Research on Ride Comfort and Driving Safety under Hybrid Damping Extension Control for Suspension Systems
Round 1
Reviewer 1 Report
The main improvement of this submission with respect to the previous submission is the presentation of some numerical results carried out using the ve-DYNA software. A reference about this software has to be included.
The numerical results improve the quality of the paper, but the presentation is poor. There are too many figures. In time domain plots the various cases connot be distinguished. In frequency domain plots the various case cannot be distinguished at high frequency.
There are still many typos.
For a mechanical engineer the relationship between the models and the equations is not very clear.
Author Response
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Reviewer 2 Report
I am not sure that in table 1 the dimension kg.m^2 used for stiffness is right. Usually they use N/m or kN/m.
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Reviewer 3 Report
This article focuses on ride comfort and safety using S-GH hybrid damping extension control for semi-active 2-DOF suspension system and validated by MATLAB/Simulink and ve-DYNA softwares. The theory of extension is suitably presented. The results are acceptable.
I am glad to say that this paper might be considered for publication.
Author Response
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This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
An interesting suspension control is presented. An extension control method is proposed for switching between three control modes (sky-hook, Hybrid and ground-hook).
The authors should improve the description of the method.
In particular:
it is difficult to find a correspondence between eq. 5 and figure 2, and between eq.38 and figure 11. References about the application of extension control in the field of suspensions should be quoted, e.g. H. Wang: Enhancing vehicle suspension system control performance based on the improved extension control Advances in Mechanical Engineering, 2018, Vol. 10(7) 1–13 More details about extension theory should be given.Does road excitation (eq. 40) take into account the phenomenon of tire filtering?
English language has to be improved.
Author Response
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Reviewer 2 Report
Dear Authors, below please find some comments for manuscript improvement:
What is the superiority of the proposed extension control method with respect to simple lookup table or rule base? The motivation for using the extension function is not convincing. Switching between different controllers under dynamically changing environment is not novel. Previously, many scholars used simple if-then rules, not to mention more complicated algorithms, to switch between the domains, whose improvement were experimentally validated. Please also analyze available patents (e.g. Tenneco Automotive, etc.)
A simple 2-DOF suspension model is a very strong approximation. I would recommend the authors to test the method on more complicated model.
Minor remarks:
Several variables used in the equations are not explained.
Figure 1: what is ECU?
Figure 3: it is not allocated, which plot corresponds to which frequency response? Please add letters a-c. The same applies to Figure 5,14, etc.
Section 4.1: the references, from where the description of the extension theory taken, should be mentioned.
How to define the parameters of extension controller?
Lines 227-229: it is impossible to have a tire deformation equal to 0. Hence, the desired value (Figure 6) of the tire radius equal to 0 is not logic. What is the initial tire deformation value?
Figure 16: the output signals are highly frequent. The actuator has a significant delay, thus, these signal plots are not realistic.
Section 5: it turns out that the sky-hook and extension control have no significant difference in performance. It is expected to observe pitch and heave accelerations/forces.
Author Response
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Round 2
Reviewer 1 Report
The paper has been improved taking into account my suggestions.
The description of figure 3 has to be improved. What is the meaning of high vibration?
Please define acronyms (BESS line 56).
English Language has to be improved, expecially at lines 10, 32, 65, 438, 439 and 443.
There are some formatting errors: lines 149, 249, 276, 369, 408, 409.
Reviewer 2 Report
Dear Authors, below please find some comments:
The authors state: “Whether simple lookup method or rule base method is adopted, numerous calibrations are inevitable, therefore theirs design process are time and effort consuming which is not suitable for the vehicle suspension design…” Furthermore, the authors state: “Because all of the parameters [in extension theory] are empirical parameters which adjusted by the repeatedly adjusted simulation, it is difficult to define these parameters precisely…”. Finally, the authors state: “…the number of calibrated parameters under extension control is less than that of two methods…” Referring to Section 4, the calibration of the extension theory is very complicated in comparison to the existing methods. Moreover, as the authors point out, it is difficult to define the extension method’s parameters precisely. Hence, in practice lookup tables and rule-based approaches are indeed suitable for vehicle suspension design. In short, the motivation for using the extension theory and its advantage with respect to other methods for suspension control is not convincing.
Adjusting ride comfort and driving safety performance for a vehicle suspension is not novel idea.
The authors state: “…if we adopt more complicated model, the extension controller will become so complicated that the time-delay phenomenon will have a bad effect on suspension system…” It automatically means that your solution does not have a practical application. The real suspension system is not 2-DOF, it is a more complicated model.
The authors will have to design the extension controller (i.e. define optimal parameters) all over again before testing it on a real suspension test rig, because the used simulation model is a very strong approximation of the real dynamic plant. It also means that the proposed solution might not work at all.
