Deformation analysis apparatus

A deformation analysis apparatus comprising:

• a plurality of sensors that are installed at a measurement target object, each sensor detecting a physical quantity acting on an installation position, and the plurality of sensors being installed such that a relative distance is changed between installation positions of at least two adjacently installed sensors by deformation of the measurement target object;
• and
• a processor programmed to function as:
• a measurement unit that, when deformation has occurred in the measurement target object, measures for each of plural specific periods of time at least one of 3D coordinate values or rotation angles of the respective installation positions of the plurality of sensors based on the physical quantity detected by each of the plurality of sensors;
• an interpolation unit that interpolates at least one of 3D coordinate values or rotation angles, for each of the specific periods of time, at each interpolation position on line segments that connect adjacently installed sensors, based on the at least one of 3D coordinate values or rotation angles of the respective installation positions of the plurality of sensors measured at each of the specific periods of time by the measurement unit;
• a distance estimation unit that estimates relative distances between the adjacently installed sensors at each of the specific periods of time by:
• computing 3D coordinate values of installation positions of the sensors based on a candidate value of the relative distances between the adjacently installed sensors based on:
• (i) the at least one of 3D coordinate values or rotation angles of the respective installation positions of the plurality of sensors measured at each of the specific periods of time by the measurement unit, and (ii) the at least one of 3D coordinate values or rotation angles of each of the interpolation positions on line segments that connect sensors interpolated at each of the specific periods of time by the interpolation unit,
• comparing the calculated 3D coordinate values against the 3D coordinate values of the installation positions of the sensors measured by the measurement unit, and
• performing the computing and comparing steps by repeatedly updating the candidate value for relative distances between the sensors;
• a coordinate computation unit configured to:
• compute 3D coordinate values of each position corresponding to a 3D shape of the measurement target object at each of the specific periods of time based on:
• the at least one of 3D coordinate values or rotation angles of the respective installation positions of the plurality of sensors measured at each of the specific periods of time by the measurement unit,
• the at least one of 3D coordinate values or rotation angles of each of the interpolation positions on line segments that connect sensors interpolated at each of the specific periods of time by the interpolation unit, and
• relative distances between the adjacently installed sensors that is:
• along a deformed shape of the measurement target object, or estimated at each of the specific periods of time by the distance estimation unit;
• and
• compare the computed 3D coordinate values to the measured 3D coordinate values to determine a difference;
• when the determined difference is larger than a specific error:
• (a) increase the candidate value in response to the computed 3D coordinate value being smaller than the measured 3D coordinate value, and (b) decrease the candidate value in response to the computed 3D coordinate value being larger than the measured 3D coordinate value, such that the difference is less than the specific error after changing the candidate value;
• and
• an output unit for outputting the computed 3D coordinate values of each position corresponding to a 3D shape of the measurement target object at each of the specific periods of time.