scholarly journals Markerless tracking suggests a tactile sensing role for forelegs of Dolomedes spiders during locomotion

2018 ◽  
Author(s):  
Kiri F. Pullar ◽  
Michael G. Paulin
Keyword(s):  
Machine Vision ◽  
Gait Analysis ◽  
Mechanical Design ◽  
Design Principles ◽  
Reference Points ◽  
Joint Mechanics ◽  
Markerless Tracking ◽  
Video Frames ◽  
Sensory Neural ◽  
Hunting Spider

Summary statementWe developed a machine vision technique for markerless tracking of locomotion in the spider Dolomedes aquaticus. Gait analysis suggests that each pair of legs plays a specific role in locomotion.AbstractBecause of their rigid exoskeleton with relatively simple joint mechanics, arthropods can provide useful models for studying the sensory-neural and mechanical design principles of agile animal locomotion. Gait analysis usually requires attaching markers or manually identifying reference points in video frames, which can be time consuming and inaccurate, especially with small animals. Here we describe a markerless motion capture technique and its application to gait analysis in the New Zealand semi-aquatic hunting spider, Dolomedes aquaticus. Our machine vision approach uses a model of the spider’s skeleton to infer the location of the centre of mass and the configuration of the skeleton in successive video frames. We found that stride length and frequency are correlated with running speed. Inter-limb coordination during the gait cycle suggests that different legs have specialized roles in locomotion. Phase relationships among the six hindmost legs exhibit an alternating tripod gait, as in hexapod insects. The middle two leg pairs appear to be primarily responsible for generating thrust, while the hind legs contribute more to stability. The front legs are not phase-coupled to the other legs and appear to be used as tactile probes during locomotion. Our machine vision approach has the potential to automate arthropod gait analysis, making it faster and easier. Our results indicate how specialization of limb function may contribute to locomotor efficiency and agility of a specialized hunting spider, and how arthropod design principles may contribute to developing efficient, agile legged robots.

Effect of Field Setup on Accuracy of Traffic Data Collection Using Machine Vision Technology

2002 ◽  
Vol 1804 (1) ◽  
pp. 62-66 ◽  
Author(s):  
Sunita Nadella ◽  
Lloyd A. Herman
Keyword(s):  
Machine Vision ◽  
Focal Length ◽  
Reference Points ◽  
Specific Reference ◽  
Traffic Data ◽  
Video Traffic ◽  
Vertical Angle ◽  
Traffic Data Collection ◽  
Camera Position ◽  
Parameter Ranges

Video traffic data were collected in 24 combinations of four different camera position parameters. A machine vision processor was used to detect vehicle speeds and volumes from the videotapes. The machine vision results were then compared with the actual vehicle volumes and speeds to give the percentage errors in each case. The results of the study provide a procedure with which to establish camera position parameters with specific reference points to help machine vision users select suitable camera positions and develop appropriate measurement error expectations. The camera position parameters that were most likely to produce the least overall volume and speed errors, for the specific site and field setup with the parameter ranges used in this study, were the low height of approximately 7.6 m (25 ft), with an upstream orientation (traffic moving toward the camera), a 50-mm (midangle) focal length, and a 15° vertical angle.

Exploring the Retention of Sustainable Design Principles in Engineering Practice Through Design Education

2015 ◽  
Author(s):  
Bryony DuPont ◽  
Addison Wisthoff
Keyword(s):  
Product Development ◽  
Design Education ◽  
Online Survey ◽  
Expert Knowledge ◽  
Mechanical Design ◽  
Sustainable Design ◽  
Design Principles ◽  
Design Guidelines ◽  
Engineering Practice ◽  
Graduate Level

