A resonant micro-rotary modulation platform

Abstract

The present invention provides a resonant micro-rotary modulation platform, which includes a base. A turntable is coaxially and rotatably installed on the base. An MEMS inertial sensor is fixed on the turntable. A hairspring is provided between the turntable and the base. The center position of the hairspring is synchronously rotationally connected with the turntable, and the outer end of the hairspring is fixed on the base. The present invention uses the hairspring structure and the turntable as the resonators of the system, so that the motion mode of the turntable is in the form of a sine wave. Through simulation verification, the sine wave rotation modulation effect is the same as that of the traditional square wave rotation modulation, but there is no influence of the square wave rotation modulation due to start-stop acceleration and deceleration, overshoot, etc. Moreover, this structure is a reciprocating motion and will not cause problems such as wire winding. It only needs to provide an intermittent pulse force to achieve continuous reciprocating motion. This method greatly reduces power consumption, is easy to realize miniaturized design and reduces the heat problems caused by high power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of suppressing and eliminating the zero-offset error of MEMS inertial sensors, and particularly to a resonant micro-miniature rotation modulation platform. Background Art

[0002] MEMS inertial sensors have the advantages of small size, light weight, low power consumption, etc., and are suitable for high-precision measurement fields such as aerospace and national defense security. The advantage of low cost in mass production is also widely used in consumer electronics fields such as mobile phones, automotive drones, etc. At present, the working accuracy of MEMS inertial sensors is gradually approaching that of high-precision inertial sensors at the macroscopic scale. However, the long-term stability of MEMS-IMU, such as zero-offset error and scale factor drift error, is still the key problem restricting the development of micro-inertial navigation. Therefore, in order to improve the accuracy of the MEMS inertial navigation system, redundant designs such as GPS are usually adopted to perform data fusion on the information collected by the MEMS inertial navigation system, so as to achieve a high-precision navigation effect. However, in some special systems or environments, such as military AUV navigation systems and drone rescue systems, due to their harsh or special environments, GPS signals or other auxiliary signals are missing, and only a single MEMS inertial navigation system can be used for positioning and navigation. Due to the influence of long-term stability, the accuracy is greatly reduced.

[0003] At present, there are mainly two methods to improve the accuracy of a single MEMS inertial sensor. One is starting from the manufacturing process, but this method is difficult to develop, has a high cost, and is difficult to implement; the second is to improve the accuracy of the MEMS inertial sensor from the system, and the rotation modulation method is used. The rotation modulation technology is currently the most effective method for suppressing the zero-offset error of MEMS inertial sensors. It can also suppress the zero drift caused by temperature with a temperature change frequency lower than the rotation frequency and is not affected by zero-offset repeatability. At present, the volume of the rotation modulation platform system can be made between 3 cm and 10 cm, which can meet part of the requirements. However, in a more miniaturized system, a millimeter-level micro-miniature rotation modulation platform is required. The micro-miniature rotation modulation platform has been studied at present, including ultrasonic motors, PCB motors, magnetic levitation motors, liquid bearing motors, etc. It has been able to achieve a very small size. However, at present, high-precision motor control cannot be realized, and the control accuracy of the motor and the high-precision angle measurement technology have a great impact on the rotation modulation effect. Therefore, it is necessary to adopt a resonant micro-miniature rotation modulation platform to solve the above problems. Summary of the Invention

[0004] The present invention proposes a resonant micro-miniature rotation modulation platform to solve the problems of power consumption and motor control accuracy in the micro-miniature rotation platform system mentioned in the above background art.

[0005] The technical solution of the present invention is realized as follows:

[0006] A resonant micro-rotary modulation platform includes a base. A turntable is coaxially and rotatably installed on the base. An MEMS inertial sensor is fixed on the turntable. A hairspring is provided between the turntable and the base. The center position of the hairspring is synchronously rotationally connected to the turntable, and the outer end of the hairspring is fixed on the base. When the turntable is driven by electrostatic force to rotate relative to the base, its energy can be converted into the rotational inertia of the turntable and the elastic potential energy of the hairspring, so that the turntable and the hairspring form a resonator, and the turntable performs simple harmonic motion.

