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为了提高外骨骼关节柔性以及穿戴舒适性,设计了基于柔性驱动关节的可穿戴式下肢外骨骼,同时针对下肢外骨骼在控制的不同相位阶段其侧重点不同的特点,提出基于双模态切换的混合控制策略.首先,针对下肢外骨骼关节的柔性问题,设计了基于双平行弹簧的串联弹性体,并将其安装于外骨骼关节驱动模块,通过双编码器实现关节力矩和位置信息的反馈.然后,分析外骨骼在不同步态相位的运动特征,提出了双模态切换控制策略,即支撑相采用自适应阻抗控制算法来提高稳定性和抗冲击能力,摆动相采用自抗扰-终端滑模控制算法来提高响应速度和跟踪精度.最后,通过控制仿真和主被动跟踪实验,验证了本文算法相较于传统PID(比例-积分-微分)和自抗扰控制算法的优越性.被动跟踪实验结果说明当关节误差收敛范围在土5%时,收敛时间可达0.28 s;在主动跟踪实验中,实验人员穿戴外骨骼时髋关节和膝关节最大均方根误差分别为0.47°和1.28°,说明本文控制算法可以实时跟踪人体运动意图,满足人机交互柔顺性需求. 相似文献
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基于磁耦合共振原理,设计了一套采用平板磁心结构的变负载恒流充电无线电能传输系统。利用等效电路模型分析影响传输功率、系统效率和充电电流的主要因素。根据超级电容恒流充电过程中等效负载电阻动态变化规律,采用不同阻值的功率电阻模拟其充电特性。首先,分析二次侧Buck变换器对充电电流的调节作用,得到占空比与充电电流的关系,采用PI控制算法实现变负载的恒流充电;其次,通过理论分析和仿真实现磁耦合机构参数优化设计;最后,搭建系统实验平台对系统设计方法进行验证。在传输距离为15cm且负载电阻为0.5~5?时,实现29A的恒流充电。当负载电阻为3.2?时,系统效率和传输功率分别为87.7%和2.58k W。 相似文献
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k]A design and optimization approach of dynamic and control performance for a two-DOF planar manipulator was proposed. After
the kinematic and dynamic analysis, several advantages of the mechanism were illustrated, which made it possible to obtain
good dynamic and control performances just through mechanism optimization. Based on the idea of design for control (DFC),
a novel kind of multi-objective optimization model was proposed. There were three optimization objectives: the index of inertia,
the index describing the dynamic coupling effects and the global condition number. Other indexes to characterize the designing
requirements such as the velocity of end-effector, the workspace size, and the first mode natural frequency were regarded
as the constraints. The cross-section area and length of the linkages were chosen as the design variables. NSGA-II algorithm
was introduced to solve this complex multi-objective optimization problem. Additional criteria from engineering experience
were incorporated into the selecting of final parameters among the obtained Pareto solution sets. Finally, experiments were
performed to validate the linear dynamic structure and control performances of the optimized mechanisms. A new expression
for measuring the dynamic coupling degree with clear physical meaning was proposed. The results show that the optimized mechanism
has an approximate decoupled dynamics structure, and each active joint can be regarded as a linear SISO system. The control
performances of the linear and nonlinear controllers were also compared. It can be concluded that the optimized mechanism
can achieve good control performance only using a linear controller. 相似文献
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研究医疗诊断图像.针对计算机断层扫描图像CT和核磁共振图像MRI只能提供人体内部的二维图像,医生们只能凭经验由多幅二维图像去估计病灶的大小和形状,"构思"病灶与其周围组织的三维几何关系,给诊断带来了困难.为了使手术医疗诊断和治疗规划更准确.提出了设计和实现一个交互性的医学图像三维重建和可视化系统.首先给出了医学图像可视化算法原理;然后进行了三维重建可视化系统设计.最后以VC和VTK为开发工具设计程序,实现了CT文件的读取、图像数据的显示和基于MC算法和MS算法的三维模型的重建.仿真结果表明:既可以作为单独三维可视化系统用于医疗诊断,也可以针对不同手术的需要进行功能扩展,证明诊断图像显示更精确,为手术提供了科学手段. 相似文献
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机器人辅助正骨手术系统虚拟环境精确建模方法 总被引:3,自引:0,他引:3
结合已经研制的机器人辅助正骨手术系统,研究在应用虚拟现实进行手术时,虚拟手术环境建模的实现.采用基于计算机图形和医学图像的混合建模方法对手术环境中复杂的机器人模型和患者、腿骨进行精确建模.利用建模工具Java3D和VTK开发机器人辅助正骨手术系统的三维虚拟环境模型及虚拟手术仿真系统.虚拟手术环境的精确建模,为在此基础上进行的手术培训、手术规划、手术预演和远程外科手术奠定了基础. 相似文献
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