Questions tagged [signal-processing]
The signal-processing tag has no usage guidance.
52
questions
1
vote
1answer
48 views
How do mobile phones produce signals?
Normally it would require alternating currents to product electromagnetic waves. Yet as mobile phone is powered by batteries which only produces direct current, what type of mechanism/structure allows ...
2
votes
1answer
58 views
What should be the sample frequency to test the response of a filter?
I am testing the frequency response as a filter as below, what should be the sample rate of the chirp signals, someone told me it should be at least 2 times of the input signals frequency, someone ...
2
votes
1answer
68 views
How do I study the frequency response of a physical system with Arduino?
I am a control engineering student and I am studying the frequency response of a system, so the Laplace domain, the Bode plot, poles, zeros,etc. ...
I have clear grasp of their meaning, but if I think ...
0
votes
1answer
55 views
Is it possible that room noises could end up on the recording when recording audio from an analogue source?
I have a VCR with a tape cartridge playing in it. The video output (SCART/RCA) goes from the back of the VCR into my Elgato video capturing device's RCA cables. The Elgato device is then connected via ...
0
votes
0answers
42 views
How to send true digital data in discrete values?
To my understanding signals in any form sent through empty space is in the form of electromagnetic waves. This implies that it is never discrete two values but it can be modulated. Looking at this ...
0
votes
0answers
42 views
How can I find the Transfer Function in Z-domain?
This is my signal;
$y[n]=x[n]+0.8x[n-0.2]$
When I take Z-transform I get;
$Y[z]=X[z]+0.8z^\frac{-1}{5}X[z])$
Then I found the Transfer function as;
$H[z]=\frac{Y[z]}{X[z]}$
$H[z]=1+0.8z^\frac{-1}{5}$
...
0
votes
0answers
15 views
How is MRI SNR affected by the frequencies that are included?
So for MRI imaging, if an image is taken, and portions of the Fourier transform image are removed so that some portion of the higher frequencies are not included, would this reduce the SNR? I assume ...
1
vote
0answers
25 views
Finding force distribution using accelerometer data
The team I'm currently working for is trying to compare bushings with different durometer ratings in the front suspension using single axis(z) accelerometer data during curb impacts. The current ...
0
votes
0answers
12 views
Relation between channel and path loss exponent
I am referring a paper "Outage Analysis of Ambient Backscatter
Communication Systems" wherein i came across the equation $y_r(n) = \frac{\tilde{h_{sr}}}{\sqrt{d_{sr}^{\alpha}}}+\frac{\tilde{...
0
votes
0answers
18 views
Methods for motion tracking without a gyroscope
I am doing a project involving motion tracking using an accelerometer. I know a lot of approaches for motion tracking also involve a gyroscope, but here there is only an accelerometer available. In ...
2
votes
1answer
94 views
Adaptive downsampling of time-series data?
I’ve been tasked with developing software to (among other things) log temperature data from samples in a furnace. Generally the temperatures are very steady, but can, at times, experience dramatic ...
0
votes
0answers
20 views
Can cross correlation be used to see if filtering of a signal has changed it too much?
I am filtering a signal, and want to check if I am not over filtering it , I wanted to use cross correlation , but I am not sure if it is a good technique. usually I get something like the following ...
2
votes
1answer
91 views
Non-observable effect of low-pass filter on the Transfer function (of Vibration measured with Laser scanner)
I have to study the effect of low-pass filters (if any) on the outcome of the experiment. And the experiment here is to measure the vibration of a (metal) specimen by hitting the said specimen with ...
1
vote
2answers
52 views
What is the output of a signal in time domain that passed through a High Pass Filter with simple transfer function
If a signal function $ U(t) = 25 – (5 – t)^2$ is passed through a high pass filter with transfer function $\frac{s}{s + ω}$. what is the output signal Y(t). I know that the transfer function $H(s) = \...
0
votes
0answers
33 views
How to take the engineering FFT of Signal in Matlab?
All,
The FFT function in matlab gives a theoretical mathematical FFT of the signal, and is not scaled to units and is real imaginary and not amplitude-frequency
is there an alternative way of FFT to ...
0
votes
0answers
28 views
How does the number of cycles for averaging in a lock-in amplifier relate to low-pass filtering and where do I set it?
Please forgive me if I ask too many questions at once or I am too much of a rookie. I want to understand the working-principle of lock-in amplifiers (LIAs).
I understood the calculation that yields ...
-1
votes
1answer
96 views
Shouldn't linear time-invariant systems be called affine time-invariant systems instead?
