Expand Speed Lookup Table

[SPDonaghy]

Description

This PR upgrades the BOAT_SPEEDS table in ompl_objectives.py to cover more wind speeds and to follow an even more realistic/data informed velocity prediction model.

The boat speed data was collected from polar data of a similar vessel here https://jieter.github.io/orc-data/site/#GRE/GRE1772/

The raw speed values from polar_sailing_speed_prediction_data were loaded into a 2d array, transformed from knots to kmph, scaled down so that the maximum value is 10 kmph (because that is our estimate of sailbot's top speed), and then transposed to obtain the new BOAT_SPEEDS array shown below

  __________________________________________________________________________________________
 | True  |                             Sailing Angle (deg)                                  |
 | Wind  |__________________________________________________________________________________|
 | Speed |       |       |       |       |       |       |      |      |      |      |      |
 | (Kmph)|   0°  |  45°  |  50°  |  60°  |  75°  |  90°  | 110° | 120° | 135° | 150° | 180° |
 |_______|_______|_______|_______|_______|_______|_______|______|______|______|______|______|
 |  0.0  |  0.0  |  0.0  |  0.0  |  0.0  |  0.0  |  0.0  |  0.0 |  0.0 |  0.0 |  0.0 |  0.0 |
 | 11.1  |  0.0  |  5.0  |  5.4  |  5.8  |  6.1  |  6.0  |  5.6 |  5.2 |  4.6 |  4.0 |  3.6 |
 | 14.8  |  0.0  |  5.9  |  6.5  |  6.9  |  7.2  |  7.1  |  6.8 |  6.5 |  5.9 |  5.3 |  4.8 |
 | 18.5  |  0.0  |  6.6  |  7.3  |  7.7  |  8.1  |  8.1  |  7.8 |  7.5 |  6.9 |  6.3 |  5.8 |
 | 22.2  |  0.0  |  7.2  |  7.9  |  8.4  |  8.7  |  8.8  |  8.6 |  8.4 |  7.8 |  7.2 |  6.7 |
 | 25.9  |  0.0  |  7.7  |  8.4  |  8.7  |  9.0  |  9.2  |  9.0 |  8.9 |  8.5 |  8.0 |  7.6 |
 | 29.6  |  0.0  |  8.0  |  8.7  |  9.0  |  9.3  |  9.4  |  9.4 |  9.2 |  9.0 |  8.6 |  8.3 |
 | 37.0  |  0.0  |  8.2  |  8.9  |  9.3  |  9.6  | 10.0  | 10.0 |  9.8 |  9.6 |  9.3 |  9.2 |
 | 55.0  |  0.0  |  8.5  |  9.3  |  9.6  | 10.0  | 10.0  | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 |
 | 75.0  |  0.0  |  8.7  |  9.6  |  9.8  | 10.0  | 10.0  | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 |
 -------------------------------------------------------------------------------------------

Below is a polar plot of the data contained in the new BOAT_SPEEDS table.

Verification

• Unit Tests
• Visual verification of polar plot in comparison with polar plots of other sailing vessels

[raghumanimehta]

Not really requesting changes, but need clarification on a couple of things before merging.

[raghumanimehta]

Do you think we can perhaps use calculate_heading_diff from local_path.py?

[SPDonaghy]

Yes, IF we can rename the function to something more generic that fits both the uses cases it would then be applied to.

[raghumanimehta]

I think it's good for now. We have other things to worry about.