Control System Design Of Pipe Cutting Robot Based On DSP

With the rapid development of the social economic and scientific technology, theprecision level of the manufacture of industrial equipment is increasing. In recent years, theindustrial robots have been widely used in many areas for its high precision and high speed.Tube overlap structure is common in engineering structures. It’s widely used in marineengineering, machinery manufacturing, building structure, as well as bridges and stadiumsconstruction industry. At first, the top of the pipe should be cutted as some special shapes inpipe lap structures. Then the pipe can be welded together. Pipe cutting was usually manual inthe past. The accuracy and efficiency is very low. So with the development of the computertechnology and CNC technology, more professional automatic cutting equipments is urgentneeded. According to the actual experience of similar products, the control method is openloop control with teaching and playback.In this paper, an industrial robot control system which is used in pipe cutting is designed.The robot’s control parts and the mechanical parts are separated in the general structure. Thecontrol parts are responsible for movement control and coordination, and the mechanicalparts are responsible for the achievement of cutting space curve. The embedded centralizedcontrol system was selected as the motion control system of the robot. The robot’s fourdegrees of freedom uses the servo motor and stepper motor to complete the movement.The paper introduces the overall design of the system, which includes the hardware andsoftware structure. The system is designed for the purpose of quickly design, low cost andeasy maintenance. TI’s TMS320F2812DSP is selected as the core of motion control system.It used cylindrical coordinates and completed the cutting trajectory with multi-axis linkage.In the control system, the hardware circuit is divided into the core circuit board and thefunction circuit board. The core circuit board contains DSP minimum system and externalmemory circuit. The function circuit board contains other functional circuit which includesthe pulse part, the information display, the keyboard part and other external interfaces. Thecore board function and the function board are connected by some pins and slots which sizeare standard. This design method of hardware circuit can enhance the control system’seconomy, stability and scalability. In software design, a modular software architecture is used.All the subroutines are independent. It’s convenient for migration and expansion ofsubroutine. And the programming code is optimized in accordance with the characteristics ofembedded systems. The system can complete human-computer interaction, movement data calculation and cutting real-time motion control independently.The system has small size, low cost and high stability characteristics. It can achieve theaccuracy and efficiency requirements in the actual test and can be applied to a variety kindsof pipe cutting operations.