1. A method for determining the arm length of a tower crane, comprising:

determining a first moment percentage according to a parameter value corresponding to a set arm length of a crane arm of the tower crane;

determining a second moment percentage according to the moment value of the cargo boom detected by the moment detection device;

comparing the first moment percentage and the second moment percentage;

determining that the set arm length does not match the actual arm length of the lift arm if the difference between the first moment percentage and the second moment percentage is greater than a first threshold.

2. The method of claim 1, wherein determining the first moment percentage based on a parameter value corresponding to a set arm length of a jib of a tower crane comprises:

acquiring the lifting capacity and the amplitude value of the tower crane through a gravity detection device and an amplitude detection device;

the first moment percentage is derived from the load lifting and the amplitude value.

3. The method of claim 1, further comprising:

and calibrating the torque detection device.

4. The method of claim 3, wherein the calibrating the torque detection device comprises:

under the condition that the tower crane is in an empty hook working condition, carrying out first point calibration on the torque detection device;

when the tower crane is in a motion working condition and the first torque percentage is larger than a stable threshold value, calibrating a second point of the torque detection device;

and obtaining the functional relation between the moment value and the expansion amount according to the first point calibration and the second point calibration.

5. The method of claim 1, further comprising:

and filtering the first moment percentage and the second moment percentage.

6. The method of claim 1, further comprising:

determining a difference between the first moment percentage and the second moment percentage if the first moment percentage or the second moment percentage is greater than a second threshold.

7. The method of claim 1, further comprising:

and sending out an alarm under the condition that the set arm length is determined to be not matched with the actual arm length of the crane arm.

8. A controller configured to perform a method for determining tower crane arm length according to any one of claims 1 to 7.

9. An apparatus for determining the arm length of a tower crane, comprising:

the moment detection device is arranged at the rotation center of the tower crane and used for acquiring the moment value of the tower crane;

the weight detection device is arranged at a fixed pulley of a crane boom of the tower crane and is used for acquiring a hoisting value of the tower crane;

the amplitude detection device is arranged at an amplitude variation mechanism of a crane arm of the tower crane and is used for acquiring the amplitude value of the tower crane;

the controller of claim 8.

10. A tower crane comprising an apparatus for determining the arm length of a tower crane according to claim 9.

Background

When the tower crane is in hoisting construction, due to the limitation of external environment and the hoisting requirement, the requirement of arm length transformation often exists, and meanwhile, along with the popularization of an industrial carrying safety monitoring system, the arm length parameter of the tower crane becomes a key parameter in the safety monitoring system, and the method is an important calculation basis for ensuring the safety construction of the tower crane. In the actual construction process, arm length conversion relates to two parts, namely, on one hand, the actual arm length of a crane arm is replaced, and on the other hand, arm length parameters in a monitoring system are modified. Due to human negligence in a construction site, the actual arm length of the crane boom is easy to change but the parameters are not modified in the safety monitoring system, or the arm length of the crane boom is not changed but the parameters set by the arm length in the safety monitoring system are changed, so that the construction working condition displayed by the safety monitoring system deviates from the real condition, and certain safety risk exists.

Disclosure of Invention

The invention aims to provide a method, a device and a controller for measuring the arm length of a tower crane, which are used for solving the problem that the safety risk exists due to the deviation between the set arm length and the actual arm length of a crane arm of the tower crane.

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

determining a first moment percentage according to a parameter value corresponding to a set arm length of a crane arm of the tower crane;

determining a second moment percentage according to the moment value of the cargo boom detected by the moment detection device;

comparing the first moment percentage and the second moment percentage;

determining that the set arm length does not match the actual arm length of the lift arm if the difference between the first moment percentage and the second moment percentage is greater than a first threshold.

In an embodiment of the present invention, determining the first moment percentage according to the parameter value corresponding to the set arm length of the jib of the tower crane includes:

acquiring the lifting capacity and the amplitude value of the tower crane through a gravity detection device and an amplitude detection device;

a first moment percentage is obtained from the load lift and the amplitude value.

In an embodiment of the invention, the method further comprises:

and calibrating the moment detection device.

In an embodiment of the present invention, calibrating the torque detection device comprises:

under the condition that the tower crane is in an empty hook working condition, carrying out first point calibration on the torque detection device;

calibrating a second point of the moment detection device under the condition that the tower crane is in a motion working condition and the first moment percentage is greater than a stable threshold value;

and obtaining the functional relation between the moment value and the expansion amount according to the first point calibration and the second point calibration.

