All MiR robots can dock to four standard types of relative markers: V-markers, VL-markers, L-markers, and Bar-markers. You can use markers to make the robot position itself more accurately relative to a physical entity.

This guide uses screenshots from software 3.x. There are small variations in the interface for software 2.x.

The example images may only show one type of marker, even if the description applies for any type of marker. It is specified if an example only applies to certain marker types.

Marker types

The four marker types described in this guide are V-markers, VL-markers, L-markers, and Bar-markers.

All of the markers must be placed so the center of the marker is 200 mm from the floor and they must be 100 mm tall at least—see the technical drawings of the markers on the Support Portal under Hardware > Drawings.

V-markers

V-markers are designed for the robot to dock with its front or its rear is facing the marker.

MiR recommends using straight docking only. Although the MiR software theoretically supports any docking orientation, the robot will dock less accurately, and there is a greater risk that the docking will fail if the robot docks at an angle.

The two plates that make the marker must be 150 mm (±1 mm) long with a 120° (±1°) angle between them.

VL-markers

VL-markers are similar to V-markers but have an additional plate that enables the robot to dock more accurately to the marker. They are also designed for the robot to either dock so its front or its rear is facing the marker.

MiR recommends using straight docking only. Although the MiR software theoretically supports any docking orientation, the robot will dock less accurately, and there is a greater risk that the docking will fail if the robot docks at an angle.

The V-shaped part must be the same as the V-marker (150 (±1 mm) long with a 120° (±1°) angle), and the plate to the right must be 350 mm (±25 mm) long.

L-markers

Robots can dock to L-markers in several different ways. Robots can both dock to the inside and outside of an L-marker, and the marker can be on any side of the robot.

MiR recommends using straight docking only. Although the MiR software theoretically supports any docking orientation, the robot will dock less accurately, and there is a greater risk that the docking will fail if the robot docks at an angle.

An L-marker must be 400 mm × 600 mm (±1 mm) with a 90° (±1°) angle between the plates.

Although L-markers can theoretically be larger, MiR does not guarantee that the robot will dock reliably to an L-marker that exceeds the described dimensions.

Bar-markers

Bar-markers are two long bars with enough space for the robot to fit between them.

Bar-markers for MiR100, MiR200, and MiR250 robots must be between 400 mm and 750 mm long, and the distance between the bars must be between 750 mm and 1500 mm.

Bar-markers for MiR500, MiR1000, MiR600, and MiR1350 robots must be between 400 mm and 2000 mm long, and the distance between the bars must be between 1010 mm and 1500 mm.

Space around markers

To see the space required around markers and all other space requirements, find the Space Requirements guide for your robot. You can find this guide on MiR Support Portal.

Detecting a marker

To detect a marker, follow these steps:

1. Ensure that the robot is localized correctly on an active map. To do this, check if the red lines representing the laser scanner line match the black lines on the map.

   

2. Drive your robot to the correct position in front of the marker. The correct position from the marker differs depending on the marker type:

   For a forward docking, make the front of the robot face the marker, and for a reverse docking, make the rear of the robot face the marker.

   • For V, VL, and Bar-markers, the robot must be positioned approximately one meter directly in front of the marker.
     

   • For L-markers, the robot must be positioned differently depending on the type of robot you are using. See the illustration below and apply the following values depending on your robot:

     • For MiR100, MiR200, and MiR250:
       A: 700 mm ±50 mm
       B: 200 mm ±50 mm

     • For MiR500, MiR600, MiR1000, and MiR1350:
       A: 1000 mm ±50 mm
       B: 200 mm ±50 mm

     

     

3. Go to Setup > Maps and select Edit  on the active map.

   

4. Within the editor, select the marker type the robot is positioned in front of in the Add position menu. A dialog will appear to create the new marker.

   

5. In the dialog, name the marker and select Detect marker. The X, Y, and orientation values will automatically be filled out with the current position of the robot.

   

• If the robot cannot detect the marker, verify that the robot is correctly positioned and that the laser scanners can detect the marker in the active map by checking that red lines are displayed on the map where the marker is.

• If you are trying to make the robot detect an L-marker but it keeps detecting other objects with a 90° angle instead, shield the objects it is not supposed to detect with a flat plate.

• If you want the robot to dock straight to the marker, set the orientation offset to 0. If you want the robot to reverse into the marker, set the orientation offset to 180°.
  

  MiR recommends using straight docking only. Although the MiR software theoretically supports any docking orientation, the robot will dock less accurately, and there is a greater risk that the docking will fail if the robot docks at an angle.

  Detecting the marker with the rear scanner will automatically set the orientation offset to approximately 180° for a reverse docking.

• If you want to change where the robot stops relative to the marker, modify the offset values.

