Design of an Anti-Slip Mechanism for Wheels of Step Climbing Robots

Round 1

Reviewer 1 Report

The paper is interesting and the presentation is good. The following comments must be fixed before its acceptance:

1) I feel like there is a gap at page 2 (lines 59-60). The limits of the existent solutions as well as the introduction of a new system must be described better. This would help the readers to visualize your contribution.

2) The SMA acronym is firstly used at page 2 (line 60), though is defined at page 3 (line 90). Please fix this.

3) I suggest to include enlarged views of Figs. 1a-1b-1c.

4) Please check typos in Fig. 5 (Horizontal plane) and enlarge the font size in Fig. 7.

5) Please make sure to explain all the symbols employed in the formulas. Check this throughout the paper.

6) Please add a references for: i) the Lazy Tong mechanism and ii) the bi-stable four bar mechanism

7) Also, how did you select such mechanisms configurations? Please clarify.

8) I suggest to write Eq. 1 at the top and then state

“where d_P0P2=

               Phi_0=

               R_P2=

…

… ”

9) The FEA analysis in Sec. 4.1 has not been described sufficiently. Add details on the developed model (mesh, element type and size, constraints, loads, simulation steps, convergence criteria, etc.).

10) In Sec. 4.2, the authors should prove the validity of the proposed mechanism by simulating the step climbing operation.

11) Please discuss the implementation of your system on real prototypes. The method is interesting though its applicability is to be demonstrated.

12) The following papers are suggested to be cited in your introduction as they represent valid examples of hybrid mobile robots:

- Design and Research of All-Terrain Wheel-Legged Robot, published in mpdi-sensors

- Functional Design of a Hybrid Leg-Wheel-Track Ground Mobile Robot, published in mdpi-machines

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript presents a wheel design for robots to climb (up and down) stairs. In simple terms, the contribution of the paper is a bistable actuator that lets a wheel add “grooves” of two different shapes so that it can (1) climb up stairs and (2) climb down stairs in addition to moving on a planar surface. The presentation of the design is well organized; copy-editing should fix a few typographical errors. However, the main criticism is the lack of any experimental prototype. The method relies on SMA that is notorious for practical applications due to its lack of reliability. To be published in an esteemed journal like “Actuators,” this reviewer thinks experimental validation is necessary. Nonetheless, the reviewer also believes that this purely design-based manuscript can be published in other technical journals; it’s just that the reviewer’s subjective opinion is the manuscript in its current form does not meet the bar of the journal “Actuators.”

Below are a few minor points. Some of them are related to typographical and grammatical errors. Copy-editing and proofreading of the entire manuscript should fix most of these problems.

(1) Abstract: “Equations are developed to dimensionalize various members …” - It is not clear what this sentence implies.

(2) Abstract: “.. the model is found to be safe under a load of 250 N with a factor of safety of 3.025.” - The manuscript should mention the size of the model, e.g., length, width, and height. A load of 250 N is impressive for an mm-sized body but not spectacular for a meter-sized object.

(3) Line 19: “Some of the fields like surveillance, exploration, and rescue in dangerous locations (e.g. nuclear or fire disasters), deployment of robots instead of human rescuers, reduces the risk of dangers or accidents.” - This sentence is not clear.

(4) Line 29: “Researchers have developed systems based on articulated legs [4]. Complex control design algorithms are used to maneuver such robots.” - These sentences are too generic without much information. The authors may consider describing the “legs” or “complex control design” in a few words or adding their own commentary on these prior works.

(5) Captions of figure 1 and figure 2: The captions have capitalization issues. For example, the caption of figure 1 is “Working principle of Anti-slip mechanism; (a) At plane surface; ; (b) During Climbing Upon stairs; (c) During Climbing down stairs” Some words are randomly capitalized. Punctuation marks (period and semicolon) should be properly used.

(6) Line 96: “Encircled numbers attached to the links are used to denominate different links and throughout the article.” I think “denominate” should be replaced with “denote.”

(7) Line 98: “ Chain 1 and 3 are based on Lazy Tong mechanism and chain 2 is based on a bi-stable four-bar mechanism.” The paper should provide appropriate references for the Lazy Tong mechanism and the bi-stable four-bar mechanism. If they are not available, it should be mentioned that subsequent sections will describe these words. It will aid the reader in following the storyline.

(8) Figure 5: “Hrozontal” should be “Horizontal.”

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have addressed all my concerns and therefore the paper can be accepted for publication.