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Project Help and Ideas » Latest Drive by Wire Test Run Video

July 09, 2013
by esoderberg
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test run

Not a big change in performance from last video post, but lots of updates under the hood that make it much safer and more robust: dual redundant gyro/accel's, dual speed sensor inputs(using off the shelf ABS speed sensors vice my previous custom Hall Switch circuit), software error checking routines, and a Warning Panel. The driver's view video was taken one handed with my cell phone, so its not Hollywood quality, but it gets the idea across.

Eric

July 09, 2013
by JKITSON
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Amazing. I think I might look into ABS sensors for my Pull Sled. They sure work good for you. Thanks for the "show".. Jim

July 14, 2013
by pcbolt
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Great job, Eric.

How are you actually steering, by wire or by detecting motion like a Segway?

July 14, 2013
by esoderberg
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PCBolt,

Tilt rate, accel, and velocity are measured and used by the micro-controller to make all of the direct steer inputs, probably very similar to the Segway. The driver input only controls how much the vehicle tilts, with no direct control of the steering actuator. Obviously, as the vehicle tilts in a particular direction the steering will eventually follow to allow a turn, but it's more complicated than just electrically powered steering. The driver inputs are via a joystick; I have two control modes: one where the tilt rate is proportional to the stick input and another where the tilt angle is proportional to the stick input. As a pilot, I prefer the former, but if you are only used to driving a car the latter is probably more familiar.

Eric

July 15, 2013
by pcbolt
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Ah...gotcha. Very cool. Do you use the other axis of the joystick to control speed/braking?

July 15, 2013
by esoderberg
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PCBolt,

The joystick I'm using has only one axis (it makes up for it by having two dual redundant outputs, because safety is first, (or at least second or third)). The speed and braking is as low tech as it gets; I pulled the brake and throttle off the handle bars that came with the bike and with just a little bit of welding set them up as brake and gas pedals respectively. That loop of cable you can see in the video is the brake line coming off the top of the brake "pedal".
I think it's a cool concept that you have in mind though and have pondered having a two axis joystick with tilt/steering on one axis and throttle/brake on the other. If I get around to building an all electric version, I may well try to implement that kind of control scheme.

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