The 3D Touch-trigger Probe Based On Single Photoelectric Sensor

With the rapid development of micro-nano machining technology,higher requirements are put forward for the measurement accuracy in the field of precision engineering.As the key part of the micro / nano coordinate measurement machine(CMM),the probe system determines its accuracy to a large extent.According to the research status of the micro-nano 3D probes at home and abroad,a touch trigger probe based on single photoelectric sensor is proposed in this paper,accomplished by the following work:1?The leaf springs,floating plate and stylus with appropriate shape and size were selected based on the parameters of the elastic mechanism.The software ANSYS was used to simulate the elastic mechanism.The results of the simulation show that the elastic mechanism meets the requirements of the probe in terms of stiffness and natural frequency.The optimal design of the elastic mechanism was completed2?The optical path of the photoelectric sensor was analyzed and a 3D sensitivity model was established.The position and size parameters of each optical element were optimized by using the principle of equal sensitivity in 3D.3?The probe with optimized structure was processed?assembled and debugged.An experimental platform was established by using the PI micro platform as the test benchmark.The sensitivity,repeatability,resolution and stability of the probe were tested on the experimental platform.The sensitivity of the probe in x?y and z direction is approximately equal to 0.42?0.44 and 0.40 V/?m respectively,which meets the requirement of the sensitivity optimization model.The permissible measurement range of the probe is larger than ±14 ?m;the repeatability in 1?m is within 15 nm;the minimum resolution is less than 5 nm;the drift of the probe is less than 24 nm in two hours.4?In order to verify the measurement accuracy of the probe,the flatness and the step height of the probe were tested by using the 0-grade standard optical flat and a 4 ?m standard step height.The results show that the standard deviation of 0-grade standard optical flat is 25 nm.The mean value of 4 ?m standard step height is 4.094 ?m,and the standard deviation is 38 nm.The test results show that the measuring precision of the probe meets the requirements of the CMM.5?The errors in the design,assembly and test of the probe were analyzed.