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Design of avionics controller

1. Controller redundancy scheme. The redundancy design in aviation control system is diverse and has its own characteristics. We mainly introduce the structural design of dual redundancy NC channel. The composition of the NC channel depends on different modules. The main modules include signal conditioning, input, CPU, output, bit, communication, fault switching, drive output, etc. One of the two modules can be used as the main control channel, and the other can assist it, and ensure that it is in the hot backup state. If there is a fault, just switch the module to ensure the continuous operation of the system.
2. CPU module scheme. CPU module is the core of the whole control system. The performance of this single module directly affects the function of the whole control system. The specific tasks of CPU module include: data acquisition, digital and logical operation, ensuring data storage, real-time interruption, ensuring data output and meeting the requirements of communication. In this control system, we use the embedded microprocessor PC104, whose mainboard is integrated with intel486 processor. It has low energy consumption, timer and interrupt controller. The external interface of the mainboard has not only compatible parallel port, serial port, but also optional serial port. The main features are small size, low function loss, good seismic resistance and wide bus range, which basically meet the requirements of the engine.
3. Input signal processing mode. Different processing methods should be set for different types of input signals. If it is a temperature signal, the circuit should be conditioned by using the temperature sensor to expand the signal as much as possible. At the same time, the compensation of the reference contact and certain linearization processing should be carried out to make the signal gradually meet the system requirements. Output signal processing mode the output signal is relatively special and can not directly drive the execution structure. A certain conversion is very necessary. Specifically, different actuators should be treated in combination with different actuators, including electro-hydraulic servo valve, high-speed solenoid valve and stepping motor. The types of electro-hydraulic servo valve control include hardware and software closed-loop control. The response speed of hardware closed-loop control is very fast and the CPU occupied is relatively small, while the software closed-loop control has parameters, which can be adjusted conveniently and realize efficient control; The control of high-speed solenoid valve needs to design the circuit of signal generation due to the characteristics of signal, and the integrated chip can meet these requirements, because it has a large number of circuits inside.

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