Vu 8 Channel LiDAR Module, 48°/0.3°, USB, CAN Bus, RS485 & UART - User Manual

Table Of Contents
LeddarVu User Guide Page 38 of 129
Light Source Control
There is a total of 5 light source power levels. Their approximate relative power is evenly distributed
between 0 through 100%. There were three power control mode: manual, automatic mode 1 and
automatic mode 2.
With the manual mode, the light power source of the sensor is set to a fixed value. This mode can
be used in a controlled environment of sensor FOV.
For automatic mode, the change delay defines the number of measurements required before
allowing the LeddarVu module to increase or decrease by one the light source power level. For
example, with the same change delay, the maximum rate of change (per second) of the light source
power will two times higher at 12.5 Hz than at 6.25 Hz. The change delay can be set by the number
of detection frame and the number of channel in saturation mode can be tolerated (automatic mode
1 only).
NOTE: Since the change delay parameter is a number of measurements, the delay will vary if the
measurement rate is changed (through modification of the accumulation and oversampling
parameters).
Keeping the module in automatic light source power mode (default setting) ensures it adapts to
varying environments. Close range objects may reflect so much light they can saturate the module,
reducing the quality of the measurements. The automatic mode 1, will adapt the light output within
the change delay setting (channel and frame parameter) to reach the optimal amplitude. On the
other hand, low amplitudes provide lower accuracy and precision.
This automatic light source power mode will select a light source intensity that provides the highest
intensity that avoids the saturation condition. The automatic mode 2, will adapt the light output
within the change delay (frame parameter only) to reach at least one or more channels in saturation
condition to provides the highest detection range. This mode is useful to keep a highest detection
range into non-saturated channels when a strongly reflective object is detected.
NOTE: When a strongly reflective or near object is present in the field of view while monitoring
farther distances, the automatic adjustment mode 1 will reduce the effective range of the module
(reduce light source intensity) and may prevent detection of long range or low reflectivity objects.
For these applications, the automatic mode 2 may be a better setting.