Crane hook target motion trail control system and control method thereof

Abstract

The invention provides a crane hook target motion trail control system and a control method thereof.The crane hook target motion trail control system comprises a pressure control system, a winch system, a power source system and a sensing system.The pressure control system is used for monitoring the state of a clutch, controlling the winch speed of the winch clutch and feeding back pressure data in real time; one end of the winch system is connected with the pressure control system, and the other end of the winch system is connected with the power source system; the power source system is connected with the winch system and is used for providing power for the operation of the crane hook; the sensing system is connected with the controller through a signal transmission line and used for detecting pressure and rotating speed data in the operation process of the lifting hook and transmitting the pressure and rotating speed data to the controller for analysis. According to the invention, speed trajectory path planning and preventive real-time control can be carried out when the crawler crane does a free hook falling working condition, so that stable braking can be realized when the lifting hook lifts different weights of loads, and a winding drum can be effectively braked.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a crane hook target motion trajectory control system and a control method thereof. Background Art

[0002] With the steady development of economic construction, cranes are increasingly used in many industries such as industrial production, infrastructure, transportation, etc., to achieve cargo transfer and intelligent assembly, and provide high-end equipment engineering support for the country. At the same time, with the rapid rise of information industrialization and Internet of Things technology, the intelligence, intensiveness and precision of cranes will inevitably become the development trend of current lifting equipment. High efficiency, high accuracy and high safety requirements are put forward for cranes.

[0003] In the rapid development of automation control technology and robot control technology, safe and stable highly automated equipment can better replace mechanical manual labor and reduce production costs. If the flexibility of robot technology and the efficiency of automation technology are integrated and extended to crawler crane systems, it can replace more experienced workers, continuously reduce errors caused by human factors, and improve operation efficiency and stability. The automated crane system can automatically match the hook to the appropriate acceleration according to the predetermined position through trajectory planning, avoiding the phenomenon of hook braking impact caused by the operator's emergency stepping on the pedal due to excessive falling acceleration, while reducing the labor intensity of personnel operation and effectively improving the overall execution efficiency; and the automatic crane can better suppress the load braking impact, reduce the risk of accidents, and can meet the normal performance of the crane in most dangerous environments, expanding the scope of operation.

[0004] At present, the operation of crawler cranes mainly relies on manual practical experience, that is, the operator gradually becomes familiar with the performance and operating environment of the equipment through daily operation and experience accumulation, and continuously tests and corrects, and finally realizes the smooth fall of the hook load. This method requires long-term exploration and practice by the operator, and the complexity of the construction environment is sometimes unpredictable and untimely. Especially when working in bad weather and dangerous environments, it is necessary to meet personal safety and falling speed at the same time, which is more demanding for the operator and increases the practical difficulty of crawler cranes. In the actual process, it is found that when operating the crawler crane hook winch, the winch speed is not controlled by the pedal, resulting in an abnormal speed decline phenomenon, and the hook cannot be steadily and steadily descended at the predetermined speed. The decline speed exceeds the maximum working speed and is in a state of free acceleration. For example, when the operating handle controls the winch to lift or fall, the load falls rapidly. When the hook is freely dropped by loosening the foot pedal, the hook falls rapidly and cannot be stopped. If the foot pedal is stepped on urgently, the action cannot be stopped, causing damage to the brake and motor, resulting in operating errors. In severe cases, it may even cause the wire rope or boom to break, resulting in catastrophic consequences. Therefore, it is imperative to find a suitable control method for the controllability and stability of the free-fall hook brake. Effective planning of the motion trajectory of the hook drop is of great significance to improving the working efficiency and safety of the entire machine.

[0005] After a lot of research, it was found that the existing technology: Publication No. CN102040160A proposed a trajectory tracking control method for smooth transition trajectory, and obtained good experimental results on the crawler crane test platform, but the multiple iterations to optimize the control parameters were cumbersome. Subsequently, in-depth research was conducted again to plan the acceleration transition trajectory of the crawler crane hook based on the three-stage acceleration trajectory phase plane, but the designed acceleration trajectory was not very smooth during the experiment, which easily brought a large impact to the hook. In severe cases, the hook slipped and could not be stopped, which greatly affected the construction safety. However, since smooth transition trajectory planning is a method based on acceleration motion control, it can directly reflect the displacement change, speed and acceleration limit of the crawler crane, and realize the uniform drop of the hook of the free-fall hook system. This method does not apply the good acceleration trajectory involved to engineering practice. Due to the complexity of the control parameters, the acceleration trajectory curve is discontinuous in different braking stages, and there is no transition at the node. In addition, the matching relationship between the acceleration parameters and the braking force under different loads is not considered, and the braking shock is still present at the moment of braking.

[0006] Publication No. CN116281600A proposes a trajectory planning method and system for the positioning and swing suppression of bridge crane hooks. By obtaining the displacement length of the trolley and bridge frame, and combining the swing angle of the hook and load, a bridge crane system dynamics model is constructed. Finally, according to the results of the model, the trajectory planning of the trolley, bridge frame movement and hook is obtained to achieve the positioning and swing suppression control of the bridge crane. The running trajectory is determined according to the displacement of the trolley and bridge frame. In this process, the movement is almost uniform and the hook swing is eliminated. Although this method is very suitable for the posture of the bridge crane, it is obviously not suitable for the free hook drop condition of the crawler crane.

[0007] Publication No. CN117819393A proposes a method and controller for detecting the posture of a crane hook, which obtains the working condition data of the crane in the current operating state, calculates the reaction force of each leg, obtains the actual reaction force of each leg mechanism of the crane in the current state, and determines the current posture of the crane hook. Publication No. CN112850495B proposes a trajectory planning method and system for a rotary crane considering state constraints, including establishing a crane dynamics model, determining the trajectory of eliminating the swing angle acceleration according to the nonlinear coupling relationship between the boom pitch angle, hook swing and load swing, and realizing precise positioning of the crane. However, these two technical solutions only confirm the posture of the crane, and neither provides a braking solution for controlling the load during free fall.

