High Speed Road Texture Measurement Using Laser Displacement Sensors

Non-contact rotor position sensors are an essential part of control systems in magnetically suspended high-speed drives. In typical active magnetic bearing (AMB) levitated high-speed machine applications, the displacement of the rotor in the mechanical air gap is measured with commercially available eddy current-based displacement sensors. The aim of this paper is to propose a robust and compact three-dimensional position sensor that can measure the rotor displacement of an AMB system in both the radial and axial directions. The paper presents a sensor design utilizing only a single unified sensor stator and a single shared rotor mounted target piece surface to achieve the measurement of all three measurement axes. The sensor uses an inductive measuring principle to sense the air gap between the sensor stator and rotor piece, which makes it robust to surface variations of the sensing target. Combined with the sensor design, a state of the art fully digital signal processing chain utilizing synchronous in-phase and quadrature demodulation is presented. The feasibility of the proposed sensor design is verified in a closed-loop control application utilizing a 350-kW, 15,000-r/min high-speed industrial induction machine with magnetic bearing suspension. The inductive sensor provides an alternative solution to commercial eddy current displacement sensors. It meets the application requirements and has a robust construction utilizing conventional electrical steel lamination stacks and copper winding.

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High Speed, High Temperature, Fault Tolerant Operation of a Combination Magnetic-Hydrostatic Bearing Rotor Support System for Turbomachinery

Volume 6: Turbo Expo 2004 ◽

10.1115/gt2004-53321 ◽

2004 ◽

Cited By ~ 3

Author(s):

Mark Jansen ◽

Gerald Montague ◽

Andrew Provenza ◽

Alan Palazzolo

Keyword(s):

High Temperature ◽

High Speed ◽

Closed Loop ◽

Fault Tolerant ◽

Active Vibration Control ◽

Control Algorithms ◽

Displacement Sensors ◽

Rotor Support ◽

Active Vibration ◽

Speed Computer

Closed loop operation of a single, high temperature magnetic radial bearing to 30,000 RPM (2.25 million DN) and 540°C (1,000°F) is discussed. Also, high temperature, fault tolerant operation for the three axis system is examined. A novel, hydrostatic backup bearing system was employed to attain high speed, high temperature, lubrication free support of the entire rotor system. The hydrostatic bearings were made of a high lubricity material and acted as journal-type backup bearings. New, high temperature displacement sensors were successfully employed to monitor shaft position throughout the entire temperature range and are described in this paper. Control of the system was accomplished through a stand alone, high speed computer controller and it was used to run both the fault-tolerant PID and active vibration control algorithms.

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Experimental Measurements of System Dynamics Between Two Stages of Wire Drawing Machine

Archive of Mechanical Engineering ◽

10.1515/meceng-2015-0004 ◽

2015 ◽

Vol 62 (1) ◽

pp. 61-72 ◽

Cited By ~ 1

Author(s):

Goce Tasevski ◽

Kocho Angjushev ◽

Zlatko Petreski ◽

Dejan Shishkovski

Keyword(s):

High Speed ◽

Wire Drawing ◽

Main Role ◽

Drawing Machine ◽

Feedback Information ◽

Displacement Sensors ◽

Multi Stage ◽

Tensile Forces ◽

The Wire ◽

Angular Displacements

Abstract In multi-stage wire drawing machines productivity growth can be achieved at higher drawing speeds by preventing wire breakage during the process. One disadvantage of high-speed wire drawing is the requirement imposed by machine dynamics in terms of its stability and reliability during operation. Tensile forces in the wire must maintained by fast synchronization of all capstans speed. In this process, the displacement sensors play the main role in providing the control system with feedback information about the wire condition. In this study, the influences between the sensors and actuator driven capstans have been studied, and tuner roll concept of a wire drawing machine was experimentally investigated. To this aim, measurements were carried out on two drawing stages at different drawing speeds and obtained results were presented. These results clearly show the fast changes of the capstans speed and the angular displacements of the rollers that tighten the wire, which only confirms the high dynamics of the wire drawing machine.

