Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper proposes a hierarchical adaptive gear shift strategy for two-speed electric vehicles to address the limitations of fixed-rule strategies under complex driving conditions. By introducing shift frequency and gear duty ratio to characterize transmission operating states, the study establishes a three-layer framework: driving demand evaluation, transmission behavior evaluation, and strategy matching. A fuzzy logic-based shift threshold correction is further applied to suppress unnecessary shifts. Simulations and bench tests under WLTC, UDDS, CLTC-C, and CLTC-P cycles demonstrate that the proposed adaptive strategy effectively balances energy efficiency and dynamic performance while reducing shift frequency compared to conventional economic or dynamic strategies.

The work provides a practical solution for enhancing two-speed transmission stability and longevity. However, the manuscript still contains several issues related to methodology, experimental details, and grammatical accuracy that require correction to enhance its professionalism, rigor, and overall credibility.

Here are some suggestions for revision:

1. The literature review in the introduction lacks a critical gap analysis concerning transmission state awareness. While the paper enumerates rule-based, optimization-based, and data-driven strategies, it should more explicitly contrast why existing methods are ineffective in preventing gear shift cycling under boundary conditions and how the proposed frequency/duty indicators directly address this specific limitation.
2. Section 3.3 and 3.4 contain extensive fuzzy rule tables and membership function plots, but the rationale behind specific rule definitions is insufficiently explained. It is recommended that the authors provide further clarification regarding the basis for these specific rule definitions.
3. The paper uses a 30-second rolling window to calculate shift frequency and duty ratio, but there is no sensitivity analysis regarding this window size. It is recommended to discuss the impact of different window lengths on strategy responsiveness and stability, as this parameter significantly affects the real-time characterization of transmission behavior.
4. The simulation validation in Section 4 compares the adaptive strategy solely with the three basic strategies. To bolster the contribution claim, it would be advantageous to incorporate a comparison with at least one other state-of-the-art adaptive or predictive shift strategy from recent literature to showcase superior performance.
5. The captions and quality of Figures need improvement. Several subplots appear blurry, and the labeling of axes in the fuzzy correction characteristic plots is insufficient. High-resolution vector graphics with clear font sizes are required for publication.
6. The manuscript contains several typographical and formatting errors that detract from its professionalism. A thorough proofreading of the final manuscript is strongly advised.

Author Response

Please see the attachment.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Thnak you for this munscript, there are some comments that should be answe to improve the munscript.

1.  Please provide a comprehensive review table comparing your study with existing literature. Ensure that the specific novelties and contributions of your work are clearly highlighted in relation to the state of the art.
2.  Several legends and labels, specifically in Figure 8, are too small to be legible. Please ensure that all graphical text and legends are large enough to be easily readable in the final version.
3. The conclusion currently contains excessive detail. Please revise this section to provide a more concise and high-level summary of the paper’s findings.
4.  Please remove any unnecessary dashes (—) or inconsistent punctuation throughout the manuscript.
5. Please clarify the nomenclature used for each training cycle. Furthermore, specify whether the testing cycle differs from the training cycles, as they currently appear nearly identical.
6. Please explain the high frequency of variations in the State of Charge (SoC) curves. Since these fluctuations typically accelerate battery degradation, why did the authors not include a smoothing term or a degradation-based penalty in the reward function to achieve a smoother profile?
7. Please clarify how the authors performed the system sizing shown in Figure 1.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf