Mobile Robot Regulation With Image Based Visual Servoing

2018 ◽  
Author(s):  
Aaron Hao Tan ◽  
Abdulrahman Al-Shanoon ◽  
Haoxiang Lang ◽  
Moustafa El-Gindy
Keyword(s):  
Visual Servoing ◽  
Target Object ◽  
Feature Points ◽  
Matlab Simulation ◽  
The Past ◽  
Vision Sensors ◽  
Servo Controller ◽  
Differential Drive Robot ◽  
Proportional Controller ◽  
Mobile Base

The development of image processing algorithms grew exponentially over the past few decades with improvements in vision sensors and computational power. In this paper, a visual servo controller is designed and developed using the image-based method for a differential drive robot. The objective is to reach a desired pose relative to a target object placed in the world frame with four feature points. A full system model that includes the mobile base and camera is presented along with the design of a proportional controller. The system is implemented in the Husky A200 Robot by Clearpath Robotics. MATLAB Simulation and experimental results are analyzed and discussed with conclusion and future works recommendation in the end.

Short article: Verb aspect and perceptual simulations

2009 ◽  
Vol 62 (7) ◽  
pp. 1294-1303 ◽  
Author(s):  
Carol J. Madden ◽  
David J. Therriault
Keyword(s):  
Language Comprehension ◽  
Word Reading ◽  
Target Object ◽  
Short Article ◽  
Surface Features ◽  
The Past ◽  
Verb Aspect ◽  
Over Time

Two experiments investigate the influence of verb aspect on situation representations. The results demonstrate that comprehenders use verb aspect as a cue to regulate the activation of ongoing simulations of situations over time. Experiment 1 measured word-by-word reading as well as sensibility judgements on sentences in which a target object word had been replaced by a picture. For the past imperfective sentences, participants were faster to process the picture, the two words following the picture, and the sensibility judgements when objects were pictured in use rather than not in use. However, this in-use facilitation was limited to processing of the picture for the past perfect sentences. Experiment 2 served as a control to ensure that the use effect and its interaction with verb aspect were a result of contextual manipulations rather than surface features of the pictures themselves. The results are interpreted within the framework of perceptual simulations during language comprehension.

Multi-View 3D Object Reconstruction Using Coordinate Transformation

2013 ◽  
Vol 284-287 ◽  
pp. 2167-2170 ◽  
Author(s):  
Ji Hun Park
Keyword(s):  
Coordinate Transformation ◽  
Digital Camera ◽  
Optimal Solution ◽  
Calibration Method ◽  
Target Object ◽  
Feature Points ◽  
Geometric Information ◽  
Local Coordinates ◽  
Camera Parameters ◽  
Parameter Values

The algorithm presented in this paper takes at least two images taken by an ordinary digital camera, computes camera parameters and outputs scene geometric information. The method takes at least one right-angle triangle in the scene, install a local coordinate at each triangle, and compute camera parameters by using the local coordinate transformation. The algorithm computes orientations and displacement relationships among the triangles in the scene while correcting the previously computed camera parameter values. In order to find optimal solution, we set optimization variables as camera calibration parameters and coordinate transformation values between local coordinates. The background eliminated images and calculated camera parameters allow us to reconstruct a 3D target object in VRML. The merit of this algorithm is in handling varying focal camera, in easy initial guessing value computation and in using fewer feature points compared to Zhang’s calibration method.

scholarly journals Calibration of Binocular Vision Sensors Based on Unknown-Sized Elliptical Stripe Images

2017 ◽  
Author(s):  
Zhen Liu ◽  
Suining Wu ◽  
Yang Yin ◽  
Jinbo Wu
Keyword(s):  
Optical Filter ◽  
Optical Filters ◽  
Calibration Method ◽  
High Accuracy ◽  
Feature Points ◽  
Physical Experiments ◽  
Binocular Stereo Vision ◽  
Vision Sensors ◽  
Calibration Methods ◽  
Binocular Stereo

Most of the existing calibration methods for binocular stereo vision sensor (BSVS) depend on high-accuracy target with feature points that are difficult to manufacture and costly. In complex light conditions, optical filters are used for BSVS, but they affect imaging quality. Hence, the use of a high-accuracy target with certain-sized feature points for calibration is not feasible under such complex conditions. To solve these problems, a calibration method based on unknown-sized elliptical stripe images is proposed. With known intrinsic parameters, the proposed method adopts the elliptical stripes located on the parallel planes as a medium to calibrate BSVS online. In comparison with the common calibration methods, the proposed method avoids utilizing high-accuracy target with certain-sized feature points. Therefore, the proposed method is not only easy to implement but is a realistic method for the calibration of BSVS with optical filter. Changing the size of elliptical curves projected on the target solves the difficulty of applying the proposed method in different fields of view and distances. Simulative and physical experiments are conducted to validate the efficiency of the proposed method. When the field of view is approximately 400 mm × 300 mm, the proposed method can reach a calibration accuracy of 0.03 mm, which is comparable with that of Zhang’s method.