For a scalar $c$, the function:
$$f(x) = cx$$
Is linear in that it satisfies the superposition property. If:
$$f(x_1)=cx_1$$
$$f(x_2)=cx_2$$
Then:
$$\alpha f(x_1) + \beta f(x_2) = \alpha(cx_1)+\beta(...
3
votes
1answer
164 views
Arduino DAC to Speaker
I'm working with an Arduino Due's two DAC pins.
I want to output to a single 4W 5.7Ohm speaker to test my code, with the intent of eventually outputting to a set of speakers (woofer, mid-range, and ...
5
votes
1answer
82 views
How were the tones for DTMF chosen?
In my limited engineering knowledge, and limited research skills, I couldn't find a complete answer for the reasoning behind the chosen tones for DTMF. I did find a hint that said something about ...
0
votes
1answer
41 views
Signal convolution: continuous signals
I really didn't understand how to do it. Please, can anyone help me??
Determine h (t) * x (t) when h (t) and x (t) are the rectangular pulses shown in Fig. A. Plot the result of this convolution.
I ...
-1
votes
1answer
387 views
Nyquist Stability Theorem and Clockwise/Counter Clockwise Encirclements
According to argument principle, if a contour encircles a number of poles and zeros of a transfer function, the number of origin encirclements can be deduced by : ...
1
vote
1answer
20 views
How do I calculate the delay of two signals from different sensors?
Suppose:
I have two sensors attached to a vehicle
I have recorded the output of these two sensors (for example GPS) during a test ride
each sensor has a different frequency
one sensor is way more ...
2
votes
0answers
8 views
In Digital Signal Processing, why is the spectrum of a signal with 'real' samples better than the spectrum of the same signal with padded samles?
Say we have number of samples to be 128 and a signal sin(2*pi*1000*n*Ts)+sin(2*pi*2000*n*Ts) sampled at 8kHz.
Now say we have same signal but only N = 64 samples. But in order to create 128 samples, ...
89
votes
4answers
46k views
Why do color TVs make black and white snow?
If you let a color TV display something from an unplugged display port, it displays snow, right? Randomly varying black or white pixels on the whole screen.
My guess was that the television was ...
1
vote
1answer
33 views
Problem with RHP zero in transfer function
I have a transfer function with a RHP zero in $s=+1$, and I am trying to show in Matlab thath this limitation is present. In particular, initially I had a MIMO system, which I decoupled and then I ...
2
votes
1answer
34 views
Fourier serie signal approximation
I have to approximate the red function with Fourier harmonics.
I am calculating complex Ck the following way.
I am not sure what to put for period - T (6 or 2pi or what?). What integral limits to ...
0
votes
1answer
708 views
Difference between Hysteresis, low pass filter and deadband in control theory?
I am trying to understand the fundamental difference between the following terms in the context of control systems:
Hysteresis
Low pass filter
Deadband
Are these just fancy names that can be ...
1
vote
0answers
29 views
How to determine data size created by sensor for calculation of signal processing and transmitting over wireless communication?
I want to build some sort of SAR sensor. Since radar works high speeds and creates loads of data this should be processed faster. I am trying to find algorithms to be used for this purpose. I am at ...
0
votes
1answer
46 views
how to filter model-free observations (e.g. Kalman filter)
Before asking a question, I have no background knowledge of engineering. So I have no idea about these issues like control or signal engineering. (Also, I'm not good at using English. sorry for that.)
...
1
vote
1answer
51 views
classify ECG signal using neural network
I am looking to classify ECG signal using with neural network. I have never done signal analysis before.
From the samples of data I have, I have noramlised, transformed using the FFT , get the pics, ...
0
votes
1answer
41 views
Operating a load cell below excitation voltage
I currently have this load cell, which has a 10V excitation voltage. However, there is a very nice/convenient load cell amplifier that works with an excitation voltage of 5 VDC.
What are the ...
2
votes
3answers
363 views
What is a Butterworth filter?
What is a Butterworth filter?
I have raw X, Y, Z acceleration sensor data that I need to smooth them from noise. I have read that a Butterworth filter is one of the most appropriate for the specific ...
1
vote
2answers
2k views
what is 1P frequency in rotor (wind turbine)?
In wind turbine, Is the number of revolution taken in 1s is called 1P frequency? If not, is it possible to find the 1P rpm from rpm measured for 1 hour (that is, I have 60 rpm data points from ...
1
vote
1answer
119 views
What are the conditions for a signal to be an energy signal and a power signal?
