Research on the Model Predictive Trajectory Tracking Control of Unmanned Ground Tracked Vehicles

Round 1

Reviewer 1 Report

This study develops a model predictive trajectory tracking control of unmanned ground tracked vehicle. This manuscript has interesting content and clear structure. But before the manuscript can be accepted, the following issues need to be addressed, as (1) The contribution points are not clear and should be rewritten by comparing with current advanced methods; (2) For the MPC in the introduction section, the author lists many literature, but should summarize the research difficulties; (3) In equation (1), the definitions of B, b, wc, vR, and vL are not provided; (4) Due to the lack of specific error numerical analysis, the author should refer to the error numerical methods in fixed-time disturbance observer-based robust fault-tolerant tracking control for uncertain quadrotor uav subject to input delay; (5) Improving the Rate of convergence of the system can enhance the control performance of the system. The author can discuss relevant literature like antisaturation adaptive fixed-time sliding mode controller design to achieve faster convergence rate and its application, to enrich the background of the article and give future research directions; (6) This article should add a “Remark” to discuss the research significance of this study.

Minor editing of English language required

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Interesting concept in general terms and overall a good state-of-the-art review and introduction. I would like to make some comments to improve the quality of the presented article. Please find attached below a list of recommendations:

Line 11. To be consistent, pleas write Model Predictive Control (MPC) in the same way throughout the text. For instance, always using uppercase letters at the beginning of each word. During the text it appears as model predictive control and Model Predictive Control.

In equation 1, to express the general motion equation, a constant should be added to consider that the vehicle does not necessarily start from the origin of coordinates with a heading angle equal to zero.

2 Kinematics Model of UGTVs. The definition of the equations of this dynamical system is redundant and not very appealing for the reader. For instance, equations 2 and 3 represent the same equation, but written differently. Apart from that, these equations are just the derivative of equation 1. I believe this section should be written more concisely.

The same happened when authors discretize in time the set of equations and express the linearization with respect to the reference point.

3.1 Trajectory tracking control system scheme. Again, the notation is quite redundant and a briefer description I think it would improve readability. State space representation of a dynamical system is not a contribution of this work, and it is not necessary to explain all the steps of the discretization.

3.2.3 In the objective function why did not you add a parameter to weight the influence between control effort and the deviation from the reference tracjectory. It would be interesting to analyze how could this affect the controller. For instance, depending on the configuration, we could have a more aggressive controller that applies the maximum inputs to minimize the error or a smoother one.

Besides it would be interesting analyzing other parameters such as settling time, steady state error and overshoot of different configurations and speeds.

I find Equation 39 again redundant.

4 Experimental study.

It would be interesting knowing the accuracy of the RTK system employed, especially in the considered test, as the accuracy of these devices may depend on the day (due RTK availability) or other factors such as signal strength.

Regarding the reference position of the platform how did you obtained it, did you directly used the RTK measurements as the estimation or did you processed them with a statistical filter. For instance, a Kalman filter with the dynamical model of the cart would improve data smoothness and even accuracy.

It would be interesting as well to make an assessment of the performance of the system depending on RTK capabilities and develop error metrics such as mean error in steady state, or overshoot during settling to quantify how does this factor affect the reliability of the system.

There are some phrases during the text which are not very well cohesioned, such as for instance in line 516. Please revise the text carefully.

Conclusions should be written using past tenses.

 

 

There are some phrases during the text which are not very well cohesioned, such as for instance in line 516. Please revise the text carefully

 

Conclusions should be written using past tenses.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx