High-precision transposition locking device and method based on end face fluted disc

Abstract

The invention discloses a high-precision transposition locking device and method based on an end face fluted disc, and relates to the technical field of servo control technologies and inertial navigation systems. On one hand, the invention provides a high-precision transposition locking device based on an end-toothed disc pair, which comprises a fixed fluted disc, a movable fluted disc, a lifting transmission system and a dense ball supporting shaft system, the fixed fluted disc and the rotary fluted disc are used in pairs, so that the device has the advantages of high repeated positioning precision, automatic centering, no angular displacement or idle stroke and the like; the dense ball supporting shaft system is used as a support to realize the locking function and the stable rotation function of the movable fluted disc and the inertial unit load lifting and degrading lock under the working conditions of large inclination angle and large unbalance load, so that the high-precision mechanical locking and positioning requirements can be met, and the long-term stable work can be ensured; on the other hand, the invention provides a method for knowing angle information immediately after startup, so that the overall system calibration time is saved; the invention further provides a stepping motor jitter elimination method based on variable acceleration, and the method can overcome large eccentric disturbance torque.

Description

Technical Field

[0001] This invention relates to the fields of servo control technology and inertial navigation system technology, and in particular to a high-precision indexing and locking device and method based on an end face gear disk. Background Technology

[0002] Currently, the design of indexing devices in the field of inertial navigation system technology mainly focuses on the following aspects: As equipment places increasingly higher demands on the continuous operation time and navigation accuracy of navigation systems, rotating inertial navigation systems use rotating mechanisms to make the IMU platform mounted on it rotate and stop according to the designed rules, which can greatly improve the navigation accuracy of the system. Therefore, this type of system has become one of the main solutions. The design of traditional indexing devices mainly includes two methods: one is to use a motor direct-drive rotation action and a mechanical brake locking method; the other is to use an end gear plate locking method.

[0003] The disadvantages of direct-drive rotation by motor and mechanical brake locking are: 1. Using high-precision gratings or resolvers as angle sensors results in high costs and poor environmental adaptability; 2. Locking is unreliable under vibration and the repeatability of positioning is poor after the brake is locked.

[0004] The disadvantages of the end gear locking method are: First, under conditions of large tilt angle and large eccentric load, the eccentric force changes with the indexing, which easily causes vibration during rotation and results in poor stability; Second, most of them adopt open-loop control, which is very easy to cause misaligned teeth or tooth collision failures, resulting in insufficient reliability. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a high-precision indexing device and method based on an end gear plate to meet the low-cost requirements of achieving smooth rotation and high-precision mechanical locking positioning of the inertial navigation system indexing device under conditions of large tilt angles and large off-center loads.

[0006] The technical solution used in this invention is as follows: a high-precision indexing and locking device based on an end face gear disk, comprising a base and a servo control system. A fixed gear disk is fixedly mounted on the base, and a rotating shaft is rotatably mounted in the central area of ​​the fixed gear disk. A ball bearing support system is provided between the rotating shaft and the fixed gear disk. A rotating gear disk is fixedly mounted on the upper end face of the rotating shaft. The fixed gear disk and the rotating gear disk form a gear pair. A lifting transmission system is provided at the bottom of the base for lifting and controlling the rotating shaft. An indexing transmission system is also provided on the base for driving the rotating gear disk. An angle feedback system is provided on the base, which consists of a mechanical feedback coil, a through-beam photoelectric sensor, and an encoder. The mechanical feedback coil is fixedly mounted on the moving gear disk, and the through-beam photoelectric sensor is fixed on the fixed gear disk.

[0007] As a preferred embodiment, an adjusting washer and a loading cap are fixedly provided on the lower end of the rotating shaft, and the lower end stepped surface of the rotating shaft is supported by a lifting transmission system.

[0008] As a preferred embodiment, the lifting transmission system includes a lifting motor, a lifting worm, a lifting worm wheel, and a limit key. The lifting motor drives the lifting worm, which meshes with the lifting worm wheel. The lifting worm wheel includes an inner lifting helix, and a screw is provided inside the lifting worm wheel. The screw includes an outer lifting helix, and the inner and outer lifting helices form a helical pair. An adjusting washer and a loading cap at the lower end of the rotating shaft contact the end of the screw. The limit key is used to limit the screw so that it can move up and down. When the indexing transmission system receives an unlocking command, the rotating shaft rises, causing the rotating gear disk to disengage from the fixed gear disk. When the indexing transmission system receives a locking command, the rotating shaft descends at the target angle, eventually engaging the rotating gear disk with the fixed gear disk.

[0009] As a preferred embodiment, the indexing transmission system includes a large indexing gear, a small indexing gear, and an indexing motor. The large indexing gear is fixed to the moving gear disk, the small indexing gear is fixed on the output shaft of the indexing motor, and the indexing motor is fixedly mounted on the fixed gear disk. The small indexing gear and the large indexing gear have a meshing relationship, and the encoder on the angle feedback system is located at the tail of the indexing motor.

[0010] As a preferred embodiment, the ball bearing shaft system includes a rotatable outer shaft circle, a cage, steel balls, and a fixed gear disc inner hole, which provides support for the axial and rotary motion of the moving gear disc.

[0011] As a preferred embodiment, after the fixed gear disk and the rotating gear disk are rough-milled, they are subjected to hardening treatment, and after hardening treatment, they are ground on a gear grinding machine to make the tooth surface smooth.

[0012] Specifically, the fixed and rotating gear discs are used in pairs, offering advantages such as high repeatability, automatic centering, and no angular displacement or idle time. The lifting transmission system enables the rotating gear disc to be raised and lowered, while the ball bearing support shaft system provides support, enabling the moving gear disc and its inertial load to be raised, lowered, locked, and rotated smoothly under conditions of large tilt angles and large off-center loads. This system meets the requirements for high-precision mechanical locking and positioning while ensuring long-term stable operation. The indexing transmission system enables the rotating function of the moving gear disc, where the ball bearing support shaft system provides support for both the axial and rotary motion of the moving gear disc. The angle feedback system is responsible for sensing the position information of the moving gear disc, and the servo control system enables the moving gear disc to be precisely and smoothly indexed and locked / unlocked.

[0013] Here, we will explain in detail the machining method of the ball bearing shaft system. We will use a standard ring gauge to draw out the datum of the end face gear pair, and use the drawn datum as the machining datum of the ball bearing shaft system, as follows:

[0014] 1. After the fixed and rotary gear discs are rough-milled, they need to be hardened. After hardening, they are ground on specialized gear grinding equipment to make their end face tooth surfaces smooth. After grinding, the two gear discs have high positioning accuracy and indexing accuracy. At this time, the two gear discs are a high-precision gear disc pair.

[0015] 2. Place the standard ring gauge on the rotating gear plate, touch the ring gauge with the dial indicator, lift the moving gear plate using the lifting fixture, rotate the moving gear plate after lifting, observe the dial indicator value after it is in the symmetrical position, and adjust the position of the standard ring gauge so that the inner hole of the standard ring gauge is coaxial with the virtual axis of the gear plate, and fix the standard ring gauge.

[0016] 3. Fix the gear pair on the boring machine with tooling, and use the fixed standard ring gauge as the machining reference to bore the inner hole of the gear pair. The inner hole of the gear pair is theoretically coaxial with the standard ring gauge, that is, coaxial with the virtual axis of the gear pair.

[0017] 4. Using the inner hole of the fixed gear plate as a reference, machine the outer diameter of the rotating shaft. The theoretical value of the interference fit after adding the actual measured size of the steel ball to the outer diameter of the rotating shaft and subtracting the inner diameter of the gear plate is 0.006 to 0.010 mm.

[0018] 5. Between the outer circle of the rotating shaft and the inner hole of the fixed gear plate is a cage with steel balls. The steel balls in the cage are used in groups and multiple rows of steel balls are arranged in a spiral. Due to the average effect of the dense ball bearing, the shaft system has good rotational accuracy.

[0019] 6. During assembly, first pre-tighten and fix the rotating shaft and the moving gear plate, then place the cage with steel balls on the main shaft. Since the cage with steel balls has grease, the cage will adhere to the main shaft. Then, insert the main shaft with the cage into the inner hole of the fixed gear plate. At this time, the moving gear plate and the fixed gear plate cannot fully mesh. Then loosen the fastening screws between the main shaft and the moving gear plate, and the moving gear plate and the fixed gear plate will mesh smoothly. Finally, tighten the fastening screws between the main shaft and the moving gear plate.

