Force Control of Gripper Driven by Piezoelectric Actuator

本课题是在日本东北大学和韩国全北大学的合作下进行的，旨在实现压电驱动的夹持器的力控制。该项目的具体内容如下。压电陶瓷是铁电体，其响应基本上是非线性的，对施加的电压信号表现出明显的滞后回路。研究了非线性压电陶瓷驱动器的线性驱动问题。提出了一种补偿陶瓷驱动器迟滞环的线性驱动方法。提出了一种简单的非线性滤波器。结果表明，当非线性前置放大器置于直流电和直流电之间时，迟滞环消失。C.放大器和输入电压发生器。为了测量微小力，研制了一种具有人体指腹感觉的软触觉传感器。该传感器由两个矩形橡胶块和多个矩形橡胶块组成， ...更多信息 插入橡胶块接口之间的橡胶量规。应变计中的应变与传感器上施加的载荷大小成比例。因此，表面载荷可以通过测量压力计的输出来确定。传感器的特性进行了研究，理论和实验的几种配置的橡胶块与一个单一的嵌入式应变片。实验结果表明，该软测量方法能够有效地测量作用在传感器上的分布和集中的微小力.研制了一种由压电双晶片驱动的微型双指夹持器，研究了该夹持器的位置/力混合控制问题。该系统是由两个灵活的杠杆和一个紧凑的力传感器连接到一个手指的尖端。机电系统的理论模型的开发和应用的控制问题的研究，其中夹持器被命令抓住它的对象与时间恒定的力0.01 N在指定的命令指尖位置。采用PID和II_* 控制算法对夹持器进行驱动。从理论和实验两方面对系统控制行为进行了研究。实验结果表明，该双指系统作为微型夹持器工作良好。它可以控制0.01N数量级的抓持力在指尖。少

The present project has been pursed for the past three years under the collaboration of Tohoku University, Japan and Chonbuk National University, Korea to achieve Force Control of Gripper Driven by Piezoelectric Actuator. The details of the project are as follows.1. Piezoelectric ceramics are ferroelectric and are fundamentally nonlinear in their response, showing a significant hysteretic loopto the applied voltage signal. The problem of the linear drive of nonlinear piezoelectric ceramic actuators was studied. A linear drive method was proposed for the ceramic actuators that compensates for the hysteretic loop. A simple nonlinear preamplifier was developed. It was shown that the hysteretic loop disapeppears when the nonlinear pre-amplifier is installed between the d. c. amplifier and the input voltage generator.2. Soft tactile sensor with a sense of human digital pulp was developed in order to measure minute force. The sensor is composed of two rectangular rubber blocks and several st … More arin gauges that are inserted between the interface of the rubber blocks. The strains in the gauges are propotional to the magnitude of the applied load on the sensor. Thus, the surface load can be determined by measuring the output of the gauges. Characteristics of the sensor are investigated both theoretically and experimentally for several configurations of the rubber blocks with a single embedded strain gauge. Obtained Results showed that the proposed soft sensor measures the distributed as well as the concentrated minute force on the sensor effectively.3. A two-fingerd miniature gripper driven by piezoelectric bimorph cells and was developed and the hybrid position/force control of the system was studied. The system is composed of two flexible cantilevers and a compact force sensor attached to the tip of one finger. The theoretical model of the electro-mechanical system was developed and applied to the study of a control problem where the gripper is commanded to grasp its object with a time-constant force 0.01N at a prescribed comanded fingertip position. The PID and II_* control algorithms were introduced to drive the gripper. The system control behavior was examined both theoretically and experimentally. The results showed the two-fingerd system works well as a miniature gripper. It can control the grasping force of order 0.01N at the tip of the finger. Less