A method for estimating and counteracting the shaft unbalance moment of an inertial measurement device platform

Abstract

The present application relates to a kind of inertial measurement device platform body axis unbalance moment estimation and offset method, belong to inertial measurement technical field;Inertial coordinate system OXYZ is established based on inertial measurement device;Establish the control model of platform body axis stable loop in inertial measurement device under the influence of unbalance moment;The model of unbalance moment acting on platform body axis is established;According to unbalance moment model, establish unbalance moment parameter observer, estimate the unbalance moment parameter that platform body axis is subjected to by unbalance moment parameter observer, obtain unbalance moment parameter estimated value;According to unbalance moment parameter estimated value, calculate platform body axis compound control moment;Through platform body axis compound control moment, improve the control precision of platform body axis stable loop;The present application has the characteristics of low cost, high precision, strong engineering practicability, is applicable to the high-precision control of platform system platform body axis stable loop under the influence of unbalance moment.

Description

Technical Field

[0001] This invention belongs to the field of inertial measurement technology and relates to a method for estimating and canceling the unbalanced torque of the platform body of an inertial measurement device. Background Technology The platform system can provide a spatial inertial coordinate reference, apparent acceleration along the inertial coordinate system direction, and frame angles of the platform frame system. Its accuracy is relatively higher than that of a strapdown system, and it is often used in aircraft with high precision requirements. The platform system's stabilization loop controls the platform's isolating angle motion and maintains it in inertial space. However, because the platform's mass centerline deviates from its geometric centerline, an unbalanced torque is generated, which reduces the accuracy of the stabilization loop control and, in severe cases, affects the control and navigation accuracy of the platform system.

[0002] Currently, regarding methods for measuring and compensating unbalanced forces, patent application number 201811164733.3 proposes a balancing method for an inertial navigation system with a rotating mechanism based on measuring and compensating for static unbalanced torque. However, this invention requires the addition of three high-precision pressure sensors and counterweights, resulting in high costs. Patent application number 202010130041.8 proposes a precision balancing method for the pitch axis of a large-size photoelectric theodolite, which also requires additional counterweights. In summary, the problem of decreased accuracy of the platform system's platform axis stabilization loop caused by unbalanced torque urgently needs to be addressed. However, existing balancing methods are costly and cannot guarantee balancing accuracy. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a method for estimating and canceling the unbalanced torque of the platform axis of an inertial measurement device. This method has the characteristics of low cost, high accuracy, and strong engineering applicability, and is suitable for high-precision control of the platform axis stabilization loop of a platform system under the influence of unbalanced torque.

[0004] The solution of the present invention is: A method for estimating and canceling the unbalanced moment of an inertial measurement device platform axis, comprising: An inertial coordinate system OXYZ is established based on an inertial measurement device; Establish a control model for the axial stability loop of the inertial measurement device under the influence of unbalanced torque. ; Establish a model of the unbalanced torque acting on the axis of the platform. ; Based on the unbalanced torque model, an unbalanced torque parameter observer is established. Through the unbalanced torque parameter observer The parameters of the unbalanced torque on the axis of the platform are estimated to obtain the estimated values ​​of the unbalanced torque parameters. Calculate the composite control torque of the platform axis based on the estimated values ​​of the unbalanced torque parameters. Torque is controlled by a combination of the platform axis and the control mechanism. To improve the control accuracy of the platform axis stabilization loop.

[0005] In the above-mentioned method for estimating and canceling the unbalanced moment of the inertial measurement device platform axis, the inertial coordinate system OXYZ is: The origin O is the center of the inertial measurement unit (IMU) platform; the Y-axis is the axis of the IMU platform; the Z-axis is the inner loop axis of the IMU; and the X-axis is the outer loop axis of the IMU.

[0006] The above-mentioned method for estimating and canceling the unbalanced torque of the inertial measurement device's platform axis includes a platform axis stability loop control model. for:

[0007] In the formula, This represents the moment of inertia of the frame shaft. Indicates the angular velocity of the platform axis attitude; Indicates the angular velocity of the platform axis attitude. The first time derivative; This represents the unbalanced torque acting on the axis of the platform; This represents the control torque acting on the axis of the platform.

[0008] In the aforementioned method for estimating and canceling the unbalanced torque on the stage axis of an inertial measurement device, the model of the unbalanced torque acting on the stage axis is described. for:

[0009] In the formula, This represents the component of the unbalanced force in the OXZ plane; Indicates the component of the unbalanced lever arm in the OXZ plane; Indicates the acceleration component in the Z-axis direction; Indicates the acceleration component in the X-axis direction; This represents the component of the equivalent offset mass in the OXZ plane; This represents the angle between the component of the unbalanced lever arm in the OXZ plane and the Z-axis; and They represent The cosine and sine quantities.

