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Sinteza i usporedna analiza sustava regulacije vertikalne dinamike vozila uz primjenu aktivnog i poluaktivnog ovjesa
Get PDFAktivni i poluaktivni ovjesi mehatronički su sustavi koji omogućavaju regulaciju vertikalne dinamike vozila čime se postiže bolja udobnost vožnje uz zadržavanje dobrih voznih karakteristika vozila. Pritom se dodatno poboljšanje kvalitete regulacije može postići korištenjem unaprijedne informacije o profilu podloge. Prednosti aktivnih i poluaktivnih ovjesa poznate su nekoliko desetljeća te su kroz veliki broj znanstvenih radova predstavljene razne strategije upravljanja vertikalnom dinamikom. Jedan od najčešće korištenih pristupa sinteze nadređene strategije upravljanja vertikalnom dinamikom je linearno kvadratično (LQ) optimalno upravljanje. U ovom je radu predstavljena sinteza LQ regulatora za slučaj aktivnog i poluaktivnog ovjesa s i bez unaprijednog regulacijskog djelovanja zasnovanog na unaprijednom poznavanju profila podloge (ukupno četiri tipa ovjesa). Sinteza sustava regulacije provedena je na četvrtinskom modelu vozila s jednim stupnjem slobode gibanja koji uključuje dinamiku samo ovješene mase i na modelu s dva stupnja slobode gibanja koji uključuje i dinamiku neovješene mase. Provedena je usporedna analiza kvalitete regulacije navedena četiri tipa mehatroničkih ovjesa i pasivnog ovjesa četvrtinskog modela vozila putem prikaza međuovisnosti suprostavljenih kriterija udobnosti vožnje, upravljivosti vozilom i ograničenog hoda ovjesa s obzirom na stohastičku pobudu podloge. Na temelju prve usporedne analize broj postavki regulatora ovjesa je reduciran i fokusiran na značajne postavke te je provedena daljnja usporedna analiza koja je proširena na analizu u frekvencijskoj domeni (amplitudno-frekvencijske karakteristike) i vremenskoj domeni (simulacijski odzivi s determinističkom podlogom). Na kraju rada prikazana je implementacija sustava regulacije ovjesom, zasnovanog na četvrtinskom modelu vozila, na puni model vozila u CarSim-u te je provedena usporedna analiza kvalitete regulacije u vremenskoj domeni za tri testne procedure koje pobuđuju tri glavna gibanja ovješene mase: vertikalno gibanje, poniranje i valjanje. Rezultati usporednih analiza pokazali su da aktivni ovjes s unaprijednim djelovanjem daje najveća poboljšanja performansi po svim kriterijima i da je jeftiniji poluaktivni ovjes s unaprijednim djelovanjem vrlo blizu po performansama, a u nekim slučajevima i bolji od aktivnog ovjesa bez unaprijednog djelovanja. Također, rezultati pokazuju da je moguće postići značajna poboljšanja performansi cijelog vozila primjenom relativno jednostavnog sustava regulacije
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Izrada upravljačkog programa eksperimentalnog postava za ispitivanje percepcije vozača o udobnosti vožnje
Get PDFTema završnog rada je izrada upravljačkog programa eksperimentalnog postava za ispitivanje percepcije vozača o udobnosti vožnje. Upravljački program je izrađen u LabVIEW programskom okruženju i implementiran na NI Compact RIO platformi. Vertikalne vibracije autosjedala generira linearni servopogon pri čemu se signal reference akceleracije ovješene mase dobiva iz simulacijskog četvrtinskog modela vozila implementiranog u upravljačkoj cRIO platformi s izvođenjem u realnom vremenu. Upravljački program se sastoji od tri glavna dijela: kaskadne regulacije pozicije servopogona s podređenim regulacijskim krugom brzine, regulacije ubrzanja te simulatora četvrtinskog modela vozila. Implementirani su i dijelovi programa za nadzor i vođenje eksperimentalnih rutina, te rutine za obradu i pohranjivanje mjerenih podataka.
