6
votes
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 ...
- 6,682
6
votes
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
5
votes
Accepted
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
5
votes
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
5
votes
Accepted
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
5
votes
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
4
votes
Accepted
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
4
votes
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
4
votes
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
4
votes
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 ...
- 6,682
4
votes
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
4
votes
Accepted
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
4
votes
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
4
votes
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
3
votes
Accepted
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
3
votes
Accepted
Platooning leader follower code
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
3
votes
Accepted
How to move root locus to the left?
Brief process for pole placement in Matlab:
Check that the system is actually controllable.
.
...
- 15.9k
3
votes
Accepted
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 ...
Ben♦
- 5,865
3
votes
Accepted
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
3
votes
Accepted
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
3
votes
Accepted
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
3
votes
Accepted
3
votes
Smooth step function Simulink
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 ...
Ben♦
- 5,865
2
votes
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 ...
- 4,005
2
votes
Accepted
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
2
votes
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
2
votes
how to add a Matlab code to a simulink model?
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
2
votes
Accepted
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
2
votes
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
2
votes
Accepted
Inverse kinematics: how to specify TCP constraints in an iterative algorithm?
If you want to keep orientation constant, the simplest approach is to, well.. do exactly that. Do not solve for the tartget point and let the joint move along a seemingly arbitratry cartesian path (...
- 6,682
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