Data-driven adaptive model-based predictive control with application in wastewater systems

This study is concerned with the development of a new data-driven adaptive model-based predictive controller (MBPC) with input constraints. The proposed methods employ subspace identification technique and a singular value decomposition (SVD)-based optimisation strategy to formulate the control algorithm and incorporate the input constraints. Both direct adaptive model-based predictive controller (DAMBPC) and indirect adaptive model-based predictive controller (IAMBPC) are considered. In DAMBPC, the direct identification of controller parameters is desired to reduce the design effort and computational load while the IAMBPC involves a two-stage process of model identification and controller design. The former method only requires a single QR decomposition for obtaining the controller parameters and uses a receding horizon approach to process input/output data for the identification. A suboptimal SVD-based optimisation technique is proposed to incorporate the input constraints. The proposed techniques are implemented and tested on a fourth order non-linear model of a wastewater system. Simulation results are presented to compare the direct and indirect adaptive methods and to demonstrate the performance of the proposed algorithms

Non-Intrusive Electrodynamic Characteristic Measurement for Circular Shape Electrode

Abstract—The electrostatic sensor was used in process industry because of low cost and robust designed.Three types of electrode available in particular application such as pin shape, quarter ring shape and ring shape. The paper was focused on the investigation of the pin shape structure and the characteristic of the circular shape by using different size of structure. Non-instrusive method with circular electrode will be designed and applied to the shape.The sensitivity and spatial filtering effect of sensor will be investigated by using different size of electrodes.Then, the model will be proposed and compared with experimental result

Enhanced Position Control for Pneumatic System by Applying Constraints in MPC Algorithm

This paper demonstrates the effectiveness of applying constraints in a controller algorithm as a strategy to enhance the pneumatic actuator system’s positioning performance. The aim of the present study is to reduce the overshoot in the pneumatic actuator positioning system’s response. An autoregressive with exogenous input (ARX) model structure has been used to model the pneumatic system, while a model predictive control (MPC) has been employed as a control strategy. The input constraint has been applied to the control signals (on/off valves signals) to ensure accurate position tracking. Results show that the strategy with constraint effectively reduced overshoot by more than 99.0837 % and 97.0596 % in simulation and real-time experiments, respectively. Moreover, the performance of the proposed strategy in controlling the pneumatic positioning system is considered good enough under various loads. The proposed strategy can be applied in any industry that used pneumatic actuator in their applications, especially in industries that involved with position control such as in manufacturing, automation and robotics. The strategy proved to be capable of controlling the pneumatic system better, especially in the real-time environment

Robust Control Strategy for Pneumatic Drive System via Enhanced Nonlinear PID Controller

This paper presents the pneumatic positioning system controlled by Enhanced Nonlinear PID (NPID) controller. The characteristic of rate variation of the nonlinear gain that are readily available in NPID controller is utilized to improve the performance of the controller. A Self-regulation Nonlinear Function (SNF) is used to reprocess the error signals with the purpose of continuously generating the values for the rate variation. Subsequently, the controller has successfully been implemented on dynamically changing loads and pressures. The comparison with the other available method such as. NPID and conventional PID are performed and evaluated.  The effectiveness of this method with Dead Zone Compensator (DZC) has also been successfully demonstrated and proven through simulations and experimental studies.DOI:http://dx.doi.org/10.11591/ijece.v4i5.685

Comparison of Torque Performances on Different Core Material for Switched Reluctance Actuator without Permanent Magnet

This paper presents the comparison of torque profiles of the Switched Reluctance Actuator (SRA) without permanent magnet (PM) using two types of materials which are Low Carbon steel, Grade 1008 and Medium Carbon steel, Grade S45C. Each of the Low Carbon steel and Medium Carbon steel is distinguished by the percentage of carbon contents which is 0.1% and 0.43%, respectively. The designed SRA of both materials was according to the size of NEMA 17 standard stepper motor for small machine applications and simulated through FEM analysis. The maximum generated torque achieved by the SRA with the Low Carbon steel is 122.540mNm and with Medium Carbon steel is 54.107mNm, respectively at 2A input current. It shows that the carbon content influences the magnetic properties of the materials as the generated torque decreases approximately 50% when the carbon content is four (4) times higher. As a conclusion, the Medium Carbon steel, Grade S45C depict better working range as it capable of generating high torque at a small overlapping angle compared to Low Carbon steel, Grade 1008

Design and Development of Ankle-Foot Rehabilitation Exerciser (AFRE) System Using Pneumatic Actuator

This research presents the design and development of a novel strategy for an Ankle-Foot Rehabilitation Exerciser (AFRE) system. AFRE system can be used Continuous Passive Motion (CPM) device and strength endurance training device for early stage functional rehabilitation. The designed mechanism can allow desired maximum and minimum Range of Motion (ROM) for dorsiflexion and plantar flexion (upwards and downwards stretching). This device consists of a new moveable mechanism design prototype using a new double acting Intelligent Pneumatic Actuator (IPA), embedded controller and communication protocol. The drive system consists of a nonlinear moving pneumatic actuator that controls the angle position, force and compliance for stiffness characteristic of the ankle-foot orthosis platform. In addition, the device can be configured through MATLAB via personal computer where the user can adjust the required ROM and resistance for the user in real-time. Analysis carried out during the system validation and testing through selected subjects are presented and discussed. This AFRE system is expected to substitute the traditional therapy and motorized rehabilitation device to increase the healing time of the patient specifically