Design Of UAV Control System Based On Pulse TDOA Location

UAV has the characteristics of small size,convenient use,low requirements for working environment and strong survivability in harsh environment.Therefore,UAV has been widely used in many fields of modern society.In the aspect of target search / rescue,UAV is used to carry out the search and positioning of the persons in distress or important instruments which deviate from the predetermined position due to external factors by using the UAV with electromagnetic wave signal receiving and receiving device,and combined with specific target positioning methods.Compared with the traditional human search method,it not only saves time,reduces costs,but also has unique advantages.The purpose of this paper is to study a positioning method using electromagnetic pulse signal,design the positioning device carried by UAV,and UAV flight control system.The distance and orientation between UAV and target are calculated by the signal received by UAV,which is used as the coordinate to control the flight attitude and direction of UAV.The working process of the system is as follows: firstly,the UAV is manually controlled to cruise to the general direction of the target,and the pulse signal is sent.When the target outside the unknown direction receives the signal sent by the UAV,the echo signal is immediately sent to the UAV;then the receiver on the UAV receives the data through the directional antenna,and extracts and judges the signal characteristics of the received data Then,the calculated data is transmitted to the UAV controller,and the airborne program independently controls the UAV to fly to the target to monitor the orientation of the target in real time.The main work of this paper is as follows: the function of electromagnetic wave positioning module is analyzed,and the corresponding pulse characteristics are designed according to the requirements of the system;the principle of electromagnetic wave signal ranging and direction finding is introduced,and the distance and direction between the target and UAV are calculated by pulse ranging and equal signal strength method;the pulse signal generator is designed,and the specified pulse signal is sent according to the parameter adjustment ADC and FPGA are used to receive the signal.According to the design scheme,the schematic diagram of data acquisition circuit is drawn,and the corresponding signal feature extraction method is designed for the known transmitted pulse sequence.The hardware circuit of UAV autonomous control is designed.STM32 is used as the minimum system.The peripheral module is composed of GPS module,power supply module and motor module.Finally,the feasibility of the system is verified by the experimental results,the shortcomings of the system are analyzed,and the next research direction is proposed.