MATLAB Answers

using Matlabfunction for determinant, not enough input arguments

1 view (last 30 days)
Tony Yu
Tony Yu on 7 Jul 2020
Commented: Star Strider on 7 Jul 2020
I think there should only be L, th2, th3 and th5 in J_home, am I missing something? I am trying to solve the determinant of J_home with the assume configuration
%finding Jacobian
syms t1 t2 t3 t31 t4 t41 t5 t51 t52 t6 te th1 th2 th3 th4 th5 th6 th1_ th2_ th3_ th4_ th5_ th6_ L
t_1=pi/2 ;d_1=0;a_1=0;alpha_1=pi/2;
t0=pi/2; d0=0;a0=0;alpha0=0;
t1 = 0; d1 = th1_; a1 = 0; alpha1 = 0;
t2 = th2_+pi; d2 = 0; a2 = L; alpha2 = 0;
t3 = th3_-pi/2;d3 = 0; a3 = L; alpha3= -pi/2;
t31 = 0; d31 =L; a31 = 0; alpha31 = 0;
t4 = 0;d4 = L+th4_;a4 =-L; alpha4 = pi;
t5 = th5_+pi;d5 = 0;a5 = L; alpha5 = pi/2;
t51 = pi/2; d51= L; a51 = 0; alpha51 = pi/2;
t52 = 0; d52 = L; a52 =0; alpha52 = 0;
t6 = th6_;d6 = L;a6 = 0; alpha6 = 0;
A_1_ = inTransMat(a_1,alpha_1,d_1,t_1);
A0_ = inTransMat(a0,alpha0,d0,t0);
%setting frame 0 as shown
A1 = inTransMat(a1,alpha1,d1,t1);
A2_ = inTransMat(a2,alpha2,d2,t2);
A3_ = inTransMat(a3,alpha3,d3,t3);
A31_= inTransMat (a31,alpha31,d31,t31);
A4_ = inTransMat(a4,alpha4,d4,t4);
A5_= inTransMat(a5,alpha5,d5,t5);
A51_= inTransMat (a51,alpha51,d51,t51);
A52_= inTransMat (a52,alpha52,d52,t52);
A6_= inTransMat(a6,alpha6,d6,t6);
T_ = A_1_*A0_*A1*A2_*A3_*A31_*A4_*A5_*A51_*A52_*A6_
T01_ = A_1_*A0_*A1;
T02_ = A_1_*A0_*A1*A2_;
T03_ = A_1_*A0_*A1*A2_*A3_*A31_;
T04_ = A_1_*A0_*A1*A2_*A3_*A31_*A4_;
T05_ = A_1_*A0_*A1*A2_*A3_*A4_*A5_*A51_*A52_;
T_06= vpa(T_,2)
Z0= vpa(T01_(1:3,3),2)
Z1= vpa(T01_(1:3,3),2)
Z2= vpa(T02_(1:3,3),2)
Z3= vpa(T03_(1:3,3),2)
Z4= vpa(T04_(1:3,3),2)
Z5= vpa(T05_(1:3,3),2)
pe= T_06(1:3,4:end)
%derivative of EE with respected q
Jv1 = Z0;
Jv2 = jacobian([pe],[th2_]);
Jv3 = jacobian([pe],[th3_]);
Jv4 = Z3;
Jv5 = jacobian([pe],[th5_]);
Jv6 = jacobian([pe],[d6]);
Jw1 = [0 0 0]';
Jw2 = Z1;
Jw3 = Z2;
Jw4 = [0 0 0]';
Jw5 = Z4;
Jw6 = Z5;
%JOINT 1,4 is a prismetic joint
%combine Jv and Jw into on column
J1q = [Jv1(:);Jw1(:)];
J2q = [Jv2(:);Jw2(:)];
J3q = [Jv3(:);Jw3(:)];
J4q = [Jv4(:);Jw4(:)];
J5q = [Jv5(:);Jw5(:)];
J6q = [Jv6(:);Jw6(:)];
J = [J1q J2q J3q J4q J5q J6q]
J_home = vpa(J,2)
%end effector @ homeposition
L=100;
th2_=0;
th3_=0;
th5_=0;
%assume the following configureation
J_fcn = matlabFunction(J_home)
J_num = J_fcn(L,th2_,th3_,th5_)
J_det=det(J_num)
%matrix not in full rank
function IT = inTransMat(a,b,c,d)
IT = [cos(d) -sin(d)*cos(b) sin(d)*sin(b) a*cos(d); sin(d) cos(d)*cos(b) -cos(d)*sin(b) a*sin(d); 0 sin(b) cos(b) c; 0 0 0 1];
end
function T = TransMat(a,b,c,d)
T = [cos(d) -sin(d)*cos(b) sin(d)*sin(b) a*cos(d); sin(d) cos(d)*cos(b) -cos(d)*sin(b) a*sin(d); 0 sin(b) cos(b) c; 0 0 0 1];
end

  0 Comments

Sign in to comment.

Accepted Answer

Star Strider
Star Strider on 7 Jul 2020
I am not certain with the problem is with the ‘J_fcn’ produced by matlabFunction. (The error may refer to the reshape call within it. I did not look at it closely.)
However, if you replace ‘J_fcn’ with:
J_fcn = @(L,th2_,th3_,th4_,th5_) J_home;
your code runs without error. You need to determine if it is producing the correct results.
Also, these can be defined as anonymous funcitons:
TransMat = @(a,b,c,d) [cos(d) -sin(d)*cos(b) sin(d)*sin(b) a*cos(d); sin(d) cos(d)*cos(b) -cos(d)*sin(b) a*sin(d); 0 sin(b) cos(b) c; 0 0 0 1];
inTransMat = @(a,b,c,d) [cos(d) -sin(d)*cos(b) sin(d)*sin(b) a*cos(d); sin(d) cos(d)*cos(b) -cos(d)*sin(b) a*sin(d); 0 sin(b) cos(b) c; 0 0 0 1];
simplifying your code a bit.

