Crane force limiter system and weight calculation method

Abstract

The present application relates to the technical fields of mechanical engineering, and discloses a crane force limiter system and a weight calculation method, which comprises a force limiter host, a display, a length sensor, an angle sensor and an oil cylinder thrust sensor, the oil cylinder thrust sensor is arranged on a luffing oil cylinder, the length sensor, the angle sensor and the oil cylinder thrust sensor are respectively connected with the force limiter host in communication, for transmitting the data collected by each sensor to the force limiter host, the force limiter host is connected with the display in communication, the force limiter host receives the data collected by each sensor and processes the collected data, and finally the processed information is transmitted to the display, the display receives the information sent from the force limiter host and displays it to the operator in real time, and the present application has the beneficial effects of improving the weight calculation accuracy of the force limiter system and improving the operation safety.

Description

Technical Field

[0001] This invention relates to the field of mechanical engineering technology, specifically to a crane force limiter system and a weight calculation method. Background Technology

[0002] Torque limiting system: also known as a force limiter system, it measures cylinder pressure, boom length and angle through sensors. After calculation by the force limiter host, it displays parameters such as working radius and actual lifting capacity to the operator in real time through the display. It automatically limits the torque of the crane in dangerous working conditions such as overloading, and provides prompts or alarm information.

[0003] Currently, the lifting weight in the crane force limiter system is indirectly calculated by the luffing hydraulic pressure sensor. The sensor calculates the thrust of the luffing cylinder and uses the torque balance principle to calculate the lifting weight. However, due to the influence of cylinder friction, the luffing hydraulic pressure fluctuates during luffing motion, causing deviations in the force limiter's calculated weight. This is especially true under light load conditions, where the weight fluctuation is large and easily triggers user feedback.

[0004] Currently, the hardware of a crane torque limiting system mainly consists of three parts: hydraulic pressure sensor, length sensor, angle sensor, torque limiter main unit, and display, etc. Figure 1 and Figure 2 As shown. A length sensor, mounted on the boom, is responsible for real-time detection of the boom's extension and retraction length during crane operation. The generated signal is processed in the force limiter host to determine the actual extension and retraction length of the boom. An angle sensor, also mounted on the boom, is responsible for real-time detection of the boom's luffing angle during crane operation. The generated signal is processed in the host to determine the actual luffing angle of the boom. Hydraulic pressure sensors, typically two in number (one for the rod chamber and one for the rodless chamber), are installed on the luffing cylinder. They are responsible for real-time detection of the hydraulic pressure in the rod and rodless chambers of the luffing cylinder during crane operation. The generated signal is processed in the host and used in conjunction with other variables to calculate the actual weight of the hoisted load. The torque limiter main unit is a controller responsible for real-time acquisition and processing of valid signals generated by external sensors. It transmits the processed information, such as boom extension / retraction length, boom luffing angle, lifting equipment operating radius, actual lifting weight, and rated lifting weight, to an operable display for operator reference. It also stores and processes debugging data. Simultaneously, based on the processing results, it outputs effective control signals to the control valves used to protect the lifting equipment (e.g., limiting dangerous crane actions during torque limiting, such as hook lifting, boom extension, and boom luffing). The display receives valid information such as operating radius and actual lifting weight from the main unit and displays it to the operator in real time. See the hardware communication diagram below. Figure 3 .

[0005] The existing weight calculation method is as follows:

[0006] like Figure 4 As shown, taking the crane telescopic boom system as the object and the boom rear hinge point O as the fulcrum, the crane torque balance equation is established. Figure 4 In the middle, the torques that cause the crane to rotate clockwise and counterclockwise are respectively the luffing cylinder torque M. 油缸 M F , Hoisting wire rope tension M 卷扬 and lifting moment M 重物 boom self-weight moment M 自重 When the crane is moving at a constant speed or is stationary, the torque required to rotate the crane clockwise and counterclockwise is equal, as given by the following formula:

[0007] M 油缸 +M 卷扬 =M 自重 +M 重物

[0008] Given the crane's structural parameters, the pressure in the rod-side and rodless chambers of the luffing cylinder can be measured by a hydraulic pressure sensor. The calculation methods for the torques in the above formulas are as follows:

