Abstract：The detection of vehicles on road frontage is the main field of vehicle safety driving assist, and developing real-time testing methods with strong robustness is the effective way to realize the active safety early warning. Based on monocular vision and the vehicle ahead trapezoidal region of interest(ROI) determined by lane lines, a variable rectangular window adaptive mean variance difference method to calculate the threshold of shadows is put forward according to the characteristic of vehicle shadow. And then, based on the ground of trail width template, a horizontal traversing minimum mean method is presented to generate shadows and road intersection hypothesis. At last, the vehicle shadow line is verified by the gray value feature of the car bottom shadow, so as to detect the vehicle. The above methods are applied to the self-developed DSP experimental platform for verification. The results show that the average calculation period of the method is only 38.46 milliseconds, and the vehicle can be detected in different traffic environments and weather conditions. The method has good real-time performance and strong robustness.

Abstract：A method is proposed which combined the auto-disturbance-rejection control(ADRC) with the improved extended Kalman filter(EKF) for the problem that four rotorcraft system is strongly coupled, nonlinear and susceptible to external noise interference. The method uses a disturbance rejection controller to control a quadrotor,using improved EKF to filter out external noise. The optimal control amount of the ADRC output is taken as the control amount of the improved EKF,which outputs the attitude of the aircraft with the measurement of noise as a state variable for the improved EKF,more accurate attitude value can be output due to the improved EKF filter. The experimental results show that this method controls the attitude stabilization time of the aircraft to about 0.7 s,compared with cascade PID control. It′s attitude tracking curve is more stable,highly controlled settling time is reduced by 1.7 s and increased anti-jamming capability by 50%,so that the method enhances the stability and anti-interference ability of the four-rotor system,which meets the requirements of the four rotor attitude control.

Abstract：This paper introduces the development and characteristics of multi-rotor unmanned aerial vehicles(UAVs). Aiming at the problems and limitations in its application in wireless communication relay, this paper creatively puts forward the basic scheme of constructing the tethered multi-rotor unmanned aerial vehicle by adding the tethered power supply system. The characteristics of sustainable and stable flight are more suitable for the construction of tactical communication wireless relay platform. Combined with the needs of military applications, the predicted values of the communication distance of typical tactical radio stations are analyzed and compared, under different terrain and with or without the use of multi-rotor unmanned aerial vehicle relay conditions. The comparison of the data results shows that the relay platform composed of tactical radio stations can be used to improve the communication coverage of tactical communication system, and the application and development prospect are broad.

Abstract：With the increasing variety and enhancing function of unmanned aerial vehicle(UAV) payload, data recorder, as an important avionics equipment to record UAV flight status and payload information, is also faced with the challenges of increasing recording data, complex working environment and long working hours. The design of a versatile, reliable and accessible data recorder has become an inevitable requirement for the development of the industry. This paper makes improvements to the shortcomings of the traditional UAV data recorder, such as large power consumption, large volume, high cost, low storage efficiency and poor practicability, has firstly transplanted RT-Thread embedded real-time operating system on the STM32F4 microprocessor and the Fatfs file system to organize data, with SD card as the storage medium, has secondly put forward a multi-thread and multi-buffer strategy to storage data, has thirdly developed USB drive, making storaged data easily copied from the PC side for offline analysis. Finally, according to the software and hardware design, a small batch trial production is carried out. After the test, data recorder can accurately storage the multi-channel big data stream for a long time.

Abstract：Online route planning could make the UAV in the dynamic environment quickly and efficiently generate suitable flight routes so that it is the necessary ability of UAV mission planning. This paper presents a three-dimensional online route planning method based on the adaptive artificial potential field method，which could cope with the UAV dynamic flight environment and quickly generate the real-time safety flight route that satisfies the task requirement. The route planning method uses the reference route gravitational field and the adaptive time disturbance factor in the process of constructing environment to help the UAV escape the trap when fall into the local minimum of potential field. And a virtual target method is proposed to help effectively solve the trapping problem. Computer simulation results show that the UAV online route planning method is easier to jump out of the local minimum of the potential field than the traditional method, and has better obstacle avoidance capability.