A process for balancing a liquid floated force feedback gyroscope in oil

Abstract

The application provides a liquid floating force feedback gyroscope oil vacuum balancing process method, and solves the problems of large friction, low sensitivity, poor balancing precision and excessive dependence on the skill level of assembly workers in the existing balancing methods. Unlike the balancing method of the traditional open-loop working mode, according to the structural characteristics of the torque device of the liquid floating force feedback gyroscope, the application adopts a closed-loop working balancing method to measure the static unbalance amount of the float assembly by the size of the zero voltage difference of the IRA shaft and the vertical direction at four positions of 0°, 90°, 180° and 270°, that is, the static unbalance amount of the float assembly is directly measured by the size of the position zero voltage difference.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of liquid floated gyro assembling and adjusting, and particularly relates to a vacuum balance process method for liquid floated gyro. BACKGROUND

[0002] Static balance of the gyro float assembly is one of the key procedures in the assembly process of the liquid floated gyro, and the static drift error, position error and acceleration sensitivity coefficient of the gyro are directly dependent on the static balance precision of the float. Therefore, for many years, many gyro manufacturers have been exploring the balance method of the gyro float assembly.

[0003] The traditional static balance process method of the gyro float assembly is to support the gyro float assembly by using a knife-edge or bearing type balance support, to perform initial balance on the float in air, and then to perform fine balance in the working temperature liquid. This balance method has different balance precisions due to different design of the balance fixture, different friction of the knife-edge balance fixture, and different flexibility of the bearing type balance fixture. It can be seen that the traditional static balance process method of the gyro float assembly has the disadvantages of large friction, low sensitivity and poor balance precision, and can only be used for products with low static balance requirement or as initial balance; and the balance process excessively depends on the skill level of the assembly worker, and requires the assembly worker to have years of static balance experience, and the static balance precisions of the float assemblies balanced by different workers also have large differences.

[0004] From the traditional static balance method and detection method of the gyro float assembly, the current balance and detection method both belong to open loop working mode, i.e. no feedback loop mode.

[0005] Therefore, it is necessary to explore a closed loop working balance process method. SUMMARY

[0006] The present application aims to solve the problems of large friction, low sensitivity, poor balance precision and excessive dependence on the skill level of the assembly worker in the existing balance method, and provides a vacuum balance process method for liquid floated gyro in oil.

[0007] To achieve the above-mentioned purpose, the technical solution provided by the present application is as follows:

[0008] A vacuum balance process method for liquid floated gyro in oil, which is characterized by comprising the following steps:

[0009] 1) Initial balance

[0010] The static balance fixture is used to perform initial balance on the float assembly in air without power supply, so as to remove the larger unbalance;

[0011] 2) Static balance

[0012] 2.1) After the float assembly is assembled to the liquid-floated force feedback gyroscope, it is cleaned and installed on the oil balance fixture in the oil tank, and the input shaft of the liquid-floated force feedback gyroscope is vertically upward; clean floating liquid is injected into the oil tank, so that the liquid-floated force feedback gyroscope is immersed in the floating liquid;

[0013] 2.2) The oil tank is placed in a sealed tank, and the sealed tank is vacuumed to remove air bubbles in the floating liquid during the oil vacuum balancing process;

[0014] 2.3) Slowly release the vacuum (avoid shaking), so that the liquid-floated force feedback gyroscope is always immersed in the floating liquid, and the input shaft (IRA shaft) of the liquid-floated force feedback gyroscope is kept vertically upward, that is, the graduation line of the liquid-floated force feedback gyroscope is vertically upward, at this time the angle between the IRA shaft of the gyroscope and the vertical direction is 0°, and the floating liquid balance is started;

[0015] 2.4) The liquid-floated force feedback gyroscope is powered on, the zero voltage values of the input shaft at four different positions are measured, and the difference between the zero voltages at the four different positions is ensured to be not more than 3mV through adjustment.

[0016] The four different positions are positions where the input shaft has an angle of 0°, 90°, 180° and 270° with the vertical direction.

