Design and Autonomous Stabilization of a Ballistically Launched Multirotor

Aircraft that can launch ballistically and convert to autonomous, free flying drones have applications in many areas such as emergency response, defense, and space exploration, where they can gather critical situational data using onboard sensors. This paper presents a ballistically launched, autonomously stabilizing multirotor prototype (SQUID, Streamlined Quick Unfolding Investigation Drone) with an onboard sensor suite, autonomy pipeline, and passive aerodynamic stability. We demonstrate autonomous transition from passive to vision based, active stabilization, confirming the ability of the multirotor to autonomously stabilize after a ballistic launch in a GPS denied environment.Comment: Accepted to 2020 International Conference on Robotics and Automatio

Design and development of multiband antennas for unmanned aerial vehicles (UAVs)

Abstract. This thesis aims to design and analyze microstrip patch antennas for unmanned aerial vehicles (UAVs) for Internet of Things (IoT) communication. With the growing need for reliable and efficient communication in UAV, understanding the unique challenges and requirements of antenna design for UAV-based communication systems becomes crucial. During the process of antenna integration onto the UAV body, important attention must be given to vital factors including the availability of mounting space, weight limitations, and radiation parameters. In this study, extensive efforts were made in the design of the antenna to meet the specific requirements for UAV applications. The antenna structure chosen was a microstrip patch antenna with an inset feed technique. The design aimed at optimizing the antenna for multi-band operation, ensuring compatibility with various communication frequencies. Careful considerations were made regarding size, weight, and functionality to ensure the antenna’s suitability for UAV applications. The first part of the thesis introduces the antenna theory, highlighting significant parameters such as radiation pattern, gain, and efficiency, which are crucial for UAV antenna design. The methodology for selecting various parameters is explained, and the radiation pattern and gain of two commercially available antennas were measured in the SATIMO chamber as a benchmark. The fabricated microstrip patch antenna was also tested both with and without the presence of a UAV to examine the impact of the UAV’s body on its performance. The designed antenna demonstrated a semi-omnidirectional pattern at sub-gigahertz frequencies, achieving a gain value exceeding 6 dBi, thereby fulfilling the requirements for UAV applications. The second part of this thesis focused on further advancements in the design process. Efforts were made to improve the antenna’s performance and behavior through various design modifications and optimizations. The design process involved iterative steps, such as adjusting the dimensions and parameters of the antenna to enhance its performance metrics. The results obtained demonstrated notable improvements in terms of radiation patterns with 92 degree of 3 dB angular beamwidth, gain enhancement up to 6.7 dBi, and overall antenna performance. These findings contribute to the body of knowledge in UAV antenna design and highlight the potential for further advancements in this field

Design of microstrip patch antenna to deploy unmanned aerial vehicle as UE in 5G wireless network

The use of unmanned aerial vehicle (UAV) has been increasing rapidly in the civilian and military applications, because of UAV's high-performance communication with ground clients, especially for its intrinsic properties such as adaptive altitude, mobility, and flexibility. UAV deployment can be monitored and controlled through 5G wireless network as user equipment (UE) along with other devices. A highly directive microstrip patch antenna (MPA) could establish long-distance communication by overcoming air attenuation and reduce co-channel interference in the limited region if UAV uses a specifically dedicated band, which might enhance spatially reuse of the spectrum. Also, MPA is highly recommended for UAV because of its low weight, low cost, compact size, and flat shape. In this paper, we have designed a highly directive single-band 2×2 and 4×4 antenna array for 5.8 GHz and 28 GHz frequency respectively for UAV application in a focus to deploy UAV through 5G wireless network. Here, The Roger RT5880 (lossy) material utilize as a substrate due to its lower dielectric constant which achieves higher directivity and good mechanical stability. Inset feed technique used to feed antenna for lowering input impedance which provides higher antenna efficiency. The results show a wider bandwidth of 702 MHz and 1.596 GHz for 5.8 GHz and 28 GHz antenna array correspondingly with a compact size

Development of a Dual-Band Radio Repeater to be Carried by a Fixed-Wing small Unmanned Aerial System

With the continued rise in wildfires in California, and around the world, technological advancements are needed to improve the safety and effectiveness of wildland firefighters. One area that provides an opportunity for such development is the deployment of temporary communications networks. Currently, radio repeaters are set up on mountain tops in the response area; such repeaters do not provide flexibility once installed, still have blind spots, and require the time of valuable assets like helicopters to install. This thesis will establish the feasibility of airborne radio repeaters for wildland firefighting. In order to successfully demonstrate the feasibility of such an airborne system, the resulting system should be rapidly deployable, improve communications range and reliability, and be compatible with existing regulations and guidelines. The design process for the repeater payload is described, as well as important troubleshooting steps. The resulting product is then compared to the initial requirements through testing and observation. Although audio filtering provided by off-the-shelf handheld radios prevented the repeater from functioning as intended, the proposed 2m/70cm dual-band digital communications relay was capable of being carried by the Altavian Nova and was able to successfully demonstrate the feasibility of such a system. As such it will be an important contribution to communications needed for fighting future wildfires

