Comparison Between a Robotic Prosthetic Foot Emulator and Corresponding Commercial Prosthetic Forefoot Angular Stiffness Properties

2021 ◽  
Author(s):  
Elizabeth Halsne
Keyword(s):  
Prosthetic Foot ◽  
Stiffness Properties

scholarly journals Conceptual Design of a New Multi-Component Test Bench for the Dynamic Characterization of Running Specific Prostheses

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 75 ◽  
Author(s):  
Nicola Petrone ◽  
Gianfabio Costa ◽  
Gianmario Foscan ◽  
Francesco Bettella ◽  
Gianluca Migliore ◽  
...  
Keyword(s):  
Test Bench ◽  
Reaction Force ◽  
Dynamic Characterization ◽  
Prosthetic Foot ◽  
Load Combination ◽  
Stiffness Properties ◽  
Component Test ◽  
Static And Dynamic Loads ◽  
Force Components

Stiffness properties of running specific prostheses (RSP) for Paralympic runners are fundamental in the selection of the optimal running prosthetic foot (RPF) for sprint and jump events, depending on the athlete’s anthropometry and characteristics. RPFs are J-shaped or C-shaped, clamped to the socket or the pylon of the prosthetic leg. The aim of this work was to develop a test bench suitable for the static and dynamic characterization of a running prosthetic feet (RPF). Based on the evidence that the ground reaction force components change their relative orientation to the pylon or socket during the stance, loads were resolved in the socket reference frame and a multi-component test bench was designed and constructed. Two perpendicular actuators can apply static and dynamic loads to the foot while contacting a surrogate ground inclined at different angles. The preliminary tests show how the alignment, load combination, and ground angle can affect RPF stiffness curves.

scholarly journals Novel Method to Evaluate Angular Stiffness of Prosthetic Feet From Linear Compression Tests

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Peter G Adamczyk ◽  
Michelle Roland ◽  
Michael E. Hahn
Keyword(s):  
Center Of Pressure ◽  
Linear Displacement ◽  
Rate Of Change ◽  
Compression Tests ◽  
Prosthetic Foot ◽  
Stiffness Properties ◽  
Prosthetic Feet ◽  
Predicted Values ◽  
Parametric Adjustment ◽  
Linear Compression

Lower limb amputee gait during stance phase is related to the angular stiffness of the prosthetic foot, which describes the dependence of ankle torque on angular progression of the shank. However, there is little data on angular stiffness of prosthetic feet, and no method to directly measure it has been described. The objective of this study was to derive and evaluate a method to estimate the angular stiffness of prosthetic feet using a simple linear compression test. Linear vertical compression tests were performed on nine configurations of an experimental multicomponent foot (with known component stiffness properties and geometry), which allowed for parametric adjustment of hindfoot and forefoot stiffness properties and geometries. Each configuration was loaded under displacement control at distinct pylon test angles. Angular stiffness was calculated as a function of the pylon angle, normal force, and center of pressure (COP) rate of change with respect to linear displacement. Population root mean square error (RMSE) between the measured and predicted angular stiffness values for each configuration of the multicomponent foot was calculated to be 4.1 N-m/deg, dominated by a bias of the estimated values above the predicted values of 3.8 ± 1.6 N-m/deg. The best-fit line to estimated values was approximately parallel to the prediction, with R2 = 0.95. This method should be accessible for a variety of laboratories to estimate angular stiffness of experimental and commercially available prosthetic feet with minimal equipment.

Simplified Approach to Calculating Geometric Stiffness Properties of Tread Pattern Elements

2003 ◽  
Vol 31 (3) ◽  
pp. 132-158 ◽  
Author(s):  
R. E. Okonieski ◽  
D. J. Moseley ◽  
K. Y. Cai
Keyword(s):  
Development Process ◽  
Functional Design ◽  
Simplified Approach ◽  
Tire Industry ◽  
Geometric Stiffness ◽  
Stiffness Properties ◽  
Engineering Parameters ◽  
Net To Gross ◽  
Significant Effort

Abstract The influence of tread designs on tire performance is well known. The tire industry spends significant effort in the development process to create and refine tread patterns. Creating an aesthetic yet functional design requires characterization of the tread design using many engineering parameters such as stiffness, moments of inertia, principal angles, etc. The tread element stiffness is of particular interest because of its use to objectively determine differences between tread patterns as the designer refines the design to provide optimum levels of performance. The tread designer monitors the change in stiffness as the design evolves. Changes to the geometry involve many attributes including the number of sipes, sipe depth, sipe location, block element edge taper, nonskid depth, area net-to-gross, and so forth. In this paper, two different formulations for calculating tread element or block stiffness are reviewed and are compared to finite element results in a few cases. A few simple examples are shown demonstrating the basic functionality that is possible with a numerical method.

