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Recent content by pierluk

  1. pierluk

    angular accelerations through accelerometers

    ohh....I'm in fail...thanks for correction I have another question, if for example I need to measure the angle rate with the maximum error of +/-1°/s, but if I measure the angle acceleration what should its maximum error be for having the same max error in calculating the angle rate as...
  2. pierluk

    angular accelerations through accelerometers

    I know the sensors spacing, but I haven't understood the formula you have written. Look at this link: formula 4.4.4 at page 184; so the max err if the max error is 0,25g and the sensor spacing is 0,85 should the max error for angular acceleration be 0,25/(2*0.85)=0,14deg/s^2? Whereas I'm...
  3. pierluk

    angular accelerations through accelerometers

    IRstuff, I was in error for the calculation of the max error of angle acceleration. But why have you used that formula? Now I have another doubt, if I need a maximum error of +/- 1°/s for angle rate, for you what should be the maximum error for angle acceleration? Does a way exist to estimate...
  4. pierluk

    angular accelerations through accelerometers

    sorry IRstuff, I don't understand your calculation, may you explain better?
  5. pierluk

    angular accelerations through accelerometers

    I have other ISO standard with further recomended instruments properties. It is written it is possible to measure the angle and calculate the angle rate or acceleration through a derivate. The other ISO standard recomends: full scale maximun error for angles...
  6. pierluk

    angular accelerations through accelerometers

    Yes Greg you are on right. ISO road vehicles standard reccomeds these instrumentation maximum errors and full scale: max error full scale lateral acceleration +/- 0,15m/s^2 +/- 15ms^2 roll rate +/- 0,2°/s +/-20°/s for pitch rate I...
  7. pierluk

    angular accelerations through accelerometers

    sorry Strong, I have committed a mistake refering the reply to Greg, but it is for yor
  8. pierluk

    angular accelerations through accelerometers

    I have got an idea: I suppose a car equipped with ESP system, should have a sensor for measuring roll angle o roll rate. So can I use that sensor? Maybe I can find a wasted car, to get that sensor almost for free, or that sensor has a too low sensitiviy? In my experience sometimes vehicle...
  9. pierluk

    angular accelerations through accelerometers

    Greg, I know that with DC coupling I can measure the acceleration at 0Hz, but the question is: with AC coupling will I lose some spectral emplitude error close to 0? Thanks for the suggested sensors, but I believe we haven't these on my company, I will try to ask a collegue. However probably...
  10. pierluk

    angular accelerations through accelerometers

    Dear Greg, for my measurements, it is better to use the accelerometer in DC coupling or in AC coupling? I haven't understood, what do you mean for " 0.3 Hz cutoff sounds about right". Which cutoff frequency do you means? Do you mean the accelerometer natural frequency?
  11. pierluk

    angular accelerations through accelerometers

    Strong, I have to measure vehicle roll and pitch accelerations. I don't know what should be the maximum roll and pitching angles (but I suppose less than 6 degrees for both of them) and their acceleration values. I need to measure the angular acceleration for finding a correlation with the...
  12. pierluk

    angular accelerations through accelerometers

    I'm using entran A2 and entran D2 accelerometer with +/-50g full scale. In this link you can find the spec http://www.meassensors.com/manage/sensortypes/EGCS.pdf has you can see my accelerometers has a sensitivity of 40mV/g.
  13. pierluk

    angular accelerations through accelerometers

    Yes it isn't the best way to measure the angular acceleration, but it is possible for small angles. In my application I think the maximum angle is 6 degrees. However I think my accelerometers have low sensitity and so it should be difficult to measure very small acceleration difference, isn't it?
  14. pierluk

    angular accelerations through accelerometers

    I have to measure angular acceleration in a vehicle and since I haven't gyrobox, I have to use two accelerometer placed at known distance. At work I have only accelerometer with +/- 50g full scale. Are they good for the measurements I have to carry out? I'm doubtful, they have a low sensitivy...
  15. pierluk

    About PSD definition and practical meaning

    I'm searching the same information. I have found this interesting pdf http://cp.literature.agilent.com/litweb/pdf/5952-8898E.pdf

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