[0008] Publication No. CN115258950A proposes a flexible braking control method for a crane free-fall hook system. In the prior art literature, the speed controller is mainly designed to control the pressure of the clutch chamber and the brake chamber in the braking system. This method realizes speed control of different lifting loads by setting different brake gears. The pedal angle interval value of the electric control pedal is obtained in the free-fall hook condition of the crane and divided into three sections according to the obtained pedal angle. The operator controls the output pressure of the proportional pressure reducing valve by controlling the pedal angle to realize the flexible braking of the free-fall hook of the crane. Although this method effectively reduces the braking impact of the load falling to a certain extent and improves the responsiveness of the free-fall hook system, the movement state of the hook is not well grasped during the braking process. The speed of the hook is unstable during the movement, and the movement trajectory and speed of the hook are not designed and planned.

[0009] In summary, there are still many key problems in the free-fall hook braking process of crawler cranes, such as braking shock during the hook drop, resulting in brake setback and uneven output; after taking braking measures, the wire rope continues to drive the drum to rotate under the action of the load, causing the hook to deviate from the target position; when the crawler crane hook is hoisted, the hoisting speed is not controlled by the pedal, resulting in an abnormal speed decline, and the hook cannot be steadily and steadily dropped at the predetermined speed. The decline speed exceeds the maximum working speed and is in a state of free acceleration, etc. Although the crane technology has been perfected and widely used in our lives, it still cannot meet the on-site needs in engineering practice. Therefore, it is urgent to find a good solution to improve the current crane performance problems and improve the crane braking control effect. Summary of the invention

[0010] According to the technical problems raised above, a control system and a control method for the target motion trajectory of a crane hook are provided. The present invention mainly utilizes a pressure control system, a hoisting system, a power source system and a sensor system, combined with a control method, to perform speed trajectory path planning and preventive real-time control when the crawler crane is in a free-falling hook condition, so that the hook can achieve smooth braking and effective braking of the drum when lifting different weight loads, so as to improve the practicality of planning the target motion trajectory of the crawler crane.

[0011] The technical means adopted by the present invention are as follows:

[0012] A crane hook target motion trajectory control system includes: a pressure control system, a hoisting system, a power source system and a sensor system, wherein:

[0013] The pressure control system is connected to the hoisting system at one end and to the oil pump and the hydraulic oil tank at the other end, and is used to monitor the clutch state, control the hoisting speed of the hoisting clutch, and provide real-time feedback of pressure data;

[0014] The hoisting system is connected to the pressure control system at one end and the power source system at the other end, and is used to adjust and control the movement trajectory and lifting speed of the hook according to the load;

[0015] The power source system is connected to the hoisting system and is used to provide power for the operation of the crane hook;

[0016] The sensor system is connected to the controller via a signal transmission line, and is used to detect the pressure and speed data during the operation of the hook, and transmit them to the controller for analysis.

[0017] Furthermore, the pressure control system includes: a relief valve, an electric proportional pressure reducing valve, a power acceleration electromagnetic reversing valve, a clutch brake chamber electromagnetic reversing valve, and a clutch clutch chamber electromagnetic reversing valve, wherein:

[0018] One end of the overflow valve is connected to the oil pump, and the other end is connected to the hydraulic oil tank through a hydraulic pipeline, which is used to control the pressure input by the oil pump to the clutch clutch chamber to be constant pressure; one end of the electric proportional pressure reducing valve is connected to the oil pump, and the other end is connected to the clutch brake chamber electromagnetic reversing valve, and the electric proportional pressure reducing valve is used to control the pressure of the clutch brake chamber; the clutch brake chamber electromagnetic reversing valve is connected to the clutch brake chamber through a hydraulic pipeline; the clutch clutch chamber electromagnetic reversing valve is connected to the clutch clutch chamber.

[0019] Furthermore, the hoisting system includes: a clutch brake chamber, a clutch clutch chamber, a reducer drum, a force limiter and a brake, wherein:

[0020] The winch clutch includes a clutch brake chamber and a clutch clutch chamber. The winch clutch is coaxially connected to the reducer drum. A wire rope is wound around the reducer drum, and the end of the wire rope is connected to a hook. A force limiter is provided on the wire rope to measure the tension on the wire rope and transmit the data to the controller. The brake is provided on the central axis of the reducer drum.

[0021] Furthermore, the power source system includes: a hydraulic motor, a protection circuit balancing valve, a hydraulic motor circuit electromagnetic reversing valve and a power source variable pump, wherein:

[0022] The hydraulic motor is coaxially connected to the reducer drum to provide power for lifting the hook; one end of the protection circuit balance valve is connected to the hydraulic motor, and the other end is connected to the hydraulic motor circuit electromagnetic reversing valve, and the power source variable pump is connected to the hydraulic motor circuit electromagnetic reversing valve.

[0023] Furthermore, the sensing system includes: a clutch brake chamber pressure sensor, a clutch clutch chamber pressure sensor, an electric proportional pressure reducing valve front pressure sensor, an electric proportional pressure reducing valve rear pressure sensor and a reel speed sensor, wherein:

[0024] The clutch brake chamber pressure sensor is arranged between the clutch brake chamber electromagnetic reversing valve and the clutch brake chamber, and is used to monitor the pressure changes in the clutch brake chamber; the clutch clutch chamber pressure sensor is arranged between the clutch clutch chamber electromagnetic reversing valve and the clutch clutch chamber, and is used to monitor the pressure changes in the clutch clutch chamber; the electric proportional pressure reducing valve front pressure sensor is arranged between the oil pump and the electric proportional pressure reducing valve, and is used to monitor the pressure before pressure reduction; the electric proportional pressure reducing valve rear pressure sensor is arranged between the electric proportional pressure reducing valve and the clutch brake chamber electromagnetic reversing valve, and is used to monitor the pressure after pressure reduction; the drum speed sensor is arranged on the reducer drum, and is used to monitor the speed of the reducer drum.

