The Department of Applied Physics and Electronics at Umeå University offers education and conducts research in the field of automation and robotics. To raise the competence in automation in the CODESYS development environment it’s proposed to build a remote controlled self-balancing robot as a testing platform which is then programmed using CODESYS for Raspberry Pi.   The chassis of the robot consists of laser-cut plexiglass plates, stacked on top of each other and fixed using threaded rods, nuts and washers. On these plates the robots’ electrical components, wheels and motors are attached.   The control system is designed as a feedback loop where the robots’ angle relative to the gravity vector is the controlled variable. A PID-controller is used as the system controller and a Kalman Filter is used to filter the input signals from the IMU board using input from both the accelerometer and the gyro.   The control system is implemented in CODESYS as a Function Block Diagram (FBD) using both pre-made, standard function blocks and customized function blocks. By using the in-built web-visualization tool the robot can be remote controlled via Wi-Fi.   After tuning the Kalman Filter through plot-analysis and the PID-controller through Ziegler-Nichols method the robot can stay balanced on a flat surface.   The robots’ performance is tested through a series of test scenarios of which it only completes one out of four. The project ran out of time before further testing could be done.   For future work one could improve the performance of the PID-controller through more sophisticated tuning methods. One can also add a steering-function or test different type of controllers.

This thesis deals with complete design and manufacturing of autonomous two wheeled self-balancing robot. The goal of this thesis is to maintain the robot in up-right position and to follow black line using camera. The robot is controlled using Raspberry Pi and driven by DC motors. This thesis includes the design and implementation of hardware and software parts. Subsequently there was created the dynamic model in Matlab/Simulink. Based on this model, the LQR and PID controller was designed.

This report presents the construction of a two-wheeled self balancing robot with the ability to handle an uneven load. Two-wheeled self-balancing robots have proven to be a potential solution to the problem of efficient warehouse management, thanks to their ability to navigate tight spaces quickly and efficiently while balancing their load. The research questions defined include the ability to develop an algorithm to dynamically adjust the robot’s tilt angle, how an uneven load affects the robot’s stability, and whether a PID controller is sufficient in this context. The project was limited to constructing a prototype that could balance with an external load, with a budget of 1,000 Swedish kronor and a four-month timeframe. By testing and evaluating different control algorithms, the robot’s performance was presented in terms of stability and efficiency. The implementation of PID control was successful, and the robot was able to balance as a result. However, the goal of handling an uneven load was not met without the implementation of an additional algorithm to dynamically adjust the robot’s tilt angle. With these two control techniques, the robot was able to balance with and without an added load with good stability. To evaluate performance, tests were performed with the load placed centered and off-centered on the robot’s top plate. The results of the tests showed that the robot was able to dynamically adjust its tilt angle to balance with added weight without affecting stability. / Denna rapport presenterar konstruktionen av en tvåhjulig självbalanserande robot med förmågan att hantera snedfördelad last. Tvåhjuliga självbalanserande robotar har visat sig vara en potentiell lösning på problemet kring effektiv lagerhantering tack vare deras förmåga att hantera snäva utrymmen på ett snabbt och energieffektivt sätt samtidigt som lasten balanseras. Forskningsfrågorna som definierades inkluderar möjligheten att framställa en algoritm för att dynamiskt ställa in robotens lutningsvinkel, hur ojämn last påverkar robotens stabilitet, och om en PID-kontroller är tillräcklig i detta sammanhang. Projektet begränsades till att konstruera en prototyp som klarar av att balansera med extern last, med en budget på 1000 svenska kronor och en tidsram på fyra månader. Genom att testa och utvärdera olika kontrollalgoritmer presenterades robotens prestanda i termer av stabilitet och effektivitet. Roboten balanserade tack vare implementeringen av PID-reglering, men önskemålet om snedfördelad last uppfylldes inte och det krävdes ytterligare en algoritm för att dynamiskt reglera robotens lutningsvinkel. Med hjälp av dessa två reglertekniker kunde roboten balansera både med och utan adderad last med god stabilitet. Tester utfördes för att utvärdera prestandan när lasten var placerad både centrerat och ocentrerat på robotens topplatta. Resultaten visade att roboten kan dynamiskt anpassa lutningsvinkeln för att balansera med tillagd vikt utan att stabiliteten påverkas.

A robot capable of balancing itself on two wheels has been built and programmed. While balancing, the robot keeps within a limited area. The robot has a face with two eyes and a mouth, consisting of LED-matrices, which switch between six different facial expressions. The robot is programmed using Arduino boards, one of which implements PID regulators to control the motors.