Raja Mohd Taufika Raja Ismail

PD Fuzzy Logic with non-collocated PID approach for vibration control of flexible joint manipulator

The increased complexity of the dynamics of robots manipulator considering joint elasticity makes conventional model-based control strategies complex and difficult to synthesize. This paper presents investigations into the development of PD type Fuzzy Logic Control (FLC) with non-collocated Proportional Integral Derivative (PID) for trajectory tracking and vibration control of a flexible joint manipulator. To study the effectiveness of the controllers, a PD type Fuzzy Logic Controller is developed for tip angular position control of a flexible joint manipulator. This is then extended to incorporate a non-collocated PID Controller for vibration reduction of the flexible joint system. Simulation results of the response of the flexible joint manipulator with the controllers are presented in time and frequency domains. The performances of the non-collocated PID control schemes are examined in terms of input tracking capability, level of vibration reduction and time response specifications. Finally, a comparative assessment of the control techniques is presented and discussed.

Vibration control of flexible joint manipulator using input shaping with PD-type Fuzzy Logic Control

This paper presents investigations into the development of input shaping with Proportional-Derivative (PD)-type Fuzzy Logic Control for trajectory tracking and vibration control of a flexible joint manipulator. To study the effectiveness of the controllers, a PD-type Fuzzy Logic Controller is developed for tip angular position control of a flexible joint manipulator. This is then extended to incorporate input shaper control schemes for vibration reduction of the flexible joint system. The positive zero-vibration-derivative-derivative (ZVDD) and new modified specified negative amplitude zero-vibration-derivative-derivative (SNA-ZVDD) input shapers are then designed based on the properties of the system for vibration control. The new SNA-ZVDD is proposed to improve the robustness capability while increasing the speed of the system response. Simulation results of the response of the flexible joint manipulator with the controllers are presented in time and frequency domains. The performances of the PD-type Fuzzy Logic with input shaping control schemes are examined in terms of input tracking capability, level of vibration reduction, robustness and time response specifications. A comparative assessment of the positive ZVDD and modified SNA-ZVDD shapers to the hybrid system performance is presented and discussed.

Feed-forward Techniques for Sway Suppression in a Double-Pendulum-Type Overhead Crane

This paper presents investigations into the development of feed-forward control schemes for anti-swaying control of a double-pendulum-type overhead crane (DPTOC) system. A nonlinear DPTOC system is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. An unshaped bang-bang force input is used to determine the characteristic parameters of the system for design and evaluation of the feed-forward control techniques. Feed-forward control schemes based on input shaping and filtering techniques are to be examined. The proposed techniques are designed based on the properties of the system for anti-sway control. Simulation results of the response of the DPTOC system to the shaped inputs are presented in time and frequency domains. Performances of the control schemes are examined in terms of sway angle reduction and time response specifications. Finally, a comparative assessment of the proposed control techniques is presented and discussed.

The investigations of input shaping with optimal state feedback for vibration control of a flexible joint manipulator

This paper presents investigations into the development of input shaping with optimal state feedback for trajectory tracking and vibration control of a flexible joint manipulator. A single-link flexible joint manipulator is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. To study the effectiveness of the controllers, a linear-quadratic regulator (LQR) controller is developed for tip angular position control of a flexible joint manipulator. This is then extended to incorporate input shaper control schemes for vibration reduction of the flexible joint system. The positive zero-vibration-derivative-derivative (ZVDD) and new modified specified negative amplitude zero-vibration-derivative-derivative (SNA-ZVDD) input shapers are then designed based on the properties of the system for vibration control. The new SNA-ZVDD is proposed to improve the robustness capability while increasing the speed of the system response. Simulation results of the response of the flexible joint manipulator with the controllers are presented in time and frequency domains. The performances of the LQR with input shaping control schemes are examined in terms of input tracking capability, level of vibration reduction, robustness and time response specifications. A comparative assessment of the positive ZVDD and modified SNA-ZVDD shapers to the hybrid system performance is presented and discussed.

Speed Control of Buck-converter Driven Dc Motor Using LQR and PI: A Comparative Assessment

This paper presents the detailed account on the control design of a buck converter driven dc motor. Linear Quadratic Regulator (LQR) and Proportional-Integral (PI) are the techniques proposed in this investigation to control the speed of a dc motor. The dynamic system composed from converter/motor is considered in this investigation and derived in the state-space and transfer function forms. Complete design and analyses of simulation results for LQR and PI technique are presented in frequency domain and time domain. Performances of the controller are examined in terms of angular velocity, duty cycle input energy and armature current. Finally, a comparative assessment of the impact of each controller on the system performance is presented and discussed.

