Intelligent Tube Hydroforming Process with Micro Contact Sensors

为了建立管材液压成形智能过程控制系统，基于传感器融合的思想，研制了一种新型微型接触式传感器，用于评价管坯的装刀状态，使成形系统更精确、更灵活。主要研究内容有：(1)研制微接触式传感器并对其性能进行评价；(2)验证采用微接触式传感器的智能过程控制系统的有效性。研究方法不仅是在实验工作中，也是在有限元(FE)模拟工作中，以实现这一目标。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式换能器组成，由手工制作而成。它的输出与施加的载荷呈线性关系，并具有足够的接触式传感器性能。将传感器芯片嵌入到对冲头上，用于T形接头成形。因此，它被称为Foun…另外，该传感器在实际生产过程中可以很好地作为接触传感器，与管坯和凸模的实际接触情况与有限元模拟结果存在较大差异。换句话说，这些结果意味着实际的智能成形系统需要接触传感器，并且必须基于传感的接触数据来控制成形过程。然而，埋入的传感器在对头对准不好，影响T形精度的表面质量较差。提出了智能控制系统和刀具装夹、起皱、破损的评价函数。改进了智能控制算法，包括起皱、破损和刀具装夹的评价函数。特别是提出了一种新的基于传感数据的接触状态评估算法，并将其应用到模糊模型中。但是，对于成形过程中出现起皱的情况，新方法的适用范围有一定的局限性。虽然在微接触传感器和利用这些传感器建立智能控制算法和系统方面还存在各种问题，但本项目两年的结果表明，至少这些微接触传感器对于建立更先进、更灵活的系统是必不可少的。较少

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