Electromagnetic vibration exciter system with adjustable electro-viscoelastic suspension device

摘要

The electromagnetic vibration exciter system with an adjustable electro-viscoelastic suspension device comprises an electromagnetic vibration exciter, a power amplifier and an adjustable electro-viscoelastic suspension device, which acts as the suspension device of the electromagnetic vibration exciter. The adjustable electro-viscoelastic suspension device contains a displacement sensor detecting the displacement of the moving component, a first adjustable amplifier and a second adjustable amplifier, a differentiator, an adjustable phase shifter, an adder and a proportioner. The linearity of the stiffness and damping of the exciter system is excellent, which can be adjusted as need through the adjustment of gain of the adjustable amplifier, the proportioner, the adjustable phase shifter. This invention has adjustable and linear parameters and it is also easy to be realized.

主权项

1. An electromagnetic vibration exciter system with an adjustable electro-viscoelastic suspension device comprises an electromagnetic exciter and a power amplifier; characterized in that:
the adjustable electro-viscoelastic suspension device is used in the vibration exciter system to support and restore its moving component and comprises a displacement sensor detecting displacement of the moving component of the electromagnetic exciter, a first adjustable amplifier, a second adjustable amplifier, a differentiator, an adder and an adjustable phase shifter, a subtracter, and a proportioner; a displacement detected by the sensor and a displacement signal output by the sensor is processed by the first adjustable amplifier and a first amplified signal is produced, the displacement signal is simultaneously processed by the differentiator and the second adjustable amplifier successively and a second amplified signal is produced; the first amplified signal and the second amplified signal are added by the adder, an output of which is processed by the adjustable phase shifter; a phase-shifted signal is imported into the subtracter as subtrahend; another input terminal of the subtracter is connected with a signal generator, a standard output of which is a minuend; a subtracter output is imported into the proportioner, the output of which is amplified by the power amplifier and then is imported into the exciter as driving signals; transfer function of the exciter system is as follow:G⁡(s)=⁢X⁡(s)U⁡(s)=⁢K3⁢Kp·BlmLs3+(mR+c2⁢L)⁢s2+[Rc2+(Bl)2+K2⁢K3⁢K4⁢Kp⁢Bl]⁢s+K1⁢K3⁢K4⁢Kp⁢Bl=⁢K3⁢Kp⁢BlR·1m⁢⁢LR⁢s3+(m+c2⁢LR)⁢s2+[c2+(Bl)2+K2⁢K3⁢K4⁢Kp⁢BlR]⁢s+K1⁢K3⁢K4⁢Kp⁢BlR where m is total mass of the moving component (including a vibration table and a load under excitation; c2 is damping caused by other factors than the suspension device; B is a magnetic flux density in an air gap; l is length of a coil within a magnetic field; L and R is inductance and resistance of the coil respectively; K1, K2, K3, K4 and KP is gain of the first adjustable amplifier, the second adjustable amplifier, the proportioner, the adjustable phase shifter and the power amplifier, respectively; s=jω is a Laplace operator; ω is a circular frequency of vibration;C=c2+(Bl)2+K2⁢K3⁢K4⁢Kp⁢BlRreflects equivalent damping characteristic of the system;K=K1⁢K3⁢K4⁢Kp⁢BlRreflects its equivalent stiffness characteristic.