[0010] In the aforementioned method for estimating and canceling the unbalanced torque on the axis of an inertial measurement device, an unbalanced torque parameter observer is used. for:

[0011] In the formula, The parameters represent the unbalanced moment of the platform axis; Indicates the unbalanced moment parameters of the table axis The estimated value; Indicates auxiliary variables; To Differentiate; For observer gain; ; Indicates a diagonal matrix; express The sign function; These are the acceleration component matrices in the Z-axis direction and the X-axis direction; ; express The norm; and These represent the unbalanced torque parameters. and The upper limit.

[0012] In the aforementioned method for estimating and canceling the unbalanced moment of the stage axis in an inertial measurement device, the unbalanced moment parameter of the stage axis is defined. for:

[0013] but This is the unbalanced torque parameter observer. The output is an estimate of the unbalanced torque parameters.

[0014] In the aforementioned method for estimating and canceling the unbalanced torque of the stage axis of an inertial measurement device, the composite control torque of the stage axis... The calculation method is as follows: .

[0015] In the aforementioned method for estimating and canceling the unbalanced torque of the inertial measurement device platform axis, the acceleration components in the Z-axis and X-axis directions... and The quantities are known and are measured by the quartz accelerometers on the inertial measurement unit.

[0016] In the above-mentioned method for estimating and canceling the unbalanced torque of the inertial measurement device platform axis, the unbalanced torque parameters are... upper limit and unbalanced torque parameters upper limit All of these are known quantities.

[0017] In the aforementioned method for estimating and canceling the unbalanced torque of the stage axis of an inertial measurement device, the composite control torque of the stage axis is used. It counteracts the unbalanced torque of the platform shaft and improves the control accuracy of the platform shaft stabilization loop.

[0018] The advantages of this invention compared to the prior art are: (1) This invention establishes a control model for the stabilization loop of the inertial measurement device platform under the influence of unbalanced torque; laying the foundation for the subsequent calculation of the composite control torque of the platform axis; (2) The present invention models the unbalanced torque acting on the platform system's platform axis, and realizes an accurate calculation method for the unbalanced torque; (3) Based on the unbalanced moment model of the platform system's platform axis, this invention designs an unbalanced moment parameter observer to estimate the unbalanced moment parameters of the platform system's platform axis; (4) Based on the output value of the unbalanced torque parameter observer, the present invention designs a composite control torque for the platform shaft to counteract the unbalanced torque of the platform shaft and improve the control accuracy of the platform shaft stability loop. Attached Figure Description

[0019] Figure 1 This is a flowchart of the estimation and cancellation process for the unbalanced moment of the platform axis in this invention. Figure 2 This is a schematic diagram of the inertial coordinate system of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the embodiments.

[0021] This invention provides a method for estimating and canceling the unbalanced torque of the platform axis of an inertial measurement device. It addresses the stability loop control problem of the platform axis of a platform system affected by unbalanced torque, and designs a method for estimating and canceling the unbalanced torque of the platform axis of an inertial measurement device. This method has the advantages of low cost, high accuracy, and strong engineering applicability.

[0022] Methods for estimating and canceling the unbalanced moment of the inertial measurement device's platform axis, such as... Figure 1 As shown, the specific steps include the following: An inertial coordinate system OXYZ is established based on an inertial measurement device.

[0023] like Figure 2 As shown, the inertial coordinate system OXYZ is: The origin O is the center of the inertial measurement unit (IMU) platform; the Y-axis is the axis of the IMU platform; the Z-axis is the inner loop axis of the IMU; and the X-axis is the outer loop axis of the IMU.

[0024] Establish a control model for the axial stability loop of the inertial measurement device under the influence of unbalanced torque. .

[0025] Inertial Measurement Unit Axis Stabilization Loop Control Model for:

[0026] In the formula, This represents the moment of inertia of the frame axis.

[0027] This indicates the angular velocity of the platform axis.

[0028] Indicates the angular velocity of the platform axis attitude. The first time derivative.

[0029] This represents the unbalanced torque acting on the axis of the platform.

[0030] This represents the control torque acting on the axis of the platform.

[0031] Establish a model of the unbalanced torque acting on the axis of the platform. .

[0032] Model of unbalanced torque acting on the axis of the platform for:

[0033] In the formula, This represents the component of the unbalanced force in the OXZ plane.

[0034] This represents the component of the unbalanced lever arm in the OXZ plane.

