Fig. 1
Graphical representation of Li-Fi communication between system and AGV
Tab. 1
Comparative Summary of common data communication technologies
| Key Parameters | Li-Fi (Light Fidelity) | Wi-Fi (Wireless Fidelity) | Ethernet |
|---|---|---|---|
| IEEE Standards | 802.15.17 | 802.11b | 802.3 |
| Frequency | 10 × Tera Hz | 2.4 GHz | -NA- |
| Data Transmission Medium | Light | Radiofrequency | UTP - STP – OF |
| Speed | 1 – 3.5 Gbps | 25–250 Mbps | 10–1000 Mbps |
| Range | 10 meters | 20–100 Meters | 100 – 185 Meters |
| Security | High (direct line of sight required) | Medium (can penetrate through walls) | High (physical connection required) |
| Reliability | High | High | Very High |
| Release Date | 2011 | 1990 | 1980 |
| Connection | Wireless | Wireless | Wired |
| Cost | Cheapest | Most Expensive | Cheaper than Wi-Fi |
Fig. 2
Fishbone Diagram for connection speed
Fig. 3
CNX diagram for Taguchi DoE
Fig. 4
Main effects plot for mean connection speed
Tab. 2
Response table for mean connection speed (in mbps)
| Level | Beacon | Agv | Vibration | X Pos | Y Pos | Z Pos |
|---|---|---|---|---|---|---|
| 1 | 6.634 | 6.088 | 6.632 | 6.243 | 6.437 | 5.951 |
| 2 | 6.642 | 7.190 | 6.646 | 7.329 | 6.553 | 7.378 |
| 3 | 6.344 | 6.927 | 6.587 | |||
| Delta | 0.008 | 1.102 | 0.014 | 1.087 | 0.490 | 1.426 |
| Rank | 6 | 2 | 5 | 3 | 4 | 1 |
Fig. 5
Pareto chart of the standardised effect
Tab. 3
Model summary and coded co-efficient for the connection speed
| S | R-sq | R-sq(adj) | R-sq(pred) |
|---|---|---|---|
| 0.156972 | 7.92% | 0.00% | 0.00% |
| Term | Effect | Ratio Effect | Coef | SE Coef | T-Value | P-Value | VIF |
|---|---|---|---|---|---|---|---|
| Constant | 2.11936 | 0.00285 | 744.51 | 0.000 | |||
| Reflection | 0.00181 | 1.00182 | 0.00091 | 0.00285 | 0.32 | 0.752 | 1.00 |
| AGV Type | −0.00204 | 0.99796 | −0.00102 | 0.00285 | −0.36 | 0.722 | 1.00 |
| Cut Out | −0.00165 | 0.99835 | −0.00082 | 0.00285 | −0.29 | 0.774 | 1.00 |
| Reflection*AGV Type | −0.00539 | 0.99463 | −0.00269 | 0.00285 | −0.95 | 0.351 | 1.00 |
| Reflection*Cut Out | −0.00177 | 0.99823 | −0.00089 | 0.00285 | −0.31 | 0.758 | 1.00 |
| AGV Type*Cut Out | 0.00263 | 1.00264 | 0.00132 | 0.00285 | 0.46 | 0.647 | 1.00 |
| Reflection*AGV Type*Cut Out | −0.00632 | 0.99370 | −0.00316 | 0.00285 | −1.11 | 0.275 | 1.00 |
Fig. 6
Main effects plot for mean connection speed
Fig. 7
Process capability of pilot testing
Tab. 4
Model summary and coded co-efficient for Connection speed
| S | R-sq | R-sq(adj) | R-sq(pred) |
|---|---|---|---|
| 0.929010 | 91.56% | 90.61% | 88.99% |
| Term | Effect | Coef | SE Coef | T-Value | P-Value | VIF |
|---|---|---|---|---|---|---|
| Constant | 5.579 | 0.147 | 37.98 | 0.000 | ||
| AGV Cut-Out | −3.992 | −1.996 | 0.120 | −16.64 | 0.000 | 1.00 |
| Height | −0.757 | −0.378 | 0.147 | −2.58 | 0.013 | 1.00 |
| X Pos | −0.720 | −0.360 | 0.147 | −2.45 | 0.018 | 1.00 |
| Y Pos | 3.702 | 1.851 | 0.147 | 12.60 | 0.000 | 1.00 |
| Cut-Out*Y Pos | 2.860 | 1.430 | 0.147 | 9.74 | 0.000 | 1.00 |
| Ct Pt | 1.436 | 0.254 | 5.64 | 0.000 | 1.00 |