Leader-Follower Multimotor Speed Coordination via Adaptive Fuzzy Multiagent Consensus Scheme

Coordinated speed of interconnected motors has vast application in the industry. Typically, the smooth operation of the system relies on the coordinated speed of the multiple motors such as the conveyer belt system. Thus, the problem to have coordinated speed in a network-connected motor is mostly dealt with wire-connected architectures such as cross coupling. The presented study suggests a unique design to deal with the said problem by proposing a network model consisting of a DC chopper drive, termed as an ith agent of a network, while a leader-follower multiagent consensus algorithm is used, in a supervisory role, to ensure coordinated speed. Moreover, a hybrid controller (Fuzzy MRAC-RST), composed of Fuzzy logic controller, pole placement controller (F-RST), along with model reference adaptive controller (MRAC), is used to control the ith agent. The proposed hybrid controller along with MAS consensus algorithm forms an adaptive tracking performance and ensure coordinated speed. The MATLAB platform is used for simulation purpose, and the obtained results validate the design concept.

Improved Pole-placement Control with Feed-forward Dead Zone Compensation for Position Tracking of Electro-Pneumatic Actuator System Improved Pole-placement Control with Feed-forward Dead Zone Compensation for Position Tracking of Electro-Pneumatic Actuato

Dead-zone in the valve degraded the performances of the Electro-Pneumatic Actuator (EPA) system. It makes the system difficult to control, become unstable and leads to chattering effect nearest desired position. In order to cater this issue, the EPA system transfer function and the dead-zone model is identified by MATLAB SI toolbox and the Particle Swarm Optimization (PSO) algorithm respectively. Then a parametric control is designed based on pole-placement approach and combine with feed-forward inverse dead-zone compensation. To reduce chattering effect, a smooth parameter is added to the controller output. The advantages of using these techniques are the chattering effect and the dead-zone of the EPA system is reduced. Moreover, the feed-forward system improves the transient performance. The results are compared with the pole-placement control (1) without compensator and (2) with conventional dead-zone compensator. Based on the experimental results, the proposed controller reduced the chattering effect due to the controller output of conventional dead-zone compensation, 90% of the pole-placement controller steady-state error and 30% and 40% of the pole-placement controller with conventional dead-zone compensation settling time and rise time.

Comparison of Nonlinear and Linear Controllers for Magnetic Levitation System

Nonlinear system control belongs to advanced control problems important for real plants control design. Various techniques have been developed in this field. In this paper we compare two different approaches to a nonlinear unstable Magnetic levitation system control. The first control design approach further develops our recent results on robust discrete-time pole-placement, based on convex DR-regions. The second studied approach is based on feedback linearization and the simplified development of the corresponding nonlinear control law is provided. Both approaches are compared and evaluated. The efficiency of robust discrete-time pole-placement controller is shown as well as its competitiveness in comparison with nonlinear control for Magnetic levitation system.

Comparison of a Triple Inverted Pendulum Stabilization Using Optimal Control Technique

In this paper, modelling design and analysis of a triple inverted pendulum have been done using Matlab/Script toolbox. Since a triple inverted pendulum is highly nonlinear, strongly unstable without using feedback control system. In this paper an optimal control method means a linear quadratic regulator and pole placement controllers are used to stabilize the triple inverted pendulum upside. The impulse response simulation of the open loop system shows us that the pendulum is unstable. The comparison of the closed loop impulse response simulation of the pendulum with LQR and pole placement controllers results that both controllers have stabilized the system but the pendulum with LQR controllers have a high overshoot with long settling time than the pendulum with pole placement controller. Finally the comparison results prove that the pendulum with pole placement controller improve the stability of the system.

LMI Pole Regions for a Robust Discrete-Time Pole Placement Controller Design

Herein, robust pole placement controller design for linear uncertain discrete time dynamic systems is addressed. The adopted approach uses the so called “D regions” where the closed loop system poles are determined to lie. The discrete time pole regions corresponding to the prescribed damping of the resulting closed loop system are studied. The key issue is to determine the appropriate convex approximation to the originally non-convex discrete-time system pole region, so that numerically efficient robust controller design algorithms based on Linear Matrix Inequalities (LMI) can be used. Several alternatives for relatively simple inner approximations and their corresponding LMI descriptions are presented. The developed LMI region for the prescribed damping can be arbitrarily combined with other LMI pole limitations (e.g., stability degree). Simple algorithms to calculate the matrices for LMI representation of the proposed convex pole regions are provided in a concise way. The results and their use in a robust controller design are illustrated on a case study of a laboratory magnetic levitation system.

Aplikasi Kontrol Digital Untuk Pemupukan Secara Variable Rate Pada Sistem Pertanian Presisi

Precision agriculture has many facets including guidance, yield mapping, variable rate application and remote sensing. Variable rate nitrogen fertilization is a technique being developed for fertilizer application in recent years. One of the main problems in variable rate nitrogen fertilization is controlling the fertilizer application rate according to the soil nitrate level. In this paper, a digital control system for variable rate nitrogen fertilization is presented. A pole-placement controller design based on the simplified process model is used in this system. The system dynamic response of the pole-placement controller was simulated under the condition with torque disturbance and the condition without torque disturbance. The digital controller was then implemented into a prototype system and the dynamic response of the control system was tested under different torque disturbance conditions. The control system performed at acceptable levels under small external torque disturbance conditions. However, under large torque disturbances, the steady-state offset error in the system response was not acceptable and the use of a robust controller for both tracking control and disturbance rejection was recommended. This paper presents a simulation of the use of digital control for variable rate fertilization The benefits of using variable rate technology are very clear. Low yielding areas of the field are no longer over fertilized resulting in reduction of costs in those areas.Pertanian presisi memiliki banyak aspek diantaranya pengukuran, pemetaan hasil, aplikasi laju tidak tetap dan penginderaan jarak jauh. Pemupukan nitrogen secara laju tidak tetap (variable rate) adalah teknik yang dikembangkan untuk aplikasi pemupukan dalam beberapa tahun terakhir. Salah satu masalah utama dalam pemupukan nitrogen secara laju tidak tetap yaitu mengontrol jumlah pemakaian pupuk agar sesuai dengan kandungan nitrat tanah. Tulisan ini menyajikan studi tentang aplikasi sistem kontrol digital untuk pemupukan nitrogen secara laju tidak tetap dalam kerangka pertanian presisi (precision farming). Sebuah desain kontroler tiang-penempatan didasarkan penyederhanaan modelnya digunakan dalam sistem ini. Sistem respon dinamik dari pengontrol tiang-penempatan disimulasikan pada kondisi dengan gangguan torsi dan kondisi tanpa gangguan torsi. Kontrol digital kemudian diimplementasikan ke dalam sistem prototipe dan respon dinamik dari sistem kontrol diuji di bawah kondisi gangguan torsi yang berbeda. Sistem kontrol dilakukan pada tingkat yang dapat diterima dalam kondisi gangguan torsi eksternal yang kecil. Namun, di bawah gangguan torsi besar, kondisi steady yang mengimbangi kesalahan dalam respon sistem tidak dapat diterima. Tulisan ini menyajikan simulasi penggunaan kontrol digital untuk pemupukan secara variable rate. Tujuan penggunaan teknologi variable rate adalah agar lokasi dengan produktivitas rendah tidak lagi dipupuk secara berlebihan sehingga mengurangi biaya.Keywords: fertilization, digital control, variable rate, precision farming.