Motion Planning with Six Degrees of Freedom. Revision

1984 ◽  
Author(s):  
Bruce R. Donald
Keyword(s):  
Motion Planning ◽  
Degrees Of Freedom ◽  
Six Degrees Of Freedom

Trajectory Prediction with a Conditional Variational Autoencoder

2019 ◽  
Vol 31 (3) ◽  
pp. 493-499
Author(s):  
Thibault Barbié ◽  
◽  
Takaki Nishio ◽  
Takeshi Nishida
Keyword(s):  
Motion Planning ◽  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Computation Time ◽  
Prediction Algorithm ◽  
Robot Arm ◽  
Trajectory Prediction ◽  
Six Degrees Of Freedom ◽  
Variational Autoencoder ◽  
Planning Approaches

Conventional motion planners do not rely on previous experience when presented with a new problem. Trajectory prediction algorithms solve this problem using a pre-existing dataset at runtime. We propose instead using a conditional variational autoencoder (CVAE) to learn the distribution of the motion dataset and hence to generate trajectories for use as priors within the traditional motion planning approaches. We demonstrate, through simulations and by using an industrial robot arm with six degrees of freedom, that our trajectory prediction algorithm generates more collision-free trajectories compared to the linear initialization, and reduces the computation time of optimization-based planners.

Repetitive Motion Planning and Control on Redundant Robot Manipulators With Push-Rod-Type Joints

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Z. Zhang ◽  
Y. Zhang
Keyword(s):  
Motion Planning ◽  
Degrees Of Freedom ◽  
Quadratic Program ◽  
Error Feedback ◽  
Repetitive Motion ◽  
Six Degrees Of Freedom ◽  
Planning And Control ◽  
Joint Velocity ◽  
And Control ◽  
Joint Limit

To demonstrate the hardware realizability and efficacy of the quadratic program (QP) based methods for solving the nonrepetitive problem, this paper proposes a novel repetitive motion planning and control (RMPC) scheme and realizes this scheme on a physical planar six degrees-of-freedom (DOF) push-rod-joint (PRJ) manipulator. To control the PRJ manipulator, this scheme considers variable joint-velocity limits and joint-limit margins. In addition, to decrease the errors, this scheme considers the position-error feedback. Then, the scheme is reformulated as a QP problem. Due to control of the digital computer, a discrete-time QP solver is presented to solve the QP problem. For comparison, both of the nonrepetitive and repetitive motions are performed on the manipulator to track square and B-shaped paths. Experimental results validate the physical realizability and effectiveness of the RMPC scheme.

Control of processing at multi-tool two-support setup

2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Factor Model ◽  
Angular Displacement ◽  
Factor Models ◽  
Technological System ◽  
Displacement Control ◽  
Model Accuracy ◽  
Six Degrees Of Freedom ◽  
Angular Displacements ◽  
And Control

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]

scholarly journals Design and Calibration of a Hall Effect System for Measurement of Six-Degree-of-Freedom Motion within a Stacked Column

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3740
Author(s):  
Olafur Oddbjornsson ◽  
Panos Kloukinas ◽  
Tansu Gokce ◽  
Kate Bourne ◽  
Tony Horseman ◽  
...  
Keyword(s):  
Hall Effect ◽  
Degrees Of Freedom ◽  
Reactor Core ◽  
Degree Of Freedom ◽  
Life Extension ◽  
Scale Model ◽  
Design Development ◽  
Seismic Safety ◽  
Six Degrees Of Freedom ◽  
Six Degree Of Freedom

This paper presents the design, development and evaluation of a unique non-contact instrumentation system that can accurately measure the interface displacement between two rigid components in six degrees of freedom. The system was developed to allow measurement of the relative displacements between interfaces within a stacked column of brick-like components, with an accuracy of 0.05 mm and 0.1 degrees. The columns comprised up to 14 components, with each component being a scale model of a graphite brick within an Advanced Gas-cooled Reactor core. A set of 585 of these columns makes up the Multi Layer Array, which was designed to investigate the response of the reactor core to seismic inputs, with excitation levels up to 1 g from 0 to 100 Hz. The nature of the application required a compact and robust design capable of accurately recording fully coupled motion in all six degrees of freedom during dynamic testing. The novel design implemented 12 Hall effect sensors with a calibration procedure based on system identification techniques. The measurement uncertainty was ±0.050 mm for displacement and ±0.052 degrees for rotation, and the system can tolerate loss of data from two sensors with the uncertainly increasing to only 0.061 mm in translation and 0.088 degrees in rotation. The system has been deployed in a research programme that has enabled EDF to present seismic safety cases to the Office for Nuclear Regulation, resulting in life extension approvals for several reactors. The measurement system developed could be readily applied to other situations where the imposed level of stress at the interface causes negligible material strain, and accurate non-contact six-degree-of-freedom interface measurement is required.

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