Simulator četvrtinskog modela vozila je izrađen prema matematičkom modelu četvrtinskog modela vozila s pasivnim i aktivnim ovjesom koji su opisani u 2. i 3. poglavlju. Za upravljanje aktivnim ovjesom odabrana je LQR metoda optimalnog upravljanja čija je sinteza provjerena usporedbom rezultata s optimiranim trajektorijama varijabli stanja i upravljačke sile aktivnog ovjesa. Dana je i usporedba pasivnog i aktivnog ovjesa zasnovana na analizi postavljenih matematičkih modela i dobivenih simulacijskih rezultata za razne tipove podloga s ciljem dobivanja uvida u mogućnosti poboljšanja udobnosti vožnje uslijed ugradnje aktivnog ovjesa uz istovremeno zadržavanje performansi u pogledu upravljivosti vozila.
U poglavlju 4. je ukratko opisana struktura eksperimentalnog postava i dane su glavne značajke korištenih komponenti. U poglavlju 5. opisan je postupak identifikacije modela servopogona, te na temelju tog modela je provedena sinteza regulacijskih krugova pozicije, brzine i ubrzanja primjenom metode optimuma dvostrukog odnosa. Sinteza regulatora je provjerena na simulacijama u MATLAB/Simulink-u i LabVIEW-u, te je nakon implementacije algoritama projektiranih regulatora na FPGA integriranom krugu upravljačke jedinice cRIO, njihov rad i eksperimentalno provjeren na samom mjernom postavu.
U 6. poglavlju je opisana struktura i tijek izvođenja upravljačkog programa eksperimentalnog postava. Funkcionalnost programa je ispitana na eksperimentalnom postavu, te je izvršena provjera sigurnosnih mjera. Ustanovljeno je da je program funkcionalan, te da su sigurnosne mjere zadovoljene. Na kraju rada je dan pregled budućih nadogradnji i poboljšanja upravljačkog programa
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Design and comparative analysis of vertical vehicle dynamics control systems based on active and semi-active suspension
Get PDFAktivni i poluaktivni ovjesi mehatronički su sustavi koji omogućavaju regulaciju vertikalne dinamike vozila čime se postiže bolja udobnost vožnje uz zadržavanje dobrih voznih karakteristika vozila. Pritom se dodatno poboljšanje kvalitete regulacije može postići korištenjem unaprijedne informacije o profilu podloge. Prednosti aktivnih i poluaktivnih ovjesa poznate su nekoliko desetljeća te su kroz veliki broj znanstvenih radova predstavljene razne strategije upravljanja vertikalnom dinamikom. Jedan od najčešće korištenih pristupa sinteze nadređene strategije upravljanja vertikalnom dinamikom je linearno kvadratično (LQ) optimalno upravljanje. U ovom je radu predstavljena sinteza LQ regulatora za slučaj aktivnog i poluaktivnog ovjesa s i bez unaprijednog regulacijskog djelovanja zasnovanog na unaprijednom poznavanju profila podloge (ukupno četiri tipa ovjesa). Sinteza sustava regulacije provedena je na četvrtinskom modelu vozila s jednim stupnjem slobode gibanja koji uključuje dinamiku samo ovješene mase i na modelu s dva stupnja slobode gibanja koji uključuje i dinamiku neovješene mase. Provedena je usporedna analiza kvalitete regulacije navedena četiri tipa mehatroničkih ovjesa i pasivnog ovjesa četvrtinskog modela vozila putem prikaza međuovisnosti suprostavljenih kriterija udobnosti vožnje, upravljivosti vozilom i ograničenog hoda ovjesa s obzirom na stohastičku pobudu podloge. Na temelju prve usporedne analize broj postavki regulatora ovjesa je reduciran i fokusiran na značajne postavke te je provedena daljnja usporedna analiza koja je proširena na analizu u frekvencijskoj domeni (amplitudno-frekvencijske karakteristike) i vremenskoj domeni (simulacijski odzivi s determinističkom podlogom). Na kraju rada prikazana je implementacija sustava regulacije ovjesom, zasnovanog na četvrtinskom modelu vozila, na puni model vozila u CarSim-u te je provedena usporedna analiza kvalitete regulacije u vremenskoj domeni za tri testne procedure koje pobuđuju tri glavna gibanja ovješene mase: vertikalno