Measurement accuracy of the SG-3 laser rangefinder

1990 ◽  
Vol 33 (11) ◽  
pp. 1138-1140
Author(s):  
A. S. Maslennikov ◽  
V. S. Slastenov
Keyword(s):  
Measurement Accuracy ◽  
Laser Rangefinder

scholarly journals Improve the Estimation of Monocular Vision 6-DOF Pose Based on the Fusion of Camera and Laser Rangefinder

2021 ◽  
Vol 13 (18) ◽  
pp. 3709
Author(s):  
Zifa Zhu ◽  
Yuebo Ma ◽  
Rujin Zhao ◽  
Enhai Liu ◽  
Sikang Zeng ◽  
...  
Keyword(s):  
Measurement Error ◽  
Pose Estimation ◽  
Measurement Accuracy ◽  
Monocular Vision ◽  
Experimental Results ◽  
Estimation Methods ◽  
Depth Information ◽  
Laser Rangefinder ◽  
Fusion Strategy ◽  
Vision Measurement

Monocular vision is one of the most commonly used noncontact six-degrees-of-freedom (6-DOF) pose estimation methods. However, the large translational DOF measurement error along the optical axis of the camera is one of its main weaknesses, which greatly limits the measurement accuracy of monocular vision measurement. In this paper, we propose a novel monocular camera and 1D laser rangefinder (LRF) fusion strategy to overcome this weakness and design a remote and ultra-high precision cooperative targets 6-DOF pose estimation sensor. Our approach consists of two modules: (1) a feature fusion module that precisely fuses the initial pose estimated from the camera and the depth information obtained by the LRF. (2) An optimization module that optimizes pose and system parameters. The performance of our proposed 6-DOF pose estimation method is validated using simulations and real-world experiments. The experimental results show that our fusion strategy can accurately integrate the information of the camera and the LRF. Further optimization carried out on this basis effectively reduces the measurement error of monocular vision 6-DOF pose measurement. The experimental results obtained from a prototype show that its translational and rotational DOF measurement accuracy can reach up to 0.02 mm and 15″, respectively, at a distance of 10 m.

scholarly journals Anti-interference pulsed laser ranging system

2020 ◽  
pp. 8-14
Author(s):  
A. V. Sadchenko ◽  
O. A. Kushnirenko ◽  
E. K. Koshelev
Keyword(s):  
Measurement Accuracy ◽  
Pulsed Laser ◽  
Cost Effective ◽  
Laser Rangefinder ◽  
Probe Signal ◽  
Coding Sequence ◽  
Probing Signal ◽  
Real Value ◽  
Range Interval ◽  
Correlation Properties

Pulsed laser rangefinders prove to be cost-effective and practical devices when used at distances of several tens of kilometers due to their compactness, portability and energy efficiency. However, the measurement accuracy is significantly reduced by the presence of pulsed interference affecting the input of the optical receiver both during the sensing period and when the reflected signal is being received. Using the algorithms with the accumulation and subsequent processing of the results of several successive measurements reduces the speed of decision-making and does not guarantee the convergence of the results to the real value of the distance. The paper proposes a structural diagram of a laser rangefinder with the ability to detect pulsed interference in the range interval and correct errors that occur in the structure of the signal reflected from the target. The basis of the rangefinder circuit is a logical consistent filter, the structure of which contains multipliers (multiplication operations). The following requirements were formulated for the structure of the probe signal: — the first element should always be set to +1 to synchronize the receiver decider; — the weight of the coding sequence is equal to half its length; — the length of the coding sequence is even. Based on the requirements for coding sequences, the optimal structures of binary probing signals of length 8 were found, providing the best corrective ability. Comparison of the correlation properties of the found sequences and the sequences that are constructed using the Walsh functions showed the advantage of the optimal sequences by the criterion of the minimum level of the ACF side lobes. The simulation of the rangefinder under pulsed noise conditions has shown that the logical filter is advisable to use for those cases when the duration of the obstacle does not exceed 1/3 of the duration of the probing signal.

