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8 votes
Accepted

What is a good approach for outlier rejection during real time data filtering?

It is both acceptable and standard to use camera observations with a Kalman filter if you are talking about landmark positions in pixel or real-world space. Pixel space observations are usually ...
Gouda's user avatar
  • 902
4 votes
Accepted

Noisy magnetometer data

First, let's look at if your findings seem reasonable given the datasheet specifications for the sensor. For this, I'll assume that Wikipedia is generally correct and that the strength of Earth's ...
Chuck's user avatar
  • 16k
4 votes
Accepted

Practicality of using magnetometer inside AUV

Mags are used in almost all UAVs. It will be useful and it will be a unique source of information. Adding a some shielding between the mag and your computers and power lines will greatly reduced the ...
holmeski's user avatar
  • 1,853
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 ...
fibonatic's user avatar
  • 941
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 ...
Chuck's user avatar
  • 16k
2 votes
Accepted

Wheel odometry simulation using ground truth

You can't just take the ground truth states and get wheel encoder positions, or vice-versa, because the robot is nonholonomic. Nonholonomic is a fancy word that means "path dependent," essentially, ...
Chuck's user avatar
  • 16k
2 votes

EKF singularity problem when measurement noise R is zero

I think you need to step back a bit and think beyond the math. An (E)KF is used to estimate the true value of a signal in the presence of noise; it's only because of this noise that we even need the ...
ryan0270's user avatar
  • 2,814
2 votes
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What would be a way to estimate IMU noise covariance matrix?

Usually, IMU manufacturers implement some kind of filter to remove the noise these days, therefore the probability is your IMU is not throwing raw values. Nevertheless, you can initiate the sensor ...
Franky's user avatar
  • 536
2 votes

Eliminating drift generated from double integration of acceleration signal using Envelope Method

It looks like you are adding a constant for noise, so it makes sense the envelope output is a constant offset from the clean. I would think you need to add gaussian noise to simulate more realistic ...
Ezward's user avatar
  • 356
2 votes

accelerometer and gyroscope fusion using extended kalman filter

You should be using quaternions for fusion for good behaviour. Addition and multiplication for quaternions will be swapped out by rotation composition operations for quaternions and your orientation ...
Raggy's user avatar
  • 128
1 vote

Converting IMU random walk, bias instability to stddev, bias stddev, etc

Kalibr library has a good tutorial on how to calibrate an IMU with respect to a camera. It also has explanations of parameter data used in IMU calibrations. From the kalibr wiki: The parameters for ...
EmmanuelMess's user avatar
1 vote

What is the noise in this PWM signal?

After a bit more reading and thinking, I think I’ll answer my own question. I’d like feedback on my logic if you have it. My logic is this: the PWM signal from the MCU is clean (evidenced by the ...
RowanP's user avatar
  • 339
1 vote
Accepted

Understanding import attributes of electronics speakers, by example

A small speaker like this one should be able to play tunes as you have mentioned. You can use an arduino or a raspberry-pi to stream audio over as shown in this link.
Akhil Kurup's user avatar
1 vote

Practicality of using magnetometer inside AUV

As mentioned in the previous answer, many small, low-cost underwater (and aerial) vehicles use a magnetic compass. You need a good procedure for both hard-iron and soft-iron calibration of your ...
user96966's user avatar
  • 126
1 vote

Odometry motion model for Kalman filter, but is the error zero mean?

The noise term will always be zero mean. If you believe the odometry equations will not accurately capture wheel slip and you believe the filter will not adequately track your state then the solution ...
holmeski's user avatar
  • 1,853
1 vote
Accepted

Should the kalmanfilter have disturbance as input?

I don't like the format you're using, with $\tilde{x}$, because it masks the fact that it is actually $x-\hat{x}$. In generally, you don't actually care about the state error; what you really should ...
Chuck's user avatar
  • 16k
1 vote
Accepted

Why doesn't this kalmanfilter filter anything? Reduce disturbances and noises with LQG controller

I'm not sure if this answers the question but I think there is a mismatch between the block diagram and the state equations. In the first block of the state transition matrix (top-left $A-BL$) you ...
IRano's user avatar
  • 26
1 vote
Accepted

Why does one IMU axis influence another?

The problem is estimating angles in regions of instability. Let us look at equations used for estimation of pitch and roll angles. For aerospace rotation sequence e.g. $xyz$: $\tan(roll)=\frac{G_{y}...
Long Smith's user avatar
1 vote

Kalman filter: 3D measurement error to individiual components

Take a bunch of measurements of your system while states are static and compute the noise matrix yourself. As long as recording measurements is relatively straightforward this should be a painless ...
holmeski's user avatar
  • 1,853

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