[0007] Preferably, a main shaft is fixed at the center of the base. The main shaft passes through the central hole of the hairspring and is connected to the turntable through a bearing.

[0008] Preferably, a plurality of uniformly distributed capacitor plates are respectively provided at the opposite surfaces of the base and the turntable and near the edge positions of the two. The capacitor plates on the base and the turntable form a capacitor.

[0009] Preferably, the base is made of FR-4 substrate material, and the capacitor plates are made of aluminum material.

[0010] Preferably, the outer diameters of the base and the turntable are both 10 mm, the maximum diameter of the hairspring is 5 mm, and the minimum diameter of the annular region formed by the capacitor plates is greater than 5 mm.

[0011] Preferably, the material of the hairspring is silicon.

[0012] By adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0013] The present invention adopts a hairspring structure and a turntable as the resonator of the system, so that the motion mode of the turntable is in the form of a sine wave. Through simulation verification, the sine wave rotation modulation effect is the same as that of the traditional square wave rotation modulation effect, but there is no influence of the square wave rotation modulation due to start-stop acceleration and deceleration and overshoot, etc. And this structure is a reciprocating motion and will not cause problems such as winding. It only needs to provide an intermittent pulse force to achieve continuous reciprocating motion. This method greatly reduces power consumption, is easy to realize miniaturized design and reduces the heat problems caused by large power consumption. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 Stereogram of the present invention;

[0016] Figure 2 Exploded view of the present invention;

[0017] Figure 3 Structural diagram of the base of the present invention;

[0018] Figure 4 Structural diagram of the turntable of the present invention;

[0019] Figure 5 Structural diagram of the hairspring of the present invention.

[0020] Wherein:

[0021] 1. Base; 2. Main shaft; 3. Capacitor plate; 4. Hairspring; 5. Turntable; 6. MEMS inertial sensor. Specific embodiments

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] Refer to Figures 1 - 5 , a resonant micro-rotary modulation platform, comprising a base 1, a turntable 5 coaxially and rotatably mounted on the base 1, a MEMS inertial sensor 6 fixed on the turntable 5, and a hairspring 4 provided between the turntable 5 and the base 1. Wherein, a main shaft 2 is fixed at the center of the base 1, and the main shaft 2 passes through the central hole of the hairspring 4 and is connected to the turntable 5 through a bearing. The base 1 is the stator of the motor and is in a fixed state during operation, and the turntable 5 can rotate relative to the base 1.

[0024] The central position of the hairspring 4 is synchronously rotationally connected to the turntable 5, and the outer end of the hairspring 4 is fixed on the base 1. When the turntable 5 is driven by electrostatic force to rotate relative to the base 1, its energy can be converted into the rotational inertia of the turntable 5 and the elastic potential energy of the hairspring 4, so that the turntable 5 and the hairspring 4 form a resonator, causing the turntable 5 to perform simple harmonic motion. During the motion process, due to the influence of friction, elastic damping, etc., energy is lost. At this time, only by replenishing the lost energy can a stable reciprocating rotational motion of the system be achieved.

[0025] Specifically, a plurality of uniformly distributed capacitor plates 3 are respectively provided at the facing surfaces of the base 1 and the turntable 5 and near the edge positions of the two. In this example, each capacitor plate 3 has a sector structure. The capacitor plates 3 on the base 1 and the turntable 5 form a capacitor. Such a setting is to use the principle of variable-capacitance electrostatic drive to realize the rotation of the turntable 5. The system adopted herein is electrostatic drive. The capacitor plates 3 are distributed on both the base 1 and the turntable 5. The base 1 is fixed while the turntable 5 is rotatable. The capacitor plates 3 can not only play a driving role but also a feedback role. When the turntable 5 rotates, the change in the capacitor voltage is converted into a signal, which is converted into an angle after data processing. At the same time, due to the resonance characteristics of the turntable 5, the rotated angle can be calculated through its frequency. Fitting the results obtained by the two methods can improve the angle measurement accuracy of the system.

