The Analysis and Design Study of High Speed Robotic Devices

2013 ◽  
Vol 282 ◽  
pp. 18-26 ◽  
Author(s):  
Štefan Havlík ◽  
Jaroslav Hricko
Keyword(s):  
High Speed ◽  
Positional Accuracy ◽  
Analysis And Design ◽  
Positioning Devices ◽  
Robotic Devices ◽  
And Performance ◽  
Improving Accuracy ◽  
Kinematic Mechanisms ◽  
Stiffness And Damping ◽  
Made In

The problem of multi d.o.f. positioning devices based on compact compliant kinematic mechanisms is to guarantee the desired positional accuracy in static and especially in dynamic modes of operation. The study of accuracy and performance analysis of high speed devices is made in this paper. The influence of differences between stiffness and damping coefficients in actuated directions as well as mutual cross couplings between them are discussed in details and performance characteristics of such complex systems are simulated. As proposed the problem of improving accuracy can be solved by insertion of the compensation member into control system that could be integrated in parallel or serial way. The presented approach enables to verify the dynamical range of operation for small / micro positioning devices performing precise trajectory following tasks.

Design and Performance of a Miniaturized High-Speed Continuous-Flow Analyzer

1974 ◽  
Vol 20 (4) ◽  
pp. 424-427 ◽  
Author(s):  
William E Neeley ◽  
Stephen C Wardlaw ◽  
Helen C Sing
Keyword(s):  
Sample Size ◽  
Continuous Flow ◽  
High Speed ◽  
Clinical Laboratory ◽  
Small Animal ◽  
Sample Volume ◽  
Small Sample ◽  
Reagent Consumption ◽  
And Performance ◽  
Made In

Abstract Design features and performance of a miniaturized high-speed continuous-flow analyzer are described. Special emphasis is made in the design towards a system that is free from the operational and mechanical complexities found in most of today’s advanced systems. Depending on the particular analyses, sample size varies from 3 to 25 µl and reagent consumption is less than 180 µl per sample. Analyses are performed under steady-state conditions at sampling rates of 150 samples per hour with a 2:1 or 3:1 sample-to-wash ratio. The marked reduction in sample size makes the system ideal for microanalyses, especially in the pediatric clinical laboratory, in small animal research, and in any other cases where small sample volume is especially important.

Advanced Techniques for Engine Research and Design

1989 ◽  
Vol 203 (3) ◽  
pp. 169-183 ◽  
Author(s):  
C C J French
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Recent Past ◽  
And Performance ◽  
Research And Design ◽  
Speed Computer ◽  
Made In

This paper discusses technical improvements that have been made to internal combustion engines in the recent past. It then goes on to show that, with the availability of the high-speed computer, great possibilities exist for many more advances to be made in design and performance.

Mechanical and Rotordynamic Design, Fabrication and Testing of a High-Speed Miniature Cryocooler Motor

2007 ◽  
Author(s):  
Dipjyoti Acharya ◽  
Lei Zhou ◽  
Liping Zheng ◽  
Thomas X. Wu ◽  
Jay Kapat ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Room Temperature ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Experimental Results ◽  
Test Set ◽  
And Performance ◽  
Set Up ◽  
Made In

An attempt has been made in this work to design, fabricate and performance evaluate a 2 kW permanent magnet synchronous motor operating at 200,000 rpm and at the temperature of both room temperature and 77 K. Structural, thermal and rotordynamic aspects were considered and models were developed on an iterative basis. Prototypes were fabricated and models were validated through experimental results. The PMSM motor/generator prototype was fabricated. At this stage, experimental results were obtained for the test set-up operating at 200,000 rpm and air at room temperature. Models developed were validated comparing to experimental results.

Detailed Measurements Within a Selection of Pipe Diffusers for Centrifugal Compressors

1998 ◽  
Author(s):  
I. Bennett ◽  
A. Tourlidakis ◽  
R. L. Elder
Keyword(s):  
Cross Section ◽  
High Speed ◽  
Expansion Ratio ◽  
Compressor Stage ◽  
Pressure Pulsations ◽  
Step Size ◽  
Pressure Transducers ◽  
And Performance ◽  
Selection Of ◽  
Made In

It is well established that the flow between the impeller tip and the diffuser throat is very influential on the performance and flow range of a centrifugal compressor stage. Detailed measurements of a parametric selection of pipe diffusers have been carried out within this region using a combination of conventional pneumatic and high speed pressure transducers. Four pipe diffuser designs were examined. The first and datum consisted of 31 pipes, representing a design with minimal meridional step (or sidewall expansion) between impeller tip and diffuser throat. The step size was increased to 1.3 for the second design resulting in a 22 pipe diffuser. A further increase of sidewall expansion ratio to 1.7 with 13 pipes was completed following favourable results from the 22 pipe tests. The final diffuser was of hybrid design consisting of an oval rather than circular throat cross-section. This departure allowed for a 13 pipe diffuser without sidewall expansion. Flow range and performance comparisons are made in addition to detailed measurements which clearly show that strong planar pulsations dominate the distorted diffuser throat flow. Larger pressure pulsations are quantified for the designs with low numbers of pipes.

