From: hemanth k. <hem...@gm...> - 2008-01-08 06:07:47
|
hi does anybody have a model for a tank like vehicle which simulates its weight,shape,etc.. thanx |
From: Jordi <mu...@gm...> - 2008-01-08 06:18:47
|
I know nothing about tanks (luckily) but I guess you can use the differential_position controller with it (the pioneer example is using it). About the weight you can search wikipedia. The shape, in your sources directory you have a doc/ subdirectory with a mesh_tutorial.html file in it. There you have some links to free models that can be exported to Gazebo and instructions. You may be lucky and find a tank (and some other insteresting models). On Jan 8, 2008 3:07 PM, hemanth korrapati <hem...@gm...> wrote: > hi > > does anybody have a model for a tank like vehicle which simulates its > weight,shape,etc.. > > > thanx > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > -- Jordi Polo Carres Natural language processing laboratory NAIST http://www.bahasara.org |
From: hemanth k. <hem...@gm...> - 2008-01-09 08:17:19
|
Hey Thanks for that. But a tank has 8 wheels with equal number of them on both sides.But the controller for pioneer is for a differential drive system which is not the one in a tank. I guess it is difficult to build a controller for a tank. But is there any controller which controls a normal vehicle with four wheels ( front wheels are steered and the back wheels follow). On Jan 8, 2008 11:48 AM, Jordi <mu...@gm...> wrote: > > I know nothing about tanks (luckily) but I guess you can use the > differential_position controller with it (the pioneer example is using it). > About the weight you can search wikipedia. The shape, in your sources > directory you have a doc/ subdirectory with a mesh_tutorial.html file in it. > There you have some links to free models that can be exported to Gazebo and > instructions. You may be lucky and find a tank (and some other insteresting > models). > > > > > On Jan 8, 2008 3:07 PM, hemanth korrapati <hem...@gm...> > wrote: > > > > > > > > hi > > > > does anybody have a model for a tank like vehicle which simulates its > > weight,shape,etc.. > > > > > > thanx > > > > ------------------------------------------------------------------------- > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services for > > just about anything Open Source. > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Playerstage-gazebo mailing list > > Pla...@li... > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > -- > Jordi Polo Carres > Natural language processing laboratory > NAIST > http://www.bahasara.org > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > |
From: Jordi <mu...@gm...> - 2008-01-09 10:09:59
|
The controller you are looking for can be found in the patch tracking system. It can control any number of wheels, even 8 as steering or non-steering roles. That code has not been integrated due to a bug in how the steering wheels are managed, I hope it will be solved soon and integrated next week. Tanks are managed with steering? I'd bet they use a differential drive system. On Jan 9, 2008 5:17 PM, hemanth korrapati <hem...@gm...> wrote: > Hey > > Thanks for that. > But a tank has 8 wheels with equal number of them on both sides.But > the controller for pioneer is for a differential drive system which is > not the one in a tank. > I guess it is difficult to build a controller for a tank. But is there > any controller which controls a normal vehicle with four wheels ( > front wheels are steered and the back wheels follow). > > > On Jan 8, 2008 11:48 AM, Jordi <mu...@gm...> wrote: > > > > I know nothing about tanks (luckily) but I guess you can use the > > differential_position controller with it (the pioneer example is using > it). > > About the weight you can search wikipedia. The shape, in your sources > > directory you have a doc/ subdirectory with a mesh_tutorial.html file in > it. > > There you have some links to free models that can be exported to Gazebo > and > > instructions. You may be lucky and find a tank (and some other > insteresting > > models). > > > > > > > > > > On Jan 8, 2008 3:07 PM, hemanth korrapati <hem...@gm...> > > wrote: > > > > > > > > > > > > hi > > > > > > does anybody have a model for a tank like vehicle which simulates its > > > weight,shape,etc.. > > > > > > > > > thanx > > > > > > > ------------------------------------------------------------------------- > > > Check out the new SourceForge.net Marketplace. > > > It's the best place to buy or sell services for > > > just about anything Open Source. > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > _______________________________________________ > > > Playerstage-gazebo mailing list > > > Pla...@li... > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > -- > > Jordi Polo Carres > > Natural language processing laboratory > > NAIST > > http://www.bahasara.org > > > > > ------------------------------------------------------------------------- > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services for > > just about anything Open Source. > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Playerstage-gazebo mailing list > > Pla...@li... > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > -- Jordi Polo Carres Natural language processing laboratory NAIST http://www.bahasara.org |
