可变刚度四足机器人对角小跑控制策略

为提升足式机器人在复杂环境下的自适应稳定运动能力,针对具有主被动变刚度柔性关节的四足机器人提出一种对角小跑步态运动控制策略。基于弹簧负载倒立摆模型与控制目标解耦方法,设计了腾空相对角腿关节角规划,着地相前进速度、机身高度、俯仰角调节及腿部刚度主动调节控制策略,并基于足端触地状态完成了四足机器人对角小跑步态运动规划。研制了具有主被动变刚度柔性关节的四足机器人样机,通过实验验证了所提运动控制策略的有效性与正确性。     

主-被动复合变刚度柔性关节设计与分析

为解决传统刚性机器人在特定领域应用受限问题,为其设计一款同时具有主、被动变刚度特性的复合式柔性关节。通过调查研究国内外变刚度柔性关节结构,对变刚度柔性关节按结构原理分为杠杆机构、凸轮机构两类,并基于凸轮机构原理,通过紧凑化设计实现了主-被动变刚度在同一关节的整合。建立该柔性关节数学模型,并对凸轮槽曲线进行了优化设计,得到了关节等效刚度随柔性变形量逐渐增大的凸轮槽曲线,在此基础上对柔性关节进行了刚度特性分析。对关节样机进行了静态刚度测量及动态抛掷试验,结果表明该变刚度柔性关节能够实现主、被动刚度调节功能,且在结构设计上适应现有机器人机构应用。     

基于凸轮机构的变刚度仿生柔性关节设计与分析

为满足足式机器人跑跳等动态运动对关节柔性及其变刚度特性的迫切要求,借鉴生物关节柔性特征与主被动刚度调节机理,创新地提出了一种基于凸轮机构的新型变刚度仿生柔性关节。基于关节刚度特性分析,构建了关节整体刚度模型,并针对影响关节刚度特性的各结构参数开展了系统优化设计,研制出了一款紧凑型高集成度关节样机。关节样机性能实验结果表明,基于凸轮机构的变刚度仿生柔性关节具备理想的关节输出力矩与刚度调节范围,可通过关节固有刚度特性与动态刚度特性的主被动融合控制,实现关节瞬时刚度的动态非线性精确调节,能够满足机器人动态运动对关节柔性与刚度的需求。     

上肢康复机器人被动变刚度驱动器建模与试验

康复机器人的关节往往要求良好的变刚度特性以适应人体的柔顺性。根据上肢的关节肌肉特点,对上肢康复圆周轨迹训练中不同位置的刚度需求进行分析,并在此基础上设计了一种新型被动变刚度驱动器,其通过凸轮-滚子-簧片机构产生变化的阻力矩,从而实现上肢圆周轨迹训练过程中不同位置的刚度变化。建立了被动变刚度装置的数学模型并通过仿真和试验验证了模型的准确性和设计方案的可行性。设计的被动变刚度驱动器满足上肢康复训练过程中的刚度变化规律,结构简单且无需额外驱动与控制。     

主—被动变刚度柔性单腿建模及能耗分析

为了改善传统刚性足式机器人运动高能耗问题,通过仿生学研究总结人类跑跳运动刚度与能效相关性,建立具有主—被动复合变刚度的串联柔性单腿数学模型,对减速器、柔性关节阻尼、功率流进行了详细描述;选定单腿模型主要参数并结合仿生学设计关节"三段式"被动变刚度特性,采用Hertz模型进行触地碰撞仿真,验证了具有被动变刚度特性的柔性单腿比定刚度柔性单腿具有更好的稳定性;通过对原地跳跃运动、支撑相水平运动两个过程的仿真计算,得出不同运动情况下腿部刚度与能耗的变化规律。研制了具有主—被动复合式变刚度柔性关节及基于该关节的单腿样机,联合NI-cRIO系统实验,验证了不同运动情况下合理调整刚度系数能够改善足式机器人能耗的结论,与仿生学研究相符。     

永磁变刚度柔性关节的力学分析与控制器设计

提出一种采用永磁弹簧、绳索驱动、梯形布置的拮抗式变刚度柔性机器人关节,能够根据任务需要,实时调节关节刚度。所述永磁弹簧装置,在绳索提供力矩一定的情况下,增加了关节刚度变化范围,同时减小操作臂的质量与惯量。对提高柔性机器人关节的运动性能具有重要意义。对关节空间与绳索空间的映射关系进行推导并利用雅可比矩阵和模型间静力学关系,得到关节刚度模型,进而实现关节刚度与位置解耦。以轨迹控制为目标,设计了一种双闭环解耦控制器,并进行了试验验证。仿真分析与试验结果共同表明,该柔性关节在较宽刚度调整范围内,都具有较好的位置响应特性和轨迹跟踪能力。上述结构与控制方式同样也适用于多自由度并联柔性机器人关节。     

