Design And Implementation Of A Fully Actuated Rotor Flying Robot For Contact Operations

Rotary-wing flying robots are widely used in film and television aerial photography,inspection and survey,express delivery and search and rescue due to their various flight modes and flexible maneuverability.Aerial manipulator(AM)is a new type of robot with active operation capability in the air,which is composed of the flying robot and the operating device.Compared with the mobile operations of ground mobile robots,AM can quickly reach the highrisk and complex environments where it is difficult for ground mobile robots to enter.However,due to the under-actuated characteristics of the traditional rotary-wing unmanned aerial vehicle(UAV),its position control and attitude control are coupled with each other,so it needs to be equipped with a complex robotic arm to complete the operation task,and the operation efficiency is low.Fully-actuated flying robots can achieve independent control of position and attitude,so they are suitable for physical contact tasks,such as crack detection of natural gas steel pipes,cleaning of high-rise glass walls,and contact fault detection of tunnels and bridges.This paper mainly focuses on the design and implementation of fully-actuated flying robot and the application of practical physical contact operation.To address the problem of coupling between position control and attitude control caused by the under-actuated characteristics of traditional rotary-wing UAVs,this paper proposes a fully-actuated hexarotor.Firstly,the mechanism of the system was designed and its model was established,and the integral sliding mode controller was designed on the basis of the completed system kinematics and dynamics model.Then the simulation experiments were carried out,and the ideal position and attitude independent control experiments prove that the designed fullyactuated hexarotor has good position and attitude independent control capability,that is,it has six degrees of freedom trajectory tracking capability.Under the non-ideal condition of its own parameter uncertainty and external wind field disturbance,fixed-point hovering interference resistance experiments were carried out.The experimental results prove that the designed fullyactuated hexarotor has good anti-interference capability.The experimental results of the continuing complex trajectory tracking experiments prove that the designed fully-actuated hexarotor can not only achieve complex trajectory tracking,but also keep the attitude angle basically stable during the tracking process,and the attitude angle error is kept within ±2°.The prototype of fully-actuated hexarotor was developed and flight performance experiment was carried out.Firstly,the experiment of large-scale lateral motion was carried out.The experimental results show that compared with the traditional rotary-wing UAV,the designed fully-actuated prototype has good position independent control capability.Then,the circular trajectory tracking experiment was completed,and the experimental results prove that the designed fully-actuated prototype can complete the tracking experiment of complex trajectory while keeping the attitude basically stable,and the attitude angle error is less than 2°.Aiming at the application scenario of physical contact operation,an elastic mobile contact manipulator was developed,which was integrated with the full-actuated prototype and the wall contact operation experiment was carried out.The automatic control strategy of contact operation was designed,and the contact operation process was divided into four stages:approach,impact,moving contact and return.The experimental results prove that the attitude angle error of the fully-actuated hexarotor flying robot designed in this paper is less than 2°during the contact process and it can keep the attitude angle basically stable,which verifies the effectiveness of the prototype’s contact operation function.