|
1 | 1 | # Hand-Eye Calibration |
2 | 2 |
|
3 | | -To fully understand Hand-Eye Calibration, please see the [tutorial][Tutorial-url] in our Knowledge Base. |
| 3 | +This page provides an overview of how to **perform**, **verify**, and **use Hand–Eye Calibration** with Zivid cameras. |
4 | 4 |
|
5 | | ------------------ |
6 | | -The following applications create a **Hand-Eye Transformation Matrix** from data provided by a user: |
| 5 | +If you are new to Hand–Eye Calibration, start with the [Hand–Eye Calibration – Concept & Theory][HandEyeTutorial-url], explaining: |
7 | 6 |
|
8 | | -[**HandEyeCalibration**][HandEyeCalibration-url] |
| 7 | +- What Hand–Eye Calibration is |
| 8 | +- The difference between **eye-in-hand** and **eye-to-hand** |
| 9 | +- Best practices for dataset (point clouds and robot poses) acquisition |
9 | 10 |
|
10 | | -* An application that walks through the collection of calibration poses: |
11 | | - 1. The user provides a robot pose in the form of a 4x4 transformation matrix (manual entry) |
12 | | - 2. The application captures a point cloud of the calibration object |
13 | | - 3. The user moves the robot to a new capture pose and enters the command to add a new pose |
14 | | - 4. Steps i.-iii. are repeated until 10-20 pose pairs are collected |
15 | | - 5. The user enter the command to perform calibration and the application returns a **Hand-Eye Transformation Matrix** |
| 11 | +If you already know what you’re doing and just want to run calibration or check out our Hand-Eye calibration code, continue reading. |
16 | 12 |
|
17 | | -[**ZividHandEyeCalibration**][ZividHandEyeCalibration-url] |
| 13 | +<!-- Use "Markdown All in One plugin in VS code to automatically generate and update TOC". --> |
18 | 14 |
|
19 | | -* [CLI application][CLI application-url], which takes a collection of robot pose and point cloud pairs (e.g. output of the steps i.-iii. in [HandEyeCalibration][HandEyeCalibration-url]) and returns a **Hand-Eye Transformation Matrix**. This application comes with the Windows installer and is part of the tools deb for Ubuntu. |
| 15 | +- [Quick Start: Just Calibrate](#quick-start-just-calibrate) |
| 16 | +- [Programmatic Hand–Eye Calibration](#programmatic-handeye-calibration) |
| 17 | +- [Dataset Acquisition Samples](#dataset-acquisition-samples) |
| 18 | +- [After Hand–Eye Calibration](#after-handeye-calibration) |
| 19 | +- [Verifying Calibration Accuracy](#verifying-calibration-accuracy) |
| 20 | +- [Summary: Which Tool Should I Use?](#summary-which-tool-should-i-use) |
20 | 21 |
|
21 | | ------------------ |
| 22 | +--- |
22 | 23 |
|
23 | | -There are two samples that show how to perform the acquisition of the hand-eye calibration dataset. |
24 | | -Both samples go through the process of acquiring the robot pose and point cloud pairs and then process them to return the resulting **Hand-Eye Transform Matrix**. |
| 24 | +## Quick Start: Just Calibrate |
25 | 25 |
|
26 | | -[**UniversalRobotsPerformHandEyeCalibration**][URhandeyecalibration-url] |
| 26 | +If your goal is **only to compute the Hand–Eye Transformation Matrix**, use one of the tools below and follow Zivid’s [best-practice guide for capture poses][ZividHandEyeCalibration-url]. |
27 | 27 |
|
28 | | -* This sample is created to work specifically with the UR5e robot. |
29 | | -* To follow the tutorial for this sample go to [**UR5e + Python Hand Eye Tutorial**][URHandEyeTutorial-url]. |
