note : for discussing any technical issues or project designs with your LIDAR-Lite, please proceed to our forum and create a new topic here.
The new version of the LIDAR-Lite v3 “High Performance” (LLV3HP) is now available at RobotShop. It offers key improvements while staying compatible
Nous souhaitons utiliser ce type de capteur pour mesurer la position et la vitesse d’approche ou d’éloignement d’un sujet, et calculer son moment de passage à une certaine distance. Le but et de déclencher un DSRL (photo) en anticipant l’instant du passage d’un animal dans le plan focale, afin de compenser l’inertie du système en tenant compte de la vélocité du sujet (oiseau, mammifère, insecte) La focale doit pouvoir disperser le faisceau pour ajuster la surface de detection à la taille et à la trajectoire. La distance de mesure doit pouvoir s’étendre de 5 cm à 10 mètres. L’idéal serait un laser infra-rouge invisible.
@Snipersdimages: Le faisceau du RB-Pli-17 est en effet dispersé. Par contre, le montant de dispersion est fixe et le capteur est calibré pour celui-ci. Vous pouvez consulter les spécifications ici. Celle-ci indique que le faisceau diverge de 8 mrad. Ceci devrait donner une taille du faisceau de quelques cm de large @ 10 m.
Pour de l’aide technique au sujet de votre projet, s’il vous plaît créez un message ici.
Hi, is it possible to have the datasheet of the product? I am curious about the measurement rate setup (MEASURE_DELAY). It would be also interesteng to know how the measurement rate affects power consumption.
@Ray: The datasheet is still not out yet since the product has not entered production yet. We should be getting the official information shortly. As soon as we receive it, it will be place on the product page under Useful Links.
Hi, do you know if it will work ok with Pixhawk? I heard that the previous version of lidar-lite v3 had some issues with Pixhawk. I´m starting a project and will have to decide between this or another rangefinder. Thanks.
@Doppler_uav: Actually, the LIDAR-Lite (v1, v2, v3) always seemed to work well with Pixhawk using the PWM mode. Some versions had issues in some cases using I2C, but those were resolved with the latest LIDAR-Lite v3 and the LLV3HP. You can read as much online, such as here.
Sebastian, how can I utilize the Lidar to measure pipe diameters in a sewer remotely.
@Roger Thibeaux: Measuring the diameter directly would imply having the sensor at the periphery of the pipe. Since that is unlikely, an alternative option would be to measure part of the distance and derive the diameter from that. For example, if your sensor is in the center of the pipe, you can can simply measure the radius. Another case would be is your sensor is on a rover platform inside the pipe. The rover would be at the bottom and you could therefore measure straight up part of the diameter and add to it the displacement from the rover itself to get the full diameter. Please note the sensor has a resolution of 1 cm, so unless the pipes you are measuring are quite big, this may not be precise enough. As for remotely, you would need to use some form of wireless or wired communication. For more technical help, please create a new topic on the forum here. Make sure to include as many details about your project as possible, such as pictures, drawings, setup, requirements, goals, etc.
Hi Sébastien,
I want to use the Lidar Lite 3 in my small device (based on a raspberry pi 3) to measure the distance between the sensor and a vehicle (a range of 15 to 30m). I know heavy rain may influence the measurement but i was wondering if I’ll get one return from the water, no return at all, or multiple returns: small ones from the rain drops and a big one from the vehicle.
Thanks in advance
@Abidine: The device actually returns a measurement based on the aggregation of (typically) hundreds of signals, not just one. This is why it is able to perform well in many circumstances. In most cases, the sensor will simply need more time in order to obtain a proper measurement. That being said, if the rain is particularly heavy, it most likely will have reduced range (and accuracy) as less of the signal makes it through properly. The best would be to test the sensor in the conditions you expect it to be in and see how it performs.
Hi
I’m using LLV3HP to measure the distance of a truck from 4-24m. I am having issues with some trucks that have only black plastic in front. The truck is sometimes totally missing for 5 meters. .
This is my startup config:
writeAndWait(0x00,0x00);
writeAndWait(0x02,0x80);
writeAndWait(0x04,0x08);
writeAndWait(0x1c,0x50);
What would you recommend to do?
Best Regards,
Martin
@Martin Valvur: If you need technical support with your setup, we strongly recommend that you post your question in our forum here as mentioned at the top of the article. It is far easier to offer support there, since we can post images, code and other files more easily.
That being said, there may be a few things to be done concerning your issue. First, you may want to increase the maximum acquisition count (register 0x02) to a higher value. You should probably also experiment with the detection sensitivity (register 0x1C) and see what results you get. You can read more about these in the operation manual (page #4 and pages 8-10).
Second, you may want to aim at a different part of the truck. Typically it is recommended to aim at flat, perpendicular and (IR) reflective surfaces for best results. If possible, try and orient your sensor towards the licence plate since it is purposefully made of reflective material which should provide good results.
