Upgrading the versatility of conventional machine tools using the mechatronic approach

Figures & data

Figure 1b. Integmac User Interface Snapshots of Remedial Actions. (c) Integmac Snapshot of Computed Integrity.

Figure 1a. Flowchart of the Model of the Mechatronic System.

Figure 2. Structure of the Mechatronic System.

Table 1. Comparison between machine tools.

S. No.	Components	Lathe	Drilling machine	Milling machine	Grinding machine	Shaping machine
1.	Spindle	Yes	Yes	Yes	Yes	No
2.	Toolpost	Yes	No	Yes	No	Yes
3.	Tailstock	Yes	No	No	No	No
4.	Electric Motor	Yes	Yes	Yes	Yes	Yes
5.	Hydraulics	Yes	No	Yes	No	No
6.	Pneumatics	Yes	No	Yes	No	No
7.	Bed	Yes	No	Yes	Yes	Yes

Table 2. Probe locations and measurement.

Probe locations	Possible parameters for measurement/exclusive measurements	Actual parameters measured	Applied sensors
Headstock	G13 – Motion analysis^a G26 – Acoustic emission^a G27 – Vibration^a (three-axis MPU 6050 analogue gyro sensor/accelerometer) G51 – Electric motor G61 – Machine tool stability G63 – Wear and lubrication G65 – Transmission element G22 – Parallelism	G13 – Motion analysis	- Spindle speed Tachometer sensor
		G22 – Straightness, parallelism, squareness and coaxiallity	- Headstock/Tailstock Alignment Sensor
		G23 – Repeatability and precision	- Headstock/Tailstock Alignment Sensor
		G24 – Alignment	- Headstock/Tailstock Alignment Sensor
		G64 – Mechanical component error and accuracy	- Headstock/Tailstock Alignment Sensor
Bed	G11 – Physical elements^a G13 – Motion analysis G27 – Vibration (three-axis MPU 6050 analogue gyro sensor/accelerometer) G63 – Wear and lubrication^a	G13 – Motion analysis^a	Infrared speed digital sensor
Toolpost, carriage and cutting tool	G13 – Motion analysis^a G25 – Cutting forces G26 – Acoustic emission (ultrasonic sensor) G29 – Tool life^a G63 – Tool wear and lubrication of carriage and toolpost G65 – Transmission element	G13 – Motion analysis^a	Infrared speed digital sensor
Electric control system	G51 – Electric motor speed G52 – Switches G53 – Fuses, contactors G54 – Circuit elements G55 – Wiring	G51 – Electric motor speed	Electric motor speed sensor
Hydraulic/pneumatic systems	G62 – Mechanical hydraulic/pneumatic system	G62 – Mechanical hydraulic/pneumatic system	Pressure transducers

^aConnotes exclusive measurement. Exclusive measurement is a measurement that, if obtained in one location, does not need to be repeated in other locations. Hence, measurements in other locations can be dispensed with.

Figure 3(a). LDR Circuit Diagram, (b) Direct connection of LDR to the Arduino Board, (c) LDR Grid with a multiplexer and Jumper cables.

Figure 4. The alignment module is mounted onto the headstock, and the laser beam points towards the tailings stock.

Figure 5. Mechatronic Circuitry.

Figure 6. Mechatronic System Architecture.

Figure 7. Schematic Sketch of Mechatronic System mounted on Lathe.

Figure 8. Developed Integrity Evaluator.

Table 3. Results of component calibration.

S. No.	Tested module	Benchmark calibration instrument	Allowable accuracy from calibration equipment manufacturer	Mean percentage deviation from applied sensors^a (%)	Acceptability^b
1	Speed	Standard DT-6234B Digital Tachometer	±0.05% to ±1 digit	0.52	Yes
2	Pressure	Wika Bourdon Gauge 233.53 Model (ASME B40.100 Grade A)	±2% of span	1.82	Yes
3	Alignment	Mitutoyo 1045S Dial Indicator	±0.013 mm (±1%)	0.51	Yes

^aBased on a sample size of 10 trials.

^bAcceptability based on 3-σ criterion.

Figure 9. Spindle Speed Integrity Chart.

Figure 10. Electric Motor Speed Integrity Chart.

Figure 11. Hydraulic pressure integrity chart.

Figure 12. Pneumatic Pressure Integrity Chart.

Figure 13. Headstock-Tailstock/Toolpost Alignment.

Figure 14. Developed LDR Alignment.

Figure 15. Total alignment integrity chart.

Figure 16. Total Machine Integrity Chart.

Table 4. Total machine integrity.

Experimental runs	First run	Second run	Third run	Fourth run	Fifth run	Sixth run	Seventh run	Eighth run	Ninth run	Tenth run
	Death-knell parameters (either 0 or 1)
Cracks and faults on guideways	1	1	1	1	1	1	1	1	1	1
Leadscrew fault detection	1	1	1	1	1	1	1	1	1	1
	Pseudo-death-knell/living parameters
Electric motor speed integrity (%)	83	84	84.1	84.5	85	87	91.7	92	97	97
Spindle speed integrity (%)	67	69.4	70.6	71	72	80.7	91	91.8	97.3	97.3
Headstock/tailstock-toolpost alignment integrity (%)	86.4	86.3	87.5	87.7	87.9	88.8	89.3	91.7	94.3	95.7
Hydraulic pressure integrity (%)	74.2	79	79.7	79.7	79.7	80	86	91.3	94.8	94.8
Pneumatic pressure integrity (%)	78	80	81.2	81.3	81.3	81.6	86.6	91	94.1	94.1
Total machine integrity (%)	78.24	80.28	80.96	81.14	81.46	83.74	88.98	91.44	95.70	95.78

Figure 17. Online Paired T-Test Simulator.

Table 5. Results of performance evaluation on developed mechatronic system.

	Mean	Variance	Standard deviation
Group 1	85.763000	43.901823	6.625845
Group 2	95.516000	2.381204	1.543115
Differences	−9.753000	31.191601	5.584944
t Value	−5.522292
Degree of freedom	9
p Value	0.000369
Significant level	5%
Confidence interval	95% of the differences from −13.748228 to −5.757772

Table 6. Machine tool accuracy assessment.

Cylindrical workpiece		Cutting speed range	Cutting feed and depth	Before integrity evaluator 1.0 connection		After integrity evaluator 1.0 connection
Rough turning	Basic size (mm)	Low speed (27 rpm, 55 rpm, 75 rpm)	High feed and depth	Accuracy	Surface roughness (µm)	Accuracy (µm)	Surface roughness (µm)
	35			0.39 mm (IT 13)	18	62 (IT 9)	11.6
	60			0.46 mm (IT 13)	17.2	74 (IT 9)	12
	90			0.54 mm (IT 13)	17.5	87 (IT 9)	12.5
Step turning	35	Medium (135 rpm, 245 rpm, 330 rpm)	Small feed and depth	0.25 mm (IT 12)	7.2	39 (IT 8)	3.1
	60			0.3 mm (IT 12)	7.6	46 (IT 8)	3.4
	90			0.35 mm (IT 12)	7.7	54 (IT 8)	3.7
Finish turning	35	High speed (760 rpm, 1040 rpm, 1490 rpm)	Small feed and depth	160 µm (IT 11)	2.7	25 (IT 7)	0.91
	60			190 µm (IT 11)	2.5	30 (IT 7)	0.92
	90			220 µm (IT 11)	2.4	35 (IT 7)	0.81

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.