A low-cost calibration method for automated optical mensuration using a video camera

1994 ◽  
Vol 7 (4) ◽  
pp. 259-266 ◽  
Author(s):  
Ching-Cheng Wang
Keyword(s):  
Low Cost ◽  
Calibration Method ◽  
Video Camera

Processing Panorama Video in Real-time

2014 ◽  
Vol 08 (02) ◽  
pp. 209-227 ◽  
Author(s):  
Håkon Kvale Stensland ◽  
Vamsidhar Reddy Gaddam ◽  
Marius Tennøe ◽  
Espen Helgedagsrud ◽  
Mikkel Næss ◽  
...  
Keyword(s):  
Real Time ◽  
Graphics Processing Units ◽  
Low Cost ◽  
Video Camera ◽  
Wide Field ◽  
High Data ◽  
Data Rates ◽  
Camera Arrays ◽  
Analysis System ◽  
Performance Results

There are many scenarios where high resolution, wide field of view video is useful. Such panorama video may be generated using camera arrays where the feeds from multiple cameras pointing at different parts of the captured area are stitched together. However, processing the different steps of a panorama video pipeline in real-time is challenging due to the high data rates and the stringent timeliness requirements. In our research, we use panorama video in a sport analysis system called Bagadus. This system is deployed at Alfheim stadium in Tromsø, and due to live usage, the video events must be generated in real-time. In this paper, we describe our real-time panorama system built using a low-cost CCD HD video camera array. We describe how we have implemented different components and evaluated alternatives. The performance results from experiments ran on commodity hardware with and without co-processors like graphics processing units (GPUs) show that the entire pipeline is able to run in real-time.

scholarly journals A DCM Based Attitude Estimation Algorithm for Low-Cost MEMS IMUs

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Heikki Hyyti ◽  
Arto Visala
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Low Cost ◽  
Direction Cosine ◽  
Estimation Algorithm ◽  
Calibration Method ◽  
Attitude Estimation ◽  
Mems Sensors ◽  
Acceleration Sensors ◽  
Adaptive Extended Kalman Filter

An attitude estimation algorithm is developed using an adaptive extended Kalman filter for low-cost microelectromechanical-system (MEMS) triaxial accelerometers and gyroscopes, that is, inertial measurement units (IMUs). Although these MEMS sensors are relatively cheap, they give more inaccurate measurements than conventional high-quality gyroscopes and accelerometers. To be able to use these low-cost MEMS sensors with precision in all situations, a novel attitude estimation algorithm is proposed for fusing triaxial gyroscope and accelerometer measurements. An extended Kalman filter is implemented to estimate attitude in direction cosine matrix (DCM) formation and to calibrate gyroscope biases online. We use a variable measurement covariance for acceleration measurements to ensure robustness against temporary nongravitational accelerations, which usually induce errors when estimating attitude with ordinary algorithms. The proposed algorithm enables accurate gyroscope online calibration by using only a triaxial gyroscope and accelerometer. It outperforms comparable state-of-the-art algorithms in those cases when there are either biases in the gyroscope measurements or large temporary nongravitational accelerations present. A low-cost, temperature-based calibration method is also discussed for initially calibrating gyroscope and acceleration sensors. An open source implementation of the algorithm is also available.

Gyro Drift Calibration in Low Cost Inertial System

1999 ◽  
Author(s):  
Zhong Zhao ◽  
Rong Ma ◽  
Weiguo Zhang
Keyword(s):  
Low Cost ◽  
Fuzzy Reasoning ◽  
Calibration Method ◽  
Inertial System ◽  
Time Varying ◽  
Dynamic Estimation ◽  
Gyro Drift

Abstract An intelligent gyro drift calibration method for low-cost inertial system is presented in this paper. This method based on fuzzy reasoning and dynamic estimation can calibrate time-varying gyro drift in the motion of vehicle. Experiments have been done on three strapdown inertial all-attitude systems constituted of piezoelectric rate gyros. The result shows that this method is effective by which the residual of piezoelectric gyro drift can be reduced to about one percent of its original drift value.

scholarly journals A Fast Calibration and Compensation Method for Magnetometers in Strap-Down Spinning Projectiles

