【摘要】：并聯(lián)機(jī)構(gòu)具有剛度大、累積誤差小、控制精度高、承載能力強(qiáng)等優(yōu)點(diǎn),已在運(yùn)動(dòng)模擬、空間對(duì)接、加工制造等領(lǐng)域得到了廣泛的應(yīng)用。機(jī)構(gòu)學(xué)的發(fā)展得益于新機(jī)構(gòu)的誕生,近年來,學(xué)者們提出了一種新型并聯(lián)機(jī)構(gòu)——張拉整體并聯(lián)機(jī)構(gòu)。和傳統(tǒng)并聯(lián)機(jī)構(gòu)不同,張拉整體并聯(lián)機(jī)構(gòu)中含有彈簧構(gòu)件,彈簧的使用使這類機(jī)構(gòu)具有了欠驅(qū)動(dòng)的能力。另外,彈簧消除了運(yùn)動(dòng)副的間隙,提升了張拉整體并聯(lián)機(jī)構(gòu)的運(yùn)動(dòng)精度。本文系統(tǒng)地研究了3-SPS(Spherical joint-Prismatic joint-Spherical joint)張拉整體并聯(lián)機(jī)構(gòu)的構(gòu)型演變、位置正反解、奇異性、工作空間及其在能量采集方面的應(yīng)用,主要成果如下:1)分析了3-SPS張拉整體并聯(lián)機(jī)構(gòu)的初始構(gòu)型,此構(gòu)型由運(yùn)動(dòng)平臺(tái)、固定平臺(tái)、三個(gè)SPS驅(qū)動(dòng)支鏈和三根彈簧組成。該并聯(lián)機(jī)構(gòu)有三輸入,而輸出卻為六個(gè),因此在通常情況下其輸出是不確定的�？紤]到彈簧的約束,此并聯(lián)機(jī)構(gòu)處于平衡狀態(tài)時(shí),輸出是可控的。然而當(dāng)它不處于平衡狀態(tài)時(shí),必須通過添加從動(dòng)支鏈的辦法使其輸出可控。以此并聯(lián)機(jī)構(gòu)為初始構(gòu)型,基于螺旋理論,通過添加不同從動(dòng)支鏈演變出了20種具有不同運(yùn)動(dòng)特征的三自由度張拉整體并聯(lián)機(jī)構(gòu)。明確了本文的研究對(duì)象:一類是包含從動(dòng)支鏈的張拉整體并聯(lián)機(jī)構(gòu)(非欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu));另外一類是不包含從動(dòng)支鏈的張拉整體并聯(lián)機(jī)構(gòu)(欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu))。針對(duì)這兩類張拉整體并聯(lián)機(jī)構(gòu),提出了它們的結(jié)構(gòu)描述方法,此方法考慮了對(duì)彈簧的描述及運(yùn)動(dòng)副軸線在全局坐標(biāo)系下的方位。2)對(duì)兩類張拉整體并聯(lián)機(jī)構(gòu)的位置正解和反解進(jìn)行了研究。針對(duì)非欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu)的位置正解問題,提出了一種變步長搜索算法,該算法在變量的求解區(qū)域內(nèi)以一定的步長進(jìn)行逐點(diǎn)搜索。當(dāng)搜索不到變量的解時(shí),此算法將減小步長進(jìn)行再次搜索,依此循環(huán)下去,直到找到變量的解為止。變步長搜索算法模型簡單,對(duì)初值不敏感,可推廣至任何并聯(lián)機(jī)構(gòu)的位置正解計(jì)算問題�；谀芰糠�,推導(dǎo)了欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu)的位置正解和反解的一般方程,并通過變步長搜索算法進(jìn)行了求解。研究結(jié)果表明:非欠驅(qū)動(dòng)張拉整體的位置分析(位置正解和反解)僅與其幾何形狀有關(guān),而欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu)的位置分析不僅取決于其幾何形狀還與彈簧的內(nèi)力有關(guān)。變步長搜索算法可有效求解兩類張拉整體并聯(lián)機(jī)構(gòu)的位置分析問題。3)基于正向和反向速度雅可比矩陣,對(duì)非欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu)的奇異性進(jìn)行了研究。得到了非欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu)發(fā)生第一類奇異、第二類奇異和第三類奇異的條件,繪制了相應(yīng)的奇異位形。對(duì)這類機(jī)構(gòu)的三類奇異性條件進(jìn)行了分析,并提出了相應(yīng)的奇異性規(guī)避策略。4)對(duì)兩類張拉整體并聯(lián)機(jī)構(gòu)的工作空間進(jìn)行了研究。對(duì)于非欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu),分析了其工作空間的影響因素:①驅(qū)動(dòng)支鏈桿長約束;②運(yùn)動(dòng)副轉(zhuǎn)角限制;③連桿的干涉。建立了非欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu)工作空間區(qū)域和邊界求解的約束方程,并通過數(shù)值算法計(jì)算了其工作空間體積。分析了工作空間體積對(duì)機(jī)構(gòu)參數(shù)(位姿/姿態(tài)參數(shù))和運(yùn)動(dòng)副最大允許轉(zhuǎn)角的敏感度。通過考慮能量約束,提出了欠驅(qū)動(dòng)張拉整體并聯(lián)機(jī)構(gòu)的工作空間確定方法,并采用數(shù)值法計(jì)算了其工作空間的體積。5)提出了一種新型3-SPS張拉整體能量采集裝置。建立了線性波浪作用下,該能量采集裝置的動(dòng)力學(xué)模型。此動(dòng)力學(xué)模型考慮了剛體動(dòng)力學(xué)和流體力學(xué)之間的耦合。采用數(shù)值法對(duì)此動(dòng)力學(xué)方程進(jìn)行了仿真,分析了3-SPS張拉整體能量采集裝置的運(yùn)動(dòng)平臺(tái)在線性波浪作用下沿X軸、Z軸的平動(dòng)規(guī)律及繞Y軸的轉(zhuǎn)動(dòng)規(guī)律。將新型能量采集裝置的發(fā)電效率和傳統(tǒng)浮子式裝置的發(fā)電效率進(jìn)行了對(duì)比研究,結(jié)果表明3-SPS張拉整體能量采集裝置的發(fā)電效率比傳統(tǒng)浮子式裝置高20.85%。
[Abstract]:The parallel mechanism has the advantages of large rigidity, small accumulated error, high control precision, strong bearing capacity and the like, and has been widely applied in the fields of motion simulation, space docking, processing and manufacture and the like. The development of institution science has benefited from the birth of the new institution. In recent years, the scholars have put forward a new type of parallel mechanism, the whole parallel mechanism. Unlike the traditional parallel mechanism, the pull-pull integral parallel mechanism comprises a spring member, and the use of the spring makes the type of mechanism have the ability to underdrive. In addition, the spring eliminates the clearance of the motion pair and improves the motion accuracy of the whole parallel mechanism of the tension-pull. This paper systematically studies the configuration evolution, position positive and negative solution, singularity, working space and its application in energy collection of 3-SPS (Spherical joint-Prisma joint-Spherical joint). The main results are as follows: 1) The initial configuration of 3-SPS whole parallel mechanism is analyzed, and this configuration is composed of a motion platform. a fixed platform, three SPS driving branches and three springs. The parallel mechanism has three inputs and the output is six, and therefore its output is not determined in the normal case. The output is controllable when the parallel mechanism is in a balanced state, taking into account the restraint of the spring. however, when it is not in a balanced state, it is necessary