MIR 250 Quick start guide

Technical Guide (en)
Date: 07/2020
Revision: v.1.0

MiR250 Technical Guide (en) 07/2020 - v.1.0 ©Copyright 2020: Mobile Industrial Robots A/S. 2
Copyright and disclaimer
All rights reserved. No parts of this manual may be reproduced in any form without the
express written permission of Mobile Industrial Robots A/S (MiR). MiR makes no warranties,
expressed or implied, in respect of this document or its contents. In addition, the contents of
the document are subject to change without prior notice. Every precaution has been taken in
the preparation of this manual. Nevertheless, MiR assumes no responsibility for errors or
omissions or any damages resulting from the use of the information contained.
Copyright © 2020 by Mobile Industrial Robots A/S.
Contact the manufacturer:
Mobile Industrial Robots A/S
Emil Neckelmanns Vej 15F
DK-5220 Odense SØ
www.mobile-industrial-robots.com
Phone: [phone]
Email: [e-mail]
CVR: 35251235

MiR250 Technical Guide (en) 07/2020 - v.1.0 ©Copyright 2020: Mobile Industrial Robots A/S. 3
Table of contents
1. About this document 4
2. Robot sub-systems 5
2.1 Navigation and control system 5
2.2 Safety system 22
2.3 Motor and brake control system 39
3. Robot components 45
3.1 Safety laser scanners 45
3.2 3D cameras 50
3.3 Proximity sensor modules and indicator lights 54
3.4 Drive train 59
3.5 Power board 64
3.6 Safety contactors 66
3.7 Robot computer 70
3.8 Safety PLC 72
3.9 Router and access point 76

1. About this document
MiR250 Technical Guide (en) 07/2020 - v.1.0 ©Copyright 2020: Mobile Industrial Robots A/S. 4
1. About this document
This document describes the components, sub-systems, and connections in the MiR250
robot, providing an overview of how the robot works.
This guide is intended to be used to provide additional information regarding how MiR250
robots and their key components work. The guide focuses mainly on providing information
that may be used for troubleshooting the robot.

2. Robot sub-systems
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2. Robot sub-systems
The following sections describe these robot sub-systems:
•The navigation and control system determines the path the robot should follow to reach
its goal destination.
•The safety system monitors the robot's components and surroundings through several
functions and brings the robot to a stop if an unsafe situation occurs.
•The motor and brake system is part of the two previous systems and is used to either
move the robot along its path or to bring the robot to a stop.
2.1 Navigation and control system
The navigation and control system is responsible for driving the robot to a goal position
while avoiding obstacles.
System overview
The purpose of the navigation and control system is to guide the robot from one position on
a map to another position. The user provides the map and chooses the goal position the
robot must move to. The diagram in Figure 2.1 describes the processes in the navigation and
control system. The main processes involved in the navigation system are:
•Global planner
The navigation process starts with the global planner determining the best path for the
robot to get from its current position to the goal position. It plans the route to avoid walls
and structures on the map.
•Local planner
While the robot is following the path made by the global planner, the local planner
continuously guides the robot around detected obstacles that are not included on the
map.
•Obstacle detection
The safety laser scanners, 3D cameras, and proximity sensors are used to detect obstacles
in the work environment. These are used to prevent the robot from colliding with
obstacles.
•Localization
This process determines the robot's current position on the map based on input from the
motor encoders, inertial measurement unit(IMU), and safety laser scanners.

2. Robot sub-systems
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•Motor controller, motors, and brakes
The motor controller determines how much power each motor must receive to drive the
robot along the intended path safely. Once the robot reaches the goal position, the brakes
are engaged to stop the robot.
Each part of the process is described in greater detail in the following sections.
Figure 2.1. Flow chart of the navigation and robot system. The user provides the necessary input for the robot
to generate a path to the goal position. The robot executes the steps in the navigation loop until it reaches the
goal position and stops by engaging the brakes.

2. Robot sub-systems
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User input
To enable the robot to navigate autonomously, you must provide the following:
•A map of the area, either from a .png file or created with the robot using the mapping
function.
•A goal destination on that map.
•The current position of the robot on the map. This usually only needs to be provided when
a new map is activated.
Figure 2.2. On the map, the current position of the robot is identified by the robot icon , and the goal
destination is the robot position in this example. The robot computer now determines a path from the
current position to the goal position.
Once the robot computer has a map with the robot's current position and a goal destination,
it begins planning a route between the two positions on the map using the global planner.
Global planner
The global planner is an algorithm in the robot computer that generates a path to the goal
position.This path is known as the global path.

2. Robot sub-systems
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Figure 2.3. The global path is shown with the blue dotted line that leads from the start to the goal position.
The global path is created only at the start of a move action or if the robot has failed to
reach the goal position and needs to create a new path. The generated path only avoids the
obstacles the robot detected when the path was made and the obstacles marked on the map.
The global path can be seen in the robot interface as a dotted line from the robot's start
position to the goal position.
Figure 2.4. The dotted line from the start position of the robot to the goal position is the global path generated
by the robot computer.

2. Robot sub-systems
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Local planner
The local planner is used continuously while the robot is driving to guide it around obstacles
while still following the global path.
Figure 2.5. The global path is indicated with the dotted blue line. The local path is indicated with the blue arrow,
showing the robot driving around a dynamic obstacle.
Whereas the global planner creates a single path from start to finish, the local planner
continues to create new paths that adapt to the current position of the robot and the
obstacles around it. The local planner only processes the area that is immediately
surrounding the robot, using input from the robot sensors to avoid obstacles.
The local path is not displayed in the robot interfaces. The arrows in the
images here are visual aid used in this guide only.

2. Robot sub-systems
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Figure 2.6. The local planner usually follows the global planner, but as soon as an obstacle gets in the way, the
local planner determines which immediate path will get the robot around the obstacle. In this case, it will likely
choose the path indicated with a green arrow.
Once the local path is determined, the robot computer derives the desired rotational
velocity of each drive wheel to make the robot follow the local path, and sends the desired
velocities for each motor to the motor controllers—see Motor controller and motors on
page19.
Obstacle detection
The robot detects obstacles continuously while driving. This enables the robot to use the
local planner to drive around obstacles and to determine the robot's current position on the
map.
Three sensor types are responsible for detecting obstacles:
•The safety laser scanners
•The 3D cameras
•The proximity sensors
The following illustrations show how the robot sees the surrounding environment and how it
is portrayed in the robot interface.