Attitude Control of Vehicle Based on Series Active Suspensions

Round 1

Reviewer 1 Report

The large body motions produced by harsh road disturbances will seriously affect the performance of visual-based perception and localization systems. The paper proposed a potential valuable attitude control to eliminate external body motions of vehicle by using series active suspensions. A model predictive control method considered the differences between the simulated and real vehicle and the performance restrictions of actuators were used to reduce the heaving, pitching, and rolling motions of the vehicle. A second-order low-pass filter is also introduced into the series active suspension for solving the difficulty of speed control modeling of the electric servo actuator.

1. This article shows a valuable work. The simulations and experiments proved the effectiveness of the controller. Several editorial errors can be identified such as unification of spaces.I suggest the author proofread the format again.

2. The references can be expanded to describe the significance of the study in this manuscript, such references can be added as follows.

[1] Reinforcement learning control for the swimming motions of a beaver-like, single-legged robot based on biological inspiration

[2] Learning Robotic Skills through Reinforcement Learning

[3] Neural network-based motion modeling and control of water-actuated soft robotic fish

[4] Constrained Predictive Tracking Control for Unmanned Hexapod Robot with Tripod Gait

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

1.            It is quite unusual to mention research institutions of the cited authors in the manuscript. Consider removing them. It is also unusual to include the names of researchers in addition to their last names. Consider removing the names from the text and leaving only the last names. Of course, leave the names in the bibliography (References).

2.            Line 101 - results without capital letter.

3.            On page 5, the actual matrices A, B, C, and D are not listed. The actual model (matrix parameters) should be available to the reader and can be placed in the appendix or in an online data repository.

4.            In line 174, I would prefer to write, "The selected road conditions ... are relatively rough.".

5.            Figure 4: Why is the x-axis time and not distance? The same is true for figures 5 and 6.

6.            Figure 6: Here the height of the road surface is shown. Consider that the change in the lower elevation position of the wheel cannot follow the pavement elevation because of the circular shape of the wheel. This is very important because the wheel cannot follow the elevation shown. Please investigate this carefully and repeat the investigation (rewrite the paper) accordingly.

7.            Section 4: In the simulations, the entire tested model including the controller should be available to the reader online. Consider including it in the appendix or posting it in an online data repository.

8.            Line 418-419: I do not think lower improvement is a problem. In reality we always deal with some non-modelled dynamics and constraints, so the experimental results are still very good and similar enough to the simulation results.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript discusses attitude control of the experimental vehicle, taking into account today's interest in mobile robotics and autonomous vehicles, this paper will definitely be interesting for the readers.  

The research work is well done, and the manuscript is well prepared. It has a logical structure and is easy to read. The introduction has a proper background analysis, and the research gap is clearly outlined. The methodology describes methods used for research and the results are clearly presented based on simulation and real experiments.  The conclusions answer the research question. 

I suggest accepting the current manuscript to be a part of MDPI Actuators. 

Dear Authors, please change the paper template before final submission.

Author Response

Dear reviewer, we would like to thank you first for all the positive comments of our manuscript. According to your comment, we have thoroughly checked and changed the paper template.

Reviewer 4 Report

Equation (6) in wrong.

Table 6 Peak average reduction ratio 2x under three kinds of road surfaces  ? incorect names of columns.

incorrect references to drawings

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Authors have responded to all of my comments. I have ho further questions and I feel that the paper can be published.