[0025] The present invention also includes a control method for a crane hook target motion trajectory control system, the specific steps of which include:

[0026] When the crane is free-falling, the force limiter collects the pressure on the wire rope, transmits the collected data to the controller and converts it into the weight value of the current load;

[0027] According to the weight value of the current load, the preset braking speed trajectory is matched, and the controller outputs a speed matching signal, and the crane hook target motion trajectory control system brakes according to the preset braking speed trajectory;

[0028] The power acceleration electromagnetic reversing valve is used to change the direction, change the angle of the electric control pedal, and control the output pressure of the electric proportional pressure reducing valve, so that the pressure monitored by the pressure sensor behind the electric proportional pressure reducing valve is equal to the pressure monitored by the clutch brake chamber pressure sensor. The clutch friction plate is controlled to engage and disengage by controlling the pressure difference between the clutch brake chamber and the clutch clutch chamber, and the load begins to freely drop the hook;

[0029] The drum speed sensor monitors the speed of the reducer drum in real time, rotates it in the direction of load lowering through the hydraulic motor, and brakes it through the brake, so that the load moves according to the preset braking speed trajectory, realizing automatic hook-drop braking of the crane hook.

[0030] Furthermore, the preset braking speed trajectory introduces a smooth transition function into the three-stage speed trajectory curve to calculate the trajectory equation during the hook braking process;

[0031] When the load of the crane in free-falling hook condition is 0~T1 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0032]

[0033] Wherein, j represents the change value of hook acceleration per unit time during the falling process, t represents the pedal brake opening time during the hook power acceleration process, 0<t<t1 represents the first stage of falling, t1<t<t2 represents the second stage of falling, t2<t<t3 represents the third stage of falling, acc0 represents the acceleration value of the hook at the initial moment or position, vel0 represents the velocity value of the hook at the initial moment or position, pos0 represents the displacement value of the hook at the initial moment or position,, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0034] When the load of the crane under free-fall hook working condition is T1~T2 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0035]

[0036] in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0037] When the load of the crane under free-fall hook working condition is T2-T3 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0038]

[0039]

[0040] in, Indicates the acceleration value of the first stage, is the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0041] When the load of the crane under free-fall hook condition is T3-T4 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0042]

[0043]

[0044] in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0045] When the load under the free-falling hook condition of the crane is greater than T4 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0046]

[0047] in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage.

[0048] Compared with the prior art, the present invention has the following advantages:

[0049] The crane hook target motion trajectory control system and control method provided by the present invention can accurately obtain the key physical quantities of the crane hook at the initial moment, such as displacement, velocity and acceleration, and accurately plan the hook motion trajectory based on this, which greatly improves the reliability and accuracy of trajectory planning. Secondly, by determining the final state parameters of the hook target motion trajectory, the entire motion process is made more controllable and predictable. This means that possible problems can be predicted and avoided in advance, ensuring the smooth progress of construction. The present invention also comprehensively considers the relevant parameters of the initial and terminal states of the hook, meets the winch brake requirements to the greatest extent, and realizes the stability of the crawler crane hook motion trajectory, which effectively reduces the impact caused by emergency stops or sudden speed changes, and reduces equipment losses and failure risks.

[0050] The crane hook target motion trajectory control system and control method provided by the present invention plan the displacement, speed and acceleration trajectory curves of the hook movement under different loads. Unlike the original method in which the hook motion trajectory can be planned only when the initial state and the terminal state are both in a static state, the motion trajectory of the hook and the wire rope can be planned in any state when the hook is in free falling condition, so that the hook can be smoothly braked and the drum can be effectively braked when the hook is lifting different weight loads, and the hook can be controlled within a safe range during the operation to the greatest extent, and the braking speed of the hook falling movement can be controllable, and the crawler crane can achieve smooth braking during the hook falling process, so as to improve the practicability of planning the target motion trajectory of the crawler crane.

[0051] Based on the above reasons, the present invention can be widely promoted in the technical field of engineering machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0053] Figure 1 It is a schematic diagram of the structure of the crane hook target motion trajectory control system in the present invention.

[0054] Figure 2 The present invention is a flow chart of a method for controlling a pedal braking speed trajectory during a free-falling hook power acceleration process of a crawler crane.

[0055] Figure 3 It is a curve diagram of the acceleration trajectory of the crawler crane hook during the braking process of the power accelerator pedal.

[0056] Figure 4 The present invention is a running speed trajectory curve diagram of the crawler crane hook during the braking process of the power accelerator pedal.

[0057] Figure 5 The present invention is a curve diagram of the hook displacement trajectory during the crawler crane hook power accelerator pedal braking process.

[0058] Figure 6 The present invention is a curve diagram of the acceleration, speed and displacement trajectory of the hook during the braking process of the crawler crane hook power accelerator pedal.

[0059] Figure 7 The present invention is a flow chart of the safe operation of the multifunctional crawler crane hook torque limiter.

[0060] Figure 8 It is a schematic diagram of the multifunctional crawler crane hook operation safety control system in the present invention.

[0061] In the figure: 1. Oil pump; 2. Overflow valve; 3. Electric proportional pressure reducing valve; 4. Power acceleration electromagnetic reversing valve; 5. Clutch brake chamber electromagnetic reversing valve; 6. Clutch clutch chamber electromagnetic reversing valve; 7. Clutch brake chamber pressure sensor; 8. Clutch clutch chamber pressure sensor; 9. Electric proportional pressure reducing valve front pressure sensor; 10. Electric proportional pressure reducing valve rear pressure sensor; 11. Clutch brake chamber; 12. Clutch clutch chamber; 13. Reducer drum; 14. Drum speed sensor; 15. Force limiter; 16. Brake; 17. Hydraulic motor; 18. Protection circuit balance valve; 19. Hydraulic motor circuit electromagnetic reversing valve; 20. Power source variable pump; 21. Hydraulic oil tank. DETAILED DESCRIPTION

[0062] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0063] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0065] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0066] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0067] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0068] like Figure 1 As shown, the present invention provides a crane hook target motion trajectory control system, including: a pressure control system, a hoisting system, a power source system and a sensor system, wherein:

[0069] The pressure control system has one end connected to the hoisting system and the other end connected to the oil pump 1 and the hydraulic oil tank 21, and is used to monitor the clutch state, control the hoisting speed of the hoisting clutch, and provide real-time feedback of pressure data;

[0070] The winch system is connected to the pressure control system at one end and the power source system at the other end, and is used to adjust and control the movement trajectory and lifting speed of the hook according to the load;

[0071] The power source system is connected to the hoisting system and is used to provide power for the operation of the crane hook;

[0072] The sensing system is connected to the controller through a signal transmission line. It is used to detect the pressure and speed data during the operation of the hook and transmit them to the controller for analysis.

