Design and Modeling for Revolute Control of USBM Simplified Model Mohd Syakirin Ramli, Reza Ezuan Samin, Mohd Razali Daud and Mohd Ashraf Ahmad Faculty of Electrical & Electronics Engineering Universiti Malaysia Pahang syakirin@ump.edu.my, reza@ump.edu.my, mrazali@ump.edu.my, ash_usc@hotmail.com Abstract – Universal Stretch and Bending Machine (USBM) is a combination of Stretch Machine and Bending Machine which are used in car door sash production. The main purpose of combining these two machines is to reduce the number of machines, space utilization and increase productivity. This paper basically focuses on the design and modeling for revolute control of USBM simplified model. The best controller between modern control (Integral Control State Feedback Controller) and intelligent control (Fuzzy Logic Controller) systems that suites the USBM simplified model are evaluated. The evaluation is done by comparing the performances in terms of maximum percentage overshoot and steady-state error. Prior to that, mathematical model of the system is first derived and verified by SIMULINK/MATLAB. Based on the simulation result, the Fuzzy Logic Controller is better than the Integral Control State Feedback Controller in terms of maximum percentage overshoot and steady state error. Key-words: Full-state feedback control, Bass and Gura’s approach, Fuzzy Logic Controller, State-space, Servomotor, Integral control. I. INTRODUCTION In recent car door sash production requires for both stretch and bending machines. In minimizing the usage of two machines and by combining them into a single machine but with two functions as before, this could lead to space utilization and increase productivity. The Universal Stretch and Bending Machine comprises of prismatic and revolute movements. The studies for these movements are conducted individually on the simplified model for choosing the controller that best suites the design requirement before it can be implemented on the prototype machine. In recent years, the CNC controller [1]-[2] is still used in controlling machine. Yet, CNC controller can still be explored for improving its performance. The objective of this paper is to study and compare the performance in terms of percentage overshoot and steady- state error between the Integral Control State Feedback Controller with Fuzzy Logic Controller on revolute control of USBM simplified model. In designing the Integral Control State Feedback Controller, the pole-placement design via Bass and Gura’s approach [3] is proposed. The pole-placement design is chosen since it produces best performance in terms of oscillation and settling time [4] as compared to other controllers. Moreover, the pole- placement design could also handle system with time- varying state space conditions [5] or systems with multiple operating conditions [6]. Addition to that, the pole- placement design could also handle systems with multi- input-multi-output (MIMO) signal condition [7]. One lack of advantages in designing the Integral Control State Feedback Controller is prior to obtain the controller’s parameters; the state space representation of the system must first be identified. This further requires for system identification technique and parameter estimation in order to maximize the performance using this controller’s structure. Designing the Fuzzy Logic Controller, on the other hand, does not require for prior knowledge on system characteristic equation. The so called intelligent controller function much closer in spirit to human thinking and natural language than traditional logical system where it provides a means of converting a linguistic control strategy based on expert knowledge into an automatic control strategy [8]. The implementation of Fuzzy Logic Controller in [9] using microcontroller proves the robustness of this controller where the results for both simulation and experimental are identical with regard to the load mass change. II. REVOLUTE MODEL The revolute model for the USBM was adapted from the model of the DC servomotor. DC servomotor is chosen since it is easier to control where by changing the armature voltage or current, the position or the speed of the DC servomotor can be varied. Fig.1 below shows the schematic of the armature controlled DC servomotor with a fixed field circuit. For transfer function derivation, this system was divided into three major components of equation, which are electrical equation, mechanical equation, and electro- mechanical equation. Fig.1. Schematic of DC servomotor system 4th International Colloquium on Signal Processing and its Applications, March 7-9, 2008, Kuala Lumpur, Malaysia. © Faculty of Electrical Engineering, UiTM Shah Alam, Malaysia. ISBN: 978-983-42747-9-5 668