Jongkol Ngamwiwit

Application of coefficient diagram method for rotational inverted pendulum control

In this paper, a design of the augmented state feedback controller by using the concept of coefficient diagram method (CDM) for a servo type of the rotational inverted pendulum system is presented. An integrator is augmented to the system due to the responses exhibiting steady-state error. In order to apply the CDM method, the augmented system must be firstly linearized and converted into controllable canonical form by a transform matrix. Then a feedback gain matrix in sense of CDM can be obtained. One can observe that the design procedure of the proposed controller is easy compared to other methods. The experimental results are shown in order to verify the effectiveness of the controller.

Hybrid Controller for Swinging up Inverted Pendulum System

A hybrid controller for swinging up inverted pendulum system is proposed in this paper. The controller composes of two parts. The first part is the PD position control for swinging up the pendulum from the natural pendent position by moving the cart back and forth until the pendulum swings up around the upright position. The second part is a servo state feedback control designed by LQR which will be switched to stabilize the inverted pendulum in its upright position. The effectiveness and reliability of the proposed hybrid controller for swinging up inverted pendulum on cart are also shown by the experimental results

Fuzzy I-PD Controller for Level Control

This paper introduces a level control system using a fuzzy I-PD controller. The proposed controller composes of Mamdani fuzzy I and Mamdani fuzzy PD controllers and is adjusted to meet the desired control system performances both in transient state and steady state. The simulation results in controlling the level processes by using the fuzzy I-PD controller with the same parameters (proportional gain, integral gain and derivative gain) as the conventional I-PD controller are shown in this paper

Hybrid controller for swinging up and stabilizing the inverted pendulum on cart

In this paper, a hybrid controller for swinging up and stabilizing an inverted pendulum on cart is presented. The energy control concept is employed to swing the inverted pendulum up to around the upright position within the assigned switching condition. After that, the stabilizing controller is then switched to stabilize the inverted pendulum at the upright position. The stabilizing controller is a linear servo state feedback controller designed by coefficient diagram method. The simulation results show that the designed hybrid controller can be mutually operated with acceptable efficiency.

I-PD and PD controllers designed by CRA for overhead crane system

An overhead crane system controlled by an I-PD controller incorporating with PD controller is presented in this paper. The characteristic ratio assignment method is employed to design the I-PD controller and the PD controller for controlling the position of trolley and for controlling the load swing angle of the overhead crane system, respectively. Using the concept of characteristic ratio assignment method, the speed of the step response can also be increased by using a design factor k. The simulation results show that the step response can reach to the desired position without overshoot and with small load swing angle. The slightly change of the step responses when changing the parameters of the overhead crane system are also shown. The simulation results also show that when the speed of the step response is increased, the load swing angle is large related to the speed increased while the disturbance effect rejection is fast.

Fuzzy logic control for speed of wound rotor induction motor with slip energy recovery

Fuzzy logic control is considered for speed of wound rotor induction motors with slip energy recovery. The speed is limited at some range of sub-synchronous speed of the rotating magnetic field. By controlling speed by adjusting the resistance value in the rotor circuit the efficiency of power is reduced, because of the slip energy lost when it passes through the rotor resistance. The control system is designed to maintain efficiency of the motor. A fuzzy logic control method is applied for self-tuning the system by keeping the speed constant and adjusting the rotor current appropriate to the load. Good transient response without overshoot can be obtained.

PID/spl times/(n-2) stage PD cascade controller for SISO systems

To obtain the response of sampled system better than of using the Zero Order Hold (ZOH) method. The approximation to the integral using Bilinear discretization is proposed. The results from simulation show that the obtained response from the bilinear or Tustin method is better than the ZOH method at the same sampling time. However, if another of descretization method is necessaries, the overall closed-loop system should be considered.Presents a design technique for a two degree of freedom (2-DOF) control system using PID (proportional-integral-derivative)/spl times/(n-2) stage PD as a cascade controller for an n/sup th/ order plant. It is intended to satisfy both transient and steady state response specifications based on the root locus approach. This controller can be used instead of a conventional PID controller to obtain better performance without relying upon any tuning methods. The overall system is approximated as a stable and robust second order system. The cascade controller gain can be adjusted to meet faster responses with a little or no overshoot. The simulation results show that the desired performances are achieved. The merit of this approach for a plant with uncertain parameters is also shown.

PI controller design with feedforward by CDM for level processes

A second-order level process controlled by PI controller designed from coefficient diagram method (CDM) can meet the desired performances both in transient and steady-state response. However, the transient response generally still has long rise time. This paper presents an additional idea to improve the speed of the system response by including a feedforward controller (FFC) in the closed-loop system. The structure of the FFC is a phase lead structure with a parameter that can be varied greater than one. The faster step response of the controlled system can be obtained while the rejection speed of the effect due to constant output disturbance is not affected by the proposed FFC.

Hybrid Controller for Inverted Pendulum System

In this paper, a hybrid controller designed for swinging up and stabilizing an inverted pendulum on cart system is presented. The controller composes of a PD controller and a sliding mode controller. The PD controller is implemented to control the position of the cart to swing up the pendulum from the natural pendent position to around the upright position, while the sliding mode controller is implemented to stabilize the inverted pendulum in the upright position. Root-locus method is applied to design the PD controller and LQR method is employed to design the sliding mode controller. The implementation results of the proposed hybrid controller are shown in this paper.

Adaptive fuzzy sliding mode controller for two cascaded tanks level control

This paper proposes an indirect adaptive fuzzy sliding mode controller for a nonlinear plant. Fast convergence of the controlled system is first obtained from the indirect approach by roughly estimating the nonlinear functions of the plant. Then the sliding mode control approach with boundary layer is used to compensate the deteriorated system performance due to the model mismatch and unmodeled dynamics obtained from the indirect adaptive fuzzy control approach. The simulation results show that the level controlled system of a two cascaded tanks is stable, tracking error is significantly small and system convergence is fast for wide operating range while the chattering of the control input still occurs.