  2 Comments

Tony Yu
Tony Yu on 7 Jul 2020
I used your line as follow, but it seems like it still doesn't want to take the input(L,th2,th3,th4,th5), I also need to find q_dot.
%finding Jacobian
syms t1 t2 t3 t31 t4 t41 t5 t51 t52 t6 te th1 th2 th3 th4 th5 th6 th1_ th2_ th3_ th4_ th5_ th6_ L x q_dot
t_1=pi/2 ;d_1=0;a_1=0;alpha_1=pi/2;
t0=pi/2; d0=0;a0=0;alpha0=0;
t1 = 0; d1 = th1_; a1 = 0; alpha1 = 0;
t2 = th2_+pi; d2 = 0; a2 = L; alpha2 = 0;
t3 = th3_-pi/2;d3 = 0; a3 = L; alpha3= -pi/2;
t31 = 0; d31 =L; a31 = 0; alpha31 = 0;
t4 = 0;d4 = L+th4_;a4 =-L; alpha4 = pi;
t5 = th5_+pi;d5 = 0;a5 = L; alpha5 = pi/2;
t51 = pi/2; d51= L; a51 = 0; alpha51 = pi/2;
t52 = 0; d52 = L; a52 =0; alpha52 = 0;
t6 = th6_;d6 = L;a6 = 0; alpha6 = 0;
A_1_ = inTransMat(a_1,alpha_1,d_1,t_1);
A0_ = inTransMat(a0,alpha0,d0,t0);
%setting frame 0 as shown
A1 = inTransMat(a1,alpha1,d1,t1);
A2_ = inTransMat(a2,alpha2,d2,t2);
A3_ = inTransMat(a3,alpha3,d3,t3);
A31_= inTransMat (a31,alpha31,d31,t31);
A4_ = inTransMat(a4,alpha4,d4,t4);
A5_= inTransMat(a5,alpha5,d5,t5);
A51_= inTransMat (a51,alpha51,d51,t51);
A52_= inTransMat (a52,alpha52,d52,t52);
A6_= inTransMat(a6,alpha6,d6,t6);
T_ = A_1_*A0_*A1*A2_*A3_*A31_*A4_*A5_*A51_*A52_*A6_
T01_ = A_1_*A0_*A1;
T02_ = A_1_*A0_*A1*A2_;
T03_ = A_1_*A0_*A1*A2_*A3_*A31_;
T04_ = A_1_*A0_*A1*A2_*A3_*A31_*A4_;
T05_ = A_1_*A0_*A1*A2_*A3_*A4_*A5_*A51_*A52_;
T_06= vpa(T_,2);
Z0= vpa(T01_(1:3,3),2);
Z1= vpa(T01_(1:3,3),2)
Z2= vpa(T02_(1:3,3),2)
Z3= vpa(T03_(1:3,3),2)
Z4= vpa(T04_(1:3,3),2)
Z5= vpa(T05_(1:3,3),2)
pe= T_06(1:3,4:end)
%derivative of EE with respected q
Jv1 = Z0;
Jv2 = jacobian([pe],[th2_]);
Jv3 = jacobian([pe],[th3_]);
Jv4 = Z3;
Jv5 = jacobian([pe],[th5_]);
Jv6 = jacobian([pe],[d6]);
Jw1 = [0 0 0]';
Jw2 = Z1;
Jw3 = Z2;
Jw4 = [0 0 0]';
Jw5 = Z4;
Jw6 = Z5;
%JOINT 1,4 is a prismetic joint
%combine Jv and Jw into on column
J1q = [Jv1(:);Jw1(:)];
J2q = [Jv2(:);Jw2(:)];
J3q = [Jv3(:);Jw3(:)];
J4q = [Jv4(:);Jw4(:)];
J5q = [Jv5(:);Jw5(:)];
J6q = [Jv6(:);Jw6(:)];
J = [J1q J2q J3q J4q J5q J6q]
J_home = vpa(J,2)
%end effector @ homeposition
J3 = J(1:3,1:3);
iJ= inv(J3)
L=100;
th2_=0;
th3_=0;
th5_=0;
%assume the following configureation
x=[5 0 10]'
%given linear velocity
q_dot = iJ*x
q_dot_fcn = @(L,th2_,th3_,th4_,th5_) q_dot;
q_dot_n = q_dot_fcn (L,th2_,th3_,th4_,th5_)
J_fcn = @(L,th2_,th3_,th4_,th5_) J_home;
J_num = J_fcn(L,th2_,th3_,th5_);
J_det=det(J_fcn);
%matrix not in full rank
function IT = inTransMat(a,b,c,d)
IT = [cos(d) -sin(d)*cos(b) sin(d)*sin(b) a*cos(d); sin(d) cos(d)*cos(b) -cos(d)*sin(b) a*sin(d); 0 sin(b) cos(b) c; 0 0 0 1];
end
Star Strider
Star Strider on 7 Jul 2020
When I ran your code using my version of ‘J_fcn’, it appeared to work correctly. Since matlabFunciton did not produce a function that was usable, that was my only alternative.
I have nothing further to add. I will delete my Answer in a few minutes.

Sign in to comment.

More Answers (0)

Categories

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!