Recent content by phiby

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    Where Can I Learn About Artificial Neural Networks?

    Hi, I am a very experienced programmer in C & C++. I want to learn about Artificial Neural Networks. Can someone recommend good books or websites?
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    Finding Direction of Vector A: M & N Intersect Perpendicularly

    Given this line M & N are two vectors which intersect and are perpendicular to each other. 1) Chose A to be orthogonal to N & M. or 2) Chose A to be perpendicular to the plane in which both M & N lie. Do the above descriptions indicate the direction of A - i.e. there are 2...
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    Euler Angles - Why Post Multiplication

    In robotics, you have a co-ordinate frame which is at the base & another which is at the next joint. You want to describe the position and orientation of the 2nd frame with respect to the first in terms of position and orientation. For the position, you use a translation matrix. The...
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    Euler Angles - Why Post Multiplication

    Anybody have any idea about it. Basically, you have 2 frames who share the same origin, but axes are oriented differently. You want to describe the position and orientation of the 2nd frame with respect to the first. Let the 1st frame have axis X, Y, Z Let 2nd frame have axis x, y, z To...
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    Euler Angles - Why Post Multiplication

    You have a Fixed Frame with Axis XYZ & Mobile Frame with Axis xyz. Both the frames have the same origin. To describe the mobile frame, you could use 3 rotations about Fixed axis as t1 about X, t2 about Y, t3 about Z? Now, the rotation of the mobile axis is RZ(t3) * RY(t2) * RX(t1) or through...
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    Euler Angles - Why Post Multiplication

    Normally with column vectors, we premultiply rotation matrices if the angles are with respect to fixed axis. Why then do we post multiply if the angles are Euler Angles, angles with respect to the mobile axis?
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    FEA: Stiffness Matrix for Beam Element

    It looks like it's the sign of the BM (not the others). The first matrix uses sagging BM as negative, the 2nd one uses sagging BM as positive. That's what I think. Unfortunately when I looked through all these books in the library, I didn't think about checking the BM sign convention and I am...
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    FEA: Stiffness Matrix for Beam Element

    I have gone through Beam Element analysis in several books on FEA. 80% of books have a particular Stiffness matrix, while a very small number of books have a matrix which is subtly different in sign. http://www.flickr.com/photos/66943862@N06/7195680680/in/photostream/lightbox Most books have...
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    Solving DE with Constant: Homogenous & Non-Homogenous

    My math is a little rusty - so please bear with me if this is a stupid question. I know how to solve both homogenous and non-homogenous DEs However, I am not sure where a DE with a constant falls & how to solve it. For eg. y'' + 2y' + c = 0 (c is a constant). You cannot convert...
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    R Parameter Programming in CNC

    I am currently doing a course on CNC Programming (GCode, MCode and also APT Programming). The course is almost over and we are going to have an Exam at the end. The Exam is mostly writing programs but would also have a few theory questions. One of the questions asked in previous exams has been...
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    Inverse of Matrix - Product Form

    In a few books on Operations Research, I have found a reference to a method of finding the inverse of matrix using a method called as 'Product Form'. From the context, it looks like the product form method is used for finding the inverse of the basis matrix in a simplex table. The method may or...
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    Robotics - Need for minor axes?

    Most textbooks on industrial robotics (schilling etc) call the 1st 3 joint axes which position the end-effector/gripper as major axis & the next 3rd joint axes which orient it as minor axes. Yes, this is clear now. I was asked the question when I had just started reading the book. Once I...
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    T codes and other CNC Programming questions

    I have learned M Codes and G Codes in CNC Programming. I was looking at a programming and found some statements unfamiliar to me This is how the program goes N1 T0000; G00 X0.0 Z0.0; T0101; ... ... N2 T0000; G00 X0.0 Z0.0; M30; 1) all the programs I have studied till date number each and...
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    Understanding Basic Geometric Equations in Robotics Kinematics Analysis

    Don't bother. I was able to get it using the law of cosines.
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    Understanding Basic Geometric Equations in Robotics Kinematics Analysis

    http://www.flickr.com/photos/66943862@N06/6868453382/in/photostream/lightbox/ http://www.flickr.com/photos/66943862@N06/6868453382/in/photostream/lightbox/ I was looking at a robotics kinematics analysis & there is one geometric equation assumed in the analysis which I can't seem to...
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