Ball bearing turbocharger vibration management: application on high speed balancer

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Ball Bearing ◽  
Squeeze Film ◽  
Design And Technology ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Bearing Loads ◽  
Stiffness And Damping

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

scholarly journals Spatially Resolved Experimental Modal Analysis on High-Speed Composite Rotors Using a Non-Contact, Non-Rotating Sensor

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4705
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Juergen Czarske ◽  
...  
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Fiber Reinforced ◽  
Structural Dynamic ◽  
Spatially Resolved ◽  
Glass Fiber Reinforced ◽  
Vibration Responses ◽  
And Performance

Due to their lightweight properties, fiber-reinforced composites are well suited for large and fast rotating structures, such as fan blades in turbomachines. To investigate rotor safety and performance, in situ measurements of the structural dynamic behaviour must be performed during rotating conditions. An approach to measuring spatially resolved vibration responses of a rotating structure with a non-contact, non-rotating sensor is investigated here. The resulting spectra can be assigned to specific locations on the structure and have similar properties to the spectra measured with co-rotating sensors, such as strain gauges. The sampling frequency is increased by performing consecutive measurements with a constant excitation function and varying time delays. The method allows for a paradigm shift to unambiguous identification of natural frequencies and mode shapes with arbitrary rotor shapes and excitation functions without the need for co-rotating sensors. Deflection measurements on a glass fiber-reinforced polymer disk were performed with a diffraction grating-based sensor system at 40 measurement points with an uncertainty below 15 μrad and a commercial triangulation sensor at 200 measurement points at surface speeds up to 300 m/s. A rotation-induced increase of two natural frequencies was measured, and their mode shapes were derived at the corresponding rotational speeds. A strain gauge was used for validation.

Paper 23: The Collision of Drops with Dry and Wet Surfaces in an Air Atmosphere

1969 ◽  
Vol 184 (7) ◽  
pp. 57-63
Author(s):  
G. J. Parker ◽  
E. Bruen
Keyword(s):  
Steam Turbine ◽  
High Speed ◽  
Size Range ◽  
Drop Surface ◽  
Wet Steam ◽  
Air Atmosphere ◽  
Made In

This paper describes an investigation into the behaviour of drops which impinge upon dry and wet surfaces. This is of particular interest in the context of the wet steam turbine. Two approaches have been made in the studies; these are: (1) Drops were made to impinge normally on to various types of dry, stationary surfaces. The drops were in the size range 300–1500 μm diameter with velocities of 2–9 m/s. (2) Drops were made to impinge on to surfaces moving with considerable velocity at right angles to the motion of the drop. Surface velocities ranged up to 45 m/s. The latter study is of direct interest for the splashing of drops on turbine casings at small glancing angles, as occurs near drainage belts. Analysis of the mechanisms involved is made from the records of high-speed ciné photography.

Image-Based Versus Signal-Based Sensors for Machine Fault Detection and Isolation

2014 ◽  
Author(s):  
Heshan Fernando ◽  
Vedang Chauhan ◽  
Brian Surgenor
Keyword(s):  
Fault Detection ◽  
High Speed ◽  
Fault Isolation ◽  
Video Data ◽  
Fault Detection And Isolation ◽  
Single Camera ◽  
Multiple Faults ◽  
Multiple Sensors ◽  
Machine Fault ◽  
And Performance

This paper presents the results of a comparative study that investigated the use of image-based and signal-based sensors for fault detection and fault isolation of visually-cued faults on an automated assembly machine. The machine assembles 8 mm circular parts, from a bulk-supply, onto continuously moving carriers at a rate of over 100 assemblies per minute. Common faults on the machine include part jams and ejected parts that occur at different locations on the machine. Two sensor systems are installed on the machine for detecting and isolating these faults: an image-based system consisting of a single camera and a signal-based sensor system consisting of multiple greyscale sensors and limit switches. The requirements and performance of both systems are compared for detecting six faults on the assembly machine. It is found that both methods are able to effectively detect the faults but they differ greatly in terms of cost, ease of implementation, detection time and fault isolation capability. The conventional signal-based sensors are low in cost, simple to implement and require little computing power, but the installation is intrusive to the machine and readings from multiple sensors are required for faster fault detection and isolation. The more sophisticated image-based system requires an expensive, high-resolution, high-speed camera and significantly more processing power to detect the same faults; however, the system is not intrusive to the machine, fault isolation becomes a simpler problem with video data, and the single camera is able to detect multiple faults in its field of view.

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