| 28 | +### Hand–Eye Calibration GUI (Recommended) |
30 | 29 |
|
31 | | -[**RoboDKHandEyeCalibration**][RobodkHandEyeCalibration-url] |
| 30 | +- Tutorial: [Hand–Eye GUI Tutorial][HandEyeCalibrationGUITutorial-url] |
| 31 | +- Application: [HandEyeCalibration GUI][HandEyeCalibrationGUI-url] |
32 | 32 |
|
33 | | -The second sample uses RoboDK for robot control and can be used with any robot that the software supports. |
34 | | -The list of the robots that they support can be found [**here**][robodk-robot-library-url]. |
35 | | -Poses must be added by the user to their rdk file. |
36 | | -To find the best capture pose practice follow the instructions provided on the Zivid knowledge base for the [hand-eye calibration process][ZividHandEyeCalibration-url]. |
| 33 | +Best choice if you: |
37 | 34 |
|
38 | | ------------------ |
39 | | -The following applications assume that a **Hand-Eye Transformation Matrix** has been found. |
| 35 | +- Want a guided, no-code workflow |
40 | 36 |
|
41 | | -[**UtilizeHandEyeCalibration**][UtilizeHandEyeCalibration-url]: |
| 37 | +--- |
42 | 38 |
|
43 | | -* Shows how to transform position and rotation (pose) from the camera coordinate system to the robot coordinate system. |
44 | | -* Example use case - "Bin Picking": |
45 | | - 1. Acquire a point cloud of an object to pick with a Zivid camera. |
46 | | - 2. Find an optimal picking pose for the object and **transform it into the robot coordinate system** |
47 | | - 3. Use the transformed pose to calculate the robot path and execute the pick |
| 39 | +## Programmatic Hand–Eye Calibration |
48 | 40 |
|
49 | | -[**PoseConversions**][PoseConversions-url]: |
| 41 | +The following applications produce a Hand–Eye Transformation Matrix from robot poses and calibration captures. |
50 | 42 |
|
51 | | -* Zivid primarily operates with a (4x4) **Transformation Matrix** (Rotation Matrix + Translation Vector). This example shows how to convert to and from: |
52 | | - * AxisAngle, Rotation Vector, Roll-Pitch-Yaw, Quaternion |
| 43 | +### Minimal Hand-Eye Calibration Code Example |
53 | 44 |
|
54 | | -[**VerifyHandEyeWithVisualization**][VerifyHandEyeWithVisualization-url]: |
| 45 | +- Sample: [HandEyeCalibration][HandEyeCalibration-url] |
| 46 | +- Tutorial: [Integrating Zivid Hand-Eye Calibration][hand-eye-procedure-url] |
55 | 47 |
|
56 | | -Visually demonstrates the hand-eye calibration accuracy by overlapping transformed points clouds. |
| 48 | +Workflow: |
57 | 49 |
|
58 | | -* The application asks the user for the hand-eye calibration type (manual entry). |
59 | | -* After loading the hand-eye dataset (point clouds and robot poses) and the hand-eye output (**transformation matrix**), the application repeats the following process for all dataset pairs: |
60 | | - 1. Transforms the point cloud |
61 | | - 2. Finds cartesian coordinates of the checkerboard centroid |
62 | | - 3. Creates a region of interest around the checkerboard and filters out points outside the region of interest |
63 | | - 4. Saves the point cloud to a PLY file |
64 | | - 5. Appends the point cloud to a list (overlapped point clouds) |
| 50 | +1. User inputs robot pose in the form of a 4x4 transformation matrix (manual entry) |
| 51 | +2. Camera captures the calibration object |
| 52 | +3. User moves the robot to a new capture pose and enters the command to add a new pose |
| 53 | +4. First three steps are repeated (typically 10–20 pose pairs) |
