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Topic: Android phone following robot? (Read 4 times) previous topic - next topic

sskonbac

Hi all,

I'm new to robotics and arduino, but I have been wondering of making robot that would follow me during golf courses and carry my bag staying about 2-3 meters behind me.
Similiar producs have been made (shadow caddy) but the prices are way too much for my budget. I know some programming (PHP, HTML, javascript, VB) so I think I can handle the coding when I dig into it.
I know this is very big project and I do not have hurry with it. First I want to know if it is possible making robot to follow phone (maybe using Bluetooth and three receivers in robot which will analyse the location of phone and follow accordingly) Other option is that I will build separate transmitter and use something other that bluetooth.
I have yet not found a arduino motor controller that would be able to control app. 2x 80W motors so any help from here would be also appreciated.

Hoping to hear any suggestions of hardware to use etc. to help me to achieve my goals.

Thanks in advance!

PaulS

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I have yet not found a arduino motor controller that would be able to control app. 2x 80W motors so any help from here would be also appreciated.

80W at 1 volt and 80W at 1000 volts are quite different amounts of current. Help narrow that down a bit, OK?

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First I want to know if it is possible making robot to follow phone

Not easily. The only indication that the robot might have is the signal strength from the phone. The signal strength is not necessarily linear, and is very small, anyway. Detecting the actual direction to the phone would require that the robot be able to wave a directional antenna around.

There really does not appear to be a cheap, easy to implement, "Hey, follow me" solution. At least not that the Arduino can implement.

Now, if you were to wire two IR emitters into the shoulders of your jacket, the robot could use two receivers and determine where you were with respect to itself.

The nice thing about this approach is that when you turn your back on the robot, it could stop, instead of running you over.

Although IR might not work too well on a sunny day, and, who plays golf in the rain. Don't bother answering that. I know that lots of crazy people do.

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Similiar producs have been made (shadow caddy) but the prices are way too much for my budget.

It would be worth investigating how they work.

sskonbac

Hi,

Thanks for the reply.

I have not desided the voltage of the system, but around 12V-24V should be fine. (I'm thinking of using LiFePo4 batterys but that does not really matter i guess).
I was thinking that would it be possible to send time data from phone via Bluetooth and have several receivers on robot to determite location. similiar to GPS, but other way around?
Not the cheapest method i know but does anybody know if it can be done?

Thanks!

Magician

If I understand you correctly, there are three parts in your project :
1. Electrical motor driver , the easiest part, and better to leave it as last stage after two others designed.
2. Distance measurements, also shouldn't be any problem, I separate this part just as safety control, to prevent human been hurt, by robot running over.
3. Localization. The main part, there were a few discussions  on this forum, you can try a search engine. Was no simple solution found, AFAIK, but some ideas were promising.
RF approach, Zigbee or BT as you suggest, Wi-Fi etc, less likely to get results, simply because the speed of RF wave  is too high.
3*10^8 m/sec,  it's about 1 meter in 3 nanosecond. Times resolution is definitely above arduino can do (62.5 nanosecond),
I'm not saying it's not possible, but it would require external hardware (atomic stability generators ), and it won't be hobbyist level project with low budget.
Using sound, or ultrasound looks more realistic way.

sskonbac

Hi again.

Been thinking a bit and ultrasound could be the right approach for this.
I found following sensor and I'm wondering if this could be used in my project: http://robot-electronics.co.uk/htm/srf02tech.htm
While these sensors are quite cheap, I still want to be sure I can do what needed with these sensors:
have 1 sensor sending pulse from my belt
and have 3 (or more) sensors reading the distance to my belt.

Can someone please confirm or suggest better and or cheaper sensor.

Thanks!

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