Modeling and Simulation of an Electric Rail System: Impacts on Vehicle Dynamics and Stability
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors- A scientific article must contain assumptions that define the research area. There are no such assumptions.
- The concept of stability is used without defining what the authors mean by this. Commonly in dynamical systems, stability is defined in the Lyapunov sense. If this is not the case, please state what definition the Authors adopt. For a full discussion of stability in vehicle movement on a road, see: Kisilowski, Zalewski: Modelling of Road Traffic Events, Springer 2022
- The authors consider one type of acceleration in curved motion. According to elementary analytical mechanics, there are three types of acceleration in curved traffic. If only one type is assumed then this must be stated in the assumptions.
- The article uses the concept of optimisation, which in the literature cited (items 14 and 15) does not state what optimisation method led to the assumption that the system is optimised.
- It is common in scientific articles also on cars to show a drawing with coordinate systems. In relation to the angles of rotation around a rectangular coordinate system, the terms used in the article can be defined: tilt, yaw, etc. - then the article is readable.
- In the assumptions, it should also be stated what model of pneumatics-pavement interaction is adopted in the simulation process.
- Formulating these assumptions in the introduction will clearly define the scope of the article.
- The text should be reviewed to eliminate e.g. on page 6 ‘comparison of lateral acceleration data...’. - how obtained? - single or double lane change? - in straight track traffic there is no lateral acceleration.
Author Response
-Comment 1: Comments and Suggestions for Authors A scientific article must contain assumptions that define
the research area. There are no such assumptions.
-response 1: We acknowledge the reviewer’s comment. An assumption related to the skid
resistance has been added to the revised manuscript starting at line 39: ”Given
safety concerns, the skid resistance of conductive rails must be adequate to ensure
safe vehicle maneuvers. An insufficient level of skid resistance may lead to vehicle
instability.”Another assumption related to the vehicles was added line 68.
-Comment 2: The concept of stability is used without defining what the authors mean by this. Commonly in
dynamical systems, stability is defined in the Lyapunov sense. If this is not the case, please state
what definition the Authors adopt. For a full discussion of stability in vehicle movement on a
road, see: Kisilowski, Zalewski: Modelling of Road Traffic Events, Springer 2022
- response 2: The definition of stability was added in line 41 as follows: ’Stability, in this context,
refers to a vehicle’s ability to maintain its intended path of travel while resisting loss
of control due to skidding, spinning, or rolling over, as defined by Rajamani (2012).
-Comment 3: The authors consider one type of acceleration in curved motion. According to elementary an-
alytical mechanics, there are three types of acceleration in curved traffic. If only one type is
assumed then this must be stated in the assumptions.
- response 3: Indeed, in elementary analytical mechanics, three types of acceleration—tangential,
centripetal (radial), and total acceleration—are considered in curved motion. In our
study, we focus specifically on tangential, lateral, and vertical acceleration as clearly
shown, we added the following in line 156: ’For this study, we selected the following
parameters, as they are sufficient to detect various types of potential instability,
including lane departure, rollover, and lateral loss of control (yaw instability)’
-Comment 4: The article uses the concept of optimisation, which in the literature cited (items 14 and 15) does
not state what optimisation method led to the assumption that the system is optimised.
- response 4: The model was only calibrated to match the physical test outputs. The following
was added in line 217: ’We used a trial-and-error method to minimize the error
between the measured and simulated values. The calibration process was stopped
once the error reached a minimal value, as shown in Figure2.’
-Comment 5: It is common in scientific articles also on cars to show a drawing with coordinate systems. In
relation to the angles of rotation around a rectangular coordinate system, the terms used in the
article can be defined: tilt, yaw, etc. - then the article is readable.
- response 5: We have added figure 1 showing the coordinate system used in our analysis, see
line 137.
-Comment 6: In the assumptions, it should also be stated what model of pneumatics-pavement interaction is
adopted in the simulation process.
- response 6: We added this information in line 93: ’We used the Callas tyre model, which
is embedded in Scaner 2023.3 software, the model is based on the “Pacejka Magic
Formula”. All input data is based on physical parameters that are easily interpreted
and adjusted to improve on the model’s validity (including grip).’
-Comment 7: Formulating these assumptions in the introduction will clearly define the scope of the article.
- response 7:The introduction has been revised for clarity and now includes a more explicit
mention of the assumptions, lines 39 and 63.
