## Re: [Playerstage-developers] Theory Question

 Re: [Playerstage-developers] Theory Question From: Brian Gerkey - 2006-02-24 03:10:21 ```On Feb 23, 2006, at 6:27 PM, Michael Menefee wrote: > Well, I know everyone is busy with Player 2.0, but if you could =20 > answer a question for me, I=92d appreciate it. I=92m trying to figure = =20 > out how the velocities in the position commands are generally =20 > interpreted. If you set an x velocity of, say, 50mm/s, and a turn =20 > rate of 5 deg/s, is that generally accepted as =93I want to travel =20 > 50mm in the x dir, and the y component of my motion for this second =20= > will be determined by my turn rate=94, or =93I want to travel along an = =20 > arc of 5mm turning at a rate of 5 deg/s=94? Basically, I guess I=92m =20= > kind of asking if those commands are in world space or local =20 > space. I could interpret the commands either way, but I=92m just =20 > wondering how most player clients are written. The latter interpretation is correct. What you're doing is setting =20 the instantaneous translational and rotational velocities. So in your example, if you set 50mm/s and 5deg/s, after 1 second a =20 perfect robot will have traveled 50mm counterclockwise along a =20 circular arc. The curvature of this arc can be computed from the two =20= velocities. brian. ```

 [Playerstage-developers] Theory Question From: Michael Menefee - 2006-02-24 02:27:41 Attachments: Message as HTML ```Well, I know everyone is busy with Player 2.0, but if you could answer a question for me, I'd appreciate it. I'm trying to figure out how the velocities in the position commands are generally interpreted. If you set an x velocity of, say, 50mm/s, and a turn rate of 5 deg/s, is that generally accepted as "I want to travel 50mm in the x dir, and the y component of my motion for this second will be determined by my turn rate", or "I want to travel along an arc of 5mm turning at a rate of 5 deg/s"? Basically, I guess I'm kind of asking if those commands are in world space or local space. I could interpret the commands either way, but I'm just wondering how most player clients are written. Thanks, Michael Menefee ```
 Re: [Playerstage-developers] Theory Question From: Brian Gerkey - 2006-02-24 03:10:21 ```On Feb 23, 2006, at 6:27 PM, Michael Menefee wrote: > Well, I know everyone is busy with Player 2.0, but if you could =20 > answer a question for me, I=92d appreciate it. I=92m trying to figure = =20 > out how the velocities in the position commands are generally =20 > interpreted. If you set an x velocity of, say, 50mm/s, and a turn =20 > rate of 5 deg/s, is that generally accepted as =93I want to travel =20 > 50mm in the x dir, and the y component of my motion for this second =20= > will be determined by my turn rate=94, or =93I want to travel along an = =20 > arc of 5mm turning at a rate of 5 deg/s=94? Basically, I guess I=92m =20= > kind of asking if those commands are in world space or local =20 > space. I could interpret the commands either way, but I=92m just =20 > wondering how most player clients are written. The latter interpretation is correct. What you're doing is setting =20 the instantaneous translational and rotational velocities. So in your example, if you set 50mm/s and 5deg/s, after 1 second a =20 perfect robot will have traveled 50mm counterclockwise along a =20 circular arc. The curvature of this arc can be computed from the two =20= velocities. brian. ```
 RE: [Playerstage-developers] Theory Question From: Michael Menefee - 2006-02-24 03:20:38 ```Ah, good deal. My next question was going to be "what happens if you = turn more than 90 deg/s?" if it wasn't that way. :) Thanks. -----Original Message----- From: playerstage-developers-admin@... [mailto:playerstage-developers-admin@...] On Behalf Of Brian Gerkey Sent: Thursday, February 23, 2006 9:11 PM To: playerstage-developers@... Subject: Re: [Playerstage-developers] Theory Question On Feb 23, 2006, at 6:27 PM, Michael Menefee wrote: > Well, I know everyone is busy with Player 2.0, but if you could =20 > answer a question for me, I'd appreciate it. I'm trying to figure =20 > out how the velocities in the position commands are generally =20 > interpreted. If you set an x velocity of, say, 50mm/s, and a turn =20 > rate of 5 deg/s, is that generally accepted as "I want to travel =20 > 50mm in the x dir, and the y component of my motion for this second =20 > will be determined by my turn rate", or "I want to travel along an =20 > arc of 5mm turning at a rate of 5 deg/s"? Basically, I guess I'm =20 > kind of asking if those commands are in world space or local =20 > space. I could interpret the commands either way, but I'm just =20 > wondering how most player clients are written. The latter interpretation is correct. What you're doing is setting =20 the instantaneous translational and rotational velocities. So in your example, if you set 50mm/s and 5deg/s, after 1 second a =20 perfect robot will have traveled 50mm counterclockwise along a =20 circular arc. The curvature of this arc can be computed from the two =20 velocities. brian. ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting = language that extends applications into web and mobile media. Attend the live = webcast and join the prime developer group breaking into this new coding = territory! http://sel.as-us.falkag.net/sel?cmd=3Dk&kid=110944&bid\$1720&dat=121642 _______________________________________________ Playerstage-developers mailing list Playerstage-developers@... https://lists.sourceforge.net/lists/listinfo/playerstage-developers ```