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Chapter 5 Software Design of Measurement and Control System 143

«j System M o d e Fig.11 Fig.12 Fig.21 Fig.22 Display Scroll rate

EXPERIMENTS FOR HOT ROLLING WEAR

Experiment Series:

Experiment Pate:

Temper ature(C):

Material:

Rolling Speed(m/s):

00182

800 m M iMl

0.20

Weight (N):

08-12-96 Redraw StepCpts):

Interval (s):

Trigger T1me(min):

Pressure(MPa):

Ml

XSSL 200

Horizontal Scroll

Chapter 5 Software Design of M e a s u r e m e n t and Control System 144

Dialogue events include two aspects: soft button and parameter edit field operation.

Keyboard operation triggers the change of the parameters in edit field. TAB key is used to change one parameter editing to another one. Soft buttons may trigger control or display operation. Control button handling is quite important for the control flow of the system, which will be explained in the next section.

The system keeps acquiring the input from analog channels and timers and obtains the sample data as frequently as possible in an interval without any limit. Then at the end of an interval, the middle value of each channel is picked up as the real value. This kind of filter method is quite powerful to eliminate many erupt peak or valley

interferences. The new data are inserted into the sorted queue dynamically, which decreases the response speed to dialogue, menu and outside monitoring and control

signals. Only when the time reaches the display pixel of the horizontal coordinate, the parameters are calibrated and displayed on the screen, which can also increase the

running speed of the software.

Dynamic and static threshold judgements for some input channels can detect overload of friction force, or out of range of the displacement sensor as soon as possible.

When the time is up to the preset stop trigger time, the system is forced to stop and all the experimental data and configuration data are written into corresponding files.

The flowchart of the handling of control buttons is shown in Figure 5.30. The handling determines the whole control flow of the system. It mainly implements the handling of START, CONT. and P/STOP buttons. System status are divided into work, pause and

stop status. Push START to start an experiment, push P/STOP to pause it. Then push

Chapter 5 Software D e s i g n of M e a s u r e m e n t and Control S y s t e m 145 P/STOP once more to stop the experiment, or push CONT. to continue the experiment.

All the buttons can trigger different operations at any system status, accompanying with on-line prompt and condition display. Fault operation is tolerant and correct operation is prompted.

ESI

^original data display mode? yes motor and heating device control button handling

timer on, and open previous file

timer on, and open new file

obtain previous data number

output control signals

set work status

output control signals change edit field

set work status

B3

Chapter 5 Software D e s i g n of M e a s u r e m e n t and Control S y s t e m 1 4 6

B2

output signals to stop motor and heating device

B3

timer off and clear timeleft

close experimental data file and append configure file

set stop status

B2

P/STOP button?

work status

~

no

yes timer stop

output signals, only stop motor

set pause status status display

(return j

Figure 5.30 Flowchart of control button handling

invalid operation prompt

For example, w h e n the system is working, pushing C O N T . will not influence the running of the system, "invalid operation" is displayed in the prompt zone. W h e n the system is stop (not in pause status), push C O N T . will cause a prompt " S T A R T for a n e w test, C O N T . to continue the test". If go on to push S T A R T , " S T A R T for an incremented series, S T O P to enter a n e w series" is displayed on the prompt zone. Then push S T A R T to start a n e w experiment with a incremented serial number, or push S T O P to enter a n e w serial n u m b e r in edit field so as to start a n e w experiment.

Chapter 6

Experiments a n d

Discussions

Chapter 6 Experiments and discussions 1 4 8 All the experiments were conducted in the high temperature rolling test rig. The rig and

computer interface circuit box are shown in Figure 6.1. The Macintosh computer with MacAdios II board and interface terminal boards are shown in Figure 6.2.

Figure 6.1 H i g h temperature rolling test rig

( 1> V V %• V f- V »: *; V * »:»- j f-f-|--l

. h,J,<r <•'•<•' V.»:,-lil:>-,

A/D Teiminal Board

Figure 6.2 Macintosh computer with M a c A d i o s II board a n d interface boards

Chapter 6 Experiments and discussions 1 4 9 The motor and heating device control cabinet, transformer and cooling air tank are shown in Figure 6.3.

Figure 6.3 Power control of the rig and cooling air tank

Chapter 6 Experiments a n d discussions 1 5 0

6.1 Experimental procedure

The experimental procedure follows these steps:

1. Adjust the three screws on the top of the support beam to change the angle of the support b e a m and the roller to m a k e the roller and the disk contact evenly in the full length of the roller at high temperature;

2. Run Pre-adjustment Module in the integrated software. Adjust the micrometer at the end of the capacitance sensor to change the position of the probe tip, so as to set the sensor in measuring range;

3. Adjust the supporting nut on the support beam protective stand on the triangle beam to support all the holding block, the support beam and the roller to separate the roller

from the disk;

4. Manually start the motor then use the computer to control the motor and to turn on the heating device;

5. When temperature approaches the required temperature, manually switch on the cooling air supply;

6. After the temperature approaches the required temperature once more, loo.sen the supporting nut on the triangle beam to release the load on the holding block, the

Chapter 6 Experiments a n d discussions 1 5 1 supporting arm and the roller to the top of the disk, and apply dead weight required on

the top of the holding block;

7. Keep the rig ninning for a period of time to achieve steady state condition;

8. Stop the motor, obtain measuring datum point for the capacitance sensor and eliminate zero drift of the load cell by adjusting the position of the tip of the capacitance sensor to ensure the readout to be 100-250 |im, then separate the holding block of the support b e a m from the load cell for a period of time;

9. Finish pre-adjustment and transfer to Experimental Module automatically. Enter experimental parameters, such as stop trigger time, record interval, and load on the roller, then start the experiment;

10. In the experimental process, the operator can pause, then continue, or stop the experiment at anytime, can select any display m o d e and variables displayed on the screen, and can modify s o m e experimental parameters. T h e screen and w i n d o w can also be printed or saved. T h e condition of the rig is in-process monitored, and s o m e faults will cause the rig to stop to protect the system;

11. When it reaches the stop trigger time, the system automatically stops and all the experimental data and information are saved in an experimental file.

Chapter 6 Experiments and discussions 1 5 2