Unmanned aerial vehicle （UAV） has played an increasingly important role in recent military conflicts due to its low cost and high flexibility. This attracts wide attention from countries around the world. The number of “black flights” of UAVs in China is increasing year by year， which directly reflects the challenges of the prevention and control of low-altitude airspace UAVs. The construction of urban low-altitude airspace anti-UAV is worthy of further research. As for the urban low-altitude airspace anti-UAV problem， the possible UAV threats were analyzed. The urban anti-UAV scenarios were classified， and the challenges and problems of the urban anti-UAV were explored. Additionally， five solutions to the urban anti-UAV system were proposed. In conclusion， for the construction of the urban anti-UAV system， the positive design oriented to the target and scenarios should be conducted， and special attention should be paid to the UAV target and environment characteristics， the anti-UAV point position design， the integration of the command and control system design with user operations， and the standardization of system integration. This can provide a reference for the urban anti-UAV system design.

Permanent synchronous motor is a highly coupling non-linear time-varying system.In view of the traditional PID control method cannot fully exploit the advantages of fast response and high accuracy of maximum torque to current ratio control of Interior PMSM,an optimized PID tuning method with neural net based on differential evolution algorithm is proposed,and proved by Matlab/Simulink simulation model.Compared with traditional PID,the result turns out that the proposed method performs better in precision and dynamics.

In indoor anti-terrorism combats,a single-mode unmanned aerial vehicle (UAV) cannot adapt to complex terrain and is easily destroyed.Aiming at this problem,a small UAV which can bounce on the ground-Scyther, is proposed.The composition,structure and main parameters are firstly given.Then,the main algorithms are explained,and the feasibility of the scheme is analyzed.A combination of coaxial twin-rotor and jumping UAV are used on Scyther.When approaching the target,the coaxial twin-rotor pops up from the main body and sticks to the high position.The camera mounted on it provides a monitoring field of view.The attitude of UAV is controlled through the momentum wheel,whose path is planned using improved ant colony algorithm.Using distributed context-aware algorithm,the UAV’s trajectory will be difficult to predict within the enemy’s visible range,thereby increasing the probability of getting close to the target.Compared with traditional UAVs,Scyther can adapt to a variety of complex terrains,can be controlled remotely, and has the advantages of small size,fast speed,low power consumption,and strong maneuverability.It is suitable for both single and cluster combats,thus is very beneficial for indoor anti-terrorism combats.In addition,Scyther can be equipped with a variety of warheads for different mission requirements,and is applicable for extensive scenarios.