Research On Automatic Calibration Of Force Sensor

Force transducer, as a kind of force measuring cell which can convert force signal to electric signal, has been extensively used in many areas such as national defense, manufacture. According to state regulations, transducer should be calibrated before use to ensure the accuracy of measuring. With the development of technology, the applications based on force transducer become more and more, meanwhile there’s more of a requirement to the calibration system. However, the existing calibration system is less-automated, and cannot normally perform dynamic calibrating experiment. As a result, to develop a calibration system can solve the above problems is of great significance.In this paper, the method of demarcation of force sensor was studied. For the defect in the existing design a new scheme was proposed, and based on which the substantial platform and the system software were created. To verify the system, testing and uncertainty analysis has been implemented. The main contents are as follows:Firstly, research into the static and dynamic calibration method based on force transducer was carried out. The requirements, process and data handling method of static calibration is discussed in detail. It then analyzed the step response method, impulse method and sine wave scanning method of dynamic calibration. With the theoretical method, the scheme of whole system are introduced, including selection of force source, measurement of dynamic force, architecture of data acquisition and control, communication of devices.Secondly, the internal structure of the strain-gage type force transducer is introduced, the framework of the hardware system was achieved in this paper, the detailed descriptions of each hardware unit was also shown up. The hardware system which contains PXI chassis, control unit, data acquisition cards, accelerometer, conditioner, camera was built, this will lay the foundation of function realization.Then, utilizing LabVIEW carry the system software. It details narrated constitute and design pattern of the software. Each unit was also been discussed explicitly, signal acquisition, data processing, graphical display, management of calibration information, management of user information, report generation, OCR are taken in. Software is center of system, software can control hardware device, meanwhile, users execute work by the software panel.Finally, a system including force source, data acquisition module, image acquisition module,control module,measurement module and software was built. System testing was performed through the experiment, Interface 552608 A sensor was also been calibrated. After studying the method of uncertainty evaluation, system uncertainty was calculated to assess quality.