Based On The Embedded Cnc Laser Cutting Carving Control System Research And Development

Laser processing, a kind of non-contact processing, with its superior characteristics such as high efficiency, high accuracy and high feasibility of automation, has been widely applied in fields of electronics, aerospace and mechanical manufacturing, etc. At present, the common laser processing system in the field of art carving equipment is the Numeric Control (NC) system based on PC and motion control card, which has many shortcomings such as high cost, weak real-time and less stability. Therefore, in recent years, the embedded NC system which is of low cost, high performance and good flexibility has received more and more attention from the research of laser processing NC technology. The control system of laser cutting and engraving equipment based on embedded NC is studied and developed in this dissertation. The major achievements are as follows:The methods of speed control and trajectory control are improved to ensure machining accuracy and processing speed. An improved S-curve acceleration and deceleration control method for the stepper motor is applied to guarantee the fast and smooth control of the motor's acceleration and deceleration. Besides, an improved linear interpolation algorithm is used for trajectory control, which is more efficient in the interpolation calculation and can better stabilize the motor movement. Regulating circuit of high precision for laser power is designed to increase the smoothness of laser cutting and engraving and to support the laser engraving of 256 gray-scale image. The real-time regulation of the laser power is realized by the synchronous control of laser output power and interpolation output based on the processing velocity variation or pixel value of the gray image.The architecture of hardware and software of the control system is planned in accordance with the required performance and functions. The hardware architecture based on ARM9 and FPGA is proposed, in which the event processing and data calculation are controlled by ARM9 while the control signals are generated by FPGA which is expanded to be the 32-bit external device of ARM9. This design brings about good performance, lower cost and good expansibility of the hardware. Meanwhile, Windows CE, the embedded operating system, is taken as the software platform, on which the application software is developed by multi-thread technology. 8 task modules including human-computer interaction module, data processing and sending module, etc, are implemented concurrent processing to ensure real-time processing. In addition, the upper computer software is developed to realize the integrated control of laser image engraving, which fulfills image files processing functions such as BMP file reading, image processing and automatic generating of machining codes.Good performance of the designed control system has been achieved in the practical laser cutting and engraving processing. Good feasibility and reliability of the proposed design have been proved in the experiment. The laser art cutting and engraving equipment with the control system has bright market prospect.