Device for determining acceleration

Abstract

The technical solution provided can be implemented with the help of two miniature vessels and even one miniature vessel filled with the flowing media.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present technical solution is explained and illustrated, by way of example, in the accompanying drawings, in which it is shown as follows:

FIG. 1—a scheme of a two-channel device for determining the horizontal acceleration,

FIG. 2—a scheme of a two-channel device for determining the vertical acceleration,

FIG. 3—a scheme of a one-channel device determining the horizontal acceleration,

FIG. 4—a scheme of one-vessel device for determining the vertical acceleration.

On the accompanying drawing the vessels and the thickness of their walls are not shown. In FIGS. 1, 2 the pressure pickups are not shown, but the points for determining pressures by these pickups are shown.

DETAILED DESCRIPTION OF THE INVENTION

The present technical solution is based on determining the pressures difference to be determined in particular points of the inner cavities of the hollow vessels, in particular, one vessel, wherein the pressures caused by the cross accelerations being equal, and those caused by the acceleration determined (horizontal or vertical) being different, correspondingly.

The points for determining pressures are chosen as such that even with tilting in the operating condition, they are acted upon along the cross-sectional axes by the columns of the flowing media of equal length, and on the axis along which determination is made of the acceleration, are of different length. Therefore, the cross accelerations are not considered to make any harmful influence on determining the acceleration required, as a consequence, the sensitivity axis, irrespective of tilting, in the device for determining horizontal acceleration is always directed along the horizontal, and in the device for determining the vertical acceleration is always directed along the vertical.

By way of examples, provision is made of the two-vessel devices for determining acceleration (FIG. 1, 2) and one-vessel device for determining acceleration (FIG. 3, 4).

In FIGS. 1, 2, 3, 4 the vessels are not shown, and the cross-sections of the inner cavities 1₁ and 1₂, 1₃ and 1₄, 1₅ and 1₆ of the hollow sealed vessels are shown. On these drawings there are shown arcs 2₁ and 2₂, 2₃ and 2₄, 2₅ and 2₆, 2₇ and 2₈, 2₉ and 2₁₀, 2₁₁ and 2₁₂ of the contours of these cross-sections.

On these drawings these cross-sections are shown counter-oriented (the arcs of one and the same radius are located on either side from their centers).

By way of example, in FIGS. 1, 2, 3, 4 there are shown the cross-sections of the inner cavities of the hollow vessels in the plane passing through the vertical and longitudinal axes of a moving object, the acceleration (α_ξ or α_η) whereof is determined, in particular, through the lines parallel to said axes.

The inner cavities of the vessels are filled with the flowing media (liquid, gas or their mixture). As the liquid use can be made of silicone oil (the density whereof being practically unchangeable within a wide range of temperature changes) ligroin and others.

In FIGS. 1, 2 there are not shown pressure pickups, and there are shown points L₁ and L₂, L₃ and L₄ for determining pressures by said pickups. These points can be, in particular, used as the centers of the spherical parts of the inner cavities of the vessels by means of the radii R and r.

The pressure signals in said points are provided to the differential scheme (differential block), at the output whereof there is taken a signal of the acceleration determined (in our example α_ξ or α_η). In FIG. I the differential scheme is indicated by 3₁, in FIG. 2—by 3₂, and in FIGS. 3, 4 as said scheme use is made of an electrical bridge, accordingly.

As pressure pickups in FIGS. 1, 2 use can be made of any known pressure pickups. It is more preferable that the pressure pickups with sensitive elements of semiconductor type be used, wherein under the pressure influence specific resistance changes.

In FIG. 1 the outermost (along the vertical) points are the upper (A1 and A₂) and lower (B₁ and B₂), remaining as such (upper and lower) with tilting in the operating condition In FIG. 2 the outermost (along the horizontal) are the extreme points (E₁ and E₂, E₃ and E₄) remaining as such (extreme) with tilting in the operating condition.

Further, first there will be provided a two-vessel device for determining the acceleration (FIGS. 1, 2), and then a one-vessel device for determining the acceleration (FIGS. 3, 4).

In FIGS. 1, 2 there are shown cross-sections of the inner cavities 1₁ and 1₂, 1₃ and 1₄, of two hollow sealed vessels.

Each of these cavities is considered to consist of two spherical parts of the different radius (R and r), but with the common center (in particular, L₁ and L₂).

In FIGS. 1, 2 there are shown contours of the cross-sections of said cavities passing through the centers L₁ and L₂. Such contour is considered to comprise the arcs of a different radius: arcs 2₁ and 2₃, 2₅ and 2₇ of the radius R, as well as arcs 2₂ and 2₄, 2₆ and 2₈, of the radius r.

The inner cavities of the vessels are used to be similar, in FIG. 1 and in FIG. 2, correspondingly.

The positions of the points L₁ and L₂, L₃ and L₄ are chosen to be similar in these planes, correspondingly.

