Center Of Mass Trajectory: An Image Descriptor For Baseball Swing Analysis Based On Single Low-Cost Camera

Mobile robotic devices and other mobility related drive systems are often relegated to one of the two classes of devices available today: wheeled devices or tracked devices. Wheeled systems are more energy efficient and reliable than tracked systems, but existing designs have drawbacks related to rough-terrain driving and maneuvering in tight spaces. In this paper we describe the design and development of a drive system named the Single Motor Propelled Drive-train (SiMPl-D), which can potentially improve maneuvering over rough terrain and in tight spaces compared to traditional wheeled robots. SiMPl-D has two prominent features: a single drive motor, which provides both propulsion and turning, and is suspended under the center of mass of the device on a swingarm, which is linked through a suspension system to caster wheels; and it has reconfigurable drive wheel, which changes the turning radius of the device. Due to these features, SiMPl-D can traverse a wide range of terrain while remaining energy and cost efficient. SiMPl-D has been successfully used in an indoor/outdoor low-cost personal mobility device and is currently being implemented in other robotic mobility applications.

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A low-cost method for carrying loads during human walking

Journal of Experimental Biology ◽

10.1242/jeb.216119 ◽

2020 ◽

Vol 223 (23) ◽

pp. jeb216119

Author(s):

Christopher J. Arellano ◽

Obioma B. McReynolds ◽

Shernice A. Thomas

Keyword(s):

Low Cost ◽

Center Of Mass ◽

Metabolic Cost ◽

The Body ◽

Human Walking ◽

Metabolic Power ◽

Arm Swing ◽

Leg Motion ◽

The Cost ◽

Pendulum Dynamics

ABSTRACTHumans often perform tasks that require them to carry loads, but the metabolic cost of carrying loads depends on where the loads are positioned on the body. We reasoned that carrying loads at the arms’ center of mass (COM) during walking might be cheap because arm swing is thought to be dominated by passive pendulum dynamics. In contrast, we expected that carrying loads at the leg COM would be relatively expensive because muscular actuation is necessary to initiate and propagate leg swing. Therefore, we hypothesized that carrying loads at the arm COM while swinging would be cheaper than carrying loads at the leg COM. We further hypothesized that carrying loads at the arm COM while swinging would be more expensive than carrying loads at the waist, where the mass does not swing relative to the body. We measured net metabolic power, arm and leg motion, and the free vertical moment while subjects (n=12) walked on a treadmill (1.25 m s−1) without a load, and with 8 kg added to the arms (swinging versus not swinging), legs or waist. We found that carrying loads on the arms or legs altered arm swinging amplitude; however, the free vertical moment remained similar across conditions. Most notably, the cost of carrying loads on the swinging arms was 9% less than carrying at the leg COM (P<0.001), but similar to that at the waist (P=0.529). Overall, we found that carrying loads at the arm COM is just as cheap as carrying loads at the waist.

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Hybrid Eye-Tracking on a Smartphone with CNN Feature Extraction and an Infrared 3D Model

Sensors ◽

10.3390/s20020543 ◽

2020 ◽

Vol 20 (2) ◽

pp. 543 ◽

Cited By ~ 3

Author(s):

Braiden Brousseau ◽

Jonathan Rose ◽

Moshe Eizenman

Keyword(s):

Eye Tracking ◽

Tracking System ◽

Low Cost ◽

Center Of Mass ◽

Hybrid Approach ◽

Machine Learning Techniques ◽

Gaze Estimation ◽

Estimation Model ◽

Automotive Safety ◽

Artificial Illumination

This paper describes a low-cost, robust, and accurate remote eye-tracking system that uses an industrial prototype smartphone with integrated infrared illumination and camera. Numerous studies have demonstrated the beneficial use of eye-tracking in domains such as neurological and neuropsychiatric testing, advertising evaluation, pilot training, and automotive safety. Remote eye-tracking on a smartphone could enable the significant growth in the deployment of applications in these domains. Our system uses a 3D gaze-estimation model that enables accurate point-of-gaze (PoG) estimation with free head and device motion. To accurately determine the input eye features (pupil center and corneal reflections), the system uses Convolutional Neural Networks (CNNs) together with a novel center-of-mass output layer. The use of CNNs improves the system’s robustness to the significant variability in the appearance of eye-images found in handheld eye trackers. The system was tested with 8 subjects with the device free to move in their hands and produced a gaze bias of 0.72°. Our hybrid approach that uses artificial illumination, a 3D gaze-estimation model, and a CNN feature extractor achieved an accuracy that is significantly (400%) better than current eye-tracking systems on smartphones that use natural illumination and machine-learning techniques to estimate the PoG.

