A miniaturized micro inertial north finder

Abstract

This invention discloses a miniaturized micro-inertial north-finding instrument. The housing comprises three parts: a top cover, a base, and an aviation connector. A conductive slip ring is disposed at the lower part of the top cover and is connected to the rotation shaft of the rotor cover of the rotary drive structure through a circular hole, and is connected to the control circuit via wires. The rotary drive structure is disposed below the conductive slip ring and includes a rotor cover, an inertial device support, a rotor support, an inertial device, a coggingless motor, and an angular displacement sensor. The control circuit includes a data acquisition circuit and a motor drive circuit. The data acquisition circuit is connected to the inertial device to collect and transmit the output data of the inertial device, and the motor drive circuit is connected to the conductive slip ring to control and power the coggingless motor. This invention reduces the size of the north-finding instrument, making it more suitable for applications such as vehicle navigation, underground surveying, and weapon guidance. Furthermore, it allows for individual replacement, facilitating equipment inspection and maintenance.

Description

Technical Field

[0001] This invention relates to navigation and positioning technology, specifically to a low-cost, portable, miniaturized north-finding instrument. Background Technology

[0002] High-precision navigation and positioning technology is widely used in various military and civilian fields, and is a key technology for precise guidance of intelligent weapons, efficient military deployment, and convenient civilian production and services. However, current high-precision navigation and positioning technologies rely on satellite signal input, and cannot accurately obtain azimuth information in environments where GPS navigation information is lost, resulting in application blind spots. Gyro-based north-finding instruments, as autonomous navigation instruments that do not rely on external references and do not transmit information to the outside world, have advantages such as high accuracy and immunity to environmental factors. They can be used for initial alignment and direction control of various equipment, as well as as inertial navigation information references, thus serving as a supplement to satellite positioning and navigation. Existing gyro-based north-finding instruments mainly include fiber optic gyro-based north-finding instruments, laser gyro-based north-finding instruments, and MEMS gyro-based north-finding instruments. Among them, laser gyro and fiber optic gyro-based north-finding instruments are less affected by external factors and have higher accuracy, but are expensive and heavy. MEMS gyro-based north-finding instruments have advantages such as high reliability, low power consumption, and low cost, but their accuracy is lower and cannot be directly applied to applications requiring high north-finding accuracy. Currently, to address the low accuracy of MEMS gyroscopes, rotation modulation technology is generally used to cancel out system errors within one rotation cycle, thereby improving north-finding accuracy. However, because the inertial components and motor drive modules of current north-finding instruments are separated, it is difficult to further reduce the system size and weight. Summary of the Invention

[0003] The purpose of this invention is to propose a miniaturized micro-inertial north finder.

[0004] The technical solution to achieve the purpose of this invention is: a miniaturized micro-inertial north finder, comprising four parts: a housing, a conductive slip ring, a control circuit, and a rotation drive structure, wherein:

[0005] The housing consists of three parts: a top cover, a base, and an aviation connector. The aviation connector is located on the side of the base, and the top cover and base are closed to form a whole.

[0006] The conductive slip ring is located at the bottom of the top cover and is connected to the rotating shaft of the rotor cover of the rotary drive structure through a circular hole on it. It is also connected to the control circuit through a wire.

[0007] The rotary drive structure is located below the conductive slip ring and includes a rotor cover, an inertial device support, a rotor support, an inertial device, a coggingless motor, and an angular displacement sensor. The rotor cover is positioned on top of the rotary drive structure and is connected to the conductive slip ring via a rotating shaft on its upper surface. It is fixed to the conductive slip ring through an outer frustum mounting hole and connected to the rotor support frame mounting hole through a central circumferential mounting hole. The inertial device support is located inside the rotor support frame and is connected to the bottom of the rotor support frame through a mounting hole. The rotor support is located inside the coggingless motor, with its bottom central shaft... The rotor bracket is connected to the base's circular hole. The inner ring at the bottom of the rotor bracket is set as the permanent magnet of the slotless motor rotor. The slotless motor is placed on the upper part of the base and is used to drive the rotor and the inertial devices inside the rotor to rotate. The slotless motor includes an outer circumference, an outer ring, and an inner ring. The outer circumference is the stator coil winding, the outer ring is a heat insulation layer for heat dissipation, and the inner ring is the stator core. The angular displacement sensor includes an angle measuring rotor and an angle measuring stator. The angle measuring rotor is placed in the mounting positioning groove at the large circular ring of the rotor bracket, and the angle measuring stator is fixed through the mounting hole at the bottom of the base. It is used to synchronously detect the rotation status of the motor by the angle measuring rotor.

