中国机械工程
中國機械工程
중국궤계공정
CHINA MECHANICAl ENGINEERING
2014年
11期
1524-1529,1561
,共7页
李欢%张丽艳%周良明%刘胜兰
李歡%張麗豔%週良明%劉勝蘭
리환%장려염%주량명%류성란
余量约束%配准%点云分块%测量数据
餘量約束%配準%點雲分塊%測量數據
여량약속%배준%점운분괴%측량수거
allowance constraint%registration%point cloud segmentation%measurement data
针对复杂结构毛坯的小余量数控加工中很容易出现局部加工余量不足的问题,基于毛坯表面的点云测量数据,提出了一种层次化快速约束配准算法,从而实现加工余量的优化分配。首先通过建立一个知识向导模型并应用局部微分信息,自动分离出毛坯上需要分配余量的各待加工表面,并分别施加最小余量约束,在确定各待加工表面上参与约束配准优化的初始点集的基础上,采用广义乘子法将初始配准点集与设计数模进行约束匹配;然后采用迭代方法将不满足余量约束的测点追加到当前配准点集中,直到所有待加工表面的测点满足余量约束。实验结果表明,该配准算法在最大程度满足余量约束的前提下,显著提高了点云数据的配准效率。
針對複雜結構毛坯的小餘量數控加工中很容易齣現跼部加工餘量不足的問題,基于毛坯錶麵的點雲測量數據,提齣瞭一種層次化快速約束配準算法,從而實現加工餘量的優化分配。首先通過建立一箇知識嚮導模型併應用跼部微分信息,自動分離齣毛坯上需要分配餘量的各待加工錶麵,併分彆施加最小餘量約束,在確定各待加工錶麵上參與約束配準優化的初始點集的基礎上,採用廣義乘子法將初始配準點集與設計數模進行約束匹配;然後採用迭代方法將不滿足餘量約束的測點追加到噹前配準點集中,直到所有待加工錶麵的測點滿足餘量約束。實驗結果錶明,該配準算法在最大程度滿足餘量約束的前提下,顯著提高瞭點雲數據的配準效率。
침대복잡결구모배적소여량수공가공중흔용역출현국부가공여량불족적문제,기우모배표면적점운측량수거,제출료일충층차화쾌속약속배준산법,종이실현가공여량적우화분배。수선통과건립일개지식향도모형병응용국부미분신식,자동분리출모배상수요분배여량적각대가공표면,병분별시가최소여량약속,재학정각대가공표면상삼여약속배준우화적초시점집적기출상,채용엄의승자법장초시배준점집여설계수모진행약속필배;연후채용질대방법장불만족여량약속적측점추가도당전배준점집중,직도소유대가공표면적측점만족여량약속。실험결과표명,해배준산법재최대정도만족여량약속적전제하,현저제고료점운수거적배준효솔。
For complex structure blanks with small machining allowance,small deviations may result in a shortage of allowance during the machining operation.In order to achieve optimal allocation of machining allowance,a hierarchical and fast algorithm of constrained registration between the dense scanned data of blank parts and the nominal finished part was presented.Firstly,with the aid of an elaborately built segmentation guide,each surface to be machined was separated from the point cloud by using points'local differential information.The minimal allowance constraint and an initial data set,which will be involved in the following registration process,were then assigned to each seg-mented surface respectively.The initial registration datasets were aligned to the design model by u-sing multiplier methods,and then the measured data points that violate the allowance constraint were added iteratively into the current registration dataset until all the scanned points satisfied the allow-ance constraints.Experiments show that the proposed algorithm can achieve allowance-constrained registration with great efficiency.