CN114730191A

CN114730191A - Cloud platform control method and device, cloud platform and movable platform

Info

Publication number: CN114730191A
Application number: CN202080075521.7A
Authority: CN
Inventors: 王文杰; 谢文麟
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2022-07-08
Also published as: WO2022110034A1

Abstract

A holder control method includes: acquiring the current attitude of the holder load; predicting that a gimbal deadlock will occur or determining that a gimbal deadlock has occurred; and controlling each shaft motor of the holder to rotate to a corresponding target joint angle so as to enable the load to move to a target posture. By the method, the technical problem that the gimbal deadlock occurs on the holder to cause abnormal control can be solved, and the technical problem that the motion path of the load is not the shortest path when the load moves to the target attitude can be solved.

Description

Cloud platform control method and device, cloud platform and movable platform

Technical Field

The present application relates to the field of cloud deck technologies, and in particular, to a cloud deck control method, device, cloud deck, mobile platform, and computer-readable storage medium.

Background

The cloud platform can support the load to can control the gesture of load. In the process of attitude control of the cradle head on the load, if the cradle head moves to a singular point on kinematics or near the singular point, the gimbal deadlock can occur, at the moment, the degree of freedom of the cradle head can be lost, an attitude controller of the cradle head diverges, and the cradle head control is abnormal, even the cradle head can rotate excessively.

Disclosure of Invention

In view of this, embodiments of the present application provide a pan/tilt head control method, apparatus, pan/tilt head, a movable platform, and a computer-readable storage medium, and one of the objectives is to solve the technical problem of abnormal control due to a dead lock of a gimbal of the pan/tilt head.

In a first aspect, an embodiment of the present application provides a pan/tilt control method, including:

acquiring the current attitude of the holder load;

predicting that a gimbal deadlock will occur or is determined to have occurred;

and controlling each shaft motor of the holder to rotate to a corresponding target joint angle so as to enable the load to move to a target posture.

A second aspect of the embodiments of the present application provides a pan/tilt control apparatus, including: a processor and a memory storing a computer program, the processor implementing the following steps when executing the computer program:

acquiring the current attitude of the holder load;

predicting that a gimbal deadlock will occur or determining that a gimbal deadlock has occurred;

A third aspect of the embodiments of the present application provides a pan/tilt head, including:

a base;

the holder mechanism is connected with the base and comprises a motor and a shaft arm of at least two shafts, and the tail end of the holder mechanism is used for fixedly or detachably connecting a load;

a processor and a memory storing a computer program, the processor implementing the following steps when executing the computer program:

acquiring the current attitude of the load;

A fourth aspect of embodiments of the present application provides a movable platform, including:

a body;

the driving device is connected with the machine body and used for providing power for the movable platform;

the holder mechanism is connected with the machine body and comprises at least two shaft motors and shaft arms, and the tail end of the holder mechanism is used for fixedly or detachably connecting a load;

acquiring the current attitude of the load;

and controlling each shaft motor of the holder mechanism to rotate to a corresponding target joint angle so as to enable the load to move to a target posture.

A fifth aspect of the embodiments of the present application provides a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program implements the pan/tilt control method provided in the embodiments of the present application.

According to the cloud deck control method provided by the embodiment of the application, when universal joint deadlock is estimated to occur or determined to occur, the motors of all the shafts can be controlled to rotate to respective target joint angles respectively, decoupling and control are achieved between the motors independently, the whole process does not involve conversion between an operation space and a joint space, the problem of universal joint deadlock does not exist, and therefore loads can smoothly move to target postures. Meanwhile, because the motors of all the shafts are decoupled, and the motors of all the shafts are controlled independently, the motors can directly rotate to the corresponding target joint angles, the motors do not need to be matched with other motors, the conditions of rotation and the like do not exist, and the load can move to the target posture in the shortest path.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a pan/tilt head provided in an embodiment of the present application.

Fig. 2 is a flowchart of a pan-tilt control method provided in an embodiment of the present application.

Fig. 3 is a schematic diagram of pan-tilt attitude control provided in an embodiment of the present application.

Fig. 4 is a schematic structural diagram of a pan/tilt head control device provided in an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a movable platform provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The cradle head can be used for supporting a load and also can be used for controlling the position and the posture of the load. The types of the holders are various, and the holders are divided according to the number of the holder shafts, and can comprise two-shaft holders, three-shaft holders, four-shaft holders and the like; the load of the slave cloud platform is divided variably, and the slave cloud platform can comprise a fixed load cloud platform and a variable load cloud platform; divide from carrying on the carrier of cloud platform, can include handheld cloud platform, on-vehicle cloud platform, unmanned aerial vehicle cloud platform etc.. The load of the holder is also various, for example, the holder can be a mechanical gripper, a fixing clamp and the like, and also can be a shooting device, such as a camera, a mobile phone, a flat panel and the like.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a pan/tilt head provided in an embodiment of the present application. Fig. 1 shows a mobile phone holder, which is a three-axis holder and includes a base (handle) 110 and a holder mechanism 120 connected to the base 110. The holder mechanism comprises three

shaft arms

121a, 121b and 121c and

motors

122a, 122b and 122c corresponding to three shafts, and the tail end of the holder mechanism is a mobile phone holder 123 which can be used for fixing a mobile phone.

