Explanation of R15.08 - Safety Standard for Autonomous Mobile Robots (AMR)

Imagine that you wish to mount an industrial robot arm to an AGV. Which safety standard should you apply? R15.06, because it has an industrial robot arm, or B56.5 because it's mounted to an AGV?

 

What is ANSI/RIA R15.08-1-2020? Safety standard for AMR

  

The R15.08 defines is the safety standards for Industrial Mobile Robots (IMR, also known as AMR.  The arrival of the Autonomous Mobile Robots (AMR), with their advanced natural navigation able to bypass obstacles by autonomously redefining new guidepaths, have raised new challenges related to safety requirements of mobile robots.

  

Moreover, AMRs are usually provided with tools such conveyors, fixed totes or more advanced robotics arms that increase the robotic system complexity.

 

On one hand, we had the R15.06 defining safety requirements for fixed industrial robots. On the other hand, we had B56.5 safety standard for Automatic Guided Vehicles.

 

It was necessary to create a standard able to assess the new risks related to these cutting-edge vehicles and their systems.

  

So, the Robotic Industrial Association (RIA) has issued the R15.08-20 part I, the safety standards for industrial mobile robots.

 

The ASI/RIA r15.08-1-2020 defines the safety requirements for Industrial Mobile Robots (IMR) and their attachments (rollers, manipulators, etc).

  

This R15.08 Part 1 is meant for the manufacturer of the industrial mobile robot, and what safety requirements the industrial mobile robot must meet. It indicates how to design and manufacture a safe IMR.

 

Every new AMR must be designed with a relevant Risk Assessment analysis. Discover SICK guys  explaining how to perform a risk assessment for AMRs/AGVs, what are the latest SICK solutions, etc. Absolutely... a MUST watch!

 

   

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The RIA committee is now working on Part 2 (to be published). Part 2 will specify the safety requirements for mobile robots (or fleets of mobile robots) installed in particular conditions.

 

For example, Part 2 should indicate the mobile robot admissible speed depending on the presence of safety sensors and escape clearance for operators.

 

With Part 1 you will have a safe robot, with Part 2 you will have a safe robot professionally installed in a given working environment.

  

After Parts 1 and 2, Part 3 will describe the user responsibilities for safe operation of the mobile robots and their systems.

 

 

  

The R15.08-1-2020 is a 122-page document that explains in detail these topics related to IMR safety:

 

• Scope
• Normative references
• Terms and definitions
• Hazard identification and risk assessment
• Design requirements and risk reduction measures
• Verification and validation of risk reduction measures
• Information for use and markings (labels)
• Annex A — (informative) List of significant hazards
• Annex B — (informative) Different types of IMR
• Annex C — (normative) Parameters and thresholds for determining required safety function performance
• Annex D — (normative) Verification and validation
• Annex E — (informative) Illustrations of spaces and zones
• Annex F — (normative) Stability tests
• Bibliography

  

Of course, if you are manufacturing or considering the possibility of manufacturing your own mobile robot, you should have and understand all these standards.

   

What is the ASI/RIA R15.08 price? 

   

The R15.08 costs $220. You can buy it in the American National Standards Institute (ANSI) webstore:

     

  

This article will explain some the most relevant elements of the R15.08

  

Table of Contents

  

• What kind of mobile robots are the scope of the R15.08?
• What are the types of IMR (Industrial Mobile Robots)?
• Hazard identification and risk assessment (chapter 4)
• Design requirements and risk reduction measures (chapter 5)
• Verification and validation of risk reduction measures (chapter 6)
• Information for use and markings (chapter 7)

   

What kind of mobile robots are the scope of the R15.08?

  

The R15.08 classifies Industrial Mobile Robots (IMR) into three categories Type A, Type B and Type C (be patient, we'll explain the later on  )

 

There are 5 elements to be taken into consideration for classifying the IMRs and to know if your robot should be under this standard.

  

1. Application of the IMR

 

The application must be “industrial”. R15.08 is applicable only to robots in the workplace, and the safety of the “safety trained” people who work around or near those robots. Industrial means factories, warehouses, laboratories, etc.

 

The R15.08 does not cover some AMRs intended for consumer or household use; undersea, military and space robots; or medical, surgical, or rehabilitative mobile robots.

 

This standard is not applicable in environments with the untrained public because their behavior is not predictable and do not know how to behave in case of emergency.

 

2. Mobility

 

Mobile refers to ground-based systems able to navigate autonomously.  Airborne systems (drones, for example) or waterborne and rails systems are out of the R15.08 scope.

 

3. Navigation

 

Industrial mobile robots can navigate to meet a specific destination. The navigation could be autonomous, automated or both. So, both AMRs and AGVs could be affected by this standard.

 

Note: AGVs are only covered by the R15.08 if they have a robotic manipulator attached, otherwise AGVS are covered by B56.5 (we will point this out later).

  

The main difference between Autonomous Mobile Robots (AMR) and Automated Guided Vehicles (AGV) is the way they run in a defined working environment.