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4157 ◽  
Author(s):  
Dafeng Long ◽  
Xiaoming Zhang ◽  
Xiaohui Wei ◽  
Zhongliang Luo ◽  
Jianzhong Cao
Keyword(s):  
Low Cost ◽  
Experimental System ◽  
Calibration Method ◽  
Attitude Estimation ◽  
Attitude Measurement ◽  
Angle Error ◽  
Estimation Errors ◽  
Zero Bias ◽  
Launch Site ◽  
Spinning Projectile

Attitude measurement is an essential technology in projectile trajectory correction. Magnetometers have been used for projectile attitude measurement systems as they are small in size, lightweight, and low cost. However, magnetometers are seriously disturbed by the artillery magnetic field during launch. Moreover, the error parameters of the magnetometers, which are calibrated in advance, usually change after extended storage. The changed parameters have negative effects on attitude estimation of the projectile. To improve the accuracy of attitude estimation, the magnetometers should be calibrated again before launch or during flight. This paper presents a fast calibration method specific for a spinning projectile. At the launch site, the tri-axial magnetometer is calibrated, the parameters of magnetometer are quickly obtained by optimal ellipsoid fitting based on a least squares criterion. Then, the calibration parameters are used to compensate for magnetometer outputs during flight. The numerical simulation results show that the proposed calibration method can effectively determine zero bias, scale factors, and alignment angle errors. Finally, a semi-physical experimental system was designed to further verify the performance of the calibration method. The results show that pitch angle error reduces from 3.52° to 0.58° after calibration. The roll angle error is reduced from 2.59° to 0.65°. Simulations and experimental results indicate that the accuracy of magnetometer in strap-down spinning projectile has been greatly enhanced, and the attitude estimation errors are reduced after calibration.

New Calibration Method for Implementing Machine Learning in Low-Cost Sensor Applications

2020 ◽  
Vol 4 (2) ◽  
pp. 1-4
Author(s):  
Niko Murrell ◽  
Ryan Bradley ◽  
Nikhil Bajaj ◽  
Julie Whitney ◽  
George T.-C. Chiu
Keyword(s):  
Machine Learning ◽  
Low Cost ◽  
Calibration Method ◽  
Sensor Applications

scholarly journals Real-Time Color Correction Method for a Low-Cost Still/Video Camera

2009 ◽  
Vol E92-D (1) ◽  
pp. 97-101
Author(s):  
Dongil HAN ◽  
Hak-Sung LEE ◽  
Chan IM ◽  
Seong Joon YOO
Keyword(s):  
Real Time ◽  
Low Cost ◽  
Video Camera ◽  
Correction Method ◽  
Color Correction

scholarly journals High Quality Zenith Tropospheric Delay Estimation Using a Low-Cost Dual-Frequency Receiver and Relative Antenna Calibration

2020 ◽  
Vol 12 (9) ◽  
pp. 1393 ◽  
Author(s):  
Andreas Krietemeyer ◽  
Hans van der Marel ◽  
Nick van de Giesen ◽  
Marie-Claire ten Veldhuis
Keyword(s):  
Low Cost ◽  
Ground Plane ◽  
Calibration Method ◽  
Single Frequency ◽  
Tropospheric Delay ◽  
Limiting Factor ◽  
Dual Frequency ◽  
High Quality ◽  
Mean Square Errors ◽  
Antenna Calibration

The recent release of consumer-grade dual-frequency receivers sparked scientific interest into use of these cost-efficient devices for high precision positioning and tropospheric delay estimations. Previous analyses with low-cost single-frequency receivers showed promising results for the estimation of Zenith Tropospheric Delays (ZTDs). However, their application is limited by the need to account for the ionospheric delay. In this paper we investigate the potential of a low-cost dual-frequency receiver (U-blox ZED-F9P) in combination with a range of different quality antennas. We show that the receiver itself is very well capable of achieving high-quality ZTD estimations. The limiting factor is the quality of the receiving antenna. To improve the applicability of mass-market antennas, a relative antenna calibration is performed, and new absolute Antenna Exchange Format (ANTEX) entries are created using a geodetic antenna as base. The performance of ZTD estimation with the tested antennas is evaluated, with and without antenna Phase Center Variation (PCV) corrections, using Precise Point Positioning (PPP). Without applying PCVs for the low-cost antennas, the Root Mean Square Errors (RMSE) of the estimated ZTDs are between 15 mm and 24 mm. Using the newly generated PCVs, the RMSE is reduced significantly to about 4 mm, a level that is excellent for meteorological applications. The standard U-blox ANN-MB-00 patch antenna, with a circular ground plane, after correcting the phase pattern yields comparable results (0.47 mm bias and 4.02 mm RMSE) to those from geodetic quality antennas, providing an all-round low-cost solution. The relative antenna calibration method presented in this paper opens the way for wide-spread application of low-cost receiver and antennas.

