Questions tagged [noise]
Unwanted or modified signals detracting from some form of reception or perception.
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Gazebo GPS Noise Model
What is the Gazebo GPS Sensor Noise Model based on? It looks like a Random Walk through the code, but would be great if I could get some confirmation about it.
Also, is HDOP and VDOP (DOP - dilution ...
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Why different noise terms are read at specific sampling interval in Allan Variance plot?
I was trying to identify Quantization Noise, Angle Random Walk, Bias Instability, and Rate Random Walk from Allan Variance plot which as Allan deviation on y axis and Sampling Time Interval ...
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Converting IMU random walk, bias instability to stddev, bias stddev, etc
I am trying to create an accurate IMU model in Gazebo based off of a real IMU that I am using.
The Gyro specs are:
Bias instability: 3.5 degrees/hr
Angular random walk: 0.1 degrees/sqrt(hr)
The ...
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accelerometer and gyroscope fusion using extended kalman filter
I'm working on my graduation project which is characterizing human body posture. I'm using IMU so I get measurements from the accelerometer and gyroscope and I'm wealing to fuse these two filters so I ...
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What is the noise in this PWM signal?
I'm in the process of calibrating servos while constructing a new hobbyist robot arm. When testing the base rotation servo I noticed some unexpected noise in the PWM signal while the servo is in ...
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What would be a way to estimate IMU noise covariance matrix?
Weirdly enough, my robot platform which has an official ROS package supported by a manufacturer doesn't provide any covariance matrices of its sensors. So, I'm basically trying to estimate these ...
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Eliminating drift generated from double integration of acceleration signal using Envelope Method
I'm trying to remove the drift generated upon the double integration of a noisy acceleration signal. But this question discusses only removing the drift upon single integration to generate velocity ...
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Understanding import attributes of electronics speakers, by example
I'm new to electronics/robotics and I'd like to start with a simple project that uses a speaker to play sound clips when a certain event/input/stimulus is detected.
Looking on Digi-Key and similar ...
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Simulating sensor readings based on an existing Alan Variance Analysis
My goal is to model an accelerometer and a gyroscope based on real hardware. I understand deterministic errors like bias and scaling but the different types of non-deterministic errors are difficult.
...
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Noisy magnetometer data
I’m looking to develop an AHRS for which I’m using a magnetometer to correct for heading errors. I wanted to check that the magnetometer I'm using is functioning to the level of accuracy (+- 1 degree) ...
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EKF singularity problem when measurement noise R is zero
my Extended kalman filter (EKF) program works well, my estimated state vector is same as real state vector when I give any positive definite number to measurement noise R. But I want to make ...
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Practicality of using magnetometer inside AUV
I have an AUV with a 12 inch diameter, 29 inch long capsule. Inside the capsule sits an Intel NUC computer, an NVIDIA Jetson GPU, an Arduino Mega, a Sparton IMU (9 DOF) as well as a custom voltage ...
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KF/ EKF - Modelling and tuning noise matrices and other parameters
I am developing C++ code to estimate roll and pitch of a camera using accelerometer and gyroscope. The roll, pitch and yaw are in my state space ($X_t$) and the process is modeled as:
$\bar{X_t} = X_{...
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Wheel odometry simulation using ground truth
I'm tracking the state of a robot $X=(x,y,\theta)$ where $x$ and $y$ are the ground coordinates and $\theta$ the heading angle.
I have the ground truth states $X_{gt}=(x_{gt},y_{gt},\theta_{gt})$.
I ...
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Heading drift on Beaglebone Blue on small AUV due to power cables (I think)
At my work we use the BeagleBone Blue boards to control somewhat small AUVs.
The board is placed in underwater tubes along with batteries, ESCs for thrusters and all other electronics.
We use the in-...
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Should the kalmanfilter have disturbance as input?
This is a kalmanfilter
As you can see, the process noise(disturbance) is not going to the kalmanfilter. But the state space model for the state feedback system is written as this: https://youtu.be/...
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Why doesn't this kalmanfilter filter anything? Reduce disturbances and noises with LQG controller
I have a state space model which look like this:
$$
\ \begin{bmatrix} \dot{x} \\ \\\dot{\tilde{x}} \end{bmatrix} =\begin{bmatrix} A - BL& BL \\ 0 & A-KC \end{bmatrix} \begin{bmatrix} x\\ \...
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Can I write the seperation principle for LQG controllers in this state space form?
Look at this picture. This is the seperation principle diagram.
