Homophileurus neptunus Dechambre, a new junior synonym of H. waldenfelsi Endrödi (Coleoptera: Scarabaeidae: Dynastinae: Phileurini)

Homophileurus neptunus Dechambre was found to be conspecific with H. waldenfelsi Endrödi after examination of types, descriptions, and illustrations. Accordingly, H. neptunus is placed in junior synonymy with H. waldenfelsi, new synonymy. Homophileurus waldenfelsi is an uncommon species and occurs in Ecuador, Colombia, Brazil, and Peru. Brazil and Peru are new country records

Diagnostic Efficacy of Morphological Characters of Larval \u3ci\u3eTramea Lacerata\u3c/i\u3e Hagen and \u3ci\u3eTramea Onusta\u3c/i\u3e Hagen (Odonata: Libellulidae) in the Prairie Region of Missouri

Distinguishing among species of larvae of the dragonfly genus Tramea historically has been problematic, largely due to conflicting characterizations of the larvae of T. lacerata Hagen and T. onusta Hagen (Odonata: Libellulidae) in the literature. The various systematic treatments usually focused on relative lengths of morphological characters to distinguish the species, but often contradicted one another and themselves as to what the diagnostic values actually were. We traced much of the confusion back to errors in the original larval description of T. onusta. We used morphometric analyses to determine the efficacy of previously published characterizations to distinguish between the larvae of T. lacerata and T. onusta. Previous characterizations, especially those involving relative lengths of the caudal appendages, were generally found to be inadequate for distinguishing larvae of the two species. The most reliable characteristic for distinguishing the two species was found to be the length of the epiproct relative to the length of the paraprocts

FASTER: Fast and Safe Trajectory Planner for Flights in Unknown Environments

High-speed trajectory planning through unknown environments requires algorithmic techniques that enable fast reaction times while maintaining safety as new information about the operating environment is obtained. The requirement of computational tractability typically leads to optimization problems that do not include the obstacle constraints (collision checks are done on the solutions) or use a convex decomposition of the free space and then impose an ad-hoc time allocation scheme for each interval of the trajectory. Moreover, safety guarantees are usually obtained by having a local planner that plans a trajectory with a final "stop" condition in the free-known space. However, these two decisions typically lead to slow and conservative trajectories. We propose FASTER (Fast and Safe Trajectory Planner) to overcome these issues. FASTER obtains high-speed trajectories by enabling the local planner to optimize in both the free-known and unknown spaces. Safety guarantees are ensured by always having a feasible, safe back-up trajectory in the free-known space at the start of each replanning step. Furthermore, we present a Mixed Integer Quadratic Program formulation in which the solver can choose the trajectory interval allocation, and where a time allocation heuristic is computed efficiently using the result of the previous replanning iteration. This proposed algorithm is tested extensively both in simulation and in real hardware, showing agile flights in unknown cluttered environments with velocities up to 3.6 m/s.Comment: IROS 201

Robust Adaptive Control Barrier Functions: An Adaptive & Data-Driven Approach to Safety (Extended Version)

A new framework is developed for control of constrained nonlinear systems with structured parametric uncertainties. Forward invariance of a safe set is achieved through online parameter adaptation and data-driven model estimation. The new adaptive data-driven safety paradigm is merged with a recent adaptive control algorithm for systems nominally contracting in closed-loop. This unification is more general than other safety controllers as closed-loop contraction does not require the system be invertible or in a particular form. Additionally, the approach is less expensive than nonlinear model predictive control as it does not require a full desired trajectory, but rather only a desired terminal state. The approach is illustrated on the pitch dynamics of an aircraft with uncertain nonlinear aerodynamics.Comment: Added aCBF non-Lipschitz example and discussion on approach implementatio