Mortar Fuze Safety System Control Logic And Arming Circuit Design

Arming and control logic circuit for the 82mm mortar fuze was designed in this thesis, its function was to ensure security in circumstance of handling, loading and propelling environment, drive the actuator of microelectromechanical systems (MEMS) fuze safety & arming(S&A) device when two environmental signals was detected.According to the characteristics of Mortar fuze, setback acceleration environment and muzzle exit magnetic signal were selected as the two stimulus, and two sensors which can adapt to the harsh and complex working environment in the fuze were selected as the first part of the system. Under the development of mortar fuze, a method of circuit design and logic processes which can be used to control MEMS S&A in the 82mm mortar was determined after analysis of the current microprocessor control circuit design at home and abroad.Hardware circuit and complex programmable logic device(CPLD) algorithm was designed followed a modular design method, CPLD discriminated and identified the amplified, filtered and digitized signals by the method of threshold value, time window and hopping trigger. CPLD sent drive signals to electrify the electromagnetic coil to arm the fuze when environmental information identified and safety logic agreed. The designed circuit was assembled by three 25mm diameter double layer printed circuit board (PCB), and its size structure and logic functions could meet the design requirements.Matching experiments between the circuit and MEMS S&A device was carried out in the end, the test result indicated that the electromagnetic coil was driven successfully, and algorithm of the program-controlled circuit was verified by method of simulating setback acceleration environment through AVEX test-bed and double environmental information input through function generator. All the experiments have proved the feasibility of the designed system.