Location-Aware Adaptive Vehicle Dynamics System: Linear Chassis Predictions

2014 ◽  
Author(s):  
Rebecca Anne Bandy ◽  
Sukhwan Cho ◽  
John B. Ferris ◽  
Joerg Schlinkheider ◽  
Marc Wimmershoff
Keyword(s):  
Vehicle Dynamics ◽  
Intervention Strategy ◽  
Analytical Relationship ◽  
Computationally Efficient ◽  
Vehicle Model ◽  
Time Step ◽  
Location Aware ◽  
Predictor Corrector ◽  
The Impact ◽  
Real Vehicle

A Location-Aware Adaptive Vehicle Dynamics System (LAAVDS) is currently being developed to predict and maintain vehicle handling capabilities through upcoming maneuvers. This system depends heavily on an understanding of the interplay between the vehicle’s longitudinal, lateral, and vertical forces, as well as their resulting moments. These vehicle dynamics impact the Performance Margin metric and ultimately the point at which the Intervention Strategy will modulate the throttle and brake controls. Real-time implementation requires the development of computationally efficient predictive models of the vehicle dynamics. A method for predicting future vehicle states for smooth but tortuous roads is developed in this work using perturbation theory. An analytical relationship between the change in these forces and the resulting change in the Performance Margin is also derived. This model is implemented in the predictor-corrector algorithm of the Intervention Strategy. Corrections to the predicted states are made at each time step using a detailed, full, non-linear vehicle model; this full vehicle model is a precursor to incorporation of the LAAVDS in a real vehicle. Eventually, this work will be expanded to include the impact of rough terrain.

Road-Vehicles Control Logic Integrating Real Time Multibody Model Follower

2015 ◽  
Author(s):  
Isabel Ramirez Ruiz ◽  
Edoardo Sabbioni ◽  
Francesco Braghin ◽  
Federico Cheli
Keyword(s):  
Real Time ◽  
Vehicle Dynamics ◽  
Vehicle Model ◽  
Control Logic ◽  
Active Systems ◽  
The Real ◽  
Multibody Model ◽  
Drive Control ◽  
Primary Model ◽  
Real Vehicle

The challenge to enhance the vehicle driving and handling with a state estimation and prediction system is presented by fusing a primary real time multibody vehicle model capable of providing a good indication of vehicle stability and control, and a secondary model able to estimate the vehicle state from vehicle real and virtual sensors to correct the indications of the primary model. A mathematical algorithm combines these two models in the drive control system improving the behavior of the active systems of the vehicle. A Multibody vehicle model has been used to achieve a high fidelity simulation of vehicle dynamics. The selected software is LMS.Virtual.Lab Motion with Real-Time Solver which complements the AMESim Real-Time Solver to handle complex real-time 3D-1D mechatronic systems without any simplified conceptual models. A Sensor Signal Processing Model has been developed to estimate the vehicle states and calculating tire-road contact forces and vehicle sideslip angle. The methodological approach uses the equations of motion of the chassis applying the fundamental principles of classical physics: Newtonian method and Euler angles. The control logic is based on the continuous updating of the preview multibody vehicle model by the controller sensors information network, which makes the model forecast behavior closer to the real one and improve comfort and linearity of the vehicle response. The driver inputs (throttle, steer angle and torque, brake, gear) are the same for the MBS real time model and for the real vehicle. A first training logic updates the MBS model based on the real vehicle behavior calculated by the sensor network, where the logic has to update in the MBS model just the factors depending on the vehicle itself (for example car weight, tire temperature, shock absorber damping forces, tires characteristics) and to understand and keep into account different environment variation (wet / dry surface). If the real vehicle is equipped with active control systems to improve handling and stability, as active camber control, drive by wire, ESP, Body movement active controls, the real time multibody model will interact with the models 1D or 3D of these vehicle dynamics controls and will improve their performance with a very high accuracy prediction of their influence on vehicle dynamic response. In conclusion with the help of the preview multibody vehicle model the drive control logic will increase the performance and drive ability of the vehicle with smart logic interacting with all the active systems.

