阅读说明：本技术 塔吊安全监控方法和系统 (Tower crane safety monitoring method and system ) 是由 舒远 蔡江 姚宏泰 于 2019-12-20 设计创作，主要内容包括：本发明提供一种塔吊安全监控方法和系统,其在第一时段内,获取塔吊的吊物与作业面之间的吊物-作业面距离、吊物相对于塔吊的相对位置、以及作业面上的作业人员相对于塔吊的相对位置并基于吊物相对于塔吊的相对位置和作业人员相对于塔吊的相对位置,获取第一时段内作业人员相对吊物的位置变化趋势,再进一步根据第一时段内作业人员相对吊物的位置变化趋势,结合吊物-作业面距离,判断在第二时段内作业人员是否将进入吊物正下方的预警危险区域并输出预设预警信号。本发明的塔吊安全监控方法和系统可以在作业人员将进入预警危险区域时对作业人员和/或塔吊的司机发出警报,降低事故发生风险。(The invention provides tower crane safety monitoring methods and systems, which are characterized in that in a time period, the distance between a hanging object and an operation surface of a tower crane, the relative position of the hanging object relative to the tower crane and the relative position of an operator on the operation surface relative to the tower crane are obtained, and based on the relative position of the hanging object relative to the tower crane and the relative position of the operator relative to the tower crane, the position change trend of the operator relative to the hanging object in the time period is obtained, then the step is carried out, according to the position change trend of the operator relative to the hanging object in the time period, the distance between the hanging object and the operation surface is combined, whether the operator enters an early warning danger area right below the hanging object in the second time period is judged, and a preset early warning signal is output.)

The safety monitoring method of tower cranes is characterized by comprising the following steps:

in a th time period, acquiring a hanging object-working surface distance between a hanging object and a working surface of the tower crane, a relative position of the hanging object relative to the tower crane and a relative position of an operator on the working surface relative to the tower crane;

acquiring a position change trend of the operator relative to the hanging object in the th time period based on the relative position of the hanging object relative to the tower crane and the relative position of the operator relative to the tower crane;

judging whether the operator enters an early warning danger area right below the hoisted object in a second time period according to the position change trend of the operator relative to the hoisted object in the th time period and by combining the distance between the hoisted object and the operation surface;

and outputting a preset early warning signal when the operator is judged to enter the early warning dangerous area in the second time period.

2. The tower crane safety monitoring method according to claim 1, characterized in that: the process of obtaining the distance between the hoisted object and the working surface comprises the following steps:

acquiring the distance between the amplitude variation trolley of the tower crane and the working surface;

acquiring the distance between the amplitude variation trolley of the tower crane and the hoisting object; and

and subtracting the distance between the amplitude variation trolley and the working surface from the distance between the amplitude variation trolley and the hanging object to obtain the distance between the hanging object and the working surface.

3. The tower crane safety monitoring method according to claim 1, characterized in that: and acquiring the relative position of the operating personnel on the operating surface relative to the tower crane by utilizing the positioning devices arranged on the tower body and the suspension arm of the tower crane.

4. The tower crane safety monitoring method of claim 3, wherein the processing of acquiring the position change trend of the operator relative to the hoisted object in the th time period and judging whether the operator enters the early warning danger area in the second time period comprises:

establishing a cylindrical coordinate system which takes a tower body of the tower crane as a rotating shaft center, takes a suspension arm of the tower crane as a radius and takes a variable amplitude trolley-suspension object distance between a variable amplitude trolley of the tower crane and the suspension object as a height, and acquiring a motion track curve, a moving speed and an acceleration of the suspension object in the cylindrical coordinate system within the th time period;

establishing an th rectangular coordinate system based on the relative position relationship between the positioning device and the tower body and the suspension arm, and acquiring a motion trail curve, a moving speed and an acceleration of the operator in the th rectangular coordinate system within the th time period;

predicting the displacement of the crane in the cylindrical coordinate system in the second period based on the motion trail curve, the moving speed and the acceleration of the crane in the cylindrical coordinate system in the th period;

predicting the displacement of the operator in the rectangular coordinate system in the second period based on a motion trail curve, a moving speed and an acceleration of the operator in the rectangular coordinate system in the period;

transforming the displacement of the hoisted object in the cylindrical coordinate system in the second period of time and the displacement of the operator in the th rectangular coordinate system in the second period of time into a displacement in a second rectangular coordinate system;

judging whether displacement overlapping exists between the lifting object and the operator in the second rectangular coordinate system within the second time period or not by combining the distance between the lifting object and the working face; and

and when the hoisted object and the operator have displacement overlap in the second rectangular coordinate system in the second time period, determining that the operator will enter the early warning danger area in the second time period.