From: hemanth k. <hem...@gm...> - 2008-01-09 10:23:33
|
Hey thanks for ur help. I too dont know whether tanks use differential drive or steering. But if a tank has 8 wheels how can we use a differential drive? I mean which wheels use the drive and which are the followers ? Also another problem is that I made a small model for the tank for which i have set the "mass" parameter as 47 tons. When I start the simulator the robot fall off through the ground. If I reduce the mass to 40 then it becomes stable. Why is it ? Can we solve it ? Thanks On Jan 9, 2008 3:39 PM, Jordi <mu...@gm...> wrote: > > The controller you are looking for can be found in the patch tracking > system. It can control any number of wheels, even 8 as steering or > non-steering roles. > That code has not been integrated due to a bug in how the steering wheels > are managed, I hope it will be solved soon and integrated next week. > > Tanks are managed with steering? I'd bet they use a differential drive > system. > > > > > > On Jan 9, 2008 5:17 PM, hemanth korrapati < hem...@gm...> > wrote: > > Hey > > > > Thanks for that. > > But a tank has 8 wheels with equal number of them on both sides.But > > the controller for pioneer is for a differential drive system which is > > not the one in a tank. > > I guess it is difficult to build a controller for a tank. But is there > > any controller which controls a normal vehicle with four wheels ( > > front wheels are steered and the back wheels follow). > > > > > > > > > > > > On Jan 8, 2008 11:48 AM, Jordi <mu...@gm...> wrote: > > > > > > I know nothing about tanks (luckily) but I guess you can use the > > > differential_position controller with it (the pioneer example is using > it). > > > About the weight you can search wikipedia. The shape, in your sources > > > directory you have a doc/ subdirectory with a mesh_tutorial.html file in > it. > > > There you have some links to free models that can be exported to Gazebo > and > > > instructions. You may be lucky and find a tank (and some other > insteresting > > > models). > > > > > > > > > > > > > > > On Jan 8, 2008 3:07 PM, hemanth korrapati <hem...@gm...> > > > wrote: > > > > > > > > > > > > > > > > hi > > > > > > > > does anybody have a model for a tank like vehicle which simulates its > > > > weight,shape,etc.. > > > > > > > > > > > > thanx > > > > > > > > > ------------------------------------------------------------------------- > > > > Check out the new SourceForge.net Marketplace. > > > > It's the best place to buy or sell services for > > > > just about anything Open Source. > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > _______________________________________________ > > > > Playerstage-gazebo mailing list > > > > Pla...@li... > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > -- > > > Jordi Polo Carres > > > Natural language processing laboratory > > > NAIST > > > http://www.bahasara.org > > > > > > > ------------------------------------------------------------------------- > > > Check out the new SourceForge.net Marketplace. > > > It's the best place to buy or sell services for > > > just about anything Open Source. > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > _______________________________________________ > > > Playerstage-gazebo mailing list > > > Pla...@li... > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > ------------------------------------------------------------------------- > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services for > > just about anything Open Source. > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Playerstage-gazebo mailing list > > Pla...@li... > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > -- > Jordi Polo Carres > Natural language processing laboratory > NAIST > http://www.bahasara.org > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > |
From: Jordi <mu...@gm...> - 2008-01-09 10:37:38
|
If you don't need a perfect simulation, you can make just a physical tank with 2 wheels and a visual mesh with 8 wheels. Maybe tanks has more wheels only because that way they have no single point of attack but all the wheels in one side are moving at the same time what to all practical effects can be managed by differencial wheeling. About the mass effect you comment I have just tried it with a 47000 kilo ball and it is falling though the ground also. It is an ODE problem and it surely can be tweaked, I think that Nate will be able to solve it, stick with 40.000 till then. On Jan 9, 2008 7:23 PM, hemanth korrapati <hem...@gm...