gibanje, poniranje i valjanje. Rezultati usporednih analiza pokazali su da aktivni ovjes s unaprijednim djelovanjem daje najveća poboljšanja performansi po svim kriterijima i da je jeftiniji poluaktivni ovjes s unaprijednim djelovanjem vrlo blizu po performansama, a u nekim slučajevima i bolji od aktivnog ovjesa bez unaprijednog djelovanja. Također, rezultati pokazuju da je moguće postići značajna poboljšanja performansi cijelog vozila primjenom relativno jednostavnog sustava regulacije.Active and semi-active suspensions are mechatronic devices used within vertical vehicle dynamics control systems for improving ride comfort while maintaining good handling performance. Additional ride comfort and vehicle handling improvements can be obtained by using the advance knowledge of upcoming road disturbance i.e. road profile preview. The potential benefits of using active and semi-active suspensions are well known, as there have been strong research activities in the area over the last several decades resulting in various vertical dynamics control strategies. One of the most popular approaches to active suspension control is the Linear Quadratic (LQ) optimal control/regulation. This Thesis presents the design of the LQ regulator (LQR) for active and semi-active suspension control system with and without road profile preview control (in total four suspension types). LQR design is based on Quarter-car model with one degree of freedom which includes sprung mass dynamics, as well as on quarter-car model with two degrees of freedom which additionally includes unsprung mass dynamics. The trade-off between conflicting criteria of ride comfort, vehicle handling and suspension stroke constraint of the four suspension types and the passive suspension is first analyzed by comparing the standard deviations of related state variables with the assumption of stochastic road input. Based on the insights of first comparative analysis, the number of designs is reduced and further analyses are carried out in the frequency domain (frequency responses) and the time domain (simulation with deterministic road input). Active and semi-active control systems, based on the quarter-car model, are then implemented on nonlinear, full-car model in CarSim. Comparative performance analysis is again carried out in the time domain using three ride comfort test procedures which excite sprung mass heave, pitch and roll motion. The results of all analyses point out that active suspension control with road preview offers highest performance improvement (in terms of all criteria) and that the performance of semi-active suspension control with road preview is similar, and in some cases better, than the performance of active suspension control system without road preview. The results also show that significant performance improvement can be obtained for the full car model by applying relatively simple decoupled suspension control system
Control software development for an experimental setup aimed at testing the driver comfort perception
No full textTema završnog rada je izrada upravljačkog programa eksperimentalnog postava za ispitivanje percepcije vozača o udobnosti vožnje. Upravljački program je izrađen u LabVIEW programskom okruženju i implementiran na NI Compact RIO platformi. Vertikalne vibracije autosjedala generira linearni servopogon pri čemu se signal reference akceleracije ovješene mase dobiva iz simulacijskog četvrtinskog modela vozila implementiranog u upravljačkoj cRIO platformi s izvođenjem u realnom vremenu. Upravljački program se sastoji od tri glavna dijela: kaskadne regulacije pozicije servopogona s podređenim regulacijskim krugom brzine, regulacije ubrzanja te simulatora četvrtinskog modela vozila. Implementirani su i dijelovi programa za nadzor i vođenje eksperimentalnih rutina, te rutine za obradu i pohranjivanje mjerenih podataka.