[0020] A method for realizing instantaneous angle information upon power-on using the aforementioned indexing and locking device includes the following:

[0021] The transmission ratio between the pinion and gear at the front of the motor is 9:1, meaning that for every 9 rotations of the indexing motor, the indexing mechanism rotates 1 rotation. While the rotary transformer and grating in the transmission can measure angles, they require that the axial direction of the rotating shaft cannot move. However, the relative axial movement of the indexing gear pair does not affect the large-angle changes of the encoder at the tail of the indexing motor. The lifting of the rotating gear disk in the indexing mechanism does not require high precision. Since the encoder is a multi-turn encoder, the position information of the indexing device can be known in real time through conversion. Originally, this type of gear disk device used a zero-return method to sense the zero position when powered on, but with the multi-turn encoder, the position information of the indexing device can be known immediately after power failure and restart, saving the overall system calibration time.

[0022] The encoder's default zero position is inconsistent with the zero position of the gear disk. The encoder's zero position needs to be corrected based on the gear disk's photoelectric switch, as detailed below:

[0023] A. Pass the light-blocking plate through the photoelectric switch from the left and right sides at a constant speed, and record the passing time to obtain the average value T;

[0024] B. At the same speed as in step A, bring the light-shielding baffle into the photoelectric switch, and stop the rotary motor after running for time T / 2.

[0025] C. At this point, the position of the multi-turn encoder is set to zero, and the encoder zero position is aligned with the zero position of the gear plate.

[0026] Furthermore, due to the large eccentricity and large tilt angle of the mechanism load, a large eccentric interference torque needs to be overcome during movement. Therefore, when the stepper motor drives the moving gear disk and its inertial load to rotate, the sudden speed change during the start and stop phases causes jitter. The greater the eccentric force, the more severe the jitter, affecting the smooth and accurate rotation of the indexing device. Therefore, a method for eliminating jitter in a variable acceleration stepper motor using the aforementioned indexing locking device is proposed, including the following: The stepper motor jitter elimination strategy can be divided into two parts: current setting and start / stop speed adjustment.

[0027] First: Set the driver current output threshold according to the power limit and speed requirements to ensure that the motor can overcome interference torques such as eccentricity and rotate smoothly when rotating at maximum speed at a constant speed.

[0028] Second: During the motor start-up phase, the speed is adjusted using formula (1), and the motor stop phase is a horizontal mirror image of the acceleration phase. Within a certain time, the motor starts and accelerates from zero to a speed threshold. The motor maintains a constant speed throughout the time, moving until it approaches the target position; The motor stops within a certain time, and the speed begins to decelerate from the speed threshold until it decreases to zero.

[0029] (1)

[0030] Compared with the prior art, the above technical solutions of the present invention have the following significant advantages:

[0031] (1) High precision: The present invention adopts the method of coinciding the virtual shaft of the dense ball shaft system and the straight tooth end face tooth disk, so that high precision locking can be achieved under the attitude of large tilt angle;

[0032] (2) High reliability: The locking method of the end toothed plate can stably guarantee the accuracy under dynamic conditions. The angle measurement is designed to be fault-tolerant, which improves the reliability of accurate positioning.

[0033] (3) Low cost: The near-absolute angle measurement system, which adopts mechanical feedback coil coarse positioning and motor encoder correction algorithm, reduces costs significantly compared to rotary transformers and their supporting circuits. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the end face structure of the mechanical feedback coil of the present invention;

[0036] Figure 3 A schematic diagram of the side structure of the mechanical feedback coil of the present invention;

[0037] Figure 4 This is a block diagram of the angle measurement and fault-tolerant system of the present invention;

[0038] Figure 5 This is a graph showing the rotation speed of the present invention.

[0039] Reference numerals: 1-Base; 2-Fixed gear plate; 3-Moving gear plate; 4-Rotating shaft; 5-Ball bearing support shaft system; 6-Index transmission system; 7-Lifting transmission system; 8-Angle feedback system; 201-Inner hole of fixed gear plate; 401-Outer circle of shaft; 501-Cage; 601-Large indexing gear; 602-Small indexing gear; 701-Lifting worm gear; 702-Lifting internal thread; 703-Lifting external thread; 704-Limit key; 705-Adjusting washer; 706-Loading cap; 801-Mechanical feedback ring; 802-Through-beam photoelectric sensor. Specific Implementation

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] First embodiment: as follows Figure 1As shown, a high-precision indexing and locking device based on an end face gear plate includes a base (1), a fixed gear plate (2) is fixedly mounted on the base (1), a rotating shaft (4) is rotatably mounted in the central area of ​​the fixed gear plate (2), a ball bearing support shaft system (5) is provided between the rotating shaft (4) and the fixed gear plate (2), and a rotating gear plate (3) is fixedly mounted on the upper end face of the rotating shaft (4); the fixed gear plate (2) and the rotating gear plate (3) form a gear pair; a lifting transmission system (7) is provided at the bottom of the base (1) for lifting and controlling the rotating shaft (4); an indexing transmission system (6) is also provided on the base (1) for driving the rotating gear plate (3); an angle feedback system (8) is provided on the base (1), the angle feedback system (8) consists of a mechanical feedback coil (801), a through-beam photoelectric sensor (802) and an encoder, the mechanical feedback coil (801) is fixedly mounted on the moving gear plate (3), and the through-beam photoelectric sensor (802) is fixed on the fixed gear plate (2).

