A Time Domain Passivity Control Scheme for Bilateral Teleoperation
Round 1
Reviewer 1 Report
Please check the attachment for specific comments.Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 1 Comments
We wish to thank the reviewer for his or her comments and suggestions.
Point 1:
The manuscript is well written. However, following issues are required to be addressed.
1) In abstract, it is not clear your main contribution comparing wit previous research. Authors has to describe clearly the main contribution in this research and the reason to study this research.
Response 1:
Thank you. The abstract is re-written to highlight the contribution. Changes are highlighted in yellow in the manuscript.
Point 2:
2) References 18, 19 and 20 are not cited in the text. Cite or remove them.
Response 2:
Thank you. They are removed.
Point 3:
3) Variables are not defined in the text. Please carefully define each variable used in each equation.
Response 3:
Undefined variables are defined. Changes are highlighted in yellow in the manuscript.
Point 4:
4) Authors should explain why the function of the power flow is defined and derived as Eqs. (3) and (4). And also you should define f_mc, v_m, …, and etc., even if you refer reference[14].
Response 4:
Why the function of the power flow is defined and derived is explained. f_mc, v_m, …, and etc. are defined. Changes are highlighted in yellow in the manuscript.
Point 5:
5) Figures are not properly explained in the text. Please explain in more detail.
Response 5:
Some figures are explained in more detail. Changes are highlighted in yellow in the manuscript.
Point 6:
6) The authors should provide more detailed explanation of simulation and experimental results by adding adequate discussion about them.
Response 6:
Discussions/remarks about simulation and experimental results are added. Changes are highlighted in yellow in the manuscript.
Point 7:
7) How much did you give time delay in simulation and experiment.
Response 7:
This is already mentioned in the paper. Time delay 0.5 s is clearly mentioned in simulation and experimental results sections.
Point 8:
8) If time delay is increasing, what will be happened. Authors should explain time delay limitation for bilateral control.
Response 8:
Time domain passivity control offers the flexibility of time delay compensation for both constant and time varying delays. In this paper, we are only dealing with the constant delays so the performance of position tracking is not affected much with an increase in time delay. A significant delay of 0.5 second is tested in both simulation and experiment and the proposed control design not only guarantees the stability but provides satisfactory results of position tracking.The paragraph is added as Remark 2 in the manuscript.
Author Response File: Author Response.pdf
Reviewer 2 Report
Well done on a well written paper, a few minor grammatic adjustments are required
Line 3: "...for the guaranteed stability" -> "...for guaranteed stability"
Line 26: "... instability and safety concern" -> "... instability and safety concerns"
Line 36: ",,, with its parameter design..." -> "with its parametric design..."
Line 149: "...was utilized as the master..." -> "...were utilized as the master..."
Figures 13-14 can be combined and the "-1" and "-2" post annotations dropped, the same can be done for Figures 15-16.
Author Response
Thanks for the carefulness of the reviewer. We have corrected them all.
Reviewer 3 Report
The aim of this paper is to propose a switching passivity control architecture for bilateral teleoperation, supposedly to avoid problems related to division by zero in other schemes.
Unfortunately, the theoretical part of the paper is not well written and difficult to follow, to the extent that the contribution, if any, is obscure. The notation of the paper is not adequately defined, the previously available control schemes are not properly recalled (what is the meaning of, e.g., "A nonnegative constant b is introduced in [14], or "E is the low bounded energy", or "If TDPC [7] and [8,9] is used, etc?) The reader is lost after the first few equations. The technical development is very brief and quite confusing. The two simple conditions (13) and (14) seem to be the main improvement but the subsequent discussion on page 4 is obscure, as well as the conclusions "Thanks to the compensation of TDPC, the dissipations at each port are zero now". Section 4 is a bit tedious and sloppy ("One can tune b around the value that makes \zeta=0.5, as best suited to the current task". What task? Why is that choice recommended?)
All in all, the possibility of evaluating any contribution hinges upon the availability of a clearly written paper, which is not the case with the present version of this manuscript.
Author Response
Response to Reviewer 3 Comments
We wish to thank the reviewer for his or her comments and suggestions.
Point 1:
The aim of this paper is to propose a switching passivity control architecture for bilateral teleoperation, supposedly to avoid problems related to division by zero in other schemes.
