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This paper presents a full research and development cycle of a vision-based system for long-term remote monitoring of civil engineering constructions. To measure displacements, the system analyzes reference mark position using a developed image processing algorithm. All computational operations are performed by FPGA to ensure high performance. The developed monitoring system has an accuracy of 0.45 mm (3 standard deviations) at the distance up to 50 m. The measurement error remains within this value even in harsh environments. The value of this paper is formed by the possibility of stable 24/7 monitoring in low-temperature conditions (up to C).

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Autocollimators (ACs) are primarily used for two-dimension measurement with small angle. A three-dimensional AC (3D-AC) with a large measurement range and capable of 3D angle measurement is proposed based on a modified cube corner reflector (MCCR). The MCCR structure is designed by establishing the space coordinate vector relation model between AC and the reflectors with the rotation relation of Euler space. A 3D-AC angle measurement equation for MCCR dimension angle recognition is established. Experiments demonstrate that the proposed 3D-AC model can be used for 3D measurement. The measurement range of 3D-AC is 10°, and the uncertainty values for the one-dimensional and combined angle measurements are (57.10″, 55.25″, 40.43″) and (394.16″, 455.36″, 319.57″), respectively.

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