检索结果-内蒙古大学图书馆

PRIEST: Projection Guided Sampling-Based optimization for Autonomous Navigation

IEEE ROBOTICS AND AUTOMATION LETTERS 2024年第3期9卷 2630-2637页

作者： Rastgar, Fatemeh Masnavi, Houman Sharma, Basant Aabloo, Alvo Swevers, Jan Singh, Arun Kumar Univ Tartu Inst Sci & Technol EE-50411 Tartu Estonia Toronto Metropolitan Univ Toronto ON Canada KU Leuven Univ Mech Engn Dept B-3000 Leuven Belgium Flanders Make KU Leuven B-3001 Leuven Belgium

Efficient navigation in unknown and dynamic environments is crucial for expanding the application domain of mobile robots. The core challenge stems from the non-availability of a feasible global path for guiding optimization-based local planners. As a result, existing local planners often get trapped in poor local minima. In this letter, we present a novel optimizer that can explore multiple homotopies to plan high-quality trajectories over long horizons while still being fast enough for real-time applications. We build on the gradient-free paradigm by augmenting the trajectory sampling strategy with a projection optimization that guides the samples toward a feasible region. As a result, our method can recover from the frequently encountered pathological cases wherein all the sampled trajectories lie in the high-cost region. We push the state-of-the-art (SOTA) in the following respects. Over the navigation stack of the Robot Operating System (ROS), we show an improvement of 7-13% in success rate and up to two times in total travel time metric. On the same benchmarks and metrics, our approach achieves up to 44% improvement over model predictive path integral (MPPI) and its recent variants. On simple point-to-point navigation tasks, our optimizer is up to two times more reliable than SOTA gradient-based solvers, as well as sampling-based approaches such as the Cross-Entropy Method (CEM) and VPSTO.

关键词： Autonomous vehicle navigation collision avoidance optimization and optimal control

来源：评论

学校读者我要写书评

暂无评论

Quaternion-Based optimal Interpolation of Similarity Transformations for Multi-Agent Formation

引用

IEEE ROBOTICS AND AUTOMATION LETTERS 2024年第6期9卷 5783-5790页

作者： Wu, Zeming Wang, Zhuping Zhang, Hao Yan, Huaicheng Tongji Univ Dept Control Sci & Engn Shanghai 201804 Peoples R China East China Univ Sci & Technol Key Lab Adv Control & Optimizat Chem Proc Minist Educ Shanghai 200237 Peoples R China Hubei Univ Technol Sch Elect & Elect Engn Wuhan 430068 Peoples R China

This letter addresses the challenge of optimal motion interpolation in multi-agent formation control. The primary goal is to generate trajectories of similarity transformations that minimize various metrics, such as distance traveled, kinetic energy consumption, and overall smoothness. The quaternion-based representation is introduced for similarity transformations, providing an innovative solution to bypass the intricate mapping between Lie group elements and Lie algebra elements. The quaternion-based approach enables the calculation of time derivatives of agents through finite algebraic operations. This feature is pivotal for efficient motion interpolation. This simplification significantly enhances the efficiency and effectiveness of the interpolation process, making it a valuable tool for multi-agent formation control. To address the optimal motion interpolation problem, we formulate it as a variational problem and derive necessary conditions for both two-point and multiple-point optimal interpolations. To further improve computational efficiency while preserving the optimal solution's structure, we propose a polynomial approximation method. Finally, we illustrate the effectiveness of the proposed method through examples of ellipsoid formation. Comparative analyses demonstrate the optimality of our approach.

关键词： Interpolation Vectors Trajectory Quaternions Manifolds Algebra Finite element analysis Computational geometry optimization and optimal control simulation and animation

来源：评论

学校读者我要写书评

暂无评论

Co-designing versatile quadruped robots for dynamic and energy-efficient motions

引用

ROBOTICA 2024年第6期42卷 2004-2025页

作者： Fadini, Gabriele Kumar, Shivesh Kumar, Rohit Flayols, Thomas Del Prete, Andrea Carpentier, Justin Soueres, Philippe Univ Toulouse CNRS LAAS Toulouse France DFKI GmbH Robot Innovat Ctr Bremen Germany Univ Trento Dept Ind Engn Trento Italy INRIA Paris France Dept Informat ENS Paris France

