As a new type of water operation platform in recent years, surface unmanned boats have gradually become a hotspot for many scholars to study. The path planning capability of unmanned boat is an important measure of the intelligence degree of unmanned boat. To address the obstacle avoidance problem of surface autonomous unmanned boat path planning, this paper proposes a global path planning method for surface autonomous unmanned boats based on the improved grid method by modeling the known water environment with a grid method. In order to accurately simulate the impact of obstacles on the path planning of surface autonomous unmanned boats due to the drifting effect, this paper simulates the drifting increment of obstacles on the water surface by setting different obstacle forms and sizes, and conducts a MATLAB simulation platform to simulate the drifting increment of obstacles on the water surface. The simulation experiments prove the real reliability of the improved obstacle avoidance strategy algorithm proposed in the main paper.
The Galvanized steel sheet is used as the automotive body material, and the evaporation of zinc into the weld seam will cause welding defects during the laser welding process. The multi-point laser beam has great development potential in automobile industry, because it can effectively reduce the integration of the galvanized layer into the weld seam during welding. In this paper, a panda-shaped three-point beam (panda beam) is proposed to replace the original single beam used in welding and three methods to realize the panda beam have been discussed. The beam splitting of the diffraction grating is performed, and the three, five and four beam-splitting ratio Daman gratings are obtained but with relatively high energy loss. Additionally, based on the theory of grating diffraction, a panda beam has been obtained by splitting the 4kW incident laser through the Bragg grating. The single front beam radius is 0.6mm with a power of 1.1261kW, and the distance between the two front beams is 3.8mm. The radius of the main beam is 1mm with a power of 1.7168kW, and the distance from the front beam to the main beam is 9.7mm. Lastly, based on the beam splitting theory of geometric optics, the multi-point beam and the panda beam are realized by the ridge reflector with an energy loss of 14.09%, which shows the great advantage of laser beam splitter compared with multi-light source structure in practical application. When welding with the panda beam, two functions of zinc coating and solder melting are carried out respectively, which can avoid zinc vapor entering the molten pool and improve the welding quality
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.