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ModelSpace
Documentation for ModelSpace models and classes.
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#include <Accelerometer.h>
Public Member Functions | |
| _accel_output_struct () | |
| _accel_output_struct (CartesianVector3 meas_accel_sf, CartesianVector3 meas_accel_sf_incl_grav, bool is_valid) | |
Public Attributes | |
| CartesianVector3 | meas_accel_sf |
| CartesianVector3 | meas_accel_sf_incl_grav |
| bool | is_valid |
Accelerometer Model.
This model simulates a simple accelerometer.
HOW DOES THIS MODEL HANDLE NOISE: The typical 3-axis accelerometer has uncorrelated noise in each of the three measurement axes. The additive noise in the accelerometer can be modeled as Gaussian white noise with a standard deviation that is dependent on measurement rate, temperature, and oversampling ratio.
The typical accelerometer also has some bias even after factory calibration. This bias is not completely stable so the bias random walk does need to be modeled for the majority of missions with a duration. The bias random walk standard deviation is constant as a function of time, however it is usually not constant as a function of temperature. Most accelerometer data sheets will have temperature effects on the bias stability.
The majority of accelerometers exhibit some amount of multiplicative noise that is very temperature and age dependent. This is due to the Micro-Electrical-Mechanical systems that are in the sensor being expanded and decompressed with temperature effects. Additionally, the internal polynomial function that is used to convert the measured voltage to an acceleration through an ADC is subject to manufacturing tolerances. The percent error standard deviation should be very small, around 0.1%-0.5%
Typically the noise profile (additive, multiplicative, and biasing) are all dependent on temperature. Because of this, the model has the values as inputs. The user has the choice to repeatedly input new noise characteristics based on an external model, or input them once and it be held constant.
Author: Alex Reynolds alex.reynolds@attx.tech Updated: James Tabony james.tabony@attx.tech Updated sensor noise, added dead-zones, added quantinization, added latency
Sensor output struct for latency model, its members are the same as the model outputs. Its default constructor populates members with defualt output values
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| bool modelspace::_accel_output_struct::is_valid |
| CartesianVector3 modelspace::_accel_output_struct::meas_accel_sf |
| CartesianVector3 modelspace::_accel_output_struct::meas_accel_sf_incl_grav |