WO2024114558A1

WO2024114558A1 - Gimbal state identification method and apparatus, and storage medium and gimbal

Info

Publication number: WO2024114558A1
Application number: PCT/CN2023/134241
Authority: WO
Inventors: 蒋宪宏; 莫德华; 王琼彪
Original assignee: 影石创新科技股份有限公司
Priority date: 2022-11-28
Filing date: 2023-11-27
Publication date: 2024-06-06
Also published as: CN118090264A

Abstract

Provided are a gimbal state identification method and apparatus, and a storage medium and a gimbal. The method comprises: acquiring an angular velocity of a target shaft of a gimbal 400 and a torque output by an electric motor of the target shaft; determining the current rotational inertia of the target shaft on the basis of the angular velocity and the torque output by the electric motor; and determining a load state of the gimbal 400 according to the current rotational inertia, wherein the load state comprises a loaded state or an unloaded state.

Description

Pan/tilt status identification method, device, storage medium and pan/tilt

Technical Field

The present application relates to the field of pan-tilt technology, and in particular to a pan-tilt state recognition method, device, storage medium and pan-tilt.

Background technique

With the rapid development of science and technology, gimbals are used more and more widely, especially in various types of shooting equipment, such as sports cameras, drones, mobile phones, etc., to provide anti-shake services as a supporting platform for shooting equipment, and can flexibly change the posture of the shooting equipment.

Among them, when the gimbal is started without any shooting equipment, the motor control output of the gimbal will be abnormal due to the inconsistency between the controlled object and the normal working state, resulting in continuous shaking of the gimbal, which will affect user use.

Summary of the invention

The embodiments of the present application provide a gimbal status recognition method, device, storage medium and gimbal, which can more accurately recognize the loading status of the gimbal.

In a first aspect, an embodiment of the present application provides a method for identifying a gimbal state, comprising:

The axis obtains the angular velocity of the target axis of the gimbal and the torque output by the motor of the target axis, wherein the target axis is connected to a fixing mechanism of the gimbal for loading a load;

Determine the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor;

The current loading state of the gimbal is determined according to the current moment of inertia, wherein the loading state includes a loaded state or an unloaded state.

In a second aspect, an embodiment of the present application further provides a gimbal state recognition device, comprising:

A data acquisition module, used for axially acquiring the angular velocity of a target axis of the gimbal and the torque output by a motor of the target axis, wherein the target axis is connected to a fixing mechanism of the gimbal for loading a load;

A data prediction module is used to determine the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor;

The state recognition module is used to determine the loading state of the gimbal according to the current moment of inertia, and the loading state includes a loaded state or an unloaded state.

In a third aspect, the present application also provides a computer-readable storage medium on which a computer A computer program, when the computer program is run on a computer, enables the computer to execute a gimbal state identification method as provided in any embodiment of the present application.

In a fourth aspect, an embodiment of the present application also provides a gimbal, comprising a gimbal body; a target axis, the target axis is connected to a fixing mechanism, wherein the fixing mechanism axis is used to load a load; and an axis controller, the controller axis is configured to execute a gimbal state identification method as provided in any embodiment of the present application.

The technical solution provided by the embodiment of the present application takes into account that whether the fixing mechanism is loaded with a load will affect the output of the motor of the target axis connected to the fixing mechanism and the angular velocity of the target axis. Therefore, the embodiment of the present application obtains the angular velocity of the target axis of the gimbal and the torque output by the motor of the target axis to determine the current moment of inertia of the target axis according to the angular velocity and the torque output by the motor. If it is determined according to the current moment of inertia that the fixing mechanism is not loaded with a load, the gimbal is determined to be in an unloaded state. If it is determined according to the current moment of inertia that the fixing mechanism is loaded with a load, the gimbal is determined to be in a loaded state. In this way, by determining the current moment of inertia of the target axis to determine the loading state of the gimbal, the accuracy of identifying the loading state of the gimbal can be improved, which is convenient for users to use.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

FIG1 is a schematic diagram of an application scenario of a gimbal status recognition method provided in an embodiment of the present application.

FIG. 2 is a flow chart of a gimbal status recognition method provided in an embodiment of the present application.

FIG3 is a schematic diagram of the structure of a handheld gimbal provided in an embodiment of the present application.

FIG4 is a logic judgment diagram of the gimbal state identification method provided in an embodiment of the present application.

FIG5 is a schematic diagram of the structure of a gimbal state recognition device provided in an embodiment of the present application.

FIG6 is a block diagram of a pan/tilt platform according to an embodiment of the present application.

Detailed ways

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, those skilled in the art will be able to use the present invention without creative work. All other embodiments obtained under this premise belong to the protection scope of this application.

Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

In order to better understand the solution provided by the embodiment of the present application, first of all, the present application provides an application scenario. Please refer to Figure 1, which is a schematic diagram of the application scenario of the gimbal state recognition method provided by the embodiment of the present application. As shown in Figure 1, at least one of the axes included in the gimbal is connected to a fixing mechanism, and the fixing mechanism is used to load the shooting equipment. When there are multiple axes, each axis is connected to a motor, and the motor provides a driving force for it to rotate the axis. Among them, when the gimbal is not loaded with a load, the gimbal is in an unloaded state, as shown in Figure 1 (a). When the gimbal is loaded with a load, the gimbal is in a loaded state, as shown in Figure 1 (b), wherein the load is the mobile phone in Figure 1 (b). When the gimbal is in a loaded state, the gimbal can drive the shooting equipment to move in one or more directions through the axis, so as to capture images in a larger range.

