects the moving speed of the scanned object. When CIS image scans the triangle figure with high speed, the gray level will change gradiently due to the influence of the hypotenuse of the triangle. In this paper, a CIS scanning system is setup with a triangle icon as scanned color tag. Through many tests and digital signal processing, the relationship between the gradient change of pixel gray value data and the moving speed of target is linear fitted. The measurement results show that the method can measure the motion speed of color tag. The accuracy of measurement depends on the resolution of CIS sensor and the sampling rate of the system.