Research On Dynamic Analysis Of Swimming Process Of Crawling And Swimming Robot

Underwater robots are important tools for observation and operations in the water.Accompanied by the development needs of marine military strategic resource development,scientific and exploration research.it is urgent for amphibious robot to adapt to the complex work environment,so as to perform a variety of near sea combat and exploration tasks that cannot be completed by human beings.Therefore,it is of great practical value and practical significance to develop amphibious robot which can adapt to the changeable terrain of land and offshore tidal flat as well as complex underwater environment.Amphibians,which can move on the land and water,are often imitated by robots,with flexible quadruped feet that crawl on land and paddle in water.However,there are relatively many studies of quadruped bionic robot' land movements at present,but few studies on swimming in water.Many creatures in nature have excellent ability of amphibious movement.Among them,as amphibians,beavers have short forelimbs,small feet,strong claws and strong hind limbs.beavers have large quality,but they still have high speed and flexibility in water movement.One of the important reasons is the crawling and swimming movement mode.In order to explore the robot during swiping posture and movement way,the paper modeling the multi-joint dynamics model of swimming process of a crawling and swimming robot based on a beaver is presented,The dynamic model including the fins,legs and the whole structure is calculated with Newton Euler iterative formula to explore the different stroke modes for modeling,which more intuitively shows the changes of the robot's joints and the overall posture in the process of crawling.Fins is an important driving device for the underwater motion of a crawling swimming robot.It's motion mode and mechanical characteristics affect the underwater motion performance of the robot.Therefore,a hydrodynamic theoretical model of flipper movement is proposed in this paper.According to the characteristics of movement mode and swimming mechanism of beaver in propulsion stage,developing a kind of motion track suitable for robot driver to guide the swimming research of robot.And proposing the stroke dynamic factor and compound stroke dynamic factor to measure the underwater stroke performance of the robot.Finally,based on MSC ADAMS and ANSYS Fluent software for simulation verification,bulding the robot experimental platform for prototype experimental verification.By comparing the results of theoretical modeling,numerical simulation and prototype experiment of the underwater crawling robot,the rationality of the prototype design of the underwater crawling robot and the accuracy of dynamic modeling are verified.The research on the flippers shows that the key to improve the efficiency of the flippers is to reduce the water receiving area of the flippers in the recovery stage,and to avoid and use the rising water flow reasonably.The simulation and experiment show that different stroke trajectories affect the position and pose of the robot in the process of swimming,and verify the accuracy of the dynamic model in the two trajectories,which lays a foundation for the research of crawling and swimming robot.