![]() |
Common or uncommon sensors used in FRC
Our team is looking into expanding our use of sensors. What sensors do y'all use? Please provide links or specific details of possible.
Thanks in Advance, Mr. B |
Re: Common or uncommon sensors used in FRC
My former team always used the old rotary limit switches that were distributed in the KOP up until 2011. I think that they can be found at this link, but I'm not entirely sure it's the same model.
http://www.automationdirect.com/adc/Shopping/Catalog/Sensors_-z-_Encoders/Limit_Switches/Double-Insulated_(PBT)_Limit_Switches_(AAP,_ABP_Series)/Side_Rotary_Adjustable_Lever_with_Polyamide_Roller _Actuator/AAP2T51Z11 They are extremely helpful for implementing soft stops for arms, kickers, and dumpers. We simply plugged them into the input pins in the DSC, and programmed the robot such that the motors can not rotate in certain directions when the switch is activated. From what I heard, this can be accomplished easier by plugging the limit switch directly into a Jaguar, and using jumpers to determine which directions the motor can rotate when the switch is activated. You will have to consult the Jaguar information sheet for this, though, as I have never attempted this. |
Re: Common or uncommon sensors used in FRC
We've always used limit switches with encoders and gyros from the KOP.
|
Re: Common or uncommon sensors used in FRC
Ultrasonic range sensors (almost every year, to find the distance from the wall) and garage door sensors (two of the last three years, to know whether we had loaded a game piece) have been useful for us.
|
Re: Common or uncommon sensors used in FRC
Quote:
|
Re: Common or uncommon sensors used in FRC
My team is also trying to branch out with our use of sensors. After tons of begging and fundraising, I convinced my team to buy one of these (the analogue version). It's perfect. Our team's autonomous and even teleop relied significantly on this, and it hasn't ever failed us. Also, I've heard from other teams that these are very decent encoders (and are easy to mount), and they work with the encoder classes provided by FIRST with the programming software.
|
Re: Common or uncommon sensors used in FRC
Garage door sensors are the IR beams used to detect if something (like a child) is in the way of your garage door as it descends. The sensor is actually a pair of devices: an IR emitter and an IR receiver. The receiver sends a different signal when it can and cannot see the emitter beam. We have used them for a variety of purposes. Taking Rebound Rumble as an example, we had a garage door sensor mounted low in the robot. When we started picking up a ball it would block the beam and the sensor would signal that something (a ball) was blocking its beam. When the ball cleared the beam and the receiver could again see the emitter the robot knew to turn off the conveyor. A similar set up at the top was used to "count" balls going to the shooter. Together these two garage door sensors let us move balls efficiently inside the robot and count the balls we picked up and shot.
|
Re: Common or uncommon sensors used in FRC
Quote:
|
Re: Common or uncommon sensors used in FRC
Quote:
|
Re: Common or uncommon sensors used in FRC
Quote:
|
Re: Common or uncommon sensors used in FRC
Quote:
Also, our team tried out a Hall Effect(magnetic) sensor this year to work was a soft stop for the cam that pushed our Frisbees into our shooter, and it worked perfectly--all the convenience and functionality of a limit switch, but with no physical contact involved, so it never wore out! |
Re: Common or uncommon sensors used in FRC
Quote:
https://www.sparkfun.com/products/9312 |
Re: Common or uncommon sensors used in FRC
We used a hall-effect sensor (put together by the team) to measure wheel speed -- two opposite-facing neodymium magnets in a bracket on the axle let us use the Counter class's getPeriod() (implemented in the cRIO's FPGA) to determine how fast it was spinning.
We also used IR bounce-back sensors (also team-constructed) for no-contact limit switching, similar to how aryker used a hall-effect sensor. After our district competitions, we also added a string-potentiometer, which in our case we used to keep our tilter from going too high and pulling out our lead screws -- yes, there were mechanical alternatives, but we didn't want to risk dismantling the system on the first day of MAR champs. Also, our drivers ended up using it as an alignment system when our camera died (that is, never worked on the field). |
Re: Common or uncommon sensors used in FRC
Our team generally uses
generally we use IR instead of ultrasonic because IR works better for the ranges we need, and generally the ultrasonics we have are too short a range.Also limit switchs are nice, the problem with them is that they break easly. last year one of the mechanical teams made us put on a Hall Effect Sensor to know the rpm for shooter wheel. We never used it because it was to much work with little benift. Not sure if they realized it wasn't pluged in. |
Re: Common or uncommon sensors used in FRC
Quote:
The best we've been able to do lately is get a potentiometer to give us output for our shooter deck angle calculations and have the camera make the robot able to chase after a frisbee on the floor in a game of "Keep Away". |
| All times are GMT -5. The time now is 05:32. |
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi