基于MATLAB的采摘手末端执行器的分析及优化

给出了一种新型欠驱动苹果采摘手三指末端执行器,并运用SolidWorks进行机构的设计与建模;而后对于该采摘手的抓取过程进行分析,计算出指节长度等参数对苹果抓持力大小的影响,运用MATLAB对各个参数进行优化,得出使得苹果受力最小的一组数据;运用该组数据,计算出所需要的扭簧以及电机参数等。该新型末端执行器可以满足不同大小苹果,具有较好的灵活性和自适应性。     

腱传动仿人手指机构的设计与分析

为了解决仿人多自由度手指机构结构复杂的问题,提出了一种基于欠驱动原理的腱传动机构,介绍了该机构的具体实现方法,主要包括手指结构设计、关节及其转角分析、扭簧设计、电机功率计算、位置/力传感器选择和自动控制系统设计等内容,在对三维模型进行分析的基础上,设计制造出了一个手指实物模型.运动试验结果表明,该手指实物模型具有结构简单的特点,能够通过弯曲和张开动作实现物体抓取.     

基于Pro/E和ADAMS的欠驱动苹果采摘机械手运动学仿真分析

将欠驱动技术应用于农业采摘领域,欠驱动手指作为水果采摘机器人的末端执行器.对手爪的抓取力进行了分析,利用Pro/E完成对苹果采摘机械手的虚拟设计与装配;利用ADAMS对机械手进行运动学、动力学仿真,获得其速度、加速度和接触力的变化情况曲线,仿真结果表明,机械手的设计符合要求,并为实现机械手的控制提供了重要依据.     

拟人机器人手多指欠驱动机构研究

欠驱动机构具有增加抓取稳定性、降低控制难度等优点得到广泛研究.与实现单个手指的多关节动力传递的传统欠驱动机构设计思想不同,提出了一种新型多指欠驱动机构.该机构利用设置于关节轴上的扭簧实现了单个电机对多个手指根部的驱动.经分析,给出了该机构的主要参数设计原则.该机构可以作为拟人机器人手的食指、中指、无名指和小指的根部关节,使机器人手在抓取物体时,四个手指能够自动适应不同形状和尺寸的物体,产生适当的抓持力,抓取稳定性高,控制容易.     

果蔬采摘欠驱动机械手爪设计及其力控制

为了实现果蔬的无损采摘,采用欠驱动原理设计出一种结构更简单、通用性更强的末端执行器。欠驱动机构是指驱动器数目少于机构本身自由度数目的机构,基于欠驱动原理设计的机械手结构简单可靠,抓取物体时具有形状自适应能力,手指可完全包络物体,可以通过最大接触力的闭环力反馈控制来实现无损采摘。基于这一设计思想设计出仅靠一个电动机驱动三个手指的机械手爪,通过理论分析、手爪机构设计与建模、结构参数优化,确定设计尺寸制出机械手爪,设计控制电路结合力反馈控制进行抓取试验。试验结果表明该手爪能实现期望的抓取与最大接触力控制功能,并具有控制简单可靠、抓取稳定、不损伤果实等特点。     

基于欠驱动原理的脐橙采摘末端执行器的设计与试验

果蔬采摘机器人的末端执行器是采摘机器人的重要组成部分,直接影响采摘的成功率与采摘效率。通过分析脐橙特性,基于欠驱动原理设计了一种夹剪一体的脐橙采摘末端执行器。其整体机构由一个两层3指机械爪手构成,两层手指中的一层为剪切机构载体,另一层则为对果实抓取固定的夹持手指;剪切机构由摇杆滑块机构组成。构建剪切机构与机械手的力学模型,根据需求对相关零部件进行了设计与选型;判断了防止机械手剪切机构发生干涉的运动误差范围,并对关键受力部位进行了有限元分析。结果表明,因关键受力点变形导致的运动误差在安全误差范围内,验证了结构的合理性。通过Adams软件对其进行运动学仿真,进一步证明了该末端执行器的可行性。最后,通过末端执行器实物样机进行脐橙采摘剪切试验,机构整体采摘成功率为95%,采摘周期为4.3 s。     

一种通用柔性末端执行器设计和分析

设计了一种用于水果采摘机器人的通用柔性末端执行器,该末端执行器采用电机带动丝杠螺母机构,驱动平行四边形连杆机构实现动作。通过调整定位螺母改变左右手指相对方向可以分别实现对球状物体和圆柱状物体的抓取动作。为了保护某些表皮娇嫩的水果,该末端执行器增加了柔性抓取功能,并且抓取刚度可以调节。最后对末端执行器进行运动学和力学分析,并用MATLAB进行了仿真分析。     

