scholarly journals Developing a Low-Cost Force Treadmill via Dynamic Modeling

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Chih-Yuan Hong ◽  
Lan-Yuen Guo ◽  
Rong Song ◽  
Mark L. Nagurka ◽  
Jia-Li Sung ◽  
...  
Keyword(s):  
Low Cost ◽  
Reaction Force ◽  
Harmonic Distortion ◽  
Testing Procedure ◽  
Force Sensors ◽  
Force Transmission ◽  
Force Transducers ◽  
Exercise Treadmill ◽  
Track Surface ◽  
Spot Motion

By incorporating force transducers into treadmills, force platform-instrumented treadmills (commonly called force treadmills) can collect large amounts of gait data and enable the ground reaction force (GRF) to be calculated. However, the high cost of force treadmills has limited their adoption. This paper proposes a low-cost force treadmill system with force sensors installed underneath a standard exercise treadmill. It identifies and compensates for the force transmission dynamics from the actual GRF applied on the treadmill track surface to the force transmitted to the force sensors underneath the treadmill body. This study also proposes a testing procedure to assess the GRF measurement accuracy of force treadmills. Using this procedure in estimating the GRF of “walk-on-the-spot motion,” it was found that the total harmonic distortion of the tested force treadmill system was about 1.69%, demonstrating the effectiveness of the approach.

Design and Analysis of a Foot Contact Sensor for Posture Control of a Biped Robot

2010 ◽  
Author(s):  
Koray K. S¸afak ◽  
T. Batuhan Baturalp
Keyword(s):  
Postural Stability ◽  
Low Cost ◽  
Reaction Force ◽  
Biped Robot ◽  
Stability Control ◽  
Ease Of Use ◽  
Force Sensors ◽  
Biped Robots ◽  
Contact Sensor ◽  
Computation Scheme

Development of a planar biped robot is currently underway at Yeditepe University. The robot consists of lower extremities with a torso that are designed at anthropomorphic dimensions. This study describes the design and testing of a foot contact sensor for the biped robot. Dynamic stability of a biped robot is commonly measured by the zero moment point (ZMP) method. Experimentally, ZMP is measured by multi-component force/torque sensors. Due to their low cost and ease of use, force sensitive resistors (FSR) are used to build a foot contact sensor for the biped robot. Four FSRs are mounted at the corners of the robot’s foot to measure the ground reaction force and its moment. Hence, by utilizing the data from the foot contact sensors, a real-time ZMP computation scheme can be implemented. The performance of the designed foot contact sensor is presented by numerical simulations of a planar biped robot’s postural stability control. Results indicate that reaction force computation by the FSR based force sensors is a viable method to monitor postural stability of biped robots. Force sensors and their electronics are currently being built to be used for the actual tests.

scholarly journals Flyback Photovoltaic Micro-Inverter with a Low Cost and Simple Digital-Analog Control Scheme

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4239
Author(s):  
Salam J. Yaqoob ◽  
Adel Obed ◽  
Rana Zubo ◽  
Yasir I. A. Al-Yasir ◽  
Hussein Fadhel ◽  
...  
Keyword(s):  
Digital Signal Processor ◽  
Low Cost ◽  
Harmonic Distortion ◽  
Single Stage ◽  
System Component ◽  
Maximum Efficiency ◽  
System Efficiency ◽  
Control Scheme ◽  
The Cost ◽  
Micro Inverter

The single-stage flyback Photovoltaic (PV) micro-inverter is considered as a simple and small in size topology but requires expensive digital microcontrollers such as Field-Programmable Gate Array (FPGA) or Digital Signal Processor (DSP) to increase the system efficiency, this would increase the cost of the overall system. To solve this problem, based on a single-stage flyback structure, this paper proposed a low cost and simple analog-digital control scheme. This control scheme is implemented using a low cost ATMega microcontroller built in the Arduino Uno board and some analog operational amplifiers. First, the single-stage flyback topology is analyzed theoretically and then the design consideration is obtained. Second, a 120 W prototype was developed in the laboratory to validate the proposed control. To prove the effectiveness of this control, we compared the cost price, overall system efficiency, and THD values of the proposed results with the results obtained by the literature. So, a low system component, single power stage, cheap control scheme, and decent efficiency are achieved by the proposed system. Finally, the experimental results present that the proposed system has a maximum efficiency of 91%, with good values of the total harmonic distortion (THD) compared to the results of other authors.

3D-PRINTED LOW-COST MODULAR FORCE SENSORS

2017 ◽  
Author(s):  
F. WASSERFALL ◽  
N. HENDRICH ◽  
F. FIEDLER ◽  
J. ZHANG
Keyword(s):  
Low Cost ◽  
Force Sensors ◽  
3D Printed

scholarly journals Assessment of the Equivalence of Low-Cost Sensors with the Reference Method in Measuring PM10 Concentration Using Selected Correction Functions

2020 ◽  
Vol 12 (13) ◽  
pp. 5368
Author(s):  
Tomasz Owczarek ◽  
Mariusz Rogulski ◽  
Piotr O. Czechowski
Keyword(s):  
Measurement Uncertainty ◽  
Low Cost ◽  
Measurement Data ◽  
Gravimetric Method ◽  
Reference Method ◽  
Testing Procedure ◽  
Coefficient Of Determination ◽  
Model Parameters ◽  
Equivalence Testing ◽  
Good Ability

