Everyone has been eager to know when the LIDAR-Lite would return to market, so we are very happy to announce it is now available for pre-order: LIDAR-Lite v3. The second thing everyone was insistent on asking was: “Will this work with my previous setup/project/custom mounting/etc.?”. In this post, we will cover in more details the similarities and differences of the new LIDAR-Lite.
@Hamed: Please note that this device is mainly for distance measurement. Of course, taking distance measurements in bursts and calculating the difference between them and their timing would give you a measurement of velocity. The device can take very quick measurement, anywhere from 500-2000 Hz, depending on the settings and environment (maximum expected distance, reflectivity of surface, angle of reflection, etc.).
The recommended option from the manufacturer is to set the device to “burst mode” and perform the velocity calculation from a microcontroller or other device.
@Hammed: There is not really a minimum or maximum range of speed, since the device uses light, which is pretty much as fast as you can go (as far as we know ). What may affect your readings is the accuracy of the device and its sampling time.
OK, lets start with the worst case: assume you are scanning @ 500 Hz (for best results) and getting a 2.5 cm accuracy (moving objects, light noise, angle of reflection, etc.). This would mean you are getting new distance data every 2 ms. This is far more than needed to get an accurate relative instantaneous velocity of an object in front of the sensor. In this case, instantaneous velocity will be calculated with a vector parallel to the sensor direction. The magnitude will be determine by delta of distance / time.
Therefore, you could measure a change in velocity as detailed as 2.5 cm / 2 ms = 1.25 cm / ms => 12.5 m/s => 45 km/h. Of course, most objects at “car speeds” will not change velocity that fast. To get an absolute instantaneous velocity, you will also need to know your instantaneous velocity if your sensor is moving.
Starting from a vertically upward-pointing attitude/angle, if the LIDAR is rotated through a 360 pan while the attitude/angle is incremented downward, should the pan speed be modified (slowed) at a corresponding rate to ensure the same number of readings (I may mean ‘density’) per revolution?
Otherwise, from a practical point of view, if a room was being ‘mapped’ (3D-wise), I would think the ceiling would have greater detail than the walls - I think…
@Don: Usually, the blog comments are meant for simple questions about the article. Since your question is more technical in nature, we recommend instead that you post it on our forum here. To help in answering your question, you could also attach one or more images showing the setup you are describing.
Hi Sébastien, what the main purpose of the lens in Lidarlite ? is it used to extend the range to 40 m ? Can use the board alone without the lens. BTW I also find the is small piece of mirror found in the receiver. I assume its some kind of optical filter.
@T RAj The lens serves the same purpose as with all lasers - to focus. We are not the manufacturer of this product so cannot really help with a dissection at this time.
). What may affect your readings is the accuracy of the device and its sampling time.