-Comment 8: The text should be reviewed to eliminate e.g. on page 6 ‘comparison of lateral acceleration
data...’. - how obtained? - single or double lane change? - in straight track traffic there is no
lateral acceleration.
- response 8: We have reviewed and clarified this part of the text, as well as other parts, to
ensure better understanding.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authorscapital D for '2.4.1 Double-lane...'
increase font size for all figures
remove frame for all figures
Appendix A not available
Please show the Figure of the simulation model.
How much similarity of replication between simulation and actual vehicle?
Please show the Figure of actual vehicle on track during experimentation on conductive rail.
capital R for '3.5. Roll angle'
Appendix H is not used the text.
Author Response
1. capital D for ’2.4.1 Double-lane...’
- The capitalization has been corrected.
2. increase font size for all figures
- The font size has been increased for all figures.
3. remove frame for all figures
- the frames have been removed from all figures.
4. Appendix A not available
- The issue with Appendix A has been resolved and is now available.
5. Please show the Figure of the simulation model.
- We have added figure 1 showing the coordinate system used in our simulation
model.
6. How much similarity of replication between simulation and actual vehicle?
-The simulation was calibrated using physical test outputs, and the results are aligned
with the real vehicle data. This was clarified in the section of calibration. However,
the rail has not been tested yet on the test track, it is planned to be tested soon.
We clarified this in the conclusion, line 462
7. Please show the Figure of the actual vehicle on track during experimentation on conductive rail.
-The rail has not been installed yet. Physical tests were carried out only on asphalt,
and simulations were performed assuming the presence of the rail. The physical tests
were used primarily for vehicle model calibration (comparing results when driving
on asphalt).
8. capital R for ’3.5. Roll angle’
This has been corrected.
9. Appendix H is not used the text.
We meant to name it Appendix A, we corrected the mistake.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThis research explores how a conductive Electric Road System (ERS) rail influences vehicle dynamics and stability through simulations and real-world testing. Different vehicle models, road friction conditions, and driving maneuvers were analyzed to assess lateral motion, braking efficiency, and ride comfort. The results indicate that while the ERS rail slightly affects vertical acceleration and braking distance, it does not significantly impact overall stability. However, at high speeds with low skid resistance, discomfort may be noticeable. These findings emphasize the necessity of optimizing skid resistance to ensure safe and effective large-scale implementation of ERS technology. The paper is well written and has clear logic.
- It is recommended to add a logical framework diagram at the beginning of Section 2 to illustrate the overall structure of the paper, making it easier for readers to understand the content.
- Since this study focuses on the impact of Electric Road System (ERS) modeling and simulation on vehicle dynamics and stability, the beginning of the testing section should emphasize the simulation scenarios and the rationale behind key test parameter settings. It should clearly describe how the study investigates the effects of ERS modeling and simulation on vehicle performance.
- The author only tested the double lane-change scenario. Would it be possible to include additional test conditions to ensure the generalizability of the research findings?
- The model calibration section should include additional result figures comparing the dynamic responses of the simulation model and the real vehicle to illustrate their alignment.
- The background section should emphasize the rapid development of SUVs in recent years and provide relevant references to highlight the significance of investigating their dynamics characteristics. The related work can refer to “A Decentralized Cooperative Control Framework for Active Steering and Active Suspension: Multi-Agent Approach, IEEE Transactions on Transportation Electrification, vol. 8, no. 1, pp. 1414-1429, March 2022”.
Author Response
1. It is recommended to add a logical framework diagram at the beginning of Section 2 to illustrate
the overall structure of the paper, making it easier for readers to understand the content.
- We have added a logical framework diagram (Figure 2) in Section 2, after line 204,
to enhance the clarity of the paper’s structure.
2. Since this study focuses on the impact of Electric Road System (ERS) modeling and simulation
on vehicle dynamics and stability, the beginning of the testing section should emphasize the sim-
ulation scenarios and the rationale behind key test parameter settings. It should clearly describe
how the study investigates the effects of ERS modeling and simulation on vehicle performance.
- In Section 2.4, we have listed the two testing scenarios (braking and double lane
change maneuver). In Section 2.5, we have detailed the parameters analyzed to
study the rail’s impact on vehicle dynamics. Appendix A presents the parameters
modified in the Scanner software to match the simulation results with the physical
test data.
3. The author only tested the double lane-change scenario. Would it be possible to include addi-
tional test conditions to ensure the generalizability of the research findings?
