bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of neonatal unplanned extubations in the neonatal intensive care unit: a best practice implementation project
Authors: Hu Xiaojing , Zhang Yuxia , Cao Yun , Huang Guoying , Hu Yan , McArthur Alexa
Published: November 2017

EXECUTIVE SUMMARY

Background:

Adverse events of mechanically ventilated neonates such as unplanned extubations may be associated with serious negative outcomes. Unplanned extubation rates have been monitored by many neonatal intensive care units as a quality of care metric.

Objectives:

The objective was to implement evidence-based best practice and assess the effects of these strategies on minimizing unplanned extubation in the neonatal intensive care unit in a large tertiary children's hospital.

Methods:

Evidence-based audit criteria were used to conduct an audit in the neonatal intensive care unit, Children's Hospital of Fudan University, Shanghai. The program included three phases and was conducted from May 2016 to October 2016. The Joanna Briggs Institute Practical Application of Clinical Evidence System and Getting Research into Practice audit tools for promoting change in health practice were used to ascertain compliance with the criteria before and after the implementation of best practice.

Results:

Compared with the baseline audit, the follow-up audit results demonstrated increased compliance rates for securement procedures, documentation of position and security of the endotracheal tube. Compliance for standardized care practice documentation increased from 0% to 100%; compliance for standard care practice implementation increased from 0% to 54.9%; and compliance for staff education increased from 66.7% to 100%. The neonatal intensive care unit also achieved the benchmark of less than one UE per 100 intubation days.

Conclusions:

This implementation project achieved a significant improvement in establishing evidence-based prevention of unplanned extubations in the neonatal intensive care unit of Children's Hospital of Fudan University, China. Standardizing the procedures represented an important step toward refining the quality improvement process.
New Adjustable Unloader Knee Brace and Its Effectiveness
Authors: Hangalur Gajendra , Bakker Ryan , Tomescu Sebastian , Chandrashekar Naveen
Published: November 2017

Unloader knee braces are prescribed for patients with unicompartmental osteoarthritis of the knee. These braces aim to reduce pain in patients by applying a coronal moment to the knee to unload the symptomatic knee compartment. However, existing unloading mechanisms use straps that go directly behind the knee joint, to apply the needed moment. This can impinge on the popliteal artery and peroneal nerves thereby causing discomfort to the patient. Hence, these braces cannot be worn for prolonged periods of time. This research focused on developing a new knee brace to improve comfort while unloading the osteoarthritic knee. A new knee brace was developed that uses a four-point bending approach to unload the knee. In this brace, unloading can be adjusted, and the unloading mechanism is away from the joint. The new brace was tested on a cadaver specimen to quantify its capability to unload the knee compartment. The brace was also worn by a patient with osteoarthritis who subjectively compared it to his existing unloader brace. During cadaver testing, the new brace design could reduce the force exerted on the medial condyle by 25%. Radiographic images of the patient's knee confirmed that the brace unloaded the medial condyle successfully. The patient reported that the new brace reduced pain, was significantly comfortable to wear and could be used for a longer duration in comparison to his existing brace.
Tuning of a Rigid-Body Dynamics Model of a Flapping Wing Structure With Compliant Joints
Authors: Calogero Joseph , Frecker Mary , Hasnain Zohaib , Hubbard James E.
Published: November 2017

A method for validating rigid-body models of compliant mechanisms under dynamic loading conditions using motion tracking cameras and genetic algorithms is presented. The compliant mechanisms are modeled using rigid-body mechanics as compliant joints (CJ): spherical joints with distributed mass and three-axis torsional spring dampers. This allows compliant mechanisms to be modeled using computationally efficient rigid-body dynamics methods, thereby allowing a model to determine the desired stiffness and location characteristics of compliant mechanisms spatially distributed into a structure. An experiment was performed to validate a previously developed numerical dynamics model with the goal of tuning unknown model parameters to match the flapping kinematics of the leading edge spar of an ornithopter with contact-aided compliant mechanisms (CCMs), compliant mechanisms that feature self-contact to produce nonlinear stiffness, inserted. A system of computer motion tracking cameras was used to record the kinematics of reflective tape and markers placed along the leading edge spar with and without CCMs inserted. A genetic algorithm was used to minimize the error between the model and experimental marker kinematics. The model was able to match the kinematics of all markers along the spars with a root-mean-square error (RMSE) of less than 2% of the half wingspan over the flapping cycle. Additionally, the model was able to capture the deflection amplitude and harmonics of the CCMs with a RMSE of less than 2 deg over the flapping cycle.
Heterogeneous Versus Homogeneous Material Considerations in Determining the Modal Frequencies of Long Tibia Bones
Authors: Yassine Reem A. , Elham Mohammad Karim , Mustapha Samir , Hamade Ramsey F.
Published: November 2017

