Papers by Keyword: Gap Control

Abstract: This paper presents a new method for controlling the gap distance in an EDM machine. Existing gap width control method using PI controller does not perform efficiently in a highly nonlinear and time-variant process such as EDM. In this method, constant tuning of the PI controller is required to achieve a stable and efficient EDM process. The new gap control method present in this paper uses an artificial intelligent type 2 fuzzy logic control to control the gap distance between the electrode and the workpiece. The main advantage of this proposed method is its robustness that would rid the practitioners from the tedious tuning job and would provide the industry with better accuracy and confidence in the control performance.

Abstract: Hardware-in-the-loop (HIL) test is a good ground for examine the dynamic model of rolling to observe the movement of the mill and monitor dynamic behavior of the hydraulic system and the mill. Nowadays hydraulic actuators/capsules are used to control the gap in rolling mills which determines the strip thickness, profile and flatness. Using HIL simulation, dynamic parameters of rolling mill stand and hydraulic gap adjustment system can be tested together in realtime. It has possibility to examine the dynamic phenomena inside the mill stand and hydraulic system using trials to test how system dynamic behavior changes when system’s parameters are shifted. In this paper a HIL real-time model was developed and realized to test the dynamic behavior of the complete rolling mill system which enables us to observe the system’s parameter variations for example when seals are worn out in the hydraulic actuator.

Abstract: Choosing of adequate shape technological parameters together with good chemical compound is very important to produce steel strip with required cross-section and material quality. The shaping rate, speed and time have an effect on strip mechanical and geometrical quality. The rate of shaping force needed for steel strip plastic deformation is determined by the strength of the steel forming. In rolling mills technology the plastic deformation of the strip is realized at high plastic strain speed so the dynamic change of shaping force might seriously affects the remaining stress of the rolled strip. The dynamic control of roll gap and force is realized with help of electrohydraulic servo actuator – so-called hydraulic capsules – which can adjust the roll gap at great rolling force dynamically. The quality of stand-mounted hydraulic capsule can greatly affect the dynamics of rolling, consequently the material quality of the rolling. The main contribution of the paper is to analyze the rolling dynamic behavior using the hydraulic capsule and rolling mill mathematical model together to show the changing of dynamic behavior of the system when internal sealing in hydraulic capsule is inefficient.