The Research Of Control System About On-machine Measurement Of Diamond Grinding Wheels’ Surface Topography Based On Embedded

As a grinding tool, the surface topography of the grinding wheel directly determines the quality of the machined surface. Most of the existing grinding wheel measuring equipment need to disassemble the grinding wheel from grinder and repositioned on measuring instruments. This process makes it difficult to real-time observation the change trend of grinding tool in the manufacturing process. In order to accurately obtain the grinding wheel whole-life surface topography change proces,it is necessary to develop an on-machine testing system for detecting grinding wheel surface topography. However, in order to achieve this function, the testing system need to have the ability of multi degree of freedom precision movement,in order to adapt to the large scale surface inspection of a series of grinding wheel. At the same time, it is need to realize the precise positioning of the sub micron level in the optical axis of the optical system. All of these requirements have put forward new challenges for the development of on-machine testing equipment. This paper is based on embedded processor with the superiority of real-time, high control precision, good stability and easy to integrate, for currently grinding wheel surface topography measuring instrument, which is based on the principle of focusing synthesis and White light vertical scanning interferometry, has an non portable acquisition and control system, intended by embedded development module to realization XYZ directions step motor drive control, CCD driving of image acquisition system and piezoelectric ceramics driving power design of on-machine measurement of diamond grinding wheels’ surface topography measuring instrument,improve control system comprehensive applicability, and the grinding wheel surface topography measurement instrument control system miniaturization.The main contents are as follows:(1)Based on the importance of gringding wheel surface topography measurement,the research status of gringding wheel surface topography on-machine measurement and the application of embedded system in image acquisition and processing are summarized. The basic principle of focusing synthesis and white light verticalscanning interferometry is analyzed, and the parameters of motion system, optical system and position feedback system of grinding wheel surface topography measurement instrument are presented.(2)Research system optimization and integration scheme, using Pi Raspberry as the core of the embedded development module, complete the system stepper motor drive control of XYZ three direction, to achieve the control of each 200~10000step;Complete the USB2.0 interface CCD camera embedded driver,to achieve the highest 12fp/s image acquisition rate; Complete the hardware circuit design of PZT drive power supply, and the fusion of the hardware drive and acquisition control strategy of the grinding wheel surface topography measuring instrument is realized under the Linux operating system.(3)In order to achieve good drive control of grinding wheel surface topography measurement instrument. human- computer interaction control interface of the system was completed by QT. Mainly includes the image display interface, a stepper motor control interface and control interface of the PZT micro displacement platform.Through the above several aspects of the work, this paper build the embedded drive control system of the grinding wheel topography on-machine measurement instrument. The experimental results show that the control system can realize the drive control system of the measuring instrument, and can meet the requirements of motion control in on-machine measurements.