USAGE FEATURES OF THE ELECTRONIC INDICATORS FOR SHIP'S AND SHORE POWER _SUPPLY TWO-STROKE INTERNAL COMBUSTION ENGINES (DIESEL ENGINES)_
DOI: 10.31618/ESU.2413-9335.2020.5.73.682 Taranin Aleksandr G.
Ex.technical superintendent for trouble shooting of worldwide trading and repairing company PT. Goltens (New York, USA, branch office - Jakarta, Indonesia), Chief engineer of worldwide shipping company International Tanker Management (Dubai, UAE), PhD, docent of F.F. Ushakov State Maritime University «Ship Power Plant Operation» department
(F.F.Ushakov State Maritime University, Novorossiysk, Russia).
Tel: +7 962 861 2522
ANNOTATION
The present publication illuminate the tasks as follows: Electronic indicator proper usage at four-stroke internal combustion engines (diesel engines) indication; Indication results & diagram proper transfer to PC; indicator diagram top dead center TDC correction and engine performance data output values such as Pmi-mean indicated pressure, Pme-mean effective pressure, Nind-indicated power and Neff-effective power proper calculations for each cylinder and engine total.
Keywords: Engine indication, performance data, electronic indicator, mean-indicated & mean-effective pressure, indicated & effective power.
Introduction
Currently on the worldwide fleet motor-vessels and shore diesel power plants for internal combustion engines-diesel engines indication and performance data measurement readings carrying-out the microprocessing gauging and systems, such as Doctor-Engine, Diesel-Doctor and Electronic indicators (different kind of brands and manufacturers) are used in most of cases. However, actually they are not carrying-out the functions of the engines technical condition (cylinder tightness, fuel injection equipment condition and turbocharger system condition) diagnostic and analysis, overload/download analysis and load distribution between the cylinders analysis, but they are electronic gauges for compression pressures Pcom, maximum combustion pressures Pmax measurement by open indicator diagrams (Fig. 1) and closed indicator diagrams for each cylinder and for engine speed measurement at each cylinder indication. All others values are required for the engine technical condition diagnostic and analysis has determined by calculation from indicator diagrams or entered manually to the electronic equipment tables.
Examine the engine indication results from Electronic indicator type HLV-2005 MK (Praezisionsmesstechnik Beawert GMBH, Germany):
The values are calculated from the indicator diagrams:
- Cylinders indicator diagrams area Ad (mm2);
- Cylinders mean-indicated pressure Pmicyl (bar) (Fif.2);
- Cylinders mean-effective pressure Pme (bar);
- Cylinders indicated power Nindcyl (IKW) (Fif.2);
- Cylinders effective power Neffcyl (EKW);
- Engine average mean-indicated pressure Pmieng (bar) (Fig.2);
- Engine average mean-effective pressure Pmeeng (bar);
- Engine indicated power Nindeng (IKW) (Fif.2);
- Engine effective power Neffeng (EKW);
- Engine mechanical efficiency ^mec (%).
2) The values are entered manually to the electronic equipment tables (Fig.2):
- Scavenging air temperature after turbocharger or before scavenging air cooler Tscbc (oC);
- Scavenging air temperature after scavenging air cooler Tscac (oC);
- Scavenging air pressure after scavenging air cooler Pscac (bar);
- Exhaust gas temperature after turbocharger Texhatc (oC);
- Turbocharger speed nTC (rpm);
- Cylinders exhaust gas temperatures Texhcyl (OC);
- cylinders fuel rack position FRP (fuel pump index FPi) (mm);
Note: However, the mentioned above values are not enough for the engine technical condition full diagnostic and analysis (cylinder tightness, fuel injection equipment condition and turbocharger system condition).
in completion of indication data entering to the Pc without TDc correction the engine average mean-indicated pressure & indicated power calculation can give tolerance up to +10%, while the same values calculation from indicator diagrams are taken by mechanical indicator with usage of computerized technology gives tolerance up to +0.5% only.
The engine average mean-indicated pressure and indicated power calculation tolerance up to +10% is not satisfactory for the engine technical condition (cylinder tightness, fuel injection equipment condition and turbocharger system condition) diagnostic and analysis, overload/download analysis and load distribution between the cylinders analysis.
