Lidar

an image showing a UST-10lx with an orange top. We can read Hokuyo Smart Urg underneath

Les Lidar utiliser par INTech sont des UST-10LX concu et vendu par Hokuyo. Une documentation non officel (mais plutot complete [existe ici])(https://sourceforge.net/p/urgnetwork/wiki/Home/). Le manuel du l'UST-10lx est télécharchable ici

UST-10lx connectivity

Il communique par Ethernet en utilisant le protocole Secure Communications Interoperability Protocol (SCIP). Ce protocol peut faire peur a premiere vue mais nous n'utilison que les commande decrit ici. Pour communiquer par ethernet, les lidar possede une adresse IP:

192.168.0.10:10940/24

Il faut donc choisir une adresse ip dans le bon sous-resaux. Nous avons arbitrairement choisi:

192.168.0.11

UST-10lx specs

an image showing a UST-10lx with an orange top. We can read Hokuyo Smart Urg underneath

Spec Value Unit
Min distance 20 mm
Max distance 30000 mm
Accuracy ±40 mm
Scan angle 270 °
Angular resolution 0.25 pt/°
Angular resolution 1440 pt/tr
Scan rate 40 Hz
Poids 130 g
Voltage 10-30 VDC
Current @24VDC 150 (450 at startup) mA

Using HokuyoReader class

This class is from micus/tcp_hokuyo.py This class is simpler than hokuyolx

Create the class instance with

sensor = HokuyoReader(IP, PORT) 

use HokuyoReader.stop() to get rid of any leftover data or problems from an improper shutdown and start mesuring with HokuyoReader.startContinuous(0, 1080) with 0 and 1080 the steps that are mesured

sensor.stop()
sensor.startContinuous(0, 1080)

Distances can be retrived as a numpy array with the HokuyoReader.rDistance() (r standing for radial)

distance_array=sensor.rDistance()

Use HokuyoReader.stop() to gracefully shutdown the lidar

sensor.stop()

Using Hokuyolx class

This class comes from SkoltechRobotics/hokuyolx. This class has considerably more options than HokuyoReader but is more complicated to understand. This class is documented at http://hokuyolx.rtfd.org/. As of 12/12/24 it doesn't work out off the box and we use HokuyoReader