  • The X-offset moves the robot closer to or further from the marker in meters measured from the center of the robot.

  • The Y-offset moves the robot further to the left or right of the marker in meters measured from the center of the robot.

  • The orientation offset changes the final orientation of the robot in degrees.

  For more information about the default docking offsets and from which point of the marker the offsets are measured from, see Marker center-points and default offsets .

  

  You may need to dock the robot to the marker multiple times to determine the correct offsets—see Docking to a marker.

6. Select Create to create the marker. The marker icon is now visible on the map.

   V-marker	VL-marker	L-marker	Bar-marker

Marker center-points and default offsets

Each marker has a center-point that the robot aims for when it docks to the marker. For V, VL, and L-markers, the center-point is inside the marker itself, so offset values are automatically applied to make sure the robot does not dock into the marker. These offsets are the ones displayed in the interface when you detect the marker, and they describe where the robot should position itself relative to the center-point of the marker in terms of X and Y displacements.

V-markers and VL-markers

The varying displacements ensure that the front safety laser scanner is always located in front of the V when the robot docks to the marker and the Y offset is set to 0.

By default, the marker offsets are set to the distance between the marker center-point and the robot's center-point and the robot's orientation when it detects the marker. This means that when the robot docks to the marker, it will position itself in the same position it was in when it detected the marker.

L-markers

The center-point of an L-marker is on either end of the long edge, depending on from which direction the robot is docking to the marker. The robot uses the end that is closest to it to orient itself when it docks.

The default offsets depend on from which side the robot docks to the L-marker. The offsets are described in the table below, and the center-point is marked in the image of each scenario.

Inside on the left MiR100/MiR200/MiR250: X offset: -0.05 m Y offset: 0.5 m MiR500/MiR600/MiR1000/MiR1350: X offset: -0.3 m Y offset: 0.9 m

Outside on the left MiR100/MiR200/MiR250: X offset: 0.3 m Y offset: 0.5 m MiR500/MiR600/MiR1000/MiR1350: X offset: 0.65 m Y offset: 0.9 m

Inside on the right MiR100/MiR200/MiR250: X offset: -0.05 m Y offset: -0.5 m MiR500/MiR600/MiR1000/MiR1350: X offset: -0.3 m Y offset: -0.9 m

Outside on the right MiR100/MiR200/MiR250: X offset: 0.3 m Y offset: -0.5 m MiR500/MiR600/MiR1000/MiR1350: X offset: 0.65 m Y offset: -0.9 m

By default, the orientation offset is always set to 0 for L-markers.

Bar-markers

The center-point of a Bar-marker is in the center between the two sidebars.

By default, the offsets are all 0, so the robot docks in the center of the marker.

Docking to a marker

There are two ways to make the robot dock to a marker: using the Send robot to in the active map or adding a Docking action to a mission. In the mission example, it is also described how to mute the Protective fields on MiR250, MiR500, MiR600, MiR1000, and MiR1350 robots when docking to an L-marker.

The Protective field sets are automatically muted when the robot docks to all types of markers besides L-markers. This ensures that the robot can drive closely to the marker without entering Protective stop.

If you are using a MiR100 or MiR200 robot, you cannot mute the Protective fields.

When you are using the Send robot to, you cannot make the robot mute its Protective fields. You can only do this in a mission.

Using Send robot to

1. Open the active map with the marker you want to send your robot to. You can either do this from a dashboard with the map widget or in the map editor.

   

2. Select the marker you want the robot to dock to and then select Send robot to. The robot will now dock to the marker.

   

Creating a mission to mute the Protective fields and dock to an L-marker

To create a mission to mute the Protective fields and dock to an L-marker, follow these steps:

1. Go to System > Settings > Features, and enable Mute protective fields. This enables you to add a mission action to mute the Protective fields.

   

2. Go to Setup > Missions, and create a new mission. To create a mission, select Create, then enter a name for the mission, and select a mission group and a site.

   

3. Add the following mission actions:

   • Under Move, select Move.

   • Under Safety system, select Mute protective fields.
     

   • Under Move, select Dock. Drag this action into the box under Mute protective fields.

     

4. Select the gearwheel  to edit each action as follows:

   • For the Move action, select the L-marker you want the robot to dock to.
     

   • For the Mute protective fields action, mute all of the sides of the robot.
     

   It is possible to select muting of side fields, front fields, and rear fields separately on MiR500 and MiR1000. If any part of the Protective field is muted, the remaining fields can not be used as a safety function to reduce the risk for collision with humans. This is because the reliability cannot be determined.

   • Risk for collision with humans shall be addressed by marking the area as Operation hazard zones, and personnel should be informed not to enter the zone while the robot is operating in it.

   • For the Dock action, select the L-marker you want the robot to dock to.
     

