Design of A Novel Wheel-Legged Robot with Rim Shape Changeable Wheels

The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain.However,most of the wheel-legged robots only have one-directional obstacle-crossing ability.During the motion,most of the wheel-legged robots’centroid fluctuates violently,which damages the stability of the load.What’s more,many designs of the obstacle-crossing part and transformation-driving part of this structure are highly coupled,which limits its optimal performance in both aspects.This paper presents a novel wheel-legged robot with a rim-shaped changeable wheel,which has a bi-directional and smooth obstacle-crossing ability.Based on the kinematic model,the geometric parameters of the wheel structure and the design variables of the driving four-bar mechanism are optimized separately.The kinetostatics model of the mobile platform when climbing stairs is established to determine the body length and angular velocity of the driving wheels.A pro-totype is made according to the optimal parameters.Experiments show that the prototype installed with the novel transformable wheels can overcome steps with a height of 1.52 times of its wheel radius with less fluctuation of its centroid and performs good locomotion capabilities in different environments.

A Closed-Loop Dynamic Controller for Active Vibration Isolation Working on A Parallel Wheel-Legged Robot

Serving the Stewart mechanism as a wheel-legged structure,the most outstanding superiority of the proposed wheel-legged hybrid robot(WLHR)is the active vibration isolation function during rolling on rugged terrain.However,it is difficult to obtain its precise dynamic model,because of the nonlinearity and uncertainty of the heavy robot.This paper presents a dynamic control framework with a decentralized structure for single wheel-leg,position tracking based on model predictive control(MPC)and adaptive impedance module from inside to outside.Through the Newton-Euler dynamic model of the Stewart mechanism,the controller first creates a predictive model by combining Newton-Raphson iteration of forward kinematic and inverse kinematic calculation of Stewart.The actuating force naturally enables each strut to stretch and retract,thereby realizing six degrees-of-freedom(6-DOFs)position-tracking for Stewart wheel-leg.The adaptive impedance control in the outermost loop adjusts environmental impedance parameters by current position and force feedback of wheel-leg along Z-axis.This adjustment allows the robot to adequately control the desired support force tracking,isolating the robot body from vibration that is generated from unknown terrain.The availability of the proposed control methodology on a physical prototype is demonstrated by tracking a Bezier curve and active vibration isolation while the robot is rolling on decelerate strips.By comparing the proportional and integral(PI)and constant impedance controllers,better performance of the proposed algorithm was operated and evaluated through displacement and force sensors internally-installed in each cylinder,as well as an inertial measurement unit(IMU)mounted on the robot body.The proposed algorithm structure significantly enhances the control accuracy and vibration isolation capacity of parallel wheel-legged robot.

Design and Optimization of Wheel-legged Robot:Rolling-Wolf

Though the studies of wheel-legged robots have achieved great success, the existing ones still have defects in load distribution, structure stability and carrying capacity. For overcoming these shortcomings, a new kind of wheel-legged robot（Rolling-Wolf） is designed. It is actuated by means of ball screws and sliders, and each leg forms two stable triangle structures at any moment, which is simple but has high structure stability. The positional posture model and statics model are built and used to analyze the kinematic and mechanical properties of Rolling-Wolf. Based on these two models, important indexes for evaluating its motion performance are analyzed. According to the models and indexes, all of the structure parameters which influence the motion performance of Rolling-Wolf are optimized by the method of Archive-based Micro Genetic Algorithm（AMGA） by using Isight and Matlab software. Compared to the initial values, the maximum rotation angle of the thigh is improved by 4.17%, the maximum lifting height of the wheel is improved by 65.53%, and the maximum driving forces of the thigh and calf are decreased by 25.5% and 12.58%, respectively. The conspicuous optimization results indicate that Rolling-Wolf is much more excellent. The novel wheel-leg structure of Rolling-Wolf is efficient in promoting the load distribution, structure stability and carrying capacity of wheel-legged robot and the proposed optimization method provides a new approach for structure optimization.