[0042] An adjusting washer (705) and a loading cap (706) are fixedly installed on the lower end of the rotating shaft (4), and the lower end of the rotating shaft (4) is supported by a lifting transmission system (7); the lifting transmission system (7) includes a lifting motor, a lifting worm (701), a lifting worm wheel, and a limit key (704); the lifting motor is used to drive the lifting worm (701), the lifting worm (701) meshes with the lifting worm wheel, the lifting worm wheel includes a lifting inner helix (702), and a screw is provided on the inner side of the lifting worm wheel, the screw includes a lifting outer helix (703), the lifting... The inner helix (702) and the lifting outer helix (703) form a helical pair. The adjusting washer (705) and the loading cap (706) at the lower end of the rotating shaft (4) contact the end of the screw. The limiting key (704) is used to limit the screw so that the screw can move up and down. When the indexing transmission system (6) receives the unlocking command, the rotation shaft (4) rises and the rotating gear disk (3) disengages from the fixed gear disk (2). When the indexing transmission system (6) receives the locking command, at the target angle, the rotating shaft (4) descends and finally makes the rotating gear disk (3) engage with the fixed gear disk (2).

[0043] The indexing transmission system (6) includes a large indexing gear (601), a small indexing gear (602), and an indexing motor. The large indexing gear (601) is fixed to the moving gear disk (3), the small indexing gear (602) is fixed on the output shaft of the indexing motor, and the indexing motor is fixedly mounted on the fixed gear disk (2). The small indexing gear (602) and the large indexing gear (601) have a meshing relationship. The encoder on the angle feedback system (8) is set at the tail of the indexing motor.

[0044] The ball bearing system (5) includes a rotatable outer circle (401), a cage (501), steel balls, and a fixed gear disc inner hole (201) for providing support for the axial and rotary motion of the moving gear disc (3).

[0045] Specifically, the fixed and rotating gear discs are used in pairs, offering advantages such as high repeatability, automatic centering, and no angular displacement or idle time. The lifting transmission system enables the rotating gear disc to be raised and lowered, while the ball bearing support shaft system provides support, enabling the moving gear disc and its inertial load to be raised, lowered, locked, and rotated smoothly under conditions of large tilt angles and large off-center loads. This system meets the requirements for high-precision mechanical locking and positioning while ensuring long-term stable operation. The indexing transmission system enables the rotating function of the moving gear disc, where the ball bearing support shaft system provides support for both the axial and rotary motion of the moving gear disc. The angle feedback system is responsible for sensing the position information of the moving gear disc, and the servo control system enables the moving gear disc to be precisely and smoothly indexed and locked / unlocked.

[0046] Here, we will explain in detail the machining method of the ball bearing shaft system. We will use a standard ring gauge to draw out the datum of the end face gear pair, and use the drawn datum as the machining datum of the ball bearing shaft system, as follows:

[0047] 1. After the fixed and rotary gear discs are rough-milled, they need to be hardened. After hardening, they are ground on specialized gear grinding equipment to make their end face tooth surfaces smooth. After grinding, the two gear discs have high positioning accuracy and indexing accuracy. At this time, the two gear discs are a high-precision gear disc pair.

[0048] 2. Place the standard ring gauge on the rotating gear plate, touch the ring gauge with the dial indicator, lift the moving gear plate using the lifting fixture, rotate the moving gear plate after lifting, observe the dial indicator value after it is in the symmetrical position, and adjust the position of the standard ring gauge so that the inner hole of the standard ring gauge is coaxial with the virtual axis of the gear plate, and fix the standard ring gauge.

[0049] 3. Fix the gear pair on the boring machine with tooling, and use the fixed standard ring gauge as the machining reference to bore the inner hole of the gear pair. The inner hole of the gear pair is theoretically coaxial with the standard ring gauge, that is, coaxial with the virtual axis of the gear pair.