Where heterogeneous material considerations may yield more accurate estimates of long bones' modal characteristics, homogeneous description yields faster approximate solutions. Here, modal frequencies of (bovine) long tibia bones are numerically estimated using the finite element method (FEM) (ANSYS) starting from anatomically accurate computed tomography (CT) scans. Whole long bones are segmented into cortical and cancellous constituents based on Hounsfield (HU) values. Accurate three-dimensional (3D) models are consequently developed. Bones' cortical and cancellous constituents are first treated as heterogeneous material. Relative to stiffness–density relations, stiffness values are assigned for each element yielding a stiffness-graded structure. Calculated modal frequencies are compared to those measured from dynamic experiments. Analysis was repeated where bone properties are homogenized by averaging the stiffness properties of bone constituents. Compared with experimental values of one control long bone, the heterogeneous material assumption returned good estimates of the frequency values in the cranial–caudal (CC) plane with of +0.85% for mode 1 and +10.66% for mode 2. For homogeneous material assumption, underestimates were returned with error values of −13.25% and −0.13% differences for mode 2. In the medial–lateral (ML) plane, heterogeneous material assumption returned good frequency estimates with −8.89% for mode 1 and +1.01% for mode 2. Homogeneous material assumption underestimated the frequency values with error of −20.52% for mode 1 and −7.50% for mode 2. Homogeneous simplifications yielded faster and more memory-efficient FEM runs with heterogeneous modal analysis requiring 1.5 more running time and twice the utilized memory.
Enlarged Controllability of Riemann–Liouville Fractional Differential Equations
Authors: Karite Touria , Boutoulout Ali , Torres Delfim F. M.
Published: November 2017

We investigate exact enlarged controllability (EEC) for time fractional diffusion systems of Riemann–Liouville type. The Hilbert uniqueness method (HUM) is used to prove EEC for both cases of zone and pointwise actuators. A penalization method is given and the minimum energy control is characterized.
Entropy Generation Minimization in a Pressure-Driven Microflow of Viscoelastic Fluid With Slippage at the Wall: Effect of Conjugate Heat Transfer
Authors: Sarma Rajkumar , Mondal Pranab Kumar
Published: November 2017

We focus on the entropy generation minimization for the flow of a viscoelastic fluid through a parallel plate microchannel under the combined influences of applied pressure gradient, interfacial slip, and conjugate heat transfer. We use the simplified Phan–Thien–Tanner model (s-PTT) to represent the rheological behavior of the viscoelastic fluid. Using thermal boundary conditions of the third kind, we solve the transport equations analytically to obtain the velocity and temperature distributions in the flow field, which are further used to calculate the entropy generation rate in the analysis. In this study, the influential role of the following dimensionless parameters on entropy generation rate is examined: the viscoelastic parameter (εDe2), slip coefficient (k¯), channel wall thickness (δ), thermal conductivity of the wall (γ), Biot number (Bi) and Peclet number (Pe). We show that there exists a particular value of the abovementioned parameters that lead to a minimum entropy generation rate in the system. We believe the results of this analysis could be of helpful in the optimum design of microfluidic system/devices typically used in thermal management, such as micro-electronic devices, microreactors, and microheat exchangers.
Tool Path Planning for Directional Freezing-Based Three-Dimensional Printing of Nanomaterials
Authors: Zhao Guanglei , Zhou Chi , Lin Dong
Published: November 2017

As an emerging and effective nanomanufacturing technology, the directional freezing-based three-dimensional (3D) printing can form 3D nanostructures with complex shapes and superior functionalities, and thus has received ever-increasing publicity in the past years. One of the key challenges in this process is the proper heat management, since the heat-induced melting and solidification process significantly affects the functional integrity and structural integrity of the printed structure. A novel approach for heat prediction out of modeling and optimization is introduced in this study. Based on the prediction, we propose a heuristic tool path planning method. The simulation results demonstrate that the tool path planning highly affects the spatial and temporal temperature distribution of the being printed part, and the optimized tool path planning can effectively improve the uniformity of the temperature distribution, which will consequently enhance the performance of the fabricated nanostructures.
Suppressing Chaotic/Hyperchaotic Dynamics of Smart Valves Network Using Decentralized and Centralized Schemes
Authors: Bagheri Mostafa , Naseradinmousavi Peiman , Ashrafiuon Hashem , Canova Marcello , Segala David B.
Published: November 2017

In this effort, we present a comprehensive comparative study of decentralized and centralized adaptive schemes to control the so-called “Smart Valves” network employed in many applications including, but not limited to, Municipal Piping Systems and oil and gas fields. The network being considered here typically includes scores of coupled solenoid actuated butterfly valves. We here examine the multiphysics network of two interconnected actuated sets. The network undergoes the coupled chaotic and hyperchaotic dynamics subject to some initial conditions and critical parameters. The control schemes’ trade-offs are thoroughly investigated with respect to robustness, computational cost, and practical feasibility of control inputs in the presence of strong nonlinear interconnections and harmful chaotic and hyperchaotic responses.
Robust Integral Backstepping Control of Quadrotors
Authors: Poultney Alexander , Gong Peiyan , Ashrafiuon Hashem
Published: November 2017