[0035] This represents the acceleration component along the Z-axis.

[0036] This represents the acceleration component along the X-axis.

[0037] This represents the component of the equivalent offset mass in the OXZ plane.

[0038] This represents the angle between the component of the unbalanced lever arm in the OXZ plane and the Z-axis.

[0039] and They represent The cosine and sine quantities.

[0040] In this invention, the acceleration components in the Z-axis and X-axis directions and The quantities are known and are measured by the quartz accelerometers on the inertial measurement unit.

[0041] Based on the unbalanced torque model, an unbalanced torque parameter observer is established. Through the unbalanced torque parameter observer The parameters of the unbalanced torque on the axis of the platform are estimated to obtain the estimated values ​​of the unbalanced torque parameters.

[0042] Unbalanced torque parameter observer for:

[0043] In the formula, The parameters represent the unbalanced moment of the platform axis.

[0044] Indicates the unbalanced moment parameters of the table axis The estimated value.

[0045] This represents an auxiliary variable.

[0046] To Find the derivative.

[0047] For observer gain; ; This represents a diagonal matrix.

[0048] express The symbolic function.

[0049] These are the acceleration component matrices in the Z-axis direction and the X-axis direction; .

[0050] express The norm of .

[0051] and These represent the unbalanced torque parameters. and The upper limit. Unbalanced torque parameters. upper limit and unbalanced torque parameters upper limit All of these are known quantities.

[0052] Define the unbalanced moment parameters of the table axis. for:

[0053] but This is the unbalanced torque parameter observer. The output is an estimate of the unbalanced torque parameters.

[0054] Calculate the composite control torque of the platform axis based on the estimated values ​​of the unbalanced torque parameters. Torque is controlled by a combination of the platform axis and the control mechanism. To improve the control accuracy of the platform axis stabilization loop.

[0055] Combined control torque of the platform axis The calculation method is as follows: .

[0056] Torque controlled by the combined axis of the platform It counteracts the unbalanced torque of the platform shaft and improves the control accuracy of the platform shaft stabilization loop.

[0057] Example The first step is to establish a platform system axial stability control model under the influence of unbalanced torque: Define an inertial coordinate system OXYZ, with point O as the origin. The X-axis is perpendicular to the paper and points inward, the Y-axis is parallel to the paper and points upward, and the Z-axis is determined by the right-hand rule. The platform's body axis coincides with the Y-axis, the inner ring axis coincides with the Z-axis, and the outer ring axis coincides with the X-axis.

[0058] Platform system axial stability loop control model under the influence of unbalanced torque for:

[0059] in, This represents the moment of inertia of the platform system's frame axis. Indicates the angular velocity of the platform axis attitude. Indicates the angular velocity of the platform axis attitude. The first time derivative, This represents the unbalanced torque acting on the axis of the platform. This represents the control torque acting on the axis of the platform.

[0060] In this implementation case, the rotational inertia of the platform system's frame axis is selected. Control torque on the platform axis .

[0061] The second step is to model the unbalanced torque acting on the platform system's axis as follows:

[0062] in, This represents the component of the unbalanced force in the OXZ plane. This represents the component of the unbalanced lever arm in the OXZ plane. This represents the acceleration component along the Z-axis. This represents the acceleration component along the X-axis. This represents the component of the equivalent offset mass in the OXZ plane. This represents the angle between the component of the unbalanced lever arm in the OXZ plane and the Z-axis. and They represent The cosine and sine quantities.

[0063] In this implementation case, the acceleration component in the Z-axis direction is selected. X-axis acceleration component The components of the equivalent offset mass in the OXZ plane The component of the unbalanced lever arm in the OXZ plane The angle between the component of the unbalanced lever arm in the OXZ plane and the Z-axis. .

[0064] The third step is to design an unbalanced moment parameter observer based on the unbalanced moment model of the platform system's platform axis, and estimate the unbalanced moment parameters acting on the platform system's platform axis: Acceleration components in the Z and X axes and The quantities are known and measured by quartz accelerometers on the platform system. The component of the unbalanced lever arm in the OXZ plane is also known. Components of equivalent offset mass in the OXZ plane And the angle between the component of the unbalanced lever arm in the OXZ plane and the Z-axis. Unknown quantities. Define the unbalanced moment parameters of the table axis. Design an unbalanced moment parameter observer. for:

[0065] in, Indicates the unbalanced moment parameters of the table axis The estimated value, Represents auxiliary variables. express The sign function, Indicates the observer gain. Indicates a diagonal matrix. , , , express norm, and Representing parameters respectively and The upper limit of is a known quantity.