The aim of the work is to demonstrate the possibility of building models to correct the results of measurements of particulate matter PM10 concentrations obtained using low-cost devices. Such devices apply the optical method to values comparable with those obtained using the reference gravimetric method. An additional goal is to show that the results corrected in this way can be used to carry out the procedure for testing equivalence of these methods. The study used generalized regression models (GRMs) to construct corrective functions. The constructed models were assessed using the coefficients of determination and the methodology of calculating the measurement uncertainty of the device. Measurement data from the two tested devices and the reference method were used to estimate model parameters. The measurement data were collected on a daily basis from 1 February to 30 June 2018 in Nowy Sącz. Regression allowed building multiple models with various functional forms and very promising statistical properties as well as good ability to describe the variability of reference measurements. These models also had very low values of measurement uncertainty. Of all the models constructed, a linear model using the original PM10 concentrations from the tested devices, air humidity, and wind speed was chosen as the most accurate and simplest model. Apart from the coefficient of determination, expanded relative uncertainty served as the measure of quality of the obtained model. Its small value, much lower than 25%, indicates that after correcting the results it is possible to carry out the equivalence testing procedure for the low-cost devices and confirm the equivalence of the tested method with the reference method.

scholarly journals Development of a Bendable Outsole Biaxial Ground Reaction Force Measurement System

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2641 ◽  
Author(s):  
Junghoon Park ◽  
Sangjoon Kim ◽  
Youngjin Na ◽  
Yeongjin Kim ◽  
Jung Kim
Keyword(s):  
Measurement System ◽  
Ground Reaction Force ◽  
Force Measurement ◽  
Reaction Force ◽  
Force Plate ◽  
Force Sensors ◽  
Measurement Systems ◽  
Cantilever Structure ◽  
Force Measurement System ◽  
Anterior Posterior

Wearable ground reaction force (GRF) measurement systems make it possible to measure the GRF in any environment, unlike a commercial force plate. When performing kinetic analysis with the GRF, measurement of multiaxial GRF is important for evaluating forward and lateral motion during natural gait. In this paper, we propose a bendable GRF measurement system that can measure biaxial (vertical and anterior-posterior) GRF without interrupting the natural gait. Eight custom small biaxial force sensors based on an optical sensing mechanism were installed in the proposed system. The interference between two axes on the custom sensor was minimized by the independent application of a cantilever structure for the two axes, and the hysteresis and repeatability of the custom sensor were investigated. After developing the system by the installation of force sensors, we found that the degree of flexibility of the developed system was comparable to that of regular shoes by investigating the forefoot bending stiffness. Finally, we compared vertical GRF (vGRF) and anterior-posterior GRF (apGRF) measured from the developed system and force plate at the same time when the six subjects walked, ran, and jumped on the force plate to evaluate the performance of the GRF measurement system.

Modeling and Evaluation of Low-Cost Force Sensors

2011 ◽  
Vol 27 (4) ◽  
pp. 815-822 ◽  
Author(s):  
C. Lebosse ◽  
P. Renaud ◽  
B. Bayle ◽  
M. de Mathelin
Keyword(s):  
Low Cost ◽  
Force Sensors

Accurate modeling of low-cost piezoresistive force sensors for haptic interfaces

2010 ◽  
Author(s):  
L Paredes-Madrid ◽  
P Torruella ◽  
P Solaeche ◽  
I Galiana ◽  
P Gonzalez de Santos
Keyword(s):  
Low Cost ◽  
Force Sensors ◽  
Haptic Interfaces

scholarly journals Gait-Ground Reaction Force Sensors Selection Based on ROC Curve Evaluation

2015 ◽  
Vol 03 (03) ◽  
pp. 13-19 ◽  
Author(s):  
Rami Alkhatib ◽  
Mohamad Diab ◽  
Bassam Moslem ◽  
Christophe Corbier ◽  
Mohamed El Badaoui
Keyword(s):  
Roc Curve ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Force Sensors

scholarly journals Design and Development of Non-Linearly Controlled Class-D Audio Amplifier

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 77
Author(s):  
Sridhar Joshi ◽  
Ravi Tripathi ◽  
Manoj Badoni ◽  
Rajeev Kumar ◽  
Pawan Khetrapal
Keyword(s):  
Sliding Mode ◽  
Low Cost ◽  
Peak Load ◽  
Harmonic Distortion ◽  
Resistive Load ◽  
Audio Frequency ◽  
Efficient Operation ◽  
Audio Amplifier ◽  
Viable Solution ◽  
Power Stage

A systematic and simple approach to develop a 20 W audio frequency range switch mode amplifier is presented in this paper. A non-linear sliding mode (SM) technique-based low cost analog controller enables the realized amplifier to deliver highly linear and efficient operation throughout the audio frequency spectrum. The theoretical aspects and practical limitations in the design and realization of subsystems, such as the signal conditioning stage, power stage and sliding mode controller, are considered, while the viable solution is also stated and justified. The hardware realization scheme is also elaborated, based on which the laboratory prototype is fabricated. Hardware results with a 4 Ω resistive load are given on which the performance of the amplifier is evaluated. The total harmonic distortion (THD) below 1% and 73% efficiency at peak load make the amplifier well suited for high quality audio application.

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