In an embodiment of the invention, the method further comprises:

and filtering the first moment percentage and the second moment percentage.

In an embodiment of the invention, the method further comprises:

in the event that the first moment percentage or the second moment percentage is greater than a second threshold, a difference between the first moment percentage and the second moment percentage is determined.

In an embodiment of the invention, the method further comprises:

and sending an alarm under the condition that the set arm length is determined to be not matched with the actual arm length of the crane arm.

A second aspect of the invention provides a controller configured to perform the method for determining a tower crane jib length described above.

In a third aspect, the present invention provides an apparatus for determining the arm length of a tower crane, comprising:

the moment detection device is arranged at the rotation center of the tower crane and used for acquiring the moment value of the tower crane;

the weight detection device is arranged at a fixed pulley of a crane boom of the tower crane and is used for acquiring a crane lifting value of the tower crane;

the amplitude detection device is arranged at a luffing mechanism of a crane arm of the tower crane and is used for acquiring an amplitude value of the tower crane;

the controller is described above.

The invention also provides a tower crane, which comprises the device for measuring the arm length of the tower crane.

Through the technical scheme, the set arm length of the crane boom of the tower crane is compared with the actual arm length, whether the set arm length is matched with the actual arm length of the crane boom is determined, the accuracy of the set arm length data of the crane boom of the tower crane is guaranteed, potential safety hazards caused by setting errors of the arm length are eliminated, and the construction safety of the tower crane is improved.

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

Drawings

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

FIG. 1 is a schematic flow chart of a method for determining a tower crane arm length according to an embodiment of the present invention;

FIG. 2 is a schematic flow diagram of a method for determining a tower crane arm length according to another embodiment of the present invention;

FIG. 3 is a schematic flow diagram of a method for determining a tower crane arm length according to yet another embodiment of the present invention;

fig. 4 is a block diagram of a controller provided by an embodiment of the present invention.

Detailed Description

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

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

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

Fig. 1 is a schematic flow chart of a method for determining the arm length of a tower crane according to an embodiment of the present invention. As shown in fig. 1, a first aspect of an embodiment of the present invention provides a method for determining a tower crane jib length, which may include the following steps.

In step S11, a first torque percentage is determined based on a parameter value corresponding to a set arm length of a jib of a tower crane. In the embodiment of the invention, the tower crane is called a tower crane for short, and is also called a tower crane. The tower crane can be composed of a crane boom, a tower body, a rotary table, a bearing seat, a balance arm, an underframe and the like. The crane boom can be used for supporting the container to be hoisted, and the loading and unloading bridge has certain hoisting height and width. The tower crane may include, but is not limited to, a hoisting mechanism, a luffing mechanism, a trolley traction mechanism, a slewing mechanism, a jacking mechanism, and a cart travel mechanism. The safety monitoring system of the tower crane can monitor the working parameters of the tower crane in real time, such as: video information, load lifting, amplitude, speed, displacement, height, tilt, wind speed, collision avoidance, etc. The user can set various parameters of the tower crane as required, for example, the arm length of the boom of the tower crane can be set, so that the amplitude value of the currently detected boom and the currently monitored weight value are determined according to the arm length of the boom, and the corresponding first moment percentage is obtained. Moment represents the physical quantity of the rotational effect produced when a force acts on an object, and the percentage of moment refers to the percentage of the current moment to the rated lifting moment. The first moment percentage is a calculated value of moment percentage obtained by the controller according to parameters set by the safety monitoring system, and the first moment percentage of the embodiment of the invention is not necessarily matched with the moment percentage corresponding to the actual arm length. The actual torque percentage also needs to be collected.

In step S12, a second torque percentage is determined based on the torque value of the lift arm detected by the torque detection device. In an embodiment of the invention, the second torque percentage is an actual value of the torque percentage obtained by a torque detection device, and the torque detection device may be disposed at a rotation center of the tower crane so as to detect an actual torque value of the boom. In one example, the torque sensing device may be a torque potentiometer, by means of which the actual value of the torque of the boom can be obtained, resulting in the second torque percentage.

