Target Tracking and Circumnavigation Control for Multi-Unmanned Aerial Vehicle Systems Using Bearing Measurements

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The problem of bearings-only target tracking and circumnavigation control for multi-UAV systems is considered. The problem statement is formulated. Circumnavigation and target state estimation algorithms employing Kalman filter are considered. Simulation results for different speed targets are discussed.

Remarks

·    Line 106, expression (2): The characteristic of bearing measurement errors has not been entered.

·    Line 250, expression (30): It is necessary to enter linear measurement errors  and describe their properties.

·    Line 320: The state vector includes accelerations, but the control inputs (line 95, expression (1)) are only absolute velocity projections. It is not clear why accelerations are included in the state vector.

·    Line 320: It is necessary to describe a state vector having a dimension of 6×1.

·    Line 321: The dynamic matrix for a discrete system corresponds to the solution a of differential equations system for a selected state vector, the matrix for process noise does not. It needs to be fixed.

·    The dynamic and process noise matrices must be disclosed, they must have a dimension of 6×6 and 6×2, respectively.

·    Lines 321 and 251, expression (31): There are no terms describing control inputs in the dynamic models.

·    Line 322: The matrix H of dimension 2×6 must be written explicitly.

·    Line 322: Instead of the matrix H, there should be a nonlinear function describing the dependence of the measurement vector on the state vector.

·    Line 327: The matrix of measurement error covariances R has a dimension of 6×6, however, the measurement vector Z (line 322) is a 2×1 vector, since only the coordinates of the location are measurements. The dimensions must be agreed upon.

·    Line 327: It is necessary to explain the proposed type of the covariance matrix R.

·    Line 327: The a priori covariance matrix of the state vector at the initial time  is given as an identity matrix. It is necessary either to explain this choice, or to correct the value of  .

·    It is necessary to supplement the list of references by adding the most significant works related to the paaper of tracking using bearing data, such as the work of the world's leading specialist Yaakov Bar-Shalom.

Editorial remarks

·    Line 2: The abbreviation UAV is used, but it is entered only in line 5.

·    Lines 3, 62, 153: The abbreviation PI is used, but it is entered only in line 193.

·    Line 103: the extra word “the”.

 

Author Response

Dear Reviewer,

Thank you very much for your valuable comments. We have made careful revision according to your comments and also made detailed responses to your comments. The responses are attached in a single PDF file.

Best regards,

Jiangping Hu

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this paper, the authors present the problem of target tracking and circumnavigation control for a multi-UAV system. The authors design an adaptive control algorithm for  solving the problem. The idea is to use  the bearing measurement. First,  the authors give the problem statements and definitions. Second, the distributed estimation and algorithm is presented. Third, the local information is estimated by using Kalman filter. Finally, simulation results are given to show the effectiveness of the proposed method.

Theoretically speaking,the distributed circumnavigation control is not a new method. Using Kalman filter is not your contribution. The authors should state theire contributions clearly.

Technically speaking, the authors use the bearing measurement for the control. It is feasible. 

 

The authors may consider the following points when revising the paper.

1) In the introduction section, the authors should mention that the collision aovidance is a keypoint in the problem and cite the following papers.

(a)Critical Design and Control Issues of Indoor Autonomous Mobile Robots: A Review, M. A. K. Niloy et al., , in IEEE Access, vol. 9, pp. 35338-35370, 2021

(b)Collision avoidance of multi unmanned aerial vehicles: A review,S Huang, RSH Teo, KK Tan,Annual Reviews in Control 48, 147-164,2019

2)In the introduction section, please state your contributions clearly.

3)Please give the maximum possible numbers of the UAVs for the formation. 

4) From (1), you consider only 2D system. This implies that your algorithm cannot be used in 3D case. Please explain this point.

5)For the collision avoidance, I cannot find Eqs (4)-(6) can achieve it. Please give your explanation.

6) In the simulation, please add the distance between any two vehicles.

 

 

 

Author Response

Dear Reviewer,

Thank you very much for your valuable comments. We have made careful revision according to your comments and also made detailed responses to your comments. The responses are attached in a single PDF file.

Best regards,

Jiangping Hu

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

see attached file

Comments for author File: Comments.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this paper, the authors design a targe tracking and formation control. In the previous version, I suggest several points for possible revision. In the revised version, the authors have given all responses following my comments. I am satisfactory at the current version.