The cloud platform can drive the motion of beam jib through the motor to drive the terminal load motion of beam jib, realize the control to the load gesture. However, in the control process of the load attitude, the pan-tilt may move to a singular point or near the singular point, causing the gimbal to be deadlocked. When the universal joint is deadlocked, the degree of freedom of the holder can be lost, the attitude controller of the holder can be dispersed, the holder can be controlled abnormally, and the holder can rotate excessively.

In order to solve the above problem, an embodiment of the present application provides a pan/tilt control method. Referring to fig. 2, fig. 2 is a flowchart of a pan/tilt control method provided in an embodiment of the present application. The method can be executed by a processor of the pan-tilt, for example, the steps of the method can be written into a corresponding computer program, and the computer program can be configured in a memory of the pan-tilt, so that the processor of the pan-tilt can call and execute the computer program to implement the execution of the pan-tilt control method. The method may comprise the steps of:

s202, obtaining the current attitude of the holder load.

And S204, predicting that the universal joint deadlock will occur or determining that the universal joint deadlock has occurred.

And S206, controlling each shaft motor of the holder to rotate to a corresponding target joint angle so as to enable the load to move to a target posture.

As mentioned previously, the load of the head may be removable or fixed. The current attitude of the pan-tilt load can be acquired in various ways. In one embodiment, an attitude sensor may be provided at the end of the pan/tilt head, and the current attitude of the load at the end may be collected by the attitude sensor. Here, if the load and the pan/tilt head are in a fixed connection relationship, the attitude sensor may be disposed on the load; if the load is connected with the holder through the holder at the tail end of the holder, the attitude sensor can be arranged on the holder at the tail end of the holder. In one example, the attitude sensor may be an inertial measurement unit IMU. In one example, the attitude may be attitude information, which may be represented by pitch angle pitch, yaw angle yaw, roll angle, for example.

Gimbal deadlock refers to a phenomenon that a gimbal control is abnormal when a gimbal moves to a kinematic singular point or a vicinity of the singular point, where the abnormal gimbal control may be, for example, a loss of one or more dimensions of control freedom. For example, for a three-axis pan/tilt head, when the gimbal deadlock occurs, one-dimensional degree of freedom will be lost, and the pan/tilt head only has two-dimensional degrees of freedom.

The universal joint deadlock may occur due to various reasons, for example, taking the load as the shooting device, in one example, the shooting device may be required to be turned to a specific angle during shooting, and the shooting device may be in an attitude corresponding to a singular point after turning to the specific angle, thereby causing the universal joint deadlock. In one example, the cradle head may move to a posture corresponding to a singular point at any time while intelligently tracking a shooting target, for example, tracking a child running from a distance by using a three-axis cloud platform, and if the child runs to the bottom of the cradle head and makes a lens of a shooting device face downwards vertically, the cradle head may be locked by a universal joint. In one example, a user may break the pan-tilt off before the pan-tilt is turned on, and break the attitude of the pan-tilt off to an attitude corresponding to the singular point, so that the pan-tilt is deadlocked by the gimbal after the pan-tilt is turned on.

For the cloud platforms with different shaft numbers, the states of the cloud platforms with different shaft numbers are different when the cloud platforms are subjected to universal joint deadlock. For example, for a two-axis pan-tilt, when the universal joint is deadlocked, the two rotating joints are coaxial; for the three-axis tripod head, when the universal joint deadlock occurs, the three rotating joints are coplanar, and the axes of the three rotating joints are parallel; for the four-axis tripod head, when the universal joint is deadlocked, the axes of the four rotating joints are converged at one point; for a five-axis tripod head, four rotating joints are coplanar when universal joint deadlock occurs; for a six-axis tripod head, when the universal joint deadlock occurs, the axes of six rotating joints are intersected with a common straight line. Therefore, in one embodiment, whether the gimbal deadlock occurs in the pan/tilt head can be determined according to the current position relationship of the rotational joint of the pan/tilt head and/or the position relationship of the axis of the rotational joint.

In one embodiment, it may also be determined from an algorithm level whether gimbal deadlock is currently occurring in the pan/tilt head, but before this is explained, the operation principle of the pan/tilt head may be explained first.