Considering that the gimbal is in an unloaded state and the gimbal is started, the motor will have abnormal output and cause continuous shaking of the gimbal, which will make it difficult for the user to install the load on the gimbal, and it is easy to cause performance loss of the gimbal. In order to solve such technical problems, this application identifies the loading state of the gimbal, and then controls whether the gimbal works according to the loading state, thereby avoiding providing anti-shake service when the gimbal is in an unloaded state. Specifically, the embodiment of the present application provides a gimbal state recognition method, device, storage medium and equipment, and the execution subject of the method can be a gimbal control device provided in the embodiment of the present application, or a gimbal integrated with the gimbal control device. Among them, the gimbal control device can be implemented in hardware or software, and the gimbal includes but is not limited to a handheld gimbal, a camera gimbal, etc. In this embodiment, a handheld gimbal is used as an example to explain the solution provided in the embodiment of the present application. Among them, the handheld gimbal can also include a handheld gimbal for a smartphone, a handheld gimbal for a sports camera, a handheld gimbal for a micro single camera, and a handheld gimbal for a professional camera, etc., which will not be repeated here. Of course, the gimbal can also be carried on various aircraft or visual robots.

Please refer to Figure 2, which is a schematic diagram of the process of the gimbal state identification method provided in the embodiment of the present application. The specific process of the gimbal state identification method provided in the embodiment of the present application can be as follows:

S110, the axis obtains the angular velocity of the target axis of the gimbal and the torque output by the motor of the target axis, wherein the target axis is connected to a fixing mechanism of the gimbal for loading a load.

Since there are many types of pan-tilts, their structures are different and cannot be listed exhaustively. In this embodiment, only a handheld pan-tilt is used as an example for illustration, and other types of pan-tilts can refer to this method to implement the solution provided in this embodiment.

Specifically, please refer to FIG. 3, which is a schematic diagram of the structure of a handheld gimbal 100 provided in an embodiment of the present application. The handheld gimbal 100 includes a roll axis 101, a pitch axis 102, and a pan axis 103 connected in sequence, wherein the roll axis 101 is connected to a fixing mechanism 104, and the fixing mechanism 104 is used to load a shooting device 105, wherein the shooting device 105 loaded on the fixing mechanism 104 is regarded as a load relative to the handheld gimbal 100. The roll axis 101 rotates in the direction A shown in the figure to drive the fixing mechanism 104 to roll in the direction A, the pitch axis 102 rotates in the direction B shown in the figure, and the pan axis 103 rotates in the direction C shown in the figure. The handheld gimbal 100 also includes a handle 106, and the user uses the handheld gimbal 100 by holding the handle 106.

Among them, the target axis is the axis connected to the fixing mechanism, which is the roll axis 101 in Figure 3. Whether the fixing mechanism is loaded with a load will affect the angular velocity of the target axis and the torque output by the motor connected to the target axis. Therefore, in this embodiment, the angular velocity of the target axis and the torque output by the motor thereon can be obtained, and then the loading state of the gimbal can be determined based on the angular velocity and the torque output by the motor. Of course, on this basis, the angular velocity of other axes and the torque output by the motor can also be combined to determine the loading state of the gimbal. Since its implementation method is the same as the method of determining the loading state of the gimbal by the angular velocity of the motor of the target axis and the torque output by the motor, it will not be repeated here. It is only necessary to explain that all methods of determining the loading state of the gimbal based on the angular velocity and the torque output by the motor mentioned in the embodiments of the present application belong to the protection scope required by the present application.

Exemplarily, the angular velocity of the target axis can be measured by an inertial measurement unit, angular velocity meter or other instrument arranged on the target axis or calculated by angle sensor data, and the torque output by the motor can be determined by data such as the current, speed or power output by the motor of the target axis.

S120: Determine the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor.

Among them, the current moment of inertia can measure the inertia of the target axis when it rotates at the current moment. If the angular velocity fluctuation of the target axis becomes larger under the same motor output, it means that the moment of inertia of the target axis has become smaller. If the moment of inertia of the target axis is less than the preset no-load threshold, it can be further determined that there is no load on the target axis. In this case, the gimbal is judged to be in an no-load state. If the angular velocity fluctuation of the target axis becomes smaller under the same motor output, it means that the moment of inertia of the target axis has become larger. If the moment of inertia of the target axis is greater than the preset load threshold, the gimbal is judged to be in a loaded state.

Among them, the methods for determining the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor are: There are many methods, for example, the angular acceleration is determined by the change of the angular velocity, and then the moment of inertia of the target axis is calculated according to the ratio of the torque output by the motor and the angular acceleration. For another example, the current moment of inertia of the target axis is predicted by inputting the angular velocity and the torque output by the motor into a pre-trained neural network model, wherein the neural network model is trained by pre-learning the mapping relationship between the angular velocity, the torque output by the motor and the moment of inertia. It can be understood that there are many ways to determine the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor, which are not listed here.

S130, determining a loading state of the gimbal according to the current moment of inertia, where the loading state includes a loaded state or an unloaded state.