5. The tower crane safety monitoring method according to claim 2, characterized in that:

acquiring the distance between the variable amplitude trolley and the working surface by using a laser range finder arranged on the variable amplitude trolley;

and acquiring the distance between the suspension arm of the tower crane and the lifting hook by using a height sensor arranged on the balance arm of the tower crane as the distance between the amplitude variation trolley and the suspended object.

6. The tower crane safety monitoring method according to claim 4, characterized in that: and establishing a cylindrical coordinate system by using the tower body as a rotating axis, the suspension arm as a radius and the luffing trolley-suspended object distance as a height by using the suspension arm angle data fed back by a rotary sensor arranged on the tower body, the luffing trolley amplitude data fed back by an amplitude sensor arranged on the suspension arm and the distance data between the suspension arm and a lifting hook of the tower crane, which are fed back by a height sensor arranged on a balance arm of the tower crane, wherein the height difference between the suspension arm and the lifting hook is the luffing trolley-suspended object distance.

7. The tower crane safety monitoring method of claim 3, wherein two positioning devices are mounted on the tower body, and positioning devices are mounted on the boom.

8. The tower crane safety monitoring method according to claim 7, characterized in that: the positioning device is an ultra-wideband base station, and the ultra-wideband base station realizes the positioning of the operator based on positioning pulses sent by an ultra-wideband tag carried by the operator.

9. The tower crane safety monitoring method of claim 8, wherein the coordinate values of the ultra-wideband tag in the th rectangular coordinate system are obtained as the coordinate values of the operator in the th rectangular coordinate system by a time-of-flight ranging technique, wherein the th rectangular coordinate system is established based on the relative position relationship between the positioning device itself and the relative position relationship between the positioning device and the tower body and the boom.

10, A tower crane safety monitoring system using the tower crane safety monitoring method of any of claims 1-9, which is characterized by comprising:

a data acquisition unit configured to acquire a crane-working surface distance between a crane and a working surface of the tower crane, a relative position of the crane with respect to the tower crane, and a relative position of an operator on the working surface with respect to the tower crane in a th time period;

the change acquiring unit is configured to acquire a position change trend of the operator relative to the hanging object in the th time period based on the relative position of the hanging object relative to the tower crane and the relative position of the operator relative to the tower crane;

a danger judging unit configured to judge whether the operator will enter an early warning danger area directly below the hoisted object in a second time period according to the position change trend of the operator relative to the hoisted object in the th time period and the distance between the hoisted object and a working surface;

and the danger early warning unit is configured to output a preset early warning signal when the operator is judged to enter the early warning danger area in the second time period.

Technical Field

The disclosure relates to the field of safety monitoring, in particular to a method and a system for monitoring safety of tower cranes.

Background

The safety monitoring scheme of the existing tower crane mainly monitors the safety condition of the tower crane by additionally arranging various sensors on a tower body, namely monitoring whether the tower crane is in a safe operation state by acquiring limiting data such as wind speed, rotation, amplitude, height, weight and the like, and realizes the visualization of the hoisted object and the dangerous area under the hoisting object by additionally arranging a camera on a luffing trolley of the tower crane.

The above scheme needs to avoid the risk that the hanging object falls to hurt people through the visual observation of the driver, has the condition of misjudgment or missed judgment under the condition of poor visibility of the visual field, and can be influenced by subjective factors of the driver (for example, the driver does not notice due to fatigue, carelessness and the like), and has great disadvantages. Therefore, a stable and reliable solution is needed to perform safety monitoring and early warning on operators during the hoisting operation of the tower crane.

Disclosure of Invention

In view of one or more of the problems identified above with respect to , tower crane safety monitoring methods and systems are provided.

The tower crane safety monitoring method comprises the steps of obtaining the distance between a hanging object and an operation surface of a tower crane, the relative position of the hanging object relative to the tower crane and the relative position of an operator on the operation surface relative to the tower crane in th time period, obtaining the position change trend of the operator relative to the hanging object in th time period based on the relative position of the hanging object relative to the tower crane and the relative position of the operator relative to the tower crane, judging whether the operator enters an early warning danger area right below the hanging object in the second time period according to the position change trend of the operator relative to the hanging object in th time period and combining the distance between the hanging object and the operation surface, and outputting a preset early warning signal when the operator is judged to enter the early warning danger area in the second time period.

