Raphael Murri

Prof. Raphael Murri

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 February 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MMMarius Miller
Marius Miller
MPMarkus Pfeil
Markus Pfeil
BRBenedikt Reick
Benedikt Reick
RMRaphael Murri
Raphael Murri
Ralf StetterRalf Stetter
Ralf Stetter
Ralph KennelRalph Kennel
Ralph Kennel
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 tires 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.

25 September 2023
Verified
Conference Paper
Open access
PDF file
MMMarius Miller
Marius Miller
MPMarkus Pfeil
Markus Pfeil
Ralph KennelRalph Kennel
Ralph Kennel
RMRaphael Murri
Raphael Murri
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.

1 January 2023 in The Evolving Scholar
Verified
Journal Article
Open access
PDF file
MMMarius Miller
Marius Miller
MPMarkus Pfeil
Markus Pfeil
Ralph KennelRalph Kennel
Ralph Kennel
RMRaphael Murri
Raphael Murri
The use of small individual vehicles for inner-city load transportation leads to the increased use of electrically driven cargo trailers for bicycles. Due to the high load capacity, an impact on the driving dynamics of the system takes place. For this reason, the driving behavior of a trailer is investigated in this research. For this purpose, a tire model with tires specially developed for cargo bicycles is used. Furthermore, different driving dynamic situations are investigated.

25 September 2023
Verified
Conference Paper
Open access
PDF file
MMMarius Miller
Marius Miller
MPMarkus Pfeil
Markus Pfeil
Ralph KennelRalph Kennel
Ralph Kennel
RMRaphael Murri
Raphael Murri
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.