> wrote: > Hey thanks for ur help. > > I too dont know whether tanks use differential drive or steering. > But if a tank has 8 wheels how can we use a differential drive? I mean > which wheels use the drive and which are the followers ? > > Also another problem is that I made a small model for the tank for > which i have set the "mass" parameter as 47 tons. When I start the > simulator the robot fall off through the ground. If I reduce the mass > to 40 then it becomes stable. Why is it ? Can we solve it ? > > Thanks > > On Jan 9, 2008 3:39 PM, Jordi <mu...@gm...> wrote: > > > > The controller you are looking for can be found in the patch tracking > > system. It can control any number of wheels, even 8 as steering or > > non-steering roles. > > That code has not been integrated due to a bug in how the steering > wheels > > are managed, I hope it will be solved soon and integrated next week. > > > > Tanks are managed with steering? I'd bet they use a differential drive > > system. > > > > > > > > > > > > On Jan 9, 2008 5:17 PM, hemanth korrapati < hem...@gm...> > > wrote: > > > Hey > > > > > > Thanks for that. > > > But a tank has 8 wheels with equal number of them on both sides.But > > > the controller for pioneer is for a differential drive system which is > > > not the one in a tank. > > > I guess it is difficult to build a controller for a tank. But is there > > > any controller which controls a normal vehicle with four wheels ( > > > front wheels are steered and the back wheels follow). > > > > > > > > > > > > > > > > > > On Jan 8, 2008 11:48 AM, Jordi <mu...@gm...> wrote: > > > > > > > > I know nothing about tanks (luckily) but I guess you can use the > > > > differential_position controller with it (the pioneer example is > using > > it). > > > > About the weight you can search wikipedia. The shape, in your > sources > > > > directory you have a doc/ subdirectory with a mesh_tutorial.html > file in > > it. > > > > There you have some links to free models that can be exported to > Gazebo > > and > > > > instructions. You may be lucky and find a tank (and some other > > insteresting > > > > models). > > > > > > > > > > > > > > > > > > > > On Jan 8, 2008 3:07 PM, hemanth korrapati < > hem...@gm...> > > > > wrote: > > > > > > > > > > > > > > > > > > > > hi > > > > > > > > > > does anybody have a model for a tank like vehicle which simulates > its > > > > > weight,shape,etc.. > > > > > > > > > > > > > > > thanx > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > Check out the new SourceForge.net Marketplace. > > > > > It's the best place to buy or sell services for > > > > > just about anything Open Source. > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > _______________________________________________ > > > > > Playerstage-gazebo mailing list > > > > > Pla...@li... > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > -- > > > > Jordi Polo Carres > > > > Natural language processing laboratory > > > > NAIST > > > > http://www.bahasara.org > > > > > > > > > > > ------------------------------------------------------------------------- > > > > Check out the new SourceForge.net Marketplace. > > > > It's the best place to buy or sell services for > > > > just about anything Open Source. > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > _______________________________________________ > > > > Playerstage-gazebo mailing list > > > > Pla...@li... > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > Check out the new SourceForge.net Marketplace. > > > It's the best place to buy or sell services for > > > just about anything Open Source. > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > _______________________________________________ > > > Playerstage-gazebo mailing list > > > Pla...@li... > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > -- > > Jordi Polo Carres > > Natural language processing laboratory > > NAIST > > http://www.bahasara.org > > > > > ------------------------------------------------------------------------- > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services for > > just about anything Open Source. > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Playerstage-gazebo mailing list > > Pla...@li... > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > -- Jordi Polo Carres Natural language processing laboratory NAIST http://www.bahasara.org |
From: hemanth k. <hem...@gm...> - 2008-01-09 11:11:41
|
But in that case , if we use only two wheels will it be able to traverse a rough terrain ? On Jan 9, 2008 4:07 PM, Jordi <mu...@gm...> wrote: > > If you don't need a perfect simulation, you can make just a physical tank > with 2 wheels and a visual mesh with 8 wheels. Maybe tanks has more wheels > only because that way they have no single point of attack but all the wheels > in one side are moving at the same time what to all practical effects can be > managed by differencial wheeling. > > About the mass effect you comment I have just tried it with a 47000 kilo > ball and it is > falling though the ground also. It is an ODE problem and it surely can be > tweaked, I think that Nate will be able to solve it, stick with 40.000 till > then. > > > > > > On Jan 9, 2008 7:23 PM, hemanth korrapati <hem...@gm...