There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Limited driving range remains one of the barriers for widespread adoption of electric vehicles (EVs). To address the problem of range anxiety, this paper presents an energy consumption prediction method for EVs, designed for energy-efficient routing. This data-driven methodology combines real-world measured driving data with geographical and weather data to predict the consumption over any given road in a road network. The driving data are linked to the road network using geographic information system software that allows to separate trips into segments with similar road characteristics. The energy consumption over road segments is estimated using a multiple linear regression (MLR) model that links the energy consumption with microscopic driving parameters (such as speed and acceleration) and external parameters (such as temperature). A neural network (NN) is used to predict the unknown microscopic driving parameters over a segment prior to departure, given the road segment characteristics and weather conditions. The complete proposed model predicts the energy consumption with a mean absolute error (MAE) of 12–14% of the average trip consumption, of which 7–9% is caused by the energy consumption estimation of the MLR model. This method allows for prediction of energy consumption over any route in the road network prior to departure, and enables cost-optimization algorithms to calculate energy efficient routes. The data-driven approach has the advantage that the model can easily be updated over time with changing conditions.

https://www.mdpi.com/1996-1073/10/5/608/pdf

A Data-Driven Method for Energy Consumption Prediction and Energy-Efficient Routing of Electric Vehicles in Real-World Conditions

Measurement and modeling of skid resistance of asphalt pavement: A review

There is an increased focus worldwide on understanding and modeling rolling resistance because reducing the rolling resistance by just a few percent will lead to substantial energy savings. This paper reviews the state of the art of rolling resistance research, focusing on measuring techniques, surface and texture modeling, contact models, tire models, and macro-modeling of rolling resistance.

Rolling Resistance Measurement and Model Development

The usage of low-noise road surface can be an important and effective noise mitigation action and, in many cases, it might represent the only viable solution. After the laying of a low-noise road surface, it is necessary to verify if the planned objectives have been actually obtained: the Close Proximity Method (CPX) could be a possible method to achieve this result. The current release of the ISO 11819 draft regarding CPX redirects to a future third part for all details about the reference tyre to be used, while the previous one gave indications on dimensions, kind of tread pattern and maintenance conditions. As well known, tyre dimensions and tread pattern are the main sources of variability of rolling noise. Even though many tyres available on the market comply with all ISO requirements, the choice of a brand or a model rather than another one could nevertheless influence results of measurements. In this work, results obtained in several measurement sessions, repeated using different tyres, are compared, aiming to analyse the influence of the tyre choice in assessing the acoustic performance of a low-noise road surface. Limitations and advantages of the CPX method in regards to the evaluation of the effectiveness of a noise mitigation action are reported, and new perspectives are suggested, in order to improve the relationship with the noise level reduction at the receiver.

The influence of tyres on the use of the CPX method for evaluating the effectiveness of a noise mitigation action based on low-noise road surfaces

In the article the principle of measuring of tyre/road rolling resistance tyres in road conditions applied in a special measuring trailer is presented. This trailer was built in Faculty of Mechanical Engineering at Gdansk University of Technology. The construction of two special devices used in this trailer was discussed. These devices eliminate the influence of some chosen confounding measurements factors such as: the inertia force acting on the measuring arm with the wheel and the tested tyre and vibrations of the measuring arm. The operation of these devices was proven in practice. The conclusions arising from the use of these systems are described.

Relieving the Measuring System of the Trailer for Tyre/Road Rolling Resistance Measurements from the Inertia Force

Road surfaces have a direct impact on noise generated by rolling tyres, the main and dominant source of noise of moving vehicles. Road surface texture, porosity and stiffness/elasticity govern the pavement contribution to tyre/road noise the most. An experimental PoroElastic Road Surface (PERS) is a wearing course with a high content of interconnected voids (pores) and with an elastic behavior due to the use of small particles of rubber as the main aggregate. It was already proved, that using that type of pavement, a road traffic noise reduction up to 12 dB can be achieved. The new project SEPOR founded by the Polish National Centre for Research and Development has started in 2018 aiming in further development of poroelastic road surface. Its main goal is to enhance durability of PERS by optimization of mix composition, improvement of the production process, increasing the interlayer bonding strength and to optimize noise reduction and skid resistance. Experimental test sections will be constructed within a trafficked road and tested for noise, rolling resistance, skid resistance and fire suppression properties. The paper presents the results of noise and rolling resistance measurements performed on a pilot small-scale test section of PERS built on a construction yard.

Further development of the poroelastic road surface within the new Polish project SEPOR

Poroelastic road surfaces are characterized by low noise of tires running on them. Road pavements of this type are promising solution to problems related to traffic noise in cities and on rural roads. Some technical problems still have to be solved, in particular regarding durability and skid resistance on wet surface. Ongoing and planned works are to contribute to to create a quiet, durable and safe road surface, which will become an alternative to acoustic screens and vehicle speed reduction as an efficient noise reduction measure. The paper presents the results of laboratory and road tests of tire/road noise and rolling resistance on the prototype poroelastic surface (PERS) compared to the surfaces selected as a reference.

