Onboard Decision-Making for Nominal and Contingency sUAS Flight

This study presents an onboard decision-making architecture for small unmanned aerial systems (sUAS). The decision-maker is part of NASA's SAFE50 project that is working under the UAS Traffic Management (UTM) Technical Capability Level (TCL) 4 to provide autonomous point-to-point UAV flight in BVLOS, high-density urban environments. The decision-maker monitors various metrics to determine the safety and feasibility of the mission and categorizes flight states as Nominal, Off-Nominal, Alternate Land, and Land Now in a finite state machine. Changes in the monitored metrics serve as transitions in the state machine and trigger replanning. Navigation degradation and communication failure are simulated to show the feasibility of the decision-maker framework in appropriately switching the flight state

Fuzzy Attitude Control of Solar Sail

This study presents various fuzzy type controllers for a solar sail. First, a Twin Parallel Distributed Compensator (TPDC) is built for a Takagi-Sugeno fuzzy model of the solarsail. The T-S fuzzy model is constructed by linearizing the existing nonlinear equations fo motion of the solar sail. The T-S fuzzy model is used to solve a set of linear matrix inequalities to derive state feedback controller gains. The TPDC controls the solar sail using a combination of reaction wheels and roll stabilizer bars for attitude control and trim masses for disturbance rejection. The TPDC tracks and stabilizes the solar sail to any desired state in the presence of parameter uncertainties and external disturbances while satisfying actuator constraints. The performance of the TPDC is compared to a Ziegler-Nichols tuned proportional-integral-derivative (PID) controller. Numerical simulation shows the TPDC outperforms he PID controller when stabilizing the solar sail to a desired state. When compared to the particle swarm optimized PID controller, the TPDC has a slower response, irrespective of the initial conditions and desired states. To control the solar sail using trim masses, a hybrid fuzzy-logic supervisor with a PID attitude controller is built. Particle swarm optimization is also used to obtain gains for roll, pitch and yaw PID controllers. The calculated PID gains are used to build a fuzzy supervisor that tunes the PID controller gains based on the Euler angle error and error rate. The proposed PID controller stabilizes the solar sail about any commanded input from any initial condition. The supervisory fuzzy PID controller is shown to be robust model uncertainties and outperforms a particle swarm optimized PID controller when stabilized about a non-optimal state from a non-optimal initial condition

Vehicle to Vehicle (V2V) Communication for Collision Avoidance for Multi-Copters Flying in UTM -TCL4

NASAs UAS Traffic management (UTM) research initiative is aimed at identifying requirements for safe autonomous operations of UAS operating in dense urban environments. For complete autonomous operations vehicle to vehicle (V2V) communications has been identified as an essential tool. In this paper we simulate a complete urban operations in an high fidelity simulation environment. We design a V2V communication protocol and all the vehicles participating communicate over this system. We show how V2V communication can be used for finding feasible, collision-free paths for multi agent systems. Different collision avoidance schemes are explored and an end to end simulation study shows the use of V2V communication for UTM TCL4 deployment

Automated in-row weed trimmer

The Automated In-Row Weed Trimmer, or AIRWT, is a weed removal system designed to be used in vineyards in order to enable safe and e cient removal of weeds while preventing damage to the vines. The goal of the system is to reduce the need for the use of manual labor and herbicides while improving production rates of grapes by automating the weed removal process at vineyards. By implementing an automated system for weed removal, the team aims to resolve ethical issues in food production, primarily those surrounding human labor, environmental friendliness, and social sustainability. The focus of this report is to explore in depth the AIRWT system concept as well as its subsystems, in addition to reviewing its product development cycle

Protein Degradation via CRL4^CRBN Ubiquitin Ligase: Discovery and Structure–Activity Relationships of Novel Glutarimide Analogs That Promote Degradation of Aiolos and/or GSPT1

We previously disclosed the identification of cereblon modulator <b>3</b> (CC-885), with potent antitumor activity mediated through the degradation of GSPT1. We describe herein the structure–activity relationships for analogs of <b>3</b> with exploration of the structurally related dioxoisoindoline class. The observed activity of protein degradation could in part be rationalized through docking into the previously disclosed <b>3</b>–CRBN–GSPT1 cocrystal ternary complex. For SAR that could not be rationalized through the cocrystal complex, we sought to predict SAR through a QSAR model developed in house. Through these analyses, selective protein degradation could be achieved between the two proteins of interest, GSPT1 and Aiolos