[0017] That is, after the initial balance is completed, the float assembly is installed in the shell and fixed to the oil balance fixture, so that it is completely immersed in the floating liquid, and the liquid-floated force feedback gyroscope float assembly is in a closed loop working state under power on, and the oil balance fixture performs fine balance on the float assembly. During fine balance, first measure the zero voltage of the IRA shaft of the liquid-floated force feedback gyroscope at four different positions with a digital multimeter DC scale, and increase or decrease the balance screw to make the difference between the zero voltages of the IRA shaft of the liquid-floated force feedback gyroscope at the four different positions tend to 0, so as to ensure the static balance of the float assembly.

[0018] Further, in step 2.1), the oil balance fixture is installed on the oil tank wall, which includes a rotating disc, a rotating shaft, a first bearing, a second bearing, a bearing sleeve, a bearing cover and a fastening assembly;

[0019] The bearing sleeve is vertically installed on the oil tank wall, and the first bearing and the second bearing are coaxially arranged in the bearing sleeve; the bearing cover is assembled at the opening of the bearing sleeve, and the bearing cover is provided with a mounting hole coaxial with the first bearing and the second bearing;

[0020] One end of the rotating shaft passes through the mounting hole and is installed in the bearing sleeve through the first bearing and the second bearing, and is perpendicular to the oil tank wall;

[0021] The rotating disc comprises an inner rotating disc and an outer rotating disc arranged concentrically; the inner rotating disc is provided with a through hole arranged concentrically; the 12 o'clock position of the disc surface of the outer rotating disc is 0°, the 3 o'clock position is 90°, the 6 o'clock position is 180°, and the 9 o'clock position is 270°; wherein the outer rotating disc is fixed on the tank wall, and the inner rotating disc is installed on the other end of the rotating shaft through the through hole and can rotate relative to the outer rotating disc under the cooperation of the rotating shaft.

[0022] The fastening assembly is arranged on the inner rotating disc, and an installation position coaxial with the rotating disc for fastening and installing the liquid buoyancy feedback gyroscope is formed on the inner rotating disc, and a 0° mark line is arranged on the end face of the installation position (the graduation line of the liquid buoyancy feedback gyroscope is vertically upward, that is, the graduation line of the gyroscope is aligned with the 0° mark line).

[0023] Further, in step 2.2), when vacuumizing, the vacuum degree is less than or equal to 1.33 pa, and after visual inspection without bubbles, the vacuumizing is maintained for at least 1 h.

[0024] Further, in step 2.3), the liquid level of the liquid is at least 10 mm higher than the liquid buoyancy feedback gyroscope.

[0025] Further, in step 2.4), the zero output voltage values of the gyroscope at four different positions around the IRA axis are measured at least twice by a digital multimeter DC file, and the difference between the zero voltage values at the four different positions is not greater than 3 mV. Those skilled in the art are clear about how to design a force feedback circuit according to the basic knowledge in the art.

[0026] Further, in step 2.4), the difference between the zero voltage values at the four different positions is ensured to be not greater than 3 mV by increasing or decreasing the balance screws on the float assembly balance ring or by reducing the lead ring on the balance weight assembly.

[0027] Further, in step 1), the static balance clamp is a bearing type static balance clamp.

[0028] Further, step 3) is further included: after balancing, the gyroscope is cleaned with filtered gasoline and dried at room temperature.

[0029] Further, the fastening assembly comprises a positioning block, a pressing plate and two struts; the positioning block is a U-shaped positioning block, the two struts are installed on the end faces of the two U-shaped arms of the positioning block, and the two ends of the pressing plate are installed on the two struts, respectively, to form an installation position matched with the shape of the liquid buoyancy feedback gyroscope.

[0030] Further, in order to prevent the gyroscope shell from being scratched, a protective pad is arranged on the wall surface of the installation position.

[0031] The advantages of the present application are:

[0032] 1. The oil vacuum balancing process of the liquid floating force feedback gyroscope improves the traditional float assembly static balancing process, reduces the high dependence of the float assembly static balancing on the skill level of the operator, adjusts the traditional visual detection method to the zero voltage data size of the gyroscope IRA shaft at four different positions to judge whether the float assembly static balancing meets the design requirements, and improves the static balancing accuracy of the float assembly.

