EP4635893A1

EP4635893A1 - On-site safety control method for tower crane, controller, and computing device

Info

Publication number: EP4635893A1
Application number: EP23906054.4A
Authority: EP
Inventors: Zhouyin LIU; Ping Zhao; Xugang CHENG; Xingwang LI; Baojun HAO; Xiaojia YUAN; Hailiang TENG
Original assignee: Kyland Technology Co Ltd
Current assignee: Kyland Technology Co Ltd
Priority date: 2022-12-23
Filing date: 2023-12-21
Publication date: 2025-10-22
Also published as: EP4635893A4; CN115838119A; WO2024131897A1; CN115838119B

Abstract

Provided are an on-site safety control method for a tower crane, a controller, and a computing device. The method includes: (S110) controlling a hook to move in an axial space according to planned path points, where the hook is controlled to move between every two adjacent planned path points through a plurality of control cycles; obtaining (S120), in each of the plurality of control cycles, current coordinates of the hook in the axial space; obtaining (S130) a current maximum allowable speed of the hook in each direction of the axial space, based on a current luffing length, a hoisting weight, and a working parameter of the tower crane; and obtaining (S140) coordinates of an arrival position and a target speed of the tower crane in the axial space in a next control cycle, based on the current coordinates and a current speed of the hook in the axial space, the current maximum allowable speed of the hook in each direction, and coordinates of an un-reached planned path point of the hook. With the on-site safety control method for a tower crane, while driving the hook to move, the current maximum allowable speed in each axis direction is obtained based on the hoisting weight and the current luffing length, to control the speed on each axis not to exceed the maximum speed of the axis in the next control cycle, which can realize safe movement of the tower crane

Description

FIELD

The present disclosure relates to the field of intelligent control, and more particularly, to an on-site safety control method for a tower crane, a controller, and a computing device.

BACKGROUND

In some existing on-site safety control methods for a tower crane, each axis of the tower crane is driven according to a planned trajectory, to drive the hook to move. During this movement, each axis of the tower crane complies with kinematics constraints to ensure safety of the tower crane. In this case, the kinematic constraints are not obtained according to the actual weight and the actual position of the tower crane. Rather, the maximum speed of each axis remains the same regardless of different hoisting weights and positions, which is obviously unreasonable. A large hoisting weight may lead to mechanical safety hazards at some positions, damaging an axle mechanism or a motor of the tower crane.
In another existing technologies, each axis of the tower crane is driven according to a predetermined trajectory, to drive the hook to move, and obstacles are avoided in time during the movement to ensure safety of the tower crane on the moving trajectory. In this case, the maximum movement speed of each axis under specific weights and positions is not taken into account. The large hoisting weight may lead to mechanical safety hazards at some positions, damaging the axle mechanism or the motor of the tower crane.

