Menü
Aktuelles
Von:
Filter

Valify - my robot lawnmower project

R

raess

Member
Hi All, Very Nice Forum. I wanted to share my project. I am currently building my own custom lawnmower. The name is Valify.
You Can follow my build blog over at http://valify.se and most of the parts are available Thiniverse
Please note that this thing is still a Work in Progress. Files, instructions, and other stuff might change as the project moves on.

Some hardware specs:
Jetson TX2 Development Kit
Scanse Sweep
Intel® RealSense™ Camera ZR300
2x DC Planetary Geared Motor 24 Volt med Hall IC 30-33 RPM 8mm
2x Vapex Li-Po Battery 6S 22.2V 4000mAh 25C XT60
SparkFun 9DoF
RoboClaw 2x45A ST
Emlid Reach — RTK GNSS modules
(Mower motors for the blades I have not decided yet.)

As always I enjoy feedback both negative and positive. :)
Thanks


Some Pictures of the design:
516a43a698c1c590a08fdbe16cdda612_preview_featured.jpg
 
Hi raess,
very well looking design. I already visited you side. Nice that you share your project here.
I am very interested how your build goes further.
 
Hello Raess,

thank you for sharing your design and progress here. I found your design at Liam Facebook group. It is much easier to follow here for me (I don't understand any word they write there, just watching pictures and try to understand from translation).

What I'm missing is the build size of printer you use. It would be great if it fits on common Prusa bed site (approx 200mmx200mm) as most people will be able to print.

I will have a close watch to your progress too.

Patrick
 
Thanks Paddy. If you want to have a more complete view of the build, then check out my blog now and then. I will no write every detail of the build on forums, but I will do a quick update post now and then. http://valify.se
The build size. Yes I print with A Raise 3D N2+ with 300X300X600mm. I know not everybody has the ability to print this large objects. But most parts can be printed with 200x200 if you have Z around 400-500mm.So what build height is the Prusa? Splitting the body in even more parts is nothing I would recommend, but hey. Sure I can do it later on when I got my prototype printed. Just send me your Build sizes. But then I can't ensure the structural strength of the body.

Anyways, Second part in the printer. B) Will be ready tomorrow at 15.00.
IMG_2071.jpg


Today I also started to look at components for The cutting system. I was looking at many different motors, But I settled at 3pcs of the http://store-en.tmotor.com/goods.php?id=421T-motor P60 KV340 and 3pcs of the T-motor AIR 40A ESC.

I also started the design for the cutting system. I was aiming to use individual height control for each motor with the help of Linear Actuators. I was planning to use a 50mm stroke from Actuonix. But found that I had some space issue/limit on the two motors in front when mounting the actuator vertically. Lets look more at that later or go down to 30mm stroke.
CUTTING.jpeg


Any suggestions? just shoot me a comment.
Cheers
Attachment: https://forum.ardumower.de/data/media/kunena/attachments/4372/IMG_2071.jpg/
 
Zuletzt bearbeitet von einem Moderator:
Hello.
Very very nice work ..
I quickly went through your site and I see that you have not forgotten anything and have worked a lot.
So my remarks are.
Solar panel. I do not think it is a correct solution for a mower ,insufficient power by cm2. HVA test this in on 230Acx hybrid in the past.
For mowing motors it is important to be able to monitor the intensity absorbed or the speed of rotation to detect a possible blockage ,is it easy on ESP?
Regarding the cutting height it is important to remember that a robot that works properly never changes this height over a full season, manual adjustment is sufficient.

Rtk very good solution if it can work on 4cm accuracy into your area and under the tree.
ROS very good choice but need a lot of dev work and specific module to work.
Motor driver very good also.

So i follow all your post with a big interest.
I think also it s a good think if it s possible to print the part on standart 3D printer like prusa.

By and again very nice work.
 
Thanks for the feedback Bernard. This is my first lawnmower project. So some parts of this project will be fails until I found the best solutions.
The idea with the solar panel is not that it should be self-sufficient on it (Only a fun detail for a leftover space).