[0073] During implementation, the sensing system comprehensively and accurately obtains the displacement, velocity, acceleration and other relevant data of the crawler crane's hook at the initial moment, and uses the current displacement, velocity and acceleration of the crawler crane's hook as the displacement, velocity and acceleration of the initial state of the target motion trajectory planning; these physical quantities are all in vector form, with both size and direction.

[0074] The controller can display the current rated load and actual load of the crane, and has the functions of real-time detection of the crane working condition, self-diagnosis, rapid dangerous condition alarm and safety control. It can also judge the safe working status of the multi-functional crawler crane through the data of the sensor system and the force limiter. Once the crawler crane is in a dangerous condition, the force limiter will perform a limit action to protect the entire vehicle.

[0075] In specific implementation, as a preferred embodiment of the present invention, the pressure control system includes: a relief valve 2, an electric proportional pressure reducing valve 3, a power acceleration electromagnetic reversing valve 4, a clutch brake chamber electromagnetic reversing valve 5, and a clutch clutch chamber electromagnetic reversing valve 6, wherein:

[0076] One end of the overflow valve 2 is connected to the oil pump 1, and the other end is connected to the hydraulic oil tank 21 through a hydraulic pipeline, which is used to control the pressure input from the oil pump 1 to the clutch clutch chamber 12 to be constant pressure; one end of the electric proportional pressure reducing valve 3 is connected to the oil pump 1, and the other end is connected to the clutch brake chamber electromagnetic reversing valve 5, and the electric proportional pressure reducing valve 3 is used to control the pressure of the clutch brake chamber; the clutch brake chamber electromagnetic reversing valve 5 is connected to the clutch brake chamber 11 through a hydraulic pipeline; the clutch clutch chamber electromagnetic reversing valve 6 is connected to the clutch clutch chamber 12.

[0077] In specific implementation, as a preferred embodiment of the present invention, the hoisting system includes: a clutch brake chamber 11, a clutch clutch chamber 12, a reducer drum 13, a force limiter 15 and a brake 16, wherein:

[0078] The winch clutch includes a clutch brake chamber 11 and a clutch clutch chamber 12. The winch clutch is coaxially connected to the reducer drum 13. A wire rope is wound around the reducer drum 13, and the end of the wire rope is connected to a hook. A force limiter 15 is provided on the wire rope to measure the tension on the wire rope and transmit the data to the controller. The brake 16 is provided on the central axis of the reducer drum 13.

[0079] In specific implementation, as a preferred embodiment of the present invention, the power source system includes: a hydraulic motor 17, a protection circuit balancing valve 18, a hydraulic motor circuit electromagnetic reversing valve 19 and a power source variable pump 20, wherein:

[0080] The hydraulic motor 17 is coaxially connected to the reducer drum 13 to provide power for lifting the hook; one end of the protection circuit balance valve 18 is connected to the hydraulic motor 17, and the other end is connected to the hydraulic motor circuit electromagnetic reversing valve 19, and the power source variable pump 20 is connected to the hydraulic motor circuit electromagnetic reversing valve 19.

[0081] In specific implementation, as a preferred embodiment of the present invention, the sensing system includes: a clutch brake chamber pressure sensor 7, a clutch clutch chamber pressure sensor 8, an electric proportional pressure reducing valve front pressure sensor 9, an electric proportional pressure reducing valve rear pressure sensor 10 and a reel speed sensor 14, wherein:

[0082] The clutch brake chamber pressure sensor 7 is arranged between the clutch brake chamber electromagnetic reversing valve 5 and the clutch brake chamber 11, and is used to monitor the pressure changes in the clutch brake chamber; the clutch clutch chamber pressure sensor 8 is arranged between the clutch clutch chamber electromagnetic reversing valve 6 and the clutch clutch chamber 12, and is used to monitor the pressure changes in the clutch clutch chamber; the electric proportional pressure reducing valve front pressure sensor 9 is arranged between the oil pump 1 and the electric proportional pressure reducing valve 3, and is used to monitor the pressure before pressure reduction; the electric proportional pressure reducing valve rear pressure sensor 10 is arranged between the electric proportional pressure reducing valve 3 and the clutch brake chamber electromagnetic reversing valve 5, and is used to monitor the pressure after pressure reduction; the drum speed sensor 14 is arranged on the reducer drum 13, and is used to monitor the speed of the reducer drum 13.

[0083] The present invention also includes a control method for a crane hook target motion trajectory control system, the specific steps of which include:

[0084] When the crane is free-falling, the force limiter 15 collects the pressure on the wire rope, transmits the collected data to the controller and converts it into the weight value of the current load;

[0085] According to the weight value of the current load, the preset braking speed trajectory is matched, and the controller outputs a speed matching signal, and the crane hook target motion trajectory control system brakes according to the preset braking speed trajectory;

[0086] The power acceleration electromagnetic reversing valve 4 is used to change the direction, change the angle of the electric control pedal, and control the output pressure of the electric proportional pressure reducing valve 3, so that the pressure monitored by the pressure sensor 10 after the electric proportional pressure reducing valve is equal to the pressure monitored by the clutch brake chamber pressure sensor 7. The clutch friction plate is controlled to engage and disengage by controlling the pressure difference between the clutch brake chamber 11 and the clutch clutch chamber 12, and the load begins to fall freely.

