IRB 6700 Basic Calibration Helper

Quick guide for essential calibration tasks: updating revolution counters and verifying position based on the ABB IRB 6700 product manual (3HAC044266-001).

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When to Update Revolution Counters

According to the manual (Sec 5.1), the revolution counters must be updated if any of the following situations occur. This guide helps with the 'rough calibration' or update process.

  • SMB Battery Discharged: The battery maintaining the counter memory runs out (Warning: 38213 Battery charge low).
  • Resolver Error Occurs: The system reports a problem with a position sensor.
  • Signal Interruption: Communication between a resolver and the measurement board (SMB) is lost.
  • Axis Moved Manually Without Power: A robot axis is physically moved while the controller is off or disconnected.
  • First Installation: After connecting the robot and controller for the first time.
  • After Replacing Components: Following replacement of motors or transmission parts affecting calibration position (though full recalibration might be needed for accuracy).
Note: If resolver values are changed (e.g., due to replacing motors, transmission parts) or the robot is rebuilt, a full standard calibration (using Calibration Pendulum) is typically required. If the robot has Absolute Accuracy, recalibration with CalibWare might be needed to restore full performance (Sec 5.1, 5.2). This guide focuses *only* on updating the revolution counters.

Calibration Marks & Zero Position

Visually align the calibration marks on each axis as shown below (based on Manual Fig. 5.3) for the 0° position. These marks are essential for updating revolution counters and verifying calibration.

IRB 6700 Calibration Marks for Axes 1-6
Figure: Calibration marks for IRB 6700 Axes 1-6 (Reference: Product Manual 3HAC044266-001, Section 5.3)

Ensure the marks on the robot's physical structure line up precisely within their tolerance zones for each axis when jogging to the 0° position.

Calibration Movement Directions

To ensure accuracy and avoid errors from gear backlash, always jog each axis towards its calibration (0°) position from the same direction consistently. The positive directions for jogging are indicated below (based on Manual Fig. 5.4 concept).

Positive Calibration Movement Directions
Figure: Positive movement directions for calibration (Reference: Product Manual 3HAC044266-001, Section 5.4 - Note: Original image shows IRB 7600, principle applies).

Summary of positive directions:

  • Axis 1: Clockwise (viewed from above)
  • Axis 2: Arm moves upwards
  • Axis 3: Arm moves downwards
  • Axis 4: Wrist rotates clockwise (viewed from motor)
  • Axis 5: Wrist bends downwards
  • Axis 6: Flange rotates clockwise (viewed from front)

This is typically handled automatically by the calibration software routines, but it's crucial background knowledge.

Updating Revolution Counters (Rough Calibration)

This procedure details how to update the revolution counter value for each axis using the FlexPendant (IRC5), based on aligning the physical calibration marks (Sec 5.5).

Step 1: Manually Jog to Calibration Position

  1. Select axis-by-axis motion mode on the FlexPendant.
  2. Carefully jog each manipulator axis (1 through 6) individually until its calibration mark aligns perfectly within the tolerance zone shown on the robot body (see marks above).
  3. Once all axes are precisely positioned at their 0° mark, proceed to store the settings.

Critical Warning: Axes 4 & 6

For the IRB 6700 (and certain other models), it's extremely important that Axes 4 and 6 are positioned at the correct turn before updating.

  • These axes might have uneven gear ratios, meaning the calibration marks can appear aligned even when the axis is one or more full rotations off.
  • Always verify the axis position values on the FlexPendant correspond to 0° and double-check the calibration label on the robot (location varies: lower arm, base flange, frame) for the correct factory values if available.
  • If the robot is new or the position is certain, do NOT rotate axes 4 or 6 before the initial update.
  • If unsure, or if marks seem misaligned despite correct jogging, try rotating the affected axis (4 or 6) exactly one full turn (360°) in one direction, update, and check again. If still incorrect, try one turn in the opposite direction.

Step 2: Storing Settings with FlexPendant

  1. On the FlexPendant, navigate the menus: Tap the ABB menu, then tap Calibration.

    You'll see a list of connected mechanical units and their calibration status.

  2. Tap the specific manipulator unit (e.g., IRB_6700) you need to update.
  3. Tap the button labelled Update Revolution Counters...
  4. A warning dialog appears about potentially changing programmed positions. Tap Yes to proceed.
  5. The axis selection window appears. Select the axes to update:
    • Tick the box next to each individual axis you have correctly positioned.
    • Or, tap Select all if all axes are confirmed to be at their zero marks.
    Then tap the Update button.
  6. A final confirmation dialog warns that the operation cannot be undone.
    • Tap Update to finalize the process for the selected axes. The ticks will disappear as counters are updated.
    • Tap Cancel to abort.

