Speed control method and device of crane, computer equipment and crane

Abstract

The invention discloses a speed control method and device of a crane, computer equipment and the crane, and belongs to the technical field of automatic control. The method comprises the following steps: acquiring an actual position and a final position of a controlled object of the crane at the current moment; determining the planned speed of the controlled object based on the actual position and the final position at the current moment; according to the actual speed, fed back at the previous moment, of the controlled object, the planned speed is corrected, and the instruction speed at the current moment is obtained; performing gear discretization processing on the instruction speed at the current moment to obtain a target gear; the gear speed corresponding to the target gear serves as the actual speed of the controlled object at the next moment; the target gear is sent to an executing mechanism of the crane, so that the executing mechanism controls the controlled object to move according to the gear speed corresponding to the target gear; the moved position is used as the actual position of the controlled object at the next moment. The operation efficiency and safety of the tower crane can be remarkably improved.

Description

Technical Field

[0001] The present application belongs to the field of automatic control technology, and in particular, relates to a speed control method, device, computer equipment and crane for a crane. Background Art

[0002] In the field of crane automatic control, common control algorithms mainly include open-loop control, single-loop control and model-based predictive control. Open-loop control is the simplest control method. It outputs fixed operations according to preset instructions, which is simple to implement and low cost.

[0003] Point-by-point planning is common in traditional open-loop control algorithms. In the traditional point-by-point planning mode, for a path with a known starting point and end point, it is necessary to first run a path planning algorithm such as A* (A*search algorithm) or use path linear interpolation for these two points to obtain dozens or even hundreds of path points, and then make the path run in a specific shape. After obtaining the path, speed planning is performed to obtain the trajectory. When planning the path in this way, there is a coupling relationship between every two points, and the amount of calculation is huge, which makes acceleration and deceleration very slow, which in turn leads to low efficiency in lifting tower crane operations. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the related art. To this end, the present application proposes a speed control method, device, computer equipment and crane for crane to improve the efficiency of tower crane operation.

[0005] In a first aspect, the present application provides a speed control method for a crane, the method comprising:

[0006] Obtain the actual position and end position of the controlled object of the crane at the current moment;

[0007] Determining a planned speed of the controlled object based on the actual position at the current moment and the end position;

[0008] According to the actual speed of the controlled object fed back at the last moment, the planned speed is corrected to obtain the command speed at the current moment;

[0009] The command speed at the current moment is subjected to gear discretization processing to obtain a target gear; the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment;

[0010] The target gear is sent to the actuator of the crane, so that the actuator controls the controlled object to move according to the gear speed corresponding to the target gear; the position after the movement is used as the actual position of the controlled object at the next moment.

[0011] According to one embodiment of the present application, before sending the target gear position to the actuator of the crane, the method also includes: obtaining a release length of the controlled object and determining a safety gear position corresponding to the release length; and when the target gear position exceeds the safety gear position, redetermining the target gear position as the safety gear position.

[0012] According to one embodiment of the present application, before sending the target gear to the actuator of the crane, the method also includes: determining a gear switching frequency from the target gear at the previous moment to the target gear at the current moment; when the gear switching frequency exceeds a preset threshold, determining a smaller value between the target gear at the previous moment and the target gear at the current moment; and redetermining the target gear at the current moment as the smaller value.

[0013] According to one embodiment of the present application, before sending the target gear to the actuator of the crane, the method also includes: determining a preset upper gear and a lower gear; when the target gear is higher than the upper gear, redetermining the target gear as the upper gear; and / or, when the target gear is lower than the lower gear, redetermining the target gear as the lower gear.

[0014] In a second aspect, the present application provides a speed control device for a crane, the device comprising:

[0015] An acquisition module is used to acquire the actual position and the terminal position of the controlled object of the crane at the current moment;

[0016] A position module, used to determine the planned speed of the controlled object based on the actual position at the current moment and the end position;

[0017] A speed module, used to correct the planned speed according to the actual speed of the controlled object fed back at the previous moment, to obtain the command speed at the current moment;

[0018] A gear module, used to discretize the command speed at the current moment to obtain a target gear; the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment;

[0019] The output module is used to send the target gear to the actuator of the crane, so that the actuator controls the controlled object to move according to the gear speed corresponding to the target gear; the position after the movement is used as the actual position of the controlled object at the next moment.

[0020] In a third aspect, the present application provides a crane, characterized in that it comprises a speed control device for the crane as described in the second aspect.

[0021] In a fourth aspect, the present application provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the speed control method of the crane as described in the first aspect above is implemented.

[0022] In a fifth aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the speed control method of the crane as described in the first aspect above is implemented.