SUMMARY

In view of this, an embodiment of the present disclosure provides an on-site safety control method for a tower crane, a controller, and a computing device. With the technical solution according to the embodiments of the present disclosure, while driving the hook to move, a current maximum allowable speed in each axis direction is obtained based on the hoisting weight and the current luffing length, to control a speed in each axis not to exceed a maximum speed of the axis in the next control cycle, so as to ensure safe movement of the tower crane.
In a first aspect, an on-site safety control method for a tower crane is provided according to an embodiment of the present disclosure. The method includes: controlling a hook to move in an axial space according to planned path points, where the hook is controlled to move between every two adjacent planned path points through a plurality of control cycles, where a coordinate in a luffing axis direction is represented by a luffing length; obtaining a current maximum allowable speed of the hook in each direction of the axial space, based on a current luffing length, a hoisting weight, and a working parameter of the tower crane; and obtaining coordinates of an arrival position and a target speed of the tower crane in the axial space in a next control cycle, based on the current coordinates and a current speed of the hook in the axial space, the current maximum allowable speed, and coordinates of an un-reached planned path point of the hook.
From the above, with the technical solution of the embodiment of the present disclosure, while driving the hook to move, the current maximum allowable speed in each axis direction is obtained based on the hoisting weight and the current luffing length, to control the speed on each axis not to exceed the maximum speed of the axis in the next control cycle, which can realize safe movement of the tower crane.
In a possible embodiment of the first aspect, the obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the current luffing length, the hoisting weight, and the working gear of the tower crane includes: obtaining a current maximum allowable hoisting weight and a maximum allowable working torque in the luffing axis direction, based on the current luffing length; calculating a current weight ratio and a current torque ratio, the weight ratio being a ratio of the hoisting weight to the maximum allowable hoisting weight, and the torque ratio being a ratio of a working torque of the tower crane in the luffing axis direction to the maximum allowable working torque; and obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio.
From the above, the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction are obtained by using the tower crane based on the current luffing length, and the current maximum allowable speed of the hook in each direction of the axial space is obtained based on the working parameter of the tower crane, the ratio of the current hoisting weight to the maximum allowable hoisting weight, and the ratio of the current working torque in the luffing axis direction to the maximum allowable working torque. The maximum allowable speed is more accurate, further improving movement safety of the tower crane.
In a possible embodiment of the first aspect, the obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and the at least one of the weight ratio and the torque ratio includes at least one of: obtaining a first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and a working gear of the tower crane, and determining, for each direction of the axial space, the first maximum allowable speed in the direction as the maximum allowable speed in the direction; obtaining a second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear, and determining, for each direction of the axial space, the second maximum allowable speed in the direction as the maximum allowable speed in the direction; and determining, for each direction of the axial space, a smaller one of the first maximum allowable speed in the direction and the second maximum allowable speed in the direction as the maximum allowable speed in the direction.
From the above, the current first maximum allowable speed of the hook in each direction of the axial space is obtained based on the working parameter of the tower crane, and the ratio of the current hoisting weight to the maximum allowable hoisting weight, the current second maximum allowable speed of the hook in each direction of the axial space is obtained based on the working parameter of the tower crane and the ratio of the current working torque in the luffing axis direction to the maximum allowable working torque, and then the smaller one is determined as the maximum allowable speed, to further improve the movement safety of the tower crane.
In a possible embodiment of the first aspect, the obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio further includes: for each direction of the axial space, obtaining a third maximum allowable speed of the hook in the direction, based on the working gear and at least one of a position limit and a deceleration limit of the tower crane in the direction of the axial space, where the working parameter further includes at least one of the position limit and the deceleration limit; and determining a smaller one of the third maximum allowable speed of the hook in the direction and the maximum allowable speed in the direction as the maximum allowable speed in the direction.
From the above, the position limit and/or deceleration limit of the tower crane are used to correct the maximum allowable speed, further improving the movement safety of the tower crane.
In a possible embodiment of the first aspect, the obtaining the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction, based on the current luffing length includes: obtaining the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction, based on the current luffing length and by using a first curve group of the tower crane, where the first curve group includes relationships between allowable hoisting weights of the tower crane and luffing lengths at different tower crane reeving.
From the above, the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction are obtained based on the relationships between the allowable hoisting weights of the tower crane and the luffing lengths at different tower crane reeving, to further improve the movement safety of the tower crane.
In a possible embodiment of the first aspect, the obtaining the first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and the working gear of the tower crane includes: obtaining the first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and the working gear of the tower crane and by using a second curve group, where the second curve group includes relationship curves between maximum allowable speed limits of the hook in each direction of the axial space and the weight ratio at respective working gears of the tower crane.
From the above, the first maximum allowable speed is obtained based on the relationship curve between the maximum allowable speed limit of the hook in each direction of the axial space and the weight ratio at each working gear of the tower crane, further improving the movement safety of the tower crane.
In a possible embodiment of the first aspect, the obtaining the second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear includes: obtaining, the second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear and by using a third curve group, where the third curve group includes relationship curves between maximum allowable speeds of the hook in each direction of the axial space and the torque ratio at respective working gears of the tower crane.
From the above, the second maximum allowable speed is obtained based on the relationship curve between maximum allowable speed of the hook in each direction of the axial space and the torque ratio at each working gear of the tower crane, further improving the movement safety of the tower crane.
In a possible embodiment of the first aspect, the method further includes: stopping movement of the tower crane and outputting a planned path abnormality signal when the current torque ratio is greater than a rated torque.
From the above, when the current working torque exceeds the rated torque, the tower crane stops moving, which further improves safety of the tower crane.
In a possible embodiment of the first aspect, the axial space further has a hoisting direction and a slewing direction.
From the above, safety control is performed for the luffing direction, the hoisting direction and the slewing direction, which further improves the safety of the tower crane.
In a possible embodiment of the first aspect, the obtaining current coordinates of the hook in the axial space in each control cycle includes: obtaining the current coordinates of the hook in the axial space in each control cycle by an encoder on each axis of the tower crane.
From the above, an actual position of the hook of the axial space is obtained by the encoder, resulting in more accurate safety control for the tower crane.
In a possible embodiment of the first aspect, the method further includes obtaining the hoisting weight by a weight sensor after the tower crane hoists the hook.
From the above, an actual hoisting weight is obtained by the weight sensor, resulting in more accurate safety control for the tower crane.
In a second aspect, a tower crane controller is provided according to an embodiment of the present disclosure. The tower crane controller includes: a motion control module configured to control a hook to move in an axial space according to planned path points, where the hook is controlled to move between every two adjacent planned path points through a plurality of control cycles, where a coordinate in a luffing axis direction is represented by a luffing length; a data obtaining module configured to obtain, in each of the plurality of control cycles, current coordinates of the hook in the axial space; a safety control module configured to obtain a current maximum allowable speed of the hook in each direction of the axial space, based on a current luffing length, a hoisting weight, and a working parameter of the tower crane; and a trajectory control module configured to obtain coordinates of an arrival position and a target speed of the tower crane in the axial space in a next control cycle, based on the current coordinates and a current speed of the hook in the axial space, the current maximum allowable speed, and coordinates of an un-reached planned path point of the hook.
From the above, with the technical solution according to the embodiment of the present disclosure, while driving the hook to move, the current maximum allowable speed in each axis direction is obtained based on the hoisting weight and the current luffing length, to control the speed on each axis not to exceed the maximum speed of the axis in the next control cycle, which can realize safe movement of the tower crane.
In a possible embodiment of the second aspect, the safety control module is configured to: obtain a current maximum allowable hoisting weight and a maximum allowable working torque in the luffing axis direction, based on the current luffing length; calculate a current weight ratio and a current torque ratio, the weight ratio being a ratio of the current hoisting weight to the maximum allowable hoisting weight, and the torque ratio being a ratio of a working torque of the tower crane in the luffing axis direction to the maximum allowable working torque; and obtain the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio.
From the above, the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction are obtained by using the tower crane based on the current luffing length, and the current maximum allowable speed of the hook in each direction of the axial space is obtained based on the working parameter of the tower crane, the ratio of the current hoisting weight to the maximum allowable hoisting weight, and the ratio of the current working torque in the luffing axis direction to the maximum allowable working torque. The maximum allowable speed is more accurate, further improving movement safety of the tower crane.
In a possible embodiment of the second aspect, the safety control module being configured to obtain the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and the at least one of the weight ratio and the torque ratio includes at least one of: the safety control module being configured to obtain a first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and a working gear of the tower crane, and determine, for each direction of the axial space, the first maximum allowable speed in the direction as the maximum allowable speed in the direction, the working parameter including the working gear; obtain a second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear, and determine, for each direction of the axial space, the second maximum allowable speed in the direction as the maximum allowable speed in the direction; and determine, for each direction of the axial space, a smaller one of the first maximum allowable speed in the direction and the second maximum allowable speed in the direction as the maximum allowable speed in the direction.
From the above, the current first maximum allowable speed of the hook in each direction of the axial space is obtained based on the working parameter of the tower crane, and the ratio of the current hoisting weight to the maximum allowable hoisting weight, the current second maximum allowable speed of the hook in each direction of the axial space is obtained based on the working parameter of the tower crane and the ratio of the current working torque in the luffing axis direction to the maximum allowable working torque, and then the smaller one is determined as the maximum allowable speed, to further improve the movement safety of the tower crane.
In a possible embodiment of the second aspect, the safety control module being configured to obtain the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio further includes: the safety control module being configured to, for each direction of the axial space, obtain a third maximum allowable speed of the hook in the direction, based on the working gear and at least one of a position limit and a deceleration limit of the tower crane in the direction of the axial space, where the working parameter further includes at least one of the position limit and the deceleration limit; and determining a smaller one of the third maximum allowable speed of the hook in the direction and the maximum allowable speed in the direction as the maximum allowable speed in the direction.
From the above, the position limit and/or deceleration limit of the tower crane are used to correct the maximum allowable speed, further improving the movement safety of the tower crane.
In a possible embodiment of the second aspect, the tower crane controller further includes a process control module configured to stop movement of the tower crane and output a planned path abnormality signal when the current working torque ratio is greater than the rated torque.
From the above, when the current working torque exceeds the rated torque, the tower crane stops moving, which further improves safety of the tower crane.
In a possible embodiment of the second aspect, the safety control module being configured to obtain the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction, based on the current luffing length includes: the safety control module being configured to obtain the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction, based on the current luffing length and by using a first curve group of the tower crane, where the first curve group includes relationships between allowable hoisting weights of the tower crane and luffing lengths at different tower crane reeving.
From the above, the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction are obtained according to the relationships between the allowable hoisting weights of the tower crane and the luffing lengths at different tower crane reeving, to further improve the movement safety of the tower crane.
In a possible embodiment of the second aspect, the safety control module being configured to obtain the first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and the working gear of the tower crane includes: the safety control module being configured to obtain the first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and the working gear of the tower crane and by using a second curve group, where the second curve group includes relationship curves between maximum allowable speed limits of the hook in each direction of the axial space and the weight ratio at respective working gears of the tower crane.
From the above, the first maximum allowable speed is obtained based on the relationship curves between maximum allowable speed limits of the hook in each direction of the axial space and the weight ratio at each working gear of the tower crane, further improving the movement safety of the tower crane.
In a possible embodiment of the second aspect, the safety control module being configured to obtain the second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear includes: the safety control module being configured to obtain the second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear and by using a third curve group, where the third curve group includes relationship curves between maximum allowable speeds of the hook in each direction of the axial space and the torque ratio at respective working gears of the tower crane.
From the above, the second maximum allowable speed is obtained based on the relationship curves between maximum allowable speeds of the hook in each direction of the axial space and the torque ratio at each working gear of the tower crane, further improving the movement safety of the tower crane. In a possible embodiment of the second aspect, the axial space of the hook further has a hoisting direction and a slewing direction.
From the above, safety control is performed for the luffing direction, the hoisting direction and the slewing direction, which further improves the safety of the tower crane.
In a possible embodiment of the second aspect, the data obtaining module is configured to obtain, in each control cycle, the current coordinates of the hook in the axial space by using an encoder on each axis of the tower crane.
From the above, the actual position of the hook of the axial space is obtained by using the encoder, resulting in more accurate safety control for the tower crane.
In a possible embodiment of the second aspect, the data obtaining module is further configured to obtain the hoisting weight by using a weight sensor after the tower crane hoists the hook.
From the above, the actual hoisting weight is obtained by using the weight sensor, resulting in more accurate safety control for the tower crane.
In a third aspect, a computing device is provided according to the embodiment of the present disclosure. The computing device includes: a bus; a communication interface connected to the bus; at least one processor connected to the bus; and at least one memory connected to the bus and storing program instructions. The program instructions, when executed by the at least one processor, cause the at least one processor to implement the method according to any of the embodiments of the first aspect of the present disclosure.
In a fourth aspect, a computer-readable storage medium is provided according to the embodiment of the present disclosure. The computer-readable storage medium has program instructions stored thereon. The program instructions, when executed by a computer, cause the computer to implement the method according to any of the embodiments of the first aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the technical solutions in the embodiments of the present disclosure more clearly, the drawings to be used in the embodiments will be briefly introduced below. It should be understood that, the following drawings are only some embodiments of the present disclosure, and should not be regarded as limiting the scope of the present disclosure. For those skilled in the art, other related drawings can be obtained based on these drawings without any inventive efforts.

