阅读说明：本技术 基于图像处理的塔式起重机异常预警方法及系统 (Tower crane abnormity early warning method and system based on image processing ) 是由 王建玲 杨航 李静 杨其锋 于 2021-03-01 设计创作，主要内容包括：本发明提供了一种基于图像处理的塔式起重机异常预警方法及系统；该方法包括：判断塔式起重机升降机构制动器是否发生故障；若发生故障,则根据塔式起重机和所吊重物的状态参数得到实时理想可掉落区域；在所述实时理想可掉落区域中剔除不可掉落区域,得到实时实际可掉落区域；获取所述实时实际可掉落区域对应的地面图像,基于所述地面图像在实时实际可掉落区域中选择实时最优掉落区域；光束照射在所述实时最优掉落区域,并将吊钩移动到所述实时最优掉落区域上方。本发明可以在故障发生后及时将重物移动至实时最优掉落区域,并以光束提醒相关人员远离实时最优掉落区域,避免重物坠落造成人财物的损失。(The invention provides an image processing-based tower crane abnormity early warning method and system; the method comprises the following steps: judging whether a brake of a lifting mechanism of the tower crane breaks down or not; if the fault occurs, obtaining a real-time ideal droppable area according to the state parameters of the tower crane and the lifted weight; rejecting non-droppable areas from the real-time ideal droppable area to obtain a real-time actual droppable area; acquiring a ground image corresponding to the real-time actual droppable area, and selecting a real-time optimal droppable area from the real-time actual droppable area based on the ground image; and irradiating the real-time optimal falling area by using a light beam, and moving the lifting hook above the real-time optimal falling area. According to the invention, the heavy object can be moved to the real-time optimal falling area in time after a fault occurs, and related personnel are reminded to be far away from the real-time optimal falling area by the light beam, so that the loss of people and property caused by the falling of the heavy object is avoided.)

1. An image processing-based tower crane abnormity early warning method is characterized by comprising the following steps:

judging whether a brake of a lifting mechanism of a tower crane breaks down or not; if the fault occurs, executing the step two;

step two, assuming that no object exists on the ground, obtaining a real-time ideal droppable area according to real-time state parameters of the tower crane and the lifted heavy object; the real-time state parameters comprise weight of a heavy object, real-time falling speed and real-time falling acceleration of the heavy object, length of a sling between the trolley and the winch, length of the sling between the heavy object and the winch, maximum moving speed of the trolley and maximum angular speed of the suspension arm;

rejecting non-droppable areas from the real-time ideal droppable area to obtain a real-time actual droppable area;

acquiring a ground image corresponding to the real-time actual droppable area, and selecting a real-time optimal droppable area from the real-time actual droppable area based on the ground image;

irradiating the real-time optimal falling area by using light beams, and moving a heavy object to the position above the real-time optimal falling area;

and step three, repeatedly executing the step two in the process of moving the heavy object above the real-time optimal falling area until the real-time ideal falling area is reduced to one point, and the heavy object falls.

2. The tower crane abnormity early warning method based on image processing as claimed in claim 1, wherein the method for obtaining the real-time ideal droppable area comprises: and inputting the real-time state parameters into a regional prediction neural network to obtain a boundary equation of a real-time ideal droppable region.

3. The image processing-based tower crane abnormality early warning method according to claim 2, wherein the acquisition method of the label data used for the regional prediction neural network training is as follows: and calculating corresponding reachable position points according to different operations of the crane trolley and the suspension arm, obtaining a boundary equation of an ideal droppable area according to all reachable position points, and using the label data as coefficients of the boundary equation.

4. The image processing-based tower crane abnormality warning method according to claim 3, wherein the different operations performed on the crane trolley and the boom comprise:

the method comprises the following steps of firstly, only operating the crane trolley or the suspension arm at the same time;

a second operation, simultaneously operating the crane trolley and the suspension arm at the same time;

and a third operation including the first operation and the second operation.

5. The image processing-based tower crane abnormality warning method according to claim 4, wherein the reachable position point is determined in relation to a falling time of the weight, and the falling time of the weight when the trolley is operated is determined by: dropping heavy objects when the trolley is not operatedAfter a period of time the distance between the weight and the ground isWhen the crane trolley is operated, the heavy object falls offDistance between weight and ground after timeGreater than or less thanWherein, in the step (A),the position of the crane trolley when the fault occurs is the initial point,for operating trolleysAfter the time, the trolley is separated from the initial point by a certain distance in a certain direction,is a real-time influence coefficient, andis a positive or negative number; based onCalculating the remaining drop time of the weight，Andthe sum is the falling time of the heavy object when the crane trolley is operated.