There are many ways to determine the loading state of the gimbal according to the current moment of inertia. For example, a mapping relationship between the moment of inertia and the loading state of the gimbal is preset. In this embodiment, the loading state preset by the gimbal system includes a loaded state and an unloaded state. One loading state may correspond to one or more moments of inertia, or one loading state may correspond to a numerical range of the moment of inertia. Specifically, if the current moment of inertia corresponds to the loaded state, it can be determined that the gimbal is in a loaded state. If the current moment of inertia corresponds to the unloaded state, it can be determined that the gimbal is in an unloaded state.

For another example, the change trend of the moment of inertia before a period of time is determined, and the loading state of the gimbal is determined according to whether the change trend is an upward or downward trend. Specifically, when the change trend is an upward trend, the gimbal is determined to be in a loaded state, and when the change trend is a downward trend, the gimbal is determined to be in an unloaded state.

In specific implementation, the present application is not limited by the execution order of the various steps described. If no conflict occurs, some steps can be performed in other orders or simultaneously.

The gimbal state identification method provided in the embodiment of the present application obtains the angular velocity of the target axis and the torque output by the motor of the target axis, and then determines the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor, wherein the current moment of inertia can accurately identify the situation in which the target axis is subjected to external force, and further can describe the loading state of the gimbal. The loading state of the gimbal includes a loaded state and an unloaded state. By determining whether the gimbal is currently in a loaded state or an unloaded state, the gimbal can be controlled so that the gimbal does not provide anti-shake service when it is in an unloaded state, thereby avoiding the situation in which the gimbal continuously shakes, making it easier for users to load loads on the gimbal, effectively improving the user experience, and further improving the stability and reliability of the use of the gimbal, extending the service life of the gimbal.

In some embodiments, determining the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor includes:

The inverse of the currently observed moment of inertia and the currently observed angular velocity are determined as state quantities, and the currently measured angular velocity is determined as a measured quantity;

Construct Kalman state equation and Kalman measurement equation according to state quantity and measurement quantity;

According to the Kalman state equation and the Kalman measurement equation, the current moment of inertia of the target axis is obtained.

Taking the influence of noise into consideration, in this embodiment, the current moment of inertia is calculated by Kalman filtering, and the moment of inertia satisfies the minimum variance estimation, and its value is more accurate. Furthermore, the accurately calculated current moment of inertia can more accurately describe the load state of the gimbal.

For example, the Kalman state equation can be constructed by taking the inverse of the current observed moment of inertia and the current observed angular velocity as state quantities, and the Kalman measurement equation can be constructed by taking the current measured angular velocity as the measurement quantity. The observed angular velocity and observed moment of inertia at the current moment can be solved by bringing the moment of inertia and angular velocity at the previous moment and the torque at the current moment into the Kalman state equation. The corrected angular velocity and corrected moment of inertia at the current moment can be solved by the measurement equation and the Kalman gain.

The process of constructing the Kalman state equation and the Kalman measurement equation is as follows:

First, considering that the torque output by the motor of the target axis is related to the inverse of the moment of inertia and the angular acceleration, the angular acceleration is expressed by the inverse of the moment of inertia and the torque output by the motor, and the expression is as follows:

in, represents angular acceleration, F represents the torque output by the motor, and G represents the inverse of the moment of inertia.

Furthermore, considering the influence of the eccentric torque on the torque output by the motor, the torque output by the motor can be corrected by the eccentric torque, so that the torque output by the motor is more accurate. The eccentric torque is measured in advance, and its measurement method includes but is not limited to collecting the output data of the motor under static stabilization and calculating it. After considering the influence of the eccentric torque, the expression of the angular acceleration can be as follows:

Where _M0 represents the eccentric moment.

After that, the state equation can be constructed by determining the inverse of the current observed moment of inertia and the current observed angular velocity at the current moment as state quantities. The expression of the state equation is as follows:

Among them, k represents the current moment and k-1 represents the previous moment. and is the state quantity, which is the value to be solved. Represents the inverse of the current observed moment of inertia at the current moment, Indicates the current The current observed angular velocity at the time. dt represents a preset period, which can represent the update period of the state equation. Represents the historical angular velocity at the previous moment. It represents the inverse of the historical moment of inertia at the previous moment, where the inverse of the historical moment of inertia can be obtained through the historical moment of inertia. _{d k-1} represents the observation noise, which is related to the system environment and can be obtained through offline test evaluation.

By taking the current measured angular velocity at the current moment as the measurement quantity, which is a value detected in real time by an inertial measurement unit or an angular velocity sensor, the constructed measurement equation is as follows:

Wherein, ω _k represents the current angular velocity measured in real time by the inertial measurement unit at the current moment, is the current observed angular velocity at the current moment, and v _k-1 represents the measurement noise, which is related to the measurement error of the inertial measurement unit. This value can be obtained by offline test evaluation.

As above, the inverse of the current observed moment of inertia can be obtained through the above state equation and measurement equation The current observed moment of inertia can be further determined based on the reciprocal.

In some embodiments, the current moment of inertia of the target axis is obtained according to the Kalman state equation and the Kalman measurement equation, including:

Solve the current torque output by the motor, the historical moment of inertia at the previous moment, and the historical angular velocity input state equation to obtain the current observed angular velocity and the current observed moment of inertia;

The current corrected angular velocity and the current corrected moment of inertia are calculated according to the Kalman measurement equation and the Kalman gain, and the current corrected moment of inertia is determined as the current moment of inertia of the target axis.

