1. A control method for a crane, comprising:

acquiring a peripheral image of a rotating platform of a crane;

judging whether an obstacle exists on a rotation path of the turntable or not according to the peripheral image;

determining the distance between the collision point of the rotary table and the obstacle under the condition that the obstacle is judged to exist on the rotary path; and

and executing corresponding early warning operation according to the distance.

2. The control method according to claim 1, wherein the performing the corresponding early warning operation according to the distance comprises:

judging whether the distance is greater than a safe distance;

and sending out an alarm signal under the condition that the distance is greater than the safe distance.

3. The control method of claim 2, wherein the performing the corresponding early warning operation according to the distance further comprises:

and executing a deceleration operation when the distance is less than or equal to the safe distance.

4. The control method according to claim 3, wherein the performing a deceleration operation includes:

acquiring the rotation angular speed of the crane;

calculating deceleration from the distance and the turning angular velocity;

a deceleration operation is performed according to the deceleration.

5. The control method according to claim 4, wherein solving for the deceleration from the distance and the turning angular velocity satisfies the following formula:

wherein a is the deceleration, v is the revolution angular velocity, L_aIs the distance.

6. The control method according to claim 1, wherein the determining whether or not an obstacle exists on a revolving path of the turntable based on the peripheral image includes:

establishing a plurality of image coordinate systems by taking each image acquisition device arranged on the surface of the crane as a first origin respectively;

establishing a world coordinate system by taking the rotation center of the rotary table as a second origin and determining the area of the motion track coordinate of the rotary table in the world coordinate system;

determining target image coordinates in the plurality of image coordinate systems;

converting the target image coordinates into target world coordinates;

judging whether the target world coordinate falls into the area of the motion trail coordinate;

and determining that an obstacle exists on the rotary path of the rotary table under the condition that the target world coordinate falls in the area of the motion trail coordinate.

7. A processor configured to perform the control method for a crane according to any one of claims 1 to 6.

8. A control device for a crane, comprising:

the image acquisition equipment is arranged on the outer wall of the rotary table of the crane and is used for acquiring a peripheral image of the rotary table of the crane;

the processor according to claim 7, connected to the image acquisition device, for processing the peripheral image and sending a corresponding warning signal to a controller;

and the controller is connected with the processor and used for controlling the crane according to the early warning signal sent by the processor.

9. The control device according to claim 8, characterized by further comprising:

the actuator is connected with the controller and used for receiving the deceleration signal sent by the controller and executing deceleration operation;

and the display is connected with the controller and used for receiving the alarm signal sent by the controller and displaying the alarm signal.

10. A crane, characterized by comprising a control device for crane slewing according to claim 8 or 9.

Background

When the automobile crane works, the upper part needs to rotate. When the crane performs a rotation action, the upper mounting part can rotate 360 degrees, and at the moment, if an obstacle appears at a position where the visual field of an operator is poor, the operator of the crane is difficult to perceive the obstacle, so that safety accidents are easily caused. The traditional safety measure is that a safety worker comprehensively checks the environment of a crane construction site before construction operation, and determines that no collision danger exists during crane construction so as to carry out construction. In a complex construction situation, the operator's view is affected, and an observer outside the crane can guide the driver to operate the crane, which results in a low working efficiency of the crane and still risks accidents.

Disclosure of Invention

The invention aims to provide a control method, a control device, a processor and a crane for the crane, which are used for solving the problems that the crane in the prior art has low working efficiency and still has the risk of accidents.

In order to achieve the above object, a first aspect of the present invention provides a control method for a crane, comprising:

acquiring a peripheral image of a rotating platform of a crane;

judging whether an obstacle exists on a rotation path of the turntable or not according to the peripheral image;

determining the distance between the collision point of the rotary table and the obstacle under the condition that the obstacle exists on the rotary path; and

and executing corresponding early warning operation according to the distance.

In the embodiment of the present invention, the performing the corresponding early warning operation according to the distance includes:

judging whether the distance is greater than the safety distance;

and sending out an alarm signal under the condition that the distance is greater than the safe distance.

In the embodiment of the present invention, the executing the corresponding early warning operation according to the distance further includes:

in the case where the distance is less than or equal to the safe distance, the deceleration operation is performed.

In an embodiment of the present invention, performing the deceleration operation includes:

acquiring the rotation angular speed of the crane;

calculating deceleration according to the distance and the rotation angular speed;

the deceleration operation is performed according to the deceleration.

In the embodiment of the present invention, the following formula is satisfied by solving the deceleration from the distance and the revolution angular velocity:

where a is deceleration, v is revolution angular velocity, L_aIs a distance.