[0033] 2. The balancing and debugging process for simulating the position error change state of the liquid floating gyroscope in the working state solves the problem of large position error change of the liquid floating gyroscope before and after oil filling.

[0034] 3. Unlike the traditional open-loop balancing method, according to the structural characteristics of the liquid floating force feedback gyroscope with a torque device, the closed-loop balancing method is adopted to measure the static unbalance of the float assembly by the size of the zero output voltage difference of the IRA shaft at 0°, 90°, 180° and 270° positions, that is, the static unbalance of the float assembly is directly measured by the size of the position zero voltage difference.

[0035] 4. The special tool (oil balancing clamp) used in the oil vacuum balancing process can quickly align the IRA shaft with the vertical angle of 0°, 90°, 180° and 270°.

[0036] 5. In the implementation of the present application, the assembly needs to be placed in a clean floating liquid for vacuumizing, and the disturbance of the air bubbles in the floating liquid to the unbalance during the oil vacuum balancing process is excluded. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a structural principle diagram of the liquid floating force feedback gyroscope; wherein, the input shaft is the IRA shaft, the output shaft is the ORA shaft, and the rotation shaft is the H shaft.

[0038] Figure 2 It is a zero voltage circuit block diagram for measuring the oil vacuum balancing of the float assembly of the present application.

[0039] Figure 3 It is a structure of the oil vacuum balancing clamp of the liquid floating force feedback gyroscope of the present application Figure 1 ;

[0040] Figure 4 It is a structure of the oil vacuum balancing clamp of the liquid floating force feedback gyroscope of the present application Figure 2 ;

[0041] Figure 5 It is a structure of the oil vacuum balancing clamp of the liquid floating force feedback gyroscope of the present application Figure 3 ;

[0042] The reference signs are as follows:

[0043] 1-Oil groove; 2-Knurled screw; 3-Pin; 4-Steel sleeve; 5-Turntable; 6-Pressure plate; 7-Support column; 8-Positioning block; 9-Screw; 10-Screw; 11-Screw; 12-O-ring seal; 13-Second bearing; 14-Shaft; 15-First bearing; 16-Bearing sleeve; 17-Bearing cover; 18-Fixing screw; 19-Screw; 20-Floating liquid. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0045] The principle of this invention:

[0046] like Figure 1 As shown, when the liquid buoyancy feedback gyroscope has an angular rate ω input around its input axis (IRA axis), the gyroscope's float assembly rotates around its output axis (ORA axis) and exhibits a rotation angle β (the appearance of rotation angle β is instantaneous, and the magnitude of β is related to the design parameters in the control loop (mainly referring to the design parameters of the torque converter in the gyroscope and the design parameters of the circuit board in the matching test equipment (force feedback circuit). The liquid buoyancy feedback gyroscope must work together with the matching force feedback circuit board and cannot work independently). The signal device will then generate a voltage U1 = K proportional to the rotation angle β. u β(K u The signal gradient, after being converted and amplified by the current amplification circuit of the control loop (the circuit in the matching test equipment), outputs a current I = K, which is proportional to the voltage U1. I U1(K I (For the amplifier gain), this current, after passing through the feedback loop (the circuit in the accompanying test equipment), is fed back to the torque converter of the liquid buoyancy feedback gyroscope. The torque converter then generates a torque M = K proportional to the current I. m I(K m (This is the torque scale factor), and the magnitude of this torque is equal to and opposite in direction to the gyro torque M = Hω (where H is the angular momentum of the liquid buoyancy feedback gyroscope), i.e., M = K. m If I = Hω, then I = Hω / K m By connecting a sampling resistor R in series with the torque converter coil. s (The sampling resistor in the accompanying test equipment; the output of the gyroscope is the DC voltage signal across the sampling resistor), from the sampling resistor R s The DC voltage signal U2, which is proportional to the input angular velocity ω, is obtained, i.e., U2 = R. s I = R s Hω / K m .

