At present, realizes to the vehicle emissions pollution carries on the active control to become our country environmental protection urgent duty, needs to carry on the examination in the production to the automobile exhaust pollutant. This article conforms to the EU-2 standard on one kind, based on embedded Windows the CE operating system and the configuration king 6.0 configuration software’s collection operating mode simulation, type gas gathering, the type gas analysis carries on the introduction in a body’s automobile exhaust pollutant intelligence examination system.
First, system summary
The overall system by the central control unit, the chassis measurement of power machine, the exhaust sample unit, the analytic instrument unit as well as the related supporting facility is composed. The first chassis measurement of power machine simulation automobile’s operating mode, then the exhaust sampling system carries on precise quota gathering to the type gas, finally performs the quota examination by in the analytic instrument unit’s to type gas pollutant density, the central control unit realizes to overall system’s automatic control. And the central control unit uses the embedded system to take the core control unit, the system operation stands to move WIndows the CE embedded operating system and the configuration king 6.0 inserting version configuration software’s labor controls machine, is responsible to issue that the order for takes the scene control and order functional element’s PLC. The same work paid by time controls machine uses the TCP/IP agreement with long-distance superior PC between to carry on the communication.
Simplification Windows the CE embedded operating system causes the movement to carry out the efficiency on this operating system’s inserting version configuration king 6.0 configuration software to be very high, definitely may satisfy the equipment scene movement the need.
(one) principle of work
Figure 1 automobile exhaust examination system schematic drawing
System overall schematic drawing as shown in Figure 1. Turns on engine’s automobile to simulate each kind of travel operating mode on the chassis measurement of power machine, its exhaust emissions pollutant under air blower function after ambient air filter enters the exhaust sampling system sampling instrument, carries on the constant volume dilution sample (CVS). The analytic instrument from the background air pocket, the diluted exhaust air pocket sample gas carries on the analysis separately, the survey obtains the pollutant the volume concentration. In the automobile exhaust the pollutant emissions value carries on the computation by the below formula:
mi=1/S*V*di*ci/106 (i for HC, NOx, CO)
In the formula: as soon as mi discharges pollutant quality; As soon as S exercises the distance; A V temperature is 273K, the atmospheric pressure is under the 101.33KPa reference condition the diluted exhaust total volume, the unit: m3; di- each kind of pollutant in temperature 273K, time atmospheric pressure 101.33 KPa densities; dco=1.25kg/m3; dHC=0.619kg/m3; dNO2=2.05kg/m3 (in exhaust the NOx density uses NO2 equivalent expression); in ci - diluted exhaust pollutant volume density, 10-6.
(two) control system’s work process
The labor controls machine through the CVS system and the analysis unit sensor gain metrical data, transforms through the data acquisition module to conform to the RS-485 standard digital signal, will transmit gives the touchscreen, the touchscreen the metrical data will transmit through the TCP/IP agreement for PC machine (superior machine), will complete the data processing work. At the same time, touchscreen basis gathering signal value judgment present active status, control command transmission for analysis unit and CVS system’s PLC. Analysis unit’s PLC mainly completes the half to analyze the instrument to carry on the operation which a series of air course cut, the measuring range transform, CVS system PLC mainly to CVS carries on the flow control, realizes the self-cleaning, the sampling and so on a series of functions. Control command after the PLC processing, transforms for the direct relay make and break signal, realizes turns on and closes the CVS system solenoid valve, the sample pump’s duty. Moreover, the distributing box has also provided the 380V power electricity switch for the air blower, but hand control air blower’s start and stop. Control system structure diagram as shown in Figure 2.
Second, system hardware composition
In order to guarantee that system’s accuracy and the reliability, this article selected the labor to control in the domain stable reliable Windows the CE embedded operating system controlled as the labor machine the control core. Part stable properties and so on data acquisition module, PLC, relay, gathering and the control precision are high, the speed of response is quick.
(one) the labor controls machine
The labor which stands as the operation controls machine the client side application procedure which 6.0 (128 spots) develops based on embedded operating system Windows CE and the embedded configuration software configuration king. Windows the CE embedded system’s superiority lies in its device management simply highly effective, supports the different category the equipment, supports management pattern which and equipment energy conservation control namely inserts namely uses; Processing system’s input output has the real-time response ability.
The configuration king inserted version 6.0 to provide based on the embedded operating system’s development platform, because the configuration king inserted the version 6.0 stabilities to be high, took the system resources to be small, the configuration software itself provided the massive general purpose equipment’s driver, the development cycle is short, therefore selected the configuration king to insert version 6.0 to take the development kit.
What the hardware selects is ADVANTECH- grinds the Chinese TPC064 touchscreen (embedded integrated labor to control machine), its main system parameters are as follows:
Liquid-crystal display size: 5.7 ” TFT; CPU basic frequency: ARM9266MHz; Memory: 64M; CF card: 64M.
The touchscreen foreign data transmission connection mainly has four RS232 connections, two RS485 connections, a USB connection, 1 10/100M network interface.
