Table of Content

25 December 2022, Volume 33 Issue 24

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Design and Experimental Study of Full-ocean-depth Macro-organisms Pressure-retaining Sampling-culture System

LIU Guangping, JIN Yongping, PENG Youduo, LIU Deshun, WAN Buyan

2022, 33(24):  2899-2907.  DOI: 10.3969/j.issn.1004-132X.2022.24.001

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A new design method of a macro-biological pressure-retaining sampling-culture system at full-ocean depth(operating water depth of 11 000 m) was presented. The system might realize macro-biological pressure-retaining sampling in the full-ocean-depth environment, and at the same time met the requirements of pressure-free transferring and in-situ culture in the laboratory. The basic structure and working principles of the full-ocean-depth macro-biological pressure-retaining sampling-culture system were introduced in details, and the full-ocean-depth macro-biological pressure-retaining sampling-culture system were designed and analyzed. With the developed engineering prototype of the full-ocean-depth macro-biological pressure-retaining sampling, the pressure-retaining performance and sample transfer tests of the full-ocean-depth macro-biological pressure-retaining sampling were carried out. The experimental results show that the full-ocean-depth macro-biological pressure-retaining sampling may bear the pressure of 127 MPa, and the greater the internal pressure of the sampler, the better the pressure-retaining performance, and the transfer without pressure drop is realized in the ultra-high pressure environments, to provide high-quality macro-biological pressure-retaining samples for deep seabed scientific research.

Study on Influences of Reciprocating Speed Planning on Curve Grinding Processes

XIE Zhaolong, XU Liming, WANG Kunzi, ZHOU Chao, ZHAO Da

2022, 33(24):  2908-2916.  DOI: 10.3969/j.issn.1004-132X.2022.24.002

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Reciprocating machining was common in metal cutting such as grinding and planing, the smoothness of the machining processes directly affected the machining quality, energy efficiency and even the life of the machine tools. Firstly, the influences of reciprocating(stroke) motion speed planning on the smoothness of motion processes were explored, based on the analysis of the kinematics performance of common speed planning, according to the characteristics of grinding stroke motion, it was proposed to reduce the influences of soft impact on machined surface quality by changing the spatial distribution of jerks, and two speed planning algorithms were designed based on jerk continuity. Then, the relationship between speed planning algorithm and grinding force smoothness, machining surface roughness and machining energy consumption were studied, the method of reducing energy consumption by changing the spatial distribution of acceleration was proposed.The experimental results show that the speed planning of reciprocating motions is related to the smoothness of grinding forces, the roughness of machined surfaces and the energy consumption of machining. By changing the spatial distributions of jerk and acceleration, the smoothness of grinding forces and the quality of machined surfaces are improved, and the energy consumption of machining is reduced.The comprehensive performance of the proposed type Ⅱ speed planning is superior to other planning. Compared with the trapezoidal speed planning, the cutting force fluctuation, machining surface roughness and motor driving energy consumption are significantly reduced.

Control of Foot Landing Flexibility in Metamorphic Robot Reconstruction and Steering

LIU Jun, RUAN Xiaodong, YANG Pengliang, WU Di, ZHENG Minyi

2022, 33(24):  2917-2926.  DOI: 10.3969/j.issn.1004-132X.2022.24.003

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Metamorphic robot might switch naturally between wheeled driving and foot walking according to the changes of external environments, so that the robot might both run fast on the smooth structure of the road and climb over obstacles in rugged mountains. Based on the generalized coordinate method, a kinematics model of the steering and reconstruction processes of the transformer robots was established. Considering the impacts of the swinging leg in contact with the environment during the reconstruction processes, an impedance control method was proposed to realize the landing smoothness control of the swinging legs. Based on the traditional impedance control, an adaptive impedance controller was designed based on Lyapunov asymptotic stability theorem, and the parameters of impedance control were optimized by particle swarm optimization algorithm. Through simulation analysis under different environmental stiffness, it is proved that the adaptive impedance controller after parameter optimization may follow the expected contact force well, and improve the adaptability of the variable cell robots to the unknown and changeable environments. Finally, a road experiment was carried out for the transformation robot to land on the feet in the reconfiguration processes, which further confirmed the superiority of the optimized adaptive impedance control method.

