SlotForum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
550 Posts
Discussion Starter · #1 ·
A crazy idea just popped into my head (God knows what went to make room).


I know its quite common to have pace cars and just set the lowest voltage so a car can lap without crashing, but is it possible to go one better? If you wire up sensors round the track, you could set brake and acceleration points. I initially thought of controlling from a PC but I'm sure it could all be self contained electronically. You could set 2 or 3 different brake point amounts depending on bend intensity.

So any opinions? What would be the best way to do this? Reed switches? For an electronics novice how simple would it be to switch between 3 or 4 different resistors (or diodes?) triggered by reed switches?

Of course the big question would be, if it was all set up right would a human driver beat it?
 

·
Rich Dumas
Joined
·
3,546 Posts
You can put tape over the rails in stragic places so that the pace car can be run at a higher voltage. There have been more sophisticated systems with "robot" pace cars, I did not bookmark any references to those.
 

·
Premium Member
Joined
·
923 Posts
I don't know about intelligent. It ran a lap or two to learn the track. And with enough magna to not spin out it worked fairly well.
But expensive to a fault.
 

·
Registered
Joined
·
730 Posts
Love the idea. The simplest if not cheapest way to do it would be something like an industrial PLC (programmable logic controller) with each pre and post corner sensor acivating an output or combination of to give the track voltage required, HO would be great for this as the domination of magnets on the overal dynamics mean the sudden increases/decreases would be more tolerable.

The weakness of this set up is it would be what is known as 'open loop' in that the system would have no idea if the outputs were having the desired effect and as we know clean fresh arm and clean tyres are alot different to tired and dirty.

so yes a human would beat it easily given the amount of calculations your brain does as you drive.

A fully closed loop system would be the ultimate, the more inputs the better measuring as many peramiters as possible like current draw/time between sensors and anylising the trends over time lap by lap would be unbeatable and would require a pretty sophisticated computer program, but very little processing power.

The all conquring Williams FW14B (the car not the gobby bloke) was run from a psion organiser after all and whether the rumoured 'drone' lap of Silverstone by Mclaren ever actually happened we don't know, but the fully closed loop active ride/traction control and fly by wire nature of the car means it was feasable.

Back to your original question, YES! micro processors are just a load of relays and so you can easily construct logic gates using them or simply use a sensor on the way in to switch a certain resistance/diodes in to the track feed and a sensor on the way out to switch back out. You would just have to have a changeover relay for each corner in series with the feed to the rail. It would be pretty rudimentry but a fun project.

And yes reed relays would work no problem with HO, estimated cost if you bought everything from M*plin would be about £7 a corner.
 

·
Registered
Joined
·
730 Posts
QUOTE (Julian_Boolean @ 8 Mar 2012, 20:04) <{POST_SNAPBACK}>A PLC is a grand idea, in fact a two grand idea for a Siemens PLC.

Glad I've never had to pay for one then, i did say if not the cheapest.

Sloique (remember him?) brought his Sportworld over to my house a few times and we actually ran some very painful meetings with it. The concept was fantastic and had it even come close to working properly I would have gone out and bpought one the next day! It boasted race control software as good as any i've seen, online racing that could have been such a hit around the world with those not close to a club and the pacer car feature that became more effective the more dead sections you installed.

In the event it was unimaginably bad. Dead sections as sensing devices were it's downfall as track breaks, dirty braids and even accidents could confuse it and it tripped out ALL THE TIME.

The same tech was used for the first generation of SSD that's why you saw those guys having so much 'fun' copper taping tracks and the strong home dev scene I guess.

Somebody sat in a meeting and had a great idea, the tech guys just couldn't deliver it.......but they released it anyway.
 

·
Registered
Joined
·
3,748 Posts
QUOTE (marctownsend @ 8 Mar 2012, 21:33) <{POST_SNAPBACK}>Somebody sat in a meeting and had a great idea, the tech guys just couldn't deliver it.......but they released it anyway.

Did they also work for Microsoft, or Cisco, or Siemens etc. etc. Oh how I love working in IT, about the only kit we've had that worked straight away was some Motorola stuff.
 

·
Registered
Joined
·
3,748 Posts
I just had a thought, you could wire in a Scalextric Pacer to do this, all the Pacer does is record the throttle settings you do in a lap and then "play them back" to the car each lap, but the timing tends to slip with the Pacer if you do a lot of laps.
 

·
Registered
Joined
·
550 Posts
Discussion Starter · #10 ·
Lots of fanciful and possibly expensive ideas, some of which have gone straight over my head!


That Pacer car sounds fun but I'm thinking more of controlling on the fly rather than having to program one car.

Suppose I wanted 4 speeds (straight, fast bend, medium bend and slow bend), if I had 4 paths from the power to track (add a diode rotary switches to make each voltage adjustable) I would then just need to switch between circuit paths. Sort of like an AV source selector - only thing is it would need to work on the signals from the track rather than hard switching. That's the bit that's stumping me - turning one path on and the other three off with a pulse. Guessing a PIC controlling a relay board would be the easy way to go? Never done any PIC programming before (lots of computer stuff though), so can any one point me in the direction of what I might need hardware wise or tutorials for a complete PIC novice?

As a test I think it would be cool to build a small oval and try and get the car slowing for the bends and speeding up the straights.

To the electronics wise out there this probably sounds like the ramblings of a madman!

All comments or suggestions appreciated.
 

·
Rich Dumas
Joined
·
3,546 Posts
This would make an interesting project, it probably would work better with slower cars. You would have to break one lane up into sections with the ability to control the voltages in the curves. There would have to be braking areas as well. You could use diodes to drop the voltage, but voltage regulators would give better control.
 

·
Registered
Joined
·
550 Posts
Decided to have a play today with some reed switches. I've not used these with slot cars before (always been IR) so I wanted to make sure they would work, especially for braking at the end of a long straight as I've heard they often miss fast cars.

Rigged up a bit of track with a reed switch and LED and stuck it at the end of my fastest straight. Good news is it worked fine. Super G+, Mega G, Micro Scalextric, Tyco 440x2 and Artin F were all fine. At 50p a switch I think it's on to the next stage of the project. The cost and operation of the sensors was the one thing that would make or break the idea, as I really couldn't see me wiring up dozens of light bridges! In theory the rest should all work.

Had a crash course on PIC programming from my boss on Friday, so its time to get my head round that side of things. Should be pretty straightforward to get four inputs to control four relays... if you know what you're doing.
 
1 - 13 of 13 Posts
Top