Development Of The Displacement Sensor With Multi-point Measurement Function For Laser Cutting Head

With the wide application of laser cutting technology, undoubtedly the quality and efficiency of laser cutting are the most important two factors. In laser cutting process, especially 3D laser cutting, the distance between the cutting head with work piece and the verticality of laser beam axis with processed surface impact efficiency and quality seriously. At present, there are still not related commercial products in our country. So, the research on the sensor which can both test the distance between laser cutting head with work piece and inspect surface normal vector has important realistic meaning and practical value.Based on the requirements of laser cutting process and sensor own performance, put forward a kind of displacement sensor with multi-point measurement function for laser cutting head. It is based on the working principle of changing gap capacitance sensor, multiple capacitance sensors work at the same time to detect the distance between cutting head with work piece and the surface normal vector.According to the requirements of laser cutting, establish the mathematical model of multi-point measurement sensor detection principle. To detect the normal vector of surface with multiple capacitance sensors is feasible in theory. According to the actual working condition, analyze the affecting factors to the performance of the sensors, and design the laser cutting head with multi-point measurement sensor.Based on the demand upon the performance of sensors in the subject, develop a sensor detection circuit. Sensor signal detection circuit is the important section in the measuring system of sensor. This paper will introduce the circuit design process particularly. Through the testing experiment about one capacitance sensor performance, verify both the circuit which we design can satisfy the job's requirements and the performance of single sensor is good.Using with self-designed detection circuit of multi-point measurement sensors, do some experiments. The results proof that the sensors do not exist mutual interference. Both the performance of distance measurement and the function of normal vector measurement are good. The results indicate that multi-point measurement sensors can satisfy the requirements which the laser cutting demands.