A Gearbox Composite Fault Diagnosis Based on Enhanced CYCBD

QI Yongsheng, SHAN Chengcheng, JIA Shunyu, LIU Liqiang, DONG Chaoyi,

2022, 33(24):  2927-2941,2952.  DOI: 10.3969/j.issn.1004-132X.2022.24.004

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Aiming at the problems that the gearbox composite fault vibration signals were susceptible to severe interference from background noise, which made it difficult to accurately separate the impact characteristics of composite faults with traditional methods, an adaptive CYCBD and 1.5-dimensional derivative spectrum were proposed for composite fault diagnosis. First, the cyclic frequency components associated with the fault characteristics in the composite fault vibration signals were detected by using cyclic spectrum analysis to construct cyclic frequency sets of different target types. After that, an improved algorithm for adaptively selecting the optimal filter length of CYCBD with the third-order cumulative sparsity(TCS) as the index was proposed according to different types of cyclic frequency sets, so as to better obtain the optimal filter length containing different fault shock components. Finally, a new 1.5-dimensional derivative spectrum was proposed for feature enhancement to improve the signal-to-noise ratio and to analyze the prominent fault feature frequencies in the spectrum to discriminate the fault types. The algorithm was validated by simulated signals and fault experimental platform data, and the results show that the method may achieve the accurate separation and diagnosis of compound faults in gearboxes.

Design and Lubrication Characteristics of a New Integrated Slipper/Swashpalte Interface in Seawater Hydraulic Piston Pumps

GUO Ming, NIE Songlin, JI Hui, YIN Fanglong

2022, 33(24):  2942-2952.  DOI: 10.3969/j.issn.1004-132X.2022.24.005

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In the traditional seawater hydraulic piston pumps, the inherent structure of the slippers made it susceptible to problems such as eccentric wear and slipper burning. A new integrated slipper was proposed to fundamentally eliminate the overturning problem of slippers caused by centrifugal forces and to reduce the lateral force on the pistons. The lubrication mathematical model of the integrated slipper/swashplate interface was established, and the influences of temperature and working condition parameters on the lubrication and energy consumption characteristics were analyzed. The results show that with the increase of medium temperature, the dynamic pressure effects of integrated slipper decreases, the water film thickness decreases, resulting in the decrease of leakage. And the viscosity decreases with the increase of temperature, the friction forces on the integrated slipper decrease, and the viscous friction power losses decrease. With the increase of working pressure, the water film thickness increases, the leakage increases, and on the contrary, the viscous friction power losses decrease. With the increase of the shaft speed, the volumetric power losses and viscous friction power losses of the integrated slipper/swashplate interface increase.

Effects of Porous Baffle on Characteristics of Liquid Sloshing Impact Pressure

SHEN Minmin, SUN Chuanbin, TONG Baohong, HOU Tongshen

2022, 33(24):  2953-2960.  DOI: 10.3969/j.issn.1004-132X.2022.24.006

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The liquid sloshing in the tank was excited by ship navigation in waves. The exciting forces would cause local damages to the tank structure and affect the ships motion attitude, which might effectively avoid by the porous baffles. A large-amplitude horizontal excitation test platform was constructed to discuss the response laws of impact pressure to frequency. The time domain and frequency domain characteristics of impact pressure were analyzed under the influences of porous baffles at different excitation frequencies. The reasons for the difference of impact pressure characteristics were explained from the aspect of baffle structure and vortex strength. The results show that the nonlinear characteristics such as wave overturning and breaking under large amplitude excitations will lead to the deviation of resonance frequency from natural frequency. The porous baffle may reduce the peak value and peak width of liquid sloshing impact pressure, and the reduction rate of pressure peak value is more significant at the first natural frequency. The porous baffle does not change the primary frequency component in the amplitude-frequency, and there is only a low-frequency component with low energy in the time spectrum. The solid structure of the porous baffle blocks most of the fluid movement in the traveling wave, and a small part of the remaining fluid will produce vortex movement through the pores to dissipate energy and slow down the impact of the fluid on the liquid bulkhead surfaces.

