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液体静压支承 2

9 + 2结构 1

KTP 1

WEM法 1

主动控制 1

事件触发控制;分段仿射系统;线性矩阵不等式;执行器饱和;H∞性能 1

二次调节 1

产乙酸菌 1

亲/疏水界面修饰 1

人工纤毛 1

人工肌肉;智能材料;介电弹性体(DE);聚氯乙烯(PVC)凝胶;执行器;可穿戴式人体助力;运动康复 1

仿生系统 1

传统节流器 1

传递函数 1

低雷诺数 1

体硅键合技术 1

倍频 1

光遗传学 1

分数阶系统;稳定性;中立时滞;鲁棒性;饱和性 1

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Multi-objective optimization of surface texture for the slipperswash plate interface in EHA pumps

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0704-4

摘要: Well-designed surface textures can improve the tribological properties and the efficiency of the electro-hydrostatic actuator (EHA) pump under high-speed and high-pressure conditions. This study proposes a multi-objective optimization model to obtain the arbitrarily surface textures design of the slipper/swash plate interface for improving the mechanical and volumetric efficiency of the EHA pump. The model is composed of the lubrication film model, the component dynamic model considering the spinning motion, and the multi-objective optimization model. In this way, the arbitrary-shaped surface texture with the best comprehensive effect in the EHA pump is achieved and its positive effects in the EHA pump prototype are verified. Experimental results show a reduction in wear and an improvement in mechanical and volumetric efficiency by 1.4% and 0.8%, respectively, with the textured swash plate compared with the untextured one.

关键词: electro-hydrostatic actuator     axial piston pump     slipper/swash plate interface     multi-objective optimization     surface texture    

基于扩展干扰观测器的电液执行器的模糊阻抗控制 Regular Papers-Research Articles

Ming-jie LI, Jian-hua WEI, Jin-hui FANG, Wen-zhuo SHI, Kai GUO

《信息与电子工程前沿(英文)》 2019年 第20卷 第9期   页码 1221-1233 doi: 10.1631/FITEE.1800155

摘要: 在本文中,我们同时处理遭受外干扰及参数不确定影响的单出杆电液执行器的速度控制和力控制。在某些应用中,速度控制和力控制两者都有要求。阻抗控制和扩展干扰观测器的结合可以解决该问题。阻抗控制可调节执行器的速度和输出力之间的动态关系,有助于执行器与作用环境或者工件间避免冲击和保持合适的接触力。阻抗规则参数可由模糊算法调节。扩展干扰观测器被用于补偿外部干扰和参数不确定性,实现精确的速度跟踪。为扩展干扰器的开发,提出精确的负载力动力学模型。分析了系统稳定性。实验数据表明所提控制算法具有高精度速度跟踪性能,同时具有良好的力调节能力,在工程机械和装配中具有较大应用前景。

关键词: 模糊控制;阻抗控制;干扰观测器;参数不确定性;电液执行器    

Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0706-2

摘要: Multiobjective trajectory planning is still face challenges due to certain practical requirements and multiple contradicting objectives optimized simultaneously. In this paper, a multiobjective trajectory optimization approach that sets energy consumption, execution time, and excavation volume as the objective functions is presented for the electro-hydraulic shovel (EHS). The proposed cubic polynomial S-curve is employed to plan the crowd and hoist speed of EHS. Then, a novel hybrid constrained multiobjective evolutionary algorithm based on decomposition is proposed to deal with this constrained multiobjective optimization problem. The normalization of objectives is introduced to minimize the unfavorable effect of orders of magnitude. A novel hybrid constraint handling approach based on -constraint and the adaptive penalty function method is utilized to discover infeasible solution information and improve population diversity. Finally, the entropy weight technique for order preference by similarity to an ideal solution method is used to select the most satisfied solution from the Pareto optimal set. The performance of the proposed strategy is validated and analyzed by a series of simulation and experimental studies. Results show that the proposed approach can provide the high-quality Pareto optimal solutions and outperforms other trajectory optimization schemes investigated in this article.