-In addition to the double lane change test, we also conducted emergency braking
tests, with the results presented in Section 4. A wide range of testing scenarios
was carried out to reflect real-world road driving conditions. We varied two key
parameters: speed (50, 70, 90, 110, and 130 km/h) and skid resistance, representing
different rail surface conditions—from dry (SFC = 0.6) to slippery surfaces such as
those encountered in rain or snow slush (SFC = 0.2 and 0.3).
4. The model calibration section should include additional result figures comparing the dynamic
responses of the simulation model and the real vehicle to illustrate their alignment.
- Different outputs were compared to calibrate the simulation model. However,
to avoid overwhelming the article with figures, we only included two key parame-
ters—braking distance and lateral acceleration—in the manuscript. we added this
information at line 349.
5. The background section should emphasize the rapid development of SUVs in recent years and
provide relevant references to highlight the significance of investigating their dynamics character-
istics. The related work can refer to “A Decentralized Cooperative Control Framework for Active
Steering and Active Suspension: Multi-Agent Approach, IEEE Transactions on Transportation
Electrification, vol. 8, no. 1, pp. 1414-1429, March 2022”.
- While the focus of this paper is not on SUV development, we acknowledge that the
study may impact SUV stability. The paper briefly mentions active safety systems
like ABS, which were active during both the simulation and on-track tests, see
section 2.4 and Appendix A.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI propose to add a statement that the stability of a mechanical system in the sense of Lyapunov is not considered. There are a number of inaccuracies in Rajamani's (2012) book from a mechanical point of view, but I do not wish to elaborate on these inaccuracies.
To clarify note 4 - It should be added that there was not an optimisation process but only a comparison of the result from the real object with the results of the model - the simulation. The comparison is not an optimisation process.
Author Response
Comment:
I propose to add a statement that the stability of a mechanical system in the sense of Lyapunov is not considered. There are a number of inaccuracies in Rajamani's (2012) book from a mechanical point of view, but I do not wish to elaborate on these inaccuracies.
To clarify note 4 - It should be added that there was not an optimisation process but only a comparison of the result from the real object with the results of the model - the simulation. The comparison is not an optimisation process.
-Response: Thank you for your suggestions. We appreciate your engagement with our work.
We chose not to use Lyapunov stability in our analysis because, in our view, it is not well suited to the specific nature of our application. For instance, under Lyapunov's definition, the system could be classified as unstable even in the absence of the rail, particularly during dynamic maneuvers such as a double lane change. In such cases, although the vehicle may start near an equilibrium point, it will inevitably deviate from it due to the nature of the maneuver itself. Instead, we adopted the stability perspective presented by Rajamani (2012), which emphasizes safety under realistic driving conditions—even in scenarios that would be considered Lyapunov unstable. We found this approach more appropriate for addressing our research objectives.
While we acknowledge that Rajamani’s book may contain some mechanical inaccuracies, we do not find it necessary to elaborate on these, as they do not affect the central findings of our analysis.
Regarding the suggestion to explicitly state what the article does not include, we believe that a scientific paper should focus on clearly defining its scope and methodology, rather than enumerating all aspects that are outside its scope. Our paper does not claim to adopt Lyapunov’s definition of stability, nor to implement an optimization-based approach, and we believe this is sufficiently clear from the context. Therefore, we prefer to maintain the current structure.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe author has addressed my concerns well. However, the author should add more description to highlight the advantages and limitations of the proposed method. In addition, the reference we mentioned last round can be added to the background review for describing vehicle stability control.
Author Response
-comment: The author has addressed my concerns well. However, the author should add more description to highlight the advantages and limitations of the proposed method. In addition, the reference we mentioned last round can be added to the background review for describing vehicle stability control.
-Response: We added at line 69 the following ( By evaluating the system’s safety performance through simulations, this paper takes advantage of the fact that simulations are risk-free, allow for a wide range of testing scenarios, and enable easy manipulation of system parameters. However, simulations have limitations—they do not accurately capture driver behavior or certain road characteristics, such as surface unevenness and variability in road adhesion. The absence of these real-world factors highlights the importance of conducting on-road testing, which is planned for a later stage of this project to account for all relevant inputs affecting vehicle dynamics.)
We added at line 136 citing the proposed reference 'Modern vehicles are equipped with multiple active safety functions designed to enhance stability and control, particularly during risky maneuvers \cite{liang2021}. Accordingly, two vehicle models from the SCANeR 2023.3 database were selected to closely match the characteristics of the two instrumented vehicles regularly'