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An FPGA-Based Omnidirectional Vision Sensor for Motion Detection on Mobile Robots

International Journal of Reconfigurable Computing ◽

10.1155/2012/148190 ◽

2012 ◽

Vol 2012 ◽

pp. 1-16 ◽

Cited By ~ 6

Author(s):

Jones Y. Mori ◽

Janier Arias-Garcia ◽

Camilo Sánchez-Ferreira ◽

Daniel M. Muñoz ◽

Carlos H. Llanos ◽

...

Keyword(s):

Image Processing ◽

Mobile Robots ◽

Background Subtraction ◽

Vision System ◽

Low Cost ◽

Center Of Mass ◽

Omnidirectional Vision ◽

Embedded Microprocessor ◽

Xpc Target ◽

Convex Mirror

This work presents the development of an integrated hardware/software sensor system for moving object detection and distance calculation, based on background subtraction algorithm. The sensor comprises a catadioptric system composed by a camera and a convex mirror that reflects the environment to the camera from all directions, obtaining a panoramic view. The sensor is used as an omnidirectional vision system, allowing for localization and navigation tasks of mobile robots. Several image processing operations such as filtering, segmentation and morphology have been included in the processing architecture. For achieving distance measurement, an algorithm to determine the center of mass of a detected object was implemented. The overall architecture has been mapped onto a commercial low-cost FPGA device, using a hardware/software co-design approach, which comprises a Nios II embedded microprocessor and specific image processing blocks, which have been implemented in hardware. The background subtraction algorithm was also used to calibrate the system, allowing for accurate results. Synthesis results show that the system can achieve a throughput of 26.6 processed frames per second and the performance analysis pointed out that the overall architecture achieves a speedup factor of 13.78 in comparison with a PC-based solution running on the real-time operating system xPC Target.

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Design of a Low-Cost Open-Source Underwater Glider

10.31224/osf.io/kvqmh ◽

2018 ◽

Cited By ~ 2

Author(s):

Alexander Williams

Keyword(s):

Data Collection ◽

Open Source ◽

Low Cost ◽

Center Of Mass ◽

Continuous Operation ◽

Use Case ◽

Underwater Glider ◽

Underwater Gliders ◽

Price Point ◽

3D Printed

Typical buoyancy engine-based Underwater Gliders are highly-complex and cost-prohibitive, generally ranging in price-point from 50,000USD to 250,000USD. A low-cost, Open-Source Underwater Glider (OSUG) was thus developed as a low-cost data-collection and research tool. This glider, OSUG, is a sub-1000USD, 1.2m long, 12kg, and capable of 50-hours of continuous operation. Its efficiency, and use-case feasibility were evaluated. The buoyancy engine is constructed of medical grade syringes that pull in water from the environment to simplify the system and lower costs. Direction of locomotion is controlled by altering pitch and roll via changing the center-of-mass. The system was designed to be primarily three-dimensionally (3D) printed and fully-modular to limit cost and ensure reproducibility.

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Quantifying Planarian Behavior as an Introduction to Object Tracking and Signal Processing

The Biophysicist ◽

10.35459/tbp.2020.000159 ◽

2021 ◽

Author(s):

Nicole C. Stowell ◽

Tapan Goel ◽

Vir Shetty ◽

Jocelyne Noveral ◽

Eva-Maria S. Collins

Keyword(s):

Undergraduate Students ◽

Animal Behavior ◽

Low Cost ◽

Center Of Mass ◽

Interdisciplinary Approach ◽

Large Size ◽

Biological Phenomena ◽

Quantitative Image ◽

Periodic Signals ◽

Pilot Implementation

ABSTRACT Answers to mechanistic questions about biological phenomena require fluency in a variety of molecular biology techniques and physical concepts. Here, we present an interdisciplinary approach to introducing undergraduate students to an important problem in the areas of animal behavior and neuroscience—the neuronal control of animal behavior. In this lab module, students explore planarian behavior by quantitative image and data analysis with freely available software and low-cost resources. Planarians are ∼1–2-cm-long aquatic free-living flatworms famous for their regeneration abilities. They are inexpensive and easy to maintain, handle, and perturb, and their fairly large size allows for image acquisition with a webcam, which makes this lab module accessible and scalable. Our lab module integrates basic physical concepts such as center of mass, velocity and speed, periodic signals, and time series analysis in the context of a biological system. The module is designed to attract students with diverse disciplinary backgrounds. It challenges the students to form hypotheses about behavior and equips them with a basic but broadly applicable toolkit to achieve this quantitatively. We give a detailed description of the necessary resources and show how to implement the module. We also provide suggestions for advanced exercises and possible extensions. Finally, we provide student feedback from a pilot implementation.