Simulator četvrtinskog modela vozila je izrađen prema matematičkom modelu četvrtinskog modela vozila s pasivnim i aktivnim ovjesom koji su opisani u 2. i 3. poglavlju. Za upravljanje aktivnim ovjesom odabrana je LQR metoda optimalnog upravljanja čija je sinteza provjerena usporedbom rezultata s optimiranim trajektorijama varijabli stanja i upravljačke sile aktivnog ovjesa. Dana je i usporedba pasivnog i aktivnog ovjesa zasnovana na analizi postavljenih matematičkih modela i dobivenih simulacijskih rezultata za razne tipove podloga s ciljem dobivanja uvida u mogućnosti poboljšanja udobnosti vožnje uslijed ugradnje aktivnog ovjesa uz istovremeno zadržavanje performansi u pogledu upravljivosti vozila.
U poglavlju 4. je ukratko opisana struktura eksperimentalnog postava i dane su glavne značajke korištenih komponenti. U poglavlju 5. opisan je postupak identifikacije modela servopogona, te na temelju tog modela je provedena sinteza regulacijskih krugova pozicije, brzine i ubrzanja primjenom metode optimuma dvostrukog odnosa. Sinteza regulatora je provjerena na simulacijama u MATLAB/Simulink-u i LabVIEW-u, te je nakon implementacije algoritama projektiranih regulatora na FPGA integriranom krugu upravljačke jedinice cRIO, njihov rad i eksperimentalno provjeren na samom mjernom postavu.
U 6. poglavlju je opisana struktura i tijek izvođenja upravljačkog programa eksperimentalnog postava. Funkcionalnost programa je ispitana na eksperimentalnom postavu, te je izvršena provjera sigurnosnih mjera. Ustanovljeno je da je program funkcionalan, te da su sigurnosne mjere zadovoljene. Na kraju rada je dan pregled budućih nadogradnji i poboljšanja upravljačkog programa.The bachelor‟s thesis deals with the control software development for an experimental setup aimed at testing the driver comfort perception for various suspension setups. The control software was developed in LabVIEW development environment and it is implemented in NI Compact RIO platform. Vertical vibrations of the car seat are generated by linear servodrive, with sprung mass acceleration reference generated in real-time by a quarter car model simulator implemented in the controller. Control software consists of three main parts: cascade position control structure with inner speed control loop, acceleration control loop and quarter-car model simulator. The rest of the software contains code for experiment supervision and control, and parts of code for acquisition, signal processing and data logging of measured data.
Quarter-car model simulator is made according to mathematical models of a quarter-car model with passive and active suspension presented in chapters 2 and 3. For active suspension control, the LQR linear optimal control method was chosen and the controller synthesis was validated by comparison with optimal trajectories of state variables and control inputs of active suspension. Also presented, is the comparison of passive and active suspension based on analysis of mathematical models and simulation results for different road surfaces to see to which extent the ride comfort can be improved without sacrificing road holding ability by using active suspensions.
Chapter 4 gives a brief overview of the experimental setup and key features of its components. In chapter 5, the identification of servodrive model parameters is given, which are then used in position, velocity and acceleration control loop synthesis. Control loops synthesis was done using damping optimum criterion and synthesis was validated in the Matlab/SIMULINK and LabVIEW simulation environments, and experimentally validated after implementation in the FPGA .
