Questions tagged [imu]

Inertial Measurement Unit

Filter by
Sorted by
Tagged with
16
votes
2answers
7k views

How to choose a good IMU for a wheeled robot?

At our lab, we have a several "Kurt" type robots (about the size of a Pioneer, six wheels, differential drive). The built-in gyroscopes are by now really outdated; the main problem is that the ...
13
votes
4answers
7k views

Do magnets affect IMU values?

Im in the process of making a robot which requires 12 3x10mm cylindric magnets for the construction. They are 30mm from the center of the robot where I plan to have the IMU. I was thinking about ...
9
votes
2answers
1k views

Do I really need a gyro for an airplane flight stabilization system?

I'm working on a basic airplane flight stabilization system, as the precursor to a full autopilot system. I'm using a salvaged Wii Motion Plus and Nunchuk to create a 6DOF IMU. The first goal is to ...
9
votes
1answer
490 views

Chaining Kalman filters

My team is building a robot to navigate autonomously in an outdoor environment. We recently got a new integrated IMU/GPS sensor which apparently does some extended Kalman filtering on-chip. It gives ...
8
votes
2answers
11k views

Accelerometer, gyro, and magnetometer sensor fusion in 2d

I have not yet built this so this is basically a theoretical question. I am still wrestling with some C code to manage i2c ...
8
votes
4answers
2k views

Why do 3-axis accelerometers seemingly have a left-handed coordinate system?

Careful inspection of page 35 (figure 58) of the ADXL345 datasheet shows that under gravitational loading only, the chip uses a left-handed coordinate system. My own experiments with this chip ...
8
votes
2answers
278 views

At which stage should filtering be applied to the sensors data?

Shall I filter (kalman/lowpass) after getting the raw values from a sensor or after converting the raw values to a usable data? Does it matter? If so, why? Example: Filter after getting raw values ...
8
votes
1answer
5k views

Angle Random Walk vs. Rate Noise Density (MPU6050)

I’ve made a datalog from a MPU6050 (IMU: gyroscope and accelerometer) at 500Hz sample rate. Now I want to calculate the characteristics from the gyro to evaluate the sensor. For the gyro I’ve found ...
7
votes
1answer
7k views

How are units of noise measurement related to units of a sensor's data measurement?

I'm trying to understand how noise is represented for accelerometers, gyroscopes, and magnetometers so that I can match the requirements of my project with the standard specs of these sensors. I ...
7
votes
1answer
5k views

Quadcopter PID Algorithm

I'm trying to implement a PID control on my quadcopter using the Tiva C series microcontroller but I have trouble making the PID stabilize the system. While I was testing the PID, I noticed slow or ...
7
votes
3answers
17k views

Open source implementations for GPS+IMU sensor fusion?

Are there any Open source implementations of GPS+IMU sensor fusion (loosely coupled; i.e. using GPS module output and 9 degree of freedom IMU sensors)? -- kalman filtering based or otherwise. I did ...
7
votes
2answers
8k views

How to track robot position?

I'm a software researcher, who in my spare time mentors a robotics team, helping on the software side of things. For years, I keep coming back to the same question: How to determine the robots ...
6
votes
3answers
37k views

How to estimate yaw angle from tri-axis accelerometer and gyroscope

I would like to estimate the yaw angle from accelerometer and gyroscope data. For roll and pitch estimate I've used the following trigonometric equations: ...
6
votes
2answers
535 views

Explanation of Quadcopter Dynamics, Components and Control

I am about to build my own quadcopter from scratch. However i am having problem with understanding how it is possible to control the quadcopter without knowing the current rpm of the BLDC motors. ...
6
votes
6answers
1k views

How to measure displacement, cheaply and without using an accelerometer?