Active Control Method for Energy Conversion and Experimental Test of Hopping Robots

WANG Jian, MIAO Long, ZHANG Wenxiang, WANG Shukun

2022, 33(24):  2961-2970.  DOI: 10.3969/j.issn.1004-132X.2022.24.007

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 To change the present situations of the low energy conversion efficiency, a new type hopping robot was proposed. The basic thought was to control the energy storage and release by non-circular gear meshing. Based on the principles of robot mechanisms, the main structure of the hopping robots was built. Motion principle was analyzed and motion procedure of the hopping robots was developed. According to the pre-given key parameters of energy conversion curve, pitch curves of non-circular gears were investigated by exploring the energy conversion curves, while hopping properties of hopping robots were revealed by exploring meshing properties of non-circular gears. The mathematical models of non-circular gear transmission were established. A detailed introduction about the design processes of non-circular gears was given by using examples. Using 3D printing technique, the robot prototype was developed, and the experiments for hopping robots were carried out. The results confirm that the stable hopping may be realized, and the experimental results are close to the pre-given values.

Research on Longitudinal-Torsion Compound Ultrasonic Vibration Dry Milling Characteristics for AlMgSc Alloys Formed by Arc Micro-casting and Forging Additive Manufacturing

HAN Guangchao, YANG Jiakai, YE Zejiu, XU Linhong, ZHANG Haiou, YANG Haitao

2022, 33(24):  2971-2979,2989.  DOI: 10.3969/j.issn.1004-132X.2022.24.008

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The longitudinal-torsion compound ultrasonic vibration dry milling characteristics were experimentally studied for AlMgSc alloys formed by arc micro-casting and forging additive manufacturing. The influence rules of ultrasonic milling parameters, such as cutting force, surface morphology, work hardening and tool wear, were discussed about the dry milling forming characteristics of AlMgSc alloys. Results show that the arc micro-casting and forging additive manufactured AlMgSc alloys which have more dense microstructure, higher strength and hardness comparing with conventional forging and common arc added material forming aluminum alloys, may produce larger milling forces in ultrasonic dry milling processes and be more likely to occur work hardening phenomenon. And the longitudinal-torsion compound ultrasonic vibration dry milling may get lower surface roughness and is helpful to reduce the tool wear comparing with conventional dry milling.

Highly Robust Two-stage LiDAR-IMU External Parameter Online Calibration Algorithm

LIN Xin, ZHANG Jie, FENG Jingyi, MENG Jie, WANG Shuting

2022, 33(24):  2980-2989.  DOI: 10.3969/j.issn.1004-132X.2022.24.009

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Aiming at the problems that the degraded sensor data were difficult to calibrate external parameters when the vehicles were moving in an approximate plane, a highly robust two-stage LiDAR-IMU external parameters online calibration algorithm was proposed. The calibration algorithm included two stages: initial value calculation and online iterative optimization using nonlinear sliding window. In the first stage, the outliers in the pre-data set were eliminated, the hand-eye calibration model that contained only the rotation components was solved multiple times in the form of a sliding window, meanwhile, the conditions of the analytical solution screening were improved, the singular value decomposition（SVD） analytical solution of multiple weighted rotation external parameters was solved. The second stage minimized the residual function containing the external parameters, and used the rotational analytical solution as the initial value sliding window to iteratively optimize the six-degree-of-freedom external parameters, so that the external parameters converged quickly. In order to avoid the degradation of external parameters, when the degenerate motion and error history constraints were too large, the external parameters would be fixed. Compared with the original algorithm, the algorithm is robust to degraded sensor data, which may achieve accurate and robust online calibration of external parameters without the initial values of the external parameters.

