Research And Development Of Position And Attitude Control System For Helicopter Tail Support Equipment

Helicopter is a typical dual-use aircraft,its powerful maneuverability is widely used in many fields,such as fire strike,transportation,patrol,tourism,rescue and so on.Wind tunnel test is an indispensable part of helicopter development.When the helicopter is in flight,the reaction torque of main rotor rotation will make the helicopter rotate in the opposite direction of rotor rotation,and the role of tail rotor is to offset it to obtain yaw stability.It is a reliable guarantee for helicopter performance analysis to obtain accurate research data of tail rotor,which has a significant impact on the performance of the whole helicopter.Therefore,it is very important to study the helicopter tail support control system with excellent maneuverability and high reliability.In this paper,according to the requirements of a certain PLA department,a set of high precision and high reliability motion control system of helicopter tail support device is developed.First of all,according to the requirements of the project,the functional characteristics and control requirements of the helicopter’s tail support mechanism are analyzed,and the joints of the tail support mechanism are determined to use the motor and the electric actuator as the power mechanism.The motion control system of the tail support device will adopt the industrial control computer as the upper computer,the embedded PC as the main control system,and the servo motor as the actuator.The servo motor is used to drive the joint motion of the tail support device,to realize the rotation of the angle of attack,the angle of sideslip and the angle of pitch of the tail support device and the movement in the x,y and z directions,so as to realize the adjustment and accurate positioning of the end model of the tail support device.The DH parameter method is used to establish the mathematical model of the tail brace device and calculate its forward kinematics and reverse kinematics.The mathematical model of the tail support device is simulated based on the forward and inverse kinematics of MATLAB,and the end movement range of the tail support mechanism is simulated by Monte Carlo method.Secondly,according to the analysis and demonstration of the system,the control scheme of the tail brace device is designed and implemented,which is composed of Twin CAT platform based on Embedded PC and the third-party driver.According to the requirements of the project,hardware selection and configuration are carried out,and three closed-loop series PID is used to adjust the motor parameters.The communication between controller and driver is realized by Ether CAT high speed bus protocol,and the communication between upper computer and lower computer is realized by ads protocol.The motion control program and Twin CAT PLC control instruction are developed in Twin CAT PLC environment by St programming language of iec61131-1 international standard.Using Lab Windows/CVI programming environment to develop the upper computer control software of the tail support device,to realize the upper computer’s monitoring of the running state of the tail support device and the issuance of a variety of motion mode control instructions.Finally,the control parameters and accuracy of each joint motor of the helicopter tail brace device are adjusted by experiments.After the joint power device is installed in the body of the tail support device,the accuracy test and control test are carried out,and the single key movement and multi joint linkage are tested respectively.The test results meet the control accuracy requirements of the helicopter tail support device.