一种基于弹簧片的可变刚度关节

随着机器人环境友好、安全可靠的发展趋势,可变刚度弹性驱动关节成为了研究热点。变刚度弹性驱动关节能够缓冲碰撞,消除机械震荡,提高机器人对人和环境的安全性。提出了一种以弹簧片为弹性元件的变刚度柔性关节,可以在一定范围内调节其刚度,并建立了关节的数学模型,推导了关节刚度计算公式,实现了刚度的调节控制。     

绳索驱动式变刚度关节柔顺控制与力补偿方法研究

机器人柔顺运动有助于提高机器人交互运动时的安全性与稳定性,越来越受到人们的重视。针对一种绳索驱动式具有主被动柔顺性的柔性机器人关节,提出一种适用于绳索驱动式变刚度关节的刚度与位置解耦控制方式,实现了关节位置控制的同时,又实现了关节柔顺性的统一。利用雅可比矩阵和模型间静力学关系,得到关节刚度模型,并通过优化方法对变刚度装置的力学模型和刚度模型构成的非线性方程组求解,实现变刚度关节刚度与位置的非线性解耦。在解耦控制基础上提出一种力矩观测方法,实现了关节力矩补偿,增强了关节位置控制能力;建立了绳索驱动式变刚度关节样机和控制系统,并通过仿真和实验分析的方式验证了所提柔顺控制方式的可行性和有效性。     

基于曲柄滑块机构变刚度关节的设计与分析

为了解决人机交互中的物理接触带来的刚性碰撞和安全隐患问题,以机器人关节模块为出发点,提出了一种新型变刚度关节。设计了变刚度关节的曲柄滑块刚度调节机构,分析了变刚度原理,建立了数学模型,搭建了样机,分别就关节刚度与关节偏转角度、板簧有效长度、调节机构输入角等参数关系进行了实验分析。实验证明,该方案可实现关节刚度的调节。     

柔性齿条式变刚度关节驱动器设计与研究

关节驱动器对于提升机器人环境适应能力和降低能量消耗具有重要意义。设计并实施一种柔性齿条式变刚度关节驱动器,能够根据任务需要,实时调节关节刚度。详细阐述关节驱动器的变刚度原理,详细展示该关节驱动器的机械结构。建立柔性齿条式关节驱动器的静力学模型,推导关节刚度与调整位移之间的理论关系式。完成了软件仿真和系统试验,验证了本方案的可行性。柔性齿条式变刚度关节驱动器能够有效缩小驱动器的整体体积,同时具有较大的刚度调整范围以及较短的刚度调节时间。     

一种TPMS无源化方案设计

针对TPMS系统无电池供应模式的发展趋势,从机械能转化电能角度,介绍了国内外两种无源方案,提出了一种新的设计方案,对新方案机构的运动规律进行了分析和研究.     

Mechanics of the passive knee joint. Part 1: The role of the tibial articular surfaces in guiding the passive motion

The motion of the unloaded knee is associated with tibial internal rotation and femoral posterior translation. Although it is known that the passive motion is the result of the interaction between the articular surfaces and the ligaments, the mechanism through which the particular pattern of motion is guided is not completely understood. The goal of this study was to focus on the tibial geometry and to identify the roles that its geometric features have in guiding the passive knee motion. The method used in this study simplified the geometry of the tibial plateaux and the menisci into basic features that could be eliminated individually. The generated tibial geometry was implemented in a computer model to simulate the passive motion. Different parts of the geometry were eliminated individually and the comparison between the simulation results was used to identify the role that each part of the geometry had in guiding the passive motion. The medial meniscus was found as the feature that promoted the tibial internal rotation and restrained the femoral posterior translation. The lateral meniscus and the medial aspect of the tibial eminence, on the other hand, were found as the elements that confined the tibial internal rotation.     

