orb:lidar

LIDAR

  • Model: Picollo Laser Distance Sensor, External Link
  • Interface: UART, 8N1, 115200, RX=brown/TX=orange/+5V=red/GND=black
  • Motor: 3.0V@25°C, 6-9V@-20°C - -30°C
  • Warning: Motor requires a control loop as data is only delivered when RPM > 180
  • Mechanical info here
  • Aperture here
LIDAR mounted on Rover frame at 45°

Overall result: Scan is stable at all temperatures tested. Motor requires control loop as its consumption varies with temperature. LIDAR was not spinning after 12hours in the freezer. This is because the rubber O-ring had frozen. The reason might have been that because the temperature dropped further, the motor slowed down, letting the almost motionless O-ring to freeze. Video of problem here.

Bench PSU buttons clearly visible (circled), grid=10cm
Tape roll (108mm diameter) clearly visible (circled), grid=10cm
Scan at -12°C, grid=10cm
Scan at -17°C, grid=10cm
grid=10cm
Scan at -30°C running at 9V, grid=10cm
LIDAR test script from here
Time °C V mA RPM Comment
19:30 25 3.0 100 190 Data OK
19:42 ? 3.0 170 No Data
19:42 ? 3.4 200 Changed voltage, Data is back
19:46 ? 3.4 No Data
19:46 ? 3.7 200 Changed voltage, Data is back
19:55 ? 3.7 No Data
19:55 ? 4.1 205 Changed voltage, Data is back
19:57 ? 4.1 No Data
19:57 ? 5 180 240 Changed voltage, Data is back
20:10 -13°C 5 No Data
20:10 -13°C 5 240 239 Changed voltage, Data is back
next day, 10:00 -29°C 5 No Data, not spinning
  • With 3V the motor turns at 190 rpms.
  • PID controller has been implemented and can be found on the github (ROS/pid)
  • pid node subscribes to /rpms topic and publishes into /control_effort topic ⇒ This is working
  • The rpms need then to be “converted” into tension (V) that will be sent to the motor driver as PWM value.
  • The node rpms2volts subscribes to /control_effort and publishes into /motor_input ⇒ Nothing is published… yet
  • orb/lidar.txt
  • Last modified: 5 years ago
  • by ekixs