1189 - Human-Bot Arm Control

[jmcr8on]

I will give a couple of answers:

Autonomous: The vest/arm hang on the OI board. At the end of autonomous the operator walks up, puts the vest over hear head (and safety glasses) and slides her arm in to the supports...the velcros the straps. In the meantime the driver starts to move the bot.

Sneezing or something: A concern we had was getting distracted and turning to talk to someone, etc. Just like driving a car, and sneezing, care must be taken. The arm disable button could be pressed on the onset of the sneeze...if the operator had their wits about them. If not...then the robot arm would move the same way the human arm did durign the sneeze....and then would move to the position the human arm was in 'after' the sneeze.

In our pit area and the practice area we set up orange cones around our work cell/area and warned people to not enter the area. We also called 'clear' when the arm was enabled...and completely cleared the area when the turret was to be used.

[LightWaves1636]

Originally Posted by jmcr8on

I will give a couple of answers:

Autonomous: The vest/arm hang on the OI board. At the end of autonomous the operator walks up, puts the vest over hear head (and safety glasses) and slides her arm in to the supports...the velcros the straps. In the meantime the driver starts to move the bot.

Sneezing or something: A concern we had was getting distracted and turning to talk to someone, etc. Just like driving a car, and sneezing, care must be taken. The arm disable button could be pressed on the onset of the sneeze...if the operator had their wits about them. If not...then the robot arm would move the same way the human arm did durign the sneeze....and then would move to the position the human arm was in 'after' the sneeze.

In our pit area and the practice area we set up orange cones around our work cell/area and warned people to not enter the area. We also called 'clear' when the arm was enabled...and completely cleared the area when the turret was to be used.

That is really cool. Way to go on safety as well.

[Qbranch]

What did you mount the arm to? Football shoulderpads or something? Cut in half? Or did you guys lay your own fiberglass?

-q

[kramarczyk]

Originally Posted by Qbranch

What did you mount the arm to? Football shoulderpads or something? Cut in half? Or did you guys lay your own fiberglass?

-q

They are a set of lacrosse pads that are basically unmodified.

[vivek16]

where did you guys get your potentiometers?
ive been looking and i cant seem to find any that specify that the input from them is through pwm cables

[jmcr8on]

Originally Posted by vivek16

where did you guys get your potentiometers?
ive been looking and i cant seem to find any that specify that the input from them is through pwm cables

Yeah....well...I am not sure that any company would really want to embrace PWMs as a connection standard....

That being said we clipped PWMs and soldered the female ends to the pots.


***Ugly #1*** We use cable bundles to get from the RC up the mast/arm with a DB15 disconnect between chassis and mast. PWM cables are soldered to the DB15 on the chassis. PWM cables are soldered into the cable bundle to connect to the PWM cables soldered to the pots and other sensors.

*** Ugly #2 *** For this human-arm application we used DB15 (game port) to Cat5 cables to modular connectors...to Cat5 cables to the vest....then to modular connectors...back to Cat5 cables..then soldered on PWM cables...to the pots. We wanted the ability to disconect the vest assembly in multiple places therefore the use of Cat5 modular connectors.

and...we are always looking for a better way to manage connections across the bot and also the OI. Suggestions?

We used the pots referenced in this white paper: http://www.chiefdelphi.com/media/papers/1743

We bought the pots from Allied Electronics (www.alliedelec.com)....the account exec was VERY helpful and even assisted in getting pots from another supplier when he was short of stock.

[vivek16]

yeah after a bit more research pwms are not used primarily on pots...

thank you, this is going to make a great after season project

we might have time trials to see what we can get accomplished in six weeks.

[sporno]

very coool ... i saw this and it made me raise an eyebrow!

[Scott L.]

Wow, thats awsome, I would love to build one of those. Could I get the so called white paper?

Thanks

[Chief Pride]

does this actually move to the exact position the arm is in? i believe the team is 910, they have a mini one, but it doesnt just travel to where the mini arm is, instead, its still forward and back...

