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| resources:eval:user-guides:inertial-mems:imu:adis16448 [02 May 2016 18:31] – [EQUIPMENT LIST] Mark Looney | resources:eval:user-guides:inertial-mems:imu:adis16448 [11 Feb 2021 18:03] (current) – Ioana Chelaru |
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| {{:resources:eval:user-guides:inertial-mems:imu:448-imueval-tutex-accel-dynamicresponse-02.png?nolink&600|}} | {{:resources:eval:user-guides:inertial-mems:imu:448-imueval-tutex-accel-dynamicresponse-02.png?nolink&600|}} |
| ====Gyroscope Bias Correction==== | ====Gyroscope Bias Correction==== |
| The [[adi>ADIS16448|ADIS16448]] datasheet (page 19, revision 0) offers a three-step process for gyroscope bias correction. This exercise implements these steps, using the [[adi>ADIS16448|ADIS16448]]/[[adi>AEVAL-ADIS|EVAL-ADIS]]. | The [[adi>ADIS16448|ADIS16448]] datasheet (page 19, revision 0) offers a three-step process for gyroscope bias correction. This exercise implements these steps, using the [[adi>ADIS16448|ADIS16448]]/[[adi>EVAL-ADIS|EVAL-ADIS]]. |
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| **__STEP #1: Set SENS_AVG = 0x0104__** | **__STEP #1: Set SENS_AVG = 0x0104__** |
| {{:resources:eval:user-guides:inertial-mems:imu:adis16488-gyro-accel-noise-test-01.png?nolink&500|}} | {{:resources:eval:user-guides:inertial-mems:imu:adis16488-gyro-accel-noise-test-01.png?nolink&500|}} |
| ====In-run Bias Stability==== | ====In-run Bias Stability==== |
| For the [[adi>ADIS16448|ADIS16448]] gyroscopes and acceleroemeters, "In-run Bias Stability" refers to the best resolution available, when averaging sequetital, time domain data. This has a direct impact on the accuracy of a bias correction and therefore, has a direct impact on angle measurement drift. In reviewing the Allan Variance curve for the gyroscopes ([[adi>http://www.analog.com/static/imported-files/data_sheets/ADIS16448.pdf#Page=08|Figure 7]]), the minima of the the best performance curve (//mean - 1 sigma//) is associated with an integration time of ~100 seconds. However, many of the units (from //mean// and //mean + 1 sigma// curves)) start approaching their minima at ~40 seconds. While selecting the best settings may require some iteration, this exercise starts with an integration of 40 seconds, an output data rate of 51.2 SPS (SMPL_PRD = 0x0401) and a dyanmic range of +/-250 degrees/second (SENS_AVG = 0x0104). | For the [[adi>ADIS16448|ADIS16448]] gyroscopes and acceleroemeters, "In-run Bias Stability" refers to the best resolution available, when averaging sequetital, time domain data. This has a direct impact on the accuracy of a bias correction and therefore, has a direct impact on angle measurement drift. In reviewing the Allan Variance curve for the gyroscopes ([[adi>static/imported-files/data_sheets/ADIS16448.pdf#Page=08|Figure 7]]), the minima of the the best performance curve (//mean - 1 sigma//) is associated with an integration time of ~100 seconds. However, many of the units (from //mean// and //mean + 1 sigma// curves)) start approaching their minima at ~40 seconds. While selecting the best settings may require some iteration, this exercise starts with an integration of 40 seconds, an output data rate of 51.2 SPS (SMPL_PRD = 0x0401) and a dyanmic range of +/-250 degrees/second (SENS_AVG = 0x0104). |
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| Here is a snapshot of the **Data Access** and **Data Capture** screens, which configures the software to take 50 sets of z-axis gyroscope data, that contain 40-second time records each, at a read rate of 51.2SPS. | Here is a snapshot of the **Data Access** and **Data Capture** screens, which configures the software to take 50 sets of z-axis gyroscope data, that contain 40-second time records each, at a read rate of 51.2SPS. |