This paper presents a concurrent optimization approach for the design and motion of a quadruped in order to achieve energy-efficient cyclic behaviors. Computational techniques are applied to improve the development of a novel quadruped prototype. The scale of the robot and its actuators are optimized for energy efficiency considering the complete actuator model including friction, torque, and bandwidth limitations. This method and the optimal bounding trajectories are tested on the first (non-optimized) prototype design iteration showing that our formulation produces a trajectory that (i) can be easily replayed on the real robot and (ii) reduces the power consumption w.r.t. hand-tuned motion heuristics. Power consumption is then optimized for several periodic tasks with co-design. Our results include, but are not limited to, a bounding and backflip task. It appears that, for jumping forward, robots with longer thighs perform better, while, for backflips, longer shanks are better suited. To explore the tradeoff between these different designs, a Pareto set is constructed to guide the next iteration of the prototype. On this set, we find a new design, which will be produced in future work, showing an improvement of at least 52% for each separate task.

关键词： legged robots actuation and joint mechanisms methods and tools for robot system design optimization and optimal control simulation and animation mechanism design

来源：评论

学校读者我要写书评

暂无评论

Geometry-Aware Safety-Critical Local Reactive controller for Robot Navigation in Unknown and Cluttered Environments

引用

IEEE ROBOTICS AND AUTOMATION LETTERS 2024年第4期9卷 3419-3426页

作者： Li, Yulin Tang, Xindong Chen, Kai Zheng, Chunxin Liu, Haichao Ma, Jun Hong Kong Univ Sci & Technol Guangzhou Robot & Autonomous Syst Thrust Guangzhou Peoples R China Hong Kong Univ Sci & Technol Div Emerging Interdisciplinary Areas Hong Kong Peoples R China HKUST Shenzhen Hong Kong Collaborat Innovat Res In Futian Shenzhen Peoples R China Hong Kong Baptist Univ Dept Math Hong Kong Peoples R China

This work proposes a safety-critical local reactive controller that enables the robot to navigate in unknown and cluttered environments. In particular, the trajectory tracking task is formulated as a constrained polynomial optimization problem. Then, safety constraints are imposed on the control variables invoking the notion of polynomial positivity certificates in conjunction with their Sum-of-Squares (SOS) approximation, thereby confining the robot motion inside the locally extracted convex free region. It is noteworthy that, in the process of devising the proposed safety constraints, the geometry of the robot can be approximated using any shape that can be characterized with a set of polynomial functions. The optimization problem is further convexified into a semidefinite program (SDP) leveraging truncated multi-sequences (TMS) and moment relaxation, which favorably facilitates the effective use of off-the-shelf conic programming solvers, such that real-time performance is attainable. Various robot navigation tasks are investigated to demonstrate the effectiveness of the proposed approach in terms of safety and tracking performance.

关键词： Robots Safety optimization Geometry Collision avoidance Task analysis Real-time systems motion control optimization and optimal control

来源：评论

学校读者我要写书评

暂无评论

Tailoring Solution Accuracy for Fast Whole-Body Model Predictive control of Legged Robots

引用

IEEE ROBOTICS AND AUTOMATION LETTERS 2024年第12期9卷 11074-11081页

作者： Khazoom, Charles Hong, Seungwoo Chignoli, Matthew Stanger-Jones, Elijah Kim, Sangbae MIT Dept Mech Engn Dept Cambridge MA 02139 USA

Thanks to recent advancements in accelerating non-linear model predictive control (NMPC), it is now feasible to deploy whole-body NMPC at real-time rates for humanoid robots. However, enforcing inequality constraints in real time for such high-dimensional systems remains challenging due to the need for additional iterations. This letter presents an implementation of whole-body NMPC for legged robots that provides low-accuracy solutions to NMPC with general equality and inequality constraints. Instead of aiming for highly accurate optimal solutions, we leverage the alternating direction method of multipliers to rapidly provide low-accuracy solutions to quadratic programming subproblems. Our extensive simulation results indicate that real robots often cannot benefit from highly accurate solutions due to dynamics discretization errors, inertial modeling errors and delays. We incorporate control barrier functions (CBFs) at the initial timestep of the NMPC for the self-collision constraints, resulting in up to a 26-fold reduction in the number of self-collisions without adding computational burden. The controller is reliably deployed on hardware at 90 Hz for a problem involving 32 timesteps, 2004 variables, and 3768 constraints. The NMPC delivers sufficiently accurate solutions, enabling the MIT Humanoid to plan complex crossed-leg and arm motions that enhance stability when walking and recovering from significant disturbances.

