Adaptive Swimming of Underwater Snake-like Robot in Different Underwater Environment

Hydrodynamic force is an important factor that affects the performance of underwater vehicle.Adapting to the current underwater environment by changing its shape is an important feature of underwater snake-like robots(USLR).An experiment was implemented to verify the swimming along the straight line of USLR.A simulation platform is also established for the analysis of the swimming of USLR.To figure out adaptive swimming of USLR to different underwater environments,the relationships between CPG parameters and maximum swimming speed have been discussed,and the switching between different swimming modes has been implemented.

Environmental Adaptive Control of a Snake-like Robot With Variable Stiffness Actuators

This work investigates adaptive stiffness control and motion optimization of a snake-like robot with variable stiffness actuators. The robot can vary its stiffness by controlling magnetorheological fluid(MRF) around actuators. In order to improve the robot's physical stability in complex environments, this work proposes an adaptive stiffness control strategy. This strategy is also useful for the robot to avoid disturbing caused by emergency situations such as collisions. In addition, to obtain optimal stiffness and reduce energy consumption, both torques of actuators and stiffness of the MRF braker are considered and optimized by using an evolutionary optimization algorithm. Simulations and experiments are conducted to verify the proposed adaptive stiffness control and optimization methods for a variable stiffness snake-like robots.

Modeling and Control of Head of the Underwater Snake-like Robot Swimming

In order to solve oscillation of head of the underwater snake-like robot,the Central Pattern Generator( CPG)-based control scheme with head-controller was presented. The Kane dynamic model was constructed to be processed with a commercial package MotionGenesis Kane 5. 3,to which the proposed control scheme was applied. The relation between CPG parameters and orientation offset of head was investigated. The target orientation of head-controller was calculated through a convenient method. The advantage of this control scheme is that the head of the underwater snake-like robot remains in the forward direction during swimming. To prove the feasibility of the proposed methodology,two basic motion patterns,swimming along the straight line and swimming along the curved path,had been implemented in our simulation platform. The results showed that the simulation platform can imitate the swimming of the underwater snake-like robot and the head of the underwater snake-like robot remains in a fixed orientation directed towards the target. The oscillation of head's orientation is inhibited effectively.

Kinematic Research on Hinged Synchronous Universal Joint Applied for Snake-like Manipulator

The structure and motion principle of a hinged synchronous universal joint (HSUJ) is introduced, also whose kinematics is theoretically analyzed. As a result, a few kinematic characters of the HSUJ are obtained,which establish the foundation of its application for snake-like manipulator. Making use of the HSUJ ss actuating mechauism, the developed snake-like manipulator has the merits of small curve radius, fewer actuator, and small volume etc.

Knowledge presentation by the MNSM-based controller for swimming motion of a snake-like robot

A MNSM( mirror neuron system mechanism)-based controller is developed to present the swimming rhythm of a snake-like robot in Cartesian space. From engineering viewpoint,the proposed controller is composed of a neuron for rhythm angle and two neurons for motion knowledge in XY plane. The given knowledge is a rhythm curve for swimming motion of a snake-like robot. Experimental results show that the proposed controller can present the knowledge of swimming rhythm,which represents the corresponding control law to drive the snake-like robot to swim with different speeds and turning motion. This work provides a novel method to present the knowledge for swimming motion of snake-like robots.

Head Orientation Stability of Underwater Snake-Like Robot Swimming

In prior research,the orientation of head of the snake-like robot is changed according to the sinusoidal wave. To solve this problem,we propose Central Pattern Generator( CPG)-based control scheme with head-controller to stabilize the head of the underwater snake-like robot. The advantage of the CPG-based control scheme with head-controller is that the head of the underwater snake-like robot is direct to the target orientation during swimming. The relation between CPG parameters and orientation stability of head is discussed.The adaptation of the proposed method to environment changes is tested. The influences of CPG parameters and hydrodynamic forces on the orientation offset of head are investigated. The target orientation( the input of headcontroller) with an experimental optimization is calculated through a convenient method. To prove the feasibility of the proposed methodology,the different swimming modes have been implemented in our simulation platform.The results show that the oscillation of head's orientation is inhibited effectively,and the proposed method has strong adaptation to environment and CPG parameters changes.