关键词: trajectory planning     electro-hydraulic shovel     cubic polynomial S-curve     multiobjective optimization     entropy weight technique    

New nonlinear stiffness actuator with predefined torque‒deflection profile

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0721-3

摘要: A nonlinear stiffness actuator (NSA) could achieve high torque/force resolution in low stiffness range and high bandwidth in high stiffness range, both of which are beneficial for physical interaction between a robot and the environment. Currently, most of NSAs are complex and hardly used for engineering. In this paper, oriented to engineering applications, a new simple NSA was proposed, mainly including leaf springs and especially designed cams, which could perform a predefined relationship between torque and deflection. The new NSA has a compact structure, and it is lightweight, both of which are also beneficial for its practical application. An analytical methodology that maps the predefined relationship between torque and deflection to the profile of the cam was developed. The optimal parameters of the structure were given by analyzing the weight of the NSA and the mechanic characteristic of the leaf spring. Though sliding friction force is inevitable because no rollers were used in the cam-based mechanism, the sliding displacement between the cam and the leaf spring is very small, and consumption of sliding friction force is very low. Simulations of different torque‒deflection profiles were carried out to verify the accuracy and applicability of performing predefined torque‒deflection profiles. Three kinds of prototype experiments, including verification experiment of the predefined torque‒deflection profile, torque tracking experiment, and position tracking experiment under different loads, were conducted. The results prove the accuracy of performing the predefined torque‒deflection profile, the tracking performance, and the interactive performance of the new NSA.

关键词: compliant actuator     nonlinear stiffness actuator     nonlinear spring     predefined torque−deflection profile    

Influence of boundary conditions and turntable speeds on the stability of hydrostatic oil cavity

Zhaomiao LIU, Chengyin ZHANG, Feng SHEN

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 359-368 doi: 10.1007/s11465-011-0222-2

摘要:

The flow, bearing, and carrying capacity of the cycloidal hydrostatic oil cavity in hydrostatic turntable systems are numerically simulated, considering the rotation speeds of a turntable from 0 to 5 m/s and different boundary conditions. The vortex effect is weakened, and the stability of the oil cavity is enhanced with the increase in lubricant viscosity. However, the increase in inlet speed, depth, and inlet radius of the oil cavity causes the vortex effect to increase and the stability of oil cavity to reduce. With the increase in the oil film thickness, the carrying capacity of the oil cavity diminishes. The oil cavity pressure increases along the direction of the motion of the turntable; it is distributed unevenly because of the rotation of the turntable. With the increase in turntable speed, the location and size of the vortex scope in the oil cavity flow field and the strength of the vortex near the entrance gradually weaken and move away from the entry. The distribution of pressure is determined by the locations of the vortex. When the vortex is close to the wall, the wall pressure increases at its location. Otherwise, the wall pressure decreases first and then increases after the center of the vortex.

关键词: hydrostatic oil cavity     flow state     oil cavity pressure     stability     vortex    

A model reference adaptive control based method for actuator delay estimation in real-time testing

Cheng CHEN, James M. RICLES

《结构与土木工程前沿(英文)》 2010年 第4卷 第3期   页码 277-286 doi: 10.1007/s11709-010-0072-8

摘要: Real-time testing provides a viable experimental technique to evaluate the performance of structural systems subjected to dynamic loading. Servo-hydraulic actuators are often utilized to apply calculated displacements from an integration algorithm to the experimental structures in a real-time manner. The compensation of actuator delay is therefore critical to achieve stable and reliable experimental results. The advances in compensation methods based on adaptive control theory enable researchers to accommodate variable actuator delay and achieve good actuator control for real-time tests. However, these adaptive methods all require time duration for actuator delay adaptation. Experiments show that a good actuator delay estimate can help optimize the performance of the adaptive compensation methods. The rate of adaptation also requires that a good actuator delay estimate be acquired especially for the tests where the peak structural response might occur at the beginning of the tests. This paper presents a model reference adaptive control based method to identify the parameter of a simplified discrete model for servo-hydraulic dynamics and the resulting compensation method. Simulations are conducted using both numerical analysis and experimental results to evaluate the effectiveness of the proposed estimation method.