   If you have several L-markers where the robot needs to mute its Protective fields, you can make this mission reusable by using a variable  in the Move and Dock actions instead. Make sure you use the same variable for both actions.

When docking to a marker, the robot slows down, reducing the size of its Protective field to the minimum. The robot may drive very close to an object or person before stopping, making it necessary to mark the area where there is a risk of personnel being trapped between the robot and marker as an operating hazard zone. 

Undocking from markers

A MiR robot can undock from markers automatically (except L-markers). When undocking, the robot reverses from the marker until it is outside of the undocking area—see Figure 1.3. The robot will keep muting its Protective fields while it undocks. Once the robot begins a new action that requires it to plan a new path, the Protective fields are activated again, and the robot continues normal operation.

To enable automatic undocking, go to System > Settings > Docking and enable Undock from markers.

To undock from L-markers the robot needs to use a Relative move as part of its mission. The Relative move action makes the robot drive an appropriate distance from the marker either forward or backward, depending on the robot's orientation. The distance depends on the docking offsets.

Enter a value in the X field of the Relative move action to define how the robot should move. A positive value moves the robot forward, and a negative value moves it backward.

You can modify the size of the undocking area under System > Settings > Docking > Advanced  by using the parameters Docked at marker reverse distance and Docked at marker side threshold—see Table 1.1.

The undocking sequence will always occur if a robot begins an action where it plans a new route while inside the undocking area, even if the robot was not previously docked to the marker. This means the sequence is also initiated on robots that have entered the area via a Relative move action or Manual control.

The robot will reverse from the marker as long as its orientation to the marker is below 90°. If the orientation difference is greater than 90°, the robot will move forward to exit the undocking area instead. This means that if the robot reverses into the area or is perpendicular to the marker, it will undock by moving forward.

L-markers are the only markers that do not support automatic undocking. If you want a robot to undock from an L-marker, you must use a Relative move action.

The only case where the robot will not execute the undocking sequence is if you use a Relative move action right after the Dock action. The robot will always execute the Relative move action first, and if the robot is outside of the undocking area after finishing the Relative move action, it will continue to the next action without undocking.

Changing the Entry position

The Entry position is the position the robot drives toward before docking to the marker. The Entry position is automatically generated approximately one meter in front of the marker when it is created. The robot must be able to detect the marker from the Entry position.

In software version 2.8.0, the Fast docking feature was implemented, which makes the robot drive toward the Entry position of a marker, but as soon as it can detect the marker itself, it begins the docking procedure without necessarily reaching the center of the Entry position.
This can be overruled by creating a Move action to the marker's Entry position before the Docking action.

Often, the default position of the Entry position is the optimal position, but if you do want to change the position of the marker's Entry position, you can do so with the following steps:

1. Go to Setup > Maps, and select Edit  for the map with the marker you want to edit.

   

2. Select the marker you want the robot to dock to. The following dialog box is displayed.

   

3. Select Show entry position(s). The Entry position for the marker is displayed on the map.

   

4. Select the Entry position on the map, and then select Settings.

   

5. There are two ways to change the position of the Entry position:

   • Modify the X, Y, and orientation values.

   • If you are using the active map, and the robot is in the position you want the Entry position to be, select Place at the robot's current position.

     

Using markers with Shelf positions

MiR recommends that you use markers to increase the accuracy when the robot places shelves on Shelf positions.

For all shelf lifting robots, MiR currently only recommends using V and VL-markers with Shelf positions. The robot will not be able to detect Bar-markers and L-markers reliably while carrying a shelf because the shelf legs reduce the laser scanners' field of view.

To set up a Shelf position with a marker, you must:

• Create a physical marker and define it on a map.

• Create a Shelf position in front of the physical marker.

• Make the X and Y coordinates of the Entry position to the Shelf position the same as the Entry position to the marker.
  

• In missions, make the robot dock to the marker when placing the shelf, and make the robot dock to the Shelf position when picking up the shelf.

Docking to overhangs

Applications using markers often have overhangs that are above the laser scanners' plane of view, meaning the robot will not detect them if the overhang is also outside the field of view of the 3D cameras. In cases where the robot drives with loads or top modules that risk colliding with the overhang, it is a good idea to mark the overhang with a Forbidden zone.

To do so, follow these steps:

1. Create a marker as described in Detecting a marker.

2. Send the robot to dock to the marker as described in Docking to a marker.

3. Open the active map with the map editor. The robot should still be docked to the marker.

4. Within the editor, select Draw a new shape and then select Forbidden zone.
   

5. Create a Forbidden zone on top of the overhang, making sure not to include the area where the robot is or the area where the robot needs to dock to the marker. To create the zone, select the corners of the overhang on the map.

   

Now, the robot will never drive into the overhang.