Cooperative Reference Velocity Regulation Control for Virtual Coupling Systems of Heavy-Haul Trains
Round 1
Reviewer 1 Report
This manuscript proposed a cooperative reference velocity regulation control method for virtual coupling systems of heavy-haul trains, which can smoothly adjust the train velocity during the operation process. Based on the cyber-physical model, a cooperative tracking control strategy is designed for braking process. Overall, this work is well organized, but some problems need to be further improved.
1. The Figure 2 should be described in detail and the font of Figure 2 should be bigger to make it more readable.
2. The Laplacian matrix of the interactive topology of velocity and distance information of each train should been constructed respectively.
3. The motivation for the introduction of SPAARP needs to be explained clearly in Section 3.2.
4. The effect of metrics RMSE, MVF and MRDF should be given in Section 4.2 to compare the performance of different methods.
5. Some expression mistakes in this paper should be corrected. For example, “The mechanical resistance rmi” in Section 2-->“The mechanical resistance rmi(t)”; “flucatuations” in Abstract--> “fluctuations”; “.” in equation (32)-->“,”; “The proposed method is evaluated using several performance metrics” in Section 4.2-->“The proposed method is evaluated using four performance metrics”.
Minor revision.
Author Response
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Author Response.pdf
Reviewer 2 Report
Figure 2: e_(i,1) should be denoted as e_(i,d), e_(i,2) as e_(i,v) in order to be consistent the given equations (13) and (15)
there is an inconsistency of the physical units for the error terms:
e_(i,v) is an velocity according (13),
e_(i,d) is a distance according (15),
so they actually cannot be added up.
I would assume that the artifical potential function (14) requires an additional multiplier term, e.g. compared to the spring constant in the elastic potential function of a spring. Such a constant would scale the two different error terms with respect to each other and could be used to fix the unit inconsistency. Maybe it is even interesting to see the influence of this error scaling on the overall result.
As regards the simulation results: it is not clear, which two methods are compared:
The text in 4.3.1 says proposed method compared to traditional method. I assume the proposed method is the method from Chapter 3, but what is the traditional method?
Figure 5 and 6 or Table 1 and 2, respectively denote a cooperative and a proposed method, but what is the cooperative method when the proposed method in Chapter 3 is called "Cooperative Precitive Reference Regulation Control"?
To some extent the answers to these questions are given (or hidden) in the introduction, but this must be additionally clarified and uniquely denoted in the simulation chapter.
Author Response
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Reviewer 3 Report
The contributions of the paper are unclear.
The state of the art needs to be greatly improved. Authors should justify why they propose this methodology. Most authors use MPC and only a few use consensus-based approaches and artificial potential fields. I suggest looking at some review papers on virtual coupling.
I have important concerns.
Firstly, how do the authors handle constraints like e.g. safety distance, maximum allowed speed, maximum power, etc.?
Secondly, the authors mention several resistances such as slope and curve, but in the simulations they apparently do not take them into account. Gradient resistance is especially important for heavy vehicles.
Furthermore. The authors do not mention the length of the train. In long heavy vehicles, length has a significant influence. How do they deal with it?
No comments
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
My concerns have been addressed. The paper is fine.