6. The image processing-based tower crane abnormity early warning method according to claim 5, wherein the real-time influence coefficientThe weight is obtained by prediction of a coefficient regression neural network, and the input of the coefficient regression neural network is weight of a heavy object and falling of the heavy objectFalling speed and falling acceleration of heavy object after time, length of sling between trolley and winch, length of sling between heavy object and winch, maximum moving speed of trolley, and operation of trolleyThe distance between the crane trolley and the initial point after the time is output as a real-time influence coefficient。

7. The image processing-based tower crane abnormality early warning method according to claim 6, wherein the eliminating the non-droppable area comprises:

selecting a first position point and a second position point which can be reached by the crane trolley on the suspension arm, wherein the first position point is located between the rotation center point and the initial point, the initial point is located between the rotation center point and the second position point, calculating first distances and second distances between the first position point and the rotation center point and between the second position point and the rotation center point respectively, and obtaining a first circular area and a second circular area by taking the rotation center point as a circle center and the first distances and the second distances as radiuses respectively; wherein, the rotation center point is the intersection point of the suspension arm and the tower body; selecting a second position point according to the length of the suspension arm;

removing the first circle area from the real-time ideal falling area, and then taking an intersection area with the second circle area; and performing region elimination in the intersection region based on the height of the object on the ground to obtain a real-time actual falling region.

8. The image processing-based tower crane abnormality early warning method according to claim 7, wherein the selecting of the real-time optimal falling area from the real-time actual falling areas specifically comprises: segmenting the bare ground area, the object placing area and the building area of the ground image, and distributing weights to the bare ground area, the object placing area and the building area; and calculating the suitability of the sliding window area based on the exposed ground area, the object placing area, the area of the building area and the corresponding weight in the sliding window area, wherein the area corresponding to the sliding window area with the maximum suitability in the real-time actual droppable area is the real-time optimal droppable area.

9. An image processing-based tower crane abnormity early warning system is characterized by comprising a fault judgment subsystem, a real-time optimal falling area acquisition subsystem and a real-time optimal falling area updating subsystem; wherein:

the fault judgment subsystem is used for judging whether a brake of the lifting mechanism of the tower crane has a fault or not, and if the brake has the fault, executing a real-time optimal falling area acquisition subsystem;

a real-time optimal falling area obtaining subsystem, which obtains a real-time ideal falling area according to real-time state parameters of the tower crane and the lifted heavy object on the assumption that no object exists on the ground; the real-time state parameters comprise weight of a heavy object, real-time falling speed and real-time falling acceleration of the heavy object, length of a sling between the trolley and the winch, length of the sling between the heavy object and the winch, maximum moving speed of the trolley and maximum angular speed of the suspension arm; rejecting non-droppable areas from the real-time ideal droppable area to obtain a real-time actual droppable area; acquiring a ground image corresponding to the real-time actual droppable area, and selecting a real-time optimal droppable area from the real-time actual droppable area based on the ground image; irradiating the real-time optimal falling area by using light beams, and moving a heavy object to the position above the real-time optimal falling area;

and the real-time optimal falling area updating subsystem repeatedly executes the real-time optimal falling area acquiring subsystem in the process of moving the heavy object to the position above the real-time optimal falling area until the real-time ideal falling area is reduced to one point, and the heavy object falls.

Technical Field

The invention relates to the field of cranes and image processing, in particular to an image processing-based tower crane abnormity early warning method and system.

Background

If the brake of the lifting mechanism of the tower crane breaks down, a slip hook can be caused, and the slip hook is a reason that the main winch does not brake and the automobile brake fails. Sometimes, the slip hook is caused by loosening of the band-type brake or serious abrasion of the brake pad. Once a brake of a single brake crane in China has a problem, a hanging object is easy to slip, and then a heavy object freely falls, so that an accident is easily caused. When the tower crane hook slides downwards, the tower crane hook should be hooked upwards or slowly dropped at a low speed, and the tower crane hook should not slide in a neutral position. In a common crane, a slip hook can be controlled by backing up, but for a crane controlled by frequency conversion, the backing up during slipping of the hook easily causes failure of a frequency converter, so that the frequency converter fails, and heavy objects still fall down.