手指关节可独立控制的欠驱动灵巧手

为了实现对物体的精准抓取,针对欠驱动灵巧手手指关节转动不可控问题提出一种新颖的关节可锁紧的单腱欠驱动灵巧手的设计方案,完成了灵巧手关节锁紧机构和指间耦合机构的结构设计,并运用Matlab对灵巧手手指工作空间进行仿真。对关节锁紧机构和指间耦合机构动作起到关键作用的耦合弹簧和复位弹簧进行了设计,对影响关节驱动力矩的参数优化分析,得到优化后的手指传动机构和腱绳张紧机构。通过灵巧手样机对不同形状、大小物体的抓握试验,证明本欠驱动灵巧手可实现手指关节锁紧的动作,具有良好的包络抓握能力和较强的精确抓取能力。     

欠腱驱动多指灵巧手的设计

提出一种欠腱驱动多指灵巧手，它具有结构简单，操作灵巧，控制容易，较高的操作适应性，每个多指节手指仅用一个腱驱使手指弯曲运动。文中描述了欠腱驱动多指灵巧手的结构设计与手指位移分析，与现有的多指灵巧手和欠驱动多指杆机器人手相比，这种手指灵巧手的结构更为简单紧凑，且能减少控制的复杂性、重量和成本，并能实现多功能地抓取不同物体的能力。     

一种新型欠驱动三指节手指机构的结构设计及优化

针对当前存在的欠驱动假肢手手指机构拟人特性较差这一缺陷,通过综合耦合型手指在结构上的优势,引入能够使得各手指进行耦合运动的耦合连杆,提出了一种能够实现自适应包络抓取并具有较强拟人特征的新型三指节欠驱动手指结构,从而很好的弥补了欠驱动手在抓取过程中动作僵硬、耦合性差的不足。分析该手指的抓取过程,初步验证了该欠驱动手指完成包络抓取的可行性。根据虚功原理对手指的抓取静力学模型进行分析,得出完成包络抓取时各指节对物体的接触力,基于三指节手指抓取力尽可能均匀分布这一原则,建立手指结构优化的目标函数,利用matlab遗传算法工具箱对手指进行优化设计,得到满足上述原则的欠驱动手指机构的各杆件尺寸及抓取姿态。     

周转轮系的传动效率分析

周转轮系的传动比计算比较复杂,也常被设计者所忽略,然而,有些周转轮系却因效率太低而失去意义.在分析影响传动效率的众多因素的基础上,将周转轮系分为8种情形,分别推导出其效率计算公式.最后通过一系列的应用实例,验证了计算方法的有效性和核算轮系效率的丛要性,指出轮系的效率,不仅取决于单个齿轮副的效率,还与哪个轴被固定、哪根轴...     

Outsourcing capacity planning for an an IC design house

The management of outsourcing capacity is one of the key issues for IC design houses. There are two fundamental problems in outsourcing capacity management; they are the estimation of net capacity and the allocation of capacity. The purpose of this paper is to propose a framework of outsourcing capacity planning (OCP) for an IC design house to solve these two problems. The framework of OCP contains three parts: Net IC Product Demand Planning, Net Capacity Demand Planning, and Booking Capacity Planning. Linear Programming (LP) is employed to generate a net IC demand plan. A transformation process that transforms net IC product demand into net capacity demand is applied to obtain the net capacity demand plan. Finally, we use Analytic Hierarchy Process (AHP) to combine the factors, which an IC design house considers for outsourcing, into a Utility Index (U.I.). We then employ U.I. to develop a heuristic method to deal with the booking capacity planning problem. The result of OCP yields a better performance than that of the practice approach. In addition, OCP provides a decision procedure to assist IC design houses in monitoring the performance of each subcontractor.     

Developing an Integrated Intelligent Framework to Support an Engineering Change Process for an Axial Piston Pump

Since the concepts of concurrent engineering were introduced in mid 1980s, the product design process has become complicated. This is because many factors related to the life cycle of the product may need to be considered during the design stage. Therefore, shortening product development time becomes important for the survival of an enterprise. In this paper, an integrated intelligent environment to support concurrent engineering is proposed. Two major modules are provided by this system to assist change management. One is a constraint network module that analyses the related constraints about a design change to find the design variables influenced. Another is a product assembly module that extracts the design data from a CAD database to analyse the spatial relationships relating to an assembly. The data in the above two modules are integrated in a data integrated module, in which an entity relational data model was developed to describe the integrated data. Finally, a web-based query system was developed to provide a multiplatform environment for the user to refer to the data in the constraint network module and the product assembly module during a design change process. The proposed environment is implemented in the design change process for an axial piston pump.     

