WALK-ASSISTING BALANCE SYSTEM OF THE EXOSKELETON ROBOT FOR DISABLED PEOPLE

A novel methodology for a walk-assisting balance system of the exoskeleton robot for dis-abled people is presented. The experiment on the walk-assisting balance system is implemented using amini-type ropewalker robot. The mechanism of the ropewalker robot is designed, its dynamic model isbuilt, and its control system based on PWM is developed. The emulations in Matlab and the results ofexperiments prove that this methodology is effective.

A novel methodology for complex part motion planning

A motion planning strategy for the assembly task of inserting a dissymmetrical T-shaped part into a C-shaped slot is presented. The coarse motion planning strategy is expounded by geometric reasoning. A medial axis diagram decreases the unnecessary configuration states and optimizes the planning strategy. Due to the uncertainties, force sensing and force control is indispensable for motion planning. Combining the coarse motion planning strategy with fine motion planning strategy, the task of assembling a dissymmetrical T-shaped part can be completed successfully.

基于O2O模式的家具企业信息流管理方法研究

家具行业面临着日益激烈的竞争环境,随着互联网和大数据技术的发展,传统的商业模式已经不能满足新的市场环境和消费者需求,O2O模式作为一种新的电子商务模式,有效地将线上与线下相结合,为家具企业的电子商务提供了新的思路,成为家具行业未来发展转型的一大方向。笔者基于O2O模式的关键要素和家具企业的运营特点,运用数据化思维分析得出家具企业在运营过程中需要和产生的信息,主要包括了人流信息、订单流信息、物流信息和资金流信息,通过对各部分信息的要素分析构建基本模型,并对有关技术和工具进行解读,归纳总结出各类信息流管理的模式和方法,对于家具企业的产品设计、销售,用户服务体系的建立以及企业的运营具有指导性意义。

中高端消费群体生活形态研究与家具设计探析

最新调查结果显示,我国高收入人群占比提升,国内人群将成为居家消费升级的主要动力,并带动中高端家具需求的提升。本文基于AIO系统和事理学理论生活形态模型两大生活形态理论研究,结合中高端消费群体实际住宅生活背景与生活形态调研分析结果,从使用者、使用环境、使用时间三个维度建立中高端消费群体的生活形态模型,从整体家居环境、细分功能空间和产品两大层面总结其具体需求点,并且有针对性地提出中高端消费群体的家具设计路径,旨在为相关企业研发新产品提供参考。

Bioelectrochemical control mechanism with variable-frequency regulation for skeletal muscle contraction-Biomechanics of skeletal muscle based on the working mechanism of myosin motors(Ⅱ)

This paper presents a bioelectrochemical model for the activation of action potentials on sarcolemma and variation of Ca2+ concentration in sarcomeres of skeletal muscle fibers.The control mechanism of muscle contraction generated by collective motion of molecular motors is elucidated from the perspective of variable-frequency regulation,and action potential with variable frequency is proposed as the control signal to directly regulate Ca2+ concentration and indirectly control isometric tension.Furthermore,the transfer function between stimulation frequency and Ca2+ concentration is deduced,and the frequency domain properties of muscle contraction are analyzed.Moreover the conception of "electro-muscular time constant" is defined to denote the minimum delay time from electric stimulation to muscle contraction.Finally,the experimental research aiming at the relation between tension and stimulation frequency of action potential is implemented to verify the proposed variable-frequency control mechanism,whose effectiveness is proved by good consistence between experimental and theoretical results.

A dynamic model of skeletal muscle based on collective behavior of myosin motors-Biomechanics of skeletal muscle based on working mechanism of myosin motors(I)

A dynamic model of skeletal muscle is developed to describe its activation kinetics and contraction dynamics based on the collective working mechanism of myosin II motors with a statistical mechanics method.According to the structure of sarcomeres arranged in series and in parallel,the mechanical properties of skeletal muscle are studied.This model reveals the relations between action potential and muscle characteristics.It is shown that calcium concentration in sarcoplasmic(SP) increases linearly with the increasing stimulation frequency and gradually reaches saturation.Active force and contraction velocity follow the trend of calcium concentration and reach a peak value at the maximum stimulation frequency.Contraction velocity is inversely proportional to the load while the contraction power increases to maximum and then reduces to zero with the increasing load.These properties are consistent with published physiological experimental results of skeletal muscle.

Geometrical principium of fewer-axis grinding for large complex optical mirrors

Ultraprecision grinding is an important approach to efficiently fabricate large complex optical mirrors, and five-axis grinding method is commonly used for ultraprecision grinding. However, this method can hardly meet the high stiffness requirement for grinding large mirror, especially with a diameter over 2 m. Meanwhile, the use of fewer-axis grinding solves this problem, as it reduces the number of the grinder's axes to improve the rigidity of the system and minimize deformation for hard and brittle materials. But its characteristic of unfixed grinding point which changes with workpiece surface curvature increases geometric complexity and requires a higher geometric shape accuracy of grinding wheel. This paper parameterizes grinding wheel's geometric shape, reveals the relationship between fewer-axis and five-axis grinding methods from the point of view of the differential geometry, and establishes virtual-axis equivalence principium of feweraxis grinding. A quantitative method to determine grinding wheel's geometric parameters and its shaft inclination angle is proposed based on the requirements of geometric properties of optical mirror, grinder features and grinding process. Moreover, according to the properties of Gauss curvature of curved surface, the wear law of the toric grinding wheel is found and the surface geometric error distribution due to wear is achieved for fewer-axis grinding. The correctness of the principium and method above are verified through simulations.

A dynamical system-Markov model for active postsynaptic responses of muscle spindle afferent nerve

Motoneuron is the control unit of skeletal muscles,and the dynamic frequency-regulating feedback from the afferent nerve of receptors like muscle spindles forms the physical basis of its closed-loop regulation.Focused on the synapses of muscle spindle afferents,this paper established a dynamical system-Markov model starting from presynaptic stimulations to postsynaptic responses,and further verified the model via comparisons between theoretical results and relevant experimental data.With the purpose of describing the active features of dendritic membrane,we employed the methods of dynamical systems rather than the traditional passive cable theory,and identified the physical meaning of parameters involved.For the dynamic behavior of postsynaptic currents,we adopted simplified Markov models so that the analytical solutions for the open dynamics of postsynaptic receptors can be obtained.The model in this paper is capable of simulating the actual non-uniformity of channel density,and is suitable for complex finite element analysis of neurons;thus it facilitates the exploration of the frequency-regulating feedback and control mechanisms of motoneurons.