Autonomous system (mathematics)

About: Autonomous system (mathematics) is a research topic. Over the lifetime, 1648 publications have been published within this topic receiving 38373 citations.

Chaos in an anharmonic oscillator

Abstract: Using Melnikov's method, the existence of chaotic behaviour in the sense of Smale in a particular time-periodically perturbed planar autonomous system of ordinary differential equations is established. Examples of planar autonomous differential systems with homoclinic orbits are provided, and an application to the dynamics of a one-dimensional anharmonic oscillator is given.

Navigation and learning experiments by an autonomous robot

Abstract: Developing an autonomous mobile robot capable of navigation, surveillance and manipulation in complex and dynamic environments is a key research activity at CESAR, Oak Ridge National Laboratory's Center for Engineering Systems Advanced Research. The latest series of completed experiments was performed using the autonomous mobile robot HERMIES-IIB ( H ostile E nvironment R obotic I ntelligence E xperiment Series II-B).

Suitable Strategies for In-plane Orbit Acquisition using Micro-thrusters

Abstract: The deviations in the injection orbital parameters, resulting from launcher dispersions, need to be corrected through a set of acquisition maneuvers to achieve the desired nominal parameters. When multiple satellites are injected into a single orbital plane, as a part of constellation establishment, they have to positioned in the plane with appropriate semi-major axis ‘a’ and mean anomaly ‘M’. In this paper, three strategies are studied for achieving orbit acquisition. The first strategy is by deriving an analogy to the Linear Quadratic Regulator (LQR). The state dynamics and the control law are of the form U X X B A + = & and X U K − = . The feedback gain K is calculated by minimizing the cost function. Under this strategy the thrust (N) and velocity increment ( V ∆ ) are functions of time and only the matrix K needs to be up-linked. Any revision in the current or the target states, will then lead to a simple re-calculation of K and up-linking them. The second strategy assumes that V ∆ is same for each maneuver and calculates the number of maneuvers and the V ∆ required for each maneuver. If the maneuvers are stopped for reasons like orbit assessment, and thruster performance evaluation, the strategy can be restarted easily without having any penalty on the overall V ∆ . Besides these two strategies, a third strategy based on the application of Fuzzy Modified Potential Function is also studied for autonomous orbit acquisition with constraints in the path. By adding Fuzzy logic to the potential function it is shown that, maneuvers can be changed gradually ahead of the constraints. Onboard implementation related aspects are also briefly addressed for all the strategies. Introduction Due to the increasing cost of the ground operations, worldwide interest is towards autonomy in spacecraft operations. Thanks to the recent advances in VLSI and MEMS technologies, onboard autonomy is becoming a reality. Missions like PROBA (Project for Onboard Autonomy), as the name suggests, are aimed at demonstrating the autonomous operations in space. A fully autonomous system would make use measurements that are from passive sources and carryout estimation and control with no dependence on ground systems. The autonomy could be in terms of house keeping operations, attitude control and finally orbit control and maintenance. Autonomous orbit control or maintenance is a mission critical operation as it involves fuel expenditure and any unexpected anomaly can lead to mission catastrophes. Any autonomous orbit correction strategy should therefore have very small corrections at each step and be able to revise the strategy with minimal cost on the total fuel. Besides the advances in technology, many launchers are now offering piggyback launches for micro and nano-satellites. This has enabled many academic institutions to take up design and development of small satellites. Towards

An introduction to linear differential systems with the aid of personal computers

Abstract: Linear systems of ordinary differential equations are a basic topic in the mathematical background of an engineer. In this paper we present an interactive program about planar linear systems, which runs on a personal computer. In particular, the concepts of phase space and stability of equilibrium are emphasized.

A Framework for Designing Autonomous Parallel Data Warehouses.

Abstract: Parallel data platforms are recognized as a key solution for processing analytical queries running on extremely large data warehouses (DWs). Deploying a DW on such platforms requires efficient data partitioning and allocation techniques. Most of these techniques assume a priori knowledge of workload. To deal with their evolution, reactive strategies are mainly used. The BI 2.0 requirements have put large batch and ad-hoc user queries at the center. Consequently, reactive-based solutions for deploying a DW in parallel platforms are not sufficient. Autonomous computing has emerged as a paradigm that allows digital objects managing themselves in accordance with high-level guidance by the means of proactive approaches. Being inspired by this paradigm, we propose in this paper, a proactive approach based on a query clustering model to deploying a DW over a parallel platform. The query clustering triggers partitioning and allocation processes by considering only evolved query groups. Intensive experiments were conducted to show the efficiency of our proposal.