FIG. 1 is a schematic flowchart illustrating a first embodiment of an on-site safety control method for a tower crane according to the present disclosure.
FIG. 2 is a schematic flowchart illustrating a second embodiment of an on-site safety control method for a tower crane according to the present disclosure.
FIG. 3 is a schematic structural diagram of a first embodiment of a tower crane controller according to the present disclosure.
FIG. 4 is a schematic structural diagram of a second embodiment of a tower crane controller according to the present disclosure.
FIG. 5 is a schematic structural diagram of a computing device according to various embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following description, reference is made to "some embodiments", which describes a subset of all possible embodiments, but it should be understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict.
In the following description, the terms "first/second/third" or a module A, a module B, a module C mentioned in the embodiments of the present disclosure are used only to distinguish between similar objects or different embodiments, rather than implying a particular sequence of the objects. It should be understood that the terms "first/second/third" may be interchanged in a particular order or sequence where permitted, to enable the embodiments of the present disclosure described herein to be implemented in an order other than that illustrated or described herein.
In the following description, reference numerals denoting steps, such as S110, S 120, etc., do not necessarily mean that the steps must be performed in that specific order. The sequence of steps may be interchanged or the steps may be executed simultaneously, where permitted.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the present disclosure. The terms used herein are intended to describe the embodiments of the present disclosure only, rather than limit the present disclosure.
According to the embodiments of the present disclosure, an on-site safety control method for a tower crane, a controller, and a computing device are provided. The method includes: controlling a hook to move in an axial space according to planned path points, where the hook is controlled to move between every two adjacent planned path points through a plurality of control cycles; obtaining, in each of the plurality of control cycles, current coordinates of the hook in the axial space; obtaining a current maximum allowable speed of the hook in each direction of the axial space, based on a current luffing length, a hoisting weight, and a working parameter of the tower crane; and obtaining coordinates of an arrival position and a target speed of the tower crane in the axial space in a next control cycle, based on the current coordinates and a current speed of the hook in the axial space, the current maximum allowable speed of the hook, and a next planned path point of the hook. With the technical solution according to the embodiment of the present disclosure, while driving the hook to move, a current maximum allowable speed of the hook in each axis direction is obtained based on the hoisting weight and the current luffing length, to control a speed of the hook in each axis not to exceed the maximum allowable speed in the axis in the next control cycle, so as to ensure safe movement of the tower crane.
Various embodiments of the present disclosure will be described below with reference to the accompanying drawings.
First, a tower crane system according to various embodiments of the present disclosure is introduced, which includes a tower crane and a tower crane controller. The tower crane includes several axes, for example, a luffing axis, a hoisting axis, and a slewing axis. An encoder is mounted at each axis for recording a position of each axis, i.e. coordinates in the axial space. The tower crane further includes a weight sensor for sensing a hoisting weight.
The working parameter of the tower crane includes a working gear, and a position limit and a deceleration limit on each axis. Exemplarily, the working gear includes five gears. Exemplarily, the position limit includes: an outer luffing stop limit and an inner luffing stop limit for the luffing axis, which are a maximum luffing length and a minimum luffing length, respectively; an upper hoisting stop limit and a lower hoisting stop limit of the hoisting axis, which are a maximum value and a minimum value of a hoisting height, respectively; and a left slewing stop limit and a right slewing stop limit of the slewing axis, which are a maximum leftward slewing angle and a maximum rightward slewing angle, respectively. Exemplarily, the deceleration limit includes: an outer luffing deceleration limit and an inner luffing deceleration limit of the luffing axis, which are an outer luffing length and an inner luffing length at which outward and inward movement must begin to decelerate in the luffing axis direction, respectively; an upper hoisting deceleration limit and a lower hoisting deceleration limit of the hoisting axis are hoisting heights at which deceleration must occur during upward and downward movement, respectively; a left slewing deceleration limit and a right slewing deceleration limit for the slewing axis are slewing angles at which the slewing must begin to decelerate in a leftward direction and a rightward direction, respectively.
A first embodiment of an on-site safety control method for a tower crane according to the present disclosure will be described below with reference to FIG. 1.
The first embodiment of the on-site safety control method for the tower crane is performed in a tower crane controller. The method includes: controlling a hook to move in an axial space according to planned path points, where the hook is controlled to move between every two adjacent planned path points through a plurality of control cycles; obtaining, in each of the plurality of control cycles, current coordinates of the hook in the axial space; obtaining a current maximum allowable speed of the hook in each direction of the axial space based on a current luffing length, a hoisting weight, and a working parameter of the tower crane; and obtaining coordinates of an arrival position and a target speed of the tower crane in the axial space in a next control cycle, based on the current coordinates and the current speed of the hook in the axial space, the current maximum allowable speed of the hook, and the next planned path point of the hook. With the technical solution according to the embodiment, while driving the hook to move, the current maximum allowable speed in each axis direction is obtained based on the hoisting weight and the current luffing length, to control the speed in each axis not to exceed the maximum allowable speed in the axis in the next control cycle, so as to ensure safe movement of the tower crane.
FIG. 1 shows a flowchart of a first embodiment of an on-site safety control method for a tower crane, including following steps S110 to S140.
At S110, an axis of a tower crane is controlled to move in an axial space according to planned path points.
The planned path points are key point between a hook-hoisting point and a hook-dropping point of the hook. The hook is controlled to move between every two adj acent planned path points through a plurality of control cycles.
Coordinates of the planned path points, which are obtained from another module of the tower crane, are coordinates in the axial space of the tower crane. If the obtained coordinates are coordinates in Cartesian space, the coordinates are converted into coordinates in the axial space of the tower crane through kinematic inverse solution.
At S120, in each of the plurality of control cycles, a current position of the hook in the axial space is obtained.
The position is represented by coordinates in the axial space of the tower crane, which includes at least a coordinate in a luffing axis direction. The coordinate in the luffing axis direction is represented by the luffing length. In some embodiments, the coordinates in the axial space of the tower crane further include a coordinate in a hoisting axis direction represented by a hoisting height, and a coordinate in a slewing axis direction represented by a slewing angle.
In some embodiments, the current position of the hook in the axial space is obtained in real time through an encoder mounted on each axis of the tower crane.
At S130, current maximum allowable speeds of the hook in three directions of the axial space are obtained based on a current luffing length, a hoisting weight, and a working parameter of the tower crane.
The hoisting weight is obtained by a weight sensor after the tower crane hoists the hook.
The working parameter of the tower crane includes at least a working gear of the tower crane.
In some embodiments, a current maximum allowable hoisting weight and a maximum allowable working torque in the luffing axis direction are obtained based on the current luffing length; a current weight ratio and a current torque ratio are calculated, where the weight ratio is a ratio of the hoisting weight to the current maximum allowable hoisting weight, and the torque ratio is a ratio of a working torque of the tower crane in the luffing axis direction to the current maximum allowable working torque; and the current maximum allowable speed of the hook in each direction of the axial space is obtained based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio.
In other embodiments, the working parameter of the tower crane further includes at least one of: a position limit and a deceleration limit of the tower crane in each direction of the axial space. For each direction of the axial space, a third maximum allowable speed of the hook in the direction is further obtained based on the working gear of the tower crane and one of the position limit and the deceleration limit of the tower crane in the direction of the axial space, the maximum allowable speed in the direction is adjusted based on the third maximum allowable speed of the hook in the direction, where the adjusted maximum allowable speed of the hook in the direction is a smaller one of the maximum allowable speed in the direction before adjustment and the third maximum allowable speed in the direction.
The obtaining the current maximum allowable speed of the hook in each direction of the axial space based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio includes the following three possible embodiments.