[0087] The drum speed sensor 14 monitors the speed of the reducer drum 13 in real time, rotates in the load lowering direction through the hydraulic motor 17, and brakes through the brake 16, so that the load moves according to the preset braking speed trajectory, realizing automatic hook-dropping braking of the crane hook.

[0088] At present, when planning the target motion path trajectory of the hook of a crawler crane, S-type motion trajectory planning is usually performed, that is, the initial state and the final state of the hook of the crawler crane are both required to remain in a static state, that is, the displacement, speed, and acceleration of the hook of the crawler crane at the current moment are all 0. Therefore, the control method of the present invention can adjust the speed and smoothness of the operation speed by controlling the maximum value of the hook lowering acceleration and the time of the acceleration stage, so that the speed trajectory planning of the hook during the braking process is more stable and reliable. In addition, when designing the hook lowering speed curve, considering the influence of the brake switching between the pedal angle intervals, a smooth transition function is introduced into the three-stage speed trajectory curve, and the trajectory equation of the hook during braking is calculated, so that the hook is controlled within a safe range during the working process to the greatest extent, and the hook falling movement speed braking is allowed to be controllable, and the crawler crane hook can achieve smooth braking during the falling process.

[0089] In specific implementation, as a preferred embodiment of the present invention, the preset braking speed trajectory introduces a smooth transition function into the three-stage speed trajectory curve to calculate the trajectory equation during the hook braking process;

[0090] When the load of the crane in free-falling hook condition is 0~T1 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0091]

[0092] Wherein, j represents the change value of the hook acceleration per unit time during the falling process, t represents the pedal brake opening time during the hook power acceleration process, 0<t<t1 represents the first stage of the fall, t1<t<t2 represents the second stage of the fall, t2<t<t3 represents the third stage of the fall, acc0 represents the acceleration value of the hook at the initial moment or position, vel0 represents the velocity value of the hook at the initial moment or position, pos0 represents the displacement value of the hook at the initial moment or position, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0093] When the load of the crane under free-fall hook working condition is T1~T2 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0094]

[0095] in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0096] When the load of the crane under free-fall hook working condition is T2-T3 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0097]

[0098]

[0099] in, Indicates the acceleration value of the first stage, is the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0100] When the load of the crane under free-fall hook condition is T3-T4 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0101]

[0102]

[0103] in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage;

[0104] When the load under the free-falling hook condition of the crane is greater than T4 tons, the target motion speed planning curve designed during the power acceleration of the hook is:

[0105]

[0106] in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage.

[0107] The division of tonnage ranges mainly depends on the following aspects:

[0108] 1. The rated lifting capacity of the crane is limited. During the free-fall hook braking process, the hook and its load accelerate down at the speed of free acceleration. The brake operation is suddenly performed during the operation. Due to the existence of load inertia, loads of different tonnages have different loads on the crane's lifting mechanism, transmission system and hoisting mechanism. If different hook operation trajectories are not set according to the load tonnage, the crane may exceed its safe load range during operation, resulting in mechanical failure or even accidents. If the operation trajectories of different loads are set, the controller will automatically match the operation trajectory within the appropriate range according to the load weight fed back by the force limiter to avoid damage to larger tonnage loads and overly fast braking trajectories due to instantaneous overload. Therefore, for larger tonnage loads, a more stable and slow operation trajectory is required to ensure that the lifting mechanism can withstand huge tension and pressure to avoid damage due to time overload.

[0109] 2. Considering the load stability of the hoisting weight, loads of different tonnages affect the overall stability of the crane, causing a significant change in the center of the crane and reducing stability. Through the running tracks of loads of different tonnages, the center of gravity distribution of the crane is adjusted to improve its stability during the hoisting process;

[0110] 3. From the perspective of work efficiency and the coordination of actuators, different tonnage loads have different requirements for operation time. Small tonnage loads can complete the entire free-fall hook braking process in a relatively short time, while large tonnage loads require more time to ensure safety and need to match more parameters to participate, thereby increasing the complexity of the operation. Therefore, setting different operation trajectories can optimize the operation time according to the load tonnage. At the same time, for large tonnage loads, it is necessary to carefully select the operation trajectory to ensure safety while minimizing the operation time. Secondly, the operation trajectories of different tonnage will reduce the energy loss during the braking process. By setting a reasonable operation trajectory, the friction loss and friction plate failure of the crane's hoisting mechanism and winch mechanism can be reduced on the premise of meeting the hook braking, thereby improving the energy utilization of the braking system.

[0111] 4. According to the requirements of the free-falling brake test of a certain type of crawler crane, the maximum hoisting load under single-rate working condition is 20t. In order to verify the correctness of the output control effect of the controller of the braking process of the lifting mechanism under this rate, several tonnage ranges are set, generally 0-3t, 3-7t, 7-10t, 10-15t, 15-20t.

[0112] According to the target speed motion trajectory curve of the hook braking process planned according to the different weights of the load, by planning the braking speed trajectory of different weight loads, it can effectively reduce the overspeed decline caused by untimely braking, so that the hook starts to fall according to the predetermined braking drop speed, ensures that the hook accurately falls to the target position, and ensures that the drop speed at that time is zero, does not cause braking impact on the crane boom and produces abnormal braking noise, and improves the safety of operation. If the hook movement speed is not zero after reaching the target position, the drum will continue to rotate under the drive of the load, and the wire rope will continue to extend through the pulley block, causing the wire rope slip rate to increase, the load offsets the target position, and the wire rope length increases, which increases the complexity of operation and reduces work efficiency. Therefore, by planning the path curve of the braking process of movement speed, movement acceleration and movement displacement, it can meet the braking requirements of different tonnage loads and meet the precise position braking of the hook, improve the safety of construction operations, effectively reduce the driver's operating procedures, make the braking process of the hook drop more accurate, and improve the reliability and stability of the braking process of the free drop hook system power acceleration process.

