Estimating Dynamics On-the-Fly Using Monocular Video

2011 ◽  
Author(s):  
Priyanshu Agarwal ◽  
Suren Kumar ◽  
Jason J. Corso ◽  
Venkat Krovi
Keyword(s):  
Physical System ◽  
Sequential Optimization ◽  
Physical Parameters ◽  
Double Pendulum ◽  
Equivalent System ◽  
Pendulum System ◽  
System Parameters ◽  
Optimization Framework ◽  
Video Images ◽  
Monocular Image

We present an optimization framework to help estimate on-the-fly both the motion and physical parameters of an articulated multibody system using uncalibrated monocular image sequences. The algorithm takes video images of a physical system as input and estimates the motion together with the physical system parameters, given only the underlying articulated model topology. A valid initial pose of the system is found using a sequential optimization framework and used to bootstrap the successive pose estimation as well as estimation of physical system parameters (kinematic/geometric lengths as well as mass, inertia, damping coefficients). We also address the issue of robustly estimating a dynamically-equivalent system using partial state information (solely from noisy visual observations) and without explicit inertial parameter information. This framework results in a robust dynamically-equivalent system with good predictive capabilities when tested on a double pendulum system.

scholarly journals Sector search strategies for odor trail tracking

2021 ◽  
Author(s):  
Gautam Reddy ◽  
Boris I. Shraiman ◽  
Massimo Vergassola
Keyword(s):  
Close Contact ◽  
Sequential Optimization ◽  
Odor Trail ◽  
Optimization Framework ◽  
Behavioral Paradigm ◽  
Scent Trails ◽  
Loss Of Contact ◽  
Tracking Behavior ◽  
Geometric Elements ◽  
Unified Description

Terrestrial animals such as ants, mice and dogs often use surface-bound scent trails to establish navigation routes or to find food and mates, yet their tracking strategies are poorly understood. Tracking behavior features zig-zagging paths with animals often staying in close contact with the trail. Upon sustained loss of contact, animals execute a characteristic sequence of sweeping “casts” – wide oscillations with increasing amplitude. Here, we provide a unified description of trail-tracking behavior by introducing an optimization framework where animals search in the angular sector defined by their estimate of the trail’s heading and its uncertainty.In silicoexperiments using reinforcement learning based on this hypothesis recapitulate experimentally observed tracking patterns. We show that search geometry imposes limits on the tracking speed, and quantify its dependence on trail statistics and memory of past contacts. By formulating trail-tracking as a Bellman-type sequential optimization problem, we quantify the basic geometric elements of optimal sector search strategy, effectively explaining why and when casting is necessary. We propose a set of experiments to infer how tracking animals acquire, integrate and respond to past information on the tracked trail. More generally, we define navigational strategies relevant for animals and bio-mimetic robots, and formulate trail-tracking as a novel behavioral paradigm for learning, memory and planning.

Advanced modeling and optimal control of a cart-double pendulum system

2019 ◽  
Author(s):  
◽  
Cecil Jr. Shy
Keyword(s):  
Optimal Control ◽  
Lagrange Equation ◽  
Control Technique ◽  
Tuning Parameter ◽  
Microgravity Environment ◽  
Double Pendulum ◽  
Overhead Crane ◽  
Material Transport ◽  
Pendulum System ◽  
Industry Standards

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The Overhead Crane has evolved in scope since its inception in the late 1800's. Its early use as a hoist for material transport is now proceeded by new found applications, such as in the Active Response Gravity Offload System (ARGOS) at the NASA Johnson Space Center. ARGOS is an astronaut training facility designed to simulate reduced gravity environments such as Lunar, Martian, or microgravity. By industry standards, it is essentially a repurposed Overhead Crane; in academia it can be conceptualized as a cart-double pendulum system. Anti-sway control of cart-pendulum systems has been heavily researched; however, these methods are not typically designed for space simulation. The goal of this research is to design a controller that provides both energy and error minimization for the cart-pendulum, so that its payload moves as if it were floating freely in a microgravity environment (according to Newton's 1st law). The Euler-Lagrange equation is used to model the system and an optimal control technique called the [alpha]-shift is used to control the system. Most treatments on optimal linear control do not include the [alpha]-shift, but its addition allows one to stabilize the system faster and provides an extra tuning parameter while maintaining the simplicity of the solution. Numerical experiments show that the [alpha]-shift method significantly improves the cart-pendulum's ability to control its payload; especially for payloads in the cart-double-pendulum case.

