Design considerations for optical pointing and scanning mechanisms

Sweeney, Michael N.; Erdelyi, Emery; Ketabchi, Mehrdad; Kent, Blanche

doi:10.1117/12.523415

Cited by 6 publications

(5 citation statements)

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“…Selecting vectors M x and M y in the plane where the FSM is located, the plane formed by O f − X f M x is perpendicular to the rotating axis F y , and the plane formed by O f − Y f M y is perpendicular to the rotating axis F x . According to the mechanism of the FSM movement, when the FSM drives the secondary mirror to rotate along axes of α, β, the coordinates of M x , M y in the FSM coordinate system are M x F , M y F , as shown as Equation ( 1), and its normal vector is N F , shown as Equation (2).…”

Section: Analysis Of the Optical Coupling In The 2d Compensationmentioning

confidence: 99%

“…IMC capability is the main factor in verifying the detective performance of the current wide-field imaging system. In particular, the advent of remote high-resolution telephoto cameras has advanced the requirements for higher technology of the IMC [1,2]. In terms of different causes, there are four types of image motion, including forward image motion caused by flight of the carrier, random image motion caused by attitude change of the carrier, scanning image motion caused by optical system scanning, and vibration image motion caused by the vibration of the carrier.…”

Section: Introductionmentioning

confidence: 99%

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Research on 2D Image Motion Compensation for a Wide-Field Scanning Imaging System with Moving Base

Chang,

Chen,

Cao

et al. 2023

Photonics

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The wide-field imaging system carried on a high-altitude or near-space vehicle takes high-resolution images of the ground to measure and map targets. With the improvement of imaging resolution and measurement accuracy, the focal length of the wide-field imaging system is getting longer. The requirement for image motion compensation (IMC) accuracy is getting higher, and the influence of optical path coupling is increasing within the process of two-dimensional (2D) IMC. To further improve the IMC accuracy of the wide-field imaging system, an innovative IMC method is first proposed in this paper. The method is based on the 2D motion of the scanning platform and secondary mirror. Secondly, to solve the optical coupling problem in the process of 2D IMC, the coupling phenomenon is analyzed. The coupling relationships between 2D scanning motion, 2D secondary mirror motion and image motion is derived from the compensation process. A complete 2D IMC model is established, and a 2D IMC method, including an optical path decoupling correct regulator (ODCR), is designed. Finally, the method is verified in laboratory and field flight tests. The results show that the proposed method can effectively correct the coupling error of the optical path in the process of IMC and achieve high-resolution 2D IMC. When the scanning speed is 60°/s and the exposure time is 2 ms, the accuracy of the 2D IMC is up to 0.57pixels (RMS) in the pitch direction, and 0.46 pixels (RMS) in the roll direction.

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Section: Analysis Of the Optical Coupling In The 2d Compensationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Research on 2D Image Motion Compensation for a Wide-Field Scanning Imaging System with Moving Base

Chang,

Chen,

Cao

et al. 2023

Photonics

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“…Fisk et al [150] analyze possible sources of error, such as runout of bearings, non-orthogonality of axes, or the misalignment of other positioning sensors. Sweeney et al [151] provide a set of general design rules for high-precision pointing mechanisms. These focus though on classical serial and parallel mechanisms and mainly focus on utilizing expensive and high-quality components.…”

Section: Pointing Mechanismsmentioning

confidence: 99%

“…The high-torque capability is especially beneficial due to the resistance created from the pre-loading of bearings within the various components. Sweeney et al [151] also discusses the utility of ball screws in precision mechanisms, and how these can be utilized effectively.…”

Section: Ball Screwsmentioning

confidence: 99%

High-Precision Low-Cost Gimballing Platform for Long-Range Railway Obstacle Detection

Assaf

Cornelius

Cadena

et al. 2022

Sensors

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Increasing demand for rail transportation results transportation by rail, resulting in denser and more high-speed usage of the existing railway network, making makes new and more advanced vehicle safety systems necessary. Furthermore, high traveling speeds and the greatlarge weights of trains lead to long braking distances—all of which necessitates Long braking distances, due to high travelling speeds and the massive weight of trains, necessitate a Long-Range Obstacle Detection (LROD) system, capable of detecting humans and other objects more than 1000 m in advance. According to current research, only a few sensor modalities are capable of reaching this far and recording sufficiently accurate enoughdata to distinguish individual objects. The limitation of these sensors, such as a 1D-Light Detection and Ranging (LiDAR), is however a very narrow Field of View (FoV), making it necessary to use ahigh-precision means of orienting to target them at possible areas of interest. To close this research gap, this paper presents a novel approach to detecting railway obstacles by developinga high-precision pointing mechanism, for the use in a future novel railway obstacle detection system In this work such a high-precision pointing mechanism is developed, capable of targeting aiming a 1D-LiDAR at humans or objects at the required distance. This approach addresses To address the challenges of a low target pricelimited budget, restricted access to high-precision machinery and equipment as well as unique requirements of our target application., a novel pointing mechanism has been designed and developed. By combining established elements from 3D printers and Computer Numerical Control (CNC) machines with a double-hinged lever system, simple and cheaplow-cost components are capable of precisely orienting an arbitrary sensor platform. The system’s actual pointing accuracy has been evaluated using a controlled, in-door, long-range experiment. The device was able to demonstrate a precision of 6.179 mdeg, which is at the limit of the measurable precision of the designed experiment.

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“…Generally, FSM has two kinds of actuators, voice coil actuators (VCA) [7] and piezoelectric actuators (PZT) [8]. FSM driven by VCA can offer large scanning angle but suffers from low resonant frequency and scanning accuracy, which limits its application [9].…”

Section: Introductionmentioning

confidence: 99%

A new two-dimensional fast steering mirror based on piezoelectric actuators

Chen

et al. 2014

2014 4th IEEE International Conference on Information Science and Technology

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A new two-dimensional fast steering mirror (FSM) based on piezoelectric actuators is designed, which has high scanning angle and resonance frequency. The FSM is driven by three piezoelectric actuators. Each piezoelectric actuator and its displacement amplification mechanism compose of the Amplified Piezoelectric Actuator (APA).The three APAs have a staggered arrangement to acquire compact structure and close driven point. The mechanism structure and principle of the FSM are introduced. The algorithm of decoupling and hysteresis compensation is proposed. In order to test the performance of the FSM, a performance test system is built up. The test result shows that the FSM has a two-dimensional scanning angle of 2 ,two axis' nonlinearities of 1.7% and 1.1% after compensation and main resonance frequency of 640Hz and 1290Hz.

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Design considerations for optical pointing and scanning mechanisms

Cited by 6 publications

References 0 publications

Research on 2D Image Motion Compensation for a Wide-Field Scanning Imaging System with Moving Base

Research on 2D Image Motion Compensation for a Wide-Field Scanning Imaging System with Moving Base

High-Precision Low-Cost Gimballing Platform for Long-Range Railway Obstacle Detection

A new two-dimensional fast steering mirror based on piezoelectric actuators

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