scholarly journals Application of a Jaw Motion Tracking Device That Measures Six Degrees of Freedom Using Optoelectronics

2006 ◽  
Vol 50 (2) ◽  
pp. 210-218 ◽  
Author(s):  
Takumi Ogawa ◽  
Yuko Shigeta ◽  
Eriko Ando ◽  
Shinya Hirai ◽  
Mayumi Suma ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Six Degrees Of Freedom ◽  
Tracking Device

scholarly journals Studies Evaluating Measurement Accuracy of CMS-JAW, a Jaw Motion Tracking Device with Six Degrees of Freedom Using an Ultrasonic Recording System

2008 ◽  
Vol 52 (3) ◽  
pp. 350-359 ◽  
Author(s):  
Takashi Uchida ◽  
Jun Sakai ◽  
Yasuhiro Okamoto ◽  
Tsukasa Watanabe ◽  
Tsuyoshi Kitagawa ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Measurement Accuracy ◽  
Recording System ◽  
Six Degrees Of Freedom ◽  
Tracking Device

Experiments on Linear and Nonlinear Control of a Multi-DOF Parallel Mechanism

2003 ◽  
Author(s):  
Sandor Riebe ◽  
Heinz Ulbrich
Keyword(s):  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Parallel Robot ◽  
Parallel Kinematics ◽  
Control Laws ◽  
Six Degrees Of Freedom ◽  
Position Accuracy ◽  
Nonlinear Approach ◽  
Linear Approach ◽  
Measurement Results

Parallel kinematics with multi degrees-of-freedom (DOF), like hexapod-systems, are mostly used in applications where high demands on position accuracy are required and/or high accelerations are needed. Adequate control concepts are essential in order to achieve the desired dynamic response. This paper deals with a comparative study of two structural different control concepts applied on a parallel robot with six degrees-of-freedom. The first one is a decentral linear approach and the second one is a multivariable nonlinear approach. The two concepts are presented and implemented on an experimental hexapod-system. In order to verify the used dynamic model comparisons between simulation and measurement results are shown. Finally, experiments have been carried out to compare the control laws with respect to their motion tracking performance.

scholarly journals A wearable wrist haptic display for motion tracking and force feedback in the operational space

2021 ◽  
Vol 2 ◽  
Author(s):  
Marco Laghi ◽  
Manuel G. Catalano ◽  
Giorgio Grioli ◽  
Antonio Bicchi
Keyword(s):  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Force Feedback ◽  
Inertial Sensors ◽  
Research Directions ◽  
Six Degrees Of Freedom ◽  
Operational Space ◽  
Haptic Displays ◽  
Different Types ◽  
Remote Perception

Abstract Force feedback is often beneficial for robotic teleoperation, as it enhances the user’s remote perception. Over the years, many kinesthetic haptic displays (KHDs) have been proposed for this purpose, which have different types of interaction and feedback, depending on their kinematics and their interface with the operator, including, for example, grounded and wearable devices acting either at the joint or operational space (OS) level. Most KHDs in the literature are for the upper limb, with a majority acting at the shoulder/elbow level, and others focusing on hand movements. A minority exists which addresses wrist motions. In this paper, we present the Wearable Delta (W $ \Delta $ ), a proof-of-concept wearable wrist interface with hybrid parallel–serial kinematics acting in the OS, able to render a desired force directly to the hand involving just the forearm–hand subsystem. It has six degrees of freedom (DoFs), three of which are actuated, and is designed to reduce the obstruction of the range of the user’s wrist. Integrated with positions/inertial sensors at the elbow and upper arm, the W $ \Delta $ allows the remote control of a full articulated robotic arm. The paper covers the whole designing process, from the concept to the validation, as well as a multisubject experimental campaign that investigates its usability. Finally, it presents a section that, starting from the experimental results, aims to discuss and summarize the W $ \Delta $ advantages and limitations and look for possible future improvements and research directions.

