publications

2023

1. USPTO

   Spatiotemporal controller for controlling robot operations

   J.W. Dinius, B.K. Pennington, R.C. Voorhies, and 2 more authors

   2023

   U.S. Patent

   Abs

   A robot may include a spatiotemporal controller for controlling the kinematics or movements of the robot via continuous and/or granular adjustments to the actuators that perform the physical operations of the robot. The spatiotemporal controller may continuously and/or granularly adjust the actuators to align completion or execution of different objectives or waypoints from a spatiotemporal plan within time intervals allotted for each objective by the spatiotemporal plan. The spatiotemporal controller may also continuously and/or granularly adjust the actuators to workaround unexpected conflicts that may arise during the execution of an objective and delays that result from a workaround while still completing the objective within the allotted time interval. By completing objectives within the allotted time intervals, the spatiotemporal controller may ensure that conflicts do not arise as the robots simultaneously operate in the site using some of the same shared resource.

2018

1. arXiv

   PythonRobotics: a Python code collection of robotics algorithms

   A. Sakai, D. Ingram, J. Dinius, and 3 more authors

   ArXiv e-prints, Aug 2018

   Abs

   This paper describes an Open Source Software (OSS) project: PythonRobotics. This is a collection of robotics algorithms implemented in the Python programming language. The focus of the project is on autonomous navigation, and the goal is for beginners in robotics to understand the basic ideas behind each algorithm. In this project, the algorithms which are practical and widely used in both academia and industry are selected. Each sample code is written in Python3 and only depends on some standard modules for readability and ease of use. It includes intuitive animations to understand the behavior of the simulation.

2014

1. Dynamical Properties of a Generalized Collision Rule for Multi-Particle Systems

   Joseph Dinius

   Aug 2014

   Abs

   The theoretical basis for the Lyapunov exponents of continuous- and discrete-time dynamical systems is developed, with the inclusion of the statement and proof of the Multiplicative Ergodic Theorem of Oseledec. The numerical challenges and algorithms to approximate Lyapunov exponents and vectors are described, with multiple illustrative examples. A novel generalized impulsive collision rule is derived for particle systems interacting pairwise. This collision rule is constructed to address the question of whether or not the quantitative measures of chaos (e.g. Lyapunov exponents and Kolmogorov-Sinai entropy) can be reduced in these systems. Major results from previous studies of hard-disk systems, which interact via elastic collisions, are summarized and used as a framework for the study of the generalized collision rule. Numerical comparisons between the elastic and new generalized rules reveal many qualitatively different features between the two rules. Chaos reduction in the new rule through appropriate parameter choice is demonstrated, but not without affecting the structural properties of the Lyapunov spectra (e.g. symmetry and conjugate-pairing) and of the tangent space decomposition (e.g. hyperbolicity and domination of the Oseledec splitting). A novel measure of the degree of domination of the Oseledec splitting is developed for assessing the impact of fluctuations in the local Lyapunov exponents on the observation of coherent structures in perturbation vectors corresponding to slowly growing (or contracting) modes. The qualitatively different features observed between the dynamics of generalized and elastic collisions are discussed in the context of numerical simulations. Source code and complete descriptions for the simulation models used are provided.

2. AAS

   Near optimal feedback guidance design and the planar restricted three-body problem

   Joseph Dinius, Roberto Furfaro, Francesco Topputo, and 1 more author

   Aug 2014

   Abs

   In this paper, we present the application of the ZEM/ZEV guidance algorithm to the planar restricted three-body problem (PR3BP). The ZEM/ZEV guidance law as a feedback guidance strategy is presented and applied to the PR3BP. The fuel optimal solution to the PR3BP for a transfer from GTO to L1 in the Earth-Moon system is presented as a point for comparison, showing the near optimality of the closed-loop guidance approach. Challenges of the approach and strategies for implementation in spacecraft mission design are discussed.