In this embodiment, the Kalman filtering algorithm is used to calculate the current moment of inertia at the current moment based on the torque output by the motor of the target axis and the angular velocity of the target axis, thereby filtering out the influence of white noise on the calculation of the current moment of inertia, reducing the calculation error of the current moment of inertia, and improving the accuracy of the current moment of inertia.

In some embodiments, determining the loading state of the gimbal according to the moment of inertia includes:

When the gimbal is in an unloaded state, if the current moment of inertia is greater than the preset load threshold and lasts for a preset time, the gimbal's loading state is switched to a loaded state;

When the gimbal is in a loaded state, if the current moment of inertia is less than a preset no-load threshold and lasts for a preset time, the loaded state of the gimbal is switched to the no-load state.

Among them, the present application pre-determines two thresholds, namely a preset no-load threshold and a preset load threshold, and then compares the current moment of inertia with the preset no-load threshold and the preset load threshold respectively, to determine whether its loading status needs to be changed in combination with the current loading status of the gimbal.

For example, when the gimbal is in an unloaded state, if the current moment of inertia is greater than a preset load threshold, the moment of inertia of the target axis is continuously detected within a preset time period, and the moment of inertia detected at each moment within the preset time period is called the current moment of inertia at that moment, and then it is determined whether the moment of inertia is greater than the preset load threshold. If so, the loading state of the gimbal is switched from the unloaded state to the loaded state. If not, the loading state of the gimbal can be re-determined, or the gimbal can be determined to be in an unloaded state.

It can be understood that after the current moment of inertia is greater than the preset load threshold, the moment of inertia of the target axis at each moment can be continuously detected within a preset time period thereafter, and the moment of inertia of the target axis at multiple moments can also be detected at sampling rate intervals. The specific real-time method is not limited here.

Accordingly, when the gimbal is in a loaded state, if the current moment of inertia is less than the preset no-load threshold, the current moment of inertia of the target axis is continuously detected within a preset period of time to determine whether the current moment of inertia is still less than the preset no-load threshold. If so, the loading state of the gimbal is switched from the loaded state to the no-load state.

In this embodiment, the loading state of the gimbal is judged according to the current loading state of the gimbal and combined with the current moment of inertia to determine whether to switch the loading state. On the one hand, it can verify whether the result of the current loading state is accurate. On the other hand, by continuously judging the size of the current moment of inertia, the loading state of the gimbal is judged after the current moment of inertia data is stable, which can avoid judgment errors and improve the accuracy of the loading state recognition of the gimbal.

In some embodiments, after determining the loading state of the gimbal according to the moment of inertia, the method further includes:

If the loading state of the gimbal is switched to the no-load state, and the current moment of inertia is greater than the preset no-load threshold and less than the preset load threshold, it is determined that the loading state of the gimbal is still the loaded state;

If the loading state of the gimbal is switched to the no-load state, and the current moment of inertia is greater than a preset no-load threshold and less than a preset load threshold, it is determined that the loading state of the gimbal is still the no-load state.

In this embodiment, after the loading state of the gimbal is switched, the current moment of inertia is still used to determine whether the loading state of the gimbal needs to be changed, that is, when the current moment of inertia is within the range between the preset no-load threshold and the preset load threshold, the loading state of the gimbal can be maintained. This method can avoid misjudgment of the loading state of the gimbal due to the value fluctuation of the current moment of inertia, thereby improving the accuracy of identifying the loading state of the gimbal.

In some embodiments, the preset no-load threshold is less than the preset load threshold, wherein the preset load threshold is less than the moment of inertia measured by the measuring instrument when the gimbal is loaded with a load, and the preset no-load threshold is greater than the moment of inertia measured by the measuring instrument when the gimbal is loaded with a load. The moment of inertia of the platform is measured by a measuring instrument when there is no load on the platform.

For example, the moment of inertia of the target axis can be measured multiple times by a measuring instrument when the gimbal is not loaded with a load, so as to determine a preset no-load threshold value according to multiple moments of inertia, and the moment of inertia of the target axis can be measured multiple times by a measuring instrument when the gimbal is loaded with a load, so as to determine a preset load threshold value according to multiple moments of inertia. Among them, any instrument capable of measuring the moment of inertia can be used in the embodiments of the present application to measure the moment of inertia of the gimbal.

Furthermore, the method of determining the preset no-load threshold or the preset load threshold based on the rotational inertia measured multiple times may be, for example, to obtain statistical values such as the average value, mean, median, extreme value, etc. of the rotational inertia measured multiple times, and then determine one of the statistical values as the preset no-load threshold or the preset load threshold.

Furthermore, the statistical value can be fine-tuned based on it to determine a preset no-load or preset load threshold. For example, based on the statistical value obtained when the gimbal is no-loaded, the preset no-load threshold is obtained by increasing the statistical value, and correspondingly, based on the statistical value obtained when the gimbal is loaded, the preset load threshold is obtained by decreasing the statistical value. The amplitude of decreasing or increasing the statistical value can be 5%, 10%, 12%, 15%, etc. as the adjustment amplitude based on it.

Wherein, _Je represents the statistical value obtained when the gimbal is unloaded, _J0 represents the preset unloaded threshold, _Jd represents the statistical value obtained when the gimbal is loaded, and _J1 represents the preset load threshold. The relationship is as follows:
J _e ＜J ₀ ＜J ₁ ＜J _d

In this embodiment, the moment of inertia of the target axis of the gimbal is measured in advance by a measuring instrument in two situations: when the gimbal is not loaded with a load and when it is loaded with a load, so as to determine a preset no-load threshold and a preset load threshold based on multiple measurement results, wherein the preset no-load threshold and the preset load threshold can accurately divide the no-load state and the loaded state of the gimbal, and there is a difference between the two thresholds, which has hysteresis performance, and can more accurately determine the loading state of the gimbal, making the switching of the loading state of the gimbal more stable.

