The risk assessment according to EN ISO 13849-1 can be used to assess the hazardous situation and, therefore, the requirements for the safety system. The minimum distance between the safety device and the danger zone is calculated with the EN ISO 13855 standard. This dimension is important to be able to define the maximum range the light barrier must monitor. It should be noted that different speeds of approach apply to the different degrees of protection (person, hand, or finger).
A close-meshed light curtain with a resolution of 30 mm was chosen as the safety device for the hexapod and it was assumed that the required stopping distance was 3 mm at a motion velocity of the hexapod of 100 mm/s.
Using the following formula, which is valid for light curtains with a resolution of < 40 mm, a safety distance of 316 mm can be calculated: