• 한국군사과학기술학회지
• /
• 제27권4호
• /
• pp.495-506
• /
• 2024

In this study, we propose the terrain following algorithm using model predictive control and nonlinear disturbance observer-based backstepping sliding mode controller for an aircraft system. Terrain following is important for military missions because it helps the aircraft avoid detection by the enemy radar. The model predictive control is used to replace the generating trajectory and guidance with the flight path angle constraint. In addition, the aircraft is affected to the parameter uncertainty and unknown disturbance such as wind near the mountainous terrain. Therefore, we suggest the nonlinear disturbance-based backstepping sliding mode control method for the aircraft that has highly nonlinearity to enhance flight path angle tracking performance. Through the numerical simulation, the proposed method showed the better tracking performance than the traditional backstepping method. Furthermore, the proposed method presented the terrain following maneuver maintaining the desired altitude.

• 제어로봇시스템학회논문지
• /
• 제2권2호
• /
• pp.115-120
• /
• 1996

In this paper, a sliding mode controller which is characterized by high accuracy, fast response and robustness is applied to speed control of AC-SERVO motor. The control input is changed to the continuous one in the boundary layer to reduce the chattering phenomenon, and the boundary layer converges to zero when the state variables of system reach to steady state values. The integral compensator is added to reduce steady state error and to provide the continuous torque reference. The acceleration which is necessary for the sliding plane is estimated by an obsever. Sliding surface is included in control input to enhance the robustness and transient response without increasing sliding mode controller gain. The proposed controller is implemented by DSP(digital signal processor). The effectiveness of the proposed scheme is demonstrated through experimental works.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
• /
• pp.306-307
• /
• 1995

In this paper, a binary disturbance observer is implemented, and the validity is verified by experiments. A disturbance observer with binary control is proposed to suppress the chattering of the conventional sliding mode observer in estimation of the external disturbance. As a result of experiments, it is confirmed that the robust and high precision position control is possible by the proposed binary observer.

• 제어로봇시스템학회논문지
• /
• 제4권1호
• /
• pp.45-55
• /
• 1998

In this paper, a robust path tracker and depth controller of Autonomous Underwater Vehicle based on sliding mode control is presented. We have also designed augmented equivalent control inputs by analyzing the sliding mode with the reaching mode. This can enhance the reaching rate, and improve chattering problems, that is, noise caused by the control plane actuator of the vehicle, which is one of the problems that occur when sliding mode control is used. Also to resolve the steady state error generated in the path tracker under current effect, a modified sliding plane is constructed. Also a redesigned sliding plane and control input using transformation matrix is proposed to do easy design of MIMO depth controller. For state variables that cannot be measured directly, reduced order sliding mode control is used to design an observer. The performance of designed path tracker and depth controller is investigated by computer simulation. The results show that the proposed control system has robust performance to parameter variation, modelling error and disturbance.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 D
• /
• pp.2212-2214
• /
• 2003

We design a sliding mode cascade observer to estimate state of the output. In the 1st step of the observer, the output will be estimated, and the 1st order state of the output will be estimated via the 2nd step of the observer. Also, nth order state of the output will be estimated in the n+1th step of the observer. Therefore, this paper will be presented to design the slide mode observer of cascade based cascading convergence concept of state observer error.

• 한국생산제조학회지
• /
• 제19권1호
• /
• pp.101-107
• /
• 2010

This paper presents motion control of the precision stage composed of the piezoelectric actuator and flexible hinges. The stage shows approximately 27% overshoot when the stage was applied to 30V square wave input voltage. Also, the stage shows nonlinear response characteristics including hysteresis. This paper proposes feedback control technique to suppress the phenomenon of hysteresis and overshoot using the sliding mode control scheme with the integrator. Also, this paper suggests the method that searches important parameters of sliding mode control and observer using Genetic Algorithm. To demonstrate the effectiveness of the proposed control algorithm, experimental validations are performed.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집A
• /
• pp.469-474
• /
• 2000

A sliding mode control method using the parameterization of both the hyperplane and the compensator for output feedback and reduced observer is presented for rotational inverted pendulums. This control strategy overcomes the problem of unattainable velocity state which is resulted from severe noise of analogue sense and constructs numerical algorithms designs of dynamic output feedback sliding mode hyperplane and controller. The result of the experiment shows the superior performance compared with the LQ controller and the robustness with respect to both tapping disturbances and certain initial conditions.

• 한국정밀공학회지
• /
• 제9권4호
• /
• pp.126-135
• /
• 1992

Up to now, there has been a lot of researches on the sliding mode control which has the insensitive characteristics to the variations of plant parameters, nonlinearities and external disturbances. One difficulty in applying the sliding mode control is the need for the knowledge of the full-state vector. The use of state observer is a natural step towards the relaxation of this condition. However, the exact plant-modeling is assumed to be known. Recently, there has been a remarkable advance in the microprocessor and one can construct the controller which could not realize due to hardware restriction in the past. Therefore in this paper, the PID sliding mode controller which has only one output feedback signal is suggested by means of microprocessor and the performance of electro-hydraulic servosystem compensated with this controller is proved.

• 제어로봇시스템학회논문지
• /
• 제12권11호
• /
• pp.1081-1087
• /
• 2006

Generally, biped walking is difficult to control because a biped robot is a nonlinear system with various uncertainties. In this paper, we propose a hybrid sliding-mode control method using a WNN uncertainty observer for stable walking of the 5-link biped robot with model uncertainties and the external disturbance. In our control system, the sliding mode control is used as main controller for the stable walking and a wavelet neural network(WNN) is used as an uncertainty observe. to estimate uncertainties of a biped robot model, and the error compensator is designed to compensate the reconstruction error of the WNN. The weights of WNN are trained by adaptation laws that are induced from the Lyapunov stability theorem. Finally, the effectiveness of the proposed control system is verified through computer simulations.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
• /
• pp.215-218
• /
• 1995

In this paper, a sliding mode controller (SMC) which can be characterized by high accuracy, fast response and robustness is applied to speed control of AC-SERVO motor. The control input is changed to continuous one in the boundary layer to reduce the chattering phenomenon, and the boundary layer converges to zero when the state variables of system reach to steady state values. The integral compensator is added to reduce steady state error and to provide the continuous torque reference. The acceleration which is necessary to get the sliding plane is estimated by an observer. Sliding surface is included in control input to enhance the robustness and transient response without increasing sliding mode controller gain. The proposed controller is implemented by DSP(digital signal processor). The effectiveness of the proposed control scheme for speed controller is shown by the real-time experimental results in the paper.