RU225965U1 - Gyroinertial block - Google Patents

Abstract

The utility model relates to the field of measurement technology, namely to the gyroinertial unit of a strapdown inertial navigation system for object control. The gyroinertial unit contains a housing in which a secondary power source, a linear acceleration measuring device, and an angular velocity measuring device are fixed, which are combined into a sensor unit. The linear acceleration measuring device consists of three compensation-type pendulum accelerometers. In order to minimize the device, the secondary power source is built into the housing of the gyroinertial sensor unit. The angular velocity measuring device consists of two dynamically adjustable gyroscopes with a sensitive element in the form of a flywheel and a suspension unit designed to ensure monolithic embedding of torsion bars from a single workpiece using the electroerosive method. The gyro-inertial unit additionally includes a discriminator amplifier, an eight-channel converter, an acceleration unit, load resistors and small-sized shock absorbers. The discriminator amplifier is made in the form of a four-channel amplifier, which is a board with discrete elements. The eight-channel converter is a board with eight channel microcircuits for converting analog signals from accelerometers and a temperature sensor, angular velocity sensors and a temperature sensor, a microcircuit for organizing digital exchange, an optoelectronic relay for switching channel scales and carrying out built-in control, and supply voltage stabilizers for analog and digital microcircuits. The overclocking unit is a board with a static voltage converter from a secondary DC power supply to AC voltage and controllers.

Description

The utility model relates to the field of inertial navigation, namely to the gyro-inertial unit of strapdown inertial navigation devices for automatic control of the movement of objects.

The prior art in this field is characterized by the following information.

From the RF patent for invention No. 2117250 (priority date 08/10/1998) a method is known for measuring the coordinates of an operator’s helmet with an inertial system containing a gyroinertial unit consisting of three angular velocity sensors and three accelerometers.

The disadvantage of such a gyroinertial unit is that it does not provide stable operation during vibration under acceleration conditions.

From the RF utility model patent No. 134314 (priority date 03/05/2013) a hybrid gyroscope is known as part of a strapdown inertial navigation system, which includes a block of sensitive elements on a fiber-optic circuit, an accelerometer and a micromechanical angular velocity sensor.

The utility model allows us to solve the problem of stability of operation under conditions of large shock mechanical loads.

The disadvantage of this technical solution is that it is not aimed at ensuring stability during vibration under acceleration conditions.

From the PRC patent CN No. 212903235 (priority dated 06/04/2021) a miniature inertial measurement unit for inertial measurement systems is known, which contains a supporting frame with an outer wall equipped with four protrusions connected in series to form a tetrahedron, three fiber-optic gyroscopes, two of which installed on the outer wall of the supporting frame, and another gyroscope is mounted on one of the protrusions. On the inside of the supporting frame there are ceramic spacers on which three accelerometers are located orthogonal to each other in space.

On four protrusions, connected in series to form a tetrahedron, damping (vibration-absorbing) pads are installed, forming four-point damping (attenuation) of vibration in space, where the center of mass of the measuring unit, the center of four-point damping in space, the intersection of the main axes of three accelerometers and the intersection of the normals of three fibers -optical gyroscopes are located at the same point.

The disadvantage of such a device is the complex design of the measuring unit.

It is known that vibration damping is the artificial suppression of vibrations of mechanical, electrical and other systems. Damping can be carried out by increasing attenuation, for which dampers are installed on the system (for example, pistons moving in a viscous medium). Another damping method consists of suppressing oscillations of a certain frequency using an additional oscillatory system tuned to this frequency and creating a force equal in magnitude to the force causing the oscillations (Great Soviet Encyclopedia. - M.: Soviet Encyclopedia, 1969-1978; http:// www.help-rus-student.ru/text/22/723.htm).

However, vibration under acceleration conditions can increase 50 times, and to suppress such vibrations to ensure normal uninterrupted operation of the device, damping may not be enough, and in the event of vibrations at high speeds, there is a high risk of premature failure of both dampers and and the device itself.