Disclosure of Invention

In order to solve the problems, the invention provides an image processing-based tower crane abnormity early warning method, which comprises the following steps:

judging whether a brake of a lifting mechanism of a tower crane breaks down or not; if the fault occurs, executing the step two;

step two, assuming that no object exists on the ground, obtaining a real-time ideal droppable area according to real-time state parameters of the tower crane and the lifted heavy object; the real-time state parameters comprise weight of a heavy object, real-time falling speed and real-time falling acceleration of the heavy object, length of a sling between the trolley and the winch, length of the sling between the heavy object and the winch, maximum moving speed of the trolley and maximum angular speed of the suspension arm;

rejecting non-droppable areas from the real-time ideal droppable area to obtain a real-time actual droppable area;

acquiring a ground image corresponding to the real-time actual droppable area, and selecting a real-time optimal droppable area from the real-time actual droppable area based on the ground image;

irradiating the real-time optimal falling area by using light beams, and moving a heavy object to the position above the real-time optimal falling area;

and step three, repeatedly executing the step two in the process of moving the heavy object above the real-time optimal falling area until the real-time ideal falling area is reduced to one point, and the heavy object falls.

Further, the method for obtaining the real-time ideal droppable area comprises the following steps: and inputting the real-time state parameters into a regional prediction neural network to obtain a boundary equation of a real-time ideal droppable region.

Further, the method for acquiring the label data used for the regional prediction neural network training comprises the following steps: and calculating corresponding reachable position points according to different operations of the crane trolley and the suspension arm, obtaining a boundary equation of an ideal droppable area according to all reachable position points, and using the label data as coefficients of the boundary equation.

Further, the different operations performed on the trolley and the boom comprise:

the method comprises the following steps of firstly, only operating the crane trolley or the suspension arm at the same time;

a second operation, simultaneously operating the crane trolley and the suspension arm at the same time;

and a third operation including the first operation and the second operation.

Further, the determination of the reachable position point is related to the drop time of the weight, which is determined by operating the trolley: dropping heavy objects when the trolley is not operatedThe distance between the weight and the ground is H after the time, and the weight falls off when the crane trolley is operatedAfter a time the distance H' between the weight and the ground is greater or less than H, wherein,the position of the crane trolley when the fault occurs is the initial point,for operating trolleysAfter the time, the trolley is spaced from the initial point, the spacing distance has a direction, K is a real-time influence coefficient, and K is a positive number or a negative number; calculating remaining drop time of weight based on H，Andthe sum is the falling time of the heavy object when the crane trolley is operated.

Further, the real-time influence coefficient K is obtained by predicting a coefficient regression neural network, wherein the coefficient regression neural network inputs the weight of the heavy object and the falling of the heavy objectFalling speed and falling acceleration of heavy object after time, length of sling between trolley and winch, length of sling between heavy object and winch, maximum moving speed of trolley, and operation of trolleyAnd after time, the distance between the crane trolley and the initial point is output as a real-time influence coefficient K.

Further, the rejecting non-drop areas comprises:

selecting a first position point and a second position point which can be reached by the crane trolley on the suspension arm, wherein the first position point is located between the rotation center point and the initial point, the initial point is located between the rotation center point and the second position point, calculating first distances and second distances between the first position point and the rotation center point and between the second position point and the rotation center point respectively, and obtaining a first circular area and a second circular area by taking the rotation center point as a circle center and the first distances and the second distances as radiuses respectively; wherein, the rotation center point is the intersection point of the suspension arm and the tower body; selecting a second position point according to the length of the suspension arm;

removing the first circle area from the real-time ideal falling area, and then taking an intersection area with the second circle area; and performing region elimination in the intersection region based on the height of the object on the ground to obtain a real-time actual falling region.

Further, selecting a real-time optimal drop zone from the real-time actual drop zones specifically includes: segmenting the bare ground area, the object placing area and the building area of the ground image, and distributing weights to the bare ground area, the object placing area and the building area; and calculating the suitability of the sliding window area based on the exposed ground area, the object placing area, the area of the building area and the corresponding weight in the sliding window area, wherein the area corresponding to the sliding window area with the maximum suitability in the real-time actual droppable area is the real-time optimal droppable area.

