Subchapter 3.10
Safe use of mobile autonomous machinery
AGVs (automatic guided vehicles) and AMRs (autonomous mobile robots) are conquering both warehouse and production environments. Though equipped with smart safety sensing their operation may cause some safety issues particularly in “brownfield” settings. Find out which on-site measures can enhance safety.
Function and safety aspects of IMRs
More recently, AGVs and AMRs have been referred to collectively as industrial mobile robots (IMR).
They can transport many different types of storage units. They may lift, carry and move pallets, entire racks or even very large unit loads but are more likely to be used for boxes, bins and totes.
IMRs feature presence-sensors that will prevent accidents. The vehicles generally move slowly in areas roamed by people and stop when they encounter obstacles or people in their path. Nonetheless, there are some safety concerns, because presence-sensing has its limitations and the operating environment may result in additional risk.
Achieving safety of IMR applications
Typical hazards and possible safety measures that help cope with them
- Crushing and shearing with adjacent equipment in locations with limited travelling space (racking, narrow aisles, machinery, parts of a building, doorways/gates simultaneously used by people)
Safety measure: Limit people’s access to the “playground” roamed by the vehicles, especially where they operate in swarms. Use fencing, or pedestrian barriers to separate people and drive passages. - Crushing and shearing during load transfer, docking and at charging stations
Safety measure: Clearly define, indicate and demarcate such areas by installing pedestrian barriers or lower “awareness” barriers to alert people to areas they should not enter. Use guard fencing for high-risk areas. - Accidents caused by IMRs leaving their designated operating area. Some IMRs are small and can pass underneath equipment and fencing. They may drop into openings in the floor or topple down stairs.
Safety measure: Use footrails or no gap guard fencing, install floor-mounted barriers that can be detected by the IMRs to keep them out of hazard spots. - Trapping of people by failing IMRs in narrow aisles or escape routes. In a failure situation large AGVs can block exit from an area.
Safety measure: Carefully analyze the risks and plan escape routes that cannot be entered by the vehicles.
For more information see chapter 4.0 Automated Warehouses
