检索结果-内蒙古大学图书馆

Learning Performance Graphs From Demonstrations via Task-Based Evaluations

IEEE robotics AND automation LETTERS 2023年第1期8卷 336-343页

作者： Puranic, Aniruddh G. Deshmukh, Jyotirmoy V. Nikolaidis, Stefanos Univ Southern Calif Comp Sci Dept Los Angeles CA 90089 USA

In the paradigm of robot learning-from-demonstra tions (LfD), understanding and evaluating the demonstrated behaviors plays a critical role in extracting control policies for robots. Without this knowledge, a robot may infer incorrect reward functions that lead to undesirable or unsafe control policies. Prior work has used temporal logic specifications, manually ranked by human experts based on their importance, to learn reward functions from imperfect/suboptimal demonstrations. To overcome reliance on expert rankings, we propose a novel algorithm that learns from demonstrations, a partial ordering of provided specifications in the form of a performance graph. Through various experiments, including simulation of industrial mobile robots, we show that extracting reward functions with the learned graph results in robot policies similar to those generated with the manually specified orderings. We also show in a user study that the learned orderings match the orderings or rankings by participants for demonstrations in a simulated driving domain. These results show that we can accurately evaluate demonstrations with respect to provided task specifications from a small set of imperfect data with minimal expert input.

关键词： formal methods in robotics and automation learning from demonstration reinforcement learning

来源：评论

学校读者我要写书评

暂无评论

Planning of Heterogeneous Multi-Agent Systems Under Signal Temporal Logic Specifications With Integral Predicates

引用

IEEE robotics AND automation LETTERS 2021年第2期6卷 1375-1382页

作者： Buyukkocak, Ali Tevfik Aksaray, Derya Yazcoglu, Yasin Univ Minnesota Dept Aerosp Engn & Mech Minneapolis MN 55455 USA Univ Minnesota Dept Elect & Comp Engn Minneapolis MN 55455 USA

We address the problem of coordinating the trajectories of heterogeneous multi-agent systems under spatio-temporal specifications. In particular, we consider global Signal Temporal Logic (STL) constraints to express the number and type of agents that should be present at specific locations within the desired time windows. We also introduce an integral predicate to specify cumulative progress that can he achieved asynchronously by multiple agents. In order to generate optimal trajectories, we formulate a mixed-integer linear program whose objective is minimizing the agent movement subject to the heterogeneous abstracted dynamics of the agents and a global STL specification including the novel integral predicate. We demonstrate the performance of the proposed method via simulations and experiments with drones.

关键词： formal methods in robotics and automation multi-robot systems optimization and optimal control

来源：评论

学校读者我要写书评

暂无评论

Temporal Logic Task Allocation in Heterogeneous Multirobot Systems

引用

IEEE TRANSACTIONS ON robotics 2022年第6期38卷 3602-3621页

作者： Luo, Xusheng Zavlanos, Michael M. Duke Univ Dept Mechan Engn & Mat Sci Durham NC 27708 USA

We consider the problem of optimally allocating tasks, expressed as global linear temporal logic (LTL) specifications, to teams of heterogeneous mobile robots of different types. Each task may require robots of multiple types. To obtain a scalable solution, we propose a hierarchical approach that first allocates specific robots to tasks using the information about the tasks contained in the nondeterministic B ii chi automaton (NBA) that captures the LTL specification and then designs low-level paths for robots that respect the high-level assignment. Specifically, motivated by "lazy collision checking" methods in robotics, we first prune and relax the NBA by removing all negative atomic propositions, which simplifies the planning problem by checking constraint satisfaction only when needed. Then, we extract sequences of subtasks from the relaxed NBA along with their temporal orders and formulate a mixed integer linear program to allocate these subtasks to robots. Finally, we define generalized multirobot path planning problems to obtain low-level paths that satisfy both the high-level task allocation and the constraints captured by the negative atomic propositions in the original NBA. We show that our method is complete for a subclass of LTL that covers a broad range of tasks and present numerical simulations demonstrating that it can generate paths with lower cast, considerably faster than existing methods.

关键词： formal methods in robotics and automation motion and path planning path planning for multiple mobile robots or agents task planning

来源：评论

学校读者我要写书评

暂无评论

Event-Based Signal Temporal Logic Synthesis for Single and Multi-Robot Tasks

引用

IEEE robotics AND automation LETTERS 2021年第2期6卷 3687-3694页

作者： Gundana, David Kress-Gazit, Hadas Cornell Univ Sibley Sch Mech & Aerosp Engn Ithaca NY 14853 USA

We propose a new specification language and control synthesis technique for single and multi-robot high-level tasks;these tasks include timing constraints and reaction to environmental events. Specifically, we define Event-based Signal Temporal Logic (STL) and use it to encode tasks that are reactive to uncontrolled environment events. Our control synthesis approach to Event-based STL tasks combines automata and control barrier functions to produce robot behaviors that satisfy the specification when possible. Our method automatically provides feedback to the user if an Event-based STL task cannot be achieved. We demonstrate the effectiveness of the framework through simulations and physical demonstrations of multi-robot tasks.

