Linear dynamometer testing of hydraulic artificial muscles with variable recruitment

2017 ◽  
Vol 28 (15) ◽  
pp. 2051-2063
Author(s):  
Jordan Chipka ◽  
Michael A Meller ◽  
Alexander Volkov ◽  
Matthew Bryant ◽  
Ephrahim Garcia
Keyword(s):  
Energy Savings ◽  
Artificial Muscles ◽  
Loading Conditions ◽  
Hydraulic Actuator ◽  
Control Scheme ◽  
Study Results ◽  
Test Platform ◽  
In Series ◽  
Variable Recruitment ◽  
Characterization Test

A novel, meso-scale hydraulic actuator characterization test platform, termed a linear hydraulic actuator characterization device, is demonstrated and characterized in this study. The linear hydraulic actuator characterization device is applied to testing McKibben artificial muscles and is used to show the energy savings due to the implementation of a variable recruitment muscle control scheme. The linear hydraulic actuator characterization device is a hydraulic linear dynamometer that can be controlled to enable a desired force and stroke profile to be prescribed to the artificial muscles. The linear hydraulic actuator characterization device consists of a drive actuator that is connected in series with the test muscles. Thus, the drive cylinder can act as a controlled disturbance to the artificial muscles to simulate various loading conditions. With the ability to control the loading conditions of the artificial muscles, the linear hydraulic actuator characterization device offers the ability to experimentally validate the muscles’ performance and energetic characteristics. For instance, the McKibben muscles’ quasi-static force–stroke capabilities, as well as the power savings of a variable recruitment control scheme, are measured and presented in this work. Moreover, the development and fabrication of this highly versatile characterization test platform for hydraulic actuators is described in this article, and the characterization test results and efficiency study results are presented.

Variable recruitment in bundles of miniature pneumatic artificial muscles

2016 ◽  
Vol 11 (5) ◽  
pp. 056014 ◽  
Author(s):  
Sylvie A DeLaHunt ◽  
Thomas E Pillsbury ◽  
Norman M Wereley
Keyword(s):  
Artificial Muscles ◽  
Pneumatic Artificial Muscles ◽  
Variable Recruitment

Development of an Adaptive Human-Machine-Interface to Minimize Driver Distraction and Workload

2013 ◽  
Author(s):  
Matthew Westin ◽  
Ronald Dougherty ◽  
Christopher Depcik ◽  
Austin Hausmann ◽  
Charles Sprouse
Keyword(s):  
Performance Metrics ◽  
Sensory Information ◽  
Driver Distraction ◽  
Test Drive ◽  
Workload Management ◽  
City Street ◽  
Proximity Detection ◽  
Test Platform ◽  
In Series ◽  
And Performance

The original use of the vehicle dashboard was to provide enough sensory information to inform the driver of the current engine and vehicle status and performance. Over time, it has evolved into an entertainment system that includes person-to-person communication, global positioning information, and the Internet, just to name a few. Each of these new features adds to the amount of information that drivers must absorb, leading to potential distraction and possible increases in the number and types of accidents. In order to provide an overview of these issues, this paper summarizes previous work on driver distraction and workload, demonstrating the importance of addressing those issues that compete for driver attention and action. In addition, a test platform vehicle is introduced which has the capability of assessing modified dashboards and consoles, as well as the ability to acquire relevant driving performance data. Future efforts with this test platform will be directed toward helping to resolve the critical tug-of-war between providing more information and entertainment while keeping drivers and their passengers safe. The long-term goal of this research is to evaluate the various technological innovations available for inclusion in the driving environment and determining how to optimize driver information delivery without excessive distraction and workload. The information presented herein is the first step in that effort of developing an adaptive distraction/workload management system that monitors performance metrics and provides selected feedback to drivers. The test platform (1973 VW Beetle converted to a plug-in series hybrid) can provide speed, location (GPS), 3-D acceleration, and rear proximity detection. The test drive route was a 2 km × 3 km city street circuit which took approximately 25 minutes to complete. Data is provided herein to demonstrate these capabilities. In addition, the platform has driver selectable layouts for the instrument cluster and console (LCD screens). The test platform is planned for use to determine driver preferences (e.g., dashboard/console configurations) and attention performance in addition to identifying optimal real-time feedback for drivers with different demographics.

