Control Strategy of Speed Segmented Variable Constant Power Powertrain of Electric Construction Machinery
Round 1
Reviewer 1 Report
Formulas (2) and (3) describe the operation modes of variable pumps with simple almost constant power controllers like type A10VO LA... by Rexroth. Some producers (including Rexroth) offer variable pumps with true constant power controllers (with nonlinear relationship between pressure and displacement setting).
On the Fig. 3 has shown a 3-way proportional reducing valve. Two of valve's connection are closed, third is connected to tank. So the acting of this valve on the setting of a constant power valve is negleted due no powering.
The quality of Fig. 4 should be improved - too low resolution.
The boxes of load steps on flowchart shown on Fig. 6 have same desriptions for different system pressures.
"Variable constant power valve" shown on Fig. 7 can be an element of real constant power controller only if the pump displacement setting will be a input signal for control the proportional pressure reducing valve, of course together with the delivery pressure signal.
The excess actual flow rate observed around 7, 11 and 14 seconds of the simulation should be eliminated by the automatic decrease of the pump displacement setting from the LS valve acting.
Same effect can be observed on Fig. 12.
The charts shown in fig. 13 and 14 are very small and reader must significantly zoom them.
The sentence given in lines 536 and 537 is contradictory, the discharge pressure cannot increase and decrease at the same time.
Typos on Fig. 15 (eg. "Piolt pressure measurement valve block", "Hydualic handle").
Please explain if the designation "motor judgment speed" used on Fig. 17 is equal to "required motor speed"?
The course of filtered pressure shown on Fig. 19 isn't a result of threshold filtering. But the course of control current can be accepted as a result of treshold filtering of outlet pressure.
Author Response
The manuscript has been revised according to the reviewers' comments.
Author Response File: 
Author Response.doc
Reviewer 2 Report
1. Please redraw the digram. Figure 3. Internal schematic diagram of load sensing pump.
2. Introduction is weak, please. Relook with new references
3. Results are adiquvate. However more results, particularly in transient behavior, is a must.
4. Figure 4. Constant power curve under different working conditions. and Figure 6. Schematic diagram of speed segmented variable constant power control. Also not visible clearly.
5. Show the bigger results Fig for all results. no notation is viable. very hard to read.
6. Conclusion is very vague
The work done here is much appreciated. However, the way of writing papers and showing results are very poor.
Author Response
The manuscript has been revised according to the reviewers' comments.
Author Response File: Author Response.doc
Reviewer 3 Report
This is an important research topic. The article requires an extension of the introduction with systems reducing energy consumption. Several papers have been proposed, and so far the authors have used only scientific papers whose authors are scientists from Asia. The proposed control concepts are well and precisely described, but the figures are completely illegible, making the analysis difficult. Minor changes to the conclusion are also required. The abstract should contain numerical values describing the benefits obtained, not only the general nature of the changes. In the first paragraph of the introduction, the authors may also refer to the results of research on emissions and energy consumption of machines used, among others, in construction, e.g. Small engine machines used to build road infrastructure (exhaust emissions due to the fuel supply system and fuel type - gasoline, LPG, CNG): Warguła, Ł., Lijewski, P., & Kukla, M. (2022). Influence of non-commercial fuel supply systems on small engine SI exhaust emissions in relation to European approval regulations. Environmental Science and Pollution Research, 1-16. Emissions from construction machinery: Tu, R., Li, T., Meng, C., Chen, J., Sheng, Z., Xie, Y., ... & Liu, Y. (2021). Real-world emissions of construction mobile machines and comparison to a non-road emission model. Science of The Total Environment, 771, 145365. In the second paragraph on traditional internal combustion engines, the authors may add information about other energy-reducing systems, such as: - Disabling the work of selected cylinders Zsiga, N .; Ritzmann, J .; Soltic, P. Practical Aspects of Cylinder Deactivation and Reactivation. Energies 2021, 14, 2540. - change of rotational speed during idle operation Warguła, Ł .; Krawiec, P .; Waluś, K.J .; Kukla, M. Fuel Consumption Test Results for a Self-Adaptive, Maintenance-Free Wood Chipper Drive Control System. Appl. Sci. 2020, 10, 2727. https://doi.org/10.3390/app10082727 Choosing more effective working mechanisms: Spinelli, R., Cavallo, E., Eliasson, L., Facello, A., & Magagnotti, N. (2015). The effect of drum design on chipper performance. Renewable Energy, 81, 57-61. https://doi.org/10.1016/j.renene.2021.09.039 Improving the processes and working conditions carried out by machines: Rymaniak, Ł., Lijewski, P., Kamińska, M., Fuć, P., Kurc, B., Siedlecki, M., ... & Jagielski, A. (2020). The role of real power output from farm tractor engines in determining their environmental performance in actual operating conditions. Computers and Electronics in Agriculture, 173, 105405. Savickas, D .; Steponavičius, D .; Špokas, L .; Saldukaite, L .; Semenišin, M. Impact of Combine Harvester Technological Operations on Global Warming Potential. Applied Sciences 2021, 11, 8662 Savickas, D .; Steponavičius, D .; Domeika, R. Analysis of Telematics Data of Combine Harvesters and Evaluation of Potential to Reduce Environmental Pollution. Atmosphere 2021, 12, 674. Paragraph about electric construction machines, I understand that they are zero emission, but do they work with the same power range? Are eclectic machines usually not less powerful? Are the power ranges of combustion engines (machines) available for machines with electric engines? For example, in chain saws or rescue fans, commercial electrical appliances are half the wattage. Second, can electric machines run more than 12 hours a day, as is often the case with internal combustion machines? It seems to me that in some aspects machines with an electric motor are better, but it is also necessary to mention their imperfections in relation to internal combustion machines. Fig. 4 - the drawing needs to be improved is very illegible. Fig. 6 - needs improvement it is illegible, it is too small. Fig. 7 - needs improvement it is illegible, it is too small. Fig. 10 - needs improvement it is illegible, it is too small. Figs. 11, 12, 13, 14, 15, 16 - needs improvement it is illegible, it is too small. Fig. 17, 18, 19, 20 - very very illegible Text or symbols in many drawings are unreadable. Conclusions Suggest further research directions, indicate the limitation of your analyzes.
Author Response
The manuscript has been revised according to the reviewers' comments.
Author Response File: Author Response.doc
Round 2
Reviewer 2 Report
Thanks for the improvement of the paper.
Reviewer 3 Report
The article has been corrected in line with the comments.
References have small editing errors: "[J]" or "[C]" brackets appear at the end of journal names at the end in many places
There are also mistakes in the abbreviations of the names and surnames of the authors of the articles, e.g. from item No. 1 is "Warguła U." and it should be Warguła Ł.
Finally, the authors could add in abstract and conclusion numerical values indicating the range of technical parameters after applying their concepts. It can also be expressed in percentage change of parameters.
