MANEUVERABILITY OF THE 15-METER BUS

Abstract

Buses play a significant role in the public transport system and, in particular, in the transpor-tation of passengers in intercity traffic. This is the most common way of moving people over short and medium distances both in cities and in most rural areas. The bus industry as a part of the general automotive industry has its own characteristic feature: despite the fact that the total production of buses is only a few percent of the total output of automotive equipment, their production is carried out at a much larger number of enterprises than cars and even trucks, and very often in limited quantities. The idea of using extra-large buses seems ap-propriate, because there are a number of city routes on which the use of 12-meter buses will lead to their over-load, and the use of 18-meter articulated buses can lead to their underloading, or to increase the intervals of traffic. When developing any bus, including an extra-large capacity bus, the mass and geometric limitations laid down in the regulatory documents must be taken into account. At the same time, a 15-meter three-axle city bus without special devices cannot meet the requirements of GOST due to its increased length. Therefore, it is still relevant today to improve the fitting of such buses into the transport network of large cities. This problem can be solved by controlling not only the front but also the rear wheels of the bus. The paper shows that the control of an extra-large capacity bus can be carried out not only by a kinematic method – by turning the steered wheels of the bus, but also in a combined method – by controlling the steered wheels of the bus and its driving wheels by creating different torques on the wheels of this axis or by creating braking moments on the third axis, which can significantly simplify the bus control system. At the same time, the dependence of the difference in the torques on the wheels of the driving axle of the bus, the braking moments on the wheels of the third axle and total moments on the second (driving) and third axles of the bus was obtained, which is equivalent to the angle of rotation of the steered wheels of the bus. For different control methods, it has been established that the bus according to the kinematic control method (turning the steered wheels of the bus – the control system) does not meet the requirements of UNECE Regulation No. 36.03 regarding maneuverability. With the combined method of bus control for the magnitude of the difference in moments on the wheels of the second and third axles within Delta-M=2550-3000 Nm, these requirements are met, and the preferred design is the control system, which uses the braking of the wheels of the third axle. However, this method of turning can only be proposed to improve maneuverability at low speeds (up to 10 m/s). When the speed increases above 10 m/s, the wheel con-trol system of the third axle should be blocked.