A Kind Of High-precision I/F Converter

Strapdown inertial navigation system is a development direction of inertial technology recent years. As the strapdown inertial navigation system it has a series of advantages in many applications, there are probably to replace the platform-type inertial navigation system. Nevertheless, the accelerometer inertial navigation system is one of the core components. Accelerometer is used to measure vehicle acceleration sensor, the measurement precision of the whole system is essential. The micro-accelerometer output current signal is not conducive to high-precision measurements, is not conducive to high-precision calculation of the collection and follow-up treatment. Strapdown inertial navigation system for the accelerometer signal acquisition of high-precision requirements, this paper presents the use of I/F conversion technology for high precision accelerometer output signal transformation method.Because the traditional current-frequency transformating methods have kinds of short comings, this paper does some research on a new method that can improve the measurement accuracy, the measurement of speed and so on.This new design based Atmega128 microcontroller is a high-precision current-frequency transformation system which will be proportional to its transformation with the cycle of the pulse signal so as to more precise measurements and more convenient data collection. The system uses current-voltage transformation module, AD, and Atmega128 microcontroller to design a high-speed, high-precision current frequency conversion system. Which completes the high-precision accelerometer output current conversion. At the same time it can also communicate with the PC through the serial port,so that the PC can analyze and process following data.This paper describes a complete system designing process. firstly, it introduces the operational principle, and then determine the overall design plan of hardware and software accordding to analysis of functional requirements. Secondly the thesis expounds the hardware circuit and PCB drawing in detail ,including each hardware module drivers and application software design process.Finally debugging process, problems encountered and debugging the system are descibed.The system has been designed, and after experimental testing.It is running in good condition to achieve the desired design purpose.