Modeling and Optimal Force Control of a Nonlinear Electrostatic Microgripper
Modeling and Optimal Force Control of a Nonlinear Electrostatic Microgripper
复制标题
DOI：
10.1109/tmech.2012.2197216
复制
发表时间：
2013-06-01
影响因子：
6.4
通讯作者：
Le Gorrec, Yann
中科院分区：
文献类型：
--
作者：
Boudaoud, Mokrane;Haddab, Yassine;Le Gorrec, Yann
集成了力传感器的微型抓取器是非常有效的工具，可以灵活地操纵微观世界中的物体(尺寸小于100微米)。在本文中，我们首先提出了一种带集成力传感器的非线性静电微夹持器在处理经过校准的直径为80微米的微玻璃球时的建模方法。研究了微夹持器的线性工作范围的极限，建立了大位移下的非线性模型，并进行了实验验证。然后，我们提出了最优力反馈控制器的设计，以确保在适当的抓取力的情况下可靠的操作。为了克服传感器提供的低信噪比带来的局限性，使用卡尔曼滤波从噪声测量中估计过程的状态。在最坏情况下的噪声水平(峰值噪声幅值)达到8µN的情况下，对10µN的夹持力基准进行了实时实验，并对控制律进行了验证。通过与外部干涉测量结果的比较，证明了最优滤波的有效性。
Microgrippers with integrated force sensors are very efficient tools for dexterous manipulation of objects in the microworld (size less than 100 mu m). In this paper, we first propose a modeling approach of a nonlinear electrostatic microgripper with integrated force sensor while handling calibrated microglass balls of 80-mu m diameter. Limit of the linear operating range of the microgripper is investigated and a nonlinear model is proposed and validated experimentally for large displacements. We then propose the design of an optimal force feedback controller to ensure reliable handling operations with appropriate gripping forces. To overcome the limitation caused by the low signal-to-noise ratio provided by the sensor, a Kalman filter is used to estimate the states of the process from noise measurements. The control law is implemented and validated using real-time experiments for 10 mu N gripping force reference with a noise level (peak-to-peak magnitude of the noise) reaching 8 mu N in the worst case. The effectiveness of the optimal filter is proven by comparison with external interferometric measurements.