63 research outputs found
Unifying Foundation Models with Quadrotor Control for Visual Tracking Beyond Object Categories
Visual control enables quadrotors to adaptively navigate using real-time
sensory data, bridging perception with action. Yet, challenges persist,
including generalization across scenarios, maintaining reliability, and
ensuring real-time responsiveness. This paper introduces a perception framework
grounded in foundation models for universal object detection and tracking,
moving beyond specific training categories. Integral to our approach is a
multi-layered tracker integrated with the foundation detector, ensuring
continuous target visibility, even when faced with motion blur, abrupt light
shifts, and occlusions. Complementing this, we introduce a model-free
controller tailored for resilient quadrotor visual tracking. Our system
operates efficiently on limited hardware, relying solely on an onboard camera
and an inertial measurement unit. Through extensive validation in diverse
challenging indoor and outdoor environments, we demonstrate our system's
effectiveness and adaptability. In conclusion, our research represents a step
forward in quadrotor visual tracking, moving from task-specific methods to more
versatile and adaptable operations
Vision-based Autonomous Tracking of a Non-cooperative Mobile Robot by a Low-cost Quadrotor Vehicle
The goal of this thesis is the detection and tracking of a ground vehicle, in particular a car-like robot, by a quadrotor. The first challenge to address in any pursuit or tracking scenario is the detection and unique identification of the target. From this first challenge, comes the need to precisely localize the target in a coordinate system that is common to the tracking and tracked vehicles. In most real-life scenarios, the tracked vehicle does not directly communicate information such as its position to the tracking one. From this fact, arises a non-cooperative constraint problem. The autonomous tracking aspect of the mission requires, for both the aerial and ground vehicles, robust pose estimation during the mission. The primary and crucial functions to achieve autonomous behaviors are control and navigation. The principal-agent being the quadrotor, this thesis explains in detail the derivation and analysis of the equations of motion that govern its natural behavior along with the control methods that permit to achieve desired performances. The analysis of these equations reveals a naturally unstable system, subject to non-linearities. Therefore, we explored three different control methods capable of guaranteeing stability while mitigating non-linearities. The first two control methods operate in the linear region and consist of the intuitive Proportional Integrate Derivative controller (PID). The second linear control strategy is represented by an optimal controller that is the Linear Quadratic Regulator controller (LQR). The last and final control method is a nonlinear controller designed from the Sliding Mode Control Theory. In addition to the in-depth analysis, we provide assets and limitations of each control method. In order to achieve the tracking mission, we address the detection and localization problems using respectively visual servoing and frame transform techniques. The pose estimation challenge for the aerial robot is cleared up using Kalman Filtering estimation methods that are also explored in depth. The same estimation method is used to mitigate the ground vehicle’s real-time pose estimation and tracking problem. Analysis results are illustrated using Matlab. A simulation and a real implementation using the Robot Operating System are used to support the obtained results
Geometric Tracking Control of a Multi-rotor UAV for Partially Known Trajectories
This paper presents a trajectory-tracking controller for multi-rotor unmanned
aerial vehicles (UAVs) in scenarios where only the desired position and heading
are known without the higher-order derivatives. The proposed solution modifies
the state-of-the-art geometric controller, effectively addressing challenges
related to the non-existence of the desired attitude and ensuring positive
total thrust input for all time. We tackle the additional challenge of the
non-availability of the higher derivatives of the trajectory by introducing
novel nonlinear filter structures. We formalize theoretically the effect of
these filter structures on the system error dynamics. Subsequently, through a
rigorous theoretical analysis, we demonstrate that the proposed controller
leads to uniformly ultimately bounded system error dynamics
A review of aerial manipulation of small-scale rotorcraft unmanned robotic systems
Small-scale rotorcraft unmanned robotic systems (SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years (2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem, trends, and challenges are described from three aspects. Conclusions of the paper are presented, and the future of SRURSs is discussed to enable further research interests
A survey on fractional order control techniques for unmanned aerial and ground vehicles
