introduction
There are two methods for measuring wire diameters in industrial production. One is static measurement and the other is dynamic measurement. Static measurement solutions are often performed using traditional precision measuring tools. In production practice, online measurement is often encountered. For example: On-line inspection of outer diameter of product in cable industry; Measurement of steel wire diameter in the process of drawing steel wire by metalwork factory. The solution can only adopt dynamic non-contact measurement. Baoding Lanpeng Measurement and Control Technology Co., Ltd. Developed dual diameter measuring instrument, using CCD image sensor and single-chip processing system, to achieve a dual dynamic non-contact diameter measurement, accuracy of 0.003 mm, suitable for wire diameter measurement applications.
1, the basic principle of the measurement system
Dual diameter gauge is online non-contact measurement of wire diameter instrument The measured steel wire is irradiated by a parallel light source and amplified by a measuring objective lens to be imaged on the photosurface of the CCD. The CCD is a core device for photoelectric signal pickup. The amount of charge taken by each pixel is proportional to the light intensity radiated on it. By the CCD driver, a discrete voltage signal is obtained at the output of the CCD, the size of which corresponds to the intensity of light received by the photosensitive element, and the order of the signal output is consistent with the order of the photosensitive elements. After conversion by the A/D converter to 8 bits Digital quantity, after data processing, the wire diameter is calculated online by the microcontroller.
Probe composition
The measuring head consists of an optical system and a CCD drive template.
The optical system is a two-path caliper used to obtain optical measurement signals in two parts.
(1) Illumination part. Through the collimator lens, the point light source is changed to light, and the point light source is selected with a high-brightness LED lamp. The green light source has a fixed wavelength and is not affected by ambient light.
(2) Imaging system. The object to be measured is irradiated with parallel light and is directly imaged on a CCD. The resolution is the size of the CCD sensor. To improve the resolution of the caliper, a small hole imaging method is used to generate the measured wire. Scale up imaging on the CCD, after calculation, can get accurate wire diameter value.
The two-path diameter measuring instrument uses two sets of probes to measure the diameter of the steel wire. The two sets of probes are vertically distributed (according to the requirements, the angle can also be customized). The wire diameter and ellipticity dimensions in two directions can be measured.
2, wire diameter control
The dual diameter gauge is a diameter measuring instrument that detects and controls the wire diameter from two directions. In order to increase the production efficiency, the dual path diameter gauge has a PID adjustment function, and the dual path diameter gauge uses an incremental PID. Butt a variety of external devices, forming a closed-loop control, so as to automatically control the diameter of the wire to make it within the specified range of production.
Our two-path diameter gauges are divided into two types, one is a touch-screen diameter measuring instrument, and the other is a button-type diameter measuring instrument. According to your operating habits, you can select a suitable two-path diameter measuring instrument. The diameter meter can be equipped with an external display. It displays the measured diameter, average and elliptical dimensions in both directions.
3, measuring frequency
The measurement frequency is related to the measurement speed. We all know that the manual detection basically uses the sampling inspection, and vernier calipers are used to detect every other distance. This method not only has hysteresis, but also cannot ensure the outer diameter value of each inch of steel wire. The on-line automatic diameter gauge has become the most advantageous measurement tool.
The figure above shows the number of detection points for different frequencies. It can be seen from the figure that the larger the measurement frequency, the more points are detected and the more dense, therefore, the higher measurement frequency can ensure more data to be detected for the same wire. The measuring frequency of each set of probes can reach 500Hz. It is a high-frequency detection device, and can also be customized as a 1000Hz caliper.
The dual-path diameter gauge has a fast detection speed and is many times of manual detection. It can detect 500 data per second, and ensure accurate measurement data. It can also control the wire diameter. It is a very important helper in steel wire production.
Conclusion
Two-path caliper instrument is installed on the steel wire drawing machine for on-site measurement and can work continuously. The dual caliper instrument can adapt to the environment of the steel wire production workshop. The anti-jamming type is strong, and the long-term continuous operation achieves the desired effect. And the measured value and the micrometer, Vernier caliper and other test data are consistent, and when the two-path caliper is out of tolerance, it can give an out-of-tolerance alarm signal in time. The double-path caliper is a high-performance on-line detection equipment, which plays an important role in improving the quality of steel wire.
This article consists of Baoding Lanpeng Measurement & Control Technology Co., Ltd. write
