Thank you! Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Skip Morrow <[log in to unmask]> Date: 10/7/19 5:22 AM (GMT-05:00) To: "aprille.j.ericsson" <[log in to unmask]> Cc: [log in to unmask] Subject: Re: [VADCFLL-L] Use sensors? Dr. Ericsson,We have shielded our light sensors a few different ways. First of all, your sensor should be between one beam and two beams above the table surface. In other words, you should be able to slide a single beam under your sensor, but should not be able to slide two stacked beams under the sensor. If your sensor is too high, you will be stuck with very low readings to begin with, and will be much more susceptible to external lighting messing with the readings. In this case, the sensor casing itself sort of provides some shielding, unless it is mounted too high, but it not be enough.Other shielding designs are possible. If you are using the "kit bot" (that is, the standard robot for which there are building instructions that came with the EV3), the sensor is completely exposed on all sides, Consider building a box out of beams and 5x3 "L" beams that can fit around the sensor. Support the box around the sensor so that it stays in place. This can shield some more external lighting.If you are using a different design, such as the square "box turtle" design, you can mount your sensors inside the box where there should be plenty of good shielding.Once you have a design built, you can test it with a flashlight shining on the table in the area of the light sensors to see how effective the shields are. In general it doesn't have to be perfect, but you do want to strike a balance between effective shielding and overall robot design.On Sun, Oct 6, 2019 at 9:11 PM aprille.j.ericsson <[log in to unmask]> wrote:Claire can I ask how did they shield the sensors? Dr. ESent from my Verizon, Samsung Galaxy smartphone-------- Original message --------From: Claire Fornsel <[log in to unmask]> Date: 10/6/19 8:16 PM (GMT-05:00) To: [log in to unmask] Subject: Re: [VADCFLL-L] Use sensors? Rajeev,Something to think about with the color sensor is the type of lighting at the tournaments. The first year our team was out, the students mastered light sensor programming in my fluorescent lit classroom, but the tournament was in a gym with halogen lighting and the light sensor programs did not perform well. The next year out the team decided to shield the light sensors so the type of lighting was not an issue and the team performed well.ClaireOn Sun, Oct 6, 2019 at 8:08 PM Jeff Borek <[log in to unmask]> wrote:Rajeev,I'll share my 2-cents to add to what others have seen. I've coached 4th and 5th graders for a number of years. I have had a team get 2nd place in the robot game without using any sensors at competition (after briefly trying gyro and color sensor for line following). I have had a team with great success using a color sensor for line detection and touch sensor for where to stop. I would estimate maybe a little less than half of Division I teams make good use of a sensor.I really encourage teams to try to use a sensor (or other technique) to get precise movements. The default seems for the kids just to keep trying to add 0.1 rotation here or there or change where the robot starts in order to try to get it to end up where they want it to. Of course if they learn that is not effective, then want to try something else better, that would be great, but I'll admit I really encourage them to do something other than just iterating.This year the sample Crane solution from First has a good simple proportional line follower using color sensor. Given more time I think better to start them with 2-state (right if black, left if white) approach then move to proportional but this year just jumped in with that.For sensors in general, I think the touch sensor is the best place to start. A program that says drive until the touch sensor hit is pretty simple. And definitely remember you can add things to the touch sensor so it can detect a "touch" at more than just the one point.I think the conventional wisdom is the gyro and ultrasonic sensor are not reliable enough to be effective in competition, but I had a team do very well one year using the gyro (though had to be slow turns). And of course they are still effective in learning!Hope that helps.Jeff On Sun, Oct 6, 2019 at 6:52 PM Rajeev Mehra <[log in to unmask]> wrote:
Greetings!
Coach of a rookie team here. I am wondering if other teams use the sensors available in the kit?
I see there are plenty of opportunities, like ultrasonic sensor to guide the robot to a certain location away from something else, color sensor for following the black lines on the mat, gyro sensor for accurate turns and straight line driving.............BUT........do
FLL teams actually use them? Are they just too difficult to use and/or understand?
I wonder if I should spend the time teaching the kids about these "advanced options", or should I just let them figure it out themselves or let them choose whether or not to use these fancy things.
Sincerely,
Rajeev Mehra
Coach: Ultimate Onions
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-- CLAIRE FORNSEL | Design Thinking & ComputingLego Robotics CoachOld Dominion University M.S. Education Norfolk State University B.S. ChemistrySuffolk County Community College A.A.S. Marine Technology
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