, preferably, the process of obtaining the hoist-to-work surface distance includes:

acquiring the distance between the amplitude variation trolley of the tower crane and the working surface;

acquiring the distance between the amplitude variation trolley and the hanging object; and

and subtracting the distance between the amplitude variation trolley and the working surface from the distance between the amplitude variation trolley and the hanging object to obtain the distance between the hanging object and the working surface.

preferably, the relative position of the operator on the working surface relative to the tower crane is obtained by using the positioning device arranged on the tower body and the suspension arm of the tower crane.

, preferably, the process of obtaining the position change trend of the operator relative to the hoisted object in the th time period and judging whether the operator will enter the pre-warning danger area in the second time period includes:

establishing a cylindrical coordinate system which takes a tower body of the tower crane as a rotating shaft center, takes a suspension arm of the tower crane as a radius and takes a variable amplitude trolley-suspension object distance between a variable amplitude trolley of the tower crane and the suspension object as a height, and acquiring a motion track curve, a moving speed and an acceleration of the suspension object in the cylindrical coordinate system within the th time period;

establishing an th rectangular coordinate system based on the relative position relationship between the positioning device and the tower body and the suspension arm, and acquiring a motion trail curve, a moving speed and an acceleration of the operator in the th rectangular coordinate system within the th time period;

predicting the displacement of the crane in the cylindrical coordinate system in the second period based on the motion trail curve, the moving speed and the acceleration of the crane in the cylindrical coordinate system in the th period;

predicting the displacement of the operator in the rectangular coordinate system in the second period based on a motion trail curve, a moving speed and an acceleration of the operator in the rectangular coordinate system in the period;

transforming the displacement of the hoisted object in the cylindrical coordinate system in the second period of time and the displacement of the operator in the th rectangular coordinate system in the second period of time into a displacement in a second rectangular coordinate system;

judging whether displacement overlapping exists between the lifting object and the operator in the second rectangular coordinate system within the second time period or not by combining the distance between the lifting object and the working face; and

and when the hoisted object and the operator have displacement overlap in the second rectangular coordinate system in the second time period, determining that the operator will enter the early warning danger area in the second time period.

, preferably, acquiring the distance between the amplitude variation trolley and the working surface by using a laser range finder arranged on the amplitude variation trolley;

and acquiring the distance between the suspension arm of the tower crane and the lifting hook by using a height sensor arranged on the balance arm of the tower crane as the distance between the amplitude variation trolley and the suspended object.

, preferably, a cylindrical coordinate system is established by using the tower body as a rotation axis, the suspension arm as a radius and the distance between the suspension arm and a lifting hook of the tower crane as a height by using the suspension arm angle data fed back by a rotation sensor installed on the tower body, the amplitude trolley amplitude data fed back by an amplitude sensor installed on the suspension arm and the distance data between the suspension arm and the lifting hook of the tower crane fed back by a height sensor installed on a balance arm of the tower crane, wherein the height difference between the suspension arm and the lifting hook is the amplitude trolley-lifting hook distance.

it is preferable that two positioning devices are installed on the tower body, and positioning devices are installed on the suspension arm.

, the positioning device is preferably an ultra-wideband base station, which locates the worker based on the positioning pulse sent by the ultra-wideband tag carried by the worker.

, preferably, obtaining coordinate values of the ultra-wideband tag in the rectangular coordinate system as coordinate values of the operator in the rectangular coordinate system by using a time-of-flight ranging technique, wherein the rectangular coordinate system is established based on the relative position relationship between the positioning device itself and the relative position relationship between the positioning device and the tower body and the boom.

The tower crane safety monitoring system comprises a data acquisition unit, a change acquisition unit, a danger judgment unit and a danger early warning unit, wherein the data acquisition unit is configured to acquire a hanging object-operation surface distance between a hanging object and an operation surface of a tower crane, a relative position of the hanging object relative to the tower crane and a relative position of an operator on the operation surface relative to the tower crane in th time period, the change acquisition unit is configured to acquire a position change trend of the operator relative to the hanging object in th time period based on the relative position of the hanging object relative to the tower crane and the relative position of the operator relative to the tower crane, the danger judgment unit is configured to judge whether the operator enters an early warning danger area right below the hanging object in the second time period according to the position change trend of the operator relative to the hanging object in the th time period and combines the hanging object-operation surface distance, and the danger early warning unit is configured to output a preset early warning signal when the operator is judged to enter the early warning area in the second.