[0008] The control circuit includes a data acquisition circuit and a motor drive circuit. The data acquisition circuit is connected to the inertial device and is used to acquire and transmit the output data of the inertial device. The motor drive circuit is connected to the conductive slip ring and is used to control and power the coggingless motor.

[0009] Furthermore, the top cover is connected to the base through mounting holes. The base is provided with a wiring groove for connecting the motor drive circuit and the conductive slip ring through wires, and for transmitting data with external devices through an aviation plug.

[0010] Furthermore, the inertial device includes a gyroscope and two accelerometers. The sensitive axis of the gyroscope is parallel to the horizontal plane and is placed on the inner wall of the inertial device support, perpendicular to the two accelerometers. The sensitive axes of the two accelerometers are both parallel to the horizontal plane and orthogonal to each other, and are placed on the upper surface of the inertial device support.

[0011] Furthermore, the data acquisition circuit includes a gyroscope data acquisition circuit and an accelerometer data acquisition circuit. The gyroscope data acquisition circuit includes a gyroscope and its peripheral measurement and control circuit, which is connected to the conductive slide via a wire through the groove on the rotor cover. It is located on the inner wall of the inertial device support and is used to power the gyroscope and transmit data. The accelerometer data acquisition circuit includes an accelerometer and its peripheral measurement and control circuit, which is connected to the gyroscope data acquisition circuit via a wire. It is located on the upper surface of the inertial device support and is used to power the accelerometer and transmit data.

[0012] Furthermore, the motor drive circuit is located in the groove at the bottom of the base, and mounting holes are provided at its four corners to fix it to the base.

[0013] Furthermore, the stator core of the slotless motor rotor is made of soft magnetic ferrite ring, and the permanent magnet of the slotless motor rotor is made of titanium iron boron permanent magnet ring.

[0014] Furthermore, after connecting to external devices via an aviation connector, the conductive slip ring is powered. The conductive slip ring powers the data acquisition circuit and inertial devices via wires. According to the transmitted motor control commands, the motor drive circuit controls the cogless motor to rotate. The rotation of the motor drives the rotor and the inertial devices and angle measuring rotor inside the rotor to rotate. The data from the inertial devices and angle measuring rotor is collected by the data acquisition circuit and transmitted to the motor drive circuit for data processing. The processed data is then transmitted to external devices via the aviation connector.

[0015] Compared with the prior art, the significant advantages of this invention are: by adopting an integrated structure of inertial support frame, rotor and cogless motor, the size of the north-finding instrument is reduced, making it more suitable for vehicle navigation, underground surveying and weapon guidance; by adopting separate assembly of inertial devices, rotating structure and motor control circuit, they can be replaced individually, which is beneficial for equipment inspection and maintenance. Attached Figure Description

[0016] Figure 1 This is an overall structural diagram of a miniaturized micro-inertial north finder according to the present invention.

[0017] Figure 2 This is a structural diagram of the rotor cover of a miniaturized micro-inertial north finder according to the present invention.

[0018] Figure 3 This is a bottom structural diagram of the rotor support frame of a miniaturized micro inertial north finder according to the present invention.

[0019] Figure 4 This is a structural diagram of the base and motor circuit components of a miniaturized micro inertial north finder according to the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] like Figure 1 As shown, the present invention provides a miniaturized micro inertial north finder, which comprises four parts: a housing, a conductive slip ring 101, a rotary drive structure, and a control circuit.

[0022] The housing comprises three parts: a top cover 201, a base 202, and an aviation connector 203. The aviation connector 203 is located on the side of the base 202. The top cover 201 and the base 202 are closed to form a whole. A conductive slip ring 101 is located at the lower part of the top cover 201 and is connected to the rotor cover rotation shaft 1101 through a round hole to supply power to the control circuit. The control circuit is connected to the conductive slip ring 101 through wires and uses feedback data from inertial devices and motors to realize closed-loop drive control of the motor. The control circuit includes a data acquisition circuit 150 and a motor drive circuit 141. The rotary drive structure includes a rotor cover 111, an inertial device support 123, a rotor support 124, an inertial device, a cogless motor 160, and an angular displacement sensor. This rotary drive structure is located below the conductive slip ring 101, is connected to the conductive slip ring 101 through the rotor cover rotation shaft 1101, and is connected to the base 202 through the central shaft 117 of the rotor support.

