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Now showing items 1 - 16 of 20

  • Hybrid EEG-EOG Brain-Computer Interface System for Practical Machine Control

    Punsawad, Yunyong   Wongsawat, Yodchanan   Parnichkun, Manukid  

    Practical issues such as accuracy with various subjects, number of sensors, and time for training are important problems of existing brain-computer interface (BCI) systems. In this paper, we propose a hybrid framework for the BCI system that can make machine control more practical. The electrooculogram (EOG) is employed to control the machine in the left and right directions while the electroencephalogram (EEG) is employed to control the forword, no action, and complete stop motions of the machine. By using only 2-channel biosignals, the average classification accuracy of more than 95% can be achieved.
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  • Fusion of GPS, Compass, and Camera for Localization of an Intelligent Vehicle

    Deelertpaiboon, Chirdpong   Parnichkun, Manukid  

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  • Petri Net model of repetitive push manufacturing with Polca to minimise value-added WIP

    Aziz, M. H.   Bohez, Erik L. J.   Pisuchpen, Roongrat   Parnichkun, Manukid  

    A common simplifying assumption used in the literature is to minimise average Work In Process (WIP), while achieving maximum production rate, which does not consider the fact that the value of WIP increases down the stream of a production process as labour, time, energy and resources are added to it. This paper aims at minimising queues of parts waiting downstream of production process and in turn minimising value-added WIP by constraining more and more inventory of unfinished products at the earlier stages of production. For this reason, generic black token closed loop Petri Net (PN) model of Flexible Flow Shop (FFS) with Paired-cell Overlapping Loops with Card Authorisation (POLCA) is developed. Tokens in the control loops represent Polca cards to control the flow of material from order release till finished products. Marking of PN is done through Mix Integer Linear Programming after the computation of semi-positive P invariants. Simulation is being done to obtain queues of parts, waiting at each station during demand variation. Results were compared with PN model of FFS without Polca. Results showed the constriction of unnecessary WIP towards the initial stage of production instead of at bottlenecks, with proposed model, and in turn minimisation of value-added WIP.
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  • Control of rotary double inverted pendulum system using mixed sensitivity H infinity controller

    Sanjeewa, Sondarangallage D. A.   Parnichkun, Manukid  

    Balancing control of a rotary double inverted pendulum system is a challenging research topic for researchers in dynamics control field because of its nonlinear, high degree-of-freedom, under actuated and unstable characteristics. The system always works under uncertainties and disturbances. Many control algorithms fail or ineffectively control the rotary double inverted pendulum system. In this article, mixed sensitivity H infinity control is proposed to balance the rotary double inverted pendulum system. The controller is proposed to ensure the robust stability and enhance the time domain performance of the system under uncertainties and disturbances. Structure of the system, dynamics model and controller synthesis are presented. For performance evaluation, the proposed mixed sensitivity H infinity controller is compared with linear quadratic regulator from both simulation and experiment on the rotary double inverted pendulum system. The results show high performance of the proposed controller on the rotary double inverted pendulum system with model uncertainties and external disturbances.
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  • Sensitivity Analysis of Cable Parameters on Tension of a Suspended Cable under Combination Resonances

    Kim, Kyu Won   Park, No-Cheol   Song, Weon Keun   Kim, Moon Kyum   Parnichkun, Manukid  

    This paper studies the vibration of a suspended cable with small sag excited by a second excitation (normal) mode causing combination resonance in the three modes, i.e. tangent, normal and bi-normal modes. The displacement response spectra in the time domain and phase portraits are provided as evidence of the transition from the unstable steady-state motion to the stable one for nonlinear cable oscillation. A nondimensional equation for the cable tension is established with its variation evaluated for the unstable zone. The half-normalized sensitivity analysis of cable parameters, such as damping coefficient, excitation amplitude, arc length parameter and initial conditions, for their influence on cable tension is conducted in the time domain by a direct integration method. Also, the characteristics of the dynamic sensitivity of cable tension to the parameters are discussed. As a result, a sensitivity ranking chart is prepared based on the sensitivity analyses for the parameters considered. It is clearly revealed that cable tension is very sensitive to tangent and normal initial displacements in spite of their small values, whereas the same is not true for the arc length parameter and bi-normal damping coefficient. To verify the sensitivity analysis algorithm, a forced Rayleigh oscillator is introduced. A feasibility study using the oscillator shows that the numerical results obtained are in good qualitative agreement with the analytical predictions, implying that the associated algorithm works well.
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  • Development of a robust attitude control for nonidentical rotor quadrotors using sliding mode control