Therefore, the columns lengths of the flowing media acting on these points under the influence of the horizontal lateral acceleration α_ζ are considered to be equal one another, irrespective of tilting. As a consequence, the acceleration α_ζ is not expected to make any harmful influence, even with tilting, on determining the horizontal longitudinal acceleration α_ξ (FIG. 1) and on determining the vertical acceleration α_η (FIG. 2).

Owing to presence of the outermost, along the vertical, points (A₁ and B₁, A₂ and B₂) the vertical acceleration α_η is not expected any harmful influence, either, even with tilting, on determining the acceleration α_ξ (FIG. 1).

Let's show it by way of example: the locations of the points L₁ on the straight line A₁B₁ and the locations of the point L₂ on the straight line A₂B₂, and choosing A₁B₁=A₂B₂, B₁L₁=B₂L₂. The points L₁ and L₂ are acted upon by the columns of the flowing media, the heights whereof being h₁ and h₂, h₃ and h₄. These heights are measured from the outermost points A₁ and A₂, B₁ and B₂ up to the horizontals (straight lines perpendicular to the vertical) passing through the points L₁ and L₂. In particular, in the initial position h₁=A₁L₁, h₂=A₂L₂, h₃=B₁L₁, h₄=B₂L₂. With tilting at the angle ν, we have

h ₁ =A ₁ L ₁ cos ν, h₂=A₂L₂ cos ν, h₃=B₁L₁ cos ν, h₄=B₂L₂ cos ν  (3)

But since choice is made of A₁L₁=A₂L₂, B₁L₁=B₂L₂, in particular, A₁L₁=A₂L₂=B₁L₁=B₂L₂, then h₁=h₂=h₃=h₄. This means that with tilting the heights of the columns of the flowing media acting on the points L₁ and L₂, being changed with tilting, remain to be equal. Due to that, determining α_Ξ is not expected to depend on the influence of α_η.

Let's consider the operation of the device of the horizontal acceleration α_ξ (FIG. 1) in case of applying the centers of said spherical parts as the points for determining pressure.

Let the acceleration α_ξ in FIG. 1 be directed from right to left. In this case the point L₁ is acted by the column of the flowing media at length R, the point L₁ is acted upon by the column of the flowing media at length r. Therefore, in these points there occur pressures P₁ and P₂, equal to

P₁=ρα_ξR, P₂=ρα_ξr   (4)

The signals of these pressures u₁ and u₂ are provided to the differential scheme 3₁ at the output whereof there is taken a signal

$\begin{array}{cc}{a}_{\xi }=\frac{U_1-U_2}{k\rho \left(R-r\right)},\mathrm{where}U_1>>U_2& \left(1\right)\end{array}$

In case the acceleration α_ξ in FIG. 1 is directed from left to right, then

$\begin{array}{cc}{a}_{\xi }=\frac{U_2-U_1}{k\rho \left(R-r\right)},\mathrm{where}U_2>>U_1& \left(5\right)\end{array}$

From (1) and (5) it follows that

• with tilting the difference of the lengths of columns of the flowing media (R-r) acting on the points L₁ and L₂ is considered to remain stable,
  • the device for determining the horizontal acceleration α_ξ is considered to determine not only the module of said acceleration but also its direction.

The device for determining the horizontal lateral acceleration α_ζ is the same as the device for determining the horizontal longitudinal acceleration α_ξ having the same merits. The difference consists in the fact that the cross-sections of the inner cavities of the vessels with the counter-orientation are located in the plane passing through the vertical and cross-sectional axes of a moving object the acceleration α_ζ whereof is determined.

Let's consider the peculiarities of a two-vessel device for determining the vertical acceleration α_η (FIG. 2):

• the inner cavities (as well as their contours) are counter-oriented unlike the devices for determining the horizontal acceleration along the vertical and not along the horizontal;
• presence, irrespective of tilting, of the outermost (along the horizontal) points E₁ and E₂, E₃ and E₄, the location, by way of example, of the points for determining pressure L₃ and L₄ on the straight lines E₁E₂, E₃E₄, correspondingly, when choosing E₁L₃=E₃L₄, E₂L₃=E₄L₄ are considered to prevent any harmful influence of the horizontal acceleration ( in our example, α_ξ);
• determination is made of the vertical acceleration α_η both according to the module and to the sign.

In two-vessel devices determining the acceleration (FIGS. 1, 2) use is made of the two pressure pickups with two sensitive elements of pressure (each pressure pickup having its sensitive clement of pressure). Therefore, it is necessary to choose the pressure pickups, the sensitive elements whereof having similar parameters, which is considered to be of some difficulty.

For preventing any harmful influence of the parameters spread of sensitive elements of pressure the device is made for determining the acceleration with one sensitive element of pressure in the form of the flexible diaphragm with holes (FIGS. 3, 4.).