> > wrote: > > Hey thanks for ur help. > > > > I too dont know whether tanks use differential drive or steering. > > But if a tank has 8 wheels how can we use a differential drive? I mean > > which wheels use the drive and which are the followers ? > > > > Also another problem is that I made a small model for the tank for > > which i have set the "mass" parameter as 47 tons. When I start the > > simulator the robot fall off through the ground. If I reduce the mass > > to 40 then it becomes stable. Why is it ? Can we solve it ? > > > > Thanks > > > > > > > > > > On Jan 9, 2008 3:39 PM, Jordi <mu...@gm...> wrote: > > > > > > The controller you are looking for can be found in the patch tracking > > > system. It can control any number of wheels, even 8 as steering or > > > non-steering roles. > > > That code has not been integrated due to a bug in how the steering > wheels > > > are managed, I hope it will be solved soon and integrated next week. > > > > > > Tanks are managed with steering? I'd bet they use a differential drive > > > system. > > > > > > > > > > > > > > > > > > On Jan 9, 2008 5:17 PM, hemanth korrapati < hem...@gm...> > > > wrote: > > > > Hey > > > > > > > > Thanks for that. > > > > But a tank has 8 wheels with equal number of them on both sides.But > > > > the controller for pioneer is for a differential drive system which is > > > > not the one in a tank. > > > > I guess it is difficult to build a controller for a tank. But is there > > > > any controller which controls a normal vehicle with four wheels ( > > > > front wheels are steered and the back wheels follow). > > > > > > > > > > > > > > > > > > > > > > > > On Jan 8, 2008 11:48 AM, Jordi <mu...@gm... > wrote: > > > > > > > > > > I know nothing about tanks (luckily) but I guess you can use the > > > > > differential_position controller with it (the pioneer example is > using > > > it). > > > > > About the weight you can search wikipedia. The shape, in your > sources > > > > > directory you have a doc/ subdirectory with a mesh_tutorial.html > file in > > > it. > > > > > There you have some links to free models that can be exported to > Gazebo > > > and > > > > > instructions. You may be lucky and find a tank (and some other > > > insteresting > > > > > models). > > > > > > > > > > > > > > > > > > > > > > > > > On Jan 8, 2008 3:07 PM, hemanth korrapati < > hem...@gm...> > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > hi > > > > > > > > > > > > does anybody have a model for a tank like vehicle which simulates > its > > > > > > weight,shape,etc.. > > > > > > > > > > > > > > > > > > thanx > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > Check out the new SourceForge.net Marketplace. > > > > > > It's the best place to buy or sell services for > > > > > > just about anything Open Source. > > > > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > > _______________________________________________ > > > > > > Playerstage-gazebo mailing list > > > > > > Pla...@li... > > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > Jordi Polo Carres > > > > > Natural language processing laboratory > > > > > NAIST > > > > > http://www.bahasara.org > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > Check out the new SourceForge.net Marketplace. > > > > > It's the best place to buy or sell services for > > > > > just about anything Open Source. > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > _______________________________________________ > > > > > Playerstage-gazebo mailing list > > > > > Pla...@li... > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > Check out the new SourceForge.net Marketplace. > > > > It's the best place to buy or sell services for > > > > just about anything Open Source. > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > _______________________________________________ > > > > Playerstage-gazebo mailing list > > > > Pla...@li... > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > -- > > > Jordi Polo Carres > > > Natural language processing laboratory > > > NAIST > > > http://www.bahasara.org > > > > > > > ------------------------------------------------------------------------- > > > > > > > > > Check out the new SourceForge.net Marketplace. > > > It's the best place to buy or sell services for > > > just about anything Open Source. > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > _______________________________________________ > > > Playerstage-gazebo mailing list > > > Pla...@li... > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > ------------------------------------------------------------------------- > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services for > > just about anything Open Source. > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Playerstage-gazebo mailing list > > Pla...@li... > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > -- > Jordi Polo Carres > Natural language processing laboratory > NAIST > http://www.bahasara.org > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > |
From: Douglas T. <dou...@gm...> - 2008-01-09 17:22:44
|
Are you actually refering to a tank e.g. M1 Abrams http://www.torrent.to/torrent/cache/doku/269/212269/2275-m1abrams005.jpg or a troop trasport like vehicle e.g. Bison http://www.armyrecognition.com/Amerique_du_nord/Canada/vehicules_a_roues/Bison_Coyote_Kodiak/Bison/Bison_Canada_Site_06.jpg A tank is a differential drive where the difference in speed results in a pivoting of vehicle due to the net resistance on one side. If the left track is going faster than the right track then the vehicle bears right. It's turning rate is controlled by the difference in speed. If it's a Bison which is an eight-wheel vehicle that runs on eight independent wheels rather than tracks then it is steered. The front four-wheels steer and all eight drive the vehicle. Therefore, a differential drive will nicely represent a tank whereas a steered system will be more conducive to the transport. On Jan 9, 2008 6:11 AM, hemanth korrapati <hem...@gm...> wrote: > But in that case , if we use only two wheels will it be able to > traverse a rough terrain ? > > On Jan 9, 2008 4:07 PM, Jordi <mu...@gm...> wrote: > > > > If you don't need a perfect simulation, you can make just a physical > tank > > with 2 wheels and a visual mesh with 8 wheels. Maybe tanks has more > wheels > > only because that way they have no single point of attack but all the > wheels > > in one side are moving at the same time what to all practical effects > can be > > managed by differencial wheeling. > > > > About the mass effect you comment I have just tried it with a 47000 kilo > > ball and it is > > falling though the ground also. It is an ODE problem and it surely can > be > > tweaked, I think that Nate will be able to solve it, stick with 40.000till > > then. > > > > > > > > > > > > On Jan 9, 2008 7:23 PM, hemanth korrapati <hem...@gm...> > > wrote: > > > Hey thanks for ur help. > > > > > > I too dont know whether tanks use differential drive or steering. > > > But if a tank has 8 wheels how can we use a differential drive? I mean > > > which wheels use the drive and which are the followers ? > > > > > > Also another problem is that I made a small model for the tank for > > > which i have set the "mass" parameter as 47 tons. When I start the > > > simulator the robot fall off through the ground. If I reduce the mass > > > to 40 then it becomes stable. Why is it ? Can we solve it ? > > > > > > Thanks > > > > > > > > > > > > > > > On Jan 9, 2008 3:39 PM, Jordi <mu...@gm...> wrote: > > > > > > > > The controller you are looking for can be found in the patch > tracking > > > > system. It can control any number of wheels, even 8 as steering or > > > > non-steering roles. > > > > That code has not been integrated due to a bug in how the steering > > wheels > > > > are managed, I hope it will be solved soon and integrated next week. > > > > > > > > Tanks are managed with steering? I'd bet they use a differential > drive > > > > system. > > > > > > > > > > > > > > > > > > > > > > > > On Jan 9, 2008 5:17 PM, hemanth korrapati < > hem...@gm...> > > > > wrote: > > > > > Hey > > > > > > > > > > Thanks for that. > > > > > But a tank has 8 wheels with equal number of them on both > sides.But > > > > > the controller for pioneer is for a differential drive system > which is > > > > > not the one in a tank. > > > > > I guess it is difficult to build a controller for a tank. But is > there > > > > > any controller which controls a normal vehicle with four wheels ( > > > > > front wheels are steered and the back wheels follow). > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Jan 8, 2008 11:48 AM, Jordi <mu...@gm... > wrote: > > > > > > > > > > > > I know nothing about tanks (luckily) but I guess you can use the > > > > > > differential_position controller with it (the pioneer example is > > using > > > > it). > > > > > > About the weight you can search wikipedia. The shape, in your > > sources > > > > > > directory you have a doc/ subdirectory with a mesh_tutorial.html > > file in > > > > it. > > > > > > There you have some links to free models that can be exported to > > Gazebo > > > > and > > > > > > instructions. You may be lucky and find a tank (and some other > > > > insteresting > > > > > > models). > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Jan 8, 2008 3:07 PM, hemanth korrapati < > > hem...@gm...> > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > hi > > > > > > > > > > > > > > does anybody have a model for a tank like vehicle which > simulates > > its > > > > > > > weight,shape,etc.. > > > > > > > > > > > > > > > > > > > > > thanx > > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > > Check out the new SourceForge.net Marketplace. > > > > > > > It's the best place to buy or sell services for > > > > > > > just about anything Open Source. > > > > > > > > > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > > > _______________________________________________ > > > > > > > Playerstage-gazebo mailing list > > > > > > > Pla...