A novel trajectory tracking, hovering, and yaw motion control is presented for fully nonlinear model of quadrotors based on integral backstepping. The control law is developed by relating the second time derivatives of linear accelerations to thrust force and roll and pitch moments. A separate control law is then derived for yaw motion. The controller is shown to be asymptotically convergent in presence of modeling uncertainties and constant disturbances. Several simulations and experiments are performed with a quadrotor to verify the controller performance.
Experimental Derivation of Models of Human Drivers Executing Emergency Steering Maneuvers
Authors: Horak Dan T.
Published: November 2017

Tests with human drivers in a driving simulator are used for developing dynamic models of drivers during emergency highway steering maneuvers. The maneuvers were required to avoid colliding with suddenly emerging simulated lane-blocking vehicles and objects. The driver models are intended for forming vehicle-driver simulation models that are used in analysis of highway accidents caused by lane obstructions. Four standard driver models are derived based on the test results, ranging from a cautious driver to an aggressive driver. Test data is provided to allow derivation of additional driver models.
Robot Tool Calibration in Precise Glass Handling
Authors: Yu Xiaowen , Baker Thomas , Zhao Yu , Tomizuka Masayoshi
Published: November 2017

In the cell phone protective glass manufacturing industry, glass need to be first ground to a desired thickness, which requires human workers to place the glass pieces precisely into the grinder. We propose to use a 6 DOF industrial robot equipped with vision sensors to automate the process by the “pick and place” task. The precision of the placing depends not only on the vision detection, but also on the calibration of the camera and the glass plane. In this paper, a Maximum a Posteriori (MAP) method is proposed to increase the calibration accuracy. A nominal calibration is first obtained with standard method, then it is corrected with observations. Experimental results shows the increased accuracy of placing.
A Multi-Zone Reaction-Based Diesel Combustion Model for Model-Based Control
Authors: Men Yifan , Zhu Guoming G.
Published: November 2017

A physics-based control-oriented combustion model is developed to accurately predict in-cylinder pressure and temperature of a diesel engine. The model is under the assumption that the combustion chamber consists of three zones: a liquid fuel zone, a reaction zone, and an unmixed zone. These zones are formulated to account for three key events in diesel combustion: fuel evaporation, chemical reaction, and fuel-air mixing, respectively. The liquid fuel zone is assumed to be of spherical shape. The evaporation of fuel is governed by Fick’s first law of diffusion. The reaction zone is modeled as a reactive system consisting of six species and two reaction steps. The burn rate is calculated based on species concentrations and reaction zone temperature. The unmixed zone contains only air and inert gas. The results of simulations are compared to the test data from a GM 6.7 L 8-cylinder Duramax diesel engine. The multi-zone model is shown to be capable of predicting in-cylinder pressure accurately with more degree of freedoms, compared to the singlezone reaction-based model.
Online Sensor Noise Covariance Identification Using a Modified Adaptive Filter
Authors: Madhag Aqeel , Zhu Guoming George
Published: November 2017

Modern control systems heavily relay on sensors for closed-loop feedback control. Degradation of sensor performance due to sensor aging affects the closed-loop system performance, reliability, and stability. Sensor aging characterized by the sensor measurement noise covariance. This paper proposes an algorithm used to identify the slow varying sensor noise covariance online based on system sensor measurements. The covariance-matching technique, along with the adaptive Kalman filter is utilized based on the information about the quality of weighted innovation sequence to estimate the slow time-varying sensor noise covariance. The sequential manner of the proposed algorithm leads to significant reduction of the computational load. The covariance-matching of the weighted innovation sequence improves the prediction accuracy and reduces the computational load, which makes it suitable for online applications. Simulation results show that the proposed algorithm is capable of estimating the slow time-varying sensor noise covariance for MIMO systems with white noise whose covariance varies linearly, exponentially, or linearly with added sinusoid perturbation. Furthermore, the proposed estimation algorithm shows a reasonable convergence rate.
A Continuous First-Order Sliding Mode Control Law
Authors: Mohammadi Keyvan , L’Afflitto Andrea
Published: November 2017

Sliding mode control is a technique to design robust feedback control laws. In its classical formulation, this approach involves discontinuous controls that arise several theoretical and practical challenges, such as the existence of non-unique solutions of nonlinear differential equations and chattering. Numerous variations of the sliding mode control architecture, such as the higher-order sliding mode method, have been presented to overcome these issues. In this paper, we present an alternative sliding mode control architecture that involves Hölder continuous feedback control laws, is simpler to implement than other non-classical nonlinear robust control techniques, guarantees robustness and uniform asymptotic stability of the closed-loop system, and ensures both existence and uniqueness of the closed-loop system’s trajectory. Our results are applied to design a robust nonlinear observer in the same form as the Walcott and Żak observer. Moreover, a numerical example illustrates our theoretical results and compares the proposed control law to the classical sliding mode control, the second order sliding mode control, and the super-twisting control.
System Identification and Optimal Control of Half-Car Active Suspension System Using a Single Noisy IMU With Position Uncertainty
Authors: Attia Tamer , Kochersberger Kevin , Bird John , Southward Steve C.
Published: November 2017

