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Correlate the readings of a robot's instrument, sensor, etc. with those of a standard in order to check its accuracy. Adjust experimental results to take external factors into account or to allow comparison with other data.

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1answer
65 views

Calibrating Logitic C920 HD 1080p using ros kinetic

I am trying to follow the ROS monocular camera calibration for a USB camera I have, but the calibration routine fails when I try to run it. I was expecting to see an image like the one below, but I ...
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1answer
28 views

measurement model of the accelerometers in IMU

I am new to IMU. About the measurements from IMU, different materials give different explanations. From the link: https://www.it.uu.se/edu/course/homepage/systemid/vt14/tokp2.pdf Here the b maybe ...
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2answers
47 views

Practicality of using magnetometer inside AUV

I have an AUV with a 12 inch diameter, 29 inch long capsule. Inside the capsule sits an Intel NUC computer, an NVIDIA Jetson GPU, an Arduino Mega, a Sparton IMU (9 DOF) as well as a custom voltage ...
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1answer
64 views

Why adding odometry data as control vectors to EKF-Monoslam algorithm fails?

I am working on EKF-MonoSlam (Davson) method for the mere input as a webcam, (it works "fine" if we calibrate and use reasonable sigmas) , and I am trying to add the odometry of some dataset (as ...
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1answer
32 views

Extrinsic Calibration Target Depth Camera

What's a good calibration object for the extrinsic calibration (rotation + translation) of a depth camera (no color sensor, only depth)? With RGB, people seem to typically use chessboard pattern or ...
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0answers
15 views

GNSS-aided IMU calibration

I have a physical system that consists of a GNSS receiver and an inertial measurement unit (IMU) with accelerometer and gyroscope. I would like to determine to some level of precision the angular and ...
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3answers
171 views

Zero-Point/Home Position/Origin of Absolute Encoder: What is the Proper Name?

I'm writing an academic paper describing the calibration of a system. Part of that system is an absolute rotary encoder measuring the angle of a joint. However, the position at which the encoder gives ...
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1answer
76 views

How is gyroscope bias exposed and tracked?

For an accelerometer, the measurement is defined in the following way: $$a_m = R_w^b(a_{w} - g) + b_a + v_a$$ Where $R$ is a rotation matrix, $g$ is gravity, $v_a$ is noise, and $b_a$ is the bias. ...
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2answers
161 views

Robot Calibration using DH parameters

I'm new in robotics. My problem is the next one: I have a 6DOF robot manipulator and because the implementation was for real-time application my calculation time had to be really fast so that I used ...
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0answers
48 views

ABB IRB 140 Calibration help

I wonder if anyone has experience calibrating an ABB with an SC4 controller using the encoder values stamped on the robot base. I need help identifying the correct method to calibrate the robot given ...
3
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1answer
87 views

OpenCV get topdown view of planar pattern by using intrinsic and extrinsic from cameraCalibrate

Originally I have a image with a perfect circle grid, denoted as A I add some lens distortion and perspective transformation to it, and it becomes B In camera calibration, A would be my destination ...
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1answer
60 views

Hand eye calibration wrong result

I am trying to do hand eye calibration between the robotic arm end effector and Kinect V1. I am using handeye_calib_camodocal repository for calibration and trying to find $X$ by solving the equation: ...
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1answer
181 views

Poor accuracy of hand eye calibration when using vanilla Tsai's method

I’m working on the hand eye calibration for the robotic arm. I attached the camera near the tip of the robot (or end effector) and took around 40 pictures of an asymmetric circles pattern. I ...
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1answer
39 views

Can someone explain what is going on in this calibration video?