According to the tower crane safety monitoring method and system provided by the embodiment of the invention, the positions of the operating personnel and the hoisted objects can be monitored when the tower crane is hoisted, and early warning is given to the operating personnel and/or a driver of the tower crane when the operating personnel enters an early warning dangerous area, so that the problems of misjudgment, missed judgment and the like caused by subjective factors of the driver, objective factors of the environment and the like in the conventional tower crane safety monitoring scheme are avoided.

Drawings

The invention may be better understood from the following description of specific embodiments thereof taken in conjunction with the accompanying drawings, in which:

fig. 1 shows a schematic diagram of a tower crane safety monitoring system according to an embodiment of the invention.

Fig. 2 shows a schematic diagram of a tower crane safety monitoring method according to an embodiment of the invention.

Fig. 3 is a schematic composition diagram of a tower crane hardware system to which the tower crane safety monitoring method and system according to the embodiments of the present invention can be applied.

Fig. 4 is a schematic diagram showing the change of the early warning danger area (namely, the falling radius of the hanging object) right below the hanging object of the tower crane in the tower crane hardware system shown in fig. 3 along with the change of the distance from the hanging object of the tower crane to the operation surface.

Fig. 5 shows a schematic diagram of a tower cylindrical coordinate system established based on the gyroscopic sensor, the amplitude sensor, and the height sensor shown in fig. 3, and a rectangular coordinate system with the tower as an origin.

Fig. 6 shows a schematic diagram of a UWB rectangular coordinate system established based on the UWB positioning principle.

Fig. 7a and 7b show the movement locus curve of the operator with time t in the UWB rectangular coordinate system shown in fig. 6.

Fig. 7c and 7d show the motion curve of the crane hoist in the tower column coordinate system shown in fig. 5 as a function of time t.

Fig. 8 shows a flowchart of a process of determining whether a worker will enter an early warning danger area and providing an early warning to the worker according to an embodiment of the present invention.

Fig. 9a to 9d show the moving track curves of the crane hoist and the operator in the same rectangular coordinate system.

Detailed Description

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, it will be apparent to those skilled in the art that the present invention may be practiced without these details .

In view of or more problems existing in the existing tower crane safety monitoring scheme, the invention provides novel tower crane safety monitoring methods and systems, fig. 1 shows a schematic diagram of a tower crane safety monitoring system according to an embodiment of the invention, fig. 2 shows a schematic diagram of a tower crane safety monitoring method according to an embodiment of the invention, and the tower crane safety monitoring systems and methods according to the embodiments of the invention are described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, a tower crane safety monitoring system 100 according to an embodiment of the invention includes a data acquisition unit 102, a change acquisition unit 104, a danger judgment unit 106, and a danger early warning unit 108, wherein the data acquisition unit 102 is configured to acquire a crane-working surface distance between a crane and a working surface of a tower crane, a relative position of the crane with respect to the tower crane, and a relative position of an operator on the working surface with respect to the tower crane in th time period (i.e., execute step S202), the change acquisition unit 104 is configured to acquire a position change trend of the operator with respect to the crane in th time period based on the relative position of the crane with respect to the tower crane and the relative position of the operator with respect to the tower crane, the danger judgment unit 106 is configured to judge whether the operator will enter a danger area directly below the crane in second time period in combination with the crane-working surface distance according to the position change trend of the operator with respect to the crane in th time period (i.e., execute step S204), and the danger early warning unit 108 is configured to output a preset early warning signal when the operator will enter the danger area in the second time period (i.e., execute step S206.

It may be preferable that of the th time period, the second time period, or all of them take a preset time period.

Fig. 3 is a schematic diagram of an tower crane hardware system to which the tower crane safety monitoring method and system according to the embodiment of the present invention may be applied, as shown in fig. 3, the tower crane hardware system includes an altitude sensor 302, a gyroscopic sensor 304, an amplitude sensor 306, a laser range finder 308, a directional horn 310, a third UWB base station A3, a UWB base station a1, a second UWB base station a2, and a UWB tag T, where:

the height sensor 302 is installed on a balance arm of the tower crane, and the zero point is calibrated at the position where the lifting hook of the tower crane is close to the amplitude variation trolley 2, so as to measure the distance h from the lifting hook of the tower crane to the suspension arm in real time (namely, the amplitude variation trolley-suspension object distance from the amplitude variation trolley 2 of the tower crane to the suspension object B).