Position-Mode Haptic-Based Control of Teleoperated Hydraulic Actuators

2011 ◽  
Author(s):  
Kurosh Zarei-nia ◽  
Nariman Sepehri
Keyword(s):  
Invariant Set ◽  
Haptic Device ◽  
Position Tracking ◽  
Good Position ◽  
View Point ◽  
Hydraulic Actuator ◽  
Control Laws ◽  
Hydraulic Actuators ◽  
Control Scheme ◽  
On Line

A control scheme for teleoperation of hydraulic actuators, using a haptic device, is developed and experimentally evaluated in this paper. In the control laws, the position error between the displacement of the haptic device and the hydraulic actuator movement is used at both master and slave sides to maintain good position tracking at the actuator side while providing a haptic force to the operator. Lyapunov’s stability theory and LaSalle’s invariant set theorems are employed to prove the asymptotic stability of the system. It is shown that beside stability, the system performs well in terms of position tracking of the hydraulic actuator and providing a feel of telepresence to the operator. Proposed controller only needs system’s pressures and displacements that are easy to obtain via on-line measurements. Additionally, the controller does not need any information about the parameters of the system. These characteristics make the controller very attractive from the implementation view point.

scholarly journals Impact of reflective roofs on the overall energy savings of whole buildings

2020 ◽  
Vol 172 ◽  
pp. 25008
Author(s):  
Hamed H. Saber ◽  
Ali E. Hajiah ◽  
Wahid Maref
Keyword(s):  
Energy Savings ◽  
Three Dimensional ◽  
Short Wave ◽  
Solar Absorption ◽  
Thermal Emissivity ◽  
Study Results ◽  
Potential Energy Saving ◽  
Energy Simulations ◽  
Cool Roofs ◽  
Storey Building

Many previous studies by the authors of this paper and others have shown that installing white/reflective/cool roofing systems resulted in energy savings. The amount of energy savings depended on the longwave thermal emissivity and the short-wave solar reflectivity of the rooftop surfaces. The question is “what is the percentage energy savings for the whole building as a result of using cool roofing systems instead of conventional/black roofing systems? To answer this question, three-dimensional energy simulations are conducted for typical Saudi buildings when they are subjected to the natural weathering conditions of the Eastern Province of Saudi Arabia. Several Window-to-Wall Ratios (WWRs) having different thermal resistances (R-values) and Solar Heat Gain Coefficients (SHGCs) are considered in the study. The windows are located in the different main solar orientations. To investigate the effect of the area ratio of the roof to the walls on the potential energy saving due to using cool roofs, one storey and two-storey are considered in this study. Results showed that using reflective materials with lower short-wave solar absorption coefficients in the roofing systems have resulted in a decrease in the yearly total energy loads of one-storey building and two-storey building.

scholarly journals Characterization and application of FRCM as a strengthening material for shear-critical RC beams

2018 ◽  
Vol 199 ◽  
pp. 09004
Author(s):  
Adel Younis ◽  
Usama Ebead
Keyword(s):  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Structural Capacity ◽  
Test Parameters ◽  
Study Results ◽  
Glass Carbon ◽  
Characterization Test ◽  
Fabric Reinforced Cementitious Matrix

This paper investigates the effectiveness of fabric reinforced cementitious matrix (FRCM) systems in shear-strengthening of reinforced concrete beams. Three types of FRCM systems were considered, namely, polyparaphenylene benzobisoxazole (PBO)-FRCM, Carbon-FRCM, and Glass-FRCM. At first, tensile characterization test was performed on 15 FRCM coupons with the aim of identifying the tensile properties of the FRCM systems adopted. After that, seven shear-critical RC beams were tested under three-point loading, with the consideration of two test parameters: (a) FRCM material (glass/carbon/PBO); and (b) strengthening configuration (full/intermittent). The study results revealed the use of FRCM as a strengthening material to achieve a considerable improvement in the structural capacity of shear-critical RC beams. The average gain in the shear capacity of the FRCM-strengthened beams was 57%. The beam specimens strengthened with carbon-FRCM showed the highest improvement as compared to those strengthened with glass-and PBO-FRCM systems. As intuitively expected, the shear capacity improvement achieved with the full-length strengthening systems was generally higher than that with the intermittent counterparts.