It is an LQG controller which going to control the real life process. What I want to do, is to create a state space model for this ...
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Why does one IMU axis influence another?
For a home robotics project I just bought a BerryIMU to connect it to my Raspberry Pi. After hooking it up I ran the provided Python code to read out some values while moving it around.
If I keep the ...
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Kalman filter: 3D measurement error to individiual components
I'm working on a Kalman filter for estimating the position of a point in 3D space. I know that I can measure its 3D position directly with a variance of about 2 mm (in other words: the variance of the ...
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What is a good approach for outlier rejection during real time data filtering?
I'm trying to finish up a localization pipeline, and the last module I need is a filtering framework for my pose estimates. While a Kalman filter is probably the most popular option, I'm using cameras ...
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Odometry motion model for Kalman filter, but is the error zero mean?
I was planning on using the odometry model in the prediction stage of an Extended Kalman Filter.
State transition equations:
$$ f(X_t,a_t) = \begin{bmatrix}
x_{t+1} = x_t + \frac{\delta s_r + \delta ...
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Filtering IMU angle discontinuities
I try to measure Euler angles from an IMU, but some discontinuities happens during measurement, even in vibrationless environment, as shown in the images below.
Can someone explain which type of ...
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The uncertainty is big while the sensor is rather accurate at measuring a landmark in EKF-SLAM
I've a 2D sensor which provides a range $r$ and a bearing $\phi$ to a landmark. In my 2D EKF-SLAM simulation, the sensor has the following specifications
$$
\sigma_{r} = 0.01 \text{m} \ \ ,\sigma_{\...
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Eliminating Electrical Noise from my motor driver
Background:
I am using an Arduino Mega connected to a RoboClaw 2x60A motor driver. I asked this question about the system, but I have since narrowed the scope of the problem. I tried adding a bunch ...
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What Does the Sensitivity Function Mean?
I'm studying for a test in Automatic Control and I have some troubles understanding sensitivity functions and complementary sensitivity functions.
There's one assignment from an old exam that sais
"...
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How to choose the state space model for 1 axis gyroscope to implemnt a good kalman filter
I am using this gyroscope in order to measure the rotation of my robot around the z axis.
I want to implement a kalman filter in order to improve the values.
What i came with since now is this space ...
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IMU based acceleration parameters for differential drive robot
I have a differential drive robot whose motors are virtually quiet while driving on a completely flat surface, but the motors make a lot of noise when on a incline. This is likely due to the ...
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Velocity Model Motion in Matlab (Probabilistic Robotics)
I want to implement the velocity motion model in Matlab. According to Probabilistic Robotics page 124, the model is as following
\begin{align*}
\hat{v} &= v + sample(\alpha_{1} v^{2} + \...
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Can motion model noise be zero?
Can I assume the noise of motion model to be zero? If so, what are the consequences of doing so?
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covariance matrix in EKF?
I'm struggling with the concept of covariance matrix.
$$
\Sigma
=
\begin{bmatrix}
\sigma_{xx} & \sigma_{xy} & \sigma_{x \theta} \\
\sigma_{yx} & \sigma_{yy} & \sigma_{y \theta} \\
\...
- 2,452
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Kalman Filter and the state noise vector?
I'm reading Probabilistic Robotics by Thrun. In the Kalman filter section, they state that
$$
x_{t} =A_{t}x_{t-1} + B_{t}u_{t} + \epsilon_{t}
$$
where $\epsilon_{t}$ is the state noise vector. And ...
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ArduIMU noisy output in Quadrotor
We are using ArduIMU (V3) as our Quadrotor's inertial measurement unit. (we have a separate board to control all motors, not with ArduIMU itself).
Now we have a problem with ArduIMU's sensors output....
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How are units of noise measurement related to units of a sensor's data measurement?
I'm trying to understand how noise is represented for accelerometers, gyroscopes, and magnetometers so that I can match the requirements of my project with the standard specs of these sensors.
I ...
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How do you determine EKF process noise for pre-recorded data sets?
I've seen this question, which asks about determining the process noise for an EKF. I don't see anything there about pre-recorded data sets.
My thought on how to determine the noise parameters, ...
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How to model the noise in a range sensor's return?
Range sensors (for example sonar, infrared, and lidar) are notoriously noisy. How can I characterize the noise characteristics to include these in a probabilistic localization sensor model?
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What determines the amount of noise an actuator produces?
Many robots and other mechanical devices produce the signature whirring noise as they move, some produce less. What makes the difference? What restrictions a silence requirement places on a robot?
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