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SVR

We won. Woo!

We brought home the entire super structure/arm as part of our withholding allowance. We will be working on the kicker and tying to make it more consistent. There were some issues at SVR where a “Middle” distance kick would just kind of putt the ball forward. You can see that happen in this video at 1:50ish.

We will also be working on refining the arm, and making it hang faster. Yay for continuous improvement.

Possible causes for kicker inconsistencies:

1. Balls being grabbed too hard – When ramming balls into the wall, it is possible that the ball is being grapsed so hard that the kicker has trouble ejecting it from its grasp. After initial auton testing on Thursday, the code was changed to remove the slight roller pause during kicking, which likely was previously releasing the tight grasp on the ball, giving a more repeatable kick. When testing on the practice field, we were gingerly placing the ball into the roller before kicking. This differed greatly from on field interaction, as more often than not the ball was rammed into the wall or bump, forcing it further into the roller and causing it to grab very hard.

2. Who knows? I will put money on cause #1 – TC

More Autonomous Development

Here is the idea for SVR auto modes:

1) Far Zone – Shoot 3 Balls – Long Kicks
2) Far Zone – Shoot 3 Balls – Bounce kicks in middle zone (more accurate shots, but more chance of ball hitting partner)
3) Middle Zone – Shoot 2 Balls – Start touching tower and go in at angle
4) Close Zone – Shoot 1 Ball – Start touching tower and go in at angle

Number 2 is working as of tonight. It can consistently hit 2/3 shots, but with a bigger field I imagine this will be better.

Beginning Competition Preparations

Preparations for Competition next week have begin. Numerous teams of students have been working hard to complete the Competition Robot’s superstructure, which will be carried in as part of the withholding allowance. Several students worked to complete a bill of materials and plan out the packing of the crate from Silicon Valley to Las Vegas. Batteries have been ordered.

Bill of Materials

Autonomous Development – Part 1

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It’s a start…

Kicker Testing

Kicker testing continued today, after a series of mishaps with the arm last night.  We found that we could shoot well from midfield and poorly from either extreme with the current configuration.

We milled the kicker plate down by 1/8″ from it’s already shortened state to make it a total of 5/16″ shorter than designed.  With the new length we can now shoot extremely repeatably from midfield, well from anywhere in the far zone, and well from the back third of the home zone. 

Videos below demonstrate the kicker at various positions on the field. Any variations in kick distance are due to varying air pressure of the balls.
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open source video, online video platform, video streaming, video solutions

Position 0: 13 Encoder Counts
Position 1: 16 Counts
Position 2: 18 Counts
Position 3: 23 Counts

Roller Improvements

Today, several improvements on the roller assembly were completed. The holes on both roller plates were hex broached to accommodate a new lower roller. A design flaw in the previous design allowed the lower roller to free itself and spin in a direction that did not allow the robot to properly hold the ball. A new shaft was completed. Additional shafts for the remaining robots will be manufactured in coming days, once the design is tested.

Work continued to tune the kicker positions for accurate ball scoring. With our 128 count encoder on the kicker, it zeros itself on every kick and is able to winch back accurately each time. The trampoline springs provide extremely repeatable force (as long as ball pressure is consistent). We have been working to tune the number of encoder counts which the kicker must winch back for optimum scoring from any point on the field.

New Plates!

Today, the second prototype plates to replace the hard stop plates were completed and installed. These plates included mounting provisions for attaching three trampoline springs to power the kicker and allow the arm to stow properly, two features not included in the initial prototype. Four full sets of these plates will be manufactured as soon as the material arrives and will be anodized for final robot use.

Progress

Today, the team worked to optimize the kicker and arm. The surgical tubing on the kicker was replaced with trampoline springs, to make it more easy to get a repeatable and known force. A gas spring was installed on the first stage of the arm to aid in arm deployment. Finally, limit switches were added in the pole grabber and on the arm to completely automate the lifting.

Now, thanks to help from the software team, once the arm deployed switch is flipped, the arm will deploy automatically. While the switch is still up, the robot will lift immediately once it is locked onto the bar and will stop when it has reached its final lifted position. This automation is an improvement in speed over what human drivers were able to obtain, due to prior uncertainty about whether or not the robot was locked on the pole.

Design Progress

Today, the design team worked to design the polycarbonate side shields for the robots. Due to weight issues, we will probably not be able to implement all of the polycarbonate shields on the robot.

The team also designed the cutouts which will be made on the bumper spacer tubes. The cutouts reduce the weight of the tube by over 50% by pocketing the side faces to keep proper bumper spacing and facing down the top and bottom faces from 1/8″ to 1/16″.

Score to Hang – 10 seconds

With mentors as drivers, no less…

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