scholarly journals Fault Diagnosis Research on Impact System of Hydraulic Rock Drill Based on Internal Mechanism Testing Method

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yelin Li ◽  
Youxin Luo ◽  
Xiao Wu
Keyword(s):  
Fault Diagnosis ◽  
Fault Rock ◽  
Impact Performance ◽  
Rock Drill ◽  
Diagnosis Method ◽  
New Type ◽  
Internal Mechanism ◽  
Left And Right ◽  
Improved Model ◽  
The Impact

In the production and manufacturing process of hydraulic rock drill, there are small impact energy and low impact frequency, and a fault diagnosis method based on the internal mechanism testing and testing of the hydraulic rock drill is proposed. This method is used to test the change law of hydraulic oil in the rock drill, by retaining the test holes on the cylinder body and other important components of the hydraulic rock drill. At the same time, the mathematical method is used to deal with the test curve, and the influence of pressure pulsation characteristics of the front and rear chambers of the impact piston and the left and right valve chambers of the reversing valve on the impact performance of the rock drill is analyzed. Based on Newton’s law, the model of the impact piston and reversing valve is established. According to the velocity and other parameters of the impact piston, the size of the impact piston switch point is calculated. The coupling between the movement of the impact piston and the movement of the reversing valve is analyzed according to the model established. Comparing the results of the experimental data, the correctness of the fault diagnosis analysis method and model is verified. The effect of the fault rock drill and the improved model is compared, and the theoretical basis is provided for the fault diagnosis of the rock drill and the design of a new type of rock drill.

scholarly journals An Early Fault Diagnosis Method of Rolling Bearings on the Basis of Adaptive Frequency Window and Sparse Coding Shrinkage

Entropy ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 584
Author(s):  
Shuting Wan ◽  
Bo Peng
Keyword(s):  
Fault Diagnosis ◽  
Frequency Band ◽  
Sparse Coding ◽  
Optimal Frequency ◽  
Rolling Bearings ◽  
Diagnosis Method ◽  
Frequency Window ◽  
Envelope Spectrum ◽  
The Impact ◽  
Periodic Components

Early fault information of rolling bearings is weak and often submerged by background noise, easily leading to misdiagnosis or missed diagnosis. In order to solve this issue, the present paper puts forward a fault diagnosis method on the basis of adaptive frequency window (AFW) and sparse coding shrinkage (SCS). The proposed method is based on the idea of determining the resonance frequency band, extracting the narrowband signal, and envelope demodulating the extracted signal. Firstly, the paper introduces frequency window, which can slip on the frequency axis and extract the frequency band. Secondly, the double time domain feature entropy is proposed to evaluate the strength of periodic components in signal. The location of the optimal frequency window covering the resonance band caused by bearing fault is determined adaptively by this entropy index and the shifting/expanding frequency window. Thirdly, the signal corresponding to the optimal frequency window is reconstructed, and it is further filtered by the sparse coding shrinkage algorithm to highlight the impact feature and reduce the residue noise. Fourthly, the de-noised signal is demodulated by envelope operation, and the corresponding envelope spectrum is calculated. Finally, the bearing failure type can be judged by comparing the frequency corresponding to the spectral lines with larger amplitude in the envelope spectrum and the fault characteristic frequency. Two bearing vibration signals are applied to validate the proposed method. The analysis results illustrate that this method can extract more failure information and highlight the early failure feature. The data files of Case Western Reserve University for different operation conditions are used, and the proposed approach achieves a diagnostic success rate of 83.3%, superior to that of the AFW method, SCS method, and Fast Kurtogram method. The method presented in this paper can be used as a supplement to the early fault diagnosis method of rolling bearings.

scholarly journals Model-Based Fault Diagnosis Approach for Rotor System with Unidentified Supporting Parameters

2011 ◽  
Vol 2-3 ◽  
pp. 773-778
Author(s):  
Hong Liang Yao ◽  
Hong Bin Ma ◽  
Qing Kai Han ◽  
Bang Chun Wen
Keyword(s):  
Fault Diagnosis ◽  
Fault Location ◽  
Synthesis Method ◽  
Strong Impact ◽  
Rotor Systems ◽  
Modal Test ◽  
Model Based ◽  
Diagnosis Method ◽  
Fixed Interface ◽  
Improved Model

The model based diagnosis method can detect both the fault location and the fault extent of the rotating machinery at the same time as it can combine the dynamics and fault diagnosis method together. However, the modal test of the supporting part is necessary when using the existing model based method, and the precision of the modal test results make a strong impact on the diagnosis results. In order to improve this case, an improved model based diagnosis method is presented herein by combining the fixed-interface modal synthesis method with the traditional model based diagnosis method. The DOF of the unidentified parameter due to the supporting parts are partitioned to interface DOF, and the displacement information of the supporting parts can be measured by the mounted sensors. Therefore, the model based diagnosis method can be carried out by only using the parameters of the rotor without considering the effects from the supporting, which can greatly improve the diagnosis precision and efficiency. This method is fit for the rotor systems with unidentified supporting parameter, and the rotor systems with unknown nonlinear supporting parameter. Both the numerical simulation results and the experiment results in the example proved the efficiency of this method.