Methods for Restricting Maximum Exposure Rate in Computerized Adaptative Testing

Methodology ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Juan Ramon Barrada ◽  
Julio Olea ◽  
Vicente Ponsoda
Keyword(s):  
Measurement Accuracy ◽  
Computerized Adaptive Testing ◽  
Computation Time ◽  
Adaptive Testing ◽  
Exposure Rate ◽  
Control Parameters ◽  
The Impact ◽  
Two Alternatives ◽  
Selection Of ◽  
Maximum Exposure

Abstract. The Sympson-Hetter (1985) method provides a means of controlling maximum exposure rate of items in Computerized Adaptive Testing. Through a series of simulations, control parameters are set that mark the probability of administration of an item on being selected. This method presents two main problems: it requires a long computation time for calculating the parameters and the maximum exposure rate is slightly above the fixed limit. Van der Linden (2003) presented two alternatives which appear to solve both of the problems. The impact of these methods in the measurement accuracy has not been tested yet. We show how these methods over-restrict the exposure of some highly discriminating items and, thus, the accuracy is decreased. It also shown that, when the desired maximum exposure rate is near the minimum possible value, these methods offer an empirical maximum exposure rate clearly above the goal. A new method, based on the initial estimation of the probability of administration and the probability of selection of the items with the restricted method ( Revuelta & Ponsoda, 1998 ), is presented in this paper. It can be used with the Sympson-Hetter method and with the two van der Linden's methods. This option, when used with Sympson-Hetter, speeds the convergence of the control parameters without decreasing the accuracy.

Structured methods for improving flow measurement accuracy in pipelines

2020 ◽  
pp. 30-35
Author(s):  
Gurami N. Akhobadze
Keyword(s):  
Flow Measurement ◽  
Measurement Accuracy ◽  
Directional Coupler ◽  
Signal To Noise Ratio ◽  
Scattered Wave ◽  
Orthogonal Polarization ◽  
Flow Sensors ◽  
Information Signal ◽  
Mass Flows ◽  
Processing Device

In the age of digital transformation of production processes in industry and science the development and design of intelligent flow sensors for granular and liquid substances transferring through pipelines becomes more important. With this in view new approaches for improving the accuracy of microwave flowmeters are proposed. Taking into account the characteristics ofelectromagnetic waves propagating through a pipeline, a wave scattered by inhomogeneities of the controlled medium is analyzed. Features of the transformation of the polarized scattered wave limiting the geometric dimensions of the pipeline and optimizing the values of the useful scattered signal are revealed. Expediency of collection of the information signal with orthogonal polarization of the scattered wave and through a directional coupler is substantiated. The method of estimating the measurement accuracy with reference to the signal-to-noise ratio at the input of the processing device is given. The research results can be used in cryogenic machine engineering to measure volume and mass flows of liquid cryogenic products.

94-LB: Measurement Accuracy of a Newly Developed Prototype System for Noninvasive Glucose Monitoring

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 94-LB
Author(s):  
GUIDO FRECKMANN ◽  
STEFAN PLEUS ◽  
PETER WINTERGERST ◽  
DELIA WALDENMAIER ◽  
NINA R. JENDRIKE ◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
Glucose Monitoring ◽  
Prototype System ◽  
Noninvasive Glucose Monitoring

Liver density in routine and low-dose computed tomography: the effect of image noise on measurement accuracy

2020 ◽  
Vol 24 (1) ◽  
pp. 39-47
Author(s):  
A. P. Gonchar ◽  
V. A. Gombolevskij ◽  
A. B. Elizarov ◽  
N. S. Kulberg ◽  
V. G. Klyashtorny ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Measurement Accuracy ◽  
Low Dose ◽  
Image Noise ◽  
Low Dose Computed Tomography

Electronic Package Failure Analysis Using TDR

2000 ◽  
Author(s):  
Dima A. Smolyansky
Keyword(s):  
Failure Analysis ◽  
Fault Location ◽  
Measurement Accuracy ◽  
Time Domain Reflectometry ◽  
Acoustic Imaging ◽  
X Ray ◽  
Analysis Techniques ◽  
Bga Packages ◽  
Impedance Profile ◽  
Nature Of Time

Abstract The visual nature of Time Domain Reflectometry (TDR) makes it a very natural technology that can assist with fault location in BGA packages, which typically have complex interweaving layouts that make standard failure analysis techniques, such as acoustic imaging and X-ray, less effective and more difficult to utilize. This article discusses the use of TDR for package failure analysis work. It analyzes in detail the TDR impedance deconvolution algorithm as applicable to electronic packaging fault location work, focusing on the opportunities that impedance deconvolution and the resulting true impedance profile opens up for such work. The article examines the TDR measurement accuracy and the comparative package failure analysis, and presents three main considerations for package failure analysis. It also touches upon the goal and the task of the failure analysts and TDR's specific signatures for the open and short connections.

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