In recent years, numerous applications of science and engineering for modeling and control of unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) systems based on fractional calculus have been realized. The extra fractional order derivative terms allow to optimizing the performance of the systems. The review presented in this paper focuses on the control problems of the UAVs and UGVs that have been addressed by the fractional order techniques over the last decade
Single chip solution for stabilization control & monocular visual servoing of small-scale quadrotor helicopter
This thesis documents the research undertaken to develop a high-performing design
of a small-scale quadrotor (four-rotor) helicopter capable of delivering the speed and
robustness required for agile motion while also featuring an autonomous visual servoing
capability within the size, weight, and power (SWaP) constraint package. The
state of the art research was reviewed, and the areas in the existing design methodologies
that can potentially be improved were identified, which included development
of a comprehensive dynamics model of quadrotor, design and construction of a performance
optimized prototype vehicle, high-performance actuator design, design of a
robust attitude stabilization controller, and a single chip solution for autonomous vision
based position control. The gaps in the current art of designing each component
were addressed individually. The outcomes of the corresponding development activities
include a high-fidelity dynamics and control model of the vehicle. The model
was developed using multi-body bond graph modeling approach to incorporate the
dynamic interactions between the frame body and propulsion system. Using an algorithmic
size, payload capacity, and flight endurance optimization approach, a quadrotor
prototype was designed and constructed. In order to conform to the optimized
geometric and performance parameters, the frame of the prototype was constructed
using printed circuit board (PCB) technology and processing power was integrated
using a single chip field programmable gate array (FPGA) technology. Furthermore, to actuate the quadrotor at a high update rate while also improving the power efficiency
of the actuation system, a ground up FPGA based brushless direct current
(BLDC) motor driver was designed using a low-loss commutation scheme and hall
effect sensors. A proportional-integral-derivative (PID) technology based closed loop
motor speed controller was also implemented in the same FPGA hardware for precise
speed control of the motors. In addition, a novel control law was formulated for robust
attitude stabilization by adopting a cascaded architecture of active disturbance rejection
control (ADRC) technology and PID control technology. Using the same single
FPGA chip to drive an on-board downward looking camera, a monocular visual servoing
solution was developed to integrate an autonomous position control feature with
the quadrotor. Accordingly, a numerically simple relative position estimation technique
was implemented in FPGA hardware that relies on a passive landmark/target
for 3-D position estimation.
The functionality and effectiveness of the synthesized design were evaluated by
performance benchmarking experiments conducted on each individual component as
well as on the complete system constructed from these components. It was observed
that the proposed small-scale quadrotor, even though just 43 cm in diameter, can lift
434 gm of payload while operating for 18 min. Among the ground up designed components,
the FPGA based motor driver demonstrated a maximum of 4% improvement in
the power consumption and at the same time can handle a command update at a rate
of 16 kHz. The cascaded attitude stabilization controller can asymptotically stabilize
the vehicle within 426 ms of the command update. Robust control performance under
stochastic wind gusts is also observed from the stabilization controller. Finally, the
single chip FPGA based monocular visual servoing solution can estimate pose information
at the camera rate of 37 fps and accordingly the quadrotor can autonomously
climb/descend and/or hover over a passive target
Vision-Based Target Tracking and Autonomous Landing of a Quadrotor on a Ground Vehicle
This paper addresses vision-based tracking and landing of a micro-aerial vehicle (MAV) on a ground vehicle (GV). The camera onboard the MAV is mounted so that the optical axis is aligned with the downward-facing axis of the body-fixed frame. A novel supervised learning vision algorithm is proposed as the method to detect the ground vehicle in the image frame. A feedback linearization technique is developed for the MAV to fly over and track the GV so that visibility with the tracked target is maintained with certain guarantees. The efficacy of the visual detection algorithm, and of the tracking and landing controller is demonstrated in simulations and experiments with static and mobile GV
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