High-frequency ZVS PWM power amplifier system with high-precision magnetic-field current tracking control scheme

2002 ◽  
Author(s):  
H. Fukuda ◽  
M. Nakaoka
Keyword(s):  
Magnetic Field ◽  
Power Amplifier ◽  
High Precision ◽  
High Frequency ◽  
Tracking Control ◽  
Control Scheme

scholarly journals High-Precision Acceleration Measurement System Based on Tunnel Magneto-Resistance Effect

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1117 ◽  
Author(s):  
Lu Gao ◽  
Fang Chen ◽  
Yingfei Yao ◽  
Dacheng Xu
Keyword(s):  
Magnetic Field ◽  
High Precision ◽  
Measurement System ◽  
Frequency Modulation ◽  
High Frequency ◽  
Low Noise ◽  
Acceleration Measurement ◽  
Field Source ◽  
Modulation Technique ◽  
Magneto Resistance

A high-precision acceleration measurement system based on an ultra-sensitive tunnel magneto-resistance (TMR) sensor is presented in this paper. A “force–magnetic–electric” coupling structure that converts an input acceleration into a change in magnetic field around the TMR sensor is designed. In such a structure, a micro-cantilever is integrated with a magnetic field source on its tip. Under an acceleration, the mechanical displacement of the cantilever causes a change in the spatial magnetic field sensed by the TMR sensor. The TMR sensor is constructed with a Wheatstone bridge structure to achieve an enhanced sensitivity. Meanwhile, a low-noise differential circuit is developed for the proposed system to further improve the precision of the measured acceleration. The experimental results show that the micro-system achieves a measurement resolution of 19 μg/√Hz at 1 Hz, a scale factor of 191 mV/g within a range of ± 2 g, and a bias instability of 38 μg (Allan variance). The noise sources of the proposed system are thoroughly investigated, which shows that low-frequency 1/f noise is the dominant noise source. We propose to use a high-frequency modulation technique to suppress the 1/f noise effectively. Measurement results show that the 1/f noise is suppressed about 8.6-fold at 1 Hz and the proposed system resolution can be improved to 2.2 μg/√Hz theoretically with this high-frequency modulation technique.

High Precision Tracking Control Using Piezoelectric Actuator Network

2005 ◽  
Author(s):  
X. Xue ◽  
J. Tang
Keyword(s):  
Sliding Mode Control ◽  
High Precision ◽  
Piezoelectric Actuator ◽  
Tracking Control ◽  
Sliding Mode ◽  
The State ◽  
Control Action ◽  
Minimum Phase ◽  
Hysteresis Nonlinearity ◽  
Control Scheme

Although piezoelectric actuators have been widely used in active control, the hysteresis nonlinearity and the non-minimum phase characteristic could potentially deteriorate the system performance, especially in high precision control applications under disturbance. In this study, a resistance/inductance circuit is connected to the piezoelectric actuator to form an actuator network. With the actuator dynamics, the system model can be directly cast into the state-space whereas the system nonlinearity appears as explicit functions of the state variables. We then develop an integral continuous sliding mode control scheme to tackle the hysteresis nonlinearity and the disturbance issues. Instead of inverse hysteresis cancellation which might not be reliable due to the measurement noise, a direct piezoelectric hysteresis compensation can be achieved using this control strategy. The newly developed control scheme combines the advantages of both integral control and continuous sliding mode control with cubic state feedback. Not only can the control action react efficiently and effectively for the non-minimum phase response, but also, a zero steady state tracking error is guaranteed. Detailed analysis and case studies demonstrate that this new methodology can lead to improved tracking control precision, enhanced control robustness, and smoother control action.

Design of the Vehicular Eletro-Optical Tracking Turntable Servo System and the Research on its Tracking Control Scheme

2013 ◽  
Vol 712-715 ◽  
pp. 2119-2123
Author(s):  
Dong Ji ◽  
Hua Pei Wang ◽  
Qing Guo ◽  
Qing Lu
Keyword(s):  
High Precision ◽  
Tracking Control ◽  
High Performance ◽  
Servo System ◽  
Optical Tracking ◽  
Quality Data ◽  
Measurement Tool ◽  
Position Measurement ◽  
Loop Control ◽  
Control Scheme

In order to realize the high precision tracking control of the vehicular eletro-optical tracking turntable with the car bodys vibration, it is necessary to design a high performance turntable servo system and a set of high precision eletro-optical tracking control scheme. In this paper, a digital servo system is designed, which has the control platform based on PC104 processor, has the torque motor as the actuator, has the gyro as the inertial velocity measurement tool and has the high precision encoder as the position measurement tool. Then, the gyrostabilized double speed loop control algorithm with disturbance observer compensating is designed to realize a good inertial velocity stability performace; and, a set of eletro-optical tracking compound position loop control scheme based on the target-missing quality data processing, the segmented PID control and the acceleration lag compensating control is proposed to enhance the eletro-optical tracking precision. The result shows that the tracking turntable based on the control technology designed in this paper is reliable, responses quickly, has a good speed stability performance and a high eletro-optical tracking precision performance.

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