Kinematic Control of Wheeled Snake-Like Mobile Robot

From a bionics viewpoint , this paper proposes a mechanical model of a wheeled snake like mobile mechanism. On the hypothesis of the existing non holonomic constraints on the robot kinematics, we set up the relationship among the kinetic control parameters in the snake like movement using Lie group and Lie algebra of the principle fiber bundle and provide some theoretical control methods to realize the snake like locomotion.

Dynamic Model of Underwater Snake-Like Robot Using Kane's Method

In this paper, a dynamic model for an underwater snake-like robot is developed based on Kane's dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. The generalized active forces and the generalized inertia forces are deduced. The model developed in this paper includes inertia force, inertia moment, gravity, control torques, and three major hydrodynamic forces: added mass, profile drag and buoyancy. The equations of hydrodynamic forces are deduced. Kane's method provides a direct approach for incorporating external environmental forces into the model. The dynamic model developed in this paper is obtained in a closed form which is well suited for control purposes. It is also computationally efficient and has physical insight into what forces really influence the system dynamics. The simulation result shows that the proposed method is feasible.

Simulation Platform for the Underwater Snake-Like Robot Swimming Based on Kane's Dynamic Model and Central Pattern Generator

A systematic method for swimming control of the underwater snake-like robot is still lacking. We construct a simulation platform of the underwater snake-like robot swimming based on Kane's dynamic model and central pattern generator(CPG). The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. Hydrodynamic coefficients are determined by experiments. Then, we design a CPG-based control architecture implemented as the system of coupled nonlinear oscillators. The CPG, like its biological counterpart, can produce coordinated patterns of rhythmic activity while being modulated by simple control parameters. The relations between the CPG parameters and the speed of the underwater snake-like robot swimming are investigated. Swimming in a straight line, turning, and switching between swimming modes are implemented in our simulation platform to prove the feasibility of the proposed simulation platform. The results show that the simulation platform can imitate different swimming modes of the underwater snake-like robot.

Gaits-transferable CPG controller for a snake-like robot

With slim and legless body, particular ball articulation, and rhythmic locomotion, a nature snake adapted itself to many terrains under the control of a neuron system. Based on analyzing the locomotion mechanism, the main functional features of the motor system in snakes are specified in detail. Furthermore, a bidirectional cyclic inhibitory （BCl） CPG model is applied for the first time to imitate the pattern generation for the locomotion control of the snake-like robot, and its characteristics are discussed, particularly for the generation of three kinds of rhythmic locomotion. Moreover, we introduce the neuron network organized by the BCI-CPGs connected in line with unilateral excitation to switch automatically locomotion pattern of a snake-like robot under different commands from the higher level control neuron and present a necessary condition for the CPG neuron network to sustain a rhythmic output. The validity for the generation of different kinds of rhythmic locomotion modes by the CPG network are verified by the dynamic simulations and experiments. This research provided a new method to model the generation mechanism of the rhythmic pattern of the snake.

耳穴疗法联合普瑞巴林胶囊治疗气滞血瘀型带状疱疹后遗神经痛临床观察

目的分析耳穴疗法联合普瑞巴林胶囊治疗气滞血瘀型带状疱疹后遗神经痛(PHN)的临床效果。方法经随机方式把80例带状疱疹(HZ)住院患者归入对照组、治疗组,分别实施常规治护+普瑞巴林胶囊口服止痛疗法、常规治护+中医耳穴压豆+普瑞巴林胶囊口服止痛疗法,对比两组神经痛改善状况。结果在疼痛缓解方面,相较对照组,治疗组具有显著优势(P<0.05)。治疗组总有效率为90.00%(36/40),高于对照组的77.50%(31/40);治疗组的复发率为10.00%(4/40),低于对照组的22.50%(9/40)(P<0.05)。结论耳穴压豆+普瑞巴林胶囊疗法对于气滞血瘀型PHN的缓解有着积极作用,同时止痛效果相较单用普瑞巴林胶囊更具优势。