In Chapter 6 of the thesis the control software structure and flowchart are explained. Software‟s functionality was tested on the experimental setup, and all safety precautions were checked. It was concluded that the software is functional and that it meets all safety precautions. The thesis concludes with an insight on future works and refiments of software
Model predictive control of a passenger cabin heating and air-conditioning system of an electric vehicle
No full textBaterijska električna vozila imaju značajno smanjen domet u ekstremno toplim i hladnim
okolišnim uvjetima zbog visoke potrošnje električne energije od strane sustava grijanja i
hlađenja putničkog prostora (HVAC sustavi). Stoga se električna vozila opremaju novim,
energetski učinkovitim, integriranim HVAC sustavima, koji se trebaju optimalno upravljati radi
postizanja maksimalne energetske učinkovitosti uz zadržavanje visokog stupnja toplinske
ugode. U radu se prvo prikazuje novi koncept HVAC sustava temeljen na principu dizalice
topline koji osim hlađenja omogućava i grijanje putničkog prostora. Za modelski zasnovano
optimiranje i upravljanje postavljaju se upravljanju-orijentirani modeli predmetnog HVAC
sustava koji se parametriraju na temelju detaljnog fizikalnog simulacijskog modela. Zatim se
provodi numeričko optimiranje upravljačkih varijabli, koje se temelji na dinamičkom
programiranju te daje uvide u optimalno ponašanje sustava u zimskim i ljetnim okolišnim
uvjetima, kao i temeljne smjernice za sintezu sustava upravljanja. Prvi predloženi sustav
upravljanja uključuje kaskadnu regulaciju temperature zraka u putničkom prostoru vozila uz
optimalnu alokaciju upravljačkih ulaza i podređenu regulaciju HVAC sustava. Mape optimalne
alokacije formiraju se van realnog vremena primjenom višekriterijskog optimiranja na temelju
genetskog algoritma i detaljnog fizikalnog modela, pri čemu se u prvom problemu optimiranja
maksimizira koeficijent učinkovitosti HVAC sustava, a u drugom problemu minimizira
potrošnja električne energije i indeks toplinske ugode. Drugi predloženi sustav upravljanja
uključuje nelinearno modelsko prediktivno upravljanje (NMPC), koje zadaje reference
podređenim regulacijskim krugovima HVAC sustava. NMPC minimizira potrošnju električne
energije i indeks toplinske ugode, uzimajući u obzir dinamiku i ograničenja sustava te
postojanje informacije o poremećajnim varijablama na pomičnom vremenskom horizontu u
budućnosti. Projektirani upravljački sustavi podrobno su ispitani u simulacijskom okruženju. K
tome, sustav kaskadne regulacije s optimalnom alokacijom upravljačkih ulaza implementiran
je na eksperimentalnom električnom vozilu B klase i ispitan u laboratorijskim uvjetima.Consumer acceptance of electric vehicles is increasing strongly, with the trend bound to
continue in the future due to beneficial regulations, government incentives, and consumer's
awareness and willingness to shift towards sustainable mobility. Although the innovation in
automotive industry is accelerating and the declared range of current battery electric vehicles
(BEVs) is increasing, their mass market share is still hindered due to long and widely
unavailable charging and end-users’ perception of lacking BEVs range. The already restricted
driving range of BEVs is significantly reduced in extremely hot and cold ambient conditions
due to high energy consumption of the heating, ventilation and air-conditioning (HVAC)
system. To overcome the BEV range reduction in extreme weather conditions, new energyefficient
HVAC systems have been developed recently for improved cabin heating and cooling
efficiency. These are typically vapor-compression cycle-based heat pump systems with
integrated cabin, battery, and powertrain thermal management, and they support operation in
both heating and cooling mode. The advanced BEV HVAC systems are characterized by an
increased number of actuators, which makes the energy management and control system design
more challenging. To minimize the power consumption at a favourable level of thermal
comfort, it is necessary to develop new control systems that can optimally coordinate multiple
and often redundant actuators of the HVAC system, and which utilize optimisation-based
control methods, such as control allocation or model predictive control.
The thesis first presents modelling of an advanced heat pump-based BEV HVAC system and a
cabin thermal dynamics system, which paves the road for model-based optimal control system
design. Next, dynamic programming-based offline control trajectory optimization is carried out
to gain insight into the optimal control actions for various operating conditions and obtain
guidelines for the design of online control systems. Finally, a cascade control strategy based on
the optimal control allocation and a nonlinear model predictive control strategy are designed
for the considered HVAC system. Both control systems are verified in simulation environments,
while the cascade control strategy is also implemented in a B-segment BEV and experimentally
examined in hot and cold weather conditions.
