Relative position measurement system for vehicles using diffuse light from LEDs

We have been developing a position measurement system for navigation of automated guided vehicles (AGVs) called SPARS. In this system, the AGV’s ultrasonic position measurement module communicates via ultrasonic waves with ultrasonic transponders that serve as land markers on a path to measure its relative position during travel. In previous studies, we conducted experiments and introduced improvements using the relative position between the AGV and land marker estimated from position information from a single land marker. It was found, however, that the ultrasonic communication S/N ratio decreases, lowering position accuracy, when the land marker distance and its direction angle are great. To solve this problem and improve accuracy, we examine position measurement based on distance information from two land markers.

Download Full-text

Adaptation of a 3-D Local Position Measurement System for 1-D Applications

European Radar Conference, 2005. EURAD 2005. ◽

10.1109/eurad.2005.1605634 ◽

2006 ◽

Cited By ~ 1

Author(s):

K. Pourvoyeur ◽

A. Stelzer ◽

A. Fischer ◽

G. Gassenbauer

Keyword(s):

Measurement System ◽

Position Measurement

Download Full-text

Underwater visual position measurement system for high-accuracy beam installation

Optik ◽

10.1016/j.ijleo.2016.01.128 ◽

2016 ◽

Vol 127 (8) ◽

pp. 3964-3968 ◽

Cited By ~ 1

Author(s):

Yongming Bian ◽

Xiaojun Fang ◽

Meng Yang ◽

Jixiang Yang

Keyword(s):

Measurement System ◽

High Accuracy ◽

Position Measurement

Download Full-text

An Acoustic System for Pipeline Profile Measurement

Journal of Energy Resources Technology ◽

10.1115/1.3230956 ◽

1983 ◽

Vol 105 (4) ◽

pp. 475-479

Author(s):

H. Van Calcar

Keyword(s):

Measurement Technique ◽

Measurement System ◽

Performance Enhancement ◽

Three Dimensional ◽

Profile Measurement ◽

Baseline Measurement ◽

Acoustic System ◽

Position Measurement ◽

Long Baseline ◽

Hardware Configuration

This paper presents an acoustic position measurement system used for precise three-dimensional flowline profile measurement. The system measures several points along the flowline using the long-baseline measurement technique and augments this measurement with depth telemetry repeaters to maintain elevation accuracy throughout the changing installation geometry. The paper discusses both the measurement system and the performance enhancement features. The paper concludes with a discussion of the hardware configuration and the accuracy that can be expected when the technique is extended into deeper operating areas.

Download Full-text

Machine vision-based sensing for helicopter flight control

Robotica ◽

10.1017/s0263574799002192 ◽

2000 ◽

Vol 18 (3) ◽

pp. 299-303 ◽

Cited By ~ 5

Author(s):

Carl-Henrik Oertel

Keyword(s):

Machine Vision ◽

Measurement System ◽

Flight Control ◽

A Priori ◽

Image Data ◽

Two Dimensional ◽

Position Measurement ◽

Additional Information ◽

Helicopter Flight ◽

Template Tracking

Machine vision-based sensing enables automatic hover stabilization of helicopters. The evaluation of image data, which is produced by a camera looking straight to the ground, results in a drift free autonomous on-board position measurement system. No additional information about the appearance of the scenery seen by the camera (e.g. landmarks) is needed. The technique being applied is a combination of the 4D-approach with two dimensional template tracking of a priori unknown features.

Download Full-text

A Self-Calibration Method for Robotic Measurement System

10.1115/imece1999-0753 ◽

1999 ◽

Author(s):

Chunhe Gong ◽

Jingxia Yuan ◽

Jun Ni

Keyword(s):

Coordinate System ◽

Measurement System ◽

Calibration Method ◽

Position Measurement ◽

Robot Calibration ◽

Robot System ◽

Self Calibration ◽

World Coordinate System ◽

Robot Accuracy ◽

Calibration Methods

Abstract Robot calibration plays an increasingly important role in manufacturing. For robot calibration on the manufacturing floor, it is desirable that the calibration technique be easy and convenient to implement. This paper presents a new self-calibration method to calibrate and compensate for robot system kinematic errors. Compared with the traditional calibration methods, this calibration method has several unique features. First, it is not necessary to apply an external measurement system to measure the robot end-effector position for the purpose of kinematic identification since the robot measurement system has a sensor as its integral part. Second, this self-calibration is based on distance measurement rather than absolute position measurement for kinematic identification; therefore the calibration of the transformation from the world coordinate system to the robot base coordinate system, known as base calibration, is not necessary. These features not only greatly facilitate the robot system calibration but also shorten the error propagation chain, therefore, increase the accuracy of parameter estimation. An integrated calibration system is designed to validate the effectiveness of this calibration method. Experimental results show that after calibration there is a significant improvement of robot accuracy over a typical robot workspace.

Download Full-text

Active Vibration Absorption Using Delayed Resonator With Relative Position Measurement

Volume 3C: 15th Biennial Conference on Mechanical Vibration and Noise — Vibration Control, Analysis, and Identification ◽

10.1115/detc1995-0560 ◽

1995 ◽

Author(s):

Nejat Olgac ◽

Martin Hosek

Keyword(s):

Relative Position ◽

Primary Structure ◽

Vibration Suppression ◽

Control Force ◽

Range Analysis ◽

Position Measurement ◽

Harmonic Force ◽

Stability Range ◽

Vibration Absorption ◽

Active Vibration

Abstract A novel active vibration absorption technique, the Delayed Resonator, has been introduced recently as a unique way of suppressing undesired oscillations. It suggests a control force on a mass-spring-damper absorber in the form of a proportional position feedback with a time delay. Its strengths consist of extremely simple implementation of the control algorithm, total vibration suppression of the primary structure against a harmonic force excitation and full effectiveness of the absorber in a semi-infinite range of disturbance frequency, achieved by real-time tuning. All this development work was done using the absolute displacements of the absorber in the feedback. These displacement measurements may be difficult to obtain and for some applications impossible. This paper deals with a substitute and easier measurement: the relative motion of the absorber with respect to the primary structure. Theoretical foundations for the Delayed Resonator (DR) are briefly recapitulated and its implementation on a single-degree-of-freedom primary structure disturbed by a harmonic force is introduced utilizing both absolute and relative position measurement of absorber mass. Methods for stability range analysis and transient behavior are presented. Properties acquired for the same system with these two different feedback are compared. Relative position measurement case is found to be more advantageous in most applications of the Delayed Resonator method.

Download Full-text