Wide Band Embedded Slot Antennas for Biomedical, Harsh Environment, and Rescue Applications

For many designers, embedded antenna design is a very challenging task when designing embedded systems. Designing Antennas to given set of specifications is typically tailored to efficiently radiate the energy to free space with a certain radiation pattern and operating frequency range, but its design becomes even harder when embedded in multi-layer environment, being conformal to a surface, or matched to a wide range of loads (environments). In an effort to clarify the design process, we took a closer look at the key considerations for designing an embedded antenna. The design could be geared towards wireless/mobile platforms, wearable antennas, or body area network. Our group at UT has been involved in developing portable and embedded systems for multi-band operation for cell phones or laptops. The design of these antennas addressed single band/narrowband to multiband/wideband operation and provided over 7 bands within the cellular bands (850 MHz to 2 GHz). Typically the challenge is: many applications require ultra wide band operation, or operate at low frequency. Low frequency operation is very challenging if size is a constraint, and there is a need for demonstrating positive antenna gain

Fabrication and characterization of flexible spray-coated antennas

This paper investigates the potential of using spray coating as a methodology for flexible antenna fabrication. The methodology has advantages compared with other antenna-printing techniques, such as screen-printing and gravure printing (more flexibility in design), or inkjet printing (faster production). The methodology is demonstrated using two different types of folded dipole antennas that are designed to operate in the ultra-high frequency radio-frequency identification (UHF RFID) band. Both antennas show good agreement between simulation and measurement of the spray-coated samples in terms of power reflection coefficient and gain. The two folded dipoles, with and without ground plane, show comparable performance in terms of gain, as similar antennas found in literature. The folded dipole on a ground plane is more stable near conductive surfaces and on the human body. Given these results, we conclude that spray coating is a good technique for printing small to medium sized batches of antennas

Additive Manufacturing for Antenna Applications

This thesis presents methods to make use of additive manufacturing (AM) or 3D printing (3DP) technology for the fabrication of antenna and electromagnetic (EM) structures. A variety of 3DP techniques based on filament, resin, powder and nano-particle inks are applied for the development and fabrication of antennas. Fully and partially metallised 3D printed EM structures are investigated for operation at mainly microwave frequency bands. First, 3D Sierpinski fractal antennas are fabricated using binder jetting printing technique, which is an AM metal powder bed process. It follows with the introduction of a new concept of sensing liquids using and non-planer electromagnetic band gap (EBG) structure is investigated. Such structure can be fabricated with inexpensive fuse filament fabrication (FFF) in combination with conductive paint. As a third method, inkjet printing technology is used for the fabrication of antennas for origami paper applications. The work investigates the feasibility of fabricating foldable antennas for disposable paper drones using low-cost inkjet printing equipment. It then explores the applicability of inkjet printing on a 3D printing substrate through the fabrication of a circularly polarised patch antenna which combines stereolithography (SLA) and inkjet printing technology, both of which use inexpensive machines. Finally, a variety of AM techniques are applied and compared for the production of a diversity WLAN antenna system for customized wrist-worn application

Design and Autonomous Stabilization of a Ballistically-Launched Multirotor

Aircraft that can launch ballistically and convert to autonomous, free-flying drones have applications in many areas such as emergency response, defense, and space exploration, where they can gather critical situational data using onboard sensors. This paper presents a ballistically-launched, autonomously-stabilizing multirotor prototype (SQUID - Streamlined Quick Unfolding Investigation Drone) with an onboard sensor suite, autonomy pipeline, and passive aerodynamic stability. We demonstrate autonomous transition from passive to vision-based, active stabilization, confirming the multirotor’s ability to autonomously stabilize after a ballistic launch in a GPS-denied environment

Design and Autonomous Stabilization of a Ballistically-Launched Multirotor

Aircraft that can launch ballistically and convert to autonomous, free-flying drones have applications in many areas such as emergency response, defense, and space exploration, where they can gather critical situational data using onboard sensors. This paper presents a ballistically-launched, autonomously-stabilizing multirotor prototype (SQUID - Streamlined Quick Unfolding Investigation Drone) with an onboard sensor suite, autonomy pipeline, and passive aerodynamic stability. We demonstrate autonomous transition from passive to vision-based, active stabilization, confirming the multirotor’s ability to autonomously stabilize after a ballistic launch in a GPS-denied environment