Dynamic Environment Characteristics Of Inclined Environment Of Dual Hemispherical Capsule Robot

Capsule robot can not only alleviate the diagnostic pain of patients with gastrointestinal tract,but also control the robot to avoid diagnostic visual blind area through human-computer interaction system.Under the control of external magnetic field,the dual hemisphere capsule robot can achieve precise control,so as to achieve interventional therapy and diagnosis in the environment of non-structural abundance such as esophagus,stomach and colon.Because of its high safety,stable and reliable in vivo diagnosis,it has universal clinical application and popularization value,and is also a hot field of international medical research on micro-robots.This paper mainly studies the dynamic characteristics,climbing performance and motion stability of the dual hemisphere capsule robot in inclined environment.Firstly,by switching between two modes,the dual hemispheric robot not only achieves the stable movement of active mode in inclined environment and climbing,but also realizes the hovering and attitude adjustment operation in passive mode.The control separation of dual-mode operation of robot in inclined environment provides a theoretical basis for medical diagnosis and ergodic inspection in non-structurally abundant space such as esophagus and stomach.Secondly,in the process of research,it is found that no matter what mode the robot works in,the capsule robot always autobiographes the active hemisphere.As the main body of motion,the passive hemisphere follows the magnetic field,and does not rotate around the axis,forming an underactuated state.The attitude characteristics and azimuth information of the dual hemisphere capsule robot are analyzed in depth,and the coordinate system of the fixed-point gyro motion is introduced.At the same time,based on Lagrange equation and gyroscope mechanics,the fixed-point kinematics model of hovering attitude adjustment in passive mode and rolling dynamics model in active mode are deduced.According to the stability condition of the robot's hovering attitude adjustment,the maximum tilt angle and the range of control parameters are determined,and according to the climbing performance of the robot,the climbing motion condition and the maximum climbing angle under different parameters are determined.Finally,because the motion model of the dual hemisphere robot is a complex time-varying non-linear dynamic equation,it is impossible to obtain a general analytical solution,and only numerical analysis can be carried out by simulation tools.In this paper,the robot model is deduced by Maple,and the non-linear models of different motion states of the robot are simulated and analyzed by using MATLAB.By analyzing the convergence of the attitude angle of the robot in passive mode,the stability of the hovering attitude of the robotunder passive condition is verified according to Lyapunov stability condition.In order to verify the anti-jamming ability of the robot,the time response curve of the attitude angle of the robot is also fully analyzed.In addition,the robot has the characteristic of self-standing,which ensures that the axis orientation of the robot is always only one,so that the attitude angle of the robot can be accurately controlled.In active mode,under the control of a certain magnetic field,the robot achieves rolling walking and climbing motion in inclined environment through active and passive mode conversion,which enables the robot to reach the specified position according to the requirements for inspection,and lays the foundation for the robot to move in the unstructured and abundant space.