طراحي كنترلر فازي چند وظيفه اي براي ربات هاي شناور با تراسترهاي دو وضعيتي

چكيده انگليسي :

Design of a Multi Task Fuzzy Controller for Free Floating Robots with on off Thruster Saeid Dadashi s dadashi@me iut ac ir Date of Submission 2011 07 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 ir AbstractCuriosity in environment is one of the reasons for technological advancement Among the environmentsspace and oceans have special importance These environments have serious dangers for human being forthis reason man invented some equipments to access these environments and exploit resources available inthem Some of these equipments are free floating robot and underwater vehicles There are many importantapplications where an underwater robotic system can be useful Applications include ocean surveying inspection data collection laying pipe line underwater cable burial construction and maintenance ofunderwater structures drilling mining rescue and recovery maintenance of underwater nuclear plants anddefense program of navy These equipments have a mobile base and a manipulator mounted on base A generic manipulation task isusually given in terms of position orientation motion trajectories for the end effector When the roboticsystem used to perform the manipulation task possesses more degrees of freedom than those strictly requiredto execute the given motion of the end effector it is said to be kinematically redundant In this sense anunderwater vehicle manipulator is always kinematically redundant due to the mobility provided by thevehicle itself in addition to the dofs provided by the manipulator Motion planning of underwater vehicle manipulator systems UVMS is one of the most important aspects for autonomous task execution Themotion planning of a UVMS is a difficult problem because of several reasons A UVMS is a kinematicallyredundant system For a redundant system the inverse kinematics problem admits an infinite number of jointspace solutions for a given Cartesian space coordinates and can be applied aimed at achieving additionalcontrol objectives besides the doing main task In this work an inverse kinematic approach with the ability ofpreceding between tasks is proposed The fuzzy technique is used both to distribute the motion betweenvehicle and manipulator and to handle multiple secondary tasks In following we design a controller for thissystem by considering the studying problem tracking a path by a robot and also the nonlinear motionequation for underwater vehicle manipulator a computed torques controller is proposed for this system Trajectories computed from the inverse kinematic are used as desired trajectories in designing controller Inspace applications the vehicle uses on off thruster for position and orientation control therefore we need toconvert the continuous output from continuous controller to discontinuous value Pulse modulators convertcontinuous input commands in a sequence of switching signals suitable for the command of on off thrusters A pulse modulation scheme based on two modulation curves is proposed for applications in spacecraftposition and attitude control using thrusters which may be subjected to switching restrictions Theseconstraints are taken into account explicitly during the design of the modulation scheme Finally considering the fact that a task can be performed by choosing different degrees of freedom ofvehicle that some of these cases aren t suitable in practice a decision making fuzzy technique is proposed tochoose a suitable case from available motions Keywords Vehicle Manipulator Inverse kinematic Fuzzy controller Task priority On off thruster Pulsemodulation

داداشي، سعيد

طراحي كنترلر فازي چند وظيفه اي براي ربات هاي شناور با تراسترهاي دو وضعيتي

وسيله-بازوي مكانيكي , سينماتيك معكوس , اولويت وظايف , مدولاسيون پالس