The School of Mechanical, Industrial, and Manufacturing Engineering at Oregon State University is home to one of the largest academic Mechanical Design groups in the country. As a leader in undergraduate design education, we have been able to keep in touch with a large group of mechanical design graduates, and as such are capable of assessing how students retain information learned in undergraduate coursework to see how this understanding is employed in real-world engineering practice. However, the principles governing the design of sustainable products and processes are relatively novel and are only now being integrated into the undergraduate and graduate mechanical design curriculum. It is our hypothesis that particular means of learning and understanding sustainable design — via lectures, homework assignments, design projects, and the use of various sustainability-related LCA tools — will enable the highest retention of sustainable design understanding, and a higher likelihood that this sustainable design knowledge will be propagated into design practice in industry. Multiple curricular studies that explore dissemination and retention of sustainable design skills are being explored, including a junior-level introductory mechanical design course and a graduate level sustainable product development course. In the junior-level course, baseline sustainability knowledge is tested by allowing students to make sustainable design decisions by applying varied skill sets, including general principles, a list of sustainable design guidelines, and an innovative online survey (The GREEn Quiz). The graduate-level course, which employs sustainable design principles within a larger product development architecture, will capitalize on more “expert” knowledge. Future work will also be discussed, including planned validation studies and curriculum improvements, as well as the means of quantifying the retention of sustainable design information.

MECHANICAL DESIGN OF WALKING ROBOT PASIBOT-PARAMETRIC MODEL AND GAIT ANALYSIS

2009 ◽  
Author(s):  
HIGINIO RUBIO ◽  
JESÚS MENESES ◽  
CRISTINA CASTEJÓN ◽  
ALBERTO JARDÓN ◽  
ANTONIO GIMÉNEZ ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Mechanical Design ◽  
Parametric Model ◽  
Walking Robot

scholarly journals Author response: Mechanical design principles of a mitotic spindle

2014 ◽  
Author(s):  
Jonathan J Ward ◽  
Hélio Roque ◽  
Claude Antony ◽  
François Nédélec
Keyword(s):  
Mitotic Spindle ◽  
Mechanical Design ◽  
Design Principles ◽  
Author Response

Mechanical Design Principles

2017 ◽  
pp. 145-184
Author(s):  
Matthew David ◽  
Stephen Sheridan ◽  
Stephen Turley ◽  
Robin Underwood ◽  
Joseph Kanu ◽  
...  
Keyword(s):  
Mechanical Design ◽  
Design Principles

scholarly journals A 2D Markerless Gait Analysis Methodology: Validation on Healthy Subjects

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Andrea Castelli ◽  
Gabriele Paolini ◽  
Andrea Cereatti ◽  
Ugo Della Croce
Keyword(s):  
Gait Analysis ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Video Camera ◽  
Standing Position ◽  
Parameters Estimation ◽  
Reference Points ◽  
Analysis Methodology ◽  
Spatiotemporal Parameters ◽  
The Cost

A 2D markerless technique is proposed to perform lower limb sagittal plane kinematic analysis using a single video camera. A subject-specific, multisegmental model of the lower limb was calibrated with the subject in an upright standing position. Ankle socks and underwear garments were used to track the feet and pelvis segments, whereas shank and thigh segments were tracked by means of reference points identified on the model. The method was validated against a marker based clinical gait model. The accuracy of the spatiotemporal parameters estimation was found suitable for clinical use (errors between 1% and 3% of the corresponding true values). Comparison analysis of the kinematics patterns obtained with the two systems revealed high correlation for all the joints(0.82<R2<0.99). Differences between the joint kinematics estimates ranged from 3.9 deg to 6.1 deg for the hip, from 2.7 deg to 4.4 deg for the knee, and from 3.0 deg to 4.7 deg for the ankle. The proposed technique allows a quantitative assessment of the lower limb motion in the sagittal plane, simplifying the experimental setup and reducing the cost with respect to traditional marker based gait analysis protocols.

A Minimax Approach to the Best Mechanical Alignment Problem

1984 ◽  
Vol 106 (1) ◽  
pp. 31-40
Author(s):  
J. W. Bandler ◽  
M. A. El-Kady ◽  
W. Kellermann ◽  
W. M. Zuberek
Keyword(s):  
Mechanical Design ◽  
Two Dimensions ◽  
Reference Points ◽  
Mechanical Alignment ◽  
Coordinate Systems ◽  
Minimax Optimization ◽  
Minimax Approach ◽  
Design Specifications ◽  
Alignment Problem