[0050] 4. Using the inner hole of the fixed gear plate as a reference, machine the outer diameter of the rotating shaft. The theoretical value of the interference fit after adding the actual measured size of the steel ball to the outer diameter of the rotating shaft and subtracting the inner diameter of the gear plate is 0.006 to 0.010 mm.

[0051] 5. Between the outer circle of the rotating shaft and the inner hole of the fixed gear plate is a cage with steel balls. The steel balls in the cage are used in groups and multiple rows of steel balls are arranged in a spiral. Due to the average effect of the dense ball bearing, the shaft system has good rotational accuracy.

[0052] 6. During assembly, first pre-tighten and fix the rotating shaft and the moving gear plate, then place the cage with steel balls on the main shaft. Since the cage with steel balls has grease, the cage will adhere to the main shaft. Then, insert the main shaft with the cage into the inner hole of the fixed gear plate. At this time, the moving gear plate and the fixed gear plate cannot fully mesh. Then loosen the fastening screws between the main shaft and the moving gear plate, and the moving gear plate and the fixed gear plate will mesh smoothly. Finally, tighten the fastening screws between the main shaft and the moving gear plate.

[0053] Furthermore, the transmission ratio between the pinion and gear at the front of the motor is 9:1, meaning that for every 9 rotations of the indexing motor, the indexing mechanism rotates 1 rotation. While the rotary transformer and grating in the transmission can measure angles, they require that the axial direction of the rotating shaft remain stationary. The relative axial movement of the indexing gear pair does not affect the large-angle changes of the encoder at the tail of the indexing motor. The lifting of the rotating gear disk in the indexing mechanism does not require high precision. Since the encoder is a multi-turn encoder, the position information of the indexing device can be known in real time through conversion. Previously, this type of gear disk device used a zero-return method to sense the zero position upon startup, but with the multi-turn encoder, the position information of the indexing device can be known immediately after power failure and restart, saving overall system calibration time. Therefore, this invention proposes a method for using an indexing locking device to achieve instant angle information upon startup.

[0054] Second embodiment: A method for realizing angle information upon power-on using a rotation locking device, including the following scheme:

[0055] The encoder's default zero position is inconsistent with the zero position of the gear disk. The encoder's zero position needs to be corrected based on the gear disk's photoelectric switch, as detailed below:

[0056] A. Pass the light-blocking plate through the photoelectric switch from the left and right sides at a constant speed, and record the passing time to obtain the average value T;

[0057] B. At the same speed as in step A, bring the light-shielding baffle into the photoelectric switch, and stop the rotary motor after running for time T / 2.

[0058] C. At this point, the position of the multi-turn encoder is set to zero, and the encoder zero position is aligned with the zero position of the gear plate.

[0059] Furthermore, due to the large eccentricity and large tilt angle of the mechanism load, a large eccentric interference torque needs to be overcome during movement. Therefore, when the stepper motor drives the moving gear plate and its inertial load to rotate, the sudden speed change during the start and stop phases causes a jitter phenomenon. The greater the eccentric force, the more severe the jitter, which affects the smooth and accurate rotation of the indexing device. Therefore, a method for eliminating jitter in a variable acceleration stepper motor using the aforementioned indexing locking device is proposed.

[0060] Third embodiment: as follows Figure 5As shown, a method for debouncing a variable-acceleration stepper motor using the aforementioned indexing locking device includes the following: the stepper motor debouncing strategy can be divided into two parts: current setting and start / stop speed adjustment;

[0061] First: Set the driver current output threshold according to the power limit and speed requirements to ensure that the motor can overcome interference torques such as eccentricity and rotate smoothly when rotating at maximum speed at a constant speed.

[0062] Second: During the motor start-up phase, the speed is adjusted using formula (1), and the motor stop phase is a horizontal mirror image of the acceleration phase. Within a certain time, the motor starts and accelerates from zero to a speed threshold. The motor maintains a constant speed throughout the time, moving until it approaches the target position; The motor stops within a certain time, and the speed begins to decelerate from the speed threshold until it decreases to zero.

