What's the concept?
 

I'm curious how teams like 610 are able to shoot discs in rapid succession while still maintaining a high degree of accuracy.

Re: What's the concept?
 

Stability, consistent speed of shooter, consistent feed... There's a number of variables that go into it but they all boil down to the system being consistent every shot.

Re: What's the concept?
 

Sturdy shooting platform, flywheel shooter, and a high shooter wheel contact time all help.

Re: What's the concept?
 

Programming and weeks of iteration.

Nothing complex mechanically, 1/4 arc shooter driven by a Mini CIM, pneumatic firing, stacked hopper.

Re: What's the concept?
 

Hmm... The reason I brought this topic up is I was thinking maybe we could make our shooter do the same thing. We have the exact same setup we've just never tried pushing its limits.

Edit: Using a regular CIM though.

Re: What's the concept?
 

Aside from keeping everything stable and minimizing vibration, the real key is to design your system such that the wheel can reach the exact same speed prior to every disk entering it. Put an encoder on the wheel and learn how to use PID control. Only push the next disc into the shooter if the wheel has hit the target speed.

This can be assisted with a flywheel - a weighted wheel designed to help maintain speed during shooting. With a flywheel, it will take longer to spin up initially, but the wheel will slow down less when it fires a disc. This helps to maintain a constant speed as you shoot.

Re: What's the concept?
 

Good shooter control system:
Accurate, fast speed measurement and an appropriate controller.

For example, 4183's robot has its shooter on a photosensor based bang-bang controller with automatic firing when at speed. It can fire at least 1.5 discs per second with great consistency and power. I don't know exactly what 610 did, though.

Re: What's the concept?
 

You speak as if we're not already doing this ;)

Re: What's the concept?
 

It also depends on hardware. If powerful motors with the correct gear ratio are used, the shooter can get back up to speed quickly.

Re: What's the concept?
 

Here are two pictures that I took of 610's Robot after the Final matches.
I too, was curious about how they managed the rapid fire.

I don't know if I was able to show enough information, nonetheless, since you are looking for some clues.

Re: What's the concept?
 

1. Relentless design iteration.
2. Motor power.
3. Tight/close disc containment/control. The only way to make an object behave the way you want it to at high speeds is to exert tight, forceful control over it.

Re: What's the concept?
 

I can't speak to the mechanical aspects, but we use a velocity PID with feed forward. We also use a Banner optical sensor to measure wheel speed. The result is we can hold wheel speeds to within about 1% of our target. The gearing on the motor basically puts the shot recovery right through the middle of the power curve.

Our feeder has an "auto-fire" trigger where the operator holds down the trigger, and the code detects when the shooter's wheel speed has recovered, and automatically fires the next disc.

There's quite a bit of good information on ChiefDelphi about feed-forward and optical sensors/encoder jitter, particularly since the last two games have depended on spinning wheels to launch game pieces.

And yes, iteration is key... Zeus, Marley, Cyclops, Snowman, Enterprise, Mini-Cyclops were just some of the codenames of our prototype shooters - and each one had a series of their own iterations.

Re: What's the concept?
 

Thanks for the images :)