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1.
在未知环境中基于模糊逻辑的移动机器人行为控制   总被引:2,自引:1,他引:2       下载免费PDF全文
本文介绍了一种在未知环境中基于模糊逻辑的移动机器人行为控制方法.传统的行为控制方法存在两个弱点:①行为不易描述;②多个行为之间的冲突和竞争难以协调.这篇文章的主要思想是将模糊逻辑控制与行为控制相结合致使这两个问题得到有效的解决.仿真实验结果表明:所提的方法通过多个行为如避障边沿行走和目标导向的融合,能够有效地对机器人在复杂和未知环境中导航.另外,该方法还适用于多传感器的融合与集成.  相似文献   

2.
本文研究了障碍环境下多关节机器人自主实时避碰运动理论、技术与方法. 研制的新型红外传感皮肤, 可以为多关节机器人提供所需要的周围环境信息. 针对非结构化环境下的多关节机器人实时避障问题, 提出了一种未知环境下的机器人模糊路径实时规划新方法. 实验结果表明: 基于研制的红外传感皮肤和模糊运动规划算法, 多关节机器人可以在未知或时变环境下自主工作.  相似文献   

3.
本文结合线性时序逻辑理论与模糊控制方法,设计并实现了一种满足复杂任务需求的移动机器人巡回控制系统,它既能够针对复杂时序任务进行路径规划,又能够对机器人进行模糊控制实现路径跟踪.首先,基于线性时序逻辑理论,确定能够满足复杂巡回任务需求的全局最优路径.接着,根据所获得的最优路径,采用模糊控制方法设计轨迹跟踪控制器,使其通过实时位姿反馈对机器人进行路径跟踪控制.仿真结果验证了移动机器人巡回控制系统的有效性.最后,基于E-Puck移动机器人构建了能够满足复杂任务需求的移动机器人巡回控制实验系统.基于所提出的最优巡回路径规划算法和模糊控制器设计方法,通过图像处理、数据通信、算法加载等软件模块的实现完成了满足复杂任务需求的移动机器人巡回控制.  相似文献   

4.
本文针对关节式移动机器人在斜面上运动时稳定性和安全性的要求对其进行动力学分析 ,利用传感器融合技术对机器人进行局部定位 ,提出了它的基于模糊逻辑的控制策略 .实验证明这种方法是可行的和有效的  相似文献   

5.
Obstacle Avoidance Using the Human Operator Experience for a Mobile Robot   总被引:2,自引:0,他引:2  
In this paper, a neuro-fuzzy technique has been used to steer a mobile robot. The neuro-fuzzy approach provides a good way to capture the information given by a human. In this manner, it has been possible to obtain the rules and membership functions automatically whereas a fuzzy approach needs to make a prior definition of the rules and membership functions. In order to apply the neuro-fuzzy strategy, two mobile robots have been developed. However, in this paper only the smallest one has been considered. Similar results are obtained for the biggest one. The results of the approach are satisfactory, avoiding the obstacles when the mobile robot is steered to the target.  相似文献   

6.
In this paper a new approach for steering a binocular head is presented. This approach is based on extracting the expert’s knowledge in order to improve the behaviour of the classical control strategies. This is carried out without inserting new elements in the system. Neuro–Fuzzy techniques have been chosen in order to reach this target. As a result a more friendly robotic system is achieved.  相似文献   

7.
    
Highly accurate real‐time localization is of fundamental importance for the safety and efficiency of planetary rovers exploring the surface of Mars. Mars rover operations rely on vision‐based systems to avoid hazards as well as plan safe routes. However, vision‐based systems operate on the assumption that sufficient visual texture is visible in the scene. This poses a challenge for vision‐based navigation on Mars where regions lacking visual texture are prevalent. To overcome this, we make use of the ability of the rover to actively steer the visual sensor to improve fault tolerance and maximize the perception performance. This paper answers the question of where and when to look by presenting a method for predicting the sensor trajectory that maximizes the localization performance of the rover. This is accomplished by an online assessment of possible trajectories using synthetic, future camera views created from previous observations of the scene. The proposed trajectories are quantified and chosen based on the expected localization performance. In this study, we validate the proposed method in field experiments at the Jet Propulsion Laboratory (JPL) Mars Yard. Furthermore, multiple performance metrics are identified and evaluated for reducing the overall runtime of the algorithm. We show how actively steering the perception system increases the localization accuracy compared with traditional fixed‐sensor configurations.  相似文献   

8.
    
