How to transform self drive lawn mower into robot that drives itself

[gl1]

Hi all,

I want to make a project, convert a self propelled lawn mower into a robot.
Any one got some good pointers for me, im totally new to robotics.

I will want the bot to drive itself around the garden, reverse, go forward and avoid objects.

Any ideas what i use to control the forward/reverse gear selection, and what components i will need to have the bot guide itselef around the garden

I plan to use a PIC microcontroller as the brains, as i am familiar with programming mico controllers.
But interfacing the little electronics to the mechanical hardwarwe i have no experience.

Thanks

 

[BradtheRad]

You'll need to install a mechanism to steer the mower. It will be easier if the front wheels already pivot (assuming the rear wheels are propelled). You'll add either a solenoid, or a servo. This will move an arm attached to both wheels.

A similar solenoid/servo arrangement will engage/disengage the propelling drive.

You exert physical force to do these things. Your mechanisms must have the power to exert the same amount of force. So you'll need to add a battery to power these mechanisms.

To recognize obstacles, it may not be enough to use photo-sensors. It will probably require a webcam or two. Plus some expert programming.

 

[gl1]

Thanks for Reply Brad,

Could you recommend a servo/solenoid combo to apply approx 100/150N force.

IS there any other solution to using a webcam, this i think would take a lot of programming(a DSP would be required)

Thanks,

 

[BradtheRad]

I believe I've heard there are larger, more powerful servos.
Don't know what to suggest. I only have experience with the little servos in radio-controlled airplanes.

As an alternative to a camera, there are cheap infra-red motion sensors such as the type which turn on lights when something passes in front of it.

Or, mount a photosensor on the front of the mower. Shine a bright led spotlight ahead of it. An approaching obstacle will reflect light back to the photosensor. That's the theory anyway.
(Flash the led's at a rapid frequency. Make your detection circuit tuned at the same frequency.)