[0023] In a sixth aspect, the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the speed control method of the crane as described in the first aspect.

[0024] In a seventh aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the speed control method of the crane as described in the first aspect above.

[0025] The speed control method, device, computer equipment, crane, non-transitory computer-readable storage medium, chip and computer program product of the crane provided in the embodiments of the present application obtain the actual position and terminal position of the controlled object of the crane at the current moment, and directly perform speed planning based on the current position and terminal position to determine the ideal speed from the actual position to the terminal position, without the need for complex point-by-point path planning or path interpolation, thereby improving planning efficiency; determine the planned speed of the controlled object through the actual position and terminal position at the current moment, and correct the planned speed according to the actual speed of the controlled object fed back at the previous moment to obtain the command speed at the current moment, and integrate the position planning and speed planning to achieve precise control of the crane's motion process, so that its operation approaching the target position is smoother and overshoot or deviation is avoided; then perform gear discretization processing on the command speed at the current moment to obtain the target gear, and then send the target gear to the crane's actuator to control the movement of the controlled object of the crane, and the gear discretization processing enables the tower crane operation to be accurate and efficient. At the next moment, the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment, and the position after movement is used as the actual position of the controlled object at the next moment, realizing double closed-loop control and improving the anti-disturbance ability of the tower crane system.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 is a schematic diagram of an application scenario of a speed control method for a crane provided in some embodiments of the present application;

[0029] Figure 2 is a flow chart of a speed control method for a crane provided in some embodiments of the present application;

[0030] Figure 3 is a schematic diagram of the operation of gear discretization provided in some embodiments of the present application;

[0031] Figure 4 is a schematic diagram of the principle of a speed control method for a crane provided in some embodiments of the present application;

[0032] Figure 5 is a schematic structural diagram of a speed control device for a crane provided in some embodiments of the present application;

[0033] Figure 6 It is a schematic diagram of the structure of a computer device provided in some embodiments of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0035] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0036] In the following, in conjunction with the accompanying drawings, the speed control method of a crane, the speed control device of a crane, a computer device, and a readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0037] In the field of automatic control of cranes, such as tower cranes or tower cranes, there are obvious defects such as open-loop control and single-loop control. For example, the open-loop control algorithm has the problem of too frequent gear shifting, which not only accelerates the wear of tower crane-related components, reduces the service life of the equipment, and increases maintenance costs, but also frequent gear shifting will affect the stability and continuity of tower crane operation, and have an adverse effect on the accuracy of lifting. In addition, the robustness of the open-loop algorithm is not high enough. When facing the complex and changeable construction site environment and various interference factors, it is difficult to ensure the stability and reliability of the tower crane control system, and it is impossible to always maintain a good working state.

[0038] In view of this, the embodiment of the present application provides a speed control method for a crane based on double closed-loop control, which does not require complex path planning, and directly controls the starting point and the end point in combination with the position and speed. By discretizing the speed into the speed corresponding to the gear position for control, it can replace the tower crane in the traditional crane control scheme, and imitate the operation of the tower crane to realize intelligent automatic control of the running speed of the tower crane, and realize unmanned control or operation of the running speed of the tower crane. It can not only realize some more complex tower crane actions, but also bring more flexibility and accuracy to the construction operation and make the operation safer and more convenient, which can reduce the risk of accidents and make the control of the tower crane more in line with actual needs. This innovative control idea is expected to bring new development opportunities to the field of automatic control of tower cranes and improve the efficiency and safety of tower crane operations.

[0039] The speed control method of the crane can be applied to a computer device, and can be specifically executed by hardware or software in the computer device.

[0040] The crane speed control method provided in the embodiment of the present application may be executed by a computer device or a functional module or functional entity in the computer device that can implement the crane speed control method. The computer device mentioned in the embodiment of the present application includes but is not limited to industrial control equipment, industrial automation equipment, controller, etc. The crane speed control method provided in the embodiment of the present application is described below using a computer device as an example of the execution subject.

[0041] The cranes in the embodiments of the present application include but are not limited to tower cranes, bridge cranes, gantry cranes, and boom type cranes, etc. For example, a tower crane (referred to as a tower crane) is used as an example for description.

[0042] The speed control method of the crane provided in the embodiment of the present application can be applied to Figure 1 In the application scenario shown in Figure 1 As shown, the crane 10 includes a controlled object 110. Taking a tower crane as an example, the controlled object 110 is generally a hook, etc. The crane 10 to which the embodiment of the present application is applicable may be a manned crane or an unmanned crane. The encoder in the crane 10 may be connected to the computer device 20 for communication via a wired communication network or a wireless communication network. The computer device 20 may be set on the crane 10, or the crane 10 may be remotely controlled.

