Based on the timing constraints event model of rtl ( real time logic ), the compiling algorithms for timing constraints event transform the problem of how to detect timing constraints event to the problem of how to find negative cycle in weighted directed graph, which is named as constraints graph . by simplifying constraints graph, the efficient detecting algorithms for timing constraints event have been developed, which not only has good time complexity but also can find events that violate timing constraints as early as possible . in order to verify the event detecting methods based on dynamic rules and to check its efficiency in application, experiment schemes are designed and performed on the implemented prototype system in linux environment 帶時(shí)間約束事件的編譯算法以rtl(realtimelogic)事件模型為基礎(chǔ),將帶時(shí)間約束事件的檢測(cè)轉(zhuǎn)化為在帶權(quán)值的有向圖(此即受限圖)中尋找負(fù)圈的問題,它通過化簡(jiǎn)受限圖得到最小有效約束集;運(yùn)行時(shí)事件檢測(cè)算法在最小有效約束集上檢查事件的時(shí)間約束,不但有較好的執(zhí)行效率,而且能盡早地發(fā)現(xiàn)違反時(shí)間約束的事件。
Based on the timing constraints event model of rtl ( real time logic ), the compiling algorithms for timing constraints event transform the problem of how to detect timing constraints event to the problem of how to find negative cycle in weighted directed graph, which is named as constraints graph . by simplifying constraints graph, the efficient detecting algorithms for timing constraints event have been developed, which not only has good time complexity but also can find events that violate timing constraints as early as possible . in order to verify the event detecting methods based on dynamic rules and to check its efficiency in application, experiment schemes are designed and performed on the implemented prototype system in linux environment 帶時(shí)間約束事件的編譯算法以rtl(realtimelogic)事件模型為基礎(chǔ),將帶時(shí)間約束事件的檢測(cè)轉(zhuǎn)化為在帶權(quán)值的有向圖(此即受限圖)中尋找負(fù)圈的問題,它通過化簡(jiǎn)受限圖得到最小有效約束集;運(yùn)行時(shí)事件檢測(cè)算法在最小有效約束集上檢查事件的時(shí)間約束,不但有較好的執(zhí)行效率,而且能盡早地發(fā)現(xiàn)違反時(shí)間約束的事件。
Modeling in conceptual design is a key technology in cacd system . considering the characteristics of conceptual design and the feature classification of vp, this paper presents a novel virtual prototype-based product model, v-desmodel . v-desmodel introduces virtual feature concept in product's view models, and employs expandable 3d entity-constraint graph to describe the constraints between design objects 概念設(shè)計(jì)建模一直是計(jì)算機(jī)輔助概念設(shè)計(jì)系統(tǒng)的核心與關(guān)鍵技術(shù),本文在分析虛擬原型的特征分類以及概念設(shè)計(jì)過程特點(diǎn)的基礎(chǔ)上,提出一種基于虛擬原型的概念設(shè)計(jì)描述模型v-desmodel,其核心特點(diǎn)是采用產(chǎn)品視圖模型描述設(shè)計(jì)對(duì)象,將虛擬特征概念融入視圖模型中,并采用可擴(kuò)展“三維實(shí)體?約束圖”描述設(shè)計(jì)對(duì)象之間的約束關(guān)系。
At first every method of constraint solving is presented in this paper . through comparing the advantages and disadvantages of one method with another the method of constraint solving based geometrical constraint graph in which geometrical constraint system is expressed by graph, and which can deal with over-constraints and down-constraints is proposed 本文首先總結(jié)了二維參數(shù)化設(shè)計(jì)中的各種約束求解方法,并權(quán)衡每種約束求解方法的利弊,提出了基于幾何約束圖的約束求解方法,此方法是用圖來表示幾何約束系統(tǒng),能夠有效地處理欠約束和過約束的情況。