本文選題：自由度 + 過約束　； 參考：《北京工業(yè)大學》2014年碩士論文

【摘要】：多環(huán)耦合機構是一類新型的復雜機構，已作為重要的組件應用于仿生機器人、航空、避難等多種領域，，但其理論研究還很缺乏。在機構學中，對一個新機構最基本的理論認識就是先知道它的自由度。但是目前而言，關于多環(huán)耦合機構的自由度方法研究很少，并且由于結構的復雜性和耦合性，導致傳統(tǒng)的自由度方法不能正確計算此類機構的自由度。因此，探討適合多環(huán)耦合機構的自由度方法，是一個新的研究方向，也是多環(huán)耦合機構構型設計和運動分析的基礎。 本文針對多環(huán)耦合機構的自由度問題，從最關鍵的耦合特性和約束分析兩個方面出發(fā)，提出了運動分流法、耦合機構解耦法以及機構等效分析法，形成了一種適合多環(huán)耦合機構末端件自由度分析的新方法，并通過實例分析來驗證此方法的有效性和適用性。主要內(nèi)容如下： 對多環(huán)耦合機構開展耦合特性分析。提出三種基礎耦合模型，并根據(jù)其運動特性，提出對應的運動分流標記法及標記原則，并擴展應用于多環(huán)耦合機構，提出了耦合機構的結構解耦法，將耦合機構轉(zhuǎn)化為含多個獨立結構的運動鏈組合。 基于螺旋理論，對每一個獨立運動鏈進行運動和約束分析。利用前述標記方法，從一級節(jié)點開始，對節(jié)點構件的運動和約束進行分析，利用“廣義運動鏈”等效替換，迭代進行后一級節(jié)點的約束分析和等效替換，直至將每一個獨立運動鏈結構最終等效為一個單鏈。至此，多環(huán)耦合機構等效為常規(guī)的并聯(lián)機構。 分析等效并聯(lián)機構末端件的連續(xù)自由度。計算等效并聯(lián)機構的運動螺旋和約束螺旋，并利用約束的線性相關性確定機構的過約束，用修正的Grübler-Kutzbach公式計算等效并聯(lián)機構末端件的自由度數(shù)，或?qū)Φ刃C構的約束螺旋系求二次反螺旋，就得到末端件的自由度性質(zhì)，并根據(jù)連續(xù)有限位型進行自由度瞬時性判別。 應用提出的新方法分別對三類典型多環(huán)耦合機構進行了自由度分析，包括：具有獨立分支局部耦合結構的混聯(lián)機構、非對稱耦合機構和對稱耦合機構。通過Solidworks三維軟件對這些機構進行實體建模和仿真模擬，以及與其它方法的對比分析，驗證了此方法的有效性和適用性。 本文提出的新方法是對現(xiàn)有的基于螺旋理論的自由度原理的發(fā)展和創(chuàng)新，對多環(huán)耦合機構的進一步開發(fā)應用具有積極的促進作用。
[Abstract]:Multi-loop coupling mechanism is a new type of complex mechanism, which has been used as an important component in many fields such as bionic robot, aviation, shelter and so on, but its theoretical research is still lacking. In mechanism, the most basic theoretical understanding of a new mechanism is to know its degree of freedom. But at present, there are few researches on the degree of freedom method of multi-loop coupling mechanism, and because of the complexity and coupling of the structure, the traditional freedom of freedom method can not calculate the degree of freedom of this kind of mechanism correctly. Therefore, it is a new research direction to discuss the degree of freedom method suitable for multi-ring coupling mechanism, which is also the basis of configuration design and motion analysis of multi-ring coupling mechanism. In this paper, the motion shunt method, the decoupling method and the equivalent mechanism analysis method are proposed to solve the problem of the degree of freedom of the multi-ring coupling mechanism from the two aspects of the most critical coupling characteristics and constraint analysis, such as motion shunt method, coupling mechanism decoupling method and mechanism equivalent analysis. A new method for the analysis of the degrees of freedom of the end parts of a multi-loop coupling mechanism is proposed. The effectiveness and applicability of the method are verified by an example. The main contents are as follows: The coupling characteristics of multi-ring coupling mechanism are analyzed. In this paper, three kinds of basic coupling models are proposed, and according to their motion characteristics, the corresponding motion shunt marking method and marking principle are proposed, and extended to the multi-ring coupling mechanism, the structure decoupling method of the coupling mechanism is proposed. The coupling mechanism is transformed into a combination of motion chains with multiple independent structures. Based on the helical theory, the motion and constraint analysis of each independent kinematic chain is carried out. By using the above marking method, the motion and constraint of the node members are analyzed from the first level node, the equivalent substitution of "generalized motion chain" is used, and the constraint analysis and equivalent substitution of the post-primary node are carried out iteratively. Until each independent kinematic chain structure is finally equivalent to a single chain. So far, the multi-loop coupling mechanism is equivalent to the conventional parallel mechanism. The continuous degree of freedom of the end part of the equivalent parallel mechanism is analyzed. The kinematic spiral and constraint screw of the equivalent parallel mechanism are calculated, and the over-constraint of the mechanism is determined by the linear correlation of the constraints. The number of degrees of freedom of the end parts of the equivalent parallel mechanism is calculated by using the modified Gr 眉 bler-Kutzbach formula. The degree of freedom of the end part is obtained by solving the quadratic inverse helical system of the equivalent mechanism, and the instantaneous degree of freedom is judged according to the continuous finite position type. The new method is applied to analyze the degrees of freedom of three typical multi-loop coupling mechanisms, including: the hybrid mechanism with independent branch local coupling structure, the asymmetric coupling mechanism and the symmetric coupling mechanism. The effectiveness and applicability of this method are verified by Solidworks 3D modeling and simulation of these mechanisms, as well as comparison with other methods. The new method proposed in this paper is the development and innovation of the existing freedom of freedom principle based on the helical theory, and it has a positive effect on the further development and application of the multi-ring coupling mechanism.
【學位授予單位】：北京工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TP242;TH112

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本文編號：1868136