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Contexts for Symbiotic Autonomy: Semantic Mapping, Task Teaching and Social Robotics

AAAI Conferences

Home environments constitute a main target location where to deploy robots, which are expected to help humans in completing their tasks. However, modern robots do not meet yet user's expectations in terms of both knowledge and skills. In this scenario, users can provide robots with knowledge and help them in performing tasks, through a continuous human-robot interaction. This human-robot cooperation setting in shared environments is known as Symbiotic Autonomy or Symbiotic Robotics. In this paper, we address the problem of an effective coexistence of robots and humans, by analyzing the proposed approaches in literature and by presenting our perspective on the topic. In particular, our focus is on specific contexts that can be embraced within Symbiotic Autonomy: Human Augmented Semantic Mapping, Task Teaching and Social Robotics. Finally, we sketch our view on the problem of knowledge acquisition in robotic platforms by introducing three essential aspects that are to be dealt with: environmental, procedural and social knowledge.


Planning in Dynamic Environments Through Temporal Logic Monitoring

AAAI Conferences

We present a framework that enables online planning for robotic systems in dynamic environments. The PLANrm framework presented in this work utilizes the theory of robustness and monitoring of Metric Temporal Logic (MTL) specifications to inspect and modify available plans to both avoid obstacles and satisfy specifications in a dynamic environment. The use of MTL allows the practitioner to set complex event and timing based specifications that need to be satisfied in the execution of the plan. The monitoring algorithm inspects the possible paths in a bounded window and selects and adjusts a path to satisfy the specifications. In this paper, we present initial results on the framework and an extended summary of the algorithmic results. The approach is illustrated using a running example of a car-like model with a number of MTL specifications.


An Architecture for Hybrid Planning and Execution

AAAI Conferences

This paper describes Hy-CIRCA, an architecture for verified, correct-by-construction planning and execution for hy- brid systems, including non-linear continuous dynamics. Hy-CIRCA addresses the high computational complexity of such systems by first planning at an abstract level, and then progressively refining the original plan. Hy-CIRCA is an extension of our Playbook approach, which aims to make it easy for users to exert supervisory control over multiple autonomous systems by “calling a play.” The Playbook approach is implemented by combining (1) a human-machine interface for commanding and monitoring the autonomous systems; (2) a hierarchical planner for translating commands into executable plans; and (3) a smart executive to manage plan execution by coordinating the control systems of the individual autonomous agents, tracking plan execution, and triggering replanning when necessary. Hy-CIRCA integrates the dReal non-linear SMT solver, with enhanced versions of the SHOP2 HTN planner and the CIRCA Controller Synthesis Module (CSM). Hy-CIRCA’s planning process has 5 steps: (1) Using SHOP2, compute an approximate mission plan. While computing this plan, compute a hybrid automaton model of the plan, featuring more expressive continuous dynamics. (2) Using dReal, solve this hybrid model, establishing the correctness of the plan, and computing values for its continuous parameters. To execute the plan, (3) extract from the plan specifications for closed-loop, hard real-time supervisory controllers for the agents that must execute the plan. (4) Based upon these specifications, use the CIRCA CSM to plan the controllers. To ensure correct execution, (5) verify the CSM-generated controllers with dReal.


Policy Communication for Coordination with Unknown Teammates

AAAI Conferences

Within multiagent teams research, existing approaches commonly assume agents have perfect knowledge regarding the decision process guiding their teammates' actions. More recently, ad hoc teamwork was introduced to address situations where an agent must coordinate with a variety of potential teammates, including teammates with unknown behavior. This paper examines the communication of intentions for enhanced coordination between such agents. The proposed decision-theoretic approach examines the uncertainty within a model of an unfamiliar teammate, identifying policy information valuable to the collaborative effort. We characterize this capability through theoretical analysis of the computational requirements as well as empirical evaluation of a communicative agent coordinating with an unknown teammate in a variation of the multiagent pursuit domain.