In an embodiment of the present invention, determining whether an obstacle exists on a rotation path of the turn table based on the peripheral image includes:

establishing a plurality of image coordinate systems by taking each image acquisition device arranged on the surface of the crane as a first origin respectively;

establishing a world coordinate system by taking the rotation center of the rotary table as a second origin and determining the area of the motion track coordinate of the rotary table in the world coordinate system;

determining target image coordinates in a plurality of image coordinate systems;

converting the target image coordinates into target world coordinates;

judging whether the target world coordinate falls into the area of the motion trail coordinate;

and determining that an obstacle exists on the rotary path of the rotary table under the condition that the target world coordinate falls in the area of the motion trail coordinate.

A second aspect of the invention provides a processor configured to perform a control method for a crane according to the above.

A third aspect of the present invention provides a control device for a crane, comprising:

the image acquisition equipment is arranged on the outer wall of the rotary table of the crane and is used for acquiring a peripheral image of the rotary table of the crane;

the processor is connected with the image acquisition equipment and used for processing the peripheral image and sending a corresponding early warning signal to the controller;

and the controller is connected with the processor and used for controlling the crane according to the early warning signal sent by the processor.

In an embodiment of the present invention, further comprising:

the actuator is connected with the controller and used for receiving the deceleration signal sent by the controller and executing deceleration operation;

and the display is connected with the controller and used for receiving the alarm signal sent by the controller and displaying the alarm signal.

A fourth aspect of the invention provides a crane comprising a control device for crane slewing according to the above.

According to the embodiment of the invention, whether an obstacle exists on a rotation path of the turntable is judged through the peripheral image of the turntable of the crane, and corresponding early warning operation is executed according to the distance between the collision point of the turntable and the obstacle under the condition that the obstacle exists. Therefore, the monitoring of the surrounding environment of the crane is completed through the visual images, the collision detection and early warning of the rotation of the crane are completed, the working efficiency of the crane can be improved, and the risk of accidents is reduced.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic flow chart of a control method for a crane according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a crane according to an embodiment of the present invention;

FIG. 3 is a schematic flow chart of a control method for a crane according to another embodiment of the present invention;

FIG. 4 is a schematic flow chart diagram of a control method for a crane according to another embodiment of the present invention;

fig. 5 is a schematic flowchart of a method for determining whether an obstacle exists on a rotation path of a turntable according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a control device for a crane according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a control device for a crane according to another embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

Fig. 1 is a schematic flow chart of a control method for a crane according to an embodiment of the present invention. As shown in fig. 1, an embodiment of the present invention provides a control method for a crane, which may include:

in step S11, a peripheral image of the turntable of the crane is acquired. In the embodiment of the present invention, the crane means a multi-motion crane that lifts vertically and carries a heavy object horizontally within a certain range. The rotation of the crane refers to the process that a rotary table of the crane rotates around a rotation center. According to the embodiment of the invention, a plurality of image acquisition devices can be arranged on the surface of the rotating platform of the crane so as to acquire the peripheral image of the rotating platform of the crane. The image capturing device may include, but is not limited to, a camera, a video camera, and the like, which may capture images. After the peripheral image of the turntable is acquired by the image acquisition equipment, the peripheral image is sent to a processor for processing the image, and the processor acquires the peripheral image sent by the image acquisition equipment.

In order to capture the peripheral image of the turntable in all directions, at least four image capturing devices may be provided, each capturing an image in at least one direction. Fig. 2 is a schematic structural diagram of a crane according to an embodiment of the present invention. In one example, four image capturing devices are respectively disposed in a horizontal direction of a turn table of the crane, see fig. 2, No. 1, No. 2, No. 3, and No. 4, and 5 is a booth of the turn table of the crane. No. 1 image acquisition equipment mounted position is on the anterior extension support of hangar 5, and No. 2, 4 image acquisition equipment install on the shell of hangar 5, and the tail at the revolving stage structure body is installed to No. 3 hangars. In this way, all the image information in the horizontal direction of the turntable can be acquired through the four image acquisition devices. It should be noted that the embodiment of the present invention is not limited to the installation method of the image capturing apparatus described above, and may be another installation method that can meet the requirement of capturing the peripheral image of the turntable. For example, six, eight, etc. cameras are mounted. In order to better acquire the peripheral image of the state, the image acquisition apparatus of the embodiment of the present invention may also be preferably a wide-angle camera.