The Psychology of Opioid Tapering

2021 ◽  
pp. 231-250
Author(s):  
Daniel M. Doleys ◽  
Nicholas D. Doleys
Keyword(s):  
Chronic Pain ◽  
Physical System ◽  
Evidence Based ◽  
Double Pendulum ◽  
The Future ◽  
Opioid Tapering ◽  
The Individual ◽  
Evidence Based Guidelines ◽  
Existing Data ◽  
The Way

The pendulum has swung; in this case, it may be a double pendulum. The double pendulum is a pendulum hanging from a pendulum. It is a simple physical system used in physics to demonstrate mathematical chaos. When the motion of its tip is monitored, it appears very predictable at the outset, but soon reveals a very chaotic and unpredictable pattern. It is very difficult to know where the tip of the double pendulum will be at any given time in the future. This seems to describe the course of the use of opioids, especially for the treatment of chronic pain. Once, all but ignored, then heralded, and then demonized. At every step of the way, pundits will argue the incompleteness, absence, or misinterpretation of existing data. It is important to understand the psychological environment is which the opioid tapering movement occurs and to carefully consider the process in the context of the individual patient. Simply instituting another set of presumptive evidence-based guidelines could have unforeseen, and potentially tragic, consequences for the patient.

Fractal Basin Boundaries and Chaotic Motions in Spring-Pendulum System

2003 ◽  
Author(s):  
Aria Alasty ◽  
Rasool Shabani
Keyword(s):  
Numerical Simulations ◽  
Multiple Scales ◽  
Basins Of Attraction ◽  
Chaotic Attractors ◽  
Global Behavior ◽  
Chaotic Motions ◽  
Pendulum System ◽  
Fractal Basin Boundaries ◽  
System Parameters ◽  
Basin Boundaries

This study investigates chaotic response in the spring-pendulum system. In this system beside of strange attractors, multiple regular attractors may coexist for some values of system parameters, where it is important to study the global behavior of the system using the basin boundaries of the attractors. Multiple scales method is used to distinguish the regions of stable and unstable attractors. In unstable regions, bifurcation diagram and poincare´ maps are used to study the existence of quasi-periodic and chaotic attractors. Results show that the jumping phenomena may occur when multiple regular attractors exist and for this case fractal basins of attraction are developed using numerical simulations.

scholarly journals Genetic-based optimization of a multi insulator tunneling diode for THz energy harvesting

2020 ◽  
Vol 7 (1) ◽  
pp. 60-64
Author(s):  
Mazen Shanawani ◽  
Diego Masotti ◽  
Alessandra Costanzo
Keyword(s):  
Energy Harvesting ◽  
Physical Parameters ◽  
Dynamic Resistance ◽  
Figures Of Merit ◽  
Tunneling Diodes ◽  
Optimization Framework ◽  
Tunneling Diode ◽  
Current Voltage ◽  
The Impact ◽  
Current Voltage Relation

AbstractThe deployment of multi-insulator tunneling diodes has recently had more attention to be used as rectifiers in energy harvesting rectennas with good potentiality for a millimeter and terahertz range. However, with the rather complicated math to obtain the current–voltage relation, it is difficult to evaluate the design figures of merit (FOM)s such as asymmetry, nonlinearity, responsivity, and dynamic resistance and monitor the impact of changing physical parameters on them. This complicates the decision-making process for the required physical parameters. In this work, a heuristic optimization framework using genetic algorithm is suggested using the transfer matrix method to find the combination of physical parameters which satisfies the minimum required FOM set by users and weighted by their preference.

Numerical Location of Painlevé Paradox-Associated Jam and Lift-Off in a Double-Pendulum Mechanism

2017 ◽  
Vol 12 (6) ◽  
Author(s):  
Shane J. Burns ◽  
Petri T. Piiroinen
Keyword(s):  
Numerical Simulation ◽  
Mechanical System ◽  
Coefficient Of Friction ◽  
Double Pendulum ◽  
Painlevé Paradox ◽  
Forward Solution ◽  
Pendulum System ◽  
Graphical Technique ◽  
Lift Off

In this article, we will introduce the phenomenon known as the Painlevé paradox and further discuss the associated coupled phenomena, jam and lift-off. We analyze under what conditions the Painlevé paradox can occur for a general two-body collision using a framework that can be easily used with a variety of impact laws, however, in order to visualize jam and lift-off in a numerical simulation, we choose to use a recently developed energetic impact law as it is capable of achieving a unique forward solution in time. Further, we will use this framework to derive the criteria under which the Painlevé paradox can occur in a forced double-pendulum mechanical system. First, using a graphical technique, we will show that it is possible to achieve the Painlevé paradox for relatively low coefficient of friction values, and second we will use the energetic impact law to numerically show the occurrence of the Painlevé paradox in the double-pendulum system.

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