[0043] Among them, the computer device can be a terminal device or a server. The terminal device can be, but is not limited to, one or more of various desktop computers, laptops, smart phones, tablet computers, Internet of Things devices, or portable wearable devices, etc. The Internet of Things device can be one or more of smart speakers, smart TVs, smart air conditioners, or smart car-mounted devices, etc. The portable wearable device can be one or more of a smart watch, a smart bracelet, or a head-mounted device, etc. The server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, and big data and artificial intelligence platforms.

[0044] like Figure 2 As shown, the speed control method of the crane includes: steps 210 to 250.

[0045] Step 210: Obtain the actual position and terminal position of the controlled object of the crane at the current moment.

[0046] The controlled object of the crane refers to the crane hook, etc. The actual position of the controlled object at the initial moment is the preset initial position, for example, it can be an initial position at a certain distance from the horizontal plane, etc. The final position is the position to which the controlled object will move. For example, in a cargo handling task, the crane needs to move the cargo from position A to position B, and position B is the final position.

[0047] Specifically, the computer device can obtain the actual position of the controlled object at the current moment through the encoder on the crane. The encoder or sensor converts the mechanical movement (such as rotation, displacement, etc.) of the controlled object into an electrical signal and feeds it back to the computer device. In the embodiment of the present application, the data fed back by the encoder or sensor is received and processed by the computer device to control the speed of the controlled object. The end position can be predetermined or set in real time according to the on-site situation.

[0048] Step 220: Determine the planned speed of the controlled object based on the actual position at the current moment and the end position.

[0049] The computer device determines the remaining distance to the terminal position based on the difference between the actual position of the controlled object at the current moment and the terminal position. Based on the remaining distance, the computer device can plan an ideal speed, which is the planned speed. Exemplarily, the computer device can pre-set the corresponding relationship between the remaining distance and the planned speed, such as setting a relationship table between the remaining distance and the planned speed, so as to match the corresponding planned speed according to the remaining distance. Alternatively, the computer device can also perform numerical calculations based on the remaining distance and given parameters to obtain the planned speed of the controlled object.

[0050] The planned speed is dynamically adjusted as the remaining distance changes to ensure that the hoisted object gradually and smoothly approaches the target position. For example, the farther away from the end position, the faster the planned speed; the closer to the end position, the slower the planned speed, which can effectively reduce the running time and improve the running efficiency.

[0051] Step 230: According to the actual speed of the controlled object fed back at the previous moment, the planned speed is corrected to obtain the command speed at the current moment.

[0052] The planned speed is the ideal speed of the controlled object under ideal conditions, but in actual situations it may be limited by the site and other conditions. For example, too high a speed may pose a safety hazard. Therefore, after obtaining the planned speed, the computer equipment also needs to correct the planned speed according to the actual situation to avoid sudden and drastic changes in speed.

[0053] To this end, the computer device introduces feedback of the actual speed at the previous moment, and can dynamically adjust the speed based on the planned speed to obtain the command speed at the current moment, thereby making the tower crane operation smoother. For example, the computer device can set a weight for the feedback of the actual speed at the previous moment, and perform a weighted average based on the actual speed at the previous moment and the planned speed to obtain the command speed at the current moment. For another example, the computer device can calculate the adjustment amount for the planned speed based on the actual speed at the previous moment, and change the planned speed by the adjustment amount to obtain the command speed at the current moment.

[0054] Step 240: discretize the command speed at the current moment into gears to obtain a target gear; the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment.

[0055] The computer device can obtain multiple pre-set gears. The gears are divided according to the control requirements of the tower crane, usually set to multiple gears such as low, medium, and high, or 1st gear, 2nd gear, 3rd gear, 4th gear, 5th gear, etc. The system can set the upper / lower limit of the gear, or the speed range of the highest / lowest gear, etc., to ensure the safety of the tower crane operation.

[0056] After obtaining the command speed, the computer device discretizes the command speed and discretizes the continuous speed value into corresponding gears. Different gears correspond to different speed ranges. Generally speaking, low-speed gears are used to make the controlled object approach a certain position accurately, while high-speed gears are used to make the controlled object move quickly at a distance from a certain position. Through gear discretization, the same or adjacent gears can be allowed to be controlled when the speed does not change much, avoiding the vibration and instability caused by frequent gear shifting and ensuring smooth operation.

[0057] In some embodiments, the target gear corresponds to a gear speed, and the computer device can determine that the target gear matches the command speed based on the error between the command speed at the current moment and the gear speed when the error is less than a preset range. The gear speed is used as speed feedback and as the actual speed of the controlled object at the next moment.

