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The purpose of this paper is to propose cuckoo optimization algorithm (COA)-based back propagation neural network (BPNN) to reduce the effect of the nonlinearities presented in laser triangulation displacement sensors. The 3D positioning and posture sensor allows access to the third dimension through depth measurement; the performance of the sensor varies according to the level of nonlinearities presented in the system, which leads to inaccuracies in measurement.

While applying optimization approach, the mathematical model and the relationship between the key parameters in the laser triangulation ranging and the indexes of the measuring system were analyzed.

Based on the performance of the parametric optimization method, the measurement repeatability reached 0.5 µm with an STD value within 0.17 µm, an expanded uncertainty of measurement was within 5 µm, the angle error variation of the object’s rotational plane was within 0.031 degrees and nonlinearity was recorded within 0.006 per cent in a full scale. The proposed approach reduced the effect of the nonlinearity presented in the sensor. Thus, the accuracy and speed of the sensor were greatly increased. The specifications of the optimized sensor meet the requirements for high-accuracy devices and allow wide range of industrial application.

In this paper, COA-based BPNN is proposed for laser triangulation displacement sensor optimization, on the basis of the mathematical model, clarifying the working space and working angle on the measurement system.

This paper aims to use 3D laser sensors to collect high‐density data that are required for defect detection and localization at high‐production rates in manufacturing facilities.

The high‐speed sensors use Ethernet communications to transport large amounts of data and resolve any synchronization issues.

Modern laser sensor technology provides the ability to detect and quantify defects in high‐volume manufacturing, wherever defects are located. Laser line sensors provide high speed, high‐density data for full surface inspection. Synchronization and communications issues are simplified by the FireSync™ platform, making system integration straightforward, and maximizing reliability.

This paper provides detailed 3D data at high speed and uses multiple (binocular) scanners to overcome problems of occlusion.

Laser triangulation is a very efficient non‐contact point‐measurement procedure, very similar to a mechanical gauge, but much faster. However, the special characteristics of the laser triangulation sensor (LTS) must be taken into account for its use. The correct selection of sensor and test‐equipment verification, complying with norm ISO 9001, can be facilitated or implemented with the test‐bench for LTS, developed in the quality and production measurement technology laboratory of the Neu‐Technikum Buchs, Switzerland. A wide range of LTSs has been collated in a market analysis; differences of performance have been determined in a widespread comparison.

Looks at the use of non‐contact displacement and vibration sensors and notes their value for difficult sensing measurements. Mentions various situations which may dictate the use of a non‐contact sensor. Focuses on fibre‐optic sensors and laser triangulation sensors. Concludes that practical uses for such devices are rapidly expanding.

The purpose of this paper is to present a combined scheme of active laser‐based triangulation and a morphological edge detection, to quantify features dimensions (width and depth) over smooth plastic surfaces. The inspected target is an automotive polyethylene, optically black fender, with average roughness of 1μm, while the sought features are mold sinks with depth variations of 0.3‐1.0 mm and a width of ∼3 mm.

Several non‐contact scanning and reconstruction optical modalities are discussed along with its associated noise for current application; such techniques include interferometry and triangulation. The proposed system projects a linear coherent illumination and scans its reflection profile to infer the reflected component position using trigonometry and its width using a Sobel morphological operator. The retrieved dimensions are then reconstructed into feature boundaries that enable a depth and width quantification.

The proposed setup and processing are validated through experimental scans of actual molded fenders with artificial deviations. The proposed system accuracy is then analyzed and its spatial resolution is found to be 0.14 mm using the current charge‐coupled device format of 640 × 480. Additionally the proposed system is benchmarked against a commercial 3D stereo‐based scanner; proposed system proved to be more accurate with faster scanning rates.

The post processor combines the predicted width and depth values in real‐time to synthesize a 3D surface profile for sought features, with a resolution of 0.14 mm, an accuracy of 0.09 mm, and a repeatability of 0.11 mm. The proposed scheme is customized to current laser illuminant and to the plastic surface profile, which further modifications for other illuminations and roughness values.

New image processing code is used to reduce the laser speckle effect and the moving mechanism vibration using a moving Gaussian illuminant and a double thresholding scheme coupled with sequential averaging, respectively.

Discusses the use of two commercially available non‐contact laser triangulation sensors. First, describes a standard dual view sensor called REVERSA and demonstrates the use of the scanner in the production of flatware tooling. Second, introduces a novel hand‐held scanner which is retro‐fitted to a portable CMM and describes two examples of its use in the automotive industry.

Existing calibration methods mainly focus on the camera laser-plane calibration of a single laser-line length, which is not convenient and cannot guarantee the consistency of the results when several three-dimensional (3D) scanners are involved. Thus, this study aims to provide a unified step for different laser-line length calibration requirements for laser profile measurement (LPM) systems.

3D LPM is the process of converting physical objects into 3D digital models, wherein camera laser-plane calibration is critical for ensuring system precision. However, conventional calibration methods for 3D LPM typically use a calibration target to calibrate the system for a single laser-line length, which needs multiple calibration patterns and makes the procedure complicated. In this paper, a unified calibration method was proposed to automatically calibrate the camera laser-plane parameters for the LPM systems with different laser-line lengths. The authors designed an elaborate planar calibration target with different-sized rings that mounted on a motorized linear platform to calculate the laser-plane parameters of the LPM systems. Then, the camera coordinates of the control points are obtained using the intersection line between the laser line and the planar target. With a new proposed error correction model, the errors caused by hardware assembly can be corrected. To validate the proposed method, three LPM devices with different laser-line lengths are used to verify the proposed system. Experimental results show that the proposed method can calibrate the LPM systems with different laser-line lengths conveniently with standard steps.

The repeatability and accuracy of the proposed calibration prototypes were evaluated with high-precision workpieces. The experiments have shown that the proposed method is highly adaptive and can automatically calibrate the LPM system with different laser-line lengths with high accuracy.

In the repeatability experiments, there were errors in the measured heights of the test workpieces, and this is because the laser emitter had the best working distance and laser-line length.

By using this proposed method and device, the calibration of the 3D scanning laser device can be done in an automatic way.

The calibration efficiency of a laser camera device is increased.

The authors proposed a unified calibration method for LPM systems with different laser-line lengths that consist of a motorized linear joint and a calibration target with elaborately designed ring patterns; the authors realized the automatic parameter calibration.