Image Stabilization System Research Articles

Focus control of a concave–convex ultrasonic gel lens in the radial direction

Optical image stabilization (OIS) systems maintain the three-dimensional focal position of a lens through mechanical actuation systems. This paper examines an optical lens for OIS that utilizes ultrasound vibration to alter the focal position, not only in the depth direction but also in the radial direction. The lens has a simple structure with no mechanical moving parts and consists of an ultrasound transducer divided into four pieces, a glass disk, and a transparent viscoelastic gel film that functions as a lens. The acoustic radiation force generated by the resonant flexural vibration of the glass disk can alter the surface profile of the gel film, allowing for a variable-focus function. The concave and convex lenses can be interchanged using two resonant vibration modes: the standing-wave mode, in which the vibration loop appears at the center, and the traveling-wave mode, in which the vibration node appears at the center. The positions of ultrasound vibrations on the lens can be controlled in a two-dimensional plane by adjusting the driving amplitudes of each channel, thereby achieving focus control in the radial direction. The focusing characteristics of the lens are evaluated through ray-tracing simulation.

SuperBIT Superpressure Flight Instrument Overview and Performance: Near-diffraction-limited Astronomical Imaging from the Stratosphere

SuperBIT was a 0.5 m near-UV to near-infrared wide-field telescope that launched on a NASA superpressure balloon into the stratosphere from New Zealand for a 45-night flight. SuperBIT acquired multiband images of galaxy clusters to study the properties of dark matter using weak gravitational lensing. We provide an overview of the instrument and its various subsystems. We then present the instrument performance from the flight, including the telescope and image stabilization system, the optical system, the power system, and the thermal system. SuperBIT successfully met the instrument’s technical requirements, achieving a telescope pointing stability of 0.″34 ± 0.″10, a focal plane image stability of 0.″055 ± 0.″027, and a point-spread function FWHM of ∼0.″35 over 5-minute exposures throughout the 45-night flight. The telescope achieved a near-diffraction-limited point-spread function in all three science bands (u, b, and g). SuperBIT served as a pathfinder to the GigaBIT observatory, which will be a 1.34 m near-UV to near-infrared balloon-borne telescope.

Measurements of seeing-induced crosstalk in tip–tilt corrected solar polarimetry

We present measurements of seeing-induced crosstalk using spectropolarimetric observations of sunspots recorded simultaneously in the Hα and Ca ii 8662 Å lines with the Kodaikanal Tower Tunnel (KTT) telescope. The Kodaikanal Tower Tunnel telescope is integrated and installed with an image stabilization system consisting of a tip–tilt and an autoguider system. Additionally, the spectropolarimeter at KTT is upgraded to allow for the simultaneous recording of spectropolarimetric observations in three spectral lines. The tip–tilt system is shown to have a cutoff frequency of 80 Hz, effectively reducing the seeing induced crosstalk in the measured Stokes parameters by at least a factor of 2.

Design of Vehicle Image Stabilization System and Imaging Quality Impact Test for Typical Grasslands

Design of Vehicle Image Stabilization System and Imaging Quality Impact Test for Typical Grasslands

The closed-loop control method based on dual-port adaptive internal model control for fine image stabilization of space telescopes.

In view of the complex working environment of space astronomical telescopes, the influence of various disturbance sources on the imaging quality cannot be ignored. This paper focuses on compensating for the space telescope line-of-sight (LOS) deviation and suppressing the low-frequency disturbance problem in astronomical observation. A closed-loop control method based on dual-port adaptive internal model control (AIMC) for the fine image stabilization system (FISS) was proposed. To be specific, the fine guidance sensor (FGS) as the high-precision detection unit of the FISS calculates the telescope LOS deviation and sends it to the controller unit in real time. The controller unit drives the large-aperture fast steering mirror (FSM), which performs high-precision two-dimensional rotation to compensate for the telescope LOS deviation, according to the dual-port AIMC control algorithm. Moreover, the dual-port AIMC control method adds an AIMC loop on the basis of the feedback loop and adjusts the filter parameters adaptively according to the target angular velocity of the FSM, achieving higher disturbance suppression capability. The experimental results verify that the control method proposed can effectively compensate for the LOS deviation and suppress the composite frequency disturbance. In the 0-8Hz frequency band, the power spectral density integral values of the star centroid deviation in the X and Y directions of the FGS are, respectively, suppressed by 97.38% and 98.38%.