关键词: real-time testing     actuator delay     compensation     adaptive control     MIT rule     discrete transfer function    

Development of a masticatory robot using a novel cable-driven linear actuator with bidirectional motion

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0687-1

摘要: Masticatory robots are an effective in vitro performance testing device for dental material and mandibular prostheses. A cable-driven linear actuator (CDLA) capable of bidirectional motion is proposed in this study to design a masticatory robot that can achieve increasingly human-like chewing motion. The CDLA presents remarkable advantages, such as lightweight and high stiffness structure, in using cable amplification and pulley systems. This work also exploits the proposed CDLA and designs a masticatory robot called Southeast University masticatory robot (SMAR) to solve existing problems, such as bulky driving linkage and position change of the muscle’s origin. Stiffness analysis and performance experiment validate the CDLA’s efficiency, with its stiffness reaching 1379.6 N/mm (number of cable parts n = 4), which is 21.4 times the input wire stiffness. Accordingly, the CDLA’s force transmission efficiencies in two directions are 84.5% and 85.9%. Chewing experiments are carried out on the developed masticatory robot to verify whether the CDLA can help SMAR achieve a natural human-like chewing motion and sufficient chewing forces for potential applications in performance tests of dental materials or prostheses.

关键词: masticatory robot     cable-driven     linear actuator     parallel robot     stiffness analysis    

液体静压支承动态性能新表达式探索与实验验证

孟心斋,杨建玺,孟昭焱

《中国工程科学》 2003年 第5卷 第3期   页码 62-66

摘要:

液体静压支承具有很多优良性能:高运动精度,低摩擦功耗,小轴心偏移,大承载能力,强抗振性能与长使用寿命等,但这些优良的静态性能必须在上佳的动态性能保证下才能充分显示出来,因此,液体静压支承静态性能保证机床运动与加工精度,而动态性能则保证设备的安全与工作条件。文章根据力平衡与流量连续条件建立支承系统传递函数,导出支承系统动态性能新表达式即稳定性判别、抗瞬态干扰能力、固有频率与在稳态周期干扰力作用下产生的动刚度与最大振幅。通过试验台实验证实,液体静压支承动态性能新表达式计算结果可靠而且物理概念清晰,公式简单,故可用于实际。

关键词: 动态性能     传递函数     动刚度     谐振     频率     液体静压支承    

Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 711-725 doi: 10.1007/s11465-021-0647-1

摘要: The safety of human–robot interaction is an essential requirement for designing collaborative robotics. Thus, this paper aims to design a novel variable stiffness actuator (VSA) that can provide safer physical human–robot interaction for collaborative robotics. VSA follows the idea of modular design, mainly including a variable stiffness module and a drive module. The variable stiffness module transmits the motion from the drive module in a roundabout manner, making the modularization of VSA possible. As the key component of the variable stiffness module, a stiffness adjustment mechanism with a symmetrical structure is applied to change the positions of a pair of pivots in two levers linearly and simultaneously, which can eliminate the additional bending moment caused by the asymmetric structure. The design of the double-deck grooves in the lever allows the pivot to move freely in the groove, avoiding the geometric constraint between the parts. Consequently, the VSA stiffness can change from zero to infinity as the pivot moves from one end of the groove to the other. To facilitate building a manipulator in the future, an expandable electrical system with a distributed structure is also proposed. Stiffness calibration and control experiments are performed to evaluate the physical performance of the designed VSA. Experiment results show that the VSA stiffness is close to the theoretical design stiffness. Furthermore, the VSA with a proportional–derivative feedback plus feedforward controller exhibits a fast response for stiffness regulation and a good performance for position tracking.

