On-Board System Identification of Systems With Unknown Input Nonlinearity and System Parameters

Author(s):  
Song Liu ◽  
Bin Yao

Input nonlinearities, or actuator nonlinearities, can be seen in a lot of systems and have significant effects on the system performance. From the controller design point of view, accurate yet simple model of input nonlinearities is essential to compensate their effects and to achieve high level control performance. Unfortunately, most input nonlinearities are neither known nor easy to characterize, especially when the input nonlinearities and unknown system parameters are present simultaneously in the system dynamics. Off-board calibration may be possible yet it is very time consuming and requires additional calibration systems. This paper focuses on a class of systems with unknown input nonlinearities and system parameters and proposes an on-board system identification process to model the unknown nonlinearities. The input nonlinearities are decomposed into localized orthogonal basis and then estimated together with the system parameters. The proposed method is applied to model the nonlinear flow mapping of cartridge valves. Simulation and experimental results are obtained to illustrate the effectiveness and practicality of the proposed method.

Author(s):  
Alejandro Fernandez Canosa ◽  
Baisravan HomChaudhuri

This paper presents a computationally-efficient fuel-economic control strategy for a group of connected vehicles in urban roads. We assume the availability of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication. Apart from fuel economy, the proposed higher-level controller also focuses on reducing red light idling, which improves traffic mobility and in turn improves vehicle emissions. The red light idling avoidance problem is formulated as a two-point boundary value problem and sampling-based approach is employed to evaluate a feasible solution in real-time. This leads to control solutions that can ensure avoidance of red light idling despite the number of vehicles in front of it. We have shown that sampling from a Gaussian distribution whose mean depends on the target velocity can improve fuel economy to a good extent. This higher-level control solution provides a good initial solution for any deterministic lower-level controller. Simulation results show the efficacy of the proposed method in terms of fuel economy and computational efficiency.


2020 ◽  

BACKGROUND: This paper deals with territorial distribution of the alcohol and drug addictions mortality at a level of the districts of the Slovak Republic. AIM: The aim of the paper is to explore the relations within the administrative territorial division of the Slovak Republic, that is, between the individual districts and hence, to reveal possibly hidden relation in alcohol and drug mortality. METHODS: The analysis is divided and executed into the two fragments – one belongs to the female sex, the other one belongs to the male sex. The standardised mortality rate is computed according to a sequence of the mathematical relations. The Euclidean distance is employed to compute the similarity within each pair of a whole data set. The cluster analysis examines is performed. The clusters are created by means of the mutual distances of the districts. The data is collected from the database of the Statistical Office of the Slovak Republic for all the districts of the Slovak Republic. The covered time span begins in the year 1996 and ends in the year 2015. RESULTS: The most substantial point is that the Slovak Republic possesses the regional disparities in a field of mortality expressed by the standardised mortality rate computed particularly for the diagnoses assigned to the alcohol and drug addictions at a considerably high level. However, the female sex and the male sex have the different outcome. The Bratislava III District keeps absolutely the most extreme position. It forms an own cluster for the both sexes too. The Topoľčany District bears a similar extreme position from a point of view of the male sex. All the Bratislava districts keep their mutual notable dissimilarity. Contrariwise, evaluation of a development of the regional disparities among the districts looks like notably heterogeneously. CONCLUSIONS: There are considerable regional discrepancies throughout the districts of the Slovak Republic. Hence, it is necessary to create a common platform how to proceed with the solution of this issue.


2021 ◽  
Vol 21 (2) ◽  
pp. 1-24
Author(s):  
Louise Ann Lyon ◽  
Chelsea Clayton

Female-focused, grassroots communities purporting to help women learn to code are popping up in a variety of settings, indicating the motivation on the part of the participants to evade male-dominated settings while learning. However, little is known about how these groups function as an activity system. With current technology enabling the forming of virtual communities and the meteoric rise in use of the Salesforce CRM (customer relationship management) platform, a group of women have formed a coaching and learning community designed to help women move from Salesforce administrators to software developers through learning to code. We used activity systems analysis (ASA) to investigate this real-world instance of the larger phenomenon using an ethnographic approach. We used ASA to organize and make sense of the data by first creating a table listing the points on the activity system triangle (subject, rules, object, etc.) and filling in the points of the triangle based on the design of the coaching and learning group as described by participants; this gave us a high-level view of the activity system. To understand the subjects’ point of view of the system, we then created a new column in the table to fill in themes that emerged from our qualitative data analysis organized by dimension of the activity system. This process enabled us to capture the activity and the voices of participants as well as tensions that had emerged in the system. Findings show a range of outcomes, from participants crediting the group as a kickstart to the journey to successfully landing a job as a developer to members stalling in their progress after involvement. Results also show that purposeful tensions of welcoming novice questions and offering unsolicited verbal encouragement built into the activity system create a welcoming, safe environment for women learning to code.