scholarly journals Application of Shore-Based Video and Unmanned Aerial Vehicles (Drones): Complementary Tools for Beach Studies

2020 ◽  
Vol 12 (3) ◽  
pp. 394 ◽  
Author(s):  
Donatus Bapentire Angnuureng ◽  
Philip-Neri Jayson-Quashigah ◽  
Rafael Almar ◽  
Thomas Christian Stieglitz ◽  
Edward Jamal Anthony ◽  
...  
Keyword(s):  
Low Cost ◽  
Video Camera ◽  
Video Data ◽  
Camera System ◽  
Camera Systems ◽  
Camera View ◽  
Aerial Vehicle ◽  
One Year ◽  
Video Camera System ◽  
Good Agreement

Video camera systems have been used over nearly three decades to monitor coastal dynamics. They facilitate a high-frequency analysis of spatiotemporal shoreline mobility. Video camera usage to measure beach intertidal profile evolution has not been standardized globally and the capacity to obtain accurate results requires authentication using various techniques. Applications are mostly site specific due to differences in installation. The present study examines the accuracy of intertidal topographic data derived from a video camera system compared to data acquired with unmanned aerial vehicle (UAV, or drone) surveys of a reflective beach. Using one year of 15-min video data and one year of monthly UAV observations, the intertidal profile shows a good agreement. Underestimations of intertidal profile elevations by the camera-based method are possibly linked to the camera view angle, rectification and gaps in data. The resolution of the video-derived intertidal topographic profiles confirmed, however, the suitability of the method in providing beach mobility surveys matching those required for a quantitative analysis of nearshore changes. Beach slopes were found to vary between 0.1 and 0.7, with a steep slope in May to July 2018 and a gentle slope in December 2018. Large but short-scale beach variations occurred between August 2018 and October 2018 and corresponded to relatively high wave events. In one year, this dynamic beach lost 7 m. At this rate, and as also observed at other beaches nearby, important coastal facilities and infrastructure will be prone to erosion. The data suggest that a low-cost shore-based camera, particularly when used in a network along the coast, can produce profile data for effective coastal management in West Africa and elsewhere.

Some Considerations in the Design of Low Cost Remotely-Piloted Aircraft for Civil Remote Sensing Applications

1983 ◽  
Vol 37 (3) ◽  
pp. 157-167 ◽  
Author(s):  
G. F. Tomlins
Keyword(s):  
Aerial Photography ◽  
Low Cost ◽  
Video Camera ◽  
Low Noise ◽  
Wildlife Habitat ◽  
Camera System ◽  
Black And White ◽  
Sensing Applications ◽  
Site Mapping ◽  
Remotely Piloted Aircraft

Early in 1982, B.C. Research began to evaluate the feasibility, advantages and limitations of using Remotely-Piloted Aircraft (RPA) to acquire aerial photography in environmental applications. Advantages associated with these aircraft include low costs, ease of operation, low noise levels, portability, safety and very low speed-low altitude capability. In the first phase of this program, a three-meter span fixed-wing aircraft was constructed from a commercial model kit and modified to carry a remotely-operated 35 mm camera system. In summer 1982, this system was used to acquire aerial photography in a variety of applications including forestry, pollution detection, wildlife habitat assessment, site mapping, publicity, wildlife inventories and shoreline mapping. Various operational limitations were encountered including difficulty of navigation and aircraft control, the fragility of the “model” airframe and its limited payload capability. These limitations are being addressed in Phase II of the program, during which a purpose-built airframe is under development, equipped with automatic flight controllers and emergency systems, and employing digitally-encoded radio signals for secure aircraft command. A black-and-white video camera installed in the airframe provides real-time imagery as an aid to navigation and photoframing.

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