Abstract:This paper presents a framework that can interpret humans' navigation commands containing temporal elements and directly translate their natural language instructions into robot motion planning. Central to our framework is utilizing Large Language Models (LLMs). To enhance the reliability of LLMs in the framework and improve user experience, we propose methods to resolve the ambiguity in natural language instructions and capture user preferences. The process begins with an ambiguity classifier, identifying potential uncertainties in the instructions. Ambiguous statements trigger a GPT-4-based mechanism that generates clarifying questions, incorporating user responses for disambiguation. Also, the framework assesses and records user preferences for non-ambiguous instructions, enhancing future interactions. The last part of this process is the translation of disambiguated instructions into a robot motion plan using Linear Temporal Logic. This paper details the development of this framework and the evaluation of its performance in various test scenarios.
Abstract:We propose a threshold decision-making framework for controlling the physical dynamics of an agent switching between two spatial tasks. Our framework couples a nonlinear opinion dynamics model that represents the evolution of an agent's preference for a particular task with the physical dynamics of the agent. We prove the bifurcation that governs the behavior of the coupled dynamics. We show by means of the bifurcation behavior how the coupled dynamics are adaptive to the physical constraints of the agent. We also show how the bifurcation can be modulated to allow the agent to switch tasks based on thresholds adaptive to environmental conditions. We illustrate the benefits of the approach through a decentralized multi-robot task allocation application for trash collection.
Abstract:This paper presents a cooperative multi-robot multi-target tracking framework aimed at enhancing the efficiency of the heterogeneous sensor network and, consequently, improving overall target tracking accuracy. The concept of normalized unused sensing capacity is introduced to quantify the information a sensor is currently gathering relative to its theoretical maximum. This measurement can be computed using entirely local information and is applicable to various sensor models, distinguishing it from previous literature on the subject. It is then utilized to develop a distributed coverage control strategy for a heterogeneous sensor network, adaptively balancing the workload based on each sensor's current unused capacity. The algorithm is validated through a series of ROS and MATLAB simulations, demonstrating superior results compared to standard approaches that do not account for heterogeneity or current usage rates.
Abstract:We propose, analyze, and experimentally verify a new approach for robot social navigation in human-robot corridor passing that is driven by nonlinear opinion dynamics. The robot forms an opinion over time in response to its observations, and its opinion drives its motion control. The algorithm inherits a key feature of the opinion dynamics: deadlock, also known as the "freezing robot" problem, is guaranteed to be broken even if the robot has no bias or evidence for whether it is better off passing on the right or the left. The robot can also overcome a bias that is in conflict with the passage choice the human makes. The approach enables rapid and reliable opinion formation, which makes for rapid and reliable navigation. We verify our analytical results on deadlock breaking and rapid and reliable passage with human-robot experiments. We further verify through experiments that a single design parameter can tune the trade-off between efficiency and reliability in human-robot corridor passing. The new approach has the additional advantage that it does not rely on a predictive model of human behavior.