3.4.2
Range finding
The device emits beams pulsed by a laser diode. If the laser beam is reflected by an
object, the reflected beam is received by the sensor.
The distance to the object is calculated on the basis of the time that the pulsed light
beam requires to be reflected and received by the sensor.
t
1
2
1
Emitted pulse
2
Receive pulse
3.4.3
Direction measurement
The laser beams are emitted using an internally rotating sender-receiver unit (SRUs)
and scan the surroundings orbitally. The received measured values are assigned to the
associated angular cut and thus to the direction.
3.4.4
Impact of object surfaces on the measurement
Remission value
Remission is the ability of a material to reflect light. The remission correlates with the
amount of laser light emitted by the LiDAR sensor which is reflected by an object (see
Lambert’s law).
Glossy surfaces have different remissions at the same distance with different angles of
impact. In the case of shiny surfaces, maximum remission is achieved when the beam
makes vertical impact.
Matt and dull surfaces have diffuse remission. They therefore exhibit similar relative
remissions with the same angle of impact regardless of the distance from the zero
point.
Table 3: Typical remissions of frequently used materials
Material
Typ. relative remission
Rubber tires (vulcanized, black)
2%
Foam rubber (black)
2.4%
Photographic board (black, matte)
10%
Cardboard (gray)
20%
Wood (untreated fir, soiled)
40%
PVC (gray)
50%
Paper (white, matte)
80%
Plaster (white)
100%
Aluminum (black anodized)
110 … 150%
Steel (stainless, shiny)
120 … 150%
Steel (high gloss)
140 … 200%
Reflector
> 1,000%
3
PRODUCT DESCRIPTION
12
O P E R A T I N G I N S T R U C T I O N S | LRS4000
8026338/0000/2022-02-15 | SICK
Subject to change without notice
