# Matlab Question

1. Dec 5, 2005

### Shawnzyoo

I am not sure if this is in the right forum
but i have 2 matrices in Matlab

T =
[ r11, r12, r13, dx]
[ r21, r22, r23, dy]
[ r31, r32, r33, dz]
[ 0, 0, 0, 1]

T04 =
[sin(theta2+theta4+theta1), cos(theta2+theta4+theta1),0, 7*cos(theta1+theta2)+4*cos(theta1)]
[-cos(theta2+theta4+theta1),sin(theta2+theta4+theta1),0, 7*sin(theta1+theta2)+4*sin(theta1)]
[0,0,1,-d3]
[0,0,0,1]

I want to set T=T04 and solve for
theta1, theta2, theta4, and d3 in terms of r11 r12 r13 dx r21 r22 r23 dy r31 r32 r33 dz
is there a command that will do this for me?
thank you

2. Dec 8, 2005

I don't understand your notation here. Is that supposed to be a nonlinear system of 16 equations, or something else?

3. Dec 8, 2005

### chingkui

Are you trying to solve them symbolically?

4. Dec 9, 2005

### Shawnzyoo

what I am trying to solve is the Inverse Kinematics of a RRP robotic manipulator
what those equations represent is this
T04 is the D-H convention of a robotic manipulator
T is the position vector of a teach pendant

right now i tried using a for loop
to equate the 2 matrices

and then invoked the solve(eqn, var) command to solve for theta1, theta2 .. ect
and it seems to be working correctly

yes i am trying to solve them symbolically
thanks

5. Dec 9, 2005

### Cyrus

I need to do something like that too! But I think an iterrative solution is probably the only one that will be realisitic. I dont know if all systems of nonlinear equations can be solved, probably not.