Simultaneous Force and Stiffness Control of a Pneumatic Actuator
Simultaneous Force and Stiffness Control of a Pneumatic Actuator
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DOI：
10.1115/1.2745850
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发表时间：
2007-07
影响因子：
1.7
通讯作者：
Xiangrong Shen;M. Goldfarb
中科院分区：
文献类型：
--
作者：
Xiangrong Shen;M. Goldfarb
本文提出了一种新的方法来设计一个机器人驱动器的物理变刚度。所提出的方法利用了气动致动器固有的动态特性，其本质上表现为串联弹性致动器。通过用一对三通阀取代用于控制典型气动执行器的四通伺服阀，可以独立于执行器输出力调节串联弹性元件的刚度。基于这一概念，作者提出了一种控制方法，同时控制执行器的输出力和刚度。由于可实现的输出力和刚度耦合和配置依赖，作者还提出了一个控制律，提供最大或最小的致动器输出刚度为给定的位移和所需的力输出。一般的控制和最大/最小刚度的方法进行了实验证明，并示出提供高保真度的力和刚度的控制，并另外示出提供一个因素的6动态范围的刚度。
This paper proposes a new approach to the design of a robot actuator with physically variable stiffness. The proposed approach leverages the dynamic characteristics inherent in a pneumatic actuator, which behaves in essence as a series elastic actuator. By replacing the four-way servovalve used to control a typical pneumatic actuator with a pair of three-way valves, the stiffness of the series elastic component can be modulated independently of the actuator output force. Based on this notion, the authors propose a control approach for the simultaneous control of actuator output force and stiffness. Since the achievable output force and stiffness are coupled and configuration-dependent, the authors also present a control law that provides either maximum or minimum actuator output stiffness for a given displacement and desired force output. The general control and maximum/minimum stiffness approaches are experimentally demonstrated and shown to provide high fidelity control of force and stiffness, and additionally shown to provide a factor of 6 dynamic range in stiffness.