Eric Ragnarsson

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These are questions asked by Eric Ragnarsson

Hi

I am trying to implement a recursive algorithm for matrix inverses, its a seventh-order method

for n to 7 do
    new := (1/16*old) . (120*I + ((A . old) . (735*I + ((A . old) . (-861.*I + ((A . old) . (651*I + ((A . old) . (93*I + (A . (old(-15*I + (A . old)))))))))))));
    old := new;
    print(n);
end do

However I get a error informing me that this is a recursive statment. Which it is, but maple thinks this is a bad thing.

So it is clear that I am doing somthing wrong, Can anyone help me by explaining what I am doing wrong?

Mvh

Eric Ragnarsson

 

Hi

I am trying to implement a maplesim block that takes two vectors as input and a 6x6 matrix as an output. I alrady got help with how to implement the inputs and the outputs however it was for an one input one output system.

The current code is the following

However this results in both inputs being placed ontop of each other

Do anybody know how to change the position of the two inputs so that they are not on top of each other?

Mvh
Eric Ragnarsson

Hi

I am on my way to construct a matrix for centripetal and Coriolis forces for a robot arm. However this requeers that I use a sum where the matrix index is the sumations index.

So I started testing things out before I constructed the full expresion, this is what I did.

According to the error page, this is du to that k in M[1,k] is an bad index, however in the sum this would be k=1 och k=2 whitch are vallid.

Do anybody know a way around this problem or can tell me what I did wrong.

 

Many thanks

Eric Ragnarsson

Hi

I am trying to construct a controler for a UR5e robot, I have a simulation of the robot in maplesim and have started to look for a way to use multibody analysis to provide me with the Jacobian. However it only provieds the constraint Jacobian and as I have no position constraints on the robot, it returns nothing.

I then came across 

Link: https://www.youtube.com/watch?v=d3xJge_09E0&t=374s

However it is old and does not exactly say how to do it.

So I thought I should ask this wonderful comunity if they have an recomended way to construct the Jacobian from a maplesimmodel? I am still a beginner at maplesim and maple so any help is appreciated.

 

With thanks for helping me

Eric Ragnarsson

 

Hi

I am trying to implement a controler for a 6dof robot. This requires a number of matrixis one among them is the mass matrix.

I have the matrix equation from using the multibody analysis tool and was thinking to use this matrix equation to construct a custom componet that takes the angels of the robot joints as inputs and have the 6 x 6 mass matrix as an output.

However when I complete the component generation am I greeted with this error message.

(in MapleSim:-Modelica:-PrintModel) unable to print Matrix(6, 6, {(1, 1) = ((1/5000)*(5000*`msim/RNAME`(_msim_End_effector_M)+5000*`msim/RNAME`(_msim_Wrist_2_M)+2500)*(`msim/RNAME`(_msim_Wrist_1_H)+`msim/RNAME`(_msim_Wrist_2_H))*`msim/RNAME`(_msim_Upper_Arm_H)*cos(`msim/RNAME`(_msim_R3_theta))-(1/5000)*(5000*`msim/RNAME`(_msim_End_effector_M)*(`msim/RNAME`(_msim_End_effector_H)+`msim/RNAME`(_msim_Wrist_2_W))+5000*`msim/RNAME`(_msim_End_effector_H)+2500*`msim/RNAME`(_msim_Wrist_2_W))*sin(`msim/RNAME`(_msim_R5_theta))*`msim/RNAME`(_msim_Upper_Arm_H)*sin(`msim/RNAME`(_msim_R3_theta))+(1/5000)*(5000*`msim/RNAME`(_msim_End_e ... NAME`(_msim_Wrist_1_M)+(1/8)*`msim/RNAME`(_msim_Wrist_1_W)^2+7/10000})

Error in Component btnGenComponent with caption "Generate MapleSim Component

 

Most of it is just fragments of the (1,1) equations but what I take away from it is that it complains on a missmach between the 6 X 6 matrix and the output port. 

After researching the question, however, I have not managed to find a good answer to this so I ask this wonderful forum for help.

Is it posible to have a matrix as an output from a custom component? If it is then how?

Mvh

Eric Ragnarsson

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