[0058] In some embodiments, the target gear corresponds to a range of gear speed values, and the computer device can determine the corresponding target gear according to the range of values ​​that the command speed at the current moment falls into. When performing speed feedback, the lowest value, the highest value, or the average value of the range of values ​​can be used as the actual speed of the controlled object at the next moment.

[0059] Step 250: Send the target gear position to the actuator of the crane, so that the actuator controls the controlled object to move according to the gear speed corresponding to the target gear position; the position after the movement is used as the actual position of the controlled object at the next moment.

[0060] After determining the target gear position, the computer device sends the target gear position to the actuator of the tower crane. The actuator includes but is not limited to one or more of the lifting mechanism, the slewing mechanism, the luffing mechanism, etc. After receiving the target gear position, the actuator outputs the speed corresponding to the target gear position to the controlled object through the frequency converter, motor or other driver, so that the controller moves.

[0061] After the actuator controls the controlled object to move according to the target gear, the actual position of the controlled object is also updated. The actual position after the movement is fed back to the control system as the actual position of the next cycle, and re-enters the next control cycle. Therefore, by cyclically updating the position feedback information, the control system continuously adjusts the gear and speed, gradually approaches the terminal position, and ensures the accuracy of the tower crane operation. In this process, through the feedback speed and position signals, the system can detect possible abnormal conditions in real time (such as vibration caused by wind load or other interference), and adjust the gear or dynamically limit the speed when necessary to cope with external disturbances.

[0062] The speed control method of the crane provided in the embodiment of the present application obtains the actual position and the terminal position of the controlled object of the crane at the current moment, and directly plans based on the current position and the terminal position, without the need for complex point-by-point path planning or path interpolation, thereby improving planning efficiency; the planned speed of the controlled object is determined by the actual position and the terminal position at the current moment, and the planned speed is corrected according to the actual speed of the controlled object fed back at the previous moment to obtain the command speed at the current moment, and the position planning and speed planning are integrated to achieve precise control of the crane's motion process, so that the operation of approaching the target position is smoother and avoids overshoot or deviation; the target gear is obtained by discretizing the command speed at the current moment, and the target gear is sent to the actuator of the crane to control the movement of the controlled object of the crane. The gear discretization processing can reduce the problem of frequent gear shifting, avoid system instability caused by too fast gear switching, effectively reduce equipment wear, and extend the service life of crane components. At the next moment, the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment, and the position after movement is used as the actual position of the controlled object at the next moment, thereby realizing double closed-loop control and improving the anti-interference ability of the tower crane system. Even in complex construction environments, the stability and control effect of the system can be guaranteed, which significantly improves the applicability of automated tower cranes in changing environments. The double closed-loop control proposed in this application does not require complex hardware configuration or algorithm models, is easy to install and debug, and is easy to adjust and maintain. Flexible parameter settings can be made according to the specific characteristics and working requirements of different types of cranes, so as to better adapt to various types of cranes and improve the versatility and adaptability of crane automatic driving systems.

[0063] In some embodiments, based on the actual position and the end position at the current moment, the planned speed of the controlled object is determined, including: determining the remaining distance between the actual position and the end position, and fusing the remaining distance and the position proportional coefficient to obtain an intermediate value; and using the first-order derivative of the intermediate value as the planned speed.

[0064] Specifically, the computer device calculates the difference between the actual position and the end position as the remaining distance between the two to guide the subsequent speed planning. The computer device multiplies the remaining distance by the position scale coefficient through the preset position scale coefficient to obtain an intermediate value. The size of the intermediate value changes dynamically. The longer the distance, the larger the intermediate value is, and it gradually decreases as the distance decreases, so as to achieve the gradual deceleration of the controlled object, thereby achieving the effect of smoothly approaching the target.

[0065] The position proportionality coefficient is a preset parameter used to adjust the smoothness and stability of the tower crane approaching the target position. For example, the position proportionality coefficient can be debugged on-site by field engineers according to the physical characteristics of different tower cranes to find a more suitable value.

[0066] Then, the computer device calculates the first-order derivative of the intermediate value, which represents the rate of change and is used as the current planned speed. The planned speed obtained by the first-order derivative can smoothly decelerate the controlled object when it approaches the target position to prevent overshoot. This first-order derivative is actually equivalent to the conversion from position to speed, making the movement of the controlled object more natural and smooth.

[0067] On the basis of real-time feedback from the system, the computer equipment can periodically calculate and adjust the planned speed according to the continuously updated actual position. That is, in each control cycle, the remaining distance, the intermediate value after proportional adjustment and its derivative are recalculated based on the updated current position, so as to ensure that the movement speed of the controlled object is adapted to the remaining distance, thereby ensuring the real-time and accuracy of the tower crane operation.

