A 10 m/s 3kg 4WD indoor rover ... Is it possible?

Hello,

I am wondering if I can build an autonomous 4WD rover with approx. velocity of 8…10 m/s (indoor only) to carry e.g. 3kg.
One of the my stupid questions is how to stop it and reverse the direction.
This is for educational purpose.

Do you have such an experience?
Ideas?

Thanks in advance!

Hi,

We sell a lot of 4wd robot kits that could be used to do this. It all depends on the size of the robot you need.

The direction would be manage by the controller required to control the robot.
For example, here is a complete kit that include the frame and a controller: robotshop.com/en/4wd-romeo-mobile-platform.html?product-code=RB-Dfr-395

As for the payload, it all depends on the incline, or the surface. If you go in a straight line it will probably be good but if you try to turn it might not work great (4WD robots are not great for turning on the spot.)
So if you need your robot to be more agile, you might want to consider a 2WD Mobile plateform robot.

I hope this gives you some Ideas for your project.

Thanks,

However - looking at the kit (Romeo) details as shown:
• 4WD Mobile Platform Motors: 3-12V DC
• Speed: 90cm/s

This is 10 times less than needed.
Do you have any recommendations re: the motors?
Possible options?

HI,

Sorry for the speed confusion, we are used to much slower speeds. In that case, you will have to go with a fully custom approach.

I don’t have a direct motor recommendation as it requires some calculations specific to your application We have a simple calculation tool
on our blog: robotshop.com/blog/en/drive-motor-sizing-tool-9698 that should help you know what you are looking for.

Once you know, you will have to find the appropriate DC motors, wheels, chassis like this [(robotshop.com/en/lynxmotion- … a4wd1.html](https://www.robotshop.com/en/lynxmotion-aluminum-chassis-a4wd1.html)) and controller.

I hope this points you toward the right direction.

Best regards,

Well,

Already did it - be sure, however, I still have the same availability and related questions.
Hope you already have the right answers and/or right experience, so - slower:

  1. Input (as an example): velocity = 8 m/s, acceleration = 4 m/s2, total mass = 5 kg, 4wd/4 motors, indoor/max incline = 0.

  2. My stupid questions:

… Recommended motors for HIGH speed …
What I usually see is " With its integrated reduction box, it is specially designed to operate at low speed." as e.g. for GHM-12 and GHM-13 found around the a4wd1 chassis description.

Then:
… Do I have to think about a kind of brakes for a 5 kg 4wd rover …
… Wheels type & diameter recommended where it makes sense …
… What else is critical for the design…


Sure that the correct answers and examples will be of use not only for me!
Thanks in advance!

Hi,

The thing is, you want to move 5kg and go fast, so you do not only need a motor for speed, but also an motor that will be strong enough.

These robot wheel would be the minimum I would recommend for size (about 12 mm): robotshop.com/en/rblyn23-off-road-robot-tire.html?product-code=RB-Lyn-23
The calculation is (Rpm * 3.1415 * Diameter in meters) / 60 = robot speed in meters/s

In your case: (1500 * 3.1415 * .12) = 9.42 m/s, so you need a motor that can do around 1500 rpm + has a lot of torque ( probably around 1.5Nm or more) which is not a common motor we have in stock.
You will probably need to find high speed motor with a gear box to get to the desired speed/force configuration. What you are looking for is more in the realm of Brushless DC RC cars. You might be able to find
one on the RC market and adapt it to your application. (30km/h is extremely fast for indoor, are you sure this is what you want ?)

… Do I have to think about a kind of brakes for a 5 kg 4wd rover … : If you plan to go a 30km/h with 5kg, indoor, yes it might be a good idea.

… What else is critical for the design… High speed, high torque will mean high current. Motor controller and battery choice will be critical.

Best regards,

Thanks Simon,

This is in line with my own thoughts!
Do you have a good example of a RC car of 4…5 kg with a good enough BLDC, gear box and brakes?
Still trying to re-use the kit(s) - if available.

HI,

I am sorry but I don’t have any example.

Best regards,