We’ve all heard the complaints from oldsters: “Cars used to be so simple that all you needed to fix them was a couple of wrenches and a rag. Now, you need a computer science degree to even pop the hood!” It’s true to some extent, but such complexity is the cost of progress in the name of safety and efficiency. And now it seems this complexity is coming way down-market, with this traction control system for a Power Wheels Lamborghini.
While not exactly an entry-level model from the Power Wheels line of toddler transportation, the pint-sized Lamborghini Aventador [Jason] bought for his son had a few issues. Straight from the factory, its 6-volt drivetrain was a little anemic, with little of the neck-snapping acceleration characteristic of an electric drive. [Jason] opted to replace the existing 6-volt drive with a 12-volt motor and battery while keeping the original 6-volt controller in place. The resulting rat’s nest of relays was unsightly but sufficient to see a four-fold increase in top speed.
With all that raw power sent to only one wheel, though, the Lambo was prone to spinouts. [Jason] countered this with a traction control system using optical encoders on each of the rear wheels. A NodeMCU senses speed differences between the wheels and controls the motor through an H-bridge to limit slipping. As a bonus, a smartphone app can connect to the Node for in-flight telemetry. Check out the build and the car being put through its paces by the young [Mr. Steal Your Girl] in the video below.
The Power Wheels platform is infinitely hackable – from repairs to restorations to enhancements of questionable sanity, it seems like there’s nothing you can’t do with these little electric vehicles.
No rollcage, gl & hf!
Tot-Sized? This is significantly larger than any tater tot! ;)
So…
You mean that the US Marine Corps “Toys for Tots” program is just a scheme for them to resell the toys you donate just so they can have Tater Tots with their S.O.S.?
B^)
this project is way too much overkill… I LOVE IT!!!
I liked the way the video described all the problems he encountered and how he solved them.
Unfortunately the reasons for the 30A FET being damaged was not being explained. So perhaps I can do a suggestion. When the FET switches ON, everything is fine, current flows through the motor and through the FET. But when the motor needs to stop, the FET opens, the motor will acts as a flyback generator and fries the FET. Just add a diode.
Another thing is/could also be the case, when the motor is powered the car moves, when the motor is switched off the car is still moving and keeps the motor running making the motor act like a generator… again not good.
To prevent the FET from seeing to high voltages (and these voltages can be really high, as the motor is pretty inductive load) they need to be diverted from the FET. A simple diode can do that. Just place that diode across the motor (place the diode in the opposite direction). This way voltages generated by the motor could never exceed the voltage drop of the diode keeping the FET save from harm.
A good idea would be to choose a beefy diode to handle the energy coming from the motor when it acts as a generator.
Choosing a ready made arduino style H-brigde board solves (most of) these problems…
PS: traction control… BRILLIANT!
How about adding regenerative braking?
When a motor acts as generator the voltage can in theory not get higher than it’s operating voltage. The voltage depends on the rotational speed, it’s unlike inductive kickback. Of course the motor windings have some (not very high) inductance, which could induce a voltage spike. If you use a freewheeling diode, you can not power the motor in reverse any more. But the FET could also have been damaged by overcurrent. 30A are not that much and if it is rated for this current it can carry it only under perfect cooling conditions (t_case=25°) But I did not watch the video, so I am not sure.
now you need cameras on it so you don’t need a driver at all.
Over kill and I love it.
It looks like you learnt a lot. great job.
I all most for got. You need 4 – 6 motors and propellers to make it fly as well. and get rid of that remote and make a new one with a 5 to 10 mile range and some cammers. and maybe a parachute for the pilot. Ejection seat will work too. if the pilot can get out of she seat by them self use duct tape.( a lot of duct tape.)
Great job love it. I wish my boys were still young.
That kid almost hit a parked car! That’s hilarious! Could you imagine calling in and explaining that to your insurance company? “Yeah I need to replace the front wheel. Another driver hit me. What? Yeah the little speed demon was going at 12 mph!?
He actually did hit a car
Fantastic.
I do wonder how parents find time to do this stuff though. Is the Mum home with the kid all day?
Often, once parents find the time, the kids are too old.
My dad built us a treehouse thing using the few free moments he had. Started when we were ~5 and, unfortunately, it wasn’t ready to play on until we were ~16.
“With all that raw power sent to only one wheel, though, the Lambo was prone to spinouts.”
Sounds like to me it needs a 3D printed differential back there, with air shocks and anti-sway bar.
Ren, you left out the words self locking from the line “3D printed differential. ….”
B^)
You don’t need a differential if you implement independent motorized wheels… Hell, making four wheel drive would be awesome
…with torque vectoring… :P
A helmet please!
That speed is more than typical average cruise speeds on bicycles in city, and it is mandatory for children to wear helmets when they are traveling on a bicycle. This is based on good reasons and statistics. The skull is not yet fully developed, and the head injuries at these speeds to children less than 6-8 years old are more likely to cause brain injuries.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5005552/
The study you link to is based on bicycles in traffic.
It’s a toy car not intended for use in traffic.
It’s a toy car that you sit in not on, the driver is unlikely to fall off.
It’s a toy car and the driver is really close to the floor so any fall would be less than the impact of running and falling over.
It’s a toy car and as such has a wheel at each corner, so unlike a bicycle it doesn’t fall over when you stop.
It’s a toy car!
More people die as a result of leaving the womb than will ever die from not wearing a plastic hat.
Statistics show that 10% of traffic accidents involve alcohol or excess speed, this means that 90%of traffic accidents are caused by sober people that are not speeding.
So much for statistics.
Plastic hats are not mandatory everywhere, some people have evolved to a point where they can make their own decisions and avoid smacking their heads into stuff.
My dad used to be proud of nailing a couple of boards together. This is great :)
You should put an ultrasonic radar in front to stop the car if there are an obstacle so your child stay safe
OK, I need to build a traction control system for a drag car. can use ABS wheel sensors. can stutter the ignition. you got any ideals?