BNO055 IMU Sensor

Measure acceleration, angular rate, and magnetic field, and calculate fusion values such as Euler angles, quaternion, linear acceleration, and gravity vector along the axes of BNO055 sensor

• Library:

• Simulink Support Package for Arduino Hardware / Sensors

• 

Description

The BNO055 IMU Sensor block reads data from the BNO055 IMU sensor that is connected to the hardware. The block has two operation modes: Non-Fusion and Fusion.

The block outputs acceleration, angular rate, and strength of the magnetic field along the axes of the sensor in Non-Fusion and Fusion mode. In Fusion mode, the block also outputs the the orientation of the sensor as an Euler angle or quaternion, as well as the linear acceleration, gravity vectors, and calibration status of the sensor. The values emitted in the Non-Fusion mode are raw values, whereas the values emitted in the Fusion mode are calibrated values. The block outputs all the values except for quaternion and calibration status as a 3-by-1 array of double data type. The quaternion is a 4-by-1 array of double data type, and the calibration status is a 4-by-1 array of int8 data type.

This illustration shows the default orientation of the x-, y-, and z- axes of the BNO055 sensor.

If you simulate a model that contains the BNO055 IMU Sensor block without connecting the hardware, the block outputs zeros. For more information, see Block Produces Zeros or Does Nothing in Simulation.

Ports

Output

Accel — Acceleration including force of gravity along axes of sensor

vector

The Accel port outputs acceleration along the x, y, and z axes of the sensor as a 3-by-1 vector. In Fusion mode, the elements of the vector represent calibrated values, whereas in Non-Fusion mode, the elements represent raw values. The acceleration is measured in m/s² and also includes acceleration due to gravity.

Dependencies

The Accel port is available only when you select the Acceleration (m/s^2) parameter.

Data Types: double

Ang rate — Angle of rotation per second along axes of sensor

vector

The Ang rate port outputs the angle of rotation per second along the x-, y-, and z- axes of the sensor as a 3-by-1 vector. In Fusion mode, the elements of the vector represent calibrated values, whereas in Non-Fusion mode, the elements represent raw values. The angular rate is measured in dps.

Dependencies

The Ang rate port is available only when you select the Angular rate (dps) parameter.

Data Types: double

Mag field — Strength of magnetic field along axes of sensor

vector

The Mag field port outputs the strength of the magnetic field along the x-, y-, and z- axes of the sensor as a 3-by-1 vector. In Fusion mode, the elements of the vector represent calibrated values, whereas in Non-Fusion mode, the elements represent raw values. The magnetic strength is measured in μT.

Dependencies

The Mag field port is available only when you select the Magnetic field (μT) parameter.

Data Types: double

Euler — Sensor orientation given as Euler angles

vector

The Euler port outputs the orientation along the axes of the sensor as a 3-by-1 vector. The elements of the vector represent the orientation using three angular quantities – azimuth (rotation around z- axis), roll (rotation around y- axis), and pitch (rotation around x- axis) of the sensor.

Angular Quantity	Description	Range in Degrees
Azimuth	Angle between y- axis of the sensor and magnetic north	[0, 360]
Roll	Angle between z- axis and x- axis of the sensor	[−90, 90]
Pitch	Angle between z- axis and y- axis of the sensor	[−180, 180]

Dependencies

The Euler port is available only when you set the Operation mode to Fusion and select the Euler angles (degrees) parameter.

Data Types: double

Quat — Sensor orientation given as a quaternion

quaternion array

The Quat port outputs the orientation along the w-, x-, y-, and z- axes of the sensor as a 4-by-1 vector. The orientation is measured in quaternion.

Dependencies

The Quat port is available only when you set the Operation mode to Fusion and select the Quaternion (quaternion) parameter.

Data Types: double

Lin accel — Acceleration excluding force of gravity along axes of sensor

vector

The Lin accel port outputs linear acceleration along the x-, y-, and z- axes of the sensor as a 3-by-1 vector. The acceleration is measured in m/s² and does not include acceleration due to gravity.

Dependencies

The Lin accel port is available only when you set the Operation mode to Fusion and select the Linear acceleration (m/s^2) parameter.

