Thermomechanical ring rolling with predictive property control

切向环轧制是一种通过对成形速度和温度的闭环控制，同时有针对性地影响组织和硬度，从而生产出接近净形的环件几何形状的工艺。为此，采用了PID和预测模型的结合方法，以便使用完整的现有工艺窗口，从而同时实现最终几何形状、微观结构和硬度的目标值。在FÖP I和II中，进行了系统架构的开发，所需的软传感器和相关模型，以及能够实时测量数据采集系统的实现，以实现环轧机的闭环控制。级联控制回路用于控制成形速度和气流，从而控制冷却速度和最终的微观组织。在实验测试中，分析了过程变量和干扰变量，并对其影响进行了表征，验证了所实现的温度控制回路在FÖP II过程中的有效性。微结构发展软传感器结合了本项目开发的温度传感器和涡流传感器，以快速的温度、材料和成形模型记录表面微结构，预测环内的环性能。根据实测数据和预测模型不断调整最优输入参数。FÖP II的研究结果产生了轧环机控制和确定相关工艺窗口的概念，这将在第三个资助期进行。FÖP III的目标是在接近生产的条件下完成控制器的实现。这将有助于识别和量化控制回路在不同配置下对过程性能的影响。此外，工艺限制的识别确保了所开发方法的可转移性，例如，不同的环几何形状或材料。为此，对现有的数字孪生进行了扩展，以允许对过程进行模拟，包括闭环控制。在真实机器上验证后，将有可能将几何形状和配置的控制策略转移到现有轧机上不可行的情况下。对过程和系统性能的分析将允许在系统架构（执行器、传感器、建模和控制）方面推导设计原则和规则，以实现热机械控制的环轧制。

Thermomechanical tangential ring rolling (TMR) is a process for the production of near-net-shape ring geometries with simultaneous targeted influencing of the microstructure and hardness by closed loop control of the forming speed and temperature. For this, a combined approach of PID and predictive models is used, in order to use the full existing process window in such a way that the target values for final geometry, microstructure and hardness can be achieved simultaneously. In FÖP I and II, the development of the system architecture, the required soft sensors and associated models, as well as the implementation of a real-time capable measurement data acquisition system were carried out in order to realize a closed control loop on the ring rolling machine. Cascaded control loops were used to control the forming speed and air flow and, as a result, the cooling rate and the resulting microstructure. In experimental tests, the process and disturbance variables were analysed and their influence characterized, and the effectiveness of the implemented temperature control loop was demonstrated in the course of FÖP II. The soft sensor for microstructure development combines temperature sensors and an eddy current sensor developed in the project to record the microstructure on the surface with fast temperature, material and forming models to predict the ring properties inside the ring. The optimal input parameters are continuously adjusted based on the measured data and a prediction model. The findings from FÖP II led to a concept for the control of the ring rolling machine and the identification of associated process windows, which will be taken up in the third funding period. The goal in FÖP III is to complete the implementation of the controller under near-production conditions. This will serve to identify and quantify the influence of the control loops on process performance in different configurations. Furthermore, the identification of the process limits ensures the transferability of the developed methodology, e.g., to different ring geometries or materials. For this purpose, the existing digital twin is extended to allow a simulation of the process, including the closed loop control. After validation on the real machine, it will be possible to transfer the control strategy for geometries and configurations to cases that are not feasible on the existing rolling mill. An analysis of the process and system performance will allow the derivation of design principles and rules in terms of system architecture (actuators, sensors, modelling and control) for the implementation of thermomechanically-controlled ring rolling.