[JesseK]

This is all great work guys, I hope the next manipulator-based game sees you doing it again!

1731 had an arm that had 6 degrees of freedom and even though it was delicate and somewhat slow they could still get 5-6 rings/match if left alone. They did win the VCU Driving Tomorrow's Technology award this year, and from talking to the students and mentors they have several ways it could be sped up.

Once FIRST moves to a new controller, if it has the capability of doing either integral math or at least a faster iterative processor then those pretty-pictured Matlab simulations for the control of this type of stuff could become a reality. Can't wait to see.

[FoleyEngineer]

Hi Zinefer,

You're right. Team 910 did build a miniature arm that exactly replicated the arm of the robot. It rotated 360 degrees at the base, the shoulder had 180 degrees of forward back travel, the elbow was almost 360 degrees of rotation, and the gripper switch had 3 positions (open, loose, tight).

The operator moved the small arm (each joint being about 6 inches) in 3D space, and the robot copied the movement exactly. It used PID control so that if you made a quick move, it raced to keep up. Closest way to imagine it is how a cursor follows your mouse movement, only in 3D. We also built a 3 tier rack that had shelves that corresponded to each of the three levels of the spider legs. The operator could put the arm on a shelf and it would place the arm at the exact height necessary to reach over a leg and then drop the tube.

We also supplemented the controls with buttons for ground loading, wall loading, jogging left/right, locking the shoulder in place or freeing up left/right shoulder rotation, and three buttons for semi or full automatic capping on all three heights (low,mid,high) using our autonomous code. That last feature we didn't implement until the off-season, but with our autonomous cranked up to hyper speed (4 seconds to drive 13 feet, score and release a tube) it made it pretty fun to hit that button and blast a tube on! Especially with a spoiler onto the back side of the rack at the end of a match.

We also won an award for the design, the Xerox Creativity Award at Western Michigan. Such fun!

Take care!

[Chief Pride]

Originally Posted by FoleyEngineer

Hi Zinefer,

You're right. Team 910 did build a miniature arm that exactly replicated the arm of the robot. It rotated 360 degrees at the base, the shoulder had 180 degrees of forward back travel, the elbow was almost 360 degrees of rotation, and the gripper switch had 3 positions (open, loose, tight).

The operator moved the small arm (each joint being about 6 inches) in 3D space, and the robot copied the movement exactly. It used PID control so that if you made a quick move, it raced to keep up. Closest way to imagine it is how a cursor follows your mouse movement, only in 3D. We also built a 3 tier rack that had shelves that corresponded to each of the three levels of the spider legs. The operator could put the arm on a shelf and it would place the arm at the exact height necessary to reach over a leg and then drop the tube.

We also supplemented the controls with buttons for ground loading, wall loading, jogging left/right, locking the shoulder in place or freeing up left/right shoulder rotation, and three buttons for semi or full automatic capping on all three heights (low,mid,high) using our autonomous code. That last feature we didn't implement until the off-season, but with our autonomous cranked up to hyper speed (4 seconds to drive 13 feet, score and release a tube) it made it pretty fun to hit that button and blast a tube on! Especially with a spoiler onto the back side of the rack at the end of a match.

We also won an award for the design, the Xerox Creativity Award at Western Michigan. Such fun!

Take care!

so it did copy the exact position the miniature arm? when it was being driven it looked like it just went in the DIRECTION that the miniature arm was held... thanks!

[Robostang 548]

We did something similar to this before I joined 548. You can check it out here: http://www.chiefdelphi.com/media/photos/21259

[kramarczyk]

Originally Posted by sanddrag

What happens if you like, sneeze or something? Does the robot go crazy?

If she sneezes it autonomously hangs 8 ringers... in the code we call it 'A.Baker'. Getting the accelerometer and gyro to set-up to detect that took hours. Unfortunately, now she only has a raspy cough.

Seriously though, there is an enable/disable button on the handle in her hand as well as buttons to rotate the wrist CW/CCW. FYI... the $60 bionic arm also controls turret rotation.