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Stepper motors are widely used in open-loop positioning applications. They are the choice of actuation for the collimators in the Large Hadron Collider, the largest particle accelerator at CERN. In this case the combination of precise positioning requirements and the highly radioactive operating environment is unique. The latter forces both the use of long cables to connect the motors to the drives...
This paper proposes the switching control method to realize stable landing for a biped robot. If the landing of the biped robot is unstable, the robot may fall down. Therefore, it is necessary for the biped robot to realize stable landing. In order to achieve the stable landing, force controller should be implemented at the moment of landing. Since force control enables the sole to softly contact...
In this paper, position controllers for IPMSM using sliding mode controller are compared. The sliding trajectory is predefined according to position error. And then, the performances of PI speed controller, sliding mode controller, and improved sliding mode controller that is combined PI controller and sliding trajectory calculator by merge function are compared. These position controllers are verified...
This paper presents a direct torque control technique for Brushless DC motors with non-sinusoidal back electromotive force. Direct torque control has some benefits such as faster torque response and reduced torque ripple for driving the Brushless DC motors. The Sliding mode observer, which is robust to parameter uncertainties, can be used to estimate the back-EMF and generate the torque. It is employed...
Cost minimizing of the electrical machine drives is more attractive for low cost applications. The low cost BLDC driver is achieved by the reduction of switch device, cost down of control, and saving of hall and current sensors. In this paper, a simple position sensorless control strategy for four-switch three-phase BLDC motor drives using single current sensor is proposed. The whole working process...
According to the work characteristics of the electromechanical actuator, a control scheme of direct DC electromechanical actuator based on discrete-time variable structure controller is designed. The effect of hinge moment is considered in the mathematical model, and the coefficients of its transfer function are appropriately amended. The effect of the three parameters in the design of discrete-time...
A novel high performance torque control scheme for switched reluctance motors(SRMs) is proposed based on online fuzzy neural network modeling and adaptive sliding-mode current control. Firstly, an adaptive neural fuzzy inference system(ANFIS) is designed to learn the nonlinear static position-torque-current characteristic and the flux-linkage characteristic of an SRM offline. Then each phase torque...
Since PID control does not meet the high accuracy requirement for gyro stabilized sighting system of airborne optoelectronic pod operated in the circumstance of strong interference, this paper introduces the application of sliding mode variable structure controller for the position loop of the stabilized system. After the sliding mode variable structure controller with exponential approach law is...
High motion performance, stiffness, and accuracy are crucial for industrial robot applications, but these requirements are in practice contradictory. Using a novel type of robot, the so called Gantry Tau, new combinations of stiffness and accuracy are in principle possible, except for the backlash in the drive-trains of each joint. Existing techniques for backlash reduction are either mechanically...
This paper presents and evaluates a novel on-line optimal trajectories generator algorithm for high performance industrial servodrives. In order to completely avoid current saturation, the optimal trajectories are calculated considering the maximum speed and current constrains, the inertial torque component and the load torque estimated by a disturbance observer. Using this information, optimum acceleration...
This paper describes the design of a new simple antiwindup control based on a PI control with an initial value of the integral state variable as a design parameter. It is combined a P controller and a PI controller. Before the changeover point, it uses a P controller. It is changed from the P controller to the PI controller after the changeover point. The changeover point is simply defined by using...
The paper proposes an adaptive sliding observer to accurately estimate the rotor position for a direct-drive permanent magnet synchronous generator (PMSG). Without any position sensor, the generator torque and flux responses retain high performance both in the steady state and during transients. The problem on the shaft encoder installation difficulty, reliability and disturbance in encoder cable...
This paper describes the tracking control of a harmonic drive actuator that features flexible transmission with significant torque ripples. The plant is modeled as a flexible-joint mechanism, and a design approach superior to the conventional integrator backstepping design is demonstrated to obtain a nominal controller. To deal with the torque ripples, internal model principle-based sliding-mode disturbance...
A reliable control method is proposed for multiple loop control systems. If a feedback loop fails (e.g., as a result of a sensor breakdown), the control system develops an unstable fluctuation. To cope with this problem, the proposed method uses an equivalent transfer function (ETF) for active redundancy compensation after loop failure. The ETF is used to maintain the transfer function of the entire...
The electrical motion drives are more and more used in various industrial processes. The choice of the motor drive is based on power, speed, precision, and cost requirements. There are many different types of motors for motion drives application. AC and DC motors feature brushed or brushless designs are suitable for a variety of industrial applications. Speed, torque and position control are the most...
A control system for permanent magnet synchronous motor electric drives with a significant torsion vibration mode is presented based entirely on sliding mode principles to achieve robustness against external load torques and parametric modelling uncertainties in the motor and/or the driven mechanical load. The sliding mode control law respects the vector control condition by keeping the direct axis...
The position tracking control of a missile electrohydraulic servo mechanism is studied. Since the dynamics of the system are highly nonlinear and have large extent of model uncertainties, such as big changes in load and parameters, a design method of adaptive fuzzy sliding mode control is presented. The adaptive fuzzy controller is introduced to approach the equivalent control of sliding mode control,...
The control system for position control of the drive employing PMSM based on the principles of sliding mode control and respecting the principles of vector control is presented. Designed controller is chattering free and complies with demanded control precision. Described control technique divides PMSM into two channels, which enable to control motor flux and torque separately. The controller is of...
Direct torque control (DTC) can directly control the inverter states in order to reduce the torque error within the prefixed band limit. DTC of brushless dc drive with trapezoidal back-EMF is presented in this paper. Using the rotor flux vector position in alpha-beta axis stationary reference frame and torque error, the proper switching pattern can be selected to control the generated torque and reducing...
This paper proposes a gain switching algorithm for joint position control of a hydraulic humanoid robot. Accurate position control of the lower body is one of the basic requirements for robust balance and walking control. Joint position control is more difficult for hydraulic robots than it is for electric robots because of a slower actuator time constant and the back-drivability of hydraulic joints...
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