scholarly journals Correcting Decalibration of Stereo Cameras in Self-Driving Vehicles

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3241
Author(s):  
Jon Muhovič ◽  
Janez Perš

Camera systems in autonomous vehicles are subject to various sources of anticipated and unanticipated mechanical stress (vibration, rough handling, collisions) in real-world conditions. Even moderate changes in camera geometry due to mechanical stress decalibrate multi-camera systems and corrupt downstream applications like depth perception. We propose an on-the-fly stereo recalibration method applicable in real-world autonomous vehicles. The method is comprised of two parts. First, in optimization step, external camera parameters are optimized with the goal to maximise the amount of recovered depth pixels. In the second step, external sensor is used to adjust the scaling of the optimized camera model. The method is lightweight and fast enough to run in parallel with stereo estimation, thus allowing an on-the-fly recalibration. Our extensive experimental analysis shows that our method achieves stereo reconstruction better or on par with manual calibration. If our method is used on a sequence of images, the quality of calibration can be improved even further.

2021 ◽  
Author(s):  
Haitham Afifi

<div>We develop a Deep Reinforcement Learning (DeepRL) based multi-agent algorithm to efficiently control</div><div>autonomous vehicles in the context of Wireless Sensor Networks (WSNs). In contrast to other applications, WSNs</div><div>have two metrics for performance evaluation. First, quality of information (QoI) which is used to measure the</div><div>quality of sensed data. Second, quality of service (QoS) which is used to measure the network’s performance. As</div><div>a use case, we consider wireless acoustic sensor networks; a group of speakers move inside a room and there</div><div>are microphones installed on vehicles for streaming the audio data. We formulate an appropriate Markov Decision</div><div>Process (MDP) and present, besides a centralized solution, a multi-agent Deep Q-learning solution to control the vehicles. We compare the proposed solutions to a naive heuristic and two different real-world implementations: microphones being hold or preinstalled. We show using simulations that the performance of autonomous vehicles in terms of QoI and QoS is better than the real-world implementation and the proposed heuristic. Additionally, we provide theoretical analysis of the performance with respect to WSNs dynamics, such as speed, rooms dimensions and speaker’s talking time.</div>


2020 ◽  
Vol 2020 (16) ◽  
pp. 149-1-149-8
Author(s):  
Patrick Mueller ◽  
Matthias Lehmann ◽  
Alexander Braun

Simulation is an established tool to develop and validate camera systems. The goal of autonomous driving is pushing simulation into a more important and fundamental role for safety, validation and coverage of billions of miles. Realistic camera models are moving more and more into focus, as simulations need to be more then photo-realistic, they need to be physical-realistic, representing the actual camera system onboard the self-driving vehicle in all relevant physical aspects – and this is not only true for cameras, but also for radar and lidar. But when the camera simulations are becoming more and more realistic, how is this realism tested? Actual, physical camera samples are tested in laboratories following norms like ISO12233, EMVA1288 or the developing P2020, with test charts like dead leaves, slanted edge or OECF-charts. In this article we propose to validate the realism of camera simulations by simulating the physical test bench setup, and then comparing the synthetical simulation result with physical results from the real-world test bench using the established normative metrics and KPIs. While this procedure is used sporadically in industrial settings we are not aware of a rigorous presentation of these ideas in the context of realistic camera models for autonomous driving. After the description of the process we give concrete examples for several different measurement setups using MTF and SFR, and show how these can be used to characterize the quality of different camera models.


2021 ◽  
Author(s):  
Haitham Afifi

<div>We develop a Deep Reinforcement Learning (DeepRL) based multi-agent algorithm to efficiently control</div><div>autonomous vehicles in the context of Wireless Sensor Networks (WSNs). In contrast to other applications, WSNs</div><div>have two metrics for performance evaluation. First, quality of information (QoI) which is used to measure the</div><div>quality of sensed data. Second, quality of service (QoS) which is used to measure the network’s performance. As</div><div>a use case, we consider wireless acoustic sensor networks; a group of speakers move inside a room and there</div><div>are microphones installed on vehicles for streaming the audio data. We formulate an appropriate Markov Decision</div><div>Process (MDP) and present, besides a centralized solution, a multi-agent Deep Q-learning solution to control the vehicles. We compare the proposed solutions to a naive heuristic and two different real-world implementations: microphones being hold or preinstalled. We show using simulations that the performance of autonomous vehicles in terms of QoI and QoS is better than the real-world implementation and the proposed heuristic. Additionally, we provide theoretical analysis of the performance with respect to WSNs dynamics, such as speed, rooms dimensions and speaker’s talking time.</div>


Author(s):  
Stephen Verderber

The interdisciplinary field of person-environment relations has, from its origins, addressed the transactional relationship between human behavior and the built environment. This body of knowledge has been based upon qualitative and quantitative assessment of phenomena in the “real world.” This knowledge base has been instrumental in advancing the quality of real, physical environments globally at various scales of inquiry and with myriad user/client constituencies. By contrast, scant attention has been devoted to using simulation as a means to examine and represent person-environment transactions and how what is learned can be applied. The present discussion posits that press-competency theory, with related aspects drawn from functionalist-evolutionary theory, can together function to help us learn of how the medium of film can yield further insights to person-environment (P-E) transactions in the real world. Sampling, combined with extemporary behavior setting analysis, provide the basis for this analysis of healthcare settings as expressed throughout the history of cinema. This method can be of significant aid in examining P-E transactions across diverse historical periods, building types and places, healthcare and otherwise, otherwise logistically, geographically, or temporally unattainable in real time and space.