Thus, damping, without optimizing weight and size characteristics, cannot ensure the accuracy of measurement of motion parameters and stable operation of the gyro-inertial unit during vibration under acceleration conditions.

From the RF patent No. 2704198 (priority dated March 28, 2019), an inertial unit is known, which is part of the strapdown inertial system (SINS). The inertial block is made in the form of a monoblock with a sealed lid and a mounting frame. The monoblock is equipped with fixing elements for securing the monoblock to the mounting frame.

The monoblock body has a handle on the outer surface for carrying and moving the monoblock in the mounting frame and connecting elements for electrical connection of the functional elements of the SINS with external devices.

The functional elements are located inside the inertial monoblock and are made in the form of an interconnected block of sensitive elements, a sensor signal converter, at least one computer and a power source.

The internal cavity of the inertial block contains first and second compartments separated by a partition.

In the first compartment there is a block of sensitive elements, made in the form of a single cubic body with four planes sealed using covers.

In three mutually orthogonal planes there are rectangular ring lasers with functional electronics of a laser gyroscope, and in the fourth there is a high-voltage voltage source, a device for regulating the perimeter and monitoring of laser gyroscopes, as well as a block of three accelerometers located in a single housing.

The housing of the sensor block is closed from the outside with magnetic screens and is equipped with shock absorbers for attachment to the walls of the inertial monoblock.

The second compartment contains a secondary power supply, a sensor signal converter and a computer.

The disadvantage of such a system is the low accuracy of measuring motion parameters due to the complexity of the design, significant dimensions and weight, which leads to low resistance to external influences, especially vibrations under acceleration conditions.

From the RF patent No. 2430333 (priority dated June 21, 2010) a device for measuring linear acceleration for a navigation system with three sensitive elements located along three mutually perpendicular axes is known, a device for measuring angular velocity with three fiber-optic channels located along three mutually perpendicular axes,

Gyroscopes in the navigation system are located on the side of two adjacent side faces and the top edge of the body. Gyroscopes and accelerometers are fixed in the housing on base surfaces.

Adjacent side faces of the housing are equipped with protective casings designed to accommodate gyroscopes and accelerometers.

The disadvantages of such a device are the low accuracy of measuring motion parameters and low resistance to external influences.

The lack of orthogonality of the base surfaces of the housing due to the complex design leads to a decrease in measurement accuracy.

All of the above design flaws do not allow for accurate measurement of motion parameters during vibration under acceleration conditions.

The closest analogue of the claimed device is the sensor unit from RF patent No. 2771790 (priority dated May 21, 2021), which is part of a strapdown inertial navigation control system.

The sensor block includes a linear acceleration measuring device with three sensitive elements located along three mutually perpendicular axes and an angular velocity measuring device with three fiber-optic channels located along three mutually perpendicular axes and a data acquisition unit.

The angular velocity measuring device is fixed on one side of a rigid load-bearing base made in the form of a disk, and on its reverse side there is a linear acceleration measuring device with a data collection unit, which are combined into a sensor unit with the condition of ensuring parallelism of the measuring axes of the linear acceleration measuring device, measuring device angular velocity and sensor unit.

Executing the sensor block on a rigid supporting base, on one side of which there is a device for measuring angular velocity, and on the reverse side, a linear acceleration device with a data collection unit, which are combined into a sensor block, with the condition that the measuring axes of the device are parallel between these devices, allows you to reduce the error misorientation of measuring axes and increase the accuracy of conversion of motion parameters.

Making the load-bearing base in the form of a disk and securing the measuring devices and data collection unit on the load-bearing base ensures the rigidity of the system structure due to the reliability of the structure's fastening.

The technical result is to increase the accuracy of measuring motion parameters while ensuring resistance to external influencing factors, such factors, thus eliminating side resonances at low frequencies and ensuring durability under conditions of broadband random vibration and mechanical shock.

The device for measuring angular velocity in the prototype uses a block of gyroscopes of the TIUS 500 brand and a block of accelerometers of the A-30C brand.

