SU1679395A1 - Compensatory pendulous accelerometer - Google Patents

Abstract

This invention relates to compensatory linear accelerometers intended for operation as part of inertial navigation systems. The purpose of the invention is to improve the accuracy of measurement of accelerations. During the measurement of the accelerations, the silicon base of the sensing element is deflected. This changes the capacitance of the angle sensor formed by the base and the electrodes located on the housing rings. In the process of assembling, the electrodes — sectors of the tuning capacitances located on the plates of the outer ends of the magnetic conductors, are disconnected by removing the jumpers between them. The output of the angle sensor through the electronic amplifier is fed as a feedback current to the coils of the torque sensor. As a result, the sensing element returns to its original position. 5 hp f-ly, 9 ill.

Description

(L

with

The invention relates to the measurement of motion parameters, in particular, to compensating linear acceleration meters, intended for operation as part of inertial navigation systems.

The purpose of the invention is to improve the accuracy of measurement of accelerations.

FIG. 1 shows the proposed accelerometer; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one; in fig. 4 — accelerometer, embodiment; in fig. 5 shows a section B-B in FIG. one; in fig. 6 - connection of case rings with racks; in fig. 7 is a view of D in FIG. four; in fig. 8 - case ring, embodiment, section EE; in fig. 9 is an electrical diagram of an accelerometer angle sensor.

The accelerometer has a split housing consisting of two halves 1 and 2, an antenna sensitive element 3, beams 4 of the elastic suspension of the sensitive element, carrier frame 5 and case rings 6 and 7. The base 8 of the sensitive element, beam 4 of the elastic suspension and carrier frame 5 made of a single plate of silicon single crystal. Body rings 6 and 7 are made of sitala or policor - materials that have the same coefficient of thermal expansion as silicon.

The silicon base 8 of the sensing element 3 is a moving electrode (rotor) of a capacitive angle sensor. Stationary (stator) electrodes 9 and 10 are U-shaped. form and are located on the body rings 6 and 7, respectively, on the side facing the base 8 of the sensing element. Sital (policore) is a dielectric, and electrodes 9 and 10 are formed by spraying a metal (for example, VI

measures, nickel, aluminum, gold) on the surface of the body rings.

The carrier frame 5 is based on the body rings 6 and 7 by means of a plate 11 having a height of 15-20 µm. The upper planes of the plates 11 are covered with a soft metal, for example, gold. The accelerometer case rings are interconnected by racks 12 of a sieve (policor) and have openings 13 located opposite the technological jumpers 14. Rings 6 and 7 are in contact with halves 1 and 2 of the split housing along elevation planes 15. On hull rings 6 and 7 on the side opposite to the base 8 of the sensing element, there are electrodes - platics 16 tuning capacitors. They are connected to common conductor 17 by breakable junctions 18 and are connected in parallel with the working capacitance of the angle sensor.

On the basis of the 8 sensitive element 3 through the transition sleeve 19 installed coil 20 and 21 of the magnetoelectric moment sensor. The feedback current to the moving coils 20 and 21 is supplied through conductors 22 sprayed through the beams 4 of the elastic suspension. An embodiment of the conductors 22 in the form of free-hanging strip current leads is also possible. The sensor stators are formed by permanent magnets 23 and 24, pole pieces 25 and 26, and magnetic conductors, which are the halves 1 and 2 of a detachable accelerometer housing. The electrode sectors 27 of the tuning capacitors are located on the boards 28 fastened at the outer ends of the magnetic conductors. The second electrode of the tuning capacitance is the magnetic circuit (Fig. 6). The halves 1 and 2 of the split housing of the device have through holes 29 located (as well as holes 13 in rings 6 and 7) opposite technological jumpers 14.

The halves of the accelerometer case with an appropriate assembly between them (consisting of case rings B and 7, struts 12, carrier frame 5 and sensor 3) are interconnected into a single whole by known methods: either a ring or a special sleeve (3, 4 ),

The output of the angle sensor through the electronic amplifier 27 is supplied as a feedback current to the coils 20 and 21 of the torque sensor.

The accelerometer works as follows.

