As a typical reciprocating engine power machinery, complex structure determines its failure brings about the complexity and diversity, it shows the uncertainties of operating environment, system noise and sensor accuracy, and engine fault diagnosis accuracy rate is reduced, taking into account the limitations of traditional BP neural networks, improved BP algorithms include statistical algorithms, additional momentum method, variable learning rate method and conjugate gradient method are studied. Finally, the engine is as an example, engine fault diagnosis experimental system is set, the vibration signals are measured in the normal state, left one and right six cylinders off the oil and air filter blockage in the load of 2565Nm, and the speed of 1500r/min, 1800r/min and 2200r/min. The test and analysis by comparing above mentioned methods indicate it is verified the superiority improved BP neural network with the conjugate gradient method.

Engine is as a power machine, the operating status is good or bad, directly affects the working status of equipment. The status monitoring and fault diagnosis is very necessary to ensure that the equipment runs in its best, and improves equipment maintenance quality and efficiency. The engine failure shows the complexity and diversity of the interaction and complex relationship between the various subsystems of the engine, that is the fault of complexity, ambiguity, correlation, relativity and multiple faults coexistence. The available information are much in the engine diagnosis, for example, the vibration signal from bearings, cylinder head or cylinder block surface; oil, cooling water, pressure of intake, exhaust and fuel; temperature signal; noise, speed or oil-sample signals. In this paper, an engine as an example, engine fault diagnosis experimental system is built, the normal state, left one and right six cylinders off the oil, air filter blockage (inlet wood blockage is 30%, the inlet has screen cloth.) in the load of 2565Nm, and the speeds of 1500r/min, 1800r/min, 2200r/min are studied. The experimental results analysis, feature extraction and fault diagnosis are finished based on the time domain and frequency domain. Keywords: engine, fault diagnosis, time domain, frequency domain.

Auto-loading system is as an important part of weapons and equipment, its work reliability determines the combat effectiveness and their own safety of weapon systems. As the core of the automatic loading system control, the control software’s reliability of automatic loading system is especially important. In introducing the importance of software testing, from the basic method of software testing starts, design methods is detailing on test and a case of black box test of the automatic loading system, and finally, combined with the equip software testing, software evaluation model was constructed, Results consistent with test results from platform, shooting range, altitude, cold regions, thermal zone, they are proved the software testing and evaluation are valid.

Steam manage system is a great delay system. The optimum design is necessary to ensure its speed response, quick follow in concrete system. The paper introduces optimizing digital controller design principle, and builds transfer function of pure lag system and constitutes modal of control system. Based on introducing the dynamic characteristics of the steam treatment system, analyzing the character of object function and determines it, and system emulation is put up on known object function and PID controller is confirmed. Experimental emulation proves the objective function, overshoot and adjustable time of dynamic response have effectively improved in optimized system, and the optimum design of the system is significant by comparing optimized system with unoptimized system.

With the circuit fabrication technology continues toward high-speed, high-density, low-power direction, modern circuit design techniques have changed radically. The speed improvement of digital system means rise and fall time of signals as short as possible, the improvement of frequency and edge rates will bring a series of high-speed design problems, these problems bring great challenges to the system hardware design, the correct design from logical point of view, if there is improper in the actual PCB design will lead to failure of the entire design. EMI radiation of PCB is analyzed, EMC simulation of PCB and optimizing improved are finished. The PCB electromagnetic compatibility is analyzed by using Protel 99SE and Ansoft Designer 2.2 software, and simulation result indicates optimizing design is correct and effective.