Hello,
I am trying to calculate inverse kinematics in 2D space with 2 DOF according to this tutorial(1) and formulas within using [expr]. For some reason my calculations for "c2" using [expr] deliver quite a different result than the excel sheet calculation that the tutorial provides.
What am I doing wrong here? It may be I don't quite understand how "^" is used?
Using: Linkage 1 length of 5 Linkage 2 length of 4
and plotting my the end of joint 2 at (3.56, 6.43) I should get c2 to equal 0.3254625 but get 0.25 with [expr]. Because of this further calculations to get joint angles are also off, obviously.
attached is patch.
but maybe someone has already done this type of work which might save me some trouble...
cheers m
(1) http://www.societyofrobots.com/robot_arm_tutorial.shtml#inverse_kinematics
hello,
I think expr did not compute long expression in the order you want it to. with more parenthesis, result are different. see attachement cheers c
Le 25/01/2017 à 17:03, me.grimm a écrit :
Hello,
I am trying to calculate inverse kinematics in 2D space with 2 DOF according to this tutorial(1) and formulas within using [expr]. For some reason my calculations for "c2" using [expr] deliver quite a different result than the excel sheet calculation that the tutorial provides.
What am I doing wrong here? It may be I don't quite understand how "^" is used?
Using: Linkage 1 length of 5 Linkage 2 length of 4
and plotting my the end of joint 2 at (3.56, 6.43) I should get c2 to equal 0.3254625 but get 0.25 with [expr]. Because of this further calculations to get joint angles are also off, obviously.
attached is patch.
but maybe someone has already done this type of work which might save me some trouble...
cheers m
(1) http://www.societyofrobots.com/robot_arm_tutorial.shtml#inverse_kinematics
-- ____________________ m.e.grimm, m.f.a, ed.m. syracuse u., tc3 megrimm.net http://megrimm.net ____________________
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
In expr, ^ is bitwise-exclusive-or, but you want exponentiation. Just replace $f1^2 with $f1*$f1.
On Wed, Jan 25, 2017 at 11:03 AM, me.grimm megrimm@gmail.com wrote:
Hello,
I am trying to calculate inverse kinematics in 2D space with 2 DOF according to this tutorial(1) and formulas within using [expr]. For some reason my calculations for "c2" using [expr] deliver quite a different result than the excel sheet calculation that the tutorial provides.
What am I doing wrong here? It may be I don't quite understand how "^" is used?
Using: Linkage 1 length of 5 Linkage 2 length of 4
and plotting my the end of joint 2 at (3.56, 6.43) I should get c2 to equal 0.3254625 but get 0.25 with [expr]. Because of this further calculations to get joint angles are also off, obviously.
attached is patch.
but maybe someone has already done this type of work which might save me some trouble...
cheers m
(1) http://www.societyofrobots.com/robot_arm_tutorial.shtml#inverse_ kinematics
-- ____________________ m.e.grimm, m.f.a, ed.m. syracuse u., tc3 megrimm.net ____________________
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/ listinfo/pd-list
hey matt yeah that does work out correctly. thank for the help...
i figured i was using the "^" operator wrong here....
cheers m
On Wed, Jan 25, 2017 at 11:10 AM, Matt Barber brbrofsvl@gmail.com wrote:
In expr, ^ is bitwise-exclusive-or, but you want exponentiation. Just replace $f1^2 with $f1*$f1.
On Wed, Jan 25, 2017 at 11:03 AM, me.grimm megrimm@gmail.com wrote:
Hello,
I am trying to calculate inverse kinematics in 2D space with 2 DOF according to this tutorial(1) and formulas within using [expr]. For some reason my calculations for "c2" using [expr] deliver quite a different result than the excel sheet calculation that the tutorial provides.
What am I doing wrong here? It may be I don't quite understand how "^" is used?
Using: Linkage 1 length of 5 Linkage 2 length of 4
and plotting my the end of joint 2 at (3.56, 6.43) I should get c2 to equal 0.3254625 but get 0.25 with [expr]. Because of this further calculations to get joint angles are also off, obviously.
attached is patch.
but maybe someone has already done this type of work which might save me some trouble...
cheers m
(1) http://www.societyofrobots.com/robot_arm_tutorial.shtml# inverse_kinematics
-- ____________________ m.e.grimm, m.f.a, ed.m. syracuse u., tc3 megrimm.net ____________________
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/li stinfo/pd-list
for those interested I am sharing forward and inverse 2d 2dof kinematics.
next up is 2d/3d 3dof but only when i find a decent tutorial/implementation that will translate to [expr] easy.... which also might not be so easy
cheers m
On Wed, Jan 25, 2017 at 11:25 AM, me.grimm megrimm@gmail.com wrote:
hey matt yeah that does work out correctly. thank for the help...
i figured i was using the "^" operator wrong here....
cheers m
On Wed, Jan 25, 2017 at 11:10 AM, Matt Barber brbrofsvl@gmail.com wrote:
In expr, ^ is bitwise-exclusive-or, but you want exponentiation. Just replace $f1^2 with $f1*$f1.
On Wed, Jan 25, 2017 at 11:03 AM, me.grimm megrimm@gmail.com wrote:
Hello,
I am trying to calculate inverse kinematics in 2D space with 2 DOF according to this tutorial(1) and formulas within using [expr]. For some reason my calculations for "c2" using [expr] deliver quite a different result than the excel sheet calculation that the tutorial provides.
What am I doing wrong here? It may be I don't quite understand how "^" is used?
Using: Linkage 1 length of 5 Linkage 2 length of 4
and plotting my the end of joint 2 at (3.56, 6.43) I should get c2 to equal 0.3254625 but get 0.25 with [expr]. Because of this further calculations to get joint angles are also off, obviously.
attached is patch.
but maybe someone has already done this type of work which might save me some trouble...
cheers m
(1) http://www.societyofrobots.com/robot_arm_tutorial.shtml# inverse_kinematics
-- ____________________ m.e.grimm, m.f.a, ed.m. syracuse u., tc3 megrimm.net ____________________
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/li stinfo/pd-list
-- ____________________ m.e.grimm, m.f.a, ed.m. syracuse u., tc3 megrimm.net ____________________
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