[0066] In this implementation case, the observer gain is selected. ,parameter and upper limit , .

[0067] The fourth step is to design a composite control torque for the platform shaft based on the output value of the unbalanced torque parameter observer, in order to counteract the unbalanced torque of the platform shaft and improve the control accuracy of the platform shaft stabilization loop.

[0068] in, This indicates the combined control torque of the platform axis. and These represent the unbalanced moment parameters of the table axis. and The estimated value.

[0069] This invention establishes a stabilization loop control model for the platform axis of an inertial measurement device under the influence of unbalanced torque, laying the foundation for subsequent calculation of the composite control torque of the platform axis. This invention models the unbalanced torque acting on the axis of the inertial measurement device platform, and realizes an accurate calculation method for the unbalanced torque; Based on the unbalanced moment model of the platform axis of the inertial measurement device, this invention designs an unbalanced moment parameter observer to estimate the unbalanced moment parameters of the platform system's platform axis. Based on the output value of the unbalanced torque parameter observer, this invention designs a composite control torque for the platform shaft to counteract the unbalanced torque of the platform shaft and improve the control accuracy of the platform shaft stabilization loop.

[0070] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for estimating and canceling the unbalanced torque on the axis of an inertial measurement device, characterized in that: include: An inertial coordinate system OXYZ is established based on an inertial measurement device; The inertial coordinate system OXYZ is: The origin O is the center of the inertial measurement unit (IMU) platform; the Y-axis is the axis of the IMU platform; the Z-axis is the inner loop axis of the IMU; and the X-axis is the outer loop axis of the IMU. Establish a control model for the axial stability loop of the inertial measurement device under the influence of unbalanced torque. ; Inertial Measurement Unit Axis Stabilization Loop Control Model for: In the formula, This represents the moment of inertia of the frame shaft. Indicates the angular velocity of the platform axis attitude; Indicates the angular velocity of the platform axis attitude. The first time derivative; This represents the unbalanced torque acting on the axis of the platform; This represents the control torque acting on the axis of the platform. Establish a model of the unbalanced torque acting on the axis of the platform. ; Model of unbalanced torque acting on the axis of the platform for: In the formula, This represents the component of the unbalanced force in the OXZ plane; Indicates the component of the unbalanced lever arm in the OXZ plane; Indicates the acceleration component in the Z-axis direction; Indicates the acceleration component in the X-axis direction; This represents the component of the equivalent offset mass in the OXZ plane; This represents the angle between the component of the unbalanced lever arm in the OXZ plane and the Z-axis; and They represent The cosine and sine quantities; Based on the unbalanced torque model, an unbalanced torque parameter observer is established. Through the unbalanced torque parameter observer The parameters of the unbalanced torque on the axis of the platform are estimated to obtain the estimated values ​​of the unbalanced torque parameters. Unbalanced torque parameter observer for: In the formula, The parameters represent the unbalanced moment of the platform axis; Indicates the unbalanced moment parameters of the table axis The estimated value; This is the unbalanced torque parameter observer. The output is an estimated value of the unbalanced torque parameter; Indicates auxiliary variables; To Differentiate; For observer gain; ; Indicates a diagonal matrix; express The sign function; These are the acceleration component matrices in the Z-axis direction and the X-axis direction; ; express The norm; and These represent the unbalanced torque parameters. and The upper limit; Calculate the composite control torque of the platform axis based on the estimated values ​​of the unbalanced torque parameters. Torque is controlled by a combination of the platform axis and the control mechanism. To improve the control accuracy of the platform axis stabilization loop.

2. The method for estimating and canceling the unbalanced moment of the inertial measurement device platform according to claim 1, characterized in that: Define the unbalanced moment parameters of the table axis. for: 。 3. The method for estimating and canceling the unbalanced moment of the inertial measurement device platform according to claim 2, characterized in that: Combined control torque of the platform axis The calculation method is as follows: 。 4. The method for estimating and canceling the unbalanced moment of the inertial measurement device platform according to claim 1, characterized in that: Acceleration components in the Z and X axes and The quantities are known and are measured by the quartz accelerometers on the inertial measurement unit.

5. The method for estimating and canceling the unbalanced moment of the inertial measurement device platform according to claim 1, characterized in that: Unbalanced torque parameters upper limit and unbalanced torque parameters upper limit All of these are known quantities.

6. The method for estimating and canceling the unbalanced moment of the inertial measurement device platform according to claim 3, characterized in that: Torque controlled by the combined axis of the platform It counteracts the unbalanced torque of the platform shaft and improves the control accuracy of the platform shaft stabilization loop.

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