scholarly journals Computationally efficient model of myocardial electromechanics for multiscale simulations

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255027
Author(s):  
Fyodor Syomin ◽  
Anna Osepyan ◽  
Andrey Tsaturyan
Keyword(s):  
Interstimulus Interval ◽  
Cardiac Electrophysiology ◽  
Multiscale Simulation ◽  
Multiscale Simulations ◽  
Muscle Strain ◽  
Computationally Efficient ◽  
Time Step ◽  
Contraction Coupling ◽  
The Impact ◽  
High Stimulation Frequency

A model of myocardial electromechanics is suggested. It combines modified and simplified versions of previously published models of cardiac electrophysiology, excitation-contraction coupling, and mechanics. The mechano-calcium and mechano-electrical feedbacks, including the strain-dependence of the propagation velocity of the action potential, are also accounted for. The model reproduces changes in the twitch amplitude and Ca2+-transients upon changes in muscle strain including the slow response. The model also reproduces the Bowditch effect and changes in the twitch amplitude and duration upon changes in the interstimulus interval, including accelerated relaxation at high stimulation frequency. Special efforts were taken to reduce the stiffness of the differential equations of the model. As a result, the equations can be integrated numerically with a relatively high time step making the model suitable for multiscale simulation of the human heart and allowing one to study the impact of myocardial mechanics on arrhythmias.

scholarly journals A Computationally Efficient Shallow Water Model for Mixed Cohesive and Non-Cohesive Sediment Transport in the Yangtze Estuary

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1435
Author(s):  
Peng Hu ◽  
Junyu Tao ◽  
Aofei Ji ◽  
Wei Li ◽  
Zhiguo He
Keyword(s):  
Sediment Transport ◽  
Yangtze Estuary ◽  
Water Model ◽  
Cohesive Sediments ◽  
Shallow Water Model ◽  
Computationally Efficient ◽  
Time Step ◽  
The Yangtze Estuary ◽  
Erosion Coefficient ◽  
Cohesive Sediment Transport

In this paper, a computationally efficient shallow water model is developed for sediment transport in the Yangtze estuary by considering mixed cohesive and non-cohesive sediment transport. It is firstly shown that the model is capable of reproducing tidal-hydrodynamics in the estuarine region. Secondly, it is demonstrated that the observed temporal variation of suspended sediment concentration (SSC) for mixed cohesive and non-cohesive sediments can be well-captured by the model with calibrated parameters (i.e., critical shear stresses for erosion/deposition, erosion coefficient). Numerical comparative studies indicate that: (1) consideration of multiple sediment fraction (both cohesive and non-cohesive sediments) is important for accurate modeling of SSC in the Yangtze Estuary; (2) the critical shear stress and the erosion coefficient is shown to be site-dependent, for which intensive calibration may be required; and (3) the Deepwater Navigation Channel (DNC) project may lead to enhanced current velocity and thus reduced sediment deposition in the North Passage of the Yangtze Estuary. Finally, the implementation of the hybrid local time step/global maximum time step (LTS/GMaTS) (using LTS to update the hydro-sediment module but using GMaTS to update the morphodynamic module) can lead to a reduction of as high as 90% in the computational cost for the Yangtze Estuary. This advantage, along with its well-demonstrated quantitative accuracy, indicates that the present model should find wide applications in estuarine regions.

scholarly journals Impact of public health interventions to curb SARS-CoV-2 spread assessed by an evidence-educated Delphi panel and tailored SEIR model

2021 ◽  
Author(s):  
Bernd Brüggenjürgen ◽  
Hans-Peter Stricker ◽  
Lilian Krist ◽  
Miriam Ortiz ◽  
Thomas Reinhold ◽  
...  
Keyword(s):  
Public Health ◽  
Transmission Rate ◽  
Latency Period ◽  
Policy Decision ◽  
Sensitivity Analyses ◽  
Delphi Panel ◽  
Time Step ◽  
Seir Model ◽  
Health Policy Decision ◽  
The Impact

