This system can be applied to dam deformation detection, railway monitoring, landslide monitoring, bridge monitoring, high-rise building monitoring, etc. It is an ideal system for automatic monitoring of building deformation. At the same time, this product can be used to measure the height and rail irregularity of rails when equipped with a special measuring frame.
The main body of the photoelectric image type micro-deformation automatic monitoring system adopts the photoelectric image method, which is composed of a photoelectric target, an imaging measurement system, and the like. It analyzes the small deformation of the measured target by the image formed by the photoelectric target fixed on the measured target on the photosensitive device.
It can not only measure the small deformation of the target, but also measure the vibration of the target at the same time. The force vibration frequency, natural frequency and amplitude of the measurement target can be given, and parameters such as impact coefficient and power spectrum can be obtained through spectrum analysis. The specific configuration of the system's hardware, software and accessories quantity and specifications can be determined according to engineering needs. This instrument is used to facilitate remote monitoring during long-term monitoring, and is suitable for long-term monitoring and short-term observation in fields such as unattended fields and incapable of wiring. It has intelligent functions such as remote monitoring, automatic measurement cycle completion, real-time evaluation of measurement results, and real-time display of deformation trends. Field data can be collected on any computer with Internet access.
Working principle for deformation monitoring
Fix the special target on the measurement target, combine the target and the measurement target to form a resonance, convert the vibration into the vibration of the light source with a specific wavelength, and analyze the light signal to be measured to the special high-precision industrial CCD through the optical analysis system. The change of the center coordinates of the upper imaging can accurately measure the longitudinal and lateral displacement of the measurement target under load and its response curve to time. The K value (Kx, Ky) of the system, which is the actual displacement value represented by each pixel on the CCD, can be calibrated before measurement. The test system detection schematic is shown below:
System test schematic diagram (Figure 1)
Technical indicators for deformation monitoring:
1. Two-dimensional measurement can be performed at the same time, the maximum measurement range: not less than 1 meter
2. Measuring distance: 5m ～ 500m
3. Frequency response: 0 ～ 50Hz
4. Uncertainty: One thousandth of the measurement range.
5. Sampling time: multiple files can be preset. Can also use automatic measurement work
6. Working temperature: -20 ℃ ～ 40 ℃, relative humidity: ≤90%
7. Battery powered.
Fourth, the characteristics of the instrument used in deformation monitoring:
1. This monitoring method can accurately measure the small deformation of a target at a distance of 1000 meters, and the accuracy is higher than similar equipment;
2. The industrial design of the whole machine is suitable for long-term field monitoring, which cannot be replaced by general total station, theodolite and other measurement methods;
3. The system and the instrument are convenient for remote monitoring, and are suitable for long-term monitoring and short-term observation in fields such as unattended and unwieldy fields;
4. According to customer needs, software with intelligent functions such as real-time evaluation of measurement results and real-time display of deformation trends can be developed.
Five, installation and use instructions for deformation monitoring
1.Install the target
The target is installed at a place with a wide field of view on the dam, and the target is provided with a mounting fixing hole to fix the target at the detected point. Turn on the power switch for easy monitoring. The target power can be made as a remote switch. In this way, you can enter the power saving mode when you do not measure again.
2. Install the host
Install the host to install the pier and abutment near the detection point. The pier and abutment structure should be concrete, and the structure should be stable, reliable, and easy to install. There are 4 mounting holes on the main unit, which can be fixed with expansion bolts.
Mount the monitor opposite the target. Aim the target and make the two lights on the target image on the monitor, as shown below:
Tighten the bracket.
3. After restarting, the left and right, up and down displacement of the target (unit: mm) will be displayed in the upper left corner of the screen, and these two values will be output at the same time.
Its format is: UXX.X, XX.X0D0A, that is, the first byte is "U", followed by the horizontal displacement and vertical displacement, and it is terminated by a carriage return and a line feed.
Such as: U1.1, 2.3
1.1mm horizontal, 2.3mm vertical
6. Slip and Settlement Methods for Measurement Points in Deformation Monitoring
1. Set observation points, reference points, and measurement points
It is best to construct pier and abutment at observation point, reference point and measurement point to facilitate the next observation. The pier is convenient for the host and target to be fixed.
1) For the first measurement, install the host and target at observation point, reference point and measured point respectively. Level the host blisters, aim the fiducial point target so that it is all in the data collector window, and then restart the data collector. Use a pen to record the horizontal angle A1 and vertical angle B1 on the host.
2) Rotate the host to aim at the measured points so that they are all in the data collector window. Use a pen to record the horizontal angle A2 and vertical angle B2 on the host, and record the two-dimensional coordinates (X1, Y1) displayed by the data collector. ). This coordinate is the relative coordinate between the measured point and the reference point. This completes the first measurement.
3) The next time you measure the slip and settlement, place the host and the target in order, aiming at the reference point first, so that the target is imaged in the data collector. Restart the data collector and use the note to record the horizontal angle A3 and vertical angle B3 on the host.
4), mobilize the host so that the horizontal angle A4 = A3 + (A2-A1), the vertical angle B4 = B3 + (B2-B1), and read out the two-dimensional coordinates (X2, Y2) displayed by the data collector. X2-X1 is the slip of the measurement point, and Y2-Y1 is the settlement of the measurement point.
5) Repeat steps 3 and 4 for each subsequent measurement.