User's Manual

Tail: 22 bytes

Table 3.4 Point Cloud Data UDP Data-Tail

Reserved 2 bytes reserved data, meaningless

Reserved 5 bytes reserved data, meaningless

High Temperature

Shutdown Flag

1 byte

0x01 means high temperature; 0x00 means normal operation

· during normal operation, shutdown ﬂag keeps being 0x00

· if high temperature is detected and system needs to be shut down, the shutdown ﬂag will be set to 0x01, and the

system will be shut down after 60 seconds. The ﬂag keeps being 0x01 during the 60 seconds and shutdown period

· after the high temperature shutdown, the LiDAR temperature will decrease. When the system is not in high

temperature status, the shutdown ﬂag will be reset to 0x00 and the system can return to normal operation

Motor Speed 2 bytes speed_2_bytes [15:0] = speed (RPM)

GPS Timestamp 4 bytes the packing time of this data packet, the unit is 1 μs, value range 0 μs-1000000 μs (1 s)

Return Mode Information 1 byte the strongest return (0x37), the last return (0x38), dual return (0x39)

Factory Information 1 byte 0x42 (or 0x43)

UTC 6 bytes year, month, date, hour, minute, second, decimal digit

By now, the direction and distance of this point have been decided, and this obstacle point could be drawn in the polar or rectangular

coordinate system. The real-time point cloud data of Pandar20A/B can be drawn by analyzing every data in the UDP Data Packet using the

above method.

Taking Pandar20A's Channel 5 in block 3 of a UDP Data Packet as an example:

1) Horizontal angle oﬀset of the laser is 3.125°, and vertical angle of the laser is 1.67° for Channel 5 (refer to Appendix I).

2) Horizontal angle is the current reference angle of the rotor plus horizontal angle oﬀset, so the result is (Azimuth 3+(3.125)) degree.

(NOTE We deﬁne clockwise as a positive direction of the angle from top view)

3) Analyze the “Channel 5 Unit 3” from the UDP Data Packet, and the distance formed by upper 2 bytes multiplied by 4 mm is the actual

distance in millimeters in the real world.

Example of UDP Data Analysis

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