# Tag Info

Accepted

### How can I apply different control approach without having a state space model?

Many control strategegies (PID is not neceserily one of these) are computing some of their parameters from your system. If you do not want to model your system yourself (or play around with it until ...
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### About official robotics system toolbox Matlab and Peter Corke Robotics toolbox matlab

There are very few problems having both toolboxes installed. The biggest gotcha is the function angdiff() which is provided by both toolboxes but defined differently. If you want to stick with ...
• 1,712
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### Does simulink accepts robotics toolbox in matlab?

The MATLAB function block in Simulink has some limitations. The fact that Link.m is referred to as a function not a class is a worry. I recreated your Simulink model and get similar error messages, ...
• 1,712

### Mathematical modelling of system dynamic on matlab

the Simulink diagram is straightforward. It is a matter of connecting blocks. For the differential equations provided in your post, the simulink is For $u_1$ and $u_2$, I've chosen the unit step. ...
• 2,452
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### Meaning of a negative step response with quaternion

Welcome to Robotics, PaoloH! This is a fantastic question for Robotics - It has some Matlab/Simulink, some control theory, some spatial (quaternion) representations, etc. Robotics is the place to come ...
• 15.9k

### How to take prediction step in particle filter?

The prediction step generates a new set of states from the old set of states. The motion model of the system is used to make this best estimate of what we think the new state might be. The motion ...
• 124
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### Complimentary filter issues

There are quite a few things wrong here. I'll split them into two sections: technical errors, and coding warnings. Technical Errors: You are not calculating your angles from accelerometer readings ...
• 15.9k

### Human arm inverse kinematics

You are tackling two non trivial problem at the same time 1. Inverse kinematics of an overactuated manipulator 2. Obstacle avoidance using the null space By definition of the null-space projection ...
• 1,411

### Does simulink accepts robotics toolbox in matlab?

You appear to be using a third-party toolbox, the Robotics Toolbox. If it's not running in Simulink, then it might not run in Simulink. If you want something that does, try the official toolbox. ...
• 15.9k

### Matlab Inverse Kinematics 6 DOF

Ideal solution can be defined in many ways. The simplest way to choose one is to compare which of the 8 solutions is closest to your current pose in joint space. This is usually a good idea if you ...
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### Can I write the seperation principle for LQG controllers in this state space form?

Both state space representations are equivalent. For example the eigenvalues of the two closed-loop system matrices should be the same. However when implementing LQG you only have access to the ...
• 941
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### Determine the relative camera pose given two RGB camera frames in openCV-python

If you understand how relative pose estimation works in theory, it should be quite trivial to translate it into OpenCV code. First, you can pick any feature detection/description approach you like (...
• 1,106

### Is the translational vector (positon) in transformation matrices in cm or another unit (MATLAB)?

They are in whatever units the kinematic analysis uses. It could be feet, inches, meters, millimeters, or whatever. Your question is a bit like asking “what unit is the Pythagorean theorem written ...
• 4,406

### Solving pseudo inverse of Jacobian in Matlab/Octave

After running your code, it looks like everything is behaving how you have defined it to. The problem you are running into has more to do with the Jacobian itself and less to do with any mistakes you ...
• 904
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### Reading multiple signed digits from serial port

It looks like you're doing this in a very round-about manner. You said, The matlab function in sumlink is supposed to read the received ASCII characters and add them to a variable until it reaches ...
• 15.9k
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I don't have access to the article, so I have to guess about the expected behavior. Looking at your code, the first thing I did was to change all of your atan ...
• 15.9k
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### How to move root locus to the left?

Brief process for pole placement in Matlab: Check that the system is actually controllable. . ...
• 15.9k
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### How to get Max Torque on Robot arm 's Joints (RRR)

Torque is pretty easy to calculate for a single static arm configuration. Torque is just the length of the moment arm * the perpendicular force. And it is easy to decompose the problem into X and Y ...
• 5,865
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### Can I write the seperation principle for LQG controllers in this state space form?

This is really a lot to look at, but the most glaring issue I noticed off the bat is your definition of the control signal $u(t)$. What is the input to your controller? What should be the input to ...
• 15.9k
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### Inconsistent results between Simulink derivative model and tf for PD controller

After some investigation, there is a problem with the derivative block in Simulink. tf yields the correct response in my case. While the values of Kd has been ...
• 2,452
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### Control system in Matlab with RSA encryption

:EDIT: Your numbers must be integers POSITIVE INTEGERS. (link) This is probably the root of the trouble you're having. Interesting that the paper didn't mention anything about this. I'm not sure how ...
• 15.9k
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### Roy Featherstone toolbox robot model

I changed the code and now it works properly. ...
• 99

There are a variety of functions that can give you an "S" curve like you want. Check out the Sigmoid function. I usually use something like this: $f(x) = \frac{x}{\sqrt{1+x^2}}$ And it can ...
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### Pole placement gains tuning

I assume that you'd aim to place the poles in $-0.5 \pm 0.2 \cdot i$ for stability reasons. In the s-domain, the transfer function is: $$\frac{\Phi_c}{\Phi}=\frac{K_p}{s^2+K_ds+K_p}.$$ Computing the ...
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### Pitch angle is either +90° or -90°

The problem is that the quaternions given in id: 4 distance: 1048 q0: 646 q1: -232 q2: -119 q3: 717 are not normalized. In fact, $$\|\textbf{q}\| = \sqrt{q_0^2+q_1^2+q_2^2+q_3^2} = 999.6950$$ I ...
• 385

### Why I'm getting very long terms in the inertia matrix (or dynamics model) of the robot using matlab script?

Long formulas are to be expected. I actually have derived such equations of motion for a planar RRRR manipulator. I assumed real symbolic variables assume(A, 'real')...
• 156

You can use from simulink library browser under User-defined functions figure out which one is suitable for your system. If you get some delay while calling Matlab function than you can also use a ...
• 153
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### Problem with inverse kinematics in robotic arm using Matlab

In the documentation of the Robotics Toolbox by Peter Corke it is stated that the ikine() method does not regard motion limits. (Notes -> Joint limits are not considered in this solution.) You can ...
• 6,682
Accepted

### showing error while using inverse kinematics "ikine" for 4 dof robotic arm

In the Robotics Toolbox SerialLink.ikine() can only be used for 6 dof or higher structures. The masking option you have used, can be used fo underactuated robots. There is an example in the ...
• 6,682