Control Research of Dual Chamber Hydro-Pneumatic Suspension

Vehicle riding comfort and handling stability are directly affected by suspension performance.A novel dual chamber hydro-pneumatic(DCHP)suspension system is developed in this paper.Based on the structural analysis of the DCHP suspension,an equivalent suspension model is proposed for the control purpose.A cuckoo search(CS)based fuzzy PID controller is proposed for the control of the DCHP suspension system.The proposed controller combines the advantage of fuzzy logic and PID controller,and CS algorithm is used to regulate the membership functions and PID parameters.Compared with tradition LQR controller and passive suspension system,the CSFPID controller can reduce the sprung mass acceleration,and at the same time with no deterioration of tire deflection.

Investigation of Semi-Active Hydro-Pneumatic Suspension for a Heavy Vehicle Based on Electro-Hydraulic Proportional Valve

Hydro-pneumatic suspension is widely used in heavy vehicles due to its nonlinear characteristics of stiffness and damping. However, the conventional passive hydro-pneumatic suspension can’t adjust parameters according to the complicated road environment of heavy vehicles to fulfill the requirements of the vehicle ride comfort. In this paper, a semi-active hydro-pneumatic suspension system based on the electro-hydraulic proportional valve control is proposed, and fuzzy control is used as the control strategy to adjust the?damping force of the semi-active hydro-pneumatic suspension. A 1/4?semi-active hydro-pneumatic suspension model is established, which is co-simulated with AMESim and MATLAB/Simulink. The co-simulation results show that the semi-active hydro-pneumatic suspension system can significantly reduce vibration of the vehicle body, and improve the suspension performance comparing with passive hydro-pneumatic suspension.

Development of a Composite Suspension with a Coil and Hydro-Pneumatic Spring

A new composite suspension is developed, where a coil spring and a hydro-pneumatic spring are used in order to improve the poor reliability of off-road vehicle with pure hydro-pneumatic suspension. According to road conditions, the two springs play different roles. The method for matching the composite suspension stiffness and distributing the load is proposed. The working pressure of hydro-pneumatic spring as well as the load and stiffness characteristics of composite suspension is compared with a pure hydro-pneumatic suspension. In addition, the ISO weighted vehicle body acceleration, suspension travel and relative dynamic load of the wheels between two kinds of suspension are analyzed with a quarter vehicle mode. The simulation result shows that the developed composite suspension is more suitable for off-road vehicle than the one hydro-pneumatic suspension, because the composite suspension can reduce the working pressure, improve the reliability and keep a similar ride comfort with hydro-pneumatic suspension.

A Population Balance Model for Disperse Systems:Particle Size Distribution in Suspension Polymerization

On the basis of population balance a mathematical model is developed to describe the formation of polymer particle in styrene suspension polymerization. The characteristics of coalescence and breakage of droplets and the gel effect are analyzed in particular. Parameters of the models are estimated by experimental data on reaction conversion and particle size distribution. The results show that the model is suitable for predicting polymerization processes.

Control algorithm for vehicle height adjustable system of hydro-pneumatic suspension based on LuGre model

In order to control the vehicle body position precisely,1/4 nonlinear mathematical model of hydro-pneumatic suspension is established,and the influence of the frictional force in a hydraulic cylinder is analyzed.The friction characteristics are described based on the LuGre model when the piston of a hydraulic actuator is operated at a low speed.Due to the fact parameters of the friction model are effected by the system condition,an adaptive friction compensation（AFC）controller is designed through the Backstepping method,and a dual-observer has been implemented to estimate the friction state.The global asymptotic convergence of a closed-loop system is proven by the Lyapunov theorem.The simulation results show that the positional accuracy of the adaptive friction compensation yiedls a significant improvement in the vehicle height adjustment as compared to the PID control,demonstrating the effectiveness of the adaptive fiction compensation method in the vehicle height adjustable system of the hydro-pneumatic suspension.

Experimental study on wheeled vehicle hydro-pneumatic suspension fault detection

A four-channel MTS road simulation system,which is used to regenerate the acceleration signal at the axle head is presented. A new fault detection method is proposed,which is based on the remote parameter control（ RPC） technology for vehicle hydro-pneumatic suspension system. The transfer function between the drive signals and the axle head acceleration should be identified before the RPC iterative calculation on a computer. By contrasting with the desired frequency response functions（ FRF）,excited through the sample spectrum of road,the iterative convergence speed of the drive function and weighted error are used to detect faults existing in the vehicle＇s suspension. Experimental results show that during the process of regeneration of the acceleration signal at the axle head,the characteristics of failure of the hydro-pneumatic spring are changed randomly resulting in a dramatic increase in calculation of the RPC iterative,which enables relatively large iterative convergence errors. This method can quickly detect and locate a suspension fault and is a simple bench test way in suspension fault detection.