As mentioned above, the pan/tilt head can control the attitude of the load, and the objective of the attitude control of the load is to make the current attitude of the load as close to the target attitude as possible, even if the difference between the current attitude and the target attitude is within a preset threshold. Here, the target pose may be different poses in different scenes. In one scenario, the target posture may be a centering posture after the pan/tilt centering, and the centering posture may be various postures, in an example, the centering posture may at least include a pitch angle pitch of 0, and the roll angle may be different according to different requirements, for example, the roll angle of the centering posture of the mobile phone pan/tilt may respectively correspond to 0 ° and 90 ° in both the pan and tilt modes, and the yaw angle yaw may be any specified angle. In one scenario, the target pose may be a specified pose set by the user to be maintained. In one scenario, the load may be a shooting device, and the target pose may be a pose determined by the pan/tilt head according to a set track when the shooting device is used for applications such as intelligent following and track delay shooting. For example, during intelligent follow-up, the shooting target can be tracked according to the image shot by the shooting device, and the target posture of the shooting device can be determined according to the tracking result, so that follow-up shooting of the shooting target is realized.

When the tripod head controls the current posture of the load, the load is indirectly controlled to rotate in each direction by controlling the rotation angular velocity of each shaft motor. Referring to fig. 3, fig. 3 is a schematic diagram of a pan/tilt head attitude control provided in an embodiment of the present application. As shown in fig. 3, the current attitude of the load may be measured by the inertial measurement unit, and the measured current attitude may be compared with the target attitude to obtain an attitude deviation (in one example, the attitude deviation may be expressed by a quaternion) between the current attitude and the target attitude. After determining the attitude deviation, a first target rotational angular velocity of the load in each direction in the operation space, which is a rotational angular velocity required for changing the current attitude of the load to the target attitude, may be determined from the attitude deviation.

Since the first target rotational angular velocity of the load in each direction is a rotational angular velocity based on the operation space, and the actual controllable pan/tilt head is a rotational angular velocity based on each axis motor of the joint space, in one embodiment, the first target rotational angular velocity may be mapped from the operation space to the joint space, so that the second target rotational angular velocity corresponding to each axis motor may be obtained. After the second target rotational angular velocity corresponding to each axis motor is determined, each axis motor may be controlled to move the current posture of the load to the target posture according to the second target rotational angular velocity.

The working principle of the cradle head for controlling the load attitude is described above. Wherein in mapping the first target rotational angular velocity from the operating space to the joint space, in one embodiment, the mapping may be performed by an inverse of a jacobian matrix. Since the jacobian matrix can be used to map the rotational angular velocity from the joint space to the operation space, if the rotational angular velocity needs to be mapped from the operation space to the joint space, the inverse of the jacobian matrix can be used. The Jacobian matrix can be determined according to the axial direction of each shaft of the holder and the current joint angle of each shaft motor, under the normal condition, the Jacobian matrix is reversible, but when the holder is subjected to universal joint deadlock, the Jacobian matrix becomes irreversible, so that the rotation angular velocity of at least one dimensionality is infinitely great after being mapped to a joint space from an operation space, the attitude controller diverges, and holder control abnormity occurs.

Therefore, when determining whether the gimbal deadlock occurs, in an embodiment, the jacobian matrix may be determined according to the axial direction of each axis of the pan/tilt and the current joint angle of each axis motor, and it is determined whether the jacobian matrix is reversible, and if the jacobian matrix is not reversible, it may be determined that the gimbal deadlock occurs in the pan/tilt.

In an implementation mode, the occurrence of the dead lock of the universal joint can be estimated in advance, so that the reaction can be performed in advance according to the estimation result, and the occurrence of the dead lock of the universal joint is avoided. Specifically, in an example, the motion trajectory of each axis of the pan/tilt head may be determined according to the attitude deviation between the current attitude and the target attitude of the load, and then whether the gimbal deadlock will occur in the future may be determined according to the motion trajectory of each axis. Here, the motion trajectory may be a motion trajectory generated in an application such as smart follow-up or trajectory delay photography, or may be a motion trajectory set by a user.

After the universal joint deadlock is estimated to occur or determined to occur, the motors of all the shafts of the holder are controlled to rotate to the corresponding target joint angles, so that the load moves to the target attitude.

As can be known from the foregoing description of the operating principle of the pan/tilt head, when the pan/tilt head controls the attitude of the load, the pan/tilt head needs to perform the conversion from the rotational angular velocity of the load in the operating space to the rotational angular velocity of the motor in the joint space, and when the gimbal deadlock occurs, because the jacobian matrix is irreversible, the conversion from the operating space to the joint space will result in that the rotational angular velocity in at least one direction tends to infinity after the conversion, the attitude controller diverges, and the pan/tilt head control is abnormal. And based on this kind of theory of operation of cloud platform, have certain coupled relation between its each axle motor, the motor needs the motor of cooperation or other axles of transference when rotating to in some cases, the motor probably carries out gyration or carries out other unnecessary rotations, leads to the load can not move to the target gesture with the shortest motion path.

According to the method provided by the embodiment of the application, when the occurrence or the determination of the occurrence of the universal joint deadlock is estimated, the motors of the shafts can be controlled to rotate to respective target joint angles, decoupling and control between the motors are independent, the whole process does not involve conversion between an operation space and a joint space, the problem of universal joint deadlock does not exist, and therefore the load can smoothly move to a target posture. Meanwhile, because the motors of all the shafts are decoupled, and the motors of all the shafts are controlled independently, the motors can directly rotate to the corresponding target joint angles, the motors do not need to be matched with other motors, the conditions of rotation and the like do not exist, and the load can move to the target posture in the shortest path.