Spacecraft Fault Diagnosis Based on Telemetry Data Mining and Fault Tree Analysis and Design of Expert System

2013 ◽  
Vol 760-762 ◽  
pp. 1062-1066 ◽  
Author(s):  
Xiang Gao ◽  
Tao Zhang ◽  
Hong Jin Liu ◽  
Jian Gong
Keyword(s):  
Data Mining ◽  
Fault Diagnosis ◽  
Expert System ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Telemetry Data ◽  
Tree Analysis ◽  
Analysis And Design ◽  
Diagnosis Method ◽  
The Impact

In this paper, a fault diagnosis method for spacecraft based on telemetry data mining and fault tree analysis was proposed. Decision trees are constructed from the history telemetry data of the spacecraft, and are used to classify the current data which is unknown whether it is fault. If there is a fault, the fault tree method will be used to analyze the fault reason and the impact on the spacecraft system. This method can effectively solve the problem of diagnostic knowledge acquisition. We design and construct a fault diagnosis expert system for spacecraft based on this diagnosis method. An experiment is presented to prove the effectiveness and practicality of the expert system.

Flocking with Fault Tolerant Control and Obstacles Avoidance for Mobile Robots Based on Grid Maps

2014 ◽  
Vol 631-632 ◽  
pp. 669-675
Author(s):  
Yong Xiong ◽  
Ji Liang Lin
Keyword(s):  
Fault Tolerance ◽  
Fault Diagnosis ◽  
Mobile Robots ◽  
Control Strategy ◽  
Control Algorithm ◽  
Fault Tolerant ◽  
Actuator Failure ◽  
Diagnosis Method ◽  
Tolerance Control ◽  
The Impact

Taking α-lattice flocking as research object, the influence when faults occur in flock and its fault tolerance control algorithm is studied. The impact on flocking performance is analyzed by means of flocking property indexes when communication error, actuator failure or sensor malfunction occur. A flocking fault diagnosis method and fault tolerance control strategy based on communication and data association are introduced. Considering failure mobile robots as obstacles, a complex shaped obstacles avoidance algorithm is proposed. Simulation shows the effectiveness of the method.

Research on Fault Diagnosis System for Aircraft Hydraulic Power Carts Based on Fuzzy Diagnosis Theory

2012 ◽  
Vol 220-223 ◽  
pp. 607-610
Author(s):  
Wei Qiang Zhao ◽  
Yong Xian Liu ◽  
Mo Wu Lu
Keyword(s):  
Fault Diagnosis ◽  
High Reliability ◽  
Complex Structure ◽  
Hydraulic Power ◽  
Diagnosis System ◽  
Diagnosis Method ◽  
New Type ◽  
Fault Diagnosis System ◽  
Fault Mode ◽  
Fuzzy Diagnosis

Aircraft hydraulic power carts are important aviation support equipment. Because of their complex structure they have high failure rate. Therefore fault diagnosis system for hydraulic power carts is necessary to ensure high reliability and maintainability for hydraulic power carts. This paper presents a diagnosis method based on fuzzy diagnosis theory in the developing process of a new type of hydraulic power carts. The fault Symptom, critical value and fault causes are established based on the research of fault mode for hydraulic power carts. And also the mathematical model of fault diagnosis for hydraulic power carts is established based on fuzzy diagnosis theory. The practical test results and fault diagnosis instances show that with this fault diagnosis system fast fault diagnosis for hydraulic power carts was carried out successfully.

scholarly journals Research on the Matching of Impact Performance and Collision Coefficient of Hydraulic Rock Drill

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yelin Li
Keyword(s):  
Stress Wave ◽  
Wave Model ◽  
Wave Theory ◽  
Collision Velocity ◽  
Impact Performance ◽  
Impact Stress ◽  
Material Condition ◽  
Rock Drill ◽  
The Impact ◽  
The Relationship

The stress wave produced by the piston impact, on the drill rod, is an important factor affecting impact performance. It is particularly important to control the stress waveform generated by the piston impact on the drill rod to meet the requirements of efficiency and component durability of some impact mechanical systems. Based on wave theory, the impact stress wave model of rock drilling is established, a dimensionless collision coefficient γ is put forward, and the matching relationship between different collision coefficients γ and stress waveforms is analysed. The length of the impact piston under the same material condition determines the change rule of the waveform. The stress waveform experimental verification is thus designed. The pressure chamber curves of different pistons in the rock drill were tested, the collision velocity of the piston was obtained, and the impact energy and impact power were calculated. The relationship between the impact performance and the collision coefficient γ is analysed. When γ is in the range of 9–11, the impact piston’s design of a high-power rock drill can be satisfied. When γ is in the range of 3∼5, it is mainly designed for low-power rock drills.

