Posts Tagged ‘protoyping

16
Jan
12

Prototyping and Trying it out

I hope everyone is doing well this second week of Robot build season. Last week and possibly early this week everyone should have a chassis planned, a way to get up and down the field, and maybe some way to get the balls to a hoop.

But first, a lot of people are having trouble setting up the cRio and LabVIEW software. I’d like to suggest to RTM (Read The Manual). Most of the information is in the document at this link (https://decibel.ni.com/content/docs/DOC-20204)

On with prototyping: You don’t necessarily need to do everything in the game. If you’re a rookie team you might think about doing one thing very well. One thing that can be helpful is getting the balls from one end of the field to the other. Or you might play defense well, keep the balls from moving or have some type of shield that moves up to 84 inches to block shots.

No matter what, by now you should understand the game and how you plan on playing it.

When you know how you want to play the game and are designing your robot to play you should brainstorm on how to get your robot to do it. Prototyping is a way of trying out thing quickly before going to the time and expense of building it on your robot.

To prototype, decide what you are trying to test to see if it would work, quickly build something out of wood or plastic that is approximately what you want and try it. Sometimes parts are C-Clamped together or tied with rope.

One example is a couple of years ago on Breakaway, we were prototyping a ball kicker. First we rigged up some pneumatics on the kitbot, held a pneumatic cylinder by hand and punched the ball. It didn’t work well. We then screwed a frame down to the floor (Our Robot room is an old trailer), took some surgical tubing, rigged up a wooden kicker on a long meddle screw. We would pull the kicker by hand and see how well it would work.  We the switched the surgical tubing to pneumatics and tried it again. We liked the pneumatics the best. It took about 5 hours to try everything, we didn’t waste time building a full robot part to see if something worked or not, and we had a pretty good robot that could score from two-thirds of the field and move the ball the full distance.

Good luck to all

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23
Jan
11

FRC build week 2 musings

I hope everyone’s Robot planning is going well. I’m also hoping all the teams have their strategy down and have a plan to fit the Robot to the strategy. Make sure whatever strategy is chosen is done well. If it’s a defensive strategy make sure the Robot is built to push other Robots around or to be the best blocker possible. If you have a scoring robot, make sure you can score quickly and efficiently.

The Kit Of Parts (KOP) came with many sensors, everyone should try to make use of them where they can. The sensors can be used to aid the driver in Robot operation and to help in autonomous mode. Some of the sensors like the wheel encoders can let you know the distance you move. The linear encoder can help the Robot tell the distance an actuator moves. The gyro can help your robot tell which direction it is pointing. All the sensors have examples that are runnable. To get to them, open LabVIEW and in the lower right hand corner of the opening screen are the FRC examples. All examples have diagrams of how to hookup the sensor. Also, all the data sheets are located on the site http://www.usfirst.org/roboticsprograms/frc/content.aspx?id=18530. Make sure you scroll down.

Right now is a very important time in the build, some parts of the Robot are coming together well, some parts are not coming together and are in need of redesigned. Don’t get discouraged, just keep working at it. There are only four weeks left in the build season but it is plenty of time to get things together.

One thing people should think about is Prototyping. Prototyping is to build a quick and dirty model of whatever you are prototyping. One example is the kicker on last year’s robot. We (team 704) built a wooden frame, screwed it down to the floor and then used different things to kick a soccer ball. We made a kicker and tried various pneumatics, surgical tubing, and bungee cords. We made prototypes of different ways to kick a soccer ball. This year you might prototype various ways to put the game pieces on the scoring pegs. Come up with a way to score the game pieces and build something to try out your ideas.

It’s important to get your robot to a point you can test it before the ship date. Getting out there and running it through its paces is a key to success. Last year’s FRC challenge contained humps the robot had to go over. Our robot was ready somewhat early (a week early) and so we did some testing on a practice field.

During testing last year, after a couple of test runs our chains started to fall off and this bent axle is what we discovered. This along with a torn aluminum pan holding the battery. You don’t want to find out about this during the competition.

Good luck to all. Figure out what to do and do it.