In step S12, it is determined whether or not an obstacle is present on the rotation path of the turntable based on the peripheral image. In an embodiment of the invention, the swivel path of the turntable is a circumferential range of rotation about the center of the turntable. Since the number of the image capturing devices may be multiple, the processor may acquire images of multiple positions of the periphery of the turntable, and therefore, the processor needs to integrate multiple peripheral images into one image in order to analyze whether an obstacle exists on the rotation path of the turntable. In one example, the depth information of the image acquired by the image acquisition device may be acquired by using a time of flight (TOF) method, and then the pixel coordinate system and the image coordinate system are respectively established. The image is composed of pixels, the pixel coordinates are the positions of the pixels in the image, and the image coordinates can be obtained according to coordinate conversion after the pixel coordinates are obtained. Therefore, a plurality of image coordinate systems can be respectively established with each image acquisition device as a first origin, and pixel coordinates of the target can be converted into image coordinates, namely target image coordinates, by using the image depth information and the focal length. Meanwhile, a world coordinate system can be established by taking the rotation center of the rotary table as a second origin, and the area of the motion track coordinate of the rotary table in the world coordinate system is determined according to the input structural parameters of the rotary table of the crane. According to the position parameters of the image acquisition equipment relative to the rotation center and the edge of the rotary table, the target image coordinate can be converted into a target world coordinate, and then the target world coordinate is compared with the area of the motion track coordinate of the rotary table. In the case where the target world coordinate falls within the area of the motion trajectory coordinate, it may be determined that an obstacle exists on the revolving path of the turntable, and in the case where the target world coordinate does not fall within the area of the motion trajectory coordinate, it may be determined that an obstacle does not exist on the revolving path of the turntable. The camera coordinates of the image acquisition equipment are converted into world coordinates, images of the image acquisition equipment can be integrated in the same coordinate system, and therefore judgment of the obstacles is more convenient, faster and comprehensive.

In step S13, when it is determined that an obstacle is present on the turning path, the distance between the collision point of the turn table and the obstacle is determined. In the embodiment of the invention, if an obstacle exists on the rotation path, the distance between the obstacle and the collision point of the turntable needs to be further determined, so that corresponding early warning operation can be executed according to different conditions. The collision point is a position obtained according to the rotating direction of the rotary table, the world coordinate of the obstacle and the coordinate of the outer surface of the rotary table which is overlapped in the rotating process, and is used for judging the distance between the rotary table and the obstacle. In one example, the distance between the collision point and the obstacle may be calculated from the coordinates of the collision point at this time in the world coordinate system and the coordinates of the obstacle at this time in the world coordinate system.

In step S14, a corresponding warning operation is performed according to the distance. In the embodiment of the invention, different early warning operations can be respectively carried out according to the distance between the collision point and the obstacle. For example, when the distance between the collision point and the obstacle is relatively long, an alarm signal can be sent to remind the operator to perform corresponding operation. In the case that the distance between the collision point and the obstacle is relatively short, a deceleration signal can be sent to the actuator to uniformly decelerate the crane until the crane stops. Therefore, the working efficiency of the crane can be improved, the automatic danger avoidance is realized, and the running stability of the crane can be ensured. In one example, the processor may obtain a safety distance preset by a user, and compare the distance between the current collision point and the obstacle with the safety distance. In case the distance between the current collision point and the obstacle is greater than the safe distance, the processor sends a secondary warning signal to the controller, which may for example send a warning signal to the cockpit. The alarm signal can be prompted by sound signal, video signal, character signal and the like to inform the operator that the collision danger exists at present, and the operator can process the alarm signal correspondingly after receiving the alarm signal. And under the condition that the distance between the current collision point and the obstacle is less than the safe distance, the processor sends a high-level early warning signal to the controller. At this time, the controller is not controlled by the handle of the operator, but calculates the deceleration according to the rotating angular speed calculated by the data provided by the rotating encoder and the distance of the obstacle calculated by the processor according to the image, and then controls the crane to perform uniform deceleration movement, so that the crane stops smoothly.

According to the embodiment of the invention, whether an obstacle exists on a rotation path of the turntable is judged through the peripheral image of the turntable of the crane, and corresponding early warning operation is executed according to the distance between the collision point of the turntable and the obstacle under the condition that the obstacle exists. Therefore, the monitoring of the surrounding environment of the crane is completed through the visual images, the collision detection and early warning of the rotation of the crane are completed, the working efficiency of the crane can be improved, and the risk of accidents is reduced.

Fig. 3 is a schematic flow chart of a control method for a crane according to another embodiment of the present invention. As shown in fig. 3, performing the corresponding early warning operation according to the distance may include:

step S15, judging whether the distance is greater than the safety distance;

and step S16, sending out an alarm signal when the distance is greater than the safe distance.

In an embodiment of the invention, in case the distance between the current collision point and the obstacle is greater than the safe distance, the processor sends a secondary warning signal to the controller, for example, a warning signal may be sent to the cockpit. The alarm signal can be displayed on the display through prompts such as sound signals, video signals, character signals and the like so as to inform an operator that the collision danger exists at present, and the operator can process the alarm signal correspondingly after receiving the alarm signal. Therefore, the danger of collision can be timely reminded to the operator, the operator can be allowed to correspondingly process the collision within enough time, the possibility of collision is reduced, and the rotation safety of the crane is improved.