/pdf/tire-road-noise-and-tire-rolling-resistance-on-the-prototype-4kp2okcd1a.pdf

Tire/road noise and tire rolling resistance on the prototype PERS surface

The paper describes results of research on heavy vehicle tyre with Run Flat VFI insert. The experiment has included the determination of heat generation, rolling resistanceand radial stifnessof two different tyre designes (textile and steel carcass). The results have been used for the purpose of ewalution of tyre operating characteristics. The study included research on non-inflated tyre properties. The purpose of the paper is nto determine chracteristics of the tyres equipped with inserts, which are essenical for driving wheeled APCs. The inserts are composed of polymer rings mounted on rims inside the tyres. If the inflation pressure of the tyres is very low or of there is no inflation pressure at all, the rings transfers the loads imposed on the tyre to the run. Usually in such a case, there is coctact of the ring and inn er surdace of the tyre tread area. Laboratory facility for surveys of heavy vehicles tyres summary characteristicsof radial stiffness and histeresis of the tyres, temperature destribution on the external surface of the test tyre, comparison of radial characteristics of the tyres tested, example of stiffness characteristics, destribution of the temperature on the side of tyre during the road test and carcass damages on the flat tyre are presented in the paper.

/pdf/research-on-operational-characteristics-of-tyres-with-run-52gpq3rbln.pdf

Research on operational characteristics of tyres with run flat insert

Tyre/road noise is one of the major environmental problems related to road traffic. There are several measuring methods of tyre/road noise that may be carried out on the road (for example Coast-down and Close Proximity Method) or in the laboratory (Drum Method). Road measurements are preferred for evaluations of pavement properties while laboratory methods are mostly used to evaluate tyres. One of the biggest problems associated with laboratory methods is to ascertain that tyre interfaces with pavement that has texture, porosity and mechanical impedance the same as with the real road surface. The paper presents results of tests performed by the Close Proximity Method (with test trailer Tiresonic Mk.4) and drum method where very similar or exactly the same surfaces are used. The reported measuring program includes tests performed on an innovative poroelastic road surface called PERS. Tyre/road noise is nowadays one of the most important issues related to the tyre and road interface. Intensive investigation of noise generated by rolling tyres started in the sixties of the twentieth century. At that time every researcher used his/her own methodology of measurements so comparison of the results was not easy. Basically two different groups of measuring methods started to evaluate after a while. One group, preferred by tyre manufacturers was based on indoor measurements with use of roadwheel (drum) facilities, and road measurements preferred by road constructors and road authorities. Drum measurements were relatively easy to perform and all measuring conditions were straightforwardly controllable, with exception of pavement characteristics. A lot of early measurements were made on plain steel drums or at the best on drums covered with sand-paper like material called "Safety Walk". Of course results obtained on plain steel surface or "Safety Walk" were not at all representative to real road conditions but equipping drums with replica road surfaces was very difficult and expensive. Road measurements at first were based on ISO 362 standard that was intended to evaluate overall noise from different types of vehicles. In order to separate noise generated by tyre/road interaction from other noise sources the acceleration pass-by required by the standard was being replaced by coast-by. In the 1970s first trailers intended for tyre/road noise measurements began to appear (1, 2). At present, the following methods are in use:  the Drum Method (tyre rolls on the test drum, usually on its outer surface that is covered by replica road surfaces having the same texture as real road pavement of a certain kind, microphones are placed close to the tyre/pavement interaction zone);  the Coast-By Method (vehicle equipped with test tyres coasts-down on the test pavement, microphones are placed 7.5 m or 15 m from the centre of the test track);  the Close Proximity Method "CPX" (test tyre is mounted on trailer or on ordinary vehicle and the microphones are mounted "on-board", very close to the tyre/road interaction zone;  the Trailer Coast-By (a hybrid method using a specially designed trailer that coasts-by during measurements and microphones positioned on the road side). All measurements reported in this paper were performed on facilities owned by the Technical University of Gdansk, Poland. Laboratory tests were performed on three different drum facilities:

/pdf/comparison-of-road-and-laboratory-measurements-of-tyre-road-11zy7nedar.pdf

Grzegorz Ronowski

Papers

Relieving the Measuring System of the Trailer for Tyre/Road Rolling Resistance Measurements from the Inertia Force

Further development of the poroelastic road surface within the new Polish project SEPOR

Tire/road noise and tire rolling resistance on the prototype PERS surface

Research on operational characteristics of tyres with run flat insert

Comparison of road and laboratory measurements of tyre/road noise