A Non-Contact Measurement Method for Restitution Coefficient of Object Collision

Abstract

The invention relates to a noncontact measurement method for the collision recovery coefficient of an object. The method comprises the following steps: 1) constructing a high-speed camera photogrammetry network: arranging a high speed camera, arranging an illumination light source, calibrating parameters of the high speed camera, placing a planar marker, and measuring a control point; 2) synchronously acquiring the real-time sequential image of the object to be measured in collision test; 3) determining the initial image coordinates of a target point by adopting an ellipse identifying and positioning technology, and carrying out tracking matching to obtain the sequential image coordinates of the target point; (4) balancing based on the calibrated parameters of the high-speed camera and thecoordinates of the control point through adopting a sequence image-based whole beam technology to obtain the sequential three-dimensional space coordinates of the target point; and (5) acquiring displacement data of the object to be measured according to the sequential three-dimensional space coordinates of the target point in the collision test, and calculating the collision recovery coefficientof object to be measured. Compared with the prior art, the method has the advantages of noncontact, high frequency, and accurate three-dimensional measurement.

Description

technical field [0001] The invention relates to the field of material properties, in particular to a non-contact method for measuring the collision restitution coefficient of an object. Background technique [0002] The collision restitution coefficient represents the dissipation degree of the block energy before and after the collision, and can be defined as the ratio of the velocity or kinetic energy before and after the collision to the velocity or kinetic energy before the collision. The collision process is one of the most difficult objects to accurately measure in the field of material testing, and its process often requires a time resolution of microseconds. Since the object only experiences a few milliseconds during the entire falling collision process, it is necessary to decompose the millisecond-level motion process into microsecond-level or even smaller time units to achieve the purpose of accurate measurement. In traditional material engineering experiments, tra...

AI Technical Summary

Problems solved by technology

In traditional material engineering experiments, traditional sensors such as displacement meters, accelerometers, and laser rangefinders cannot measure this kind of collision-type experiments at all, and the frame rate of ordinary cameras is difficult to meet the subtleties of the movement process of collision objects. Measurement

Images