[0068] Through the above embodiment, through dynamic adjustment of the intermediate value and derivative calculation, smooth deceleration of the controlled object when approaching the target position can be achieved, overshoot and vibration caused by too fast approach can be avoided, and the accuracy and smoothness of the operation can be improved. In addition, this method effectively simplifies the speed planning process of the tower crane, and can automatically adjust the speed according to the real-time distance between the current position and the target position without relying on complex path algorithms, thereby greatly improving the efficiency of tower crane operations.

[0069] In some embodiments, the planned speed is corrected according to the actual speed of the controlled object fed back at the previous moment to obtain the command speed at the current moment, including: determining the speed difference between the actual speed and the planned speed according to the actual speed of the controlled object fed back at the previous moment; fusing the speed difference and the speed proportional coefficient to obtain the command speed at the current moment.

[0070] The computer device can obtain the actual speed of the controlled object (such as the hook) of the tower crane at the last moment through an encoder or other speed sensors. Then, the computer device calculates the difference between the actual speed at the last moment and the planned speed at the current moment to reflect the difference between the planned speed and the actual speed. By reducing this difference, the controlled object gradually approaches the planned speed to ensure the stability of the control. The computer device multiplies the speed difference by the speed proportionality coefficient through a preset speed proportionality coefficient to obtain the command speed at the current moment.

[0071] The speed proportional coefficient is used to adjust the sensitivity of speed adjustment. The larger the value, the faster the control system responds to the speed difference; the smaller the value, the smoother the system adjustment. The proportional coefficient can be set according to the model and load requirements of the tower crane to meet different control accuracy requirements.

[0072] In each control cycle, the computer device recalculates the speed difference based on the latest actual speed and planned speed and updates the command speed.

[0073] Through the above-mentioned embodiments, speed feedback is combined with proportional control to realize closed-loop control and feedback, so that the tower crane gradually approaches the planned speed, avoids instability or vibration caused by sudden changes in speed, and makes the tower crane operation more stable and precise. Through periodic adjustment, it is ensured that the tower crane control object gradually approaches the target position, while avoiding excessive fluctuations and vibrations, and achieving smoother speed control. Therefore, the embodiment of the present application can utilize the real-time value returned by the encoder, and combine it with the above-mentioned proportional control mechanism to make the speed inversely proportional to the position, so that the tower crane can plan a larger speed at a distance from the end point, thereby enabling the tower crane to quickly approach the end point, effectively reducing the operating time and improving the operating efficiency. In addition, the design structure of this solution is simple and has good adaptability and scalability.

[0074] When determining the gear position, in addition to the position data and speed data of the controlled object, it is also necessary to consider the on-site conditions or some other restrictive conditions. For example, in some tower crane operations, if the gear position is too high and the speed is too fast, it will cause serious shaking, thus causing serious safety hazards. To this end, in some embodiments, before sending the target gear position to the actuator of the crane, the above method also includes: obtaining the release length of the controlled object and determining the safe gear position corresponding to the release length; when the target gear position exceeds the safe gear position, the target gear position is re-determined as the safe gear position.

[0075] In each control cycle, the computer device obtains the release length of the controlled object through sensors or encoders. The release length of the controlled object refers to the current extension length of the sling or cable, such as the current sling has been extended by 20 meters. The release length reflects the height change of the hook relative to the lifting position of the tower crane. The larger the release length, the closer the hook is to the ground and the higher the load.

[0076] The computer device determines the safety gear corresponding to the release length according to the current release length and with reference to a preset safety gear table or calculation formula.

[0077] The safety gear is usually set to a lower gear level as the release length increases. That is, when the hook position is high, that is, the release length is short, a higher gear can be used; when the release length is long and the hook position is low, a lower gear needs to be used to ensure the safety of the load and the sling.

[0078] Then, the computer device compares the target gear calculated in the previous step with the safety gear corresponding to the current release length. If the target gear exceeds the safety gear, that is, the operating speed of the controlled object of the tower crane may exceed the safety limit and there is an operational risk, the computer device will further limit the target gear to prevent accidents caused by too fast descent or lifting.

[0079] Exemplarily, when the target gear is higher than the safety gear, the system automatically adjusts the target gear to the safety gear to ensure that the operation is within a predetermined safety range.

[0080] Through the above-mentioned embodiments, automatic gear limitation of the controlled object is realized, which can effectively prevent the tower crane from running beyond the safe speed and gear under special circumstances such as high load and low release length, thereby ensuring the reliability and safety of operation. At the same time, it also makes the tower crane run more smoothly at a larger release length, reduces unnecessary impact or shaking, and makes the tower crane operation process more stable.

