Papers by Keyword: Positioning Control

Abstract: This paper presents the comparison of positioning control between conventional PID controller and fuzzy PID controller. The controllers are applying into the ball screw system driven by DC motor to observe and analyze the change of the positioning output responses. The DC motor is used because it is easy to setup and control, has precise rotation and most importantly is low cost. As for ball screw mechanism itself, has smooth motion, not easy to wear out and high mechanical efficiency. The problem is arise when the used of conventional PID controller in the ball screw system driven by DC motor shows less adaptability to the changes of system parameter. Therefore, the objective of this project is to design an adaptive fuzzy PID controller to overcome the limitation of conventional PID controller. The performances between the conventional PID controller and fuzzy PID controller will be compared in order to validate the robustness of the fuzzy PID controller. So this project is to compare the robustness of two proposed controllers by comparing the results of ball screw table position when the parameter mass of load is set to vary. The experiment is started with designing the algorithms of fuzzy PID control and conventional PID controller, then the designed algorithm is applied onto the experimental that has been setup. The performances especially the transient response and steady state error between the controllers will be collected and compared by conducting the point to point positioning, tracking and variation of load weight experiments.

Abstract: A two-degree-of-freedom (2-DOF) PID controller is designed for an AC servo ball screw driven XY table. XY table is widely used in manufacturing industry especially in CNC machineries. The most commonly used controller in industries is conventional PID controller. This controller has satisfactory performance, simple structure, and is one-degree-of-freedom (1DOF). Nonetheless, PID controller can only achieve either good set-point response or good disturbance response. This leads to introduction of 2-DOF PID controller which can achieve both good set-point response and disturbance response. In this project, 2-DOF PID is used for accurate tracking purpose. 2-DOF PID controller is designed using two-steps-tuning-method. Disturbance response is optimized by tuning parameters of KP, Ti, and TD using Ziegler-Nichols 2^nd method, followed by optimization of set-point response by tuning of 2-DOF parameters, α and β. Tracking performance of 2-DOF PID controller is compared with conventional PI and 1-DOF PID. Maximum absolute error, sum of absolute error, and mean square error are analyzed for all tracking performance of compensated system. Result shows that tracking error compensation (set-point response) of 1-DOF PID controller is better than 2-DOF PID controller. However, this is due to tuning of α and β parameters in simulation in this project. α and β values should be tuned experimentally. Disturbance response of 1-DOF PID and 2-DOF PID are almost similar due to same KP, Ti, and TD values are used in both controllers.

Abstract: Researches have been conducted into the technology of data transmission and position detection based on induction radio to realize positioning control in mobile locomotive location, and the locomotives positioning control systems by induction radio have been designed. The principles and methods of induction radio technology are mainly analyzed. The reliable information transmission systems between locomotives and center control room are built, and the mobile locomotive location can be acquired by detecting the phase and amplitude of induced emf. The basic principles of data transmission by induction radio are discussed in this paper. The technology of co-channel interference in data transmission is described, and the hardware circuit of data transmission by induction radio is also provided. The system principle mentioned in this paper is easy, and the design methods are reasonable, which can meet the requirements of positioning control in mobile locomotive location.

Abstract: The mathematical model of the tracking and positioning system was presented and established by analyzing the kinematics of the free pendulum system. According to the system designs requirements, a performance dedicated circuit was designed for it. The sensors, controllers, and execution units were selected. The circuit of control system was designed. A system was made for debugging and a high-performance fuzzy controller was designed. Its algorithm was based on the fuzzy control PID theory. The core of the fuzzy controller was a set of fuzzy associative memory rules that correlate each group of fuzzy control input sets to a fuzzy control output set. We finished the high precision tracking and locating system design. Through the system performance test, test results showed that the system had good performance.

Abstract: According to the nonlinearity and time-variation of the positioning control in hydraulic system, a kind of Hybrid Fuzzy-PID Controller with Coupled Rules (HFPIDCR) is proposed. In this control system, the bulk modulus is considered as a variable. The novelty of this controller is to combine the fuzzy logic and PID controllers in a switching condition. Simulation results of the HFPIDCR are compared with the results of traditional PID, Fuzzy Logic Controller (FLC), and Hybrid Fuzzy-PID Controller (HFPID). It is demonstrated that the HFPIDCR has fast response, short adjustment time, high control precision and other advantages, and it can meet the requirements of the positioning control in hydraulic system.

Abstract: According to the perturbation in lithography positioning control system, a novel gain scheduled PID controller using a root mean square (RMS) signal is proposed. Perturbation is also referred as the stage hunting, and the positioning control system will be very weak against small disturbances such as electrical noise or even structural vibration of the building in which the stage is installed. The gain scheduled PID controller is used to minimize the stage hunting and simultaneously maximize the immunity to disturbances. Simulations results verify the effectiveness of the gain scheduled PID controller for the positioning control in the lithography stage, as compared with the traditional PID controller.

Abstract: This paper establishes the mathematical model of the system of container crane, and then introduced the CMAC and PID compound control principle and characteristics, and PID control of the position of the container crane , CMAC-PID control of the position of the container crane, and CMAC-PID control of container crane's position and angle. The simulation results show that the crane based on the CMAC and PID compound control has a very good positioning and anti-swing effect.

Abstract: This paper has developed the bimodal USM a novel actuation pattern, which can actuate the bimodal USM in nanometer magnitude with single actuation pattern instead of combination control of AC actuation pattern, pulse actuation pattern and DC actuation pattern. The novel actuation pattern utilizes a single chip micro-computer to produce a kind of wavelet actuation unit which contains several sine voltage waves with different amplitudes, each wavelet actuation unit is exerted on bimodal USM according to the instruction, by which the step control is obtained. Across the two electrodes of bimodal USM, the differential wavelet actuation voltages are applied to reduce the moving distance of each actuation step, thus the nanometer magnitude actuation sensitivity is achieved. The grating is used as position sensor and the subdivision formulae of mutual compensation functions are adopted to promote the real-time response. The experiment indicated that, with the novel wavelet differential actuation pattern, the actuation characteristic of bimodal USM was improved, the micro-nanometer positioning control was easy to be implemented and the important positioning control parameters under every different actuation conditions could be obtained through the study in the process of actuation.