[0009] M 油缸 =F 油缸 *L b =(F1-F2+F f )*L b

[0010] M 卷扬 =F 卷扬 *L r =(G 重物 / N)*L r

[0011] M 自重 =G 自重 *R'

[0012] M 重物 =G 重物 *R

[0013] In the above formula, F1 represents the force on the rodless chamber of the luffing cylinder, which can be measured by the rodless chamber hydraulic pressure sensor; F2 represents the force on the rod chamber of the luffing cylinder, which can be measured by the rod chamber hydraulic pressure sensor; F f For the friction force of the variable amplitude cylinder; L b Indicates the lever arm of the variable amplitude cylinder; G 重物 G represents the weight of the suspended object, N represents the magnification ratio, and L represents the weight of the suspended object. r R represents the lever arm of the hoisting wire rope; G represents the working radius. 自重 G represents the weight of the boom itself, and R' represents the lever arm of the boom's own weight.

[0014] G 重物 =(M 油缸 -M 自重 ) / (RL r / N)=[(F1-F2+F f )*L b -G 自重 *R'] / (RL r / N)

[0015] It can be seen that G 重物 Friction force F with the hydraulic cylinder f Regarding the current hydraulic cylinder friction force F f Friction cannot be directly measured and usually requires extensive real-vehicle testing for calibration. Because friction is affected by various factors such as cylinder seals, movement speed, cylinder machining deviations, and the external environment, it is difficult to accurately calibrate, leading to G... 重物 The calculated results deviate significantly from the actual lifting weight (the deviation is more pronounced when the load is unloaded or lightly loaded), and it is difficult to calibrate and compensate for this. This poses a risk of overloading, which may result in damage to the boom or the entire machine tipping over.

[0016] Furthermore, during dynamic luffing operations, the luffing cylinder is subjected to inertial force at the moment of stopping, causing an impact on the cylinder pressure. Although the actual load remains unchanged, the impact causes fluctuations in the calculated weight. The faster the luffing speed, the greater the fluctuation caused by the impact at the stop. The weight data on the cab display keeps fluctuating, leading to user complaints and even causing the driver to doubt the stability and accuracy of the equipment, resulting in distrust of the vehicle and even the brand. Summary of the Invention

[0017] To address the shortcomings of existing technologies, this invention provides a crane force limiter system and a weight calculation method, which improves the weight calculation accuracy of the force limiter system and enhances operational safety.

[0018] To achieve the above objectives, the present invention provides the following technical solution:

[0019] In a first aspect, the present invention proposes a crane force limiter system, including a force limiter host, a display, a length sensor, an angle sensor, and a hydraulic cylinder thrust sensor. The hydraulic cylinder thrust sensor is mounted on the luffing cylinder. The length sensor, angle sensor, and hydraulic cylinder thrust sensor are each communicatively connected to the force limiter host to transmit their respective collected data to the force limiter host. The force limiter host is communicatively connected to the display. The force limiter host receives the data collected by each sensor and processes the collected data. Finally, the processed information is transmitted to the display. The display receives the information sent from the force limiter host and displays it to the operator in real time.

[0020] The length sensor is installed on the boom and is responsible for real-time detection of the boom's extension length during crane operation. The generated valid signal is effectively processed in the force limiter host to obtain the actual extension length of the boom.

[0021] The angle sensor is installed on the boom and is responsible for real-time detection of the boom's luffing angle during crane operation. The generated valid signal is effectively processed in the force limiter host to obtain the actual luffing angle of the boom.

[0022] The hydraulic cylinder thrust sensor is installed inside or outside the cylinder rod of the luffing cylinder to directly measure the axial support force F of the luffing cylinder. 油缸 The resulting hydraulic cylinder thrust signal is sent to the force limiter host in real time, and together with the other variables mentioned above (actual telescopic length, actual amplitude angle), the actual weight of the hoisted cargo is calculated.

