LIDAR and which one

Hi, there. I am a new owner of the Magni-Silver “God of Strength, very cool”.
I have gotten everything running an I like it. :grinning:
I have not used ad-hoc and zeroconf in a robot since my crawler interest day’s and the (Older spider robot from what was erle-robotics). It is fun to see your system seems nice and tight, good job! The above mentioned system would crash / trash there ad-hoc zerconf system if you tried to run a update, so cu-does for doing it the right way.
Here is my question, what Lidar would you suggest or recommend?
Remembering we wish to run outside as well as inside a building, and need drivers
for a raspberry pi on ROS?
I plan to mount it in the center of the top plate and price, under say $2,000.00.

We have used the SICK551 pretty successfully on the robot, but pricing on that (while not publicly available) seems to be out of your budget (~$2500).

The base model Hokoyu seems to fit within your budget, and should work with ROS on the Raspberry Pi https://www.robotshop.com/en/hokuyo-urg-04lx-ug01-scanning-laser-rangefinder.html

Thank you, I believe I have that unit. I’ll let ya know how it goes. P.S. I have the
Seeed Studio RPLiDAR S1 Portable ToF Laser Scanner Kit - 40M Range on order.
I hope this might do the job, if i can get drivers this could be the best bang for the buck.

Yes you’ll note that there are 5 and 12V power supplies available on the MCB board.

Also note that for the SICK on the front of the robot you have mount points for the LIDAR. You may have to remove the Sonar board to fit everything in, but you should be able to mount the SICK lidar without having to make any modifications to the chassis.

@LloydF

What happened with the slamtec S1 in the end ?
How well did that work for you? Did you have to use the sick lidar instead?
What ros navigation package did you try? (Move_base ? Something else?)
Did you publish anything on GitHub?

The slamtec lidars are being used by open robotics in singapore (they are one of our customers). They will be publishing a full github repo which include 3-d printed parts for mounting etc.

Natively the SICK is the one we recommend. Case in point the slamtec LIDAR that open robotics is using is the A3 - and they are using 3-D printed parts because Slamtech changes their design frequently.

Open robotics is developing a full open source fleet management solution, and our robots are among those that they are using for testing.

HI David,

What do you think about this?
YDLIDAR X4
https://www.sgbotic.com/index.php?dispatch=products.view&product_id=3021

We haven’t evaluated this particular LIDAR, but it appears to be a clone of the well known neato XV-11 LIDAR - that itself is a copy of an open sourced triangulation design.

We evaluated the XV-11 and found that while it was functional it didn’t have particularly good noise characteristics or range. As such mapping results were inconsistent.

Its one of those things that will work most of the time, but if it fails to scan match on 10% of your missions is going to be a serious problem then I would either evaluate this design carefully before proceeding or evaluate other designs.

It should also be noted that as neato has already awarded US patents on their version of the design - sometimes you can encounter difficulty in bringing this type of thing in to the US and using it. Obviously plenty of these things slip under the radar but if you are expecting to use it in large volumes consider the patent situation.

Hi David,

How about RPLIDAR A2M8R4?
https://www.sgbotic.com/index.php?dispatch=products.view&product_id=2510

and RPLIDAR A1M8
https://www.dfrobot.com/product-1125.html

Mmmmm looks like the RPLIDAR A2 is a laser device with power well in to the Class 3b range.

Quoting from this source

Class 3B : " A Class 3B laser is hazardous if the eye is exposed directly"
[sic]
Protective eyewear is typically required where direct viewing of a class 3B laser beam may occur. Class-3B lasers must be equipped with a key switch and a safety interlock.

I would be surprised if you intend to only operate your robot in a lab where you have safety interlocks and where protective eyewear is required. As for the other LIDAR it appears to be a class 3A / 3R device

Class 3R : A Class 3R laser is considered safe if handled carefully, with restricted beam viewing. With a class 3R laser, the MPE [sic Maxiumum Permissible Exposure] can be exceeded, but with a low risk of injury.

I am quite certain that placing said laser on a rotating platform and spraying it in all directions does not constitute “restricted beam viewing” nor “handled carefully” also note the use of the term “low risk” and not “no risk”.

Laser eye strikes are rare and very few roboticists will experience one - but I have heard of them, fortunately with lower powered beams. Obviously these days high powered lasers are cheap and can compensate for low grade optics downstream thus making the overall system very inexpensive. While I did run a class 3b / 4 laser lab in a former life and had to manage laser safety risks as part of running the lab - I am not a dedicated laser safety professional and far be it from me to tell you what to do purely from a laser safety point of view. As such I would encourage you to make your own risk assessment balancing the costs saved against the risks to and value of one’s eyesight.

There are other, considerably more expensive products, that get similar range, but do not fall in to the Class 3b laser safety class.