Enabling Unmanned Aerial Vehicles (Drones) to use Tools in Complex Dynamic Environments
This project is led by the University of Canterbury, funded by the New Zealand Ministry of Business, Innovation and Employment
Karl Stol, Bruce MacDonald, Peter Xu, Shahab Kazemi, Nicholas Kay, Salim Al-zubaidi, Chantelle Singh, Caleb Probine, David Yang, Jonty Kirk, Katrina Chan, Jos Spaans, Sam Gilbert, Benjamin Holt, Cameron Dallas, Lex Hostler, Raymond Hu
Unmanned aerial vehicles (UAVs/drones) are revolutionising surveying and inspection tasks which once required manned aircraft, and are becoming a standard tool for a wide range of applications. However, one glaring omission is the ability to accurately use tools to perform precision tasks in high and hard-to-reach locations.
This research will design, build and demonstrate a compact UAV with precise six degrees-of-freedom positioning capability enabled by new control methods, airframe designs, aerodynamic models, and position estimation (visual odometry) in dynamically changing (windy) environments.
Rotor Configuration and Control of High Precision Drones
PhD Research
Salim Al-zubaidi. Supervisors: Karl Stol & Peter Xu
With the rise of the UAV use in interaction, the ability of the UAV to change the contact force instantaneously and the control of all axes independently became important aspect of the UAV performance.
This research aims to present a new UAV configuration with the potential for improved horizontal agility. An optimisation process is developed to maximise the horizontal bandwidth. A control algorithm will be developed to make use of the improved capabilities of the UAV.
Related:
- Enabling Unmanned Aerial Vehicles (Drones) to use Tools in Complex Dynamic Environments
- Experimental Validation of a UAV Configuration Optimisation Algorithm
- Drone Airframe Optimization
- Variable-Pitch Propellers for Highly Agile Drones
Read:
- Al-Zubaidi, S., Stol, K. “Analysis of the Transient Response of UAV Rotors”, 14th Annual International Micro Air Vehicle Conference and Competition, Aachen, Germany, 2023
- Al-Zubaidi, S., Stol, K. “Preliminary design optimisation of a novel fixed-tilt heterogeneous UAV for horizontal agility”, 2022 International Conference on Unmanned Aircraft Systems (ICUAS), 2022
Dexterity assessment of over-actuated drones
Masters Research
Chantelle Singh. Supervisor: Karl Stol
Aerial manipulation is the ability to interact with the environment using a UAV. This is typically achieved using a tool or an aerial manipulator. An important characteristic in whether manipulation is successful is dexterity. There is yet to be a standardized way to assess the dexterity of UAVs.
This project will focus on developing a standardized dexterity assessment consisting of several tests to determine how dexterous an over-actuated UAV is. It will be such that it is easily replicated and can be used on a range of UAVs.
Related:
Case Studies on Octocopter Performance
Caleb Probine. Supervisor: Karl Stol
The work in this project focuses on answering questions surrounding how different UAV parameters affect the final station keeping performance. Examined in the context of planar octocopters, this includes comparing various actuation methods, or determining the octocopter characteristics which most directly influence station keeping performance.
Related:
Read:
Experimental Validation of a UAV Configuration Optimisation Algorithm
David Yang. Supervisor: Karl Stol
One of the main contributions to the MBIE project currently being developed is an optimisation algorithm for multicopter UAV configuration.
This project emphasizes on the validation of this algorithm, where an “instance” of the optimised UAV configuration is built according to specification. This instance’s properties and performance, such as mass, moment of inertia, maximum force, and agility, are evaluated against the optimisation prediction. A prototype UAV can then be developed with off-the-shelf components, tested for performance validation, and exploiting the PX4 architecture for full control of the UAV during testing.
Related:
Watch:
Drone Flight Control for Contact Testing of Powerlines
BE(Hons) Research Project
Jonty Kirk & Katrina Chan. Supervisor: Karl Stol
UAVs in autonomous power line inspection hold great potential for transmission and distribution companies. Our project conducts research on the stability control of an autonomous over-actuated UAV semi-perched on a simulated power transmission line. We will explore how different parameters such as approach angle and probe length affect the controller performance. This study will leverage the benefits of over-actuated drones that have more actuators than degrees of freedom.
This research will investigate how the flight controller can improve the efficiency and safety of power line inspections using drones.
Related:
Improving Control Allocation for Fully-Actuated UAVs
BE(Hons) Research Project
Jos Spaans & Sam Gilbert. Supervisor: Karl Stol
A UAV’s control allocator aims to distribute motor control effort to produce forces and moments that closely resemble those commanded by the controller. Commonly, the control allocator is derived by considering drone geometry, but this fails to account for aerodynamic effects like rotor interaction which introduce errors into the system.
This project aims to compensate for the complex aerodynamic interaction of an over-actuated octocopter by optimising the control allocator with a parameter estimation approach, using motion capture data to estimate generated forces and moments. The resulting allocation scheme should allow for improved reference-tracking performance during free flight.
Related:
Drone Airframe Optimization
BE(Hons) Research Project
Benjamin Holt & Cameron Dallas. Supervisor: Peter Xu
DTRG is developing over-actuated drones which can perform physical interaction tasks. Such drones require superior agility to accomplish these tasks.
This project will explore the application of genetic algorithms to optimize the drone airframe of over-actuated drones subject to agility. The team has defined the term “drone airframe” as inclusive of rotors (propeller and motor), battery, cant angle and dihedral angle of the rotors, total mass, and motor to motor diameter. The genetic algorithm is to be coded in python with the aid of existing evolutionary algorithm libraries: LEAP and DEAP.
Related:
Variable-Pitch Propellers for Highly Agile Drones
BE(Hons) Research Project
Lex Hostler & Raymond Hu. Supervisor: Nicholas Kay
The use of fixed-pitch propellers limits the agility and manoeuvrability of modern-day drones. Increasing both the diameter of the propeller and the motor size increases the maximum thrust capabilities but reduces the achievable bandwidth due to the increased rotational inertia.
This is where variable pitch mechanisms come into play. Instead of modulating purely motor speed, a combination of motor speed and blade pitch angle can be used to increase drone positioning and disturbance rejection control. This project aims to assess the transient performance of variable-pitch propellers that will later be used to design a novel overactuated drone.
Related:
Development of a Flying Meteorological Station
BE(Hons) Research Project
Hannah Brighouse and Kathy Hastie. Supervisor: Nicholas Kay
Coastal and mountainous regions of New Zealand currently lack the required atmospheric data to produce accurate weather prediction models. Multirotor UAVs are inexpensive and manoeuvrable, giving them the potential to provide sufficiently high-resolution data from these remote areas with difficult terrain. An external sensor mounted to a small UAV can measure wind speed and direction, but challenges arise due to the UAV’s motion relative to the ground and the effects of rotor downwash. This project aims to process raw sensor data taken in the boundary layer wind tunnel to produce accurate wind measurement results.
Free Flight of a Fixed-Wing UAV in a Wind Tunnel
BE(Hons) Research Project
Isabelle Burr, Jannik Wittgen. Supervisor: Nicholas Kay
The current methods used to test fixed-wing aircraft involves statically mounting a model airframe in a wind tunnel. This dampens the oscillatory responses of the model, resulting in potential inaccuracies in measurements. This project aims to allow for dynamic testing of airframes in the wind tunnel to avoid this issue. A fixed-wing UAV has been sourced and modified, with successful manual flights undertaken in the BLWT. The platform is now being developed further to allow for automated tests and to research the benefits of dynamic testing over static testing.