The invention also provides an image processing-based tower crane abnormity early warning system, which comprises: the system comprises a fault judgment subsystem, a real-time optimal falling area acquisition subsystem and a real-time optimal falling area updating subsystem; wherein:

the fault judgment subsystem is used for judging whether a brake of the lifting mechanism of the tower crane has a fault or not, and if the brake has the fault, executing a real-time optimal falling area acquisition subsystem;

a real-time optimal falling area obtaining subsystem, which obtains a real-time ideal falling area according to real-time state parameters of the tower crane and the lifted heavy object on the assumption that no object exists on the ground; the real-time state parameters comprise weight of a heavy object, real-time falling speed and real-time falling acceleration of the heavy object, length of a sling between the trolley and the winch, length of the sling between the heavy object and the winch, maximum moving speed of the trolley and maximum angular speed of the suspension arm; rejecting non-droppable areas from the real-time ideal droppable area to obtain a real-time actual droppable area; acquiring a ground image corresponding to the real-time actual droppable area, and selecting a real-time optimal droppable area from the real-time actual droppable area based on the ground image; irradiating the real-time optimal falling area by using light beams, and moving a heavy object to the position above the real-time optimal falling area;

and the real-time optimal falling area updating subsystem repeatedly executes the real-time optimal falling area acquiring subsystem in the process of moving the heavy object to the position above the real-time optimal falling area until the real-time ideal falling area is reduced to one point, and the heavy object falls.

The invention has the beneficial effects that: when a tower crane driver slips, the tower crane driver often cannot take countermeasures within the first time due to panic and misbehavior.

The influence of the moving crane trolley on the falling time is considered when the ideal droppable area is determined, so that the ideal droppable area obtained by the method is more accurate.

According to the invention, the optimal falling area of the heavy object is rapidly judged through computer vision, the movement of the suspension arm and the crane trolley is controlled by the computer, the heavy object is moved above the optimal falling area, and the influence caused by the falling accident of the heavy object is reduced.

Drawings

FIG. 1 is a flow chart of the method of the present invention.

FIG. 2 is a system configuration diagram of the present invention.

FIG. 3 is a schematic diagram of an intersection region in the embodiment.

Detailed Description

In order that those skilled in the art will better understand the present invention, the following detailed description is given with reference to the accompanying drawings.

The invention aims to automatically control the crane in time according to real-time state parameters of the tower crane and a lifted heavy object and an actual ground image to reduce accident loss when a brake of a lifting mechanism of the tower crane breaks down. The invention can reduce the experience requirement and the response speed requirement of a tower crane driver for processing the slip hook accident caused by the failure of the lifting mechanism brake.

The first embodiment is as follows:

the embodiment provides an image processing-based tower crane abnormity early warning method, and the implementation flow of the method is shown in fig. 1, and specifically comprises the following steps:

step one, judging whether a brake of a lifting mechanism of the tower crane breaks down, if so, executing step two, wherein the specific judging method comprises the following steps:

the method has the advantages that the color marks are arranged on the sling, yellow color marks are arranged on the sling every other meter in the embodiment, and the first camera is arranged on the tower crane and used for collecting images of the sling; the method for processing the images is used for judging the state of the sling image, and judging whether a brake of the lifting mechanism breaks down or not by combining a control instruction of a winch, wherein the specific judgment process comprises the following steps:

a) collecting a multi-frame sling image, extracting a color mark in the sling image, and specifically, transferring the sling RGB image to an HSV color space to extract the color mark;

b) calculating the inter-frame intersection ratio IOU marked by the same color according to the multi-frame sling images to obtain the motion direction of the lifted heavy object;

c) determining sampling time, acquiring the moving pixel distance of the same color mark based on a multi-frame sling image in the sampling time, obtaining an actual moving distance according to the moving pixel distance, and obtaining the movement speed of a heavy object according to the actual moving distance and the sampling time;

d) acquiring a control instruction of a winch, acquiring a motor rotation direction and a rotation speed input by a tower crane driver, acquiring a set direction of a heavy object according to the motor rotation direction, and acquiring a set speed of the heavy object according to the rotation speed;

e) and judging whether the brake of the lifting mechanism breaks down or not based on the moving direction and the moving speed of the weight, the set direction and the set speed of the weight.