Accelerometers of this brand are highly impact resistant due to the fact that they have a bronze sensitive element, which worsens the weight and size characteristics of the device.

TIUS 500 gyroscopes are three-axis inferometric fiber-optic gyroscopes with a complex design. The gyroscope uses one emitter for three channels. All three gyroscope channels operate identically and independently of each other. The gyroscope also contains an electronics unit and a photodetector, which also worsens the weight and size characteristics.

The disadvantage of the prototype is also that in order to ensure the accuracy of measuring parameters in the design, the order of fastening and arrangement of all elements of the device relative to each other must be strictly observed, thereby ensuring the accuracy of measuring movement parameters.

Taking into account the shortcomings of the prototype, the task of the claimed device is to simplify the design of the device and minimize the weight and size characteristics, without losing the accuracy of measuring motion parameters and the stability of the device during vibration under acceleration conditions.

The technical result is to simplify the design of the device with a reduction in weight and size characteristics, without losing the accuracy of measuring motion parameters and the stability of the device during vibration under acceleration conditions.

The claimed device is a gyroinertial unit for a strapdown inertial navigation control system (BINSU) of an object, including a secondary power source, a linear acceleration measuring device and an angular velocity measuring device, combined into a sensor unit.

The device for measuring linear acceleration consists of three linear accelerometers of the compensation type with a sealed monoblock design, including an inertial mass in the form of a pendulum with an elastic suspension (spring) made of monocrystalline silicon, an inertial mass movement sensor and a magnetoelectric feedback amplifier with a corrective link.

The linear accelerometer is a pendulum accelerometer of the compensation type.

In such an accelerometer, under the action of acceleration, the inertial mass suspended on a spring made of monocrystalline silicon deviates from its original position. This deviation causes the capacitive bridge to become unbalanced. The imbalance in the form of an electrical signal enters the magnetoelectric feedback amplifier, which acts on the inertial mass with a force equal in magnitude but opposite in direction to the inertial force. The current in the feedback amplifier is proportional to the actual acceleration.

The angular velocity measuring device consists of biaxial angular velocity sensors (ARS) based on two dynamically adjustable gyroscopes (DNG) with a sensitive element in the form of a two-ring elastic suspension with rings of different diameters, made from a single workpiece using the electroerosive method and cantilever mounted on the drive motor shaft.

The sensitive element of the DNG, which is a flywheel, is connected to the axis of the drive motor through the chain “external elastic torsion bar - intermediate ring - internal elastic torsion bar”.

The flywheel is cantilever mounted on the drive motor shaft, which minimizes the influence of thermal fields and, in turn, ensures a stable position of the gyroscope's center of mass, which has a positive effect on the accuracy of measuring motion parameters during vibration under acceleration conditions.

Dynamically adjustable gyroscopes have miniature dimensions. The wire temperature sensor, located directly on the stator block of the angle and torque sensors, allows you to measure the temperature inside the gyroscope with an accuracy of 0.1 ° C.

DNG is functionally a GUS and belongs to the class of gyroscopes with an elastic (relative to the angles of rotation) connection of the mass of a rapidly rotating rotor with its shaft driven by an electric motor. In the design of the DNG, for such an elastic connection of the rotor with the shaft, the so-called internal cardan suspension in the form of a torsion bar system is used.

Dynamic tuning of the DNG consists of precise automatic adjustment of the angular speed of rotation of the rotor to the natural frequency of its oscillations on the shaft.

Dynamically adjustable gyroscopes offer several advantages over other types of gyroscopes.

Rational use of the device volume due to the transfer of the cardan suspension inside the flywheel-sensitive element (on the drive shaft) provides the DNG with smaller dimensions and weight (with equal kinetic moments.

The advantages of DNG also include high stability of characteristics and low cost.

A feature of such DNGs is the combination of size, weight, accuracy parameters, and a large range of measured angular velocities.

The design of such gyroscopes is sealed and highly resistant to mechanical stress.