Fig. 4 is a flowchart illustrating a control method for a crane according to another embodiment of the present invention. As shown in fig. 4, in the embodiment of the present invention, performing the corresponding early warning operation according to the distance may further include:

step S17, in the case where the distance is less than or equal to the safe distance, performs a deceleration operation.

In an embodiment of the invention, the processor sends a high-level warning signal to the controller in case the distance between the current collision point and the obstacle is smaller than a safe distance. At this time, the controller is not controlled by the handle of the operator, but calculates the deceleration according to the rotating angular speed calculated by the data provided by the rotating encoder and the distance of the obstacle calculated by the vision processor according to the image, and then controls the actuator of the crane to perform uniform deceleration movement, so that the crane stops smoothly.

In an embodiment of the present invention, performing the deceleration operation may include:

acquiring the rotation angular speed of the crane;

calculating deceleration according to the distance and the rotation angular speed;

the deceleration operation is performed according to the deceleration.

Specifically, after the controller receives the advanced early warning signal, the data of the rotary encoder are filtered and resolved to obtain the rotary angular speed, the deceleration is resolved according to the current rotary angular speed and the distance between the obstacle and the collision point resolved by the processor according to the image, and then the crane is controlled to perform uniform deceleration movement, so that the crane is stably stopped. Therefore, the crane can automatically avoid danger and ensure the stable operation of the crane.

In the embodiment of the present invention, the following formula can be satisfied by solving the deceleration from the distance and the revolution angular velocity:

where a is deceleration, v is revolution angular velocity, L_aIs a distance.

In particular, it can be determined from a ═ v/t and vt-at²＝L_aThe above-described calculation formula of the deceleration is derived. The minimum deceleration can be obtained as long as the slewing angular velocity and the distance between the collision point and the obstacle are known, and the slewing motion can be stopped before the obstacle collides with the collision point as long as the deceleration is larger than the minimum deceleration, so that the crane avoids danger and can stably run.

Fig. 5 is a schematic flowchart of a method for determining whether an obstacle exists on a rotation path of a turntable according to an embodiment of the present invention. As shown in fig. 5, the step S12 of determining whether an obstacle exists on the rotation path of the turntable according to the peripheral image may include:

s51, establishing a plurality of image coordinate systems by taking each image acquisition device arranged on the surface of the crane as a first origin respectively;

step S52, establishing a world coordinate system by taking the rotation center of the rotary table as a second origin and determining the area of the motion trail coordinate of the rotary table in the world coordinate system;

step S53, determining target image coordinates in a plurality of image coordinate systems;

step S54, converting the target image coordinates into target world coordinates;

step S55, judging whether the target world coordinate falls in the area of the motion trail coordinate;

and step S56, determining that an obstacle exists on the rotation path of the turntable when the target world coordinate falls in the area of the motion trail coordinate.

In an embodiment of the invention, the swivel path of the turntable is a circumferential range of rotation about the center of the turntable. Since the number of the image capturing devices may be multiple, the processor may acquire images of multiple positions of the periphery of the turntable, and therefore, the processor needs to integrate multiple peripheral images into one image in order to analyze whether an obstacle exists on the rotation path of the turntable. In one example, the depth information of the image acquired by the image acquisition device may be acquired by using a time of flight (TOF) method, and then the pixel coordinate system and the image coordinate system are respectively established. The image is composed of pixels, the pixel coordinates are the positions of the pixels in the image, and the image coordinates can be obtained according to coordinate conversion after the pixel coordinates are obtained. Therefore, a plurality of image coordinate systems can be respectively established with each image acquisition device as a first origin, and pixel coordinates of the target can be converted into image coordinates, namely target image coordinates, by using the image depth information and the focal length. Meanwhile, a world coordinate system can be established by taking the rotation center of the rotary table as a second origin, and the area of the motion track coordinate of the rotary table in the world coordinate system is determined according to the input structural parameters of the rotary table of the crane. According to the position parameters of the image acquisition equipment relative to the rotation center and the edge of the rotary table, the target image coordinate can be converted into a target world coordinate, and then the target world coordinate is compared with the area of the motion track coordinate of the rotary table. In the case where the target world coordinate falls within the area of the motion trajectory coordinate, it may be determined that an obstacle exists on the revolving path of the turntable, and in the case where the target world coordinate does not fall within the area of the motion trajectory coordinate, it may be determined that an obstacle does not exist on the revolving path of the turntable. The camera coordinates of the image acquisition equipment are converted into world coordinates, images of the image acquisition equipment can be integrated in the same coordinate system, and therefore judgment of the obstacles is more convenient, faster and comprehensive.

Embodiments of the present invention also provide a processor configured to execute the control method for a crane according to the above. In an embodiment of the invention, the processor is configured to:

acquiring a peripheral image of a rotating platform of a crane;

judging whether an obstacle exists on a rotation path of the turntable or not according to the peripheral image;

determining the distance between the collision point of the rotary table and the obstacle under the condition that the obstacle exists on the rotary path; and

and executing corresponding early warning operation according to the distance.

