【作者】 石振振；

【导师】 郭锐锋；

【作者基本信息】 中国科学院研究生院（沈阳计算技术研究所） ， 计算机应用技术， 2010， 硕士

【摘要】 随着现代数控技术的不断发展,高速高精加工已经成为新的趋势。而轨迹间的转接速度严重影响着机床效率和精度,当相邻轨迹间形成的转角较大时,会造成运动速度矢量变化过大,对机床产生较大冲击,因此实现相邻轨迹间的速度平滑转接,减小转角处速度突变对机床的冲击,是提高加工效率和精度的关键因素。目前数控系统处理轨迹间速度平滑的方法多局限于对无拐点的相邻轨迹段的研究,而且基于简单的直线加减速曲线,存在电机连续启停,加工效率低,加工表面不光滑等问题。针对上述速度平滑方法的不足,为实现数控加工轨迹间的速度平滑转接,满足数控系统对高速高精加工的需求,并考虑一个加工工件的轮廓通常有普通曲面(非小线段)和复杂曲面(小线段)组成,本文分别对数控加工中非小线段轨迹间和小线段轨迹间的速度平滑方法进行了研究。首先,本文介绍了蓝天数控平台的体系结构,并对相关的运动规划流程进行了研究。其次,本文论述了用于非小线段速度平滑处理的矢量转接方法的原理。该方基于S曲线加减速,通过把相邻轨迹段同时进行加减速规划来实现速度平滑转接。再次,本文论述了用于小线段速度平滑处理的小线段动态转接规划方法的实现原理。该方法通过聚集多个轨迹段为加工链,然后求解加工链之间的衔接速度来实现小线段的速度平滑转接。最后,把以上两种方法初步应用到蓝天数控平台的运动规划器中,针对不同的加工轨迹,进行实验测试和分析。本文所设计的方法简单、可靠,能够实现加工轨迹段间的高速平滑转接,满足现代数控系统对高效率、高精度的需求。更多还原

【Abstract】 With the development of modern CNC technology, high-speed and high-accuracy machining has become a new trend. While the transfer speed of inter-trajectory influences the efficiency and accuracy of machine seriously, when the corner angle of inter-trajectory is bigger, larger changes in speed at the corner will cause greater impact on the machine. So realizing the smoothing transfer of speed of inter-trajectory and reducing the impact of machine caused by sudden change of speed at corner is a key factor to improve the efficiency and accuracy of machining.At present, the studies of speed smoothing of inter-trajectory for NC system are mostly limited to non-turning point of the adjacent trajectory segment and based on simple trapezoidal accelection and decelection, which have the shortcoming of frequent stops of motor, lower efficiency, not-smoothing surface and etc. For the drawbacks of above-mentioned method, in order to realize the speed smoothing of inter-trajectory and satisfy the need of high-speed and high-accuracy of CNC, and considering that the contour of a special part commonly consists of common surface (non-micro segments) as well as the complicated surfaces (micro segments), this paper has mainly studied the speed smoothing method for non-micro segments and micro segments respectively.Firstly, the architecture of Lantian NC Platform and design scheme of related motion plan were introduced.Secondly, the principle of vector transfer method for speed smoothing of non-micro segments was discussed. The method was based on the s-curve and had achieved the speed smoothing by planning the adjacent segments at the same time.Thirdly, the principle of dynamic transfer planning method for micro segments was discussed. The method had achieved the speed smoothing by forming multiple segments into machining chain, and then solving the transfer speed of the machining chains.Finally, the application on the Lantian NC Platform of the two methods was given. For different trajectories, a large number of tests were carried out and the results were analyzed.The methods designed are simple, reliable, and able to achieve smooth and high-speed transfer of inter-trajectory, so can meet the requirement of modern CNC system for high-efficiency and high-accuracy.更多还原