Risk-Aware Decision Making for Human–Robot Collaboration With Effective Communication

Human-robot collaboration is crucial for integrating robots into intelligent manufacturing (IM). However, a significant challenge is rational decision-making for the human-cyber-physical system (HCPS) in IM to enhance cognitive limits of human operators and overcome the potential irrationality. Since humans dominate the collaboration in IM, it is essential to address two critical issues: determining the next task for the robot and deciding whether the human operator should be informed. We propose a risk-aware decision-making framework for task allocation and human-robot interaction (HRI) to achieve a balance between the autonomy level of the human operator and task efficiency. To quantify the efficiency risk, we utilize conditional value-at-risk (CVaR) considering the uncertainty of human operators. We then obtain the optimal task allocation and selection for the robot by minimizing the efficiency risk. We also establish a necessary collection of tasks that must be performed by the human operator. Furthermore, we develop two criteria to quantify the necessity of explicit HRI. Experiments with a real mechanical arm platform demonstrate that our methods can enhance human-robot collaboration (HRC), reduce the need for extensive communication, and grant human operators greater execution freedom.
Note to Practitioners
—This research is motivated by the fact that the imperfect information sharing between human operators and robots in IM. It results in the inability of human operators to accurately comprehend the robot’s capability constraints and the robot’s limitations in perceiving the current or next action of the human operator. As a result, the effectiveness of HRC then inevitably decreases. Our proposed method introduces the efficiency risk to quantify the need of robot active intervention in HCPS. This approach aids in determining when and what to communicate with the human operator, thereby empirically ensuring efficiency and providing the human operator with a greater degree of freedom. Experimental studies suggest that the efficiency risk can serve as a new metric for balancing the amount of human-robot communication and the improvement of efficiency. Our research can also find utility in human-centric scenarios where communication between the human operator and the robot is constrained or costly.