Questions tagged [sensor]

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6
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1answer
9k views

How to determine covariance matrix $Q$ and $R$ in Kalman-filter

I am implementing getting orientation from smartphone. I want to use Kalman filter and should determine process noise covariance matrix $Q$ and measurement noise covariance matrix $R$. (newbie to ...
5
votes
1answer
236 views

What type of low-pass filter to use for gyroscope filtering in control application?

I am using a gyroscope to generate a feedback signal that drives a motor to resist rotation, just as in a camera gimbal. The gyroscope is sampling at 32 KHz with a bandwidth of 8 KHz, and my control ...
5
votes
1answer
367 views

Finding dependence between two sparse signals

I am new to signal processing and would really appreciate your help. happy to provide more context/details. In my research, I have a system that has many sensors $X_1, \ldots, X_N$ and using this ...
3
votes
2answers
3k views

Detecting outliers/noise from sensor data

I am trying to detect outliers/noise as indicated on the diagram below from sensor data. Can anyone advice how to go about it? I can only do this in python, so are there libraries in python that I can ...
3
votes
1answer
182 views

How to interpret Allan Deviation plot for gyroscope?

Regions with different slopes correspond to different types of noises in Allan Deviation plot of a steady gyroscope at steady temperature. My doubts are: What is significance of x axis in this plot, ...
3
votes
1answer
111 views

FFT of resultant of signals

If one has two signals (say, two acceleromters mounted perpendicularly) and a piece-wise resultant acceleration signal is determined, it appears that frequency content information cannot be determined ...
2
votes
3answers
189 views

Kalman Filter Sensor Processing

Kalman filter achieves convergence of state vector by using sensor observations. Assuming a sensor such like velocity sensor, giving two axis velocity information in X-axis as well as Y-axis(see edit ...
2
votes
2answers
163 views

Why do we assume zero mean noise in sensor data?

I am reading a paper on measuring respiratory patterns from video data. In defining the model, the authors formulate the problem mathematically as: $x_i(t)=h_i(t) \ast g(t) + n_i(t) $ Where $n_i(t)...
2
votes
3answers
320 views

Why is my laser beam intensity profile not Gaussian?

I am kind of new to laser physics and signal processing, I hope I am in the right place to ask this question. I am also sorry for my not-great English. I have been asked to study the transverse ...
2
votes
2answers
459 views

detect and distinguish driving maneuvers via smartphone sensors

I want to do some driving style analysis via smartphone. Therefore, I programmed an app that records a 2D acceleration (when accelerating/braking and turning left/right). The app calibrates itself in ...
2
votes
2answers
1k views

Measuring walking speed with iPhone accelerometer

As part of a research project, I have been tasked with determining gait speed (walking speed) for a subject using a handheld iPhone. The main constraint is that walking distances are very short (10-30 ...
2
votes
2answers
265 views

Compressed / Compressive Sensing - Sensor Placement

I have a beam fixed at one end and free at the other. It obviously results in vibrations due to the disturbances in the environment or when induced. This system can be represented using a differential ...
2
votes
0answers
161 views

Software based synchronizing of multiple data streams/sensors with slightly differing sampling rates

Situation: I try to synchronize the data streams of multiple sensors (ADXL372) of the same type but with different data output rates. The data sheet states all sensors should have the same sampling ...
2
votes
2answers
166 views

Detecting pattern from signal data by gaussian mixture model?

I'm a machine learning newbie. I have sensor data which is generated by several sensors. The data is a series of 'time's. (it is not labeled, in other words, I cannot know which sensor generates ...
2
votes
0answers
133 views

Vibration signal analysis of non-stationary movement

my task is to develop a condition monitoring system of a machine module. For that I am using the vibration sensors placed on the machine housing. I want to focus on only one module of the machine, a ...
2
votes
0answers
33 views

How to determine load cell response to arbitrary temperature changes with known step response(s)

We have a loadcell, the output of which is (naturally) temperature dependent. Under static load conditions, we have observed a dynamic response to temperature changes. Therefore, we did a step ...
2
votes
0answers
82 views

Obtaining n values from n-1 sensors

As the questions states, lets consider we have 3 gas sensors giving me data for: A B C Note that only sensors for A and B give absolute values, yet we need the absolute values for all four species:...
2
votes
0answers
126 views

Open source GPS+IMU sensor fusion?

