Anth's Computer Cave

Autonomous Trike

Here's a quick look at our latest autonomous vehicle, an electric Trike. It started life as a kid's chopper, but we've cut it down and added an axle from a 4-wheel-motorbike to create a trike that should go anywhere.

This is a multi-purpose vehicle. I'll use it to test autonomous driving concepts like following me on my push bike to carry my stuff. Brett will test it as a large-scale RC car.

We've created a phone-based RC controller program for manual operation, which can work with any Raspberry Pi-based wheeled devices.

You can set maximum speeds and change acceleration and deceleration rates for both the drive and steering motors.

We'll post the code here soon.

We have all the accessories required to bling the trike up, including a working head light and tail light.

The large pieces will also act as enclosures for the electronics to provide a level of splash-proofing from puddles, rain, beer, etc.

The Raspberry Pi and Arduino mount inside the plastic engine, along with the two 12V drive batteries and two Double BTS 7960 motor controllers.

This makes the engine enclosure a self-contained vehicle-control unit that we can easily disconnect and mount to other vehicles we create later.

The trike is powered by an E150 24V scooter motor

This motor is made to push a small adult on a scooter at running pace so it should really drive the lighter trike well. We plan to double the gear ratio and see if we can get about 30Kph out of it.

The motor will mount inside the fake air-box under the seat with just the sprocket protruding

The steering uses a Holden Commodore steering column and wiper motor assembly for a motorized gooseneck.

We've built a potentiometer-based rotary encoder onto the wiper assembly so our computers can know exactly where the front wheel is pointed at all times

This encoder feeds back a voltage to the Arduino that varies with the steering position. With the wheel turned hard left it will read about 1V and full right it will read about 4V, meaning center should be around 2.5V

Stay tuned for more details.

Cheers

Anth


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