Brandon Stark

ADS-B for small Unmanned Aerial Systems: Case study and regulatory practices

Sense and Avoid Systems (SAASs) are one of the last technical challenges for the safe integration of Unmanned Aerial Systems (UASs) into the U.S. National Airspace System (NAS). While military applications still dominate UAS use, civilian UAS usage is expected to grow dramatically over the next several years. However with this growth, there are significant air safety concerns. SAASs have been proposed as potential solutions for air traffic collisions and obstacle avoidance, but the technical implementations have been largely unsatisfactory. The development of the Next Generation Air Transportation System (NextGen) surveillance tracking technology known as Automatic Dependent Surveillance-Broadcast (ADS-B) has been proposed as one of the potential solutions. This technology, mandated to be in all aircraft by 2020, is designed to improve situational awareness for pilots and improve air traffic management but may also be utilized by UASs. However there remains implementation issues and regulatory issues, especially for small UASs (SUASs) that are expected to be used significantly by civilian operators. This paper examines the use of ADS-B in future SAASs and their implementations in SUAS for domestic use.

A payload verification and management framework for small UAV-based personal remote sensing systems

Small, unmanned aerial systems are becoming more important in many fields, including civilian, scientific applications. Affordable systems that allow remote sensing at a small scale-personal remote sensing-are possible with proper system design. To assure data mission success (i.e., reliable and safe data collection) with low-cost or consumer-level sensor hardware, a well-designed payload management system is needed, along with sensor interface development and standardized testing frameworks for verification. This payload management system ensures a level of airworthiness for Data Mission Assurance. This paper presents such a system, along with motivations and choices such as system architecture and implementation, as well as standardized testing and verification. Data results from flight of a fixed-wing example payload is also included.

A detailed field study of direct correlations between ground truth crop water stress and normalized difference vegetation index (NDVI) from small unmanned aerial system (sUAS)

Aerial images with high spatial resolution and high temporal resolution were used to detect water stress based on canopy level normalized difference vegetation index (NDVI). We attempted to determine the correlation between stem water potential (SWP) and canopy NDVI with and without shade. Results indicated that removing the shade from the canopy improved the correlation between the NDVI of canopy and SWP with coefficient of determination (R2) from 0.001 to 0.0052. We further compared SWP and the NDVI of the canopy without shade over a period of one week to four weeks. The correlation between NDVI with SWP was highest in the time range of three weeks. However, both cases show that there is no obvious relationship between NDVI of canopy and SWP. Therefore, canopy level NDVI does not indicate water stress. Further research is needed beyond pretty pictures.

Take-Home Mechatronics Control Labs: A Low-Cost Personal Solution and Educational Assessment

Control theory, once described as the “Physics of the 21st Century,” is pervading to almost all subjects of higher learning. However, it is a difficult topic for many students, especially when introduced at the undergraduate lower level. Providing hands-on experience is often a great aid for teaching difficult concepts, but for control theory forcing a hands-on component can distract from the learning if the students are unprepared. An effective control theory laboratory curriculum builds on the foundations of statics and dynamics, circuit theory, signal processing and programming course-work. However, undergraduate students have a limited educational experience and are typically lacking in one or more of those foundations. Coupled with the unfamiliarity of the common equipment found in teaching labs, students often find themselves overwhelmed and struggle with the setups, limiting their exposure to the topic of control theory. Some industry and education companies have introduced extensive control workstations to bring integrated control theory to a teaching laboratory; however these systems are expensive and specialized, limiting their reach and effectiveness. In this paper, a low-cost mechatronics control theory personal laboratory setup with a proposed curriculum is developed for undergraduate students that addresses their uncertain foundation and improves accessibility by introducing portability to maximize the learning outcomes.Copyright

Survey of Thermal Infrared Remote Sensing for Unmanned Aerial Systems

As Unmanned Aerial System (UAS) technology matures, the list of potential civilian applications continues to grow substantially. Currently, the majority of applications are centered around providing optical imagery, either in real-time video or high resolution mapping. But as more sophisticated applications are desired, the limitations of simple imagery are becoming more evident, especially for precision agricultural applications. However, recent advancements in UAS based precision agriculture have demonstrated the effectiveness of including thermal infrared (TIR) cameras. In many situations, decision support indicators are evident in the TIR spectrum, whereas they are undetectable in the visible light and near-infrared spectrum. In this paper, a survey of some of the applications under development utilizing TIR imagery is presented along with implementation strategies to provide guidance for researchers wishing to add TIR imagery into their applications.

