Where Are Safety Mats, Safety Edges, and Safety Bumpers Used?
Typical applications, design tips, and compliance notes for pressure-sensitive protective devices in modern automation cells.
1) Quick definitions (so we’re talking about the same things)
- Safety mats (pressure-sensitive mats): floor sensors that trip when a person steps on a defined area to command a safe stop before contact.
- Safety edges (pressure-sensitive edges): deformable rubber profiles mounted on a moving edge (gates, AGVs, machine tables) that actuate after the documented force and displacement are reached. The resulting stop must keep travel and contact forces within acceptable limits.
- Safety bumpers: thicker, energy-absorbing versions of edges for higher inertia or larger stopping distances.
Standards context you’ll see in data sheets: ISO 13856 series (pressure-sensitive protective devices), ISO 13849 (control reliability/PL), ISO 13855 (positioning of safeguards), IEC 60204-1 (machine electrical).
2) Safety mat applications — presence before contact
- Robot cells & gantries: define stop/slow zones when optical devices struggle with glare/coolant.
- Press brakes & forming: defined foot-presence zones; validate the required machine-specific stop. A mat does not protect fingers at the tool or provide SS1/SS2 by itself.
- Packaging & palletizing: perimeter entry points where gates must stay open for flow.
- Assembly/test cells: quick to deploy and re-layout during line changeovers.
- Stage machinery (industrial class): keep -out zones near lifts and moving platforms under low light or smoke.
3) Safety edge applications — contact on a moving edge
- Automatic doors & shutters:bottom/vertical edges initiate a validated stop/reversal after actuation; verify remaining travel and force.
- Machine tables & moving guards:reduce a defined crushing risk only when actuation, stopping travel and force limits are validated.
- Conveyors & shuttles: front lip and side edges on pushers and transfer carts.
- AGVs/AMRs: perimeter edges provide contact-actuated stopping where force and travel are acceptable. Ordinary lidar/cameras are perception only; pre-contact personnel protection requires its own safety-rated function.
- Theater scenery (industrial builds):edges on moving set pieces for crew protection.
4) Safety bumper applications — high-energy zones
- Large AGVs & transfer carts: thick bumpers can provide compression travel and initiate a stop, but thickness alone does not establish acceptable contact forces.
- Heavy carriages & gantries: bumpers at ends/undersides where slow but massive impacts can occur.
- Automotive body shops: rotating fixtures and tight entrances that need longer usable overtravel.
- AS/RS systems: maintenance-aisle bumpers on shuttles and lifts.
5) Choosing between mat, edge, or bumper
| Question | Choose… | Why |
|---|---|---|
| Need presence detection before reaching the hazard? | Assess a mat | Detects a person stepping in; contact with the mat is required, but contact with the hazard is not. |
| Clearly defined moving edge may strike/pinch? | Edge | Initiates a stop after actuation; stopping travel and contact force must be verified. |
| High mass or non-negligible speed? | Assess a bumper | Evaluate documented overtravel and force limits; high mass alone does not prove suitability. |
| Optical sensors fail (steam, chips, glare)? | Mat | Not optically affected by glare, but steam, chips, loading and contamination still require environmental assessment. |
| Space extremely tight? | Edge | Low-profile device on the moving member. |
Many cells combine devices: e.g., lidar for warning + edge/bumper for contact stop; gate switch + mat at the operator station.
6) Integration & performance (what engineers check)
Safety control architecture
- Select a compatible documented sensor/controller combination and validate the complete function against required PLr (ISO 13849-1).
- Match the exact mat/edge circuit and controller diagnostics; dual channels or EDM alone do not establish PL d/e.
Stopping distance & placement
- For mats: position so a person cannot reach the hazard before safe state is achieved.
- For edges/bumpers: compare travel with travel, not time with distance. Determine movement during sensor/controller response and machine stopping, then verify the selected profile’s usable overtravel and force-displacement curve at the actual speed and contact geometry.
Environment & diagnostics
- Check IP rating, chemical resistance, temperature range; protect cables with sealed glands.
- Implement required short/open-circuit diagnostics with a compatible controller. HMI alarms are auxiliary information, not safety authority.
Reaction time budget
- Sensor response + cabling/relay + drive stop; consider worst-case AGV speed/gradient.
7) Application examples to validate
- Press brake (illustrative): assess a mat for a defined presence zone only; it does not by itself protect fingers at the tool. Validate the machine-specific guarding and stop function.
- AGV (illustrative): a documented safety-scanner function for pre-contact protection, with a bumper only where its verified overtravel and force limits suit the worst-case vehicle stop; no generic 50–100 mm allowance.
- Roll-up door: bottom edge stops/reverses on contact; side photoeyes add pre-contact detection.
- Robot cell: dual mats (operator panel & feeder zone) with local teach zoning.
8) Installation & maintenance checklist
- Mats: use beveled ramps; remove trip hazards; seal cable entries; follow the manufacturer and risk-assessment test intervals, including checks after installation or changes.
- Edges/ bumpers: mount rigidly for proper compression; verify actuation along the full length, including corners.
- Control system: validate the required stopping function and restart interlock. Implement external-device monitoring only through a documented compatible controller circuit where the design requires it.
- Records: keep PL calculations, layouts, and periodic test logs in the technical file.
9) FAQs
Can I use mats where pallets roll through?
Only if the exact mat is rated for the wheel load, contact pressure, traffic and environment. Pallet trucks or forklifts can damage a personnel-detection mat or create permanent actuation and blind areas. Obtain the manufacturer's approval for that loading and layout; ramps and cable protection alone do not establish suitability.
Do edges replace laser scanners on AGVs?
No. An edge or bumper is contact-actuated; a safety-rated scanner can provide a validated pre-contact protective function where correctly applied. Ordinary LiDAR or cameras are perception devices and must not be credited as personnel protection. Select the required combination from the mobile machine risk assessment, stopping distance and allowable contact-force limits.
How long do mats last?
Use the exact manufacturer's operating-life and environmental limits, inspection procedure and replacement criteria. There is no universal millions-of-operations guarantee. Check damage, actuation across the sensing area, cable faults, controller response and restart prevention at the specified intervals and after relevant changes.
Source and application limits
ISO 13856-1 addresses pressure-sensitive mats/floors; its scope leaves sensing-area layout and suitability application-specific. Mayser bumper documentation illustrates profile-specific designs, while the Rockwell mat-controller manual shows model-specific reset and integration circuits. These sources explain design principles, not compatibility with JT14 or DA31; obtain the corresponding manufacturer manuals.