With the significant increase in demand for artificial intelligence, environmental map reconstruction has become a research hotspot for obstacle avoidance navigation, unmanned operations, and virtual reality. The quality of the map plays a vital role in positioning, path planning, and obstacle avoidance. This review starts with the development of SLAM (Simultaneous Localization and Mapping) and proceeds to a review of V-SLAM (Visual-SLAM) from its proposal to the present, with a summary of its historical milestones. In this context, the five parts of the classic V-SLAM framework—visual sensor, visual odometer, backend optimization, loop detection, and mapping—are explained separately. Meanwhile, the details of the latest methods are shown; VI-SLAM (Visual inertial SLAM) is reviewed and extended. The four critical techniques of V-SLAM and its technical difficulties are summarized as feature detection and matching, selection of keyframes, uncertainty technology, and expression of maps. Finally, the development direction and needs of the V-SLAM field are proposed.

A novel SiC Schottky barrier diode (SBD) hydrogen gas sensor with trench-insulator structure was proposed in this paper. A physical model is built for this hydrogen sensor based on 4H-SiC SBD thermionic emission theory, tunneling effect of carriers, adsorption/desorption principle of hydrogen and modulation effects of Schottky barrier height. Use Silvaco TCAD, the semiconductor simulation software, to analyze SBDs with trench-insulator layer and to compute current-voltage characteristics at different temperature, hydrogen concentration and trench width under forward bias. The temperature and hydrogen concentration affect the I–V characteristics of the devices by changing the Schottky barrier height. Compared with normal metal-silicon carbide and metal-insulator-silicon carbide devices at 573 K in terms of on-off voltage, current resolution, response speed, and stability, the trench-insulator hydrogen sensor showed good performance. Relationship between device characteristics and trench width was researched using the above model. Trench width has an opposite effect on sensor resolution and sensitivity.

In this research paper, we design a touch mode capacitive micro pressure-sensor with circular stepped-cavity and SiC-AlN-SiC material structure, which can be more precisely measured pressure in a high-temperature environment. Using the finite element analysis method (based on ANSYS software), we found that the sensitivity of the sensor reached 3.5 pF/MPa, up almost one-third from traditional single-cavity structure in the long linear working range as 0.9–1.4 MPa. Moreover, the research to thermal behaviours of the sensor is shown that high temperature has affected the diaphragm deformation and the von Mises stress of the sensor due to thermal buckling. But the thermal deformation did not change the intrinsic characteristics of this sensor. Consequently, the sensor packaging with high-temperature ceramic material is endured the higher temperature to be applied in a harsh environment.