[0023] The force limiter host is a controller responsible for real-time acquisition and processing of valid signals generated by various external sensors. It transmits the processed information, such as the extension and retraction length of the boom, the boom luffing angle, the working range of the lifting equipment, the actual lifting weight, and the rated lifting weight, to an operable display for the operator's reference. It also stores and processes debugging data. At the same time, based on the processing results, it outputs valid control signals to the control valves used to protect the safety of the lifting equipment (such as limiting some dangerous actions of the crane when the torque is limited, such as the lifting of the hook, the extension of the boom, and the lowering of the boom luffing angle).

[0024] The display is responsible for receiving effective information such as the working range and actual lifting weight sent by the force limiter host and displaying it to the operator in real time.

[0025] In conjunction with the first aspect, the force limiter system further includes a handle operation signal sensor, which is communicatively connected to the force limiter host and is used to collect whether the amplitude change stop command of the handle is issued. Once the amplitude change stop command is issued, the amplitude change stop signal is sent to the force limiter host, which calculates the weight using a weight fluctuation calculation method.

[0026] In conjunction with the first aspect, the cylinder thrust sensor is further installed inside or outside the cylinder rod of the luffing cylinder.

[0027] In conjunction with the first aspect, further, the cylinder thrust sensor is a sensor capable of measuring the force of a variable amplitude cylinder, preferably a strain gauge type force sensor, for measuring the axial support force F of the cylinder. 油缸 The measurement is performed directly, and the system communicates with the force limiter host to send the hydraulic cylinder thrust signal to the force limiter host in real time for weight calculation.

[0028] Secondly, this invention proposes a method for calculating the weight of a crane force limiter system. Based on the aforementioned crane force limiter system, the formula for weight calculation is as follows:

[0029] G 重物 =(M 油缸 -M 自重 ) / (RL r / N)=(F 油缸 *L b -G 自重 *R') / (RL r / N)

[0030] Among them, F 油缸 The thrust of the luffing cylinder is directly measured by the cylinder thrust sensor; L b Indicates the lever arm of the variable amplitude cylinder; G 重物 G represents the weight of the suspended object, N represents the magnification ratio, and L represents the weight of the suspended object. r R represents the lever arm of the hoisting wire rope; G represents the working radius. 自重 G represents the weight of the boom itself, and R' represents the lever arm of the boom's own weight.

[0031] In conjunction with the second aspect, the weight calculation method further includes the following steps:

[0032] Step S1: The handle operation signal sensor collects the handle signal in real time and determines whether to issue a variable amplitude stop command;

[0033] Step S2: When the handle operation signal sensor determines that the luffing stop command has been triggered, the luffing stop signal is sent to the force limiter host.

[0034] Step S3: The force limiter host receives the amplitude stop signal input from the handle operation signal sensor and records the currently calculated weight G'. 重物 Collect the current amplitude angle signal and convert it into amplitude angular velocity w;

[0035] Step S4: Based on the amplitude angular velocity w obtained in step S3 and the weight fluctuation range limit value ΔG preset in the force limiter host, obtain the weight fluctuation range limit value ΔG corresponding to this amplitude stop command;

[0036] Step S5: The force limiter host processes the weight G calculated in real time. 重物 The force limiter host determines the magnitude of the force and matches the result with the weight value displayed on the screen. The logic for the force limiter host's determination and execution is as follows: when the calculated weight G is output in real time... 重物 In G' 重物 When it is within ±ΔG, directly put G 重物 The weight (G) is transmitted to the display screen and shown in real time.重物 Below G' 重物 When G is within -ΔG, G' is directly supplied. 重物 -ΔG is displayed on the monitor; the calculated weight G is output in real time. 重物 Higher than G' 重物 When it is within +ΔG, directly deliver G' 重物 +ΔG to the display.

[0037] In conjunction with the second aspect, the method for obtaining the amplitude angular velocity w is to differentiate the current amplitude angle collected.

