Kinematic Identification Method for Cable-Driven Rescue Robots in Unstructured Environments

2003 ◽  
Vol 15 (5) ◽  
pp. 571-578 ◽  
Author(s):  
Satoshi Tadokoro ◽  
◽  
Richard Verhoeven ◽  
Ulrike Zwiers ◽  
Manfred Hiller ◽  
...  
Keyword(s):  
Error Analysis ◽  
Reference Frame ◽  
Large Scale ◽  
Optimal Number ◽  
Parallel Robots ◽  
Kinematic Parameters ◽  
Identification Error ◽  
Unstructured Environments ◽  
Identification Method ◽  
Rescue Robots

Cable-driven parallel robots are being developed for rescue operations in large-scale earthquake disasters. This paper proposes an identification method of kinematic parameters for the installation, such as the position of cable fixture by initializing motion on site. This problem is unique to robots in natural fields, such as disaster sites because the environment is not structured. On the basis of identification error analysis and simulation, the optimal number of measurement points and the size of an identification reference frame are obtained.

A simple and rapid calibration methodology for industrial robot based on geometric constraint and two-step error

2018 ◽  
Vol 45 (6) ◽  
pp. 715-721 ◽  
Author(s):  
Jiabo Zhang ◽  
Xibin Wang ◽  
Ke Wen ◽  
Yinghao Zhou ◽  
Yi Yue ◽  
...  
Keyword(s):  
Coordinate System ◽  
Large Scale ◽  
Industrial Robot ◽  
Geometric Constraint ◽  
Machining Process ◽  
Kinematic Parameters ◽  
Robot Calibration ◽  
Positioning Accuracy ◽  
Content Type ◽  
Rapid Calibration

Purpose The purpose of this study is the presentation and research of a simple and rapid calibration methodology for industrial robot. Extensive research efforts were devoted to meet the requirements of online compensation, closed-loop feedback control and high-precision machining during the flexible machining process of robot for large-scale cabin. Design/methodology/approach A simple and rapid method to design and construct the transformation relation between the base coordinate system of robot and the measurement coordinate system was proposed based on geometric constraint. By establishing the Denavit–Hartenberg model for robot calibration, a method of two-step error for kinematic parameters calibration was put forward, which aided in achievement of step-by-step calibration of angle and distance errors. Furthermore, KUKA robot was considered as the research object, and related experiments were performed based on laser tracker. Findings The experimental results demonstrated that the accuracy of the coordinate transformation could reach 0.128 mm, which meets the transformation requirements. Compared to other methods used in this study, the calibration method of two-step error could significantly improve the positioning accuracy of robot up to 0.271 mm. Originality/value The methodology based on geometric constraint and two-step error is simple and can rapidly calibrate the kinematic parameters of robot. It also leads to the improvement in the positioning accuracy of robot.

scholarly journals Large-scale 3D printing with cable-driven parallel robots

2017 ◽  
Vol 1 (1-4) ◽  
pp. 69-76 ◽  
Author(s):  
Jean-Baptiste Izard ◽  
Alexandre Dubor ◽  
Pierre-Elie Hervé ◽  
Edouard Cabay ◽  
David Culla ◽  
...  
Keyword(s):  
3D Printing ◽  
Large Scale ◽  
Parallel Robots

scholarly journals The Differential Astrometric Reference Frame on short timescales in the Gaia Era

2017 ◽  
Vol 12 (S330) ◽  
pp. 79-80
Author(s):  
Ummi Abbas ◽  
Beatrice Bucciarelli ◽  
Mario G. Lattanzi ◽  
Mariateresa Crosta ◽  
Mario Gai ◽  
...  
Keyword(s):  
Reference Frame ◽  
Large Scale ◽  
Total Error ◽  
Systematic Errors ◽  
Field Of View ◽  
Small Field ◽  
Inertial Reference Frame ◽  
Error Budget ◽  
G 14 ◽  
High Cadence

AbstractWe use methods of differential astrometry to construct a small field inertial reference frame stable at the micro-arcsecond level. Using Gaia measurements of field angles we look at the influence of the number of reference stars and the stars magnitude as well as astrometric systematics on the total error budget with the help of Gaia-like simulations around the Ecliptic Pole in a differential astrometric scenario. We find that the systematic errors are modeled and reliably estimated to the μas level even in fields with a modest number of 37 stars with G <13 mag over a 0.24 sq. degrees field of view for short timescales of the order of a day for a perfect instrument and with high-cadence observations. Accounting for large-scale calibrations by including the geometric instrument model over such short timescales requires fainter stars down to G=14 mag without diminishing the accuracy of the reference frame.

Vibration suppression for large-scale flexible structures based on cable-driven parallel robots

2020 ◽  
pp. 107754632096194
Author(s):  
Haining Sun ◽  
Xiaoqiang Tang ◽  
Senhao Hou ◽  
Xiaoyu Wang
Keyword(s):  
Large Scale ◽  
Vibration Suppression ◽  
Control Method ◽  
External Disturbance ◽  
Flexible Structures ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Lyapunov Theory ◽  
Normal Operation ◽  
Control Methods

Specific satellites with ultralong wings play a crucial role in many fields. However, external disturbance and self-rotation could result in undesired vibrations of the flexible wings, which affect the normal operation of the satellites. In severe cases, the satellites would be damaged. Therefore, it is imperative to conduct vibration suppression for these flexible structures. Utilizing fuzzy-proportional integral derivative control and deep reinforcement learning (DRL), two active control methods are proposed in this article to rapidly suppress the vibration of flexible structures with quite small controllable force based on a cable-driven parallel robot. Inspired by the output law of DRL, a new control method named Tang and Sun control is innovatively presented based on the Lyapunov theory. To verify the effectiveness of these three control methods, three groups of simulations with different initial disturbances are implemented for each method. Besides, to enhance the contrast, a passive pretightening scheme is also tested. First, the dynamic model of the cable-driven parallel robot which comprises four cables and a flexible structure is established using the finite element method. Then, the dynamic behavior of the model under the controllable cable force is analyzed by the Newmark-ß method. Finally, these control methods are implemented by numerical simulations to evaluate their performance, and the results are satisfactory, which validates the controllers’ ability to suppress vibrations.

Large-scale spatial angle measurement and the pointing error analysis

2016 ◽  
Vol 12 (3) ◽  
pp. 229-232 ◽  
Author(s):  
Wen-jian Xiao ◽  
Zhi-bin Chen ◽  
Dong-xi Ma ◽  
Yong Zhang ◽  
Xian-hong Liu ◽  
...  
Keyword(s):  
Error Analysis ◽  
Large Scale ◽  
Angle Measurement ◽  
Pointing Error

Multi-view scans alignment for 3D spherical mosaicing in large-scale unstructured environments

2010 ◽  
Vol 114 (11) ◽  
pp. 1248-1263 ◽  
Author(s):  
Daniela Craciun ◽  
Nicolas Paparoditis ◽  
Francis Schmitt
Keyword(s):  
Large Scale ◽  
Unstructured Environments
Sign in / Sign up

Export Citation Format

Share Document