Dynamics and Wheel's Slip Ratio of a Wheel-legged Robot in Wheeled Motion Considering the Change of Height

The existing research on dynamics and slip ratio of wheeled mobile robot （WMR） are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS- Ⅱ. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS- Ⅱ in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified, Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height.

Wheel-legged Hexapod Robots:a Multifunctional Mobile Manipulating Platform

Robots are widely used to replace people in some burdensome or hamaful areas. Not only the moving ability but also the manipulating ability is needed in the missions of complex multitasking requirements. In the last decades, wheel-legged hexapod robots are extensively studied to ineet this condition.

Efficient Body-Transfer Wheelchair for Assisting Functionally Impaired People

Functionally impaired people always have difficulty accomplishing activities of daily living.In this regard,tasks including toileting and bathing have a higher prevalence rate of injuries and greater risk of falling.In this study,a body-transfer wheelchair was developed to assist people in transferring from bed to wheelchair for bathing,and toileting.The bodytransfer wheelchair is a semi-automatic wheelchair that has features such as a controlled leg and backrest,linkage commode slot,and height adjustment.The wheelchair consists of a seat and a main frame that can be detached to enable bathtub transfer.This mechanism lets the user stay on the seat while being transferred into the bathtub without any risk of falling.A linkage mechanism was developed as a part of the seat for ease of toileting.Kinematic and force analysis was conducted to calculate the force required for each actuator.It has been proved by the experimental results that the wheelchair can securely and comfortably transfer a patient from the bed to the toilet or bathtub.A survey has been conducted to evaluate the wheelchair prototype design idea.Two focus groups were chosen:one comprised of functionally impaired people,and the other comprised of caregivers.The results of the survey show that 60%of both functionally impaired people and caregivers would like to use the body-transfer wheelchair for toileting and bathing purpose.Additionally,on average 65%of both focus groups find it convenient to operate the body-transfer wheelchair independently.

生活方式视角下获得性下肢残疾青年轮椅体验设计

目的 源于对获得性下肢残疾青年群体社会融入问题的关注,探讨其生活方式转变与轮椅设计需求的关系,通过体验设计的提升,促进目标群体生活信心的重建。方法 在理解获得性下肢残疾青年群体特征和社会融入问题的基础上,结合网络文本分析和用户访谈结果,改良AIOD生活方式测量模型,建立该群体生活方式的测量维度。基于测量模型维度,进行问卷调查,通过统计分析建构该群体的生活方式并进行细分。以生活方式测量结果为依据,结合CUE体验设计框架,输出轮椅体验设计机会点。结果 研究发现获得性下肢残疾青年群体的生活方式可细分为积极乐观型、安稳生活型、消极懈怠型,从包容各类型方式的角度出发提出适应多元化生活方式的轮椅设计策略,进行可控性、有效性、易用性、感知性和认可性等方面的优化轮椅体验,满足生活转型产生的新需求,进一步促进生活转型积极心理的形成。

设计驱动的产品颠覆性创新方法研究

通过设计驱动创新与颠覆性创新的理论研究,提出了包含意义发掘、功能系统调整、产品语言表达3个阶段的设计驱动产品颠覆性创新过程模型,以完善设计领域对于颠覆性创新方法的研究。首先基于SET洞察市场趋势设想新意义,由内而外接受批评以发掘可行性意义;然后对目标用户进行研究,运用AD将功能需求转化为设计参数,并与源产品技术对比进而进行技术调整,获得颠覆性创新技术解;接着将新意义特征及提升、添加技术所对应的部件确定为意义诠释区域,并采用类比推理选取样本;最后通过相似性分析确定设计原型并提取其特征要素,利用可拓变换优化产品语言表达,获得颠覆性创新产品语言解。以电动轮椅设计为实例验证了该模型的可行性,为其他设计驱动的产品颠覆性创新提供参考。