In step S13, the first moment percentage and the second moment percentage are compared. In an embodiment of the present invention, the first torque percentage refers to a calculated value of the torque percentage obtained by the controller according to the parameters set by the safety monitoring system, and the second torque percentage refers to an actual value of the torque percentage obtained by the torque detection device. The set arm length of the lift arm of the safety system setup may not match the actual arm length, and therefore, the first and second torque percentages need to be compared to determine if the set arm length matches the actual arm length.

In the embodiment of the present invention, before comparing the first moment percentage and the second moment percentage, the first moment percentage and the second moment percentage may be filtered, and the filtering may eliminate the interference of the electromagnetic wave on the electronic signal and the interference of the mechanical shake on the moment detection apparatus. At this time, the first moment percentage or the second moment percentage can be compared only when the first moment percentage or the second moment percentage is greater than the second threshold, otherwise the error between the first moment percentage and the second moment percentage is negligible. For example, the first moment percentage is the first moment percentage, the second moment percentage is the second moment percentage, and the second threshold is 50%. The first moment percentage and the second moment percentage are compared only if they are greater than 50%, otherwise the difference is negligible.

In step S14, it is determined that the set arm length does not match the actual arm length of the lift arm if the difference between the first moment percentage and the second moment percentage is greater than the first threshold. In an embodiment of the invention, the first threshold is used to determine whether the difference between the first moment percentage and the second moment percentage is too large. If the difference between the first moment percentage and the second moment percentage is too large, it indicates that the set arm length does not match the actual arm length of the crane arm. Additionally, the set arm length may be determined to match the actual arm length of the lift arm where the difference between the first moment percentage and the second moment percentage is less than or equal to the first threshold. Examples of the first threshold may include, but are not limited to, 1%, 2%, 5%, etc., and the user may set the first threshold as desired.

Through the technical scheme, the set arm length of the crane boom of the tower crane is compared with the actual arm length, whether the set arm length is matched with the actual arm length of the crane boom is determined, the accuracy of the set arm length data of the crane boom of the tower crane is guaranteed, potential safety hazards caused by setting errors of the arm length are eliminated, and the construction safety of the tower crane is improved.

Fig. 2 is a schematic flow chart of a method for determining the arm length of a tower crane according to another embodiment of the present invention. As shown in fig. 2, determining the first moment percentage according to the parameter value corresponding to the set arm length of the boom of the tower crane may include:

s21, acquiring the lifting capacity and amplitude value of the tower crane through a gravity detection device and an amplitude detection device;

step S22, a first moment percentage is derived based on the lift and amplitude values.

In an embodiment of the invention, the moment is the vector product of the force and the arm, and the magnitude of the moment of the force at a point is the length of a perpendicular drawn from the point to the line of action of the force. Thus, the first moment percentage may be determined by a weight value and an amplitude value, which may be obtained by a weight detection device and an amplitude detection device, e.g. a weight sensor and an amplitude sensor, provided at the tower crane. The weight sensor can be arranged at a fixed pulley of a crane arm of the tower crane and is used for collecting the weight sensor. The amplitude detection device can be arranged at a luffing mechanism of a crane arm of the tower crane and is used for acquiring the amplitude value of the tower crane. The first moment percentage can be calculated from the cross product of the weight value and the amplitude value.

In an embodiment of the present invention, the method may further include:

and calibrating the moment detection device.

Specifically, the calibration means that the accuracy of the torque detection device needs to be detected when the torque detection device is used, and whether the torque detection device meets the standard or not is judged.

In an embodiment of the present invention, calibrating the torque detection apparatus may include:

under the condition that the tower crane is in an empty hook working condition, carrying out first point calibration on the torque detection device;

calibrating a second point of the moment detection device under the condition that the tower crane is in a motion working condition and the first moment percentage is greater than a stable threshold value;

and obtaining the functional relation between the moment value and the expansion amount according to the first point calibration and the second point calibration.

Specifically, the torque detection device may be calibrated by a two-point calibration method, which measures two data points of known true values, and then calibrates the torque detection device according to the measured values of the two points. In the embodiment of the invention, two points of the tower crane under the working condition of empty hook and the working condition of movement can be respectively taken. And when the tower crane is in a no-hook condition and is not calibrated, calibrating a first point of the moment detection device, and when the tower crane is in a motion working condition and is in a stable condition, namely the first moment percentage is greater than a stable threshold value, calibrating a second point of the moment detection device. Therefore, the functional relation between the moment value and the expansion amount can be obtained. In one example, the torque value is a function of the amount of flex: and y is kx + b, wherein y is a moment value, x is an expansion and contraction quantity, and k and b are known coefficients. After the moment detection device is calibrated, the moment value of the crane boom can be detected. The relationship between the torque value and the expansion amount in the embodiment of the present invention is not limited to the linear functional relationship, and may be other functional relationships.

