Page - 56 - in Joint Austrian Computer Vision and Robotics Workshop 2020

Modification dimension Product Position during collaboration - end effector height Robot velocity Resource allocation trestle feed Resource allocation insert screw Resource allocation tighten screw Safety function Type of safety device for distance monitoring Position of safety device for distance monitoring Safety function Type of safety device for distance monitoring Position of safety device for distance monitoring Parameter value A A&BB hmin ≤ hcol ≤ hmax vmin ≤ vrob ≤ vmax by UR10 from feeder by UR10 from conveyor belt human screwdriver UR10 CHIMERA human screwdriver UR3 force limitation distance monitoring dsafe≥dsafe< force limitation distance monitoring dsafe≥dsafe< human safety fence light curtain laser scanner software CHIMERA laser safety mat light curtain laser scanner software CHIMERA laser Position during collaboration - robot base pmin ≤ pbase ≤ pmax Table1. Morphologicalbox indicating modificationdimensions in the labusecase. solutionsareaggregatedinasocalledMorphological Box (MB) representing specific attributes and their individual characteristics. This multi-dimensional matrixmapsallpossible solutionsbycombiningone characteristic for eachattribute. WiththeassistanceofaMB,afar-reachingriskas- sessment can be carried out to clarify whether a new risk assessment (or even a new risk estimation) must be carried out when modifying the robot system. To be able to make this decision, a distinction must be made between changes that have been considered in advanceandchanges thathavenotyetbeenassessed. Onepossibilityforaconsideredchangecanbe, for example, the storage area, which was defined in ad- vance as an area and does not focus on the required storagepointas is traditionally thecase. Thisenables the MB to check whether the changed placement point iswithin thesedefined limitsbycomparingco- ordinatesandtoprovidetheoperatorwithclear infor- mationas towhetheranewriskassessment isneces- sary. The maximum safe speed can be used as a fur- ther example. During the application definition, the considered speed is not the one required for the pro- cess, but the maximum safe speed. This has the ad- vantage thatachangecanbeevaluatedusing theMB withtheadditionalparameters thatarenowavailable. These two examples show, that already during plan- ning and integration the safety assessment must be implemented in the process via the MB to be able to make practical comparisons in everyday life. Fur- thermore, it becomes apparent that simple changes canbeclarifiedclearlyandefficiently,whereascom- plex changes require a thorough examination using mathematical models that support the MB. An ex- ample with a much higher degree of complexity is the change of a possible contact point between hu- mans and robots. These must be verified and vali- datedinaccordancewithISO/TS15066:2016point6 or tested and measured in accordance with EN ISO 10218-2:2012AnnexG. Due to the complexity of such changes, the MB can be used to conclude that a new risk assessment is required. During such a reassessment, the MB can provide support by showing specific dependen- cies that need to be considered for the reassessment in the risk assessment, e.g. the system limits of the gripping technology, the change in the permissible force/pressure values due to the shifting of the con- tact between human and machine. When using the MB, such restrictions can only be prevented by de- termining all relevant modifications in the planning phase tocover thebroadestpossible range. In this sense, the MB presented in this paper in- dicatesdesiredandpossiblemodificationdimensions foraspecificusecase. Here, themodificationdimen- sionsrepresent theattributeswhile theparameterval- ues represent the characteristics. By combining spe- cific parameter values for each modification dimen- sion, different system variants of the use case can be defined. In contrast to conventional morphological 56