Design And Experimental Research Of Small Amphibious Robot Using Direct Vibration Drive

In recent years,as the exploitation of oceans,lakes and swamps continues going deeper,the research of amphibious robots has gradually aroused people's interest.Amphibious robots are an important research direction in the field of robotics,because of its good adaptive capabilities in complex water and land environments.Amphibious robots have unique advantages in many fields such as resource detection,environmental reconnaissance,and disaster relief.In the mean while,micro-robots are the current research hotspot and development direction of robotics due to their small size,light weight and flexible movement.However,because the amphibious robot needs to realize the driving mode in two different environments simultaneously,it is difficult to minimize its structure.As a new kind of driving method,the vibration driving method has the advantages of no transmission mechanism,flexible driving form,and compact structure.In response to the problems of the existing amphibious robot,such as driving mode redundancy,complicated structural design,difficulty to achieve miniaturization,the research on miniature amphibious robot is carried out based on the driving principle of direct vibration drive.A new type of amphibious robot is designed,and a new kind of amphibious robot is proposed.The amphibious drive mode of the amphibious robot combines the ground and the water drive mode,so that the entire amphibious robot has a very compact structure,and the volume has also been significantly reduced.Firstly,this thesis determines and verifies the driving scheme of the robot on the ground and on the water after iterative design of multiple schemes,which starts from the driving method of bionic fish.The appearance design of the amphibious robot is completed by referring to the shape of the rays.The configuration of the robot is optimized and analyzed from the waterline,stability and motion resistance.Then,the driving unit of the robot was analyzed separately,and the amphibious driving principle of the small amphibious robot was deeply studied.For the ground driving principle,the two modes of inertial driving and friction driving are analyzed respectively and the critical conditions for switching between the two modes are researched.A vibration isolation analysis is carried out to the driving element to avoid the couple of vibration of the feet.At the same time,the structural parameters of the robot drive unit are optimized so that the robot drive module can reach the resonance state.For the water surface driving principle,a new theoretical model about the influence of the wet mode of the flat sheet on the surface flow field on the water surface is proposed.The main method is the combination of simulation analysis and experimental verification.The PIV method is used to observe the surface flow field and the trend of change is analyzed theoretically to provide support for the new theoretical model.Next,the control system of the amphibious robot is designed in a semi-closed loop feedback form.Through voltage feedback,the robot can be effectively controlled to realize basic movement modes such as acceleration,deceleration,and steering.The STM32 single-chip microcomputer are used as the control unit of the robot.Two upper host controllers on the PC and the Android device are designed,and the Bluetooth Low Energy(BLE)module is used to realize the communication with the single-chip microcomputer.The host controllers issue instructions and can process the information transmitted by the client microcomputer promptly.In the process of design of the control system,the power consumption of the robot is analyzed with emphasis,and the internal control components are tested for power consumption and model selection to ensure a longer battery endurance.Finally,the prototype of the robot is fabricated.The size of the final prototype is about 75mm×95mm×21mm,and the mass of the robot prototype is 35 g.The experiment verifies the switching of the two ground driving modes of the robot.The experiment results show that the amphibious robot has the fastest ground linear motion speed of about 83 cm/s and the fastest turning speed of about 9.2 rad/s.In water,the fastest linear motion speed of the robot is about 17cm/s,and the turning speed is about 2.8rad/s.The amphibious robot can directly achieve amphibious transitional motion without manual intervention and maintain its stability.The effective battery life of the robot is about 20 minutes,and the maximum control distance is about 30 m.The amphibious robot based on the principle of direct vibration developed in this paper makes full use of the advantages of vibration driving mode,such as compact and flexible.It greatly simplifies the structure of the existing amphibious robot,and reduces the volume of the amphibious robot.This long-distance small amphibious robot with body loaded power supply will have certain application value in the fields of environmental reconnaissance and resource detection in the future.In principle,the robot adopts two main driving modes of vibration drive in ground motion.The influence of the mode of the flexible sheet on the change of the surface flow field on the water surface is researched and its theoretical explanation is presented.A brand-new water surface driving scheme is proposed,which provides a new design idea for the water surface driving method.The research of this subject proves the feasibility of vibration drive principle in amphibious drive,and further promotes the application of vibration drive scheme in practice.