In FIG. 3 there is shown a one-vessel device for determining the horizontal acceleration (α_ξ or α_ζ), and in FIG. 4—a one-vessel device for determining the vertical acceleration (α_η).

Each of said devices is made in the form of one vessel, the inner cavities 1₅ and 1₆ whereof being in the form of hemispheres are separated by a flexible diaphragm (4₁ and 4₂) with holes (presence of holes is shown by dotted line).

Said diaphragm and the walls of the inner cavities located on either side therefrom are electrically insulated from each other and are electrodes of two capacitors. Said capacitors are included in some neighboring arms of said bridge the elements with electrical resistances of the equal value are included, which is more preferable.

Said diaphragm is like an aggregate of plurality of pairs of the points to be similarly located on either side therefrom. Since the thickness of said diaphragm is considered to be insignificant, then geometrically each pair of the points of that kind can be considered as one point (though physically these are different points since they are located in different hemispheres). Therefore, with tilting, the points of each said pair are acted upon by the columns of similar length. Due to that, with tilting, said diaphragm is not expected to change its position (is not deflected).

Under the influence of the acceleration to be determined the difference of pressure is created, as a consequence, said diaphragm is deflected. Herewith, capacitance of one capacitor increases and of another decreases, correspondingly. As a consequence, at the output of said electrical bridge there occurs voltage proportional to the acceleration determined.

Since every point for determining pressure (on the diaphragm) is acted upon by the pressure of filling the vessel with the flowing media and the pressure caused by the column of this media located over this point, then the sensitivity thread of each device provided is equal to zero (thus, it is not necessary to overcome non-sensitivity zone). This means that the most insignificant acceleration causes the signal at the output of the differential scheme.

Since the inner cavities of the vessels (vessel) are similar, the location of the points of determining the pressure in them is similar and use is made of the differential scheme, then not only cross accelerations but also other disturbance factors (in particular, vibrations and temperature changes) are not considered to cause any harmful influence on the accuracy of determining the acceleration.

Since with tilting (relative to the horizontal plane) at the angles ν≈45° and more the device for determining the horizontal acceleration turns into the device for determining the vertical acceleration and, vice versa, then the joint application of said devices with corresponding displacement of the outermost points one relative to another enables it to accurately determine the acceleration (both horizontal and vertical) irrespective of tilting practically within the range of 360°, i.e. with any tilting.

The operation of the technical solution provided is based on determining the pressures difference determined in particular points of the flowing media, providing the signals of said pressures to said differential scheme and taking off the signal of the acceleration determined from the output of said scheme.

Considerable differences of the technical solution provided compared with the prior art are as follows:

• the inner cavity of the vessel in a two-vessel device is considered to consist of two counter-oriented spherical parts (contours) of different radii;
• use is made, in particular, of the centers of said spherical parts as points of determining the pressure in a two-vessel device;
• counter-orientation of the inner cavities of the vessels (in a two-vessel device) is made by means of the location of said spherical parts of one and the same radius on either side from the centers of said parts;
• the inner cavities of a one-vessel device are made in the form of two hemispheres separated by a flexible diaphragm with the holes.

Claims

1. Device for determining acceleration comprising of interconnected: two hollow sealed vessels fastened on the platform, in particular, on the body of a moving object, filled with the flowing media, containing two, predominantly similar, counter-oriented inner cavities, each whereof comprising two counter-oriented, spherical parts of different radii, in particular, with the common center, having on its surface in the plane passing through said center and through the vertical axis of a moving object, in particular, through the line parallel to said axis, two points being opposite located, being the outermost along the axis perpendicular to said axis, wherealong the acceleration to be determined, remaining as said, the outermost points with tilting in the operating condition,two pressure pickups connected with the vessels, as points of determining pressure whereof use being used of the points, in particular, similarly located in the inner cavities of the vessels on the straight lines connecting the corresponding outermost points,a differential scheme switched to the pressure pickups, the output wherefrom the signal of the acceleration determined being taken off.

2. Device as set forth in claim 1, wherein said counter-orientation of the inner cavities of the vessels being implemented by the location of the spherical parts of said cavities of one and the same radius on either side from the centers of said spherical parts.

3. Device for determining acceleration comprising interconnected: a sealed hollow vessel fastened on the platform, in particular, on the body of a moving object filled with flowing media, the inner cavities whereof in the form of two hemispheres being separated by the diaphragm with holes,two pressure pickups being capacitors, the electrodes whereof being said diaphragm and the walls of said inner cavities located on either side thereof, the former and the latter being electrically insulated from each other,a differential scheme, in particular, an electrical bridge fed by the electrical voltage through the input diagonal, into some neighboring arms whereof said capacitors being included, and into the other neighboring arms elements with predominantly similar electrical resistances being included, correspondingly, from the output whereof through the output diagonal the signal of the acceleration determined being taken off.