Hisashi Onari

FAST SCHEDULING SCHEME FOR ON-LINE PRODUCTION CONTROL.

A real-time scheduling on a shop floor control mini-computer is more important in a FMS than in a conventional shop to deal with a dynamic environment of jobs and processes. Since a scheduling is a typical NP complete problem, a two stage heuristic algorithm is adopted for a good (near optimal) solution with a short processing time.

Development of a Flexible Assembly Center

The authors created a flexible assembly center that can be organized to meet the needs of various assembly operations. For this, a precision autonomous robot that does not require a teaching process was developed. The flexible assembly center is composed of multiple table robots, arm robots, and part/tool feeders, and has the following characteristics : (1) Complicated operations can be performed by using the flexible arm and table setup. (2) The positioning accuracy necessary for precision assembly can be maintained through the use of direct drive mechanisms and auto-calibration, without requiring a teaching process. (3) Precise operation can be accomplished autonomously by real-time control with visual and force sensor feedback. This system is particularly effective for production systems involving frequent setup changes.