As in the above examples, various implementation methods for determining the loading state of the gimbal according to the current moment of inertia of the target axis are provided. Here, a specific flowchart is provided to explain in detail the gimbal state identification method provided in the embodiment of the present application. Specifically, please refer to FIG. 4, which is a logic judgment diagram of the gimbal state identification method provided in the embodiment of the present application.

S210: Obtain the angular velocity of the target axis and the torque output by the motor.

S220: Determine the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor.

S230: When the gimbal is in an unloaded state, if the current moment of inertia is greater than the preset load threshold and continues After the preset time, the gimbal's loading state is switched to the load state;

After S230, executing S231, if the current moment of inertia is greater than the preset no-load threshold and less than the preset load threshold, determining that the loading state of the gimbal is still the loaded state;

S240, when the gimbal is in a loaded state, if the current moment of inertia is less than a preset no-load threshold and lasts for a preset time, switching the loaded state of the gimbal to a no-load state;

After S240, S241 is executed. If the current moment of inertia is greater than the preset no-load threshold and less than the preset load threshold, it is determined that the loading state of the gimbal is still in the no-load state.

In some embodiments, the loading state is a load state; after determining the loading state of the gimbal according to the current moment of inertia, the method further includes:

Determine the target control parameters of the axis of the gimbal according to the current moment of inertia;

The axis is stabilized and controlled according to the target control parameters of the axis.

For example, if a target shaft is loaded with a load, the current moment of inertia of the target shaft is related to the weight of the load loaded thereon, and the weight of the load can be determined by the current moment of inertia. The corresponding relationship between the current moment of inertia and the control parameter is preset, and by selecting different control parameters according to the weight of the load, the anti-shake effect on the load can be improved.

Exemplarily, the control parameters may include: motor torque information of each axis, response speed to load posture, motor rotation speed of each axis, etc.

Among them, after determining the target control parameters of each axis of the gimbal according to the current moment of inertia, the anti-shake service of the gimbal can be started according to the target control parameters to perform stabilization control on each axis, thereby performing targeted anti-shake control on the load, which can improve the shooting effect when the load is on the shooting equipment.

In some embodiments, after determining that the loading state of the gimbal is an unloaded state, the method further includes:

Control the motor unloading force of the gimbal axis; or,

Control the axis of the gimbal to move to a preset position; or,

Control the gimbal's axis to move to the preset position, stay there for a preset time, and then release the force.

Among them, when the gimbal is in a no-load state, the motor of the axis on the gimbal can be controlled to unload force. After the motor of the axis is unloaded, the axis is in a free state, and the axis can rotate accordingly by the external force (including gravity) applied thereto, and the torque output by the motor is zero, and the motor will not continue to vibrate, which is convenient for users to use. Among them, only the motor of the target axis can be unloaded, or the motors of all axes of the gimbal can be unloaded. The specific details can be determined according to actual needs and are not limited here. Taking the handheld gimbal mentioned above as an example, and combined with Figure 3, if the roll axis is unloaded, Then the roll axis can rotate freely in direction A based on the external force. For example, if the roll axis is only acted upon by gravity, the fixing mechanism connected to the roll axis is consistent with the direction of gravity.

Alternatively, when the gimbal is in an unloaded state, the target axis can be driven to move to a preset position by the motor of the target axis. After the target axis is driven to the preset position, the target axis is controlled to be locked, that is, the fixing mechanism connected to the target axis is controlled to be locked, so that the user can load the load on the fixing mechanism.

Of course, each axis of the gimbal can also be controlled to move to its corresponding preset position so that the load can be quickly loaded on the fixed mechanism. The preset position can be, for example, the position of the axis corresponding to the motor when the motor is in the reference zero position, the preset position can also be a position specified by the user, or a position determined according to the user's usage habits. When the user adjusts the axis to a certain position multiple times when loading the load, the position can be determined as the preset position.

Exemplarily, the axes of the gimbal are moved to their corresponding preset positions through linkage, so that the gimbal is in a specified posture, which can be a posture for the user to load a load on the fixing mechanism, a posture facing the user, or a default posture.

In some embodiments, the determined load state of the gimbal may also be matched with the current mode of the gimbal. When the two do not match, a prompt message is issued to prompt the user.

For example, if it is determined that the gimbal is in an idle state, the operating mode of the gimbal is obtained. If the operating mode is the idle mode, it means that the two match. If the operating mode is the working mode, it means that the two do not match, and a prompt message is issued.

For another example, if it is determined that the gimbal is in a load state, the operating mode of the gimbal is obtained. If the operating mode is a no-load mode, it means that the two do not match, and a prompt message is issued. If the operating mode is a working mode, it means that the two match.

More specifically, the prompt information can be output through the gimbal in the form of voice, text, vibration, etc., or output through an external device connected to the gimbal, where the external device is, for example, a mobile phone, headphones, a remote control, etc. The specific implementation method is not limited here.

Determine the force release duration used to control the gimbal to enter sleep mode;

Control the gimbal to slowly enter sleep mode based on the force unloading duration.

