Remote Controlling an Actual Vehicle

[straight_stewie]

So I need to RC an old truck (a 2000 Chevy 1500 to be exact). It must have an emergency cutoff, be capable of stopping the truck immediately, and  be able to shut off the engine pretty quickly.

 

So here's what I was thinking for the basic control system:

• Linear actuators on the throttle and brake pedals
• Gear reduction system powered by an electric motor for steering

 

And here's what I was thinking for the safety systems:

• A custom circuit board to both crank the engine and shut it off. Think of it as being able to turn the key
• A simple "door down" mechanism to lower a metal plate over the air intake in the manifold
• A linear actuator on the emergency/parking brake pedal.

 

I feel it prudent to mention that this will only ever be driven on a 300 acre field surrounded by 20+ feet deep ditches and thick woods on all sides. In other words, the truck will not be able to escape the safety area.
Do yall think this will be a good system? If not, what should I change? What radio system would you use, and why would you use it?

[Hackentosher]

I think a solenoid valve on the fuel line would be a better solution to kill the engine. I think you could probably get away with a bunch of relays tied to the rc receiver. What's your budget here? 

[straight_stewie]

17 minutes ago, Hackentosher said:

I think a solenoid valve on the fuel line would be a better solution to kill the engine. I think you could probably get away with a bunch of relays tied to the rc receiver. What's your budget here? 

I was thinking that, but then I remembered back to my days as a John Deere mechanic: An engine will die instantly without air, but by cutting off the fuel line (even doing so as close to the engine as possible) it can run for 10-30 seconds just on residual fuel.

My budget is $3,000 total.

[Hackentosher]

1 hour ago, straight_stewie said:

I was thinking that, but then I remembered back to my days as a John Deere mechanic: An engine will die instantly without air, but by cutting off the fuel line (even doing so as close to the engine as possible) it can run for 10-30 seconds just on residual fuel.

My budget is $3,000 total.

Sheit, well you could use an irrigation solenoid valve for the air. 

[straight_stewie]

11 minutes ago, Hackentosher said:

Sheit, well you could use an irrigation solenoid valve for the air. 

Can you give a link of what you were thinking of? All I could find where solenoids (like fuel shut offs in a carbueretor). While looking for your answer I did find out that some companies already make emergency intake air shutoff valves for large diesel engines. They are like $800-$1000 but that's within my budget I think.

What do you think of the steering? Do you think that a gear reduction system will be fast enough to make the truck look "real" being driven around? 
This is for filming after all.

[Hackentosher]

11 minutes ago, straight_stewie said:

Can you give a link of what you were thinking of? All I could find where solenoids (like fuel shut offs in a carbueretor). While looking for your answer I did find out that some companies already make emergency intake air shutoff valves for large diesel engines. They are like $800-$1000 but that's within my budget I think.

What do you think of the steering? Do you think that a gear reduction system will be fast enough to make the truck look "real" being driven around? 
This is for filming after all.

Go down to home Depot and pick up the biggest irrigation solenoid you can find. People make air canons with these as an electronic valve. 

[johnny5c]

2 hours ago, straight_stewie said:

I was thinking that, but then I remembered back to my days as a John Deere mechanic: An engine will die instantly without air, but by cutting off the fuel line (even doing so as close to the engine as possible) it can run for 10-30 seconds just on residual fuel.

My budget is $3,000 total.

I think a dual system would be best, a solenoid for the fuel line and a relay on the main ignition wire that powers the coils...unless it's a diesel then a air cutoff.  A relay on the signal wire for the throttle position sensor would probably work too, it would trigger the "redced engine power" safety mode on a Chevy.

 

As for the steering; not sure if you could find one cheap enough but check out the electronic controlled hydraulic steering boxes they use for rear steering systems in rock crawlers.

[mariushm]

Fuel line + hand brake + disconnect battery from engine ? 

Maybe change the brakes to something like big trucks use (you have to pump air to loosen the brakes, so if you need to brake suddenly you just vent the air)

 

[corrado33]

I feel like you could just use a pneumatic actuator on the brakes then the "kill switch" would just be to open the valve all of the way so the actuator slams on the brakes. You're going to need a "signal" to make the air filter door close anyway, may as well put the brakes on. 

 

Or make the actuator work against a very heavy spring, so that when it loses power the spring pulls the brakes "ON". So basically the actuator works to let the brakes OFF, not the other way around. 

 

The more I think about it, the better pneumatic actuators are looking. You don't need super precise position on the brake pedal, and you can move pneumatic actuators when they aren't powered, so again, if we're going with the spring idea, the actuator works against the spring to lift the brake pedal. If the rig loses power or loses signal, the actuator is vented and power is cut, the spring will pull the brake on.

 

I've seen far too many people try to remote control a car that have had issues. I mean seriously, just watch any of the mythbusters videos where they tried to do it. And they had a hell of a lot bigger budget than you do. So making the truck's default position "BRAKES ON" would be a heck of a lot safer. 

[straight_stewie]

5 hours ago, corrado33 said:

Or make the actuator work against a very heavy spring, so that when it loses power the spring pulls the brakes "ON". So basically the actuator works to let the brakes OFF, not the other way around. 

I really like this idea. I think what I'll do to enact it is four things:

• A cylinder pushing the brake pedal off and a pnuematic spring pushing it on. I don't like the idea of an actual spring in this case, I feel like an actual spring big enough to lock the brakes would be dangerous to work with, but a cylinder fighting another cylinder, with the latter being hooked up to an accumulator is just the ticket.
• A cylinder pushing the gas pedal down against an actual spring.
• A cylinder driven by an accumulator on the emergency brake.
• A valve block with fail open valves on all actuators. When the valves controlling the control cylinders lose power they will dump control air, and when the valves controlling the emergency cylinders lose power they will fail open and allow air to be pushed from the accumulator to the cylinder.

On 11/25/2016 at 0:25 AM, johnny5c said:

As for the steering; not sure if you could find one cheap enough but check out the electronic controlled hydraulic steering boxes they use for rear steering systems in rock crawlers.

That's way to0 expensive. I think on this end I'm going to unfortunately be stuck with the gear reduction system. The only better and still relatively inexpensive thing I can think to do would be to bypass the steering wheel completely and use electronic valves between the power steering pump and the steering cylinder. In fact, I think I'll explore the latter idea a little further.

 

On 11/24/2016 at 11:19 PM, Hackentosher said:

Go down to home Depot and pick up the biggest irrigation solenoid you can find

I'll have to look harder on this front, my local Home Depot and Lowes don't have anything near large enough. 3/4 inch valves were the largest I could find.

[Hackentosher]

58 minutes ago, straight_stewie said:

I'll have to look harder on this front, my local Home Depot and Lowes don't have anything near large enough. 3/4 inch valves were the largest I could find.

This might be big enough, or you could get a couple of them leading into a single, larger pipe and then into the engine. Wire them together, and Bob's your aunty. https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=1"+solenoid+valve&rh=i%3Aaps%2Ck%3A1"+solenoid+valve