In an embodiment of the present invention, the method may further include:

and filtering the first moment percentage and the second moment percentage.

Specifically, before comparing the first moment percentage and the second moment percentage, the first moment percentage and the second moment percentage may be filtered, and the filtering may eliminate interference of electromagnetic waves on electronic signals and interference of mechanical jitter on the moment detection device.

In an embodiment of the present invention, the method may further include:

in the event that the first moment percentage or the second moment percentage is greater than a second threshold, a difference between the first moment percentage and the second moment percentage is determined.

In particular, the first moment percentage or the second moment percentage can only be compared when they are greater than the second threshold, otherwise the error between the first moment percentage and the second moment percentage is negligible. For example, the first moment percentage is the first moment percentage, the second moment percentage is the second moment percentage, and the second threshold is 50%. The first moment percentage and the second moment percentage can be compared only if they are greater than 50%, otherwise the difference is negligible.

Fig. 3 is a schematic flow chart of a method for determining the arm length of a tower crane according to another embodiment of the present invention. As shown in fig. 3, the method may further include:

and step S31, sending out an alarm when the set arm length is determined not to be matched with the actual arm length of the crane arm.

In an embodiment of the invention, in case the difference between the first moment percentage and the second moment percentage is larger than the first threshold value, it may be determined that the set arm length does not match the actual arm length of the jib, at which time the controller may send an alarm signal. The alarm signal may include, but is not limited to, an audible alarm signal, a text alarm display, a light alarm signal, and the like. For example, a device capable of emitting light signals or sound signals is installed at a set position of the tower crane, so that a worker can see or hear current information, or a character alarm signal is displayed on a display. The alarm signal can enable the staff to find the problem in time, and reduce the operation danger of the tower crane.

Fig. 4 is a block diagram of a controller provided by an embodiment of the present invention. As shown in fig. 4, an embodiment of the present invention provides a controller configured to perform the above-described method for determining the arm length of a tower crane. The controller may include a processor 410 and a memory 420. The memory 420 may store instructions that, when executed by the processor 410, may cause the processor 410 to perform the method for controlling boom speed described in the previous embodiments.

Specifically, in an embodiment of the present invention, the processor 410 is configured to:

determining a first moment percentage according to a parameter value corresponding to a set arm length of a crane arm of the tower crane;

determining a second moment percentage according to the moment value of the cargo boom detected by the moment detection device;

comparing the first moment percentage and the second moment percentage;

determining that the set arm length does not match the actual arm length of the lift arm if the difference between the first moment percentage and the second moment percentage is greater than a first threshold.

In the embodiment of the invention, the tower crane is called a tower crane for short, and is also called a tower crane. The tower crane can be composed of a crane boom, a tower body, a rotary table, a bearing seat, a balance arm, an underframe and the like. The crane boom can be used for supporting the container to be hoisted, and the loading and unloading bridge has certain hoisting height and width. The tower crane may include, but is not limited to, a hoisting mechanism, a luffing mechanism, a trolley traction mechanism, a slewing mechanism, a jacking mechanism, and a cart travel mechanism. The safety monitoring system of the tower crane can monitor the working parameters of the tower crane in real time, such as: video information, load lifting, amplitude, speed, displacement, height, tilt, wind speed, collision avoidance, etc. The user can set various parameters of the tower crane as required, for example, the arm length of the boom of the tower crane can be set, so that the amplitude value of the currently detected boom and the currently monitored weight value are determined according to the arm length of the boom, and the corresponding first moment percentage is obtained. Moment represents the physical quantity of the rotational effect produced when a force acts on an object, and the percentage of moment refers to the percentage of the current moment to the rated lifting moment. The first moment percentage is a calculated value of moment percentage obtained by the controller according to parameters set by the safety monitoring system, and the first moment percentage of the embodiment of the invention is not necessarily matched with the moment percentage corresponding to the actual arm length. The actual torque percentage also needs to be collected.