[0047] The final output of the liquid floated force feedback gyro to the system (i.e. the system with which the gyro is used, such as inertial navigation, attitude heading, flight control system, etc.) is voltage, and the size of the interference torque M d is directly represented and measured by the size of the gyro zero voltage. Since the output voltage U2 of the gyro is R s I, it can be known from Hω+M d =K m I that I=(Hω+M d ) / K m =(Hω+Hω d ) / K m ; in the formula, K m is the scale factor of the torque device, ω is the input angular rate of the gyro, and ω d is the drift angular rate of the gyro. When ω=0, it is the zero output voltage U0 of the gyro, i.e. U0=R s M d / K m =R s Hω d / K m .

[0048] From the working principle of the above liquid floated force feedback gyro, when the sampling resistance R s and the scale factor K m of the torque device are constant, the size of the zero output voltage U0 of the gyro represents the size of the interference torque M d , and the static unbalance of the gyro float assembly is in the form of the interference torque, so the static unbalance of the float assembly can be measured by the difference of the zero output voltage U 0i of the gyro IRA axis at four different positions (the angle between the IRA axis and the vertical direction is 0°, 90°, 180°, and 270°), i.e. the static unbalance of the float assembly is directly measured by the difference of the zero output voltage at different positions. It can be known from U0=R s M d / K m that ΔU0=R s ΔM d / K m . When the zero output voltage of the gyro IRA axis at four different positions is equal, i.e. ΔU0=0, the static unbalance of the float assembly is 0. According to this principle, the above gyro closed loop working balance method is used for the float assembly of the liquid floated force feedback gyro.

[0049] The present application does not carry out vacuumizing in the early stage of exploring new process, and the oil balance clamp is completely immersed in the clean liquid, and the gyroscope is clamped on the oil balance clamp. At this time, the liquid completely immerses the gyroscope. Then the gyroscope is normally powered, and the IRA axis is measured in four different position zero voltage to measure the float assembly static balance. But it is found in the implementation process that during the position turning process, bubbles are constantly coming out from the liquid, resulting in that the zero voltage collected by the gyroscope is different when the gyroscope is turned to the same position each time, and the float assembly static balance cannot be accurately carried out.

[0050] The research team of the present application analyzes that the bubbles in the liquid adhere to the float assembly, and the buoyancy of the bubbles acts on the float assembly, resulting in that the zero voltage error collected by the gyroscope is large, so the whole process is carried out in a vacuumizing way to eliminate the influence of the buoyancy of the bubbles on the zero error of the gyroscope. Specifically,

[0051] A kind of liquid floating force feedback gyroscope oil vacuumizing balancing process method, comprising the following steps:

[0052] 1) initial balance

[0053] Using bearing type static balance clamp, the float assembly is initially balanced in air without power supply, to remove the larger unbalance;

[0054] 2) static balance

[0055] 2.1) after the float assembly is assembled to the liquid floating force feedback gyroscope and cleaned, it is installed on the oil balance clamp in the oil tank, clean liquid (methyl silicone oil) is injected into the oil tank, so that the liquid floating force feedback gyroscope is immersed in the liquid, preferably the liquid level is at least 10mm higher than the gyroscope, to avoid that when shaking, the liquid floating force feedback gyroscope cannot be completely immersed in the liquid;

