User Guide

54A0049_7.0_EN / Leddar Pixell – User Guide 125 | 127
Information Returned From the Leddar Pixell
The Leddar Pixell sensor returns echoes tagged with a global segment number (0-767) and a distance (see
section 4.3 on page 28). For each segment number, there is a general angular mapping stored in the sensor
based on production data for a target at maximum range. A transformation should be applied to find the
position (x, y, z) in space according to the distance of the echoes and the segment number.
Azimuth u and elevation v angles for each segment car be read once at start-up and used in the conversion
equations (see section “Constant, Structure, and Data Type Definitions.”)
Diagram showing the three sub-fields of view
From the segment number (0-767) of an echo reported by the sensor, its field of view of origin can be found
using the mathematical function modulo with 96 as argument (remainder of the division by 96). A result from
this function between 0-31 points to the left field, between 32-63 points to the central field, and between 64-
95 to the right field of view. This sorting is needed to select the right constants in the table below. For
example, a global segment number of 505 represents local segment 25 in the left field of view (remainder of
505 divided by 96).
Mapping Using Opto-Mechanical Parameters of the Leddar Pixell
The following table lists translation values to transform the relative position of the internal sensors toward
the external mechanical reference point.
Table 57: Opto-mechanical constants for each field of view