The analysis of gear shift indicator test results

Analizirani su rezultati dobijeni ispitivanjima prema Pravilniku (EU) 65/2012, koji se odnosi na indikatore promene stepena prenosa, na 59 različitih vozila. Osnovni parametri analize su vrednosti brzine vozila pri kojima indikator preporučuje promenu stepena prenosa i njihova odstupanja od standardnih brzina u kojima se menjaju prenosni odnosi u toku ispitivanja izduvne emisije prema Testu I UNECE pravilnika broj 83, pri čemu je zaključeno da standardne brzine treba revidirati. Analizirane su i relativne uštede goriva za slučajeve promene stepena prenosa prema indikatoru i prema standardnim brzinama (prosečna 5,2%, maksimalna 19,9%). Takođe, pokazano je da sledeći preporuke indikatora, automatski menjači u manuelnom modu pružaju mogućnost veće uštede nego manuelni menjači. Zaključeno je da se statistička analiza o tome u kojoj meri vozači poštuju preporuke indikatora može iskoristiti za unapređenje trenutno važećih ispitivanja samih indikatora, potrošnje goriva i izduvne emisije.The results of tests according to Regulation (EU) No 65/2012 regarding gear shift indicators on 59 different vehicles are analyzed. Primary parameters were the vehicle speeds at which the gear shift is indicated through gear shift indicator (GSI), and based on their deviation from standard gear shift points defined for type I emission tests in UNECE Regulation No 83, it is concluded that standard gear shift points need to be revised. Relative fuel savings when shifting according to GSI instructions compared to standard gear shift points were analyzed (average 5.2%, maximum 19.9%). It is also shown that automaatic transmission gave bigger fuel saving when manual mode is used according to GSI, compared to manual transmission, also used with GSI. It is concluded that statistical analysis on how drivers follow GSI instructions may be used to improve current test procedures for GSI efficiency, fuel consumption measurement and emission tests

The analysis of gear shift indicator test results

Analizirani su rezultati dobijeni ispitivanjima prema Pravilniku (EU) 65/2012, koji se odnosi na indikatore promene stepena prenosa, na 59 različitih vozila. Osnovni parametri analize su vrednosti brzine vozila pri kojima indikator preporučuje promenu stepena prenosa i njihova odstupanja od standardnih brzina u kojima se menjaju prenosni odnosi u toku ispitivanja izduvne emisije prema Testu I UNECE pravilnika broj 83, pri čemu je zaključeno da standardne brzine treba revidirati. Analizirane su i relativne uštede goriva za slučajeve promene stepena prenosa prema indikatoru i prema standardnim brzinama (prosečna 5,2%, maksimalna 19,9%). Takođe, pokazano je da sledeći preporuke indikatora, automatski menjači u manuelnom modu pružaju mogućnost veće uštede nego manuelni menjači. Zaključeno je da se statistička analiza o tome u kojoj meri vozači poštuju preporuke indikatora može iskoristiti za unapređenje trenutno važećih ispitivanja samih indikatora, potrošnje goriva i izduvne emisije.The results of tests according to Regulation (EU) No 65/2012 regarding gear shift indicators on 59 different vehicles are analyzed. Primary parameters were the vehicle speeds at which the gear shift is indicated through gear shift indicator (GSI), and based on their deviation from standard gear shift points defined for type I emission tests in UNECE Regulation No 83, it is concluded that standard gear shift points need to be revised. Relative fuel savings when shifting according to GSI instructions compared to standard gear shift points were analyzed (average 5.2%, maximum 19.9%). It is also shown that automaatic transmission gave bigger fuel saving when manual mode is used according to GSI, compared to manual transmission, also used with GSI. It is concluded that statistical analysis on how drivers follow GSI instructions may be used to improve current test procedures for GSI efficiency, fuel consumption measurement and emission tests

Advanced theoretical-experimental method for optimization of dynamic behavior of firefighting vehicle modular superstructures