| 54 | +5. User enters the command to perform calibration and the application returns a Hand-Eye Transformation Matrix |
65 | 55 |
|
66 | | -This application ends by displaying all point clouds from the list. |
| 56 | +Use this if you: |
67 | 57 |
|
68 | | -[**RobodkHandEyeVerification**][RobodkHandEyeVerification-url] |
| 58 | +- Want the simplest integration example |
| 59 | +- Are building your own calibration pipeline |
69 | 60 |
|
70 | | -Serves to verify the hand-eye calibration accuracy via a touch test. |
| 61 | +--- |
71 | 62 |
|
72 | | -* After loading the hand-eye configuration, the required transformation matrices, and the type of the calibration object, the application runs in the following steps: |
73 | | - 1. The robot moves to the Capture Pose previously defined. |
74 | | - 2. The user is asked to put the Zivid Calibration Object in the FOV and press Enter. |
75 | | - 3. The camera captures the Zivid Calibration Object and the pose of the touching point is computed and displayed to the user. |
76 | | - 4. When the user presses the Enter key, the robot touches the Zivid Calibration Object at a distinct point. |
77 | | - 5. Upon pressing the Enter key, the robot pulls back and returns to the Capture Pose. |
78 | | - 6. At this point, the Zivid Calibration Object can be moved to perform the Touch Test at a different location. |
79 | | - 7. The user is asked to input “y” on “n” to repeat or abort the touch test. |
| 63 | +### Hand Eye Calibration CLI Tool |
| 64 | + |
| 65 | +- Tutorial: [Zivid CLI Tool for Hand–Eye Calibration][CLI application-url] |
| 66 | +- Installed with: |
| 67 | + - Windows Zivid installer |
| 68 | + - `tools` deb package on Ubuntu |
| 69 | + |
| 70 | +Use this if you: |
| 71 | + |
| 72 | +- Already have a dataset (robot poses + point clouds) |
| 73 | +- Want a command-line, batch-style workflow |
| 74 | + |
| 75 | +--- |
| 76 | + |
| 77 | +## Dataset Acquisition Samples |
| 78 | + |
| 79 | +The samples below show how to acquire robot poses and point clouds, then compute the Hand–Eye Transformation Matrix. |
| 80 | + |
| 81 | +### RoboDK-Based (Robot-Agnostic) |
| 82 | + |
| 83 | +- Sample: [RoboDKHandEyeCalibration][RobodkHandEyeCalibration-url] |
| 84 | +- Tutorial: [Any Robot + RoboDK + Python Hand–Eye Tutorial][RoboDKHandEyeTutorial-url] |
| 85 | +- Supported robots: [RoboDK robot library][robodk-robot-library-url] |
| 86 | + |
| 87 | +Features: |
| 88 | + |
| 89 | +- Works with any RoboDK-supported robot |
| 90 | +- Capture poses are manually defined in the `.rdk` file |
| 91 | +- Fully automated robot control |
| 92 | + |
| 93 | +--- |
| 94 | + |
| 95 | +### Universal Robots (e.g. UR5e) |
| 96 | + |
| 97 | +- Sample: [UniversalRobotsPerformHandEyeCalibration][URhandeyecalibration-url] |
| 98 | +- Tutorial: [UR5e + Python Hand–Eye Tutorial][URHandEyeTutorial-url] |
| 99 | + |
| 100 | +Features: |
| 101 | + |
| 102 | +- Designed specifically for UR robots |
| 103 | +- Fully automated robot control |
| 104 | + |
| 105 | +--- |
| 106 | + |
| 107 | +## After Hand–Eye Calibration |
| 108 | + |
| 109 | +The following applications assume that a **Hand–Eye Transformation Matrix already exists**. |
| 110 | + |
| 111 | +### Utilize Hand-Eye Calibration |
| 112 | + |
| 113 | +- Sample: [UtilizeHandEyeCalibration][UtilizeHandEyeCalibration-url] |
| 114 | +- Tutorial: [How To Use The Result Of Hand-Eye Calibration][UtilizeHandEyeCalibrationTutorial-url] |