Research on Multi-source Transfer Learning Bearing Fault Diagnosis Based on Shapelets Time Series

LI Ke, , YAN Han, GU Jiefei, , SU Lei, SU Wensheng, XUE Zhigang

2022, 33(24):  2990-2996,3006.  DOI: 10.3969/j.issn.1004-132X.2022.24.010

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Aiming at the problems that the available fault data of rolling bearing fault diagnosis were scarce in industrial productions, a multi-source transfer learning bearing fault diagnosis method was proposed based on shapelets time series. Firstly, source domain sets were constructed by the laboratory data which included abundant typical fault information and sufficient label information, and the source domain feature extractor and classifier were trained using the training data of each source domain. Then, the shapelets learning algorithm based on dynamic time warping (DTW) was used to extract the shapelets of the source domain and the target domain as the discriminant structure, the source domain data was optimized through the measurement discriminant structure, and the source domain network classifier was fine tuned to obtain the diagnostic model. Finally, according to the difference between the shapelets of each source domain and the target domain, the results of each classifier were aggregated by using the adaptive domain weight to obtain the diagnosis results. Experimental results show that the proposed method has good fault diagnosis performance in the case of few shot and high noise.

Compliance Control of Dual-arm Space Robot Capture Satellite Based on Barrier Lyapunov Functions

ZHU An, AI Haiping, CHEN Li

2022, 33(24):  2997-3006.  DOI: 10.3969/j.issn.1004-132X.2022.24.011

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Space robot would inevitably contact and impact with satellites during the capture operations. If the joints were not effectively protected in this process, it was easy to cause the failures of the capture operations. Therefore, a spring-damper device(SDD) between the joint motors and the manipulators was proposed and added, the device might absorb the impact energy and suppressed the flexible vibrations, and might mathch the designed compliance strategy designed to achieve compliance of capture operations. The dynamics model of dual-arm space robot open-loop system and satellite system before capture was established by using Lagrange function based on dissipation theory and Newton-Euler function respectively. Combined with Newtons third law, velocity constraints of capture points, closed-chain geometric constraints, the closed-chain dynamics model of hybrid system after capture was obtained, and the impact effects and impact forces were calculated by utilizing the momentum conservation. Based on the barrier Lyapunov functions, a state constraint control method was designed to realize high-precision tracking of trajectory, the influences of system parameter uncertainty were solved by fuzzy adaptive controller. The stability of the system was proved by Lyapunov theorem, and the impact resistance of the device and the effectiveness of the proposed strategy were verified by numerical simulations.

Selection of Shield Construction Parameters in Specific Sections Based on e-SVR and Improved Particle Swarm Optimization Algorithm

XU Zhedong, HOU Gongyu, YANG Li, HUANG Xiaojun

2022, 33(24):  3007-3014.  DOI: 10.3969/j.issn.1004-132X.2022.24.012

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To achieve more accurate selection of shield construction parameters in specific sections, a shield construction parameter selection model was proposed based on e-SVR and IIWDSPSO algorithm. Firstly, the nonlinear relationship model among tunneling parameters, formation parameters, geometric parameters and surface settlement was established based on e-SVR, and the performance was compared with ANN(artificial neural network) and RF(random forests) models based on the actual shield construction data. Secondly, the influences of inertia weight decreasing speed on algorithm performance were studied by 10 groups of simulation experiments. The tunneling parameters in specific formation parameters and geometric parameter intervals were optimized based on the improved PSO algorithm. The results show that e-SVR model has better fitting and generalization ability for shield construction data samples, and the proposed IIWDSPSO algorithm has better accuracy, stability and convergence probability. The practical engineering application results also verify that the proposed model may obtain the tunneling parameters in a specific section, which may make the ground settlement value relatively smaller. The obtained tunneling parameters may provide a more accurate and reliable reference for practical engineering.

Construction of Knowledge Graph of Maintainability Design Based on Multi-domain Fusion of High-speed Trains

GUO Heng, LI Rong, ZHANG Haizhu, WEI Yongjie, DAI Yuebin

2022, 33(24):  3015-3023.  DOI: 10.3969/j.issn.1004-132X.2022.24.013

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 In order to realize the knowledge extraction, knowledge fusion and structured storage of unstructured high-speed trains multi-domain data, the construction method of high-speed trains maintainability design knowledge graph was studied based on multi-domain data fusion. The ontology concept elements of model layer, the processes of the construction of the data layer and the knowledge fusion of high-speed trains maintainability design knowledge graph were analyzed closely, the bogie knowledge graph platform and the knowledge retrieval system were displayed based on Neo4j graph database. The knowledge graph construction technology studied may extract and integrate knowledge from multi-source and multi-domain data in the field of high-speed trains, assist designers in product maintainability design and improve product quality.