This study presents a novel octree‐based three‐dimensional (3D) exploration and coverage method for autonomous underwater vehicles (AUVs). Robotic exploration can be defined as the task of obtaining a full map of an unknown environment with a robotic system, achieving full coverage of the area of interest with data from a particular sensor or set of sensors. While most robotic exploration algorithms consider only occupancy data, typically acquired by a range sensor, our approach also takes into account optical coverage, so the environment is discovered with occupancy and optical data of all discovered surfaces in a single exploration mission. In the context of underwater robotics, this capability is of particular interest, since it allows one to obtain better data while reducing operational costs and time. This study expands our previous study in 3D underwater exploration, which was demonstrated through simulation, presenting improvements in the view planning (VP) algorithm and field validation. Our proposal combines VP with frontier‐based (FB) methods, and remains light on computations even for 3D environments thanks to the use of the octree data structure. Finally, this study also presents extensive field evaluation and validation using the Girona 500 AUV. In this regard, the algorithm has been tested in different scenarios, such as a harbor structure, a breakwater structure, and an underwater boulder.  相似文献   

9.
    
A key challenge in autonomous mobile manipulation is the ability to determine, in real time, how to safely execute complex tasks when placed in unknown or changing world. Addressing this issue for Intervention Autonomous Underwater Vehicles (I‐AUVs), operating in potentially unstructured environment is becoming essential. Our research focuses on using motion planning to increase the I‐AUVs autonomy, and on addressing three major challenges: (a) producing consistent deterministic trajectories, (b) addressing the high dimensionality of the system and its impact on the real‐time response, and (c) coordinating the motion between the floating vehicle and the arm. The latter challenge is of high importance to achieve the accuracy required for manipulation, especially considering the floating nature of the AUV and the control challenges that come with it. In this study, for the first time, we demonstrate experimental results performing manipulation in unknown environment. The Multirepresentation, Multiheuristic A* (MR‐MHA*) search‐based planner, previously tested only in simulation and in a known a priori environment, is now extended to control Girona500 I‐AUV performing a Valve‐Turning intervention in a water tank. To this aim, the AUV was upgraded with an in‐house‐developed laser scanner to gather three‐dimensional (3D) point clouds for building, in real time, an occupancy grid map (octomap) of the environment. The MR‐MHA* motion planner used this octomap to plan, in real time, collision‐free trajectories. To achieve the accuracy required to complete the task, a vision‐based navigation method was employed. In addition, to reinforce the safety, accounting for the localization uncertainty, a cost function was introduced to keep minimum clearance in the planning. Moreover a visual‐servoing method had to be implemented to complete the last step of the manipulation with the desired accuracy. Lastly, we further analyzed the approach performance from both loose‐coupling and clearance perspectives. Our results show the success and efficiency of the approach to meet the desired behavior, as well as the ability to adapt to unknown environments.  相似文献   

10.
This paper discusses the work undertaken at the U.K. National Advanced Robotics Research Centre in the area of path planning. Experiments have been undertaken with the Best First Planner (BFP) and Random Path Planner (RPP) algorithms developed at Stanford University by Barraquand and Latombe. These look particularly suitable for solving a wide range of motion planning problems and for providing the basic mechanism for path planning in an advanced robotic architecture. From this basic mechanism higher level functional primitives have been developed to enable paths to be planned with a pre-defined orientation of the end effector at the goal location or maintaining an orientation throughout the whole path. These functions are achieved through placing additional constraints on the search through configuration space and modifying the workspace potential.  相似文献   