Picks employing labor controls machine way, but the multi-serial port input, the processing speed is quick, the efficiency is high, moreover the touchscreen had the good man-machine conversation contact surface, the operation is simple, is direct-viewing, has satisfied the check-out facility true-time operation and the real time display function.
(two) PLC
This article selects SIMATIC S7-200 series PLC, the main module and the labor control machine through the RS-232 serial port communication, realizes the software programming with step7-Microwin. PLC takes one kind to use in the industrial production process control specially the field apparatus, has the reliability to be high, the compatibility is strong, the communication and the programming are convenient, structure modulation characteristic.
The PLC execution operation station sends out the instruction and carries on warning processing and so on simple operation. In the overall system the PLC control’s hardware switch quantity altogether has 24, the analytic instrument unit has 5 Three Contacts solenoid valves and a sample pump, the CVS unit has 7 two solenoid valves, 8 Three Contacts solenoid valves and three pumps.
(three) sensor and data acquisition module
In the system the analytic instrument unit survey density value simulates the quantity output after rear panel’s output terminal, the CVS unit flow measurement unit metrical data simulates the quantity output by the sensor, the concrete sensor includes:
Standard major axis spray nozzle flowmeter: BYW-S-80,4 m3/min~8 m3/min, jet size 80mm, uses in the main flow channel constant discharge survey;
Digital pressure transmitting instrument: BYD-8, before standard major axis spray nozzle flowmeter, terminal pressure survey, output signal 4 mA~20mA DC,24V;
Electric capacity type differential pressure transmitting instrument: 1151DP3E22M183, front end standard major axis spray nozzle flowmeter, rear end pressure difference survey, output signal 4-20mA DC,24V;
Explosion-proof digit temperature transmitting instrument: BWD-8, behind standard major axis spray nozzle flowmeter temperature survey, output signal 4 mA ~20mA DC,24V, measuring range 0~50℃;
Pressure transmitting instrument: CS20FUCIIIERC3Lm (3) A, uses in controlling the type gas to take the bags for sample pressure and to protect it, output signal 4 mA ~20mA DC, power supply scope 15 V ~28VDC.
Data acquisition module: Grinds Chinese 16 channel A/D the PCL-818 data acquisition card.
(four) communication module
The system communication way divides into two kinds: Serial port communication and TCP/IP agreement communication. PLC and the data acquisition module and the labor control machine between for the serial port communication; The labor controls machine and between PC machine uses the TCP/IP agreement to carry on the communication. The hardware parameter is as follows: The labor controls machine the network card: 1 10/100M network interface; PC machine network card - TP-LINK,100M.
Third, system software design
This embedded control system’s programming divides into two parts; first, the PLC software programming, realizes to the working space scene control; Second, the operation station touchscreen’s programming, the touchscreen the metrical data judgment present active status which gains according to the sensor, then the control command transmission for various units’ PLC, simultaneously will produce the interactive man-machine conversation contact surface.
(one) PLC programming
1. control flow description
Analytic instrument unit’s PLC is responsible for the air course and the measuring range cut operation, CVS unit PLC mainly carries on the flow control to the CVS system, realizes the self-cleaning, the automatic sampling and so on a series of functional control. Take the CVS system as the example, PLC first controls the CVS unit equivalent process, aerocyst in waste gas evacuation; Then the control clean process, carries on the pipeline clean; Finally the control automatic sampling, pulls out separately the background gas and the dilution gas to two aerocysts, prepares for analytic instrument’s gasometric analysis. The above process mainly contains to the pump, the valve switch and fixed time the time delay control. Controlled process as shown in Figure 3.
Figure 3 CVS system PLC control flow feudal official
2. control procedure
The entire control procedure we use the procedure code programming, it compared with the trapezoidal chart, the functional module is nimble, is convenient, the structure is compact. The master routine module is:
LD SM0.1 // initialization, transfer subroutine 0
CALL SBR_0
S M2.0,4 // establishment program execution flag bit
LD M0.1 // begins using the wait routine
A M2.0 //M2.0 supposes is 1
LPS
LD M8.1 // has the replacement request
ALD
CALL SBR_I//transfer subroutine 1
//SBR_0:
LD SM0.0
…. // initialization pump valve condition
CRET
, SBR_I:
LD SM0.0
LD M3.0
…. // controls the CVS work flow
CRET
(two) touchscreen control procedure design
In the system operates stands we to use the touchscreen to realize the interactive man-machine conversation. Including 5 main contact surfaces: System main contact surface, CVS contact surface, analytic instrument contact surface, report form and historical data inquiry printing contact surface, manual contact surface. The design by the button form simple, controls the PLC movement intuitively, has demonstration functions and so on operating status and data, malfunction alert as well as report form inquiry.
Fourth, concluding remark
The overall system satisfies the automobile Manufacturer scene monitor automobile exhaust pollutant content completely the request. Realizes the complex operation through the simple direct-viewing man-machine conversation contact surface, overcame the observation system reliability to be formerly low, the failure rate high, operated the duplicate efficiency low status shortcoming, thus raised our country automobile Manufacturer production management level effectively.
