RESUMEN
Structured light systems often suffer interference of the fringes by blooming when scanning metal objects. Unfortunately, this problem cannot be reliably solved using conventional methods such as the high dynamic range (HDR) method or adaptive projection technique. Therefore, this study proposes a method to adaptively suppress the oversaturated areas that cause blooming as the exposure time increases and then fuse the multi-exposure time decoding results using a decoding inheritance method. The experimental results demonstrate that the proposed method provides a more effective suppression of blooming interference than existing methods.
RESUMEN
This study proposes a novel FSM compensation system for four degrees of freedom (DOF) laser errors compensation, which has the advantage of shorter optical path length, fewer elements and an easier set-up process, meaning that it can be used at different locations. A commercial software, Zemax, is used to evaluate the function of the proposed FSM compensation system and the mathematical modelling of the proposed FSM compensation system is established by using a skew-ray tracing method. Finally, the proposed FSM compensation system is then verified experimentally using a laboratory-built prototype and the result shows that the proposed FSM compensation system achieves the ability to compensate the 4 DOF of the laser source.
RESUMEN
We investigate the modeling of inverse dynamics without prior kinematic information for holonomic rigid-body robots. Despite success in compensating robot dynamics and friction, general inverse dynamics models are nontrivial. Rigid-body models are restrictive or inefficient; learning-based models are generalizable yet require large training data. The structured kernels address the dilemma by embedding the robot dynamics in reproducing kernel Hilbert space. The proposed kernels autonomously converge to rigid-body models but require fewer samples; with a semi-parametric framework that incorporates additional parametric basis for friction, the structured kernels can efficiently model general rigid-body robots. We tested the proposed scheme in simulations and experiments; the models that consider the structure of function space are more accurate.
RESUMEN
For a fiber Bragg grating (FBG) surface-bonded to a substrate subjected to tension, the FBG reflective wavelength spectrum measured using an optical spectrum analyzer is different in either the location of the center wavelength or the spectral shape from that calculated using the transfer matrix (T-matrix) method. We show that the difference in the two wavelength spectra is caused by the adhesive layer used to bond the FBG to the substrate and a birefringence effect within the strained FBG. In the former case, the adhesive reduces the strain transferred from the substrate to the FBG and, therefore, causes the T-matrix method to overestimate the shift in the center wavelength. In the latter case, a birefringence effect is induced within the FBG because only the lower part of the FBG is bonded to the stressed substrate. As a result, both the peak power and the full width at half-maximum of the experimental spectrum differ from that predicted by the T-matrix method, in which the effects of birefringence are ignored. However, it is shown that when the strain transmission loss and birefringence effect are compensated using a strain transmission correction factor and a modified T-matrix formulation based on a discretized value of the refractive index, respectively, a good agreement is obtained between the calculated spectrum and that measured experimentally.