Motion is known to be confined in a sphere with radius of about 0.5m, and resolution doesn't have to be very high (5cm is enough). The device will actually be incorporated in a toy designed for kids. ...
6
votes
2answers
602 views

Need help regarding development of Extended Kalman Filter for sensor-data fusion of odometry and IMU data

I'm trying to develop an Extended Kalman Filter (EKF) for the positioning of a wheeled vehicle. I have a 'Baron' robot frame with 4 static wheels, all driven by a motor. On the 2 rear wheels I have an ...
6
votes
1answer
824 views

Quadrotor control using ArduIMU

We are using ArduIMU (V3) as our Quadrotor's inertial measurement unit. (we have a separate board to control all motors, not with ArduIMU itself). As mentioned here , the output rate of this module ...
6
votes
4answers
2k views

PID control of tank-like robot and IMU

Consider a tank like robot with a motor driver channel for each side of the robot (two motors on the left and two motors on the right) and an IMU. I'm interested in driving the robot in a straight ...
6
votes
1answer
4k views

Euler Angles from 9DOF IMU

Using the Adafruit 9DoF module I Need to convert the Accel + Magneto + Gyro into Euler Angles for a motion capture application. Any hints on where to start? Managed to get X,Y,Z when the IMU is ...
5
votes
2answers
7k views

Kalman Filter GPS + IMU

I know this probably has been asked a thousand times but I'm trying to integrate a GPS + Imu (which has a gyro, acc, and magnetometer) with an Extended kalman filter to get a better localization in my ...
5
votes
3answers
1k views

Does multiple IMU increase accuracy

I'm just starting up with IMU's and I really want to work on my own flight controller, but a question always hits my mind and I am not able to find answer anywhere, so I'm here. Will multiple IMUs ...
5
votes
1answer
3k views

Kalman filter GPS + IMU fusion get accurate velocity with low cost sensors

I'm new to all this robotics stuff. Especially to Kalman filter. My initial goal is to have velocity as accurate as possible Here is my case: I have a phone which is mounted, for example in the ...
5
votes
1answer
2k views

Simple Sensor Fusion for pose estimation

I am currently working on a balancing robot project, which features fairly low-cost sensors such as an 9-Dof IMU with the measurement states $\textbf{x}_\text{IMU} = \left[a_x, a_y, a_z, g_x, g_y, ...
5
votes
1answer
522 views

Gyro measurement to absolute angles

Let us assume we have a gyro that is perfectly aligned to a global frame ($X,Y,Z$). From what I know the gyro data give me the angular rate with respect to the gyro axis ($x,y,z$). So let's say I ...
5
votes
1answer
240 views

Inferring joint orientation on multi-joint arm

Not a robotics question in the strictest sense, I guess, but related closely enough, I hope: I have an arm-like articulated two(-plus-one)-joint appliance that I want to use as a 3D input device. It ...
4
votes
3answers
2k views

Can I use IMUs to improve the position/posture measurement of fingers in a “data glove”?

I have been using the Cyberglove to control a humanoid robot hand, but found it disappointing as it doesn't measure the posture of the human hand very accurately. I have been wondering about the ...
4
votes
3answers
2k views

imu position without GPS or camera

I have a IMU that has 3-axis accelerator, 3-axis magnetometer, 3-axis gyroscope and row, yaw, pitch value. I want to get the location of the IMU coordinate(the beginning point is (0,0,0)) but I know ...
4
votes
1answer
2k views

Simulate IMU (2D gyro and accelerometer) data

If I have a robot path in 2D space, i.e. a vector of (x,y) locations, and I need to generate artificial IMU data (simulate them), how would I go about it? How do I model equations to generate the ...
4
votes
1answer
804 views

Filtering IMU angle discontinuities

I try to measure Euler angles from an IMU, but some discontinuities happens during measurement, even in vibrationless environment, as shown in the images below. Can someone explain which type of ...
4
votes
1answer
264 views

Is increasing gyro , accelerometer sensor range is good or bad ? how does it affect the accuracy

I've been using mpu6050 IMU unit ( gyro + accelerometer ) I found that I can set acc range to +/- 2g or 4g till 16 g and same for gyro +/- 250 deg/sec , 500 deg/sec and so I know that they are ...
4
votes
2answers
595 views

IMU based acceleration parameters for differential drive robot

I have a differential drive robot whose motors are virtually quiet while driving on a completely flat surface, but the motors make a lot of noise when on a incline. This is likely due to the ...
4
votes
1answer
344 views

MPU6050: Changing Gyro Output Range Throws off Positional Reading

I am using the MPU6050 in conjunction with an Arduino and Jeff Rowberg's i2cdev library, and my project requires that the gyro rate outputs be more precise than the default setting, which is 1/16.4 of ...
3
votes
1answer
931 views

Stabilizing a Drone

I have my IMU and I can get attitude (pitch, roll, yaw) as well as gyro (x, y, z) As far as I can tell, ...
3
votes
2answers
549 views

Multi-Rate Sensor Fusion using EKF

Context: I have an IMU(a/g/m) + Wheel Odometry measurement data that I'm trying to fuse in order to localize a 2D (ackermann drive) robot. The state vector ...
3
votes
3answers
1k views

How to combine odometry information with time-shifted information from IMU?