Dynamic flight modeling of a multi-mode flying wing quadrotor aircraft

As the demand for versatile and efficient aerial vehicles increases, the limits of current aerial vehicles become more apparent. There is a necessity for autonomous unmanned aerial vehicles (UAVs) which can execute tasks that no manned aircraft has the ability to perform. This paper focuses on vertical take off and landing (VTOL) hybrids, a category of UAVs that encompasses features from both VTOL rotorcraft and fixed-wing aircraft. While there is a multitude of unique UAVs that can perform specific tasks, an effective autonomous UAV is one that retains the versatility of VTOL and the efficiency of a winged aircraft. The research presented demonstrates the navigation, guidance, and transition modeling of a VTOL hybrid. The research presented focuses heavily on the future of navigation models concerning this vehicle, where the full potential of a VTOL hybrid will be most useful in real world situations. The models developed are low fidelity to focus on the development of a navigation algorithm.

Concept of Operations for Personal Remote Sensing Unmanned Aerial Systems

Unmanned Aerial Systems (UASs) have rapidly grown into a significant part of the world-wide aviation budget. However, regulations and official standards have lagged significantly. Within the U.S., there has been significant pressure to develop the regulations to allow commercial and governmental agencies to utilize UASs within the National Airspace System (NAS). The authors propose a concept of operation document that incorporates existing regulations and ensures an acceptable level of performance based on experience with a Personal Remote Sensing (PRS) Unmanned Aerial System (UAS).

An analysis of the effect of the bidirectional reflectance distribution function on remote sensing imagery accuracy from Small Unmanned Aircraft Systems

Small Unmanned Aircraft Systems (SUASs) are increasingly being utilized for remote sensing applications due to their low-cost availability and potential for the collection of high-resolution on-demand aerial imagery. However, the field is still maturing, and there remains many questions on the accuracy and the validity of the data collected. While many researchers have investigated means of improving calibrations and data collection techniques, there are other sources of error that require investigation. In this paper, two unique characteristics of SUAS remote sensing are analyzed as potential sources of error: the use of wide field-of-view (FOV) imaging sensors and solar motion during one or more data collection flights. Both of these characteristics are related to the bidirectional reflectance distribution function (BRDF), a description of light reflection as a function of illumination direction and observer viewing angles. The wide FOV of many imaging equipment creates an inherent radial variation in viewing angle, and the solar motion creates a non-static illumination source. The results of this paper indicates that these two factors have significant contributions to errors and should not be assumed to be negligible.

Design, Modeling and Validation of a T-Tail Unmanned Aerial Vehicle

This paper addresses the design and modeling process of a T-tail unmanned aerial vehicle (UAV). A methodology is presented of how to make tradeoffs among the payload requirements, energy efficiency and aerodynamic stability. A linear decoupled model of longitudinal and lateral dynamics is abstracted from a physical airframe. Instead of subjectively estimating the order, error and time delay for system identification (system ID), equations of motion derived from aerodynamics are employed to provide more precise estimation of the model structure. System ID is carried out with regard to the flight data collected by the autopilot data logger. The resulted model is refined based on the simulation and comparison.

Optimal pest management by networked unmanned cropdusters in precision agriculture: A cyber-physical system approach

Abstract Unmanned Aerial Systems (UASs) are expected to see the largest application within the agricultural market. These versatile platforms have shown promise ushering in the next wave of precision agriculture. While remote sensing applications have been well documented and developed, there remains significant advances left to be made in improving the use of UASs for precision application of pesticides. Although the current mode of aerial spraying or application of pesticides within the U.S. is done using full-sized aircraft, future implementations for autonomous crop dusting are likely to utilize small unmanned aircraft systems (SUASs) due to their much lower cost and ease of use. However, these smaller platforms have limited payload capacities, thus the development of cooperative swarms of SUASs is necessary. In this paper, a swarm of cooperative SUASs are utilized within a cyber-physical system framework to optimize the use of pesticides with precision spraying. Through the use of Centroid Voronoi Tessellation, the swarm makes the most efficient use of pesticides to attack an invasive pathogen. Simulation results are presented to validate the performance of the proposed method.