  

An AGV navigates automatically along given paths (physical or virtual). AGVs stick to that path and cannot abandon it. In the case that the AGV safety sensors detect an obstacle, the AGV stops and waits for the obstacle to be removed.

  

An AMR navigates autonomously, so it can follow a guidepath but can also decide different paths. In the case that the AMR safety sensors detect an obstacle, the AMR can get around the obstacle by defining a new path rather than remain stopped, waiting for the obstacle to be removed.

  

The following articles will help you to understand better the differences between AGVs and AMRs

 

AGV vs AMR. What should you buy? Differences? Pros & Cons? - Who is the winner?

What is an AMR Robot? The autonomous revolution is here

What is an AGV? All the answers in one shot

  

4. Inclusion of a manipulator

 

 An IMR could include manipulator... or not. 

 

5. The presence of addition of other attachments (conveyors, etc)

  

An IMR could include an attachment... or not. 

  

 

 

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What are the types of IMR (Industrial Mobile Robots)?

  

The R15.08 identifies three different types of IMRs: Type A, Type B, and Type C.

 

It is important to realize that an AMR is not different from an IMR, but it is only one type IMR.

 

• Type A and Type B have an AMR as mobile platform

 

• Type C might use an AMR mobile platform or could use and AGV instead.

  

For this reason, the R15.08 talks about not only AMRs but IMRs as well. There is also one type (the Type C) that uses an AGV and not an AMR.

 

This diagram will help you to better understand the different types of IMRs.

 

You can find this diagram with further details in the R15.08 

  

What is an IMR Type A?

An IMR Type A is the most basic type of Autonomous Mobile Robot (AMR) without any attachment.

 

Here you have an example:

  

 

 

 

What is an IMR Type B?

An IMR Type B is composed by an IMR Type A plus an active or passive attachment such us conveyors, roller tables, lifting devices, fix totes, etc. (excluding manipulators).

 

This is an IMR Type B, so an AMR with a lifting device to transport totes:

  

 

 

  

AMRs by Wellwit Robotics. Click here to discover more

 

What is an IMR Type C?

   

An IMR Type C, is an AMR or AGV base with a robotic manipulator. For example, this one:

  

 

 

  

  AMRs by Wellwit Robotics. Click here to discover more

  

There are other types of mobile robots that are out of the scope of the R15.08, for example:

 

• Mobile robots or vehicles able to transport one or more riders. 

 

• Automated or autonomous forklifts, low-lift and high-lift fork trucks are covered by B56.5. For example, this kind of vehicle:

 

  

 

   

AMRs by Wellwit Robotics. Click here to discover more

  

• Autonomous robots not intended for industrial applications. For example, this UV Disinfection Autonomous Robot:

  

If you wish to know more about the B56.5 and the Safety Systems for AGVs, you can download our whitepaper. 

     

Click here to download the whitepaper

   

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Hazard identification and risk assessment (chapter 4)

In the R15.08 Annex A contains a list of hazards that could arise in an IMR.

  

Same as other machines, it is necessary to:

  

• Perform a hazard analysis to identify potential hazards

  

• Perform a risk assessment to eliminate or reduce those hazards

  

The chapter 4 provides several key elements to be taken into consideration. For example:

  

What happens in case of:

 

• Unexpected loss of power
• Unexpected start-up

 

In this chapter, you will also find an iterative risk reduction process that will help you make your robot as safe as possible.

 

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Design requirements and risk reduction measures (chapter 5)

 

Of course, this is “biggest” chapter, it deserves 27 pages.

 

These requirements are intended for the manufacturers of IMRs Type A; attachments for IMRs; and IMRs Type B and Type C.

 

Depending on the hazard identification and risk assessment result, it is necessary to implement different measures to have a safe IMR.

 

This chapter explores several topics for each type of IMR.

 

General requirements for IMRs and attachments

 

• General

 

• Conformity with other standards

  

Depending on the IMT Type, indicates the relationship with the ANSI/ITSDF B56.5 or ISO 3691-4 and ANSI/RIA R15.06,

  

Which one should be applied?

  

• Modes of operation
  • General requirements for modes of operation
  • Automatic mode
  • Semi-automatic and/or assisted manual mode
  • Manual mode
  • Maintenance mode
  • Selection of mode of operation

                     

The standard defines and explains the safety requirements for different operating modes and their selection mode.

  

• Portable control unit

 

• Control functions
  • Restart functions
  • Emergency stop function
  • Protective stop function

  

We must consider different control functions; how do the robot behave and what elements are needed for the above functions?

   

• Stopping distance

  

Just as described in the B56.5 for AGVs, the stopping distance depends on the speed, the maximum rated load and the working environment.

  

The stopping distance for an IMR running fast with 2,000 lbs load running on a wet surface should be much higher than the stopping distance for an IMR running slow with 500 lbs on a dry surface.

  

 

 

Everything is related to the primary risk assessment procedure.

 

• Navigation and control
  • General requirements for navigation functions
  • Collision avoidance
  • Velocity limiting
  • Collision avoidance
  • Velocity limiting

 

With AMRs, navigation can be understood as a safety feature. AMRs can recalculate their trajectory for different reasons. For example: obstacle avoidance.