关键词： Legged robots whole-body motion planning and control optimization and optimal control solution accuracy self-collision avoidance Legged robots whole-body motion planning and control optimization and optimal control solution accuracy self-collision avoidance

来源：评论

学校读者我要写书评

暂无评论

Scheduling Dual-Arm Multi-Cluster Tools With Residency Time Constraints Beyond Swap-Based Strategies and Module-Bound Regions

引用

IEEE ROBOTICS AND AUTOMATION LETTERS 2024年第11期9卷 10177-10184页

作者： Li, Xin Lu, Chao Educ Univ Hong Kong Dept Math & Informat Technol Hong Kong 200000 Peoples R China China Univ Geosci Sch Comp Sci Wuhan Peoples R China

Multi-cluster tools are widely utilized in wafer fabrications. It is of great significance to schedule such tools optimally to improve productivity and ensure wafer quality. However, previous research mainly focuses on scheduling dual-arm multi-cluster tools by adopting swap-based strategies, leaving a gap on other alternative schedules. Additionally, process-bound and transport-bound regions are distinguished for analysis. How to connect both regions is open. This study aims to address such gaps by dealing with more general conditions beyond swap-based strategies and module-bound regions in dual-arm multi-cluster tools with residency time constraints. Based on detailed analysis of operations in the system, specifically more practical positions on the two-arm configuration, a mixed integer linear programming model is formulated to tackle the challenging problem. Furthermore, this model can be directly adopted to single-arm tools by assigning all operations to the same arm, enabling it to schedule all types of dual-arm, single-arm, and hybrid cluster tools in general. In addition, the model is extended to minimize total post-processing time in all process modules. To validate the proposed approach, two illustrative examples which were previously considered unschedulable are tested, conducting the model's efficiency and validity. Furthermore, a sensitivity analysis on transport module times conducts a transition shift between process-bound and transport-bound regions for the first time. Results of randomly generated instances conduct that larger transportation module times correlate with increased computing times.

关键词： Time factors Robots Schedules optimal scheduling Semiconductor device modeling Productivity Manipulators Job shop scheduling Indexes Throughput Automated manufacturing systems materials handling optimization and optimal control productivity semiconductor manufacturing

来源：评论

学校读者我要写书评

暂无评论

3D Hopping in Discontinuous Terrain Using Impulse Planning With Mixed-Integer Strategies

引用

IEEE ROBOTICS AND AUTOMATION LETTERS 2024年第7期9卷 6194-6201页

作者： Fey, Nolan Frei, Robert J. Wensing, Patrick M. MIT Dept Mech Engn Cambridge MA 02139 USA Univ Michigan Dept Robot Ann Arbor MI 48109 USA Univ Notre Dame Dept Aerosp & Mech Engn Notre Dame IN 46556 USA

As quadruped controllers approach greater maturity for locomotion on level ground, a next challenge relates to enabling these systems to carefully choose contacts in cluttered or discontinuous terrain. In pursuit of this goal, this letter proposes an approach to motion generation for dynamic hopping in clutter. Due to fundamental scalability limitations of mixed-integer programming (MIP) formulations, it is common to adopt simplified models, most often focused on the center of mass (COM) or the centroidal dynamics, to generate a motion sketch for subsequent whole-body planning. This letter considers a MIP formulation on a single-rigid-body model, but simplifies the locomotion planning problem by considering each stance phase as impulsive. We show that this reduction enables our MIP formulation to address locomotion in discontinuous and cluttered environments, while including 3D orientation evolution and actuator limitations, and keeping the computational demands manageable for real-time deployment. Once contacts are fixed, the resulting motion sketch can be readily post-processed by existing optimization tools to remove the impulse assumption and smooth the desired COM trajectory. The work is validated in experiments with the MIT Mini Cheetah executing multiple consecutive hops between surfaces while avoiding obstacle regions.

