Measurement of Transmission Error Using Rotational Laser Vibrometers

2007 ◽  
Author(s):  
Robert White ◽  
Vikrant Palan
Keyword(s):  
Transmission Error ◽  
Time Averaging ◽  
Error Measurement ◽  
Gear Noise ◽  
Alternative Method ◽  
Inspection Data ◽  
Synchronous Time ◽  
Development Engineer

Transmission error is the quantity that best correlates with gear noise. Using gear inspection data, one can estimate transmission error, however actually measuring it is a substantial task. For the most part, there are two groups of people who measure transmission error: those doing gear inspection and researchers. While it could prove useful in gearbox development, it is rarely done in this context because the equipment required to make transmission error measurements doesn’t package well, is expensive, can be difficult to use and is generally not very flexible. Transmission error is usually measured on test stands built particularly for that reason. An alternative method for transmission error measurement is now available to the development engineer who desires to make this measurement on his gearbox (such as for transmission noise development). This technique makes use of two rotational laser vibrometers and a synchronous time averaging algorithm. The laser approach is particularly appealing because it requires very little modification to the gearbox. Furthermore, it allows one to access gears within the gearbox which do not extend through the gearbox walls. The laser approach, however, has some of its own special challenges, but when those are adequately addressed, one has the capability to measure transmission error between nearly any two gears in a gearbox.

Accuracy of small encoders for gear transmission errors

2001 ◽  
Vol 215 (8) ◽  
pp. 995-998 ◽  
Author(s):  
J. D. Smith
Keyword(s):  
Production Control ◽  
Transmission Error ◽  
Gear Transmission ◽  
Development Work ◽  
Error Measurement ◽  
Gear Noise ◽  
Transmission Errors ◽  
Gear Drives

For noise investigations and development work or precision production control of gear drives there are major advantages to using small encoders for transmission error measurement in situ owing to reduced size, inertias and cost. As there was uncertainty concerning the accuracies that would be obtained in practice, a small encoder was calibrated and found to be surprisingly accurate at those frequencies of importance for gear noise.

Investigation of Impact Profile and Isolation Effect in Automated Impact Device Design and Control for Operational Modal Analysis

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Z. C. Ong ◽  
C. C. Lee
Keyword(s):  
Modal Analysis ◽  
Isolation Effect ◽  
Time Averaging ◽  
Impact Device ◽  
Lack Of Information ◽  
Analysis Technique ◽  
And Control ◽  
Phase Angles ◽  
Synchronous Time

A novel modal analysis technique called impact-synchronous modal analysis (ISMA) was introduced in previous research. With the utilization of impact-synchronous time averaging (ISTA), this modal analysis can be performed in presence of ambient forces whereas the conventional analysis method requires machines to be totally shut down. However, lack of information of phase angles with respect to impact in ISMA has caused it to be labor-intensive and time-consuming. An automated impact device (AID) is introduced in this study in the effort to replace the manually operated impact hammer and prepare it to be used in the current practice of ISMA on the purpose of enhancing its effectiveness and practicability. Impact profile and isolation effect are noted to be the contributing parameters in this study. This paper devoted on calibrating and controlling of the AID which gives the desired impact profiles as compared to the manual impact hammer. The AID is found effective in the determination of dynamic characteristics when the device is isolated from the boundary condition of the test structure.

A New Numerical Algorithm for Transmission Error Measurement at Gears Meshing

2012 ◽  
Vol 472-475 ◽  
pp. 1563-1567
Author(s):  
Ai Jun Xu ◽  
Xiao Zhong Deng ◽  
Jing Zhang ◽  
Kai Xu ◽  
Ju Bo Li
Keyword(s):  
Numerical Algorithm ◽  
Angular Resolution ◽  
Angular Displacement ◽  
Transmission Error ◽  
Comparison Method ◽  
Dynamic Measurement ◽  
Driving Mechanism ◽  
Error Measurement ◽  
Measurement Algorithm ◽  
Constrained Conditions

Many different methods have been developed for the measurement of transmission error (T.E.) at gears meshing. Each strategy improved the measurement performance is based on comparing the phases of sequence signals by counting the number of encoder pulses. The phase comparison method of T.E. is a dynamic measurement algorithm with lower angular resolution and many constrained conditions. This paper presents a new numerical algorithm aimed to provide the high accuracy information of instantaneous T.E. in the form of angular displacement. The analysis approach uses phase shift and demodulation technology in frequency domain to process the signals generated by encoders fixed on the both shaft of the gear driving mechanism. Finally, the algorithm is tested by simulation of gear meshing signal in Matlab software.

