Ahmad Nor Kasruddin Nasir

PERFORMANCE COMPARISON BETWEEN LQR AND PID CONTROLLERS FOR AN INVERTED PENDULUM SYSTEM

The objective of this paper is to compare the time specification performance between two conventional controllers for an inverted pendulum system. The goal is to determine which control strategy delivers better performance with respect to pendulum’s angle and cart’s position. The inverted pendulum represents a challenging control problem, which continually moves toward an uncontrolled state. Two controllers are presented such as Linear‐Quadratic‐Regulator (LQR) and Proportional‐Integral‐Derivatives (PID) controllers for controlling the linearized system of inverted pendulum model. Simulation study has been done in Matlab simulink environment shows that both controllers are capable to control multi output inverted pendulum system successfully. The result shows that LQR produced better response compared to PID control strategies and is presented in time domain.

A novel hybrid spiral dynamics bacterial chemotaxis algorithm for global optimization with application to controller design

This paper presents a hybrid optimization algorithm, referred to as hybrid spiral dynamics bacterial chemotaxis (HSDBC) algorithm. HSDBC synergizes bacterial foraging algorithm (BFA) chemotaxis strategy and spiral dynamics algorithm (SDA). The original BFA has higher convergence speed while SDA has better accuracy and stable convergence when approaching the optimum value. This hybrid approach preserves the strengths of BFA and SDA and thus has the capability of producing better results. Moreover, it has simple structure, hence reduced computational cost. Several unimodal and multimodal benchmark functions are employed to test the algorithm in finding the global optimum point. Furthermore, the proposed algorithm is tested in the design of PD controller for a flexible manipulator system. The results show that the HSDBC outperforms SDA and BFA in all test functions and successfully optimizes the PD controller.

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.

Vibration and input tracking control of flexible manipulator using hybrid fuzzy logic controller

This paper presents investigations into the development of hybrid fuzzy logic control schemes for end-point vibration suppression and input tracking of a flexible manipulator. A constrained planar single-link flexible 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 proportional-derivative (PD)-type fuzzy logic controller (FLC) is developed for control of rigid body motion. This is then extended to incorporate a non-collocated PID controller for control of vibration (flexible motion) 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 time response specifications. Finally, a comparative assessment of the control techniques is presented and discussed.

Performance Comparison between Fuzzy Logic Controller (FLC) and PID Controller for a Highly Nonlinear Two-Wheels Balancing Robot

The research on two-wheels balancing robot has gained momentum due to their functionality and reliability when completing certain tasks. This paper presents investigations into the performance comparison of Fuzzy Logic Controller (FLC) and PID controller for a highly nonlinear 2 -- wheels balancing robot. The mathematical model of 2-wheels balancing robot that is highly nonlinear is derived. The final model suffers from mismatched condition. Two system responses namely the robot position and robot angular position are obtained. The performances of the FLC and PID controllers are examined in terms of input tracking capability. Simulation results of the responses of the nonlinear 2 -- wheels balancing robot are presented in time domain. A comparative assessment of both control schemes to 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.

A novel hybrid spiral-dynamics bacterial-foraging algorithm for global optimization with application to control design

This paper presents a hybrid optimization algorithm referred to as Hybrid spiral dynamics bacterial foraging (HSDBF). The algorithm synergizes spiral adaptive simplified bacterial foraging algorithm (BFA) and spiral dynamics inspired optimization algorithm (SDA). The standard BFA has better exploitation strategy while SDA has superior exploration approach and stable convergence when approaching the optimum value. The hybrid algorithm preserves the strengths of BFA and SDA, thus producing better results. Moreover, it has simple structure and involves less computational burden. Several unimodal and multimodal benchmark functions are employed to test the algorithm in determining the global optimum point. Furthermore, the proposed method is applied to a proportional-derivative (PD) controller optimization for a flexible manipulator system (FMS). The results show that HSDBF outperforms BFA in all test functions and successfully optimizes the PD controller.

Techniques of anti-sway and input tracking control of a gantry crane system

This paper presents investigations into the development of control schemes for anti-swaying and input tracking control of a gantry crane system. A nonlinear overhead gantry crane system is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. To study the effectiveness of the controllers, initially a collocated PD control is developed for cart position control of gantry crane. This is then extended to incorporate a non-collocated PID and an input shaper control schemes for anti-swaying control of the system. The positive input shapers with the derivative effects are designed based on the properties of the system. Simulation results of the response of the gantry crane with the controllers are presented in time and frequency domains. The performances of the control schemes are examined in terms of level of input tracking capability, swing angle reduction and time response specifications in comparison to the PD control. Finally, a comparative assessment of the control techniques is presented and discussed.

An Improved Spiral Dynamic Optimization Algorithm With Engineering Application

This paper presents the development of an improved spiral dynamic optimization algorithm with application to nonparametric fuzzy logic modeling of a twin rotor system (TRS). The spiral motion and dynamic step size are generated by a spiral model that produces unique exploration and exploitation strategies of a spiral dynamic algorithm (SDA). However, the algorithm is subjected to settling into local optima at the end of the search process, due to insufficient exploration throughout the search area. An elimination-dispersal strategy of a bacterial foraging algorithm is adopted to solve the problem. The proposed strategy is validated with various benchmark functions and a nonparametric test analysis is performed to evaluate its significant achievement in comparison to the SDA. Moreover, nonlinear dynamic modeling of a TRS in hovering mode is presented and the results show the effectiveness of the proposed algorithm to solve real-world problems. The result of the modeling work is presented in both time-domain and frequency-domain. It shows how the fuzzy model optimization represents the characteristic behavior of the TRS very well.

Composite Fuzzy Logic Control Approach to a Flexible Joint Manipulator

The raised complicatedness of the dynamics of a robot manipulator considering joint elasticity makes conventional model-based control strategies complex and hard to synthesize. This paper presents investigations into the development of hybrid intelligent control schemes for the trajectory tracking and vibration control of a flexible joint manipulator. To study the effectiveness of the controllers, a collocated proportional-derivative (PD)-type Fuzzy Logic Controller (FLC) is first developed for the tip angular position control of a flexible joint manipulator. This is then extended to incorporate a non-collocated Fuzzy Logic Controller, a non-collocated proportional-integral-derivative (PID) and an input-shaping scheme for the vibration reduction of the flexible joint system. The positive zero-vibration-derivative-derivative (ZVDD) shaper is designed based on the properties of the system. The implementation results of the response of the flexible joint manipulator with the controllers are presented in time and frequency domains. The performances of the hybrid 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.