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。     

考虑柔性关节的仿袋鼠跳跃机器人落地稳定性研究

对具有柔性关节的仿袋鼠跳跃机器人落地稳定性进行了研究。用拉格朗日方法建立了机构在着地阶段的动力学方程。结合实例,运用Matlab和Adams软件对机器人进行仿真分析,给出了机器人在着地阶段的各关节转角、关节驱动力矩、着地压力及ZMP随时间的变化规律。分析结果表明:膝关节,特别是踝关节引入柔性关节,不仅能显著地吸收落地能量而获得落地缓冲能力和降低关节输入力矩峰值而减小驱动元件的功率,而且能有效地提高跳跃机构的弹跳能力和落地稳定性。     

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。     

基于足地接触力跟踪的单足机器人弹跳运动控制

为了使足式弹跳机器人在运动中避免由于地面接触刚度的变化对弹跳运动产生的影响,首先建立了单足弹跳机器人在弹性地面条件下的运动简化模型,进而分析了地面弹簧刚度变化对机体重心运动轨迹以及着地相中足地接触力的影响。采用足地接触力补偿控制的手段,通过主动控制单腿的伸缩,使模型中弹簧系统的足力输出与期望保持一致,消除了地面刚度变化对机体运动的干扰。利用仿真实验表明了控制方法的可行性。     

液压驱动单腿跳跃机器人柔顺着地分析与控制

为缓解液压驱动足式机器人动态步态行走时着地瞬间足端冲击对机器人系统及其运动控制的影响,提出了一种基于关节运动规划的机器人柔顺着地控制方法。以液压驱动单腿跳跃机器人为研究对象,分析机器人足端着地冲量,通过选择合适的机器人着地姿态和减小机器人着地前足端速度实现机器人柔顺着地,为此在空中相进行余弦速度曲线关节运动轨迹规划,以及着地相进行余弦函数关节运动轨迹规划。将该方法分别应用于基于MATLAB/Simulink软件建立的仿真模型和试验样机进行单腿竖直跳跃控制实验,仿真和试验结果显示采用该方法的机器人跳跃控制消除了足端着地瞬间地面作用力在膝关节液压缸无杆腔形成的液压冲击,实验结果表明提出的基于关节运动规划的机器人柔顺着地控制方法合理可行。     

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。     

液压四足机器人单腿竖直跳跃步态规划

针对机器人跳跃运动落地时冲击力大的问题,面向竖直跳跃运动,以液压四足机器人单腿为研究对象,建立液压驱动四足机器人单腿运动学模型,并分别对机器人单腿处于起跳相、落地相和腾空相时进行轨迹规划;根据关节参数,通过运动学逆解求得驱动函数,利用仿真软件ADAMS进行竖直跳跃步态仿真;搭建单腿实验平台,进行实验验证,依据得到的动态特性,分析步态规划的准确性及合理性,为后续液压四足机器人动步态的研究提供设计和控制依据。     

柔性轮式移动弹跳机器人设计与运动性能研究

为了提高机器人在复杂环境中的适应性能,解决弹跳机器人姿态调整和翻转复位的问题,设计一种柔性轮系机构与集弹跳、调姿和翻转复位一体的多链弹跳机构结合的柔性轮式移动弹跳机器人。运用柔性轮系机构实现机器人平坦路面快速稳定的移动,通过柔性轮的弹性变形消除弹跳运动的部分落地冲击力,并基于铁木辛柯梁理论对柔性轮进行受力变形分析。多链弹跳机构能实现机器人的弹跳运动、起跳角度调节和落地后翻转复位,具有单机构多功能的特点。设计了一种复合螺母机构,当复合螺母机构的螺母片闭合时,储能电机驱动丝杆转动实现机器人弹跳储能;当螺母片分离时,瞬间释放弹簧的弹性势能实现机器人的弹跳运动。运用ADAMS对机器人的姿态调整、弹跳运动和翻转复位进行仿真,研制柔性轮式弹跳机器人原理样机并进行弹跳运动实验,结果表明,该柔性轮式移动弹跳机器人的设计具有可行性。     

欠驱动三刚体仿袋鼠跳跃机器人落地冲击分析

根据袋鼠的生物结构特性,建立了液压驱动的欠驱动仿袋鼠跳跃机器人三刚体模型.利用拉格朗日方法建立了机器人在着地阶段的动力学方程及主、被动关节动力学耦合方程,利用Maple 15进行符号计算得出耦合因子.结合实例,应用Matlab7.0分别对碰撞力、地面的反作用力、系统动能、及总质心在y方向上的位移变化进行了计算和仿真;并与全驱动的仿袋鼠跳跃机器人刚性模型进行了对比分析.还通过跳跃机器人两种模型的跳跃模拟对比实验,用加速度传感器测得落地冲击时质心加速度曲线.结果表明:弹性元件的引入有效地起到了缓冲的作用,减轻了着地时机器人与地面的振动和冲击,提高了跳跃机器人的落地稳定性,节省了系统损耗的能量.     

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。     

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.     

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。     

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.