Numerical Investigation of Multistage Viscous Micropump Configurations

2005 ◽  
Vol 127 (4) ◽  
pp. 734-742 ◽  
Author(s):  
M. Abdelgawad ◽  
I. Hassan ◽  
N. Esmail ◽  
P. Phutthavong
Keyword(s):  
Flow Rate ◽  
Numerical Data ◽  
Future Research ◽  
Shear Stresses ◽  
Vertical Rotor ◽  
Viscous Micropump ◽  
Study Results ◽  
In Series ◽  
The Subject ◽  
Drag And Lift

The viscous micropump consists of a cylinder placed eccentrically inside a microchannel, where the rotor axis is perpendicular to the channel axis. When the cylinder rotates, a net force is transferred to the fluid because of the unequal shear stresses on the upper and lower surfaces of the rotor. Consequently, this causes the surrounding fluid in the channel to displace toward the microchannel outlet. The simplicity of the viscous micropump renders it ideal for micropumping; however, previous studies have shown that its performance is still less than what is required for various applications. The performance of the viscous micropump, in terms of flow rate and pressure capabilities, may be enhanced by implementing more than one rotor into the configuration either horizontally or vertically oriented relative to each other. This is analogous to connecting multiple pumps in parallel or in series. The present study will numerically investigate the performance of various configurations of the viscous micropumps with multiple rotors, namely, the dual-horizontal rotor, triple-horizontal rotor, symmetrical dual-vertical rotor, and eight-shaped dual-vertical rotor. The development of drag-and-lift forces with time, as well as the viscous resisting torque on the cylinders were studied. In addition, the corresponding drag, lift, and moment coefficients were calculated. The flow pattern and pressure distribution on the cylinders’ surfaces are also included in the study. Results show that the symmetrical dual-vertical rotor configuration yields the best efficiency and generates the highest flow rate. The steady-state performance of the single-stage micropump was compared to the available experimental and numerical data and found to be in very good agreement. This work provides a foundation for future research on the subject of fluid phenomena in viscous micropumps.

Asymptotic Impact Control of Hydraulic Actuators With Friction

2004 ◽  
Author(s):  
P. Sekhavat ◽  
N. Sepehri ◽  
Q. Wu
Keyword(s):  
Steady State ◽  
Nonlinear Control ◽  
Dry Friction ◽  
Position Control ◽  
Past Research ◽  
Hydraulic Actuator ◽  
Stick Slip ◽  
Hydraulic Actuators ◽  
Control Scheme ◽  
Control Schemes

The focus of this work is stabilization of hydraulic actuators during the transition from free motion to constraint motion and regulating the intermediate impacts that could drive the system unstable. In our past research, we introduced Lyapunov-based nonlinear control schemes capable of fulfilling the above goal by resting the implement on the surface of the environment before starting the sustained-contact motion. The hydraulic actuator’s stick-slip friction effect was, however, either not included in the analysis or not compensated by the control action. In this paper, the application of our previously introduced friction compensating position control scheme is extended to impact regulation of a hydraulic actuator. Theoretical solution and stability analyses as well as actual experiments prove that such control scheme is also effective for asymptotic impact control (with no position steady-state error) of hydraulic actuators in the presence of actuator’s dry friction.

PID PARAMETERS OPTIMIZATION USING PSO TECHNIQUE FOR NONLINEAR ELECTRO HYDRAULIC ACTUATOR

2015 ◽  
Vol 77 (28) ◽  
Author(s):  
Siti Marhainis Othman ◽  
Mohd Fua’ad Rahmat ◽  
Sahazati Md. Rozali ◽  
Sazilah Salleh
Keyword(s):  
Particle Swarm Optimization ◽  
Simulation Study ◽  
Pid Control ◽  
Parameters Optimization ◽  
Model Parameters ◽  
Time Varying ◽  
Proportional Integral Derivative ◽  
Hydraulic Actuator ◽  
Swarm Optimization ◽  
Control Scheme

Electro-hydraulic actuator (EHA) system inherently suffers from uncertainties, nonlinearities and time- varying in its model parameters which cause the modeling and controller designs are more complicated. Proportional Integral Derivative (PID) control scheme has been proposed and the main problem with its application is to tune the parameters to its optimum values. This study will look into an optimization of PID parameters using particle swarm optimization (PSO). Simulation study has been done in Matlab and Simulink. 

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