关键词: variable stiffness actuator     variable stiffness module     drive module     symmetrical structure     double-deck grooves     expandable electrical system    

Design and characteristic research of a novel electromechanical-hydraulic hybrid actuator with two transmission

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0735-x

摘要: Servo-hydraulic actuators (SHAs) are widely used in mechanical equipment to drive heavy-duty mechanisms. However, their energy efficiency is low, and their motion characteristics are inevitably affected by uncertain nonlinearities. Electromechanical actuators (EMAs) possess superior energy efficiency and motion characteristics. However, they cannot easily drive heavy-duty mechanisms because of weak bearing capacity. This study proposes and designs a novel electromechanical-hydraulic hybrid actuator (EMHA) that integrates the advantages of EMA and SHA. EMHA mainly features two transmission mechanisms. The piston of the hydraulic transmission mechanism and the ball screw pair of the electromechanical transmission mechanism are mechanically fixed together through screw bolts, realizing the integration of two types of transmission mechanisms. The control scheme of the electromechanical transmission mechanism is used for motion control, and the hydraulic transmission mechanism is used for power assistance. Then, the mathematical model, structure, and parameter design of the new EMHA are studied. Finally, the EMHA prototype and test platform are manufactured. The test results prove that the EMHA has good working characteristics and high energy efficiency. Compared with the valve-controlled hydraulic cylinder system, EMHA exhibits a velocity tracking error and energy consumption reduced by 49.7% and 54%, respectively, under the same working conditions.

关键词: electromechanical-hydraulic hybrid actuator (EMHA)     integration     transmission mechanisms     power assistance     energy efficiency     working characteristics    

Dynamic modeling of hydrostatic guideway considering compressibility and inertia effect

Yikang DU,Kuanmin MAO,Yaming ZHU,Fengyun WANG,Xiaobo MAO,Bin LI

《机械工程前沿(英文)》 2015年 第10卷 第1期   页码 78-88 doi: 10.1007/s11465-015-0331-4

摘要:

Hydrostatic guideways are used as an alternative to contact bearings due to high stiffness and high damping in heavy machine tools. To improve the dynamic characteristic of bearing structure, the dynamic modeling of the hydrostatic guidway should be accurately known. This paper presents a “mass-spring-Maxwell” model considering the effects of inertia, squeeze, compressibility and static bearing. To determine the dynamic model coefficients, numerical simulation of different cases between displacement and dynamic force of oil film are performed with fluent code. Simulation results show that hydrostatic guidway can be taken as a linear system when it is subjected to a small oscillation amplitude. Based on a dynamic model and numerical simulation, every dynamic model’s parameters are calculated by the Levenberg-Marquardt algorithm. Identification results show that “mass-spring-damper” model is the most appropriate dynamic model of the hydrostatic guidway. This paper provides a reference and preparation for the analysis of the dynamic model of the similar hydrostatic bearings.

关键词: hydrostatic guidway     dynamic model     dynamic mesh technique     Levenberg-Marquardt     mass-spring-damper model    

液体静压支承静态性能新表达式探索

孟心斋,杨建玺,孟昭焱

《中国工程科学》 2002年 第4卷 第5期   页码 63-66

摘要:

文章分析了液体静压支承传统的静态性能表达式存在的严重缺陷及其产生原因,提出了新的静态性能表达式。这种新的静态性能表达式精确地表达了外加载荷与轴承间隙之间的非线性关系,真实地反映了支承的静态性能。新的静态性能通用表达式可表达各种传统节流器与新型可变节流器节流时支承的主要静态性能,很有应用价值。新的静态性能表达式只有一个变量即外加载荷与油垫推力比,故可在支承节流与尺寸参数未确定之前知道支承的主要静态性能,它有利于事先选择与确定支承在应用时的主要性能,为正确应用液体静压支承提供了可靠的技术基础。

关键词: 液体静压支承     传统节流器     新型可变节流器     静态性能    

Identification of resistant pharmaceuticals in ozonation using QSAR modeling and their fate in electro-peroxone

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-021-1394-6

摘要:

• Effect of converting ozonation to E-peroxone was studied on pharmaceutical removal.

