| In the age of high-speed development of science and technology,the application of robots becomes more and more widely.As an important branch of robots,micro wheeled robots have important applications in many fields,such as medical and military fields.However,the traditional motor driving method limits the further miniaturization of wheeled robots because of its high cost and complex structure.Therefore,it is necessary to explore a new and simple driving mode.Room temperature liquid metal is a kind of metal that is liquid at room temperature with the dual properties of both fluid and metal.It has good driving performance due to the large controllable surface tension gradient under the action of electric field.And it is expected to be used as a new driving motor,which provides power source for micro wheeled robot.In this paper,based on the micro nano scale electrodynamics mechanism of gallium based liquid metal and the motion mode of altering the center of gravity of wheeled robot,the liquid metal motor is applied to the driving system of micro wheeled robot with centimeter level.The shape and position of liquid metal droplets in the wheeled robot are adjusted by the electric field,so as to change the device’s center of gravity and generate torque to pull the wheeled robot to roll.This design has the advantages of simple structure,flexible control and low cost.It not only provides a new application direction for liquid metal motor controlled by electric field,but also provides a new driving scheme for micro wheeled robot with centimeter level.Firstly,the principle of electric field controlling the movement of liquid metal and the mechanism of altering center of gravity is analyzed.Besides,it is explained that the influence of continuous electrowetting effect and electrochemical reaction on the surface tension gradient of liquid metal.The force analysis of liquid metal and the mechanism of altering center of gravity is carried out.And its mathematical model is established,which lays the foundation for simulation analysis.Secondly,the basic experiment is designed to explore the general law of the movement of liquid metal controlled by electric field,analyze the principle of simultaneous stretching and movement of liquid metal caused by electric field,verify the correctness of the theory of electric field controlling liquid metal,and determine the influencing factors,so as to provide the basis for the experiment of wheeled robot driven by liquid metal.Thirdly,the different structures of the wheeled robot driven by liquid metal are designed,and the kinematics simulation analysis of wheeled robots with different structures is carried out by Adams software.The experiments are carried out to explore the motion characteristics of wheeled robots driven by liquid metal with different structures.The simulation and experimental results are analyzed comprehensively to verify the correctness of the theory and mechanism of liquid metal driving wheeled robot,which lays the foundation for its application.Finally,the vehicle application experiments of the wheeled robot driven by liquid metal are carried out to explore the influence of different factors on its motion performance and bearing capacity.On this basis,the integrated wheeled robot driven by liquid metal is designed to get rid of the limitation of external DC power supply and wire length on the application field and moving distance of wheeled robot,realizing the integration and functional application of wheeled robot driven by liquid metal. |
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