Research On The System Of Three-dimensional Whole Incised Probe

Probe is one of the key hardwares used in CMM. The measurement accuracy, operational performance, automation level and measurement efficiency of CMM are restricted by the development level of probe directly. The probe of CMM can be regarded as a kind of sensor, which can feel sampling pulse signal and tiny displacement in three directions in order to realize the two functions of sampling and measuring. Aiming at the designs of structure and circuit of probe, deep research and practice have been done in this thesis. The main contents of the thesis are as follows: The classification and characteristic of CMM, probe and sensor are explained. On this basis, the characteristic of the inductance type sensor and its operation principle are discussed in detail. Two improvements are given. One is on the structure; the other is the circuit. As to the structure, The railway of the probe on which the parallel spring moves along three directions is whole incised, which not only overcomes the limitations of traditional probe (such as the difficulty to keep the parallel spring balance, large manufacture error,assembly error and volume because of too many parts in the probe,and etc.) but also improves the repetition property and respondence property of the probe. As to the circuit, simultaneous sampling A/D converters are used in order to replace traditional demodulation and decrease the errors caused by analog circuit, which can improve the differentiate of the probe. Virtual instrumentation technology is applied. Based on LabWindows/CVI, a complete-function user program with soft virtual panel is programmed. By the soft virtual panel, the user can conveniently set parameters for measuring, and choose the ways for fitting and filtering. By using the software of ANSYS, the static finite element analysis and modal analysis of the structure of the probe are done, and the displacement figure, the stress distribution figure, the natural frequency and the shaking type of the probe are obtained. Experiments have proved that the probe can meet the requires of new NC and be used in copying process and precise measurement.