The gyration sensor 304 is installed below a cab 1 of the tower crane, and is used for calibrating a zero point at a position where a boom of the tower crane points to a certain specific direction (for example, a south-positive direction) and measuring the gyration angle theta of the boom of the tower crane in real time.

The amplitude sensor 306 is installed on a suspension arm of the tower crane, and the zero point is calibrated at the position close to the cab 1 of the tower crane, so as to measure the distance r from the amplitude-variable trolley 2 of the tower crane to the rotation center (namely, the cab 1) in real time.

The laser range finder 308 is installed on the amplitude variation trolley 2 of the tower crane, moves along with the amplitude variation trolley 2 of the tower crane, and adopts a time of flight (TOF) ranging technology to measure the distance H from the amplitude variation trolley 2 of the tower crane to an operation surface (ground or structural layer floor) in real time.

The directional horn 310 is mounted on the amplitude variation trolley 2 of the tower crane, moves along with the amplitude variation trolley 2 of the tower crane, and sends out warning sound with a directional function, so as to warn operators when the tower crane safety monitoring system monitors that the operators on the operation surface enter an early warning danger area right below a hanging object B of the tower crane according to the embodiment of the invention.

UWB base station A1 and second UWB base station A2 install on the tower body of tower crane, and third UWB base station A3 is installed on the davit of tower crane, and these three UWB base stations receive the location pulse that the UWB label sent in real time for with UWB label constitute UWB positioning system.

The UWB tag T is carried by an operator on the operation surface of the tower crane, and sends positioning pulses to the UWB base station in real time to form a UWB positioning system together with the UWB base station .

Table 1 below gives a list of electrical components inside the luffing carriage 2 and cab 1 of the tower crane shown in fig. 3.

TABLE 1

As can be seen from table 1, the electrical components inside the luffing jib 2 of the tower crane mainly include a power supply system, a switch, a remote I/O module (e.g., a Modbus Transmission Control Protocol (TCP) communication module) for receiving a signal from the tower crane safety monitoring system according to the embodiment of the present invention and controlling the operation of the directional horn, the directional horn for warning an operator when the operator enters an early warning dangerous area directly below the hoisted object B of the tower crane, a laser range finder (i.e., the laser range finder 308) for measuring the distance from the luffing jib 2 of the tower crane to the working surface in real time, a serial server for converting RS232 data uploaded by the laser range finder into Modbus TCP data for reading by the tower crane safety monitoring system according to the embodiment of the present invention, and a wireless bridge -transmitting terminal for communicating with the wireless bridge -receiving terminal of the cab 1.

As can be seen from table 1, the electrical components inside the cab 1 mainly include a power supply system, a switch, a remote I/O module (e.g., a Modbus TCP communication module) for receiving signals from the tower crane safety monitoring system according to the embodiment of the present invention and controlling the operation of the audible and visual alarm, an audible and visual alarm for giving an audible and visual alarm to the driver when an operator enters the early warning danger area directly below the crane B of the tower crane, a black box for receiving data from the rotation angle sensor, the amplitude sensor, and the height sensor and uploading the data to the tower crane safety monitoring system according to the embodiment of the present invention, a wireless bridge -receiving end for communicating with the wireless bridge -receiving end on the luffing trolley 2, and a wireless bridge two-transmitting end for communicating with the wireless bridge two-receiving end of the ground monitoring room.

In , the data obtaining unit 102 may obtain the hoisted object-operation surface distance between the hoisted object B and the operation surface of the tower crane by obtaining the luffing trolley-operation surface distance between the luffing trolley 2 and the operation surface of the tower crane, obtaining the hoisted object-operation surface distance between the luffing trolley 2 and the hoisted object of the tower crane, and subtracting the luffing trolley-operation surface distance from the luffing trolley-hoisted object distance to obtain the hoisted object-operation surface distance H between the luffing trolley 2 and the operation surface of the tower crane by using a time of flight (TOF) ranging technique using a laser range finder 308 mounted on the luffing trolley 2 of the tower crane in the tower crane hardware system shown in fig. 3, and then obtaining the distance H between the boom and the hook of the tower crane as the luffing trolley-hoisted object distance between the luffing trolley 2 and the operation surface of the tower crane by using a height sensor 302 mounted on a balance arm of the tower crane, and obtaining the hoisted object-operation surface distance H between the boom and the hoisted object B of the tower crane, and then obtaining the hoisted object-operation surface distance H = the luffing trolley 2 of the luffing trolley-operation surface H of the tower crane (L-operation surface H).