Study on Outboard Inductive Damping Valve in Hydro-pneumatic Suspension

A new outboard inductive damping valve without any electronic control system is developed. Its working principle,structure and external characteristic are studied. Its mathematical model is presented and its damping characteristic is investigated on the basis of fluid continuity equation,differential equations of motion and Bernoulli equation. The influence of the valve parameters on the damping characteristic is studied numerically. The effects of outboard inductive damping valve and common damping valve on ride and tire load are compared also. The external characteristic of the valve is verified in bench test. The results show that the valve’s mathematical model is quite accurate and the developed valve can be adjust in two stages,which can also meet the requirements of the dynamic characteristic of the vehicle suspension system.

Testing Research of Accumulator Performance in the Hydro-pneumatic Suspension of a Vehicle

Taking a 2.5 liter accumulator with hydro-pneumatic suspension in a CXP1032 crane made in Germany as the research object and taking both the overall-road simulative test-bed and the control equipment made by the Schenck Company of Germany as the testing instrument, the structure performance and mechanism are theoretically clarified and the variation of gas states are obtained. This illustrates the accumulating and releasing process of a 2.5 liter accumulator in a 32t crane in the real condition. The preliminary volume and pressure of accumulator would directly affect the stiffness performance of the hydro-pneumatic suspension in a vehicle.

Optimization design of the hydro-pneumatic suspension system for high clearance self-propelled sprayer using improved MOPSO algorithm

Large high clearance self-propelled sprayers were widely used in field plant protection due to their high-efficiency operation capabilities.Influenced by the characteristics of field operations such as high power,heavy weight,high ground clearance,and fast operation speed,the comprehensive requirements for the ride comfort,handling stability and road friendliness of the sprayer were increasingly strong.At the present stage,the chassis structure of the high clearance selfpropelled sprayer that attaches great importance to the improvement of comprehensive performance still has the problems of severe bumps,weak handling performance and serious road damage in complex field environments.Therefore,this paper proposes an optimization design method for hydro-pneumatic suspension system of a high clearance self-propelled sprayer based on the improved MOPSO(Multi-Objective Particle Swarm Optimization)algorithm,covering the entire process of configuration design,parameter intelligent optimization,and system verification of the high clearance self-propelled sprayer chassis.Specifically,chassis structure of the hydro-pneumatic suspension suitable for the high clearance self-propelled sprayer was designed,and a design method combining the improved MOPSO algorithm based on time-varying fusion strategy and adaptive update with the parameter optimization of hydro-pneumatic suspension based on this algorithm was proposed,and finally the software simulation and bench performance verification were carried out.The results show that the optimized hydropneumatic suspension has excellent vibration reduction effect,and the body acceleration,suspension dynamic deflection and tire deflection were increased by 16.5%,9.9%and 0.9%respectively,compared with those before optimization.The comprehensive performance of the hydro-pneumatic suspension designed in this study is better than that of the traditional suspension.

Bobath疗法联合悬吊技术对脑瘫患儿康复的影响

目的从小腿骨骼肌发育、粗大运动功能、肢体平衡能力方面探究Bobath疗法联合悬吊技术在脑瘫患儿康复治疗中应用价值。方法选取2021年3月至2023年3月自贡市妇幼保健院98例脑瘫患儿,按照1∶1对照原则,采用随机数字表法分为对照组(n=49例)、研究组(n=49例)。对照组采用Bobath疗法治疗,研究组采用Bobath疗法联合悬吊技术治疗,治疗3个月。比较2组治疗效果及治疗前、治疗第1个月、3个月粗大运动功能测试量表(GMFM-88)、小腿骨骼肌发育[胫前肌、内侧腓肠肌、比目鱼肌肌肉厚度(MT)、肌束长度(FL)]、Berg平衡量表(BBS)、脑动脉血流量[大脑前动脉(ACA)、中动脉(MCA)及后动脉(PCA)平均血流速度(Vm)]、脑瘫患儿日常生活能力评价表(ADL)、改良Ashworth痉挛量表(MAS)。结果研究组治疗总有效率89.80%高于对照组73.47%(P<0.05);治疗第1个月、3个月,2组胫前肌、内侧腓肠肌、比目鱼肌MT、FL大于治疗前,且研究组大于对照组(P<0.05);治疗第1个月、3个月,2组GMFM-88、BBS、ADL评分高于治疗前,且研究组高于对照组(P<0.05);治疗第1个月、3个月,2组ACA、MCA、PCA的Vm高于治疗前,且研究组高于对照组(P<0.05);治疗第1个月、3个月,研究组F波波幅低于对照组,F波刺激阈值高于对照组(P<0.05);治疗第1个月、3个月,2组MAS评分低于治疗前,且研究组低于对照组(P<0.05)。结论Bobath疗法联合悬吊技术治疗脑瘫患儿的效果确切,可促进小腿骨骼肌发育、粗大运动功能恢复,提高平衡能力,改善脑动脉血流量。