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Low-Cost Experimental System for Center of Mass and Center of Pressure Measurement (June 2018)

IEEE Access ◽

10.1109/access.2018.2864677 ◽

2018 ◽

Vol 6 ◽

pp. 45021-45033 ◽

Cited By ~ 2

Author(s):

Cai Xia Yang

Keyword(s):

Pressure Measurement ◽

Center Of Pressure ◽

Low Cost ◽

Center Of Mass ◽

Experimental System

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The Residual Center of Mass: An Image Descriptor for the Diagnosis of Alzheimer Disease

Neuroinformatics ◽

10.1007/s12021-018-9390-0 ◽

2018 ◽

Vol 17 (2) ◽

pp. 307-321

Author(s):

Alexandre Yukio Yamashita ◽

◽

Alexandre Xavier Falcão ◽

Neucimar Jerônimo Leite

Keyword(s):

Alzheimer Disease ◽

Center Of Mass ◽

Image Descriptor

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Symmetry in External Work (SEW): A Novel Method of Quantifying Gait Differences Between Prosthetic Feet

Prosthetics and Orthotics International ◽

10.1080/03093640902777254 ◽

2009 ◽

Vol 33 (2) ◽

pp. 148-156 ◽

Cited By ~ 20

Author(s):

Vibhor Agrawal ◽

Robert Gailey ◽

Christopher O'Toole ◽

Ignacio Gaunaurd ◽

Tomas Dowell

Keyword(s):

Low Cost ◽

Center Of Mass ◽

External Work ◽

Prosthetic Limbs ◽

Reaction Forces ◽

Vertical Ground ◽

Body Center ◽

Prosthetic Feet ◽

Vertical Ground Reaction Forces ◽

Transtibial Amputees

Unilateral transtibial amputees (TTAs) show subtle gait variations while using different prosthetic feet. These variations have not been detected consistently with previous experimental measures. We introduce a novel measure called Symmetry in External Work (SEW) for quantifying kinetic gait differences between prosthetic feet. External work is the result of changes in kinetic and potential energy of body center of mass (CoM). SEW is computed by integrating vertical ground reaction forces obtained using F-scan in-sole sensors. Since various prosthetic feet have different designs, we hypothesized that SEW will vary with the type of foot used. This hypothesis was tested with a single unilateral TTA using four prosthetic feet (Proprio, Trias+, Seattle Lite and SACH). The Proprio (mean symmetry 94.5% ± 1.1%) and the Trias+ (92.1% ± 2.5%) feet exhibited higher symmetry between the intact and prosthetic limbs, as compared to the Seattle (67.8% ± 19.3%) and SACH (35.7% ± 11.1%) feet. There was also a good agreement in vertical CoM excursion between the intact foot and prosthetic feet with heel-toe foot plate designs. Results indicate that SEW measure may be a viable method to detect kinetic differences between prosthetic feet and could have clinical applications because of relatively low cost instrumentation and minimal subject intervention.

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Validity of Pendant-Based IMU Assessment of Postural Stability Under Varying Balance Conditions Compared to a Sensor Positioned on the Lower Back

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1071181319631296 ◽

2019 ◽

Vol 63 (1) ◽

pp. 1159-1163 ◽

Cited By ~ 1

Author(s):

Shubo Lyu ◽

Stephen Piazza ◽

Danielle Symons Downs ◽

Andris Freivalds

Keyword(s):

Postural Stability ◽

Low Cost ◽

Center Of Mass ◽

Roc Curves ◽

The Body ◽

Anova Analysis ◽

Inertial Measurement ◽

Lower Back ◽

Measurement Units ◽

High Level

Body-worn inertial measurement units (IMUs) have been widely used in postural stability and balance studies because of their low cost and high level of convenience. In most studies, single IMU sensors are put on the lower back attached to a belt, placing the sensor near the body’s center of mass (COM). For some populations, such as pregnant women, wearing the sensor on a belt over the lower back presents challenges in terms of fit and comfort. Thus, it may be necessary to identify a better location for the sensor and a more comfortable means for attaching the sensor to the body. This study aims to implement and test a novel pendant IMU sensor hanging from the subject’s neck and placed over the sternum. Three standing tasks (double-leg, tandem, and single-leg standing) were performed under open- and closed-eye conditions for preliminary assessments of the ability of the new sensor to discriminate between balance conditions. Standard deviations were analyzed in different conditions, along with ROC curves and ANOVA analysis. The results showed that the pendant sensor can detect the signals as good as the sensor on the waist.

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