When the tower crane is used for hoisting operation, the operation surface below the hoisting object B of the tower crane can be the ground or the floor of a structural layer. The corresponding drop radius of the hoisted object can be calculated in real time according to the distance from the hoisted object of the tower crane to the operation surface. Fig. 3D shows an early warning danger area, and fig. 4 shows a schematic diagram of the early warning danger area right below the hanging object of the tower crane in the tower crane hardware system shown in fig. 3, which changes with the distance from the hanging object of the tower crane to the working surface.

Fig. 4 illustrates a situation that the distance H between the amplitude variation trolley 2 of the tower crane and the working surface is measured in real time by the laser range finder additionally arranged on the amplitude variation trolley 2 of the tower crane:

1) when the working surface is the ground, the measuring method of the distance L1 between the hanging object of the tower crane and the ground is as follows: the distance H1 between the amplitude variation trolley 2 of the tower crane and the ground is measured in real time through a laser range finder 308 arranged on the amplitude variation trolley 2 of the tower crane, and the distance H1 from the amplitude variation trolley 2 of the tower crane to a hanging object, which is measured in real time by a height sensor, is read from a black box in an operator cab 1 of the tower crane, so that the distance L1= H1-H1 from the hanging object of the tower crane to the ground is obtained;

2) when the working face is a structural layer, the measuring mode of the distance L2 from the hanging object of the tower crane to the structural layer is as follows: the distance H2 between the amplitude variation trolley 2 of the tower crane and the structural layer is measured in real time through the laser range finder 308 arranged on the amplitude variation trolley 2 of the tower crane, and the distance H2 from the amplitude variation trolley 2 of the tower crane to a hanging object, which is measured in real time by a height sensor, is read from a black box in the cab 1 of the tower crane, so that the distance L2= H2-H2 from the hanging object of the tower crane to the structural layer is obtained.

The corresponding drop radii of the hoisted objects of the tower crane are different when the hoisted objects are different in height from the operation surface according to the national relevant standards (GBT 3608-2008, JGJ 80-2016). For example, when the distance from the hanging object of the tower crane to the working surface is 2m < L < 5m, the corresponding falling radius R =3m of the hanging object; when the distance between a hanging object of the tower crane and the operation surface is more than 5m and less than or equal to 15m, the corresponding falling radius R =4m of the hanging object; when the distance between a hanging object of the tower crane and the operation surface is more than 15m and less than or equal to 30m, the corresponding hanging object falling radius R =5 m; when the distance from a hanging object of the tower crane to the operation surface is 30m < L, the corresponding falling radius of the hanging object is R =6 m. Thus, the falling radius of the hoisted object can be determined according to the corresponding ranges of L1 and L2, as shown in fig. 4, the early warning danger area corresponding to the hoisted object when the working surface is the ground is D1, and the early warning danger area corresponding to the hoisted object when the working surface is the structural layer is D2.

In order to determine whether an operator enters an early warning danger area right below a hanging object of the tower crane, the change acquiring unit 104 may establish a tower column coordinate system with the tower body of the tower crane as a rotation axis, the hanging arm of the tower crane as a radius, and the distance h from the hanging hook of the tower crane to the hanging arm, which is fed back by a height sensor mounted on a balance arm of the tower crane, by reading the angle data θ from the hanging arm mounted on the tower body of the tower crane, the amplitude data R from the amplitude sensor mounted on the hanging arm of the tower crane, and the distance h from the hanging hook of the tower crane to the amplitude trolley, so as to obtain a real-time coordinate value of the hanging object of the tower crane in a rectangular coordinate system with the tower body; the UWB rectangular coordinate system can be established based on the relative position relations of 3 UWB base stations A1, A2 and A3 arranged on the tower body and the tower arm 4 of the tower crane and the relative position relations of the base stations A1, A2 and A3 and the tower body and the suspension arm of the tower crane, the real-time coordinate value of a UWB tag carried by an operator in the UWB rectangular coordinate system is obtained through calculation of the TOF ranging technology, and then the real-time coordinate value in the UWB rectangular coordinate system is transformed to the real-time coordinate value in the rectangular coordinate system with the tower body as the origin through a homogeneous transformation matrix.