In one embodiment, the target joint angle may be determined based on the current attitude of the base (base attitude), the target attitude, and the axial direction of the respective axes of the pan/tilt head. As mentioned above, the cradle head may include a base, where the attitude of the base is distinguished from the attitude of the load, such as the mobile phone cradle head of fig. 1, the base (i.e., the handle) is held by the user, and the attitude of the load changes in real time with the holding attitude of the user, and the attitude of the load refers to the attitude of the mobile phone, and the attitude of the load can be maintained at a desired target attitude without being influenced by the attitude of the base under the control of the cradle head mechanism.

For the base attitude, in one embodiment, it may be determined from the current attitude of the load and the current joint angles of the axis motors; in one embodiment, an attitude sensor (e.g., inertial measurement unit IMU) may be disposed on the base such that the base attitude may be measured by the attitude sensor.

The operational principle of the foregoing pan/tilt head is to control the attitude of the load by controlling the rotational angular velocity of the motor, and this operational mode of the pan/tilt head can be referred to as a first operational mode. When the universal joint deadlock is predicted to occur or determined to occur, the cradle head can control the load attitude by controlling the motor to rotate to the target joint angle, and the working mode of the cradle head can be called as a second working mode. In the second working mode, after the shaft motors rotate to the respective corresponding target joint angles, that is, after the current joint angles of the shaft motors are matched with the respective corresponding target joint angles (the matching here may be, for example, that the difference between the current joint angles and the target joint angles is within a preset threshold), since the universal joint deadlock is disengaged at this time, the first working mode can be switched back, that is, the attitude of the load is continuously controlled by controlling the rotational angular velocities of the shaft motors, so as to improve the accuracy of the load attitude control.

The above is a detailed description of the pan/tilt control method provided in the embodiments of the present application.

According to the method provided by the embodiment of the application, when the universal joint deadlock is estimated to occur or determined to occur, the motors of all the shafts can be controlled to rotate to respective target joint angles respectively, decoupling and control are achieved between the motors independently, the whole process does not involve conversion between an operation space and a joint space, the problem of universal joint deadlock does not exist, and therefore the load can smoothly move to a target posture. Meanwhile, because the motors of all the shafts are decoupled, and the motors of all the shafts are controlled independently, the motors can directly rotate to the corresponding target joint angles, the motors do not need to be matched with other motors, the conditions of rotation and the like do not exist, and the load can move to the target posture in the shortest path.

Reference may be made to fig. 4, and fig. 4 is a schematic structural diagram of a pan/tilt head control device provided in an embodiment of the present application. The apparatus may include: a processor 410 and a memory 420 having stored thereon a computer program which when executed by the processor performs the steps of:

acquiring the current attitude of the holder load;

Optionally, the cradle head comprises a base, and the load is connected to the base through a shaft arm.

Optionally, the target joint angle is determined according to a base posture of the base, the target posture, and each axis of the cloud platform.

Optionally, the attitude of the base is determined according to the current attitude of the load and the current joint angle of each axis motor.

Optionally, the attitude of the base is measured by an attitude sensor arranged on the base.

Optionally, the processor is configured to determine a motion trajectory of each axis of the pan/tilt head according to an attitude deviation between the current attitude and the target attitude when predicting whether gimbal deadlock will occur; and predicting whether universal joint deadlock will occur or not according to the motion trail of each shaft.

Optionally, the processor is configured to determine whether the gimbal deadlock has occurred according to a current position relationship of a rotational joint and/or an axis of the pan/tilt when determining whether the gimbal deadlock has occurred.

Optionally, the pan/tilt head includes at least two rotation joints coplanar when the gimbal deadlock occurs.

Optionally, the pan/tilt head comprises a two-axis pan/tilt head.

Optionally, when the gimbal is deadlocked, the two rotational joints are coaxial.

Optionally, the holder comprises a three-axis holder.

Optionally, when the tripod head is in a gimbal deadlock, the three rotational joints are coplanar, and the axes of the three rotational joints are parallel.

Optionally, the holder includes a four-axis holder.

Optionally, when the gimbal is deadlocked, the axes of the four rotational joints of the pan and tilt assembly meet at a point.

Optionally, the processor is further configured to control the posture of the load by controlling the rotational angular velocity of each axis motor when the current joint angle of each axis motor matches the respective corresponding target joint angle.

Optionally, the processor, when controlling the attitude of the load by controlling the rotational angular velocity of each axis motor, is configured to determine a first target rotational angular velocity of the load in each direction in the operation space according to an attitude deviation between a current attitude and a target attitude of the load; mapping the first target rotation angular velocity of each direction to a joint space to obtain a second target rotation angular velocity corresponding to each axis motor; and controlling each shaft motor according to a second target rotation angular velocity corresponding to each shaft motor.

