CN102608669B - Gravity gradient flexible sensitive structure with motional and rotational freedoms - Google Patents

Abstract

The invention discloses a gravity gradient flexible sensitive structure with motional and rotational freedoms, which comprises a flexible Hooke hinge, a rigid rod and a fixed outer frame, wherein two ends of the rigid rod are respectively connected with the flexible Hooke hinge to form one group of restraining rods, the flexible Hooke hinge comprises two serially-connected flexible hinges with vertically-crossed axial lines and can deform respectively along the transverse direction and the longitudinal direction; three groups of restraining rods are symmetrically arranged along the circumference of the fixed outer frame, two groups of restraining rods are arranged along the vertical direction of the fixed outer frame at intervals, a mass block is connected with the fixed outer frame through six groups of restraining rods; and a gravity gradient axial component is measured by suing the motional freedom, and the gravity gradient cross component is measured by the rotational freedom. The gravity gradient flexible sensitive structure can be simultaneously measuring the gravity gradient axial component and the gravity gradient cross component and ensuring coincidence of measurement points of the two components, and has the advantages of compact structure, reduced refrigeration cost and high measurement precision.

Description

A kind of flexible sensitive structure of gravity gradient with mobile and rotational freedom

Technical field

The present invention relates to the gradiometry technical field, relate in particular to a kind of flexible sensitive structure of the mobile gravity gradient with rotational freedom that has.

Background technology

At present, gravity field can use the higher derivative (gravitational vector gradient, i.e. gravity gradient) of gravity position, gravity position gradient (gravitational vector) and gravity position to mean.Specifically, getting geocentric coordinate is inertial system, and body axis system is moving system, analyzes the stressed equation of mass in body axis system, known

$\stackrel{\‾}{f}+\stackrel{\‾}{g}=\stackrel{\‾}{\mathrm{\ω}}\×(\stackrel{\‾}{\mathrm{\ω}}\×\stackrel{\‾}{R})+\frac{d\stackrel{\‾}{\mathrm{\ω}}}{\mathrm{dt}}{|}_p\×\stackrel{\‾}{R}+\stackrel{\‾}{a}---\left(1\right)$

In above formula

the specific force born for unit mass;

for gravity;

angular velocity for the relative geocentric coordinate system of body axis system;

for the radius vector of mass barycenter in inertial coordinates system;

linear acceleration for the relative geocentric coordinate system of body axis system; Subscript p is illustrated in body axis system.Then along body axis system

get coordinate components and ask the space local derviation, with

coordinate components is example, and the axial component that obtains gravity gradient is

$\frac{{\∂g}_i}{{\∂x}_i}=-\frac{{\∂f}_i}{{\∂x}_i}-{\mathrm{\ω}}_j^2-{\mathrm{\ω}}_k^2---\left(2\right)$

And the cross-product of gravity gradient is

$\frac{{\∂g}_i}{{\∂x}_j}=-\frac{{\∂f}_i}{{\∂x}_j}+{\mathrm{\ω}}_i{\mathrm{\ω}}_j-\frac{{\mathrm{d\ω}}_k}{\mathrm{dt}}{|}_p$

$\frac{{\∂g}_i}{{\∂x}_k}=-\frac{{\∂f}_i}{{\∂x}_k}+{\mathrm{\ω}}_i{\mathrm{\ω}}_k+\frac{{\mathrm{d\ω}}_j}{\mathrm{dt}}{|}_p---\left(3\right)$

Hence one can see that, after measuring specific force gradient and angular acceleration, can obtain full tensor gravity gradient.But in the prior art scheme, the sensitive structure of gradiometry only has single sensitive direction, full tensor gradiometry need to comprise two cover autonomous systems, a set of is the axial component measuring system that contains the linear acceleration sensitive structure, and another set of is the cross-product measuring system that contains the angular acceleration sensitive structure; Simultaneously, for residual error is compensated, two cover systems all need the additional accelerometer of measuring for distracter, i.e. the additional angular accelerometer of axial component measuring system, and the additional linear accelerometer of cross-product measuring system.Will cause like this that whole equipment volume weight is large, refrigerating capacity require high, operating cost is high, application scenario is limited, two complete equipment measuring points are inconsistent, has reduced measuring accuracy.

Summary of the invention

The purpose of this invention is to provide a kind of flexible sensitive structure of the mobile gravity gradient with rotational freedom that has, this sensitive structure can be measured axial component and the cross-product of gravity gradient simultaneously, and guarantees that measuring point coincidence, compact conformation, minimizing refrigeration cost, the measuring accuracy of two components are high.