to make its output controllable by adding a method from a dynamic chain. With this parallel mechanism as the initial configuration, the three-degree-of-freedom (three-degree-of-freedom) integral parallel mechanism with different motion characteristics is developed by the addition of different dynamic branches based on the spiral theory. The object of the study is defined in this paper: one is the whole parallel mechanism (not under-actuated pull-pull overall parallel mechanism) of the pull-pull integral parallel mechanism (not under-actuated pull-pull overall parallel mechanism) from the dynamic branch chain, and the other is a pull-and-pull integral parallel mechanism (under-actuated pull-pull integral parallel mechanism) from the dynamic branch chain. In this paper, the description of the spring and the orientation of the sub-axis of motion in the global coordinate system are put forward. In this paper, a variable-step search algorithm is proposed for the position-positive solution of the non-underactuated tension-pull integral parallel mechanism, and the algorithm performs point-by-point search in a certain step size in the solution area of the variable. When the solution of the variable is not found, this algorithm will decrease the step size for re-search until the solution of the variable is found. The variable step search algorithm is simple, insensitive to the initial value, and can be extended to any parallel mechanism position positive solution calculation problem. Based on the energy method, the general equation of the position positive and inverse solutions of the under-drive tension-pull integral parallel mechanism is derived and solved by the variable-step search algorithm. The results of the study show that the position analysis of the whole parallel mechanism of the under-actuated tension is only related to the geometric shape, and the position analysis of the under-actuated pull-pull integral parallel mechanism depends not only on its geometry but also on the internal force of the spring. The variable-step search algorithm can effectively solve the problem of the position analysis of two types of pull-pull integral parallel mechanisms. 3) The singularity of the non-underactuated tension-pull integral parallel mechanism is studied based on the Jacobian matrix of forward and reverse speed. The first kind of singular, the second kind of singular and the third kind of singular condition of the non-underactuated pull-pull integral parallel mechanism are obtained, and the corresponding singular bit shape is drawn. The three kinds of singular conditions of this kind of mechanism are analyzed, and the corresponding singularity avoidance strategy is put forward. In this paper, the influence factors of the working space are analyzed for the non-underactuated pull-pull integral parallel mechanism. The analytic equation of the working space region and the boundary of the non-underactuated pull-pull integral parallel mechanism is established, and the volume of the working space is calculated by the numerical algorithm. The sensitivity of the working space volume to the mechanism parameters (the position and attitude parameters) and the maximum allowable rotation angle of the motion pair is analyzed. In this paper, the working space determination method of the total parallel mechanism under the under-drive tension is proposed by considering the energy constraint, and the volume of its working space is calculated by the numerical method. The dynamic model of the energy-collecting device under the action of linear wave is established. This dynamic model takes into account the coupling between rigid body dynamics and fluid mechanics. In this paper, the numerical method is used to simulate the dynamic equation, and the translational law of the motion platform of the 3-SPS whole energy collecting device along the X-axis, the Z-axis and the rotation rule about the Y-axis under the action of linear wave are analyzed. The power generation efficiency of the new energy-collecting device and the power generation efficiency of the conventional float-type device are compared and studied. The results show that the power generation efficiency of the 3-SPS whole energy-collecting device is 20. 85% higher than that of the conventional float-type device.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：TH112

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 路懿;胡波;;少自由度并聯(lián)機(jī)構(gòu)研究進(jìn)展[J];燕山大學(xué)學(xué)報(bào);2011年05期

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本文編號(hào)：2364406