IMU Accelerometer & Gyroscope¶
This example shows accelerometer and gyroscope at a combined/synchronized 500 hz rate using the onboard IMU. Returns acceleration [m/s^2] and angular velocity [rad/s].
Demo¶
Example script output
~/depthai-python/examples$ python3 imu_gyroscope_accelerometer.py
Accelerometer timestamp: 0.000 ms
Accelerometer [m/s^2]: x: -0.162806 y: 6.445191 z: 3.189077
Gyroscope timestamp: 1.642 ms
Gyroscope [rad/s]: x: -0.040480 y: 0.088417 z: -0.168312
Accelerometer timestamp: 2.073 ms
Accelerometer [m/s^2]: x: -0.229843 y: 6.263232 z: 3.572149
Gyroscope timestamp: 3.663 ms
Gyroscope [rad/s]: x: -0.072438 y: 0.115049 z: -0.350472
Setup¶
Please run the install script to download all required dependencies. Please note that this script must be ran from git context, so you have to download the depthai-python repository first and then run the script
git clone https://github.com/luxonis/depthai-python.git
cd depthai-python/examples
python3 install_requirements.py
For additional information, please follow installation guide
Source code¶
Also available on GitHub
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 | #!/usr/bin/env python3 import cv2 import depthai as dai import time import math # Create pipeline pipeline = dai.Pipeline() # Define sources and outputs imu = pipeline.create(dai.node.IMU) xlinkOut = pipeline.create(dai.node.XLinkOut) xlinkOut.setStreamName("imu") # enable ACCELEROMETER_RAW at 500 hz rate imu.enableIMUSensor(dai.IMUSensor.ACCELEROMETER_RAW, 500) # enable GYROSCOPE_RAW at 400 hz rate imu.enableIMUSensor(dai.IMUSensor.GYROSCOPE_RAW, 400) # it's recommended to set both setBatchReportThreshold and setMaxBatchReports to 20 when integrating in a pipeline with a lot of input/output connections # above this threshold packets will be sent in batch of X, if the host is not blocked and USB bandwidth is available imu.setBatchReportThreshold(1) # maximum number of IMU packets in a batch, if it's reached device will block sending until host can receive it # if lower or equal to batchReportThreshold then the sending is always blocking on device # useful to reduce device's CPU load and number of lost packets, if CPU load is high on device side due to multiple nodes imu.setMaxBatchReports(10) # Link plugins IMU -> XLINK imu.out.link(xlinkOut.input) # Pipeline is defined, now we can connect to the device with dai.Device(pipeline) as device: def timeDeltaToMilliS(delta) -> float: return delta.total_seconds()*1000 # Output queue for imu bulk packets imuQueue = device.getOutputQueue(name="imu", maxSize=50, blocking=False) baseTs = None while True: imuData = imuQueue.get() # blocking call, will wait until a new data has arrived imuPackets = imuData.packets for imuPacket in imuPackets: acceleroValues = imuPacket.acceleroMeter gyroValues = imuPacket.gyroscope acceleroTs = acceleroValues.getTimestampDevice() gyroTs = gyroValues.getTimestampDevice() if baseTs is None: baseTs = acceleroTs if acceleroTs < gyroTs else gyroTs acceleroTs = timeDeltaToMilliS(acceleroTs - baseTs) gyroTs = timeDeltaToMilliS(gyroTs - baseTs) imuF = "{:.06f}" tsF = "{:.03f}" print(f"Accelerometer timestamp: {tsF.format(acceleroTs)} ms") print(f"Accelerometer [m/s^2]: x: {imuF.format(acceleroValues.x)} y: {imuF.format(acceleroValues.y)} z: {imuF.format(acceleroValues.z)}") print(f"Gyroscope timestamp: {tsF.format(gyroTs)} ms") print(f"Gyroscope [rad/s]: x: {imuF.format(gyroValues.x)} y: {imuF.format(gyroValues.y)} z: {imuF.format(gyroValues.z)} ") if cv2.waitKey(1) == ord('q'): break |
Also available on GitHub
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 | #include <cstdio> #include <iostream> #include "utility.hpp" // Includes common necessary includes for development using depthai library #include "depthai/depthai.hpp" int main() { using namespace std; using namespace std::chrono; // Create pipeline dai::Pipeline pipeline; // Define sources and outputs auto imu = pipeline.create<dai::node::IMU>(); auto xlinkOut = pipeline.create<dai::node::XLinkOut>(); xlinkOut->setStreamName("imu"); // enable ACCELEROMETER_RAW at 500 hz rate imu->enableIMUSensor(dai::IMUSensor::ACCELEROMETER_RAW, 500); // enable GYROSCOPE_RAW at 400 hz rate imu->enableIMUSensor(dai::IMUSensor::GYROSCOPE_RAW, 400); // it's recommended to set both setBatchReportThreshold and setMaxBatchReports to 20 when integrating in a pipeline with a lot of input/output connections // above this threshold packets will be sent in batch of X, if the host is not blocked and USB bandwidth is available imu->setBatchReportThreshold(1); // maximum number of IMU packets in a batch, if it's reached device will block sending until host can receive it // if lower or equal to batchReportThreshold then the sending is always blocking on device // useful to reduce device's CPU load and number of lost packets, if CPU load is high on device side due to multiple nodes imu->setMaxBatchReports(10); // Link plugins IMU -> XLINK imu->out.link(xlinkOut->input); // Pipeline is defined, now we can connect to the device dai::Device d(pipeline); bool firstTs = false; auto imuQueue = d.getOutputQueue("imu", 50, false); auto baseTs = std::chrono::time_point<std::chrono::steady_clock, std::chrono::steady_clock::duration>(); while(true) { auto imuData = imuQueue->get<dai::IMUData>(); auto imuPackets = imuData->packets; for(auto& imuPacket : imuPackets) { auto& acceleroValues = imuPacket.acceleroMeter; auto& gyroValues = imuPacket.gyroscope; auto acceleroTs1 = acceleroValues.getTimestampDevice(); auto gyroTs1 = gyroValues.getTimestampDevice(); if(!firstTs) { baseTs = std::min(acceleroTs1, gyroTs1); firstTs = true; } auto acceleroTs = acceleroTs1 - baseTs; auto gyroTs = gyroTs1 - baseTs; printf("Accelerometer timestamp: %ld ms\n", static_cast<long>(duration_cast<milliseconds>(acceleroTs).count())); printf("Accelerometer [m/s^2]: x: %.3f y: %.3f z: %.3f \n", acceleroValues.x, acceleroValues.y, acceleroValues.z); printf("Gyroscope timestamp: %ld ms\n", static_cast<long>(duration_cast<milliseconds>(gyroTs).count())); printf("Gyroscope [rad/s]: x: %.3f y: %.3f z: %.3f \n", gyroValues.x, gyroValues.y, gyroValues.z); } int key = cv::waitKey(1); if(key == 'q') { return 0; } } return 0; } |