Step two:

the method comprises the following steps of firstly, assuming that no object exists on the ground, and obtaining a real-time ideal droppable area according to real-time state parameters of a tower crane and a hung heavy object, specifically:

in order to accelerate the calculation speed and facilitate timely response measures when a fault occurs, the method inputs real-time state parameters into the regional prediction neural network to obtain a boundary equation of a real-time ideal droppable region. The reason for adopting the regional predictive neural network is that the calculation process for obtaining the real-time ideal droppable region according to the mathematical method is complex, the time for obtaining the result is long, and the DNN can be rapidly inferred, so that the real-time requirement is met.

The real-time state parameters comprise weight of a heavy object, falling speed and falling acceleration of the heavy object, length of a sling between the trolley and the winch, length of the sling between the heavy object and the winch, maximum moving speed of the trolley and maximum angular speed of the suspension arm.

The training process of the regional prediction neural network comprises the following steps: acquiring state parameters and label data used for training in a simulator; based on the obtained state parameters and label data, training a regional prediction neural network by adopting a mean square error loss function; the method for acquiring the label data comprises the following steps: calculating corresponding reachable position points according to different operations of the crane trolley and the suspension arm, obtaining a boundary equation of an ideal droppable area according to all reachable position points, wherein the label data is a coefficient of the boundary equation; preferably, the boundary equation is a power series equation.

In the process of operating the trolley, the lifting force is applied to the heavy object on the lifting hook, meanwhile, the stretching force is applied to the winch, the stress analysis and calculation are directly carried out, and the process is complex, so that in order to more accurately obtain state parameters and label data, a simulator is used for carrying out simulation to obtain data; the friction force at the winch is set to be fixed friction force in the simulator, and the traction force of the amplitude-variable trolley is also fixed value, namely the torque of the motor of the trolley is fixed.

The different operations performed on the trolley and the boom comprise: the method comprises the following steps of firstly, only operating the crane trolley or the suspension arm at the same time; a second operation, simultaneously operating the crane trolley and the suspension arm at the same time; and a third operation including the first operation and the second operation.

The specific method for calculating the corresponding reachable position points according to different operations performed on the trolley and the suspension arm comprises the following steps:

acquiring an reachable position point according to a first operation:

the method comprises the steps of constructing a polar coordinate system by taking a rotation central point as a pole and the position of a suspension arm when a fault just occurs as a polar axis, wherein the coordinates of a position point in the polar coordinate system are (theta, R), the theta represents an included angle between the current suspension arm and the polar axis after the suspension arm is operated, the theta has positive and negative values, in the embodiment, when the current suspension arm and the polar axis are anticlockwise, the included angle is positive, and the R represents the distance between a crane trolley and the rotation central point.

a) When only the suspension arm is operated in the whole operation process, the suspension arm moves without influencing the falling time of the weight, so that the real-time distance between the weight and the ground, the real-time falling speed and the real-time falling acceleration of the weight are obtained, the real-time swing arm limit time is calculated based on the obtained real-time distance, the real-time falling speed and the real-time falling acceleration, the coordinates of two critical reachable position points in a polar coordinate system are calculated according to the real-time swing arm limit time and the maximum angular speed of the suspension arm, and all reachable position points corresponding to the operation can be obtained according to the two critical reachable position points, namely the coordinates belong to (, [ 2 ]，],) The point of the range is such that,、respectively representing two criticalitiesThe included angle between the position of the suspension arm corresponding to the position reachable point and the polar axis; the positions of the suspension arms are symmetry axes when a fault just occurs, and the two obtained critical reachable position points are symmetrical about the symmetry axes.

b) When the whole operation process is only carried out on the trolley, the falling time of the heavy object can be influenced by moving the trolley, so that the heavy object falls when the trolley is not operatedThe distance between the weight and the ground is H after the time, and the weight falls off when the crane trolley is operatedAfter a time the distance H' between the weight and the ground is greater or less than H, wherein,the position of the crane trolley when the fault occurs is the initial point,for operating trolleysAfter the time, the trolley is spaced from the initial point, the spacing distance has a direction, K is a real-time influence coefficient, and K is a positive number or a negative number; calculating the remaining drop time of the weight based on H', the drop velocity and the drop acceleration of the weight at that time，Andthe sum is the falling time of the heavy object when the crane trolley is operated.