Abstract Aim To use a Delphi-panel-based assessment of the effectiveness of different non-pharmaceutical interventions (NPI) in order to retrospectively approximate and to prospectively predict the SARS-CoV-2 pandemic progression via a SEIR model (susceptible, exposed, infectious, removed). Methods We applied an evidence-educated Delphi-panel approach to elicit the impact of NPIs on the SARS-CoV-2 transmission rate R0 in Germany. Effectiveness was defined as the product of efficacy and compliance. A discrete, deterministic SEIR model with time step of 1 day, a latency period of 1.8 days, duration of infectiousness of 5 days, and a share of the total population of 15% assumed to be protected by immunity was developed in order to estimate the impact of selected NPI measures on the course of the pandemic. The model was populated with the Delphi-panel results and varied in sensitivity analyses. Results Efficacy and compliance estimates for the three most effective NPIs were as follows: test and isolate 49% (efficacy)/78% (compliance), keeping distance 42%/74%, personal protection masks (cloth masks or other face masks) 33%/79%. Applying all NPI effectiveness estimates to the SEIR model resulted in a valid replication of reported occurrence of the German SARS-CoV-2 pandemic. A combination of four NPIs at consented compliance rates might curb the CoViD-19 pandemic. Conclusion Employing an evidence-educated Delphi-panel approach can support SARS-CoV-2 modelling. Future curbing scenarios require a combination of NPIs. A Delphi-panel-based NPI assessment and modelling might support public health policy decision making by informing sequence and number of needed public health measures.

Toward a Robust Canopy Hydrology Scheme with Precipitation Subgrid Variability

2007 ◽  
Vol 8 (3) ◽  
pp. 439-446 ◽  
Author(s):  
Dagang Wang ◽  
Guiling Wang
Keyword(s):  
Land Surface ◽  
Surface Characteristics ◽  
Hydrological Processes ◽  
Canopy Interception ◽  
Time Step ◽  
Covered Area ◽  
Surface Models ◽  
Physically Based ◽  
Interception Loss ◽  
The Impact

Abstract Representation of the canopy hydrological processes has been challenging in land surface modeling due to the subgrid heterogeneity in both precipitation and surface characteristics. The Shuttleworth dynamic–statistical method is widely used to represent the impact of the precipitation subgrid variability on canopy hydrological processes but shows unwanted sensitivity to temporal resolution when implemented into land surface models. This paper presents a canopy hydrology scheme that is robust at different temporal resolutions. This scheme is devised by applying two physically based treatments to the Shuttleworth scheme: 1) the canopy hydrological processes within the rain-covered area are treated separately from those within the nonrain area, and the scheme tracks the relative rain location between adjacent time steps; and 2) within the rain-covered area, the canopy interception is so determined as to sustain the potential evaporation from the wetted canopy or is equal to precipitation, whichever is less, to maintain somewhat wet canopy during any rainy time step. When applied to the Amazon region, the new scheme establishes interception loss ratios of 0.3 at a 10-min time step and 0.23 at a 2-h time step. Compared to interception loss ratios of 0.45 and 0.09 at the corresponding time steps established by the original Shuttleworth scheme, the new scheme is much more stable under different temporal resolutions.

Recreational Drumming: A Creative Arts Intervention Strategy for Social Work Teaching and Practice

2010 ◽  
Vol 15 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Tina Maschi ◽  
Carolyn Bradley
Keyword(s):  
Social Work ◽  
Intervention Strategy ◽  
Social Work Students ◽  
Well Being ◽  
Creative Arts ◽  
Stress Energy ◽  
Msw Students ◽  
Interpersonal Connectedness ◽  
Diverse Groups ◽  
The Impact

Recreational music-making has been shown to decrease stress and increase feelings of well-being and empowerment among diverse groups. This study examined the impact of recreational drumming among social work students on measures of well-being, empowerment, and connectedness. It used a pretest-posttest design to evaluate outcomes among a sample of 31 participants in the 2-hour I–We Rhythm Program for recreational drumming. Results of paired t-test analyses revealed significant differences in levels of stress, energy, and feelings of empowerment and community. Using this creative-arts intervention can be an effective self-care strategy for BSW and MSW students, practitioners, and/or clients in educational or agency-based settings to increase feelings of well-being and interpersonal connectedness, which, in turn, may help to increase effectiveness in practice.

