CN-122014798-A - Nonlinear stiffness automatic adjusting vibration isolation device and control method

Abstract

The invention discloses a nonlinear rigidity automatic adjusting vibration isolation device and a control method, the device comprises a base, a supporting seat, a positive stiffness mechanism, a negative stiffness mechanism and a dynamic adjusting assembly. The negative stiffness mechanism adopts a three-layer uniformly-distributed connecting rod-tension spring transmission unit design, generates negative stiffness by converting vertical displacement of the supporting seat into horizontal motion of the tension spring, and is connected with positive stiffness provided by the positive stiffness mechanism in parallel to form a quasi-zero stiffness core mechanical framework. The dynamic adjusting component can accurately adjust the working height of the positive stiffness mechanism, and is combined with a feedback control system taking an angle sensor as a core to realize self-adaptive adjustment of the balance position of the system under different loads and maintenance of a quasi-zero stiffness state. The positive stiffness mechanism integrated magneto-rheological damper can realize real-time and intelligent adjustment by a feedforward-feedback composite control strategy based on multi-sensor information fusion so as to inhibit resonance, impact and broadband vibration. The invention solves the problems of narrow vibration isolation frequency band, incapability of self-adapting load, unintelligent damping adjustment and the like in the prior art, and realizes high-bearing, strong vibration reduction and full-working-condition self-adapting vibration isolation.

Inventors

• FU ZHIJUN
• DING JINQUAN
• LIU XIAOLI
• ZHOU FANG
• LU SHAOWEI
• ZHANG ZHIGANG
• JIA MENGYANG
• HU JIA
• ZHAO DENGFENG
• LI JINGHAN
• LIU DELU
• ZHANG JIAHAN

Assignees

• 郑州轻工业大学

Dates

Publication Date

20260512

Application Date

20260323

Priority Date

20260119

Claims (2)

1. 1. The utility model provides a nonlinear rigidity automatically regulated vibration isolation device, includes base (1), supporting seat (2), its characterized in that still includes: The positive rigidity mechanism (3) is arranged inside the base (1) and is used for providing positive rigidity for the main support in the vertical direction; a negative stiffness mechanism (4) arranged inside the base (1) and connected in parallel with the positive stiffness mechanism (3) for generating negative stiffness opposite to the positive stiffness mechanism (3); The dynamic adjusting component (5) is fixed on the inner bottom wall of the base (1) and acts on the positive stiffness mechanism (3), and the system presents quasi-zero stiffness characteristic at the balance position by adjusting the working height of the positive stiffness mechanism (3).
2. 2. A control method for the nonlinear stiffness automatic regulating vibration isolation apparatus as described in claim, characterized by comprising the steps of: S1, acquiring and processing signals of a base acceleration, a supporting seat acceleration and an angle sensor in real time to obtain system state information; S2, calculating feedforward control force based on the measurable basic acceleration and a system nonlinear model to offset main disturbance and nonlinear force, and performing physical realizability verification according to a semi-active constraint principle; s3, designing a front feedback controller on the basis of a linear quadratic form optimal (LQR) controller, and calculating optimal state feedback control force; S4, adopting a multi-objective optimization algorithm to carry out self-adaptive setting on parameters of the LQR controller; S5, synthesizing feedforward control force and feedback control force, and performing amplitude limiting and direction checking to obtain physical realizable expected control force; s6, mapping the expected control force into an input current signal according to a calibrated magneto-rheological damper inverse model; S7, outputting a current signal to drive the magnetorheological damper to generate damping force; s8, continuously monitoring load change, and when the angle sensor detects that the system deviates from a rated balance position, adjusting the working height of the positive stiffness mechanism (3) through the dynamic adjusting component (5) to enable the system to recover to a quasi-zero stiffness state; And S9, updating the system state and returning to the step S1 to form closed-loop control.

Description

Nonlinear stiffness automatic adjusting vibration isolation device and control method Technical Field The invention relates to the technical field of vibration isolation, in particular to a nonlinear stiffness automatic adjusting vibration isolation device and a control method. Background A seat is a seat that provides support for a user for improved seating comfort and safety. In vibration environments such as vehicles, construction machines, aerospace, etc., seats must have a vibration damping function, which is mainly because harmful mechanical vibrations and impacts transmitted from the outside to the human body are isolated or damped. The sitting comfort is directly related, and the health problems of vertebra injury, whole body vibration diseases and the like caused by long-term exposure of driving and operating staff to the vibration environment can be effectively prevented. The performance of the vibration reduction seat in the prior art still has a plurality of inherent defects, and the requirements of high bearing capacity and strong vibration reduction are difficult to meet at the same time: First, the vibration isolation band is narrow, and particularly, the low frequency vibration isolation effect is poor. The vibration isolation performance of the existing vibration reduction seat is limited by fixed rigidity parameters, so that the effective vibration isolation frequency band is narrow. For example, chinese patent publication No. CN220557708U discloses a vibration damping seat for an automobile, which adopts a double-spring stacked structure, and can improve vibration damping effect in a certain range, but its rigidity is still fixed. Such a linear vibration isolation system based on fixed rigidity has a natural frequency which is difficult to reduce, and according to the vibration isolation theory, the system only has a frequency which exceeds the natural frequency The vibration isolation region can be effectively accessed when the vibration isolation region is doubled. The traditional seat has poor low-frequency vibration isolation effect on vehicles and machines, is easy to generate resonance due to frequency matching, and seriously jeopardizes riding comfort and personnel health. This is the primary problem that needs to be solved in the prior art. Second, the load change cannot be adapted, resulting in damping of the vibration isolation performance with load change. The existing vibration reduction seat lacks automatic compensation capability for load change, so that the optimal vibration isolation performance of the existing vibration reduction seat is designed only for specific loads, and the practicability is severely limited. When the weight of the user is different or the load is changed, the balance position of the system can deviate, so that the system cannot work in the preset optimal vibration isolation state. Although an intelligent vibration damping seat disclosed in Chinese patent publication No. CN116552345A tries to adjust the pressure of an air bag to adapt to load through a pressure sensor, the adjusting mechanism of the intelligent vibration damping seat does not change the rigidity characteristic of a system fundamentally, and the bearing capacity and long-term stability of the intelligent vibration damping seat are limited by the material strength and durability of the air bag, so that stable and high-performance vibration isolation effect can not be continuously provided under different loads. Therefore, developing a system capable of adaptively compensating for load variation and maintaining an optimal vibration isolation state is a highly desirable problem. Third, the performance of the negative stiffness mechanism is limited, and the realization precision and stability of the quasi-zero stiffness characteristic are affected. In the related art, the quasi-zero stiffness can be realized by connecting positive and negative stiffness mechanisms in parallel, so that the natural frequency is reduced and the low-frequency vibration isolation bandwidth is widened. However, the mechanism for realizing the negative stiffness in the prior art generally adopts a single-layer or double-layer 'connecting rod-spring' design, the negative stiffness provided by the structure is limited in adjusting range and precision, and the friction damping in the kinematic pair can directly influence the accurate generation and offset of the negative stiffness, so that the integral vibration isolation performance of the system is influenced. How to design a low-friction and high-precision negative stiffness mechanism is one of the key challenges for realizing high-performance quasi-zero stiffness vibration isolation. Fourth, the damping characteristics are fixed or not intelligently adjusted, and the broadband vibration suppression requirement cannot be met. The damping characteristics of the existing vibration reduction seat are often fixed or have limited adjusting range, and resonance