11.
Automatic motion planning is one of the basic modules that are needed to increase robot intelligence and usability. Unfortunately, the inherent complexity of motion planning has rendered traditional search algorithms incapable of solving every problem in real time. To circumvent this difficulty, we explore the alternative of allowing human operators to participate in the problem solving process. By having the human operator teach during difficult motion planning episodes, the robot should be able to learn and improve its own motion planning capability and gradually reduce its reliance on the human operator. In this paper, we present such a learning framework in which both human and robot can cooperate to achieve real-time automatic motion planning. To enable a deeper understanding of the framework in terms of performance, we present it as a simple learning algorithm and provide theoretical analysis of its behavior. In particular, we characterize the situations in which learning is useful, and provide quantitative bounds to predict the necessary training time and the maximum achievable speedup in planning time.  相似文献   

12.
We solve the Motion Planning Problem for nonholonomic systems without drift when their inputs are restricted to take values in a prescribed discrete levels set of finite cardinality. In particular, we propose algorithms that produce the proper sequence of input levels as well as the corresponding switching times providing exact steering when the system is nilpotent or feedback nilpotentizable. For a general drift-free system, i.e. for a drift-free system that is neither nilpotent nor feedback nilpotentizable another algorithm provides approximate steering within a permissible error. Finally, we apply the proposed algorithms in motion planning for a car-like mobile robot.  相似文献   

13.
    
Narrow corridors are a cause of intense problems in sampling‐based approaches due to the small probability of generation of samples inside the narrow corridor. The obstacle‐based sampling and bridge test sampling techniques rely on generating fresh samples at every iteration. Memory of the forbidden configuration space can lead to the discovery of new narrow corridors or generating additional key samples inside the same narrow corridor. Hence, in this paper, it is proposed to additionally solve the problem of generating a roadmap in the forbidden configuration space, called as the dual roadmap. The dual roadmap, so generated, has vertices that are collision‐prone and stores the structure of the forbidden configuration space. To reduce memory and computation time, only the boundary of the forbidden configuration space is stored, which is more informative. The dual roadmap, so constructed, is used to generate valid samples inside the middle of the narrow corridors. The construction of the additional roadmap takes a very small time and memory and is largely the biproduct of obstacle‐based sampling that is normally thrown away. Experimental results show that the proposed sampling method is very effective for finding narrow corridors as compared to popular sampling methodologies existing in the literature.  相似文献   

14.
    
Most algorithms in probabilistic sampling-based path planning compute collision-free paths made of straight line segments lying in the configuration space. Due to the randomness of sampling, the paths make detours that need to be optimized. The contribution of this paper is to propose a basic gradient-based algorithm that transforms a polygonal collision-free path into a shorter one. While requiring only collision checking, and not any time-consuming obstacle distance computation nor geometry simplification, we constrain only part of the configuration variables that may cause a collision, and not entire configurations. Thus, parasite motions that are not useful for the problem resolution are reduced without any assumption. Experimental results include navigation and manipulation tasks, eg a manipulator arm-filling boxes and a PR2 robot working in a kitchen environment. Comparisons with a random shortcut optimizer and a partial shortcut have also been studied.  相似文献   

15.
Bennett  Scott W.  DeJong  Gerald F. 《Machine Learning》1996,23(2-3):121-161
In executing classical plans in the real world, small discrepancies between a planner's internal representations and the real world are unavoidable. These can conspire to cause real-world failures even though the planner is sound and, therefore, proves that a sequence of actions achieves the goal. Permissive planning, a machine learning extension to classical planning, is one response to this difficulty. This paper describes the permissive planning approach and presents GRASPER, a permissive planning robotic system that learns to robustly pick up novel objects.  相似文献   

16.
    