This paper provides an attempt to formulate and to solve the best mechanical alignment problem, which arises in many practical situations when a relatively expensive manufactured product does not meet design specifications and a decision is to be made for partial retreatment of the product. We define and use concepts of regular points, reference points, and referenced points for a mechanical design. These points represent important features which must be reproduced subject to tolerances, which are defined with respect to (w.r.t.) various coordinate systems. The algorithm proposed identifies candidates for reworking using minimax optimization. While the concepts introduced and the method presented resulted from a variety of approaches to solving mechanical problems in two dimensions, this class of problem can arise in other areas and further generalization is possible.

scholarly journals A System of Driving Fatigue Detection Based on Machine Vision and Its Application on Smart Device

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Wanzeng Kong ◽  
Lingxiao Zhou ◽  
Yizhi Wang ◽  
Jianhai Zhang ◽  
Jianhui Liu ◽  
...  
Keyword(s):  
Machine Vision ◽  
Real Time ◽  
Traffic Accidents ◽  
Candidate Region ◽  
Front Face ◽  
Smart Device ◽  
Adaboost Algorithm ◽  
Video Frames ◽  
Driving Fatigue ◽  
Fatigue Detection

Driving fatigue is one of the most important factors in traffic accidents. In this paper, we proposed an improved strategy and practical system to detect driving fatigue based on machine vision and Adaboost algorithm. Kinds of face and eye classifiers are well trained by Adaboost algorithm in advance. The proposed strategy firstly detects face efficiently by classifiers of front face and deflected face. Then, candidate region of eye is determined according to geometric distribution of facial organs. Finally, trained classifiers of open eyes and closed eyes are used to detect eyes in the candidate region quickly and accurately. The indexes which consist of PERCLOS and duration of closed-state are extracted in video frames real time. Moreover, the system is transplanted into smart device, that is, smartphone or tablet, due to its own camera and powerful calculation performance. Practical tests demonstrated that the proposed system can detect driver fatigue with real time and high accuracy. As the system has been planted into portable smart device, it could be widely used for driving fatigue detection in daily life.

Mechanical Design Pitfalls

2006 ◽  
Vol 220 (6) ◽  
pp. 887-899 ◽  
Author(s):  
H A Arafa
Keyword(s):  
Mechanical Design ◽  
Planetary Systems ◽  
Design Principles ◽  
Fluid Power ◽  
Manufacturing Processes ◽  
Mechanical Equipment

Design pitfalls are defined as those obscure mistakes that can be attributed to negligence or ignorance of particular details and characteristics of the design and, in some cases, the manufacturing processes. This paper presents ten actual cases where a designer could be tempted or misled into design pitfalls that would create weird encounters during assembling or operating mechanical equipment. The pitfalls could have immediate, embarrassing consequences, or eventually lead to hazardous situations and failure in unexpected modes. The consequences of these pitfalls and their remedies are also discussed. The design examples lie in various areas such as gearing and planetary systems, bearings, and fluid power. They are classified under generic headings, some of which are seen to qualify, and are therefore suggested, as design principles, to be added to the repertory. It is deemed that this paper will stimulate further investigations leading to the identification of design pitfalls in these and other areas.

Reflections on Photogrammetry

2018 ◽  
pp. 34-41
Author(s):  
Alexander W. Schindler
Keyword(s):  
Object Recognition ◽  
Machine Vision ◽  
Three Dimensional ◽  
Standard Technique ◽  
Ground Truth ◽  
Reference Points ◽  
Two Dimensional ◽  
Three Dimensional Model ◽  
Technological Field ◽  
Image Capturing

This article presents an overview of the history, principles, and current developments in the media technological field of photogrammetry. By chronicling the isomorphic shift taking place in image capturing, we seek to show that photogrammetry has led the way forward in seeing technical images not only as two dimensional projections, but as three-dimensional model-based images. In the mid-nineteenth century, photogrammetry was first used for the documentation of architectural objects and it later became a standard technique in aerial photography. Although its fields of application have become more extensive, photogrammetry’s basic principle hasn’t fundamentally changed: it is still defined as the three- dimensional geometric reconstruction of two-dimensional photographs through the measuring of reference points. With digital technological standards and advances in camera technology, photogrammetric imaging nowadays is intensively used for object recognition in machine vision and robotics. Beside this, photogrammetry is also opening new possibilities for documentation in the fields of investigative arts, this being explored with a discussion on the “Ground Truth” project from Forensic Architecture. Keywords: investigative art, machine vision, object recognition, photogrammetry, photography

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