An active suspension based on Linear Quadratic Gaussian (LQG) optimal controller is an effective system for enhancing the ride comfort and handling characteristics of a vehicle. LQG requires a good plant model for success, and this may be difficult to extract using a single inertial measurement device in the presence of noise. This paper presents a method for estimating the vehicle states by measuring both the vehicle bounce and pitch accelerations using an Inertial Measurement Unit (IMU) with position uncertainty relative to the sprung mass center of gravity. Frequency domain methods are used for System Identification (SysId). The state estimation is based on channel-by-channel model estimation using uncorrelated random excitation which is applied to the front wheels, rear wheels, front actuator, and rear actuator. An anti-aliasing filter eliminates false response harmonics and a Kalman filter is used to estimate the current states of the actual plant and the LQR block for the full-states-feedback controller. The controllers and observer are implemented in simulation using a four degree-of-freedom half car linear model.
A Comprehensive Inverse Dynamics Problem of a Stewart Platform by Means of Lagrangian Formulation
Authors: Mostashiri Naser , Akbarzadeh Alireza , Dhupia Jaspreet , Verl Alexander , Xu Weiliang
Published: November 2017

In this paper, using the Lagrange’s method a comprehensive inverse dynamics problem of a 6-3 UPS Stewart platform is investigated. First, the inverse kinematics problem is solved and the Jacobian matrix is derived. Next, the full inverse dynamics problem of the robot, taking into account the mass of links and inertia, is investigated and its governing equations are derived. The correctness of the dynamics equations are verified in two ways, first, using the results of the virtual work method and second using the results of a commercial multi-body dynamics software. Because the dynamic calculation is time consuming, two simplifying assumptions are considered. First, the link is assumed to have a zero mass and next it is assumed as a point mass. Studying the former assumption is rather straightforward. However, more complex equations are needed and derived in the present paper for the latter assumption. Required actuator forces for the two assumptions are compared with the case where the mass and link inertial is fully considered. It is shown that the first simplifying assumption significantly affects the accuracy of the required joint torques.
On-Line Identification of Three-Dimensional Shear Building Models
Authors: García-Illescas M. A. , Alvarez-Icaza Luis
Published: November 2017

An on-line identification scheme for shear building models using recursive least squares with a matrix parameterized model is presented. Based on Gershgorin circles and tridiagonal matrices properties, the identified model stability is guaranteed in the presence of low excitation or low damping. Stability of the model helps in the design of more robust control laws. The scheme is evaluated in an experimental test-bed with a scaled five stories building where an on-line reduced order model is derived. Results indicate that when employing this matrix parametrization, a significant reduction in the number of calculations involved is achieved, when compared to the standard vector parametrization based schemes, such that real-time applications are feasible to implement. Moreover, the stability on the identified model is preserved.
Nonlinear Responses of Inextensible Cantilever and Free-Free Beams Undergoing Large Deflections
Authors: McHugh Kevin , Dowell Earl
Published: November 2017

A theoretical and computational model has been developed for the nonlinear motion of an inextensible beam undergoing large deflections for cantilevered and free-free boundary conditions. The inextensibility condition was enforced through a Lagrange multiplier which acted as a constraint force. The Rayleigh-Ritz method was used by expanding the deflections and the constraint force in modal series. Lagrange’s Equations were used to derive the equations of motion of the system, and a 4th order Runge-Kutta solver was used to solve them. Comparisons for the cantilevered beam were drawn to experimental and computational results previously published and show good agreement for responses to both static and dynamic point forces. Some physical insights into the cantilevered beam response at the 1st and 2nd resonant modes were obtained. The free-free beam condition was investigated at the 1st and 3rd resonant modes and the nonlinearity (primarily inertia) was shown to shift the resonant frequency significantly from the linear natural frequency and lead to hysteresis in both modes.
Voltage Response of Parametric Resonance of Double Wall Carbon Nanotube Under Electrostatic Actuation
Authors: Juarez Ezequiel , Caruntu Dumitru I. , Park Young-Gil
Published: November 2017

In this paper, the Method of Multiple Scales is used to investigate the influences of damping and detuning frequency parameters on the amplitude-voltage response of an electrostatically actuated double-walled carbon nanotube. The forces responsible for the nonlinearities in the vibrational behavior are intertube van der Waals and electrostatic forces. Herein, the coaxial case is investigated, which eliminates the influence of the cubic van der Waals in the first-order solution. The double-walled carbon nanotube structure is modelled as a cantilever beam with Euler-Bernoulli beam assumptions since the double-walled carbon nanotube is characterized with high length-diameter ratio. The results shown assume steady-state solutions in the first-order Method of Multiple Scales solution. The importance of the results in this paper are the effect of damping and detuning frequency on the Hopf bifurcations, as these define the intervals of voltage for nonzero amplitudes.
Real-Time Brain Machine Interaction via Social Robot Gesture Control
Authors: Abiri Reza , Borhani Soheil , Zhao Xiaopeng , Jiang Yang
Published: November 2017

