Arief Syaichu-Rohman

Model predictive control implementation on a programmable logic controller for DC motor speed control

Model predictive control (MPC) has been widely applied in various industrial plants, which are relatively slow processes. MPC application for faster processes is usually limited with the availability of faster optimization algorithms or digital processor. While it is widely employed, programmable logic controller (PLC) is not usually utilized as a implementation target of MPC in industry due to its low computation performance. A special MPC processor module attached to the standard PLC is used instead. This paper presents an experiment of using Mitsubishi Electric MELSEC-Q PLC as an MPC for DC motor speed control. A very simple quadratic program (QP) algorithm that has been proposed in the literature is adopted here. The algorithm involves a simple computation with a large number of iterations and may be optimized for faster convergence speed. The MPC with this QP algorithm is programmed into the PLC by standard ladder program and an proportional-integral ant-windup (PI-AW) controller is also implemented in the PLC for comparative purpose. Before PLC implementation, some simulation runs are taken to verify and fine-tuned the PI-AW and MPC for a DC motor speed control. The results of MPC implementation in the PLC have shown that MPC with a simple QP algorithm may be implemented in a PLC with a comparable performance with PI-AW

Implementation model predictive control (MPC) algorithm-3 for inverted pendulum

Model Predictive Control (MPC) is based on the idea to produce control input as a solution to real-time optimization problem. Optimization itself is based on the system model. MPC is used to solve multivariable control problem which has more than one variable that may have significant effect on the process. The advantage of MPC is that MPC can works effectively within constraints of the real actuator which are relatively narrow. The disadvantage of MPC lies on its complex algorithm that needs longer time than the other controller. This paper discusses the MPC application for inverted pendulum. The algorithm used is algorithm-3 for floating point. The general guidelines are modeling the system, designing the system using MATLAB, simulating the design using MATLAB, implementing the MPC algorithm on AVR ATmega32 and analyzing the result. After the guideline have been implemented, it can be seen that MPC algorithm-3 with 9 horizon and 1 iteration of quadratic programming can return the pendulum rod at the balance point by the time external force applied.

Static output feedback control synthesis for nonlinear polynomial fuzzy systems using a sum of squares approach

This paper addresses the static output feedback control synthesis problem for nonlinear polynomial fuzzy systems using a sum of squares (SOS) approach. The open-loop nonlinear systems is represented in the polynomial fuzzy model. By considering the closed-loop system in the output feedback control scheme and the polynomial Lyapunov functions that contain quadratic Lyapunov functions as special cases, sufficient conditions for a solution to the problems of stability analysis and control design can be derived in the representation form of the SOS. It can be numerically solved via the SOSTOOLS.

Model predictive control (MPC) design and implementation using algorithm-3 on board SPARTAN 6 FPGA SP605 evaluation kit

Model Predictive Control (MPC) is based on the idea to produce control input as a solution to real-time optimization problem. The advantage of MPC is that MPC can works effectively within constraints of the real actuator which are relatively narrow. The disadvantage of MPC lies on its complex algorithm that needs longer time than the other controller. This paper discuss the MPC application for TITO (Two Input Two Output) system and its implementation on board SPARTAN 6 FPGA SP605 Evaluation Kit with Microblaze MCS. The implemented MPC algorithm 3 on board SPARTAN 6 FPGA SP605 Evaluation Kit with Microblaze MCS can be used by different plant with fast responses, with minimal plants time constant is 3.9 seconds.

The saturated quaternion control law with application for spacecraft formation flying

Rotation matrix parameterization using unit quaternion can represent attitude globally. However, it is not unique and may generates the unwinding phenomenon, besides the issue on the globally asymptotically stability guarantee. This paper proposes a piecewise-continuous scheme of quaternion-based control law that employs a saturation element such that would avoid the unwinding phenomenon. This paper also proposes a consensus control scheme based on the saturated quaternion control law that would show the property of the unwinding phenomenon avoidance and the corresponding graph only need to have a directed spanning tree.

Static anti-windup compensator design of linear Sliding Mode Control for input saturated systems

A feedback control system involving a linear Sliding Mode Controller (SMC) and an input saturated linear plant is considered here. The linear SMC is designed for linear plant without saturation on its input. The resulting feedback system will not necessarily show an intended performance if the control input to the plant is saturated. In addition, a directionality problem for multivariable input systems may occur during the saturation. As a result, transient response performance could be degraded and its control signals may not be stabilizing the feedback system anymore. In this case, a directionality compensator may be designed to overcome the problem while optimizing its performance.

Quaternion-Based attitude control system design of single and cooperative spacecrafts: boundedness of solution approach

It is well known that single equilibrium orientation point in matrix rotation is represented by two equilibrium points in quaternion. This fact would imply nonefficient control effort as well as problem in guaranteeing stability of the two equilibrium points in quaternion. This paper presents a solution to design quaternion-based spacecraft attitude control system whose saturation element is in its control law such that those problems are overcome. The proposed feature of methodology is the consideration on boundedness of solution in the control system design even in the presence of unknown external disturbance. The same methodology is also used to design cooperative spacecrafts attitude control system. Through the proposed method, the most relaxed information-state topology requirement is obtained, that is, the directed graph that contains a directed spanning tree. Some numerical simulations demonstrate effectiveness of the proposed feature of methodology.

The quaternion-based attitude control system with an augmented dynamic

Quaternion-based attitude determination system is considered since it can represent all physical attitudes, but not uniquely. An inappropriate quaternion-based control law would imply to a non-efficient control effort and difficulty in guaranteeing global stability. Many research efforts decide to add complexity in the controller by using jump-discontinuity function and/ or hybrid system. In contrast, this paper proposes a continuous quaternion-based attitude control system with an augmented dynamic that guaranteed to be able to regulate any physical state asymptotically. The effectiveness of the designed system is verified through simulations.

Consensus-based controllers for spacecraft attitude alignment: Simulation results

Spacecraft formation flying control using consensus algorithm means each spacecraft or satellite in a team updates its state based on the information states of its local neighbours in such a way that the final information state of each agent converges to a common value. This paper discusses spacecraft formation within scope of rotational motions i.e. attitude alignment. Two attitude alignment controllers based on consensus algorithm proposed here.Simulations that run as preliminary proof a concept are presented. Simulations run indicate the proposed control laws might solve the attitude alignment problem i.e. consensus is achieved.

The application of input constrained controls on a power plant model

Input saturation is a nonlinear constraint that is widely encountered in physical systems. The success of dealing with input saturation may increase safety level of the systems operation and its economic benefits as well. This paper presents the applicatons of some input constrained controls in the literatures to a power plant model. Especially, we carry out the design and analysis of the feedback control using model predictive control (MPC) and both continuous and discrete time anti-windup schemes. The simulation results are presented and the implications on the implementation and its related computation is discussed.