كاربرد الگوريتم كنترل موقعيت/ نيرو در اصلاح مسير ربات هاي دوپا براي حركت روي سطح ناصاف

چكيده انگليسي :

Application of Postion Force Control for Improving Trajectory of Bipeds Moving on Rought Terrains Masoud Fazeli Varzaneh m fazeli@me iut ac ir Date of Submission 2012 03 12 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Jafar Sadigh jafars@cc iut ac irAbstract Due to the similarity between human beings and humanoid robots this kind of robot can serve in diverseapplications instead of human such as servant for elderly people working in hazardous environments andeven as a robotic soldier Therefore in recent years a great number of researchers in all over the world havebeen attracted to this field and many studies have been focused on this subject Although one of thepriorities of this robot in comparison to others is its capability in crossing rough terrains the challengingproblem of stable walking makes the progress in the field slow in a way with a small bump or pit in theground profile might cause the robot to fall However for biped robots to exist around they must be able toroboustly cross rough terrains The aim of this thesis is to improve the movement of biped robots on roughterrains To this aim a seven link planar biped robot equipped with four force sensors under the feet hasbeen considered These four sensors are placed beneath the tow and heel of each foot and their data are usedto detect the ground profile during robot movements in rough terrain environments Trajectory planning ofbiped has been done assuming the walking is on a flat surface In this research a position force controller isproposed which modify the initial trajectory based on the errors in tracking of desired forces Thiscontroller consists of three main parts The first part of controller is a closed loop position controller totrack the desired trajectory the second one is an open loop force controller to compensate for applied forceon the feet and the third part is a closed loop adjustable force controller In case of error in the appliedforce on the feet the controller has the property to automatically modify the base trajectory of the robot tocompensate the error in the force tracking This modification can improve the adaptability of robot todifferent ground profiles i e an 80 percent improvement in step down situation and a 16 percentimprovement in step up In order to further improve the movement of the robot in rough terrain anothercontroller is also proposed This controller has the ability to independently control the trajectory of the hipjoint and absolute angle of the trunk while possessing other properties of the previous position forcecontroller Numerical simulations shows that with this new controller the performance improves by 340percent in step down and 133 percent in step up motion Due to the fact that all of the proposed controllers are model based controllers equations of motion ofrobot are required We used MATLAB as a symbolic tool to derive equations of motion of our seven linkplanar biped using Lagrange method In order to simulate the behavior of controlled system the Yoboticssoftware is used which is a free full featured software package written in Java language develop in MITleg s lab for easily and quickly investigating the behavior of robots biomechanical systems and mechanicaldevices Keywords Biped robot Position Force Control Rough Terrain Force Sensor Yobotics TrajectoryImprovement

فاضلي ورزنه، مسعود

كاربرد الگوريتم كنترل موقعيت/ نيرو در اصلاح مسير ربات هاي دوپا براي حركت روي سطح ناصاف

سطح ناهموار , سنسور نيرو , يوبوتيكز