Thereby we suggest the engine (2-stroke engine) indicated power accurate calculation procedure, afterwards it is possible a TDc accurate correction for each cylinder, and then a cylinders mean-indicated pressure Pmicyl, cylinders indicated power Nindcyl & engine average mean-indicated pressure Pmieng same accurate calculation within tolerance +0.5%.
Work object
The high accuracy obtaining in the indicator diagram treatment and as results high accuracy in the cylinder power calculation, determination of load distribution between cylinders and cylinders/engine condition diagnostic & analysis without engine dismantling.
Ways of investigation
Investigations has carried out on the vessel's (with effective power from 736 EKW up to 11900 EKW) with different kind of micro-processing gauging and
systems (Doctor-Engine, Diesel-Doctor and Electronic indicator) & with mechanical indicators. Investigation results and discussion about l.The indicator diagrams TDC correction and each cylinder/total engine output data calculation after the 2-stroke Diesel Propulsion Engine MAN-B&W type 6S50MC-Mk indication by Electronic indicator type HLV-2005 MK.
The Diesel Propulsion Engine performance data some measurement readings are taken during the indication (table 1):
Table l
Engine indication start ths hrs by observation 13
Engine indication start tms min by observation 45
Engine indication stop the hrs by observation 14
Engine indication stop tme min by observation 42
Engine indication period tind min tind = (the — ths) • 60 + tme - tms 57
Eng.revolution counter at start Res revoluton by observation 20344122
Eng.revolution counter at stop rce revoluton by observation 20344788
Engine speed neng rpm neng = (rce - rcs) • 10 / tind 116,80
Engine FO flowmeter at start qfos ltrs by observation 1711963
Engine FO flowmeter at stop qfoe ltrs by observation 1713290
Engine FO consumption qfo ltrs / hr qfo = (qfoe — qfos) ' 60 / tind 1396,762
FO temperature inlet flowmete tfo OC by observation 130,3
FO specific gravity @ 15 OC Pfo15 kg / ltr from FO bunker specification sertificate 0,9672
FO expansion factor kfo kg/ltr.°C ko = 0,00183224 — 0,00131724 • Pfo 15 0,00056
FO specific gravity at flowmete „ t Pfo kg / ltr Pfo = Pfo — kF° • (tf° — 15) 0,9028
FO sulfur content S % from FO bunker specification sertificate 1,86
FO lower calorific value LCV LCV kcal / kg LCV = 12900 — 7095 • S / 100 — 3162 • Pfo 15 9710
Engine FO consumption gfo kg / hr gfo = qfo • Pfo 1261,051
Engine average fuel rack posit. FRP mm by observation 64,3
Turbocharger speed NTC rpm by observation 11000
Scavenging air pressure psc kg / cm2 by observation 2,08
Air temperature air filter inlet TlNL °C by observation 38,4
Scav.air temp.air cooler inlet tsc °C by observation 177
Scav.air temp.air cooler outlet tsc °C by observation 41,8
Scav.air temp.in scav.air manif tsc °C by observation 42,5
Exhaust gas temp.turbine inlet T BTC texh °C by observation 393
Exhaust gas temp.turbine outle T ATC °C by observation 263
FW temp.scav.air cooler inlet TFW °C by observation 30,5
FW temp.scav.air cooler outlet TFW °C by observation 44
Air cooler termoefficiency Пт °C Пт = (tscbc — tscac) • 100 / (tscbc - tfwbc) 92,29
Atmospheric pressure PATM kg / cm2 by observation 1,037
The Diesel Propulsion Engine ambient (reference) conditions and FO data from shop trial test results (table
2):
Table 2
Engine Room temperature ter °C from shop trial test results 23,9
Atmospheric pressure p ST pATM kg / cm2 from shop trial test results 1,035
SW temp.scav.air cooler inlet tsw °C from shop trial test results 18,1
FO temperature inlet flowmete T ST tfo °C from shop trial test results 34,3
FO specific gravity @ 15 OC pst kg / ltr from shop trial test results 0,9136
FO expansion factor k ST kFO kg/ltr.°C kFOST = 0,00183224 - 0,00131724 • pST15 0,000629
FO specific gravity at flowmete т PST kg / ltr pST = pST — kFO • (TFO — 15) 0,9015
