Development of stair-climbing mechanism with passive crawlers (Analysis of limitation for crawler rotation angle and test vehicle performance)

A vibration amplifier is first proposed for adding to a test vehicle to enhance its capability to detect frequencies of the bridge under scanning. The test vehicle adopted is of single-axle and modeled as a single degree-of-freedom (DOF) system, which was proved to be successful in previous studies. The amplifier is also modeled as a single-DOF system, and the bridge as a simple beam of the Bernoulli–Euler type. To unveil the mechanism involved, closed-form solutions were first derived for the dynamic responses of each component, together with the transmissibility from the vehicle to amplifier. Also presented is a conceptual design for the amplifier. The approximations adopted in the theory were verified to be acceptable by the finite element simulation without such approximations. Since road roughness can never be avoided in practice and the test vehicle has to be towed by a tractor in the field test, both road roughness and the tractor are included in the numerical studies. For the general case, when the amplifier is not tuned to the vehicle frequency, the bridge frequencies can better be identified from the amplifier than vehicle response, and the tractor is helpful in enhancing the overall performance of the amplifier. Besides, the amplifier can be adaptively adjusted to target and detect the bridge frequency of concern. For the special case when the amplifier is tuned to the vehicle frequency, the amplifier can improve the vehicle performance by serving as a tuned mass damper, as conventionally known. This case is of limited use since it does not allow us to target the bridge frequencies. Both bridge damping and vehicle speed are also assessed with their effects addressed.

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The synthesis of a segmented stair-climbing wheel

International Journal of Advanced Robotic Systems ◽

10.1177/1729881417749470 ◽

2018 ◽

Vol 15 (1) ◽

pp. 172988141774947 ◽

Cited By ~ 1

Author(s):

Vladimir Mostyn ◽

Vaclav Krys ◽

Tomas Kot ◽

Zdenko Bobovsky ◽

Petr Novak

Keyword(s):

Rotation Angle ◽

Stair Climbing ◽

Circular Segment ◽

Circular Profile ◽

Bidirectional Movement ◽

Centre Of Rotation ◽

Flat Ground

The article describes the process of development of an essentially new wheel suitable both for moving on flat ground and for travelling on stairs. The stair-climbing wheel is composed of rotary circular segments arranged around a shared carrier with arms to form a complete circular profile of the wheel adapted for moving on flat ground; for travelling on stairs, individual segments are rotated by an appropriate angle to touch down tangentially on the stepping surface of the stairs. The dimensions of individual segments, the centre of rotation of individual segments and the angle of their partial turn have been chosen so that the length of the arc along which the circular segment rolls is equal to the length of the stepping surface of an average stair, and, at the same time, the circular segment touches down tangentially on the stepping surface while the wheel turns around the edge of the previous segment. Using the rotation angle of the turnable segments, the wheel can be adapted to the height of non-standard stairs. The segments can be inclined in both directions for bidirectional movement of the wheel up and down the stairs. An undercarriage equipped with these wheels can be used in the field of exploratory robots and for the transportation of persons and materials on stairs.

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Research on Key Technologies of Signal Processing in Automobile Performance Virtual Detection System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.562-564.963 ◽

2012 ◽

Vol 562-564 ◽

pp. 963-967

Author(s):

Ping Wu

Keyword(s):

Signal Processing ◽

Virtual Instrument ◽

Performance Test ◽

Detection System ◽

High Accuracy ◽

Test System ◽

New Method ◽

Test Vehicle ◽

Vehicle Performance ◽

Key Technologies

Aiming at the shortcoming of test system used in our country and fulfilling the practical need of the enterprise, this paper advances a new method to test vehicle performance based on virtual instruments, studies and builds a new vehicle performance test system based on virtual instrument technique. This paper develops and applies a series of new critical technologies about signal processing. The test proves that the system offers high accuracy and reliability by use of these key technologies and realizes the fully compatible in connection of sensor and second instrument.

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Structure and migration of planar defects in crystals observed in atomic scale

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108568 ◽

1978 ◽

Vol 36 (1) ◽

pp. 284-285 ◽

Cited By ~ 1

Author(s):

H. Hashimoto ◽

Y. Sugimoto ◽

Y. Takai ◽

H. Endoh

Keyword(s):

Electron Microscope ◽

Rotation Angle ◽

Crystal Surface ◽

Electron Gun ◽

Atomic Scale ◽

Present Observation ◽

Twist Boundary ◽

Optical Magnification ◽

Zinc Crystal ◽

And Migration

As was demonstrated by the present authors that atomic structure of simple crystal can be photographed by the conventional 100 kV electron microscope adjusted at “aberration free focus (AFF)” condition. In order to operate the microscope at AFF condition effectively, highly stabilized electron beams with small energy spread and small beam divergence are necessary. In the present observation, a 120 kV electron microscope with LaB6 electron gun was used. The most of the images were taken with the direct electron optical magnification of 1.3 million times and then magnified photographically.1. Twist boundary of ZnSFig. 1 is the image of wurtzite single crystal with twist boundary grown on the surface of zinc crystal by the reaction of sulphur vapour of 1540 Torr at 500°C. Crystal surface is parallel to (00.1) plane and electron beam is incident along the axis normal to the crystal surface. In the twist boundary there is a dislocation net work between two perfect crystals with a certain rotation angle.

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Preparation of integrated circuits for TEM electromigration in situ studies

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100145753 ◽

1986 ◽

Vol 44 ◽

pp. 882-883

Author(s):

J. V. Maskowitz ◽

W. E. Rhoden ◽

D. R. Kitchen ◽

R. E. Omlor ◽

P. F. Lloyd

Keyword(s):

Integrated Circuits ◽

Crystallographic Orientation ◽

Silicon Wafers ◽

Minimum Size ◽

Test Vehicle ◽

In Situ Studies ◽

Boron Doped ◽

Doped Silicon ◽

Drill Holes

The fabrication of the aluminum bridge test vehicle for use in the crystallographic studies of electromigration involves several photolithographic processes, some common, while others quite unique. It is most important to start with a clean wafer of known orientation. The wafers used are 7 mil thick boron doped silicon. The diameter of the wafer is 1.5 inches with a resistivity of 10-20 ohm-cm. The crystallographic orientation is (111).Initial attempts were made to both drill and laser holes in the silicon wafers then back fill with photoresist or mounting wax. A diamond tipped dentist burr was used to successfully drill holes in the wafer. This proved unacceptable in that the perimeter of the hole was cracked and chipped. Additionally, the minimum size hole realizable was > 300 μm. The drilled holes could not be arrayed on the wafer to any extent because the wafer would not stand up to the stress of multiple drilling.

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