The main aim of the thesis is to design optimal control systems for a passenger cabin heating
and cooling system of an electric vehicle, which coordinate multiple redundant actuators,
accounts for the dynamics and constraints of the overall system and utilizes predictive information such as vehicle's driving cycle and ambient conditions, in order to improve energy
efficiency and maintain high level of thermal comfort in extremely cold and hot weather
conditions.
The thesis is organized in nine chapters, whose content is summarized in what follows.
Chapter 1: Introduction. Outlines the motivation for the presented research and gives a
literature review of the three main topics of the thesis, which are modelling, optimization, and
control of BEV HVAC systems. Finally, it states the main hypothesis and overviews the thesis.
Chapter 2: Functional description of passenger cabin heating and air-conditioning system.
Presents the considered heat pump-based BEV HVAC system. The chapter first describes the
working principle of two main operating modes: heating and cooling. Next, the main feedback
control loops are defined, and the control system design requirements are described, including
the considered thermal comfort index. Finally, two control system concepts, which are designed
in the rest of the thesis, are proposed. The first concept is based on cascade control structure, in
which the superimposed cabin air temperature controller commands the heating/cooling power
to optimal control input allocation algorithm, which transforms the power demand into
references for low-level feedback controllers and auxiliary open-loop control inputs. The
second concept is based on nonlinear model predictive control (NMPC) that regulates the cabin
air temperature and replaces the superimposed cabin air temperature controller and optimal
allocation, while directly setting the references for low-level controllers.
Chapter 3: Modelling of passenger cabin heating and cooling system. Outlines several
simulation models used in the thesis. Detailed physics-based HVAC system model, developed
within a wider project team and implemented in Dymola environment, is used for the purpose
of control system simulation verification, multi-objective optimisation-based control input
allocation design, and low-order models' parametrization. The low-order control-oriented
models are used for the low-level HVAC control system design, control trajectory optimization
and NMPC system design. The low-level HVAC feedback control system design is based on a
linear autoregressive model with exogenous inputs, which describes the cabin inlet air and
superheat temperature transients with respect to compressor speed and electronic expansion
valve control inputs. Next, nonlinear HVAC system models of first and second order are
presented, which describe the low-level controlled cabin inlet air temperature dynamics
including the superheat temperature control loop. Model parameters (time constants and damping ratio) are determined by means of numerical identification procedure, which is based
on detailed physics-based simulation model responses for a large set of operating points. The
obtained model parameter maps are fitted by appropriate analytical functions. Next, nonlinear
regression models of HVAC system power consumption and PMV thermal comfort index are
presented, which are needed for the sake of cost function formulation. Finally, nonlinear singlezone
cabin models of first and second order are presented. The first-order nonlinear cabin model
describes the cabin air temperature transient process, and it is used in control trajectory
optimization, whereas the second-order model additionally describes the cabin body
temperature transient process, and it is used in NMPC system design.
Chapter 4: Control trajectory optimization. Proposes a dynamic programming-based (DP)
method for optimization of HVAC system control trajectories. The HVAC system and cabin
dynamics are represented by the first-order nonlinear models, and the DP algorithm is
implemented in C++ programming language to enhance the computational efficiency. The cost
function reflects the following two conflicting criteria: PMV-based thermal comfort index and
HVAC system energy efficiency. Two approaches of accounting for the energy efficiency are
considered: (i) through maximization of HVAC system coefficient of performance (COP) and
(ii) via minimization of HVAC system electric power consumption. Minimization of the DP
cost function is subject to hard constraints on control variables, as well as constraints that reflect
a limited HVAC operating range. Control trajectory optimization is carried out for winter and
summer ambient conditions, and different cost function setups, thus yielding Pareto optimal
frontiers. The optimization results are analysed with the aim of gaining insights into the optimal
control performance and obtaining guidelines for control system design.