You are properly right on the ESC. I will explore this a bit more and also look at the VESC there are also ROS package for this. http://vedder.se/2015/01/vesc-open-source-esc/
RTK will be used in parallel to the other systems. So the Idea is that the other systems will be used when the RTK enters a dark spot ( Lets explore this later on).

Once again, noted about the build size, I can slice it for you Pursa needs when I have completed my prototype.

Cheers
 
Reading a bit on the solutions for the motors on the robot. I currently are using the DC Planetary Geared Motor 24 Volt med Hall IC 30-33 RPM 8mm sold in the store here.
But I think they are a bit loud? I want my mower to be as silent as possible. Maybe I should change the motors to brushless in order to keep in silent. The VESC board seems to be a good solution to get the stuff I need. It also makes it possible for regenerative braking which are great when robot changing directions alot.

Anyone here using the VESC?
 
The problem with the VESC board is, that you have build it by your own. In my opinion this is too time consuming.
 
Hi.
All depend on what you want exactly (Fun and discovery like many member on this forum or full autonomous working mower).

DC/DC motor are perfect for low cost,easy current control and long life working (Ihave a Robomow RL1000 from 2005 so 13 years of mowing and the motor brush are Ok) but yes they make noise
For the driving Wheel i think you can find DC/DC motor very silencious.(I think the noise came from ball bearing quality and not brush)
For the cutting be very carreful not only on the motor ,but also on the blade choise, a disk like HVA make no noise but a blade like robomow is very Noisy (like a Drone).

Good luck and hope you have a lot of free time to implement all these new kind of parts.
 
@Roland why do I have to build it on my own? There are lot of suppliers that sell pre-built.

For example: https://diyelectricskateboard.com/products/torque-esc-vesc-bldc-electronic-speed-controller
 
Zuletzt bearbeitet von einem Moderator:
I was going to use DC Brushed Planetary Geared Motor, because of the noise I have now bought new motors. I have already started designing the new drive system (that will also functions as a support frame for the rear parts). The new Drive-system will be CNC milled in Aluminum for better strength. To reduce noises I will switch over to use a belt-drive. This way I can also change pulleys quite easy and allowing me to change the gear ratio quite easy.

So the New motors are 6355 Sensored Brushless (BLDC) motors 190kv. I also bought new motor controllers, VESC 4.12 PCB R-SNAKE/ FLIER equipped with heatsink to avoid overheating of the Mosfets on long runnings or in extreme conditions of use requiring a lot of the motor and consequently of the VESC. The motors and VESC arrives in approximately 4-14 days. So It gives me plenty of more time to design this further.


You can read the full post here: http://valify.se/2018/03/06/changes-to-the-robots-drive-system/
Here is the first concept sketch of the Drive-system
drivesystem2.jpg

Attachment: https://forum.ardumower.de/data/media/kunena/attachments/4372/drivesystem2.jpg/
 
Zuletzt bearbeitet von einem Moderator:
Hi.
I know Nothing on ESC motor but Something very important in robot mower is the Battery life.
Did the ESC or stepper motor use less or more power than DC/DC motor during accel ??
The Belt is not very good for power consumption.Direct drive or gearing is better.
By.
 
So the fourth part for the Valify Robot Lawnmower was completed 30 minutes ago and the results are partly successful. This part was a tricky 3D print. It was very tall and relatively narrow. First off I got some minor warping/lifting in both ends making the part a bit oblique. But good enough to maybe work anyway. Because it was oblique the support beam structure was not as easy to slide in, I needed to apply some force making minor cracking in 3 places (lets see if I can retouch/fix this).
I will do some further investigations tomorrow if this part can be used on the robot. I need to confirm if the part can handle applied force and fix the cracks. I would also need to check if/or the oblique has any impact on the overall quality and that the front wheels would line up.


IMG_2101.jpg


as always you can follow the build on my blog http://valify.se Attachment: https://forum.ardumower.de/data/media/kunena/attachments/4372/IMG_2101.jpg/
 
Zuletzt bearbeitet von einem Moderator:
Du musst dich einloggen oder registrieren, um hier zu antworten.
Oben