[0023] In the above embodiment, the control circuit includes a data acquisition circuit 150 and a motor drive circuit 141. The data acquisition circuit 150 is used to acquire and transmit the output data of the inertial device, and the motor drive circuit 141 is used to control the rotation of the motor. The data acquisition circuit 150 includes a gyroscope data acquisition circuit 121 and an accelerometer data acquisition circuit 122. The sensitive axis of the gyroscope is parallel to the horizontal plane and is placed on the inner wall of the inertial device support 123, perpendicular to the two accelerometers. The gyroscope data acquisition circuit 121 includes the gyroscope and its peripheral measurement and control circuit, through... A wire is connected to a conductive slip ring 101 via a groove 1102 on the rotor cover and is located on the inner wall of the inertial device support 123. This wire powers the high-precision gyroscope and transmits data. The sensitive axes of the two accelerometers are parallel to the horizontal plane and orthogonal to each other, and are placed on the upper surface of the inertial device support 123. The accelerometer data acquisition circuit 122 includes the accelerometer and its peripheral measurement and control circuit, and is connected to the gyroscope data acquisition circuit 121 via a wire. Located on the upper surface of the inertial device support 123, it powers the accelerometer and transmits data. The motor drive circuit 141, as shown... Figure 4 As shown, the groove 125 at the lower part of the base has mounting holes at its four corners. It is fixed to the base 202 through the mounting holes and connected to the conductive slip ring 101 through the wires. It is used to control and power the cogless motor 160.

[0024] In the above embodiments, the rotor cover 111 in the rotary drive structure, as shown... Figure 2As shown, the rotor cover 111, located on top of the rotary drive structure, is connected to the conductive slip ring 101 via the upper surface rotation shaft 1101, fixed to the conductive slip ring 101 via the mounting hole of the outer frustum 1103, and connected to the mounting hole of the rotor support frame 124 via the central circumferential mounting hole; the inertial device bracket 123 is located inside the rotor support frame 124 and is connected to the bottom of the rotor support frame 124 via a mounting hole; the rotor bracket 124, as shown... Figure 3 As shown, the central shaft 117 at the bottom of the slotless motor 160 is connected to the circular hole of the base 202 inside the slotless motor 160. The inner ring at the bottom of the rotor support 124 is set as the permanent magnet 134 of the slotless motor rotor. The slotless motor 160 is placed on the upper part of the base 202 and is used to drive the rotor and the inertial devices inside the rotor to rotate. The slotless motor 160 includes an outer periphery, an outer ring, and an inner ring. The outer periphery is the stator coil winding 133, the outer ring is the heat insulation layer 132 for heat dissipation, and the inner ring is the stator core 131. The control circuit receives commands through signal lines to control the rotation of the slotless motor 160.

[0025] The angular displacement sensor includes an angle-measuring rotor 143 and an angle-measuring stator 142. The angle-measuring rotor 143, as shown... Figure 3 As shown, the mounting and positioning slot is located at the large annulus of the rotor support 124, and the angle measuring stator 142 is placed on the upper surface of the motor drive circuit, as shown. Figure 4 As shown, the base 202 is fixed through the mounting holes at the bottom and is used to detect the rotation state of the motor with the angle measuring rotor; the angle displacement sensor adopts a grating structure, and the relative position between the angle measuring rotor 143 and the angle measuring stator 142 can be adjusted appropriately;

[0026] In the above embodiment, a soft magnetic ferrite ring is used as the stator core 131 of the motor, and the inner ring permanent magnet 134 at the bottom of the rotor support is a titanium iron boron permanent magnet ring. The slotless motor 160 uses an angular displacement sensor to measure the angle of the rotor 143, thereby determining the correct conduction state of the stator winding. The motor is controlled by the motor drive circuit 141 to generate a stable and continuous electromagnetic torque. The inner ring permanent magnet 134 at the bottom of the rotor support drives the rotation drive structure to rotate. The error of the MEMS gyroscope is reduced by the rotation modulation technology, and the north-finding accuracy is improved.

[0027] The rotor support 124 and the rotor cover 111 are closed to form an integral whole and are located inside the slotless motor 160. The inertial device support 123 is disposed inside the rotor whole. When the rotor rotates, it drives the inertial device support 123 and its internal inertial devices to rotate simultaneously.

[0028] The top cover 201 is connected to the base 202 through mounting holes. The base 202 is provided with a wiring groove for connecting the motor drive circuit 141 and the conductive slip ring 101 through wires and transmitting data with external devices through the aviation plug 203.

[0029] In this embodiment, the conductive slip ring 101 is powered by connecting to an external device via an aviation connector 203. The conductive slip ring 101 powers the gyroscope data acquisition circuit 121, the accelerometer data acquisition circuit 122, and the inertial device via wires. According to the transmitted motor control command, the motor drive circuit 141 controls the cogless motor 160 to rotate. The rotation of the motor drives the rotor and the inertial device and the angle measuring rotor 142 inside the rotor to rotate. The data from the inertial device and the angle measuring rotor 143 are collected by the gyroscope and accelerometer data acquisition circuits 121 and 122 and transmitted to the motor drive circuit 141 for data processing. The processed data is transmitted to the external device via the aviation connector 203. This data is input into the north-finding algorithm to calculate the azimuth information, thereby achieving assisted navigation in tunnels and underwater environments without satellite signals.

