Torque Encoders (Electric)

[O. Jenkins]

In the rules for the new U.S. FSAE Electric competition it is specified that we have to use a torque encoder to measure the angle of the accelerator pedal to control the motors. I can't figure out what torque encoders are; are they some special type of rotary encoder or are they one and the same? Can anyone provide any input on this?

[JulianH]

There are rotational potentiometers you can use but they are probably difficult to fit in your pedalbox.

We used linear potentiometers mounted between the torque pedal and the "fixed part" of the pedal box.
Here a picture of the 2012 pedal box, the "green parts" are the potentiometers, red is the accelerator pedal, black the mounting of the pedal box.

http://s1.directupload.net/images/130112/qs4ebfk9.png


The movement of the pedal was then transformed into a linear movement and you could measure the angle of the torque pedal.

What you use is basically up to you. Just make a device that is able to say if the driver is pressing the accelerator a little or a little more http://fsae.com/groupee_common/emoticons/icon_smile.gif

[O. Jenkins]

Great response, thanks!

[TMichaels]

It is in general a good idea to have a look at the electric cars that the European teams built since 2010. They have a lot of experience in building cars to these rules as the FSAE Electric rules have been taken over from the European events.
Quite some pictures of these cars can be found here:
http://media.formulastudent.de/

[TMichaels]

Adding to Julian's post:
With that setup it is good engineering practice to wire the second potentiometer the other way around such that the signal of encoder 1 travels from 0V to 5V, while the signal of encoder 2 travels from 5V to 0V for example. Thus the implausibility function will also detect, if there is an electrical short circuit in the wiring of the encoders.