Roll-over analysis of a new design carbon fiber prosthetic foot

2019 ◽  
Author(s):  
Mohsin Noori Hamzah ◽  
Abdurrahman AbdulhessenGatta
Keyword(s):  
Carbon Fiber ◽  
Prosthetic Foot

scholarly journals Sensorless environment stiffness and interaction force estimation for impedance control tuning in robotized interaction tasks

2021 ◽  
Author(s):  
Loris Roveda ◽  
Dario Piga
Keyword(s):  
Impedance Control ◽  
Interaction Force ◽  
Industrial Robots ◽  
Force Estimation ◽  
Interaction Control ◽  
Stiffness Properties ◽  
Implementation Effort ◽  
Coupling Dynamics ◽  
And Control ◽  
Assembly Tasks

AbstractIndustrial robots are increasingly used to perform tasks requiring an interaction with the surrounding environment (e.g., assembly tasks). Such environments are usually (partially) unknown to the robot, requiring the implemented controllers to suitably react to the established interaction. Standard controllers require force/torque measurements to close the loop. However, most of the industrial manipulators do not have embedded force/torque sensor(s) and such integration results in additional costs and implementation effort. To extend the use of compliant controllers to sensorless interaction control, a model-based methodology is presented in this paper. Relying on sensorless Cartesian impedance control, two Extended Kalman Filters (EKF) are proposed: an EKF for interaction force estimation and an EKF for environment stiffness estimation. Exploiting such estimations, a control architecture is proposed to implement a sensorless force loop (exploiting the provided estimated force) with adaptive Cartesian impedance control and coupling dynamics compensation (exploiting the provided estimated environment stiffness). The described approach has been validated in both simulations and experiments. A Franka EMIKA panda robot has been used. A probing task involving different materials (i.e., with different - unknown - stiffness properties) has been considered to show the capabilities of the developed EKFs (able to converge with limited errors) and control tuning (preserving stability). Additionally, a polishing-like task and an assembly task have been implemented to show the achieved performance of the proposed methodology.

scholarly journals Physical, Deformation, and Stiffness Properties of Recycled Concrete Aggregate

2021 ◽  
Vol 13 (8) ◽  
pp. 4245
Author(s):  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Wojciech Sas
Keyword(s):  
Recycled Concrete ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Granulometric Analysis ◽  
Stiffness Properties ◽  
Grain Distribution ◽  
Natural Aggregates ◽  
Critical Reduction

The construction sector is currently struggling with the reuse of waste originating from the demolition and modernization of buildings and roads. Furthermore, old buildings are gradually being replaced by new structures. This brings a significant increase of concrete debris to waste landfills. To prevent this, many studies on the possibilities of recycling concrete, known as recycled concrete aggregate (RCA), have been done. To broaden the applicability of reused concrete, an understanding of its properties and engineering behavior is required. A difficulty in sustainable, proper management of RCA is the shortage of appropriate test results necessary to assess its utility. For this reason, in the present study, the physical, deformation, and stiffness properties of RCA with gravely grain distribution were analyzed carefully in the geotechnical laboratory. To examine the mentioned properties, an extensive experimental program was planned, which included the following studies: granulometric analysis, Proctor and oedometer tests, as well as resonant column tests. The obtained research results show that RCA has lower values of deformation and stiffness parameters than natural aggregates. However, after applying in oedometer apparatus repetitive cycles of loading/unloading/reloading, some significant improvement in the values of the parameters studied was noticed, most likely due to susceptibility to static compaction. Moreover, some critical reduction in the range of linear response of RCA to dynamic loading was observed.

scholarly journals Effect of high temperature on the stiffness properties of cracked composite laminates with different off-axis angles

2020 ◽  
Vol 28 ◽  
pp. 864-872
Author(s):  
Mohamed Khodjet Kesba ◽  
A. Benkhedda ◽  
E.A. Adda bedia ◽  
B. Boukert
Keyword(s):  
High Temperature ◽  
Composite Laminates ◽  
Stiffness Properties
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