  

The AMR detects the obstacle and, based on environmental information, decides to change its guidepath with a new trajectory.

  

Such trajectory re-planning shall not introduce new hazards.

  

• Presence-sensing devices
  • General requirements for presence-sensing devices
  • Non-contact presence-sensing devices
  • Contact presence-sensing devices
  • Suspended or variable presence-sensing
  • Safety distances

  

This point indicates the specifications that contact (for example bumpers) or non-contact (for example safety scanners) must comply with.

  

• Working space and stow configurations
  • IMR working space
  • Stow configurations

  

• Movement without drive and/or system power

  

• Safety-related parts of control systems
  • General requirements for safety-related parts of control systems
  • Performance requirements
  • Safety function inputs and outputs (Safety I/O)

  

• Indicators and warning devices
  • General requirements for warning devices
  • Activation of IMR indicators

  

• Interface requirements
  • Wired communication interface
  • Cableless (wireless) communication interface
  • Electrical and fluid power energy interfaces
  • Mounting points

  

• Rated capacity
  • General requirements for rated capacity

  

• Stability & center of mass
  • Stability requirements
  • Static stability
  • Dynamic stability

  

• Energy control
  • Electrical equipment
  • Power loss or variation
  • Electromagnetic compatibility (EMC)
  • Hazardous energy control
  • Hazardous stored energy

  

• Hazardous mechanical power transmission components

  

• Guidance for IMRs intended to operate as part of a fleet

  

What happens if you have a fleet of IMRs connected to a management software? This point indicates what information should be exchanged and available in the fleet management software.

  

For example, an IMR should communicate any necessary information to the fleet manager to allow the fleet manager to determine if IMR is compliant with the fleet management. In a case where the IMR is not compliant, the IMR must remain inactivated.

  

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Verification and validation of risk reduction measures (chapter 6)

  

This chapter explains what types of verifications and validations of design and manufacture the manufacturer must comply with, in order to minimize risks.

  

• Verification and validation: Methods and requirements

  

Depending on the risk assessment analysis, the verification and validation must be performed upon different criteria such us visual inspection, measurement, etc.

   

The Annex D lists specific requirements that are identified as essential to the safety of the robot.

  

For example:

  

“Stopping distance has been determined by maximum rated load, velocity and specified operating environment.”

  

Requires: practical tests, measurement, review of application-specific schematics, circuit diagrams, design material and review of task-based risk assessment.

  

• Test pieces

  

Functional safety tests must be performed using appropriate pieces in accordance with sensors capabilities.

  

This point describes how should testing pieces be following different criteria. For example, in case they represent an adult human, so human-analog, they must be analysed under a variety of orientations (standing, sitting, kneeling, or lying prone).

  

Regarding non-human test pieces, we could find overhanging objects, negative obstacles, transparent objects, etc.

  

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Information for use and markings (chapter 7)

 

IMR’s Information for use shall contain all information and instructions necessary to ensure safe and correct use of the IMR and shall provide information and warnings to the user about any residual risks.

  

The information for use of the IMR shall be in accordance with the requirements of ANSI/ISO 12100 or ANSI B11.0.

  

This chapter describes into detail all the necessary documentation to ensure IMR safety standards:

  

• Information for operation and maintenance of machinery

  

• Marking
  • Safety signs and labels
  • Nameplate 

  

• Description of the specified operating environment

  

• General requirements for deployment

  

The IMR manufacturer must indicate how should the operating environment be to perform safely. 

  

For example, it is necessary to indicate if additional safeguards and under what conditions.

  

• Travel surface
  • Roughness
  • Coefficient of friction
  • Maximum permissible incline grade

  

• Environmental conditions
  • Brightness for obstacle avoidance and navigation functionality
  • Restrictions on interference from electrical sources
  • Maximum permissible ambient noise

  

• Requirements for obstacle avoidance

  

• Environmental stability

  

In case the IMR uses mapping function for navigation (SLAM, for example), it is necessary to provide information about the environmental stability to allow the IMR navigate properly.

  

For example, it is necessary to indicate:

   

• Frequency of map updates and/or remapping
• Percentage of changes to the environment that can be supported before requiring a new remapping
• Map quality

  

This point is crucial for Autonomous Navigation. AMRs maps the environment first and matches the theorical map with what it is seeing while navigating.

   

What happens if something does not match? What is the acceptable gap between theorical and real?

  

 

 

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As you can see ANSI and RIA people have made a great job to define the requirements and rules for safe IMRs. There's a lot to know and to do but it is mandatory to ensure a safe vehicle. 

  

More and more customers will ask you to comply with the R15.08. It will become a must and a competitive advantage.

  

 

 

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Keep on learning! More related articles:

   

Mobile Robot Sensors – The eyes and ears of mobile robots

Automated Guided Vehicles Safety Rules 

Autonomous mobile robots applications? - Autonomous navigation allows huge flexibility and incredible new applications