A High-Flexible ACC/DEC Look-Ahead Strategy Based on Quintic Bezier Feed Rate Curve

To realize real-time generation of a feed rate profile during NC machining process, the look-ahead strategy utilizing bidirectional scanning algorithm is widely adopted. However, the strategy is time-consuming since the acceleration/deceleration (ACC/DEC) scheduling is called frequently. To overcome the deficiency, a high-flexible ACC/DEC look-ahead strategy is proposed in this paper, which is composed of a ACC/DEC scheduling and a backward scanning and forward revision (BSFR) algorithm. Firstly, the ACC/DEC scheduling based on quintic Bezier curve is presented, and a total of 20 types of feed rate profiles are deduced. The scheduling has the characteristics of jerk continuity, simple calculation, and ease of implementation. After that, to deduce the number of times that the ACC/DEC scheduling is called, the BSFR algorithm is put forward. Meanwhile, constraints such as machine's kinematics, chord error, and command feed rate are also taken into account. Experiments are performed at last. Not only is the optimum feed rate profile generated in real time, but also it has nearly 40% decrement on the number of calls of scheduling, which demonstrates the proposed strategy is valid and feasible in NC machining.