Chapter 5: Optimal control input allocation. Proposes an offline multi-objective genetic
algorithm-based optimization method for generating control input allocation maps. According
to the cascade control concept, the inputs to optimal control allocation are the cooling or heating
power demand, and the cabin air state determined by temperature and relative humidity. The
optimization method relies on detailed physics-based HVAC simulation model, while cabin
model is omitted as cabin air state is reflected by an operating point for which the optimization
is conducted. Firstly, the COP is maximized in both operating modes to obtain optimal control
inputs, which include cabin inlet air temperature reference, blower fan air mass flow, secondary
coolant loop pumps’ speeds and main radiator fan power level. The obtained optimal control
input allocation maps are fitted by proper analytical functions to facilitate implementation and calibration. Additionally, multi-objective optimization is carried out with the aim of
simultaneously minimizing the HVAC power consumption and the thermal comfort index. In
this case, infrared heating panels' (IRP) control inputs are considered, as well. The multiobjective
optimization yields Pareto optimal frontiers, which are analysed with the aim of
gaining insight into potential thermal comfort improvement when utilizing infrared heating
panels and providing guidelines for online thermal comfort control system design.
Chapter 6: Hierarchical control strategy design. The optimal control input allocation maps,
obtained in Chapter 5, are incorporated into a proper cascade control strategy. This chapter first
outlines the design of a superimposed cabin air temperature feedback controller and a PMVbased
feedback controller acting through IRPs. Next, the design of low-level feedback
controllers is presented, including optimization-based design of gain-scheduling maps. The
cascade control system performance is verified through simulations in heat-up and cool-down
scenarios, which start from ambient conditions and last until the thermal comfort is reached.
The impact of various superimposed controller and control allocation setups on energy
consumption and thermal comfort metrics is analysed. Finally, steady-state simulations are
carried out to analyse the extent to which the cabin air temperature reference can be lowered
for reduced power consumption, where the thermal comfort degradation is compensated for by
applying IRPs.
Chapter 7: Nonlinear model predictive control (NMPC). Presents the design of NMPC-based
HVAC system control strategy. First, the optimal control problem is formulated, and it includes
optimization of cabin inlet air temperature and mass flow trajectories on a receding horizon,
which simultaneously minimizes the thermal comfort index and the HVAC system electric
energy consumption. NMPC accounts for the HVAC system and cabin dynamics, a limited
HVAC operating range and predictive information about disturbances, such as vehicle velocity
and ambient air temperature. Next, transformation of the optimal control problem into a
nonlinear program based on the direct multiple shooting method is presented. Finally, the
NMPC system is verified in winter and summer ambient conditions for different cost function
settings, and it is compared with cascade control strategy.
Chapter 8: Experimental verification of cascade control strategy. Presents implementation of
the cascade control strategy, designed in Chapter 6, within an experimental B-segment battery
electric vehicle (BEV). The chapter first describes the experimental vehicle and its control
hardware system, consisting of the main computer, which is used for HVAC system control and human-machine interface communication, and an electronic control unit, which communicates
with actuators and sensors and contains safety features. Then, details of cascade control strategy
implementation within the control hardware are presented, including implementation of
practical modifications, such as safety-related refrigerant pressure controllers and robust HVAC
system start-up procedure. Results of initial commissioning of the control strategy are
presented, which are the basis for additional control strategy calibration. The modified control
strategy is experimentally validated in a climate chamber in hot and cold ambient conditions,
and the obtained performance metrics are analysed.
Chapter 9: Conclusion. Gives the concluding remarks, outlines the possible future work
directions, and states the following main contributions of the doctoral thesis: (i) dynamic
programming-based control trajectory optimization algorithm for a passenger cabin heating and
cooling system of an electric vehicle, which minimizes the electric energy consumption and
provides a high level of passenger thermal comfort; (ii) a cascade control strategy of passenger
cabin heating and cooling system based on a superimposed cabin air temperature controller and
optimal allocation of references for low-level controllers; (iii) an optimal control strategy of
passenger cabin heating and cooling system based on model predictive control, which
coordinates multiple actuators with the aim of increasing vehicle driving range while
maintaining high level of passenger thermal comfort
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