Research on system of ultra-flat carrying robot based on improved PSO algorithm.

Ultra-flat carrying robots (UCR) are used to carry soft targets for functional safety road tests of intelligent driving vehicles and should have superior control performance. For the sake of analyzing and upgrading the motion control performance of the ultra-flat carrying robot, this paper develops the mathematical model of its motion control system on the basis of the test data and the system identification method. Aiming at ameliorating the defects of the standard particle swarm optimization (PSO) algorithm, namely, low accuracy, being susceptible to being caught in a local optimum, and slow convergence when dealing with the parameter identification problems of complex systems, this paper proposes a refined PSO algorithm with inertia weight cosine adjustment and introduction of natural selection principle (IWCNS-PSO), and verifies the superiority of the algorithm by test functions.

False-positive colloidal gold-based immunochromatographic strip assay reactions for antibodies to SARS-CoV-2 in patients with autoimmune diseases.

Background: The outbreak of the novel 2019 coronavirus disease (COVID-19) was declared a global pandemic by the World Health Organization (WHO) on March 11, 2020. The diagnosis of COVID-19 is frequently based on a positive serological test. We noted the occurrence of false-positive results for COVID-19 in the colloidal gold-based immunochromatographic strip (ICS) assay in sera from patients with autoimmune diseases (ADs).

Mitigation of speckle noise in laser Doppler vibrometry by using a scanning average method.

We present a scanning average method used in laser Doppler vibrometry systems for mitigating the noise induced by dynamic speckles. In this method, the measurement beam is scanned over the target surface within the area of interest at a relatively high frequency. Then an averaging operation (e.

Six-beam homodyne laser Doppler vibrometry based on silicon photonics technology.

This paper describes an integrated six-beam homodyne laser Doppler vibrometry (LDV) system based on a silicon-on-insulator (SOI) full platform technology, with on-chip photo-diodes and phase modulators. Electronics and optics are also implemented around the integrated photonic circuit (PIC) to enable a simultaneous six-beam measurement. Measurement of a propagating guided elastic wave in an aluminum plate (speed ≈ 909 m/s @ 61.

Nonlinearity error in homodyne interferometer caused by multi-order Doppler frequency shift ghost reflections.

This paper reports a hitherto undiscovered cyclic error whose origin is different from that of conventional errors in homodyne interferometers. To explain this error, a model based on ghost reflections and the interference principle is developed. In general, in homodyne interferometers, multi-order Doppler frequency shift ghost beams participate in the final interference and generate multi-order cyclic errors.

Homodyne laser vibrometer capable of detecting nanometer displacements accurately by using optical shutters.

This paper describes a homodyne laser vibrometer with optical shutters. The parameters that define the nonlinearity of the quadrature signals in a vibrometer can be pre-extracted before the measurement, and can then be used to compensate for nonlinear errors, such as unequal AC amplitudes and DC offsets. The experimental results indicated that the homodyne laser vibrometer developed has the ability to accurately detect the vibration state of the object to be measured, even when the amplitude is ≤λ/4.

DC-offset-free homodyne interferometer and its nonlinearity compensation.

This study presents an analysis of the cyclic nonlinearity in the homodyne interferometer starting from the interference principle. We present the design for an enhanced homodyne interferometer without DC offset, for which the nonlinearity model will not be influenced by the intensity of the measurement beam. Our experimental results show that the enhanced interferometer can suppress the nonlinearity to less than 0.

Compensation for the variable cyclic error in homodyne laser interferometers.

This paper presents a real-time method to compensate for the variable cyclic error in a homodyne laser interferometer. The parameters describing the quadrature signals of the interferometer are estimated using simple peak value detectors. The cyclic error in the homodyne laser interferometer was then corrected through simple arithmetic calculations of the quadrature signals.