天轨悬吊减重康复训练模式对脑卒中偏瘫患者下肢运动及平衡功能的影响

目的 探讨天轨悬吊减重康复训练模式对脑卒中偏瘫患者下肢运动及平衡功能的影响。方法 选取杭州市中医院2020年9月至2022年1月期间住院治疗的脑卒中偏瘫患者为研究对象,按照不同楼层病房分为对照组(n=35)和观察组(n=36)。对照组采用常规康复护理,观察组采用天轨悬吊减重康复训练模式,均干预20 d。干预前后使用下肢Fugl-Meyer运动功能评定量表、Berg平衡量表、Sheikh躯干控制能力评分表比较两组患者下肢运动功能及平衡功能。结果 观察组干预前后下肢Fugl-Meyer运动功能评定量表评分差值为(14.61±2.59)分,大于对照组的(10.17±2.50)分;观察组干预前后Berg平衡量表评分差值为(13.81±2.72)分,大于对照组的(8.80±2.94)分;观察组干预前后Sheikh躯干控制能力评分表评分差值为(21.19±11.65)分,大于对照组的(12.94±7.11)分。以上差异均有统计学意义(P<0.05)。结论 天轨悬吊减重康复训练模式可有效改善脑卒中偏瘫患者下肢运动功能,提高平衡功能及躯干控制能力。

基于特性的商用车整体式车桥及耦合悬架动力学模型研究

车桥及悬架是汽车的重要部件,为了实时模拟商用车的整体式车桥及多种结构类型的悬架,本文采用基于总成特性的建模技术路线,将车桥的运动解耦为Motion运动学和Ride动力学,将悬架特性划分为耦合承载特性、RC/PC导向特性和耦合K&C运动学特性,创新性地考虑了车桥的俯仰动态效应、桥间承载非线性动态耦合关系、桥间K&C运动学耦合关系,建立了能够激发出商用车制动抖振负面现象的动力学模型,并提出了针对耦合悬架的K&C试验方案和模型参数辨识方法。最后,通过对比K&C试验数据,并与TruckSim模型作对比,系统层级上验证了本模型的精准性;通过将车辆参数填入UniTruck软件,对某款商用车进行了仿真,并与TruckSim仿真结果作对比,整车层级上验证了本模型的有效性。

高精度经颅直流电刺激联合悬吊运动训练对脑卒中患者下肢运动功能的影响

目的 观察高精度经颅直流电刺激(HD-tDCS)联合悬吊运动训练对脑卒中患者下肢运动功能的影响。方法 选择2022年1月-2023年2月在山东大学附属山东省立第三医院康复医学部住院治疗的脑卒中患者120例,按照随机数字表法分为对照组、HD-tDCS组、悬吊组和联合治疗组,每组30例。治疗过程中有4例因中途出院无法继续接受治疗而脱落,其中对照组3例,HD-tDCS组1例,最终对照组、HD-tDCS组、悬吊组和联合治疗组分别纳入27、29、30、30例。对照组接受运动疗法和神经肌肉电刺激等常规康复治疗,25 min/d,1次/d,5 d/周,持续治疗8周;HD-tDCS组在对照组基础上接受HD-tDCS治疗,主要刺激电极置于偏瘫侧脑初级运动皮层M1区(C3/C4),4个接受极分别置于M1区四周约3.5 cm处的C1/C2、C5/C6、FC3/FC4、CP3/CP4区,电流恒定强度2 mA,电流起伏时间30 s,20 min/次,1次/d,5 d/周,持续治疗8周;悬吊组在对照组基础上接受偏瘫侧下肢分离组合运动、动态闭链稳定运动、骨盆摆动和放松运动等悬吊运动训练,25 min/次,1次/d,5 d/周,持续治疗8周;联合治疗组在对照组基础上接受HD-tDCS联合悬吊运动训练。分别于治疗前和治疗4、8周后,采用Fugl-Meyer运动功能量表下肢部分(FMA-LE)评定患者下肢运动功能;采用Berg平衡量表(BBS)评定患者平衡功能;采用功能性步行能力量表(FAC)评定患者功能性步行能力;采用视频步态分析系统评定患者步态时空参数(步频、步速、步长和步行周期)。结果 与治疗前比较,4组治疗4、8周后FMA-LE评分、BBS评分、FAC等级及步态时空参数(步频、步速、步长和步行周期)均明显提高,差异具有统计学意义(P<0.05)。与对照组、HD-tDCS组、悬吊组同一时间点比较,联合治疗组治疗4、8周后FMA-LE、BBS评分均明显更高,治疗8周后FAC等级及步态时空参数(步频、步速、步长及步行周期)均明显更高,差异具有统计学意义(P<0.05)。结论 HD-tDCS联合悬吊运动训练可有效提高脑卒中患者下肢运动功能、平衡能力和步行能力,值得临床推广应用。

