Current control of a PWM power amplifier by an approximate 2-degree-of-freedom digital controller

2009 ◽  
Vol 14 (3) ◽  
pp. 433-439 ◽  
Author(s):  
Keisuke Fujita ◽  
Kohji Higuchi ◽  
Kazushi Nakano ◽  
Koji Matsushita ◽  
Tatsuyoshi Kajikawa ◽  
...  
Keyword(s):  
Power Amplifier ◽  
Current Control ◽  
Degree Of Freedom ◽  
Digital Controller

Multi Degree-of-Freedom Hydraulic Human Power Amplifier With Rendering of Assistive Dynamics

2016 ◽  
Author(s):  
Sangyoon Lee ◽  
Fredrik Eskilsson ◽  
Perry Y. Li
Keyword(s):  
Power Amplifier ◽  
Degree Of Freedom ◽  
Hydraulic Actuator ◽  
Full Account ◽  
Control Approach ◽  
Human Power ◽  
Natural Energy ◽  
Control Objective ◽  
Pressure Dynamics ◽  
Mechanical Tool

The hydraulic human power amplifier (HPA) is a tool similar to exoskeleton that uses hydraulic actuation to amplify the applied human force. The control objective is to make the system behave like a passive mechanical tool that interacts with the human and the environment passively with a specified power scaling factor. In our previous work, a virtual velocity coordination approach recasts the single degree-of-freedom human power amplifier control problem into a velocity coordination with a fictitious reference mechanical system. Force amplification becomes a natural consequence of the velocity coordination. In this paper, this control approach is extended for fully coupled multi-DoF systems. A passivity based control approach that uses the natural energy storage of the hydraulic actuator to take full account of the nonlinear pressure dynamics is used to define the flow requirement. Additional passive assistance dynamics are designed and implemented to enable the user to perform specific tasks more easily. Guidance is achieved using a passive velocity field controller (PVFC), and obstacle avoidance is achieved using a potential field. Experimental results demonstrate good performance on a 2-DoF Human Power Amplifier.

scholarly journals Design of a Robust PWM Power Amplifier Using Approximate 2-Degree-of-Freedom Integral Type Control

2002 ◽  
Vol 122 (2) ◽  
pp. 96-103
Author(s):  
Kohji Higuchi ◽  
Kazushi Nakano ◽  
Kuniya Araki ◽  
Fumiho Chino
Keyword(s):  
Power Amplifier ◽  
Degree Of Freedom ◽  
Integral Type

The Research on Switch-Linear Hybrid of Precise Current Source

2013 ◽  
Vol 416-417 ◽  
pp. 559-564
Author(s):  
Li Yi Li ◽  
Qi Ming Chen ◽  
Jia Xi Liu ◽  
He Zhu ◽  
Guang Jun Tan
Keyword(s):  
Power Amplifier ◽  
Power Supply ◽  
High Efficiency ◽  
Current Source ◽  
Power Converter ◽  
Current Control ◽  
Current Loop ◽  
Special Power ◽  
Switch Power ◽  
Linear Power Amplifier

In this paper, a novel current control strategy of precise current source is presented, which combines switch power conversion mode with linear amplification mode. The linear power amplifier is used as the power converter in the current loop. The current controller is a double cascaded PI (DCPI) controller which is put up by the way of analog circuit, it can suppress the high frequency disturbance signal effectively. The switch-filter circuit can generate a special power supply for linear power amplifier, the voltage of this special power supply changes as the load voltage does. The topology of four-level H-Bridge works as the power converter of the switch power amplifier, the LC filter circuit can eliminate the current ripple caused by the PWM chopper.The simulation and experimental results verify that the Switch-Linear Hybrid (SLH) scheme is of high efficiency and output quality. The bandwidth of the precise current source is 5.4 kHz and the phase margin is 42 degree.

A New Realization Method of Control System for Magnetic Bearing

2010 ◽  
Vol 43 ◽  
pp. 32-35
Author(s):  
Wen Yue Zhang ◽  
Yan Jun Ge ◽  
Jun Yue Yang
Keyword(s):  
Control System ◽  
Power Amplifier ◽  
Control Strategy ◽  
Digital Signal Processor ◽  
Control Strategies ◽  
Digital Signal ◽  
Magnetic Bearing ◽  
Current Control ◽  
Common Control ◽  
The Difference

Aiming at the problems of complex circuit and parameter adjustment in traditional current type power amplifier of Magnetic Bearing (MB), a new realization method of control system based on DSP (Digital Signal Processor) is proposed. The difference with traditional power amplifier is that the current control loop is realized through software in DSP, so some advanced control strategies will be adopted easily, and the control parameters could be modified freely. Besides, the models established in MATLAB using common control strategy and advanced strategy are simulated separately, and the simulation results show the better effect can be obtained with the latter. Finally, the rotor of a 1-DOF MB prototype can be suspended within 0.01mm in the experiment, and the control strategy and parameters can be modified freely by software in DSP.

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