Related Experiment Video
Updated: Aug 12, 2025

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Three-degree-of-freedom autocollimation angle measurement method based on crosshair displacement and rotation
Yan Guo1, Haobo Cheng2, Gang Liu3
1School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an 710048, China.
Abstract:
The classic autocollimation method manages to measure the two-degree-of-freedom (2-DOF) angles, namely pitch and yaw, but fails to measure the roll angle. This paper proposes an autocollimation method that enables the simultaneous measurement of 3-DOF angles in which a carefully designed cooperated reflector (CR) splits the collimated beam into two returning beams parallel to the optical axis. The 3-DOF angles of the CR can be obtained by detecting the displacement and rotation of the crosshair images received by two photodetectors. The measurement principle is dissected, and the experimental results reveal that the constructed system achieves an accuracy of better than ±1.54 arcsec in the range of ±1000 arcsec. In addition, it is demonstrated that the system can be applied to the 3-DOF angle measurement of long-distance targets.
More Related Videos
05:12Robotized Testing of Camera Positions to Determine Ideal Configuration for Stereo 3D Visualization of Open-Heart Surgery
Published on: August 12, 2021
08:27Three-Dimensional Finger Motion Tracking during Needling: A Solution for the Kinematic Analysis of Acupuncture Manipulation
Published on: October 28, 2021
Related Concept Videos
Adjusting a Traverse
Relative Motion Analysis using Rotating Axes-Problem Solving
Here, in order to determine the magnitude of velocity and acceleration for point...
Relative Motion Analysis using Rotating Axes - Acceleration
Time differentiation is...
Rotational Motion about a Fixed Axis
Relative Motion Analysis using Rotating Axes
However, to express the relative position of point B relative to point A, an additional frame of reference, denoted as x'y', is necessary. This additional frame not only translates but also rotates relative to the fixed frame, making it...
Design Example: Traverse Angle Computations