The hoisting trolley can move towardsThe movement is carried out in two directions: the first moving direction is that the trolley is close to the tower body, and the obtained spacing distance is positive when the moving direction of the trolley is the first moving direction; the second moving direction is that the trolley is far away from the tower body, and the obtained spacing distance is negative when the moving direction of the trolley is the second moving direction; the moving direction of the trolley is different, the influence on the falling time of the heavy object is also different, and the falling time of the heavy object can be prolonged or shortened when the moving direction of the trolley is the first moving direction; when the moving direction of the hoisting trolley is the second moving direction, the falling time of the heavy object can be shortened; therefore, the travelling directions of the crane carriages are different, the obtained falling time of the heavy object is also different, and therefore, the first carriage travelling time can be obtained corresponding to the first travelling direction and the second travelling directionSecond carriage moving timeAccording to、Obtaining a first maximum spacing distance from the maximum moving speed of the crane trolleySecond maximum separation distanceFinally, two critical reachable position points are obtained, then theta is 0, and the R value belongs to [ alpha ], [ alpha ],]The point in the range is corresponding to the operationThere are reachable location points; min is a minimum function and max is a maximum function.

It should be noted that, in the calculation of the second carriage moving time, it is assumed that the trolley can move along the second moving direction all the time, but the trolley has an end point along the first moving direction and cannot move all the time, and the end point is a rotation center point.

Wherein the real-time influence coefficient K is obtained by predicting a coefficient regression neural network, and the input of the coefficient regression neural network is weight of the heavy object and falling of the heavy objectFalling speed and falling acceleration of heavy object after time, length of sling between trolley and winch, length of sling between heavy object and winch, maximum moving speed of trolley, and operation of trolleyAnd after time, the distance between the crane trolley and the initial point is output as a real-time influence coefficient K.

The training label data of the coefficient regression neural network is an influence coefficient K under different conditions acquired by a simulator, the interval distance of the crane trolley in a certain time period and the change value of the length of the sling between a heavy object and a winch before and after the crane trolley moves in the time period are acquired in the simulator, and the ratio of the interval distance to the change value of the length of the sling is K; input data used in training the coefficient recurrent neural network are also obtained in the simulator, the coefficient recurrent neural network is trained by using K corresponding to the input data and the input data, specifically, the real-time interval distance between a crane trolley and an initial point in the input data is continuously adjusted to obtain an influence coefficient K of network output, and a mean square error loss function is adopted to reduce the difference between the influence coefficient of the network output and the actually calculated influence coefficient; the purpose of the network is to influence the regression of the coefficients.

The reason for using DNN to obtain the influence coefficient is: the simulation times and data are limited, so that very comprehensive data cannot be obtained, and the establishment of a mathematical model is difficult, so that the DNN is used for fitting the mapping relation among the data in order to obtain the influence coefficients under various conditions.

c) During the whole operation process, when the trolley is operated firstly and then the suspension arm is operated, firstly, the spacing distance of the trolley is obtained, after the spacing distance is obtained, the remaining dropping time corresponding to different spacing distances is obtained according to the method for calculating the remaining dropping time in the step b), and secondly, the rotation angle of the suspension arm is calculated according to the obtained remaining dropping time; thus, varying the trolley separation distance results in all the reachable position points for the operation.

d) The whole operation process is that when the suspension arm is operated firstly and then the trolley is operated, the time for operating the suspension arm is firstly obtainedDetermined according to the direction of movement of the trolleyWhether it is less than the first carriage-moving time or the second carriage-moving time is determined according toCalculating the rotation angle of the suspension arm according to the maximum angular speed of the suspension arm; obtaining weight dropAfter the time, calculating the distance between the heavy object and the ground, the falling speed of the heavy object and the falling acceleration of the heavy object, calculating the falling time of the heavy object when the heavy object operates the crane trolley at the height according to the method in b), and calculating the interval distance of the crane trolley according to the calculated falling time; change ofThe value of (d) can then be used to obtain all reachable location points corresponding to the operation.