Unfortunately, the theoretical part of the paper is not well written and difficult to follow, to the extent that the contribution, if any, is obscure. The notation of the paper is not adequately defined, the previously available control schemes are not properly recalled (what is the meaning of, e.g., "A nonnegative constant b is introduced in [14], or "E is the low bounded energy", or "If TDPC [7] and [8,9] is used, etc?) The reader is lost after the first few equations. The technical development is very brief and quite confusing. The two simple conditions (13) and (14) seem to be the main improvement but the subsequent discussion on page 4 is obscure, as well as the conclusions "Thanks to the compensation of TDPC, the dissipations at each port are zero now". Section 4 is a bit tedious and sloppy ("One can tune b around the value that makes \zeta=0.5, as best suited to the current task". What task? Why is that choice recommended?)
All in all, the possibility of evaluating any contribution hinges upon the availability of a clearly written paper, which is not the case with the present version of this manuscript.
Response 1:
Sections 2, 3, and 4 are carefully revised. The theoretical part of the paper is re-written to make the contribution clear. The notation of the paper is defined more clearly and the previously available control schemes are properly recalled. Changes are highlighted in yellow in the manuscript.
what is the meaning of, e.g., "A nonnegative constant b is introduced in [14]”
b is a nonnegative constant, and it is introduced for the derivation of Eqn. (4) from Eqn. (3). This is a technique used in [14].
"E is the low bounded energy", or "If TDPC [7] and [8,9] is used, etc?)
f is the force applied on an object, and v is the resulted velocity. Then P=fv is the power. Suppose that E is the energy stored in the object, and Pdiss is the power dissipation of the object. Then based on the energy conservation principle, we have Eqn. (1). "If TDPC [7] and [8,9] is used, etc?) is changed to “If the conventional TDPC in [7,8,9] is used”.
The reader is lost after the first few equations. The technical development is very brief and quite confusing. The two simple conditions (13) and (14) seem to be the main improvement but the subsequent discussion on page 4 is obscure, as well as the conclusions "Thanks to the compensation of TDPC, the dissipations at each port are zero now".
Section 3 is revised and re-segmented. The subsequent discussion is made clear. Particularly, “Thanks to the compensation of TDPC, the dissipations at each port are zero now” is changed to “Comparing (17) and (18) with (1), the dissipation at each port Pdiss=0.”
Section 4 is a bit tedious and sloppy ("One can tune b around the value that makes \zeta=0.5, as best suited to the current task". What task? Why is that choice recommended?)
Section 4 is revised and separated into 3 subsections. b should consider the demands from both sides of the teleoperation system. For a second-order system, a \zeta around 0.5 generally makes the flat part of the magnitude response the widest, as shown in Fig. 3, which is the consideration from the slave side. The choice of b should also cater for the master side demand. By observing the master side in Fig. 1, one can see that b serves as a damper to the operator. High values of b mean strong resistance to the motion of the operator’s hand. Small values of b result in quick moves. To balance the demands from both sides, one can tune b around the value that makes \zeta=0.5 to achieve the best teleoperation experience.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The reviewed manuscript was edited according to reviewer.
But, some issues are not corrected yet.
So, authors should rewrite again one more time precisely as follows:
1.The explanation for main contribution and purpose of this research is weak and unclear yet in introduction. So, authors has to edit more to clarify the contribution.
2. Authors did not give the information of a maximum available time delay. You just give 0.5 second time delay in simulation and experiment. If time delay is increased over 0.5 sec, authors survey and describes what will happened.
3. What is the zeor division? You have to define and explain exactly at Chapter 2. of the manuscript.
4. What is Chapter 8. Authors Contributions. I think that it is not necessary to present like that way.
Author Response
As attached.
Author Response File: Author Response.pdf
Reviewer 3 Report
Despite some effort by the authors to improve the manuscript with respect to the previous version, this paper still needs to be substantially improved before its contribution can be evaluated.
This reviewer is still quite concerned with the development of the theoretical part in Section 2. In particular, there is still a lot of confusion between the review of the standard TDPC (11)-(12) and the presentation of the proposed scheme. More specifically, all derivations (i.e., eqs. (4)-(8)) are made in the presence of the dampers (b, 1/b) at the master and the slave sides, respectively. Then, the PO is introduced and the formulas (11)-(12) for f_d and v_d are derived. Such expressions contradict, e.g., the expression f_d = b v_m used previously. What the authors are trying to explain here can be guessed but the way it is presented is extremely unclear. Furthermore, an explanation of the expression (7) of stored energy is required (i.e., why (7) represents stored energy). This section should be completely reworked and expanded. Section 3 is now more clear.
Author Response
As attached.
Author Response File: Author Response.pdf
Round 3
Reviewer 3 Report
The revised manuscript looks fine now.