    Promkajin, Nicom   Parnichkun, Manukid  

    This work proposes a novel development of sliding mode control (SMC) for quadrotor helicopters utilizing offset cancellation technique. Most of the works on sliding mode control for quadrotors assumed that all rotors were identical, but in fact, the rotors even from the same factory are not exactly the same in aerodynamics properties. In addition, rotor deformation due to shock or heavy usage during operation may cause changes in parameters such as lift and drag coefficients, and so on, which, lead to offset error in the responses of attitude control. By applying the proposed offset cancellation technique to the sliding mode control, the attitude error is forced to have a zero average. The proposed controller is used to control attitude and position of a quadrotor helicopter which is composed of four direct current (DC) brushless motors to generate lift forces independently. Performance comparison with the other control algorithms such as the proportional-integral-derivative controller and the conventional sliding mode control is simulated and experimented on two real quadrotor platforms and results are discussed.
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  • Kinematics control of a pneumatic system by hybrid fuzzy PID

    Parnichkun, Manukid   Ngaecharoenkul, Charoen  

    In a pneumatic system, normally, the piston can stop at only two terminal endpoints. In order to extend the capabilities of the system, this research is conducted to develop a kinematics control-based pneumatic system. Both position and velocity of the pneumatic piston are controlled in such a way that the controlled piston is able to move with the specified velocity to the target position. A hybrid of fuzzy and proportional-plus-integral-plus-derivative (PID) control algorithm is proposed in this paper as the solution. The control algorithm is separated into two parts: fuzzy control and PID control. The fuzzy controller is used to control the piston when the piston locates far away from the target position whereas the PID controller is applied when the piston is near the desired position. The development starts with designing of a position sensor to detect position information of the piston. The sensor-manipulating circuit consisting of potentiometer, inverting amplifier, summing amplifier, low-pass filter and analog-to-digital converter is then designed and realized. Next, the proposed hybrid of fuzzy and PID control is implemented and programmed on the microprocessor. In order to test performance of the system, settling time and steady-state error of five control algorithms – proportional (P) control, proportional-plus-integral (PI) control, proportional-plus-derivative (PD) control, PID control, and hybrid of fuzzy and PID control – are investigated. The results from the experiments show that the proposed hybrid of fuzzy and PID control gives the most satisfied settling time and steady-state error.
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  • IMPLEMENTATION OF A LONG RANGE LRF BY AUTOMATIC MULTI-MODE MEASUREMENT SCHEME

    PARNICHKUN, MANUKID   SAMADI, VIRAPHAN  

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  • Pulse-signaling algorithm: a non-device-based robotics control and communication

    Parnichkun, Manukid   Airtan, Prapot  

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  • Haptics control of an arm exoskeleton for virtual reality using PSO-based fixed structure H infinity control

    Silawatchananai, Chaiyaporn   Parnichkun, Manukid  

    This article proposes a robust haptics control algorithm for an arm exoskeleton in virtual reality application that guarantees the robustness of the force displaying performance. The developed arm exoskeleton allows the user to sense the profile of virtual objects through joints at wrist, elbow, and shoulder. Forces exerted by the user are directly measured by load cells attached to the links, which are used to determine the corresponding velocity command based on virtual impedance. Due to the imperfection of modeling and the measurement noises from load cells and encoder quantization, the force displaying performance of the device tends to degrade with increasing oscillation, causing permanent damages to the device and user. To solve this problem, a Particle swarm optimization (PSO)-based fixed structure H infinity controller is proposed to control the developed arm exoskeleton. The control performance of the proposed controller is evaluated by both simulation and experiment. The results show that the proposed controller can achieve better tracking performance in comparison with proportional-integral-derivative controller in terms of less oscillation and fast response.
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  • CDCSMA-CD communication method for cooperative robot systems

    Parnichkun, Manukid   Ozono, Shigeo  

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  • MLP,ANFIS,and GRNN based real-time coagulant dosage determination and accuracy comparison using full-scale data of a water treatment plant

    Kim, Chan Moon   Parnichkun, Manukid  

    Real-time determination of appropriate coagulant dosage under wide fluctuation of raw water quality in a water treatment plant (WTP) is a challenging task due to nonlinearity relation between coagulant dosage and raw water characteristics. In this research, three techniques, multilayer perceptron (MLP), adaptive neuro fuzzy inference system (ANFIS), and generalized regression neural network (GRNN), are applied to determine the coagulant dosage at Bansong drinking WTP. Each model is developed based on 8,760 historical data sets with hourly resolution for a whole year. Several statistical properties are determined to obtain the best-fit model from each method. The top performing models of each method are evaluated by external validation indices and absolute relative error according to nine turbidity zones. From the result, MLP and ANFIS models meet all conditions of validation indices, but GRNN cannot. The MLP shows the best result for high turbidity zones over 20 NTU as well as for overall performance. Meanwhile, ANFIS provides consistent results and better performance than MLP for low turbidity zones which have higher disorder of coagulant dosage data. The GRNN shows high accuracy for the highest turbidity zone which occurs during the rainy season. It is concluded that MLP, ANFIS, and GRNN can support operators effectively for real-time determination of coagulant dosage.
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  • Kinematics Performance and Structural Analysis for the Design of a Serial-parallel Manipulator Transferring a Billet for a Hot Extrusion Forging Process