I know how to find the power and the energy of a signal. What I have a problem with is knowing whether a signal is an energy signal or a power signal.
According to my teacher, a signal is a power ...
2
votes
0answers
33 views
How to control an underactuated platform with a single servo
What's the best way to control the following type of platform so that it remains balanced and upright?
It's a box supported by a single leg that can pivot at the foot (F) and at the hip (H). The foot ...
0
votes
1answer
62 views
dB/s/Hz in spectrum efficiency
Here is link of research paper in which spectrum efficiency is given in terms of dB/s/Hz. How can we define it?
https://jwcn-eurasipjournals.springeropen.com/articles/10.1186/s13638-016-0792-0
1
vote
0answers
456 views
How to use VBA on Aspen Hysys? [closed]
I am trying to write a program on Aspen Hysys. Hysys has a script manager to write scripts using Visual Basics for Applications syntax. Having no background in VBA, I'd like some help to:
Import the ...
1
vote
2answers
76 views
Filtering Long-duration Signal
I have a long-duration EMG signal (~4 hours long) with a sampling frequency of 1 kHz. If I want to filter the data with a low-pass filter in 10 Hz in MATLAB, should I filter the signal with ...
0
votes
3answers
140 views
PED or DSP for mechatronic student [closed]
I am doing mechatronics engineering and i am to choose an elective module. We have the choice of taking up Digital Signal Processing or Power Electronics and Drive. Majority of my friends are taking ...
1
vote
0answers
29 views
Why does Experimental Modal Analysis need a reference signal?
I need to conduct a vibration experiment with 3 accelerometers for a gear box. I'm reading the theory of mainly how to perform the vibration analysis but I don't understand why EMA needs a reference ...
0
votes
2answers
3k views
How to get natural frequencies from accelerometer measurements?
I will be performing some tests and measuring the vibrations of a planetary gearbox. The accelerometer I will be using stays attached to the gearbox and saves the data into a log, which is available ...
2
votes
0answers
137 views
How does smartphone VR positioning work? [closed]
I've recently came across Google's cartboard VR headset, which allows you to use your smartphone as a virtual reality device.
The headset basically splits the screen in your left and right eyes, ...
-1
votes
1answer
76 views
Designing a simple measurement system [closed]
I am trying to get a better understanding of measurements and instrumentation before starting an online class next week. I have been reading a text book and came across a concept question I am stuck ...
2
votes
1answer
290 views
What happens when very bright coherent light and weaker incoherent background light passes through doubly cascaded diffraction gratings?
Double diffraction is where a light beam passes through an grating with distance D1 between ridges and then passes through an grating with distance D2 The image after passing through diffraction ...
3
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0answers
24 views
Pearson correlation of neural responses with it's linear estimation
I am trying to anderstand the following fact from this article (page 13):
How can single neurons predict behavior
Suppose I have a linear estimation of a stimulus:
$ \hat{s} = \mathbf{w}^T(\mathbf{r} ...
0
votes
1answer
204 views
Is it possible to make a tunable coherent light filter with 1.8 nanometer bandwidth for visible light?
On January 1991, the esteemed Swedish professor of optics filed a patent titled "Coherence filter", that blocks coherent light regardless of laser light wavelength using destructive interference and ...
4
votes
2answers
109 views
Finding the sampling period to avoid loss of signal
We have:
$$ s(t) = 4u(t)−u(t−1)−2u(t−2)−2u(t−3.5)+2u(t−4) $$
where $u$ is the Heaviside function.
I had to draw the graph and find the minimum sampling period so we wont have loss of signal. I have ...
1
vote
1answer
71 views
Are there any methods to work out what appliances are running in my home from an aggregate power consumption sampled 6 times a minute?
I recently got a gizmo installed at home that samples my electricity usage once every 10 seconds. I've become a little transfixed watching the graph update as various appliances in my home turn on and ...
2
votes
2answers
310 views
Acoustical Design considerations for Active Noise Cancellation Project for Air vent [closed]
I am working on ''Active noise cancellation for air vent'' project. I am using NI myRIO1900 it has FPGA module(Xylinx Z-7010) , Audio Technica ATR 3350 omni directional microphones and Tevion ...
10
votes
1answer
594 views
Response of a system to a step function (Heaviside function)
I'd like to compute the response to a step function of a electrical/thermal system. Generally I can "easily" compute the transfer function $H$:
$$H(\omega) = \frac{V_{out}(\omega)}{V_{in}(\omega)}$$
...
