robot circuit

Filipe Marques's picture

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Joined: Jan 21, 2017

Replies: 1
robot circuit
January 21, 2017 - 1:35am

I have a robot that I drive with a command as shown in the figure.
I want the robot to make a circuit on a football field according to red lines.
The football field has the measures of 110 meters by 65 meters.
No sensors are required because the circuit to be made is always the same static without obstacles.
Basically I want the robot to travel 100 meters, then turn left and go 2 meters, then turn left and go 100 meters, then turn right and go 2 meters, etc.
The project I want can be seen at www.playgrass.pt/robot.jpg
How can you help me develop this project?
 

Aswinth Raj's picture

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Joined: Aug 16, 2016

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Hi Filipe,
January 21, 2017 - 8:52am

Hi Filipe,

I assume that the robot arena that you are speaking about has a fixed Starting and Ending Point and the distance mentioned by you does not change.

In that case, your robot can be made to accomplish the task by using a speed sensor or distance sensor.

So, when you turn ON your bot it should move 100m stright then turn left and move 2m then turn left again and move 100m and then turn right and move 2m.

For this to happen your bot should know when it reaches that 100m or 2m distance. So, let us make a distance sensor. There a lot of ways to do it, but the most simple way is to use a magnet and a hall Sensor.

Stick a magnet to the wheel and place the hall sensor on the chases. So that, the hall sensor will be triggered each time the magnet crosses the hall sensor. Now, for every one rotation of the wheel the sensor will  be triggered. Lets say the diameter of the wheel is 5cm then if the robot moves 5cm the sensor will be triggered. Like wise use the MCU to calculate for 100m and 2m and make the required turns.

Let us know if you face any problem. 

ALL THE BEST

Filipe Marques's picture

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Joined: Jan 21, 2017

Replies: 1
arduino robot
January 23, 2017 - 3:07am

Hi Aswinth,

Thanks for your feedback.
The big question is how can i mantain a straight line with the robot.

Do you have ideas?

Aswinth Raj's picture

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Joined: Aug 16, 2016

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Use PID Algorithum
January 25, 2017 - 6:31am

If you have planned to  use a differential drive, then you must be careful while actuating your motors, because no two motors are completely identical.

You can either,

1.Reduce the traction of the Arena if possible

2. Merge a line follower if the Arena allows.

But, if both are not possible, then you have to try implementing a PID control. to do this, place rotary encoder for both the wheel. Make your MCU to track the rotation of the wheel and make sure it is identical. If not correct them to fall back into phase by using PID.