Optionally, the target posture comprises a centering posture of the pan/tilt head.

Optionally, the centering posture at least includes a pitch angle of 0.

Optionally, the target gesture includes a designated gesture set by a user.

Optionally, the load comprises a camera.

Optionally, the target posture is determined by performing target following on the image captured by the capturing device.

For the specific implementation of the various embodiments of the pan/tilt control apparatus provided above, reference may be made to the corresponding description in the foregoing, and details are not described herein again.

The device provided by the embodiment of the application can respectively control the motors of all the shafts to rotate to respective target joint angles when universal joint deadlock is estimated to occur or determined to occur, decoupling and control are mutually independent between the motors, the whole process does not involve conversion between an operation space and a joint space, and the problem of universal joint deadlock does not exist, so that a load can smoothly move to a target attitude. Meanwhile, because the motors of all the shafts are decoupled, and the motors of all the shafts are controlled independently, the motors can directly rotate to the corresponding target joint angles, the motors do not need to be matched with other motors, the conditions of rotation and the like do not exist, and the load can move to the target posture in the shortest path.

The embodiment of the application further provides a holder, and the structure of the holder can refer to the handheld holder in fig. 1. The cloud platform that this application embodiment provided includes:

a base;

acquiring the current attitude of the load;

Optionally, the target joint angle is determined according to a base posture of the base, the target posture, and an axial direction of each axis of the pan/tilt head.

Optionally, the tripod head includes at least two rotation joints coplanar when the gimbal deadlock occurs.

Optionally, the pan/tilt head comprises a two-axis pan/tilt head.

Optionally, when the tripod head is locked by the universal joint, the two rotating joints are coaxial.

Optionally, the holder comprises a three-axis holder.

Optionally, when the tripod head is in a gimbal deadlock, the three rotational joints are coplanar and the axes of the three rotational joints are parallel to each other.

Optionally, the holder includes a four-axis holder.

Optionally, the processor is further configured to control the posture of the load by controlling a rotational angular velocity of each axis motor when the current joint angle of each axis motor matches the respective target joint angle.

Optionally, the centering posture at least includes a pitch angle of 0.

Optionally, the target gesture includes a designated gesture set by a user.

Optionally, the load comprises a camera.

The cloud platform that this application embodiment provided, when predicting will take place or confirm that universal joint deadlock has taken place, can control each axle motor respectively and rotate to respective target joint angle, realize decoupling zero between the motor, control mutual independence, whole process does not relate to the conversion between operation space and the joint space, does not have the problem of universal joint deadlock, therefore the motion that the load can be smooth reaches the target gesture. Meanwhile, because the motors of all the shafts are decoupled, and the motors of all the shafts are controlled independently, the motors can directly rotate to the corresponding target joint angles, the motors do not need to be matched with other motors, the conditions of rotation and the like do not exist, and the load can move to the target posture in the shortest path.

Reference may be made to fig. 5, where fig. 5 is a schematic structural diagram of a movable platform provided in an embodiment of the present application. The movable platform may be any device having movement capabilities, such as a drone, drone vehicle, drone, robot, etc., the drone shown in fig. 5 being merely one example. The movable platform may include:

a body 510;

a driving device 520 connected to the body for providing power to the movable platform;

a pan/tilt mechanism 530 connected to the body, the pan/tilt mechanism including a motor and a shaft arm of at least two shafts, the end of the pan/tilt mechanism being used to connect a load 540 fixedly or detachably;

a processor 550 and a memory 560 in which a computer program is stored, said processor realizing the following steps when executing said computer program:

acquiring the current attitude of the load;

Optionally, the target joint angle is determined according to a base posture of the base, the target posture, and an axial direction of each axis of the pan/tilt mechanism.

Optionally, the processor is configured to determine a motion trajectory of each axis of the pan/tilt head mechanism according to an attitude deviation between the current attitude and the target attitude when predicting whether gimbal deadlock will occur; and predicting whether universal joint deadlock will occur or not according to the motion trail of each shaft.

Optionally, the processor is configured to determine whether the gimbal deadlock has occurred according to a position relationship of a current rotational joint and/or axis of the pan/tilt mechanism when determining whether the gimbal deadlock has occurred.

Optionally, the pan-tilt mechanism includes at least two rotation joints coplanar when the gimbal deadlock occurs.

Optionally, the pan-tilt mechanism includes a two-axis pan-tilt.

Optionally, when the gimbal mechanism is deadlocked, the two rotating joints are coaxial.

Optionally, the pan-tilt mechanism includes a three-axis pan-tilt.

Optionally, when the gimbal mechanism is deadlocked, the three rotational joints are coplanar and the axes of the three rotational joints are parallel to each other.

Optionally, the holder mechanism includes a four-axis holder.

Optionally, when the gimbal mechanism is deadlocked, the axes of the four rotational joints intersect at one point.

Optionally, the target attitude comprises a centering attitude of the pan and tilt head mechanism.

Optionally, the centering posture at least includes a pitch angle of 0.