In an embodiment of the invention, the second torque percentage is an actual value of the torque percentage obtained by a torque detection device, and the torque detection device may be disposed at a rotation center of the tower crane so as to detect an actual torque value of the boom. In one example, the torque sensing device may be a torque potentiometer, by means of which the actual value of the torque of the boom can be obtained, resulting in the second torque percentage.

In an embodiment of the present invention, the first torque percentage refers to a calculated value of the torque percentage obtained by the controller according to the parameters set by the safety monitoring system, and the second torque percentage refers to an actual value of the torque percentage obtained by the torque detection device. The set arm length of the lift arm of the safety system setup may not match the actual arm length, and therefore, the first and second torque percentages need to be compared to determine if the set arm length matches the actual arm length.

In the embodiment of the present invention, before comparing the first moment percentage and the second moment percentage, the first moment percentage and the second moment percentage may be filtered, and the filtering may eliminate the interference of the electromagnetic wave on the electronic signal and the interference of the mechanical shake on the moment detection apparatus. At this time, the first moment percentage or the second moment percentage can be compared only when the first moment percentage or the second moment percentage is greater than the second threshold, otherwise the error between the first moment percentage and the second moment percentage is negligible. For example, the first moment percentage is the first moment percentage, the second moment percentage is the second moment percentage, and the second threshold is 50%. The first moment percentage and the second moment percentage are compared only if they are greater than 50%, otherwise the difference is negligible.

In an embodiment of the invention, the first threshold is used to determine whether the difference between the first moment percentage and the second moment percentage is too large. If the difference between the first moment percentage and the second moment percentage is too large, it indicates that the set arm length does not match the actual arm length of the crane arm. Additionally, the set arm length may be determined to match the actual arm length of the lift arm where the difference between the first moment percentage and the second moment percentage is less than or equal to the first threshold. Examples of the first threshold may include, but are not limited to, 1%, 2%, 5%, etc., and the user may set the first threshold as desired.

Through the technical scheme, the set arm length of the crane boom of the tower crane is compared with the actual arm length, whether the set arm length is matched with the actual arm length of the crane boom is determined, the accuracy of the set arm length data of the crane boom of the tower crane is guaranteed, potential safety hazards caused by setting errors of the arm length are eliminated, and the construction safety of the tower crane is improved.

Further, the processor 410 is further configured to:

determining the first moment percentage according to the parameter value corresponding to the set arm length of the crane arm of the tower crane comprises the following steps:

acquiring the lifting capacity and the amplitude value of the tower crane through a gravity detection device and an amplitude detection device;

a first moment percentage is obtained from the load lift and the amplitude value.

In an embodiment of the invention, the moment is the vector product of the force and the arm, and the magnitude of the moment of the force at a point is the length of a perpendicular drawn from the point to the line of action of the force. Thus, the first moment percentage may be determined by a weight value and an amplitude value, which may be obtained by a weight detection device and an amplitude detection device, e.g. a weight sensor and an amplitude sensor, provided at the tower crane. The weight sensor can be arranged at a fixed pulley of a crane arm of the tower crane and is used for collecting the weight sensor. The amplitude detection device can be arranged at a luffing mechanism of a crane arm of the tower crane and is used for acquiring the amplitude value of the tower crane. The first moment percentage can be calculated from the cross product of the weight value and the amplitude value.

Further, the processor 410 is further configured to:

and calibrating the moment detection device.

Specifically, the calibration means that the accuracy of the torque detection device needs to be detected when the torque detection device is used, and whether the torque detection device meets the standard or not is judged.

Further, the processor 410 is further configured to:

calibrating the torque detection device comprises:

under the condition that the tower crane is in an empty hook working condition, carrying out first point calibration on the torque detection device;

calibrating a second point of the moment detection device under the condition that the tower crane is in a motion working condition and the first moment percentage is greater than a stable threshold value;

and obtaining the functional relation between the moment value and the expansion amount according to the first point calibration and the second point calibration.