After determining that the PTZ is in an idle state, it is also possible to determine the state for controlling the PTZ to enter a dormant state. The force unloading time of the gimbal can be determined, and the gimbal can be controlled to slowly enter the dormant state according to the force unloading time. This can provide a buffer for the gimbal force unloading, avoid damage to the gimbal, improve the safety of the gimbal operation, and increase the service life of the gimbal.

Specifically, after the gimbal is in a no-load state, the motor's unloading speed can be determined based on the torque output by the motor and the unloading time, and then the target axis can be controlled to slowly unload the force according to the unloading speed to control the gimbal to enter a sleep state. After the gimbal enters the sleep state, the power consumption of the gimbal is reduced, which is conducive to extending the use time of the gimbal.

In some embodiments, after controlling the PTZ to enter a dormant state, the method further includes:

Upon receiving the user's exit sleep command, the PTZ is controlled to switch from sleep state to no-load state.

This embodiment provides a solution for the user to exit the sleep state. If the gimbal receives the user's exit sleep command, it can control the gimbal to switch from the sleep state to the no-load state. The user's exit sleep command can be triggered by, for example, the user operating a virtual or physical button on the gimbal, or by an external device connected to the gimbal. Of course, it can also be voice triggered or gesture triggered. It can be understood that it can also be proposed to control the gimbal to switch from the load state or the no-load state to the sleep state according to the user's sleep command. The specific implementation method will not be repeated here.

As can be seen from the above, the gimbal state recognition method proposed in the embodiment of the present invention can obtain the angular velocity of the target axis and the torque output by the motor of the target axis, and then calculate the current moment of inertia at the current moment according to the torque and angular velocity output by the motor through the Kalman filter algorithm, filter out the influence of white noise on the calculation of the current moment of inertia, reduce the calculation error of the current moment of inertia, and improve the accuracy of the current moment of inertia. Among them, when determining the loading state of the gimbal according to the current moment of inertia, the current moment of inertia is also compared with the preset no-load threshold and the preset load threshold, and then when the gimbal is in a loaded state and the current moment of inertia is less than the preset no-load threshold, the loading state of the gimbal is switched to the no-load state, and when the gimbal is in an no-load state and the current moment of inertia is greater than the preset load threshold, the loading state of the gimbal is switched to the loaded state. Among them, the preset load threshold is greater than the preset no-load threshold, and has hysteresis performance, which can more accurately determine the loading state of the gimbal, so that the switching of the loading state of the gimbal is more stable. In addition, after that, the loading status is still determined, which can avoid judgment deviation and improve the accuracy of the loading status identification of the gimbal. Secondly, after determining that the gimbal is in an unloaded state, the motor of the upper axis of the gimbal is controlled to unload force; or the axis of the gimbal is controlled to move to a preset position, which can facilitate user use. And when the motor unloads force, it also provides a buffer for the gimbal by slowly unloading force, avoiding damage to the gimbal. After the gimbal is determined to be in a load state, the anti-shake effect of the load can be improved by performing stabilization control on each axis.

In one embodiment, a gimbal state recognition device is also provided. Please refer to FIG. 5, which is a schematic diagram of the structure of the gimbal state recognition device provided in the embodiment of the present application. The gimbal state recognition device 300 is applied to the gimbal, and the gimbal state recognition device 300 includes:

The data acquisition module 310 is used to acquire the angular velocity of the target axis of the gimbal and the torque output by the motor of the target axis, wherein the target axis is connected to a fixing mechanism of the gimbal for loading a load;

A data prediction module 320, for determining a current moment of inertia of the target shaft based on the angular velocity and the torque output by the motor;

The state identification module 330 is used to determine the loading state of the gimbal according to the current moment of inertia, where the loading state includes a loaded state or an unloaded state.

In some embodiments, the data prediction module 320 is further configured to:

Substituting the moment of inertia and angular velocity of the previous moment and the torque output by the motor at the current moment into the Kalman state equation can solve the observed angular velocity and observed moment of inertia at the current moment;

The corrected angular velocity and corrected moment of inertia at the current moment can be calculated through the Kalman measurement equation and the Kalman gain.

In some embodiments, the state identification module 330 is further configured to:

In some embodiments, the preset no-load threshold is less than the preset load threshold, wherein the preset load threshold is less than the moment of inertia measured by the measuring instrument when the gimbal is loaded with a load, and the preset no-load threshold is greater than the moment of inertia measured by the measuring instrument when the gimbal is not loaded with a load.

In some embodiments, after determining that the loading state of the gimbal is an unloaded state, the state identification module 330 is further used to:

Control the motor unloading force of the gimbal axis; or,

Control the axis of the gimbal to move to a preset position; or,

Control the gimbal's axis to move to a preset position and stay there for a preset time before releasing the force.

It should be noted that the gimbal state recognition device 300 provided in the embodiment of the present application belongs to the same concept as the gimbal state recognition method in the above embodiment. Any method provided in the gimbal state recognition method embodiment can be implemented through the gimbal state recognition device 300. The specific implementation process is detailed in the gimbal state recognition method embodiment, which will not be repeated here.