| 115 | + |
| 116 | +Demonstrates how to: |
| 117 | + |
| 118 | +- Transform poses from camera coordinates to robot coordinates |
| 119 | +- Use the transform in real applications (e.g., bin picking) |
| 120 | + |
| 121 | +Example workflow: |
| 122 | + |
| 123 | +1. Capture a point cloud with a Zivid camera |
| 124 | +2. Find an object pick pose in camera coordinate system |
| 125 | +3. Transform the pose into robot coordinate system |
| 126 | +4. Plan and execute the robot motion |
| 127 | + |
| 128 | +--- |
| 129 | + |
| 130 | +### Pose Conversions |
| 131 | + |
| 132 | +- Sample: [PoseConversions][PoseConversions-url] |
| 133 | +- Application: [PoseConversions GUI][PoseConversionsGUI-url] |
| 134 | +- Theory: [Conversions Between Common Orientation Representations][PoseConversionsTheory-url] |
| 135 | + |
| 136 | +Zivid primarily operates with a (4x4) Transformation Matrix (Rotation Matrix + Translation Vector). This example shows how to convert to and from: |
| 137 | + |
| 138 | +- Axis–Angle |
| 139 | +- Rotation Vector |
| 140 | +- Roll–Pitch–Yaw |
| 141 | +- Quaternion |
| 142 | + |
| 143 | +Useful for integrating with robot controllers. |
| 144 | + |
| 145 | +--- |
| 146 | + |
| 147 | +## Verifying Calibration Accuracy |
| 148 | + |
| 149 | +### Verify Hand-Eye With Visualization |
| 150 | + |
| 151 | +- Sample: [VerifyHandEyeWithVisualization][VerifyHandEyeWithVisualization-url] |
| 152 | + |
| 153 | +Application validation approach: |
| 154 | + |
| 155 | +- Loads the hand-eye dataset and output (transformation matrix) |
| 156 | +- For each dataset pair: |
| 157 | + - Transforms the point cloud to common coordinate system |
| 158 | + - Finds the checkerboard centroid cartesian coordinates |
| 159 | + - Removes the points outside the the checkerboard ROI |
| 160 | +- Overlaps transformed point clouds |
| 161 | +- Visualizes alignment accuracy |
| 162 | + |
| 163 | +Best for: |
| 164 | + |
| 165 | +- Visual verification |
| 166 | +- Detecting systematic rotation/translation errors |
| 167 | + |
| 168 | +--- |
| 169 | + |
| 170 | +### RoboDK Touch Test Verification |
| 171 | + |
| 172 | +- Script: [RobodkHandEyeVerification][RobodkHandEyeVerification-url] |
| 173 | +- Tutorial: [Verify Hand-Eye Calibration Result Via Touch Test][RobodkHandEyeVerificationTutorial-url] |
| 174 | + |
| 175 | +Verification steps: |
| 176 | + |
| 177 | +1. Robot moves to a predefined capture pose |
| 178 | +2. User places the calibration object in the FOV |
| 179 | +3. Camera estimates a touch point |
| 180 | +4. Robot physically touches the calibration object |
| 181 | +5. User repeats the test at multiple locations |
| 182 | + |
| 183 | +Best for: |
| 184 | + |
| 185 | +- Physical validation |
| 186 | +- High-accuracy requirement applications |
| 187 | + |
| 188 | +--- |
| 189 | + |
| 190 | +## Summary: Which Tool Should I Use? |
| 191 | + |
| 192 | +| Goal | Recommended Tool | |
| 193 | +|------|------------------| |
| 194 | +| Conceptual understanding | [Knowledge Base article][HandEyeTutorial-url] | |
| 195 | +| Guided calibration | [Hand–Eye GUI][HandEyeCalibrationGUITutorial-url] | |
| 196 | +| Minimal integration example | [HandEyeCalibration][HandEyeCalibration-url] | |
| 197 | +| Existing dataset | [Hand–Eye GUI][HandEyeCalibrationGUITutorial-url]| |
| 198 | +| UR robots | [Hand–Eye GUI][HandEyeCalibrationGUITutorial-url] or [UR Hand–Eye sample][URHandEyeTutorial-url] | |