U radu je predstavljena teorijsko-eksperimentalna metoda razvijena sa ciljem optimizacije dinamičkog ponašanja modularnih nadgradnji vatrogasnih vozila. Teški uslovi eksploatacije u kojima se vatrogasna vozila koriste, kao i posebni zahtevi za ovu vrstu vozila zahtevaju posvećenost u pristupu optimizaciji nadgradnji sa stanovišta napona, deformacija, zamora, buke, kao i udobnosti i efektivnosti vozila. Optimizacija podrazumeva izbor optimalnih oblika, materijala, dimenzija, veza, oslanjanja, prigušenja i izolacije modula, sa ciljem postizanja optimalnog dinamičkog ponašanja nadgradnje. Metoda opisana u radu sastoji se od dva međusobno povezana dela - teorijskog i eksperimentalnog. Teorijski deo sastoji se od numeričkog modeliranja varijanti nadgradnje i proračuna odziva na dinamičke pobude korišćenjem metode konačnih elemenata, čiji se rezultati naknadno verifikuju kroz eksperimente. Eksperimentalni deo zasniva se na pobudi fizičkih modela nadgradnji pomoću posebno razvijenog mehaničkog pobudnog uređaja, praćenju odziva nadgradnji, kao i promeni ulaznih parametara u procesu projektovanja nadgradnji, sa ciljem dobijanja nadgradnje sa što boljim dinamičkim karakteristikama. Sopstvene frekvencije nadgradnje, važne u smislu rezonantnih zona, dobijene su korišćenjem testa udarom i FFT analize. Ova metoda se pokazala adekvatnom za optimizaciju dinamičkog ponašanja modularnih nadgradnji, kao što su one kod vatrogasnih vozila. Celokupna ispitna instalacija korišćena kroz ovu metodu ilustrativno je prikazana u radu. Takođe, date su smernice za dalje aktivnosti, razvoj i unapređenje ove metode.This paper shows elaborated theoretical-experimental method used to optimize dynamic behavior of modular superstructures of firefighting vehicles. Harsh exploitation conditions under which firefighting vehicles operates and special requirements for this type of vehicles require dedicated approach to optimization of superstructures in terms of stress, deformation, fatigue, noise, comfort and effectiveness. Optimization implies selection of optimal shapes, materials, dimensions, mountings, suspension, damping and insulation of modules to attain optimal dynamic behavior of superstructure. Method described in this paper can be divided into two interconnected parts - theoretical and experimental. Theoretical part consists of numerical modeling of superstructure variants and calculation of their responses to dynamic excitations using FEM, whose results are later validated through experiments. Experimental part of this method is based on excitation of superstructure physical models with, for this purpose specially developed, mechanical exciter, monitoring of superstructure response and changing of the input parameters in the design of superstructure to create the superstructure with best possible dynamic characteristics. Natural frequencies of structures, important in terms of resonant zones, are obtained using bump tests and FFT analysis. This method has proved suitable for optimization of dynamic behavior of modular superstructures such as those of firefighting vehicles. Complete testing installation used in this method is illustratively shown in this paper. Also, there are guidelines for further development and improvement of this method

Research into truck transmission torsion vibrations under longitudinal acceleration

The development of a modern motor vehicle is aimed at improving the performance in the field of dynamics (both longitudinal and lateral), economy, safety and ergonomic characteristics. Special attention is paid to passenger comfort. Torsional oscillations in transmission cause longitudinal vibrations of the vehicle, depending on inertial parameters, as well as on stiffness and damping of the transmission. Taking into account the complexity of the problem, it is estimated that it is useful to analyse the impact of the transmission design parameters on the longitudinal (fore and aft) vibrations of freight motor vehicle. For this purpose, the dynamic simulation method was used, and the analysis of the influence of certain constructive parameters on the longitudinal oscillations of the vehicle was performed using the sensitivity function