Novel adaptive spiral dynamics algorithms for global optimization

This paper presents adaptive versions of spiral dynamics algorithm (SDA) referred to as adaptive SDA (ASDA). SDA is known as fast computing algorithm due to its simplicity in the structure and it has stable convergence response when approaching the optimum point in the search space. However, the performance of SDA is still poor due to incorporation of single radius value during the whole search process. In ASDA, the spiral radius is made dynamic by employing novel mathematical equations and incorporating non-mathematical fuzzy logic strategy establishing the relationship between fitness value and spiral radius. This results in better performance in terms of convergence speed, accuracy, and total computing time while retaining the simple structure of SDA. Several uni-modal and multi-modal benchmark functions are employed to test the algorithm in finding the global optimum point. The results show that ASDA outperforms SDA in all test functions considered.

Investigations of feed-forward techniques for anti-sway control of 3-D gantry crane system

This paper presents investigations into the development of feed-forward control schemes for anti-swaying control of a gantry crane system. A nonlinear 3-D gantry crane system is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. An unshaped bang-bang force input is used to determine the characteristic parameters of the system for design and evaluation of the feed-forward control techniques. Feed-forward control schemes based on input shaping and filtering techniques are to be examined. The proposed techniques are designed based on the properties of the system for anti-sway control. Simulation results of the response of the gantry crane system to the shaped inputs are presented in time and frequency domains. Performances of the shapers are examined in terms of swing angle reduction and time response specifications. Moreover, the robustness of the feed-forward control schemes is discussed. Finally, a comparative assessment of the proposed control techniques is presented and discussed.

Trajectory tracking and anti-sway control of three-dimensional offshore boom cranes using second-order sliding modes

The growing usage of ocean facilities and land constraints have necessitated transfers of equipment and cargos to and from support vessels, complex lifts and other stevedoring operations in open sea conditions. Recently, there has been increasing research interests in three-dimensional control and automation of offshore cranes. Suspended cargos in a ship-mounted crane system are caused to swing due to the vibratory motion of the ship induced by ocean waves, which can lead to collision between cargos and deck. Therefore, it is crucial for offshore crane systems to satisfy rigorous requirements in terms of safety and efficiency. This paper presents the modelling and control development for three-dimensional offshore boom cranes. A second-order sliding mode control law is proposed for trajectory tracking and anti-sway control, making use of its capability of actuator chattering alleviation while achieving high tracking performance and preserving strong robustness. The asymptotic stability of the closed-loop system is guaranteed in the Lyapunov sense. Simulation results indicate that the proposed controller can significantly reduce the effect of disturbances coming from gusty waves and other dynamic loadings.

Input shaping techniques for anti-sway control of a 3-D gantry crane system

This paper presents investigations into the development of feedforward control schemes for anti-swaying control of a gantry crane system. A nonlinear 3-D gantry crane system is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. An unshaped bang-bang force input is used to determine the characteristic parameters of the system for design and evaluation of the input shaping control techniques. The positive zero-sway-derivative-derivative (ZSDD) and new modified specified negative amplitude zero-sway-derivative-derivative (SNA-ZSDD) input shapers are then designed based on the properties of the system for anti-sway control. Simulation results of the response of the gantry crane system to the shaped inputs are presented in time and frequency domains. Performances of the shapers are examined in terms of swing angle reduction and time response specifications. Finally, a comparative assessment of the proposed control techniques is presented and discussed.

Comparison of Hybrid Control Schemes for Vibration Suppression of Flexible Robot Manipulator

This paper presents a comparative assessment of control schemes for vibration suppression and end-point trajectory tracking of a flexible robot manipulator. A constrained planar single-link flexible robot manipulator is considered and the dynamic model of the system is derived using the assumed mode method. To study the effectiveness of the controllers, initially a collocated PD controller is developed for control of rigid body motion. This is then extended to incorporate a non-collocated PID controller and a feedforward controller based on input shaping techniques for control of vibration (flexible motion) of the system. For input shaping controller, the positive input shapers with different derivatives are proposed and designed based on the properties of the system. Simulation results of the response of the manipulator with the controllers are presented in time and frequency domains. The performances of the control schemes are assessed in terms of level of vibration reduction, input tracking capability and speed of response. Finally, a comparativeassessment of the control techniques is presented and discussed.