FO sulfur content sst % from shop trial test results 0,26
FO lower calorific value LCV LCVst kcal / kg LCVST = 12900 - 7095 • SST / 100 - 3162 • pST15 9993
The Diesel Propulsion Engine FO consumption GFO correction to the shop trial test reference conditions:
^DO -
JFO
LCV 1261.051 • 9710
LCV
ST
9993
- 1225.3 kg / hr
Draw the diagram of the engine indicated power dependence of Fo consumption from shop trial test results table and found its dependence function by the trend line (Diagram 1):
The engine calculated indicated power by the function is founded from the diagram 1:
WIND1 = - 8.379938 • 10-7 • GDO3 + 1.881655 • 10-3 • GDO2 + 6.772031 • CDO + 355.0778 = = - 8.379938 • 10-7 • 1225.33 + 1.881655 • 10-3 • 1225.32 + 6.772031 • 1225.3 + + 355.0778 = 9937 IHP
The Diesel Propulsion Engine turbocharger speed Ntc correction to the shop trial test reference conditions:
^tcst = ntc
M
(273 + Tinl)
(273 + Ter)
= 11000
M
(273 + 38.4)
(273 + 23.9)
= 11266 rpm
Draw the diagram of the engine indicated power dependence of turbocharger speed from shop trial test results table and found its dependence function by the trend line (in the same way as Diagram 1):
The engine calculated indicated power by the function is founded from the diagram by item 7):
WIND2 = - 1.41411647 • 10-12
+ 3.79006967 •NSTTC = - 1.41411647 • 10-12
Nsttc4 + 5.25309184 10-8 • Nst - 5945.706 -• 112664 + 5.25309184 10-8
+ 3.79006967 • 11266 - 5945.706 = 10195 IHP
The Diesel Propulsion Engine multiply FRP • nENG correction to the shop trial test reference conditions:
tc
112663
3- 6.2157409 • 10-4 •NST
tc
+
6.2157409 • 10-4 • 112662 +
FRPst • "eng=
FRP • nENG • LCV • pFOr 64.3 • 116.8 • 9710 • 0.9028
lcvst • pst7
9993 • 0.9015
= 7303 mm • rpm
Draw the diagram of the engine indicated power dependence of multiply FRPst • neng from shop trial test results table and found its dependence function by the trend line (in the same way as Diagram 1):
The engine calculated indicated power by the function is founded from the diagram by item 10):
WIND3 = 2.48249632 • 10-12
ind 4
(FRPst • "ENG)4- 6.76738036 • 10-8 • (FRPST • ^NG)3 + (FRPST • nENG)2-0.769905624 • (FRPST • nENG)+2042.11999 -
10-4 • 73032-
+6.18921346 • 10
= 2.48249632 • 10-12 • 73034- 6.76738036 • 10-8 • 73033+ 6.18921346 - 0.769905624 • 7303 + 2042.11999 = 10132 IHP
The Diesel Propulsion Engine scavenging air pressure correction to the shop trial test reference conditions:
Psc=Psc+0.002856 • (7inl-7er) • (Patm+Psc)-0.00222 • (7wbc-Tswbc) • (Patm+Psc) -
= 2.08 + 0.002856 • (38.4-23.9) • (1.037 + 2.08)-0.00222 • (30.5- 18.1) • (1.037 + 2.08) = = 2.123 kg / cm2
Draw the diagram of the engine indicated power dependence of scavenging air pressure from shop trial test results table and found its dependence function by the trend line (in the same way as Diagram 1):
The engine calculated indicated power by the function is founded from the diagram by item 13):
Nind4 - 44.4567458 • PSTSC3 - 527.060152 • PSTSC2 + 5032.75628 • PSTSC + 1441.75234 -
- 44.4567458 • 2.1233 - 527.060152 • 2.1232 + 5032.75628 • 2.123 + 1441.75234 -
- 10177IHP
2
The engine average indicated power is calculated by the indirect values:
^Vind1+Nind2+Nind3+Nind4 9937+10195+10132+10177 NIND = —- . -— = -:- = 10110 IHP =
4
= 7436 IKW
Enter the engine indication and performance data to the PC (Fig. 1, Fig.2):
Conclusion: As we have seen from the Fig. 1 the engine all cylinders indicator diagrams compression lines are in different position (arrow 1), that is what can not be for the same designed cylinders. They are should be in one line, that is can be adjusted by cylinders TDC correction individually (arrow 2). As we have seen from the Fig.2 the engine indicated power is 6464 IKW instead of calculated in item 15 - 7436 IKW, that is become 13.1% tole rance, which is not acceptable for the engine technical condition diagnostic and analyses. We have to correct the engine cylinders TDC totally.