[0038] In conjunction with the second aspect, further, the method for determining the weight fluctuation range limit value ΔG is as follows: by calibrating the weight fluctuation range limit value ΔG corresponding to the stop of the amplitude change under different amplitude angular velocities w, a multiple regression equation based on angular velocity can be established, such as the bivariate regression equation ΔG = aw. 2 +bw+c, where a and b are the calibrated equation coefficients, and c is the calibrated constant. The larger the angular velocity w, the larger the weight fluctuation range ΔG.

[0039] Compared with the prior art, the present invention provides a crane force limiter system and a weight calculation method, which has the following beneficial effects:

[0040] (1) The force limiter system of the present invention eliminates the traditional hydraulic pressure sensor and uses a thrust sensor to directly measure the thrust of the variable amplitude cylinder for weight calculation. It also realizes real-time communication with the force limiter host for safety protection and warning, thereby improving the weight calculation accuracy of the force limiter system and improving operational safety.

[0041] (2) The weight calculation method of the force limiter system of the present invention improves the stability of weight calculation when the amplitude changes and stops instantly, and can achieve stable control of weight calculation, thus solving the problem of weight calculation fluctuation caused by amplitude change stopping. Attached Figure Description

[0042] Figure 1 This is a diagram showing the distribution of various hardware components in a force limiter system on the operating machinery in the existing technology.

[0043] Figure 2 for Figure 1 Enlarged view of the intermediate luffing hydraulic cylinder.

[0044] Figure 3 for Figure 1 A diagram showing the communication relationships between various hardware components.

[0045] Figure 4 This is a schematic diagram of the force distribution in the calculation of the lifting weight in the prior art and embodiments of the present invention;

[0046] Figure 5This is a schematic diagram of the force limiter system in an embodiment of the present invention;

[0047] Figure 6 for Figure 5 Enlarged structural schematic diagram of the intermediate amplitude hydraulic cylinder;

[0048] Figure 7 This is a flowchart of the weight calculation method when the amplitude change stops instantaneously in an embodiment of the present invention;

[0049] Figure 8 for Figure 7 The curve showing the relationship between the intermediate angular velocity w and the weight fluctuation range limit ΔG;

[0050] Figure 9 The actual calculated G in this embodiment of the invention before performing logical calculations. 重物 ;

[0051] Figure 10 The actual calculated G in this embodiment of the invention is obtained after performing logical calculations. 重物 (for Figure 9 (Comparison chart).

[0052] The meanings of the reference numerals in the figure are as follows:

[0053] 1-Luffing cylinder; 2-Length sensor; 3-Angle sensor; 4-Cylinder thrust sensor; 5-Display; 6-Force limiter main unit. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0056] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention.

[0057] like Figure 5 and Figure 6 As shown, the force limiter system proposed in this invention includes a force limiter host 6, a display 5, a length sensor 2, an angle sensor 3, and a hydraulic cylinder thrust sensor 4. The hydraulic cylinder thrust sensor 4 is installed inside or outside the cylinder rod of the luffing cylinder 1. The length sensor 2, angle sensor 3, and hydraulic cylinder thrust sensor 4 are respectively communicatively connected to the force limiter host 6 to transmit their respective collected data to the force limiter host 6. The force limiter host 6 is communicatively connected to the display 5. The force limiter host 6 receives the data collected by each sensor and processes the collected data. Finally, the processed information is transmitted to the display 5. The display 5 receives the information sent from the force limiter host 6 and displays it to the operator in real time.

[0058] In one specific embodiment of this example, the force limiter system further includes a control handle that can output an amplitude control analog signal. The control handle is communicatively connected to the force limiter host 6 and is used to collect whether the amplitude stop command of the handle is issued. Once the amplitude stop command is issued, the amplitude stop signal is sent to the force limiter host 6. The force limiter host 6 calculates the weight using a weight fluctuation calculation method.

[0059] In one specific embodiment of this invention, the hydraulic cylinder thrust sensor 4 is a sensor capable of measuring the force of the variable amplitude hydraulic cylinder 1, preferably a strain gauge type force sensor, to measure the axial support force F of the hydraulic cylinder. 油缸 The measurement is performed directly, and communication is established with the force limiter host 6. The hydraulic cylinder thrust signal is sent to the force limiter host 6 in real time for weight calculation.

