# Pose Measurement Method Based on Machine Vision and Novel Directional Target
## 4 Results
### Pose Solving Practical Filling Experiments  
The experimental system of monocular vision pose measurement built in the actual scene is shown in Figure 12, and the testing platform is mainly composed of a two-axis rotary table and a camera. The model of the two-axis rotary table is PTU-E46-17P70T, the accuracy of the pitch axis is up to 0.003 degrees, and the accuracy of the tumble axis is up to 0.013 degrees. The camera chosen is a Basler ace2 a2A2840-48 ucBAS, equipped with a Sony IMX546 CMOS chip, with a frame rate of 48 fps, a resolution of 8 megapixels, and horizontal and vertical pixel dimensions of 2.74 \(\mu\)m. The lens of choice is the Ricoh Lens FL-CC0616A-2M, with a focal length of 6.0 mm and an aperture of F1.4-F16.0. According to the settings of the simulation experiment, the pictures are taken with the same pose. The actual shooting pose solution results are shown in Figures 13-16. The line chart above represents the pitch angle error value, the line chart below represents the roll angle error value, the green line represents the average error value of the attitude angle, and the red line represents the maximum error value of the attitude angle. The combination of the angle of the upper and lower line graphs corresponds to complete attitude angle errors of the actual shooting graph. Figure 11: Repeat accuracy error at roll angle \(-20^{\circ}\) and pitch angle \(-10^{\circ}\). Figure 14: Smaller angle of rotation in the negative direction. Figure 12: Experimental system for monocular vision pose measurement. Figure 13: Smaller angle of rotation in the positive direction..  
From the results shown in Figure 13-16, it can be seen that using this method after considering the camera imaging noise and the overall mechanical error, the measurement error of the tumbling angle perpendicular to the optical axis direction is 0.01911\({}^{\circ}\) at most, and the average error is 0.01423\({}^{\circ}\) at most; the measurement error of the pitch angle is 0.03077\({}^{\circ}\) at most, and the average error is 0.02085\({}^{\circ}\) at most. The measurement error of the roll angle is generally much more minor than the pitch angle's, the accuracy is inversely proportional to the pitch angle, and the angular error in the roll direction is more stable. In addition to the large difference in accuracy, the change rule of the error is consistent with the simulation results. Based on the simulation experiments, the two poses of roll angle 10\({}^{\circ}\), pitch angle 5\({}^{\circ}\), and roll angle \(-\)20 \({}^{\circ}\), pitch angle \(-\)10 \({}^{\circ}\) were further selected, and 15 pictures were taken for each pose. Their average error was taken as a systematic error. The error of each image subtracted from the value of the systematic error was taken as the error of the repeatability accuracy. The experimental results are shown in Figures 17 and 18. The line chart above represents the pitch angle error value, the line chart below represents the roll angle error value, the green line represents the average error value of the attitude angle, and the red line represents the maximum error value of the attitude angle. The combination of the angle of the upper and lower line graphs corresponds to the complete attitude angle errors of the actual shooting graph. Figure 16: Larger angle of rotation in the negative direction. Figure 15: Larger angle of rotation in the positive direction. method based on machine vision and a new type of directional target is proposed to achieve high-precision measurement of object pose. The new directional target is designed and manufactured, and the object-matching algorithm for the target is implemented; the high-precision calibration of the camera is realised based on the target; various algorithms are introduced to improve the accuracy of the coordinates of the feature points and further reduce the error of the pose calculation.