便携式膝关节康复智能轮椅结构设计与分析

目的 为解决目前膝关节康复设备便捷性差、医疗成本高、普适性不强等问题,该文设计了一种便携式膝关节康复智能轮椅。方法 通过对膝关节结构与康复机理分析,设计电推杆驱动式康复机构,采用模块化思想设计多功能模块,搭配STM32单片机,实现车体与各功能模块的控制,利用SolidWorks软件建立三维模型,结合Adams和Ansys仿真软件对膝关节康复机构及核心零部件进行运动学与静力学分析。最后,搭建实物样机对实际使用性能进行验证。结果 经实物样机测试得出,膝关节摆杆实际角度为15.1°~88.9°,摆杆角速度为-7.9~8.1°/s,摆杆角加速度为-4.2~1.6°/s~2,电动推杆推力范围为-82.6~153.1 N,载荷踏板最大形变量约为1.7 mm,腿托最大形变约为1.5 mm。结论 膝关节康复式智能轮椅能够满足各项设计功能,实际性能符合设计准则,验证了结构设计的合理性与可行性。

融合表面肌电和姿势信息的轮椅绩效评价方法

目的为客观评价轮椅的使用效益,使用表面肌电设备测试轮椅使用过程中的肌电信号,并融合姿势信号IMU来构建人机评价模型。方法分别对轮椅的折叠、刹车方式及行驶坡度进行试验来评估轮椅的使用绩效,通过对比用力肌群间的疲劳状况来判定较为舒适的轮椅折叠及刹车方式。实验要求被试者在执行轮椅任务时,分别使用两种折叠方式和三种刹车方式不同的轮椅进行实验,并在操作动作任务过程中采集sEMG和IMU信号,在实验任务结束后填写NASA-TLX量表。结果根据模型的评价指标对实验数据进行了比较与分析,横向收折式折叠和凹口式刹车(手刹位于前方)的轮椅疲劳度低,在3~4°坡度范围下轮椅使用者的受力最小,较为舒适,从而验证了模型在轮椅人机评价上的可行性,为优化轮椅设计提供参考。结论人机评价模型适用于评估产品绩效,同时提出的融合表面肌电和姿势信息的轮椅绩效评价方法具有较高的精度和准确性,能够有效地评估轮椅使用者的绩效水平。

基于人体工学的手动轮椅助力装置研究

针对我国失能、半失能老人使用非电动轮椅推行费力的现状,综合考虑使用者功能需求、使用环境与可行技术支撑三方面的要素,从动力系统可靠性理论计算、人体工学设计以及智能控制设计等方面开展研究,研发一款新型助力装置。该装置通过基于人体工学的集成优化设计实现了轻量化(≤5 kg)、小型化(390 mm×130 mm×140 mm)结构设计要求;创新地采用基于单手操作的快速挂接结构,实现了面向市面大部分手动轮椅的高适配要求和5 s内快速装卸的易操作要求;基于使用环境的动力学分析与设计实现了室内外行进20 km的续航里程要求;通过手环控制器和摇杆控制器的多元控制方式开发,实现了不同驱动人员对助力装置启停控制和速度控制的简易化操作要求。

新型爬梯轮椅结构设计及越障性能分析

针对目前轮履复合式爬梯轮椅存在轮胎易干涉履带、爬梯时轮椅与顶端平台发生碰撞等问题,设计了一种新型的爬梯轮椅。通过建立其数学模型,得出轮椅质心的坐标、计算出轮椅攀爬垂直障碍物的最高高度为170.4mm、跨越沟壑的最宽宽度达516.33mm;最后在RecurDyn的TrackLM环境下对轮椅在三种典型工况下进行仿真,仿真结果表明在考虑轮椅速度和履带与地面之间的作用力的情况下,轮椅晃动攀爬障碍物的最高高度220mm和晃动跨越沟壑最宽宽度580mm都大于计算值。通过该轮椅的相关研究,对这类爬梯轮椅的设计提供了相关理论依据。