| 199 | +| Any robot | [Hand–Eye GUI][HandEyeCalibrationGUITutorial-url] or [RoboDK Hand–Eye sample][RoboDKHandEyeTutorial-url] | |
| 200 | +| Use calibration result | [UtilizeHandEyeCalibration][UtilizeHandEyeCalibrationTutorial-url] | |
| 201 | +| Verify visually | [Hand–Eye GUI][HandEyeCalibrationGUITutorial-url] or [VerifyHandEyeWithVisualization][VerifyHandEyeWithVisualization-url] | |
| 202 | +| Verify physically | [Hand–Eye GUI][HandEyeCalibrationGUITutorial-url] or [RoboDK Touch Test][RobodkHandEyeVerification-url] | |
| 203 | + |
| 204 | + |
| 205 | +[HandEyeTutorial-url]: https://support.zivid.com/latest/academy/applications/hand-eye.html |
80 | 206 |
|
81 | 207 | [HandEyeCalibration-url]: hand_eye_calibration.py |
| 208 | + |
| 209 | +[HandEyeCalibrationGUI-url]: hand_eye_gui.py |
| 210 | +[HandEyeCalibrationGUITutorial-url]: https://support.zivid.com/en/latest/academy/applications/hand-eye/hand-eye-gui.html |
| 211 | + |
82 | 212 | [UtilizeHandEyeCalibration-url]: utilize_hand_eye_calibration.py |
| 213 | +[UtilizeHandEyeCalibrationTutorial-url]: https://support.zivid.com/en/latest/academy/applications/hand-eye/how-to-use-the-result-of-hand-eye-calibration.html |
| 214 | + |
83 | 215 | [VerifyHandEyeWithVisualization-url]: verify_hand_eye_with_visualization.py |
84 | 216 | [ZividHandEyeCalibration-url]: https://support.zivid.com/latest/academy/applications/hand-eye/hand-eye-calibration-process.html |
85 | | -[Tutorial-url]: https://support.zivid.com/latest/academy/applications/hand-eye.html |
| 217 | +[hand-eye-procedure-url]: https://support.zivid.com/en/latest/academy/applications/hand-eye/hand-eye-calibration-process.html#custom-integration |
| 218 | + |
86 | 219 | [PoseConversions-url]: pose_conversions.py |
| 220 | +[PoseConversionsGUI-url]: pose_conversion_gui.py |
| 221 | +[PoseConversionsTheory-url]: https://support.zivid.com/en/latest/reference-articles/pose-conversions.html |
| 222 | + |
87 | 223 | [CLI application-url]: https://support.zivid.com/latest/academy/applications/hand-eye/zivid_CLI_tool_for_hand_eye_calibration.html |
| 224 | + |
88 | 225 | [URhandeyecalibration-url]: ur_hand_eye_calibration/universal_robots_perform_hand_eye_calibration.py |
89 | | -[URHandEyeTutorial-url]: https://support.zivid.com/en/latest/academy/applications/hand-eye/ur5-robot-+-python-generate-dataset-and-perform-hand-eye-calibration.html |
| 226 | +[URHandEyeTutorial-url]: https://support.zivid.com/en/latest/academy/applications/hand-eye/ur5-robot-%2B-python-generate-dataset-and-perform-hand-eye-calibration.html |
| 227 | + |
90 | 228 | [RobodkHandEyeCalibration-url]: robodk_hand_eye_calibration/robodk_hand_eye_calibration.py |
| 229 | +[RoboDKHandEyeTutorial-url]: https://support.zivid.com/en/latest/academy/applications/hand-eye/robodk-%2B-python-generate-dataset-and-perform-hand-eye-calibration.html |
| 230 | + |
91 | 231 | [RobodkHandEyeVerification-url]: robodk_hand_eye_calibration/robodk_verify_hand_eye_calibration.py |
92 | | -[robodk-robot-library-url]: https://robodk.com/supported-robots |
| 232 | +[RobodkHandEyeVerificationTutorial-url]: https://support.zivid.com/en/latest/academy/applications/hand-eye/hand-eye-calibration-verification-via-touch-test.html |
| 233 | + |
| 234 | +[robodk-robot-library-url]: https://robodk.com/supported-robots |
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