Acquiring an reachable position point according to a second operation:

the trolley moves at the firstMove in the moving directionTime, boom rotationThe time of day is,the value range of (a) is [0,]then is based onCalculating partial reachable position points according to the maximum moving speed of the crane trolley, the maximum angular speed of the suspension arm and the rotation direction of the suspension arm;

the trolley moves in a second direction of movementTime, boom rotationThe time of day is,the value range of (a) is [0,]then is based onAnd the maximum moving speed of the crane trolley, the maximum angular speed of the suspension arm and the rotation direction of the suspension arm can calculate other reachable position points.

Acquiring an reachable position point according to a third operation:

setting the spacing distance of the lifting trolleysThe spacing distance is obtained by comparing the maximum moving speed of the hoisting trolleyTo obtain falling of heavy objectsThe height of the rear part from the ground, and the residual falling time of the heavy object is obtained based on the height，Taking the maximum angular speed of the suspension arm as the rotation angle of the suspension arm when the crane trolley and the suspension arm are operated simultaneously，Multiplying the maximum angular speed of the suspension arm to the rotation angle when the suspension arm is operated independently，Andif there is a positive or negative sign, the coordinates of the reachable position point are: (+，)，The distance length from the initial point to the revolution center point is taken as the length; is changedAnd combining the rotation direction of the suspension arm to obtain all reachable position points corresponding to the operation.

All reachable location points are obtained so far.

Secondly, rejecting non-droppable areas from the real-time ideal droppable area to obtain a real-time actual droppable area; because the crane trolley is supposed to move along the second moving direction all the time when the real-time ideal region which can be dropped is obtained, namely the length of the supposed suspension arm during calculation is possibly longer than that of the suspension arm in actual life, the region which can not be dropped needs to be removed in the real-time ideal region which can be dropped, and the specific process of removing the region which can not be dropped is as follows:

selecting a first position point and a second position point which can be reached by the crane trolley on the suspension arm, wherein the first position point is located between the rotation center point and the initial point, the initial point is located between the rotation center point and the second position point, calculating a first distance and a second distance between the first position point and the rotation center point and between the second position point and the rotation center point respectively, and obtaining a first circular area and a second circular area by taking the rotation center point as a circle center and the first distance and the second distance as radiuses respectively; wherein, the centre point of gyration is the nodical of davit and body of the tower.

Selecting a first position point on the suspension arm according to experience or related research data, wherein the first position point is set to avoid accidents caused by too small distance between the trolley and the rotation central point, and the point in the first circular area is a point with too small distance between the trolley and the rotation central point; when the distance between the critical reachable position point in the first moving direction and the turning center point is greater than the distance between the first position point and the turning center point, no overlapping area exists between the real-time ideal droppable area and the first circular area, namely the distance between the critical reachable position point in the first moving direction and the turning center point is a safe distance; when the distance between the critical reachable position in the first moving direction and the rotation center point is smaller than the distance between the first position and the rotation center point, the distance between the critical reachable position in the first moving direction and the rotation center point is too small, and the crane trolley is moved to the critical reachable position, which may cause an accident.

The reason for setting the second position point is that, when the trolley is operated only to obtain the critical reachable position point in the second moving direction, it is assumed that the trolley can move along the second moving direction all the time, and therefore, the distance between the obtained critical reachable position point in the second moving direction and the rotation center point may be greater than the length of the boom in actual life, and therefore, the second position point needs to be set, and the second position point is selected according to the length of the boom, specifically: when the distance between the critical reachable position point in the second moving direction and the rotation central point is more than or equal to the length of the suspension arm in actual life, the second position point is positioned at the tail end of the suspension arm, and the distance between the second position point and the rotation central point is the actual length of the suspension arm at the moment; when the distance between the critical reachable position point in the second moving direction and the rotation center point is smaller than the length of the suspension arm in actual life, the critical reachable position point in the second moving direction is the second position point.

Removing the first circle area from the real-time ideal falling area, and then taking an intersection area with the second circle area; when the distance between the critical reachable position point in the first moving direction and the rotation center point is smaller than the distance between the first position point and the rotation center point, and the distance between the critical reachable position point in the second moving direction and the rotation center point is smaller than the length of the boom in actual life, the intersection area is as shown in fig. 3, the circle with the smaller radius in fig. 3 is the first circle area, the circle with the larger radius is the second circle area, the shaded area is the intersection area, the rectangle represents the boom, and the black point is the initial point.

