Optimal Base Placement of a 6-DOFs Robot to Cover Essential Activities of Daily Living

Abstract

The number of individuals with upper or lower extremities dysfunction (ULED) has considerably increased in the past decades resulting in a high economic burden for the families and society. Individuals with ULEDs require assistive robots to fulfill all their activities of daily living (ADLs). Thus, this research presents an objective function for base placement optimization of assistive robots to increase the workspace required to fulfill ADLs (workspace coverage). The workspace coverage was determined using the xArm 6 robot and experimenting with different ADLs. Also, an object collision algorithm is implemented to avoid collisions between the robot and the user within the workspace. Moreover, the algorithm determines the existence of singularities within the workspace by computing the manipulability index. However, since the manipulability index computation depends on the Jacobian matrix’s eigenvalues yielding incongruences in the units, we divided the Jacobian matrix into two parts; one for the angular and another for the linear velocity. Finally, using the objective function with a genetic algorithm (GA), the optimal base placement for the robot is obtained and validated experimentally.