Study of an efficient temperature measurement for an industrial bioreactor

In this study, a measurement method of parametric temperature model for industrial bioreactor is proposed. The system of industrial bioreactor is an integrating process with time delay. Obviously, it cannot hold a stable system response since the characteristic roots are located on the imaginary axis of the complex plane. In this paper, the temperature model of the bioreactor was obtained by maintaining the bioreactor continuous response to a monopulse signal. This proposed method has a powerful ability to steady system response. The bioreactor consists of 30 L fermentor, two impellers and four baffles. By using the proposed method and Bierman algorithm, the parameters of the temperature model for bioreactor are successfully measured on-line. Simulation results are given to show the effectiveness of the measurement method.     

Simulation study of an AGV system in an FMS environment

A simulation program written in ECSL to simulate an AGV system serving an FMS is presented. It incorporates a special algorithm to enable ‘intelligent’ routing of the AGVs with minimum control requirements. The program was used to examine several parameters and scheduling/control disciplines affecting the AGV system's performance for a specific FMS. Results show that selection of an appropriate combination of parameter values can have a beneficial effect on the FMS.     

Development of an ankle physiotherapy device using an MR damper

This paper presents design and development of an ankle physiotherapy device using a linear MR (magnetorheological) damper. After exploring many possible configurations of the MR valve, the proposed design makes sure that the damper is test- and research-friendly in that the damper can be easily assembled and disassembled with simple tools and procedure. The structural and functional integrity of the damper was maintained even with the simple layout of the damper. The dimensions of the MR valve are optimally determined using finite element analysis. The damper performance under steady shear is experimentally evaluated with an INSTRON test machine. The test results showed that the prototype had fulfilled the basic requirements of the desired MR ankle physiotherapy.     

Ride quality evaluation of an actively-controlled stretcher for an ambulance

This study considers the subjective evaluation of ride quality during ambulance transportation using an actively-controlled stretcher (ACS). The ride quality of a conventional stretcher and an assistant driver's seat is also compared. Braking during ambulance transportation generates negative foot-to-head acceleration in patients and causes blood pressure to rise in the patient's head. The ACS absorbs the foot-to-head acceleration by changing the angle of the stretcher, thus reducing the blood pressure variation. However, the ride quality of the ACS should be investigated further because the movement of the ACS may cause motion sickness and nausea. Experiments of ambulance transportation, including rapid acceleration and deceleration, are performed to evaluate the effect of differences in posture of the transported subject on the ride quality; the semantic differential method and factor analysis are used in the investigations. Subjects are transported using a conventional stretcher with head forward, a conventional stretcher with head backward, the ACS, and an assistant driver's seat for comparison with transportation using a stretcher. Experimental results show that the ACS gives the most comfortable transportation when using a stretcher. Moreover, the reduction of the negative foot-to-head acceleration at frequencies below 0.2 Hz and the small variation of the foot-to-head acceleration result in more comfortable transportation. Conventional transportation with the head forward causes the worst transportation, although the characteristics of the vibration of the conventional stretcher seem to be superior to that of the ACS.     

Research on an algorithm for an NC machining hypoid pinion

Based on the flexibility characteristics of the NC machine tool, which means that various motions can be performed arbitrarily on NC machine tools, a new algorithm for manufacturing a hypoid pinion is proposed. This gets rid of the limitation of traditional mechanical machine tools and their algorithms. When the cutter tilt method is combined with the modification method, a method of manufacturing the pinion with a prescribed-size cutter on an NC machine tool can be realised. This helps to simplify cutter specifications and realise the error compensation of the cutter size. In this paper the algorithm is derived. According to the equations of cutting, the machine settings are calculated.     

电梯特殊故障排除案例分析

介绍了两例电梯故障的特点及排障过程,并对故障进行了分析。     

Performance evaluation of an innovative design modification of an orifice meter

This paper evaluates the effect of innovative design modification on the performance of an orifice meter. The orifice meter of 10 mm plate thickness is considered as reference meter and the plate has been modified by changing the surface topology to curvature on both the sides of the orifice plate and the performance has been evaluated using CFD. The performance of the meter is evaluated in terms of coefficient of discharge (C_d) and standard deviation. The study reveals very interesting phenomenon. The newly designed orifice meter has higher discharge coefficient with an improvement of about 22% compared to the reference orifice meter with β-value of 0.6. The performance of the new orifice meter with β-value of 0.6 and radius of curvature of 7.07 mm (2R/d = 0.471) is nearly independent of Reynolds number over the entire range of flow conditions studied (10³ ≤ Re ≤ 10⁶).