基于空间相似性的蛇形机械臂末端定位精度补偿研究

针对线驱动蛇形机械臂末端定位精度问题开展研究。根据蛇形机械臂的结构,建立机械臂运动学解耦方程,以机械臂定位误差的空间相似性分析为基础,对机械臂的运动学参数标定开展分析,提出一种机械臂末端定位误差线性无偏最优估计的非运动学标定方法,实现误差的准确预测,提出了机械臂定位误差补偿方法。搭建了蛇形机械臂实验平台,进行基于空间相似性的末端定位误差补偿实验,结果表明,提出的定位误差补偿方法有效。

欠驱动蛇形机器人轨迹跟踪算法

蛇形机器人由于其狭长的机械臂和超冗余自由度,在复杂极端环境中具有优越的灵活性。本文在欠驱动蛇形臂机器人的结构基础上,提出了基于等效杆长和等效虚拟关节的两种轨迹跟踪算法,实现蛇形臂机器人对目标曲线的跟踪,满足蛇形臂机器人的运动控制需求。最后,设计了臂长1075 mm包含7关节单元的蛇形机器人样机,并进行了轨迹跟踪实验,结果表明蛇形机器人可轻松穿过直径90 mm以上的狭小管道。运动过程平稳、无振动,验证了轨迹控制算法的正确性和结构设计的合理性。

长蛇灸治疗心脾两虚型失眠临床观察

目的观察长蛇灸治疗心脾两虚型失眠的临床效果。方法选取2021年6月—2022年11月在丰城市中医院就诊的60例失眠患者作为研究对象,按就诊顺序随机分为长蛇灸组、药物组,每组30例。观察两组患者治疗前后的匹兹堡睡眠质量指数量表(PSQI)评分、中医证候积分及总有效率。结果治疗后,两组患者的PSQI评分及中医证候积分均降低,且长蛇灸组的分数低于药物组,差异均有统计学意义(P<0.05)。长蛇灸组总有效率为93.3%(28/30),高于药物组的76.7%(23/30),差异有统计学意义(P<0.05)。结论长蛇灸可有效治疗心脾两虚型失眠、缓解患者临床症状、提高其睡眠质量,且效果优于口服归脾丸治疗。

水下软体蛇三维转向机构设计及仿真

为了解决当前水下软体机器蛇实现三维转向的问题,设计一种水下软体机器蛇三维转向机构。通过ABAQUS有限元仿真软件进行验证,利用仿真数据标定了机构变形时,方位角与载荷压力比、弯曲角与基准压力和压力比之间的关系,从而建立了将载荷压力与弯曲角度和方向相关联的开环控制模型。利用控制算法控制三维转向机构,能够在空间内实现任意角度的转向。仿真结果证实,该设计在任意角度转向控制方面表现良好,0°~60°范围内的弯曲角最大误差仅为1.31071°,方位角最大误差仅为3.60489°。在控制仿真中,弯曲角和方位角的最大误差率分别为2.185%和1.001%。仿真结果证明了该设计的可发展性,为软体水蛇三维转向的实现提供了理论支撑。