[0026] Specifically, the base 1 is made of FR-4 substrate material, which is specifically composed of glass fiber cloth and epoxy resin, and has good insulation performance and mechanical strength. The capacitor plate 3 is made of aluminum material, which has a relatively high capacitance density and low cost.

[0027] Specifically, the outer diameters of both the base 1 and the turntable 5 are 10 mm, the maximum diameter of the hairspring 4 is 5 mm, and the minimum diameter of the annular region formed by the capacitor plates 3 is greater than 5 mm. Such a setting is to stagger the hairspring 4 and the capacitor plates 3, so as to reduce the influence of the presence of the hairspring 4 on the upper and lower capacitor plates 3.

[0028] Specifically, the hairspring 4 is made of silicon. Compared with a metal hairspring 4, it is not easily affected by capacitance.

[0029] This resonant micro-miniature rotation modulation platform proposed in this embodiment only needs to provide a single-pulse force to achieve sinusoidal motion control, which has high control accuracy, and sinusoidal control has also been verified to be able to achieve rotation modulation. In addition, high-precision angle measurement technology can be achieved by combining the characteristics of the resonant system with the method of capacitive grating angle measurement, enabling this rotation platform to be applied to rotation modulation and solving the problems of power consumption and motor control accuracy in the micro-miniature rotation platform system.

[0030] Traditional rotation modulation is uniform rotation (i.e., modulation with a square-wave rotational speed). However, due to the influence of the start-stop acceleration and deceleration of the actual motor, a certain amount of error will be introduced, but this is not the reason for using sine-wave rotation modulation. To reduce the power consumption of the micro-miniature rotation modulation platform, in this example, a hairspring 4 is adopted, which forms a harmonic oscillator with the turntable 5. Only the energy lost needs to be replenished for each cycle, and there is no need to continuously supply energy to it all the time. Therefore, the power consumption of the system is reduced. The motion speed of this resonant system is non-uniform motion in the form of a sine wave, which is not applicable to the traditional uniform rotation theoretical model. Therefore, Matlab is used to perform theoretical calculations and simulations on the rotation modulation of this non-uniform sine-wave motion. The result shows that the maximum effect it can achieve at a specific rotation angle is the same as the maximum effect during uniform rotation.

[0031] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A resonant micro-rotation modulation platform, characterized in that: The invention comprises a base (1), a turntable (5) is coaxially and rotatably mounted on the base (1), a MEMS inertial sensor (6) is fixed on the turntable (5), a hairspring (4) is arranged between the turntable (5) and the base (1), the center position of the hairspring (4) is synchronously rotatably connected with the turntable (5), and the outer end of the hairspring (4) is fixed on the base (1), when the electrostatic force drives the turntable (5) to rotate relative to the base (1), its energy can be converted into the rotational inertia of the turntable (5) and the elastic potential energy of the hairspring (4), so that the turntable (5) and the hairspring spring (4) form a resonator, so that the turntable (5) performs simple harmonic motion; A plurality of uniformly distributed capacitor plates (3) are respectively provided on the facing surfaces of the base (1) and the turntable (5) and near the edges of the two, and the capacitor plates (3) on the base (1) and the turntable (5) form a capacitor.

2. The resonant micro-rotation modulation platform according to claim 1, characterized in that: A main shaft (2) is fixed at the center of the base (1); the main shaft (2) passes through the center hole of the hairspring (4) and is connected to the turntable (5) via a bearing.

3. The resonant micro-rotation modulation platform according to claim 1, characterized in that: The base (1) is made of FR-4 substrate material, and the capacitor plate (3) is made of aluminum material.

4. The resonant micro-rotation modulation platform according to claim 1, characterized in that: The outer diameters of the base (1) and the turntable (5) are both 10 mm, the maximum diameter of the hairspring (4) is 5 mm, and the minimum diameter of the annular area formed by the capacitor plate (3) is greater than 5 mm.

5. The resonant micro-rotation modulation platform according to claim 1, characterized in that: The hairspring spring (4) is made of silicon.

Images