Neural network-based motion vector estimation algorithm for dynamic image sequences

With the rapid development of deep learning, convolutional neural networks have gradually become the main means to extract features of dynamic image sequences. The motion vector estimation algorithm, as the key to the stability of image sequences, directly affects the performance of image stabilization systems, so the motion estimation algorithm for convolutional neural networks is necessary. The study proposes an improved convolutional neural network based on loss-free function, and applies it to the extraction of dynamic image features. On this basis, the motion estimation algorithm is then optimised by combining grey-scale projection and block matching methods. The experimental results show that the new loss-free function-based convolutional neural network has better recognition capability with an error rate of only 15% in dynamic image recognition. The accuracy of the optimised motion estimation algorithm is as high as 95.1% with a PSNR value of 16.636, which is higher than that of the traditional grey-scale projection algorithm. In terms of video processing, the improved algorithm has a higher PSNR value than the search block matching method, the bit-plane matching method and the full search block matching method, with a higher steady image accuracy and high operational efficiency, providing a new research idea for the improvement of motion estimation algorithms. In general, the proposed algorithm is a significant improvement over the current mainstream algorithms in terms of image accuracy, processing performance and number of operations, and it provides a new research idea for the improvement of motion estimation algorithms.

All‐Optically Controlled Retinomorphic Memristor for Image Processing and Stabilization

AbstractImage stabilization is a crucial field in machine vision, aiming to eliminate image blurring or distortion caused by the camera or object jitter. However, traditional image stabilization techniques often suffer from the drawbacks of requiring complex equipment or extensive computing resources, resulting in inefficiencies. In contrast, the human retina performs a highly efficient all‐in‐one system, encompassing the detection and processing of light stimuli. In this study, an all‐optically controlled retinomorphic memristor based on the CsxFAyMA1‐x‐yPb(IzBr1‐z)3 is proposed, which integrates perception, storage, and processing functions. This memristor exhibits significant advantages in image stabilization. It is capable of positively and negatively modulating its conductance using specific intensities (11.8 and 0.9 mW cm−2, respectively) of red light (630 nm). To demonstrate the effectiveness of the proposed approach, handwritten digit recognition simulations are conducted. The application of specific light stimuli effectively highlights the characteristics of blurred images. The processed images are then fed into a conductance‐mapped neural network for rapid recognition. Remarkably, the recognition rates of the processed images reach 83.5% after 19 000 iterations, surpassing the performance of blurred images (only 56.2% after 19 000 iterations). These results highlight the immense potential of retinomorphic memristors as the hardware foundation for next‐generation image stabilization systems.

Hysteresis Modeling and Compensation for a Fast Piezo-Driven Scanner in the UAV Image Stabilization System

The fast piezo-driven scanner (FPDS) compensates for vibrations in the unmanned aerial vehicle (UAV) image stabilization system. However, the hysteresis nonlinearity reduces the positioning accuracy of the FPDS. To address this challenge, this paper presents a novel weighted polynomial modified Bouc–Wen (WPMBW) model cascaded with a linear dynamic model to describe counterclockwise, asymmetric, and rate-dependent hysteresis loops of an FPDS. The proposed approach utilizes the weighted polynomial function to describe the asymmetric characteristic and the linear dynamic model to capture the rate-dependent behavior. By modifying the last two terms in the classical Bouc–Wen (CBW) model, the modified BW model directly characterizes the counterclockwise hysteresis loops with fewer parameters, circumventing the algebraic-loop problem that arises in the inverse CBW model. The pseudorandom binary sequence (PRBS) input is employed to decouple the linear dynamic model from the WPMBW model. The sinusoidal input is then applied to stimulate the hysteresis phenomenon, and the parameters of the WPMBW model are estimated by the particle swarm optimization (PSO) toolbox. Experimental results on a commercial FPDS show that the proposed model is superior to the CBW and traditional asymmetric BW models in modeling accuracy and feedforward hysteresis compensation.

