Development of a Self-Orienting CubeSat Solar Array

The sponsor of this conceptual design project was the Air Force Institute of Technology (AFIT) at WrightPatterson Air Force Base in Dayton, Ohio. AFIT was striving to give CubeSats more capability to conduct research, reconnaissance, and other functions. One of the major barriers for AFIT to overcome to give CubeSats more capability was the ability of the CubeSat to generate usable power while in orbit. All of AFIT’s CubeSats generated the power needed while in orbit with solar panels that are rigidly mounted to the outside of the craft. AFIT believes that a new design for the solar array used on the CubeSat will generate the power needed to increase their capabilities. The design that was deemed the most appropriate at the conclusion of this stage of the project was a design for a two degree of freedom mechanism that is attached to the solar panels to better orient them towards the sun. There are three aspects of the new design coming from this project that will make it unique. 1) Draws no direct power from the CubeSat Energy Storage to perform the movement. 2) Takes up less space on the CubeSat than competing designs. 3) Takes up less of the weight limit of the CubeSat than competing designs. The new Solar Array design should be able to orient four times more solar panel area towards the sun, as compared to the current AFIT design. There will be between 3 to 4 times more energy generation from the new design of solar array as a result, and an increase in the capabilities of the CubeSats

A Synthesis of Automated Planning and Model Predictive Control Techniques and its Use in Solving Urban Traffic Control Problem

Most desired applications for planning and scheduling typically have the characteristics of a continuous changing world. Unfortunately, traditional classical planning does not possess this characteristic. This drawback is because most real-world situations involve quantities and numeric values, which cannot be adequately represented in classical planning. Continuous planning in domains that are represented with rich notations is still a great challenge for AI. For instance, changes occurring due to fuel consumption, continuous movement, or environmental conditions may not be adequately modelled through instantaneous or even durative actions; rather these require modelling as continuously changing processes. The development of planning tools that can reason with domains involving continuous and complex numeric fluents would facilitate the integration of automated planning in the design and development of complex application models to solve real world problems. Traditional urban traffic control (UTC) approaches are still not very efficient during unforeseen situations such as road incidents when changes in traffic are requested in a short time interval. For such anomalies, we need systems that can plan and act effectively in order to restore an unexpected road traffic situation into a normal order. In the quest to improve reasoning with continuous process within the UTC domain, we investigate the role of Model Predictive Control (MPC) approach to planning in the presence of mixed discrete and continuous state variables within a UTC problem. We explore this control approach and show how it can be embedded into existing, modern AI Planning technology. This approach preserves the many advantages of the AI Planning approach, to do with domain independence through declarative modelling, and explicit reasoning while leveraging the capability of MPC to deal with continuous processes. We evaluate the possibility of reasoning with the knowledge of UTC structures to optimise traffic flow in situations where a given road within a network of roads becomes unavailable due to unexpected situations such as road accidents. We specify how to augment the standard AI planning engine with the incorporation of MPC techniques into the central reasoning process of a continuous domain. This approach effectively utilises the strengths of search-based and model-simulation-based methods. We create a representation that can be used to capture declaratively, the definitions of processes, actions, events, resources resumption and the structure of the environment in a UTC scenario. This representation is founded on world states modelled by mixed discrete and continuous state variables. We create a planner with a hybrid algorithm, called UTCPLAN that combines both AI planning and MPC approach to reason with traffic network and control traffic signal at junctions within the network. The experimental objective of minimising the number of vehicles in a queue is implemented to validate the applicability and effectiveness of the algorithm. We present an experimental evaluation showing that our approach can provide UTC plans in a reasonable time. The result also shows that the UTCPLAN approach can perform well in dealing with heavy traffic congestion problems, which might result from heavy traffic flow during rush hours

Planning Solar Array Operations on the International Space Station

Flight controllers manage the orientation and modes of eight large solar arrays that power the International Space Station (ISS). The task requires generating plans that balance complex constraints and preferences. These considerations include context-dependent constraints on viable solar array configurations, temporal limits on transitions between configurations, and preferences on which considerations have priority. The Solar Array Constraint Engine (SACE) treats this operations planning problem as a sequence of tractable constrained optimization problems. SACE uses constraint management and automated planning capabilities to reason about the constraints, to find optimal array configurations subject to these constraints and solution preferences, and to automatically generate solar array operations plans

