Vision metrology applied for configuration and displacement

Vision metrology using digital cameras has been used for accurately measuring the configurations of large industrial products such as ships, aircraft and automobiles. This paper refers to the application of this technique to measurement of engineering structures, mainly tunnels. Vision metrology is nearly established, but its use in civil engineering requires solution of numerous problems. A test was therefore conducted in an actual tunnel to verify its measurement accuracy for tunnel configurations to assess its applicability to convergence measurement in tunnels. The resulting measurements were as accurate as those obtained by Total Station instruments. This paper outlines the test and reports how the technique was applied to various objects on a trial basis.