The engine cylinders TDC angles (Fig.1) in degreases of crank angle CA:
Cylinder 1 TDC = - 1.5 O CA; Cylinder 2 TDC = - 1.5 O CA; Cylinder 3 TDC = - 2.5 O CA;
Cylinder 4 TDC = - 2 O CA; Cylinder 5 TDC = -2.5 O CA; Cylinder 6 TDC = - 4 O CA;
Correct the engine cylinders TDC first of all individually for making the diagrams compression lines in one line (arrow 1), then totally for making the engine indicated power same as calculated in item 15 (arrow 2), (Fig.3, Fig.4):
Cylinder 1 TDC = - 4 O CA; Cylinder 2 TDC = -3.5 O CA; Cylinder 3 TDC = - 4 O CA;
Cylinder 4 TDC = - 4 O CA; Cylinder 5 TDC = -4 O CA; Cylinder 6 TDC = - 5.5 O CA;
Conclusion: As we have seen from the Fig.3 the engine all cylinders indicator diagrams compression lines are in one line (arrow 1) after TDC correction (arrow 2), that is what to be for the same designed cylinders. As we have seen from the Fig.4 the engine indicated power is 7431 IKW and almost the same with calculated in item 15 - 7436 IKW, that is become -0.007% tolerance, which is perfect for the engine technical condition diagnostic and analyses.
Diagram 1
Engine indicated power dependence of FO consumption diagram
ig 7300
Ni 8,379938 10- 1,881655-10 G + 6,772031 G DO + 355,0778
500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 180 DO CONSUMPTION - GDO (KG/HR)
2800
2300
0800
0300
9800
9300
8800
E 8300
7800
6800
6300
5800
5300
4800
4300
3800
3300
| Enginediagnosticsystem - Initial ME-26.05.1 2.eng
IfileBenginesBload datai presentation basic settings help
Heasuiing Diagrams
Result of the actual TDC-correction. Please fill in your manual data by clicking the respective cylinder.
Cylinder 1 1,5°
, Iil 1 'I> i 2 - -1,5° -¿У
Cylinder 3 = -2,5° **
Cylinder 4 = -2,0°
Cylinder 5 - 2.5°
Cylindei 6 - 4,0°
ok cancel
angle = 0.00 '
CH. 1 107,46 ba
№ / 105,98 ba
M il 103,63 ba
№1. 4' 104.71 ba
Uli h' 103,73 ba
LH b. 103,36 ba
180 ■*[]
Figure 1. Cylinders open indicator diagrams before TDC correction
I Enginediagnosticsystem - Initial ME-26.05.12.eng
Pile engines load data basic settings help
X
Measuring Diagrams
Engine type: Cylinder Count: Lenght of Con.rod [mm]: bore [mm]:
T before cooler 1 [ C]: P after cooler 1 [bar]: T after blower 1 [ C]
6S50MC Stroke:
6 Swept Volume [cmi]: 2170 Half stroke [mm]: 500 Compression room [cmi]: 21447 177 T after Cooler 1 [ C]: 41,8
2,01 Blower revs [rpm]: 11000
258,6
Cylinder n [rpm] pmax [bar] pi [bar] Power [kW] Rack Set [mm] T.exhaust [C]
1. 27.02.12 13:54 116,8 124,27 16,22 1 183,83 64,0 339,5
2. 27.02.12 13:58 116,9 121.91 14.73 1 075.76 65.0 330.8
3. 27.02.12 14:00 116,1 120,21 14,52 1 053,50 65,0 348,1
4. 27.02.12 14:03 116.4 120.82 15.11 1 099.90 65.5 339.5
5. 27.02.12 14:07 115,6 122,99 14,26 1 030,10 63,0 325,8
6. 27.02.12 14:10 116,3 118,20 14,06 1 021,41 63,0 337,6
О 116,3 0121,40 0 14,82 2 60464,51 О 64,25 0 336,88
Figure 2. Cy/inders indication & performance data results table before TDC correction
I Enginediagnosticsystem ME 26.05.12.eng
file engines load data presentation basic settings help
Measuring Diagrams | Statistics J Table
P [bar] 130--I 120 -110100-90 -80 -70 -• GO -• jJ ♦ |o
Result of the actual TDC-correction. Please fill in your manual data by clicking the respective cylinder. -1- + angle - 0,00 "
Cjl Cjl Cjl. Cjl Cjl Cjl. 1 2 3 4 5 6 105.42 bar 104,39 bar 102,65 bar 103.29 bar 102,34 bar 103,00 bar
2
Cylinder 2 = -3,5° J^^ Cylinder 3 = 4,0° Cylinder 4 = 4,0° Cylinder 5 = 4,0° Cylinder 6 = -5.5°
1
i
ok cancel | i
\
\
30 -•
20 -•
10-
0-10- -
-180 -150 -120 -90 -GO -30 TDC 3D ED 90 12D 150 1 BD »11
Figure 3. Cylinders open indicator diagrame after TDC correction
I Enginediagnosticsystem - ME-26.05.12.eng
File engines load data basic settings help Measuring Diagrams
