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From version < 95.2 >
edited by Xiaoling
on 2022/06/10 11:03
To version < 95.5 >
edited by Xiaoling
on 2022/06/10 11:28
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... ... @@ -912,7 +912,56 @@
912 912  **Firmware Upgrade Method: **[[Firmware Upgrade Instruction>>path:/xwiki/bin/view/Main/Firmware%20Upgrade%20Instruction%20for%20STM32%20base%20products/]]
913 913  
914 914  
915 += 3.  LiDAR ToF Measurement =
915 915  
917 +== 3.1 Principle of Distance Measurement ==
918 +
919 +The LiDAR probe is based on TOF, namely, Time of Flight principle. To be specific, the product emits modulation wave of near infrared ray on a periodic basis, which will be reflected after contacting object. The product obtains the time of flight by measuring round-trip phase difference and then calculates relative range between the product and the detection object, as shown below.
920 +
921 +[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png]]
922 +
923 +
924 +
925 +== 3.2 Distance Measurement Characteristics ==
926 +
927 +With optimization of light path and algorithm, The LiDAR probe has minimized influence from external environment on distance measurement performance. Despite that, the range of distance measurement may still be affected by the environment illumination intensity and the reflectivity of detection object. As shown in below:
928 +
929 +[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image002.png]]
930 +
931 +
932 +①Represents the detection blind zone of The LiDAR probe, 0-10cm, within which the output data is unreliable.
933 +
934 +②Represents the operating range of The LiDAR probe detecting black target with 10% reflectivity, 0.1-5m.
935 +
936 +③Represents the operating range of The LiDAR probe detecting white target with 90% reflectivity, 0.1-12m.
937 +
938 +
939 +Vertical Coordinates: Represents the radius of light spot for The LiDAR probe at the different distances. The diameter of light spot depends on the FOV of The LiDAR probe (the term of FOV generally refers to the smaller value between the receiving angle and the transmitting angle), which is calculated as follows:
940 +
941 +
942 +[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image003.png]]
943 +
944 +
945 +In the formula above, d is the diameter of light spot; D is detecting range; β is the value of the receiving angle of The LiDAR probe, 3.6°. Correspondence between the diameter of light spot and detecting range is given in Table below.
946 +
947 +[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image004.png]]
948 +
949 +
950 +If the light spot reaches two objects with different distances, as shown in Figure 3, the output distance value will be a value between the actual distance values of the two objects. For a high accuracy requirement in practice, the above situation should be noticed to avoid the measurement error.
951 +
952 +
953 +
954 +== 3.3 Notice of usage: ==
955 +
956 +Possible invalid /wrong reading for LiDAR ToF tech:
957 +
958 +* Measure high reflectivity object such as: Mirror, Smooth ceramic tile, static milk surface, will have possible wrong readings.
959 +* While there is transparent object such as glass, water drop between the measured object and the LiDAR sensor, the reading might wrong.
960 +* The LiDAR probe is cover by dirty things; the reading might be wrong. In this case, need to clean the probe.
961 +* The sensor window is made by Acrylic. Don’t touch it with alcohol material. This will destroy the sensor window.
962 +
963 +
964 +
916 916  = 4.  Configure LLDS12 via AT Command or LoRaWAN Downlink =
917 917  
918 918  (((
... ... @@ -1040,6 +1040,7 @@
1040 1040  * Reply to the confirmation package: 26 01
1041 1041  * Reply to non-confirmed packet: 26 00
1042 1042  
1092 +
1043 1043  Device will send an uplink after got this downlink command. With below payload:
1044 1044  
1045 1045  Configures info payload:
... ... @@ -1061,7 +1061,7 @@
1061 1061  Always 0x02
1062 1062  )))
1063 1063  
1064 -**Software Type**: Always 0x03 for LSPH01
1114 +**Software Type**: Always 0x03 for LLDS12
1065 1065  
1066 1066  
1067 1067  **Frequency Band**:
... ... @@ -1107,7 +1107,7 @@
1107 1107  
1108 1108  0x06: LSNPK01
1109 1109  
1110 -0x07: LDDS12
1160 +0x07: LLDS12
1111 1111  
1112 1112  
1113 1113  
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