With the development of industrial and defense technologies, diving equipment is increasingly demanding high, precise and sophisticated detection techniques in various applications, especially in military applications. In the development of various diving equipment technology, the important submersible fully reflects this point. In order to improve the deep diving ability of the submersible, the submersible is equipped with an integrated navigation display control system to ensure the submersible can accurately snorkel. , successfully complete various underwater operations tasks. Due to the size and load limitation of the submersible, the sensor used in the integrated navigation display control system must be small in size, light in weight, high in pressure resistance, and functionally capable of obtaining the navigation parameters of the submersible quickly and accurately. In measuring seawater temperature, conductivity, pressure, depth, salinity, sound velocity, density and other state parameters, SBE 37-SI MicroCAT temperature and salt depth sensor can measure the seven state parameters of the above seawater in one, and in accuracy, It meets the requirements of system design in terms of volume and weight, and is a sensor that is very suitable for use on a submersible. The following is a discussion on the data acquisition process of the SBE 37-SI MicroCAT temperature and depth sensor in the submersible. The transmission format does not correspond and it is not convenient for direct transmission. A feasible design scheme and ideas are proposed, and a An example of an application has been described.
1 SBE 37-SI MicroCAT temperature and salt depth sensor in the submersible
The integrated navigation display control system of the submersible mainly uses the integrated navigation technology and the information fusion technology to organically combine the various navigation devices. The filter technology is used to process various navigation information without changing the navigation devices. Various navigation information complement each other to improve navigation and positioning accuracy. By centrally displaying navigation information, centralized control and comprehensive processing, it is possible to maximize the role of each navigation information and provide comprehensive and optimal navigation to the device in real time. information. The function of the temperature and humidity sensor is to measure various state parameters of seawater in real time, such as temperature, conductivity, pressure, depth, salinity, speed of sound, density, and send it to the integrated navigation display control system, and then display it for use by other devices. In order to ensure the safety of the submarine navigation and the completion of the salvage search and rescue mission, the measurement of the sensor on the submersible must meet the requirements of navigation; the refresh rate of the data must meet the requirements of the submersible; the measured data must be stable and reliable. The SBE 37-SI MicroCAT temperature-deep-sink sensor achieves performance in these areas and meets the requirements of navigation systems.
The SBE 37-SI MicroCAT temperature and depth sensor is currently used in many submersibles and submarines abroad, and is rarely used in China. As shown in Fig. 1, the outer dimensions are 43.69 cm long, the maximum height is 13.97 cm, the maximum width is 10.8 cm, and the weight is about 2.9 kg. The SBE 37-SI MicroCAT temperature and depth sensor has a very high measurement accuracy, for example, a temperature range of -5 to 30 ° C and an accuracy of 0.0001 ° C. It can also measure the required pressure at a water depth of 7,000 m. Precise navigation information. SBE 37-SI MicroCAT and other devices mainly perform serial port asynchronous communication according to NMEA-0183 standard, exchange data and transmit in both directions. Its external interface is EIA RS-232, and the transmission baud rate is selectable from 1200bit/s to 38400bit/s. The character code sent is ASCII code, and the rate of measurement data transmission can also be selected by the output parameters. The time interval of each measurement data output ranges from 1.15 seconds to 22.19 seconds.
2 SBE 37-SI MicroCAT interface circuit design
The output data format of the SBE 37-SI MicroCAT temperature and depth sensor is in common format with general navigation equipment, such as GPS data format: $PASHR, POS, n, ..., tt.t, vvvv*cc[CR][LF] It contains the start symbol $, the data content, the code and the flag *, the code and the cc, the data terminator [CR][LF]. The output data format of the SBE 37-SI MicroCAT has no start symbols, codes and flags, and code sums. It also has a big feature: the output of the SBE 37-SI MicroCAT temperature-deep sensor has level protection. When it is powered off, it is powered back on, the output level is zero, and the measurement data is not sent out autonomously. It must be sent an excitation signal (data send command) to trigger it. Its trigger signal is two carriage return line-feed bytes (ie 0x0D, 0x0A), but it cannot be sent continuously. It must be sent twice in two seconds, so that the sensor can be triggered to send data out according to the set format and rate. .
In order to make the data format of the temperature and depth sensor output consistent with the data format of the common navigation device, it is necessary to design a data format conversion interface circuit, which needs to complete the work: first obtain an external command or generate a trigger command to send to the sensor , triggering the sensor; then receiving an external command to change the baud rate of the SBE 37-SI MicroCAT output data, transmitting the update rate of the data; and receiving data from it, plus the start character, code and flag, and code sum; if in the data If there is a space, replace the space with zero; finally output the data to the integrated navigation display console. In this way, the data format conversion interface circuit handles the interruption of the control instruction and realizes changing the baud rate and data update rate of the sensor on the one hand, and serial data communication with the sensor on the other hand.
Lighting Pole, Outdoor Lighting Pole, Led Lighting Pole, Park Lighting Pole
YIXING FUTAO METAL STRUCTURAL UNIT CO.,LTD( YIXING HONGSHENGYUAN ELECTRIC POWER FACILITIES CO.,LTD.) , https://www.chinasteelpole.com