@li... > > > > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > Jordi Polo Carres > > > > > > Natural language processing laboratory > > > > > > NAIST > > > > > > http://www.bahasara.org > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > Check out the new SourceForge.net Marketplace. > > > > > > It's the best place to buy or sell services for > > > > > > just about anything Open Source. > > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > > _______________________________________________ > > > > > > Playerstage-gazebo mailing list > > > > > > Pla...@li... > > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > Check out the new SourceForge.net Marketplace. > > > > > It's the best place to buy or sell services for > > > > > just about anything Open Source. > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > _______________________________________________ > > > > > Playerstage-gazebo mailing list > > > > > Pla...@li... > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > -- > > > > Jordi Polo Carres > > > > Natural language processing laboratory > > > > NAIST > > > > http://www.bahasara.org > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > > > > > > > > Check out the new SourceForge.net Marketplace. > > > > It's the best place to buy or sell services for > > > > just about anything Open Source. > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > _______________________________________________ > > > > Playerstage-gazebo mailing list > > > > Pla...@li... > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > Check out the new SourceForge.net Marketplace. > > > It's the best place to buy or sell services for > > > just about anything Open Source. > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > _______________________________________________ > > > Playerstage-gazebo mailing list > > > Pla...@li... > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > -- > > Jordi Polo Carres > > Natural language processing laboratory > > NAIST > > http://www.bahasara.org > > > > > ------------------------------------------------------------------------- > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services for > > just about anything Open Source. > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Playerstage-gazebo mailing list > > Pla...@li... > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > |
From: Nate K. <nk...@us...> - 2008-01-11 16:59:25
|
The simulator will have a tough time handling such large masses. Here is a quote from the ODE manual: "Say you need to simulate some behavior on the scale of a few millimeters and a few grams. These small lengths and masses will usually work in ODE with no problem. However occasionally you may experience stability problems that are caused by lack of precision in the factorizer. If this is the case, you can try scaling the lengths and masses in your system to be around 0.1..10. The time step should also be be scaled accordingly. The same guideline applies when large lengths and masses are being used. In general, length and mass values around 0.1..1.0 are better as the factorizer may not lose so much precision. This guideline is especially helpful when single precision is being used." Try scaling you masses. Or decrease the time step significantly. -nate On Jan 9, 2008 9:22 AM, Douglas Thom <dou...@gm...> wrote: > Are you actually refering to a tank > > e.g. M1 Abrams > http://www.torrent.to/torrent/cache/doku/269/212269/2275-m1abrams005.jpg > > or a troop trasport like vehicle > > e.g. Bison > http://www.armyrecognition.com/Amerique_du_nord/Canada/vehicules_a_roues/Bison_Coyote_Kodiak/Bison/Bison_Canada_Site_06.jpg > > A tank is a differential drive where the difference in speed results in a > pivoting of vehicle due to the net resistance on one side. If the left track > is going faster than the right track then the vehicle bears right. It's > turning rate is controlled by the difference in speed. If it's a Bison which > is an eight-wheel vehicle that runs on eight independent wheels rather than > tracks then it is steered. The front four-wheels steer and all eight drive > the vehicle. > > Therefore, a differential drive will nicely represent a tank whereas a > steered system will be more conducive to the transport. > > > > On Jan 9, 2008 6:11 AM, hemanth korrapati <hem...@gm...> > wrote: > > > But in that case , if we use only two wheels will it be able to > > traverse a rough terrain ? > > > > > > > > > > On Jan 9, 2008 4:07 PM, Jordi <mu...@gm...> wrote: > > > > > > If you don't need a perfect simulation, you can make just a physical > tank > > > with 2 wheels and a visual mesh with 8 wheels. Maybe tanks has more > wheels > > > only because that way they have no single point of attack but all the > wheels > > > in one side are moving at the same time what to all practical effects > can be > > > managed by differencial wheeling. > > > > > > About the mass effect you comment I have just tried it with a 47000 kilo > > > ball and it is > > > falling though the ground also. It is an ODE problem and it surely can > be > > > tweaked, I think that Nate will be able to solve it, stick with 40.000 > till > > > then. > > > > > > > > > > > > > > > > > > On Jan 9, 2008 7:23 PM, hemanth korrapati < hem...