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Zalophus: A robot


Valerio
(@valerio)
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Hello everyone

I hope you're all well.

 

Yesterday I started putting together a robot that I had designed last week.

This robot will be controlled by a computer program, and will communicate with the computer using bluetooth.

It will have a rotating infrared rangefinder that will send data to the computer, which in turn will create a map of the surrounding area using the data.

This way you can see what's in front of the robot even if it is in another room.

Zalophus

The robot has two motor wheels and one ball caster.

The microcontroller board used is an Elegoo Arduino Uno.

The motors are solarobotics GM9

The motor board is an L298N

The rangefinder is a VL53L0X on a breakout board.

The power source are 4 NiMh AA batteries

 

I hope you like this project (by the way, the name comes from the scientific name of a sea lion family).

Have a nice day!

 

 

 


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Inq
 Inq
(@inq)
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Joined: 5 months ago
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@valerio - Certainly do like it!  And the name sounds appropriate.  I imagine the robot's gate will be similar to a sea lion's.  

I've used the GM9 type motors and L298N on a remote control style robot.  I look forward to your progress... especially with the mapping and computer control. 

VBR,

Inq

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, Access Point Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


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Valerio
(@valerio)
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@inq

Update:

Zalophus Finished

I've managed to make the motors work, without too many issues.

I've also managed to make bluetooth control work as well.

 

The issue is that when I tried to implement usage of the servo it overheated and released smoke.

I don't want to simply plug in another servo, because I'm afraid that it will burn like the first one.

And this issue ended up being the last straw when it comes to continuing this project, since the chassis has quite a few mechanical flaws and the robot sometimes becomes incapable of moving forward or backward, even though the wheels spin in the right direction.

 

I may finish the project in the future (or more likely start

over), but for now i will leave it as a simple bluetooth control car.

Which is already something I haven't done before.

 

I'm still relatively happy about this project, although it could have been better if I ordered the components

before designing the 3d printed objects.

 

Have a nice day

 


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Ron
 Ron
(@zander)
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Joined: 2 years ago
Posts: 2755
 

Knowing when to start over is a valuable skill that many never master.

It is considered poor judgement to traverse a chasm in 2 leaps.


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Mark Bolton
(@mark-bolton)
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Posts: 106
 

I like to start with a rough as guts prototype and incrementally tidy it up.

 

Cheers M


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Inq
 Inq
(@inq)
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Posted by: @valerio

And this issue ended up being the last straw when it comes to continuing this project, since the chassis has quite a few mechanical flaws and the robot sometimes becomes incapable of moving forward or backward, even though the wheels spin in the right direction.

I suspected you'd have troubles when I saw your original image.  There is a fundamental mechanical engineering concept that I take for granted that does not seem to be common knowledge. 

Engineering term - The further the distance of a weight from the axis of rotation, the harder it is to turn and it is a function of the square of the distance.

How this would greatly help your design - The axis of rotation (when trying to Yaw) for your robot will be half way between the two driven wheels.  You should always put the heaviest things directly over this point.  I noted your battery is in the worse possible place at the far end away from your driven wheels.  As a side benefit having the weight over the wheels, gives them more traction.  Put the lightest things furthest away.

Maybe you can use hot glue or something and re-organize your pieces on your chassis.  If you do you will find your robot moves and yaws quite nimbly.

VBR,

Inq

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, Access Point Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


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Valerio
(@valerio)
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Posts: 67
Topic starter  

@inq

Yes, you're right, it will probably help even though the robot already turns quite quickly on the spot.

I've actually fixed the servo issue, but due to a hardware issue with the infrared sensor I'm forced to suspend this project until either I get another sensor or I create a holder for an HC-SR04 that will replace it.

But what I'm going to do is probably to move on to a completely new chassis where I fix this and other mechanical issues like wrong size for screw holes and the lack of a hole for the servo cable (the cable was supposed to get under the chassis, but there is barely space for the servo alone).

And that's if my next project is a redo of this one, which I'm not sure about.

 

Anyways, thank you for the suggestion.

 

Have a nice day

 

 

 


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Mark Bolton
(@mark-bolton)
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Posts: 106
 

@valerio On a Philosophical note; when I was in Industry - I was very expensive - and being paid to play about was never an option. When things all got a little bit too much, the Samson Option (burn it all down and Return to Go ) was often a Savior. One can mess about and pour more time and money into a lost cause ... I believe it is called the Sunk Cost fallacy or some such. "You are so close but yet so far away." Chuck it in the bin and start over. I know it is brutal but "tinkering" can be such a trap. I know this approach represents an asymptote but it has saved my sorry hide more than once. 

I tend to err on the side of Samson with Linux. I am more likely to crack the whip and reinstall and set it up again and get my system going in twenty minutes, in preference to  finding out what exactly was causing my OS to spit up fur-balls ..alas my curiosity was not satisfied but I "got on with the job" ...

My first foreman after I graduated from Trade School was Swiss and a God in my eyes. He called me over once and asked "Mark - can you explain the Correct Use of Pockets? ~pause~ When you are not sure what is going on you put your'e hands in them" Brilliant advice and over the years it saved my employers millions. But, logically, at some point, one must remove one's hands from one's pockets and get the machine going again.

Kindest of Regards

 

M


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