[0060] This invention also proposes a method for calculating the weight of a crane force limiter system. Based on the above-mentioned crane force limiter system, the weight calculation method is as follows:

[0061] Taking the crane telescopic boom system as the object and the boom rear hinge point O as the fulcrum, the crane torque balance equation is established. Figure 4 In the middle, the torques that cause the crane to rotate clockwise and counterclockwise are respectively the luffing cylinder torque M. 油缸 M F , Hoisting wire rope tension M 卷扬 and lifting moment M 重物 boom self-weight moment M 自重 When the crane is moving at a constant speed or is stationary, the torque required to rotate the crane clockwise and counterclockwise is equal, as given by the following formula:

[0062] M 油缸 +M 卷扬 =M 自重 +M 重物

[0063] Given the structural parameters of the crane, the calculation methods for each torque in the above formula are as follows:

[0064] M 油缸 =F 油缸 *L b

[0065] M 卷扬 =F 卷扬 *L r =(G 重物 / N)*L r

[0066] M 自重 =G 自重 *R'

[0067] M 重物 =G 重物 *R

[0068] We can obtain:

[0069] G 重物 =(M 油缸 -M 自重 ) / (RL r / N)=(F油缸 *L b -G 自重 *R') / (RL r / N)

[0070] Among them, F 油缸 The thrust of the luffing cylinder 1 is directly measured by the cylinder thrust sensor 4; L b Indicates the lever arm of the variable amplitude cylinder; G 重物 G represents the weight of the suspended object, N represents the magnification ratio, and L represents the weight of the suspended object. r R represents the lever arm of the hoisting wire rope; G represents the working radius. 自重 G represents the weight of the boom itself, and R' represents the lever arm of the boom's own weight.

[0071] R = L·cosα

[0072] Where L is the reach arm length measured by the length sensor; α is the amplitude angle (angle between the reach arm and the horizontal direction) measured by the angle sensor.

[0073] F 油缸 The force can be directly measured by the cylinder thrust sensor 4 installed inside the lever of the luffing cylinder 1. It can be seen that G... 重物 Friction force F with the hydraulic cylinder f Irrelevant (F) f (For the friction force of the variable amplitude cylinder 1), it can greatly improve the accuracy of weight calculation and improve the safety of operation.

[0074] In one specific implementation of this embodiment, such as Figure 7 As shown, the weight calculation method of the present invention includes the following steps:

[0075] Step S1: The handle operation signal sensor collects the handle signal in real time and determines whether to issue a variable amplitude stop command.

[0076] Step S2: When the handle operation signal sensor determines that the amplitude stop command has been triggered, the amplitude stop signal is sent to the force limiter host 6.

[0077] Step S3: The force limiter host 6 receives the amplitude stop signal input from the handle operation signal sensor and records the currently calculated weight G'. 重物 The current amplitude angle signal is acquired and converted into an amplitude angular velocity w. The amplitude angular velocity w is obtained by differentiating the acquired current amplitude angle.

[0078] Step S4: Based on the amplitude change angular velocity w obtained in step S3 and the weight fluctuation range limit value ΔG preset in the force limiter host 6, the weight fluctuation range limit value ΔG corresponding to this amplitude change stop command is obtained, such as... Figure 8 As shown.

[0079] The method for determining the weight fluctuation range limit ΔG is as follows: By calibrating the weight fluctuation range limit ΔG corresponding to the stop of the amplitude change under different amplitude angular velocities w, a multiple regression equation based on angular velocity can be established, such as the bivariate regression equation ΔG = aw. 2 +bw+c, where a and b are the calibrated equation coefficients, and c is the calibrated constant. The larger the angular velocity w, the larger the weight fluctuation range ΔG.

[0080] Step S5: The force limiter host 6 calculates the weight G in real time. 重物 The force limiter host 6 judges the size and matches the weight value displayed on the display 5 according to the judgment result; the judgment and execution logic is as follows: when the real-time calculated weight G is output, the force limiter host 6 judges the size and executes the weight value displayed on the display 5 according to the judgment result. 重物 In G' 重物 When it is within ±ΔG, directly put G 重物 The weight is transmitted to display 5 and the calculated weight G is displayed in real time. 重物 Below G' 重物 When G is within -ΔG, G' is directly supplied. 重物 -ΔG is displayed on monitor 5; the calculated weight G is output in real time. 重物 Higher than G' 重物 When it is within +ΔG, directly deliver G' 重物 +ΔG to display on monitor 5.

