Design And Implementation Of Distributed Multi-axis Cutting Robot

A large number of tubes are required to be cut in the building of offshore drillingplatform. And the tubes need cut along the intersecting line. The exact cutting of large tube isa difficult problem. The traditional roller bed pipe cutter can’t solve this problem because ofits size and weight capacity, and the roller bed pipe cutter can’t reduce the error in thelongitudinal weld of the tube.In order to solve the problem of exact cutting of the large tube, a rotatable cutter isdesigned. By keeping the tube static and making the cutter rotate around the pipe whilecutting, this problem is solved well.The control system is chosen to be distributed construction. Using industrial PC as theupper computer and several MCU as the lower computer, the control system is designed. Anda non-contact distance measure module is included in it. According to the demand the controlsystem, CAN bus is used to connect all modules in this distributed control system.CAN bus application layer protocol is designed. This protocol is common, simple,standard, scalable and low-load. Extended Frame in PeliCAN mode is used in this protocol tomake it rich, memorable and scalable. Dual Filter mode is used in this protocol to make thebroadcast feature is achieved. Broadcast feature reduces the load of CAN bus and improvesthe accuracy rate and stability.Aiming at the features that the MCU have to achieve, the program library is designed.This program library is hierarchy, modular, portable and reusable. This program librarycontains CAN bus receive function, send function, keyboard detect function, keyboard dealfunction and a large number of motion control functions. To solve the problem of thecoordinated movement of the multi-axis system, considering in synchronization andcontinuity, a new solution is designed and programmed.Industrial PC control program is designed using MFC. This MFC application hasfriendly GUI interface and powerful motion control features. Whole operation procedure isestablished, and features like type choose, parameter input, equipment adjust, teach, autoincise and auto speed change is completed.In order to improve the precision of incising, the way of teaching and playback is chosen.The whole teaching solution is established, including sensor calibration, distance measuring,data acquisition, data stabilizing, data smoothing, dynamic adjustment of radius, tube circlefitting, weld recognition and processing. In order to meet demand of industrial production, an safe incising speed control method is developed. And a practical function is completed toincise the tube starting from the break point, with no need to start from the very beginning.This control system run stable and has good performance. The accuracy of tube cutting is in±1.5mm.