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Search Publications by: Prem Rachakonda (Fed)

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Displaying 1 - 25 of 38

Filtering Organized 3D Point Clouds for Bin Picking Applications

January 23, 2024
Author(s)
Marek Franaszek, Prem Rachakonda, Kamel S. Saidi
In many manufacturing applications, autonomous robot action is guided by a perception system integrated with the robot. The quality of the acquired 3D data must be high to ensure smooth and uninterrupted execution of robotic tasks. Unfortunately, many

Improving Fitting CAD to 3D Point Cloud Acquired with Line-of-Sight Sensor

November 7, 2023
Author(s)
Marek Franaszek, Prem Rachakonda, Kamel S. Saidi
Due to self-occlusions in 3D point clouds acquired with line-of-sight sensors, an incomplete representation of an object's surface is used in fitting a CAD (computer-aided design) model to the data. For certain types of object geometry, CAD pose fitted

Evaluating the depth resolution of 3D sensors for manufacturing automation applications

July 21, 2023
Author(s)
Prem Rachakonda, Geraldine S. Cheok, Marek Franaszek, Kamel S. Saidi
The Intelligent Systems Division (ISD) at the National Institute of Standards and Technology (NIST) is performing research to support the development of documentary standards within ASTM E57.23. This subcommittee is addressing the performance evaluation of

Workshop Report: Standards and Performance Metrics for On-Road Autonomous Vehicles

October 27, 2022
Author(s)
Craig I. Schlenoff, Suzanne Lightman, Vinh Nguyen, Prem Rachakonda, Tao Zhang, Omar Aboul-Enein, Nicholas Barbosa, C Cameron Miller, Daniel Sawyer, Ann Virts
On-road autonomous vehicles are expected to significantly influence key aspects of everyday life. However, these complex systems can pose a safety risk in the event of unexpected system performance. Therefore, NIST held the Standards and Performance

Preface: Uncertainty Evaluation by Monte Carlo Method

March 16, 2020
Author(s)
Prem Rachakonda, Vishal Ramnath, Vinay Shankar Pandey
Measurement uncertainty is a parameter that is used to characterize the dispersion of the values attributed to a measurand. There are multiple definitions of measurement uncertainty that were adopted by various international working groups. The differences

A First realization of ASTM E3125-17 test procedures for laser scanner performance evaluation

February 1, 2020
Author(s)
Ling Wang, Balasubramanian Muralikrishnan, Vincent D. Lee, Prem K. Rachakonda, Daniel S. Sawyer, Joe Gleason
Spherical coordinate three-dimensional (3D) imaging systems, such as Terrestrial Laser Scanners (TLS), are already used widely in different fields. Their measurement performance evaluation is a topic of active research. In 2017, the first comprehensive

Methods to calibrate a three-sphere scale bar for laser scanner performance evaluation per the ASTM E3125-17

February 1, 2020
Author(s)
Ling Wang, Balasubramanian Muralikrishnan, Vincent D. Lee, Prem K. Rachakonda, Daniel S. Sawyer, Joe Gleason
A scale bar with sphere targets is one way of realizing the symmetric and asymmetric length tests to evaluate terrestrial laser scanner (TLS) performance per the ASTM E3125-17 standard. The length of the scale bar is required to be known with an expanded

Sources of Errors in Structured Light 3D Scanners

April 15, 2019
Author(s)
Prem K. Rachakonda, Bala Muralikrishnan, Daniel S. Sawyer
Structured light (SL) scanners have been commercially available for over a decade and some commercial scanners are evaluated using one of two German guidelines – VDI/VDE 2634 parts 2 and/or 3. Several other research groups and NMIs have developed physical

Methods to Characterize 3D Scanners for Forensic Applications

February 22, 2019
Author(s)
Prem K. Rachakonda, Balasubramanian Muralikrishnan
Forensic photography has been one of the most valuable tool for investigators over many decades. They preserve the history of the scene and provide a way for investigators to analyze the scene of interest. However, it is difficult to obtain any objective

Roles and Responsibilities of NIST in the Development of Documentary Standards

July 27, 2018
Author(s)
Prem K. Rachakonda, Balasubramanian Muralikrishnan, Daniel S. Sawyer
The National Institute of Standards and Technology (NIST) is a non-regulatory federal agency of the Department of Commerce and is the national metrology institute of the US. The background of NIST's role in the development of voluntary consensus standards