I am trying to understand this IMU calibration video. https://www.youtube.com/watch?v=xF7sLU0fX7k&feature=em-comments In the video the operator gets accelerometer data when pointing each axis in ...
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1answer
85 views

Tool calibration- orientation

I'm currently working on calibration of robot tool. I have found some simple methods to get the tool centre point. But I'm sure how to get the tool orientation wrt the robot's tip (the point where the ...
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0answers
19 views

Are homogeneous coordinates represented by appending image coordinates with a 1 in camera imaging

In camera imaging, there are several terms for point coordinates. World coordinates: [X, Y, Z] in physical unit Image coordinates: [u, v] in pixel. Do these coordinates become homogeneous ...
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1answer
1k views

normalized point coordinates in undistortPoints function

In undistortPoints function from OpenCV, the documentations says that http://docs.opencv.org/2.4/modules/imgproc/doc/geometric_transformations.html#undistortpoints where undistort() is an ...
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1answer
92 views

Calibrating a laser scanner to a line camera

We have a high-resolution Riegl laser scanner and mounted atop it a Resonon Pika L, which is a hyperspectral camera which records one spatial column at a time, using the second dimension of the sensor ...
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1answer
259 views

Correct Fish eye camera radial distortion and blurry stretch at the image edges

There are a lot of questions regarding this topic, but I am trying to get a more clear picture from these questions. I am trying to calibrate a fish eye camera and I am using OpenCV ...
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1answer
39 views

Correct calibration parameters of stereo system due to vibrations

In stereo vision, the camera is calibrated using the popular chessboard before use. During the course of use, the camera maybe be subject to environmental factors such as vibrations.This may cause ...
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1answer
124 views

setup requirement of stereo camera

In the stereo camera system, two cameras are needed and should be mounted side by side. I see someone just glues two cameras to a wooden board. However one mobile phone manufacture claimed that the ...
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1answer
169 views

Effect of camera misalignment errors in dual cameras

In the camera module assembly process, parameters of camera modules vary due to manufacturing tolerance. Camera calibration is performed to obtain actual parameters. In the paper Effects of camera ...
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2answers
1k views

Wheel Odometry Covariance Matrix for Custom Robot

I have been looking around in the forums, but could not find any answer for how to go about getting the wheel odometry covariance matrix for a custom built planar robot (I found some posts related to ...
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2answers
87 views

Why are two cameras mounted in paralle in stereo application?

For stereo cameras on the market, two cameras are always mounted side by side and with a displacement that is perpendicular to the cameras’ optical axes. I take this setup for granted. One idea came ...
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1answer
191 views

Gauss Newton Method for Accelerometer calibration

I am following the code obtained in matlab file exchange for the paper http://ieeexplore.ieee.org/document/4655611/ He calculates the Hessian matrix as follows using Jacobian Matrix J, ...
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0answers
170 views

Accelerometer, gyro, and magnetometer sensor fusion for material resource survey

As a hardware engineer, I have studied quite a lot on sensor spec such as Accel, Gyro and Magnetometer including custom made fluxgate. I have studied matrix and quadarion (complex number) and so on. I ...
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0answers
316 views

How to properly calibrate a magnetometer in IMU for precise yaw?

EDIT: Moved to ElectricalEngineering StackExchange Community I'm using Sparkfun Razor IMU 9DOF sensor which incorporates accelerometer, gyroscope, and magnetometer, for giving the Euler's angles (yaw,...
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2answers
177 views

Inverse kinematics after calibration

I am working on a 6DOF robot arm project and I have one big question. When I first derived the inverse kinematics (IK) algorithm after decoupling (spherical wrist), I could easily get the equations ...
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1answer
3k views

Making a car go straight [duplicate]

I'm trying to work a car that's being controlled by an Arduino. I'm using the following chassis: New 2WD car chassis DC gear motor, wheels easy assembly and expansion and an L298N motor driver. The ...
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0answers
23 views

Is the distortion introduced by a lens protector significant in practice?

