26 research outputs found
Knowledge based traffic signal control model for signalized intersection
Intelligent transportation systems have received increasing attention in academy and industry. Being able to handle uncertainties and complexity, expert systems are applied in vast areas of real life including intelligent transportation systems. This paper presents a traffic signal control method based on expert knowledge for an isolated signalized intersection. The proposed method has the adaptive signal timing ability to adjust its signal timing in response to changing traffic conditions. Based on the traffic conditions, the system determines to extend or terminate the current green signal group. Using the information from its traffic detectors of isolated intersection, the proposed controller gives optimal signals to adapt the phase lengths to the traffic conditions. A comparative analysis between proposed control algorithm, fuzzy logic (FLC) and fixed-timed (pre-timed) controllers has been made in traffic flows control, with varying traffic volume levels, by using simulation software ‘Arena’. Simulation results show that the proposed traffic signal control method (EKC) has better performance over fuzzy logic and conventional pre-time controllers under light and heavy traffic conditions
Computer traffic simulation
Didėjant transporto srautams vis ilgiau prastovima eismo kamščiuose, kurie didina ekologines problemas, kelia didesnį triukšmą, vibraciją, patiriami dideli ekonominiai kaštai. Norint sumažinti transporto spūstis reikia tiesti papildomus kelius, statyti vedukus ir pan., tačiau finansiniai ištekliai ne visada tai leidžia padaryt, todėl vienas iš efektyvių būdų mažinti kamščius- atlikti kompiuterinį transporto srautų modeliavimą. Šiame darbe apžvelgiami transporto srautų modeliavimo paketai, modeliai, metodai. Pasirinkus vieną iš adaptyvaus eismo srautų valdymo metodų (neraiškios logikos) buvo sukurti makro-imitaciniai modeliai fiksuotam laiko ir fuzzy logikos valdikliams. Juos tarpusavy palyginus, neraiškios logikos valdiklis parodė kur kas geresnius rezultatus. Ištirtas nepriklausomumo f-jų efektyvumas atsižvelgiant į jų formą ir pagrindo plotį, taip pat pasiūlytas efektyvesnis modeliuojamos sankryžos modelis.Nowadays traffic congestion is a big problem all over the world. To solve this problem governments build broader roads, establish more reasonable traffic rules. Adaptive traffic signal control is a good and efficient way to reduce traffic congestion. In this master thesis was made macro-simulation model for existing intersection. With this model was simulating two traffic signal control methodologies: fixed time and fuzzy logic. The result shown that fuzzy logic traffic control systems better then fixed on peak and non peak time. The dependent function research shown, that the best function form, in fuzzy logic system- triangle, the worst- trapezium. Also was composed new model for fixed traffic signal control method in existing intersection.Vytauto Didžiojo universiteta
Modeling and verification of fuzzy control systems using piece linear aggregate formalism
Darbe pristatomas neraiškių valdymo sistemų modeliavimas ir verifikavimas atkarpomis tiesiniu agregatiniu formalizavimo metodu. Ši metodika leidžia pagal vieną formalaus modelio aprašą kurti realiojo laiko neraiškių valdymo sistemų modelius, skirtus sistemos funkcionavimo ir elgsenos analizei. Sistemų modeliavimui buvo sukurti agregatai, kurie realizuoja neraiškios sprendimo priėmimo sistemos pagrindinius komponentus. Pagal analizuojamos neraiškios valdymo sistemos struktūrą sujungus šiuos agregatus, gaunamas neraiškios sprendimo priėmimo sistemos agregatinis modelis, kuris gali būti taikomas sistemos funkcionavimo ir elgsenos analizei. Darbe taip pat pristatoma sukurta realiojo laiko agregatinių modelių verifikavimo metodika, kurią sudaro agregatinio modelio transformavimas į laiko automatus, verifikuojamų savybių užrašymas laiko logikoje bei modelių tikrinimo įrankio UPPAAL panaudojimas sistemos savybėms patikrinti. Sukurta neraiškių valdymo sistemų modeliavimo ir verifikavimo metodika agregatiniam formalizavimo metodui buvo pritaikyta transporto srautų valdymo ir vaistų leidimo pompų sistemų analizei. Panaudojant sukurtus transporto srautų valdymo ir vaistų leidimo pompų agregatinius modelius, buvo sudaryti imitaciniai modeliai, kurie leido įvertinti modelių funkcionavimo charakteristikas ir juos tarpusavyje palyginti. Realiojo laiko agregatinių sistemų verifikavimo metodika panaudota