Angle measurement technology based on magnetization vector for narrow space applications

Abstract

With the wide application of laser in the field of skin plastic surgery, micro laser galvanometer scanner has made great progress in this field with its portability. However, the measurement method used to measure the deflection angle of laser galvanometer in the narrow space of scanner with high precision remains to be studied. In this paper, an angle measurement method based on magnetic field is proposed, and the effect of the shapes of permanent magnets (PMs) on the measurement is studied by theoretical and experimental study under the condition that the maximum available space for the PMs is a 10 mm side cube. An angle measuring experimental device is set up, and the contrast experiment is carried out with different PMs which are the same as simulation. The experimental results show that cylindrical PM is more suitable than other PMs, which is consistent with the simulation results, and the maximum nonlinearity error is 0.562%. This method has the advantages of small volume, non-contact measurement, small moment of inertia, good dynamic response and no external excitation for the PMs, so it has a broad application prospect in micro laser galvanometer scanner.

Robot grasping detection technology based on 3D structured light

“…The three-dimensional principle of structured light [4,8] is shown in Figure 1. The laser projector projects a single laser line each time, which can project multiple laser lines by rotating the scanning galvanometer.…”

“…The monocular vision mode [2] has a small depth of field, which can obtain the plane features of the product, but it is unable to obtain the depth information of the product or the depth information accuracy is low, which is suitable for the case of plane loading and small height change. 3D vision can also be divided into binocular vision [3] and structured light [4][5][6][7][8]. Binocular vision [3] is applicable to products with rich surface features for feature matching, but cannot be applied to products with few or no surface textures.…”

“…Compared with passive vision, 3D structured light has strong adaptability for product surface materials and is insensitive to ambient light [4][5][6][7]. The 3D structured light method is mainly divided into fringe projector method [4][5][6] and laser projector method [7][8]. The fringe projector uses DLP to project fringe patterns, which has the characteristics of high resolution, high precision and low cost, but is greatly affected by surface materials, especially for black objects and strongly reflective surfaces.…”

An Omni-Azimuth Angle Sensor for Tilt Measuring Based on FBG Array

“…It is widely used in civil engineering [1], mechanical manufacturing [2], geophysical observation [3] and aeronautical engineering [4]. The existing angle sensors are mainly divided into electric [5]- [7], magnetic [8]- [11] and optical fiber [12]- [15]. Optical fiber angle sensor [16]- [19] not only has the unique advantages of optical fiber sensor [20]- [22], such as against electromagnetic interference, but also has the measurement accuracy and sensitivity no lower than the first two [23]- [24].…”