Location-Aware Adaptive Vehicle Dynamics System: Concept Development

2014 ◽  
Vol 7 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Rebecca Anne Bandy ◽  
Sukhwan Cho ◽  
Cullen Matthews ◽  
John Celli ◽  
Robert Binns ◽  
...  
Keyword(s):  
Vehicle Dynamics ◽  
Concept Development ◽  
Location Aware ◽  
System Concept

scholarly journals Studying the Impact of Radioactive Charging on the Microphysical Evolution and Transport of Radioactive Aerosols with the TOMAS-RC v1 framework

2017 ◽  
Author(s):  
Petros Vasilakos ◽  
Yong-Ηa Kim ◽  
Jeffrey R. Pierce ◽  
Sotira Yiacoumi ◽  
Costas Tsouris ◽  
...  
Keyword(s):  
Background Radiation ◽  
Atmospheric Transport ◽  
Long Range Transport ◽  
Radioactive Aerosol ◽  
Computationally Efficient ◽  
Radioactive Aerosols ◽  
Model Studies ◽  
Aerosol Mass ◽  
Range Transport ◽  
The Impact

Abstract. Radioactive charging can significantly impact the way radioactive aerosols behave, and as a result their lifetime, but such effects are neglected in predictive model studies of radioactive plumes. The objective of this work is to determine the influence of radioactive charging on the vertical transport of radioactive aerosols in the atmosphere, through its effect on coagulation and deposition, as well as quantifying the impact of this charging on aerosol lifetime. The TwO-Moment Aerosol Sectional (TOMAS) microphysical model was extended to account for radioactive charging effects on coagulation in a computationally efficient way. The expanded model, TOMAS-RC (TOMAS with Radioactive Charging effects), was then used to simulate the microphysical evolution and deposition of radioactive aerosol (containing the isotopes 131I and 137Cs) in a number of idealized atmospheric transport experiments. Results indicate that radioactive charging can facilitate or suppress coagulation of radioactive aerosols, thus influencing the deposition patterns and total amount of radioactive aerosol mass available for long-range transport. Sensitivity simulations to uncertain parameters affirm the potential importance of radioactive charging effects. An important finding is that charging of neutral, coarse mode aerosol from background radiation can reduce coagulation rates and extend its lifetime in the atmosphere by up to a factor of 2.

Investigation on three-directional dynamic interaction between a heavy-duty vehicle and a curved bridge

2017 ◽  
Vol 21 (5) ◽  
pp. 721-738 ◽  
Author(s):  
Shaohua Li ◽  
Jianying Ren
Keyword(s):  
Interaction Model ◽  
Element Model ◽  
Driver Model ◽  
Impact Factors ◽  
Lateral Impact ◽  
Heavy Duty ◽  
Vehicle Model ◽  
Curved Bridge ◽  
Bridge Model ◽  
The Impact

Considering the nonlinear property of suspension damping and tire stiffness, a full-vehicle model is built for a heavy-duty truck. A modified preview driver model with nonlinear time delay is inserted into the vehicle model to compute the suitable steering angle of the front wheel and to make the vehicle follow the required route. Next, the finite element model of a five-span continuous curved highway bridge is established, and the bridge’s inherent frequencies and modes are obtained. The curved bridge and the vehicle are coupled by three-directional tire forces, and a three-directional driver–vehicle–bridge interaction model is presented. The presented vehicle model and bridge model are verified by comparing with the published works. The dynamic impact factors of vertical, lateral, and torsional displacements of the bridge are calculated when a vehicle is traversing through the bridge, and the impact factors’ distributions along the bridge are analyzed. The effects of vehicle driving conditions on impact factors are also researched. It is found that the impact factor calculated from the present specification for a straight bridge is smaller than that from the three-directional driver–vehicle–bridge interaction model, and the vertical and torsional impact effects at the third span midpoint are greater than the lateral impact effect.

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