ASTM E3125 Laser Scanner Standard: Challenges and Role of NIST

July 24, 2018
Author(s)
Prem K. Rachakonda
The Dimensional Metrology Group (DMG) at National Institute of Standards & Technology (NIST), along with various other organizations were involved in the development of the ASTM E3125-17 documentary standard for 3D imaging systems. The ASTM E57 committee

Concept to Commercialization of an Artifact for Evaluating 3D Imaging Systems per the ASTM E3125- 17

June 29, 2018
Author(s)
Balasubramanian Muralikrishnan, Prem K. Rachakonda, Vincent D. Lee, Katharine M. Shilling, Daniel S. Sawyer, Geraldine S. Cheok, Luc Cournoyer, Joe Gleason
The newly released ASTM E3125-17 standard describes several point-to-point distance tests to evaluate the performance of spherical coordinate 3D imaging systems, commonly referred to as terrestrial laser scanners (TLS). The relative-range error test, which

Terrestrial laser scanner geometric error model parameter correlations in the Two-face, Length-consistency, and Network methods of self-calibration

April 26, 2018
Author(s)
Balasubramanian Muralikrishnan, Ling Wang, Prem K. Rachakonda, Daniel S. Sawyer
Terrestrial laser scanners (TLS) are increasingly used in a variety of applications where accuracies on the order of few tenths of a millimeter or smaller are routinely demanded. Self-calibration is a quick and cost-effective way to improve the accuracy of

Method to Determine the Center of a Contrast Target from Terrestrial Laser Scanner Data

November 3, 2017
Author(s)
Prem K. Rachakonda, Balasubramanian Muralikrishnan, Daniel S. Sawyer, Ling Wang
Terrestrial laser scanners (TLSs) are instruments that can measure 3D coordinates of objects at high speed resulting in high density 3D point cloud data without the necessity of a cooperative target. Contrast targets, also known as checkerboard targets

Challenges in measuring spherical geometry using terrestrial laser scanners

November 1, 2017
Author(s)
Balasubramanian Muralikrishnan, Prem K. Rachakonda, Katharine M. Shilling, Vincent D. Lee, Daniel S. Sawyer, Geraldine S. Cheok, Luc Cournoyer
Terrestrial laser scanners (TLS) measure 3D coordinates in a scene by recording the range, the azimuth angle, and elevation angle of discrete points on target surfaces. They are increasingly used in a variety of applications, including manufacturing and

An Overview of Activities at NIST Towards the Proposed ASTM E57 3D Imaging System Point-to-Point Distance Standard

October 16, 2017
Author(s)
Prem K. Rachakonda, Balasubramanian Muralikrishnan, Katharine M. Shilling, Geraldine S. Cheok, Daniel S. Sawyer
The Dimensional Metrology Group (DMG) at the National Institute of Standards & Technology (NIST), along with various other organizations has been involved in the development of a documentary standard for 3D imaging instruments that acquire data in

Methods and Considerations to Determine Sphere Center from Terrestrial Laser Scanner Point Cloud Data

September 6, 2017
Author(s)
Prem K. Rachakonda, Balasubramanian Muralikrishnan, Luc Cournoyer, Geraldine S. Cheok, Vincent D. Lee, Katharine M. Shilling, Daniel S. Sawyer
The Dimensional Metrology Group (DMG) at the National Institute of Standards and Technology (NIST) is performing research to support the development of documentary standards within ASTM E57 committee. This committee is addressing the point-to-point

Techniques to Evaluate Terrestrial Laser Scanner Errors

July 26, 2017
Author(s)
Bala Muralikrishnan, Prem K. Rachakonda
Forensic photography has been one of the most important tool for investigators over many decades. They preserve the history of the scene and provides a way for investigators to revisit the scene. However, it is difficult to ascertain any objective

Relative range error evaluation of terrestrial laser scanners using a plate, a sphere, and a novel dual-sphere-plate target

July 21, 2017
Author(s)
Balasubramanian Muralikrishnan, Prem K. Rachakonda, Vincent D. Lee, Katharine M. Shilling, Daniel S. Sawyer, Geraldine S. Cheok
Terrestrial laser scanners (TLS) are a class of 3D imaging systems that produce a 3D point cloud by measuring the range and two angles at different sampling locations. The ranging unit of a TLS realizes the SI unit of length. Relative range error is one