高速数控加工速度的自适应控制

Research on Adaptive Algorithm for Feed-Rate Control of High Speed Machining

为了满足高速加工的要求,提出了一种基于最小冲击的多程序段运动速度控制自适应算法。该算法根据两相邻的运动矢量之夹角和两程序段运动的速度,计算出拐角处冲击的大小,并根据对机床产生最小冲击原理,计算出拐角处的速度值,实现进给速度提前自适应地减速,从而防止刀具在拐角处发生过载,并有效地减少了工件形状在拐角处,或小半径圆弧处的伺服跟踪误差;在高速加工时获得了高的加工精度与良好的表面光洁度。该算法简单、有效,已在最新开发的高速铣床上得到应用。

To satisfy the need of high speed machining, moves can be contoured together to make smooth paths, a series of moves in a contoured move are joined together so that they are performed with a constant path velocity. Based on the principle of minimum impulse, an adaptive algorithm is proposed for feed-rate control of a series of moves of high speed machining. The proposed algorithm uses the inter-vector angle and velocity of two adjoining motion vectors to calculate the impulse on the comer, and then work out the velocity where the impulse is minimum, to realize the procession of adaptive speed adjustment. The adaptive speed adjustment avoids the occurrence of overload of cutter tools on the comer and reduces the servo track error of parts on the corner or in small arc move. High accuracy and fine surface quality can be obtained while machining speed is high. The algorithm is effective and has been adopted by CNC system of newly developed high-speed milling machine.