Brain-Machine Interaction (BMI) system motivates interesting and promising results in forward/feedback control consistent with human intention. It holds great promise for advancements in patient care and applications to neurorehabilitation. Here, we propose a novel neurofeedback-based BCI robotic platform using a personalized social robot in order to assist patients having cognitive deficits through bilateral rehabilitation and mental training. For initial testing of the platform, electroencephalography (EEG) brainwaves of a human user were collected in real time during tasks of imaginary movements. First, the brainwaves associated with imagined body kinematics parameters were decoded to control a cursor on a computer screen in training protocol. Then, the experienced subject was able to interact with a social robot via our real-time BMI robotic platform. Corresponding to subject’s imagery performance, he/she received specific gesture movements and eye color changes as neural-based feedback from the robot. This hands-free neurofeedback interaction not only can be used for mind control of a social robot’s movements, but also sets the stage for application to enhancing and recovering mental abilities such as attention via training in humans by providing real-time neurofeedback from a social robot.
Undersea Vehicle Autopilot Off Weight Design Compensation
Authors: Begg Colin D. , Bowman Daniel J. , Lewis A. Scott
Published: November 2017

A service issue that can adversely affect the performance of many undersea vehicles in general application is either over or under weight operation. Depth keeping precision can be impacted when a vehicle is launched at a weight different from that specified in the nominal flight control system design. As a result, overall maneuvering performance and the vehicle application objectives can be significantly impacted. This paper presents a compensation method based on simple expansion of the vehicle’s autopilot depth controller trim schedule. Expansion is defined relative to a vehicle’s nominally fixed weight-buoyancy flight control equilibrium trim design point and refers to practical variances in both net buoyancy and buoyancy-weight center geometric offset. This implementation requires only a simple, highly feasible, dry dockside launch under/overweight measurement for operational flight static reference. Off weight compensation is enabled by a priori determination of the vehicle’s steady speed, straight-horizontal flight path, body pitch, and elevator trim angles when subjected to the expected set range of weight-buoyancy variations. The method and implementation are outlined. A depth step change maneuver, using a high fidelity autopilot-software-in-the-loop maneuvering simulation, is examined to verify the implementation feasibility and effectiveness.
Competing Swarms of Autonomous Vehicles: Intruders Versus Guardians
Authors: Shishika Daigo , Sherman Katarina , Paley Derek A.
Published: November 2017

We consider a competition between two swarms of aerial vehicles, where multiple intruder vehicles try to approach and then leave an area that multiple guardian vehicles are protecting. Pre-existing swarming strategies for the guardians to maximize the probability of capturing a single intruder are summarized. This work considers the case where multiple intruders approach the protected area sequentially with varied time intervals, to study the impact of intrusion frequency on the probability of capture. In addition, we formulate a payoff function treating the competition as a zero-sum game, and use this function to design strategies for the intruders, i.e., how to optimize the time interval between intrusions. We propose an intrusion strategy and demonstrate its performance with numerical simulations.
System Diagnosis and Fault Mitigation Strategies for an Automated Manual Transmission
Authors: Trask Simon J. H. , Jankord Greg J. , Modak Aditya A. , Rahman Brian M. , Rizzoni Giorgio , Midlam-Mohler Shawn W. , Guercioni Guido R.
Published: November 2017

The introduction of hybrid vehicle architectures into the mass car market has dramatically increased fault detection and mitigation strategies seen in vehicles to match the growth in potential failures coming from increasingly complex powertrain architectures. To meet this increased demand for fault detection and mitigation of multiple powertrain components, advanced methodologies have been developed to determine the functional safety of systems. This paper focuses on the use of one of those advanced methodologies, structural analysis, to develop the design, implementation, diagnostics, and control of a prototype automated manual transmission. Structural analysis is the concept of analyzing the mathematical structure of a system to determine the diagnostic capabilities of sensors in the system. From this information, a controls strategy can be developed to address potential failure modes of a system utilizing the derived equations and knowledge of which sensors provide coverage for failure modes analyzed. Moreover, the need for additional sensors can be determined through this analysis. Using structural analysis, the Ohio State University EcoCAR 3 research team carried out a diagnostic and mitigation study during the development of their automated manual transmission.
Analysis of Effects of Fuel Cell System Dynamics on Optimal Energy Management
Authors: Wu Kai , Kuang Ming , Milacic Milos , Zhang Xiaowu , Sun Jing
Published: November 2017