(1) In some embodiments, for each direction of the axial space, a first maximum allowable speed of the hook in the direction of the axial space is obtained based on the weight ratio and the working gear of the tower crane, and is determined as the maximum allowable speed in the direction. For different working gears, there are different correspondences between the maximum allowable speed of the tower crane in each direction of the axial space and the weight ratio.
(2) In some embodiments, for each direction of the axial space, a second maximum allowable speed of the hook in the direction is obtained based on the torque ratio and the working gear of the tower crane, and is determined as the maximum allowable speed in the direction. For different working gears, there are different correspondences between the maximum allowable speed of the tower crane in each direction of the axial space and the torque ratio.
(3) In other embodiments, for each direction of the axial space of the hook, the first maximum allowable speed and the second maximum allowable speed of the hook in the direction are obtained, and a smaller one of the first maximum allowable speed and the second maximum allowable speed is determined as the maximum allowable speed in the direction.

At S140, a target position and a target speed to be reached by the hook in the axial space in a next control cycle are obtained, based on the current position and a current speed of the hook in the axial space, the current maximum allowable speeds of the hook in three directions of the axial space, and coordinates of an un-reached planned path point of the hook.
In this step, planning is performed while the tower crane is in motion to determine the target position and the target speed in each axis to be reached in the next control cycle. During movement from the current position to the target position for the next control cycle, the tower crane's speed does not exceed the maximum speed obtained in step S130, to ensure safe operation of the tower crane.
This step may be performed through a trajectory planning algorithm. In some embodiments, all un-reached planned path points are selected to participate in the calculation. In other embodiments, a number of planned path points closest in time are selected to participate in the calculation to reduce the calculation volume.
In summary, in the first embodiment of the on-site safety control method for the tower crane, the current luffing length of the hook is obtained in each control cycle, and the current maximum allowable speed of the hook in each direction of the axial space is obtained based on the luffing length, the hoisting weight, and the working parameter of the tower crane, in such a manner that a speed of the tower crane is controlled not to exceed the maximum allowable speed in the next control cycle, realizing the safe movement of the tower crane.
A second embodiment of the on-site safety control method for the tower crane according to the present disclosure will be described below with reference to FIG. 2. The maximum allowable speed obtained based on the hoisting weight, the working torque, and the position limit and the deceleration limit for each axis improves the safety.
The second embodiment of the on-site safety control method for the tower crane is performed in the tower crane controller, and is a more detailed implementation of the first embodiment of the on-site safety control method for the tower crane. When determining the maximum allowable speed for each control cycle, a current first maximum allowable speed of the tower crane is obtained based on the working gear and a ratio of the current hoisting weight to a current maximum allowable hoisting weight, a current second maximum allowable speed of the tower crane is obtained based on the working gear and a ratio of a current working torque to a current maximum allowable working torque, and a third maximum allowable speed of the tower crane on each axis is obtained based on the working gear of the tower crane, and the position limit and the deceleration limit for each axis. A smallest one of the first maximum allowable speed, the current second maximum allowable speed, and the third maximum allowable speed for each axis is determined as the current maximum allowable speed in the direction, in such a manner that the speed of the tower crane is controlled not to exceed the maximum allowable speed in the next control cycle, realizing the safe movement of the tower crane.
The axis of the tower crane of the second embodiment of the on-site safety control method for the tower crane includes the luffing axis, the hoisting axis, and the slewing axis. Position coordinates of the hook in the axial space are represented by the luffing length, the hoisting height, and the slewing angle.
Table 1 shows input parameters of the tower crane during working. In each working cycle of the tower crane, the tower crane controller obtains corresponding data from the input parameter, which includes:

