| Unmanned aerial vehicles（UAV）laser communication has the characteristics of high bandwidth,anti-interference and security,and has become a research hotspot today."Laser energy transmission"can charge the drone’s battery until the mission is completed before landing.Laser communication and laser energy transmission technology have something in common.If the two are effectively combined,the performance of the drone will be further improved.The process of UAV laser communication and laser energy transmission is mainly affected by atmospheric channel and tracking error.The mechanisms of these two influencing factors on laser communication and laser energy transmission are not completely the same,and the traditional channel and tracking technology cannot take into account the performance of laser communication and laser energy transmission.Therefore,it has theoretical significance and practical application value to study the influence mechanism of atmospheric turbulence and tracking error on the performance of communication energy transfer link.The specific research work of the paper is as follows:（1）To study the working mechanism of UAV laser communication and energy transfer system,taking the key components such as laser source,transmitter,receiver and control system as the research object,and compare and analyze the similarities and differences between the two systems.The basic theory of atmospheric channel for laser transmission is investigated,including atmospheric absorption and scattering effects.In the theoretical research,the relevant theories and calculation methods of laser transmission under the atmospheric channel are analyzed,and the different models of atmospheric turbulence are analyzed,and the similarities and differences of laser communication and energy transmission are compared and analyzed.（2）Focusing on the application background of UAV laser communication and energy transmission,the vibration characteristics of the airborne platform are analyzed,the UAV vibration spectrum is fitted,and the mechanism of tracking error generation under the large maneuvering platform is studied.Furthermore,the influence of tracking error on laser transmission is discussed,and a joint channel model is established to describe the influence of both atmospheric turbulence and tracking error on laser communication and energy transfer.In the joint channel model,the atmospheric turbulence and tracking error are regarded as two interacting interference factors,and the influence of the joint channel on the communication bit error rate and energy transfer efficiency are discussed respectively,and the proposed joint channel model is verified by numerical simulation accuracy.（3）Experimental research and experimental verification of the joint channel model are carried out.Experiments are conducted to verify the influence of channel and tracking errors on communication and energy transfer efficiency.Specifically,it includes atmospheric factors such as atmospheric turbulence and visibility,and alignment error factors such as GPS positioning error,attitude information,platform vibration,and tracking bandwidth.Experiment results show that when the UAV is hovering,the communication bit error rate is 1.2×10-10,and the energy transmission efficiency is 25.3%;when the UAV is moving,communication the bit error rate is 8.5×10-6in 100 seconds,with a short-term burst error,and the energy transfer efficiency was 6.8%;during the whole experiment,error-free time lasts as long as 35s,which verified the feasibility and reliability of the UAV laser communication energy transfer system. |