关键词： Legged Robots multi-contact whole-body motion planning and control optimization and optimal control

来源：评论

学校读者我要写书评

暂无评论

A Minimum-Jerk Approach to Handle Singularities in Virtual Fixtures

引用

IEEE ROBOTICS AND AUTOMATION LETTERS 2024年第11期9卷 10256-10263页

作者： Braglia, Giovanni Calinon, Sylvain Biagiotti, Luigi Univ Modena & Reggio Emilia Dept Engn Enzo Ferrari I-41125 Modena Italy Idiap Res Inst Martigny Switzerland Ecole Polytech Fed Lausanne EPFL CH-1015 Lausanne Switzerland

Implementing virtual fixtures in guiding tasks constrains the movement of the robot's end effector to specific curves within its workspace. However, incorporating guiding frameworks may encounter discontinuities when optimizing the reference target position to the nearest point relative to the current robot position. This article aims to give a geometric interpretation of such discontinuities, with specific reference to the commonly adopted Gauss-Newton algorithm. The effect of such discontinuities, defined as Euclidean Distance Singularities, is experimentally proved. We then propose a solution that is based on a linear quadratic tracking problem with minimum jerk command, then compare and validate the performances of the proposed framework in two different human-robot interaction scenarios.

关键词： Robots Robot kinematics Trajectory Human-robot interaction Euclidean distance Tracking Jacobian matrices Vectors Recording Manifolds Human-robot collaboration motion and path planning optimization and optimal control physical human-robot interaction

来源：评论

学校读者我要写书评

暂无评论

Efficient safety-critical trajectory planning for any N-trailer system with a general model

引用

control ENGINEERING PRACTICE 2025年 158卷

作者： Gao, Liang Jia, Bobo Li, Daiwei Yang, Yi Xie, Shanshan Beijing Inst Technol Coll Automat Beijing 100081 Peoples R China

Trajectory planning for tractor-trailer vehicles (TTVs) in a cluttered environment is a highly challenging task owing to complicated kinematic and large-scale collision-avoidance constraints. It has stringent requirements for trajectory feasibility and computational efficiency. Moreover, the varying configurations of TTVs pose challenges to the scalability of the planning method. This article proposes a novel safety-critical trajectory planning method with a general model to address these challenges. Firstly, an algebraic general model is first presented to represent these N-Trailer systems with different hitching types and trailer types uniformly. Secondly, the planning problem is formulated as a nonlinear model predictive control scheme with two key efforts to accelerate calculation speed. One operation is that a novel search-guided optimization-based collision avoidance (SG-OBCA) method is developed to provide a high-quality initial guess. The other operation is that intractable non-convex collision-avoidance constraints are translated into a dual form based on exponential discrete-time control barrier function (DCBF). Finally, both comparative simulations and real-world experiments are conducted to demonstrate the efficiency and applicability of the proposed method indifferent complicated scenarios and configurations of TTVs.

关键词： optimization and optimal control Tractor-trailer vehicle Nonholonomic motion planning General model control barrier function

来源：评论

学校读者我要写书评

暂无评论

ProxDDP: Proximal Constrained Trajectory optimization

引用

IEEE TRANSACTIONS ON ROBOTICS 2025年 41卷 2605-2624页

作者： Jallet, Wilson Bambade, Antoine Arlaud, Etienne El-Kazdadi, Sarah Mansard, Nicolas Carpentier, Justin PSL Res Univ Inria Dept Informat Ecolenormale Super F-75006 Paris France LAAS CNRS F-75006 Toulouse France

Trajectory optimization has been a popular choice for motion generation and control in robotics for at least a decade. Several numerical approaches have exhibited the required speed to enable online computation of trajectories for real-time of various systems, including complex robots. Many of these said are based on the differential dynamic programming (DDP) algorithm-initially designed for unconstrained trajectory optimization problems-and its variants, which are relatively easy to implement and provide good runtime performance. However, several problems in robot control call for using constrained formulations (e.g., torque limits, obstacle avoidance), from which several difficulties arise when trying to adapt DDP-type methods: numerical stability, computational efficiency, and constraint satisfaction. In this article, we leverage proximal methods for constrained optimization and introduce a DDP-type method for fast, constrained trajectory optimization suited for model-predictive control (MPC) applications with easy warm-starting. Compared to earlier solvers, our approach effectively manages hard constraints without warm-start limitations and exhibits good convergence behavior. We provide a complete implementation as part of an open-source and flexible C++ trajectory optimization library called aligator. These algorithmic contributions are validated through several trajectory planning scenarios from the robotics literature and the real-time whole-body MPC of a quadruped robot.

关键词： Legged robots model-predictive control (MPC) optimization and optimal control optimization and optimal control optimization and optimal control

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：