Method and apparatus for controlling lift of a structural object

Apparatus for controlling the lift of at least one large structural object so as to be easily moved in horizontal direction while maintaining the bottom plate of the object horizontal, comprising: a plurality of air-casters each of which has a torus bag; piping for feeding compressed air into the air-caster; flow control valve installed in the piping; a pressure gauge installed in each air-caster for measuring an inner pressure of the torus bag; a lift distance measuring gauge installed in each air-caster for measuring the lifted distance of the air-caster; and a data processing unit for receiving pressure data measured by the pressure gauge and lift distance data measured by the lifted distance measuring gauge and sending a valve opening control signal to the flow control valve based on the pressure data and/or lifted distance data.