SparkFun Forums

[namith11]

Hey,
I am working on this project that consists of a trolley with a total weight of about 600 kgs, whose 2 main wheels are run by two separate motors. With respect to steering of the trolley, i will be using a handle(about 1 and a half feet). I need to know what kind of sensors i need to use on the handle that will detect slight push on the right and left side of the handle.So if i apply some force on the right side of the handle, the sensor should pick it up and send the info to the controller, which in turn will increase the speed of the right motor, and will result in the trolley turning left.
So basically, i will have to push down the switch(which will start the motor), and steer the trolley in the desired direction. Should i use 2 pressure transducers that will detect the force i apply on either side?
Thanks

[Mee_n_Mac]

"We" will need the answer to two questions first. Is the steering proportional or just left/straight/right ? Do you get a sharper turn the harder you push ?

Does this tiller handle move or deflect when you push on it ? Or is it stiff as steel and you need to detect pressure ?

Your answer might range from simple switches to pots to flex or force sensors depending on the answers to the above.

Lastly what kind of interface is there for steering input to whatever controller there is ? What kind of signal is it expecting ?

[namith11]

Hey thanks for the reply!Steering is limited to left, right and straight. Also there is some amount of play in the handle i.e it is attached to two strips that will cause it to move slightly in the left/right direction. I want to know what kind of transducers i need that will sense that slight movement in either direction.

[Mee_n_Mac]

This is so dependent on the details that it's hard to answer. What you want to do is detect any small relative motion btw the 'rods' that come out to the 'handle' and the body of the (unseen) trolley. Microswitches might do as well as some pressure sensor. Those would be located near the body though, not in the 'boxes' you've shown (btw the handle and rods). If you allow some flex btw the handle and rods, in those boxes ... the the same answer applies but now relying on the relative motion btw the handle and rods.

Alternately the handle itself might be able to incorporate some spring loaded slide switch to do the job.

Hard to say w/o seeing the devices themselves.

What's available to power any sensors and related circuitry ? What kind of control signal is required to do anything to the motors (speed up/down, turn off/on, ??) ?