机械工程学报
機械工程學報
궤계공정학보
CHINESE JOURNAL OF MECHANICAL ENGINEERING
2014年
17期
17-24
,共8页
卢文娟%张立杰%曾达幸%张一同
盧文娟%張立傑%曾達倖%張一同
로문연%장립걸%증체행%장일동
自由度%过约束%并联冗余约束%杆组位移参数
自由度%過約束%併聯冗餘約束%桿組位移參數
자유도%과약속%병련용여약속%간조위이삼수
mobility%overconstraint%parallel-redundant-constraint%displacement parameters of linkgroup
过约束判断是机构自由度计算的关键,也是瓶颈。为使过约束判断更简单、快速,从其产生的本质出发,考虑约束的相关性,基于一种新的自由度理论,提出结合杆组参数矩阵进行过约束判断的方法。针对夹角不为零的平行R杆组(具有平行转动轴线的杆组)位移参数确定问题,提出参数垂直分量有效法则,使考虑不同几何空间下的螺旋相关性问题转化为仅考虑平行约束的相关性判断问题。将过约束的产生归纳为三类情况,分析各类情况下过约束的数目及类型,总结过约束中公共约束判断和并联冗余约束判断的原则。以一个典型机构为例,利用上述方法对其过约束数目和性质进行求解,以进一步验证所提法则、方法的合理性和实用性。
過約束判斷是機構自由度計算的關鍵,也是瓶頸。為使過約束判斷更簡單、快速,從其產生的本質齣髮,攷慮約束的相關性,基于一種新的自由度理論,提齣結閤桿組參數矩陣進行過約束判斷的方法。針對夾角不為零的平行R桿組(具有平行轉動軸線的桿組)位移參數確定問題,提齣參數垂直分量有效法則,使攷慮不同幾何空間下的螺鏇相關性問題轉化為僅攷慮平行約束的相關性判斷問題。將過約束的產生歸納為三類情況,分析各類情況下過約束的數目及類型,總結過約束中公共約束判斷和併聯冗餘約束判斷的原則。以一箇典型機構為例,利用上述方法對其過約束數目和性質進行求解,以進一步驗證所提法則、方法的閤理性和實用性。
과약속판단시궤구자유도계산적관건,야시병경。위사과약속판단경간단、쾌속,종기산생적본질출발,고필약속적상관성,기우일충신적자유도이론,제출결합간조삼수구진진행과약속판단적방법。침대협각불위령적평행R간조(구유평행전동축선적간조)위이삼수학정문제,제출삼수수직분량유효법칙,사고필불동궤하공간하적라선상관성문제전화위부고필평행약속적상관성판단문제。장과약속적산생귀납위삼류정황,분석각류정황하과약속적수목급류형,총결과약속중공공약속판단화병련용여약속판단적원칙。이일개전형궤구위례,이용상술방법대기과약속수목화성질진행구해,이진일보험증소제법칙、방법적합이성화실용성。
Overconstraint determination is the key and bottleneck of mobility calculation. Starting from its engendered nature, the linear dependence of constraint, a novel approach to overconstraint determination combined with linkgroup parameter matrix is presented to make it easier and faster based on a new mobility theory. To ascertain displacement parameters when the angle of parallel R link group (linkgroup including revolute joints with parallel rotation axis) is not zero, the validity of its vertical component is proposed which only takes parallel constraints of screw linear dependence into account in the midst of varied geometric spaces. The number and types of overconstraint are analyzed in three different situations which derive from its generation. Meanwhile the principles of common constraint and parallel-redundant-constraint determination are concluded. A typical mechanism is taken as an instance and elicited the number and characters of its overconstraint applying the above approach to further verify the rationality and applicability of the proposed approach and principles.