As can be seen from the above, the pan-tilt state recognition device 300 proposed in the embodiment of the present application can obtain the angular velocity of the target axis and the torque output by the motor of the target axis, and then calculate the current moment of inertia at the current moment according to the torque and angular velocity output by the motor of the target axis through the Kalman filter algorithm, filter out the influence of white noise on the calculation of the current moment of inertia, reduce the calculation error of the current moment of inertia, and improve the accuracy of the current moment of inertia. Among them, when determining the loading state of the pan-tilt according to the current moment of inertia, the current moment of inertia is also compared with the preset no-load threshold and the preset load threshold, and then when the pan-tilt is in the load state and the current moment of inertia is less than the preset no-load threshold, the loading state of the pan-tilt is switched to the load state, and when the current moment of inertia is greater than the preset load threshold, it is determined that the pan-tilt is in the load state. Among them, the preset load threshold is greater than the preset no-load threshold, and has hysteresis performance, which can more accurately determine the loading state of the pan-tilt, so that the switching of the loading state of the pan-tilt is more stable. In addition, after this, the loading state is still determined, which can avoid the determination deviation and improve the accuracy of the loading state recognition of the pan-tilt. Secondly, after determining that the gimbal is in an unloaded state, the motor of the axis on the gimbal is controlled to unload force; Alternatively, the axis of the gimbal can be controlled to move to a preset position, which can facilitate user use. When the motor unloads force, it also provides a buffer for the gimbal by slowly unloading the force, avoiding damage to the gimbal, improving the safety of the gimbal operation, and increasing the service life of the gimbal. After determining that the gimbal is in a loaded state, the anti-shake effect of the load can be improved by performing stabilization control on each axis.

The embodiment of the present application also provides a gimbal, which includes but is not limited to a handheld gimbal, a fixed gimbal, an electric gimbal, a high-speed gimbal, a low-speed gimbal, etc., and can be further subdivided on this basis. For example, the handheld gimbal also includes a handheld gimbal for a smartphone, a handheld gimbal for a sports camera, a handheld gimbal for a micro-single camera, and a handheld gimbal for a professional camera, etc., which will not be repeated here. Of course, the gimbal can also be carried on various aircraft or visual robots. Please refer to Figure 6, which is a block diagram of a gimbal 400 provided in an embodiment of the present application. The gimbal 400 includes a gimbal body 410, an axis 430, and a controller 420, wherein the axis 430, one of which is a target axis connected to a fixing mechanism, and the fixing mechanism is used to load a load, wherein the axis 430 is correspondingly connected to a motor, and the motor drives the axis 430 to rotate. The controller 420 is used to control the motor to drive the corresponding axis 430 to rotate. It can be understood by those skilled in the art that the structure of the gimbal 400 shown in the figure does not constitute a limitation on the gimbal 400, and may include more or less components than shown, or combine certain components, or arrange different components.

Here, a handheld gimbal is taken as an example. The handheld gimbal includes a roll axis, a pitch axis, and a yaw axis connected in sequence, wherein the roll axis is connected to a fixing mechanism as a target axis, and the fixing mechanism is used to load a load.

Exemplarily, the controller 420 also includes a processor and a memory. The processor is the control center of the gimbal 400. It uses various interfaces and lines to connect various parts of the entire gimbal 400, execute various functions of the gimbal 400 and process data, thereby monitoring the gimbal 400 as a whole.

In the embodiment of the present application, the controller 420 in the pan/tilt platform 400 is configured to implement the following functions:

Obtaining the angular velocity of a target axis of the gimbal and the torque output by a motor of the target axis, wherein the target axis is connected to the motor by a fixing mechanism of the gimbal for loading a load;

The loading state of the gimbal is determined according to the current moment of inertia, and the loading state includes a loaded state or an unloaded state.

It can be understood that, although not shown in the figure, the gimbal 400 provided in this embodiment can also include a communication module to communicate with external devices, as well as a power supply module, an inertial measurement unit, a sensor, etc.

The specific implementation of the above operations can be found in the previous embodiments, which will not be described in detail here.

In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

As can be seen from the above, the pan-tilt platform 400 provided in this embodiment can obtain the angular velocity of the target axis and the torque output by the motor of the target axis, and then calculate the current moment of inertia at the current moment according to the torque and angular velocity output by the motor of the target axis through the Kalman filter algorithm, filter out the influence of white noise on the calculation of the current moment of inertia, reduce the calculation error of the current moment of inertia, and improve the accuracy of the current moment of inertia. Among them, when determining the loading state of the pan-tilt platform according to the current moment of inertia, the current moment of inertia is also compared with the preset no-load threshold and the preset load threshold, and then when the pan-tilt platform is in a loaded state and the current moment of inertia is less than the preset no-load threshold, the loading state of the pan-tilt platform is switched to a loaded state, and when the current moment of inertia is greater than the preset load threshold, it is determined that the pan-tilt platform is in a loaded state. Among them, the preset load threshold is greater than the preset no-load threshold, and has hysteresis performance, which can more accurately determine the loading state of the pan-tilt platform, so that the switching of the loading state of the pan-tilt platform is more stable. In addition, after this, the loading state is still determined, which can avoid the determination deviation and improve the accuracy of the loading state recognition of the pan-tilt platform. Secondly, after determining that the gimbal is in an unloaded state, the motor of the upper axis of the gimbal is controlled to unload force; or the axis of the gimbal is controlled to move to a preset position, which can facilitate user use. And when the motor unloads force, it also provides a buffer for the gimbal by slowly unloading force, avoiding damage to the gimbal, improving the safety of the gimbal operation, and increasing the service life of the gimbal. After determining that the gimbal is in a loaded state, the anti-shake effect of the load can be improved by performing stabilization control on each axis.