a planned path, including a planned hoisting point array, a planned luffing point array, a planned slewing point array, values in the three arrays of each to-be-reached path point are used for each control cycle;
the working parameter of the tower crane, including a rated torque, reeving, the working gear (1 gear among 5 gears), an outer luffing stop limit and an inner luffing stop limit for the luffing axis, an upper hoisting stop limit and a lower hoisting stop limit for the hoisting axis, a left slewing stop limit and a right slewing stop limit for the slewing axis, an outer luffing deceleration limit and an inner luffing deceleration limit for the luffing axis, an upper hoisting deceleration limit and a lower hoisting deceleration limit for the hoisting axis, a left slewing deceleration limit and a right slewing deceleration limit for the slewing axis, a current actual parameter including the hoisting weight, a luffing position. The luffing position is obtained once in each control cycle.

Table 1

Name	Value	Type	Remarks
Quantity	Num	Uint	Number of elements in the array
Planned Hoisting Point Array		Real	An array of 2500 elements
Planned Luffing Point Array		Real	An array of 2500 elements
Planned Slewing Point Array		Real	An array of 2500 elements
Reeving		Uint	Coefficient for the tower crane
Rated torque		Real	Rated torque of the tower crane
Rated weight		Real	Weight bearable by a hook of the tower crane
Upper Hoisting Deceleration Limit		Real
Upper Hoisting Stop Limit		Real
Lower Hoisting Deceleration Limit		Real
Lower Hoisting Stop Limit		Real
Outer Luffing Stop Limit		Real
Outer Luffing Deceleration Limit		Real
Inner Luffing Stop Limit		Real
Inner Luffing Deceleration Limit		Real
Left Slewing Stop Limit		Real
Left Slewing Deceleration Limit		Real
Right Slewing Stop Limit		Real
Right Slewing Deceleration Limit		Real
Hoisting Weight		Real
Luffing Position		Real

Table 2 shows output parameters of the tower crane in each control cycle. The tower crane controller outputs data to this output parameter table in each cycle. The output parameters include the target position and the target speed for the next control cycle, and a working indication signal.
The target position is represented by a target hoisting point array, a target luffing point array, and a target slewing point array. The target speed is represented by a target hoisting speed point array, a target luffing speed point array, and a target slewing speed point array. In each control cycle, the target position and the target speed for a next cycle are outputted.

The working indication signal includes: an abnormality signal indicating that the tower crane is working abnormally and the tower crane needs to stop; an abnormality ID indicating a cause for the abnormality; a completion signal indicating whether the hook has reached the hook-dropping point; a working signal indicating that the hook is to move in the next control cycle.

Table 2

Name	Value	Type	Remarks
Quantity	Num	Uint	Number of elements in the array
Target Hoisting Point Array		Real	An array of 2500 elements
Target Luffing Point Array		Real	An array of 2500 elements
Target Slewing Point Array		Real	An array of 2500 elements
Target Hoisting Speed Array		Real	An array of 2500 elements
Target Luffing Speed Array		Real	An array of 2500 elements
Target Slewing Speed Array		Real	An array of 2500 elements
Abnormality Signal	Error	Bool	Indication of abnormal operation
Abnormality ID	errorID	Uint	Cause of abnormality
Completion Signal	Done	Bool	Indication of the tower crane's movement completion
Working Signal	Busy	Bool	Indication of continued movement

FIG. 2 shows a flowchart of a second embodiment of an on-site safety control method for a tower crane, including following steps S210 to S310.
At S210, the working parameter, the planned path, and the hoisting weight of the tower crane are obtained.
The working parameter shown in Table 1 includes a factory parameter (the reeving, the rated torque) of the tower crane and the set working gear, the set position limit, and the set deceleration limit.
The hoisting weight is obtained by the weight sensor after the tower crane hoists the hook, and is maintained during subsequent movement of the hook.
The planned path is obtained from a planning module, and is represented by the planned hoisting point array, the planned luffing point array, and the planned slewing point array shown in Table 1.
At S220, the axis of the tower crane is controlled to move according to coordinates of the planned path points in the axial space.
The hook is controlled to move between every two adjacent planned path points through the plurality of control cycles. A position reached in each control cycle includes not only the adjacent planned path points, but also an intermediate position between the adjacent planned path points. The control cycle is a working cycle of the tower crane.
At S230, the current position of the hook of the axial space is obtained by the encoder at each control cycle, and the current working torque is calculated.
The position coordinates in the axial space include the luffing length, the hoisting height, and the slewing angle.
The working torque is a product of the hoisting weight and the luffing length.
At S240, it is determined whether the current working torque exceeds the rated torque. If the current working torque does not exceed the rated torque, step S250 is executed, otherwise step S310 is executed.
At S250, the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction are obtained based on the luffing length and the reeving of the tower crane by using a first curve group.
The first curve group includes relationship curves between maximum allowable hoisting weights and luffing lengths at different reeving, which are determined by characteristics of the tower crane and derived from the tower crane's factory settings.

In some embodiments, for the convenience of tabulating the first curve group, Table 3 shows a relationship between the maximum allowable hoisting weight and the luffing length at different magnifications in tabular form, where R represents reeving, RHW represents rated hoisting weight, LL represents luffing length, MAHW represents maximum allowable hoisting weight, MAWT represents maximum allowable working torque. The maximum allowable working torque is a product of the maximum allowable hoisting weight and the luffing length. In practical scenarios, a range and an interval of the luffing length can be set as desired.

Table 3

R	R H W /t	L L/ m	20	22.5	25	27.5	30	32.5	35	37.5	40	42.5	45	47.5
2	3	M A H W /t	3	3	3	2.97	2.67	2.41	2.19	1.99	1.83	1.68	1.55	1.43
2	3	M A W T/ t* m	60	67.5	75	81.6 8	80.1	78.33	76.65	74.63	73.2	71.4	69.75	67.93
4	6	M A H W /t	4.32	3.75	3.29	2.92	2.61	2.35	2.13	1.94	1.77	1.63	1.5	1.38
4	6	M A W T/ t* m	86.4	84.38	82.25	80.3	78.3	76.38	74.55	72.75	70.8	69.28	67.5	65.55

At S260, the current maximum allowable speed of the hook in each of three directions of the axial space is obtained based on the hoisting weight, the current maximum allowable hoisting weight, the maximum allowable working torque, and the working parameter.
Step S260 includes the following four sub-steps.

