Research of Intelligent Localization of Target for Manipulator Based on the Monocular Vision

2012 ◽  
Vol 246-247 ◽  
pp. 22-27
Author(s):  
Zheng Zhang ◽  
Xiao Wei Liu ◽  
Guang You Yang
Keyword(s):  
Coordinate System ◽  
Robot Manipulator ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Image Plane ◽  
Calculation Model ◽  
Monocular Vision ◽  
3D Space ◽  
Space Transformation ◽  
World Coordinate System

A kind of calculation model of 3D space transformation is introduced, which is applicable to the monocular vision of robot manipulator, and the three-dimensional space plane mapping problem of image plane to the actual horizontal plane of monocular vision has been solved. It transforms the imaging coordinate system of target in monocular vision into the world coordinate system of the manipulator, so as to calculate the relative position of targets and the manipulator. The algorithm has better accuracy and reliability, which is proved by contrasting and testing the calculation result of object coordinate system transformed to the actual position coordinates to the sampling points in embedded platform.

Robust contact force estimation for robot manipulators in three-dimensional space

2006 ◽  
Vol 220 (9) ◽  
pp. 1317-1327 ◽  
Author(s):  
J Jung ◽  
J Lee ◽  
K Huh
Keyword(s):  
Contact Force ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Contact Forces ◽  
Robust Estimator ◽  
Force Sensors ◽  
Force Estimation ◽  
Estimation Algorithms

Information on contact forces in robot manipulators is indispensable for fast and accurate force control. Instead of expensive force sensors, estimation algorithms for contact forces have been widely developed. However, it is not easy to obtain the accurate values due to uncertainties. In this article, a new robust estimator is proposed to estimate three-dimensional contact forces acting on a three-link robot manipulator. The estimator is based on the extended Kalman filter (EKF) structure combined with a Lyapunov-based adaptation law for estimating the contact force. In contrast to the conventional EKF the new estimator is designed such that it is robust to the deterministic uncertainties such as the modelling error and the sensing bias. The performance of the proposed estimator is evaluated through simulations of a robot manipulator and demonstrates robustness in estimating the contact force. The estimation results show that it can be potentially used to replace the expensive force sensors in robot applications.

scholarly journals RESEARCH ON COORDINATE TRANSFORMATION METHOD OF GB-SAR IMAGE SUPPORTED BY 3D LASER SCANNING TECHNOLOGY

2018 ◽  
Vol XLII-3 ◽  
pp. 1757-1763 ◽  
Author(s):  
P. Wang ◽  
C. Xing
Keyword(s):  
Coordinate System ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Estimation Method ◽  
Image Plane ◽  
Point Clouds ◽  
Transformation Method ◽  
Deformation Monitoring ◽  
Sar Image ◽  
3D Laser Scanning

In the image plane of GB-SAR, identification of deformation distribution is usually carried out by artificial interpretation. This method requires analysts to have adequate experience of radar imaging and target recognition, otherwise it can easily cause false recognition of deformation target or region. Therefore, it is very meaningful to connect two-dimensional (2D) plane coordinate system with the common three-dimensional (3D) terrain coordinate system. To improve the global accuracy and reliability of the transformation from 2D coordinates of GB-SAR images to local 3D coordinates, and overcome the limitation of traditional similarity transformation parameter estimation method, 3D laser scanning data is used to assist the transformation of GB-SAR image coordinates. A straight line fitting method for calculating horizontal angle was proposed in this paper. After projection into a consistent imaging plane, we can calculate horizontal rotation angle by using the linear characteristics of the structure in radar image and the 3D coordinate system. Aided by external elevation information by 3D laser scanning technology, we completed the matching of point clouds and pixels on the projection plane according to the geometric projection principle of GB-SAR imaging realizing the transformation calculation of GB-SAR image coordinates to local 3D coordinates. Finally, the effectiveness of the method is verified by the GB-SAR deformation monitoring experiment on the high slope of Geheyan dam.

scholarly journals METRIC CALIBRATION OF A FOCUSED PLENOPTIC CAMERA BASED ON A 3D CALIBRATION TARGET

2016 ◽  
Vol III-3 ◽  
pp. 449-456 ◽  
Author(s):  
N. Zeller ◽  
C. A. Noury ◽  
F. Quint ◽  
C. Teulière ◽  
U. Stilla ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Image Plane ◽  
Depth Estimation ◽  
Bundle Adjustment ◽  
Optimization Approach ◽  
Calibration Target ◽  
Projection Model ◽  
3D Space ◽  
Plenoptic Camera ◽  
Depth Distortion