基于AHP和ANSYS的养老院共享轮椅设计与研究

文章旨在研究养老院的轮椅设施使用现状,并提出养老院共享轮椅的方案,鼓励老人们走出房间,与其他老人交流和建立社交关系,提高养老生活质量。运用层次分析法得到具体需求权重,进行养老院共享轮椅设计,通过ANSYS有限元分析验证该轮椅的结构安全性。完成养老院共享轮椅的模型及系统设计。集成AHP层次分析法和ANSYS分析的轮椅创新设计流程,分析求解得到该轮椅主要承重结构可靠,确保老人使用安全,实现养老院内健康安心养老。

轮椅辅助上肢运动联合多维认知训练对脑卒中偏瘫伴认知障碍患者的干预效果

目的 探讨轮椅辅助上肢运动联合多维认知训练对脑卒中偏瘫伴认知障碍患者上肢运动、静态平衡和认知功能的影响,为加速患者的康复进程提供新的治疗方法。方法 2022年10月至2023年9月,采用便利抽样选取在某医院住院的某医院康复科住院的脑卒中偏瘫伴认知障碍患者119例为研究对象,按随机数字表法将其分为A组(n=40)、B组(n=39)和C组(n=40),三组患者均接受常规治疗,B组增加轮椅辅助上肢训练,C组在B组基础上增加多维认知训练,共4周。分别于干预前、后采用Fugl-Meyer评定量表、蒙特利尔认知评估量表对3组患者的运动、平衡和认知功能进行评定。结果 干预4周后,B组、C组上肢运动功能、平衡功能和认知功能评分均高于A组,且C组高于B组,差异均有统计学意义(均P<0.05);主效益及交互效应均有统计学意义(均P<0.05)。结论 轮椅辅助上肢运动联合多维认知训练,能有效提升脑卒中偏瘫伴认知障碍患者的上肢运动、静态平衡和认知功能。

备灾教育培训对轮椅使用者备灾行为改变的效果

目的 探索针对轮椅使用者的备灾教育干预对其备灾行为的影响,旨在提升这一特殊群体在灾害发生时的应对能力。方法 采用自身前后对照试验设计,通过便利抽样选择四川省绵竹市残疾人中心的轮椅使用者作为研究对象。通过现场讲授、案例分析、图片展示、观看录像、互动提问等教学方法,提供总共120 min的针对性备灾教育培训。结果 经过备灾教育干预后,轮椅使用者的备灾行为得分从干预前的(3.60±1.93)分显著提升至干预1个月后的(8.60±2.89)分,差异具有统计学意义(P<0.001)。具体来说,干预后,不同特征的轮椅使用者在备灾行为上均显示出改善。例如,在干预前,几乎没有研究对象制作并携带避难卡,而一个月后的随访显示,这一比例显著提升至65%。其他关键备灾行为,如准备满足三天需求的备灾包和定期检查急救药品及灭火器具的过期情况,也显示出类似的积极变化。结论 备灾教育干预能有效改善轮椅使用者的备灾行为,可为日后轮椅使用者的备灾教育研究和实践提供了有价值的参考。

一种可供踝关节康复训练的智能轮椅设计

目的 针对目前下肢康复训练设备适配性、训练效果不佳的现状,设计一种可供手术患者、脑血栓患者及下肢残疾人士踝关节康复的智能辅助轮椅。方法 通过对人体踝关节结构和运动特性进行分析,设计踝关节康复机构的整体结构,搭配STM32F103单片机设计控制电路;基于CATIA软件建立三维模型,结合Adams仿真软件搭建平台进行动力学分析;利用ANSYS软件,对辅助轮椅核心零件进行静力学分析,验证结构设计的可行性;选型、装配并搭建实物样机,对实体样机的各项功能与实际性能进行测试。结果 通过仿真分析,踝关节康复机构符合设计标准。实际踝关节纵向可翻转角度为-24.6°~13.5°,横向翻转角度为-19.6°~19.5°,踝关节翻折速度为5.8~6.7°/s,踝关节扭动速度约为7.6°/s,踝关节翻折运动扭矩约为20 N·m,外展运动所需扭矩约为17.2 N·m。结论 该踝关节康复智能辅助轮椅可实现行走、升降、智能辅助等功能。通过仿真分析及实验测试,轮椅的各项功能均可实现,各项参数指标均符合设计标准,验证了多功能踝关节康复轮椅设计的安全性与合理性。