I have a computer-vision application I made to localize a robot in a room; the software has been in use for a while and is working fine. When I calibrated the camera and got the intrinsics and lens ...
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3answers
195 views

Discontinuity in device orientation

Why is there a discontinuity in the quaternion representation of my device orientation? I'm using a SENtral+PNI RM3100+ST LSM330 to track orientation. I performed the following test: Place the ...
2
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2answers
77 views

Aligning datasets with drift

I have a dataset that contains position information from tracking a robot in the environment. The position data comes both from a very accurate optical tracking system (Vicon or similar) and an IMU. I ...
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3answers
668 views

Camera Calibration fails to run on ROS

I am running ROS Indigo on Ubuntu 14.04. I am doing a mono-camera calibration and trying to follow the camera calibration tutorial on the ROS Wiki. I give the following command: rosrun ...
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1answer
1k views

Hand Eye Calibration Solver [closed]

I have a rig for which I have a pretty good estimate of the static transformation between the camera and a joint based off of the CAD. It has some errors though and I was hoping to fix it by doing a ...
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2answers
2k views

Why do we generally prefer DH parameters over other kinematic representations of robot arms?

I am specifically interested in DH parameters versus other representations in terms of kinematic calibration. The best (clearest) source of information I could find on kinematic calibration is in the ...
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2answers
285 views

PTAM CameraCalibrator error

I am trying to run the cameracalibrator.launch using PTAM according to this Camera Calibration tutorial. However, when I do so, I get the following error: ...
3
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2answers
755 views

ROS Calibration Camera Problems

I am trying to calibrate a monocular camera using ROS with the help of this website: How to Calibrate a Monocular Camera. When I run rostopic list, I get: ...
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3answers
6k views

Hand Eye Calibration

I'm trying to use a dual quaternion Hand Eye Calibration Algorithm Header and Implementation, and I'm getting values that are way off. I'm using a robot arm and an optical tracker, aka camera, plus a ...
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1answer
135 views

FreeIMU External Magnetometer

I have been using the FreeIMU library successfully but now I want to add an external magnetometer that I can mount away from my motors. I've figured out how to modify the FreeIMU library to use an ...
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1answer
430 views

Mobile Camera Calibration and rectification frame rate

I've been searching the internet for an answer to this question, but I haven't come across anything that will help me. Basically, we have a Meka Humanoid Robot in our lab, which has a shell head in ...
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1answer
1k views

3D Magnetometer calibration algorithm

I want to calibrate my compass, which is installed on a board which inherits a GPS module. Because the GPS antenna is up-side-down the compass is 180° inverted. The easiest way to correct the problem ...
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1answer
906 views

Calculate object distance with camera

Firstly I'm unsure whether this question belongs here or on another SE site (but I'll wing it for now). I've recently been given the job of connecting up a 'smart camera' to a setup where a robotic ...
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1answer
363 views

Are stereo camera calibration data standardized?

Is there a standard format of how stereo calibration data (various matrices, usually saved in XML) are stored? Can I load calibration data generated say from a OpenCV script in C to another OpenCV ...
3
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1answer
153 views

Stereo camera baseline not needed for calibration?

I am doing stereo camera calibration as described in this blog post. I wonder I do not need to input camera baseline for the calibration. The fact probably goes back to some very basic mathematics of ...
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2answers
309 views

How to calibrate differential drive?

I'm building a robot with differential drive. I've reached the point when I can drive it around on remote control and I'm trying to get the localization working. Now I would like to exactly measure ...
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1answer
72 views

How to programatically calibrate Turningy esc?

I have a Turnigy ESC and I am controlling it from AVR. Now I need to calibrate it to set the range of the input. With a servo tester I managed to calibrate it without any problems, more or less by ...
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1answer
534 views

Re-Calibration of an articulated industrial robot

We are planning to recalibrate ABB IRB 1410 robot and conduct series of accuracy & repeatability tests using FaroArm. My questions are i) Is there any physical identification marker on the robot ...
2
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1answer
258 views

How to calibrate an industrial Robot?

I am testing an industrial robot (ABB IRB 1410) using three simple Micron Dial gauges to get x,y,z values at particular point by varying Speed, Load and distance from home position. My questions are, ...
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4answers
1k 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 ...
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2answers
1k views

Accelerometer calibration - how to get cross-axis sensitivities

I've already asked a related question (accelerometer bias removal) here on robotics and got a bit better results on corrected accelerometer output. To get even better results I found the calibration ...