关键词： formal methods in robotics and automation hybrid logical/dynamical planning and verification multi-robot systems

来源：评论

学校读者我要写书评

暂无评论

The Kinematics of Constant Curvature Continuum Robots Through Three Segments

引用

IEEE robotics AND automation LETTERS 2023年第11期8卷 7631-7638页

作者： Li, Yucheng Myszka, David H. Murray, Andrew Univ Dayton Dept Mech & Aerosp Engn Design Innovat Machines Lab DIMLab Dayton OH 45469 USA

This letter investigates the mathematical relationships between the positions and orientations at the segment tips of a piecewise constant curvature (PCC) continuum robot with up to three segments. For one-segment, a reachability criterion is proposed, simplifying the calculation of the neighboring orientation. For two-segments, a reachability criterion is proposed and the redundancy of its inverse kinematics solution is found, establishing a circle of tip locations. For three-segments, the redundancy of the inverse kinematics includes tips that lie on a sphere providing a closed-form solution to the inverse kinematics problem. These relationships are derived from the unique characteristics of the bisecting plane of a single segment. The degenerate cases for the solutions are also addressed. These outcomes stem from a specific PCC parametrization, with implications extending to the general PCC model. Note that this study is grounded solely in simulation.

关键词： Kinematics formal methods in robotics and automation soft robot applications constant curvature continuum robots

来源：评论

学校读者我要写书评

暂无评论

Decomposition-Based Hierarchical Task Allocation and Planning for Multi-Robots Under Hierarchical Temporal Logic Specifications

引用

IEEE robotics AND automation LETTERS 2024年第8期9卷 7182-7189页

作者： Luo, Xusheng Xu, Shaojun Liu, Ruixuan Liu, Changliu Carnegie Mellon Univ Robot Inst Pittsburgh PA 15213 USA Zhejiang Univ Coll Control Sci & Engn Hangzhou 310058 Peoples R China

Past research into robotic planning with temporal logic specifications, notably Linear Temporal Logic (LTL), was largely based on a single formula for individual or groups of robots. But with increasing task complexity, LTL formulas unavoidably grow lengthy, complicating interpretation and specification generation, and straining the computational capacities of the planners. A recent development has been the hierarchical representation of LTL (Luo et al., 2024) that contains multiple temporal logic specifications, providing a more interpretable framework. However, the proposed planning algorithm assumes the independence of robots within each specification, limiting their application to multi-robot coordination with complex temporal constraints. In this work, we formulated a decomposition-based hierarchical framework. At the high level, each specification is first decomposed into a set of atomic sub-tasks. We further infer the temporal relations among the sub-tasks of different specifications to construct a task network. Subsequently, a Mixed Integer Linear Program is used to assign sub-tasks to various robots. At the lower level, domain-specific controllers are employed to execute sub-tasks. Our approach was experimentally applied to domains of navigation and manipulation. The simulation demonstrated that our approach can find better solutions using less runtimes.

关键词： Robots Task analysis Robot kinematics Logic Planning Resource management Navigation formal methods in robotics and automation multi-robot systems planning scheduling and coordination

来源：评论

学校读者我要写书评

暂无评论

Safe POMDP Online Planning Among Dynamic Agents via Adaptive Conformal Prediction

引用

IEEE robotics AND automation LETTERS 2024年第11期9卷 9946-9953页

作者： Sheng, Shili Yu, Pian Parker, David Kwiatkowska, Marta Feng, Lu Univ Virginia Sch Engn & Appl Sci Charlottesville VA 22904 USA Univ Oxford Dept Comp Sci Oxford OX1 2JD England

Online planning for partially observable Markov decision processes (POMDPs) provides efficient techniques for robot decision-making under uncertainty. However, existing methods fall short of preventing safety violations in dynamic environments. This letter presents a novel safe POMDP online planning approach that maximizes expected returns while providing probabilistic safety guarantees amidst environments populated by multiple dynamic agents. Our approach utilizes data-driven trajectory prediction models of dynamic agents and applies Adaptive Conformal Prediction (ACP) to quantify the uncertainties in these predictions. Leveraging the obtained ACP-based trajectory predictions, our approach constructs safety shields on-the-fly to prevent unsafe actions within POMDP online planning. Through experimental evaluation in various dynamic environments using real-world pedestrian trajectory data, the proposed approach has been shown to effectively maintain probabilistic safety guarantees while accommodating up to hundreds of dynamic agents.