The Solar Upper Transition Region Imager (SUTRI) Onboard the SATech-01 Satellite

The Solar Upper Transition Region Imager (SUTRI) onboard the Space Advanced Technology demonstration satellite (SATech-01), which was launched to a Sun-synchronous orbit at a height of ∼500 km in 2022 July, aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne vii 46.5 nm spectral line with a filter width of ∼3 nm. SUTRI employs a Ritchey–Chrétien optical system with an aperture of 18 cm. The on-orbit observations show that SUTRI images have a field of view of ∼ 41.′6 × 41.′6 and a moderate spatial resolution of ∼8″ without an image stabilization system. The normal cadence of SUTRI images is 30 s and the solar observation time is about 16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period. Approximately 15 GB data is acquired each day and made available online after processing. SUTRI images are valuable as the Ne vii 46.5 nm line is formed at a temperature regime of ∼0.5 MK in the solar atmosphere, which has rarely been sampled by existing solar imagers. SUTRI observations will establish connections between structures in the lower solar atmosphere and corona, and advance our understanding of various types of solar activity such as flares, filament eruptions, coronal jets and coronal mass ejections.

Seeing the limited coupling of starlight into single‐mode fiber with a small telescope

AbstractAn optical fiber link to a telescope provides many advantages for spectrometers designed to detect and characterize extrasolar planets through precise radial velocity measurements. In the seeing‐limited regime, a multi‐mode fiber is typically used so that a significant amount of starlight may be captured. In the near‐diffraction‐limited case, either with an adaptive optics system or with a small telescope at an excellent site, efficiently coupling starlight into a much smaller, single‐mode fiber may be possible. In general, a spectrometer designed for single‐mode fiber input will be substantially less costly than one designed for multi‐mode fiber input. We describe the results of tests coupling starlight from a 70 cm telescope at Mt. Hopkins, Arizona into the single‐mode fiber of the MINERVA‐Red spectrometer at a wavelength of 850 nm using a low‐speed tip/tilt image stabilization system comprising all commercial, off‐the‐shelf components. We find that approximately 0.5 of the available starlight is coupled into the single‐mode fiber under seeing conditions typical for observatories hosting small telescopes, which is close to the theoretical expectation. We discuss scientific opportunities for small telescopes paired with inexpensive, high‐resolution spectrometers, as well as upgrade paths that should significantly increase the coupling efficiency for the MINERVA‐Red system.

Analysis of the multi-dimensional transformation of the perspective of new media image artworks using the image stabilization system

New media image art, an essential branch of new media art, is characterized by the primary form of expression being an image and adopting various new means of production and communication. As an emerging art form, new media art has extensive connections to various fields due to the complexity of media and diversity of expression. New media image art has been shaped by the diverse expressions enabled by the development of various production technologies, among which is the Image Stabilization System (ISS). The ISS is a series of technical systems based on a camera stabilization device, thus integrated control of camera motion attitude to complete the camera motion shooting. Recently, the ISS has gained popularity in the film and television industry and is widely used in various video production processes. This article takes the multi-dimensional transformation of the perspective of new media image artworks, using the ISS, as the research subjects. The author briefly introduces some ISSs used in new media image art, analyzes the multi-dimensional transformation of shooting perspectives (the changes in the degree of freedom, immersion and interactivity) by the application of ISS through production examples, and explores the prospect of their application in new media image art.

Vehicular Electronic Image Stabilization System Based on a Gasoline Model Car Platform

Noise, vibration and harshness (NVH) problems in vehicle engineering are always challenging in both traditional vehicles and intelligent vehicles. Although high accuracy manufacturing, modern structural roads and advanced suspension technology have already significantly reduced NVH problems and their impacts; off-road condition, obstacles and extreme operating condition could still trigger NVH problems unexpectedly. This paper proposes a vehicular electronic image stabilization (EIS) system to solve the vibration problem of the camera and ensure the environment perceptive function of vehicles. Firstly, feature point detection and matching based on an oriented FAST and rotated BRIEF (ORB) algorithm are implemented to match images in the process of EIS. Furthermore, a novel improved random sampling consensus algorithm (i-RANSAC) is proposed to eliminate mismatched feature points and increase the matching accuracy significantly. And an adaptive Kalman filter (AKF) is applied to improve the adaptability of the vehicular EIS. Finally, an experimental platform based on a gasoline model car was established to validate its performance. The experimental results show that the proposed EIS system can satisfy vehicular performance requirements even under off-road condition with obvious obstacles.