The objective of the invention is to be achieved through the following technical solutions, a kind of have a flexible sensitive structure of the mobile gravity gradient with rotational freedom, and described sensitive structure comprises flexible Hooke's hinge, rigid rod and fixing housing, wherein:

Described rigid rod two ends connect to form one group of constraining rod with described flexible Hooke's hinge respectively, and this flexibility Hooke's hinge is comprised of the series connection flexible hinge of two intersect vertical axis, can transversely and vertically deform respectively;

Circumference along described fixedly housing is arranged symmetrically with 3 groups of constraining rods, and is furnished with 2 groups of constraining rods along interval on the vertical direction of described fixedly housing, by these 6 groups of constraining rods, mass is connected with described fixedly housing;

Utilize these 6 groups of constraining rods to make described sensitive structure there is one-movement-freedom-degree and rotational freedom, utilize this one-movement-freedom-degree to measure the gravity gradient axial component, utilize this rotational freedom to measure the gravity gradient cross-product.

Described flexible Hooke's hinge comprises laterally and vertical cut (V. cut), along circumferential layout, flexible Hooke's hinge is not everywhere blocked mutually.

Described 6 groups of constraining rods comprise the flexible Hooke's hinge in 12 places, and the flexible Hooke's hinge in this 12 place all participates in distortion.

Described 6 groups of constraining rods are symmetric configuration on space form.

If measure the full tensor gravity gradient in three dimensions, utilize three pairs totally six described sensitive structures be arranged on six faces of the full tensor fixed frame of regular hexahedron and measured.

As seen from the above technical solution provided by the invention, described sensitive structure comprises flexible Hooke's hinge, rigid rod and fixing housing, wherein said rigid rod two ends connect to form one group of constraining rod with described flexible Hooke's hinge respectively, and this flexibility Hooke's hinge is comprised of the series connection flexible hinge of two intersect vertical axis, can transversely and vertically deform respectively; Circumference along described fixedly housing is arranged symmetrically with 3 groups of constraining rods, and is furnished with 2 groups of constraining rods along interval on the vertical direction of described fixedly housing, by these 6 groups of constraining rods, mass is connected with described fixedly housing; Utilize these 6 groups of constraining rods to make described sensitive structure there is one-movement-freedom-degree and rotational freedom, utilize this one-movement-freedom-degree to measure the gravity gradient axial component, utilize this rotational freedom to measure the gravity gradient cross-product.This sensitive structure can be measured axial component and the cross-product of gravity gradient simultaneously, and guarantees that measuring point coincidence, compact conformation, minimizing refrigeration cost, the measuring accuracy of two components are high.

The accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme of the embodiment of the present invention, in below describing embodiment, the accompanying drawing of required use is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite of not paying creative work, can also obtain other accompanying drawings according to these accompanying drawings.

Fig. 1 is the described schematic diagram with flexible sensitive structure of gravity gradient of mobile and rotational freedom of the embodiment of the present invention;

The structural representation of the flexible Hooke's hinge that Fig. 2 provides for the embodiment of the present invention;

The schematic layout pattern that Fig. 3 is the full tensor fixed frame of regular hexahedron in embodiment of the present invention example;

Fig. 4 is the sensitive structure distortion schematic diagram while utilizing one-movement-freedom-degree to measure in the example enumerated of the embodiment of the present invention;

Fig. 5 is the schematic diagram of sensitive structure before deforming while utilizing rotational freedom to measure in the instantiation enumerated of the embodiment of the present invention;

Fig. 6 is the schematic diagram of sensitive structure after deforming while utilizing rotational freedom to measure in the instantiation enumerated of the embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Based on embodiments of the invention, those of ordinary skills, not making under the creative work prerequisite the every other embodiment obtained, belong to protection scope of the present invention.

Embodiments of the invention provide a kind of flexible sensitive structure of the mobile gravity gradient with rotational freedom that has, this sensitive structure utilizes the parallel flexible mechanism principle, there is moving sets and revolute pair degree of freedom simultaneously, one-movement-freedom-degree is for measuring the gravity gradient axial component, rotational freedom is for measuring the gravity gradient cross-product, below in conjunction with accompanying drawing, the embodiment of the present invention is described in further detail, be illustrated in figure 1 the described schematic diagram with flexible sensitive structure of gravity gradient of mobile and rotational freedom of the embodiment of the present invention, in Fig. 1, sensitive structure comprises: flexible Hooke's hinge 1, rigid rod 2 and fixing housing 3, wherein:

On the xy axial plane, rigid rod 2 two ends connect to form one group of constraining rod with described flexible Hooke's hinge 1 respectively, and this flexibility Hooke's hinge 1 can be comprised of the series connection flexible hinge of two intersect vertical axis, can transversely and vertically deform respectively;

Circumference along described fixedly housing 3 is arranged symmetrically with 3 groups of constraining rods, and is furnished with 2 groups of constraining rods along interval on the vertical direction of described fixedly housing 3, by these 6 groups of constraining rods, mass 4 is connected with described fixedly housing 3;

Utilize these 6 groups of constraining rods to make described sensitive structure there is one-movement-freedom-degree and rotational freedom, can move or rotate around the z axle along the z axle, and utilize this one-movement-freedom-degree to measure the gravity gradient axial component, utilize this rotational freedom to measure the gravity gradient cross-product.