[0113] Example

[0114] like Figure 1 As shown, the present invention provides a crane hook target motion trajectory control system and a control method thereof. At a preset braking speed trajectory, the displacement, speed, and acceleration of the initial state of the hook target motion trajectory planning monitored by the sensor system are used. By introducing a mathematical algorithm and a path planning calculation model, the various parameters of the initial state are deeply calculated and data verified, thereby determining the displacement, speed, and acceleration of the final state of the hook target motion trajectory planning.

[0115] According to the displacement, velocity, acceleration of the initial state of the target motion trajectory planning of the hook, as well as the displacement, velocity, acceleration of the termination of the target motion trajectory planning, comprehensive consideration is given to various factors and various needs in practical applications to maximize the braking requirements of the hook of the crawler crane free drop hook system and achieve the controllability and stability of the target motion trajectory of the crawler crane hook.

[0116] The load weight acting on the wire rope of the crane's free-fall hook system is measured by a force limiter. The acceleration, speed and displacement curves of different tonnages are planned according to the different load masses. During the pedal braking process, the hook falls according to the predetermined speed trajectory curve, reducing the braking impact of the crawler crane's free-fall hook system caused by excessive speed, thereby achieving precise braking during the free-fall hook power acceleration process.

[0117] Figure 2The present invention is a flow chart of the pedal braking speed trajectory control method during the free-falling power acceleration process of the crawler crane; when the hook is lifted to a certain height and stabilized by the reducer drum 13 and the wire rope, the electromagnetic reversing valve 5 controlling the clutch brake chamber 11 and the electromagnetic reversing valve 6 controlling the clutch clutch chamber 12 are both de-energized, so that the pressure of the clutch brake chamber 11 is equal to that of the clutch chamber 12, and the pressure difference is zero. The built-in spring of the clutch 14 uses the preload force to fit the dynamic and static friction plates, and the load is kept stable at a certain height. By controlling the pedal angle, the electric proportional pressure reducing valve 3 outputs to the maximum pressure, the valve core of the electric proportional pressure reducing valve 3 begins to move, the valve port opening increases to the maximum, and the free-fall hook is prepared. The free-fall hook permission switch is turned on. When the controller receives the switch signal, the clutch brake chamber electromagnetic reversing valve 5 is controlled to reverse, thereby further controlling the pressure of the clutch brake chamber 11. The electric control foot pedal and the electric proportional pressure reducing valve are connected by welding. The output pressure of the proportional pressure reducing valve 3 is controlled by changing the pedal angle and then controlling the action of the valve core of the proportional pressure reducing valve. The operator slowly releases the pedal. At this time, the controller will receive the pedal angle change signal of the electric control foot pedal, and the pressure control signal will be output to the electric proportional pressure reducing valve 3, so that the valve back pressure output by the electric proportional pressure reducing valve 3 will be reduced accordingly, the pressure in the clutch brake chamber 11 will be reduced, and the pressure difference between the brake chamber and the clutch chamber will increase, so that the clutch hydraulic cylinder piston will move to one side. The pressure difference between the brake chamber and the clutch chamber will overcome the spring preload to increase the gap between the dynamic and static friction plates of the clutch. When the friction torque formed between the friction plates is not enough to balance the torque generated by the load, the load uses its own gravity to perform free fall motion.

[0118] Figure 3 The acceleration trajectory curve diagram of the crawler crane hook in the pedal braking process during the power acceleration of the present invention stipulates that the three-segment motion curve is used as the trajectory equation of the acceleration of this motion trajectory before the free hook drop action of the crane. According to the actual state, speed and movement direction of the crane hook falling motion, the acceleration transition point of different loads under the free hook drop condition of the crawler crane is calculated, and the three-stage motion of the motion trajectory is taken as the basis for acceleration design. The acceleration trajectory equation of the hook in the pedal braking process during the power acceleration process is as follows:

[0119] jerk=j

[0120] acc=j·t+acc0

[0121] However, special cases may occur during the design of the acceleration trajectory: the hook transitions directly from the acceleration phase to the deceleration phase. This can happen if the acceleration or deceleration is too low or if the target speed value is too high to reach a target position that is very close to the actual position.

[0122] Figure 4This is a curve diagram of the running speed trajectory of the crawler crane hook during the braking process of the power acceleration pedal, which stipulates that before the crane free-falls the hook, three smooth motion curves are used as the trajectory equation of the speed of this motion trajectory. The three-stage motion (acceleration stage-constant speed stage-deceleration stage) is accelerated according to the acceleration planned for the motion trajectory. At this time, the actual running speed of the hook is less than the target motion speed, until it reaches the predetermined speed and starts to fall at a uniform speed, and finally reaches the target position. The deceleration stage, at this time, is greater than the original target running trajectory speed, until the speed is reduced to 0. The running speed trajectory equation in the pedal braking process of the hook power acceleration is as follows:

[0123] jerk=j

[0124]

[0125] Furthermore, during the falling process of the crawler crane, trajectory planning plays an important role in the working condition of the crane. As the hook descends, the length of the drum and the wire rope changes. If the acceleration suddenly increases or decreases, it will bring huge impact and shock to the drum and reducer. In order to avoid this situation, a step-type polynomial speed reference trajectory curve is constructed to ensure that the acceleration is continuous.

[0126] Figure 5 The present invention is a graph of the displacement trajectory of the hook during the braking process of the crawler crane hook power acceleration pedal; it is stipulated that before the crane free-fall hook action, three sections of smooth motion curves are used as the trajectory equation of the displacement of this motion trajectory. In the movement of the crawler crane hook trajectory from static to the target position, the hook can accelerate at the maximum acceleration rate when the heavy load falls, and the actual acceleration level slopes down to zero just before the maximum speed is reached or the distance to the target position becomes too small to further increase the speed. As long as the actual speed slope drops to zero and does not exceed the target position, the hook can continue to move at the maximum speed, and there may be a stage of continuous deceleration afterwards to reduce the actual speed and stop the drum and hook at the target position. The displacement trajectory equation during the pedal braking process of the hook power acceleration is as follows:

[0127] jerk=j

[0128]