scholarly journals A Hybrid Gearbox Fault Diagnosis Method Based on GWO-VMD and DE-KELM

2021 ◽  
Vol 11 (11) ◽  
pp. 4996
Author(s):  
Gang Yao ◽  
Yunce Wang ◽  
Mohamed Benbouzid ◽  
Mourad Ait-Ahmed
Keyword(s):  
Feature Extraction ◽  
Fault Diagnosis ◽  
Vibration Signal ◽  
Optimization Techniques ◽  
Fault Classification ◽  
Vibration Signals ◽  
Kernel Parameter ◽  
Diagnosis Method ◽  
The Impact ◽  
Fault Feature Extraction

In this paper, a vibration signal-based hybrid diagnostic method, including vibration signal adaptive decomposition, vibration signal reconstruction, fault feature extraction, and gearbox fault classification, is proposed to realize fault diagnosis of general gearboxes. The main contribution of the proposed method is the combining of signal processing, machine learning, and optimization techniques to effectively eliminate noise contained in vibration signals and to achieve high diagnostic accuracy. Firstly, in the study of vibration signal preprocessing and fault feature extraction, to reduce the impact of noise and mode mixing problems on the accuracy of fault classification, Variational Mode Decomposition (VMD) was adopted to realize adaptive signal decomposition and Wolf Grey Optimizer (GWO) was applied to optimize parameters of VMD. The correlation coefficient was subsequently used to select highly correlated Intrinsic Mode Functions (IMFs) to reconstruct the vibration signals. With these re-constructed signals, fault features were extracted by calculating their time domain parameters, energies, and permutation entropies. Secondly, in the study of fault classification, Kernel Extreme Learning Machine (KELM) was adopted and Differential Evolutionary (DE) was applied to search its regularization coefficient and kernel parameter to further improve classification accuracy. Finally, gearbox vibration signals in healthy and faulty conditions were obtained and contrast experiences were conducted to validate the effectiveness of the proposed hybrid fault diagnosis method.

Development and Application of a New Type Rock Drill with Hydraulic Rotary Cutting and Pneumatic Impacting

2012 ◽  
Vol 152-154 ◽  
pp. 1373-1376
Author(s):  
You Xin Luo ◽  
Hui Jun Wen ◽  
Yu Zhou
Keyword(s):  
High Performance ◽  
Simple Structure ◽  
High Reliability ◽  
Price Ratio ◽  
Rock Drill ◽  
Drilling Tools ◽  
New Type ◽  
Rotary Cutting ◽  
Pneumatic Power ◽  
The Impact

A new type hydraulic rotary cutting and pneumatic impacting rock drill is used to drill medium and deep hole. This rock drill is made up of three components: impact system, rotary system and dedust mechanism. The power is provided by hydraulic liquid and compressed air, and the hydraulic power is separated with the pneumatic power. The rotary system driven by hydraulic liquid transfers motion and force by its components: motor, input gear, mid-gear, revolving sheath, etc. The maximum rotary power is greater than the impact power. Compared with other drill, this new rock drill has a simple structure, high reliability, fast drilling speed, long service life of the drilling tools, easy maintenance, high performance-price ratio and other advantages

Outline of Electromagnetic Damper and Further Research on Theoretical Model

2012 ◽  
Vol 204-208 ◽  
pp. 4523-4528
Author(s):  
Xiang Yang Zou ◽  
Xiao Tian Wang ◽  
Guang Yang ◽  
Bo Liu ◽  
Zong Yuan Zhao ◽  
...  
Keyword(s):  
Vibration Reduction ◽  
Structural Vibration ◽  
Velocity Amplitude ◽  
Simulation Calculation ◽  
Practical Engineering ◽  
New Type ◽  
Improved Model ◽  
Sound Foundation ◽  
The Impact ◽  
Electromagnetic Damper

The author firstly summarized the principles, performance and theoretical resilience model of the new type electromagnetic damper. The theoretical resilience model is further improved on this basis—normalizing the impact of vibrant frequency and vibrant amplitude on resilience as the impact of single parameter velocity amplitude. The results show that improved model can give a better effect as shown in experiment. This lays a sound foundation for simulation calculation in developing products using for practical engineering and installing the structural vibration reduction system of electromagnetic damper.

Sign in / Sign up

Export Citation Format

Share Document