zed相机官方例程，zed-example

# Tutorial 7: Getting Sensors Data This tutorial shows how to use retrieve sensor data from ZED Mini and ZED2. It will loop until 100 data samples are grabbed, printing the updated values on console.<br/> We assume that you have followed previous tutorials. ## Prerequisites - Windows 10, Ubuntu LTS, L4T - [ZED SDK](https://www.stereolabs.com/developers/) and its dependencies ([CUDA](https://developer.nvidia.com/cuda-downloads)) - [ZED SDK Python API](https://www.stereolabs.com/docs/app-development/python/install/) ## Code overview ### Create a ZED camera object ```python # Create a Camera object zed = sl.Camera() init_params = sl.InitParameters() init_params.depth_mode = sl.DEPTH_MODE.NONE # Open the camera err = zed.open(init_params) if err != sl.ERROR_CODE.SUCCESS : print(repr(err)) zed.close() exit(1) ``` ### Device Informations We first display some informations about the sensors ```python # Display camera information (model,S/N, fw version) print("Camera Model: " + str(cam_model)) print("Serial Number: " + str(info.serial_number)) print("Camera Firmware: " + str(info.camera_configuration.firmware_version)) print("Sensors Firmware: " + str(info.sensors_configuration.firmware_version)) # Display sensors parameters (imu,barometer,magnetometer) printSensorParameters(info.sensors_configuration.accelerometer_parameters) # accelerometer configuration printSensorParameters(info.sensors_configuration.gyroscope_parameters) # gyroscope configuration printSensorParameters(info.sensors_configuration.magnetometer_parameters) # magnetometer configuration printSensorParameters(info.sensors_configuration.barometer_parameters) # barometer configuration ``` ### Capture data The sensor data can be retrieved in two ways: synchronized or not synchronized to the image frames<br/> In this tutorial, we grab 100 not synchronized data ```python # Used to store the sensors timestamp to know if the sensors_data is a new one or not ts_handler = TimestampHandler() # Get Sensor Data for 5 seconds i = 0 sensors_data = sl.SensorsData() while i < 100 : # retrieve the current sensors sensors_data # Depending on your Camera model or its firmware, differents sensors are presents. # They do not run at the same rate: Therefore, to do not miss samples we iterate as fast as we can and compare timestamp to know when a sensors_data is a new one # NOTE: There is no need to acquire images with grab() function. Sensors sensors_data are running in a separated internal capture thread. if zed.get_sensors_data(sensors_data, sl.TIME_REFERENCE.CURRENT) == sl.ERROR_CODE.SUCCESS : [...] ``` ### Process data To be sure that data are updated, since they are not synchronized to camera frames, we must check that the timestamp as changed from the previous retrieved values. We use the timestamp of the IMU sensor as main value since it's the sensor that runs at higher frequency. We defined a small utility class that will handle this. <br/> ```python # Check if the data has been updated since the last time # IMU is the sensor with the highest rate if ts_handler.is_new(sensors_data.get_imu_data()): ``` If the data are updated we can extract and use them: ```python print(" - IMU:") # Filtered orientation quaternion quaternion = sensors_data.get_imu_data().get_pose().get_orientation().get() print(" \t Orientation: [ Ox: {0}, Oy: {1}, Oz {2}, Ow: {3} ]".format(quaternion[0], quaternion[1], quaternion[2], quaternion[3])) # linear acceleration linear_acceleration = sensors_data.get_imu_data().get_linear_acceleration() print(" \t Acceleration: [ {0} {1} {2} ] [m/sec^2]".format(linear_acceleration[0], linear_acceleration[1], linear_acceleration[2])) # angular velocities angular_velocity = sensors_data.get_imu_data().get_angular_velocity() print(" \t Angular Velocities: [ {0} {1} {2} ] [deg/sec]".format(angular_velocity[0], angular_velocity[1], angular_velocity[2])) # Check if Magnetometer data has been updated (not the same frequency than IMU) if ts_handler.is_new(sensors_data.get_magnetometer_data()): magnetic_field_calibrated = sensors_data.get_magnetometer_data().get_magnetic_field_calibrated() print(" - Magnetometer\n \t Magnetic Field: [ {0} {1} {2} ] [uT]".format(magnetic_field_calibrated[0], magnetic_field_calibrated[1], magnetic_field_calibrated[2])) # Check if Barometer data has been updated if ts_handler.is_new(sensors_data.get_barometer_data()): magnetic_field_calibrated = sensors_data.get_barometer_data().pressure print(" - Barometer\n \t Atmospheric pressure: {0} [hPa]".format(sensors_data.get_barometer_data().pressure)) ``` If we are using a ZED2 we have more sensor data to be acquired. IMU: ```python # Filtered orientation quaternion quaternion = sensors_data.get_imu_data().get_pose().get_orientation().get() print(" \t Orientation: [ Ox: {0}, Oy: {1}, Oz {2}, Ow: {3} ]".format(quaternion[0], quaternion[1], quaternion[2], quaternion[3])) # linear acceleration linear_acceleration = sensors_data.get_imu_data().get_linear_acceleration() print(" \t Acceleration: [ {0} {1} {2} ] [m/sec^2]".format(linear_acceleration[0], linear_acceleration[1], linear_acceleration[2])) # angular velocities angular_velocity = sensors_data.get_imu_data().get_angular_velocity() print(" \t Angular Velocities: [ {0} {1} {2} ] [deg/sec]".format(angular_velocity[0], angular_velocity[1], angular_velocity[2])) ``` Magnetic fields: ```python # Check if Magnetometer data has been updated (not the same frequency than IMU) if ts_handler.is_new(sensors_data.get_magnetometer_data()): magnetic_field_calibrated = sensors_data.get_magnetometer_data().get_magnetic_field_calibrated() print(" - Magnetometer\n \t Magnetic Field: [ {0} {1} {2} ] [uT]".format(magnetic_field_calibrated[0], magnetic_field_calibrated[1], magnetic_field_calibrated[2])) ``` Barometer data: ```python # Check if Barometer data has been updated if ts_handler.is_new(sensors_data.get_barometer_data()): magnetic_field_calibrated = sensors_data.get_barometer_data().pressure print(" - Barometer\n \t Atmospheric pressure: {0} [hPa]".format(sensors_data.get_barometer_data().pressure)) ``` ### Close camera and exit Once the data are extracted, don't forget to close the camera before exiting the program.<br/> ```python # Close camera zed.close() return 0 ``` And this is it!<br/> You can now get all the sensor data from ZED-M and ZED2 cameras.