In the embodiment of the present invention, the crane means a multi-motion crane that lifts vertically and carries a heavy object horizontally within a certain range. The rotation of the crane refers to the process that a rotary table of the crane rotates around a rotation center. According to the embodiment of the invention, a plurality of image acquisition devices can be arranged on the surface of the rotating platform of the crane so as to acquire the peripheral image of the rotating platform of the crane. The image capturing device may include, but is not limited to, a camera, a video camera, and the like, which may capture images. After the peripheral image of the turntable is acquired by the image acquisition equipment, the peripheral image is sent to a processor for processing the image, and the processor acquires the peripheral image sent by the image acquisition equipment.

In order to capture the peripheral image of the turntable in all directions, at least four image capturing devices may be provided, each capturing an image in at least one direction. Fig. 2 is a schematic structural diagram of a crane according to an embodiment of the present invention. In one example, four image capturing devices are respectively disposed in a horizontal direction of a turn table of the crane, see fig. 2, No. 1, No. 2, No. 3, and No. 4, and 5 is a booth of the turn table of the crane. No. 1 image acquisition equipment mounted position is on the anterior extension support of hangar 5, and No. 2, 4 image acquisition equipment install on the shell of hangar 5, and the tail at the revolving stage structure body is installed to No. 3 hangars. In this way, all the image information in the horizontal direction of the turntable can be acquired through the four image acquisition devices. It should be noted that the embodiment of the present invention is not limited to the installation method of the image capturing apparatus described above, and may be another installation method that can meet the requirement of capturing the peripheral image of the turntable. For example, six, eight, etc. cameras are mounted. In order to better acquire the peripheral image of the state, the image acquisition apparatus of the embodiment of the present invention may also be preferably a wide-angle camera.

In an embodiment of the invention, the swivel path of the turntable is a circumferential range of rotation about the center of the turntable. Since the number of the image capturing devices may be multiple, the processor may acquire images of multiple positions of the periphery of the turntable, and therefore, the processor needs to integrate multiple peripheral images into one image in order to analyze whether an obstacle exists on the rotation path of the turntable. In one example, the depth information of the image acquired by the image acquisition device may be acquired by using a time of flight (TOF) method, and then the pixel coordinate system and the image coordinate system are respectively established. The image is composed of pixels, the pixel coordinates are the positions of the pixels in the image, and the image coordinates can be obtained according to coordinate conversion after the pixel coordinates are obtained. Therefore, a plurality of image coordinate systems can be respectively established with each image acquisition device as a first origin, and pixel coordinates of the target can be converted into image coordinates, namely target image coordinates, by using the image depth information and the focal length. Meanwhile, a world coordinate system can be established by taking the rotation center of the rotary table as a second origin, and the area of the motion track coordinate of the rotary table in the world coordinate system is determined according to the input structural parameters of the rotary table of the crane. According to the position parameters of the image acquisition equipment relative to the rotation center and the edge of the rotary table, the target image coordinate can be converted into a target world coordinate, and then the target world coordinate is compared with the area of the motion track coordinate of the rotary table. In the case where the target world coordinate falls within the area of the motion trajectory coordinate, it may be determined that an obstacle exists on the revolving path of the turntable, and in the case where the target world coordinate does not fall within the area of the motion trajectory coordinate, it may be determined that an obstacle does not exist on the revolving path of the turntable. The camera coordinates of the image acquisition equipment are converted into world coordinates, images of the image acquisition equipment can be integrated in the same coordinate system, and therefore judgment of the obstacles is more convenient, faster and comprehensive.

In the embodiment of the invention, if an obstacle exists on the rotation path, the distance between the obstacle and the collision point of the turntable needs to be further determined, so that corresponding early warning operation can be executed according to different conditions. The collision point is a position obtained according to the rotating direction of the rotary table, the world coordinate of the obstacle and the coordinate of the outer surface of the rotary table which is overlapped in the rotating process, and is used for judging the distance between the rotary table and the obstacle. In one example, the distance between the collision point and the obstacle may be calculated from the coordinates of the collision point at this time in the world coordinate system and the coordinates of the obstacle at this time in the world coordinate system.