Are there any Open source implementations of GPS+IMU sensor fusion (loosely coupled; i.e. using GPS module output and 9 degree of freedom IMU sensors)? -- kalman filtering based or otherwise I see a ...
2
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0answers
831 views

Analyzing accelerometer data: appropriate use of rotation matrices?

I'm working on a project in which a rod is attached at one end to a rotating shaft. So, as the shaft rotates from 0 to ~100 degrees back-and-forth (in the xy plane), so does the rod. I mounted a 3-...
2
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0answers
7k views

Horizontal banding (flickering) due to electronic rolling shutters

It is a well-known artifact that in CMOS cameras with electronic rolling shutter, horizontal banding (flickering), i.e. brightness intensity variations, are observed when the image is recorded under ...
1
vote
3answers
428 views

Digital filter selection for sensor

I am having a LM35 sensor which gives $10\textrm{ mV}$ signal per degree rise of temperature. Now I have one question, which digital filter will be the best for this ? This sensor will be use in very ...
1
vote
1answer
83 views

Signal recovery from multiple noisy sensors

I'm working on detecting signals buried under the sensor noise using a multiple sensor system and using some technique (correlation?) to take what is common to all the sensors and cancel out the ...
1
vote
1answer
1k views

Using Kalman Filter to fuse two sensor readings of the same type

I have always used Kalman Filter to smooth a signal comes from one sensor only. I would like to know if Kalman Filter could be used to fuse data coming from two different sensors that provide the ...
1
vote
1answer
693 views

Filtering an acceleration signal

I have a triaxial accelerometer giving me acceleration along x, y, and z. I then combine the 3 axes by calculating magnitude of acceleration over all time points (details in my question here) I'm ...
1
vote
1answer
91 views

Combination of accelation signals from two devices

I have $x_A$, $y_A$, and $z_A$ acceleration signals collected from a smartphone and I call it: set $A$ and I also have $x_B$, $y_B$, and $z_B$ same acceleration signals from smartwatch: let's call ...
1
vote
1answer
1k views

Triaxial accelerometer to single signal

I have some smartphone recorded accelerometer data, so I have acceleration along 3 axes: $$a_{x}, a_{y}, a_{z}$$ The accelerometer data was collected by securing a phone to a walking subject. I'm ...
1
vote
1answer
270 views

Frequency measurement from acoustic emission sensor data(VDC RMS)

Currently, I am facing a problem about understanding FFT concept and getting exact frequency with acoustic emission sensor data(VDC RMS data). I want to measure the sound frequency from the acoustic ...
1
vote
1answer
191 views

How to remove ADC-induced noise from voltage measurement data?

I am measuring the various voltages involved in a solar energy system, but the recorded values vary by quite a bit, most of which is caused by the ADC in the Arduino Nano I am using to take the ...
1
vote
1answer
949 views

Accelerometer - coordinate system transformation

I'm getting some accelerometer readings from an Android phone, but it comes in on the phone's coordinate system. I want to apply a transformation to put the acceleration in the world coordinate system ...
1
vote
2answers
333 views

Multiple cheap IMUs vs one expensive IMUs

In my project, there is a possibility of either buying one expensive IMU or 5 cheaper IMUs. They have to be cheaper due to budget limitations, and the idea is to use them in order to be able to do "...
1
vote
0answers
38 views

Rocketry : Combine two accelerometers to reduce noise?

I am designing an IMU for an experimental rocket. I'll be using the BN055 9DOF that has sensor fusion - orientation quaternion - and gravity compensation. My main goal is speed computation, and I was ...
1
vote
1answer
33 views

Is there a closed form solution for a temporal calibration of two different signals?

Given two signals $f_1(t),f_2(t+dt)$ where $t$ is time and $dt$ is the time delay between the two signals, is there any closed-form solution with respect to $dt$? what are the efficient global ...
1
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0answers
39 views

Interpretation of steady state sensor signal

I try to understand some measurement results of an accelerometer MEMS sensor. I used a mikrocontroller which is sampling an accelerometer's analog signal with the built in analog-digital-converter. ...
1
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0answers
46 views

Source localization in 3d

Let's say I have a 4-sensor square-shaped array in 3d space, with sensors at $$ s_1 = [1 \ 0 \ 1] \\ s_2 = [2 \ 0 \ 1] \\ s_3 = [1 \ 0 \ 2] \\ s_4 = [2 \ 0 \ 2] \\ $$ And a single source somewhere ...
1
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0answers
201 views

How to convert magnetometer readings into orientation?