A person of ordinary skill in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be completed by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

To this end, the embodiment of the present application provides a computer-readable storage medium. A person skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium. When the program is executed, it includes the following steps:

Obtaining the angular velocity of a target axis of the gimbal and the torque output by a motor of the target axis, wherein the target axis is connected to a fixing mechanism of the gimbal for loading a load;

The above-mentioned storage medium may be ROM/RAM, a magnetic disk, an optical disk, etc. Since the computer program stored in the storage medium can execute the steps in any one of the gimbal state identification methods provided in the embodiments of the present application, the beneficial effects that can be achieved by any one of the gimbal state identification methods provided in the embodiments of the present application can be achieved, as detailed in the previous embodiments, which will not be repeated here.

The above is a detailed introduction to a gimbal state recognition method, device, medium and gimbal provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

A method for identifying a pan/tilt status, characterized in that the method comprises:

Acquire the angular velocity of the target axis of the gimbal and the torque output by the motor of the target axis, wherein the target axis is connected to a fixing mechanism of the gimbal for loading a load;

Determining a current moment of inertia of the target axis based on the angular velocity and the torque output by the motor;

The loading state of the gimbal is determined according to the current moment of inertia, wherein the loading state includes a loaded state or an unloaded state.
The method for identifying the state of a gimbal according to claim 1, wherein determining the current moment of inertia of the target axis based on the angular velocity and the torque output by the motor comprises:

The inverse of the currently observed moment of inertia and the currently observed angular velocity are determined as state quantities, and the currently measured angular velocity is determined as a measured quantity;

Constructing a Kalman state equation and a Kalman measurement equation according to the state quantity and the measurement quantity;

The current moment of inertia of the target axis is obtained according to the Kalman state equation and the Kalman measurement equation.
The gimbal state recognition method according to claim 2, characterized in that the step of obtaining the current moment of inertia of the target axis according to the Kalman state equation and the Kalman measurement equation comprises:

Input the current torque output by the motor, the historical moment of inertia at the previous moment, and the historical angular velocity into the state equation for solution to obtain the current observed angular velocity and the current observed moment of inertia;

The current corrected angular velocity and the current corrected moment of inertia are calculated according to the Kalman measurement equation and the Kalman gain, and the current corrected moment of inertia is determined as the current moment of inertia of the target axis.
The method for identifying the state of the gimbal according to claim 1, wherein determining the loading state of the gimbal according to the moment of inertia comprises:

When the gimbal is in the no-load state, if the current moment of inertia is greater than a preset load threshold and lasts for a preset time, switching the loading state of the gimbal to the loaded state;

When the gimbal is in the loaded state, if the current moment of inertia is less than a preset no-load threshold and lasts for a preset time, the loaded state of the gimbal is switched to the no-load state.
The method for identifying the state of the gimbal according to claim 4, characterized in that after determining the loading state of the gimbal according to the moment of inertia, it further comprises:

If the loading state of the gimbal is switched to the no-load state, and the current moment of inertia is greater than a preset no-load threshold and less than the preset load threshold, it is determined that the loading state of the gimbal is still the loaded state;

If the loading state of the gimbal is switched to the no-load state, and the current moment of inertia is greater than the preset no-load threshold and less than the preset load threshold, it is determined that the loading state of the gimbal is still the no-load state.
The gimbal state identification method according to claim 4 is characterized in that the preset no-load threshold is smaller than the preset load threshold, wherein the preset load threshold is smaller than the moment of inertia measured by a measuring instrument when the gimbal is loaded with a load, and the preset no-load threshold is greater than the moment of inertia measured by a measuring instrument when the gimbal is not loaded with a load.
The gimbal state recognition method according to claim 1 is characterized in that the angular velocity is detected by an angular velocity sensor arranged on the target axis.
The method for identifying the state of a gimbal according to any one of claims 1 to 7, characterized in that the loading state is the load state; after determining the loading state of the gimbal according to the current moment of inertia, the method further comprises:

Determining target control parameters of the axes of the gimbal according to the current moment of inertia;

The axis is subjected to stabilization control according to the target control parameter of the axis.
The method for identifying the state of a gimbal according to any one of claims 1 to 7, characterized in that the loaded state is the unloaded state; after determining the loaded state of the gimbal according to the current moment of inertia, the method further comprises:

Control the motor on the axis of the gimbal to unload force; or,

Control the axis of the pan/tilt head to move to a preset position; or,

The axis of the pan/tilt head is controlled to move to a preset position and stay there for a preset time before unloading the force.
A device for identifying a pan/tilt status, comprising:

A data acquisition module, used for acquiring the angular velocity of a target axis of the gimbal and the torque output by a motor of the target axis, wherein the target axis is connected to a fixing mechanism of the gimbal for loading a load;

A data prediction module, configured to determine a current moment of inertia of the target shaft based on the angular velocity and the torque output by the motor;

A state recognition module is used to determine the loading state of the gimbal according to the current moment of inertia. In the embodiment, the loading state includes a loaded state or an unloaded state.
A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is run on a computer, the computer is caused to execute the pan/tilt status identification method according to any one of claims 1 to 9.
A pan/tilt platform, characterized by comprising:

The gimbal body;

A target shaft, wherein the target shaft is connected to a fixing mechanism, wherein the fixing mechanism is used to carry a load;

A controller, wherein the controller is configured to execute the gimbal state recognition method according to any one of claims 1 to 9.