检索结果-内蒙古大学图书馆

A Specification-Guided Framework for Temporal Logic Control of Nonlinear Systems

IEEE TRANSACTIONS ON AUTOMATIC CONTROL 2023年第4期68卷 2002-2017页

作者： Li, Yinan Sun, Zhibing Liu, Jun Univ Waterloo Dept Appl Math Waterloo ON N2L 3G1 Canada Clearpath Robot Inc Kitchener ON N2R 1H2 Canada

This article proposes a specification-guided framework for control of nonlinear systems with linear temporal logic (LTL) specifications. In contrast with well-known abstraction-based methods, the proposed framework directly characterizes the winning set, i.e., the set of initial conditions from which a given LTL formula can be realized, over the continuous state space of the system via a monotonic operator. Following this characterization, an algorithm is proposed to practically approximate the operator via an adaptive interval subdivision scheme, which yields a finite-memory control strategy. We show that the proposed algorithm is sound for full LTL specifications, and robustly complete for specifications recognizable by deterministic Buchi automaton (DBA), the latter in the sense that control strategies can be found whenever the given specification can be satisfied with additional bounded disturbances. Without having to compute and store the abstraction and the resulting product system with the DBA, the proposed method is more memory efficient, which is demonstrated by complexity analysis and performance tests. A preprocessing stage is also devised to reduce computational cost via a decomposition of the specification. We show that the proposed method can effectively solve real-world control problems, such as jet engine compressor control and motion planning for manipulators and mobile robots.

关键词： Automata Heuristic algorithms Aerospace electronics Random access memory Planning Control systems Memory management Formal methods interval analysis linear temporal logic (LTL) nonlinear control

来源：评论

学校读者我要写书评

暂无评论

A Piecewise Learning Framework for Control of Unknown Nonlinear Systems with Stability Guarantees 4

A Piecewise Learning Framework for Control of Unknown Nonlin...

引用

4th Annual Conference on Learning for Dynamics and Control (L4DC)

作者： Farsi, Milad Li, Yinan Yuan, Ye Liu, Jun Univ Waterloo Dept Appl Math Waterloo ON Canada Clearpath Robot Kitchener ON Canada Huazhong Univ Sci & Technol Sch Artificial Intelligence & Automat Wuhan Peoples R China

We propose a piecewise learning framework for controlling nonlinear systems with unknown dynamics. While model-based reinforcement learning techniques in terms of some basis functions are well known in the literature, when it comes to more complex dynamics, only a local approximation of the model can be obtained using a limited number of bases. The complexity of the identifier and the controller can be considerably high if obtaining an approximation over a larger domain is desired. To overcome this limitation, we propose a general piecewise nonlinear framework where each piece is responsible for locally learning and controlling over some region of the domain. We obtain rigorous uncertainty bounds for the learned piecewise models. The piecewise affine (PWA) model is then studied as a special case, for which we propose an optimization-based verification technique for stability analysis of the closed-loop system. Accordingly, given a time-discretization of the learned PWA system, we iteratively search for a common piecewise Lyapunov function in a set of positive definite functions, where a non-monotonic convergence is allowed. This Lyapunov candidate is verified on the uncertain system to either provide a certificate for stability or find a counter-example when it fails. This counter-example is added to a set of samples to facilitate the further learning of a Lyapunov function. We demonstrate the results on two examples and show that the proposed approach yields a less conservative region of attraction (ROA) compared with alternative state-of-the-art approaches. Moreover, we provide the runtime results to demonstrate potentials of the proposed framework in real-world implementations.

关键词： Nonlinear systems learning-based control system identification piecewise affine Lyapunov analysis

来源：评论

学校读者我要写书评

暂无评论

Safe Linear Temporal Logic Motion Planning in Dynamic Environments

Safe Linear Temporal Logic Motion Planning in Dynamic Enviro...

引用

IEEE/RSJ International Conference on Intelligent robots and Systems (IROS)

作者： Li, Yinan Shahrivar, Ebrahim Moradi Liu, Jun Univ Waterloo Dept Appl Math 200 Univ Ave Waterloo ON Canada Clearpath Robot Inc 1425 Strasburg Rd Kitchener ON Canada

ISBN: (纸本)9781665417143

This paper proposes an online control framework for mobile robots to satisfy a complex mission given in the form of linear temporal logic (LTL) without colliding with moving obstacles in the environment. The proposed framework consists of three modules named the static planner, the local collision avoidance, and the patcher. The static planner is synthesized by solving a parity game for a finite abstraction of the robot model based on a world map with static obstacles to fulfill the LTL task. The local collision avoidance module computes a set of safe controls that guarantees a safe distance between the moving objects. Both of the modules can be rigorously computed offline only once via formal methods. The patcher is activated whenever a moving obstacle is detected and modifies the static plan online for a short horizon by using only provably safe controls. The resulting modified strategy can guarantee collision-free motion without losing the ability to satisfy the LTL task. As opposed to using assume-guarantee type of LTL tasks, the proposed framework can handle the situations where obstacle movement is unpredictable.