Determination of cornering stiffness through integration of a mathematical model and real vehicle exploitation parameters

U radu je prikazan prilaz identifikaciji otpora povođenju kao najznačajnijem parametru u sistemima upravljivosti i stabilnosti motornih vozila kroz integraciju empirijskih modela i parametara realne eksploatacije. Ovaj prilaz se zasniva na analizi matematičkog modela pneumatika, identifikaciji ključnih parametara iz realne eksploatacije i integraciji mehatronskog sistema za praćenje opterećenja pneumatika. Merenjem opterećenja pneumatika, i kasnijom integracijom izmerenih vrednosti u razvijeni softverski modul, obezbeđuje se precizno definisanje otpora povođenju na određenom kontaktu vozila i puta. Istraživanje podrazumeva integraciju matematičkog modela, mehaničkih, elektronskih i informacionih tehnologija u cilju obezbeđivanja sveobuhvatnog sagledavanja ponašanja pneumatika u pogledu definisanja otpora povođenju.This paper demonstrates the approach to determination of cornering stiffness as the most important parameter of motor vehicle steering and stability systems through integration of empirical models and real exploitation parameters. The approach is based on the analysis of a tire mathematical model, identification of key real exploitation parameters and integration of a mechatronic system for tire load monitoring. Measurement of tire load and subsequent integration of measured values into developed software module provide a precise definition of cornering stiffness for a certain vehicle and road contact patch. This research assumes integration of a mathematical model and mechanical, electronic and information technologies with the aim of comprehensive understanding of tire behavior in terms of cornering stiffness determination

Advanced theoretical-experimental method for optimization of dynamic behavior of firefighting vehicle modular superstructures

U radu je predstavljena teorijsko-eksperimentalna metoda razvijena sa ciljem optimizacije dinamičkog ponašanja modularnih nadgradnji vatrogasnih vozila. Teški uslovi eksploatacije u kojima se vatrogasna vozila koriste, kao i posebni zahtevi za ovu vrstu vozila zahtevaju posvećenost u pristupu optimizaciji nadgradnji sa stanovišta napona, deformacija, zamora, buke, kao i udobnosti i efektivnosti vozila. Optimizacija podrazumeva izbor optimalnih oblika, materijala, dimenzija, veza, oslanjanja, prigušenja i izolacije modula, sa ciljem postizanja optimalnog dinamičkog ponašanja nadgradnje. Metoda opisana u radu sastoji se od dva međusobno povezana dela - teorijskog i eksperimentalnog. Teorijski deo sastoji se od numeričkog modeliranja varijanti nadgradnje i proračuna odziva na dinamičke pobude korišćenjem metode konačnih elemenata, čiji se rezultati naknadno verifikuju kroz eksperimente. Eksperimentalni deo zasniva se na pobudi fizičkih modela nadgradnji pomoću posebno razvijenog mehaničkog pobudnog uređaja, praćenju odziva nadgradnji, kao i promeni ulaznih parametara u procesu projektovanja nadgradnji, sa ciljem dobijanja nadgradnje sa što boljim dinamičkim karakteristikama. Sopstvene frekvencije nadgradnje, važne u smislu rezonantnih zona, dobijene su korišćenjem testa udarom i FFT analize. Ova metoda se pokazala adekvatnom za optimizaciju dinamičkog ponašanja modularnih nadgradnji, kao što su one kod vatrogasnih vozila. Celokupna ispitna instalacija korišćena kroz ovu metodu ilustrativno je prikazana u radu. Takođe, date su smernice za dalje aktivnosti, razvoj i unapređenje ove metode.This paper shows elaborated theoretical-experimental method used to optimize dynamic behavior of modular superstructures of firefighting vehicles. Harsh exploitation conditions under which firefighting vehicles operates and special requirements for this type of vehicles require dedicated approach to optimization of superstructures in terms of stress, deformation, fatigue, noise, comfort and effectiveness. Optimization implies selection of optimal shapes, materials, dimensions, mountings, suspension, damping and insulation of modules to attain optimal dynamic behavior of superstructure. Method described in this paper can be divided into two interconnected parts - theoretical and experimental. Theoretical part consists of numerical modeling of superstructure variants and calculation of their responses to dynamic excitations using FEM, whose results are later validated through experiments. Experimental part of this method is based on excitation of superstructure physical models with, for this purpose specially developed, mechanical exciter, monitoring of superstructure response and changing of the input parameters in the design of superstructure to create the superstructure with best possible dynamic characteristics. Natural frequencies of structures, important in terms of resonant zones, are obtained using bump tests and FFT analysis. This method has proved suitable for optimization of dynamic behavior of modular superstructures such as those of firefighting vehicles. Complete testing installation used in this method is illustratively shown in this paper. Also, there are guidelines for further development and improvement of this method