考虑个体习惯的轮椅机器人人机共享避障方法

为了避免个体操作习惯对智能轮椅机器人(WR)人机共享运动控制的影响,引入动态强化学习策略,基于三重奖励系统建立个体操作习惯与碰撞风险的关联特性,提出能够自适应用户行为及保证安全性的模糊强化学习状态融合式共享控制策略.为了实现机器人的智能操控,采用距离型模糊推理算法建立基于座椅压力的方向意图识别模型和机器人人机共享控制框架.面向用户意图方向与机器人实际方向的偏差度,分别基于高斯函数与偏差率建立当前奖励函数与预测奖励函数,以估计用户操作习惯.基于边界距离建立任务奖励函数,以估计人机安全性.基于模糊强化学习策略,利用三重奖励函数构建用户操作习惯与安全性的关联性,以动态调整共享控制中的用户控制权重,适应个体习惯,提高人机共享的操控精度和安全性.在实验室搭建试验环境,验证了所提算法的有效性.

轮腿式爬楼轮椅前腿机构的控制策略研究

针对爬楼轮椅前腿的位姿调节机构在工作时不能同时触地及受力失衡等问题,文中提出基于模糊比例-积分-微分(Proportional Integral Derivative, PID)的前腿同步位姿调节控制策略。首先,建立了前腿位姿调节机构驱动装置的数学模型。其次,根据爬楼轮椅工作要求设定合适的阈值,通过偏差大小来选用最优的控制算法,建立了基于模糊控制策略与模糊自适应PID控制策略。最后,结合模糊PID复合控制模型,实现前腿机构在复杂工况下的有效控制。实验结果表明:采用模糊PID的前腿同步控制系统超调量较小,达到稳态的时间更少,具有较高的稳定性。

基于模糊PID控制的智能轮椅避障设计

为提高智能轮椅的避障精度,提出一种基于模糊PID控制的智能轮椅控制算法。建立智能轮椅的运动学模型,在传统PID控制方法的基础上,设计基于模糊PID控制的智能轮椅控制系统。使用Matlab构建仿真试验,在Simulink中设计搭建模糊控制器,并对传统PID控制和模糊PID控制的避障性能进行仿真。试验结果表明:该控制算法可实现智能轮椅避障误差的优化,与传统PID控制算法相比较,具有超调量小,响应快、精确度更高的优点。

基于西门子PLC的无障碍轮椅升降梯控制系统设计

针对我国残障人士及老年人出行困难的现状,设计了一套可用于老旧小区、地铁、体育馆等公共场所的无障碍轮椅升降梯控制系统。硬件方面,系统主要由PLC控制器、数据采集传感器、电机驱动器、变频器、监控模块、无线数据传输模块、报警模块等组成,主要负责控制升降梯的运行、主从站的无线通信、实时监控设备运行状态及危险状况语音报警;软件方面,PLC控制程序采用状态机模型进行设计,同时对设备的逻辑、联锁及保护进行严格设计保障使用的流畅性;设计了基于MODBUS协议的远程无线变频调速控制系统,利用轮询通信实时读取变频器的运行状态。系统硬件方面可靠性高、功能齐全;软件方面使用方便、设计人性化,易于扩展和调试,并具有一定的通用性。对无障碍轮椅升降梯的发展具有一定的现实意义。