Integrating Function Allocation and Operational Event Sequence Diagrams to Support Human-Robot Coordination: Case Study of a Robotic Date Thinning System

Abstract

State-of-the-art robots show promise in supporting but not completely replacing human work in most precision agriculture applications. For many potential agricultural robot applications, there are no comparable systems nor readily available information on the human operator activities to guide the systems engineering process. Such is the situation for Medjool date thinning, a tedious and hazardous manual operation for which technological assistance has yet to be developed. Here we describe using cognitive system engineering methods to develop operational concepts and human-robot coordination requirements for a pioneer system, a Robotic Medjool Date Thinning System (RDTS). We leveraged the abstraction hierarchy to characterize the RDTS’s envisioned goals and functionality. We developed alternative functional allocations to explore the design space based on the availability of different enabling technologies. After downselecting to the function allocation, including the technologies expected to be developed, we created operational event sequence diagrams to visualize the operation flow and to identify requirements related to the human operator and the joint human-robot system. Applying these methods in the early design stages helped to refine the human-robot coordination requirements and to identify gaps in the operational concept—they show great potential to support the introduction of agricultural robots and bring them to fruition.