Data Types: double

Gravity — Acceleration due to gravity along axes of sensor

vector

The Gravity port outputs acceleration due to gravity along the x-, y-, and z- axes of the sensor as a 3-by-1 vector. The acceleration due to gravity is measured in m/s².

Dependencies

The Gravity port is available only when you set the Operation mode to Fusion and select the Gravity vector (m/s^2) parameter.

Data Types: double

Status — Calibration status of overall system and gyroscope, accelerometer, and magnetometer

vector

The Status port outputs the calibration status of the overall system and the sensors (gyroscope, accelerometer, and magnetometer) located inside the BNO055 sensor as a 4-by-1 vector.

This table shows what each element values in the vector indicate about the sensor calibration status.

Value	Calibration Status
0	Uncalibrated
1 and 2	Partially calibrated
3	Fully calibrated

A partially calibrated sensor with a calibration status of 2 provides more accurate readings than the sensor with a calibration status of 1. To fully calibrate any of these sensors, see Calibrate Gyroscope, Calibrate Accelerometer, and Calibrate Magnetometer.

Note

If the Status port outputs an array with all the elements having a value of -1, ensure that the sensor is properly connected to the hardware and the value of the I2C address parameter is correct.

Dependencies

The Status port is available only when you set the Operation mode to Fusion.

Data Types: int8

Parameters

I2C address — I2C slave address of sensor

0x28 (default) | 0x29

Select the I2C address of the sensor from which the block read values.

Operation mode — Option to output calibrated or raw values

Fusion (default) | Non-Fusion

• Fusion — When you set Operation mode to Fusion, the sensor operates in 9 degrees of freedom (NDOF) mode. The block outputs calibrated values from the sensor.

  This table lists the block output, measurement unit, dimension, and the axes of the sensor along which each of these outputs are measured.

  Output	Unit	Dimension	Axes
  Acceleration	Meter per second squared (m/s2)	3-by-1	x, y, and z
  Angular rate	Meter per second squared (m/s2)	3-by-1	x, y, and z
  Magnetic field	microtesla (μT)	3-by-1	x, y, and z
  Euler angles	degrees per second (dps)	3-by-1	x, y, and z
  Quaternions	Quaternion units	4-by-1	w, x, y, and z
  Linear acceleration	Meter per second squared (m/s2)	3-by-1	x, y, and z
  Gravity vector	Meter per second squared (m/s2)	3-by-1	x, y, and z

  Note

  In Fusion mode, an internal fusion algorithm configures the range and bandwidth of the sensor with some values. These values cannot be modified.

• Non-Fusion — When you set Operation mode to Non-Fusion, the sensor operates in Accelerometer Magnetometer Gyroscope (AMG) mode. The block outputs raw values from the sensor.

  This table lists the block output, measurement unit, dimension, and the axes of the sensor along which each of these outputs are measured in Non-Fusion mode.

  Output	Unit	Dimension	Axes
  Acceleration	Meter per second squared (m/s2)	3-by-1	x, y, and z
  Angular rate	Meter per second squared (m/s2)	3-by-1	x, y, and z
  Magnetic field	microtesla (μT)	3-by-1	x, y, and z

Sample time — Interval to read values from sensor

0.1 (default) | -1 | any nonnegative value

Specify how often the block read values from the sensor, in seconds. When you specify this parameter as -1, Simulink^® determines the best sample time for the block based on the block context within the model.

Select Outputs

Acceleration (m/s^2) — Acceleration including force of gravity along axes of sensor

on (default) | off

When you select the Acceleration (m/s^2) parameter, the Accel port becomes available. For more information on the Accel port, see Accel.

Angular rate (dps) — Angle of rotation per second along axes of sensor

on (default) | off

When you select the Angular rate (dps) parameter, the Ang rate port becomes available. For more information on the Ang rate port, see Ang rate.

Magnetic field (μT) — Strength of magnetic field along axes of sensor

on (default) | off

When you select the Magnetic field (μT) parameter, the Mag field port becomes available. For more information on the Mag field port, see Mag field.