tikrinant analizuojamų sistemų gyvybingumo, saugumo ir pasiekiamumo savybes.In this research a Piece Linear Aggregate method for modelling and verification of fuzzy control systems is presented. This method allows to create an aggregate model of a real time fuzzy control system for performance and behaviour analysis in a single mathematical scheme. The main components of fuzzy inference system were created by using aggregate approach. These aggregates implement a fuzzy inference system while interacting with each other. This allows to specify fuzzy control system and to realize the development of the simulators and models for verification. Based on the behaviour equivalence, a method for transforming aggregate models into timed automata is presented for the purpose of verifying real time system. The timed automata and temporal logic formulas are used as inputs of UPPAAL model checker for verifying fuzzy control system. The proposed method for modelling and verification of fuzzy control system by using aggregate formalism was applied for analysing traffic signal control and drug delivery systems. Formal aggregate models of traffic signal and drug delivery control systems were used for creating simulation models for performance analysis. The proposed method for verification of the real time aggregate models was used to check safety, liveness and reachability properties of traffic signal and drug delivery control systems.Vytauto Didžiojo universiteta
Neraiškių valdymo sistemų modeliavimas ir verifikavimas atkarpomis tiesiniu agregatiniu formalizavimo metodu
In this research a Piece Linear Aggregate method for modelling and verification of fuzzy control systems is presented. This method allows to create an aggregate model of a real time fuzzy control system for performance and behaviour analysis in a single mathematical scheme. The main components of fuzzy inference system were created by using aggregate approach. These aggregates implement a fuzzy inference system while interacting with each other. This allows to specify fuzzy control system and to realize the development of the simulators and models for verification. Based on the behaviour equivalence, a method for transforming aggregate models into timed automata is presented for the purpose of verifying real time system. The timed automata and temporal logic formulas are used as inputs of UPPAAL model checker for verifying fuzzy control system. The proposed method for modelling and verification of fuzzy control system by using aggregate formalism was applied for analysing traffic signal control and drug delivery systems. Formal aggregate models of traffic signal and drug delivery control systems were used for creating simulation models for performance analysis. The proposed method for verification of the real time aggregate models was used to check safety, liveness and reachability properties of traffic signal and drug delivery control systems.Darbe pristatomas neraiškių valdymo sistemų modeliavimas ir verifikavimas atkarpomis tiesiniu agregatiniu formalizavimo metodu. Ši metodika leidžia pagal vieną formalaus modelio aprašą kurti realiojo laiko neraiškių valdymo sistemų modelius, skirtus sistemos funkcionavimo ir elgsenos analizei. Sistemų modeliavimui buvo sukurti agregatai, kurie realizuoja neraiškios sprendimo priėmimo sistemos pagrindinius komponentus. Pagal analizuojamos neraiškios valdymo sistemos struktūrą sujungus šiuos agregatus, gaunamas neraiškios sprendimo priėmimo sistemos agregatinis modelis, kuris gali būti taikomas sistemos funkcionavimo ir elgsenos analizei. Darbe taip pat pristatoma sukurta realiojo laiko agregatinių modelių verifikavimo metodika, kurią sudaro agregatinio modelio transformavimas į laiko automatus, verifikuojamų savybių užrašymas laiko logikoje bei modelių tikrinimo įrankio UPPAAL panaudojimas sistemos savybėms patikrinti. Sukurta neraiškių valdymo sistemų modeliavimo ir verifikavimo metodika agregatiniam formalizavimo metodui buvo pritaikyta transporto srautų valdymo ir vaistų leidimo pompų sistemų analizei. Panaudojant sukurtus transporto srautų valdymo ir vaistų leidimo pompų agregatinius modelius, buvo sudaryti imitaciniai modeliai, kurie leido įvertinti modelių funkcionavimo charakteristikas ir juos tarpusavyje palyginti. Realiojo laiko agregatinių sistemų verifikavimo metodika panaudota tikrinant analizuojamų sistemų gyvybingumo, saugumo ir pasiekiamumo savybes.Vytauto Didžiojo universiteta
