【作者】 马长波；

【导师】 陆念力； 姜洪源；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2010， 博士

【摘要】 功能性电刺激(Functional Electrical Stimulation, FES)是一种利用电极刺激失去神经控制的肌肉,使肌肉产生收缩,从而恢复人体特定部位功能的交叉前沿康复技术。FES技术在医疗及康复工程等领域有多种应用形式,FES脚踏车(FES Cycling)系统则是基于FES技术的、集成了机械、控制和康复工程的一门前沿课题,其主旨在于使患者能够主动训练,而且该系统可实现代步功能。这将有利于提高患者的心肺功能,增加肌肉强度和厚度,使患者部分运动功能得到重建;同时这还将有助于减轻患者家庭负担,提高患者治愈病患的信心,其康复效果已被大量的实验证明。本研究工作以FES脚踏车技术的实现出发,从FES脚踏车的构建、模型及控制等角度进行了研究。仿真和试验结果表明,该系统能够很好地实现对患者的康复训练,达到了预期的设计目标。本文详细综述了FES脚踏车康复训练系统的各个技术点的国内外研究现状,在参考已有技术特点的基础上,开展了以构建FES脚踏车康复训练系统为目的的研究。首先概述了FES脚踏车康复训练系统的性能特点,该系统的控制由两个闭环控制来实现,在结构上分为五大部分;从系统的硬件和软件构成等角度详细论述了各个部分工作原理及结构。为了深入研究患者在蹬踏训练过程中人体与系统相互作用的原理,建立了系统的动力学模型。该模型由运动学模型、电刺激—肌肉力模型及动力学模型组成;通过建立仿真模型得到了在系统克服腿部自重情况下的仿真结果,并将仿真结果与试验结果进行了对比,验证了该模型的准确性。在此基础上,建立了以速度和脉宽为输入数据的动力学数学和仿真模型,获得了在电机辅助给定速度和脉宽情况下的肌肉输出力矩;以辨识试验和阶跃响应试验中的速度和脉宽信号为输入数据进行了仿真,仿真结果与试验结果的对比分析表明,该模型具有较好的正确性。刺激模式的好坏直接决定了训练效果,本文首先建立了FES脚踏车康复训练系统的蹬踏运动学模型,获得了各个关节以曲柄角度的表示的极限值,通过分析在各个极限角度范围内的各个关节的状态,以及综合各个肌肉群收缩对关节状态的作用,获得了零极限刺激模式,并以此为基础建立了以肌肉蹬踏力矩最大和尽量避免肌肉群共同作用造成关节相矛盾的运动为优化目的的试验优化方法,并获得了优化结果。为了对试验优化方法进行检验,本文还建立了刺激模式的理论优化方法。以最大输出功率和最小肌肉力为目标,建立了优化目标函数,获得了在各个曲柄速度下三组肌肉群的起始角度和终止角度的优化结果。由于肌肉对电刺激反应存在延迟,通过分析肌肉电刺激延迟反应,引入了延迟常数对刺激模式进行修正。并对蹬踏运动进行了分析,确定了影响蹬踏运动波动的因素。为了实现FES脚踏车康复训练系统的恒功率输出,从速度和功率两个闭环入手,建立了以系统辨识为基础的系统模型,并进行了占空比—速度模型和脉宽—功率模型的辨识试验,获取了辨识的输入输出数据,按照选取的模型类及规则确定了模型结构和参数;通过模型输出与实际试验输出数据对比,验证了辨识模型的正确性。通过分析占空比—速度模型和脉宽—功率模型的开环性能,确定了使用RST的控制策略的闭环控制。在确定闭环控制器的性能指标后,利用RST算法设计出控制器,并对控制器的性能进行了仿真和试验研究,结果表明控制器能够达到设计指标,且其稳定性、抗干扰性及跟踪性能均达到要求。考虑到功率闭环中人体疲劳等因素对脉宽功率模型的影响,设计了具有模糊和PID共有特点的模糊PID自校正控制器,仿真和试验结果表明,系统的跟踪性能和抗干扰性能均符合要求。此外,使用模糊T-S控制策略,通过辨识人体不疲劳和疲劳两种状态下的模型,分别设计了两种状态的线性二次型最优控制器和改进RST控制器,将系统两种状态的控制器通过模糊T-S进行融合,使系统能够在不疲劳、疲劳以及中间状态能够自动按照比例输出控制量,仿真结果表明达到设计预期目标。更多还原

