A Steering-Following Dynamic Model with Driver’s NMS Characteristic for Human-Vehicle Shared Control

Round 1

Reviewer 1 Report

The paper is interesting and innovative. It presents an interesting and valid scientific ground for future research on cooperative automated driving.

The authors state that "In light of our literature review by far, there are only a few of studies involved in the following aspects." Well, if only a few studies involved these aspects, a more comprehensive framework could be provided regarding the literature review, perhaps presenting all the studies or, at least, citing them.

Several issues were found regarding the English writing (e.g., "For L3 AV, driver is required to take over the control authority of vehicle only if automation system disengaged in case of emergency situation.").

It is not clear whether this affirmation is the authors', or if it is a citation: "By investigating the influence of haptic aids on the pilot NMS response, an
online estimator of time-varying NMS dynamic method based on Recursive Least Squares is proposed [4]-[5]." If it is an affirmation from the authors, the text should be re-written to convey the idea that the authors based this proposal in references 4 and 5. Furthermore, if it is an affirmation from the authors, this sentence should be eliminated or put closer to the affirmation of the rest of the objective of this paper, (lines 76 to 79) so that the information does not appear scattered nor duplicated.

The use of the first person should be avoided. The use of the passive voice is preferable.

Author Response

Revision Report (applsci-726377)

Dear Reviewer:

Thanks for your review on our manuscript entitled ‘A Steering-Following Dynamic Model with Driver’s NMS Characteristic for Human-Vehicle Shared Control’ (ID: applsci-726377). We appreciate your feedback which is valuable and very helpful for revising and improving our paper.

We have checked the list of comments carefully and have completed a minor revision. We also performed a thorough proof-reading for possible spelling and grammatical errors in the manuscript. The revision is highlighted with red fonts in the revised manuscript. All the issues required by the reviewers have been addressed. The detailed responses to the questions are given below.

 

Comments by Reviewer #1

1．The authors should add comparison parameters between the estimated and observed values, together with statistical inference tests that prove that there are no strong differences between the data.

Thanks for this comment! For verify the rationality of estimated and observed results as request，we make some revision in the manuscript. On one hand, we validate the model identification results reasonable by explaining the range of estimated values, which has been added on lines 365-366. On the other hand, a key analysis on driver 1 has been added to verify the rationality of estimated and observed values apart from the comparisons of three drivers with covariance analysis, as marked in red in 397-415:

In order to verify that the model can observe the driver’s NMS characteristics, the principle of covariance is utilized to analyze the correlation between the actual and observed value of subject 1. From the statistical principle, the larger  value represents the higher degree of data fusion between two groups.

                                      The formula is in the attachment          (44)

where，  and  represents the initial value and the estimated value which characterizing the subject at time t respectively;  and  refers to the mean value of the initial value and estimated value respectively.

Table 5. Covariance comparison analysis for the actual value and UKF estimated value

NO.	Parameter	Coefficient	NO.	Parameter	Coefficient
1	Lateral speed	0.8621	9	Steering assistance torque	0.7156
2	Yaw rate	0.8246	10	Motion of leg	0.82323
3	Lateral offset	0.7653	11	Movement speed of leg	0.74421
4	Yaw	0.8956	12	Pedal torque	0.7021
5	Steering wheel angle	0.8663	13	Leg contraction torque	0.74421
6	Steering wheel angular rate	0.8421	14	Leg tendon motion	0.746
7	Arm active contraction torque	0.73421	15	Pedal position	0.716
8	Steering wheel torque	0.8646

As shown in table 5, fifteen correlation coefficients between the actual value and UKF estimated value are calculated with covariance analysis. From the analysis, all the coefficients greater than 0.7, which indicated that the parameter identification, as well as the UKF observer we proposed, have significant precision.

The figure is in the attachment 

Figure 12. Covariance analysis of each subject’s state value

Furthermore, for proving the model’s practicability of reflecting the personalized driver characteristics, the actual value of subject 1 is compared with three subjects’ estimated values. The covariance analysis results in Figure 12 is normalized for visualization. It is can be found that the histogram of subject1 has the highest covariance with the initial state vector. Finally, we can deduce that the HVSC dynamic model we proposed can represent the evolution of personal characteristics.

We have further elaborated the correlation by rewriting this part on 365-412 lines in the manuscript.

Author Response File: Author Response.docx

Reviewer 2 Report

The article is well structured, it is clear in reading, and written with methodological rigor.
the authors should add comparison parameters between the estimated and observed values, together with statistical inference tests that prove that there are no strong differences between the data.

Author Response

Revision Report (applsci-726377)

Dear Editor and Reviewers:

Thanks for your review on our manuscript entitled ‘A Steering-Following Dynamic Model with Driver’s NMS Characteristic for Human-Vehicle Shared Control’ (ID: applsci-726377). We appreciate your feedback which is valuable and very helpful for revising and improving our paper.

We have checked the list of comments carefully and have completed a minor revision. We also performed a thorough proof-reading for possible spelling and grammatical errors in the manuscript. The revision is highlighted with red fonts in the revised manuscript. All the issues required by the reviewers have been addressed. The detailed responses to the questions are given below.

 

Comments by Reviewer #2

1．The authors state that "In light of our literature review by far, there are only a few of studies involved in the following aspects." Well, if only a few studies involved these aspects, a more comprehensive framework could be provided regarding the literature review, perhaps presenting all the studies or, at least, citing them.

Thanks for your review! To the best of our knowledge, published studies involved in human vehicle shared control model have been added to literature review, as shown in line 45-63.

 

2．Several issues were found regarding the English writing (e.g., "For L3 AV, driver is required to take over the control authority of vehicle only if automation system disengaged in case of emergency situation.").

Thanks for your detailed comment! We have performed a thorough proof-reading for possible English writing errors with red fonts in the manuscript.

 

3．It is not clear whether this affirmation is the authors', or if it is a citation: "By investigating the influence of haptic aids on the pilot NMS response, an online estimator of time-varying NMS dynamic method based on Recursive Least Squares is proposed [4]-[5]." If it is an affirmation from the authors, the text should be re-written to convey the idea that the authors based this proposal in references 4 and 5. Furthermore, if it is an affirmation from the authors, this sentence should be eliminated or put closer to the affirmation of the rest of the objective of this paper, (lines 76 to 79) so that the information does not appear scattered nor duplicated.

Thanks for this comment! As shown in references 4 and 5, the authors proposed that the recursive least squares algorithm can be implemented to identify the NMS characteristic. However, there are several differences between our works and them. Firstly, the human-vehicle share control model we proposed is a more complex system with multiple inputs and multiple outputs. On the contrary, the model of references 4 and 5 belongs to single-dimension steering model. Moreover, the method of recursive least squares is totally different with hierarchical least square identification algorithm we utilized in the manuscript.

We have further elaborated the difference between references 4,5 and our study on 254-259 lines in the manuscript.

 

4 ．The use of the first person should be avoided. The use of the passive voice is preferable.

Thanks for your detailed comment! We have performed a thorough proof-reading for possible spelling and grammatical errors with red fonts in the manuscript.

 

Author Response File: Author Response.docx