Development of a small-size laser triangulation displacement sensor and temperature drift compensation method

Abstract

In practical applications, some special working scenarios need to take into account both narrow space and extreme temperature, which puts more strict requirements on the size and temperature adaptability of the laser triangulation displacement sensor (LTDS). In this paper, a small-size LTDS was developed and the measurement error caused by temperature drift of the sensor was corrected. Firstly, based on direct projection laser triangulation imaging with a reflector unit, a mathematical model of the compact geometry optical structure was established; then, an optimization process of the optical parameters was formulated, and the sensor was assembled. Secondly, a temperature drift error database was built by an extreme temperature experiment, and a general regression neural network model was constructed for error compensation. In addition, root mean square error and execution time were used to evaluate and compare different regression methods. Finally, the experimental results showed that the repeatability accuracy of the proposed sensor was ±2.3 µm, and the temperature linearity was 0.001% F.S. • C −1 .

Amplitude modulated feed-forward thermal drift compensation for linear and nonlinear current sensors

“…Some popular regression-based temperature error compensation schemes are discussed in the literature. In [29], a laser triangulation displacement sensor is discussed with an optimized design with a temperaturerelated error compensation scheme using regression models. This nonlinear temperature response is considered to develop a suitable error-correcting term as required in equation (11).…”

Uncertainty analysis and optimization design of long-distance laser triangulation displacement sensor applied to dynamic object

“…Temperature is the primary cause of changes in the refractive index of a medium, especially in extreme temperature environments. Reference [22] conducted extreme temperature drift experiments on the laser triangulation displacement sensor in a high-low temperature chamber. When the temperature increased from -10℃ to 40℃, the beam drifting error can be 141.36μm under the working distance of 37mm.…”

Research on laser spot location accuracy of low-power laser diode source applied to high precision laser measurement system

“…Where σ was the standard deviation of Gaussian function, which controlled the smoothing effect. The Gaussian distribution filter kernel of size 3 × 3 H 3 × 3 or filter kernel of size 5 × 5 H 5 × 5 were selected for filtering as shown in equation (3). Where the filter kernel of size 5 × 5 was applied to the environment which might cause bigger imaging noise, and the filter kernel of size 3 × 3 was applied to the environment with less noise such as a dark room with constant ambient temperature.…”

“…Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. [1], laser triangulation sensor [2,3], laser radar [4], etc. The drift and dither of the laser source will directly reduce the accuracy of laser spot location and seriously affect the accuracy of the laser measurement system [5].…”