2020 ◽  
Vol 19 (10) ◽  
pp. 943-948
Author(s):  
Peter Lio ◽  
Andreas Wollenberg ◽  
Jacob Thyssen ◽  
Evangeline Pierce ◽  
Maria Rueda ◽  
...  

2020 ◽  
Vol 9 (20) ◽  
Author(s):  
Akshay Pendyal ◽  
Craig Rothenberg ◽  
Jean E. Scofi ◽  
Harlan M. Krumholz ◽  
Basmah Safdar ◽  
...  

Background Despite investments to improve quality of emergency care for patients with acute myocardial infarction (AMI), few studies have described national, real‐world trends in AMI care in the emergency department (ED). We aimed to describe trends in the epidemiology and quality of AMI care in US EDs over a recent 11‐year period, from 2005 to 2015. Methods and Results We conducted an observational study of ED visits for AMI using the National Hospital Ambulatory Medical Care Survey, a nationally representative probability sample of US EDs. AMI visits were classified as ST‐segment–elevation myocardial infarction (STEMI) and non‐STEMI. Outcomes included annual incidence of AMI, median ED length of stay, ED disposition type, and ED administration of evidence‐based medications. Annual ED visits for AMI decreased from 1 493 145 in 2005 to 581 924 in 2015. Estimated yearly incidence of ED visits for STEMI decreased from 1 402 768 to 315 813. The proportion of STEMI sent for immediate, same‐hospital catheterization increased from 12% to 37%. Among patients with STEMI sent directly for catheterization, median ED length of stay decreased from 62 to 37 minutes. ED administration of antithrombotic and nonaspirin antiplatelet agents rose for STEMI (23%–31% and 10%–27%, respectively). Conclusions National, real‐world trends in the epidemiology of AMI in the ED parallel those of clinical registries, with decreases in AMI incidence and STEMI proportion. ED care processes for STEMI mirror evolving guidelines that favor high‐intensity antiplatelet therapy, early invasive strategies, and regionalization of care.


2021 ◽  
pp. 1-15
Author(s):  
Eduardo Tolosa ◽  
Georg Ebersbach ◽  
Joaquim J. Ferreira ◽  
Olivier Rascol ◽  
Angelo Antonini ◽  
...  

Background: A greater understanding of the everyday experiences of people with Parkinson’s disease (PD) and their carers may help improve clinical practice. Objective: The Parkinson’s Real-world Impact assesSMent (PRISM) study evaluated medication use, health-related quality of life (HRQoL) and the use of healthcare resources by people with PD and their carers. Methods: PRISM is an observational cross-sectional study, in which people with PD and their carers completed an online survey using structured questionnaires, including the Parkinson’s Disease Quality of Life Questionnaire (PDQ-39), Non-Motor Symptoms Questionnaire (NMSQuest) and Zarit Burden Interview (ZBI). Results: Data were collected from 861 people with PD (mean age, 65.0 years; mean disease duration, 7.7 years) and 256 carers from six European countries. People with PD reported a large number of different co-morbidities, non-motor symptoms (mean NMSQuest score, 12.8), and impaired HRQoL (median PDQ-39 summary score, 29.1). Forty-five percent of people with PD reported at least one impulse control behaviour. Treatment patterns varied considerably between different European countries. Levodopa was taken in the last 12 months by 85.9% of participants, and as monotherapy by 21.8% . Carers, who were mostly female (64.8%) and the partner/spouse of the person with PD (82.1%), reported mild to moderate burden (mean ZBI total score, 26.6). Conclusions: The PRISM study sheds light on the lives of people with PD and those who care for them, re-emphasising the many challenges they face in everyday life. The study also provides insights into the current treatment of PD in Europe.


2021 ◽  
pp. 135245852110196
Author(s):  
Jan Hillert ◽  
Jon A Tsai ◽  
Mona Nouhi ◽  
Anna Glaser ◽  
Tim Spelman

Background: Teriflunomide and dimethyl fumarate (DMF) are first-line disease-modifying treatments for multiple sclerosis with similar labels that are used in comparable populations. Objectives: The objective of this study was to compare the effectiveness and persistence of teriflunomide and DMF in a Swedish real-world setting. Methods: All relapsing-remitting multiple sclerosis (RRMS) patients in the Swedish MS registry initiating teriflunomide or DMF were included in the analysis. The primary endpoint was treatment persistence. Propensity score matching was used to adjust comparisons for baseline confounders. Results: A total of 353 teriflunomide patients were successfully matched to 353 DMF. There was no difference in the rate of overall treatment discontinuation by treatment group across the entire observation period (hazard ratio (HR) = 1.12; 95% confidence interval (CI) = 0.91–1.39; p = 0.277; reference = teriflunomide). Annualised relapse rate (ARR) was comparable ( p = 0.237) between DMF (0.07; 95% CI = 0.05–0.10) and teriflunomide (0.09; 95% CI = 0.07–0.12). There was no difference in time to first on-treatment relapse (HR = 0.78; 95% CI = 0.50–1.21), disability progression (HR = 0.55; 95% CI = 0.27–1.12) or confirmed improvement (HR = 1.17; 95% CI = 0.57–2.36). Conclusion: This population-based real-world study reports similarities in treatment persistence, clinical effectiveness and quality of life outcomes between teriflunomide and dimethyl fumarate.


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