Accelerometer Definition and 158 Threads

Hi Guys I am using a mobile phone to collect some accelerometer data for my walking experiments. I know this topic is done to death but a specific answer that I have never got is what does mobile phone accelerometers actually measure? Do they give the acceleration due to all the forces acting...

I have performed an impact test on different football shin guards to assess their performance. I am however confused with the readings measured by the accelerometer I have used. The sensor was attached to a striking mass of 4.3 kg which was dropped at different heights. The graph I have attached...

Homework Statement Imagine this: A rod is attached at one end to a rotating shaft. So, as the shaft rotates from 0 to 90 degrees back-and-forth (in the xy plane), so does the rod. My goal is to measure the instantaneous acceleration of the rod while its moving. I have a few 3-axis...

hi I found an article that shows how to use kalman filter to models error of accelerometer. they used markov process as stochastic error, then output of this model will be used as input of KALMAN filter. Now, I don't what to do. I'm not sure, but I think that I need to double integrate the...

I can find instructions and videos everyone for how to control a remote control car with buttons on a smartphone screen. However, what I'M hoping to do is control an arduino equipped motorized car using the gyroscope and accelerometer contained within the phone. I have found the Wireless IMU...

I'm trying to get an understanding on what's going on with some data of mine. I've attached some plots below. This data is from and accelerometer and gyroscope where I've calculated the global accelerations and velocities (top and bottom plot respectively in each figure). The data is from the...

Hey, I have only a little experience with electronics, and I'm looking for a simple sensor for a magnetometer sensitive enough to detect about a gauss and accelerometer for detecting when something is picked up. As long as I can get a good explanation (data sheets can sometimes be cryptic) I'd...

Hi all! I have a question that maybe some people of this great comunity can help. I´m working with a platform with 16 MEMS accelerometers distributed along the whole surface with a knew position and orientation, I have to measure the differences in acceleration on the Z axis, to get the surface...

I have been using an accelerometer and I have realized that it was sitting at a tilt of 18 degrees in the z direction and rotated at 5 degrees in the x y direction. How should I change my accelerometer readings to account for this?

Hay guys, so I have an accelerometer which is obtaining values in either G or m/s/s depending on how I program it. Testing it everything seems fine and I get 1 G on one of the axis depending on how I hold it which is great. The problem is I'm using an ADXL345 accelerometer which gives me...

I am bit confused on the units when you convert acceleration to displacement. The accelerometer data is in bits. I can convert this to gs or milli gs. When integrating, this will get multiplied by millisecs. What will the displacement unit be in?

Greeting fellow science enthusiasts, I just started learning physics so please excuse my primitive knowledge. I'm supposed to discuss a technology that applies concepts related to kinematics and I'd like to discuss accelerometers. Could you please explain the basic equations for motion in an...

Hi all, I am currently working on a project and have a problem. I am using a 3 axis accelerometer and attempting to measure distance with it. (Yes, I know, the double integration of doom..) My problem is not with the integration so to speak but is just with some compensations. The...

Accelerometer -- device on a parabolic track EDIT: Picture of problem in its entirety farther down. A device on a parabolic trac moves on the track described as y=x^2. Both in meters A$ find an expression for acceleration using position. B) what is a if x=20cm? My solution. First, I took...

I posted another thread here talking about two instrument designs using strain gauges. One was for measuring torque, and the other for acceleration. I would like to go ahead with designing an accelerometer using a full strain gauge bridge. The basic idea I have in mind is similar to this...

I'm having trouble understanding what accelerometers really measure. In observing a simple gravity pendulum, the accelerometer recorded this data (jpeg image attached) which is acceleration in the vertical direction (supposedly). Now I've been told all sorts of things, like that the...

I am working on a project where we will use a 3-axis accelerometer on the door and using the ax, ay, az data to calculate position and angle of the door. The accelerometer will be positioned near doorhandle. So the initial position of coordinate system will be there, where the accelerometer is...

Hi there Given a result from an accelerometer, mounted on a vibrating machinery. I would like to be able to calculate the physical amplitude. That is the actual movement of the vibration. I'm sure it should be possible, but my attempt to manipulate the formula of acceleration has not resulted...

Greetings Forum, I just bought an Invensense MPU-6050, I need to design an LPF to filter the noise. How do I analyse the signal and how do I determine the frequency beyond which the signal is altered by noise. Thanks in advance for your help. Cheers

Hello, I have an Ocean server 4000 compass/accelerometer, and I am trying to use it to gauge the position of a robot on which it is placed. I get Ax, Ay, Az, pitch, roll, and heading as the output currently. I also have the accelerometer set to do a moving average of 16 readings. I did a...

Homework Statement This is not a homework question, I am working on a project to get it data from how rough the road is, mostly road bumps/pot holes. My project is for a capstone project, I want to use an accelerometer to measure the upward G's on the car frame when goes over bumps, or into...

-- how to used the voltage output -- i bought LSM303 accelerometer (FROM NEXT LINK ) and i don't know how to used output voltage to find the acceleration . can you help me pls http://www.pololu.com/catalog/product/1273

Hi, I'm a Mechanical Engineering student and the voodoo that is electronics/ electrical engineering baffles me. However a portion of my final year project requires me to specify certain transducers and a data acquisition system. At the minute I am trying to specify an accelerometer...

Both Seismic sensors and accelerometers are used for sensing vibration. Then what is the difference between them?

Hi everyone, I have an adxl193 analog accelerometer (http://www.sparkfun.com/products/9332) that I am trying to interface with a phidget i/o board (http://www.phidgets.com/documentation/Phidgets/1011_0_Product_Manual.pdf). I am having trouble calibrating the signal because the acceleration...