[0056] Among them, such as Figures 3-5As shown, the oil balance clamp is installed on the oil tank wall, which comprises a rotating disc, a rotating shaft, a first bearing, a second bearing, a bearing sleeve, a bearing cover and a fastening assembly; the bearing sleeve is vertically installed on the oil tank wall, and the first bearing and the second bearing are coaxially arranged in the bearing sleeve; the bearing cover is assembled at the opening of the bearing sleeve, and the mounting hole coaxial with the first bearing and the second bearing is arranged on the bearing cover; one end of the rotating shaft passes through the mounting hole and is installed in the bearing sleeve through the first bearing and the second bearing, and is perpendicular to the oil tank wall; the rotating disc comprises an inner rotating disc and an outer rotating disc arranged concentrically; the inner rotating disc is provided with a through hole arranged concentrically on the inner rotating disc, and the 12 o'clock position of the disc surface of the outer rotating disc is 0°, the 3 o'clock position is 90°, the 6 o'clock position is 180°, and the 9 o'clock position is 270°; wherein, the outer rotating disc is fixed on the oil tank wall, and the inner rotating disc is installed on the other end of the rotating shaft through the through hole, and can rotate relative to the outer ring disc under the cooperation of the rotating shaft; the fastening assembly is arranged on the inner rotating disc, and the mounting position coaxial with the rotating disc for fastening and installing the liquid buoyancy feedback gyroscope is arranged on the fastening assembly, and the 0° mark line is arranged on the end face of the mounting position (the graduation line of the liquid buoyancy feedback gyroscope is vertically upward, that is, the graduation line of the gyroscope is aligned with the 0° mark line). The fastening assembly comprises a positioning block, a pressing plate and two struts; the positioning block is a U-shaped positioning block, the two struts are installed on the end faces of the two U-shaped arms of the positioning block, and the two ends of the pressing plate are respectively installed on the two struts, thereby forming an installation position matched with the outer shape of the liquid buoyancy feedback gyroscope. In order to prevent the gyroscope shell from being scratched, a protective pad is arranged on the wall surface of the installation position.

[0057] 2.2) Put the oil tank into the sealed tank, and perform vacuumization on the sealed tank to remove the gas bubbles in the oil during the vacuumization balancing process, wherein the vacuum degree is less than or equal to 1.33 pa, and after no gas bubbles are observed, the vacuumization is maintained for at least 1 h;

[0058] 2.3) Slowly release the vacuum to immerse the buoyancy feedback gyroscope in the liquid at all times, and align the gyroscope graduation line (the IRA shaft is vertically upward) in the oil tank with the 0° mark line position of the positioning block of the oil balance clamp, at this time, the angle between the IRA shaft of the gyroscope and the vertical direction is 0°, and the liquid balancing is started;

[0059] 2.4) Power on the liquid buoyancy feedback gyroscope, measure the zero voltage value of the IRA shaft at four different positions (rotating the inner rotating disc can realize the conversion of the IRA shaft of the liquid buoyancy feedback gyroscope at four positions with an angle of 0°, 90°, 180° and 270° with the vertical direction, and further ensure that the float assembly static balance of the liquid buoyancy feedback gyroscope meets the technical requirements) twice through the DC range of the digital multimeter, and ensure that the difference between the zero voltage values at the four different positions is less than or equal to 3 mV at least twice through the method of increasing or decreasing the balance screws on the balance ring of the float assembly or through the method of reducing the lead ring on the balance weight assembly;

[0060] 3) After the end of the balance, the buoyancy feedback gyroscope is cleaned with filtered gasoline, and dried at room temperature.

[0061] Notes:

[0062] 1. The oil balance fixture should be kept clean, and the liquid used for vacuum balancing should be filtered after each batch of balancing, then sealed in a clean container.

[0063] 2. The fixture used before balancing should be cleaned, and the parts, tools, and the hands of the operator should be cleaned before balancing.

[0064] 3. Dust should be prevented during balancing, and clean capacitor paper should be used to cover the gaps during operation, and foreign matter should be prevented from entering the oil tank during balancing.

[0065] 4. The liquid used for balancing should be replaced every half year in principle, and replaced every three months when used frequently, and should be dried when necessary.

[0066] 5. The liquid used for balancing is a process liquid, and is strictly prohibited from being filled into products.