Measurement of Joint Element Transmission Error in a Humanoid Walking Robot

2012 ◽  
Vol 566 ◽  
pp. 348-352 ◽  
Author(s):  
Kiyoto Itakura ◽  
Hitonobu Koike ◽  
Katsuyuki Kida ◽  
Kenji Kanemasu
Keyword(s):  
Humanoid Robots ◽  
Power Input ◽  
Transmission Error ◽  
Error Measurement ◽  
Harmonic Drive ◽  
Walking Robot ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone ◽  
Joint Element ◽  
Ether Ketone

In the present work, a prototype of a joint element to be used in lightweight and compact joints for tall humanoid robots is investigated. The newly developed element consists of a harmonic drive gearing device, a multi axis mechanism and a resin bush. Bushes produced from two kinds of bush materials: poly-ether-ether-ketone (PEEK) and polyacetal (POM) were tested. Furthermore, two testing machines to evaluate the joints were constructed: for the power input-output transmission error measurement and for the investigation of the influence of walking-load on bush wear.

scholarly journals From Transmission Error Measurements to Angular Sampling in Rotating Machines with Discrete Geometry

2005 ◽  
Vol 12 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Didier Remond ◽  
Jarir Mahfoudh
Keyword(s):  
Discrete Geometry ◽  
Signal To Noise Ratio ◽  
Transmission Error ◽  
Operating Conditions ◽  
Spectral Amplitude ◽  
Error Measurement ◽  
Rotating Machines ◽  
Analysis Window ◽  
Sampling Procedures ◽  
Monitoring And Measurement

The benefits of angular sampling when measuring various signals in rotating machines are presented and discussed herein. The results are extracted from studies on transmission error measurements with optical encoders in the field of power transmissions and can be broadened to include phase difference measurements, such as torsional vibrations, and applied to control, monitoring and measurement in rotating machines with discrete geometry. The main conclusions are primarily that the use of angular sampling enables the exact location of harmonics and, consequently, the obtaining of spectral amplitude components with precision. This is always true even if the resolution of encoders is not directly related to the studied discrete geometry. It then becomes possible to compare these harmonics under different operating conditions, especially when speed varies, without changing any parameters in spectral analysis (window length, spectral resolution, etc.). Moreover, classical techniques of improving signal to noise ratio by averaging become fully efficient in the detection of defective elements. This study has been made possible thanks to the technique of transmission error measurement with optical encoders that allows the comparison of sampling procedures, based on the same raw data.The intensive use of such transducers and the development of an original transmission error measurement technique lead to advocate the use of angular sampling in experimental measurements in rotating machines with discrete geometry.

Gear Transmission Error Accuracy with Small Rotary Encoders

1987 ◽  
Vol 201 (2) ◽  
pp. 133-135 ◽  
Author(s):  
J D Smith
Keyword(s):  
High Frequency ◽  
Transmission Error ◽  
Gear Transmission ◽  
Vibration Testing ◽  
Noise And Vibration ◽  
Gear Noise ◽  
Frequency Components

Two small (90 mm) angle encoders were tested back to back to assess sizes of high-frequency components of error. The results showed errors well below 0.1 seconds of arc at the rotation multiples likely to be relevant for gear noise and vibration testing.

OS1-3 Engagement of micro gears and development of micro rotary encoder for transmission error measurement

2011 ◽  
Vol 2011 (0) ◽  
pp. 5-6
Author(s):  
Syuhei KUROKAWA ◽  
Yoji UMEZAKI ◽  
Yoji MATSUKAWA ◽  
Osamu OHNISHI ◽  
Michio UNEDA ◽  
...  
Keyword(s):  
Transmission Error ◽  
Error Measurement ◽  
Rotary Encoder
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