40 | 50
© 2021 LeddarTech Inc.
#
Tool
Model Used
K
Computer
Running Windows 7 or Windows 10 OS
The focus of the voltage calibration is to minimize the amount of leaking of the various tiles surrounding the
intended target tile. To do this calibration, each liquid crystal cell in a low-voltage state needs to be fine-tuned
for each tile. Calibrating the high-voltage states does not provide any benefits in terms of illumination. The
tile should be selected from a configuration file provided with the digital beam steering device.
Considering that there are a total of 7 liquid crystal cells to calibrate in the digital beam steering device and
56 different tiles, this would amount to a very large amount of individual calibrations. This document
describes the manual procedure for calibrating the cells, but these operations can also be automated by
controlling the camera and DBSD controller with a computer. Specifically, LeddarTech uses an infrared
camera (Chameleon3 USB3 model CM3-U3-31S4M-CS 3.2 MP) to verify the illumination of the targeted tile.
An optimization algorithm then finds the calibrated voltage for each low-voltage cell for the targeted tile. This
procedure is repeated for the 56 tiles.
Table 25: Tile ID by azimuthal and elevation angle (degrees)
A z i m u t h a l
-53.81 -43.06 -33.97 -25.75 -18.09 -10.73 -3.56
3.56
10.73 18.09 25.75 33.97 43.06 53.81
E
lev
a
tio
n
9.24
1
2
3
4
5
6
7
8
9
10
11
12
13
14
3.07
15
16
17
18
19
20
21
22
23
24
25
26
27
28
-3.07
29
30
31
32
33
34
35
36
37
38
39
40
41
42
-9.24
43
44
45
46
47
48
49
50
51
52
53
54
55
56
The basic principle of the algorithm consists of starting with the first low-voltage liquid crystal cell (the one
closest to the system) and incrementing the voltage value of this cell until the illumination of the targeted tile
is the highest. To do so, the system starts by providing 0.5 V to the desired cell, then increments the voltage
in 0.1 V steps to verify if the illumination of the desired cell is increased. If the illumination decreases in
between two steps, then the highest voltage is kept and the voltage incrementation is reduced. The algorithm
continues these steps until the step is reduced to 0.02 V. Once this voltage is found, the same principle is
applied to all the low-voltage cells up to the 7
th
. As a given tile is being calibrated, the targeted tile should not
only become more illuminated, but the leakage should also decrease in nearby tiles.
The tiles
’ illumination
can be ordered in any fashion as long as they are all calibrated. LeddarTech suggests
starting with tile ID 1 and finishing with tile ID 56.
The resulting calibration should give the following values for the first 7 cells:
•
Low voltages should be in the range of 0.5 V to 5 V
•
High voltages should be 20 V