【Abstract】 Functional Electrical Stimulation (FES) is a cross-frontier rehabilitation technology that using electrical impulse via electrodes to stimulate the muscles that are loss of nerve control to contract, thus rebuild their function of related limbs and organs of the body. FES technology has been applied in a variety of areas with various forms. FES cycling system is based on FES technology and integrated with machinery, control and rehabilitation techniques, which can make patients realize the voluntary exercise and assistant walk. Patients may benefit from the exercise for the improvement of cardiorespiratory function, the increase of muscular strength and thickness, and the rebuilding of partial function. Furthermore, it may relieve patients from the family burden and strengthen their confidence to overcome disease. The advantages have been proved by numerous experiments. In the present study, bases on the reality of FES cycling technology, the FES cycling system was constructed and modeled, and the related control strategy was studied. The simulated and experimental results indicate that the system functioned well in the rehabilitation training of patients and achieved the proposed goal.Firstly, this paper reviews the various techniques of FES cycling system. Based on the present advantages of the cycling system, a FES cycling system based on motor assistance was studied. The characteristics of the system were summarized: it consists of two close loops for control and five structural parts. Constitutions and working principles of every part were introduced in detail with the viewpoint of hardware and software. A dynamic model was built to describe the interaction between the object and the system during the training process. In the model, the kinematical model, electrical stimulation - muscle force model and dynamics model were integrated. Then simulation was conducted under the circumstance of overcoming leg weight. The comparison between the simulated and experimental results verified the accuracy of the model. Based on this analysis, a dynamic model and a simulation model with velocity and pulse width of assistant motor as input data were established to get the muscles output torque. The velocity and pulse width in the identification test and step response test were used in the simulation. The simulation results are in accordance with experimental ones which indicate that the model is with content validity. Secondly, the system cycling kinematics model was established in this study to get the limit of the angle of related joints in terms of crank angles, which are essential to determine the joint states. Synthesized the effect of muscles contraction to joint state, a zero limit stimulation pattern was obtained to optimize the maximum muscle cadence torque and avoid joints contradictory movement caused by muscle. To testify the experimental optimization method with the aim to obtain the maximum output torque and the minimum muscle force, the optimal objective function was constructed to get the optimization results of initial and terminated angles for three groups of muscles under various crank velocities. With consideration of the delay of the response of simulated muscles, a delay factor was introduced in the model to modify the stimulating patterns. Moreover, the hacking movement was analyzed and its influence factors were determined.Finally, in order to realize the constant power output of FES cycling system, a systematic identification-based model was developed in the respect of two closed loops, velocity and power. The identifications related to PWM - speed model and the pulse width-power model were tested and the model parameters and the structure in accordance with the selected modal patterns and rules were obtained. The comparison of model output and the actual output data testifies the accuracy of identification model. The RST control strategy of the closed-loop control was used in the study based on the analysis of the open-loop performance of two models. Then, a controller was designed based on the RST algorithm after the determination of the performance specification of the closed loop controller. The simulation and experiments results show that the parameters of controller can satisfy the design requirements, and its stability, anti-disturbance and tracking performance are good. With consideration of the effect of the muscles fatigue on the pulse width - power model, a fuzzy PID auto-adjusted controller was designed with integration of advantages of fussy system and PID. The tracking and anti-disturbance performance of this controller was testified by experimental and simulated results. Besides, a LQR controller and a modified RST controller were designed using fuzzy T-S controlling strategy, based on the identification of the models for the fatigue and non-fatigue states of patients respectively. Whereat, these controllers for different state were integrated through T-S techniques to satisfy the requirements of system so that it can generate output automatically and proportionally when it works at non-fatigue, fatigue states and in-between. The simulated results indicate that the design of the controller is in good use.更多还原