I'm working with a differential-drive robot that has odometry measurements from wheel shaft encoders and heading information from an IMU (I'm using BNO055 in IMU mode to get Euler angles, primarily ...
3
votes
2answers
4k views

Tracking with accelerometer and gyro versus multiple accelerometers

I'm building quadcopter and most of the control systems use one accelerometer and gyro. I've read few papers and usually accelerometer is used as reference to the ground because gyro slowly drifts ...
3
votes
1answer
370 views

I fused a GPS and IMU and I am wondering if my results make sense

I am trying to fuse a ublox M8 (https://www.u-blox.com/sites/default/files/products/documents/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf) with a MicroStrain IMU (http://www.microstrain....
3
votes
2answers
358 views

Compensation for IMU mounting misalignment

I have an MPU6050 IMU and I would like to mount it on an FSAE car and use it to measure the yaw, pitch, roll, and angular velocities as it drives. As it's impossible to mount it perfectly flat and ...
3
votes
2answers
101 views

How reliable are IMUs for a long usage (6 hours) rotation (only) tracking?

I know they are bad for positional tracking and drift from actual position over time but would like to know what is the situation with rotation only. I know Oculus DK1 used ordinary off-the-shelf ...
3
votes
1answer
5k views

Ardupilot on Raspberry Pi

I'm making a quadcopter for the first time and want to be as low cost as possible, and when it comes to flight controllers APM is the best open-source project, and is compatible with Raspberry Pi. My ...
3
votes
2answers
1k views

Is there a way to measure 3 axis orientation without a magnetometer?

I have bought an STM iNEMO evaluation board in order to monitor the inclination of a separate magnetic sensor array as it moves in a linear scan outside of a (non-magnetic) stainless steel pipe. I ...
3
votes
2answers
1k views

How do I choose the best filter for dead reckoning with an IMU?

I'm searching filter to reduce noise and smooth the signal while dead reckoning with an IMU (6dof gyro+accelerometer). What are the differences/advantages/disadvantages of the following filters: ...
3
votes
2answers
471 views

Simon K firmware when the IMU outputs at 50HZ

I am building a Quadcopter using the Sparkfun Razor IMU which outputs the Roll, Pitch and Yaw axes values at 50 Hz, which limits the operations of the controller(implemented on Arduino IMU), to 50 Hz ...
3
votes
1answer
484 views

Is there a benefit to using 2 IMU units on a UAV set at different sensitivities?

I noticed that some IMU units are tuned to be sensitive to small changes, other to large changes and some that can be adjusted between different sensitivities. I am familiar with the use of a Kalman ...
3
votes
1answer
531 views

MPU6050 inconsistent Gyro data

I'm using an MPU6050 for a custom flight controller and I am facing an issue when reading the values from the IMU. The data shown below represents the angular velocity in the y-axis. When the angular ...
3
votes
1answer
93 views

Self balancing roboter IMU issue

I build a self-balancing robot, at least that what i should have been. now i have tried implementing a complementary filter which combines gyro and accelerometer data, but the problem is that the ...
3
votes
2answers
617 views

Using an IMU to build an INS

What's needed to utilize an IMU such as the ArduIMU+ V3 to be used in an INS. Is there any other hardware needed?
3
votes
2answers
843 views

Correctly calculating free acceleration given NED referenced orientation quaternion and sensor referenced acceleration data

I have a sensor outputting correct, calibrated North-East-Down referenced quaternions describing the orientation of the sensor. It also outputs raw, sensor referenced acceleration data, inclusive of ...
3
votes
1answer
137 views

How is the GPS fused with IMU in a kalman filter?

I've been trying to understand how a Kalman filter used in navigation without much success, my questions are: The gps outputs latitude, longitude and velocity. While the IMU outputs acceleration and ...
2
votes
2answers
8k views

What information an IMU gives to a drone?

An Inertial Measurement Unit (IMU) is an important sensor used in aerial robotics. A typical IMU will contain an accelerometer and a rate gyroscope. Which of the following information does a robot get ...