Application Cases

Experiment Name: Vibration Isolation Performance Verification of Tapered Dielectric Elastomers Based on Inverse Shaping Control

Test Equipment: High-voltage amplifier, Signal generator, Laser displacement sensor, Tapered dielectric elastomer actuator, Vibration exciter, Computer, etc.

Experimental Process:

Figure 1: Schematic diagram of the active vibration isolation system using tapered dielectric elastomer based on inverse shaping control

A vibration isolation system was constructed as shown in Figure 1. A tapered dielectric elastomer actuator was fabricated using acrylic and carbon paste, with a specific pre-stretch ratio and additional mass applied. A rigid support structure connected the dielectric elastomer actuator to the vibration exciter. Different excitation signals were generated by the signal generator. The controller, an active vibration isolation controller based on inverse shaping, consisted of a square root nonlinear compensator, a PID feedback controller, and an A-EID inverse shaper. The control signal was amplified by a high-voltage amplifier and applied to the tapered dielectric elastomer actuator in the form of a voltage signal. The output displacement signal, measured by a laser displacement sensor and data acquisition unit, was simultaneously fed back to the computer and the controller. This feedback signal formed a closed-loop control system, while also being displayed on the computer for subsequent processing and analysis. The time-domain and frequency-domain response curves, as well as the displacement transmissibility curves of the tapered dielectric elastomer actuator, were tested with and without control to evaluate the system's vibration damping performance and for comparative analysis.

Experimental Results:

Figure 2: Vibration isolation effect of the active isolation system on a 5 Hz single-frequency resonance (a) Comparison of vibration isolation effects between active and passive isolation; (b) Comparison of vibration isolation effects between two active control methods)

The vibration isolation performance of the system for single-frequency harmonic vibration was verified. Harmonic vibration is common in reciprocating mechanical equipment and unbalanced motors, and its frequency is usually related to the operating speed. The tapered dielectric elastomer actuator was placed between the vibration exciter and a 7.1 g load mass. The exciter applied a single-frequency sinusoidal signal with an amplitude of 1 mm and frequencies of 5 Hz, 15 Hz, and 20 Hz, respectively, to the base. The controller applied active control to the DEA, and the motion displacement of the load mass was measured to evaluate the system's active vibration isolation effect. As shown in Figure 2, for the 5 Hz single-frequency sinusoidal excitation signal, the vibration amplitude of the system without active isolation control was 1.03 mm. The maximum vibration amplitude under PID feedback control alone was 0.092 mm, representing a 91.07% reduction compared to passive isolation. The maximum vibration amplitude under PID feedback control based on A-EID inverse shaping was 0.089 mm, representing a 91.36% reduction. The difference between the two isolation effects was minimal.

Figure 3: Vibration isolation effect of the system on a 15 Hz single-frequency resonance (a) Comparison of vibration isolation effects between active and passive isolation; (b) Comparison of vibration isolation effects between two active control methods)

As shown in Figure 3, for the 15 Hz single-frequency sinusoidal excitation signal, the vibration amplitude of the system without active isolation control was 1.37 mm. The maximum vibration amplitude under PID feedback control alone was 0.031 mm, representing a 97.74% reduction compared to passive isolation. The maximum vibration amplitude under PID feedback control based on A-EID inverse shaping was 0.012 mm, representing a 99.12% reduction. The PID feedback control based on A-EID inverse shaping almost completely isolated the vibration.

Figure 4: Vibration isolation effect of the system on a 20 Hz single-frequency resonance (a) Comparison of vibration isolation effects between active and passive isolation; (b) Comparison of vibration isolation effects between two active control methods)

As shown in Figure 4, for the 20 Hz single-frequency sinusoidal excitation signal, the vibration amplitude of the system without active isolation control was 1.93 mm. The maximum vibration amplitude under PID feedback control alone was 0.023 mm, representing a 98.81% reduction compared to passive isolation. The maximum vibration amplitude under PID feedback control based on A-EID inverse shaping was 0.003 mm, representing a 99.84% reduction. The PID feedback control based on A-EID inverse shaping almost completely isolated the vibration.

The vibration isolation performance of the system for linear time-varying vibration was verified. The tapered dielectric elastomer actuator was placed between the vibration exciter and a 7.1 g load mass. The exciter applied a sinusoidal frequency sweep signal with an amplitude of 1 mm and a frequency linearly increasing from 5 Hz to 30 Hz at a rate of 1 Hz/s to the base. The controller applied active control to the DEA, and the motion displacement of the load mass was measured to evaluate the system's active vibration isolation effect.

Figure 5: Vibration isolation effect of the system on a frequency sweep signal (a) Comparison of vibration isolation effects between active and passive isolation; (b) Comparison of vibration isolation effects between two active control methods)

As shown in Figure 5, compared to PID feedback control alone, the PID feedback control based on A-EID inverse shaping provided better vibration isolation across the entire frequency sweep range, with the strongest vibration isolation capability observed near the resonance region of the DEA.

High-Voltage Amplifier Recommendation: ATA-7025

Figure: ATA-7025 High-Voltage Amplifier Specifications

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