Wyniki wyszukiwania - BazTech

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Calculation of brake-force distribution on three-axle agricultural trailers using simulation methods

Radzajewski Paweł

Technical Transactions

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2021

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Vol. 118, iss. 1

art. no. e2021029

EN

The paper presents a new methodology for calculating the optimal linear distribution of braking forces for a three-axle trailer with "walking beam" and "bogie" suspension of the rear axle assembly that will meet the requirements of the new European legislation, EU Directive 2015/68. On this basis, a computer program for selecting the linear distribution of braking forces between axles has been developed. The presented calculations and simulation results of the braking process can be used in the design process to select the parameters of the wheel braking mechanisms and then the characteristics of the pneumatic valves of the braking system. The adaptation of the braking system of agriculture trailers is a very important factor for improving the safety of the transportation systems.

2

Calculations of the optimal distribution of brake force in agricultural vehicles categories R3 and R4

Kamiński Zbigniew, Radzajewski Paweł

Eksploatacja i Niezawodność

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2019

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Vol. 21, no. 4

645--653

EN

Fulfilling the requirements of the EU Directive 2015/68 in the area of braking for agricultural trailers depends on the proper selection of individual components of the braking system. This paper describes the requirements regarding braking performance and distribution of brake forces in agricultural trailers in R3 and R4 categories. On this basis, a methodology for calculating the optimal linear distribution of brake forces, characteristic for agricultural trailers with pneumatic braking systems, has been developed. The examples of calculation of an optimal distribution of brake forces for a two- and three-axle trailer with a tandem suspension system of the rear axle assembly have been provided. The optimization algorithm with the Monte Carlo method has been described, based on which a computer program was developed to select a linear distribution of brake forces in a three-axle trailer with ‘walking beam’ and ‘bogie’ suspensions. The presented calculations can be used in the design process to select the parameters of wheel braking mechanisms and then the characteristics of the pneumatic valves of the braking system.

PL

Spełnienie wymagań Dyrektywy UE 2015/68 w zakresie hamowania przyczep rolniczych zależy od właściwego doboru poszczególnych komponentów układu hamulcowego. W pracy opisano wymagania dotyczące skuteczności hamowania oraz rozdziału sił hamujących w przyczepach rolniczych kategorii R3 i R4. Na tej podstawie opracowano metodykę obliczeń optymalnego liniowego rozdziału sił hamujących, charakterystycznego dla przyczep rolniczych z pneumatycznymi układami hamulcowymi. Zamieszczono przykłady obliczeń optymalnego rozdziału sił hamujących dla przyczepy dwu i trzyosiowej z tandemowym układem zawieszenia zespołu osi tylnych. Opisano algorytm optymalizacji metodą Monte Carlo, na podstawie którego opracowano program komputerowy do doboru liniowego rozdziału sił hamujących w przyczepie trzyosiowej z zawieszeniem „walking beam” i „bogie”. Przedstawione obliczenia można wykorzystać w procesie projektowania do doboru parametrów kołowych mechanizmów hamulcowych, a następnie charakterystyk zaworów pneumatycznych układu hamulcowego.

3

Design of brake force distribution model for front-and-rear-motor-drive electric vehicle based on radial basis function

Sun B., Zhang T., Gao S., Ge W., Li B.

Archives of Transport

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2018

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Vol. 48, iss. 4

87--98

EN

To achieve high-efficiency and stable brake of a front-and-rear-motor-drive electric vehicle (FRMDEV) with parallel cooperative braking system, a multi-objective optimal model for brake force distribution is created based on radial basis function (RBF). First of all, the key factors, which are the coefficient of brake force distribution between the front and rear shafts, the coefficient of brake force distribution at wheels, the coefficient of regenerative brake force distribution between front and rear axles, that influence the brake stability and energy recovery of the FRMDEV are analyzed, the fitness functions of brake stability and energy recovery are established. Secondly, the maximum allowed regenerative brake torque influenced by the state of charge of battery is confirmed, the correction model of the optimal distribution coefficient of regenerative brake force is created according to motor temperatures. Thirdly, based on HALTON sequence method, a two-factor database, vehicle velocity and brake strength, that characterizes vehicle operation is designed. Then an off-line response database of the optimal brake force distribution is established with the use of particle swarm optimization (PSO). Furthermore, based on hybrid RBF, the function model of the factor database and the response database is established, and the accuracy of the model is analyzed. Specially, the correlation coefficient is 0.995 and the predictive error variance is within the range between 0.000155 and 0.00018. The both indicate that the multi-objective distribution model has high accuracy. Finally, a hardware-in-loop test platform is designed to verify the multi-objective optimal brake force distribution model. Test results show that the real-time performance of the model can meet the demand of engineering application. Meanwhile, it can achieve both the brake stability and energy recovery. In comparison with the original brake force distribution model based on the rule algorithm, the optimized one proposed in this paper is able to improve the energy, recovered into battery, by 14.75%.