Motion Profile Control Algorithm and Corner Smoothing Technique for Trajectory Optimization of High-Precision Processing

Abstract

Processing accuracy in instrumental technology has always been of great importance. Producers of Computer Numeric Control (CNC) systems are constantly looking for novel solutions to achieve higher velocities and precision. However, most of the produced software algorithms are inaccessible to the general public. Hence the task to develop sufficient open source software arises. This paper aims to create a trajectory optimization algorithm, including feed rate control and a corner smoothing technique, which will allow effective high-speed and high-precision processing. It is intended to standardize the algorithm for application with both stepper and servo motor driven machines. The developed motion planning method is based on a cosine function to attain a smooth change of velocity that allows for vibration reduction. To achieve smooth corner processing, spline curves are applied to adjust the size and shape of a fillet and thus satisfy the required tolerance and maintain high velocities. The resulting algorithm is programmed and simulation tests are carried out. The final algorithm shows a smooth transition of velocities, which leads to vibration reduction and consequently to minimization of machining error. In corner smoothing the use of parametric curves demonstrates the ability to vary tolerance. As a result, a sufficient motion control algorithm is developed and can be used in CNC software.