Modeling Trust Evaluating Agents: Towards a Comprehensive Trust Management for Multi-agent Systems

AAAI Conferences

In multiagent systems, if interactions are based on trust, trustworthy trustees will have a greater impact on the results of interactions. Consequently, building a high trust may be an advantage for rational trustees. This work describes a trust establishment model that goes beyond trust evaluation to outline actions to direct trustees (instead of trusters). The model uses the number of transactions performed by trusters. A trustee will adjust its performance, depending on the average number of transactions carried out by that truster, relative to the mean number of transactions performed by all trusters interacting with this trustee. The proposed model does not depend on direct feedback, nor does it rely on current reputation of trustees in the community. Simulation results indicate that trustees empowered with the proposed model can be selected more by trusters.


Planning under Uncertainty for Aggregated Electric Vehicle Charging Using Markov Decision Processes

AAAI Conferences

The increasing penetration of renewable energy sources and electric vehicles raises important challenges related to the operation of electricity grids. For instance, the amount of power generated by wind turbines is time-varying and dependent on the weather, which makes it hard to match flexible electric vehicle demand and uncertain wind power supply. In this paper we propose a vehicle aggregation framework which uses Markov Decision Processes to control charging of multiple electric vehicles and deals with uncertainty in renewable supply. We present a grouping technique to address the scalability aspects of our framework. In experiments we show that the aggregation framework maximizes the profit of the aggregator while reducing usage of conventionally-generated power and cost of customers.


An MDP-Based Winning Approach to Autonomous Power Trading: Formalization and Empirical Analysis

AAAI Conferences

With the efforts of moving to sustainable and reliable energy supply, electricity markets are undergoing far-reaching changes. Due to the high-cost of failure in the real-world, it is important to test new market structures in simulation. This is the focus of the Power Trading Agent Competition (Power TAC), which proposes autonomous electricity broker agents as a means for stabilizing the electricity grid. This paper focuses on the question: how should an autonomous electricity broker agent act in competitive electricity markets to maximize its profit. We formalize the complete electricity trading problem as a continuous, high-dimensional Markov Decision Process (MDP), which is computationally intractable to solve. Our formalization provides a guideline for approximating the MDP's solution, and for extending existing solutions. We show that a previously champion broker can be viewed as approximating the solution using a lookahead policy. We present TacTex15, which improves upon this previous approximation and achieves state-of-the-art performance in competitions and controlled experiments. Using thousands of experiments against 2015 finalist brokers, we analyze TacTex15's performance and the reasons for its success. We find that lookahead policies can be effective, but their performance can be sensitive to errors in the transition function prediction, specifically demand-prediction.


Proactive Dynamic DCOPs

AAAI Conferences

The current approaches to model dynamism in DCOPs solve a sequence of static problems, reacting to the changes in the environment as the agents observe them. Such approaches, thus, ignore possible predictions on the environment evolution. To overcome such limitations, we introduce the Proactive Dynamic DCOP (PD-DCOP) model, a novel formalism to model dynamic DCOPs in the presence of exogenous uncertainty. In contrast to reactive approaches, PD-DCOPs are able to explicitly model the possible changes to the problem, and take such information into account proactively, when solving the dynamically changing problem.


Formalizing Convergent Instrumental Goals

AAAI Conferences

Omohundro has argued that sufficiently advanced AI systems of any design would, by default, have incentives to pursue a number of instrumentally useful subgoals, such as acquiring more computing power and amassing many resources. Omohundro refers to these as “basic AI drives,” and he, along with Bostrom and others, has argued that this means great care must be taken when designing powerful autonomous systems, because even if they have harmless goals, the side effects of pursuing those goals may be quite harmful. These arguments, while intuitively compelling, are primarily philosophical. In this paper, we provide formal models that demonstrate Omohundro’s thesis, thereby putting mathematical weight behind those intuitive claims.


Proposal of an Adaptive Service Providing System for a Multi-User Smart Home

AAAI Conferences

This paper presents a new system which provides services to elderly and persons suffering from motor or cognitive impair-ments in a smart home (SH). SH are alternative solutions in order to keep elderly and impaired persons as long as possible at their homes to allow them to live with more comfort. SH are dynamically evolving environments, thus the provided services by this system are context aware and customizable for every user. These services can be accessed by users through an application installed on a mobile device. The sys-tem uses a multi agent system (MAS) to have a dynamic and adaptive response to environmental change. Experiments are carried out in order to validate the chosen solutions.