# Measurement and Modeling of a Cargo Bicycle Tire for Vehicle Dynamics Simulation
###### Abstract  
In the field of inner-city cargo transportation, solutions such as electrified cargo trailers are increasingly being used. To provide an intelligent drivetrain control system that improves driving dynamics and enables safety, it is necessary to know the characteristics of the trailer system. This includes the behavior of the tires. Existing investigations of bicycle tries focus on camber-angle-dependent models. However, in most trailers, a rigid mounting of the tires without camber is used. For this reason, a bicycle tire model is created within the scope of this study using real measurement data that represent a 20 in tire with typical wheel loads and without camber. The measurements were collected with the mobile tire measurement laboratory of the Bern University of Applied Sciences on an asphalt test site under real conditions. Crosstalk occurring in the measurement hub during the data collection was successfully corrected using a matrix method. With help of the so-called Magic Formula, a tire model was created that can be used for driving dynamics simulations and controller design. tire model; bicycle tires; micromobility; cargo trailer; simulation; vehicle dynamics; magic formula; last mile; cyclist safety; crosstalk compensation Article Measurement and Modeling of a Cargo Bicycle Tire for Vehicle Dynamics Simulation  
[PERSON], [PERSON], R.  
braking or driving through a curved road, the transmissible force of the tire on the road becomes saturated, which can be triggered by the additional mass of the trailer to be braked. If there is also an angle between the trailer and the towing vehicle so that their x-axes are not parallel-aligned, the angle can be increased by the sliding towing vehicle and the pushing trailer until the systems collide. In addition to the dependence on the loading position, ref. [6] underlines the central part of the tire behavior in the described phenomena. In this context, refs. [7,8] point out the importance of tire behavior. If measurements can be used to model the tire behavior, they can be taken into account in the design of a subsequent control system. To counteract snaking and jack-knifing of the system, refs. [9,10] show exemplary different control approaches, which are all based on known tire behavior and, thus, on a tire model. For the majority of cases, linearized tire models are used, which result from a factor representing tire stiffness and its dependence on the slip angle. Furthermore, according to the studies of [11,12], a major impact on the evaluation of a vehicle's efficiency results from the tire behavior. In this context, measurement and modeling can also contribute to system optimization. If the driving behavior of cargo trailers in the field of micromobility is to be investigated or a driving dynamics control of the electric drive is to be realized, the behavior of the tires in use must also be studied more closely. However, knowledge of the tire behavior of typical bicycle tires for this application purpose is lacking for the design and parameterization of intelligent control algorithms. Existing studies, such as that of [13], cover the modeling of a wide range of bicycle tires, which are designed for conventional bicycle driving and not load transportation. Additional investigations carried out by [14] show the measurements of mountain bike tires on a test bench, as well as the generation of a mathematical magic formula model from the resulting data. The author points out that, due to the limitations of the test rig, a side-slip angle greater than \(+/-2^{\circ}\) could not be investigated. In addition, the tires are measured at different camber angles, since, in the normal use of a bicycle, cornering is performed by turning and tilting the bicycle towards the inside of the corner. Reference [15] shows similar tests, where the focus is on the comparison of different road tires.