(1) A current first maximum allowable speed of the hook in each of the three directions of the axial space is obtained based on the current weight ratio and the working gear and by using a second curve group.

The weight ratio is the ratio of the current hoisting weight to the maximum allowable hoisting weight.
The second curve group includes relationship curves between the first maximum allowable speed of the hook in each of the three directions of the axial space and the weight ratio under each working gear. Each relationship curve is derived from the tower crane's factory settings. There are 15 second curves for the five working gears. Each second curve corresponds to a combination of one working gear and one direction of the axial space.
(2) a current second maximum allowable speed of the hook in each of three directions of the axial space is obtained based on the current torque ratio and the working gear.
The torque ratio is the ratio of the current working torque in the luffing axis direction to the maximum allowable working torque.
The third curve group includes relationship curves between the second maximum allowable speed of the hook in each of the three directions of the axial space and the torque ratio under each working gear. Each relationship curve is derived from the tower crane's factory settings. There are 15 third curves for the five working gears. Each third curve corresponds to a combination of one working gear and one direction of the axial space.
(3) a third maximum allowable speed of the hook in each of the three directions of the axial space is obtained based on the position limit, the deceleration limit, and the working gear of the tower crane in the direction of the axial space.
A fourth maximum allowable speed in an upward direction of the hoisting axis is obtained based on the upper hoisting stop limit of the tower crane on the hoisting axis and the working gear of the tower crane. A fifth maximum allowable speed in the upward direction of the hoisting axis is obtained based on the upper hoisting deceleration limit of the tower crane for the hoisting axis and the working gear of the tower crane. The fourth maximum allowable speed and the fifth maximum allowable speed are derived from the tower crane's factory settings. A smaller one of the fourth maximum allowable speed and the fifth maximum allowable speed is determined as the third maximum allowable speed of the tower crane in the hoisting direction of the hoisting axis. According to the method for obtaining the third maximum allowable speed in the hoisting direction of the hoisting axis of the tower crane, the third maximum allowable speed in a downward direction of the hoisting axis of the tower crane is obtained based on the lower hoisting stop limit and lower hoisting deceleration limit for the hoisting axis, and the working gear of the tower crane.
With a method similar to the above method for obtaining the third maximum allowable speed in the upward direction and the downward direction of the hoisting axis of the tower crane, the third maximum allowable speed in an outward luffing direction and an inward luffing direction of the luffing axis is obtained based on the outer luffing stop limit, the inner luffing stop limit, the outer luffing deceleration limit, the inner luffing deceleration limit for the luffing axis, and the working gear of the tower crane.
With a method similar to the above method for obtaining the third maximum allowable speed in the upward direction and the downward direction of the hoisting axis of the tower crane, the third maximum allowable speed in a leftward slewing direction and a rightward slewing direction of the slewing axis is obtained based on the left slewing stop limit, the right slewing stop limit, the left slewing deceleration limit, the right slewing deceleration limit on the slewing axis, and the working gear of the tower crane.
Step (3) may be executed once during entire movement of the tower crane, and the obtained third maximum allowable speeds may be reused in subsequent control cycles.
Various third maximum allowable speeds obtained in step (3) are derived from the tower crane's factory settings. In some embodiments, for convenience, the third maximum allowable speeds under different working gears, the position limit, and the deceleration limit are presented in the tabular form. Table 4 shows a direction in which the third maximum allowable speed exists when the working parameter is set to various values. Numbers in each cell corresponding to each position limit and deceleration limit are an example, not the real third maximum allowable speed. Generally, the maximum allowable speed of the hook is restricted to the third maximum allowable speed in the corresponding direction in cells with a black background.
(4) The maximum allowable speed of the hook in each of the three directions of the axial space is obtained based on the first maximum allowable speed, the second maximum allowable speed, and the third maximum allowable speed.
In each of the directions of the axial space, the maximum allowable speed of the hook in the direction of the axial space is the smallest one of the first maximum allowable speed, the second maximum allowable speed, and the third maximum allowable speed in the direction.
In some embodiments, for convenience, the first maximum allowable speed corresponding to the second curve group and the second maximum allowable speed corresponding to the third curve group are tabulated. Table 5 shows the first maximum allowable speed under combinations of different working gears and different weight ratios, as well as the second maximum allowable speed under combinations of different working gears and different torque ratios. The numbers in each cell corresponding to one combination is an example, not the real first maximum allowable speed or the real second maximum allowable speed. Generally, the maximum allowable speed of the hook is restricted to the first maximum allowable speed or the second maximum allowable speed limits in the corresponding direction in cells with a black background,.
At S270, the target position and the target speed to be reached in the next control cycle are obtained based on the current position and the current speed of the hook in the axial space, a to-be-reached planned path point, and the maximum allowable speeds of the hook in the three directions of the axial space.
The target position and the target speed obtained in this step are input to corresponding positions in Table 2.
At S280, in the next control cycle, the tower crane is driven to move according to the obtained target position and the obtained target speed.
At S290, it is whether the hook-dropping point is reached. If the hook-dropping point is not reached, step S230 is performed. If the hook-dropping point is reached, step S300 is executed.
At S300, movement of the tower crane is completed.
At the end of the tower crane movement, a corresponding end signal is filled in Table 2.
At S310, movement of the hook is stopped and the abnormality signal is outputted.
When the hook stops moving, a corresponding abnormality signal is filled in Table 2, and an abnormal reason is the working torque exceeding the rated torque.
When determining the maximum allowable speed for each control cycle by using the second embodiment of the on-site safety control method for the tower crane, the current first maximum allowable speed of the tower crane is obtained based on the working gear and the ratio of the current hoisting weight to the current maximum allowable hoisting weigh, the current second maximum allowable speed of the tower crane is obtained based on the working gear and the ratio of the current working torque to the current maximum allowable working torque, and the third maximum allowable speed of the tower crane on each axis is obtained based on the working gear of the tower crane, and the position limit and the deceleration limit of each axis. The smallest one among the third maximum allowable speed, the current first maximum allowable speed, and the current second maximum allowable speed for each axis is determined as the current maximum allowable speed in the direction, in such a manner that the speed of the tower crane is controlled not to exceed the maximum allowable speed in the next control cycle, realizing the safe movement of the tower crane. In the second embodiment of the on-site safety control method for the tower crane, by obtaining the maximum allowable speed based on the hoisting weight, the working torque, and the position limit and the deceleration limit of each axis, working safety of the tower crane can be improved.
A first embodiment of a tower crane controller of the present disclosure is described below with reference to FIG. 3.
The first embodiment of a tower crane controller implements the first embodiment of the on-site safety control method for the tower crane and has all the advantages of the first embodiment of the on-site safety control method for the tower crane.
FIG. 3 shows a structure of the first embodiment of a tower crane controller. The structure includes a motion control module 310, a data obtaining module 320, a safety control module 330, and a trajectory control module 340.
The motion control module 310 is configured to control an axis of a tower crane to move in an axial space according to planned path points. Reference can be made to the step S110 of the first embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
The data obtaining module 320 is configured to obtain the current position of the hook in the axial space in each control cycle. Reference can be made to the step S120 of the first embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
The safety control module 330 is configured to obtain current maximum allowable speeds of the hook in three directions of the axial space according to the current luffing length, the hoisting weight, and the working parameter of the tower crane. Reference can be made to the step S130 of the first embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
The trajectory control module 340 is configured to obtain an arrival position and a target speed to be reached by the tower crane in the axial space in the next control cycle based on the current position and the current speed of the hook in the axial space, the maximum allowable speeds of the hook in three directions in the axial space, and coordinates of an un-reached planned path point of the hook. Reference can be made to the step S140 of the first embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
A second embodiment of a tower crane controller of the present disclosure is described below with reference to FIG. 4.
The second embodiment of the tower crane controller implements the second embodiment of the on-site safety control method for the tower crane and has all the advantages of the second embodiment of the on-site safety control method for the tower crane.
FIG. 3 shows a structure of the second embodiment of the tower crane controller. The structure includes a data obtaining module 410, a motion control module 420, a safety control module 430, a trajectory control module 440, and a process control module 450.