Estimation of tolerance on the image stabilization accuracy of on-board automatic optoelectronic aiming devices

Subject of study. This study considers controllable on-board combined optoelectronic devices with dynamic errors in their tracking and image stabilization systems depending on the atmosphere parameters, characteristics, and probability of surveillance task execution. Aim of study. The study aims to derive analytical dependences for the assessment of tolerance on the accuracy of control and image stabilization of on-board combined optoelectronic devices. Method. In order to obtain the required tolerance, we used a frequency method for the assessment of the image quality based on the modulation transfer function of the optoelectronic system depending on the modulation transfer functions of the atmosphere, objective, photodetector, and amplifier–transformer that, in turn, depend on the radiation wavelengths and spatial frequencies of resolution. The following inverse problem was solved: Equations for the assessment of tolerance on the accuracy of control of the subsystems ensuring tracking and image stabilization were obtained based on the admissible modulation transfer function of the optoelectronic system. Main results. Analytical dependences were derived and a graphical analysis algorithm was proposed for the evaluation of tolerance on the accuracy of systems for control and image stabilization of the on-board combined optoelectronic device. An example of the calculation of the tolerance on the accuracy of control and image stabilization was presented. Practical significance. The obtained results enabled the correct analysis and synthesis of algorithms for control, modeling, and testing of systems for vibration protection and automated control of on-board combined optoelectronic devices.

A computer vision-based method to identify the international roughness index of highway pavements

The International Roughness Index (IRI) is one of the most critical parameters in the field of pavement performance management. Traditional methods for the measurement of IRI rely on expensive instrumented vehicles and well-trained professionals. The equipment and labor costs of traditional measurement methods limit the timely updates of IRI on the pavements. In this article, a novel imaging-based Deep Neural Network (DNN) model, which can use pavement photos to directly identify the IRI values, is proposed. This model proved that it is possible to use 2-dimensional (2D) images to identify the IRI other than the typically used vertical accelerations or 3-dimensional (3D) images. Due to the fast growth in photography equipment, small and convenient sports action cameras such as the GoPro Hero series are able to capture smooth videos at a high framerate with built-in electronic image stabilization systems. These significant improvements make it not only more convenient to collect high-quality 2D images, but also easier to process them than vibrations or accelerations. In the proposed method, 15% of the imaging data were randomly selected for testing and had never been touched during the training steps. The testing results showed an averaged coefficient of determination (R square) of 0.6728 and an averaged root mean square error (RMSE) of 0.50.

The Airborne Infrared Spectrometer: Development, Characterization, and the 2017 August 21 Eclipse Observation

On 2017 August 21, the Airborne Infrared Spectrometer (AIR-Spec) observed the total solar eclipse at an altitude of 14 km from aboard the NSF/NCAR Gulfstream V research aircraft. The instrument successfully observed the five coronal emission lines that it was designed to measure: Si x 1.431 μm, S xi 1.921 μm, Fe ix 2.853 μm, Mg viii 3.028 μm, and Si ix 3.935 μm. Characterizing these magnetically sensitive emission lines is an important first step in designing future instruments to monitor the coronal magnetic field, which drives space weather events, as well as coronal heating, structure, and dynamics. The AIR-Spec instrument includes an image stabilization system, feed telescope, grating spectrometer, and slit-jaw imager. This paper details the instrument design, optical alignment method, image processing, and data calibration approach. The eclipse observations are described and the available data are summarized.

Oscillation suppression in a particle robotic arm by stiffness and damping regulation

Flexible arms have been widely studied by researchers in recent years, because of their adaptability and interactive security. Due to the low stiffness of the flexible arms, there will be large position deviation and long-period oscillation during de-actuated or excited, which is undesirable in many applications. This paper introduces the design principle and manufacturing method of a flexible arm with variable stiffness and damping to suppress oscillations. The arm is composed of three thin McKibben pneumatic artificial muscles and a chamber filled with discrete particles. The end position is determined by the air pressure input to the artificial muscles, the stiffness and damping of the arm can be further controlled by the vacuum pressure in the particle chamber. Models for stiffness, damping, and the effects on the oscillation suppression of the arm are established, and their validity is verified experimentally. Moreover, the significance of oscillation suppression in the proposed arm is proved by an image stabilization system.

