Telemetry-based mobile cabin indoor gas detection method
In various mobile closed chamber environment, the amount of gaseous pollutants present in dogs, these gaseous pollutants present in a molecular state, most of the inorganic gas such as CO, NO2, H2S, LEL, VOC and the like. Wireless telemetry and recording real-time collection vehicle stationary and harmful gases in the process of moving the compartment, the temperature and humidity and other environmental parameters and the status parameters, in order to analyze the influence of harmful gases in the cabin personnel health. The system can be closed cabin environment in a number of indicators of real-time monitoring of stationary and moving, all test data can be stored simultaneously via wireless real-time transmission to the monitoring center to monitor the car a few kilometers away.
1 mobile cabin atmosphere
According to incomplete statistics, tanks and armored vehicles and traveling in the actual process, the car will generate a large amount of harmful gases, such as CO, NO2, H2S, SO2, CO2, LEL, VOC, NH3, HCN, benzene, formaldehyde and dust pollution these harmful gases and dust have a driver, gunner and crew of physical and mental health caused great harm to the vehicle in a closed environment of temperature and humidity on the human body have a certain impact. Tanks and armored vehicles in the development process, timely and accurate grasp of the environmental parameters of the mobile cabin, for improved vehicle design data provide strong support. Recent widespread adoption of remote sensing and control technology, and the progressive realization of intelligent monitoring technology. Class cabin gas parameters shown in table 1.
Test Method 2
Hazardous gas monitoring system monitors the advance is mounted in a fixed position on the cabin, in the monitoring process to monitor the signals acquired local storage on the one hand, on the other hand into the telemetry transmitter means via RS 485 protocol, telemetry means for transmitting the received encoded data stream to form a standard PCM streams away transmitter. A transmitter transmitting radio waves out into the space, the ground telemetry monitoring center receives these signals are processed and plotted down, this can be visually monitored in real time to changes in the environment during the movement of the cabin. System diagram shown in Figure 1.
Telemetry transmitter subsystem principle block diagram shown in Fig. Gas-type sensor subsystem detected gas type of test data package, and is given by the RS 485 data bus interface. All data embedded into the PCM bus interface are collected encoder, encoded data collection.
PCM encoded by programmable acquisition module, the timing control modules, output modules and other components. The serial data stream output from the encoder to the transmitting device modulates, amplifies, and with sufficient power transmitted from an antenna.
Monitoring ground telemetry subsystem integration: Ground monitoring telemetry subsystem using a portable vehicle-mounted receiving scheme. All units except the system receiving antenna and a low noise amplifier are placed in industrial computer.
3 system components and realized
3.1 Selection of sensors
Selected US RAE Systems PGM-2000, MulTIRAEPGM-54, UItraRAE PGM-7200. These advanced composite / gas detection module unity, the working temperature is -20 ~ + 50 ℃, can work in a relative humidity of 0% to 95% of the environment; the lithium battery can work continuously fully charged 10 h above; with advanced plug-in "smart" gas sensors. Instrumentation is above the RS 232 interface, the communication protocol can be provided. The gas detection instrument specifications in Table 2.
Sensor Installation 3.2
Cabin wireless mobile monitoring system exists in the system design process, the following particularity, poor working conditions, internal subsystems, more cross between parts; road transport and climatic conditions make the system must face plateau, mountain, desert in the design process special conditions, cold, heat and other radiation; enclosed cabin space is small, the measurement system volume, shape demanding; most non-standard system device measuring device, a mobile interior cabin space and does not specifically provide permanent mounting position measuring device, only temporarily equipped, more difficult to install and reliable operation of test equipment. On the basis of full investigation and study on the feast of the car. For each test device, respectively, of different design and installation design. The system consists of two independent units, each unit consists of a main tank and a tank composed of pay, and paying tank main tank are connected by a jumper, the jumper length of about 2 m. The main tank can be independently connected to the overall system, to pay for the box attached to the main tank. Gas type of test subsystem physical layout shown in Fig.
Internal test instrument using EVA cushioning material, the flexible sheet-metal support, may be subjected to strong impact. Type of test gas compartment subsystem in a mobile installation diagram shown in Figure 4, arranged multiple pull-ring in the main tank and the tank 4 Li Fu-sided, high-strength strap firmly tied to the driver seat.
3.2 editing and data transmission
Gas-type gas sensor will detect the type of test data is packed, it is given by the RS 485 data bus interface. All data embedded into the PCM bus interface are collected encoder encoding data acquisition.
PCM encoded by programmable acquisition module, the timing control modules, output modules and other components. The serial data stream output from the encoder to the transmitting device modulates, amplifies, and with sufficient power transmitted from an antenna. The system uses the integration on FPGA technology interfaces, the capture and encoding functions of the measured parameters is designed so that the encoding module having programming flexibility, high integration, high speed, line programmable features. Collecting large ones and the output of the encoder code rate can be configured online. Transmitter modular design, the whole module by a modulator, the linear amplifier and the second switching power supply modules, such modules may be composed of different optional different frequencies, different frequencies, different modulation signals and different forms of code rate transmitters. Vehicle transmitting antenna omnidirectional antenna gain is greater than 5 d Bi.
Data receiving and processing 3.3
In the reception processing performed remotely monitoring station data, the industrial PC system as a platform, as a link to the PCI bus, the high frequency channel, demodulate video and computer link together to form a coherent whole. In addition to an antenna system and a low noise amplifier, the remaining portion are inserted into the expansion slot of the computer. The main function of the system components are set. In the computer, thus facilitating operation management of the system. Low-noise amplifiers and antenna are installed on demolition activities can receive tripod, so the system is very convenient to carry and set up. Telemetry data processing apparatus as shown in Fig.
4 real vehicle carrying experiments
On a vehicle in a standard training venues 5 km dynamic real vehicle test, the test vehicle is running test point schematic diagram shown in Figure 6, the central test site monitoring vehicle stationary position, movement of the vehicle to be tested, from less than 5 km , less than or equal to the tested vehicle speed of 100 km h / travel. Test running, the main function of the system and indicators continuously testing and storage battery or car battery backup power to the system, the test time is 1 ~ 2 h. Telemetry ground station interior gas obtained based environmental parameters measured, one of FIG. 7 is a data processing result.
5 Conclusion
Various classes using a gas detection module, by means of radio telemetry, so distant stations reliably obtain harmful gases moving compartment environmental data, experiment shows that the method is feasible. The testing methods may be human variety of tanks and armored vehicles - the data provide strong support ring Development and Improvement - machine. Technology area
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