Planning Solar Array Operations on the ISS

This work focuses on the problem of planning solar array operations on the International Space Station. The goal is to find a viable orientation for ten joints which attach panels to the station. These orientations and modes must satisfy various constraints and the final schedule should also take into account certain preferences. This is a task suitable for automated planning and scheduling, but new technologies are gaining very slowly in the field of the human spaceflights. In this work we will analyze the current solution of this problem and then we will propose a new algorithm that will exploit techniques of automated planning and scheduling. In the contrast with the original greedy algorithm, the suggested algorithm initially finds any solution and then tries to improve it by optimazing partial objective functions. Due to the size of the search space, the search attempts are limited by the time limit. Powered by TCPDF (www.tcpdf.org

Planning Solar Array Operations on the ISS

This work focuses on the problem of planning solar array operations on the International Space Station. The goal is to find a viable orientation for ten joints which attach panels to the station. These orientations and modes must satisfy various constraints and the final schedule should also take into account certain preferences. This is a task suitable for automated planning and scheduling, but new technologies are gaining very slowly in the field of the human spaceflights. In this work we will analyze the current solution of this problem and then we will propose a new algorithm that will exploit techniques of automated planning and scheduling. In the contrast with the original greedy algorithm, the suggested algorithm initially finds any solution and then tries to improve it by optimazing partial objective functions. Due to the size of the search space, the search attempts are limited by the time limit. Powered by TCPDF (www.tcpdf.org

Planning Solar Array Operations on the ISS

This work focuses on the problem of planning solar array operations on the International Space Station. The goal is to find a viable orientation for ten joints which attach panels to the station. These orientations and modes must satisfy various constraints and the final schedule should also take into account certain preferences. This is a task suitable for automated planning and scheduling, but new technologies are gaining very slowly in the field of the human spaceflights. In this work we will analyze the current solution of this problem and then we will propose a new algorithm that will exploit techniques of automated planning and scheduling. In the contrast with the original greedy algorithm, the suggested algorithm initially finds any solution and then tries to improve it by optimazing partial objective functions. Due to the size of the search space, the search attempts are limited by the time limit. Powered by TCPDF (www.tcpdf.org

Planning Solar Array Operations on the ISS

Práce se zabývá problémem plánování operací solárních panelů na Mezinárodní vesmírné stanici. Úkolem je nalézt vhodné orientace a módy pro deset kloubů, kterými jsou panely přichyceny ke stanici. Tyto orientace a módy musí splňovat různé podmínky a zároveň by měl výsledný rozvrh zohledňovat určité preference. Jde o úlohu vhodnou pro automatické plánování a rozvrhování, ale v oblasti pilotovaných vesmírných letů se nové technologie prosazují velmi pomalu. V práci proto bude analyzováno aktuální řešení tohoto problému a bude představen nový algoritmus, který by měl více využívat možností automatického plánování a rozvrhování. V kontrastu s původním hladovým algoritmem, navržený algoritmus nejprve nalezne libovolný rozvrh a poté se ho snaží zlepšovat optimalizováním jednotlivých částečných optimalizačních funkcí. Vzhledem k velikosti prohledávaného prostoru jsou hledání omezena časovým limitem. Powered by TCPDF (www.tcpdf.org)This work focuses on the problem of planning solar array operations on the International Space Station. The goal is to find a viable orientation for ten joints which attach panels to the station. These orientations and modes must satisfy various constraints and the final schedule should also take into account certain preferences. This is a task suitable for automated planning and scheduling, but new technologies are gaining very slowly in the field of the human spaceflights. In this work we will analyze the current solution of this problem and then we will propose a new algorithm that will exploit techniques of automated planning and scheduling. In the contrast with the original greedy algorithm, the suggested algorithm initially finds any solution and then tries to improve it by optimazing partial objective functions. Due to the size of the search space, the search attempts are limited by the time limit. Powered by TCPDF (www.tcpdf.org)Department of Theoretical Computer Science and Mathematical LogicKatedra teoretické informatiky a matematické logikyMatematicko-fyzikální fakultaFaculty of Mathematics and Physic