Abstract: To improve the accuracy of multi-axis coordinated motion in networked Computer Numerical Control (CNC) system based on real-time Ethernet with a ring topology,an instant message control mechanism was proposed to short the propagation completion time in the frame network,and IEEE 1588 protocol was optimized to increase the synchronization frequency with this mechanism to improve the clock synchronization accuracy.To meet the clock synchronization compensation requirement of synchronization frequency increasing,an algorithm which the clock drift and the clock offset should be compensated respectively was presented.Meanwhile,to improve the contour accuracy,the point-to-point cycle communication based on time piece planning was optimized to increase the interpolation frequency by this mechanism.Experiment results show that this mechanism significantly improve the accuracy of the clock synchronization and the contour in the networked CNC system.

Key words: real-time Ethernet with ring topology, CNC system, coordinated motion, instant message control mechanism, synchronous frequency, point-to-point cycle communication, interpolation frequency

摘要： 为提高基于环形实时以太网的网络化数控系统的协同运动精度,提出一种即时信息控制机制,以缩短帧在网络中的传播完成时间,并应用该机制对IEEE 1588协议进行提升同步频率的优化处理,以实现提升时钟同步精度的目标。为了满足同步频率提升对时钟同步补偿的要求,提出时钟偏移和时钟漂移分离补偿算法。同时应用该机制对基于时间片规划的点对点周期通信进行提升插补频率的优化处理,以提升轮廓精度。通过实验表明,该机制显著提升了网络化数控系统的时钟同步精度和轮廓精度。

关键词: 环形实时以太网, 数控系统, 协同运动, 即时信息控制机制, 同步频率, 点对点周期通信, 插补频率