基于内容分析法探讨长蛇灸治疗AS疗效及其影响因素

目的:采用内容分析法通过文献样本分析、总结与强直性脊柱炎(AS)患者疗效相关的影响因素。方法:基于内容分析法,通过中国知网、维普中文科技期刊全文数据库、万方数据知识服务平台、中国生物医学文献数据库、PubMed期刊数据库进行检索分析。优化研究中选取AS患者60例,均行长蛇灸治疗,按照最终疗效分为总有效组与无效组,分析影响效应指标有无应答的因素。结果:相关影响因素主要为24种,包括患者人口社会学、遗传、生活环境、病情评估、生物学信息、血清炎性指标、基因多态性与磁共振动态增强成像指标等8大类。要素差异分析显示发病年龄、病程、风湿病家族史、吸烟史、肠道感染、Bath强直性脊柱炎疾病活动指数评分、强直性脊柱炎疾病活动评分-C反应蛋白评分、神经功能分级、骨赘形成、基线白介素-34(IL-34)、IL-35、IL-18、IL-37、基线红细胞沉降率、基线C反应蛋白、基线中性粒细胞与淋巴细胞比率、基线血小板与淋巴细胞比率、亚甲基四氢叶酸还原酶1298(CC基因型)、增强因子(骶侧/髂侧)、增强斜率(骶侧/髂侧)、容积转移常数(骶侧/髂侧)、血管外细胞外间隙容积比(骶侧/髂侧)等均是影响效应指标有无应答的因素。结论:临床应重视AS患者的相关影响因素,并探索未知因素及其组合影响的深宽度,优化能有效治疗AS患者的针对性治疗方案。

一种蛇毒类凝血酶纯化新方法

目的提供一种蛇毒类凝血酶的新纯化方法。方法蛇毒经预处理后,依次经过苯甲脒琼脂糖凝胶亲和色谱、阳离子交换色谱和疏水色谱后获得蛇毒类凝血酶,分别对活性、分子量及纯度进行检测,并与使用现有专利方法制备的蛇毒类凝血酶进行质量比较。结果新方法制备的蛇毒类凝血酶与现有专利方法相比,分子量无明显差异,但新方法的比活力更高,且纯度更高,同时新方法的工艺稳定性更佳。结论新方法与现有专利方法相比,简化了工艺步骤,缩短了纯化周期,减少了过程环境暴露风险,可获得高纯度类凝血酶,工艺稳定性高,产品质量一致性好,利于临床安全用药。

三黄解毒汤靶向雾化治疗中老年肝经郁热型带状疱疹临床观察

目的探讨三黄解毒汤靶向雾化治疗中老年肝经郁热型带状疱疹疗效观察。方法将2021年2月—2023年2月梅州市第二中医医院门诊纳入的60例中老年肝经郁热型带状疱疹患者作为研究对象,按照随机数字表法分为2组,对照组(30例)进行常规抗病毒治疗,观察组(30例)进行常规抗病毒、三黄解毒汤靶向雾化皮损区治疗。比较2组的临床疗效、时效性指标、疼痛程度。结果观察组总有效率、无疼痛程度高于对照组;观察组结痂时间、脱痂时间、疼痛缓解时间短于对照组。2组的止疱时间、轻度疼痛程度比较,差异无统计学意义(P>0.05)。结论三黄解毒汤靶向雾化治疗中老年肝经郁热型带状疱疹患者的疗效显著,可缩短其结痂时间、脱痂时间、疼痛缓解时间,降低其疼痛程度。

长蛇灸联合八段锦治疗寒湿阻络型慢性下背痛临床观察

目的探讨寒湿阻络型慢性下背痛(CLBP)采用长蛇灸联合八段锦治疗的效果。方法采用随机数字表法将2021年1月—2022年1月南昌市洪都中医院收治的寒湿阻络型CLBP患者120例分为观察组和对照组,各60例。对照组采用常规治疗,观察组在对照组基础上加用长蛇灸联合八段锦,两组均治疗3周,比较两组治疗前后的腰部功能、疼痛程度、屈伸度及生活质量,统计两组治疗期间不良反应。结果治疗后,两组视觉模拟量表(VAS)评分、Oswestry功能障碍指数(ODI)评分均比治疗前低,且观察组比对照组低(P<0.05);两组治疗后指地距离(FFD)均比治疗前短,且观察组比对照组短(P<0.05);两组治疗后腰痛生活质量日本骨科协会(JOA)评分均比治疗前高,且观察组比对照组高(P<0.05);两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论长蛇灸联合八段锦治疗可改善寒湿阻络型CLBP患者屈伸度及腰部功能,缓解患者疼痛程度,提高生活质量且未增加不良反应,安全性好。