裂缝作用下CO_(2)吞吐动用基质页岩油特征

为明确裂缝作用下CO_(2)吞吐过程中基质页岩油的动用特征,通过采用实时在线称质量方法和核磁共振成像技术,研究了裂缝作用下不同混相压力、基质长度以及基质渗透率对CO_(2)吞吐效果的影响,并建立了注CO_(2)提高基质页岩油动用程度的吞吐方法。结果表明:CO_(2)在非混相、多次接触混相和一次接触混相压力下首轮吞吐动用基质深度分别为12.0、22.5、36.5 mm,累计吞吐采收率逐渐升高;但当压力大于多次接触混相压力后,累计吞吐采收率提高幅度减小;采用逐级增大衰竭压差的吞吐方式,能够弥补基质长度增加对吞吐采收率造成的不利影响,提高大尺寸基质原油的动用深度和动用程度;当裂缝密度保持不变时,基质渗透率的降低会导致累计吞吐采收率减小,且裂缝对吞吐采收率的影响程度降低;虽然增加吞吐次数和闷井时间可以提高低渗透率基质的动用程度,但提高裂缝密度、减小基质原油尺寸才是最有效的提高低渗透基质动用程度的开发方式。研究成果可为提高裂缝作用下页岩油CO_(2)吞吐采收率提供借鉴。

振动疗法联合悬吊训练前交叉韧带重建后患者运动及膝关节功能的变化

背景:物理疗法对前交叉韧带重建术后恢复至关重要。近年来,许多医师都在优化前交叉韧带重建术后的物理康复方案,但仍然缺乏高效的前交叉韧带重建术后康复训练疗法。目的:探讨振动疗法联合悬吊训练对前交叉韧带重建患者术后运动及膝关节功能的影响。方法:纳入在上海体育大学附属体育医院就诊的80例首次行单侧前交叉韧带重建患者,按照随机数字表法将患者随机分为振动疗法组和振动疗法+悬吊训练组,每组40例。振动疗法组患者在前交叉韧带重建术后第13周开始进行振动疗法训练(每次10 min,1次/d,每周6次),振动疗法+悬吊训练组患者在前交叉韧带重建术后第13周开始进行振动疗法(每次10 min,1次/d,每周6次)联合悬吊训练(每周2次),共训练8周。训练前及训练8后,采用膝关节Lysholm评分评价膝关节功能,采用等速肌力评估训练系统评估屈膝对称性指数,采用平衡测试系统评估双侧多轴平均轨迹误差差值。结果与结论:(1)与训练前比较,两组患者训练8周后的膝关节Lysholm评分、屈膝与伸膝对称性指数均升高(P<0.05),双侧多轴平均轨迹误差差值降低(P<0.05);与振动疗法组比较,振动疗法+悬吊训练组患者膝关节Lysholm评分、屈膝与伸膝对称性指数均升高(P<0.05),双侧多轴平均轨迹误差差值降低(P<0.05);(2)结果表明,与单独进行振动疗法相比,振动疗法联合悬吊训练可显著改善前交叉韧带重建患者的膝关节功能,增加肌肉力量和对称性,提高平衡稳定性。

工程车平衡悬架钢板弹簧座疲劳断裂机理研究

为解决某工程车平衡悬架钢板弹簧座失效断裂问题,利用工艺分析、断口分析、金相检验、强度检测、硬度检测以及材料疲劳极限检测等方法,对平衡悬架钢板弹簧座进行分析。结果表明:平衡悬架钢板弹簧座所用材料满足标准要求,平衡悬架钢板弹簧座的失效形式为多源高应力、低周次弯曲疲劳开裂,裂纹源处于平衡悬架钢板弹簧座与U型螺栓配合的圆角根部位置,该位置较厚大在生产工艺上易产生缩孔缩松等缺陷,在结构上是平衡悬架钢板弹簧座承受应力最大的位置,为零件的危险截面。