[0081] For some old cranes or cranes with poor performance, the design of their inverters may not be able to withstand fast and frequent gear changes. Excessive frequency will cause load fluctuations, exceeding the load response range of the inverter. For example, if the inverter of an old crane switches gears more than 5 times per second (that is, the frequency exceeds 5Hz), it may cause the inverter to report a fault. In addition, rapid gear switching increases the wear of mechanical parts and makes the motor load unstable, while frequent command changes will increase error accumulation, resulting in the control system being unable to accurately execute each switch, which may trigger the fault protection mechanism.

[0082] In view of this, in some embodiments, before sending the target gear to the actuator of the crane, the above method also includes: determining the gear switching frequency from the target gear at the previous moment to the target gear at the current moment; when the gear switching frequency exceeds a preset threshold, determining the smaller value between the target gear at the previous moment and the target gear at the current moment; and redetermining the target gear at the current moment as a smaller value.

[0083] In each control cycle, the computer device obtains the target gear position at the previous moment and the target gear position at the current moment, and calculates the switching frequency from the gear position at the previous moment to the gear position at the current moment, that is, the number of gear changes per unit time, as the basis for evaluating the gear switching frequency. The computer device then compares the calculated gear switching frequency with the preset threshold. The preset threshold is usually set based on the mechanical performance and safety requirements of the tower crane equipment to prevent excessive gear switching from causing unstable control or excessive equipment wear.

[0084] If the gear switching frequency is lower than the preset threshold, the computer device maintains the current target gear; if the gear switching frequency exceeds the preset threshold, the system will trigger the gear restriction measure to keep the lower gear unchanged to reduce the adverse effects of frequent switching and ensure that the tower crane operates at a safe speed under the current load conditions.

[0085] Through the above embodiments, by limiting the gear switching frequency, the vibration and instability of the tower crane during high-frequency gear shifting are reduced, the stability of the tower crane operation is guaranteed, and the accuracy and continuity of the tower crane operation are improved. In addition, by avoiding frequent gear shifting, the wear on components such as motors and gears is reduced, thereby extending the service life of the equipment and reducing maintenance costs.

[0086] Of course, depending on the actual situation, the tower crane can also be pre-set with upper and lower gears. For example, in a specific operation scenario, if the speed of gear 1 is too slow, it will affect the operation efficiency of the tower crane, so the engineer can set the lowest gear to gear 2. For another example, if the speed of gear 5 is too fast, it will cause the load to tip over, so the engineer can set the highest gear to gear 4, and so on.

[0087] To this end, in some embodiments, before sending the target gear to the actuator of the crane, the method further includes: determining a preset upper gear and a lower gear; when the target gear is higher than the upper gear, redetermining the target gear as the upper gear; and / or, when the target gear is lower than the lower gear, redetermining the target gear as the lower gear.

[0088] Computer equipment can pre-set upper and lower gears according to the tower crane model, operating requirements and safety regulations. The upper gear is usually based on the safety limit of the tower crane structure to prevent the hoist from exceeding the safe load when running at high speed; the lower gear is set to the lowest gear for normal operation of the equipment to prevent the system from reducing operating efficiency or poor load control due to too low gear.

[0089] In each control cycle, the computer device determines the target gear according to the current position and planned speed, compares the target gear with the preset upper and lower gear limits, and determines whether the target gear exceeds the safety range.

[0090] If the current target gear is higher than the upper gear, the target gear will be reset to the upper gear to ensure that the controlled object runs within a safe speed range and avoid operational risks caused by a high gear.

[0091] If the target gear is lower than the lower limit gear, the target gear will be reset to the lower limit gear to ensure the minimum operating efficiency and load control capability of the tower crane.

[0092] Therefore, the target gear position after safety adjustment will be output to the actuator to control the actual movement speed of the tower crane. Through gear monitoring and adjustment, it is ensured that the actual operating gear position of the tower crane is always within the safe range and can adapt to different on-site working conditions.

[0093] Through the above embodiment, by setting the upper gear limit and the lower gear limit, it is ensured that the tower crane always operates within a safe gear range to avoid operating risks caused by too high or too low gears.

[0094] In some embodiments, the method further includes: calibrating multiple preset gears of the crane to obtain a gear speed table; the gear speed table records multiple preset gears and gear speed ranges corresponding to the multiple preset gears. Accordingly, the command speed at the current moment is discretized to obtain a target gear, including: searching the gear speed table according to the command speed at the current moment to obtain a matching preset gear, and using the matching preset gear as the target gear.

