A Terminal Residual Vibration Suppression Method of a Robot Based on Joint Trajectory Optimization

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The comments can be found in the uploaded file.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Thank you for your comments. And I will respond to your comments point by point.

Comment 1: The overall organization of this manuscript needs to be greatly improved.

Response 1: Thank you for pointing this out. Therefore, the paper has been revised in accordance with the comments of the reviewers, and the revisions are marked in red.

Comment 2: Notably, the research background should be further strengthened and the descriptions of existing research should be further summarized in introduction.

Response 2: Thank you for pointing this out. Therefore, the research background and the descriptions of existing research has been modified which can be found on page 2.

Comment 3: The contributions should be refined and listed point by point to make it easier for readers to grasp the key points.

Response 3: Thank you for pointing this out. Therefore, a restatement of the innovation points has been added to the introduction on page 2.

Comment 4: In (1), the variable τ has not been defined. Additionally, there are many nonlinear expressions used to describe robot dynamics, why only linear ones are chosen?

Response 4: Thank you for pointing this out. τ is the vector of joint torque, and the definition has been added on page 3 . The nonlinear term leads to the complexity of the system phenomenon, and the model that ignores the nonlinear term is sufficient for the study in this paper.

Comment 5: Significantly, some expressions should be added with corresponding references, as they are not the first time proposed, such as:

Response 5: Thank you for pointing this out. The references to the formulas have been added to the paper on page 4 and 5.

Comment 6: In the validation section, other methods should be compared.

Response 6: Thank you for pointing this out. In the introduction, the advantages and disadvantages of various methods have been analyzed, and it is known that the input shaping method has the best practicability among the related methods, so this paper only conducts comparative experiments on the input shaping method, which can verify the advancement of the proposed method.

Comment 7: Some already existing methods, which are widely utilized these days to solve several real world problems including the described issues, multilayer neurocontrol of high-order uncertain nonlinear systems with active disturbance rejection, asymptotic tracking with novel integral robust schemes for mismatched uncertain nonlinear systems and so on.

Response 7: Thank you for pointing this out. The description of multilayer neurocontroller has been added in introduction on page 1 and line 65.

Comment 8: There are relatively few relevant references about recent

Response 8: Thank you for pointing this out. Some references to recent research have been added in page 12.

Reviewer 2 Report

Comments and Suggestions for Authors

This paper discusses the generation of optimal joint motion profiles for vibration suppression using dynamic parameters identified through an identification algorithm. Overall, the structure is well-organized, and the experimental results are well presented. The reviewer has the following questions regarding the content of the paper:

1. In Figure 7, it is observed that the amplitude of the vibrations for the optimized trajectory is higher initially compared to the results from input shaping. The reviewer is curious whether this is simply due to less optimization, or if there are other reasons.

2. The reviewer believes that the theoretical contribution of this paper is insufficient. The paper uses existing methodologies for the identification of robot parameters and the optimization process, and it needs to clarify its contributions more distinctly.

3. The reviewer thinks the trajectory used for validation is too simple. The paper has only verified the methodology on a straight trajectory, and it is necessary to emphasize the superiority of the proposed method using a wider variety of trajectories.

4. The performance comparison is made with the input shaping technique, but there needs to be more discussion on how the inputs were designed for this technique and what differences exist between the optimized profiles.

Author Response

Thank you for your comments. And I will respond to your comments point by point.

Comment 1: In Figure 7, it is observed that the amplitude of the vibrations for the optimized trajectory is higher initially compared to the results from input shaping. The reviewer is curious whether this is simply due to less optimization, or if there are other reasons.

Response 1: Thank you for pointing this out. Due to the time delay characteristic of the input shaping method, the maximum peak generated by the input shaping will lag behind the optimization method proposed in this paper at about 0.5 seconds on the same timeline.

Comment 2: The reviewer believes that the theoretical contribution of this paper is insufficient. The paper uses existing methodologies for the identification of robot parameters and the optimization process, and it needs to clarify its contributions more distinctly.

Response 2: Thank you for pointing this out. Therefore, a restatement of the innovation points has been added to the introduction on page 2.

Comment 3: The reviewer thinks the trajectory used for validation is too simple. The paper has only verified the methodology on a straight trajectory, and it is necessary to emphasize the superiority of the proposed method using a wider variety of trajectories.

Response 3: Thank you for pointing this out. In this paper, the main research object is the terminal residual vibration suppression method caused by insufficient tracking performance, and it can be seen that this problem is more significant in Cartesian space, so the typical linear motion of Cartesian space is selected as the experimental trajectory. For the trajectory that does not affect the tracking performance, the vibration effect is not obvious, so it is not selected as the experimental trajectory.

Comment 4: The performance comparison is made with the input shaping technique, but there needs to be more discussion on how the inputs were designed for this technique and what differences exist between the optimized profiles.

Response 4: Thank you for pointing this out. Therefore, corresponding modifications have been added on page 10.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The comments have been considered.

Comments on the Quality of English Language

Moderate editing of English language required.

Reviewer 2 Report

Comments and Suggestions for Authors

The response to the reviewer's comments has been thoroughly addressed.

The reviewer recommends acceptance.