Research into truck transmission torsion vibrations under longitudinal acceleration

The development of a modern motor vehicle is aimed at improving the performance in the field of dynamics (both longitudinal and lateral), economy, safety and ergonomic characteristics. Special attention is paid to passenger comfort. Torsional oscillations in transmission cause longitudinal vibrations of the vehicle, depending on inertial parameters, as well as on stiffness and damping of the transmission. Taking into account the complexity of the problem, it is estimated that it is useful to analyse the impact of the transmission design parameters on the longitudinal (fore and aft) vibrations of freight motor vehicle. For this purpose, the dynamic simulation method was used, and the analysis of the influence of certain constructive parameters on the longitudinal oscillations of the vehicle was performed using the sensitivity function

Industrial safety of pressure vessels - Structural integrity point of view

This paper presents different aspects of pressure vessel safety in the scope of industrial safety, focused to the chemical industry. Quality assurance, including application of PED97/23 has been analysed first, followed shortly by the risk assessment and in details by the structural integrity approach, which has been illustrated with three case studies. One important conclusion, following such an approach, is that so-called water proof testing can actually jeopardize integrity of a pressure vessel instead of proving it

Industrial safety of pressure vessels - Structural integrity point of view

This paper presents different aspects of pressure vessel safety in the scope of industrial safety, focused to the chemical industry. Quality assurance, including application of PED97/23 has been analysed first, followed shortly by the risk assessment and in details by the structural integrity approach, which has been illustrated with three case studies. One important conclusion, following such an approach, is that so-called water proof testing can actually jeopardize integrity of a pressure vessel instead of proving it

Identification of modular firefighting superstructures’ dynamic behaviour

Specific functional requirements for firefighting vehicles have resulted in stricter exploitation regimes and frequent off-road use. Current practice appoints the problem of the strength of a superstructure’s modules, which are very different in terms of torsional rigidity. It is important to say here that there are no unambiguous manufacturer’s guidelines for bodybuilders to complete a firefighting vehicle. In such circumstances, the identification of the dynamic behaviour of modular firefighting superstructures further gains in importance. Developed numerical-experimental approach for identification, analysis and optimisation of the dynamic behaviour of modular firefighting vehicle superstructures is shown. Experimental part of this method is based on excitation of superstructure physical models with, for this purpose specially developed mechanical exciter. Also, natural frequencies of structures, important in terms of resonant zones, are obtained using bump test and FFT analysis. Finite elements method is defined as a diagnostic tool for the identification of structure behaviour, and the measured acceleration values at characteristic points as a proof of the model’s correctness i.e. correctness of the applied optimisation approach. The numerical analysis of influence of suspension characteristics and connections of superstructure modules on their dynamic behaviour (eigen-frequencies and amplitudes) are also presented. Comparative analysis of the experimental and numerical results verified the numerical model. Such a model can save the time and money by reducing the experiments needed in the modular firefighting vehicle superstructures optimisation