Planning & Scheduling
Video Friday: Deep Learning for Cars, Space Invaders With Drones, and Disagreeable Robot
Video Friday is your weekly selection of awesome robotics videos, collected by your Automaton bloggers. We'll also be posting a weekly calendar of upcoming robotics events for the next two months; here's what we have so far (send us your events!): Let us know if you have suggestions for next week, and enjoy today's videos. Here's a taste of what's to come: In contrast to the usual approach to operating self-driving cars, we did not program any explicit object detection, mapping, path planning or control components into this car. Instead, the car learns on its own to create all necessary internal representations necessary to steer, simply by observing human drivers.
Informative Planning and Online Learning with Sparse Gaussian Processes
Ma, Kai-Chieh, Liu, Lantao, Sukhatme, Gaurav S.
A big challenge in environmental monitoring is the spatiotemporal variation of the phenomena to be observed. To enable persistent sensing and estimation in such a setting, it is beneficial to have a time-varying underlying environmental model. Here we present a planning and learning method that enables an autonomous marine vehicle to perform persistent ocean monitoring tasks by learning and refining an environmental model. To alleviate the computational bottleneck caused by large-scale data accumulated, we propose a framework that iterates between a planning component aimed at collecting the most information-rich data, and a sparse Gaussian Process learning component where the environmental model and hyperparameters are learned online by taking advantage of only a subset of data that provides the greatest contribution. Our simulations with ground-truth ocean data shows that the proposed method is both accurate and efficient.
Optimal Partial-Order Plan Relaxation via MaxSAT
Muise, Christian, Beck, J. Christopher, McIlraith, Sheila A.
Partial-order plans (POPs) are attractive because of their least-commitment nature, which provides enhanced plan flexibility at execution time relative to sequential plans. Current research on automated plan generation focuses on producing sequential plans, despite the appeal of POPs. In this paper we examine POP generation by relaxing or modifying the action orderings of a sequential plan to optimize for plan criteria that promote flexibility. Our approach relies on a novel partial weighted MaxSAT encoding of a sequential plan that supports the minimization of deordering or reordering of actions. Using a similar technique, we further demonstrate how to remove redundant actions from the plan, and how to combine this criterion with the objective of maximizing a POP's flexibility. Our partial weighted MaxSAT encoding allows us to compute a POP from a sequential plan effectively. We compare the efficiency of our approach to previous methods for POP generation via sequential-plan relaxation. Our results show that while an existing heuristic approach consistently produces the optimal deordering of a sequential plan, our approach has greater flexibility when we consider reordering the actions in the plan while also providing a guarantee of optimality. We also investigate and confirm the accuracy of the standard flex metric typically used to predict the true flexibility of a POP as measured by the number of linearizations it represents.
Functions Required for an Advanced Dynamic AI Scheduling System
A small and extremely powerful Artificial Intelligent Dynamic Scheduling System needs to schedule like a human by using the same required types and complexity as a human. This engine schedules movable components and items where a component or item can change location over time. A trainer trains the engine using specific scheduling tasks and scheduling requirements. After the engine is trained the engine identifies each component and item to schedule. Training provides the engine with the knowledge needed to properly schedule.
The IBaCoP Planning System: Instance-Based Configured Portfolios
Cenamor, Isabel, de la Rosa, Tomás, Fernández, Fernando
Sequential planning portfolios are very powerful in exploiting the complementary strength of different automated planners. The main challenge of a portfolio planner is to define which base planners to run, to assign the running time for each planner and to decide in what order they should be carried out to optimize a planning metric. Portfolio configurations are usually derived empirically from training benchmarks and remain fixed for an evaluation phase. In this work, we create a per-instance configurable portfolio, which is able to adapt itself to every planning task. The proposed system pre-selects a group of candidate planners using a Pareto-dominance filtering approach and then it decides which planners to include and the time assigned according to predictive models. These models estimate whether a base planner will be able to solve the given problem and, if so, how long it will take. We define different portfolio strategies to combine the knowledge generated by the models. The experimental evaluation shows that the resulting portfolios provide an improvement when compared with non-informed strategies. One of the proposed portfolios was the winner of the Sequential Satisficing Track of the International Planning Competition held in 2014.
Efficient Mechanism Design for Online Scheduling
Chen, Xujin, Hu, Xiaodong, Liu, Tie-Yan, Ma, Weidong, Qin, Tao, Tang, Pingzhong, Wang, Changjun, Zheng, Bo
This paper concerns the mechanism design for online scheduling in a strategic setting. In this setting, each job is owned by a self-interested agent who may misreport the release time, deadline, length, and value of her job, while we need to determine not only the schedule of the jobs, but also the payment of each agent. We focus on the design of incentive compatible (IC) mechanisms, and study the maximization of social welfare (i.e., the aggregated value of completed jobs) by competitive analysis. We first derive two lower bounds on the competitive ratio of any deterministic IC mechanism to characterize the landscape of our research. We then propose a deterministic IC mechanism and show that such a simple mechanism works very well for both the preemption-restart model and the preemption-resume model. We show the mechanism can achieve the optimal competitive ratio of 5 for equal-length jobs and a near optimal competitive ratio (within a constant factor) for unequal-length jobs.
Astronaut John Glenn's historic flight plan sold for 67K
FILE – In this June 28, 2016, file photo, former astronaut and U.S. Sen. John Glenn, D-Ohio, right, shakes hands with 8-year-old Josh Schick, left, before an event to mark the September 2016 renaming of Port Columbus International Airport to John Glenn Columbus International Airport in Columbus, Ohio. Glenn, the first American to orbit the Earth, turned 95 on Monday, July 18, 2016, and was trending on Twitter as well-wishers recognized his birthday.
The "How Does the President's Director of Scheduling Work?" Edition
Outside of Gregory Lorjuste's office, there's a whiteboard that he updates each day in large, carefully drawn characters. On the afternoon we visited him, it read, "The Final Countdown: 189 Days," a reflection of the time remaining for the Obama administration. That constantly shrinking figure holds special importance for Lorjuste, who serves as deputy assistant to the president and director of scheduling. But they're also responsible for larger calculations, most of all for figuring out how the administration can best use the time that remains.
Normative practical reasoning via argumentation and dialogue - Opus
In a normative environment an agent's actions are not only directed by its goals but also by the norms imposed on the agent. However, the potential conflicts within and between the agent's goals and norms makes decision-making in these frameworks a challenging task. The questions we are addressing in this paper are: (i) how should an agent act in a normative environment? We propose a solution in which a normative planning problem serves as the basis for a practical reasoning approach based on argumentation. The properties of the best plan(s) with respect to goal achievement and norm compliance are mapped to arguments that are used to explain why a plan is justified, using an existing proof dialogue game.
Activity Planning for a Lunar Orbital Mission
Bresina, John L. (NASA Ames Research Center)
This article describes a challenging, real-world planning problem within the context of a NASA mission called LADEE (Lunar Atmospheric and Dust Environment Explorer). One key aspect of this approach is the design of the activity planning process based on principles of problem decomposition and planning abstraction levels. The second key aspect is the mixed-initiative system developed for this task, called LASS (LADEE Activity Scheduling System). The primary challenge for LASS was representing and managing the science constraints that were tied to key points in the spacecraft's orbit, given their dynamic nature due to the continually updated orbit determination solution.