Data Types: double

Euler angles (degrees) — Orientation along axes of sensor

off (default) | on

When you select the Euler angles (degrees) parameter, the Euler port becomes available. For more information on the Euler port, see Euler.

Dependencies

The Euler angles (degrees) parameter is available only when you set the Operation mode to Fusion.

Quaternion (quaternion) — Orientation along axes of sensor

on (default) | off

When you select the Quaternion (quaternion) parameter, the Quat port becomes available. For more information on the Quat port, see Quat.

Dependencies

The Quaternion (quaternion) parameter is available only when you set the Operation mode to Fusion

Data Types: double

Linear acceleration (m/s^2) — Acceleration excluding force of gravity along axes of sensor

on (default) | off

When you select the Linear acceleration (m/s^2) parameter, the Lin accel port becomes available. For more information on the Lin accel port, see Lin accel.

Dependencies

The Linear acceleration (m/s^2) parameter is available only when you set the Operation mode to Fusion.

Gravity vector (m/s^2) — Acceleration due to gravity along axes of sensor

on (default) | off

When you select the Gravity vector (m/s^2) parameter, the Gravity port becomes available. For more information on the Gravity port, see Gravity.

Dependencies

The Gravity vector (m/s^2) parameter is available only when you set the Operation mode to Fusion.

Advanced Sensor Settings

Accelerometer range — Range of acceleration deviation measured by accelerometer

4G (default) | 2G | 8G | 16G

Specify the deviation in the acceleration that the accelerometer can measure. The smaller the accelerometer range is, the more sensitive the readings from the accelerometer are. A small range provides more detailed data, resulting in a more precise reading from the accelerometer.

Dependencies

The Accelerometer range parameter is available only when you set the Operation mode to Non-Fusion.

Accelerometer bandwidth — Frequency response of accelerometer

62.5 Hz (default) | 7.81 Hz | 15.63 Hz | 31.25 Hz | 125 Hz | 250 Hz | 500 Hz | 1000 Hz

Specify the frequency at which the accelerometer measures acceleration.

Dependencies

The Accelerometer bandwidth parameter is available only when you set the Operation mode to Non-Fusion.

Gyroscope range — Maximum angular velocity measured by gyroscope

2000 dps (default) | 125 dps | 250 dps | 500 dps | 1000 dps

Specify the maximum angular velocity that the gyroscope can measure per second.

Dependencies

The Gyroscope range parameter is available only when you set the Operation mode to Non-Fusion.

Gyroscope bandwidth — Frequency response of gyroscope

32 Hz (default) | 12 Hz | 23 Hz | 47 Hz | 64 Hz | 116 Hz | 230 Hz | 523 Hz

Specify the frequency at which the gyroscope measures angular velocity.

Dependencies

The Gyroscope bandwidth parameter is available only when you set the Operation mode to Non-Fusion.

Magnetometer output data range — Rate at which data is sampled

10 Hz (default) | 2 Hz | 6 Hz | 8 Hz | 15 Hz | 20 Hz | 25 Hz | 30 Hz

Specify the range of the magnetic field that the magnetometer can read.

Dependencies

The Magnetometer output data range parameter is available only when you set the Operation mode to Fusion

Data Types: double

More About

Calibrate Magnetometer

To fully calibrate the magnetometer inside the Adafruit^® BNO055 sensor:

1. Hold the sensor parallel to the ground and move it in a figure 8 pattern.

   Note

   Ensure that the sensor is far away from any magnetic interference.

   

2. Run your Simulink model and read the calibration status of the magnetometer.

3. Repeat this process until the calibration value of the magnetometer is 3.

Calibrate Accelerometer

To fully calibrate the accelerometer inside the AdafruitBNO055 sensor:

1. Place the Adafruit BNO055 sensor in these six stable positions for a few seconds each.

   

2. Run your Simulink model and read the calibration status of the accelerometer.

3. Repeat this process until the calibration value of the accelerometer is 3.

Calibrate Gyroscope

To fully calibrate the gyroscope inside the Adafruit BNO055 sensor:

1. Place the sensor in any stable position for a few seconds.

2. Run your Simulink model and read the calibration status of the gyroscope.

3. Repeat this process until the calibration value of the gyroscope is 3.