In the specific implementation process, be illustrated in figure 2 the structural representation of the flexible Hooke's hinge that the embodiment of the present invention provides, in Fig. 2: this flexibility Hooke's hinge is comprised of the series connection flexible hinge of two intersect vertical axis, can realize mutual transversely and vertically deforming respectively of not being coupled, and this flexibility Hooke's hinge comprises laterally and vertical cut (V. cut), along circumferential layout, flexible Hooke's hinge is not everywhere blocked mutually, thereby can utilize easily the line cutting to realize one processing, to reduce structurally internal stress, the dimensional stability while guaranteeing low-temperature working.

In addition, above-mentioned 6 groups of constraining rods are symmetric configuration on space form, can realize symmetrical mechanical characteristic, guarantee that the flexible hinge of each constraint place produces homogeneous deformation, reduce asymmetrical skew; Its this 6 groups of constraining rods comprise the flexible Hooke's hinge in 12 places altogether, and the flexible Hooke's hinge in this 12 place all participates in distortion, avoids the stress of single hinge to concentrate.

In addition, can also change the geometric parameter of above-mentioned sensitive structure, the rigidity of adjusted design direction and parasitic direction separately, also both ratio of capable of regulating, in order to adapt to different application demands.

Below with concrete example, the surveying work process to structure of the present invention describes, for instance, if need to measure the full tensor gravity gradient in three dimensions, can utilize three pairs totally six described sensitive structures be arranged on six faces of the full tensor fixed frame of regular hexahedron and measured.Be illustrated in figure 3 the schematic layout pattern of the full tensor fixed frame of regular hexahedron in embodiment of the present invention example, in Fig. 3: be furnished with two sensitive structures along the z axle, and, along x, the y axle also has respectively two sensitive structures, does not indicate in Fig. 3.

Axial two sensitive structures of the z of take are example, and two sensitive structures are along the axial half-twist again after a determining deviation separately of z, and one-movement-freedom-degree is for measuring the axial component Γ ' of gravity gradient along the z axle _zz, rotational freedom is measured the cross-product Γ ' of gravity gradient along x, y axle _xy; In like manner can obtain the measured value of other diaxons, along the axial component Γ ' of x axle _xx, along the cross-product Γ ' of y, z axle _yz, along the axial component Γ ' of y axle _yy, along the cross-product Γ ' of x, z axle _xz.The angular velocity along x, y, z of the another relative geocentric coordinate system of body axis system measured by angular-rate sensor is respectively ω _x, ω _y, ω _z, by formula (1), can obtain the full tensor gravity gradient Γ under geocentric coordinate system.

$\mathrm{\Γ}=\left[\begin{array}{ccc}{\text{\Γ}}_{\mathrm{xx}}^{\′}-{\mathrm{\ω}}_y^2-{\mathrm{\ω}}_z^2& {\mathrm{\Γ}}_{\mathrm{xy}}^{\′}+{\mathrm{\ω}}_x{\mathrm{\ω}}_y& {\mathrm{\Γ}}_{\mathrm{xz}}^{\′}+{\mathrm{\ω}}_x{\mathrm{\ω}}_z\\ {\mathrm{\Γ}}_{\mathrm{yx}}^{\′}+{\mathrm{\ω}}_y{\mathrm{\ω}}_x& {\mathrm{\Γ}}_{\mathrm{yy}}^{\′}+{\mathrm{\ω}}_z^2-{\mathrm{\ω}}_x^2& {\mathrm{\Γ}}_{\mathrm{yz}}^{\′}+{\mathrm{\ω}}_y{\mathrm{\ω}}_z\\ {\mathrm{\Γ}}_{\mathrm{zx}}^{\′}+{\mathrm{\ω}}_z{\mathrm{\ω}}_x& {\mathrm{\Γ}}_{\mathrm{zy}}^{\′}+{\mathrm{\ω}}_z{\mathrm{\ω}}_y& {\mathrm{\Γ}}_{\mathrm{zz}}^{\′}-{\mathrm{\ω}}_x^2-{\mathrm{\ω}}_y^2\end{array}\right]---\left(1\right)$

