scholarly journals Application of Visual Servo Control in Autonomous Mobile Rescue Robots

2016 ◽  
Vol 11 (5) ◽  
pp. 685 ◽  
Author(s):  
Haoxiang Lang ◽  
Muhammad Tahir Khan ◽  
Kok-Kiong Tan ◽  
Clarence W. W. De Silva
Keyword(s):  
Visual Servoing ◽  
Servo Control ◽  
Mobile Robot Navigation ◽  
Mobile Manipulation ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Advantages And Disadvantages ◽  
Configuration System ◽  
Rescue Robots ◽  
Robot Configuration

Mobile robots that integrate visual servo control for facilitating autonomous grasping nd manipulation are the focus of this paper. In view of mobility, they have wider pplication than traditional fixed-based robots with visual servoing. Visual servoing s widely used in mobile robot navigation. However, there are not so many report or applying it to mobile manipulation. In this paper, challenges and limitations of pplying visual servoing in mobile manipulation are discussed. Next, two classical pproaches (image-based visual servoing (IBVS) and position-based visual servoing (PBVS)) are introduced aloing with their advantages and disadvantages. Simulations n Matlab are carried out using the two methods, there advantages and drawbacks are llustrated and discussed. On this basis, a suggested system in mobile manipulation s proposed including an IBVS with an eye-in-hand camera configuration system. imulations and experimentations are carried with this robot configuration in a earch and rescue scenario, which show good performance.

scholarly journals Optimal Projection Pattern for Active Visual Servoing (AVS)

2021 ◽  
Author(s):  
SHOGO ARAI ◽  
Yoshihiro Miyamoto ◽  
Akinari Kobayashi ◽  
Kazuhiro Kosuge
Keyword(s):  
Visual Servoing ◽  
Target Object ◽  
Servo Control ◽  
Visual Features ◽  
Positioning Error ◽  
Robotic Control ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Optimal Projection ◽  
Projection Pattern

<p>Visual servo control uses images that are obtained by a camera for robotic control. This study focuses on the problem of positioning a target object using a robotic manipulator with image-based visual servo (IBVS) control. To perform the positioning task, the image-based visual servoing requires visual features that can be extracted from the appearance of the target object. Therefore, a positioning error tends to increase especially for textureless objects, such as industrial parts. Since it is difficult to extract differences of the visual features between current and goal images. To solve these problems, this paper presents a novel visual servoing named ``Active Visual Servoing." Active Visual Servoing (AVS) projects patterned light onto the target object using a projector. The design of the projection pattern affects the positioning error. AVS uses an optimal pattern which is theoretically derived and maximizes differences between current and goal images. The experimental results show that the proposed active visual servoing method reduces the positioning error by more than 97% compared to conventional image-based visual servoing.</p>

Recent Advances on Robot Visual Servo Control Methods

2020 ◽  
Vol 13 ◽  
Author(s):  
Hongxin Zhang ◽  
Meng Li ◽  
Shaowei Ma ◽  
Hanghang Jiang ◽  
Hongyu Wang
Keyword(s):  
Servo Control ◽  
Control Methods ◽  
Visual Servo ◽  
Improve Performance ◽  
Visual Servo Control ◽  
Multiple Sensors ◽  
Advantages And Disadvantages ◽  
Potential Problems ◽  
Feasible Solutions ◽  
Organic Combination

Background: In order to enable robots to complete complex tasks, robots are required to have higher intelligence and adaptability. RVSC (Robot Visual Servo Control) is an organic combination of machine vision and servo control and is a complex system with strong coupling and nonlinearity, which improves the performance of robots and provides feasible solutions for solving practical problems in many fields. Objective: To review the latest development of RVSC methods and provide references for researchers in related fields. Methods: RVSC related patents and literatures were analyzed from the aspects of the algorithm, innovation and application. In addition, the typical RVSC methods are summarized. Results: This paper analyzes the advantages and disadvantages of various methods in many patents and literatures. Moreover, the typical applications, potential problems and future development directions of this field is put forward. Conclusion: RVSC has better performance than traditional control methods. In addition, it can also be combined with some algorithms or knowledge to further improve performance. But, the further improvements of RVSC are needed in the following areas: the convenience of operation, the optimization of trajectory planning, the combination of multiple sensors, etc. Furthermore, more patents of the RVSC also should be invented.