Dynamic characteristics of a proton exchange membrane fuel cell (PEMFC) system can impact fuel economy and load following performance of a fuel cell vehicle, especially if those dynamics are ignored in designing top-level energy management strategy. To quantify the effects of fuel cell system (FCS) dynamics on optimal energy management, dynamic programming (DP) is adopted in this study to derive optimal power split strategies at two levels: Level 1, where the FCS dynamics are ignored, and Level 2, where the FCS dynamics are incorporated. Analysis is performed to quantify the differences of these two resulting strategies to understand the effects of FCS dynamics. While Level 1 DP provides significant computational advantages, the resulting strategy leads to load following errors that need to be mitigated using battery or FCS itself. Our analysis shows that up to 5% fuel economy penalty on New York city cycle (NYCC) and 3% on supplemental federal test procedure (US06) can be resulted by ignoring FCS dynamics, when the dominant dynamics of the FCS has settling time as slow as 8 seconds.
Teaching Real-Time Control Using Arduino: Timer ISR vs delayMicroseconds
Authors: Krauss Ryan W.
Published: November 2017

Arduino microcontrollers are inexpensive and easy to program, making them very popular among hobbyists and “makers”. Arduinos are also surprisingly capable when it comes to creating real-time feedback control systems. This paper investigates several facets of using Arduino microcontrollers to teach students to create real-time control systems. A simplified approach to enforcing the real-time execution of a control law is introduced based on the delayMicroseconds function and its accuracy is compared to the standard timer interrupt approach. Initial assessment data is presented on whether or not the delayMicroseconds approach is easier for students to understand. The accuracy of the Arduino’s built-in timing function micros is also investigated.
A Parallel Processing and Diversified-Hidden-Gene-Based Genetic Algorithm Framework for Fuel-Optimal Trajectory Design for Interplanetary Spacecraft Missions
Authors: Somavarapu Dhathri H. , Turkoglu Kamran
Published: November 2017

This paper proposes a new parallel computing genetic algorithm framework for designing fuel-optimal trajectories for interplanetary spacecraft missions. The framework can capture the deep search-space of the problem with the use of a fixed chromosome structure and hidden-genes concept, can explore the diverse set of candidate solutions with the use of the Adaptive and Twin-Space Crowding techniques, can execute on any High-Performance Computing (HPC) platform with the adoption of the portable Message Passing Interface (MPI) standard. New procedures are developed for determining trajectories in legs of the flight from the launch planet, and deep-space maneuver legs of the flight from the launch and non-launch planets. The chromosome structure maintains the time of flight as a free parameter within certain boundaries. The fitness or the cost function of the algorithm uses only the mission ΔV, and does not include the time of flight. The proposed algorithm is proven superior to the classical genetic algorithm both in terms of convergence characteristics for the cost function and the depth of the search space explored.
Detection of Vehicle Tripped and Untripped Rollovers by a Novel Index With Mass-Center-Position Estimations
Authors: Wang Fengchen , Chen Yan
Published: November 2017

This paper presents a novel mass-center-position (MCP) metric for vehicle rollover propensity detection. MCP is first determined by estimating the positions of the center of mass of one sprung mass and two unsprung masses with two switchable roll motion models, before and after tire lift-off. The roll motion information without saturation can then be provided through MCP continuously. Moreover, to detect completed rollover statues for both tripped and untripped rollovers, the criteria are derived from d’Alembert principle and moment balance conditions based on MCP. In addition to tire lift-off, three new rollover statues, rollover threshold, rollover occurrence, and vehicle jumping into air can be all identified by the proposed criteria. Compared with an existing rollover index, lateral load transfer ratio, the fishhook maneuver simulation results in CarSim® for an E-class SUV show that MCP metric can successfully predict the vehicle impending rollover without saturation for untripped rollovers. Tripped rollovers caused by a triangle road bump are also successfully detected in the simulation. Thus, MCP metric can be successfully applied for rollover propensity prediction.
Dynamics of a Circular Cylinder With a Passive Degree of Freedom Interacting With an Inviscid Fluid Containing a Point Vortex
Authors: Tallapragada Phanindra , Pollard Beau , Fedonyuk Vitaliy
Published: November 2017

In the recent past the design of many aquatic robots has been inspired by the motion of fish. Actuated internal rotors or moving masses have been frequently used either for propulsion and or the control of such robots. However the effect of internal passive degrees of freedom or passive appendages on the motion of such robots is poorly understood. In this paper we present a minimal model that demonstrates the influence of passive degrees of freedom on an aquatic robot. The model is of a circular cylinder with a passive internal rotor, immersed in an inviscid fluid interacting with point vortices. We show through numerics that the motion of the cylinder containing a passive degree of freedom is significantly different than one without. These results show that the mechanical feedback via passive degrees of freedom could be a useful way to control the motion of aquatic robots.
Muscle Effort Using a Reacher Assistive Device: The Influence of Forearm Support
Authors: Chappell Scott , Schmitz Anne , Hartmann Julie , Piovesan Davide
Published: November 2017

A reacher is an assistive device utilized for reaching items placed overhead or on the floor by individuals with arthritis, post-surgical total joint replacement, spinal injuries and more. A forearm support for a reacher device has been developed to decrease the amount of force distribution placed through the wrist. Also, allowing for movement at the wrist to decrease the range of motion needed in the upper extremity for the object retrieval process. The forearm support can fold up or collapse to allow use of the reacher device without having to utilize the forearm support. This paper analyzes and compares the effectiveness of the forearm support through the use of surface electromyography providing insight in the control strategies utilized when using such assistive devices.
Road Profile Estimation for Vehicle Localization
Authors: Gim Juhui , Ahn Changsun
Published: November 2017

