Path Following and Motion Control for Articulated Frame Steering Mobile Working Machine Using ROS2
Abdulsahib, Ahmed (2023)
2023
Automaatiotekniikan DI-ohjelma - Master's Programme in Automation Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2023-01-25
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202212319857
https://urn.fi/URN:NBN:fi:tuni-202212319857
Tiivistelmä
Autonomous vehicles (AVs) have been studied and researched at least since the middle of 19s century, and the interest in these vehicles has grown in the last decade. There are many vehicle types with different steering techniques. Each is designed and manufactured depending on the need to perform specific tasks (for example, transporting passengers, transporting goods, and doing heavy duties like cutting trees, digging earth, and harvesting crops). This thesis highlights the autonomous articulated frame steering (AFS) heavy-duty mobile working machines and aims to address the problems of autonomizing the AFS machine with basic autonomy requirements, which makes the machine move without the need for human direct and indirect control.
The working environment (like mines, forests, and construction sites), where heavy-duty machines are used to perform some tasks, requires an expert machine operator to drive it and control its manipulator, which increases the operator’s workload. However, due to the working environment’s limited area, the machine mostly has repetitive tasks that include following the same paths; therefore, we proposed implementing a path-following control system that could be used to help the operator by reducing the work amount.
The proposed path following is based on controlling the vehicle’s position and orientation to match the desired positions and orientation on a specified path where the position’s lateral error and orientation error are minimized to zero while the vehicle follows the given path. The implemented control system is divided into many subsystems; each is responsible for a specific task, and to communicate between them we used the Robot Operating System ROS2.
In this thesis, we are focusing on two of these subsystems. The first subsystem, called path following that, generates linear and angular velocities needed to make the machine follow the path. The other subsystem, called motion control, is responsible for converting the linear and angular velocities to machine commands (gear, steering, gas) and controls the machine’s acceleration and steering angle. The implemented path-following control system required understanding the machine’s kinematics and modeling the steering system.
The implemented system is tested first using an AFS robot in a simulation environment, then tested on a real AFS heavy-duty machine owned by Tampere university. Moreover, the tests repeated for another path following based on the modified pure pursuit technique provided by ROS2 navigation for compression and evaluation purposes.
The working environment (like mines, forests, and construction sites), where heavy-duty machines are used to perform some tasks, requires an expert machine operator to drive it and control its manipulator, which increases the operator’s workload. However, due to the working environment’s limited area, the machine mostly has repetitive tasks that include following the same paths; therefore, we proposed implementing a path-following control system that could be used to help the operator by reducing the work amount.
The proposed path following is based on controlling the vehicle’s position and orientation to match the desired positions and orientation on a specified path where the position’s lateral error and orientation error are minimized to zero while the vehicle follows the given path. The implemented control system is divided into many subsystems; each is responsible for a specific task, and to communicate between them we used the Robot Operating System ROS2.
In this thesis, we are focusing on two of these subsystems. The first subsystem, called path following that, generates linear and angular velocities needed to make the machine follow the path. The other subsystem, called motion control, is responsible for converting the linear and angular velocities to machine commands (gear, steering, gas) and controls the machine’s acceleration and steering angle. The implemented path-following control system required understanding the machine’s kinematics and modeling the steering system.
The implemented system is tested first using an AFS robot in a simulation environment, then tested on a real AFS heavy-duty machine owned by Tampere university. Moreover, the tests repeated for another path following based on the modified pure pursuit technique provided by ROS2 navigation for compression and evaluation purposes.