[0129] Figure 6The present invention is a curve diagram of the acceleration, speed, and displacement trajectory of the hook during the braking process of the crawler crane hook power accelerator pedal; the control method of the present invention can adjust the speed and smoothness of the operation speed by controlling the maximum value of the acceleration and the time of the acceleration stage, so that the speed trajectory planning of the hook during the braking process is more stable and reliable. In addition, when designing the speed curve, considering the influence of the braking switching between the pedal angle sections, a smooth transition function is introduced into the three-stage speed trajectory curve, and the trajectory equation under the limited performance index is calculated, so that the hook can be controlled within a safe range during the operation process to the greatest extent, and the braking speed of the hook falling movement can be controlled, and the crawler crane hook can achieve smooth braking during the falling process. The acceleration, speed, and displacement trajectory equations of the pedal braking during the power acceleration of the multifunctional crawler crane hook are as follows:

[0130] jerk=j

[0131] acc=j·t+acc0

[0132]

[0133] Figure 7 This is a safe action flow chart of the multifunctional crawler crane hook torque limiter in the present invention; the hook torque limiter control technology is crucial to the crane hook lifting operation, and the force limiter control technology refers to controlling the torque of the hook through multi-sensor fusion calculation to make it work within a safe range. It can ensure in real time that the working device in the current load state operates within a safe range, which plays a vital role in the safety of vehicles, personnel, and construction environment, and achieves precise control through the cantilever weighing sensor and weight feedback device. In the present invention, the load-bearing weight of the hook is specifically monitored and fed back in real time through a cantilever beam weighing sensor, and the data collected by the weighing sensor is fed back to the upper controller, and the current load weight of the hook is displayed on the display screen. At the same time, the controller can accurately monitor the load of the hook and adjust the working parameters according to the weight of the hoisted object. In the actual operation process, the force limiter control technology not only provides the operator with comprehensive and accurate information on the working state of the hook, so that the operator can perform the free-falling hook action within a safe range, but also when the hoisted load is overweight or unbalanced, the system will sound an alarm and automatically reduce the speed and torque of the hook to ensure the safety of the braking during the power acceleration process of the free-falling hook. In addition, the application of the force limiter control technology can also improve the working efficiency of the crane. It monitors the weight and center of gravity of the hoisted object in real time, and the system can quickly adjust the working parameters to achieve stable and efficient operation of the hook, reduce the operator's operating burden, and improve the braking efficiency of the free-falling hook.

[0134] Figure 8The schematic diagram of the multifunctional crawler crane hook operation safety control system in the present invention; in actual lifting operations, various complex factors may be encountered, and the driver operating the crane will enter a normal safe operating state that exceeds the torque limiter system planning. The basic working principle of the torque limiter system of the multifunctional crawler crane is: the main engine collects information from the angle sensor and the tension sensor, and then combines the current working structure parameters of the whole vehicle to calculate whether the current working condition is in a safe state. For example, when the actual working condition lifting torque is lower than 90% of the rated lifting torque, the system operates normally and the whole vehicle displays green operation. When the actual lifting torque is between 90% and 100% of the rated lifting torque, the whole vehicle system displays a yellow warning. When the rated lifting torque exceeds 105% of the calculated planned working condition, the safety control system is triggered to respond, and the system will stop the dangerous operation in time, and record the overload information into the black box for archiving. However, in order to make the crane load within the allowable overload range, that is, when the rated torque does not exceed 105%, the operation is restored to a safe working state. A forced operation function is usually set on crawler cranes. The driver releases the restriction of the torque limiter through the forced function knob or button switch and continues to operate the crane to perform operations.

[0135] The crawler crane free-fall hook system is a hydraulic transmission system involving multiple working conditions and a complex and changeable working environment. Through the present invention, the speed and displacement running trajectory of the hook during the crane power accelerator pedal braking process is planned, and the hook braking speed trajectory path is planned and preventively controlled in real time, so that the hook can achieve smooth braking when lifting loads of different weights; the speed trajectory is planned during the braking process by obtaining the displacement, speed and acceleration of the hook in the initial state and the displacement, speed and acceleration of the terminal state, and the speed curve is divided into three stages of movement. By changing the maximum value of the acceleration and the acceleration time during the braking process, the speed and smoothness of the running speed are adjusted. The method is to divide the hook into five different load weight intervals, and distribute speed operation trajectory curves for loads of different tonnages, so that the hook can be controlled within a safe range during operation to a greater extent, and the braking speed of the hook falling movement can be controlled, and the crawler crane hook can achieve smooth braking at the target position during the falling process; finally, the force limiter control system mainly monitors the hook operation path trajectory, timely understands the movement state of the hook during the falling process, obtains the position information at a certain moment, and facilitates the planning of the path trajectory under the influence of different factors. The crane hook operation trajectory control method and system of the present invention effectively improves the stability and rapidity of the crawler crane's hook trajectory, and increases the practicality of planning the target motion trajectory of the crawler crane.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A crane hook target motion trajectory control system, characterized in that: include: Pressure control system, winch system, power source system and sensor system, including: The pressure control system is connected to the hoisting system at one end and to the oil pump (1) and the hydraulic oil tank (21) at the other end, and is used to monitor the clutch state, control the hoisting speed of the hoisting clutch, and provide real-time feedback of pressure data; The hoisting system is connected to the pressure control system at one end and the power source system at the other end, and is used to adjust and control the movement trajectory and lifting speed of the hook according to the load; The power source system is connected to the hoisting system and is used to provide power for the operation of the crane hook; The sensor system is connected to the controller via a signal transmission line, and is used to detect the pressure and speed data during the operation of the hook, and transmit them to the controller for analysis.

