The Research And Application Of Altitude Control Of Small Unmanned Helicopter Based On ADRC

Small unmanned helicopter has broad prospects in the military and civilian fields, and it is regarded as a very important subject by military research institutions and some civil companies. Our laboratory has been engaged in the research of this area for many years and made lots of achievements. Based on these achievements, further exploration and research are carried out in this thesis.The thesis focuses on the application of Active Disturbance Rejection Control(ADRC) in vertical control of small unmanned helicopters. The main content includes: Firstly, the impact of ADRC stability and control parameters for the system is discussed, and a simple parameter setting program is designed; Secondly, ADRC is applied in vertical control of small unmanned helicopters, and a new method called model information auxiliary method is designed to improve the ADRC performance; Thirdly, ADRC is used to control the actual unmanned helicopter to test its real performance. The innovations of this thesis are as follow:1. The various effects caused by the changes of ADRC parameters are comprehensively discussed, and a simple parameter setting program is proposed. At first, a second order ADRC transfer function is derived based on the linear model of the vertical channel. The transfer function is used to study the impact of the ADRC parameters on the system closed loop characteristics, disturbance rejection ability and noise amplification characteristics. Then the restrictions of sampling rate and Peaking phenomenon on ADRC parameters is discussed. At last, a simple parameter setting program based on these discussions is presented.2. ADRC is applied in the vertical control of small unmanned helicopters, and a model information auxiliary method to improve ADRC performance is proposed. This new form of ADRC transforms the form of Extended State Observer(ESO) dynamic compensation by using disturbance information, which has a simple mechanism and is convenient to be measured. The performance of system without adjusting the ADRC parameters has been improved by using this new method.3. A number of ways to address some of the problems encountered in the practical application of ADRC is designed: A first order least square method is used to estimate Parameter b. A switching control mode is designed to ease Peaking phenomenon. A small coefficient integrator combined with ADRC is created to solve the problems brought by power consumption, which will result in the total output reduction and cause the ADRC output to reach its limit.