Fig. 6 is a schematic diagram of a UWB rectangular coordinate system established based on the UWB positioning principle, in this embodiment, the UWB rectangular coordinate system is a rectangular coordinate system in which an X, Y axis direction is a direction parallel to a working surface and a Z axis direction is a tower crane height direction perpendicular to the working surface, which are established according to the arrangement position of the known UWB base station on the tower crane.

Wherein:

the X-axis direction can be selected from the tower arm directions.

The Y-axis direction may be selected to be perpendicular to the tower arm direction.

The origin O may be selected as the location of the UWB base station a 1.

As shown in fig. 6, a1 (X1, Y1), a2 (X2, Y2), and A3 (X3, Y3) are label positions determined by using a1 base station, a2 base station, and A3 base station as calibration reference base stations, respectively, and T (X, Y) is an intersection point obtained after reference calibration is performed by using three base stations, that is, a coordinate position of the final operator in the UWB rectangular coordinate system.

According to the UWB rectangular coordinate system, the coordinate system can be expressed into a cylindrical coordinate system through a homogeneous transformation system according to the arrangement position of the UWB base station on the tower crane.

Fig. 5 shows a schematic diagram of a tower cylindrical coordinate system established based on the revolution sensor, the amplitude sensor and the height sensor shown in fig. 3 and a rectangular coordinate system with the tower as an origin, and C in fig. 5 is the real-time position of the luffing carriage.

In the tower cylindrical coordinate system shown in fig. 5, the X, Y axis is parallel to the X, Y axis of the UWB rectangular coordinate system, and the Z-axis direction is the tower crane height direction perpendicular to the working surface. And r and theta respectively represent the column coordinate components of the hanging object of the tower crane in a column coordinate system of the tower body, wherein r is the distance from the hanging object to the rotation center of the column coordinate system, and theta is the rotation angle of the suspension arm of the tower crane.

Combining the position of a hanging object of a tower crane in the tower column coordinate system and the position of an operator in the UWB rectangular coordinate system, unifying the two positions to the same coordinate systems through homogeneous coordinate transformation, and judging whether the operator enters an early warning danger area or not by calculating whether the linear distance between the hanging object and the operator in the same coordinate systems is smaller than or equal to the falling radius of the hanging object.

In particular according to t_nPrediction t of curve, speed and acceleration of movement locus of personnel and suspended object on working surface at moment_n+1The moment motion trajectory can adopt the existing fitting function method, such as:

step1. obtaining 0-t by fitting function method_nXY rectangular coordinate component motion trail function of working face personnel at any moment and r of hoisted object_θA cylindrical coordinate component motion trajectory function;

step2, differentiating motion track functions of the personnel and the hoisted objects on the operation surface to obtain respective speed functions;

step3, differentiating the speed functions of the operator and the hoisted object on the operation surface to obtain respective acceleration functions;

step4. having t_nThe coordinate components of the initial positions of the personnel and the hoisted objects on the working surface at the moment are combined with t_nThe coordinate components of speed and acceleration at each moment can be calculated and predicted to obtain t_n+1Their coordinate component values at time;

step5. hanging r of object_θThe cylindrical coordinates and UWB right-angle XY coordinates of the working face personnel are converted to the same XY right-angle coordinate system through a homogeneous transformation system ;

step6. comparing the working face personnel t respectively_n+1And whether the XY coordinate component values at the moment are overlapped in the dangerous area of the hoisted object or not is judged, if yes, the alarm is triggered, and otherwise, the alarm is not triggered.

Next, a specific process of predicting whether the operator will enter the early warning danger area and issuing an early warning to the operator based on the tower cylindrical coordinate system shown in fig. 5 and the UWB rectangular coordinate system shown in fig. 6 will be described in detail with reference to fig. 7a to 9 d.

Fig. 7a and 7b show the movement locus curve of the operator with time t in the UWB rectangular coordinate system shown in fig. 6. In fig. 7a and 7b, curves T1, T2, and T3 represent the motion trajectory curves of UWB tags (i.e., operators) carried by 3 random operators in the UWB rectangular coordinate system, respectively; abscissa X, Y represents the coordinate component of the operator in the UWB rectangular coordinate system.