[0095] The computer equipment can pre-calibrate multiple preset gears of the tower crane, that is, obtain the operating speed range of each gear through actual testing or calculation, and generate a complete gear speed table. Figure 3 As shown in the figure, the gear speed table records each preset gear (such as 1st gear, 2nd gear, 3rd gear, etc.) and its corresponding speed range. For example, the corresponding speed of 1st gear is 0-0.3m / s, 2nd gear is 0.3-0.6m / s, and so on. The calibration work is carried out according to factors such as tower crane model, load characteristics, mechanical performance, etc. to ensure that the speed range setting meets the actual operation requirements.

[0096] After calculating the current command speed, Figure 3 As shown, the computer device takes the command speed as input and searches for the preset gear in the gear speed table by table lookup to match the most suitable gear. The search process follows the matching principle, that is, a speed range that includes the command speed is found in the gear speed table, and the gear corresponding to the speed range is determined as the target gear. As a result, the computer device uses the preset gear matched in the gear speed table as the target gear and outputs it to the actuator.

[0097] Exemplarily, if the command speed exceeds the highest or lowest speed range in the gear speed table, the computer device automatically sets the target gear to the upper limit gear or the lower limit gear to prevent the speed of the controlled object from exceeding the safe range.

[0098] Through the above-mentioned embodiments, through the calibration and search matching mechanism of the gear speed table, the most suitable gear can be selected according to the command speed calculated in real time, which ensures the accuracy of speed control and provides support for efficient and accurate tower crane operation. In addition, by discretizing the command speed into gears, the continuous command speed is mapped to discrete gears, which reduces the system calculation burden, simplifies the control logic, and realizes accurate gear control. Among them, the gear speed range in the gear speed table is reasonably divided, which can avoid unstable operation and equipment wear caused by frequent gear switching, making the tower crane operation more stable and reliable.

[0099] In a specific implementation scenario, combined with Figure 4According to the double closed-loop control principle shown, the speed control method of the crane provided in the embodiment of the present application may include the following steps: the computer device obtains the actual position D1 and the terminal position D2 of the controlled object of the crane at the current moment, and determines the remaining distance between the actual position and the terminal position, that is, (D2-D1). According to the preset position proportional coefficient kp1, the computer device multiplies the remaining distance by the position proportional coefficient kp1 to obtain an intermediate value. The first-order derivative of the intermediate value is the planned speed vel1. That is, vel1=|(D2-D1)|*kp1. Then, the computer device determines the speed difference between the actual speed and the planned speed, that is, |(vel2-vel1)|, based on the actual speed of the controlled object fed back at the previous moment, and then multiplies the speed difference by the preset speed proportional coefficient kp2 to obtain the command speed vel3 at the current moment. That is, vel3=|(vel2-vel1)|*kp2. Then, the computer device discretizes the command speed vel3 at the current moment to obtain the target gear, and determines whether to modify the target gear according to one or more constraints. If modification is required, the target gear is re-determined. After that, the computer device sends the target gear to the actuator of the crane to control the controlled object to move according to the gear speed corresponding to the target gear.

[0100] At the next moment or the next control cycle, the computer device uses the gear speed vel2' corresponding to the target gear as the actual speed vel2 of the controlled object at the next moment, and uses the moved position D1' as the actual position D1 of the controlled object at the next moment, and performs the next speed control... until the controlled object reaches the terminal position D2. Thus, the double closed-loop automatic control process of the tower crane is completed.

[0101] The crane speed control method provided in the embodiment of the present application can be executed by a crane speed control device. The crane speed control method is executed by a crane speed control device as an example to illustrate the crane speed control device provided in the embodiment of the present application.

[0102] The present application also provides a speed control device for a crane. Figure 5 As shown, the speed control device of the crane includes: an acquisition module 510, a position module 520, a speed module 530, a gear module 540 and an output module 550. Among them:

[0103] The acquisition module 510 is used to acquire the actual position and the terminal position of the controlled object of the crane at the current moment.

[0104] The position module 520 is used to determine the planned speed of the controlled object based on the actual position at the current moment and the end position.

[0105] The speed module 530 is used to correct the planned speed according to the actual speed of the controlled object fed back at the previous moment to obtain the command speed at the current moment.

[0106] The gear module 540 is used to discretize the command speed at the current moment to obtain the target gear; the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment.

[0107] The output module 550 is used to send the target gear position to the actuator of the crane, so that the actuator controls the controlled object to move according to the gear speed corresponding to the target gear position; the position after movement is used as the actual position of the controlled object at the next moment.