Using a Maximum Error Statistic to Evaluate Measurement Errors in 3D Position and Orientation Tracking Systems

1993 ◽  
Vol 2 (4) ◽  
pp. 314-343 ◽  
Author(s):  
Ted Morris ◽  
Max Donath
Keyword(s):  
Relative Motion ◽  
Measurement Errors ◽  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Computer Experiments ◽  
Maximum Error ◽  
Tracking Systems ◽  
3D Motion ◽  
Six Degrees Of Freedom ◽  
Error Statistic

One approach to tracking anatomical and robot joint motion consists of tracking the XYZ locations of multiple point targets that are attached to each of the moving segments and then computing the three translations and three orientation angles between adjoining segments. The complexity of such systems requires that we introduce a new conservative maximum error statistic to be used for evaluating the accuracy of 3D motion tracking systems. This paper addresses the various phenomena that contribute to measurement error when computing six degrees of freedom associated with the relative motion between the adjacent segments. The characteristics of these errors, common to many 3D motion tracking systems, were first determined by experimentation using one such system (MnSCAN). These and additional artifacts were then modeled in order to quantitatively evaluate their effects using the maximum error statistic. Based on these computer experiments, several relationships were identified that predict how each of these phenomena influences the predicted measurement of relative motion between bodies. These suggest where design emphasis should be placed in order to minimize the error in tracking the six degrees of freedom. The methodology and the conclusions based on these results can be applied to designing most six degree of freedom position and motion measurement systems.

scholarly journals The “Skipped Segment Screw” Construct: An Alternative to Conventional Lateral Mass Fixation–Biomechanical Analysis in a Porcine Cervical Spine Model

2017 ◽  
Vol 11 (5) ◽  
pp. 733-738
Author(s):  
Kedar Prashant Padhye ◽  
Yuvaraja Murugan ◽  
Raunak Milton ◽  
N. Arunai Nambi Raj ◽  
Kenny Samuel David
Keyword(s):  
Cervical Spine ◽  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Biomechanical Testing ◽  
Biomechanical Study ◽  
Biomechanical Analysis ◽  
Lateral Mass ◽  
Six Degrees Of Freedom ◽  
Spine Stabilization ◽  
Significant Difference

<sec><title>Study Design</title><p>Cadaveric biomechanical study.</p></sec><sec><title>Purpose</title><p>We compared the “skipped segment screw” (SSS) construct with the conventional “all segment screw” (ASS) construct for cervical spine fixation in six degrees of freedom in terms of the range of motion (ROM).</p></sec><sec><title>Overview of Literature</title><p>Currently, no clear guidelines are available in the literature for the configuration of lateral mass (LM) screwrod fixation for cervical spine stabilization. Most surgeons tend to insert screws bilaterally at all segments from C3 to C6 with the assumption that implants at every level will provide maximum stability.</p></sec><sec><title>Methods</title><p>Six porcine cervical spine specimens were harvested from fresh 6–9-month-old pigs. Each specimen was sequentially tested in the following order: intact uninstrumented (UIS), SSS (LM screws in C3, C5, and C7 bilaterally), and ASS (LM screws in C3–C7 bilaterally). Biomechanical testing was performed with a force of 2 Nm in six degrees of freedom and 3D motion tracking was performed.</p></sec><sec><title>Results</title><p>The two-tailed paired <italic>t</italic>-test was used for statistical analysis. There was a significant decrease in ROM in instrumented specimens compared with that in UIS specimens in all six degrees of motion (<italic>p</italic>&lt;0.05), whereas there was no significant difference in ROM between the different types of constructs (SSS and ASS).</p></sec><sec><title>Conclusions</title><p>Because both configurations provide comparable stability under physiological loading, we provide a biomechanical basis for the use of SSS configuration owing to its potential clinical advantages, such as relatively less bulk of implants within a small operative field, relative ease of manipulating the rod into position, shorter surgical time, less blood loss, lower risk of screw-related complications, less implant-related costs, and most importantly, no compromise in the required stability needed until fusion.</p></sec>

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]

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