Design Of The Height Adjustment System For Laser Cutting Machines

Laser cutting is a hotspot of thermal cutting technology. As a new cutting mode, laser cutting has characteristics of high efficiency, high precision, low noise, small pollution etc.. The height adjusting system is an important part of laser cutting machine. It is directly related to the consistency and accuracy of laser focus position in the materials, and then determines the cutting quality. So it has important significance to design a height adjustment system for laser cutting machines. Therefore this thesis designs a height adjustment system for laser cutting machines, with the DSP as the controlling core.The paper firstly introduces the background and significance of this research, then analyses the domestic and international research’s status and development trend of the height adjustment system for laser cutting machines. Then it analyses the requirement of the control system of this system, then completed the design of the overall framework. This thesis compares the different sensors, according to the characteristics of the control system,chooses capacitance sensor as the detection method. This paper combines variable universe theory and fuzzy control theory, designs a closed-loop control system with variable universe fuzzy controller to adjust the height of cutting head.Through the analysis of the working principle and electrical characteristics of the capacitance sensor, the line of relationship between capacitance value anddistance is build. This paper designs the capacitance detection circuit with CAVA424. And the output of CAV424 is changed from analog to digital. This paper also designes a least square curve algorithms to fitting curve.The paper designs the hardware with DSP as the controlling core. Collocating with hardware circuit, the software module of system is designed to realize the function of height adjustment system. Then combines variable universe theory and fuzzy control theory, designs a closed-loop control system with variable universe fuzzy controller to adjust the height of cutting head.Finally, a platform is builded to test the performance of height adjustment for laser cutting machine. Through the test we found that the measurement had agreed with expectations.