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>

Analyses about Trackability of Hand-Eye-Vergence Visual Servoing in Lateral Direction

2015 ◽  
Vol 772 ◽  
pp. 512-517 ◽  
Author(s):  
Yu Cui ◽  
Kenta Nishimura ◽  
Yusuke Sunami ◽  
Mamoru Minami ◽  
Takayuki Matsuno ◽  
...  
Keyword(s):  
Frequency Response ◽  
Visual Servoing ◽  
Target Object ◽  
Moving Target ◽  
Lateral Direction ◽  
Nonlinear Dynamical ◽  
Pose Tracking ◽  
Tracking Ability ◽  
The One

Visual Servoing to Moving Target with Fixed Hand-Eye Cameras Mounted at Hand of Robot is Inevitably Be Affected by Hand Dynamical Oscillations, then it is Hard to Keep Target at the Centre of Camera’s Image, since Nonlinear Dynamical Effects of Whole Manipulator Stand against Tracking Ability. in Order to Solve this Problem, an Eye-Vergence System, where the Visual Servoing Controller of Hand and Eye-Vergence is Controlled Independently, so that the Cameras can Observe the Target Object at the Center of the Camera Images through Eye-Vergence Functions. the Eyes with Light Mass Make the Cameras’ Eye-Sight Direction Rotate Quickly, so the Track Ability of the Eye-Vergence Motion is Superior to the One of Fixed Hand-Eye Configuration. in this Report Merits of Eye-Vengence Visual Servoing for Pose Tracking Have been Confirmed through Frequency Response Experiments.

scholarly journals HYPERPROPERTIES-BASED OPTICAL FLOW-BASED AUTONOMOUS DRIVING SYSTEM

2017 ◽  
Vol 10 (13) ◽  
pp. 254
Author(s):  
Ankush Rai ◽  
Jagadeesh Kanna R
Keyword(s):  
Optical Flow ◽  
Autonomous Driving ◽  
Feature Points ◽  
Motion Vectors ◽  
Driving System ◽  
The Past ◽  
Non Linear ◽  
Autonomous Driving System ◽  
Constraint Sets

This study presents an autonomous driving system based on the principles of trace vectors derived from hyperproperty of a modified optical flowalgorithm. This technique allows keeping track of the past motion vectors by tracking the constraint sets to overcome the non-linear attributes ofthe deformable feature points and motion vectors. The results presented in this work exhibits stable tracking and multi-step prediction in a limitednumber of steps with less training vectors.

Extended hybrid cross-switched multilevel inverter circuit topology

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Saeed Alizadeh ◽  
Mohammad Farhadi-Kangarlu ◽  
Behrouz Tousi
Keyword(s):  
Modulation Method ◽  
Matlab Simulation ◽  
Content Type ◽  
Dc Voltage ◽  
Multilevel Inverters ◽  
The Past ◽  
Hybrid Topology ◽  
Higher Power ◽  
Electronic Switches ◽  
Hybrid Cross

Purpose Multilevel inverters (MLIs) have been studied widely over the past two decades because of their inherent advantages and interesting features. However, most of the newly introduced structures suffer from the increased standing voltage of the switches, which is defined as the maximum off-state voltage on the switches, losing modularity and increased number of direct current (DC) voltage sources. The purpose of this study is to propose a new hybrid MLI topology to alleviate the mentioned problems. Design/methodology/approach The proposed approach in this study includes using the advantage of two different topologies and combine them in a way that the advantages of both of the topologies are achieved. Therefore, the approach is to design a hybrid topology from two existing topologies so that a new topology has resulted. Findings This paper proposes a new hybrid MLI with lower power electronic switches and lowers DC voltage sources in comparison with the classic structures. The proposed MLIs maintain a balance between the number of switches, the standing voltage on the switches and the number of DC sources. The topology description, modulation method and comparative study have been presented. Also, another more reduced structure is presented for higher power factor operation. The MATLAB simulation and experimental results of a nine-level inverter have been presented to verify its operation. Originality/value The hybrid topology has a new structure that has not been presented before. It is important to emphasize that the topology combination and achieving the hybrid topology is wisely accomplished to improve some features of the MLI.

scholarly journals Development of Electrohydraulic Steering Control System for Tractor Automatic Navigation

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Chengqiang Yin ◽  
Qun Sun ◽  
Jian Wu ◽  
Chengqiang Liu ◽  
Jie Gao
Keyword(s):  
Control System ◽  
Design Method ◽  
Fast Response ◽  
Steering System ◽  
Matlab Simulation ◽  
Steering Control ◽  
Automatic Navigation ◽  
Servo Controller ◽  
Improved Design ◽  
Agricultural Tractors

The most of tractors employed in agriculture are equipped with an electrohydraulic actuator to implement steering control to realize automatic navigation. Electrohydraulic steering system plays an important role in realizing accurate steering control for an automatic navigation tractor because of its complicated characteristics. The objective of this paper is to develop an electrohydraulic steering control system used for automatically guided agricultural tractors. As for the identified electrohydraulic steering system model, a modified Smith control structure was discussed. Based on the structure, an improved design method for voltage servo controller and disturbance rejection controller was proposed to enhance the performance of the steering control subsystem. The effectiveness and the superiority of the proposed method were verified by simulation under Matlab. Simulation results demonstrated the efficiency of the proposed method by showing fast response, control accuracy, and robust performance for the steering control system.

Sign in / Sign up

Export Citation Format

Share Document