10881

10023

كارشناسي ارشد

طراحي كاربردي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي مكانيك

1394

هفده، 97ص.: مصور

مهدي كشيمري

محمدرضا احمدزاده

1394/10/22

محمد دانش، سعيد بهبهاني

مهندسي مكانيك

ID10023

چكيده در پاياننامه حاضر به استخراج معادلات سينماتيكي مسـتقيم و ـ سينماتيك مستقيم لحظها اين ربات برا دو حالت با طول اعضـا ـ ثابت و متغير پرداخته شده است بـا توجـه بـه افزونگـي ربـات ـ ـ ـ ـ ـ پيوسته تعداد و نحـوه رفتـار درجـات آزاد اضـافي و چگـونگي ـ ـ ـ ـ ـ استفاده از آنها مورد بررسي قرار گرفته است از آنجـايي كـه ـ ـ سينماتيك اين بازو غير خطي است از سـينماتيك معكـوس لحظـها ـ ـ ـ برا طراحي حركت ربات در يك وظيفه مشـخص اسـتفاده شـده اسـت ـ ـ ـ ـ همچنين ارائه و استفاده از روشهـايي بـرا بـهكارگير درجـات ـ ـ ـ ـ آزاد اضافي برا بهينهساز حركت به صـورت انجـام وظـايف هـم ـ ـ ـ ـ زمان با توجه به اولويت كار مورد توجه قرار گرفته اسـت در ـ فصل نتيجهگير با استفاده از روش سينماتيك معكوس حلقه بسـته ـ و با استفاده از معيارهايي به عنوان معيار عملكرد به انجـام ـ بهينهساز هايي شامل پرهيز از برخورد بـا موانـع فضـا كـار ـ ـ ـ ـ انطباق شكل پيكره ربات پرداخته شـده اسـت همچنـين توانـايي ـ ـ ـ ـ ربات برا حركت در مجرا صفحها دايرها شكل و غيـر دايـرها ـ ـ با پايه ثابت طول ثابت متغير و با پايه متحرك طـول ثابـت ـ ـ متغير مورد بررسي قرار گرفته است كلمات كليد ربات پيوسته افزونگي سينماتيك معكوس حلقـه ـ بسته پرهيز از برخورد با موانع انطباق شكل پيكره

Motion Planning and Optimization of a Three Link Continuum Robot with Fixed and Variable Length Mehdi Sadeghi Nezhad mehdi sadeghi@me iut ac ir Date of Submission 2015 08 12 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Dr Mehdi Keshmiri mehdik@cc iut ac irAbstract In this work direct kinematic formulations for a three link continuum robot with constant and variable lengths are derived Continuum robot is a robotic manipulator with the ability of continuously bending over all parts of itsbody like an octopus arm Unlike robots with rigid links continuum robot has infinite virtual degrees of freedom which lead to many challenges in their design modeling control and fabrication In practical applications in whichsoft and dexterous tools are required robots with rigid links have some limitations This problem leads to thedevelopment of continuum robots These robots have a wide range of applications from searching in rescueoperations to minimal invasive surgeries Since continuum robots are naturally highly redundant and dexterous theycan be used to move along narrow channels by applying many motion control strategies To have a better controlover this motion kinematic formulation for these robots must be derived Continuous nature and redundancy ofrobots with high maneuverability lead to different definitions for their kinematics Two major assumptions lead toderiving the direct kinematic formulation instead of using joint angles and lengths of the links each link bends alongits length and every link is a part of a circular arc In line with this approach curvature and length of the arc wouldbe used which give a more compatible model The shape of a continuum robot is in a way that minimizes thepotential energy of its arm This shape is achieved due to a function which is the output of a system of partialdifferential equations Since there is no general closed form solution for this system of equations to achieve theapproximate shape of each link some simplifying assumptions like ignoring the weight of each link ignoring theexternal forces and assuming the shape of each link as a continuous function of the curvature s radius are needed Since the continuum robot links bend continuously their mobility is more than the rigid link robots Moreover due to the kinematic redundancy of a continuum robot it can be used as a multi task tool Generally the secondarytasks are used as performance criteria to optimize the robot motion during its motion In case of variable lengthlinks dexterity of the robot increases In most applications the continuum robot is used to move in places wherethere are some limitations on manipulator s movement In this case it is assumed that the overall length of each linkvaries while all of the secondary backbones of each link have the same variations in their length As the dynamic ofthis robot is complicated for motion planning closed form inverse kinematics which gives suitable solutions isused From natural characteristics of bending in all sections of the arm capability of robot to move in thin channelswith different shapes is analyzed by using optimization methods like obstacle avoidance in which the controlalgorithm avoids collision between from channel walls and manipulator and the whole arm shape is changedaccording to the shape of the channel In medical applications the continuum robot is pushed into patient s bodymanually If the robot hits the internal organ with its tip or body this process would become harmful To solve thisproblem a case in which the base of the robot is not stationary is modeled Keywords Continuum Robot Redundancy Closed Loop Inverse Kinematics Optimization Obstacle Avoidance Artificial Potential Field Whole Arm Grasping

مهدي كشيمري

محمدرضا احمدزاده

محمد دانش، سعيد بهبهاني