抄録
LinuxCNC is a non-industrial PC-based CNC software which controls motor drivers with step/dir signals via LPT port, so that a new PC having no LPT port cannot drive an actual machine. However, the simulator mode is useful for playing with g-code on screen. In order to lean the kinematics and trajectory control of multi-axis machine tools, the way for simulating simultaneously on some PC’s is discussed. In five-axis CNC machine, kinematics is treated as a serial link with five degrees of freedom, just like a robotic manipulator while the cutter is treated as an end effector. Such multi-machine tools are easily simulated by applying the appropriate kinematics module, or the trivial kinematics module which is used for the most common milling machine. As LinuxCNC employs a trapezoidal velocity profile generator, it is easily shown by using the Sampler module and Excel chart that the accelerated velocity region corresponds to the parabolic region of the joint position vs. time charts. And also, it is shown that the trajectory planner in LinuxCNC uses parabolic blends applying the feed velocity and angles for every segment-segment transition in default operations, or follows G61 command to stop at the end of the next segment.