Optionally, the target gesture includes a designated gesture set by a user.

Optionally, the load comprises a camera.

For the above-provided various embodiments of the movable platform, reference may be made to the corresponding descriptions in the foregoing text for specific implementations thereof, which are not described herein again.

The movable platform provided by the embodiment of the application can respectively control the motors of all the shafts to rotate to respective target joint angles when universal joint deadlock is estimated to occur or determined to occur, decoupling and control are mutually independent between the motors, the whole process does not involve conversion between an operation space and a joint space, the problem of universal joint deadlock does not exist, and therefore loads can smoothly move to a target posture. Meanwhile, because the motors of all the shafts are decoupled, and the motors of all the shafts are controlled independently, the motors can directly rotate to the corresponding target joint angles, the motors do not need to be matched with other motors, the conditions of rotation and the like do not exist, and the load can move to the target posture in the shortest path.

The embodiment of the application also provides a computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the cloud deck control method provided by the embodiment of the application is realized.

In the above, various embodiments are provided for each protection subject, and on the basis of no conflict or contradiction, a person skilled in the art can freely combine various embodiments according to actual situations, thereby forming various technical solutions. The present disclosure is not limited to the text, and the technical solutions obtained by combining all the components cannot be expanded, but it can be understood that the technical solutions which are not expanded also belong to the scope disclosed in the embodiments of the present disclosure.

Embodiments of the present application may take the form of a computer program product embodied on one or more storage media including, but not limited to, disk storage, CD-ROM, optical storage, and the like, in which program code is embodied. Computer-usable storage media include permanent and non-permanent, removable and non-removable media, and information storage may be implemented by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of the storage medium of the computer include, but are not limited to: phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technologies, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic tape storage or other magnetic storage devices, or any other non-transmission medium, may be used to store information that may be accessed by a computing device.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The method and apparatus provided by the embodiments of the present invention are described in detail above, and the principle and the embodiments of the present invention are explained in detail herein by using specific examples, and the description of the embodiments is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

A holder control method is characterized by comprising the following steps:

acquiring the current attitude of the holder load;

predicting that a gimbal deadlock will occur or is determined to have occurred;

and controlling each shaft motor of the holder to rotate to a corresponding target joint angle so as to enable the load to move to a target posture.
The method of claim 1, wherein the head comprises a base, and the load is coupled to the base by an axle arm.
The method of claim 2, wherein the target joint angle is determined axially from a base attitude of the base, the target attitude, and respective axes of the pan and tilt head.
The method of claim 3, wherein the base attitude is determined based on a current attitude of the load and a current joint angle of the axis motors.
The method of claim 3, wherein the base attitude is measured from an attitude sensor disposed on the base.
The method of claim 1, wherein predicting whether gimbal deadlock will occur comprises:

determining the motion trail of each axis of the holder according to the attitude deviation between the current attitude and the target attitude;

and predicting whether universal joint deadlock will occur or not according to the motion trail of each shaft.
The method of claim 1, wherein determining whether a gimbal deadlock has occurred comprises:

and determining whether the universal joint deadlock occurs or not according to the position relation of the current rotating joint and/or axis of the holder.
The method of claim 1, wherein the pan/tilt head comprises at least two rotational joints that are coplanar when gimbal deadlock occurs.
The method of claim 1, wherein the pan-tilt comprises a two-axis pan-tilt.
The method of claim 9, wherein the pan and tilt head is coaxial with the two rotational joints when gimbal deadlock occurs.
The method of claim 1, wherein the pan-tilt comprises a three-axis pan-tilt.
The method of claim 11, wherein the pan and tilt head has three revolute joints coplanar and axes of the three revolute joints parallel when gimbal deadlock occurs.
The method of claim 1, wherein the pan-tilt comprises a four-axis pan-tilt.
The method of claim 12, wherein the pan and tilt head is configured such that axes of four revolute joints meet at a point when gimbal deadlock occurs.
The method of claim 1, further comprising:

and when the current joint angle of each shaft motor is matched with the corresponding target joint angle, controlling the posture of the load by controlling the rotation angular velocity of each shaft motor.
The method according to claim 15, wherein the controlling the posture of the load by controlling rotational angular velocities of the respective shaft motors comprises:

determining a first target rotation angular velocity of the load in each direction in an operation space according to the attitude deviation of the current attitude and the target attitude of the load;

mapping the first target rotation angular velocity of each direction to a joint space to obtain a second target rotation angular velocity corresponding to each axis motor;

and controlling each shaft motor according to a second target rotation angular velocity corresponding to each shaft motor.
The method of claim 1, wherein the target pose comprises a centering pose of the pan-tilt.
The method of claim 17, wherein the centering attitude comprises at least a pitch angle of 0.
The method of claim 1, wherein the target gesture comprises a specified gesture set by a user.
The method of claim 1, wherein the load comprises a camera.
The method of claim 20, wherein the target pose is a target-following determination of an image captured by the camera.
A pan/tilt control device, comprising: a processor and a memory storing a computer program, the processor implementing the following steps when executing the computer program:

acquiring the current attitude of the holder load;

predicting that a gimbal deadlock will occur or determining that a gimbal deadlock has occurred;

and controlling each shaft motor of the holder to rotate to a corresponding target joint angle so as to enable the load to move to a target posture.
The apparatus of claim 22, wherein the head comprises a base, and the load is coupled to the base by an axle arm.
The apparatus of claim 23, wherein the target joint angle is determined axially from a base attitude of the base, the target attitude, and respective axes of the pan and tilt head.
The apparatus of claim 24, wherein the base attitude is determined based on a current attitude of the load and a current joint angle of the axis motors.
The apparatus of claim 24, wherein the base attitude is measured from an attitude sensor disposed on the base.
The apparatus of claim 22, wherein the processor, when predicting whether gimbal deadlock will occur, is configured to determine a motion trajectory of each axis of the pan/tilt head according to an attitude deviation between the current attitude and the target attitude; and predicting whether universal joint deadlock will occur or not according to the motion trail of each shaft.
The apparatus of claim 22, wherein the processor, when determining whether gimbal deadlock has occurred, is configured to determine whether gimbal deadlock has occurred based on a current positional relationship of rotational joints and/or axes of the pan and tilt head.
The apparatus of claim 22, wherein the pan/tilt head comprises at least two rotational joints coplanar when gimbal deadlock occurs.
The apparatus of claim 22, wherein the pan/tilt head comprises a two-axis pan/tilt head.
The apparatus of claim 30, wherein the pan and tilt head is coaxial with the two rotational joints when gimbal deadlock occurs.
The apparatus of claim 22, wherein the pan-tilt comprises a three-axis pan-tilt.
The apparatus of claim 32, wherein the pan/tilt head has three revolute joints coplanar and axes of the three revolute joints parallel when the gimbal deadlock occurs.
The apparatus of claim 22, wherein the pan head comprises a four-axis pan head.
The apparatus of claim 34, wherein the pan/tilt head is configured such that axes of four revolute joints meet at a point when gimbal deadlock occurs.
The apparatus of claim 22, wherein the processor is further configured to control the attitude of the load by controlling a rotational angular velocity of each of the axis motors when the current joint angle of each of the axis motors matches a respective target joint angle.
The apparatus of claim 36, wherein the processor, when controlling the attitude of the load by controlling the rotational angular velocity of each axis motor, is configured to determine a first target rotational angular velocity of the load in each direction in the operation space, based on an attitude deviation of a current attitude of the load from a target attitude; mapping the first target rotation angular velocity of each direction to a joint space to obtain a second target rotation angular velocity corresponding to each axis motor; and controlling each shaft motor according to a second target rotation angular velocity corresponding to each shaft motor.
The apparatus of claim 22, wherein the target pose comprises a centering pose of the pan/tilt head.
The apparatus of claim 38, wherein the centering attitude comprises at least a pitch angle of 0.
The apparatus of claim 22, wherein the target gesture comprises a specified gesture set by a user.
The device of claim 22, wherein the load comprises a camera.
The device of claim 41, wherein the target pose is subject to a target follow determination for an image captured by the camera.
A head, characterized in that it comprises:

a base;

the holder mechanism is connected with the base and comprises a motor and a shaft arm of at least two shafts, and the tail end of the holder mechanism is used for fixedly or detachably connecting a load;

a processor and a memory storing a computer program, the processor implementing the following steps when executing the computer program:

acquiring the current attitude of the load;

predicting that a gimbal deadlock will occur or determining that a gimbal deadlock has occurred;

