A Symbolic Construction Work Flow Based on State Transition Analysis Using Simplified Primitive Static States

In this paper, a quantitative analysis method for a comprehensive work flow in construction work for identifying work states in more detail is proposed. The proposed method is based on analyzing state transitions of simplified primitive static states (s-PSS), which consist of four symbolic work states defined by using the on-off state of lever operations and manipulator loads. First, practical state transitions (PST), which are common and frequent transitions in arbitrary construction work, are defined on the basis of the transition rules, according to which an operation flag changes arbitrarily and a load flag changes only during a lever operation. Second, PST is notionally classified into essential (EST) and nonessential (NST) state transitions whose definitions change depending on the task phase, including reaching, contacting, loadworking, and releasing. Third, closed loops formed by EST represent work content and those formed by NST represent wasted movements. In work-analysis experiments using our instrumented setup, results indicated that all s-PSS definitely changes on the basis of PST under various experimental conditions and that work analysis using EST and NST easily reveals untrained tasks related to wasted movements.