All of the above advantages of such gyroscopes contribute to achieving the stated technical result.

To minimize the weight and size characteristics of the claimed device, the secondary power source is built into the body of the gyroinertial sensor unit.

The gyro-inertial unit also includes an amplifier-discriminator, which ensures operation of dynamically adjustable gyroscopes in a compensation mode, an eight-channel converter, an overclocking unit, as well as load resistors for retrieving information from sensors and small-sized ring-shaped shock absorbers.

The use of such shock absorbers can significantly reduce the resonance of the location of the primary information sensors, which has a positive effect on the accuracy of measuring motion parameters during vibration under acceleration conditions.

The discriminator amplifier is made in the form of a four-channel amplifier, which is a board with discrete elements, structurally separated into four independent channels with output transistors installed on heat sinks.

The eight-channel converter is a board with eight channel microcircuits for converting analog signals from accelerometers and a temperature sensor, angular velocity sensors and a temperature sensor, a microcircuit for organizing digital exchange, an optoelectronic relay for switching the scale of angular velocity channels and carrying out built-in monitoring, supply voltage stabilizers for analog and digital microcircuits.

The acceleration unit maintains synchronous speed of the gyroscope drive motors and is a board with a static voltage converter of the secondary DC power supply into alternating voltage and controllers that generate control signals to a two-channel three-phase generator to supply three-phase supply voltage to the gyroscope drive motors.

To minimize weight and size characteristics, a secondary power source is built into the body of the claimed device.

Figures 1-5 show drawings of a gyroinertial block.

Figure 1 shows a gyroinertial block, top view.

Figure 2 shows a gyroinertial block, front view.

Figure 3 shows a gyroinertial block, rear view.

Figure 4 shows a gyroinertial block, right view.

Figure 5 shows a gyroinertial block, left view.

Figure 6 shows a block diagram of the gyroinertial block, indicating the following positions:

1 - gyroinertial block;

2 - acceleration block;

3 - secondary power source;

4 - converter;

5 - sensor block;

6 - dynamically adjustable gyroscopes (2 pcs.);

7 - accelerometers (3 pcs.);

8 - amplifier-discriminator.

The operating principle of the claimed device is based on measuring the magnitude and direction of linear acceleration and angular velocity of an object to actually determine its position in space.

The use of linear accelerometers of the compensation type with a monoblock design in a device for measuring linear acceleration, in combination with other design features of the blocks of the claimed device, ensures the achievement of the declared technical result.

The advantages of such accelerometers are as follows:

- measurement range up to 100 g;

- stability of the zero signal is no more than 1.5×10 ^-3 g.

The principle of operation of the accelerometer is as follows. When exposed to linear acceleration, the silicon pendulum of the sensing element deviates on an elastic suspension from the equilibrium position. In this case, the capacitances between the pendulum and the metallization of the glass plates change. The imbalance of capacities is converted, amplified and normalized by an electronic converter.

Dynamically adjustable gyroscopes (DNG), for example brand DNG-2-1 and other similar types of gyroscopes, were selected as biaxial serial angular velocity sensors for the BGI sensors in the claimed device.

The DNG sensitive element contains an elastic suspension for monolithic embedding of torsion bars, connected to the axis of the drive motor through the chain “external elastic torsion bar - intermediate ring - internal elastic torsion bar”. The sensing element is fixed to the drive motor shaft, which minimizes the influence of thermal fields and, in turn, ensures a stable position of the gyroscope's center of mass.

The elastic suspension is made from a single piece using the electroerosive method in order to ensure monolithic sealing of the torsion bars.

Through the use of dynamically adjustable gyroscopes with this design, the strength characteristics of the claimed device are increased, the accuracy of measuring motion parameters during vibration under acceleration conditions is ensured, and also does not require a reduction in standard vibration accelerations in the range of 20-2000 Hz.

Other advantages of this type of DNG are:

- high accuracy characteristics (1-5°/h);

- manufacturability of the design;

- long service life (from 10,000 hours);

- increased reliability;

- ability to operate in a wide temperature range from -55 to 65°C;

- low power consumption.

