Several important factors that determine the perfo

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Several important factors determining the performance and accuracy of electronic universal testing machine

1 The first is the ball screw, which drives the motion of the sensor, because if the screw has a gap, the future test data will directly affect the maximum deformation and elongation after fracture of the test. At present, some lead screws of electronic universal testing machines on the market are T-shaped ordinary lead screws. In this case, the gap is relatively large, and the friction force is relatively large, and the service life is short. The lead screw used by Jiangdu Kaiyuan testing machinery factory is German ulleneff high-precision gapless ball screw. The surface quenching hardness is HRC, and the service life can reach decades. And ensure the accuracy unchanged

2. The second is the transmission system of the electronic universal testing machine. At present, some of the transmission systems of the testing machine in the market use reducers, and some use ordinary belts. The main disadvantages of these two transmission modes: the former requires regular lubrication, while the latter cannot ensure the synchronization of the transmission, which affects the test results. The transmission system of the testing machine of the open source instrument adopts full arc synchronous belt to decelerate, which ensures the synchronous accuracy of transmission, high transmission accuracy, high efficiency, stable transmission, low noise, no maintenance, and long service life

3 Next, the number of aircraft delivered by manufacturers in 2014 and later was set as the force value sensor of the growth testing machine again, because the quality of the sensor determines the accuracy and force measurement stability of the testing machine. At present, the sensors used in the tensile machine on the market are small. With the gradual serialization, matching and standardization of the varieties of plastic building materials, the force value is generally S-type sensors, and the force value is generally wheel and spoke sensors, The inside of the sensor is usually a resistance strain gauge. If the accuracy of the strain gauge is not high, or the anti-aging ability of the glue used to fix the strain gauge is not good, or the material of the sensor is not good, the accuracy and service life of the sensor will be affected. The imported sensor used by the open source instrument is the American Quanli sensor, a world-famous sensor manufacturer. The sensor has high precision, good linearity and very stable performance, and will not change for decades

4. Thirdly, the power source (motor) of the testing machine is also called motor. At present, some testing machines in the market use ordinary three-phase motor or variable-frequency motor, which adopts analog signal control, with slow control response, inaccurate positioning, and generally narrow speed regulation range. If there is high speed, there will be no low speed, or if there is low speed, there will be no high speed, and the speed control is inaccurate. The motor used by the open source instrument is Japan Panasonic full digital AC servo motor. The control mode adopts full digital pulse control, and the speed regulation range is wide, up to 0 Mm/min, accurate control and positioning, fast response, 0.01 seconds can be added to the full speed, the motor can ensure the accurate control of full-scale speed, and the service life is long, up to decades, without maintenance

5. The last is the measurement and control system (i.e. software and hardware) of the pilot machine. At present, the measurement and control system of most tension machines in the market adopts 8-bit single chip microcomputer control, with low sampling rate and poor anti-interference ability. The other is AD converter. If the number of bits of AD converter is low, that is, the resolution. Then the measurement will not be accurate. The measurement and control system of open source instrument adopts the controller hytestv6.0 developed by the world's most advanced 32-bit ARM technology This controller is based on 32-bit arm platform, and runs the self-care system of accommodation cost of the real-time multi task operation system developed by our company, which makes the program run more smoothly and the system more stable. The sampling rate can reach 200 times per second. With 24 bit high-precision low noise high-speed AD converter, the whole measurement and control system can control the whole test process with higher accuracy and stability. The software of the upper computer is the full digital three Bi loop control software developed by the open-source instrument for 2 years. There are two control modes: A. PID control regulation mode; B. model Lake control regulation mode (the first in the industry). The whole test process can achieve constant force control, constant displacement control, constant deformation control, low-frequency fatigue control, and arbitrary program control. (end)

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