We present results from sea trials for an autonomous surface vehicle (ASV) equipped with a collision avoidance system based on model predictive control (MPC). The sea trials were performed in the North Sea as part of an ASV Challenge posed by Deltares through a Dutch initiative involving different authorities, including the Ministry of Infrastructure and Water Management, the Netherlands Coastguard, and the Royal Netherlands Navy. To allow an ASV to operate in a maritime environment governed by the International Regulations for Preventing Collisions at Sea (COLREGs), the ASV must be capable of complying with COLREGs. Therefore, the sea trials focused on verifying COLREGs‐compliant behavior of the ASV in different challenging scenarios using automatic identification system (AIS) data from other vessels. The scenarios cover situations where some obstacle vessels obey COLREGs and emergency situations where some obstacles make decisions that increase the risk of collision. The MPC‐based collision avoidance method evaluates a combined predicted collision and COLREGs‐compliance risk associated with each obstacle and chooses the ‘best’ way out of dangerous situations. The results from the verification exercise in the North Sea show that the MPC approach is capable of finding safe solutions in challenging situations, and in most cases demonstrates behaviors that are close to the expectations of an experienced mariner. According to Deltares’ report, the sea trials have shown in practice that the technical maturity of autonomous vessels is already more than expected.  相似文献   

17.
A Simple Robust Sliding-Mode Fuzzy-Logic Controller of the Diagonal Type   总被引:5,自引:0,他引:5  
This paper derives and analyzes a new robust fuzzy-logic sliding-mode controller of the diagonal type, which does not need the prior design of the rule base. The basic objective of the controller is to keep the system on the sliding surface so as to ensure the asympotic stability of the closed-loop system. The control law consists of two rules: (i) IF sign(e(t)(t)) < 0 THEN maintain the control action, and (ii) IF sign(e(t)(t)) > 0 THEN change the control action, where e(t) = x(t) – xd(t) is the system state error, and the control action can be either an increase or decrease of the control signal, which is realized through the use of fuzzy rules. The proposed controller, which does not need the prior knowledge of the system model and the prior design of the membership functions" shape, was tested, by simulation, on linear and nonlinear systems. The performance was in all cases excellent (very fast trajectory tracking, no chattering) . Of course, as in traditional control, there was a trade-off between the rise-time and the overshoot of the system response.  相似文献   

18.
无线传感器网络的模糊功率控制技术   总被引:1,自引:0,他引:1  
赵静  陈向东  王岩 《传感技术学报》2006,19(3):882-884,889
无线传感器网络节点通过撒播造成节点分布不均,分簇后导致分簇疏密不均,影响了网络性能,需要对簇头进行功率控制使网络结构更加优化.但这是一个难以确定其准确数学模型的过程,因此提出了一种采用模糊技术调整簇头功率以改变拓扑结构的方案.最后进行了仿真,实验结果证明通过分簇大小控制以后,网络的生存时间和通信量都有增加.  相似文献   

19.
This paper presents a new adaptation mechanism for a cascaded positioncontroller. The cascaded position controller consists of P.I.D. controllersthe parameters of which are changed by a fuzzy logic adaptation mechanism.The proposed fuzzy logic adaptation mechanism is tested using thesix-degree-of-freedom-robot RV 15, manufactured by Reis Robotics. Using thefuzzy logic adaptation mechanism, the cartesian position error of the toolcenter point can be significantly reduced by 50 %. Anotherenhancement of the dynamic behaviour, which can be achieved by the fuzzylogic adaptation mechanism, is to lessen the influence of different loads onthe cartesian position error.  相似文献   

20.
    
Robot motion planning has become a central topic in robotics and has been studied using a variety of techniques. One approach, followed mainly in computational geometry, aims to develop combinatorial, nonheuristic solutions to motion-planning problems. This direction is strongly related to the study of arrangements of algebraic curves and surfaces in low-dimensional Euclidean space. More specifically, the motion-planning problem can be reduced to the problem of efficiently constructing a single cell in an arrangement of curves or surfaces. We present the basic terminology and the underlying ideas of the approach. We describe past work and then survey a series of recent results in exact motion planning with three degrees of freedom and the related issues of the complexity and construction of a single cell in certain arrangements of surface patches in three-dimensional space.  相似文献   

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