Robotski krmilnik zasnovan na Robotskem operacijskem sistemu

KAJSNER, SIMON (author), Munih, Marko (mentor)

V magistrskem delu je predstavljen robotski krmilnik, ki je bil razvit za robotsko roko s štirimi stopnjami prostosti. Za osnovno platformo in komunikacijo med programi je bil uporabljen odprtokodni Robotski operacijski sistem oziroma ROS. Namen je bil v čim večji meri uporabiti orodja in pakete, ki jih ROS ponuja. Predstavljeni so roboti, ki jih najdemo na trgu in od katerih programska oprema je bila prav tako zasnovana na Robotskem operacijskem sistemu. Nato je v grobem predstavljena strojna oprema razvite testne robotske roke z imenom GverilaBot. Opisani so izbrani aktuatorji, prenosi in dajalniki zasuka. Aktuatorji so bili krmiljeni z odprtokodnim krmilnikom ODrive. V bazi robotskega manipulatorja se nahaja mikroračunalnik Raspberry Pi 4 z operacijskim sistemom Linux in ROS Melodic. Glavni poudarek magistrske naloge je na razvoju programske opreme krmilnika, zato je podrobneje razloženo delovanje ROS-a in njegove glavne značilnosti ter osnovni pojmi. Sledi razlaga pojma kinematika, ki opiše gibanje teles. Kinematika robotskega manipulatorja GverilaBot je opisana z Denavit Hartenbergovimi parametri, nato pa je kinematika in dinamika robota opisana še s standardnim ROS URDF opisom. Opisane so knjižnice: MoveIt, OMPL, FCL, KDL in OpenRAVE, ki se uporabljajo pri načrtovanju robotskih trajektorij in izvajanju premikov. Za samo vodenje robotskega manipulatorja so uporabljeni nekoliko naprednejši ROS koncepti, kot je akcijska storitev, ki je bila integrirana kot vmesnik med planom poti in paketom pripravljenih krmilnikov ros_control. Opisana je potrebna komunikacija, da pošljemo novo ciljno pozicijo sklepov krmilniku motorjev. Uporabljeno je bilo pozicijsko vodenje, motorji pa so bili vodeni z naprednim FOC algoritmom. Nazadnje so predstavljeni različni tipi uporabniških vmesnikov, ki se uporabljajo v robotiki. Za lažje upravljanje z robotskim manipulatorjem smo razvili blokovni grafični vmesnik, ki sloni na odprtokodnem projektu Blockly in je dostopen preko poljubnega brskalnika. Z njim lahko uporabnik piše robotske aplikacije brez poznavanja programskih jezikov.

• Language: Slovenian
• Keywords: Robotski operacijski sistem, Robotski manipulator, krmilnik, kinematika, uporabniški vmesnik
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2021
• PID: 20.500.12556/RUL-131266
• COBISS.SI-ID: 77920515
• Publication date in RUL: 24.09.2021

Secondary language

• Language: English
• Title: Robot contoller based on Robot operating system

Abstract

The master's thesis addresses a robotic controller that was developed for a robotic arm with four degrees of freedom. The open-source Robotic operating system or ROS was used for the basic platform and communication between programs. The aim was to make the most of the tools and packages offered by ROS. Firstly, thesis presents robots that can be found on the market and were developed with ROS. The hardware parts, such as selected actuators, transmissions and encoders, are described which were used in developed robotic arm named GverilaBot. The actuators were controlled by open-source ODrive controllers. At the base of the robotic manipulator is a Raspberry Pi 4 microcomputer with a Linux operating system and ROS Melodic distribution. The main emphasis of the master's thesis is on the development of the controller software, therefore some basic ROS concepts and features are described in more detail. The concept of kinematics, which describes the motion of bodies, is explained in detail. The kinematics of the GverilaBot robotic manipulator are described by Denavit Hartenberg parameters. Kinematics and dynamics of the robot are described by a standard ROS URDF description. Libraries used in robot trajectory planning such as: MoveIt, OMPL, FCL, KDL and OpenRAVE are also presented. Slightly more advanced ROS concepts are used to control the robotic manipulator, such as the action service, which was integrated as an interface between the trajectory planning and the ROS package ros_control. Furthermore, communication protocols used to send the current desired position of the joints to the motor controller are described. Position control was used and the motors were controlled by an advanced FOC algorithm. Finally, the different types of user interfaces used in robotics are pointed out. To make it easier to operate the robotic manipulator, a block-based graphical user interface was developed that relies on the open-source Blockly project and is accessible via any browser. This enables the user to write robotic applications without knowing any of programming languages.

• Keywords: Robot operating system, robotic arm, controller, kinematics, user interface