[0063] (1)

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-precision indexing locking device based on an end face gear, comprising a base (1), characterized in that: The base (1) is fixedly provided with a fixed gear plate (2), the center area of the fixed gear plate (2) is rotatably provided with a rotating shaft (4), the rotating shaft (4) and the fixed gear plate (2) are provided with a tight bead supporting shaft system (5), the upper end surface of the rotating shaft (4) is fixedly provided with a rotating gear plate (3); the fixed gear plate (2) and the rotating gear plate (3) constitute a gear pair; a lifting transmission system (7) is arranged at the bottom of the base (1) and is used for lifting and controlling the rotating shaft (4); the base (1) is further provided with a transposition transmission system (6) and is used for driving the rotating gear plate (3); an angle feedback system (8) is arranged on the base (1), the angle feedback system (8) is composed of a mechanical feedback ring (801), a light-receiving photoelectric sensor (802) and a multi-turn encoder, the mechanical feedback ring (801) is fixedly arranged on the rotating gear plate (3), and the light-receiving photoelectric sensor (802) is fixed on the fixed gear plate (2).

2. The high-precision indexing and locking device based on the face gear according to claim 1, characterized in that: The lower end tail of the rotating shaft (4) is fixedly provided with an adjusting washer (705) and a loading cap (706), and the lower end step surface of the rotating shaft (4) is supported by the lifting transmission system (7).

3. The high-precision indexing and locking device based on face gear according to claim 2, characterized in that: The lifting transmission system (7) comprises a lifting motor, a lifting worm (701), a lifting worm gear, a limiting key (704); the lifting motor is used for driving the lifting worm (701), the lifting worm (701) is engaged with the lifting worm gear, the lifting worm gear comprises a lifting inner screw (702), a screw rod is arranged on the inner side of the lifting worm gear, the screw rod comprises a lifting outer screw (703), the lifting inner screw (702) and the lifting outer screw (703) constitute a screw pair, the adjusting washer (705) and the loading cap (706) at the lower end of the rotating shaft (4) are in contact with the end of the screw rod, and the limiting key (704) is used for limiting the screw rod, so that the screw rod moves up and down; the transposition transmission system (6) receives an unlocking instruction, the lifting of the rotating shaft (4) makes the rotating gear plate (3) disengage from the fixed gear plate (2), the transposition transmission system (6) receives a locking instruction, at the target angle, the rotating shaft (4) is lowered, and finally the rotating gear plate (3) is engaged with the fixed gear plate (2).

4. The high-precision indexing and locking device based on the face gear according to claim 1, characterized in that: The transposition transmission system (6) comprises a transposition large gear (601), a transposition small gear (602) and a transposition motor, the transposition large gear (601) is fixed with the rotating gear plate (3), the transposition small gear (602) is fixed on the output shaft of the transposition motor, the transposition motor is fixedly arranged on the fixed gear plate (2), the transposition small gear (602) has an engagement relationship with the transposition large gear (601), and the multi-turn encoder on the angle feedback system (8) is arranged at the tail of the transposition motor.

5. The high-precision indexing and locking device based on the face gear according to claim 1, characterized in that: The tight bead supporting shaft system (5) comprises a rotatable shaft outer circle (401), a retainer (501), a steel ball and a fixed gear plate inner hole (201), and is used for providing support for the axial and rotary motion of the rotating gear plate (3).

6. The high-precision indexing and locking device based on face gear according to claim 1, characterized in that: After rough milling of the fixed gear plate (2) and the rotating gear plate (3), hardening treatment is carried out, and then the gear is lapped on a lapping equipment to make the gear surface smooth.

7. A method for realizing the angle information known at power-on by using the transposition locking device according to claim 1. The default zero position of the encoder is inconsistent with the zero position of the gear disc, and the zero position of the encoder needs to be corrected according to the photoelectric switch of the gear disc, as follows: A. Make the light-blocking block pass through the photoelectric switch from the left and right sides at a constant speed, record the passing time to obtain the average value T; B. Make the light-blocking block enter the photoelectric switch at the same speed as in step A, run for T / 2 time, and stop the indexing motor; C. At this time, the multi-turn encoder position is set to zero, and the encoder zero position is aligned with the gear disc zero position.

8. A method for realizing variable acceleration step motor dither elimination using the indexing locking device of claim 1, characterized in that: The step motor dither elimination strategy can be divided into two parts: current setting and start-stop speed adjustment; First: set the driver current output threshold according to the power limit and speed requirement, to ensure that the motor can overcome the disturbance torque such as eccentric moment and rotate smoothly during uniform rotation at maximum speed. Second: the motor starts to adjust the speed by formula (1) in the starting stage, and the motor stops in the horizontal mirror image of the acceleration stage, The motor starts within the time, and the speed starts to accelerate from zero. The speed increases to the speed threshold value. The motor maintains uniform motion within the time, and moves to the vicinity of the target position. The motor stops within the time, and the speed starts to decelerate from the speed threshold value. The speed decreases to zero. （1）。

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