Measuring road profile is mainly used for a road maintenance purpose. Another interesting application of the knowledge on road profile is vehicle localization if the knowledge is available in real-time. A cost effective and implementable approach of measuring or estimating a road profile in a passenger vehicle is estimating the profile using inertial sensors that is readily installed for active safety features. The suggested method is a Kalman filter based disturbance observer without assuming a constant disturbance. By estimating the disturbance of k-1 time step at the k time step, the constant disturbance assumption is not necessary. The required observer structure and dynamics are presented as well as simulation and experimental results.
Development of a Swarm UAV Simulator Integrating Realistic Motion Control Models for Disaster Operations
Authors: Ahmed Siddiqui Kazi Tanvir , Feil-Seifer David , Jiang Tianyi , Jose Sonu , Liu Siming , Louis Sushil
Published: November 2017

Simulation environments for Unmanned Aerial Vehicles (UAVs) can be very useful for prototyping user interfaces and training personnel that will operate UAVs in the real world. The realistic operation of such simulations will only enhance the value of such training. In this paper, we present the integration of a model-based waypoint navigation controller into the Reno Rescue Simulator for the purposes of providing a more realistic user interface in simulated environments. We also present potential uses for such simulations, even for real-world operation of UAVs.
A Framework of Control-Oriented Reaction-Based Model for Trajectory-Based HCCI Combustion With Variable Fuels
Authors: Zhang Chen , Sun Zongxuan
Published: November 2017

A novel combustion control, i.e. the trajectory-based combustion control, was proposed previously. This control is enabled by free piston engines (FPEs) and utilizes the FPE’s controllable piston trajectory to enhance thermal efficiency, reduce emissions and realize variable fuels applications. On top of that, a control-oriented model was also developed aimed to implement the trajectory-based combustion control in real-time. Specifically, a unique phase separation method was proposed in the model, which separates an engine cycle into four phases (pure compression, ignition, heat release and pure expansion) and employs the minimal reaction mechanism accordingly. In this paper, the framework of the previous control-oriented model is extended to variable fuels, such as methane, n-heptane and bio-diesel. Such an extension is reasonable since the separated four phases are representative in typical combustion processes of all fuels within an engine cycle. Besides, a least-squares optimization is formulated to calibrate the chemical kinetics variables for each fuel. At last, simulation results and the related analysis show that all the derived control-oriented models have high fidelity and much lighter computational burdens to represent the HCCI combustion of each fuel along variable piston trajectories.
Including Vibration Characteristics Within Compressive Sensing Formulations for Structural Monitoring of Beams
Authors: Ganesan Vaahini , Das Tuhin K. , Kauffman Jeffrey L. , Rahnavard Nazanin
Published: November 2017

Vibration-based monitoring of mechanical structures often involves continuous monitoring that result in high data volume and instrumentation with a large array of sensors. Previously, we have shown that Compressive Sensing (CS)-based vibration monitoring can significantly reduce both volume of data and number of sensors in temporal and spatial domains respectively. In this work, further analysis of CS-based detection and localization of structural changes is presented. Incorporating damping and noise handling in the CS algorithm improved its performance for frequency recovery. CS-based reconstruction of deflection shape of beams with fixed boundary conditions is addressed. Formulation of suitable bases with improved conditioning is explored. Restricting hyperbolic terms to lower frequencies in the basis functions improves reconstruction. An alternative is to generate an augmented basis that combines harmonic and hyperbolic terms. Incorporating known boundary conditions into the CS problem is studied.
Modified Zero Time Delay Input Shaping for Industrial Robot With Flexibility
Authors: Zhao Yu , Tomizuka Masayoshi
Published: November 2017

Although input shaping is an effective approach for vibration suppression in a variety of applications, the time delay introduced is not desired. Current techniques to reduce the time delay can not guarantee zero delay or may cause non-smooth motion, which is harmful for the actuators. In order to address such issue, a modified zero time delay input shaping is proposed in this paper. Experimental results show the advantage of the proposed approach.
UAV Path Planning in the Framework of MILP-Tropical Optimization
Authors: Radmanesh Mohammadreza , Kumar Manish
Published: November 2017

This paper proposes a fast method for obtaining mathematically optimal trajectories for UAVs while avoiding collisions. A comparison of the proposed method with previously used Mixed Integer Linear Programming (MILP) to find the optimal collision-free path UAVs, aircraft, and spacecraft show the effectiveness and performance of this method. Here, the UAV path planning problem is formulated in the new framework named MILP-Tropical optimization that exploits tropical mathematics for obtaining solution and then casted in a novel branch-and-bound method. Various constraints including UAV dynamics are incorporated in the proposed Tropical framework and a solution methodology is presented. An extensive numerical study shows that the proposed method provides faster solution. The proposed technique can be extended to distributed control for multiple vehicles and multiple way-points.
Tilting-Rotor Quadcopter for Aggressive Flight Maneuvers Using Differential Flatness Based Flight Controller
Authors: Kumar Rumit , Nemati Alireza , Kumar Manish , Sharma Rajnikant , Cohen Kelly , Cazaurang Franck
Published: November 2017

