Sensory Feedback in Prosthetics: A Standardized Test Bench for Closed-Loop Control
Sensory Feedback in Prosthetics: A Standardized Test Bench for Closed-Loop Control
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DOI：
10.1109/tnsre.2014.2371238
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发表时间：
2015-03-01
影响因子：
4.9
通讯作者：
Farina, Dario
中科院分区：
文献类型：
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作者：
Dosen, Strahinja;Markovic, Marko;Farina, Dario
通过向假肢使用者提供感觉反馈来关闭控制回路是一项重要的挑战，对假肢的未来具有重大影响。开发和比较闭环系统是一项困难的任务，因为有许多不同的方法和技术可以用于实现系统的每个组件。在此，我们介绍了一种在MatLab Simulink中开发的测试平台，用于在标准化设置下配置和测试闭环系统的人体控制系统。该框架包括一组具有标准化输入和输出的连接的通用块，可以通过从预定义组件库中选择特定实现来定制这些通用块。该框架具有模块化和可扩展性，可用于配置、比较和测试不同的闭环系统原型，从而指导开发走向最优的系统配置。通过研究闭环控制的两个重要方面：在摆动稳定任务期间不同的电触觉反馈接口(空间与强度编码)的性能以及力控制的前馈方法(操纵杆与肌肉控制)，演示了该试验台的使用。第一个实验表明，在受过训练的受试者中，强度编码可能优于空间编码。在第二个实验中，即使有稳定和精确的控制界面(操纵杆)，力的控制也相当差，这表明当考虑到闭环控制的整体有效性时，假体的固有特性可能是一个重要的限制因素。该试验台是研究具有感觉反馈的人体手动控制各方面的重要工具。
Closing the control loop by providing sensory feedback to the user of a prosthesis is an important challenge, with major impact on the future of prosthetics. Developing and comparing closed-loop systems is a difficult task, since there are many different methods and technologies that can be used to implement each component of the system. Here, we present a test bench developed in Matlab Simulink for configuring and testing the closed-loop human control system in standardized settings. The framework comprises a set of connected generic blocks with normalized inputs and outputs, which can be customized by selecting specific implementations from a library of predefined components. The framework is modular and extensible and it can be used to configure, compare and test different closed-loop system prototypes, thereby guiding the development towards an optimal system configuration. The use of the test bench was demonstrated by investigating two important aspects of closed-loop control: performance of different electrotactile feedback interfaces (spatial versus intensity coding) during a pendulum stabilization task and feedforward methods (joystick versus myocontrol) for force control. The first experiment demonstrated that in the case of trained subjects the intensity coding might be superior to spatial coding. In the second experiment, the control of force was rather poor even with a stable and precise control interface (joystick), demonstrating that inherent characteristics of the prosthesis can be an important limiting factor when considering the overall effectiveness of the closed-loop control. The presented test bench is an important instrument for investigating different aspects of human manual control with sensory feedback.