[0067] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A method for vacuum balancing in oil for a liquid buoyancy feedback gyroscope, characterized in that, Includes the following steps: 1) Initial Equilibrium Using a static balancing fixture, the float assembly is initially balanced in the air without being energized. 2) Static equilibrium 2.1) After cleaning the buoyancy feedback gyroscope, assemble the float assembly onto the oil balance fixture in the oil tank, with the input shaft of the buoyancy feedback gyroscope pointing vertically upwards; inject clean floating liquid into the oil tank so that the buoyancy feedback gyroscope is submerged in the floating liquid; The oil balance fixture is installed on the wall of the oil tank and includes a turntable, a rotating shaft, a first bearing, a second bearing, a bearing sleeve, a bearing cover, and fastening components. The bearing sleeve is vertically installed on the wall of the oil trough, and the first bearing and the second bearing are coaxially arranged inside it; the bearing cover is assembled at the opening of the bearing sleeve, and has mounting holes coaxial with the first bearing and the second bearing. One end of the rotating shaft passes through the mounting hole and is installed in the bushing through the first bearing and the second bearing, and is perpendicular to the oil groove wall. The turntable includes an inner turntable and an outer turntable arranged concentrically; the inner turntable has concentric through holes, and the outer turntable has a 12 o'clock position of 0°, a 3 o'clock position of 90°, a 6 o'clock position of 180°, and a 9 o'clock position of 270° on its surface. The outer turntable is fixed to the wall of the oil tank, while the inner turntable is installed at the other end of the rotating shaft through the through hole and can rotate relative to the outer ring disc with the cooperation of the rotating shaft. The fastening assembly is set on the inner turntable, which has a mounting position coaxial with the turntable for fastening and installing the liquid buoyancy feedback gyroscope, and a 0° marking line is provided on the end face of the mounting position. The fastening assembly includes a positioning block, a pressure plate, and two support pillars; The positioning block is a U-shaped positioning block, with two pillars installed on the two U-shaped arm end faces of the positioning block. The two ends of the pressure plate are respectively installed on the two pillars, forming a mounting position that is compatible with the shape of the liquid buoyancy feedback gyroscope. 2.2) Place the oil tank into the sealed container and evacuate the sealed container to remove floating liquid bubbles during the vacuum equilibration process in the oil; when evacuating, the vacuum degree should be less than or equal to 1.33 Pa. After visually inspecting for no bubbles, maintain the vacuum for at least 1 hour. 2.3) Release the vacuum so that the buoyancy feedback gyroscope is always immersed in the buoyancy liquid and the input axis of the buoyancy feedback gyroscope is kept vertically upward; 2.4) Power on the liquid buoyancy feedback gyroscope, measure the zero-point output voltage value of its input axis at four different positions, and ensure that the difference between the zero-point voltages at the four different positions is not greater than 3mV by adjustment; The four different positions are the positions where the angle between the input axis and the vertical direction is 0°, 90°, 180° and 270° respectively.

2. The method for vacuum balancing in oil for a liquid buoyancy feedback gyroscope according to claim 1, characterized in that: In step 2.3), the surface of the floating liquid is at least 10 mm above the buoyancy feedback gyroscope.

3. The method for vacuum balancing in oil for a liquid buoyancy feedback gyroscope according to claim 2, characterized in that: In step 2.4), the zero-position output voltage value of the gyroscope IRA axis at four different positions is measured at least twice using a digital multimeter in DC mode, and the difference between the zero-position voltages at the four different positions is no greater than 3mV each time.

4. The method for vacuum balancing in oil for a liquid buoyancy feedback gyroscope according to claim 3, characterized in that: In step 2.4), the difference between the zero voltage at the four different positions is ensured to be no greater than 3mV by adding or removing balance screws on the balance ring of the float assembly or by cutting the lead ring on the balance counterweight assembly.

5. The method for vacuum balancing in oil for a liquid buoyancy feedback gyroscope according to claim 4, characterized in that: In step 1), the static balancing fixture is a bearing-type static balancing fixture.

6. The method for vacuum balancing in oil for a liquid buoyancy feedback gyroscope according to claim 5, characterized in that, It also includes step 3). After balancing, clean the top with filtered gasoline and let it air dry at room temperature.

7. The method for vacuum balancing in oil for a liquid buoyancy feedback gyroscope according to claim 6, characterized in that: A protective pad is provided on the wall surface of the mounting position.

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