In the embodiment of the invention, different early warning operations can be respectively carried out according to the distance between the collision point and the obstacle. For example, when the distance between the collision point and the obstacle is relatively long, an alarm signal can be sent to remind the operator to perform corresponding operation. In the case that the distance between the collision point and the obstacle is relatively short, a deceleration signal can be sent to the actuator to uniformly decelerate the crane until the crane stops. Therefore, the working efficiency of the crane can be improved, the automatic danger avoidance is realized, and the running stability of the crane can be ensured. In one example, the processor may obtain a safety distance preset by a user, and compare the distance between the current collision point and the obstacle with the safety distance. In case the distance between the current collision point and the obstacle is greater than the safe distance, the processor sends a secondary warning signal to the controller, which may for example send a warning signal to the cockpit. The alarm signal can be prompted by sound signal, video signal, character signal and the like to inform the operator that the collision danger exists at present, and the operator can process the alarm signal correspondingly after receiving the alarm signal. And under the condition that the distance between the current collision point and the obstacle is less than the safe distance, the processor sends a high-level early warning signal to the controller. At this time, the controller is not controlled by the handle of the operator, but calculates the deceleration according to the rotating angular speed calculated by the data provided by the rotating encoder and the distance of the obstacle calculated by the processor according to the image, and then controls the crane to perform uniform deceleration movement, so that the crane stops smoothly.

According to the embodiment of the invention, whether an obstacle exists on a rotation path of the turntable is judged through the peripheral image of the turntable of the crane, and corresponding early warning operation is executed according to the distance between the collision point of the turntable and the obstacle under the condition that the obstacle exists. Therefore, the monitoring of the surrounding environment of the crane is completed through the visual images, the collision detection and early warning of the rotation of the crane are completed, the working efficiency of the crane can be improved, and the risk of accidents is reduced.

Further, the processor is further configured to:

the corresponding early warning operation executed according to the distance comprises the following steps:

judging whether the distance is greater than the safety distance;

and sending out an alarm signal under the condition that the distance is greater than the safe distance.

In an embodiment of the invention, in case the distance between the current collision point and the obstacle is greater than the safe distance, the processor sends a secondary warning signal to the controller, for example, a warning signal may be sent to the cockpit. The alarm signal can be prompted by sound signal, video signal, character signal and the like to inform the operator that the collision danger exists at present, and the operator can process the alarm signal correspondingly after receiving the alarm signal. Therefore, the danger of collision can be timely reminded to the operator, the operator can be allowed to correspondingly process the collision within enough time, the possibility of collision is reduced, and the rotation safety of the crane is improved.

Further, the processor is further configured to:

executing the corresponding early warning operation according to the distance further comprises:

in the case where the distance is less than or equal to the safe distance, the deceleration operation is performed.

In an embodiment of the invention, the processor sends a high-level warning signal to the controller in case the distance between the current collision point and the obstacle is smaller than a safe distance. At this time, the controller is not controlled by the handle of the operator, but calculates the deceleration according to the rotating angular speed calculated by the data provided by the rotating encoder and the distance of the obstacle calculated by the vision processor according to the image, and then controls the crane to perform uniform deceleration movement, so that the crane stops smoothly.

Further, the processor is further configured to:

performing the deceleration operation includes:

acquiring the rotation angular speed of the crane;

calculating deceleration according to the distance and the rotation angular speed;

the deceleration operation is performed according to the deceleration.

Specifically, after the controller receives the advanced early warning signal, the data of the rotary encoder are filtered and resolved to obtain the rotary angular speed, the deceleration is resolved according to the current rotary angular speed and the distance between the obstacle and the collision point resolved by the processor according to the image, and then the crane is controlled to perform uniform deceleration movement, so that the crane is stably stopped. Therefore, the crane can automatically avoid danger and ensure the stable operation of the crane.

In the embodiment of the present invention, the following formula is satisfied by solving the deceleration from the distance and the revolution angular velocity:

where a is deceleration, v is revolution angular velocity, L_aIs a distance.

In particular, it can be determined from a ═ v/t and vt-at²＝L_aThe above-described calculation formula of the deceleration is derived. The minimum deceleration can be obtained as long as the slewing angular velocity and the distance between the collision point and the obstacle are known, and the slewing motion can be stopped before the obstacle collides with the collision point as long as the deceleration is larger than the minimum deceleration, so that the crane avoids danger and can stably run.

Further, the processor is further configured to:

judging whether an obstacle exists on a rotation path of the turntable according to the peripheral image, comprising:

establishing a plurality of image coordinate systems by taking each image acquisition device arranged on the surface of the crane as a first origin respectively;

establishing a world coordinate system by taking the rotation center of the rotary table as a second origin and determining the area of the motion track coordinate of the rotary table in the world coordinate system;

determining target image coordinates in a plurality of image coordinate systems;

converting the target image coordinates into target world coordinates;

judging whether the target world coordinate falls into the area of the motion trail coordinate;

and determining that an obstacle exists on the rotary path of the rotary table under the condition that the target world coordinate falls in the area of the motion trail coordinate.

