I am trying to create an automatic breaking system.
The design is a manual push along device so does not require any electronics to move however I want the wheels to lock if the device is pushed too fast.
I have looked into using a microcontroller and an accelerometer and it seems linear actuators could work but im struggling to work out how this would all fit together and do what i need it to.
Any insight would be greatfull! Thanks : )
Why not use centrifugal force? As the wheel spins, it forces out rubber braking pads which rub against a surface (normally held in with springs for example). The faster the wheel rotates, the more force the rubber pad is subjected to, causing friction and slowing down the wheel. However, this would not make the wheel lock, just reduce its speed. You could modify the setup to instead use teeth which, when the wheel has reached a certain speed - lock with teeth in an outer wheel, causing an immediate stop to the wheel.
An accelerometer would measure the linear acceleration / speed of the cart and and send the information to a microcontroller If it reached a certain value, you could have the microcontroller send a signal to a linear actuator to push against a braking surface of the wheel (again, not an immediate “lock”). Another option is to have the rim perforated with cutouts and have the actuator (linear or other) jam a pin into the cutout causing an immediate stop of the wheel (almost an emergency measure).
Hope this gives you some ideas,