Figure Comparison of Lidar Time and ROS time after Synchronization
Sync out Method
MiiVii device could generate one 1-30Hz signal (Pulse width: 5ms) through its sync-out pin
2
. This signal is received by sensors as trigger signal
for data acquisition. Meanwhile, MiiVii device records the moment of this signal’s rising edge. After data acquisition, MiiVii device associates
received data with the trigger signal’s rising edge moment as data timestamp. Thus, MiiVii device system obtains data acquisition time.
[ ]
2 For the hardware connection method of the Sync out, please refer to the "SYNC Ports and Pin Assignments" section in the "I/O Cable"
Figure Sync out Method Schematic (25Hz)
Also, MiiVii device provides sync-out feature for GMSL interface. See GMSL Camera Section for details.
Synchronization Verification
Set the sensor to external sync configuration. By recording ROS bags, check whether the sensor trigger signal equals to your setting or not. If the
difference is within 1Hz, it means sync-out method is functional.
Sync in Method
Sensors with sync-in mode could generate a signal at the beginning of data acquisition
3
. MiiVii device receives this signal and records its rising
edge moment. After data acquisition, MiiVii device associates received data with the signal’s rising edge moment as data timestamp. Thus, MiiVii
device system obtains data acquisition time.
[ ]
3 For the hardware connection method of the Sync in, please refer to the "SYNC Ports and Pin Assignments" section in the "I/O Cable"