关键词: Ozone     Electro-peroxone     Wastewater     Quantitative structure activity relationship     Advanced oxidation processes    

Dynamical research on spherical micro actuator with piezoelectric ceramic stacks drivers

ZHANG Ruihua, CHEN Haichu

《机械工程前沿(英文)》 2007年 第2卷 第4期   页码 433-438 doi: 10.1007/s11465-007-0074-y

摘要: This paper develops a 30 mm × 30 mm × 50 mm spherical micro actuator driven by piezoelectric ceramic stacks (PZT), and analyzes its dynamic performances. First, the space coordinate relationship of the spherical micro actuator and a dynamic model are set up. Second, The Runge-Kutta arithmetic is used to calculate the dynamical parameters of the micro actuator; the SIMULINK module of MATLAB is used to build the dynamical simulating model and then simulate it. Third, an experimental sample of the spherical micro actuator is developed, a micromanipulator is integrated with a micro-gripper based on the sample spherical micro actuator, and the experimental research on the micro assembly is conducted between a micro shaft of 180 μm and a micro spindle sleeve of 200 μm. Finally, the characteristics of the spherical micro actuator influenced by the mass of the metal sphere of the micro actuator, driving signal frequency, friction coefficient of the contact surface between the metal sphere and the friction block of the micro driving unit are analyzed. The experimental results indicate that the rotation resolution of the micro actuator reaches 0.000 1°, the rotation positioning precision reaches 0.000 5°, and the maximum working frequency is about 1200 Hz. The experimental results validate the back rotation vibration model of the spherical micro actuator. The micromanipulator integrated by the spherical micro actuator can meet the requirements of precise micro operation and assembly for micro electro mechanical systems (MEMS) or other microelements in micro degree fields.

关键词: spherical     micro-gripper     friction coefficient     dynamic     frequency    

Changes in structure and functional properties of whey proteins induced by high hydrostatic pressure:

Xiaoming LIU, Jia NING, Stephanie CLARK,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 436-442 doi: 10.1007/s11705-009-0251-0

摘要: High hydrostatic pressure (HHP) is an alternative technology to heat processing for food product modifications. It does not cause environmental pollution and eliminates the use of chemical additives in food products. This review covers the research conducted to understand the effect of HHP on structure and functional properties of whey proteins. In this paper, the mechanism underlying pressure-induced changes in -lactoglobulin and -lactabumin is also discussed and how they related to functional properties such as hydrophobicity, foam stability, and flavor-binding capacity.

关键词: -lactoglobulin     processing     functional     alternative technology     environmental    

标题 作者 时间 类型 操作

Multi-objective optimization of surface texture for the slipperswash plate interface in EHA pumps

期刊论文

基于扩展干扰观测器的电液执行器的模糊阻抗控制

Ming-jie LI, Jian-hua WEI, Jin-hui FANG, Wen-zhuo SHI, Kai GUO

期刊论文

Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

期刊论文

New nonlinear stiffness actuator with predefined torque‒deflection profile

期刊论文

Influence of boundary conditions and turntable speeds on the stability of hydrostatic oil cavity

Zhaomiao LIU, Chengyin ZHANG, Feng SHEN

期刊论文

A model reference adaptive control based method for actuator delay estimation in real-time testing

Cheng CHEN, James M. RICLES

期刊论文

Development of a masticatory robot using a novel cable-driven linear actuator with bidirectional motion

期刊论文

液体静压支承动态性能新表达式探索与实验验证

孟心斋,杨建玺,孟昭焱

期刊论文

Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

期刊论文

Design and characteristic research of a novel electromechanical-hydraulic hybrid actuator with two transmission

期刊论文

Dynamic modeling of hydrostatic guideway considering compressibility and inertia effect

Yikang DU,Kuanmin MAO,Yaming ZHU,Fengyun WANG,Xiaobo MAO,Bin LI

期刊论文

液体静压支承静态性能新表达式探索

孟心斋,杨建玺,孟昭焱

期刊论文

Identification of resistant pharmaceuticals in ozonation using QSAR modeling and their fate in electro-peroxone

期刊论文

Dynamical research on spherical micro actuator with piezoelectric ceramic stacks drivers

ZHANG Ruihua, CHEN Haichu

期刊论文

Changes in structure and functional properties of whey proteins induced by high hydrostatic pressure:

Xiaoming LIU, Jia NING, Stephanie CLARK,

期刊论文