The Designation Of Ice Thickness Sensor Based On CPLD

The present paper is a basic research for application which "the ice layer thickness sensor and the examination method's research" (60672028) under the subsidization carries on the State Natural Sciences Foundation project. In recent years, global climate warming phenomenon has drawn the close attention of the world .Through tracking and monitoring the sea ice thickness on the north-south pole to grasp the influence that global climate change impact on the natural environment, this has become a hot research in international scientific communities. There are many kinds of factors influent the ice appearance and disappearance change. An ice thickness sensor based on the air, the ice and water rsistivity difference principle has been developed by Institute of Measurement and Control Technology, Taiyuan University of Technology.this system may carry on to the ice layer interior appearance and disappearance process continuously the automated examination new ice sentiment examination system. it in the Chinese 21st, 22 South Pole scientific expedition sea ice observation experiment obtains applies and obtains the massive measured data. The experimental results of the analysis showed that, as sensor circuit complex structures, and the ice condition monitoring system as a whole more power, and influence the stability of the data collection.In response to these shortcomings, this paper presents a new ice thickness sensor improvement programme to successfully develop complex programmable logic devices (CPLD) for data acquisition circuit core of a new low-power ice thickness sensor, and obtains the application in the Chinese 24th South Pole scientific expedition.New ice thickness sensor using Altera's MAX II produced series CPLD devices EPM1270T144I5 instead of the large number of analog switches in the original system, expanded the central data processor I/O interface, completed data acquisition decoding function. Because the CPLD chip has the volume to be small, weight light, dynamic power loss extremely low characteristic, simplified the new ice layer thickness sensor data acquisition electric circuit's structure greatly, reducing overall system power consumption. In the system design, used Verilog the HDL language to compile the CPLD component's application procedure, during simplification structure's, enhanced the system reliability effectively.In order to reduce the ice layer thickness sensor's overall power loss, in the system design besides selects the low power loss component as far as possible, in view of the CPLD component static state power loss major characteristic, has used the two-circuit system power source. And a group is the controllable power source, it when gathers the data only supplies power to CPLD, other times are at the dormant state. Another group power source is for overall system power supply besides the CPLD, therefore it has been at the active status. The empirical datum is separated in the sensor system period of time to gather every time one time, therefore takes the gathering procedure interrupt routine processing, like this may reduce CPLD as far as possible the period of revolution. On the other hand microprocessor MSP430 is 16 ultra low power loss monolithic integrated circuits, it has many kinds of low power loss patterns, when after the master routine completes the system initialization, chooses the processor to enter some kind of low power loss condition, only then the interruption interval micro processing only then awakens at the appointed time from the low power loss pattern, after completing the function, may enter the corresponding low power loss pattern. Through the above method, in hardware and software aspect reduction energy consumption as far as possible.Considered the sensor must carry on the data acquisition experimental work in more than one year time intrinsic South Pole low temperature link boundary, in the sensor system has used the capacity is the 1G SD card mass memory unit continuously, its characteristic was the read-write speed is quick, the read-write was convenient, has the greatly strengthened secrecy, supported inserts hotly pulls out the function. As a result of its capacity and the sensor gathers a time data to take the space greatly to be quite small, therefore a SD card enough preserves one year empirical datum, under the South Pole extremely cold climatic conditions, the operators is very simple to the data accessing operation, has satisfied the experimental work link boundary well to the ice examination system equipment performance demand.New successfully developed new ice thickness sensor on September 22, 2007 to 18 in Dalian University of Technology marine and offshore engineering key national laboratories conducted nearly a month of low-temperature aging test. Analysis of the experimental data prove that: the new type of technology based on CPLD ice thickness sensor basically overcome the old ice detection system of the technical problems in achieving well of the whole ice and dissipation within the condition of ice, water ice under the automatic continuous Detection.