2016 ◽  
Vol 11 (1) ◽  
pp. 134
Author(s):  
Zahra Ghannadian ◽  
Shahriyar Shaghagh

Establishment of every urban element in its appropriate position requires advanced technology and science from geographical and climatic point of view. This is accompanied and synchronous with modern culture born by supreme and high level of training and education in the society. In this regard, one of the main objectives of the architectures' union is to establish science and Technology Park with the aim of facilitating and accelerating science and technology transmission from university to the society and country.Tabriz city is considered as one of the most important academic and industrial cities in the country. Establishing science and technology parks can be effective in scientific, economic and social development of the country and province. Employing organic methods in architecture to use natural energies is an effective and useful method and its structure produces less pollution. Using philosophical and introductory issues and views of technology and establishing technology parks, present article proceeds on issues of organic architecture with new approach which is inspired by ants' nest algorithm and presents a new experience of architecture in the form of Science and Technology Park.


Author(s):  
Zheng Chen ◽  
Leslie Cargill ◽  
Brent Naizer

Hydraulic fracturing is one of the key technologies for producing shale oil and gas. During hydraulic fracturing, a blender is used to mix sand with water and chemicals to obtain a fluidic mixture that will be pumped down a well to frack rocks. In order to achieve high-quality fracturing during a job, the blender needs to maintain its tub level as well as the density of the fluidic mixture. In this paper, an auto-tuning proportional-integral (PI) control is developed for the blender automation system to maintain the tub level of its fluidic mixture. The control system adopts a single-loop PI with gains that can be auto-tuned during a job. A relay feedback test is conducted for auto-tuning the PI gains online. The auto-tuning PI control has been successfully tested in a blender simulator. Experimental results have shown that the control performance was improved after auto-tuning and that the control system was adaptive to variation in system parameters.


2021 ◽  
Vol 49 (3) ◽  
pp. 653-701
Author(s):  
Heiko Hausendorf ◽  
Kenan Hochuli ◽  
Johanna Jud ◽  
Alexandra Zoller

Abstract The present paper is concerned with the lecture hall as the natural home of lecturing. We will focus on constructed, designed and equipped space as a material and communicative manifestation of science which fundamentally contributes to the multimodal practice of lecturing. Taking an interactionist point of view, we start off with introducing our concept of architecture-for-interaction which aims at spatial built-in features as a resource for social interaction, namely for situational anchoring among those present. In a second step, we identify key architectural elements of the lecture hall as material sediments of communicative problems connected with the social practice of lecturing. In doing so, we will also give a high-level overview of the historical development of the lecture hall (and its precursors) since the Middle Ages and the Early Modern Age. Turning to current data from lecturing in times of the pandemic, we will then deal with so called „ghost lectures“ behind closed doors. This current development brings out a refiguration process due to which the lecture hall undergoes a change from the classical auditorium with copresent participants to a multi-media hub allowing for tele-present participants.


BMJ Leader ◽  
2021 ◽  
pp. leader-2021-000509
Author(s):  
Marcel Levi

BackgroundThe NHS is a fascinating health care system and is enjoying a lot of support from all layers of British society. However, it is clear that the system has excellent features but also areas that can be improved.Story of selfA number of years as a chief executive in one of London’s largest hospital has brought me a wealth of impressions, experiences, and understanding about working in the NHS. Contrasting those to my previous experience as chief executive in Amsterdam (The Netherlands) provides an interesting insight.ObservationsVery strong features of the NHS are the high level of health care professionals, the focus on quality and safety, and involvement of patients and the public. However, the NHS can significantly improve by addressing the lack of clinical professionals in the lead, curtailing ever increasing bureaucracy, and reducing its peculiar preference for outsourcing even the most crucial activities to private parties. The frequent inability to swiftly and successfully complete goal-directed negotiations as well as the large but from a clinical point of view irrelevant private sector are areas of sustained bewilderment. Lastly, the drive for innovation and transformation as well as the level of biomedical research in the NHS and supported by the British universities is fascinating and outstanding.


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