The process of below again one-movement-freedom-degree being measured to the gravity gradient axial component describes, and is illustrated in figure 4 in the example that the embodiment of the present invention enumerates the sensitive structure distortion schematic diagram while utilizing one-movement-freedom-degree to measure, in Fig. 4;

The whole upper and lower translation trend of intermediate mass piece (column part in the middle of comprising and the fan-shaped part of both sides 90 degree, be all one processing, is exactly directly to connect) is exactly one-movement-freedom-degree, and why being moved is exactly because be subject to the effect of gravity.As shown in Figure 3, be subject to different gravity (vertically) effect two positions along axial two sensitive structures of z, the distance be moved will be unequal, records two displacement difference, by the gravity difference, divided by displacement difference, can solve the gravity gradient axial component.

The process of below again rotational freedom being measured to the gravity gradient cross-product describes, the intermediate mass piece does not produce upper and lower translation, but the trend that produces rotation is exactly rotational freedom, schematic diagram before being illustrated in figure 5 in the instantiation that the embodiment of the present invention enumerates sensitive structure while utilizing rotational freedom to measure and deforming, schematic diagram after being illustrated in figure 6 sensitive structure while utilizing rotational freedom to measure and deforming, from the contrast before and after Fig. 5 and 6 distortion:

Rotation has occurred in the intermediate mass piece, and why rotating is also because be subject to the effect of transverse gravity.As shown in Figure 3, along axial two sensitive structures of z, two positions, be subject to different Action of Gravity Fields, the angle rotated will be unequal, records two differential seat angles, can solve the gravity gradient cross-product.

In sum, the embodiment of the present invention can be measured axial component and the cross-product of gravity gradient simultaneously, and guarantees that measuring point coincidence, compact conformation, minimizing refrigeration cost, the measuring accuracy of two components are high; Moving mass piece and pivoted arm quality are integrated, guarantee that measuring point coincidence, compact conformation, minimizing refrigeration cost, the measuring accuracy of two components is high; Design direction to move rigidity along axle little with the rigidity of swaying, mobile rigidity and the rotational stiffness of parasitic direction (off-design direction of error) are large, Reduce measurement error; And adopt 6 groups of constraining rods in parallel, avoided the complex form of a rotational freedom of series connection after thering is an one-movement-freedom-degree, in configuration more succinct, stability is better.

The above; be only the present invention's embodiment preferably, but protection scope of the present invention is not limited to this, anyly is familiar with in technical scope that those skilled in the art disclose in the present invention; the variation that can expect easily or replacement, within all should being encompassed in protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.

Claims (5)

1. one kind has the flexible sensitive structure of the mobile gravity gradient with rotational freedom, it is characterized in that, described sensitive structure comprises flexible Hooke's hinge, rigid rod and fixing housing, wherein:

Described rigid rod two ends connect to form one group of constraining rod with described flexible Hooke's hinge respectively, and this flexibility Hooke's hinge is comprised of the series connection flexible hinge of two intersect vertical axis, can transversely and vertically deform respectively;

Circumference along described fixedly housing is arranged symmetrically with 3 groups of constraining rods, and is furnished with 2 groups of constraining rods along interval on the vertical direction of described fixedly housing, by these 6 groups of constraining rods, mass is connected with described fixedly housing;

Utilize these 6 groups of constraining rods to make described sensitive structure there is one-movement-freedom-degree and rotational freedom, utilize this one-movement-freedom-degree to measure the gravity gradient axial component, utilize this rotational freedom to measure the gravity gradient cross-product.

2. the flexible sensitive structure of gravity gradient with mobile and rotational freedom according to claim 1, is characterized in that,

Described flexible Hooke's hinge comprises laterally and vertical cut (V. cut), along circumferential layout, flexible Hooke's hinge is not everywhere blocked mutually.

3. the flexible sensitive structure of gravity gradient with mobile and rotational freedom according to claim 1, is characterized in that, described 6 groups of constraining rods comprise the flexible Hooke's hinges in 12 places, and the flexible Hooke's hinge in this 12 place all participates in distortion.

4. the flexible sensitive structure of gravity gradient with mobile and rotational freedom according to claim 1, is characterized in that,

Described 6 groups of constraining rods are symmetric configuration on space form.

5. according to one of them described flexible sensitive structure of gravity gradient with mobile and rotational freedom of claim 1-4, it is characterized in that, if measure the full tensor gravity gradient in three dimensions, utilize three pairs totally six described sensitive structures be arranged on six faces of the full tensor fixed frame of regular hexahedron and measured.

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