Intelligent Tube Hydroforming Process with Micro Contact Sensors

为了建立管件液压成形的智能过程控制系统，基于传感器融合的概念，开发了一种新型微接触传感器来评估管件毛坯的刀具配合状态，使成形系统更加精确和灵活。主要研究项目有：(1)开发微接触传感器并对其性能进行评价；(2)验证利用微接触传感器的智能过程控制系统的有效性。研究方法不仅在实验工作中，而且在有限元（FE）模拟工作中实现。研究结果如下：(1)微接触传感器的研制一种新型传感器芯片，由9个传感器和一个压电换能器组成，采用手工制作。它的输出与所施加的负载呈线性关系，并且作为接触式传感器具有足够的性能。将传感器芯片嵌入到T型接头成形反击冲床的头部。结果表明，该传感器在实际加工过程中可以很好地用作接触式传感器，且实际与管状坯料和冲床的接触情况与有限元模拟结果不同。也就是说，实际的智能成形系统需要接触传感器，并且必须基于传感接触数据来控制过程。然而，嵌入式传感器在反冲头上没有很好地对准，影响T形精度的表面质量。目前研制的传感器的这些技术问题，包括传感器的原理，都需要在不久的将来得到解决。(2)智能控制系统及起皱、破裂评估功能对智能控制算法进行了改进，包括起皱、破裂和刀具拟合评估功能。提出了一种基于传感数据的接触状态评估算法，并将其应用于模糊模型中。然而，在成形过程中出现起皱的情况下，新方法的适用范围有一定的局限性。尽管在微接触传感器以及利用传感器建立智能控制算法和系统方面还存在各种问题，但这两年的项目结果表明，至少这些微接触传感器是建立更先进、更灵活的系统所必需的。少

In this study, to establish an intelligent process control system for tube hydroforming, a new micro contact sensor is developed to evaluate the tool fitting state with a tubular blank and to make the forming system more accurate and more flexible based on their sensor fusion concept. The main research items are (1) to develop a micro contact sensor and evaluation its performance, and (2) to confirm the effectiveness of intelligent process control system utilizing the micro contact sensors. The study approaches are not only in experimental work but also in finite element (FE) simulation work to achieve the goal. The study results are as follows,(1) Development of a micro contact sensorsA new sensor chip consists of nine sensors with a piezoelectric transducer, which is made by hand. Its output shows a linear relationship with applied load and enough performance as a contact sensor. The sensor chip were embedded on the head of a counterpunch for T -joint forming. As a result, it is foun … More d that the sensor can use as contact sensor well in the real process and the actual contact situation with tubular blank and counterpunch is different from FE simulation result. In other words, these results imply that actual intelligent forming system needs the contact sensor and has to control the process based on the sensing contact data. However, embedded sensors were not in good alignment on the counter punch head, it affects worse surface quality of T -shape accuracy. These technological issues on present developed sensors shall be solved including the principle of sensor in the near future.(2) Intelligent control system and evaluation function of tool fitting, wrinkling, and ruptureImprovement of intelligent control algorithm including evaluation function of wrinkling, rupture, and tool fitting are made. Especially, a new algorithm to evaluate contact condition from sensing data is proposed and adopted in the fuzzy model. The new method, however, has some limitation of applicable scope in the case of wrinkling occurrence at the forming process. Although there have been remaining various problems on micro contact sensor and establishment of intelligent control algorithm and system utilizing the sensors, this two-year project results indicate that at least these micro contact sensors are essential to establish this system more advanced and more flexible. Less