SUMMARY

Within manufacturing and construction environments, precise positioning of heavy payloads is typically achieved through a combination of gross control via crane and fine control using taglines and push-pull sticks in the hands of the ground team. When engaging in hands-free payload manipulation, failure to follow proper communication and safety protocols can result in severe injury and even fatality. When the crane operator’s view of the payload is partially/fully obstructed, current approaches rely on verbal communication through radios or a signal person to relay commands to the crane operator via hand signals. Radio communication can be subject to delays and hand signals require the crane operator to have a clear view of the signal person. To address these challenges, we propose a new paradigm for collaborative communication between crane operators and the ground team that incorporates force and motion sensing into existing push-pull devices so that relevant information is reliably relayed to the crane operator. To accomplish this, an observer processes sensor data to estimate the crane cable angle and force on the payload. These estimates are then used to create a visual representation of the current system state using a digital display. Communication via display offers the unique advantage of safe remote operation when the crane operator’s view is fully obstructed. A basic assembly task requiring a team to maneuver and place a payload in an aluminum box was used to test our communication protocol against traditional verbal communication. Each team consisted of a crane operator and ground team member equipped with our push-pull device. Teams completed an equal number of trials using our control paradigm and an established verbal communication method. Results show statistically equivalent impulses for both methods; however, the temporal performance of the verbal method was better than that of the nonverbal method.