基于悬吊运动系统的躯干控制性训练联合有氧训练在痉挛型脑瘫患儿中的应用观察

目的:探讨基于悬吊运动系统的躯干控制性训练联合有氧训练在痉挛型脑瘫患儿中的应用效果。方法:选取新余市妇幼保健院2020年6月—2022年6月收治的痉挛型脑瘫患儿92例,按照随机数字表法将患儿分为试验组与对照组,各46例。干预期间试验组和对照组各脱落2例患儿,最终两组各有44例患儿进入本次研究。给予对照组患儿有氧训练干预,试验组在对照组基础上采用基于悬吊运动系统的躯干控制性训练,两组均干预6个月。比较两组干预前后粗大运动功能[粗大运动功能测试(CMFM-88)评分]、平衡功能[儿童平衡量表(PBS)评分],通过测量表面肌电信号方均根值(RMS)评价肌张力。结果:干预后,两组CMFM-88中A区、B区、C区、D区、E区评分均升高,且试验组均高于对照组,差异均有统计学意义(P<0.05)。干预后,两组肱二头肌、大收肌与腓肠肌RMS均降低,且试验组均低于对照组,差异均有统计学意义(P<0.05)。干预后,两组PBS评分均升高,且试验组高于对照组,差异均有统计学意义(P<0.05)。结论:基于悬吊运动系统的躯干控制性训练联合有氧训练可降低痉挛型脑瘫患儿肌张力,改善运动功能和平衡功能。

虚拟轨道列车空气互联平衡悬架的动力学性能研究

针对数字轨道电车前双轴悬架的超静定问题,提出了互联平衡悬架的解决方案。在建立空气弹簧的热力学模型和连接管路热力学模型的基础上,通过与动力学模型联合仿真,验证该优化方案的效果。互联空气悬架可以优化车辆的行驶平顺性,改善车辆动态轴荷分配。分析了互联管路直径对动力学性能的影响。结果表明:该方案改善了数字轨道电车端车的平顺性和载荷均衡性;当连接管路直径取10~20 mm、以车速20 km/h通过减速带的行驶工况下,互联空气平衡悬架的平顺性较原有结构提升了2%~6%,一、二轴的动载荷的峰值相比原有结构降低2%~16%;随着联通管路直径的增加,车辆行驶的平顺性有提高的趋势,一二轴动载荷的平衡效果也越明显;15 mm的管径能较好地平衡减速带和边坡点2种工况下的动力学性能。

悬吊训练核心肌群对帕金森病病人平衡能力及运动功能的影响

目的:探讨悬吊训练核心肌群对帕金森病病人平衡能力及运动功能的影响。方法:选取2022年3月—2023年3月医院住院治疗的帕金森病病人96例为研究对象,基于随机数字表法将病人分为观察组及对照组各48例。对照组行常规康复训练,观察组实施悬吊训练核心肌群,比较两组干预前后平衡能力、运动能力及生活质量。结果:干预后观察组平衡步态量表(POMA)相关维度评分、肢体运动功能评定量表(FMA)相关维度评分较对照组显著提升(P<0.05),而观察组干预后帕金森生活质量评定量表(PDQ-39)相关维度评分较对照组显著下降(P<0.05)。结论:悬吊训练核心肌群能有效提升帕金森病病人平衡能力及运动功能,进而改善病人生活质量。

悬吊运动康复训练对脑卒中偏瘫患者躯干控制能力及平衡功能的影响

目的探究脑卒中偏瘫患者进行悬吊运动康复训练对其平衡功能、躯干控制能力的影响.方法选取2021年6月—2023年6月苏州工业园区星湖医院收治的80例脑卒中偏瘫患者为研究对象,按照随机数字表法将其分为研究组与对照组,各40例.对照组进行常规康复训练,研究组在此基础上进行悬吊运动康复训练.比较两组患者的躯干控制能力、平衡功能及生活质量.结果训练后,研究组的躯干控制测试评分及Berg平衡量表评分分别为(18.96±2.02)分、(47.96±7.48)分,均高于对照组的(15.44±2.06)分、(41.06±8.26)分,组间差异有统计学意义(P<0.05).训练后,研究组的健康调查简表中各项目评分均高于对照组,组间差异有统计学意义(P<0.05).结论脑卒中偏瘫患者进行悬吊运动康复训练,可有效改善其躯体控制能力、平衡功能,并提高其生活质量,值得临床推广使用.