In an embodiment of the invention, the swivel path of the turntable is a circumferential range of rotation about the center of the turntable. Since the number of the image capturing devices may be multiple, the processor may acquire images of multiple positions of the periphery of the turntable, and therefore, the processor needs to integrate multiple peripheral images into one image in order to analyze whether an obstacle exists on the rotation path of the turntable. In one example, the depth information of the image acquired by the image acquisition device may be acquired by using a time of flight (TOF) method, and then the pixel coordinate system and the image coordinate system are respectively established. The image is composed of pixels, the pixel coordinates are the positions of the pixels in the image, and the image coordinates can be obtained according to coordinate conversion after the pixel coordinates are obtained. Therefore, a plurality of image coordinate systems can be respectively established with each image acquisition device as a first origin, and pixel coordinates of the target can be converted into image coordinates, namely target image coordinates, by using the image depth information and the focal length. Meanwhile, a world coordinate system can be established by taking the rotation center of the rotary table as a second origin, and the area of the motion track coordinate of the rotary table in the world coordinate system is determined according to the input structural parameters of the rotary table of the crane. According to the position parameters of the image acquisition equipment relative to the rotation center and the edge of the rotary table, the target image coordinate can be converted into a target world coordinate, and then the target world coordinate is compared with the area of the motion track coordinate of the rotary table. In the case where the target world coordinate falls within the area of the motion trajectory coordinate, it may be determined that an obstacle exists on the revolving path of the turntable, and in the case where the target world coordinate does not fall within the area of the motion trajectory coordinate, it may be determined that an obstacle does not exist on the revolving path of the turntable. The camera coordinates of the image acquisition equipment are converted into world coordinates, images of the image acquisition equipment can be integrated in the same coordinate system, and therefore judgment of the obstacles is more convenient, faster and comprehensive.

Examples of a processor may include, but are not limited to, a general purpose processor, a special purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of Integrated Circuit (IC), a state machine, and the like. The processor may perform signal encoding, data processing, power control, input/output processing.

Fig. 6 is a schematic structural diagram of a control device for a crane according to an embodiment of the present invention. As shown in fig. 6, an embodiment of the present invention provides a control device for a crane, including:

the image acquisition equipment 61 is arranged on the outer wall of the rotary table of the crane and is used for acquiring the peripheral image of the rotary table of the crane;

the processor 62 is connected to the image capturing device 61, and is configured to process the peripheral image and send a corresponding warning signal to the controller;

and the controller 63 is connected with the processor 62 and is used for controlling the crane according to the early warning signal sent by the processor 62.

In an embodiment of the invention, a plurality of image capturing 61 devices may be provided on the surface of the crane turret to capture the peripheral image of the crane turret. The image capturing device 61 may include, but is not limited to, a camera, a video camera, and the like, which can capture an image. After the image acquisition device 61 acquires the peripheral image of the turntable, the peripheral image is sent to the processor 62 for processing the image, and the processor 62 acquires the peripheral image sent by the image acquisition device 61. In order to capture the peripheral image of the turntable in all directions, at least four image capturing devices 61 may be provided, and each image capturing device 61 captures an image in at least one direction. Fig. 2 is a schematic structural diagram of a crane according to an embodiment of the present invention. In one example, four image capturing devices 61 are respectively provided in the horizontal direction of the turn table of the crane, see fig. 2, No. 1, No. 2, No. 3, and No. 4, and 5 is a booth of the turn table of the crane. No. 1 image acquisition equipment mounted position is on the anterior extension support of hangar 5, and No. 2, 4 image acquisition equipment install on the shell of hangar 5, and the tail at the revolving stage structure body is installed to No. 3 hangars. In this way, all the image information in the horizontal direction of the turn table can be acquired by the four image-acquiring devices 61. It should be noted that the embodiment of the present invention is not limited to the installation method of the image capturing apparatus described above, and may be another installation method that can meet the requirement of capturing the peripheral image of the turntable. For example, six, eight, etc. image pickup devices are installed. In order to better acquire the peripheral image of the state, the image acquisition apparatus of the embodiment of the present invention may also be preferably a wide-angle camera.

