Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: rbgerrish on May 07, 2007, 01:11:38 PM

Title: Actuators, throttle/brake control, RC help for 1:1 Project car!
Post by: rbgerrish on May 07, 2007, 01:11:38 PM
Hi folks,

A friend and I are attempting to build a 1:1 remote control car. I am quite familliar with RC, but lack the robot knowledge which would be helpful in controlling such a large machine. I've seen Monster Garage and Mythbusters 1:1 cars, but I cant seem to find any online specific details on what they used to control steering, throttle and brake, and how to tie it to a hobby RC system.

What we'd like is to use a hydraulic ram or actuator (or something similar) on the front axle of this car to steer it. The vehicle will have a gas (or diesel if we can find one) motor, so hydraulic pumps and the like can be powered, as well as alternators/genreators. Any links on information or parts that might help steer this project would be great!

We'll also need to actuate the throttle on the engine. I'm guessing this wont be as hard, and perhaps a giant scale servo could work.

Brakes will be a little trickier, as the car wont have a brake pedal to push.

One of the big questions I have is how do I control actuators and/or rams with a Futaba 9CAP transmitter? Is there some kinf of controller that can handle these big units that will plug into a standrad receiver?

Any thoughts or input will be helpful. We are still in the planning stages.

thanks,
ryan
Title: Re: Actuators, throttle/brake control, RC help for 1:1 Project car!
Post by: ed1380 on May 07, 2007, 01:39:13 PM
any thoughts on getting a beater car, and ataching sylinoids to the steering wheel, gearshift, brakes, gas, etc.
Title: Re: Actuators, throttle/brake control, RC help for 1:1 Project car!
Post by: JonHylands on May 07, 2007, 02:13:39 PM
Google search for "DARPA Grand Challenge" - all those guys have solved this problem already, some in very low-budget forms.

Post on comp.robotics.misc - some of the team guys hang out there, and are quite willing to provide advice.

- Jon
Title: Re: Actuators, throttle/brake control, RC help for 1:1 Project car!
Post by: rbgerrish on May 07, 2007, 07:29:42 PM
Thanks for those thoughts, I'll follow the leads. Any other thoughts are appreciated!
Title: Re: Actuators, throttle/brake control, RC help for 1:1 Project car!
Post by: Admin on May 13, 2007, 04:42:16 PM
If I remember right, the Red Team for the DARPA Challenge replaced their steering wheel with a big gear, than drove that gear with a motor. The motor was controlled by a PIC16F877, which in turn was controlled by a massive computer.

For RC control, you can buy RC motor drivers that are very easy to hook up.
Title: Re: Actuators, throttle/brake control, RC help for 1:1 Project car!
Post by: maverick monk on June 10, 2007, 05:37:30 AM
if the car has working power steering the wheel could be turned by a hobby servo. like a high torque one or a 1/4 scale one..., if its rc, just make sure to get a 2.4 ghz radio with auto freq. detect so somone dosent come on the same freq. causing a 2000lbs rc car to fly into somthing expencive.

for the thorottle and brake, a pnumatic system would be lighter than a hydrolic system. or, if it requires less than 20 lbs of force you could hook a linkage up to another hobby servo