Robot/Human Interaction: A Challenge for Job Design

This paper describes now a job involving robot/human interaction was designed to ensure a safe, efficient and productive workplace, and worker satisfaction with the human contribution to the job.

The job, which lasts about 4 hours, involves handling, sampling, dismantling, and visually inspecting containers of toxic materials. The job design was carried out in five phases.

1. Analysis of the requirements and hazards of each phase of the job and of the relative capabilities of the robot and of the human operator.

2. Allocation of tasks to the operator and the robot based on both the hazards involved and on the relative capabilities of each. All contact with the toxic materials and all tasks that could be preprogrammed were allocated to the robot. The operator was assigned all functions beyond the robot capabilities; for example, visual inspection for unknown debris and positioning fine alignments at locations that could not be predetermined. In addition, the operator will remain vigilant during all periods of robot activity, overseeing what the robot does and ready to take active control of the robot should it encounter anything beyond its scope.

3. Time study. A detailed time line analysis of the robot and human task sequence showed that human activity fell into three distinct peak periods with long periods of monitoring in between.

4. Workload estimation. One operator was estimated to be able to handle all human functions so that one operator per robot would comprise an efficient “team.”

5. Increasing operator vigilance. Operator boredom and inattention could be a very probable and potentially serious problem during the long monitoring. Operators might not be ready to actively enter the control loop to perform their pre-assigned alignment and visual inspection tasks. Or they might not notice the beginning of any possible robot mishap and might not take active control as soon as they should. Further steps were therefore taken in the job design to increase operator vigilance. First, a dynamic time display with appropriate auditory warning signals will give operators information about their approaching planned entry into the control loop. Second, it was assumed that operators' attention would wander and that the job should therefore be designed to make it easier for them to cognitively “find their way back.” Computer-generated graphics will therefore continuously display the robot's previous, present, and next major task steps in addition to the operator being able to see via closed-circuit TV what the robot is doing. Last, operator opinion will be sougnt and used for further ways to make the vigilance tasks less tedious and more meaningful to the operators themselves.