Adaptive Youla–Kučera parametric control of unknown tip-tilt disturbance rejection in image stabilization systems

We propose a new, to the best of our knowledge, adaptive control method to attenuate beam jitter in image stabilization systems, which breaks the restrictions of existing adaptive control methods in terms of time consumption and control stability, and then provides an innovative way for tip-tilt disturbance rejection. In this approach, disturbance rejection could be converted to optimize error attenuation through the parameters design of the Youla-Kučera (YK) parametric controller, which are determined by a new on-line power spectrum density (PSD) estimation of tip-tilt errors to identify the frequency and amplitude of unknown disturbances. Experimental results demonstrate that the proposed method working in an adaptive correction process can attenuate the beam jitter to approximately 1/3 less than the original control error.

Design and control of optical steady image system of aerial camera

In order to solve the problem of aerial photography imaging blur, an aerial camera optical image stabilization system is designed. Based on the principle of optical image stabilization, a forward image stabilization system of aerial camera was designed by analyzing the imaging blur of aerial camera. The equivalent resolution of the system is 500-1000 l p/mm, and the corresponding pixel size is 1-2 μm. Aiming at the optical image stabilization system to establish its PID and corresponding adaptive PID control model, establish its closed-loop system transfer function, and use MATLAB to simulate and analyze the control system. The results show that the whole image stabilization system becomes stable after 0.01s and can achieve the goal of image stabilization. It solves the problem of forward image motion of aerial camera, and greatly improves the imaging effect of aerial camera when it works.

METHODS OF STABILIZATION

The article is devoted to the analysis of methods of stabilization of photo-video camera and image, advantages and disadvantages of different methods of camera stabilization in order to improve the quality of photo and video shooting. The optical image stabilization system is an automated control system. In its composition, it must have a motion sensor, such as a gyroscope or accelerometer, analog or digital computing device and an actuator for motion compensation (motor). The purpose of such a control system is to maintain a fixed position relative to the inertial coordinate system, line of sight or light beam that passes through the camera lens and falls on the light-sensitive matrix. It is possible to realize it by means of the electric motor on the basis of the information from sensors. The electric motor rotates a certain stabilized optical unit, which in turn refracts the light beam. This unit is made with the possibility of rotation around the vertical and horizontal axes or the axes of the course and pitch. The optical unit rotates so that the projection of the image on the film or light-sensitive matrix fully compensates for camera shake during exposure. As a result, the projection always remains stationary with respect to the light-sensitive matrix for small oscillations of the camera. This provides the necessary image clarity. The steadic camera stabilization device provides smooth camera movement in different planes. Steadicams are used in film and video shooting, as it is the easiest way to get a quality picture in motion without shaking with minimal cost. To ensure high accuracy of image stabilization, it is proposed to use an optical stabilization system based on image stabilization. It can be used for photo and video equipment and even in systems such as binoculars and sights.

Design, Analysis and Experiment of a Bridge-Type Piezoelectric Actuator for Infrared Image Stabilization.

Piezoelectric actuators are widely used in the optical field due to their high precision, compact structure, flexible design, and fast response. This paper presents a novel piezoelectric actuator with a bridge-type mechanism, which can be used to stabilize the images of an infrared imaging system. The bridge amplification mechanism is used to amplify the actuation displacement, and its structural parameters are optimized by the response surface method. The control strategy of the image stabilization system is formulated, and the overall structure of the infrared image stabilization system is designed according to the principle of image stabilization and the control strategy. The prototype was fabricated and verified by a series of experiments. In the test, the laminated piezoelectric ceramics are used as the driving element, and its maximum output displacement was about 17 μm under a voltage of 100 V. Firstly, the performance of the piezoelectric amplification mechanism was tested, and the maximum displacement of the piezoelectric micro-motion mechanism was 115 μm. The displacement amplification ratio of the mechanism was 5.7. Then, the step distance and response time of the micro-displacement mechanism were measured by inputting the stepping signal. When the input voltage increased to 3 V, 5 V, and 7 V, the stepping displacements of the mechanism were 2.4 μm, 4.1 μm, and 5.8 μm. Finally, the image stabilization effect of the designed mechanism was verified by imaging timing control and feedback signal processing.