• Journal of international Conference on Electrical Machines and Systems
• /
• v.1 no.4
• /
• pp.405-411
• /
• 2012

This paper deals with direct torque control of an induction motor (IM) with constant switching frequency. The desired torque is obtained from the speed controller which is designed using the IP controller. Decoupling control of torque and flux is developed based on the energy model of IM using the IP controller strategies. The desired d-axis and q-axis stator voltage components are obtained from the designed controller, which decouples torque and flux. The constant switching frequency can be applied using space-vector pulse width modulation, since the desired stator voltage can be known from the decoupling torque and flux controllers. In order to achieve stable operation of the proposed IP controllers, the gains of the controllers are chosen by setting the poles in negative (left) half of s-plane and by choosing the rising time for the response of the step function. The proposed controller was verified in simulations using Matlab/Simulink and results have proven excellent performance. It was found that the proposed IP controllers can provide excellent performance to track the desired torque and speed and to reject the disturbance of load.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.4
• /
• pp.738-745
• /
• 2001

In this paper, when the moving object move to the three-dimentional space, the tracking system track the moving object using the fuzzy reasoning. The joint angle el of the manipulator rotate from $0^{\circ}\; to\; 360^{\circ}$ , and the joint angle $\theta_2$rotate from$0^{\circ}\; to\; 360^{\circ}$. The fuzzy singleton is used for fuzzification and the control rule is twenty five and the fuzzy inference method is simplified Mamdani's reasoning and the defuzzification is the SCOG(Simplified Center Of Gravity) of the fuzzy controller To measure of the performance of the designed system, the fuzzy controller is compared with the CTM(Computed Torque Method) controller at the same condition. when the disturbance torque is ON, the both of CTM and fuzzy controller tracked object without error, However, the disturbance torque changed 0.4N, the CTM controller is 10 times greater than fuzzy controller at the sum of absolute error difference. The designed system is showed it's robustness against with disturbance.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.803-806
• /
• 1997

In this paper, a force estimation method is proposed for the sensorless force control. For this, a disturbance observer is applied to each joint of an n degrees of freedom manipulator to obtain a simple equivalent robot dynamics(SERD) being represented as an n independent double integrator system. To estimate the output of disturbance observer in the absence of external force, the observer estimator is designed, where the uncertain parameters of the robot manipulator are adjusted by gradient method to minimize the output between the disturbance observer and the observer estimator. When the external force is exerted, the external force is estimated using the difference between the output of disturbance observer which include the external torque signal and that of observer estimator. And then, a force controller is designed for force feedback control employing the estimated force signal. To verify the effectiveness of the proposed force estimation method, several numerical examples are illustrated for the 2-axis planar type robot manipulator.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.488-493
• /
• 2005

In gun stabilization systems, the torque comes from the unbalance mass of gun and the base acceleration is an important source of disturbance which degrades stabilization performance. Fatigue of gear train is another important factor affecting structural safety problems. In this paper, a feedback control gain is designed by optimal control weighting to difference between motor and gun velocity, and a feedforward controller using FXLMS algorithm is adopted to investigate those problems. Experimental results show that the feedforward compensator based on FXLMS can reduce the disturbance effects. The directional convergence property according to initial conditions of the FXLMS is also shown through experiments.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.361-361
• /
• 2000

In the 2-mass system with flexible shaft, a torsional vibration is often generated because of the elastic elements in torque transmission as the newly required speed response which is very close to the primary resonant frequency. This vibration makes it difficult to achieve quick responses of speed and disturbance rejection. In this paper, 2-mass system is designed by using pole placement based on optimal control theory fur fast speed response and torsional vibration elimination and using neural network for disturbance rejection in particular. The simulation results show that the proposed controller based on neural network and full state feedback controller has better performance than 려ll state feedback controller, especially fur disturbance rejection.

• Proceedings of the KIPE Conference
• /
• 2017.11a
• /
• pp.195-196
• /
• 2017

This paper proposes a permanent magnet synchronous motor(PMSM) control using a repetitive controller. Repetitive controllers are often used to eliminate periodic disturbances. Based on this, it is possible to alleviate the torque disturbance occurring at a constant cycle to the load of the motor. This paper proposes a method of rejecting periodically generated disturbances by using a repetitive controller and verified by simulation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.2 no.2
• /
• pp.81-87
• /
• 1996

Time delay control(TDC) law has been recently suggested as an effective control technique for nonlinear time-varying systems with uncertain dynamics and/or unpredictable disturbances. This paper focuses on the applications of the TDC algorithm to torque control of an engine system and speed control of an engine/automatic transmission system. Through the stability analysis of the engien system based on TDC, determination of the appropriate time delay and control factor is investigated. It was revealed that the size of time delay of the TDC law should be greater than that of transport delay of the system for both stability and better control performance. Simulation and experimental results for the engine torque control and engine/automatic transmission speed control systems show both relatively good command following and disturbance rejection properties. However, TDC controller shows rather slow responses when applied to the system with large transport delay.

• Proceedings of the KIEE Conference
• /
• 1997.07f
• /
• pp.2107-2109
• /
• 1997

Speed sensors are required for the vector control of induction motors. These sensors reduce the sturdiness of the system and make it expensive. Therefore, a drive system without speed sensors is required. Also, the rotor inertia constant, the damping constant and the disturbed load torque of the IM are estimated by the RLS estimator and a torque observer. Then the observed disturbance torque is fed forward to increase the robustness of the IM speed drive.

• Proceedings of the KIPE Conference
• /
• 1997.07a
• /
• pp.97-100
• /
• 1997

A new control method for the robust position control of a brushless DC(BLDC) motor using the asymptotically stable adaptive load torque observer is presented. A precision position control is obtained for the BLDC motor system approximately linearized using the field-orientation method. And the application of the load torque observer is published in [1] using fixed gain. However, the flux linkage is not exactly known for a load torque observer. Therefore, a model reference adaptive observer is considered to overcome the problem of the unknown parameter in this paper. And stability analysis is carried out using Liapunov stability theorem. As a result, asymptotically stable observer gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current having the fast response.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.2
• /
• pp.425-436
• /
• 2016

In this paper, a parameter optimization based iterative learning control strategy is presented for permanent magnet synchronous motor control. This paper analyzes the mechanism of iterative learning control suppressing PMSM torque ripple and discusses the impact of controller parameters on steady-state and dynamic performance of the system. Based on the analysis, an optimization problem is constructed, and the expression of the optimal controller parameter is obtained to adjust the controller parameter online. Experimental research is carried out on a 5.2kW PMSM. The results show that the parameter optimization based iterative learning control proposed in this paper achieves lower torque ripple during steady-state operation and short regulating time of dynamic response, thus satisfying the demands for both steady state and dynamic performance of the speed regulating system.