In this paper we present a new calibration approach for focused plenoptic cameras. We derive a new mathematical projection model of a focused plenoptic camera which considers lateral as well as depth distortion. Therefore, we derive a new depth distortion model directly from the theory of depth estimation in a focused plenoptic camera. In total the model consists of five intrinsic parameters, the parameters for radial and tangential distortion in the image plane and two new depth distortion parameters. In the proposed calibration we perform a complete bundle adjustment based on a 3D calibration target. The residual of our optimization approach is three dimensional, where the depth residual is defined by a scaled version of the inverse virtual depth difference and thus conforms well to the measured data. Our method is evaluated based on different camera setups and shows good accuracy. For a better characterization of our approach we evaluate the accuracy of virtual image points projected back to 3D space.

scholarly journals METRIC CALIBRATION OF A FOCUSED PLENOPTIC CAMERA BASED ON A 3D CALIBRATION TARGET

2016 ◽  
Vol III-3 ◽  
pp. 449-456 ◽  
Author(s):  
N. Zeller ◽  
C. A. Noury ◽  
F. Quint ◽  
C. Teulière ◽  
U. Stilla ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Image Plane ◽  
Depth Estimation ◽  
Bundle Adjustment ◽  
Optimization Approach ◽  
Calibration Target ◽  
Projection Model ◽  
3D Space ◽  
Plenoptic Camera ◽  
Depth Distortion

In this paper we present a new calibration approach for focused plenoptic cameras. We derive a new mathematical projection model of a focused plenoptic camera which considers lateral as well as depth distortion. Therefore, we derive a new depth distortion model directly from the theory of depth estimation in a focused plenoptic camera. In total the model consists of five intrinsic parameters, the parameters for radial and tangential distortion in the image plane and two new depth distortion parameters. In the proposed calibration we perform a complete bundle adjustment based on a 3D calibration target. The residual of our optimization approach is three dimensional, where the depth residual is defined by a scaled version of the inverse virtual depth difference and thus conforms well to the measured data. Our method is evaluated based on different camera setups and shows good accuracy. For a better characterization of our approach we evaluate the accuracy of virtual image points projected back to 3D space.

Minimization of Common-Mode Voltage of Three-Phase Five-Level NPC Inverter Using 3D Space Vector Modulation

2020 ◽  
Vol 29 (14) ◽  
pp. 2050229 ◽  
Author(s):  
Palanisamy Ramasamy ◽  
Vijayakumar Krishnasamy
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Harmonic Distortion ◽  
Space Vector Modulation ◽  
Space Vector ◽  
Common Mode ◽  
Common Mode Voltage ◽  
3D Space ◽  
Vector Modulation ◽  
Switching State

In this paper, a three-dimensional Space Vector Modulation (3D SVM) is implemented for minimization of Common-Mode Voltage (CMV) of five-level Neutral Point Clamped (NPC) inverter. The 3D SVM control includes all merits of 2D SVM and provides better control compared to other PWM strategies. The switching state vectors are selected based on the nearest vector Switching State Vector (NSV); it selects the switching vectors which are having the minimum CMV level. It leads to minimization of the bearing voltage and protection of the drive from the damage; also this system reduces the total harmonic distortion. The switching time is calculated by reference vector identification with large and small subcubes tracking and prisms tracking in 3D cubic region. The CMV level with 3D SVM scheme is compared with other PWM methods. The simulation and hardware results are verified using Matlab Simulink and FPGA processor.

Path-Tracking Control of Stochastic Quadrotor Aircraft in Three-Dimensional Space

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
K. D. Do
Keyword(s):  
Tracking Control ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Path Tracking ◽  
Effective Control ◽  
Practical Implementation ◽  
Unit Quaternion ◽  
3D Space ◽  
Quadrotor Aircraft ◽  
Deterministic Components

Despite the fact that environmental loads (forces and moments) induced by wind on quadrotor vertical take-off and landing (VTOL) aircraft consist of both deterministic and stochastic components, all existing works on controlling the aircraft either ignore these loads or treat them as deterministic. This ignorance or treatment deteriorates the control performance in a practical implementation. This paper presents a constructive design of controllers for a quadrotor aircraft to track a reference path in three-dimensional (3D) space under both deterministic and stochastic disturbances. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to result in an effective control design, and to achieve path-tracking control results. Weak and strong nonlinear Lyapunov functions are introduced to overcome difficulties caused by underactuation and Hessian terms induced by stochastic differentiation rule. To overcome the inherent underactuation of the aircraft, the roll and pitch angles of the aircraft are considered as immediate controls. Potential projection functions are introduced to design estimates of the deterministic components and covariances of the stochastic components. Simulations illustrate the results.