Fig. 7c and 7d show the motion curve of the crane hoist in the tower column coordinate system shown in fig. 5 as a function of time t. In fig. 7c and 7d, vertical coordinates r and θ represent coordinate components of the crane sling B in the tower column coordinate system.

FIG. 8 shows a flowchart of a process of determining whether or not the worker will enter the pre-warning danger area and issue the pre-warning to the worker according to an embodiment of the present invention, as shown in FIG. 8, the change acquisition unit 104 and the danger determination unit 106 may work in cooperation, specifically, based on the tower cylindrical coordinate system shown in FIG. 5 and the UWB rectangular coordinate system shown in FIG. 6, the change acquisition unit 104 may perform a process of acquiring the worker at th time period (e.g., 0 to t @_nTime of day) in a UWB rectangular coordinate system (S802), and acquiring the motion track curve, the motion speed and the acceleration of the suspended object in a th time period (for example, 0 to t)_nTime of day), the motion trajectory curve, the motion speed, and the acceleration in the tower cylindrical coordinate system (S804) further , the risk judging unit 106 may perform a process of predicting the worker in the second period (e.g., t) based on the motion trajectory curve, the motion speed, and the acceleration of the worker in the UWB rectangular coordinate system in the th period_nTo t_n+1) Displacement in UWB rectangular coordinate system (S806), predicting the crane in the second time (for example, t) based on the motion track curve, motion speed and acceleration of the crane in tower column coordinate system in the th time_nTo t_n+1) The displacement of the crane in the tower column coordinate system in the second time interval and the displacement of the operator in the UWB rectangular coordinate system in the second time interval are converted into the displacement in the same rectangular coordinate system by the homogeneous transformation matrix introduced with the fitting function method (S808), and the crane and the operator are judged to sit at the same rectangular angle in the second time interval by combining the crane-operation surface distance (namely combining the crane falling radius depending on the crane-operation surface distance)And determining that the worker will enter the early warning danger area within a second time period when the hoists and the worker have displacement overlap in the same rectangular coordinate system within the second time period (S812).

9 a-9 d show the moving track curves of the crane lifting object B and the operators T1, T2 and T3 in the same rectangular coordinate system, as shown in FIG. 9a and FIG. 9B, at T_n+1At the moment, after the displacement component (X, Y) of the hanging object B is added with the component (X, Y) of the falling radius R of the hanging object B, no displacement overlapping exists among operators T1, T2 and T3, and therefore the fact that no operator is about to enter the early warning danger area is shown. As shown in fig. 9c and 9d, at t_n+1At the moment, after the displacement component (X, Y) of the hanging object B is added with the component (X, Y) of the falling radius R of the hanging object B, the displacement component (X, Y) of the operator T1 is overlapped, the operator T1 is about to enter an early warning danger area, and the operator T1 is triggered to send out early warning.

According to the tower crane safety monitoring method and system provided by the embodiment of the invention, the positions of the operators and the hoisted objects can be monitored when the tower crane is hoisted, and the operators and/or the driver of the tower crane are/is given an alarm when the operators enter the early warning danger area, so that the problems of misjudgment, missed judgment and the like caused by subjective factors of the driver, objective factors of the environment and the like in the conventional tower crane safety monitoring scheme are avoided.

It is to be understood that the invention is not limited to the specific arrangements and instrumentality described above and shown in the drawings. Also, a detailed description of known process techniques is omitted herein for the sake of brevity. In the above embodiments, several specific steps are described and shown as examples. However, the method processes of the present invention are not limited to the specific steps described and illustrated, and those skilled in the art can make various changes, modifications and additions or change the order between the steps after comprehending the spirit of the present invention.

Here, the functional modules described above may be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, plug-in, function card, or the like. When implemented in software, the elements of the invention are the programs or code segments to perform the required tasks. The program or code segments may be stored in a machine-readable medium or transmitted by a data signal carried in a carrier wave over a transmission medium or a communication link. A "machine-readable medium" may include any medium that can store or transfer information. Examples of a machine-readable medium include electronic circuits, semiconductor memory devices, ROM, flash memory, Erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, Radio Frequency (RF) links, and so forth. The code segments may be downloaded via computer networks such as the internet, intranet, etc.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. For example, the algorithms described in the specific embodiments may be modified without departing from the basic spirit of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.