Engine type: 6S50MC Stroke:
Cylinder Count: 6 Swept Volume [cmi]:
Lenght of Con.rod [mm]: 2170 Half stroke [mm]:
bore [mm]:
T before cooler 1 [ C]: P after cooler 1 [bar]: T after blower 1 [ C]
500 Compression room [cmi]: 21447
177 T after Cooler 1 [ C]: 41,8
2,01 Blower revs [rpm]: 11000
258,6
Cylinder n [rpm] pmax [bar] pi [bar] Power [kW] Rack Set [mm] T.exhaust [C]
1. 27.02.12 13:54 116,8 124,27 19,34 1 411,45 64,0 339,5
2. 27.02.12 13:58 116.Э 121.91 17.15 1 253.04 65.0 330.8
3. 27.02.12 14:00 116,1 120,21 16,30 1 182,65 65,0 348,1
4. 27.02.12 14:03 116,4 120,82 17,52 1 274,76 65,5 339,5
5. 27.02.12 14:07 115.6 122.99 16.04 1 159.06 63.0 325.8
6. 27.02.12 14:10 116,3 113,20 15,82 1 149,82 63,0 337,6
0116,3 0121,40 О 17,03 E 70430,79 О 64,25 О 336,88
Figure 4. Cylinders indication & performance data results table after TDC correction
The Diesel Propulsion Engine mechanical loss ME Turning Geer technical dete from instruction
pressure calculation: menuel (Table 3):
Table 3
Turning gear electromotor amperage jelm A from turning gear technical data 4,9
Turning gear electromotor voltage -jjelm V from turning gear technical data 440
Turning gear electromotor phases Nos m - from turning gear technical data 3
Turning gear electromotor active load pelm HP from turning gear technical data 3
Turning gear electromotor total load gelm HP SELM = 1.3596 • ma5 • UELM • IELM / 103 5,077
Turning gear electromotor power factor GGSQELM - cosoELM = PELM / SELM 0,59088
Turning gear electromotor frequency elm Hz from turning gear technical data 60
Turning gear electromotor pole's pairs No P - from turning gear technical data 3
Turning gear electromotor speed elm n rpm „elm rr. T-^elm , n = 60 • F / p 1200
Turning gear electromotor speed elm n rpm from turning gear technical data 1155
Turning gear speed tg n rpm from turning gear technical data 1,04
Turning gear angular velocity ®tg 1/sec mtg = n . ntg / 30 0,10891
Turning gear output shaft torque MTG N • mtr from turning gear technical data 15696
Turning gear output shaft power ntg HP Ntg = 1.3596 • MTG • roTG / 1000 2,32414
Turning gear mechanical loss power N tg nmec HP N tg = P - Ntg nmec pelm n 0,67586
Turning gear mechanical efficiency nmec - wg = Ntg / PELM 0,7747
ME mechanical loss pressure calculation by the turning gear operation data at ME opened indicator cocks (Table 4):
Table 4
Turning gear electromotor amperage I A by observation 2,75
Turning gear electromotor voltage U V by observation 446
Turning gear electromotor active load P HP P = 1.3596 • m0,5 ■ U ■ I ■ cos9 / 103 1,707
Turning gear output shaft power N HP N = P - Nmectg 1,031
ME turning time for 1 rev.by turning gear t sec by observation 298
ME speed by turning gear nME rpm nME = 60 / t 0,20134
ME mechanical loss pressure -p me pmec kg / cm2 Pmec = N / (K • nME • i) 1,024
ME mechanical loss pressure me pmec bar pmec = pmec / 1.0197 1,004
or trial test results table and found its dependence function
Draw the diagram of the engine mechanical loss by the trend line (Diagram 2): pressure dependence of the engine speed from shop The engine calculated mechanical loss pressure by
the function is founded from the diagram 2:
PMEC = 1.15598 • 10-5 • nENG2 - 1.96628 • 10-3 • nENG + 1.13493 =
= 1.15598 • 10-5 • 116.82 - 1.96628 • 10-3 • 11(5.8 + 1.13493 = 1.063 kg / cm2 = = 1.0425 bar
The Diesel Propulsion Engine mean-effective pressure calculation:
^me = Pmi - Pmec = 17.03 - 1.0425 = 15.9875 bar
where: Pmi = 17.03 bar - from the engine The Diesel Propulsion Engine effective power
performance data results table (Fig.4); calculation:
Pmec = 1.0425 bar - from item 19), sub-item d) or 1.004 bar from table 4.
