【正文】
方程,才能確定函數(shù)的全部未知數(shù)。啟動(dòng)空間機(jī)械臂的工程性研究,對(duì)于我國載人航天具有極其重要的意義。 對(duì)應(yīng)用于空間飛行器上的空間機(jī)械臂,本文限于時(shí)間和條件限制,在路徑規(guī)劃算法中假定飛行器是固定的,未考慮機(jī)械臂運(yùn)動(dòng)與運(yùn)動(dòng)基座的動(dòng)力學(xué)耦合,這在實(shí)際的空間應(yīng)用中將會(huì)增大空間飛行器燃料的消耗;在機(jī)械臂的路徑規(guī)劃算法方面研究更優(yōu)化的算法;基于改進(jìn)人工勢(shì)場(chǎng)法的避障路徑規(guī)劃算法還可在臂桿上設(shè)置更多的目標(biāo)標(biāo)記點(diǎn),用于實(shí)現(xiàn)機(jī)械臂整體結(jié)構(gòu)的避障研究。第四章 總結(jié)與展望 空間機(jī)械臂作為是一個(gè)機(jī)、電、熱、控一體化的高集成度的空間機(jī)電系統(tǒng),有著廣闊的應(yīng)用前景和很強(qiáng)的技術(shù)牽引與帶動(dòng)作用。則: (331) 所以,需要求得組位置常數(shù)系數(shù),才能得到完整的三次樣條參數(shù)方程表達(dá)式。因此,對(duì)于任意復(fù)雜的軌跡,使用更高級(jí)的插值方法勢(shì)在必行。則: 當(dāng)時(shí),則 (327) ⑥將插補(bǔ)結(jié)果返回到原坐標(biāo)中,設(shè)點(diǎn)在原坐標(biāo)系中坐標(biāo)值為,則有: (328) 由以上結(jié)果可以得到圓弧上各插補(bǔ)點(diǎn)的位置,各插補(bǔ)點(diǎn)的三個(gè)位姿角度可以各自按照位移曲線為拋物線過度的線性函數(shù)求得。 三點(diǎn)確定一段弧。最后通過關(guān)節(jié)空間軌跡規(guī)劃的方法將相鄰的兩組關(guān)節(jié)角之間進(jìn)行角度插補(bǔ),從而使工具末端的軌跡平滑且能很好的控制每個(gè)關(guān)節(jié)的角速度和角加速度[8]。 直線插補(bǔ)法: ①設(shè)已知起始點(diǎn)的位置坐標(biāo)分別為:,和為相對(duì)基礎(chǔ)坐標(biāo)系計(jì)算其長(zhǎng)度: (315) ②求間隔內(nèi)行程,需要分勻速、加速、減速三種情況進(jìn)行討論: 勻速:設(shè)速度為,則插補(bǔ)周期內(nèi)行程為; 加速:設(shè)加速度為,起始點(diǎn)速度為,則在插補(bǔ)周期內(nèi)的行程為:;整個(gè)加速度的路程為:,時(shí)間記為[6]:; ③計(jì)算總時(shí)間:; ④計(jì)算插補(bǔ)點(diǎn)數(shù):; ⑤對(duì)插補(bǔ)點(diǎn)所在段進(jìn)行判斷(勻速段、加速段、減速段),使各軸的增量得到確定,對(duì)各插補(bǔ)點(diǎn)坐標(biāo)進(jìn)行實(shí)時(shí)計(jì)算。其中關(guān)節(jié)角度和角速度曲線顯示的都相對(duì)平滑,而角加速度曲線在中間點(diǎn)B處變化稍大。關(guān)節(jié)角度曲線平滑,而速度曲線在中間點(diǎn)B處出現(xiàn)突變。給定終點(diǎn)速度,設(shè)其為0。對(duì)于無路徑的要求,應(yīng)盡量在關(guān)節(jié)空間進(jìn)行軌跡規(guī)劃。圖2 機(jī)械臂的matlab生成第一節(jié) 軌跡規(guī)劃一般問題 軌跡規(guī)劃的一般方法是在機(jī)械臂末端的初始和目標(biāo)位置之間用多項(xiàng)式函數(shù)“內(nèi)插”來抵近給定的路徑,并沿著時(shí)間軸產(chǎn)生一系列的可供操作機(jī)使用的“控制設(shè)定點(diǎn)”[3]。 機(jī)械臂的運(yùn)動(dòng)學(xué)正、逆求解實(shí)質(zhì)是機(jī)械臂關(guān)節(jié)空間與工作空間之間的非線性映射關(guān)系,兩者可相互轉(zhuǎn)換。由坐標(biāo)系中已知的各個(gè)關(guān)節(jié)角度,求解機(jī)械臂末端相對(duì)應(yīng)于原點(diǎn)坐標(biāo)系的位置和位姿。2002年:美國iRobot公司推出了吸塵器機(jī)器人Roombar,為世界上商業(yè)化最成功的家用機(jī)器人。1959年:戴沃爾與美國發(fā)明家英格伯格聯(lián)手制造出第一臺(tái)工業(yè)機(jī)器人。1971年,通用汽車公司又第一次用機(jī)器人進(jìn)行點(diǎn)焊。隨著研究的深入,各種新的路徑規(guī)劃方法層出不窮,使路徑規(guī)劃研究一直活躍在機(jī)器人學(xué)領(lǐng)域。隨著我國國民經(jīng)濟(jì)與國防工業(yè)技術(shù)的迅速發(fā)展,對(duì)航天器的需求量日益增加,對(duì)其能力的要求日臻提高。s attention. This article will space manipulator as the research object, according to the linear motion of the space manipulator, joint planning, space of the straight line and curve, the trajectory planning of several aspects of mechanical arm movement and working space are analyzed, and the trajectory planning of manipulator is verified, the trajectory of manipulator is to make use of MATLAB software simulation, verify the correctness and feasibility of the algorithm, at the same time this path planning method can improve the efficiency of mechanical arm, improve the theoretical guidance for mechanical arm operation, simulation and path planning for robot more plicated movement. This article is divided into four chapters altogether: The first chapter, first summarizes the mechanical arm motion control and path planning problem research status and research methods, summarizes the variety of trajectory planning algorithm and the method of optimization, and expounds the research background and main content of mechanical arm. The second chapter, the paper studied the space motion of mechanical arm, the numerical method, monte carlo method are deduced with the method of sampling, the workspace for mechanical arm is, at the same time the simulation in MATLAB, intuitive display mechanical arm work scope, providing theoretical basis for the next chapter of trajectory planning. At the same time through dh method of positive and inverse kinematic analysis of the mechanical arm, analyze the difference and contact. The third chapter, mainly aims at the general problem of trajectory planning is analyzed, using cartesian space trajectory planning method for trajectory planning, mechanical arm at the same time, MATLAB is used to analyse the spatial straight line and arc trajectory planning, through the simulat