@gm...> > > > wrote: > > > > Hey thanks for ur help. > > > > > > > > I too dont know whether tanks use differential drive or steering. > > > > But if a tank has 8 wheels how can we use a differential drive? I mean > > > > which wheels use the drive and which are the followers ? > > > > > > > > Also another problem is that I made a small model for the tank for > > > > which i have set the "mass" parameter as 47 tons. When I start the > > > > simulator the robot fall off through the ground. If I reduce the mass > > > > to 40 then it becomes stable. Why is it ? Can we solve it ? > > > > > > > > Thanks > > > > > > > > > > > > > > > > > > > > On Jan 9, 2008 3:39 PM, Jordi <mu...@gm...> wrote: > > > > > > > > > > The controller you are looking for can be found in the patch > tracking > > > > > system. It can control any number of wheels, even 8 as steering or > > > > > non-steering roles. > > > > > That code has not been integrated due to a bug in how the steering > > > wheels > > > > > are managed, I hope it will be solved soon and integrated next week. > > > > > > > > > > Tanks are managed with steering? I'd bet they use a differential > drive > > > > > system. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Jan 9, 2008 5:17 PM, hemanth korrapati < > hem...@gm... > > > > > > wrote: > > > > > > Hey > > > > > > > > > > > > Thanks for that. > > > > > > But a tank has 8 wheels with equal number of them on both > sides.But > > > > > > the controller for pioneer is for a differential drive system > which is > > > > > > not the one in a tank. > > > > > > I guess it is difficult to build a controller for a tank. But is > there > > > > > > any controller which controls a normal vehicle with four wheels ( > > > > > > front wheels are steered and the back wheels follow). > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Jan 8, 2008 11:48 AM, Jordi < mu...@gm... > wrote: > > > > > > > > > > > > > > I know nothing about tanks (luckily) but I guess you can use the > > > > > > > differential_position controller with it (the pioneer example is > > > using > > > > > it). > > > > > > > About the weight you can search wikipedia. The shape, in your > > > sources > > > > > > > directory you have a doc/ subdirectory with a mesh_tutorial.html > > > file in > > > > > it. > > > > > > > There you have some links to free models that can be exported to > > > Gazebo > > > > > and > > > > > > > instructions. You may be lucky and find a tank (and some other > > > > > insteresting > > > > > > > models). > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Jan 8, 2008 3:07 PM, hemanth korrapati < > > > hem...@gm...> > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > hi > > > > > > > > > > > > > > > > does anybody have a model for a tank like vehicle which > simulates > > > its > > > > > > > > weight,shape,etc.. > > > > > > > > > > > > > > > > > > > > > > > > thanx > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > > > Check out the new SourceForge.net Marketplace. > > > > > > > > It's the best place to buy or sell services for > > > > > > > > just about anything Open Source. > > > > > > > > > > > > > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > > > > _______________________________________________ > > > > > > > > Playerstage-gazebo mailing list > > > > > > > > Pla...@li... > > > > > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > Jordi Polo Carres > > > > > > > Natural language processing laboratory > > > > > > > NAIST > > > > > > > http://www.bahasara.org > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > > Check out the new SourceForge.net Marketplace. > > > > > > > It's the best place to buy or sell services for > > > > > > > just about anything Open Source. > > > > > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > > > _______________________________________________ > > > > > > > Playerstage-gazebo mailing list > > > > > > > Pla...@li... > > > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > Check out the new SourceForge.net Marketplace. > > > > > > It's the best place to buy or sell services for > > > > > > just about anything Open Source. > > > > > > > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > > _______________________________________________ > > > > > > Playerstage-gazebo mailing list > > > > > > Pla...@li... > > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > Jordi Polo Carres > > > > > Natural language processing laboratory > > > > > NAIST > > > > > http://www.bahasara.org > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > > > > > > > > > > > > > > Check out the new SourceForge.net Marketplace. > > > > > It's the best place to buy or sell services for > > > > > just about anything Open Source. > > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > > _______________________________________________ > > > > > Playerstage-gazebo mailing list > > > > > Pla...