The data obtaining module 410 is configured to obtain the working parameter, the planned path, and the hoisting weight of the tower crane, which are filled in the corresponding table entries of the input parameter table shown in Table 1, and is further configured to obtain a current position of the hook in the axial space by using the encoder in each control cycle, and calculate the current working torque. Reference can be made to the steps S210 and S230 of the second embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
The motion control module 420 is configured to control an axis of the tower crane to move based on coordinates of planned path points in an axial space. The motion control module 420 is further configured to drive the tower crane to move according to the obtained target position and the obtained target speed when the target position and the target speed for the next control cycle are obtained. Reference can be made to the steps S220 and S280 of the second embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
The safety control module 430 is configured to obtain the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction by using the first curve group based on the luffing length and reeving of the tower crane. The safety control module 430 is further configured to obtain the current maximum allowable speeds of the hook in three directions of the axial space based on the hoisting weight, the current maximum allowable hoisting weight, the maximum allowable working torque, and the working parameter. Reference can be made to the steps S250 and S260 of the second embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
The trajectory control module 440 is configured to obtain a target position and a target speed to be reached in the next control cycle based on the current position and the current speed of the hook in the axial space, a to-be-reached planned path point, and the current maximum allowable speeds of the hook in three directions of the axial space. Reference can be made to the step S270 of the second embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
The process control module 450 is configured to determine whether the current working torque exceeds a rated torque. The process control module 450 is further configured to determine whether the hook-dropping point is reached. The process control module 450 is further configured to stop the movement of the tower crane when the tower crane reaches the hook-dropping point. The process control module 450 is further configured to stop the movement of the tower crane when the current working torque exceeds the rated torque and output an abnormality signal. Reference can be made to the steps S240, S290, S300 and S310 of the second embodiment of the on-site safety control method for the tower crane for the principle and the advantages thereof.
A computing device is further provided according to an embodiment of the present disclosure, which is described in detail in FIG. 5 below.
The computing device 500 includes a processor 510, a memory 520, a communication interface 530, and a bus 540.
It should be understood that the communication interface 530 in the computing device 500 illustrated in FIG.5 may be configured to communicate with other devices.
The processor 510 may be connected to the memory 520. The memory 520 may be configured to store the program code and data. Therefore, the memory 520 may be a storage unit inside the processor 510, or an external storage unit independent of the processor 510, or a component including the storage unit inside the processor 510 and the external storage unit independent of the processor 510.
In an embodiment, the computing device 500 may further include the bus 540. The memory 520 and the communication interface 530 may be connected to the processor 510 by the bus 540. The bus 540 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 540 may be classified into an address bus, a data bus, a control bus, etc. For ease of representation, in the figure the bus is represented by only one thick line, which does not mean that there is only one bus or one type of bus.
It should be understood that in the embodiments of the present disclosure, the processor 510 may be a Central Processing Unit (CPU). The processor may be other general-purpose processors, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic components, a discrete gate or a transistor logic component, and a discrete hardware component. The general-purpose processor may be a microprocessor, or the processor may further be any conventional processor, etc. Alternatively, the processor 510 adopts one or more integrated circuits for executing related programs to implement the technical solution provided by the embodiments of the present disclosure.
The memory 520 may include a read-only memory and a random access memory, and provide instructions and data to the processor 510. A portion of the processor 510 may also include a non-volatile random access memory. For example, the processor 510 may also store information of a device type.
When the computing device 500 is in operation, the processor 510 executes computer-executable instructions in the memory 520 to perform operational steps of the method embodiments.
It should be understood that the computing device 500 according to the embodiments of the present disclosure may correspond to a corresponding body in performing a method according to the embodiments of the present disclosure. In addition, the above-described and other operations and/or functions of each module in the computing device 500 are intended to implement a corresponding flow of each method according to the embodiments of the present disclosure, respectively, and will not be repeated herein for the sake of brevity.
It can be conceivable for those of ordinary skill in the art that elements and algorithmic steps of various examples described in combination with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on specific application and design constraints of the technical solution. Different methods can be used by those skilled in the art for implementing the described functions for each particular application, but such implementations should not be considered beyond the scope of the present disclosure.
For convenience and conciseness of the description, it is clear to those skilled in the art that reference to a specific operation process of the system, the apparatus, and the unit described above can be made to the corresponding process in the method embodiments described above, and thus details thereof will be omitted here.
In several embodiments provided herein, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, division of units is only one logical function division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. In addition, couplings, direct couplings, or communication connections shown or discussed between devices or units may be indirect couplings or communication connections through interfaces, apparatuses, or units, and may be in electrical, mechanical, or other forms.
The units described as separate components may or may not be physically separate. The units displayed as units may or may not be physical units. That is, the units may be located in one place or may be distributed over a plurality of network units. Some or all of the units may be selected as desired to achieve the purpose of the solution of the method embodiment.
In addition, in each embodiment of the present disclosure, functional units may be integrated in one processing unit, or respective units may be separate physical existence, or two or more units may be integrated in one unit.
When the functions are implemented in the form of a software functional unit and sold or used as a standalone product, the functions can be stored in a computer-readable storage medium. Based on this understanding, all or part of the technical solutions according to the present disclosure, or the part thereof that contributes to the related art, can be embodied in the form of a software product. The computer software product may be stored in a storage medium and contain instructions to enable a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the decoding method described in each of the embodiments. The above-mentioned storage medium may include various mediums capable of storing program codes, such as a Universal Serial Bus flash drive, a mobile hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disc.
A computer-readable storage medium is further provided according to the embodiments of the present disclosure. The computer-readable storage medium has s computer program stored thereon. The program, when executed by the processor, is configured to implement the steps of the method embodiments.
The computer storage medium of the embodiments of the present disclosure may employ any combination of one or more computer-readable media. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media may include electrical connections having one or more wires, a portable computer magnetic disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an Erasable Programmable Read Only Memory (EPROM or a flash memory), an optical fiber, a portable Compact Disc Read-Only Memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, the computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction apparatus, system, or device.
The computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave in which a computer-readable computer program is carried. Such propagated data signals may take a variety of forms, including, but not being limited to, electromagnetic signals, optical signals, or any suitable combination of the foregoing. The computer-readable signal medium may also be any computer-readable medium other than the computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, an apparatus, or a device.
The program code contained on the computer-readable medium may be transmitted using any suitable medium, including, but not being limited to, wireless, wired, optical cable, RF, etc., or any suitable combination thereof.
Computer program codes for performing the operations of the present disclosure may be written in one or more programming languages, or combinations thereof. The above programming languages include object-oriented programming languages, such as Java, Smalltalk, C++, as well as conventional procedural programming languages, such as the "C" language or similar programming languages. The program code may be executed entirely or partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or a server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet through an Internet service provider).
The above descriptions are preferred embodiments of the present disclosure and technical principles employed. It is conceivable for those skilled in the art that the present disclosure is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of the present disclosure. Therefore, although the present disclosure is described in more detail with reference to the above embodiments, the present disclosure is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present disclosure, all of which fall within the scope of protection of the present disclosure.

