Measuring cycle riding comfort in Southampton using an instrumented bicycle

The increased environmental awareness and the rising fuel costs make bicycles a more and more attractive mode of travel for short journeys. Considering the future prospect of this mode of transportation and the great advantages that it offers in terms of space consumption, health and environmental sustainability, several city authorities worldwide are presently undertaking schemes aiming at improving cycling infrastructure. The aim of the present study is to monitor the impact of such schemes on the riding comfort of cyclists, as expressed by the, usually lower, quantity and magnitude of vibrations occurring as a result of cycling over pavement defects. Millbrook Road East in the western edge of the city center of Southampton is used as a case study, where vibration measurements are taken by means of an instrumented bicycle during periods before and after a redevelopment scheme involving the resurfacing of the road pavement. The results show a clear overall improvement in cycling comfort post-redevelopment, with statistically significant reductions in both the number of high severity vibrations and of their magnitude in "typical" cycling trips taken on the road. However, instances of finishing "snags" in some parts of the surface appear to introduce new minor defects (e.g. around manholes) that are not visible to the naked eye, and these still have some negative effect on the riding experience. Moreover, the study highlights the detrimental impact that widespread pavement defects can have on riding comfort, which affect cyclists of all ages, abilities and styles

Применение вибродиагностики при создании элементов персонального электротранспорта

The study of vibration loading of the main elements of personal electric vehicles and the search for ways to reduce vibration characteristics was conducted. The issues of measuring vibration arising on a bicycle, which is driven by human muscle power and an electric drive, are considered. Measurements of vibration acceleration and frequency spectra in a certain area of motion were carried out using the “Octave-101VM” spectrum analyzer in three stages. At the first stage, the electric bike was driven by a pedal drive, at the second – by an electric drive, at the third – the pedals and the electric drive worked in parallel. As a result of the tests carried out, it was found that the greatest vibration occurred in the “Motor” mode during the use of an electric bicycle, the least vibration occurred when driving with the electric motor turned off. It was found that the electric drive increases the vibration level (at the same time, the electric bike does not exceed the maximum permissible values of vibration levels on all axes). In order to reduce the vibration arising from the electric motor on a personal electric vehicle, a 3D computer model has been developed and an airless wheel mover has been manufactured using this model on a 3D printer (a wheel for an electric scooter with internal damping has been manufactured). Bench tests have shown that the developed wheel, in comparison with a pneumatic tire, has a smaller (up to 45 %) contact spot. The results obtained can be used in the development of competitive products, in particular personal electric vehicles.Проведено исследование вибронагруженности основных элементов персональных электрических транспортных средств и поиск путей снижения вибрационных характеристик. Рассмотрены вопросы измерения вибрации, возникающей на велосипеде, который приводится в движение мускульной силой человека и электроприводом. Измерения виброускорения и частотных спектров на определенном участке движения осуществлялись с помощью анализатора спектра «Октава-101ВМ» в три этапа. На первом этапе электровелосипед приводился в движение с помощью педального привода, на втором – электроприводом, на третьем – педали и электропривод работали параллельно. В результате проведенных испытаний установлено, что наибольшая вибрация происходила в режиме «Мотор» в процессе использования электровелосипеда, наименьшая вибрация – при езде с выключенным электродвигателем. Обнаружено, что электропривод увеличивает уровень вибрации (при этом у электровелосипеда по всем осям не происходит превышения предельно допустимых значений уровней вибраций). С целью уменьшения возникающей от электродвигателя вибрации на персональном электротранспорте разработана компьютерная 3D-модель и изготовлен по данной модели на 3D-принтере безвоздушный колесный движитель (колесо для электросамоката с внутренним демпфированием). Стендовые испытания показали, что разработанное колесо в сравнении с пневматической шиной имеет меньшее (до 45 %) пятно контакта. Полученные результаты можно использовать при разработке конкурентоспособной продукции, в частности персонального электротранспорта