2. The crane hook target motion trajectory control system according to claim 1, characterized in that: The pressure control system comprises: a relief valve (2), an electric proportional pressure reducing valve (3), a power acceleration electromagnetic reversing valve (4), a clutch brake chamber electromagnetic reversing valve (5), and a clutch clutch chamber electromagnetic reversing valve (6), wherein: One end of the overflow valve (2) is connected to the oil pump (1), and the other end is connected to the hydraulic oil tank (21) through a hydraulic pipeline, and is used to control the pressure input from the oil pump (1) to the clutch clutch chamber (12) to be constant pressure; one end of the electric proportional pressure reducing valve (3) is connected to the oil pump (1), and the other end is connected to the clutch brake chamber electromagnetic reversing valve (5), and the electric proportional pressure reducing valve (3) is used to control the pressure of the clutch brake chamber; the clutch brake chamber electromagnetic reversing valve (5) is connected to the clutch brake chamber (11) through a hydraulic pipeline; the clutch clutch chamber electromagnetic reversing valve (6) is connected to the clutch clutch chamber (12).

3. The crane hook target motion trajectory control system according to claim 1, characterized in that: The hoisting system comprises: a clutch brake chamber (11), a clutch clutch chamber (12), a reducer drum (13), a force limiter (15) and a brake (16), wherein: The hoisting clutch comprises a clutch brake chamber (11) and a clutch clutch chamber (12); the hoisting clutch is coaxially connected to a reducer drum (13); a steel wire rope is wound around the reducer drum (13); the end of the steel wire rope is connected to a hook; a force limiter (15) is arranged on the steel wire rope for measuring the tension of the steel wire rope and transmitting the data to a controller; the brake (16) is arranged on the central axis of the reducer drum (13).

4. The crane hook target motion trajectory control system according to claim 1, characterized in that: The power source system comprises: a hydraulic motor (17), a protection circuit balancing valve (18), a hydraulic motor circuit electromagnetic reversing valve (19) and a power source variable pump (20), wherein: The hydraulic motor (17) is coaxially connected to the reducer drum (13) to provide power for lifting the hook; one end of the protection circuit balance valve (18) is connected to the hydraulic motor (17) and the other end is connected to the hydraulic motor circuit electromagnetic reversing valve (19); the power source variable pump (20) is connected to the hydraulic motor circuit electromagnetic reversing valve (19).

5. The crane hook target motion trajectory control system according to claim 1, characterized in that: The sensing system comprises: a clutch brake chamber pressure sensor (7), a clutch clutch chamber pressure sensor (8), an electric proportional pressure reducing valve front pressure sensor (9), an electric proportional pressure reducing valve rear pressure sensor (10) and a reel speed sensor (14), wherein: The clutch brake chamber pressure sensor (7) is arranged between the clutch brake chamber electromagnetic reversing valve (5) and the clutch brake chamber (11) to monitor the pressure change of the clutch brake chamber; the clutch clutch chamber pressure sensor (8) is arranged between the clutch clutch chamber electromagnetic reversing valve (6) and the clutch clutch chamber (12) to monitor the pressure change of the clutch clutch chamber; the electric proportional pressure reducing valve front pressure sensor (9) is arranged between the oil pump (1) and the electric proportional pressure reducing valve (3) to monitor the pressure before pressure reduction; the electric proportional pressure reducing valve rear pressure sensor (10) is arranged between the electric proportional pressure reducing valve (3) and the clutch brake chamber electromagnetic reversing valve (5) to monitor the pressure after pressure reduction; the drum speed sensor (14) is arranged on the reducer drum (13) to monitor the speed of the reducer drum (13).

6. A control method for a crane hook target motion trajectory control system according to any one of claims 1 to 5, characterized in that: The specific steps include: When the crane is in free-falling hook operation, the force limiter (15) collects the pressure exerted on the wire rope, transmits the collected data to the controller and converts it into the weight value of the current load; According to the weight value of the current load, the preset braking speed trajectory is matched, and the controller outputs a speed matching signal, and the crane hook target motion trajectory control system brakes according to the preset braking speed trajectory; The power acceleration electromagnetic reversing valve (4) is used to change the direction, change the angle of the electric control pedal, and control the output pressure of the electric proportional pressure reducing valve (3), so that the pressure monitored by the pressure sensor (10) after the electric proportional pressure reducing valve is equal to the pressure monitored by the clutch brake chamber pressure sensor (7), and the clutch friction plate is controlled to engage and disengage by controlling the pressure difference between the clutch brake chamber (11) and the clutch clutch chamber (12), and the load begins to freely drop the hook; The drum speed sensor (14) monitors the speed of the reducer drum (13) in real time, rotates in the load lowering direction through the hydraulic motor (17), and brakes through the brake (16), so that the load moves according to a preset braking speed trajectory, thereby realizing automatic hook-dropping braking of the crane hook.

7. The control method of the crane hook target motion trajectory control system according to claim 6, characterized in that: The preset braking speed trajectory introduces a smooth transition function into the three-stage speed trajectory curve to calculate the trajectory equation during the hook braking process; When the load of the crane in free-falling hook condition is 0~T1 tons, the target motion speed planning curve designed during the power acceleration of the hook is: Wherein, j represents the change value of the hook acceleration per unit time during the falling process, t represents the pedal brake opening time during the hook power acceleration process, 0<t<t1 represents the first stage of the fall, t1<t<t2 represents the second stage of the fall, t2<t<t3 represents the third stage of the fall, acc0 represents the acceleration value of the hook at the initial moment or position, vel0 represents the velocity value of the hook at the initial moment or position, pos0 represents the displacement value of the hook at the initial moment or position, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage; When the load of the crane under free-fall hook working condition is T1~T2 tons, the target motion speed planning curve designed during the power acceleration of the hook is: in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage; When the load of the crane under free-fall hook working condition is T2-T3 tons, the target motion speed planning curve designed during the power acceleration of the hook is: in, Indicates the acceleration value of the first stage, is the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage; When the load of the crane under free-fall hook condition is T3-T4 tons, the target motion speed planning curve designed during the power acceleration of the hook is: in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage; When the load under the free-falling hook condition of the crane is greater than T4 tons, the target motion speed planning curve designed during the power acceleration of the hook is: in, Indicates the acceleration value of the first stage, Indicates the hook speed value in the first stage, represents the displacement value of the first stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the second stage, represents the displacement value of the second stage, Indicates the acceleration value of the second stage, Indicates the hook speed value in the third stage. Indicates the displacement value of the third stage.

Images