[0081] By setting the handheld operation signal sensor and using the aforementioned weight calculation method, the stability of weight calculation is improved when there is an instantaneous stop during amplitude change. This enables smooth control of weight calculation, solves the problem of weight calculation fluctuation caused by amplitude change stop, and enhances user trust and loyalty.

[0082] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method of weight calculation for a crane force limiter system, characterized by: Based on the crane force limiter system, the formula of the weight calculation is as follows: ； wherein, represents the amplitude cylinder thrust, which is directly measured by the cylinder thrust sensor; represents the amplitude cylinder force arm; represents the load weight, represents the magnification, represents the hoist wire rope tension force arm; represents the working amplitude, represents the arm self weight, represents the arm self weight force arm, represents the amplitude cylinder torque, represents the arm self weight torque; The method comprises the following steps: Step S1: The handle operation signal sensor collects the handle signal in real time and judges whether to send the luffing stop command; Step S2: When the handle operation signal sensor judges that the luffing stop command is triggered, the luffing stop signal is sent to the force limiter host; Step S3: the force limiter host receives the amplitude stop signal input by the handle operation signal sensor, records the current calculated weight , collects the current amplitude angle signal, and converts the amplitude angle signal into amplitude angular velocity ; Similarly, the weight calculated by the formula is calculated ; Step S4: The amplitude variation angular velocity is obtained according to the amplitude variation angular velocity obtained in the step S3 The weight fluctuation range limit value preset in the force limiter host The calculation model obtains the weight fluctuation range limit value corresponding to the amplitude variation stop command ; Step S5: The force limiter host processes the weight calculated in real time. The force limiter host judges the magnitude of the force and matches the result with the weight value displayed on the screen; the logic of the force limiter host in judging and executing is as follows: when the weight is calculated in real time... exist Within that time, directly The weight is transmitted to the display screen and shown in real time. Below At that time, direct delivery The weight is displayed on the monitor in real time. Higher than At that time, direct delivery Displayed on the monitor; The weight fluctuation range limit value The determination method is as follows: by calibrating different amplitude angle velocities Under different working conditions, the corresponding weight fluctuation range limit value when the amplitude stops Establish a binary regression equation based on the angle velocity The binary regression equation Wherein a and b are calibrated equation coefficients, Is a calibrated constant.

2. A method of weight calculation for a crane force limiter system according to claim 1, characterized in that: the variable amplitude angular velocity The resulting method is to differentiate the current variable amplitude angle that is collected.

3. A crane force limiter system characterized by: The weight calculation method for realizing the weight calculation method of claim 1 or 2 comprises a force limiter host, a display, a length sensor, an angle sensor and a cylinder thrust sensor, the cylinder thrust sensor is arranged on the luffing cylinder, the length sensor, the angle sensor and the cylinder thrust sensor are respectively connected with the force limiter host in communication, for transmitting the data collected by each sensor to the force limiter host, the force limiter host is connected with the display in communication, the force limiter host receives the data collected by each sensor and processes the collected data, and transmits the processed information to the display, the display receives the information sent from the force limiter host and displays it to the operator in real time.

4. A crane load limiter system according to claim 3, characterised in that: The handle operation signal sensor is also included, which is connected with the force limiter host in communication, for collecting whether the luffing stop command of the handle is sent, once the luffing stop command is sent, the luffing stop signal is sent to the force limiter host, and the force limiter host calculates the weight by using the weight fluctuation calculation method.

5. A crane load limiter system according to claim 4, characterised in that: The cylinder thrust sensor is installed inside or outside the cylinder rod of the luffing cylinder.

6. A crane load limiter system according to claim 4, characterised in that: The cylinder thrust sensor is a strain type force sensor.

Images