Claims

An on-site safety control method for a tower crane, comprising:
controlling a hook to move in an axial space according to planned path points, wherein the hook is controlled to move between every two adjacent planned path points through a plurality of control cycles, wherein a coordinate in a luffing axis direction is represented by a luffing length;

obtaining, in each of the plurality of control cycles, current coordinates of the hook in the axial space;

obtaining a current maximum allowable speed of the hook in each direction of the axial space, based on a current luffing length, a hoisting weight, and a working parameter of the tower crane; and

obtaining coordinates of an arrival position and a target speed of the hook in the axial space in a next control cycle, based on the current coordinates and a current speed of the hook in the axial space, the current maximum allowable speed of the hook in each direction, and coordinates of an un-reached planned path point of the hook.
The method according to claim 1, wherein said obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the current luffing length, the hoisting weight, and the working parameter of the tower crane comprises:
obtaining a current maximum allowable hoisting weight and a maximum allowable working torque in the luffing axis direction, based on the current luffing length;

calculating a current weight ratio and a current torque ratio, wherein the weight ratio is a ratio of the hoisting weight to the maximum allowable hoisting weight, and the torque ratio is a ratio of a working torque of the tower crane in the luffing axis direction to the maximum allowable working torque; and

obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio.
The method according to claim 2, wherein said obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and the at least one of the weight ratio and the torque ratio comprises at least one of:
obtaining a first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and a working gear of the tower crane, and determining, for each direction of the axial space, the first maximum allowable speed in the direction as the maximum allowable speed in the direction, wherein the working parameter comprises the working gear;

obtaining a second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear, and determining, for each direction of the axial space, the second maximum allowable speed in the direction as the maximum allowable speed in the direction; and

determining, for each direction of the axial space, a smaller one of the first maximum allowable speed in the direction and the second maximum allowable speed in the direction as the maximum allowable speed in the direction.
The method according to claim 3, wherein said obtaining the current maximum allowable speed of the hook in each direction of the axial space, based on the working parameter of the tower crane and at least one of the weight ratio and the torque ratio further comprises: for each direction of the axial space,
obtaining a third maximum allowable speed of the hook in the direction, based on the working gear and at least one of a position limit and a deceleration limit of the tower crane in the direction of the axial space, wherein the working parameter further comprises at least one of the position limit and the deceleration limit; and

adjusting the maximum allowable speed in the direction based on the third maximum allowable speed of the hook in the direction, wherein an adjusted maximum allowable speed of the hook in the direction is a smaller one of the maximum allowable speed in the direction before adjustment and the third maximum allowable speed in the direction.
The method according to claim 2, further comprising:
stopping movement of the tower crane and outputting a planned path abnormality signal when the current torque ratio is greater than a rated torque.
The method according to claim 2, wherein said obtaining the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction, based on the current luffing length comprises:
obtaining the current maximum allowable hoisting weight and the maximum allowable working torque in the luffing axis direction, based on the current luffing length and by using a first curve group of the tower crane, wherein the first curve group comprises relationships between allowable hoisting weights of the tower crane and luffing lengths at different tower crane reeving.
The method according to claim 3, wherein said obtaining the first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and the working gear of the tower crane comprises:
obtaining the first maximum allowable speed of the hook in each direction of the axial space based on the weight ratio and the working gear of the tower crane and by using a second curve group, wherein the second curve group comprises relationship curves between maximum allowable speed limits of the hook in each direction of the axial space and the weight ratio at respective working gears of the tower crane.
The method according to claim 3, wherein said obtaining the second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear comprises:
obtaining, the second maximum allowable speed of the hook in each direction of the axial space based on the torque ratio and the working gear and by using a third curve group, wherein the third curve group comprises relationship curves between maximum allowable speeds of the hook in each direction of the axial space and the torque ratio at respective working gears of the tower crane.
A tower crane controller, comprising:
a motion control module configured to control a hook to move in an axial space according to planned path points, wherein the hook is controlled to move between every two adjacent planned path points through a plurality of control cycles, wherein a coordinate in a luffing axis direction is represented by a luffing length;

a data obtaining module configured to obtain, in each of the plurality of control cycles, current coordinates of the hook in the axial space;

a safety control module configured to obtain a current maximum allowable speed of the hook in each direction of the axial space, based on a current luffing length, a hoisting weight, and a working parameter of the tower crane; and

a trajectory control module configured to obtain coordinates of an arrival position and a target speed of the tower crane in the axial space in a next control cycle, based on the current coordinates and a current speed of the hook in the axial space, the current maximum allowable speed of the hook in each direction, and coordinates of an un-reached planned path point of the hook.
A computing device, comprising:
a bus;

a communication interface connected to the bus;

at least one processor connected to the bus; and

at least one memory connected to the bus and storing program instructions, wherein the program instructions, when executed by the at least one processor, cause the at least one processor to implement the method according to any one of claims 1 to 8.