Taworn Benjanarasuth

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

Two-degree-of-freedom simple servo adaptive control for SCARA robot

This paper presents an application of two-degree-of-freedom simple servo adaptive control scheme in controlling DDR-type two-links SCARA robot. The SCARA robot is widely used in industries and it is generally desired to control its movement along some periodic trajectory to perform some repeated tasks. A proper control scheme is therefore required. Among various control techniques, two-degree-of-freedom simple servo adaptive control scheme possesses a prominent aspect in that it can force the systems to follow the desired reference model while the servo gain can be freely assigned to tune the disturbance rejection property independently. The simulations in applying the two-degree-of-freedom simple servo adaptive control scheme to control the SCARA robot are demonstrated to verify the applicability and effectiveness of this control technique. The effect of tuning the servo gain is also observed.

Hybrid controller for rotational inverted pendulum systems

In this paper, a controller designed by energy control technique and servo state feedback with minimum-order observer control algorithm to swing up the pendulum of the rotational inverted pendulum system from the natural pendent position to around the upright position and to stabilize the pendulum in upright position is proposed. The proposed control scheme composes of two parts. The first part is the swing-lip control using the energy-based controller and the second part is the stabilizing control using the servo state feedback with minimum-order observer controller. From the implementation of the controller to the rotational inverted pendulum system in laboratory, the pendulum can be swung up within a short period of time with small oscillation of the base angle. Furthermore, without changing the parameters of the proposed controller, the responses of the system when changing the length of the pendulum is also shown to demonstrate the robustness of the proposed control system.

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.

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.

IMC-based PID controllers design for a two-links SCARA robot

The paper presents the design of PID controllers for a two-link SCARA robot based on internal model control (IMC) technique. For the model of the two-link SCARA robot which includes an integrator, IMC filter must be selected properly so that the designed IMC controllers can be approximated as PID controllers by using Maclaurin approximation. The simulation results verify the applicability and satisfied performance of the proposed control system.

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.