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High-Speed Noncontact Profiling of Pavement Surface Texture and Its Significance

Journal of Tribology ◽

10.1115/1.3261237 ◽

1986 ◽

Vol 108 (3) ◽

pp. 455-461

Author(s):

J. C. Wambold ◽

J. J. Henry

Keyword(s):

Surface Texture ◽

High Speed ◽

Large Scale ◽

Vision System ◽

Small Scale ◽

Skid Resistance ◽

Texture Measurement ◽

Pavement Surface ◽

Texture Characteristics ◽

Regression Techniques

It is generally agreed that the friction between a tire and a wet pavement (skid resistance) is controlled by the surface texture characteristics. Therefore, by measuring the relevant parameters describing texture, or by measuring a physical process dependent on texture, regression techniques can be used to relate skid resistance to the chosen texture parameter or process. Two scales of texture are of particular importance: microtexture (small-scale asperities) and macrotexture (large-scale asperities). This paper describes work performed to: (1) review candidate macrotexture and microtexture measurement methods that can be made at highway speeds (at or about 64 km/h [40 mph]), which are presently used or have potential for use in pavement texture measurement; (2) design and build a prototype of the most promising method; and (3) evaluate the effects of pavement surface texture on skid resistance. A prototype noncontact vision system that makes texture measurements at highway speeds was developed, and several improvements were made to upgrade the system to provide an improved prototype. Both hardware and software enhancements have yielded a texture measurement system that can obtain pavement macrotexture data in a fast, efficient, and reliable way.

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Effects of Mechanical Preloads on the Rotordynamic Performance of a Rotor Supported on Three-Pad Gas Foil Journal Bearings

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4027745 ◽

2014 ◽

Vol 136 (12) ◽

Cited By ~ 6

Author(s):

Kyuho Sim ◽

Bonjin Koo ◽

Jong Sung Lee ◽

Tae Ho Kim

Keyword(s):

Test Data ◽

High Speed ◽

Experimental Tests ◽

Journal Bearings ◽

Test Results ◽

Performance Measurements ◽

Displacement Sensors ◽

Single Top ◽

Speed Up ◽

The One

This paper presents the rotordynamic performance measurements and model predictions of a rotor supported on three-pad gas foil journal bearings (GFJBs) with various mechanical preloads. The rotor with its length of 240 mm, diameter of 40 mm, and weight of 19.6 N is supported on two GFJBs and one pair of gas foil thrust bearings (GFTBs), being a permanent magnet rotor of a high speed electric motor. Each bearing pad consisting of a top foil and a bump-strip layer is installed on a lobed bearing housing surface over the arc length of 120 deg along the circumference. Test three-pad GFJBs have four different mechanical preloads, i.e., 0 μm, 50 μm, 70 μm, 100 μm with a common radial nominal clearance of 150 μm. A series of speed-up tests are conducted up to 93 krpm to evaluate the effects of increasing mechanical preloads on the rotordynamic performance. Two sets of orthogonally positioned displacement sensors record the rotor horizontal and vertical motions at the thrust collar and the other end. Test results show that the filtered synchronous amplitudes change little, but the onset speed of subsynchronous motions (OSS) increases dramatically for the increasing mechanical preloads. In addition, test bearings with the 100 μm preload show a higher OSS in load-on-pad (LOP) condition than that in load-between-pads (LBP) condition. A comparison with test results for a one-pad GFJB with a single top foil and bump-strip layer reveals that three-pad GFJB has superior rotordynamic performance to the one-pad one. Finally, the test data benchmark against linear rotordynamic predictions to validate a rotor-GFJB model. In general, predicted natural frequencies of the rotor-bearing system and synchronous rotor motions agree well with test data. However, stability analyses underestimate OSSs recorded during the experimental tests.

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