So you’ve had your first child. Congratulations; your life will never be the same again. [Dusan] was noticing how the introduction of his children into his life altered it by giving him less time for his hobbies in his home laboratory, and decided to incorporate his children into his hacks. The first one to roll out of his lab is a remote-controlled baby stroller.
After some engineering-style measurements (lots of rounding and estimating), [Dusan] found two motors to drive each of the back wheels on a custom stroller frame. He created a set of wooden gears to transfer power from the specialized motors to the wheels. After some batteries and an Arduino were installed, the stroller was ready to get on the road. At this point, though, [Dusan] had a problem. He had failed to consider the fact that children grow, and the added weight of the child was now too much for his stroller. After some adjustments were made (using a lighter stroller frame), the stroller was eventually able to push his kid around without any problems.
This is an interesting hack that we’re not sure has much utility other than the enjoyment that came from creating it. Although [Dusan]’s kid certainly seems to enjoy cruising around in it within a close distance to its operator. Be sure to check out the video of it in operation below, and don’t forget that babies are a great way to persuade your significant other that you need more tools in your work bench, like a CNC machine for example.
I’m not sure I ever really wanted a remote control stroller for my kids, but a power assist for inclines might be nice.
That would make an interesting control system. Monitor when effort increases and seamlessly add assist so the user doesn’t notice a change. Same for downhill — need a regenerative system.
Load cell in the handle…
PID to maintain 0 force (or a few pounds if you want to help the motors out).
I have wanted to make a self propelled cart like that for the Dayton Hamvention flea market… For the heavy stuff. ;)
A load cell could be expensive, and then you have to worry about analog noise.
Consider my lawnmower. The throttle is broken and is now a bar in front of the handle loosely held in place with wire. When I push on the handle, it opens the throttle and the mower moves forward. As the mower moves forward, the throttle starts to close and eventually matches my walking speed.
You can always make a load cell, like I did here:
http://hackaday.com/2015/12/15/feeling-force-through-a-servo/
Or take the load cell out of cheep digital bathroom scales. ;)
The forces actually cancel out very nicely if you just mount an accelerometer on the frame. The forward pointing axis will read exactly the force that is currently being used to counter gravity. Then you can decide to give e.g. 50% of that force from the motors, which gives torque, which gives the motor current, which can then be used in the motor PID control loop.
I’ve been using it on my ebike for a while now:
https://github.com/PetteriAimonen/ebike-controller/blob/master/src/bike_control_task.c#L92
Overall it seems to work pretty nicely, though it doesn’t detect wind and snow and other resisting forces. But for a stroller those are probably not a big issue.
Would have been more fun to give the kid the ability to pilot his own stroller :-)
Might go poorer than you expect. Even bikes can be tricky.
https://www.youtube.com/watch?v=i3lzWJGKUbg
Now THAT’S comedy.
Would be interesting to see how well the child could drive it – Some kind of joystick mounted on the stroller could work. Obviously with remote controlled override!
I once let my daughter “take the wheel” of our riding mower once.
Once…
Heh, yeah, due to actions for songs like wheels on the bus etc and brain damaged children’s shows, kids get the idea that you whip the wheel side to side to make it go…
I’m sure the mom is loving this. /s
Right. A new baby in the house and he has time to putter around on low utility projects for his own amusement.
https://www.youtube.com/watch?v=NRRxVmDiA_M
sorry, had to do it.
A friend has a commercially-produced remote controlled-cart for his golf clubs. Some hiccup at one point sent the cart out of reach and it continued rolling down a long hill into a pond. But, a remote controlled baby stroller seems like a great idea.
Simple design oversight. The wheels should have mechanical breaks (with manual release) that lock down when transmitter signal is lost.
https://hackaday.com/2012/11/12/robot-stroller-lets-baby-steer-without-mowing-down-other-toddlers/
…on second thought…
:-)
(ask my son about learning to ride a bike, and ending up in the ER with a broken arm)
When my oldest daughter (now 20 yld), was a toddler, I made a 3 wheel tank drive car child seat with two windshield wiper motors and two tires from a hand trolley. Steering was with two double switch throw switches as joysticks, so two hand tank style driving. She was a little scared about the jerkiness but otherwise got confident in moving around as a faster way than crawling on the floor. It got decommissioned after using it at the coffee table as a child chair: She reached for her cup and leaned forward pushing both switches and driving straight ahead pushing the 40 pounds coffee table into the wall! Wife didn’t liked it that much after that, even though I had added a horn and headlight.
Ok now that I love should have just added a kill switch so she could turn it of while at the table.
This is from a few years ago, but you might as well give them a wii steering wheel and collision avoidance. :)
All it needs is a “follow me” mode. And a LiDAR. And a couple of Ping Sensors. And a few IMU’s.
These guys made a one :)
https://www.youtube.com/watch?v=PUKMUZ4tlJg
Why masking its face?
Will anyone be able to recognize this cute baby in, say, 2 or 3 months????
Nope. Not gonna trust my kid in the hands of the RF jungle out there.