    Chu Anh My   Parnichkun, Manukid  

    To reduce the downtime and optimize the use of energy and manpower, a serial-parallel manipulator is designed for transferring heavy billets for a hot extrusion forging station. With the purpose of increasing the structural rigidity and restricting the end-effector (a gripper) so that it always moves in parallel with the ground surface, parallel links are added in between the serial links of the manipulator. This modification of the conventional structure must be considered in the modelling and analysis of the design. This paper addresses a methodology to investigate the kinematics performance and strength analysis of the designed robot. With respect to the parallel links, the constraint equation is derived and put together with the kinematical model. Based on the entire model that is formulated, the inverse kinematics, the transferring time, the reachable workspace, the degree of dexterity and the manipulability index are analysed and discussed to demonstrate its kinematical performance. In addition, to investigate the structural characteristics of the end-effector module, the static displacement and stress distributed on module's components are computed and simulated using the computer-aided finite element method (FEM). These research results are effective and useful in assessing and improving the robot's design.
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  • Double loop controller design for the vehicle's heading control

    Wuthishuwong, Chairit   Parnichkun, Manukid   Silawatchananai, Chaiyaporn   Suppachai, Horwimanporn  

    In this study; an electrically powered vehicle has been implemented to perform an unmanned ground vehicle purpose. The steering system is modified to automatically control by installing the DC servo motor at the steering wheel shaft. The compass sensor used as the feedback sensor to measure the current heading angle of the vehicle. The autonomous navigation system determines the general sense of direction of travel and sends that information to the vehicle's control system. The objective of this research is to control the heading of a vehicle in the real world environment under the unpredictable and unstructured surrounding. The change of heading direction and the speed of the vehicle influences to the motion of a vehicle. In this work; the double loop controller is designed. The inner loop performs the steering system control and the outer loop archives vehicle's heading control. In the simulation; 2 different conditions are simulated. First; a vehicle is controlled by using the single loop PID controller at the different levels of vehicle's ground speed and also different levels of heading angle input. Second; a vehicle is simulated at the same conditions but replacing the single loop controller with the double loops PD-PID controller. For the experiment; the PD-PID controller is applied to control the heading of a vehicle in tested field with 2 levels of speed.
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  • Improvement of Adaptive Cruise Control System based on Speed Characteristics and Time Headway

    Benalie, Nassaree   Pananurak, Worrawut   Thanok, Somphong   Parnichkun, Manukid  

    An adaptive cruise control (ACC) which was implemented on an AIT Intelligent Vehicle, a Mitsubishi Galant car, has been improved and added with more features to allow the vehicle to act with better performance compared with the previous system. An important feature of the new adaptive cruise control system is the ability to maintain a proper inter-vehicle gap based on the speed of leading vehicle and time headway (THW). To develop adaptive cruise control system, the conventional throttle valve system is modified to the drive-by-wire system which uses a DC motor to control the throttle valve position based on PD control with command compensation. In the automatic braking system, a DC motor is installed with steel cable transmission in order to pull the brake pedal to the desired level automatically by applying torque control. The brake control and velocity control have been merged together to control the speed to any desired speeds as last as possible without jerk and steady-state error. A micro switch is installed at the brake pedal to allow the driver to take over the control of the vehicle anytime. There are three important inputs of the ACC system, speed of leading vehicle read from electronic control unit (ECU), TRW set by driver, and actual gap measured from a laser scanner. The ACC processes these three inputs in order to calculate distance error and relative velocity which are used as the two inputs of a fuzzy controller. The fuzzy controller determines the desired speed command to maintain a proper gap based on current speed of the leading vehicle and the desired time headway. Experiments are conducted to evaluate the performance of the ACC system in various conditions. The results show good performance of the adaptive cruise control system.
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  • Fuzzy based Gains Tuning of PD controller for joint position control of AIT Leg Exoskeleton-I (ALEX-I)

    Parnichkun, Manukid   Aphiratsakun, Narong  

    This paper is focused on designing of Fuzzy based Gains Tuning of Proportional-Derivative (FTPD) controller for joints positions control of the Asian Institute of Technology's Leg EXoskeleton-I (ALEX-I). The main objective of this research is to obtain the desired gait motion of the whole system. The gait data from simulation is used as the input (set point) of ALEX-I; this data is simulated based on body CM balancing criteria. Fuzzy Logic Controller applies five membership functions of error and rate of error; four KP and three KD singletons output gains are adjusted according with the defined fuzzy rules. The COGS defuzzification output is sent to ARM7 controllers which control all the system joints. The performance of FTPD controller is then compared with the conventional PD controller. The results show superior performance of FTPD in smaller position error; less percentage of power consumption and less oscillation of gait motion on ALEX-I.
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