scholarly journals Imaged-Based Visual Servo Control for a VTOL Aircraft

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Liying Zou ◽  
Huiguang Li ◽  
Wei Zhao ◽  
Lei Zhu
Keyword(s):  
Control Strategy ◽  
Visual Servoing ◽  
Lyapunov Theory ◽  
Servo Control ◽  
Depth Information ◽  
Visual Servo ◽  
Aircraft Control ◽  
Visual Servo Control ◽  
Visual Model ◽  
Vtol Aircraft

This paper presents a novel control strategy to force a vertical take-off and landing (VTOL) aircraft to accomplish the pinpoint landing task. The control development is based on the image-based visual servoing method and the back-stepping technique; its design differs from the existing methods because the controller maps the image errors onto the actuator space via a visual model which does not contain the depth information of the feature point. The novelty of the proposed method is to extend the image-based visual servoing technique to the VTOL aircraft control. In addition, the Lyapunov theory is used to prove the asymptotic stability of the VTOL aircraft visual servoing system, while the image error can converge to zero. Furthermore, simulations have been also conducted to demonstrate the performances of the proposed method.

scholarly journals Mix Frame Visual Servo Control Framework for Autonomous Assistive Robotic Arms

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 642
Author(s):  
Zubair Arif ◽  
Yili Fu
Keyword(s):  
Visual Servoing ◽  
The Elderly ◽  
Human Robot Interaction ◽  
Servo Control ◽  
Control Mode ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Robotic Arms ◽  
Control Framework ◽  
Assistive Robotic

Assistive robotic arms (ARAs) that provide care to the elderly and people with disabilities, are a significant part of Human-Robot Interaction (HRI). Presently available ARAs provide non-intuitive interfaces such as joysticks for control and thus, lacks the autonomy to perform daily activities. This study proposes that, for inducing autonomous behavior in ARAs, visual sensors integration is vital, and visual servoing in the direct Cartesian control mode is the preferred method. Generally, ARAs are designed in a configuration where its end-effector’s position is defined in the fixed base frame while orientation is expressed in the end-effector frame. We denoted this configuration as ‘mixed frame robotic arms’. Consequently, conventional visual servo controllers which operate in a single frame of reference are incompatible with mixed frame ARAs. Therefore, we propose a mixed-frame visual servo control framework for ARAs. Moreover, we enlightened the task space kinematics of a mixed frame ARAs, which led us to the development of a novel “mixed frame Jacobian matrix”. The proposed framework was validated on a mixed frame JACO-2 7 DoF ARA using an adaptive proportional derivative controller for achieving image-based visual servoing (IBVS), which showed a significant increase of 31% in the convergence rate, outperforming conventional IBVS joint controllers, especially in the outstretched arm positions and near the base frame. Our Results determine the need for the mixed frame controller for deploying visual servo control on modern ARAs, that can inherently cater to the robotic arm’s joint limits, singularities, and self-collision problems.

scholarly journals Optimal Projection Pattern for Active Visual Servoing (AVS)

2021 ◽  
Author(s):  
SHOGO ARAI ◽  
Yoshihiro Miyamoto ◽  
Akinari Kobayashi ◽  
Kazuhiro Kosuge
Keyword(s):  
Visual Servoing ◽  
Target Object ◽  
Servo Control ◽  
Visual Features ◽  
Positioning Error ◽  
Robotic Control ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Optimal Projection ◽  
Projection Pattern