Visional Attentional Allocation of Top-down and Bottom-up Cues in Three-Dimensional Space

2011 ◽  
Vol 179-180 ◽  
pp. 1322-1326
Author(s):  
Ru Ting Xia
Keyword(s):  
Visual Attention ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Depth Information ◽  
Top Down ◽  
Bottom Up ◽  
Attentional Allocation ◽  
3D Space ◽  
Target Locations ◽  
Three Dimensional Space

The aim of the present experiment was to investigate visual attentional allocation of top-down and bottom-up cues in three-dimensional (3D) space. Near and far stimuli were used by a 3D attention measurement apparatus. Two experiments were conducted in order to examine top-down and bottom-up controls of visual attention. In the experiment 1, the cue about the location of a target by means of location information. In the experiment 2, color cue by brief change of color at target locations was presented. Observers were required to judge whether the target presented nearer than fixation point or further than it. The results in experiment 1 and experiment 2 show that both location and color cue have the effect on reaction time, and that shift of attention were faster from far to near than the reverse. These findings suggest that (1) attention in 3D space might be operated with both location and color controls included the depth information, (2) the shift of visual attention in 3D space has an asymmetric characteristic in depth.

scholarly journals V-Factor Indicator in the Assessment of the Change in the Attractiveness of View as a Result of the Implementation of a Specific Planning Scenario

2019 ◽  
Vol 8 (2) ◽  
pp. 78
Author(s):  
Magda Pluta ◽  
Bartosz Mitka
Keyword(s):  
Factor Analysis ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Observation Point ◽  
View Factor ◽  
Factor V ◽  
Average Value ◽  
3D Space ◽  
The Aesthetic ◽  
Special Points

This paper describes the algorithm of the view factor (V-factor). It is based on an analysis of visibility, taking into account the attractiveness of the observed elements in a three-dimensional space. The results of the V-factor analysis provide input for the decision-making process when selecting the most advantageous planning scenario so that the harmony of landscape and ecological balance can be maintained. The V-factor indicator can be successfully used in the process of spatial planning, in particular, at the stage of determining the parameters of new buildings and lines of sight between planned buildings. The purpose of the indicator is to determine the numerical values for observation points, thus facilitating a comparative assessment of the attractiveness of view available from the special points in space. The analysis uses a 3D space model that includes an integrated existing and planning state designed on the basis of planning scenarios. The V-factor analysis takes into account the distance of the observation point from the observed object, vertical and horizontal angles of observation, and the aesthetic value of the observed object. As a result, an average value of the V-factor indicator was obtained for each planning scenario, which facilitated the determination of the more beneficial one in terms of the attractiveness of view.

Flight performance and visual control of flight of the free-flying housefly ( Musca domestica L.) I. Organization of the flight motor

1986 ◽  
Vol 312 (1158) ◽  
pp. 527-551 ◽  
Keyword(s):  
Coordinate System ◽  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Rigid Bodies ◽  
The Body ◽  
Midsagittal Plane ◽  
Torque Vector ◽  
Translation Velocity ◽  
Flight Motor

Free-flying houseflies have been filmed simultaneously from two sides. The orientation of the flies’ body axes in three-dimensional space can be seen on the films. A method is presented for the reconstruction of the flies’ movements in a fly-centred coordinate system, relative to an external coordinate system and relative to the airstream. The flies are regarded as three-dimensionally rigid bodies. They move with respect to the six degrees of freedom they thus possess. The analysis of the organization of the flight motor from the kinematic data leads to the following conclusions: the sideways movements can, at least qualitatively, be explained by taking into account the sideways forces resulting from rolling the body about the long axis and the influence of inertia. Thus, the force vector generated by the flight motor is most probably located in the fly’s midsagittal plane. The direction of this vector can be varied by the fly in a restricted range only. In contrast, the direction of the torque vector can be freely adjusted by the fly. No coupling between the motor force and the torques is indicated. Changes of flight direction may be explained by changes in the orientation of the body axes: straight flight at an angle of sideslip differing from zero is due to rolling. Sideways motion during the banked turns as well as the decrease of translation velocity observed in curves are a consequence of the inertial forces and rolling. The results are discussed with reference to studies about the aerodynamic performance of insects and the constraints for aerial pursuit.

Sign in / Sign up

Export Citation Format

Share Document