Over The Shoulder Boulder Toss
Over The Shoulder Boulder Toss
by gdubb2
Wed Mar 14, 2007 2:57 am
Well, I've been playing with trying to get the RN-1 to toss a ping pong ball. This doesn't seem difficult, but to get height and distance it is not easy to do. In the "Toss" event at RoboGames, you must pick up a ball, turn 180, throw the ball at a target. Problem is, that the target is 1 meter minimum from the robot, and the "Bulls Eye" is 60 cm from the floor.
Oh Yeah.. this also has to be autonomous operation...
I started with a loop grabber as seen in the videos. This works for grabbing, but not tossing. Then I tried a set-up as seen in the throwbonova thread. This worked for short distance, but no altitude.
Then I made what you see in the vids. Woo Hoo it works...From 1 meter out, I can throw and hit the target. The ball actually goes 5 ft. (153 cm) before it hits the floor.
The bigest problem I ran into, was the servo speed. The 8498 servos are sloooow. So I had to use the combined movement of 3 to get the needed speed. Also the gripper was replaced with an 8498 with an external large gear driving a smaller gear. this gave me a 4X speed amplifier for a very short movement of the wire loop..
The videos show getting the ball, transferring it to the other hand, then tossing it over the shoulder. I don't know why, but this works better than anything else I tried.
Get the Ball:
Toss the Ball:
Closer look at the toss:
Now all I have to do is get Bheka to get the ball (done) turn around (not done) and walk toward the target about 80 cm. (not done) Then turn sideways (not done) and toss the ball hitting a 10 cm. Bulls eye..(done)
All this without getting lost...There is a video of the toss event at a Robo One event that Tempusmaster has on YouTube. It's fun to watch.
Gary
Oh Yeah.. this also has to be autonomous operation...
I started with a loop grabber as seen in the videos. This works for grabbing, but not tossing. Then I tried a set-up as seen in the throwbonova thread. This worked for short distance, but no altitude.
Then I made what you see in the vids. Woo Hoo it works...From 1 meter out, I can throw and hit the target. The ball actually goes 5 ft. (153 cm) before it hits the floor.
The bigest problem I ran into, was the servo speed. The 8498 servos are sloooow. So I had to use the combined movement of 3 to get the needed speed. Also the gripper was replaced with an 8498 with an external large gear driving a smaller gear. this gave me a 4X speed amplifier for a very short movement of the wire loop..
The videos show getting the ball, transferring it to the other hand, then tossing it over the shoulder. I don't know why, but this works better than anything else I tried.
Get the Ball:
phpBB [media]
Toss the Ball:
phpBB [media]
Closer look at the toss:
phpBB [media]
Now all I have to do is get Bheka to get the ball (done) turn around (not done) and walk toward the target about 80 cm. (not done) Then turn sideways (not done) and toss the ball hitting a 10 cm. Bulls eye..(done)
All this without getting lost...There is a video of the toss event at a Robo One event that Tempusmaster has on YouTube. It's fun to watch.
Gary
