AGV Safety Standards

Governing Standards

ISO 3691-4:2023

The dominant international standard. Updated from 2020 edition.

• Scope: Driverless industrial trucks and their systems. Covers AGVs, AMRs, and AGCs.
• Size: 82 pages, 6 sections, 5 annexes
• Status: Current edition. U.S. buyers increasingly demand ISO 3691-4 alignment over ANSI B56.5.
• Key requirement areas: Speed control, braking systems, personnel detection, operating zones, safety function performance levels

ANSI/ITSDF B56.5-2024

U.S. national standard. Updated 2024.

• Scope: Driverless automatic guided industrial vehicles and automated functions of manned industrial vehicles
• Covers: Design, operation, maintenance requirements
• Relationship to ISO 3691-4: ISO 3691-4 now dominates for intelligent mobile robots. B56.5 applies to the broader AGVS category. U.S. market is converging toward ISO 3691-4 for stricter provisions.

Key Technical Requirements

Detection Zones (Safety Laser Scanners)

Safety laser scanners create layered detection zones:

Zone	Trigger	Description
Warning field	Deceleration	Outer zone; vehicle slows
Safety/protective field	Full stop	Inner zone; vehicle stops
Monitored area	Combined	Total perimeter of detection

• Minimum clearance: 0.5m (19.7 inches) between AGV/load and external structures
• Protective fields must adapt to vehicle speed and load condition
• Scanner cost: ~$2,500-$3,500 each
• Field sets per scanner: 4 (standard) to 32+ (advanced models)
• Systems typically use at least 2-3 safety fields simultaneously

Speed Limits by Zone

Zone Condition	Maximum Speed
No laser detection coverage	0.3 m/s
Hazard zone with active scanner	1.2 m/s
Standard operating zone	2 m/s (typical maximum)
Restricted zone (ISO 3691-4 higher-speed exception)	Higher speed allowed with detailed hazard analysis and additional measures

Emergency Stop Requirements

• E-stop device required on every AGV
• Must be clearly visible, distinguishable, and accessible from any side
• Located within 600mm reach from any side of the vehicle
• Number and position determined by vehicle shape and dimensions

Bumper Requirements

• Mechanical bumpers cover areas not monitored by safety laser scanners
• Contact speed at bumper: maximum 0.3 m/s (18 m/min)
• Must safely stop vehicle within the bumper’s collapsible range

Braking Systems

• Must activate automatically on power supply interruption
• Must stop the truck within the operating range of the personnel detection zone
• Must function under all load conditions and gradients

Safety Function Performance Levels

ISO 3691-4 defines performance levels (PLd or higher) for key safety functions including:

• Personnel detection
• Speed monitoring
• Braking initiation
• Zone transitions

Compliance Responsibility Framework

ISO 3691-4 assigns shared responsibility:

• Manufacturer: Design and build to standard requirements
• Integrator: System design, hazard analysis, site-specific configuration
• Operator: Ongoing safe operation, maintenance, restricted zone access control

Practical Implications for Specifying

1. Confirm CE marking (Europe) or UL listing (U.S.) for the vehicle
2. Request ISO 3691-4:2023 compliance documentation from vendor
3. Site hazard analysis required before installation (integrator responsibility)
4. Restricted zone access controls (barriers, light curtains) are site scope, not vehicle scope
5. Safety scanner field sets must be configured per final layout - not pre-configurable from catalog