@li... > > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------- > > > > Check out the new SourceForge.net Marketplace. > > > > It's the best place to buy or sell services for > > > > just about anything Open Source. > > > > > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > > _______________________________________________ > > > > Playerstage-gazebo mailing list > > > > Pla...@li... > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > > > > > > > -- > > > Jordi Polo Carres > > > Natural language processing laboratory > > > NAIST > > > http://www.bahasara.org > > > > > > > ------------------------------------------------------------------------- > > > Check out the new SourceForge.net Marketplace. > > > It's the best place to buy or sell services for > > > just about anything Open Source. > > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > > _______________________________________________ > > > Playerstage-gazebo mailing list > > > Pla...@li... > > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > > > > > > ------------------------------------------------------------------------- > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services for > > just about anything Open Source. > > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Playerstage-gazebo mailing list > > Pla...@li... > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > |
From: Sawyer L. <sl...@to...> - 2008-01-11 13:45:04
|
I had a similar problem it can be solved by changing the ODE hardness of the wheels. In Gazebo 0.7.0 you can use this line: pcGeom->SetHardness(1e6, 1e4); I do not know if a similar mechanism is built into Gazebo 0.8 yet to set the ODE hardness. Sawyer On Wednesday 09 January 2008 3:37:41 am Jordi wrote: > If you don't need a perfect simulation, you can make just a physical tank > with 2 wheels and a visual mesh with 8 wheels. Maybe tanks has more wheels > only because that way they have no single point of attack but all the > wheels in one side are moving at the same time what to all practical > effects can be managed by differencial wheeling. > > About the mass effect you comment I have just tried it with a 47000 kilo > ball and it is > falling though the ground also. It is an ODE problem and it surely can be > tweaked, I think that Nate will be able to solve it, stick with 40.000 till > then. > > > > On Jan 9, 2008 7:23 PM, hemanth korrapati <hem...@gm...> > > wrote: > > Hey thanks for ur help. > > > > I too dont know whether tanks use differential drive or steering. > > But if a tank has 8 wheels how can we use a differential drive? I mean > > which wheels use the drive and which are the followers ? > > > > Also another problem is that I made a small model for the tank for > > which i have set the "mass" parameter as 47 tons. When I start the > > simulator the robot fall off through the ground. If I reduce the mass > > to 40 then it becomes stable. Why is it ? Can we solve it ? > > > > Thanks > > |
From: Nate K. <nk...@us...> - 2008-01-11 17:06:54
|
Ahh, thanks for reminding me of this. I still have to put this into the latest version of Gazebo. -nate On Jan 9, 2008 11:29 AM, Sawyer Larkin <sl...@to...> wrote: > I had a similar problem it can be solved by changing the ODE hardness of the > wheels. > > In Gazebo 0.7.0 you can use this line: > > pcGeom->SetHardness(1e6, 1e4); > > I do not know if a similar mechanism is built into Gazebo 0.8 yet to set the > ODE hardness. > > Sawyer > > On Wednesday 09 January 2008 3:37:41 am Jordi wrote: > > If you don't need a perfect simulation, you can make just a physical tank > > with 2 wheels and a visual mesh with 8 wheels. Maybe tanks has more wheels > > only because that way they have no single point of attack but all the > > wheels in one side are moving at the same time what to all practical > > effects can be managed by differencial wheeling. > > > > About the mass effect you comment I have just tried it with a 47000 kilo > > ball and it is > > falling though the ground also. It is an ODE problem and it surely can be > > tweaked, I think that Nate will be able to solve it, stick with 40.000 till > > then. > > > > > > > > On Jan 9, 2008 7:23 PM, hemanth korrapati <hem...@gm...> > > > > wrote: > > > Hey thanks for ur help. > > > > > > I too dont know whether tanks use differential drive or steering. > > > But if a tank has 8 wheels how can we use a differential drive? I mean > > > which wheels use the drive and which are the followers ? > > > > > > Also another problem is that I made a small model for the tank for > > > which i have set the "mass" parameter as 47 tons. When I start the > > > simulator the robot fall off through the ground. If I reduce the mass > > > to 40 then it becomes stable. Why is it ? Can we solve it ? > > > > > > Thanks > > > > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Playerstage-gazebo mailing list > Pla...@li... > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > |