| Aming at biological search and rescue in the amphibious environment and narrow space,as well as tracking investigation and other tasks,the robot need to have high mobility,high concealment,micro structure,multi functional movement patterns etc.The existing robots have insufficient mobility,limited environmental adaptability,and lack of suitable small amphibious robots.Consequently,a father-son robotic system was proposed,which is composed of an amphibious father robot and several microrobots used as the manipulators of the system.This paper mainly focused on the spherical father robot configuration for amphibious application.Furthermore,considering the single robot was difficult to accomplish multi-tasks,the multi amphibious robot system was proposed and characteristics evaluation of the system was studied.The main research works of this paper are as follows:Based on the principle of biological bionics,this paper proposed a father-son robot system,which is composed of an amphibious father robot and several microrobots.We have described a spherical robot configuration for amphibious applications.The amphibious robot can move with a relatively high velocity and for a relatively long period of time on land and underwater.Some experiments were carried out by the amphibious spherical father robot,and a series of improvements were implemented by the father robot according to experimental results,which included the structure design and integrated controller improvement and optimization.Finite element analysis theory was adopted to analyze the structural static of the critical components of amphibious spherical father robot,and the maximum water depth of the robot was verified.Simultaneously,this paper also discusses the modal and fatigue life of these critical components as well as some related optimization.Finally the fatigue life,damage,safety factors,fatigue sensitivity and some other relevant parameters are captured.The results have shown that the fatigue life of those components meets the design requirements.Add it all up,the results can find out the weak parts of these components,and provide a theoretical basis for the optimum design of the structure,even the whole amphibious spherical robot.Denavit-Hartenberg parameters and Lagrange function was used to verify kinematic characteristics and realize movement control of amphibious spherical father robot,and the Jacobian matrix,which can reflect the relation between velocity and angular velocity of the joint,can be obtained.Some kinematics and dynamics of the robot were simulated and analyzed by using ADAMS software to verify the dynamics model of the robot and the feasibility of some bionic gaits in this paper.Following the kinematic and hydrodynamic model of robot was built and simplified,the controller based on traditional PID algorithm and neural network algorithm was designed.Additionally,comparison of experimental results demonstrated that the improved robot had better amphibious motion performance,as well as more potentiality and applicability to the real structures.Based on the strategy of biological cluster,coordinated motion and behavior optimization,and according to the characteristics and requirements of practical tasks.Firstly,this paper designed the leader-follow strategy of the multi robot system,including longitudinal shape,straight line formation and triangle formation,and the multi robot cooperative strategy of the target capturing was designed.Then,the relative localization between multi robots was proposed and realized based on TOF camera and MEMS inertial sensor.Finally,a series of formation and target capturing experiments were carried out in underwater environment to verify the effectiveness of the amphibious spherical multi robot system. |
PDF Full Text Request