Improved Positioning Control Of A Rotary Switched Reluctance Actuator Using Modified PID Controller

Over the past decade, the rotary switched reluctance actuator (SRA) has been gaining attention not only in the areas of industrial applications as well in promising research areas such as robotics and automotive engineering. The popularity can be much associated with the attractive advantages SRA has to offer such as inherent fault tolerance, simple and robust structure in addition to the ability for high frequency operations. Despite the attractive advantages it has to offer, SRA exhibits significant nonlinear characteristics due to its unpredictable magnetic flux flow and operation in saturation region. Subsequently, these dynamic behaviors often make modelling and real time motion control a challenging effort. Although various control methods have been developed, these controller design procedures frequently require exact model of mechanism and deep understanding in modern control theory which leads to their impracticability. Henceforth, in this research, a practical control strategy namely the modified proportional-integral-derivative (PID) control scheme is proposed for point-to-point motion control of the rotary SRA mechanism. The practical control scheme presented heavily emphasizes on simple structure and straightforward design framework. Hence, the proposed modified PID controller includes control elements that are derived from the measured open loop responses. Complex system modelling or high computational learning algorithms are not required in the controller design process. The performance evaluation is examined and compared to a conventional PID controller through experimental works. At fully aligned and almost aligned positions, experimental results showed that the proposed controller successfully reduced steady-state error in step positioning by an average improvement of 94%. The maximum overshoot and settling time are improved by an average 62.5% and 47%. At intermediate positions, although zero steady- state error can be enjoyed on both controllers, modified PID controller performed better by showing a reduced overshoot and settling time response of 60% and 37% improvement. Overall, the proposed controller displayed superiority compared to conventional PID controller with a smoother displacement response with reduced steady-state error, overshoot and settling time in all positioning tasks

Rotary Switched Reluctance Actuator: A Review On Design Optimization And Its Control Methods

A switched reluctance actuator (SRA) is a type of electromagnetic stepper actuator that is gaining popularity for its simple and rugged construction, ability of extremely high-speed operation and hazard-free operation. SRA gained supremacy over permanent magnet actuators due to the fact that its building material are relatively low cost compared to the expensive and rare permanent magnets. SRA is already making its debut in automotive, medical and high precision applications. However, many parties are still oblivious to this new age actuator. This paper reviews the latest literature in terms of journal articles and conference proceedings regarding the different design parameters and control method of SRA. The impact of the parameters on the performance of SRA are discussed in details to provide valuable insight. This paper also discussed the advantages of various novel SRA structure designs that prove to be a huge contribution to the future technology. It is found that several design parameters such as the air gap when kept minimum, increases torque value; while increasing number of phases in SRA minimizes torque ripples. Increased stator and rotor arc angles will increase torque, not to mention a larger excitation current can also achieve the same effect. Researches are often done through Finite Element Method (FEM) analysis to verify the optimized design parameters before fabrication, whilst experimental procedures are executed to verify the simulation results. To ensure smooth phase switching and improved torque output, intelligent controllers are employed in speed control and direct torque control (DTC) methods of SRA

Experimental Investigation Of A Passive Quarter Car Suspension System

This research paper discussed the study of a two degree-of freedom quarter car model passive suspension system. An open loop characteristics experiment using system identification method was carried out to determine the transfer function of the passive suspension system. Once these steps are completed, a closed loop compensated system is designed to control the position of Platform 1; i.e. the road surface. Platform 1 will provide the road profiles of different step height for the passive quarter car suspension system. The PID controller was proven to be able to improve steady-state error by 48.6%, 31.9%, 10.9% and 21.8% for reference heights of 30cm, 32cm, 34cm and 36cm, respectively, with a slight 12% overshoot for 34cm and 36cm reference heights

Tracking Control Performances Of A Dual-Limb Robotic Arm System

This paper discuss the tracking control performances of a dual-limb robotic arm system for precision motion and high speed response. In this paper, the focus is to fabricate & analyze the control performances of an upper duallimb robotic arm system which are able to move in parallel motion. The experimental results are obtained through open-loop and closed-loop test. The system transfer function is evaluated experimentally via system identification method. In this paper the Proportional and Derivative (PD) controller is used to control the trajectory motion of the dual-limb robotic arm system. The PD controller with proportional gain Kp = 169 and derivative gain KD = 1.1412 shows good performances using step input reference. To further verify the robustness of the controller, tracking control experiments are performed with rectangular & triangular input trajectory. The PD controller shows the dual-limb robotic arm system able to show good performances with the steady state error less than 0.4° for the 15° triangular input references with 0.1Hz frequency, respectively