Design Of Sensor Module In Multi-parameters Drilling Instruments

The appearance of fieldbus sensor has realized better combination of the technologies of sensor, digitized and computer, it has met the demands in the increasingly large amount of information and high speed of measurement and control system. The application of fieldbus sensor in market is more and more extensive. In this thesis, a solution for data sampling and processing in multi-parameters drilling instrument is proposed, which is to construct a sensor network based on CAN bus. All of the sensor devices in the oil filed will be connected together by the CAN bus in the system, and accessed to the Internet. The system has bright prospect for its easy layout, high speed in data transmission, safety, and convenient management.Firstly, the general development of CAN bus is introduced and the bus structure and technical characteristic are analyzed. Then several technical aspects of sensor module in network are demonstrated. Based on those discussions, a solution that form a sensor network base on CAN bus for multi-parameters instruments is proposed. Adapting to the trend of'digital field', the hardware integration, functional stability and maintenance consideration are outlined.The software and hardware design of sensor modules are discussed and performed as one of the most important parts in this thesis. Based on the work principle, all of the sensors are classified as current type, AB-phase type, on-off type and alarm type and four kinds of design are accomplished. In the hardware design, in order to overcome the side effects of foul circumstances in the oil field, some methods in processing CAN transmission, ADC, AB-phase and so on base on MCU and FPGA are proposed. In the software design, the design for data sampling, processing and transmission is accomplished.A sensor network is formed in the laboratory test; each sensor module is a free node and can transmit or receive data. At the end, the system test is introduced in details. The result confirm the validity of network function, also the stability and real-time capacity of data sampling in the sensor module.