Modeling of a Bicycle Cargo Trailer with Magic Formula Tire Model for Vehicle Dynamics Simulation

In modern and sustainable concepts for supply chains, cargo bicycles, and cargo trailers can be a target-oriented solution in urban areas. However, drivers should be aware of the dynamics of these systems since, in the case of a loaded trailer, the trailer mass significantly exceeds the mass of the towing vehicle. However, the electrification of cargo trailers opens up the possibility of equipping these systems with an intelligent control system. This type of control system can be based on a model or tested using a model of the system. For this reason, the present research presents a single-track model of a bicycle-trailer system that considers longitudinal dynamics as well. In addition, a detailed tire model of a typical tire for cargo bikes is integrated. With the help of a prototype trailer, which forms the basis for the model’s parameters, measurement data is collected and compared with the simulation results. Within the scope of the comparison, speed, acceleration in longitudinal and lateral direction, hitch force, yaw rate, and the angle between the towing vehicle and trailer are compared in a longitudinal and lateral dynamic case. The presented model shows a good agreement with the reality in the longitudinal dynamic investigation regarding the tested scenarios. In terms of lateral dynamics, the model can reproduce a significant part of the measured data but exhibits minor differences related to environmental conditions, limited degrees of freedom, measurement errors, and the implementation of a needed driver model in this setup, which represents the human component. In the future, the model can be used to investigate the driving characteristics of bicycle-trailer systems. Furthermore, adding a model of the trailer powertrain and its control to the simulation can enable simulation-based design and testing of the required vehicle dynamics controller before implementation on a prototype.