WEFF = k • PME • n • i = 0.624761 • 15.9875 • 116.8 • 6 = 7000 EKW
where: k = 1.3084 • D2 • S • m = 1.3084 • 0.52 • S = 1.91 mtr - piston stroke;
1.91 • 1 = 0.624761 - cylinder constant; m = 1 - stroke factor (4-strike engine m = 2, 2-
D = 0.5 mtr - cylinder diameter; stroke engine m = 1).
Е 1,07
Engine mechanical loss pressure dependence of engine speed
Diagram 2
MEC = 1,15598 10-s nENG2 - 1,96628-10-3-nENG + 1,13493
/
(
/
f
/
100 105
ENGINE SPEED -
110
^ENG
(RPM)
Conclusion
As we have seen from mentioned above information for Diesel Propulsion Engines indicator diagrams TDC correction the ME indirect values measurement readings to be taken, recorded & output data have effected to the TDC correction to be calculated.
References
V.I. Korolev, A.G. Taranin, Training of engineers on watch with usage
of the engine room simulator «DIESELSIM DPS-100». Parts 1 & 2, Novorossiysk, Admiral F.F. Ushakov State Maritime University, 2010.
V.I. Korolev, A.G. Taranin, Unattended machine service: of a ship's power plant with simulator «DIESELSIM DPS-100». Parts 1 & 2, Novorossiysk, Admiral F.F.Ushakov Stata Maritime University, 2010.
A.G. Taranin, The ship's equipment operational instructions elements with usage
of the ER simulator «DIESELSIM DPS-100», Novorossiysk, Admiral F.F. Ushakov State Maritime University, 2020.
A.G. Taranin, The ship's equipment operational instructions elements with usage
of the ER simulator «NEPTUNE MC90-IV», Novorossiysk, Admiral F.F. Ushakov State Maritime University, 2020.
COMPUTER?. DESIGN COLOR DRAWING
80
85
90
95
Pavel Shlyakhtenko
Candidate of Physical and Mathematical Sciences, Doctor of Technical Sciences, Professor Emeritus, St. Petersburg State University of Industrial Technology and Design,
Russia
ANNOTATION
A program is proposed for constructing multi-level color images of two-dimensional sections of any analytically defined functions Z = Z (X, Y) on the X, Y plane at any scale on a computer display.
The program allows you to reflect on the screen in various colors located in the computer palette, any desired ranges of changes of the Zi function. The program can be used to automate or speed up the process of creating a geometric pattern of textile products (fabrics, knitwear, scarves, etc.). The work of the program is illustrated by the example of creating a variety of color patterns of carpets.
Keywords: Automating the process of creating a color pattern; Computer programs; Textile materials.
Introduction
Currently, a technology has been developed for the printer applying a color pattern to flat surfaces, as well as technology for automatically transferring a computer-generated image of a pattern to woven and knitted fabrics in the process of their controlled manufacture.
Unfortunately, the massive use of such technologies is hindered by the artist's low
productivity. It is the unpredictable and significant duration of this initial part of the process, depending on the state of the artist's creative abilities at a particular moment, that is a natural brake on the path to the complete automation of the whole process, because the problems of automation of all subsequent stages of manufacturing industrial products for a specific drawing, in principle, already resolved.