To evaluate the protection performance of SPD (surge protective device) against electromagnetic pulse, the response ability of several typical surge protective devices to wide and narrow electromagnetic pulses was tested by using a SPD response ability test system. The results showed that SPD commonly used in lightning surge protection had certain ability to suppress electromagnetic pulse conduction disturbance. Gas discharge tubes presented typical clamping characteristics for wide pulses. MOV and TVS had obvious clamping effect on wide pulses, while had no clamping effect on narrow pulses, but could obviously reduce its peak value. Zener diodes had obvious clamping effect on narrow pulses, and the clamping voltage control accuracy was high.

In terms of driverless systems, high-precision positioning technology is one among the critical aspects of driverless cars to achieve driverlessness. This study analyzed the working principles of GNSS (global navigation satellite system) and SINS (strapdown inertial navigation system) and elaborated the principles of the least square method and LAMBDA algorithm in the integer ambiguity resolution. Based on the network RTK positioning technology and the abovementioned theory, the unmanned automatic work vehicle was used as the research object, and the fusion positioning algorithm of the BDS/GPS system and inertial sensor was used to propose a high-precision positioning technology for the unmanned automatic work vehicle. The combined navigation system model was studied and constructed. Relevant verification was carried out through simulation and experiment. The results were as follows: the pitch angle error was less than 0.1°, the roll angle error was less than 0.05°, the speed error was less than 0.2 m/s, and the position error was less than 2.1 m. The outcomes indicate that an integrated navigation and positioning algorithm for driverless vehicles can significantly enhance the localisation accuracy and reliability of navigation. The research results are of engineering value and practical application for the development of unmanned automatic special vehicle positioning systems.

For the unmanned vehicle system, the state measurement and control technology is one of the key links to realize the real unmanned vehicle. Based on RTK positioning technology and ultrashort wave spread spectrum communication technology, the key technologies of special vehicles with unmanned automatic operation are studied, and a set of state monitoring and control system of special vehicles with unmanned automatic operation is developed. Through the experimental research, the unmanned vehicle state monitoring and control system can better complete the functions of vehicle location and electronic map display and meet the design requirements. The research results provide technical support for the practical application of special vehicles with unmanned automatic operation.

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