The discriminator amplifier in the claimed device is a board on which discrete elements are located, and the output transistors of the channels are installed on heat sinks.

The discriminator amplifier is a four-channel feedback amplifier and provides:

- operation of DNG-2-1 in compensation mode together with load resistors located in the gyroinertial sensor unit;

- the strength of the output signals from the angular velocity sensors of the DNG, converting them into DC voltages and closing the negative feedback of the DUS (connection of the amplifier outputs with the torque sensors through load resistors);

- organization of stable operation of the DUS feedback loops and the required bandwidth (introduction of appropriate corrective links into the control loop).

The converter in the claimed device is an eight-channel converter and performs the following functions:

- conversion of analog DC signals from DUS and accelerometers into parallel code and transmission via a serial synchronous SPI interface;

- switching the scale of analog signals in DUS channels;

- carrying out “built-in control” of DUS channels;

- power supply, measurement and conversion of analog signals from temperature sensors of 2 gyroscopes and 3 accelerometers into parallel codes;

- organization of a stabilized reference voltage for integrated ADCs;

- formation of a clock frequency for the operation of conversion channel microcircuits;

- stabilized supply voltage to power the temperature measurement circuits of 2 gyroscopes.

Acceleration block.

The acceleration unit for maintaining synchronous speed of the gyroscope drive motors provides:

- programmable generation of three-phase supply voltages for DNG-2-1 drive motors;

- issuing a command to connect terminal stages (UOS) during the forced acceleration of the DNG-2-1 drive motors;

- maintaining the operating mode of drive motors;

- generation of built-in control voltages for monitoring DUS channels.

The overclocking unit in the claimed device is a board on which are located:

- static voltage converter of the secondary DC power source into alternating voltage, and then converting it into DC voltage to supply a three-phase generator and voltages for built-in monitoring;

- controllers that generate control signals for a two-channel three-phase generator that generates three-phase supply voltages for the motors of 2 gyroscopes.

The above design features of the claimed device provide optimal weight and size characteristics of the device and resistance to mechanical stress during vibration at a frequency of 1400 Hz under acceleration conditions.

Claims (1)

A gyroinertial block of a strapdown inertial navigation system for controlling an object, including a housing in which a secondary power source is fixed, a linear acceleration measuring device and an angular velocity measuring device, combined into a sensor unit, characterized in that the linear acceleration measuring device consists of three compensation-type pendulum accelerometers with sealed monoblock design containing an inertial mass in the form of a pendulum with an elastic suspension made of monocrystalline silicon, an inertial mass movement sensor and a magnetoelectric feedback amplifier with a corrective element, the angular velocity measuring device consists of biaxial angular velocity sensors based on two dynamically adjustable gyroscopes with a sensitive element in in the form of a two-ring elastic suspension with rings of different diameters, made from a single workpiece using the electroerosive method and cantilever mounted on the drive motor shaft, and the secondary power source, to minimize the weight and size characteristics of the device, is built into the housing of the gyroinertial sensor unit, while the gyroinertial unit additionally includes load resistors for collecting information from sensors, an amplifier-discriminator to support the operation of dynamically adjustable gyroscopes in compensation mode, an eight-channel converter, an acceleration unit and small-sized ring-shaped shock absorbers, where the amplifier-discriminator is made in the form of a four-channel amplifier, which is a board with discrete elements, structurally divided into four independent channels with channel output transistors installed on heat sinks, an eight-channel converter is a board with eight channel microcircuits for converting analog signals from accelerometers and a temperature sensor, dynamically adjustable gyroscopes and a temperature sensor, a microcircuit for organizing digital exchange, an optoelectronic relay for switching the scale of angular velocity and conductivity channels built-in control, voltage stabilizers for analog and digital microcircuits, the acceleration unit maintains synchronous speed of the gyroscope drive motors and is a board with a static voltage converter of the secondary DC power source into alternating voltage and controllers.