可以稳定快速收敛的无源时差定位系统

针对无源时差定位系统实时性要求较高、初始估计误差较大的特点,分析了现有各种滤波方法在实际工程应用中的局限性,在此基础上提出对传统的迭代卡尔曼滤波(IKF)方法进行改进。从其高斯牛顿迭代逼近最大似然估计的实质入手,首先通过修正高斯牛顿迭代的目标函数得到一个基于一步高斯牛顿迭代的滤波更新公式,减小了初始估计误差对整个系统的影响,然后根据其最大似然估计的性质推导了一个新的增益计算公式,减少了求逆运算的次数,提高了整个系统的稳定性,在获得较好定位性能的同时大大提高了系统的处理速度。实验统计结果表明,改进后的IKF方法以较小的时间开销获得了与无迹卡尔曼滤波(UKF)方法相近的定位性能,但其定位性能明显优于扩展卡尔曼滤波(EKF)方法、粒子滤波(PF)方法和传统IKF方法。     

被动步行机器人稳定性能研究综述

介绍了被动步行机器人工作原理,并针对其稳定性能较差的缺点对稳定性判别及抗扰动能力计算通常采用的方法进行综述,归纳出从生物力学研究成果中获取灵感以提高其稳定性能的方法.     

被动式波浪补偿系统的研究

为消除波浪对作业船舶的影响,以被动式波浪补偿反馈控制系统作为研究对象,建立波浪补偿研究模型,分析了补偿原理和位移测量原理,合理设计出PDF控制系统。通过仿真结果表明,被动式波浪补偿完全满足波浪补偿反馈控制系统要求。     

Towards flow measurement with passive accelerometers

The aim of this project has been to find suitable methods for flow measurement and characterization with passive accelerometers. The objectives were twofold. Firstly, the process industry could make use of such a sensor for process surveillance. Secondly, the water utilities of today lack simple and cost-efficient alternatives to equip their ageing infrastructures with online flow meters. These kinds of efforts are necessary for the realization of smart maintenance and for the decrease of the currently increasing amount of maintenance needs water utilities of today are experiencing. Liquid flowing in a pipe generates vibrations, detectable with accelerometers fitted along the pipe exterior. The correlated sound from synchronized accelerometers experience a lag which is dependent on the flow rate. Also, if the acquired sound is further processed, there exist a possibility to extract enough features to estimate some additional characteristics, in this case temperature. Experiments were performed at two nominal temperatures, 20 °C and 40 °C. A deep neural network was constructed for non-linear regression purposes to predict flow velocities based on lag and mean frequencies of the vibrations. Further, a proof of concept for this methodology was shown which reached a root mean square deviation from 100.8 L/min to 171.1 L/min for a nominal flow range of 0 to 1500 L/min. In addition, we train a k-nearest neighbour classifier to predict the nominal temperature of our validation dataset with 83 percent accuracy. The work was performed at RISE Research Institutes of Sweden, serving as Sweden’s national metrology institute for liquid flow and acoustics.     

非能动控制压力管道保护装置的研究

本文提出了一种压力管道保护装置的工作原理和性能指标。该装置安装在长输管线内,当输送流体管道发生爆破事故时,可有效解决无人力或外加动力时紧急切断阀门的问题,使流体终止向事故点流动,从而起到保护作用。由于国内长输管线大多在运行中,故作者在相似原理的基础上,经过一系列模拟试验,并分析试验数据,其结果完全达到了设计指标。其优点是造价低、响应速度快、流阻小、安装环境不限等。目前,该装置已用于许多实际场合。     

Analysis of modification of the energy method of passive ranging

With regard to the problems of passive ranging, one of the modifications of the wellknown energy method for determining the range to an emitting target with partially known motion parameters on the basis of a single receiving point is developed. The problem is solved using solely the measurements of the power (amplitude) of the received signal on a predetermined time grid with no account for direction-finding data. The analytical dependences allowing for exploration of the working region of the method are obtained. An algorithm for the formation of the resulting ranging estimate in the current time taking into consideration the measurement redundancy is constructed. The results of computational experiments that confirm the possibility of practical implementation of the proposed modifications of the energy method are presented. The recommendations on the use of the results obtained in multipoint systems of passive location are given.     

Development of passive ultrasonic tomography techniques

Passive ultrasonic tomography is described. Results of developing, modeling, and testing some key techniques in passive ultrasonic tomography are provided. The techniques include an algorithm for determining arrival times of noisy acoustic signals with sloping leading edge; a method for determining the source coordinates and onset times of acoustic signals and estimating the accuracy of those; and regularizing procedures for tomographic reconstruction of nonuniform distributions of propagation speed of acoustic signals. The results of modeling the effect of measurement noises on the accuracy of source location and the mutual influence of the source location accuracy and the soughtfor nonuniform distribution of propagation speed of acoustic signals are described. Results of experimental testing of the developed techniques are also provided.