I need to track Distance on one Axis with an Accelerometer for a rocket project (i know there are bettor ways t do this but i am dead set on this one) I was thinking as follows, Read Accelerometer Accelerometer*Δt=Δv Current speed+Δv=New speed distance+New speed*Δt=New distance

Hi all, Currently, I'm doing an experiment to estimate length of a rigid body. The approach is based on information from accelerometer and gyroscope while the rigid body is moved in circular way. The relationship is: v = ω x R (all are vectors, and 'x' means cross products) v =...

I'm a few days trying to get the direction of movement using an accelerometer. For my application I need to put an object on the table (z axis fixed) and detect the movements. I know perhaps the accelerometer is not the best sensor for this kind of application but is the sensor that is available...

Hi, Please could someone explain how they think an accelerometer would work if positioned within the center of a freely rotating sphere (e.g a kicked football)? If using triple axis accelerometer and the ball was kicked from a standstill but with no spin, I would imagine that the...

I am using arduino and accelerometer MMA7341 to measure the acceleration in x direction of an oscillating metal table. But the mounting of the accelerometer is tilted by a small angle (say Q) . Is it affect the acceleration?. If it is affect the acceleration in x direction , how can correct it...

Hi, Does anyone has experience using accelerometer on a ship/vessel to detect whether the vessel is moving or stationary? The difficult part is that I took some samples at 6Hz and found that all X/Y/Z axes have accelerations going positive and negative. The pattern is exactly the same...

I am starting to learn Mobile Phone Application Development. Suddenly this idea clicked in. The app starts with the Phone in rest on your living room table. Now, the phone is picked up from the living room and transported to the dining room. Could the app be able to tell this? Here is how I...

Hi I am studying Sports Science and researching the use of an accelerometer during specific wieght training type movements. I have a MEMS device (unfortunately I only have mininal details regarding it) which can measure upto 24G and 400Hz and comes with basic software that transfers the data...

we have an Ipad mounted on a vehicle and would like to know that if the ipad is mounted in a tilted manner, would the gforces along x, y, z directions change. if so how do we calculate the tilt angle from the accelerometer readings recorded before and after the tilt.

Hi I am measuring the acceleration of an oscillating body with a triaxial accelerometer. I want to derive some kind of vector average of the 3 channel output. Someone suggested using x= √(a squared + b squared + c squared) ... where x is the vector average and a, b and c are the...

The situation is there is a ball attached to a string in a car, and the angle that the string makes is measured when the car is accelerating. I'm having a bit of trouble with the proof that a=tan(theta) so far I've gotten that weight=mg=Tcos(theta) a=ma=Tsin(theta) But what I don't...

hi can anybody tell me what does the values means and how are the calculated ? like for example : x : 0.333 y : -0.40 z : 0.523 thanks a million ;)

Hi, I have an interesting problem: most people use accelerometers to sense orientation and thus measure the DC output value. What I'm trying to do is sense higher frequency vibrations (3-10 Hz). The accelerometer will also be slowly changing orientation so the DC offset will be changing...

I have searched on web but i did not get exact explanation on about these topics. Could someone clear me. I am looking for accelemeter to my pump that can get the information about vibrations.

In the subject accelerometer (see link) the answer given is a = kgx. I get a = 2kgx. I'm wondering if anyone cares to discuss this problem. The answerer used an energy argument that I'm not sure I followed, whereas I used a simpler force-balance method. F = force on bead by parabola and is...

Hello I want to measure the lateral acceleration at the center of gravity of a vehicle. I cannot place the accelerometer here since I cannot mount it properly so I have placed it 75 cm to the left of the CG. The longitudinal and and vertical placement is approximately correct. It there som...

Homework Statement An accelerometer is made of a piece of wire with a bead on it that can slide on the wire with no friction. The wire is formed as a parabola y = kx2, as shown in the drawing. The bead rests at the lowest point of the parabola when it is at rest. When accelerated parallel to...

Hi, I have to find the best approach for tackling a problem for trying to recognize physical movements - with an iPhone in a pocket - like walking, stopping, turning left/right, sitting. The ultimate goal is to recognize urban street behaviour, mostly regarding traffic lights: is it possible to...

Our lab just got these fancy new accelerometers that I'm trying to figure out. They are triaxial, but are not yet calibrated. As I was looking into how to calibrate them, I realized that, for a given axis, I would get a different voltage reading depending on whether the axis was oriented...

Hi All, I'm a first time poster. I have a lot of data in the X-Y-Z direction from a triaxial accelerometer that had been placed inside a network appliance to understand the accelleration experienced on the unit during induced vibration. Can anyone advise the best method for analyzing this...

I have a spreadsheet of Accelerometer data out of an iPhone and I have calculated the displacement in the three axis. I would like to figure out how to take this info and calculate the frequency, avg. amplitude, and the highest amplitude. Excel has a frequency function but I would like to...

how to convert accelerometer data to metabolic equivalents(METS)?? hi all i would like to ask if how do i convert accelerometer data to metabolic equivalents(METS)?? by the way I am using this formula: Total Calories Burned = Duration (in minutes) X (MET X 3.5 X weight in kg)/200 i got that...

Hi everyone, I am currently trying to recognize different activities such as walking, sitting and falling, using a watch which features a 3 axis accelerometer. Currently I have performed 1 minute tests of each activity 20 times but I am struggling on what to do with the data. Does anyone...

Hello everyone, i'm new to this forum and this is my first post. My question is: how to get pitch and roll of a moving vehicle using an 3-axis accelerometer? accelerometer values are the same when vehicle is stopped? Thanks in advance.

Hi, I've received a new accelerometer with a scale factor declared in datasheet as: 800 mV/g @ 1.5g. I googled and searched the forum but still can't fully be sure I understand the accelerometer and its functioning, so please correct me where I'm wrong: One thing that very helped me to get...