关键词： Simulation Dynamics Games Trajectory Safety Planning Mobile robots

来源：评论

学校读者我要写书评

暂无评论

Autonomous locomotion mode transition in quadruped track-legged robots: A simulation-based analysis for step negotiation

引用

SIMULATION MODELLING PRACTICE AND THEORY 2024年 132卷

作者： Wang, Jie Davies, Krispin Univ Waterloo Elect & Comp Engn Dept 200 Univ Ave West Waterloo ON N2L 3G1 Canada Clearpath Robot Inc 1425 Strasburg Rd Suite 2A Kitchener N2R 1H2 ON Canada

Hybrid track/wheel-legged robots combine the advantages of wheel-based and leg-based locomotion, granting adaptability across varied terrains through efficient transitions between rolling and walking modes. However, automating these transitions remains a significant challenge. In this paper, we introduce a method designed for autonomous mode transition in a quadruped hybrid robot with a track/wheel-legged configuration, especially during step negotiation. Our approach hinges on a decision-making mechanism that evaluates the energy efficiency of both locomotion modes using a proposed energy-based criterion. To guarantee a smooth negotiation of steps, we incorporate two climbing gaits designated for the assessment of energy usage in walking locomotion. Simulation results validate the method's effectiveness, showing successful autonomous transitions across steps of diverse heights. Our suggested approach has universal applicability and can be modified to suit other hybrid robots of similar mechanical configuration, provided their locomotion energy performance is studied beforehand.

关键词： Track-Legged quadruped robot Rolling locomotion Walking locomotion Locomotion mode transition Climbing gaits

来源：评论

学校读者我要写书评

暂无评论

Admittance Control for robotic Loading: Design and Experiments with a 1-Tonne Loader and a 14-Tonne Load-Haul-Dump Machine

引用

JOURNAL OF FIELD robotICS 2017年第1期34卷 123-150页

作者： Dobson, Andrew A. Marshall, Joshua A. Larsson, Johan Queens Univ Min Syst Lab Kingston ON K7L 3N6 Canada Atlas Copco Rock Drills AB Div Rocktec Automat SE-701 Orebro Sweden Clearpath Robot Inc Kitchener ON N2R 1H2 Canada

This paper describes the design, tuning, and extensive field testing of an admittance-based autonomous loading controller (ALC) for robotic excavation. Several iterations of the ALC were tuned and tested in fragmented rock pilessimilar to those found in operating minesby using both a robotic 1-tonne capacity Kubota R520S diesel-hydraulic surface loader and a 14-tonne capacity Atlas Copco ST14 underground load-haul-dump (LHD) machine. On the R520S loader, the ALC increased payload by 18% with greater consistency, although with more energy expended and longer dig times when compared with digging at maximum actuator velocity. On the ST14 LHD, the ALC took 61% less time to load 39% more payload when compared to a single manual operator. The manual operator made 28 dig attempts by using three different digging strategies, and had one failed dig. The tuned ALC made 26 dig attempts at 10and11MN target force levels. All 10 11MN digs succeeded while 6 of the 16 10MN digs failed. The results presented in this paper suggest that the admittance-based ALC is more productive and consistent than manual operators, but that care should be taken when detecting entry into the rock pile. (C) 2016 Wiley Periodicals, Inc.

关键词： Piles

来源：评论

学校读者我要写书评

暂无评论

Admittance Control for robotic Loading: Underground Field Trials with an LHD 10th

Admittance Control for Robotic Loading: Underground Field Tr...

引用

10th International Conference on Field and Service robotics (FSR)

作者： Dobson, Andrew A. Marshall, Joshua A. Larsson, Johan Clearpath Robot Kitchener ON N2R 1H2 Canada Queens Univ Min Syst Lab Kingston ON K7L 3N6 Canada Atlas Copco Rock Drills AB Div Rocktec Automat SE-701 Orebro Sweden

ISBN: (纸本)9783319277028;9783319277004

In this paper we describe field trials of an admittance-based Autonomous Loading Controller (ALC) applied to a robotic Load-Haul-Dump (LHD) machine at an underground mine near Orebro, Sweden. The ALC was tuned and field tested by using a 14-tonne capacity Atlas Copco ST14 LHD mining machine in piles of fragmented rock, similar to those found in operational mines. Several relationships between the ALC parameters and our performance metrics were discovered through the described field tests. During these tests, the tuned ALC took 61% less time to load 39% more payload when compared to a manual operator. The results presented in this paper suggest that the ALC is more consistent than manual operators, and is also robust to uncertainties in the unstructured mine environment.

关键词： robotics

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：