I have a magnetometer sensor, obtaining the reading with $50$Hz rate. Unfortunately, the data is not labeled: I just know that these are $x$,$y$,$z$ axes, and that the reading are in $\mu$T (micro ...
1
vote
0answers
113 views

Interpretation of minimum discernible signal (MDS) in sonar equation

I am working on modelling and simulations of synthetic aperture sonar at component/subsystem level. I have started with standard sonar equations for calculating detection ranges for different ...
1
vote
1answer
2k views

Choosing correct filter parameters for IMU sensor datas

I have a IMU sensor breakoutboard using ITG3701, LSM303D LinkProduct. This involves accelerometer, gyroscope and magnetometer. I have connected the sensors to a Arduino and sending the datas to ...
1
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0answers
159 views

sensor fusion on GPS/IMU

can anyone gives any link or explained to me on how sensor fusion works on GPS/IMU. as of now, i have gain learn few of the algorithms on Kalman Filter. Currently, im using an arduino Uno as my data ...
1
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0answers
93 views

Sensor Data Fusion with Orientation Sensors in 3D Euclidian Space

Preconditions For measuring the position of a mobile device in 3D space, I utilize two sensors with different characteristics that measure device orientation. Sensor A (a combined sensor of ...
0
votes
1answer
40 views

Bias instability in Gyroscopes : AVER / ADEV

I am attempting to implement allan variance to determine the amount of bias that is shown in my IMU's gyroscope ( BMI160 ). I am doing this with the following formula, that was captured in the ...
0
votes
2answers
319 views

Oversampled Binary Image Sensor vs Active Pixel Sensor(CMOS)

I am a beginner in the field of Image processing.I was designing a camera sensor when I came across these two type of sensors: CMOS(Active Pixel Sensor) Oversampled Binary Image Sensor. Now, I can ...
0
votes
1answer
73 views

What type of sensors have complex Gaussian noise?

What type of sensors have complex Gaussian noise? Do strain gauges also exhibit such noise?
0
votes
1answer
54 views

Handling a number of simultaneous measurements in Extended Kalman Filter?

If I have a number of sensors whose measurements arrive at the same time - how can I handle them properly in the Kalman filter? P.S. The measurements are not necessarily taken at the same time but I ...
0
votes
1answer
4k views

What is sensor drift?

From Wikipedia: If the output signal slowly changes independent of the measured property, this is defined as drift So my question is, if I have a gyroscope with sensor drift does that mean that $E\...
0
votes
1answer
87 views

Techniques Used To Process Accelerometer Recordings [closed]

I'm currently working on a project which involves using Accelerometer data. Having searched the internet for techniques in processing the data, I am unable to find simple techniques. Is there any ...
0
votes
1answer
3k views

How to get relative rotation matrix from two orientation values in android?

Following http://www.codeproject.com/Articles/729759/Android-Sensor-Fusion-Tutorial , I get two orientation values. Then, I transform those values to rotation matrices R1, R2. I think the relative ...
0
votes
0answers
7 views

Combine correlating input signals to generate multiple output signals

Choosing a descriptive title was quite hard, as I am not sure how to describe my problem accurately. I have a mechanical system fitted with several sensors (Strain Gauges and motion Sensors). There ...
0
votes
0answers
10 views

Can we draw Accelerometer and Gyro data on the same graph using Signal Vector Magnitude(SVM)or Euclidean distance?

I am a computer science student so do not have much electronics background. I am doing my final year project where I am collecting data from 3 axis accelerometer and gyroscope from android mobile via ...
0
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0answers
20 views

Determining position and g-forces from accelerometer and gyroscope data

I'm analyzing gyroscope + accelerometer data acquired from an IMU for a run of a water skiing slalom course, sampled at 100Hz. The double spikes represent spurious ~15G jitter from crossing both ...
0
votes
0answers
17 views

Signal ECG , collecte & visualize data

I am currently working on a sensor that visualizes an ECG signal and visualizes its data. Its principle is that it has 3 electrodes that must be placed in specific parts of the body .... I would like ...