[0030] It should be understood that the north-finding algorithm in this embodiment can be completed using two-position, four-position, multi-position, continuous rotation, and other schemes.

[0031] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0032] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A miniaturized micro-inertial north finder, characterized in that, It consists of four parts: housing, conductive slip ring, control circuit, and rotary drive structure, among which: The housing consists of three parts: a top cover, a base, and an aviation connector. The aviation connector is located on the side of the base, and the top cover and base are closed to form a whole. The conductive slip ring is located at the bottom of the top cover and is connected to the rotating shaft of the rotor cover of the rotary drive structure through a circular hole on it. It is also connected to the control circuit through a wire. The rotary drive structure is located below the conductive slip ring and includes a rotor cover, an inertial device support, a rotor support, an inertial device, a coggingless motor, and an angular displacement sensor. The rotor cover is positioned on top of the rotary drive structure and is connected to the conductive slip ring via a rotating shaft on its upper surface. It is fixed to the conductive slip ring through an outer frustum mounting hole and connected to the rotor support mounting hole through a central circumferential mounting hole. The inertial device support is located inside the rotor support and is connected to the bottom of the rotor support through a mounting hole. The rotor support is located inside the coggingless motor, and its bottom central axis is connected to... The base has a circular hole connection, and the inner ring at the bottom of the rotor support is set as the permanent magnet of the slotless motor rotor. The slotless motor is placed on the upper part of the base and is used to drive the rotor and the inertial devices inside the rotor to rotate. The slotless motor includes an outer circumference, an outer ring, and an inner ring. The outer circumference is the stator coil winding, the outer ring is a heat insulation layer for heat dissipation, and the inner ring is the stator core. The angular displacement sensor includes an angle measuring rotor and an angle measuring stator. The angle measuring rotor is placed in the mounting positioning groove at the large ring of the rotor support, and the angle measuring stator is fixed through the bottom mounting hole for synchronous detection of the motor rotation status by the angle measuring rotor. The control circuit includes a data acquisition circuit and a motor drive circuit. The data acquisition circuit is connected to the inertial device and is used to acquire and transmit the output data of the inertial device. The motor drive circuit is connected to the conductive slip ring and is used to control and power the coggingless motor. The inertial device includes a gyroscope and two accelerometers. The sensitive axis of the gyroscope is parallel to the horizontal plane and is placed on the inner wall of the inertial device support, perpendicular to the two accelerometers. The sensitive axes of the two accelerometers are both parallel to the horizontal plane and orthogonal to each other, and are placed on the upper surface of the inertial device support. The data acquisition circuit includes a gyroscope data acquisition circuit and an accelerometer data acquisition circuit. The gyroscope data acquisition circuit includes a gyroscope and its peripheral measurement and control circuit, which is connected to the conductive slide via a wire through a groove in the rotor cover. It is located on the inner wall of the inertial device support and is used to power the gyroscope and transmit data. The accelerometer data acquisition circuit includes an accelerometer and its peripheral measurement and control circuit, which is connected to the gyroscope data acquisition circuit via a wire. It is located on the upper surface of the inertial device support and is used to power the accelerometer and transmit data.

2. The miniaturized micro-inertial north finder according to claim 1, characterized in that, The top cover is connected to the base through mounting holes. The base is provided with a wiring groove for connecting the motor drive circuit and the conductive slip ring through wires, and for transmitting data with external devices through an aviation plug.

3. The miniaturized micro-inertial north finder according to claim 1, characterized in that, The motor drive circuit is located in the groove at the bottom of the base, and mounting holes are provided at its four corners to fix it to the base.

4. The miniaturized micro-inertial north finder according to claim 1, characterized in that, The stator core of the slotless motor rotor is made of soft magnetic ferrite ring, and the permanent magnet of the slotless motor rotor is made of titanium iron boron permanent magnet ring.

5. The miniaturized micro-inertial north finder according to claim 1, characterized in that, After connecting to external devices via an aviation connector, the conductive slip ring is powered. The conductive slip ring then powers the data acquisition circuit and inertial devices via wires. Based on the transmitted motor control commands, the motor drive circuit controls the cogless motor to rotate. The rotation of the motor drives the rotor and the inertial devices and angle measuring rotor inside the rotor to rotate. The data from the inertial devices and angle measuring rotor is acquired by the data acquisition circuit and transmitted to the motor drive circuit for data processing. The processed data is then transmitted to external devices via the aviation connector.

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