Research On Measurement Principle Of Laser Reflective Displacement Sensor

As an indispensable and important parameter in geometric metrology,displacement measurement is widely used in machine tools,automobile manufacturing,aerospace and other fields.With the rapid development of laser detection technology and measurement methods,the accuracy of laser ranging has been significantly improved.In this paper,a displacement sensor based on laser reflection is studied.The measurement principle is analyzed theoretically.The sensor prototype is designed and experimental research is carried out.The specific research contents include the following parts :The magnification and accuracy of the laser displacement sensor with triangular mirror group and right angle mirror group are analyzed.The measurement principle of the laser reflective displacement sensor designed in this paper is studied by using the principle of space-time transformation.Combined with the measurement principle,the key components required for the design of the displacement sensor are selected,including the optical amplifier right-angle mirror group,the optical translation device piezoelectric actuator and the optical receiving device Position Sensitive Detector(PSD).The working principle of the required device in the designed laser reflective displacement sensor is described in detail.According to the selected device and the overall measurement principle,the hardware part of the laser reflective displacement sensor is designed.Firstly,the design of data transmission and acquisition circuit is carried out.By analyzing the influence of signal on the measurement accuracy of the device under different input modes,the appropriate input method is determined.Combined with the XL-80 laser interferometer produced by Renishaw,the calibration of the output data of the corresponding device is carried out.Secondly,the overall optical path structure of the laser reflective displacement sensor is designed and simulated by Trace Pro to verify the feasibility of the designed optical path.Finally,combined with the optical path structure and the selected device,the mechanical structure design of the sensor is completed.The experimental research is carried out to verify the correctness of the measurement principle of the laser reflective displacement sensor proposed in this paper,and the maximum measurement error is ±1.1μm.The experimental results show that the measurement error of the laser reflective displacement sensor combined with the principle of space-time transformation is significantly reduced compared with the laser reflective displacement sensor of the basic structure,and the sensor still has room for further improvement.