| Observation and measurement for the hydrothermal fluid in deep sea by sea sensors can give very important reference in exploration of oceanic resources. Due to the lack of resource in the world of today, it is very important to explore marine resources, in which the self-calibration deep sea sensors may play very important role. The deep sea sensor in this project is a kind of system to measure the physical and chemical parameters of the hydrothermal fluid in deep sea, whose great feature is self-calibration function.The self-calibration control strategy was applied in this deep sea sensor system. During the working process, the sensor system can complete every working step guided by the preset program. The working steps include: sampling of analytical target, data acquisition, rinse for pole, and self-calibration of the sensor (composed of standard buffer calibration and sea water calibration). With this method we successfully solved the difficulty of reference point drift during its long time working period. Finally the results showed that the accuracy and robustness of the system were improved greatly. This system can implement the self-calibration function automatically and also record the all the information during real-time working condition into flash memory automatically. Based on all the information, it can provide complete reference for analysis of the hydrothermal fluid when the sensor is offline.This dissertation firstly defined the functions of this system and clarified system principle of self-calibration sensor system. The whole plan and flowchart of the study was presented. In the study, we developed the software used in the system by C language. The software include: timing control module, real-time clock module, communication module, the module for data transmission Cyclic Redundancy Check, the module of flash memory storage. Further, the human-machine interface software for the control system was developed. Finally, some experiments were performed and the results showed that this self-calibration system for deep sea sensor could work very well.This study has implemented the self-calibration function for sensor which works under the condition of deep sea or some extreme environment. The system is built on the basis of the low-power MSP 430 microcontroller. This study with self-calibration function provides an effective method and direction for the research of control system and intelligent sensor system. |