关键词： Safety Planning Robots Trajectory Uncertainty Pedestrians Heuristic algorithms formal methods in robotics and automation planning under uncertainty robot safety AI-enabled robotics

来源：评论

学校读者我要写书评

暂无评论

Interval-Based Visua LiDAR Sensor Fusion

引用

IEEE robotics AND automation LETTERS 2021年第2期6卷 1304-1311页

作者： Voges, Raphael Wagner, Bernardo Leibniz Univ Hannover Inst Syst Engn Real Time Syst Grp RTS D-30167 Hannover Germany

Since cameras and Light Detection and Ranging (LiDAR) sensors provide complementary information about the environment, it is beneficial for mobile robot localization to fuse their information by assigning distances measured by the LiDAR to visual features detected in the image. However, existing approaches neglect the uncertainty of the fused information or model it in an optimistic way (e.g., without taking extrinsic calibration errors into account). Since the actual distribution of errors during sensor fusion is often unknown, we assume to only know bounds (or intervals) enclosing the errors. Consequently, we propose to use interval analysis to propagate the error from the input sources to the fused information in a straightforward way. To show the applicability of our approach, we use the fused information for dead reckoning. Since interval analysis is used, the result of our approach are intervals that are guaranteed to enclose the robot's true pose. An evaluation using real data shows that we are indeed able to localize the robot in a guaranteed way. This enables us to detect faults of an established approach, which neglects the uncertainty of the fused information, in three out of ten cases.

关键词： Sensor fusion formal methods in robotics and automation localization interval analysis

来源：评论

学校读者我要写书评

暂无评论

Model Predictive Robustness of Signal Temporal Logic Predicates

引用

IEEE robotics AND automation LETTERS 2023年第12期8卷 8050-8057页

作者： Lin, Yuanfei Li, Haoxuan Althoff, Matthias Tech Univ Munich Sch Computat Informat & Technol D-85748 Garching Germany

The robustness of signal temporal logic not only assesses whether a signal adheres to a specification but also provides a measure of how much a formula is fulfilled or violated. The calculation of robustness is based on evaluating the robustness of underlying predicates. However, the robustness of predicates is usually defined in a model-free way, i.e., without including the system dynamics. Moreover, it is often nontrivial to define the robustness of complicated predicates precisely. To address these issues, we propose a notion of model predictive robustness, which provides a more systematic way of evaluating robustness compared to previous approaches by considering model-based predictions. In particular, we use Gaussian process regression to learn the robustness based on precomputed predictions so that robustness values can be efficiently computed online. We evaluate our approach for the use case of autonomous driving with predicates used in formalized traffic rules on a recorded dataset, which highlights the advantage of our approach compared to traditional approaches in terms of precision. By incorporating our robustness definitions into a trajectory planner, autonomous vehicles obey traffic rules more robustly than human drivers in the dataset.

关键词： Robustness Predictive models Computational modeling Trajectory Safety Planning Autonomous vehicles formal methods in robotics and automation integrated planning and learning signal temporal logic model predictive robustness Gaussian process regression

来源：评论

学校读者我要写书评

暂无评论

Guiding Autonomous Exploration With Signal Temporal Logic

引用

IEEE robotics AND automation LETTERS 2019年第4期4卷 3332-3339页

作者： Barbosa, Fernando S. Duberg, Daniel Jensfelt, Patric Tumova, Jana KTH Royal Inst Technol Div Robot Percept & Learning S-11428 Stockholm Sweden

Algorithms for autonomous robotic exploration usually focus on optimizing time and coverage, often in a greedy fashion. However, obstacle inflation is conservative and might limit mapping capabilities and even prevent the robot from moving through narrow, important places. This letter proposes a method to influence the manner the robot moves in the environment by taking into consideration a user-defined spatial preference formulated in a fragment of signal temporal logic (STL). We propose to guide the motion planning toward minimizing the violation of such preference through a cost function that integrates the quantitative semantics, i.e., robustness of STL. To demonstrate the effectiveness of the proposed approach, we integrate it into the autonomous exploration planner (AEP). Results from simulations and real-world experiments are presented, highlighting the benefits of our approach.

关键词： Mapping motion and path planning formal methods in robotics and automation search and rescue robots

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：