Research And Design Of Polygonal Prism Grinding Control System Based On SEP4020

Embedded technology is one of the fastest developing technologies in recent years. The application of embedded system can shorten the developing cycle of products and improve the reliability and cost performance of products. In addition, embedded system has the specialties of less cost, tiny volume, low power consumption, abundant resources, supporting operating system and offers hardware and software customizability. Therefore, it has been widely used in CNC field. The combination of embedded technology and numerical control technology to develop NC system has become a hot research point.A novel design of the polygonal prism grinding control system is discussed in this paper. Based on deep study of embedded system, numerical control system and the grinding principle of polygonal prism, the general design scheme is put forward. By adopting a dual CPU-based system architecture of ARM + microcontroller consist of SEP4020 core processor and ATmega16 auxiliary module as well as expanding peripheral function modules, the hardware platform is constructed. Meanwhile, the software platform is built based on the real-time kernel ofμC/OS–II, which ensures timeliness and stability of the system.The hardware system of the polygonal prism grinding control system is designed in this paper, adopting SEP4020 as the core processor which is one kind of industrial ARM chips designed by National ASIC System Engineering Technology Research Center of Southeast University. The main peripheral circuits include memory circuit, power supply circuit, reset circuit, LCD interface circuit, JTAG interface circuit, serial interface circuit, stepper output circuit and digital input and output circuit.Based on theμC/OS-II real-time embedded operating system, the software platform is constructed in this paper, including the design of SEP4020 boot-code, the porting ofμC/OS-II on SEP4020 and the design of interrupt system, which offers good performance of rapid response on interruption or abnormal and provides environment for running the application software.The acceleration and deceleration control algorithm for stepper motor is designed and implemented. Firstly, the necessity of carrying out acceleration and deceleration control in stepper motor open-loop system is analyzed and presented. Then, after the study of the linear curve, exponential curve and S-shape curve acceleration and deceleration control algorithm, the linear control algorithm is chosen to be the mathematical model for speed control, which not only meet the requirements of fast-response and high-efficiency but also is simple and easy to be realized. Moreover, a novel algorithm of how to calculate the deceleration point during the linear speed control period is put forward. Lastly, the speed control software is developed with the PWM module of the SEP4020 processor.Combined with the polygonal prism grinding process, the application software is developed, which can control three stepper motor axes.The grinding experiment shows that the numerical control system provides good performance of stability, and it can not only meet high precision requirement but also offer good robustness, openness, man-machine interface and maintainability, which achieves the desired objectives and has broad application prospects.