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Logic-based Knowledge Awareness for Autonomous Agents in Continuous Spaces

Arabinda Ghosh, Mahmoud Salamati, Sadegh Soudjani

TL;DR

This paper utilizes an abstraction-based controller design approach, capable of managing both nonlinear dynamics and temporal requirements, and dynamically updates the controller whenever the knowledge base prompts changes in the specifications.

Abstract

This paper presents a step towards a formal controller design method for autonomous agents based on knowledge awareness to improve decision-making. Our approach is to first create an organized repository of information (a knowledge base) for autonomous agents which can be accessed and then translated into temporal specifications. Secondly, to develop a controller with formal guarantees that meets a combination of mission-specific objective and the specification from the knowledge base, we utilize an abstraction-based controller design (ABCD) approach, capable of managing both nonlinear dynamics and temporal requirements. Unlike the conventional offline ABCD approach, our method dynamically updates the controller whenever the knowledge base prompts changes in the specifications. A three-dimensional nonlinear car model navigating an urban road scenario with traffic signs and obstacles is considered for validation. Results show the effectiveness of the method in guiding the autonomous agents to the target while complying with the knowledge base and the mission-specific objective.

Logic-based Knowledge Awareness for Autonomous Agents in Continuous Spaces

TL;DR

This paper utilizes an abstraction-based controller design approach, capable of managing both nonlinear dynamics and temporal requirements, and dynamically updates the controller whenever the knowledge base prompts changes in the specifications.

Abstract

This paper presents a step towards a formal controller design method for autonomous agents based on knowledge awareness to improve decision-making. Our approach is to first create an organized repository of information (a knowledge base) for autonomous agents which can be accessed and then translated into temporal specifications. Secondly, to develop a controller with formal guarantees that meets a combination of mission-specific objective and the specification from the knowledge base, we utilize an abstraction-based controller design (ABCD) approach, capable of managing both nonlinear dynamics and temporal requirements. Unlike the conventional offline ABCD approach, our method dynamically updates the controller whenever the knowledge base prompts changes in the specifications. A three-dimensional nonlinear car model navigating an urban road scenario with traffic signs and obstacles is considered for validation. Results show the effectiveness of the method in guiding the autonomous agents to the target while complying with the knowledge base and the mission-specific objective.

Paper Structure

This paper contains 13 sections, 16 equations, 3 figures.

Figures (3)

  • Figure 1: The overall scheme of the proposed approach. The decision-making process relies on three distinct inputs: the LTL formula derived from the knowledge base, the mission-specific objective of the autonomous agent, and the system dynamics.
  • Figure 2: A motivating example of the workspace consisting of an autonomous car, traffic signals, a target destination, and obstacles.
  • Figure 3: Depiction of the path followed by the autonomous vehicle: The real-time controller synthesis adheres to both the mission-specific reach-avoid specification and the constraints set by the knowledge base. (a) Initial position of the car; (b) The car makes an immediate left turn towards the target; (c) Due to traffic restrictions, the car turns back to take an alternative route; (d) and (e) The car follows the alternative route towards the target; (f) The car reaches at the target location.

Theorems & Definitions (8)

  • Definition 1: $\mathcal{ALC}$ symbols kg-book
  • Definition 2: $\mathcal{ALC}$ concepts baader2008description
  • Definition 3: Knowledge base (KB) baader2003descriptionbaader2008description
  • Definition 4: $\mathcal{ALC}$ interpretation baader2003descriptionbaader2008description
  • Definition 5: $\mathcal{ALC}$ Satisfaction relation baader2003descriptionbaader2008description
  • Definition 6: $\mathcal{ALC}$ kg-book
  • Definition 7: LTL
  • Definition 8: $\mathcal{ALC}$-LTL