Research Of Communication System Of EOD Robot Based On Frequency Hopping Technology

In today's world,fighting against terrorism has become an important aspect of the world to safeguard national security and interests.However,due to the special nature of the war on terror,security personnel often hazarded his life to exclude some suspicious explosives,which is unavoidable for people to feel an intense fear,because a little carelessness will pay the life.Therefore,researchers around the world have long been seeking safer EOD measures and equipments.As early as 60 years ago,the western countries have developed a variety of EOD robot,who not only can help the police remove the bomb and complete security tasks in times of peace,in wartime may also replace the soldiers perform minesweeping,reconnaissance missions.The design of terrorism EOD robot control system usually involves communication and navigation technology,walking and positioning technology,information processing technology,etc.The actuating mechanism of the robot is designed mainly by tracked mobile carrier,reconnaissance detection equipment,multiple degree of freedom manipulator and multi-joint mechanical arm etc subsystems,which are responsible for the implementation of the operation.These functions' achivement need robots have comprehensive information processing capabilities and interactive capability under special circumstances EOD field.It's very important that how we can establish a reliable,stable wireless communication system which has the ability of long-distance information transmission between the robot rear command system and the front vehicle execution system.However,normal wireless communication system,most of which work on the fixed carrier frequency,and are vulnerable to outside interference.When interferred by the outside,it's communication quality will decline sharply,and even interrupt the commuication when it is serious.Therefore,development of EOD robot communication system which has a strong anti-interference ability has an important practical significance.Frequency hopping communication as a kind of spread spectrum communication,not only has good anti-interference ability,but also can improve the utilization ratio of spectrum.The system mainly use of frequency hopping communication's anti interference characteristic,through the communication system's carrier frequency changing constantly,combined with frequency hopping algorithm,and finally through the software frequency hopping protocol design,system's carrier frequency hopping is controled by frequency hopping device,which is constituted by frequency synthesizer and frequency hopping command generator.In this paper,the main research contents are as follows:1.The characteristics of frequency hopping communication system are analyzed,by contrast,analysis of several common frequency hopping sequence,we came to the frequency hopping pattern generating process.The paper illustrates the sending and receiving process of frequency hopping signal,after analyzing the waveform and spectrum of frequency hopping signal,we get the correct condition of receiving frequency hopping signal,laying the theoretical foundation for the following system design.2.The paper introduces the overall structure of EOD robot and its control system detailedly.From the robot hardware and software system's design,it is proposed communication system requirements,and through analysis we obtained technical requirements of frequency hopping systems.According to the technical requirements of the frequency hopping system,we designed baseband unit and frequency hopping communication module of the system,laying the foundation for the design of the following software frequency hopping protocol.3.The paper analyzes and studies the basic structure of software radio.Starting from the concept of software frequency hopping,according to the characteristics of frequency hopping system,we researched and analyzed of the frequency hopping algorithm,and designed the software frequency hopping protocol,gave the realization process of system adaptive hopping at the same frequency interference.The paper also analyzed the system synchronization,designed the method to realize frequency synchronization of the system.4.We tested the performance of the system from the frequency hopping rate,frequency bandwidth,number of hopping frequencies,the initial time synchronization,anti synchronization bandwidth interference ability,the biggest difference,the bit error rate and so on.Finally,we tested the system's anti-jamming capability of the communication through the experiment,the experimental data shows that the system basically achieves the technical requirements of the system,stable and reliable,which can lay a solid foundation for the development of reliable communication system of subsequent EOD robot research.