<p>Visual servo control uses images that are obtained by a camera for robotic control. This study focuses on the problem of positioning a target object using a robotic manipulator with image-based visual servo (IBVS) control. To perform the positioning task, the image-based visual servoing requires visual features that can be extracted from the appearance of the target object. Therefore, a positioning error tends to increase especially for textureless objects, such as industrial parts. Since it is difficult to extract differences of the visual features between current and goal images. To solve these problems, this paper presents a novel visual servoing named ``Active Visual Servoing." Active Visual Servoing (AVS) projects patterned light onto the target object using a projector. The design of the projection pattern affects the positioning error. AVS uses an optimal pattern which is theoretically derived and maximizes differences between current and goal images. The experimental results show that the proposed active visual servoing method reduces the positioning error by more than 97% compared to conventional image-based visual servoing.</p>

An intelligent visual servo control system for quadrotors

2018 ◽  
Vol 41 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Tolga Yüksel
Keyword(s):  
Fuzzy Logic ◽  
Control System ◽  
Visual Servoing ◽  
Landing Site ◽  
Servo Control ◽  
Field Of View ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Servo Control System ◽  
Logic Unit

While quadrotors are becoming more popular, control of these unmanned air vehicles should be improved. In this study, a new intelligent image-based visual servo control system is proposed for the flight guidance control of quadrotors. Features are essential for visual servoing and the proposed system utilizes the features of a shape that provide a clear sight of the landing site instead of point features. Furthermore, the system focuses on three problems of visual servo control: finding an appropriate gain value under velocity limits, keeping the shape features in the field of view and tracking a moving target. As a solution to the first problem, a fuzzy logic unit that uses feature error and error derivative norms as inputs are deployed to assign the gain, adaptively. The second problem is solved by defining safe and risky regions in the image plane to take precautions before field of view missing. Another fuzzy logic unit is activated when the shape passes through a risky region to provide counter velocity in x or y direction and to drag the shape through the safe region. As the last stage, Kalman filtering with Potter’s square root update is added to the proposed system to increase the feature tracking performance. This update also promises divergence avoidance. To show the performance of the proposed system, simulation results for fixed and moving targets under feature disturbance are presented for a quadrotor. The results verify that the proposed system is capable of handling visual servoing problems.

scholarly journals Visual Servo Control of a Legged Mobile Robot Based on Homography

2020 ◽  
Author(s):  
Haitao Liu ◽  
Dewei Zhang ◽  
Xianye Wang ◽  
Juliang Xiao
Keyword(s):  
Mobile Robot ◽  
Visual Servoing ◽  
Sliding Mode ◽  
Median Filter ◽  
Three Dimensional ◽  
Servo Control ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Periodic Movement ◽  
The Stability

Abstract Due to the intermittent motion of a legged mobile robot, an additional periodic movement must be introduced that directly affects the image processing accuracy and destabilizes the visual servo control of the robot. To address this problem, this paper investigates a control scheme for the visual servoing of a legged mobile robot equipped with a fixed monocular camera. The kinematics of the legged mobile robot and homography- based visual servoing are employed to allow the robot to achieve the desired pose. By investigating the homographic relationship between the current and desired poses, the approach has no need for transcendental knowledge of the three-dimensional geometry of the target image. The feature points are directly extracted from the images to evaluate the homography matrix. To reduce the effects caused by the intermittent motions of the legged robot, an improved adaptive median filter is proposed. Furthermore, a sliding mode controller is designed, and a Lyapunov-based approach is used to analyze the stability of the control system. With the aid of CoppeliaSim software, a simulation is implemented to verify the effectiveness of the proposed method.

Navigation Function Based Visual Servo Control

2004 ◽  
Author(s):  
J. Chen ◽  
D. M. Dason ◽  
W. E. Dixon ◽  
V. K. Chitrakaran
Keyword(s):  
Servo Control ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Navigation Function
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