The situation such as material placement, construction progress in the actual building site scene is complicated, consequently, need obtain real-time actual region that can drop after carrying out regional rejection in the intersection region based on the height of subaerial object, the point of the high rejection based on subaerial object is unreasonable point, and the judgement method of unreasonable point is:

using a sensor such as a millimeter wave radar to obtain the height of each position point in a real-time actual falling area, calculating the falling time of the weight from the current position to each position point based on the vertical height between the weight and each position point, and then obtaining the required operation time of the weight from the current position to each position point, wherein if the required operation time of the weight to a certain position point is greater than the corresponding falling time, the position point is an unreasonable point; wherein the operation time is the time for operating the trolley or the boom.

Thirdly, acquiring a ground image corresponding to the real-time actual droppable area, if the real-time actual droppable area is larger than the acquisition range of the camera, using the area acquired by the camera in real time in the area within the acquisition range of the camera, using a historical image acquired by the camera in the area not within the acquisition range of the camera, and splicing the image acquired in real time with the historical image to obtain the ground image corresponding to the real-time actual droppable area; the placement position of the camera for collecting the ground image is not specifically required, the ground image can be collected, and a real-time optimal falling area is selected from real-time actual falling areas based on the ground image:

dividing the bare ground area, the object placing area and the building area of the ground image, and distributing weights for the bare ground area, the object placing area and the building area, wherein the corresponding weights are 1, 0.5 and 0 respectively; and respectively taking each pixel point as a center in the ground image to obtain a plurality of sliding window areas, multiplying the areas of the exposed ground area, the object placing area and the building area in the sliding window areas by corresponding weights respectively, and then adding the areas to obtain the suitability of the sliding window areas, wherein the area corresponding to the sliding window area with the maximum suitability in the real-time actual falling area is a real-time optimal falling area, and the central point of the real-time optimal falling area is an optimal falling point.

And fourthly, irradiating the real-time optimal falling area by using light beams to perform abnormal early warning, avoiding personnel from suddenly breaking into the area, and moving a heavy object to the position above the real-time optimal falling area.

And step three, repeatedly executing the step two in the process of moving the heavy object above the real-time optimal falling area until the real-time ideal falling area is reduced to one point, and the heavy object falls.

It should be noted that, each time a real-time state parameter is input, the area prediction neural network outputs a real-time ideal droppable area; according to the time sequence, the obtained real-time ideal drop-able area is smaller and smaller, namely the real-time generated ideal drop-able area is continuously updated and reduced until the obtained real-time ideal drop-able area is a point.

Example two:

based on the same inventive concept as the method embodiment, the embodiment provides an image processing-based tower crane abnormity early warning system, which is shown in fig. 2 and specifically comprises a fault judgment subsystem, a real-time optimal falling area acquisition subsystem and a real-time optimal falling area updating subsystem; wherein:

the fault judgment subsystem is used for judging whether a brake of the lifting mechanism of the tower crane has a fault or not, and if the brake has the fault, executing a real-time optimal falling area acquisition subsystem;

a real-time optimal falling area obtaining subsystem, which obtains a real-time ideal falling area according to real-time state parameters of the tower crane and the lifted heavy object on the assumption that no object exists on the ground; the real-time state parameters comprise weight of a heavy object, real-time falling speed and real-time falling acceleration of the heavy object, length of a sling between the trolley and the winch, length of the sling between the heavy object and the winch, maximum moving speed of the trolley and maximum angular speed of the suspension arm; rejecting non-droppable areas from the real-time ideal droppable area to obtain a real-time actual droppable area; acquiring a ground image corresponding to the real-time actual droppable area, and selecting a real-time optimal droppable area from the real-time actual droppable area based on the ground image; irradiating the real-time optimal falling area by using light beams, and moving a heavy object to the position above the real-time optimal falling area;

and the real-time optimal falling area updating subsystem repeatedly executes the real-time optimal falling area acquiring subsystem in the process of moving the heavy object to the position above the real-time optimal falling area until the real-time ideal falling area is reduced to one point, and the heavy object falls.

As for the system embodiment, since it is basically similar to the method embodiment, it is relatively simple to describe, and the relevant points can be referred to the partial description of the method embodiment; the foregoing is intended to provide those skilled in the art with a better understanding of the invention, and is not intended to limit the invention to the particular forms disclosed, since modifications and variations can be made without departing from the spirit and scope of the invention.