Neraiškių valdymo sistemų modeliavimas ir verifikavimas atkarpomis tiesiniu agregatiniu formalizavimo metodu : daktaro disertacija : fiziniai mokslai, Informatika (09P)
Disertacija rengta 2008-2014 metais Vytauto Didžiojo universitete, Informatikos fakultete, Taikomosios informatikos katedrojeBibliografija: p. 113-119Taikomosios informatikos katedraVytauto Didžiojo universiteta
Fuzzy traffic control for three-sided intersection
This paper presents fuzzy logic traffic controller for three- sided isolated intersection. This controller gets and computes data on real time then it makes decision what to do, extend or to terminate the current green phase it depends on vehicles demand. Two methods has been compared: fuzzy logic with fixed time (pretimed) method. In order to reaching the goal, traffic Simulation models were created to control intersection in both cases. Varying traffic volumes, delays and queue length has been compared after simulation. The simulation results shows, that controller based oil fuzzy logic works significantly better then pretimed and it reduce average delays and queues lengthKauno technologijos universitetasTaikomosios informatikos katedraVytauto Didžiojo universiteta
Knowledge based traffic signal control model for signalized intersection
Intelligent transportation systems have received increasing attention in academy and industry. Being able to handle uncertainties and complexity, expert systems are applied in vast areas of real life including intelligent transportation systems. This paper presents a traffic signal control method based on expert knowledge for an isolated signalized intersection. The proposed method has the adaptive signal timing ability to adjust its signal timing in response to changing traffic conditions. Based on the traffic conditions, the system determines to extend or terminate the current green signal group. Using the information from its traffic detectors of isolated intersection, the proposed controller gives optimal signals to adapt the phase lengths to the traffic conditions. A comparative analysis between proposed control algorithm, fuzzy logic (FLC) and fixed-timed (pre-timed) controllers has been made in traffic flows control, with varying traffic volume levels, by using simulation software 'Arena'. Simulation results show that the proposed traffic signal control method (EKC) has better performance over fuzzy logic and conventional pre-time controllers under light and heavy traffic conditionsKauno technologijos universitetasTaikomosios informatikos katedraVytauto Didžiojo universiteta
Piece linear aggregates model for fuzzy traffic control
This paper presents a fuzzy logic controller formal specification for an isolated signalized intersection. The controller controls the traffic light timings to ensure smooth flow and avoid congestion. The formal language of the extended Piece Linear Aggregates (PLA) implements the fuzzy logic model. The PLA model was supplemented by two stages – the function for fuzzy sets which transform input data to fuzzy set and the rule base which is used to specify the current system situation depending on input data. An example of three – sided intersection system is given to illustrate the presented methoKauno technologijos universitetasTaikomosios informatikos katedraVytauto Didžiojo universiteta
Piece linear-aggregate approach for modelling and analysis of fuzzy systems
In this paper, we use a PLA model for performance and behaviour analysis of fuzzy system. This model makes connection between fuzzy logic and formalism. A case study contains an illustration how the proposed model can be fruitfully exploited to model traffic control systems based on fuzzy logic. Piece-Linear Aggregate model for traffic signal control system has been transformed into timed automaton for verification of safety, liveness, bounded- liveness and deadlockfreeness properties based on model checking. The system performance analysis was performed using Arena software package. A comparative analysis of traffic light controllers with fixed time and fuzzy logic algorithms is givenKauno technologijos universitetasTaikomosios informatikos katedraVytauto Didžiojo universiteta
Study of different patient controlled analgesia models using hybrid simulation technique
Patient Controlled Analgesia (PCA), infusion PCA (iPCA), and Target Controlled Infufusion (TCI) drug delivery protocols were studied using Quantized State System model for the creation of hybrid aggregate models. [...]Kauno technologijos universitetasTaikomosios informatikos katedraVytauto Didžiojo universiteta