Specifically, the torque detection device may be calibrated by a two-point calibration method, which measures two data points of known true values, and then calibrates the torque detection device according to the measured values of the two points. In the embodiment of the invention, two points of the tower crane under the working condition of empty hook and the working condition of movement can be respectively taken. And when the tower crane is in a no-hook condition and is not calibrated, calibrating a first point of the moment detection device, and when the tower crane is in a motion working condition and is in a stable condition, namely the first moment percentage is greater than a stable threshold value, calibrating a second point of the moment detection device. Therefore, the functional relation between the moment value and the expansion amount can be obtained. In one example, the torque value is a function of the amount of flex: and y is kx + b, wherein y is a moment value, x is an expansion and contraction quantity, and k and b are known coefficients. After the moment detection device is calibrated, the moment value of the crane boom can be detected. The relationship between the torque value and the expansion amount in the embodiment of the present invention is not limited to the linear functional relationship, and may be other functional relationships.

Further, the processor 410 is further configured to:

and filtering the first moment percentage and the second moment percentage.

Specifically, before comparing the first moment percentage and the second moment percentage, the first moment percentage and the second moment percentage may be filtered, and the filtering may eliminate interference of electromagnetic waves on electronic signals and interference of mechanical jitter on the moment detection device.

Further, the processor 410 is further configured to:

in the event that the first moment percentage or the second moment percentage is greater than a second threshold, a difference between the first moment percentage and the second moment percentage is determined.

In particular, the first moment percentage or the second moment percentage can only be compared when they are greater than the second threshold, otherwise the error between the first moment percentage and the second moment percentage is negligible. For example, the first moment percentage is the first moment percentage, the second moment percentage is the second moment percentage, and the second threshold is 50%. The first moment percentage and the second moment percentage can be compared only if they are greater than 50%, otherwise the difference is negligible.

Further, the processor 410 is further configured to:

and sending an alarm under the condition that the set arm length is determined to be not matched with the actual arm length of the crane arm.

In an embodiment of the invention, in case the difference between the first moment percentage and the second moment percentage is larger than a threshold value, it may be determined that the set arm length does not match the actual arm length of the jib, at which time the controller may send an alarm signal. The alarm signal may include, but is not limited to, an audible alarm signal, a text alarm display, a light alarm signal, and the like. For example, a device capable of emitting light signals or sound signals is installed at a set position of the tower crane, so that a worker can see or hear current information, or a character alarm signal is displayed on a display. The alarm signal can enable the staff to find the problem in time, and reduce the operation danger of the tower crane.

Examples of processor 410 may include, but are not limited to, a general purpose processor, a special purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of Integrated Circuit (IC), a state machine, and the like. The processor may perform signal encoding, data processing, power control, input/output processing.

Examples of memory 420 may include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that may be used to store information that may be accessed by a processor.

The embodiment of the invention also provides a device for measuring the arm length of the tower crane, which comprises:

the moment detection device is arranged at the rotation center of the tower crane and used for acquiring the moment value of the tower crane;

the controller is described above.

In particular, the moment detection device can be arranged at the rotation center of the tower crane so as to detect the actual moment value of the crane arm. In one example, the torque detection device may be a torque potentiometer. The second moment percentage is the actual value of the moment of the jib obtained by the moment detection means. And the controller acquires the actual moment value of the cargo boom acquired by the moment detection device so as to obtain a second moment percentage. Meanwhile, the controller can also obtain a calculated moment value of the crane boom through calculation, so that a first moment percentage is obtained. By comparing the first torque percentage with the second torque percentage, it may be determined whether the set arm length matches the actual arm length.

In an embodiment of the present invention, further comprising:

the weight detection device is arranged at a fixed pulley of a crane boom of the tower crane and is used for acquiring a crane lifting value of the tower crane;

the amplitude detection device is arranged at the amplitude variation mechanism of the crane arm of the tower crane and used for acquiring the amplitude value of the tower crane.

Specifically, the moment is the vector product of the force and the arm of force, and the magnitude of the moment of the force to a certain point is the length of a perpendicular line drawn from the point to the action line of the force. Thus, the first moment percentage may be determined by a weight value and an amplitude value, which may be obtained by a weight detection device and an amplitude detection device, e.g. a weight sensor and an amplitude sensor, provided at the tower crane. The weight sensor can be arranged at a fixed pulley of a crane arm of the tower crane and is used for collecting the weight sensor. The amplitude detection device can be arranged at a luffing mechanism of a crane arm of the tower crane and is used for acquiring the amplitude value of the tower crane. The first moment percentage can be calculated from the cross product of the weight value and the amplitude value.

The embodiment of the invention also provides the tower crane, which comprises the device for measuring the arm length of the tower crane.

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

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

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