Comprehensive state transition analysis using simplified primitive static states in construction machinery

This paper proposes an analysis method for a comprehensive work flow in construction work for identifying work states in more detail on the basis of analyzing state transitions of simplified primitive static states (s-PSS), which consist of four symbolic work states defined by using on-off state of the lever operations and manipulator loads. First, practical state transitions (PST), which are common and frequent transitions in arbitrary construction work, can be defined on the basis of the transition rules, according to which an operation flag changes arbitrary and load flag only changes during a lever operation. Second, PST can be classified into essential (EST) or nonessential state transitions (NST), and NST changes its definition depending on the task phase. Third, EST and NST represent work contents and wasted movements, respectively, so work-analysis experiments using our instrumented setup were conducted. Results indicate that all the 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.