In this paper, we present a feed-forward control approach for complex trajectory tracking by a tilting-rotor quadcopter during autonomous flight. Tilting-rotor quadcopter is a more agile version of conventional quadcopter as the propeller motors are actuated to tilt about the quadcopter arm. The tilt-rotor quad-copter is capable of following complex trajectories with ease. In this paper, we employ differential flatness based feed-forward position control by utilizing a combination of propeller rotational speeds along with rotor tilts. The rotational motion of propellers work simultaneously in sync with propeller tilts to control the position and orientation of the UAV during autonomous flight. The results for tracking complex trajectories have been presented by performing numerical simulations and a comparison is shown with respect to conventional quadcopter for similar flight conditions. It has been found that the tilt-rotor quadcopter is more efficient than the conventional quadcopter during complex trajectory following maneuvers.
A Computationally Efficient Optimal Power Management for Power Split Hybrid Vehicle Based on Pontryagin’s Minimum Principle
Authors: Ghasemi Masood , Song Xingyong
Published: November 2017

The need for less fuel consumption urges effective powertrain management optimization in hybrid vehicles. In this study, we consider the real time power optimization problem of a power split hybrid vehicle. Assuming that the power on demand at the driveline can be predicted and known for each driving cycle, the powertrain management and optimization are conducted at the hybrid powertrain system’s level in a computationally efficient fashion. Specifically, we provide an analytical formulation of the powertrain optimization for the hybrid vehicle by using the Pontryagin’s minimum principle (PMP). By approximating the optimal instantaneous fuel consumption rate as a polynomial of the engine speed, we can formulate the optimization problem into a set of algebraic equations. In order to justify the applicability of the methodology for real-time implementations, we give directions on numerical iterative solutions for these algebraic equations. The analysis on the stability of the method is shown through statistical analysis. Finally, further simulations are given to confirm the efficacy and the robustness of the proposed optimal approach.
Validation of Fingertip Force and Finger Pose in the UART Finger and Bond Graph Tendon Model During Surface Contact
Authors: Tigue James A. , Harris Sonoma , Anjewierden Chris , Mascaro Stephen A.
Published: November 2017

The intricate tendon system of the human muscular-skeletal system contributes to the human hand’s dexterity. A complex bond graph model of the index finger was developed to give insight into this system. Previous validation of this model by use of the ACT hand was difficult due to static joint friction. A new robotic testbed, Utah’s Anatomically-correct Robotic Testbed (UART) finger, has been developed to mitigate this friction. Static force and position experiments were conducted with the UART finger in contact with a surface and were compared to the bond graph model. The results suggest that the model is capable of simultaneously predicting static poses and fingertip force. The average predicted joint angle error was 2.9°. The average fingertip force magnitude error was 7.4%, and the average fingertip force direction error was 4.3°.
A Flexible Wind Turbine Blade With an Actively Variable Twist Distribution to Increase Region 2 Efficiency: Design and Control
Authors: Khakpour Nejadkhaki Hamid , Hall John F.
Published: November 2017

A method for designing and controlling a novel wind turbine blade is presented. The blade is modular, flexible, and additively manufactured. Conventional blades are monolithic and relatively stiff. The conventional method for improving aerodynamic efficiency is through generator torque control. The anisotropic nature of the additive manufacturing (AM) process has the potential to create a flexible blade with a low torsional-to-longitudinal-stiffness ratio. This enables new design and control capabilities that could be applied to the twist angle distribution (TAD). Simulation results suggest this can increase the aerodynamic efficiency during Region 2 operation. The suggested blade design includes a rigid spar with flexible AM segments that form the surrounding shells. The stiffness of each individual segment and the actuator placement define the TAD. In practice, the degree of flexibility for each segment will be established through the design and AM processes. These variations in compliance allow the blade to conform to the desired set of TAD geometries. The proposed design process first determines the TAD that maximizes the aerodynamic efficiency in Region 2. A mechanical design algorithm subsequently locates a series of actuators and defines the stiffness ratio between the blade segments. The procedure is optimized to minimize the amount of variation between the theoretical TAD and that which is obtained in practice. The free-shape TAD is also determined in the final design step. The geometry is chosen to minimize the amount of deflection needed to shape the TAD as it changes with Region 2 wind speed. A control framework is also developed to set the TAD in relation to wind speed. A case study demonstrates the capability of the proposed method. The simulation results suggest that a TAD controlled through five actuators can achieve the full range of required motion. Moreover, the design solution can increase the efficiency at cut-in and rated speeds up to 3.8% and 3.3%, respectively.