In this work, a new type of high temperature fiber grating diaphragm pressure sensor is described, including the physical design structure, in-depth analysis of optical response to changes in pressure, and a discussion of the temperature compensation method. Mathematical model of high-temperature compressive shape change and normal-temperature compressive shape change is built, and effective temperature compensation method is proposed, which can both contribute to solve temperature interference of pressure sensor at high temperature. In addition, the simulation computation is conducted for the external encapsulation of the sensor under the high-temperature and pressure according to the design model. Through analysis and comparison of data affecting the changing position of grating signal, the correctness of the simulation result is verified by the development of the prototype. The temperature compensation method is proposed to realize pressure measurement of sensor with a relative error below 4.6%F.S. and range to 50 MPa in the environment of 300, which meets with the safety research requirement of the cartridge system.

For the requirement of pressure detection in high temperature environments, this paper presents a fiber Bragg grating (FBG) based pressure sensor with a simple structure. The structural model of the sensor has been established with the consideration of a sensing principle and a small deflection effect of the circular membrane. The finite element analysis has been employed to validate the rationality of the sensor structure design and realize the digital simulation of the theoretical model. Through the analysis, the selection of packaging materials, the design of structural parameters and the pressure and temperature calibration of the developed sensor has been performed. The encapsulation of the sensor at high temperatures has been improved based on the theoretical analysis, simulation and testing, which proves the effectiveness of the sensor for pressure measurement at high temperatures of 100 °C~250 °C. The study provides a feasible sensing device for high-temperature pressure detection.

This paper introduces a design of the asynchronous serial interface detection apparatus. The device communicates with the host computer via the serial interface. Firstly, the PC control produces a particular signal source and provides the source data to the asynchronous serial communication module. Meanwhile the PC uses the device to generate fetch clock to bring back PCM stream data and send back to the host computer to carry on the analysis. At last it detects the communication process in order to detain some outcomes. Keywords-asynchronous serial interface communication; serial bus; PCM cord; FPGAAsynchronous serial communication serial data transmits with irregular data segment transmission characteristics .It has been more and more used in the field of data transmission. In asynchronous communication, the frequency of sending clock and receiving clock is not exactly the same, Allowed within the nuances. Transmission, each character must be from the start bit, stop bit end. Beginning and ending bit for 1, 1.5 or 2. In order to realize the communication smoothly, in the communication process we must guarantee the two sides have the same communication protocol. In practical applications, according to the needs of communication protocols we can have a variety of settings. Therefore, in asynchronous serial communication, when for one part the communication protocols have been defined and the other party does not know, we need to test the communication protocols which have been defined, so that the other side makes a corresponding protocol setting to let both sides of communication protocol consistency. Using FPGA as the controller for detecting device to test asynchronous serial communication protocol have a wide range of application, simple operation, friendly interface, the results show intuitional.In asynchronous serial communication, the sender and receiver clock error or baud rate error allowed from 4% to 5%.The characteristic of the asynchronous serial communication is the character framed by frame transmission and the transmission of each frame characters rely on the start bit synchronization]. In the process of data transmission, the transmission line allows free character. Due to the uncertainty of the communication transmission as well as various kinds of interference, the serial communication is often abnormal. This article describes the detection device can be generated to define the contents of asynchronous serial communication data and support the data to the lower interface, at last it recover and judge the data in form of file, Provide detection for asynchronous serial interface basis.In a lot of system design, single chip computer requirements and share resources, therefore the MCU and computer communications has become an essential part of. Another signal generation and detection of scientific research and engineering practice is one of the most important means in the past, use of hardware, system structure is more complicated, and maintainability and maneuverability is poor. Application softwar...

According to the problem of the sensor nonlinear changes occur at high temperatures, extreme learning machine model, is presented in this thesis the pressure sensitive grating and removing the temperature of the grating experiment data for training, establish a nonlinear model of wavelength, temperature, predict the experimental temperature, then the temperature data of pressure-sensitive grating the training set of training samples, the nonlinear model, temperature - wavelength prediction test set sample output wavelength, achieve the goal of improved temperature compensation method. The experimental results show that the algorithm can achieve a more ideal temperature compensation effect.