and controlling each shaft motor of the holder to rotate to a corresponding target joint angle so as to enable the load to move to a target posture.
A head according to claim 43, wherein said target articulation angle is determined axially from a base attitude of said base, said target attitude and respective axes of said head.
A head according to claim 44, wherein said base attitude is determined from a current attitude of said load and a current joint angle of said axis motors.
A head according to claim 44, wherein said base attitude is measured by means of an attitude sensor provided on said base.
A holder according to claim 43, wherein said processor, when estimating whether gimbal deadlock is to occur, is configured to determine a trajectory of motion for each axis of the holder based on an attitude deviation between the current attitude and the target attitude; and predicting whether universal joint deadlock will occur or not according to the motion tracks of the shafts.
A head according to claim 43, wherein said processor, in determining whether gimbal deadlock has occurred, is arranged to determine whether gimbal deadlock has occurred in dependence on the current positional relationship of the revolute joints and/or axes of the head.
A head according to claim 43, wherein said head comprises at least two revolute joints which are coplanar when gimbal deadlocks occur.
A head according to claim 43, wherein said head comprises a two-axis head.
A head according to claim 50, wherein said head is arranged such that, in the event of a gimbal deadlock, the two revolute joints are coaxial.
A head according to claim 43, wherein said head comprises a three-axis head.
A head according to claim 52, wherein said head is configured such that, in the event of gimbal deadlock, the three revolute joints are coplanar and the axes of the three revolute joints are parallel to each other.
A head according to claim 43, wherein said head comprises a four-axis head.
A head according to claim 54, wherein said head is arranged such that, in the event of a gimbal deadlock, the axes of the four revolute joints meet at a single point.
A head according to claim 43, wherein said processor is further configured to control the attitude of said load by controlling the angular velocity of rotation of said axis motors when the current joint angle of said axis motors matches a respective target joint angle.
A head according to claim 56, wherein said processor, when controlling the attitude of said load by controlling the angular rotation speed of said motors of said respective axes, is adapted to determine a first target angular rotation speed of said load in each direction in the operating space, in dependence upon the attitude deviation of the current attitude of said load from a target attitude; mapping the first target rotation angular velocity of each direction to a joint space to obtain a second target rotation angular velocity corresponding to each axis motor; and controlling each shaft motor according to a second target rotation angular velocity corresponding to each shaft motor.
A head according to claim 43, wherein said target attitude comprises a centering attitude of said head.
A head according to claim 58, wherein said centering attitude comprises at least a pitch angle of 0.
A head according to claim 43, wherein said target attitude comprises a specified attitude set by a user.
A head according to claim 43, wherein said load comprises photographic means.
A head according to claim 61, wherein said target attitude is a target following determination of an image taken by said camera.
A movable platform, comprising:

a body;

the driving device is connected with the machine body and used for providing power for the movable platform;

the holder mechanism is connected with the machine body and comprises a motor and an axle arm of at least two axles, and the tail end of the holder mechanism is used for fixedly or detachably connecting a load;

a processor and a memory storing a computer program, the processor implementing the following steps when executing the computer program:

acquiring the current attitude of the load;

predicting that a gimbal deadlock will occur or determining that a gimbal deadlock has occurred;

and controlling each shaft motor of the holder mechanism to rotate to a corresponding target joint angle so as to enable the load to move to a target posture.
The movable platform of claim 63, wherein the target articulation angle is determined axially from a base attitude of the base, the target attitude, and respective axes of the pan-tilt mechanism.
The movable platform of claim 64, wherein the base attitude is determined from a current attitude of the load and a current joint angle of the axis motors.
The movable platform of claim 64, wherein the base attitude is measured from an attitude sensor provided on the base.
The movable platform of claim 63, wherein the processor, when predicting whether gimbal deadlock will occur, is configured to determine a motion trajectory for each axis of the pan/tilt mechanism based on an attitude deviation of the current attitude from the target attitude; and predicting whether universal joint deadlock will occur or not according to the motion trail of each shaft.
The movable platform of claim 63, wherein the processor, when determining whether gimbal deadlock has occurred, is configured to determine whether gimbal deadlock has occurred based on a current positional relationship of a revolute joint and/or an axis of the pan and tilt mechanism.
The movable platform of claim 63, wherein the pan-tilt mechanism comprises at least two rotational joints that are coplanar when gimbal deadlocks occur.
The movable platform of claim 63, wherein the pan-tilt mechanism comprises a two-axis pan-tilt.
The movable platform of claim 70, wherein the pan-tilt mechanism is such that the two revolute joints are coaxial when a gimbal deadlock occurs.
The movable platform of claim 63, wherein the pan-tilt mechanism comprises a three-axis pan-tilt.
The movable platform of claim 72, wherein the pan-tilt mechanism has three revolute joints coplanar and three revolute joint axes parallel when gimbal deadlock occurs.
The movable platform of claim 63, wherein the pan-tilt mechanism comprises a four-axis cloud table.
The movable platform of claim 74, wherein the pan-tilt mechanism is configured such that axes of four revolute joints meet at a point when gimbal deadlock occurs.
The movable platform of claim 63, wherein the processor is further configured to control the attitude of the load by controlling a rotational angular velocity of the respective axis motor when the current joint angle of the respective axis motor matches the respective target joint angle.
The movable platform of claim 76, wherein the processor, when controlling the attitude of the load by controlling the rotational angular velocities of the respective axis motors, is configured to determine a first target rotational angular velocity of the load in each direction in the operating space based on an attitude deviation of a current attitude of the load from a target attitude; mapping the first target rotation angular velocity of each direction to a joint space to obtain a second target rotation angular velocity corresponding to each axis motor; and controlling each shaft motor according to a second target rotation angular velocity corresponding to each shaft motor.
The movable platform of claim 63, wherein the target pose comprises a centering pose of the pan and tilt mechanism.
The movable platform of claim 78, wherein the centering attitude comprises at least a pitch angle of 0.
The movable platform of claim 63, wherein the target pose comprises a specified pose set by a user.
The movable platform of claim 63, wherein the load comprises a camera.
The movable platform of claim 81, wherein the target pose is a target follow determination of an image captured by the camera.
A computer-readable storage medium, characterized in that it stores a computer program which, when executed by a processor, implements a pan-tilt control method according to any one of claims 1 to 21.