CAUTION! Irreversible Action!

Incorrectly updating a revolution counter will cause incorrect manipulator positioning. This can lead to collisions, damage to the robot or equipment, and potential injury.

ALWAYS check the calibration position carefully after each update using the methods described below (See Checking Position).

Workflow Visualization

graph TD A[Start: Need to Update Counters] --> B{Select Axis-by-Axis Mode}; B --> C[Jog Axis 1 to 0° Mark]; C --> D[Jog Axis 2 to 0° Mark]; D --> E[Jog Axis 3 to 0° Mark]; E --> F[Jog Axis 4 to 0° Mark
Check Correct Turn!]; F --> G[Jog Axis 5 to 0° Mark]; G --> H[Jog Axis 6 to 0° Mark
Check Correct Turn!]; H --> I{All Axes Positioned?}; I -- Yes --> J[FlexPendant: ABB Menu -> Calibration]; J --> K[Select Manipulator]; K --> L[Tap 'Update Revolution Counters...']; L --> M{Warn: Change Programmed Pos?}; M -- Yes --> N[Select Axes to Update]; N --> O[Tap 'Update']; O --> P{Confirm: Cannot Undo?}; P -- Update --> Q[Counters Updated]; Q --> R[END: Check Calibration Position!]; P -- Cancel --> S[Cancelled]; M -- No --> S; I -- No --> C; S --> T[Abort]; style F fill:#fef9c3,stroke:#fde047,color:#78350f style H fill:#fef9c3,stroke:#fde047,color:#78350f style R fill:#fecaca,stroke:#f87171,color:#7f1d1d classDef warning fill:#fef9c3,stroke:#fde047,color:#78350f; classDef critical fill:#fecaca,stroke:#f87171,color:#7f1d1d; class F,H warning; class R critical;

Checking the Calibration Position

After updating revolution counters, or whenever you need to verify the robot's zero position, use one of the following methods (Sec 5.6). This ensures the robot's understanding of its position matches the physical reality.

Method 1: Using a MoveAbsJ Program

This method uses a simple RAPID program to command all axes to their absolute zero position.

  1. On the FlexPendant, navigate to the Program Editor (ABB Menu -> Program Editor).
  2. Create a new program routine.
  3. Insert a MoveAbsJ instruction (found under the Motion&Proc menu or equivalent).
  4. Edit the instruction to match the following code precisely: 
    MoveAbsJ[[0,0,0,0,0,0], [9E9,9E9,9E9,9E9,9E9,9E9]] \NoEOffs, v1000, z50, Tool0;

    This commands all 6 axes to 0° with high precision zone data (9E9) and default speed/zone/tool settings.

  5. Run the program carefully in manual mode at a low speed initially.
  6. Once the robot stops, visually inspect if the calibration marks for all axes align correctly (see marks above).
  7. If any marks do not align, the corresponding revolution counter may be incorrect. Re-check the alignment and potentially re-update the counter for that specific axis, paying close attention to the correct turn for axes 4 and 6.

Method 2: Using the Jogging Window

This method involves manually jogging each axis to its displayed zero position and visually checking the marks.

  1. On the FlexPendant, open the Jogging window (ABB Menu -> Jogging).
  2. Ensure the Motion mode is set to Axis-by-axis (e.g., Axis 1-3, Axis 4-6).
  3. Select an axis to jog (e.g., tap Axis 1).
  4. Carefully jog the selected axis until the position value displayed on the FlexPendant reads exactly 0.00° (or as close as possible).
  5. Visually check if the calibration mark for that specific axis aligns correctly (see marks above).
  6. Repeat steps 3-5 for all remaining axes (1 through 6).
  7. If any marks do not align when the FlexPendant shows 0°, the corresponding revolution counter may be incorrect. Re-check the physical alignment and potentially re-update the counter for that specific axis, paying close attention to the correct turn for axes 4 and 6.

Scope and Further Calibration

This guide covers basic revolution counter updates and position checks only.

Full Standard Calibration: If resolver values have changed significantly (e.g., motor/gearbox replacement, robot rebuild), a full calibration using the Calibration Pendulum method is required for optimal performance. This is the most accurate standard method (Sec 5.2).

Absolute Accuracy Calibration: If your robot has the Absolute Accuracy option (indicated by a sticker), service operations might necessitate recalibration using CalibWare to restore full TCP accuracy. While standard calibration might suffice after some component replacements, full performance requires the specific Absolute Accuracy procedure (Sec 5.2).

Refer to the specific manuals for Calibration Pendulum and CalibWare for detailed procedures involving specialized tools.