In the embodiment of the present invention, after receiving the peripheral image, the processor 62 may process the peripheral image and send a corresponding warning signal to the controller 63. Specifically, the processor 62 needs to integrate a plurality of peripheral images into one image in order to analyze whether an obstacle exists on the revolving path of the turntable. In one example, the depth information of the image acquired by the image acquisition device 61 may be acquired by using a time of flight (TOF) method, and then the pixel coordinate system and the image coordinate system are respectively established. The image is composed of pixels, the pixel coordinates are the positions of the pixels in the image, and the image coordinates can be obtained according to coordinate conversion after the pixel coordinates are obtained. Accordingly, a plurality of image coordinate systems may be established with each image pickup device 61 as a first origin, respectively, and pixel coordinates of the object may be converted into image coordinates, i.e., object image coordinates, using the image depth information and the focal length. Meanwhile, a world coordinate system can be established by taking the rotation center of the rotary table as a second origin, and the area of the motion track coordinate of the rotary table in the world coordinate system is determined according to the input structural parameters of the rotary table of the crane. According to the position parameters of the image acquisition equipment relative to the rotation center and the edge of the rotary table, the target image coordinate can be converted into a target world coordinate, and then the target world coordinate is compared with the area of the motion track coordinate of the rotary table. In the case where the target world coordinate falls within the area of the motion trajectory coordinate, it may be determined that an obstacle exists on the revolving path of the turntable, and in the case where the target world coordinate does not fall within the area of the motion trajectory coordinate, it may be determined that an obstacle does not exist on the revolving path of the turntable. The camera coordinates of the image acquisition equipment are converted into world coordinates, images of the image acquisition equipment can be integrated in the same coordinate system, and therefore judgment of the obstacles is more convenient, faster and comprehensive. If an obstacle exists on the rotation path, the distance between the obstacle and the collision point of the turntable needs to be further determined so as to execute corresponding early warning operation according to different conditions. The collision point is a position obtained according to the rotation direction of the turntable, the world coordinate of the obstacle and the coordinate of the outer surface of the turntable which are overlapped in the rotation process, and is used for judging the distance between the collision point and the obstacle. In one example, the distance between the collision point and the obstacle may be calculated from the coordinates of the collision point at this time in the world coordinate system and the coordinates of the obstacle at this time in the world coordinate system.

In the embodiment of the invention, different early warning operations can be respectively carried out according to the distance between the collision point and the obstacle. For example, when the distance between the collision point and the obstacle is relatively long, an alarm signal can be sent to remind the operator to perform corresponding operation. In the case that the distance between the collision point and the obstacle is relatively short, a deceleration signal can be sent to the actuator to uniformly decelerate the crane until the crane stops. Therefore, the working efficiency of the crane can be improved, the automatic danger avoidance is realized, and the running stability of the crane can be ensured. In one example, the processor 62 may obtain a safety distance preset by the user, and compare the distance between the current collision point and the obstacle with the safety distance. In case the distance between the current collision point and the obstacle is greater than the safe distance, the processor sends a secondary warning signal to the controller 63, which may for example send an alarm signal to the cockpit. The alarm signal can be prompted by sound signal, video signal, character signal and the like to inform the operator that the collision danger exists at present, and the operator can process the alarm signal correspondingly after receiving the alarm signal. In the event that the distance between the current collision point and the obstacle is less than the safe distance, the processor 62 sends a high-level warning signal to the controller 63. At this time, the controller 63 solves the magnitude of deceleration from the turning angular velocity currently calculated from the data supplied from the rotary encoder and the distance of the obstacle solved from the image by the processor 62, and controls the crane to perform uniform deceleration movement, without receiving a control command from the operator's handle, thereby stopping the crane smoothly.

According to the embodiment of the invention, whether an obstacle exists on a rotation path of the turntable is judged through the peripheral image of the turntable of the crane, and corresponding early warning operation is executed according to the distance between the collision point of the turntable and the obstacle under the condition that the obstacle exists. Therefore, the monitoring of the surrounding environment of the crane is completed through the visual images, the collision detection and early warning of the rotation of the crane are completed, the working efficiency of the crane can be improved, and the risk of accidents is reduced.

Fig. 7 is a schematic structural diagram of a control device for a crane according to another embodiment of the present invention. As shown in fig. 7, the method may further include:

the actuator 64 is connected with the controller 63 and is used for receiving the deceleration signal sent by the controller 63 and executing deceleration operation;

and the display 65 is connected with the controller 63 and is used for receiving the alarm signal sent by the controller 63 and displaying the alarm signal.

In an embodiment of the invention, in case the distance between the current collision point and the obstacle is greater than a safe distance, the processor 62 sends a secondary warning signal to the controller 63, which may for example send a warning signal to the cockpit. The alarm signal may be displayed on the display 65 by a prompt such as a sound signal, a video signal, or a text signal to inform the operator that there is a danger of collision at present, and the operator may process the alarm signal accordingly when receiving the alarm signal. Therefore, the danger of collision can be timely reminded to the operator, the operator can be allowed to correspondingly process the collision within enough time, the possibility of collision is reduced, and the rotation safety of the crane is improved. In the event that the distance between the current collision point and the obstacle is less than the safe distance, the processor 62 sends a high-level warning signal to the controller 63. At this time, the controller 63 solves the magnitude of deceleration from the turning angular velocity currently calculated from the data supplied from the rotary encoder and the distance of the obstacle solved from the image by the vision processor, and then controls the actuator 64 of the crane to perform uniform deceleration movement, thereby smoothly stopping the crane, without being instructed by the control command of the operator's handle.

The embodiment of the invention also provides a crane, which comprises the control device for crane rotation.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.