In the presence of output acceleration and on the measuring axis rj of the instrument, the end sensor 3 is deflected under the action of the inertial moment m | a

The successively included angle sensors, amplifier 30 and moment sensor create moment balancing inertia. A voltage drop across the reference resistor, NET, is an accelerometer output signal.

A feature of the assembly and adjustment of the accelerometer is the following.

On the silicon part (containing

0 frame 5, base 8, beams 4 and intact technological jumpers 14), and more specifically, base sleeves 19c are mounted on the sleeves 19c with coils 20 and 21 fixed to them. Next, torque sensor electrical circuit is made: conductor 22 - coil 20 - coil 21 - conductor 22 (Fig. 5).

A casing ring 7, three

0 stand 12, silicon part with assembled

sensitive element and body

ring 6. Thermocompressor welding

racks 12 are welded with rings b and 7.

A constructive option is possible for the extraction of the body ring 6 (7), in which the place of contact of the ring with the plate 11 of the silicon carrier frame 5 is made according to FIG. eight

Bearing frame 5 is spring loaded

0 between the body rings 6 and 7 due to the elastic deformations of the cantilever projections cut into the rings. These elastic deformations occur during the execution of the technological operation of thermocompression welding of the body rings 6 and 7 and the uprights 12 into a single assembly.

Hour 12 (Fig. 6) is made in the form of three cantilever protrusions connected by a common base. When carrying out thermocomplex welding welding, the cantilever protrusions are forcibly moved apart, and after the end of this technological operation the protrusions are compressed, shrinking the housing rings b and 7 and located between them

5 frame 5.

In the first version of the accelerometer according to the invention, the node of the math sensor with the angle sensor assembled in this way is mounted vertically.

0 (the p axis is downward), the angle sensor circuit is energized and the minimum (zero) signal of the angle sensor is tuned by destroying the transitions 18.

Thereafter, technological jumpers 14 are burned through the holes 13 in the core rings.

In the second version of the accelerometer, after the instrument is assembled, the accelerometer is installed with the p axis downward and destruction

transitions 18 between sectors 27 and common conductor 17 (FIG. 7), an angle sensor is configured. After that, technological openings 14 are burned through holes 29 and 13 and the accelerometer is finally assembled.

Thus, the proposed accelerometer makes it possible to combine the position of the sensing element, in which the beams of its elastic suspension are undefermented, with the position in which the angle sensor has a zero signal. This improves the accuracy of the accelerometer.

Claims (6)

Claim 1. Compensation accelerometer accelerometer containing a split housing made in the form of two magnetic systems, located on it on an elastic beam suspension pendulum plate sensing element, differential capacitive angle sensor with rotary and stator plates, reverse-booster amplifier zi and dual magnetoelectric torque sensor, while the base of the sensing element, the beams of the elastic suspension and the frame are made of a single plate of material with a small hysteresis and the frame is installed in the half of the body through case rings made of a material with the same coefficient of temperature expansion as the sensitive element plate, characterized in that, in order to improve the measurement accuracy, the sensitive element plate is made of monocrystalline silicon. , 25 23 go 16 / ZY case rings are interconnected by pillars, the stator electrodes of a capacitive angle sensor are located on the case rings on the side facing the base of the sensing element; capacitance of the angle sensor, and the electrodes of the tuning tanks are made in the form of plates connected to the common conductor by a breakable junction E. 2. The accelerometer according to claim 1, which differs from the fact that the electrodes of the tuning capacitances are located on boards of dielectric, mounted on the outer ends of the magnetic systems, and the response electrodes of the tuning capacitances are the magnetic systems of the torque sensor. 3. Accelerometer on PP. 1 and 2, characterized in that three cantilever protrusions on which the frame is based are made in the body rings. 4. Accelerometer on PP. 1 and 2, characterized in that. that the stands are made in the form of three cantilever protrusions connected by a common base on which the housing rings are based. 5. An accelerometer according to claim 1, characterized in that the body rings and racks are made of steel. 6. The accelerometer according to claim 1, characterized in that the body rings and racks are made of policor. figure 1 P Yg "5 / W L Fig Fie.8