[0108] The speed control device of the crane provided in the embodiment of the present application obtains the actual position and the terminal position of the controlled object of the crane at the current moment, and directly plans based on the current position and the terminal position, without the need for complex point-by-point path planning or path interpolation, thereby improving planning efficiency; the planned speed of the controlled object is determined by the actual position and the terminal position at the current moment, and the planned speed is corrected according to the actual speed of the controlled object fed back at the previous moment to obtain the command speed at the current moment, and the position planning and speed planning are integrated to achieve precise control of the crane's motion process, so that the operation of approaching the target position is smoother and overshoot or deviation is avoided; the target gear is obtained by discretizing the command speed at the current moment, and the target gear is sent to the actuator of the crane to control the movement of the controlled object of the crane. The gear discretization processing can reduce the problem of frequent gear shifting, avoid system instability caused by too fast gear switching, effectively reduce equipment wear, and extend the service life of crane components. At the next moment, the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment, and the position after movement is used as the actual position of the controlled object at the next moment, thereby realizing double closed-loop control and improving the anti-interference ability of the tower crane system. Even in complex construction environments, the stability and control effect of the system can be guaranteed, which significantly improves the applicability of automated tower cranes in changing environments. The double closed-loop control proposed in this application does not require complex hardware configuration or algorithm models, is easy to install and debug, and is easy to adjust and maintain. Flexible parameter settings can be made according to the specific characteristics and working requirements of different types of cranes, so as to better adapt to various types of cranes and improve the versatility and adaptability of crane automatic driving systems.

[0109] In some embodiments, the position module is further used to determine the remaining distance between the actual position and the end position; fuse the remaining distance and the position scale coefficient to obtain an intermediate value, and use the first-order derivative of the intermediate value as the planned speed.

[0110] In some embodiments, the speed module is also used to determine the speed difference between the actual speed and the planned speed based on the actual speed of the controlled object fed back at the previous moment; and to fuse the speed difference and the speed proportional coefficient to obtain the command speed at the current moment.

[0111] In some embodiments, the above-mentioned device also includes a limiting module, which is used to obtain the release length of the controlled object and determine the safety gear corresponding to the release length; when the target gear exceeds the safety gear, the target gear is re-determined as the safety gear.

[0112] In some embodiments, the limiting module is also used to determine the gear switching frequency from the target gear at the previous moment to the target gear at the current moment; when the gear switching frequency exceeds a preset threshold, determine the smaller value between the target gear at the previous moment and the target gear at the current moment; and redetermine the target gear at the current moment as a smaller value.

[0113] In some embodiments, the limiting module is also used to determine a preset upper limit gear and a lower limit gear; when the target gear is higher than the upper limit gear, the target gear is redetermined as the upper limit gear; and / or, when the target gear is lower than the lower limit gear, the target gear is redetermined as the lower limit gear.

[0114] In some embodiments, the device further includes a calibration module, which is used to calibrate multiple preset gears of the crane to obtain a gear speed table; the gear speed table records multiple preset gears and gear speed ranges corresponding to the multiple preset gears. Accordingly, the gear module is also used to search the gear speed table according to the command speed at the current moment to obtain a matching preset gear, and use the matching preset gear as the target gear.

[0115] The speed control device of the crane in the embodiment of the present application can be a computer device, or a component in the computer device, such as an integrated circuit or a chip. The computer device can be a terminal, or other devices other than a terminal. Exemplarily, the computer device can be a mobile phone, a tablet computer, a laptop computer, a PDA, a vehicle-mounted computer device, a mobile Internet device (Mobile Internet Device, MID), an augmented reality (Augmented Reality, AR) / virtual reality (Virtual Reality, VR) device, a robot, a wearable device, an ultra-mobile personal computer (Ultra-mobile Personal Computer, UMPC), a netbook or a personal digital assistant (Personal Digital Assistant, PDA), etc. It can also be a server, a network attached storage (Network Attached Storage, NAS), a personal computer (Personal Computer, PC), a television (Television, TV), a teller machine or a self-service machine, etc., which is not specifically limited in the embodiment of the present application.

[0116] The speed control device of the crane in the embodiment of the present application may be a device having an operating system. The operating system may be a Microsoft (Windows) operating system, an Android (Android) operating system, an IOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0117] The speed control device of the crane provided in the embodiment of the present application can achieve Figure 1 To avoid repetition, the various processes implemented by the method embodiment are not described here.

[0118] In some embodiments, Figure 6 As shown, the embodiment of the present application also provides a computer device 600, including a processor 601, a memory 602, and a computer program stored in the memory 602 and executable on the processor 601. When the program is executed by the processor 601, each process of the above-mentioned crane speed control method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0119] It should be noted that the computer device in the embodiment of the present application includes the above-mentioned mobile computer device and non-mobile computer device.

[0120] The embodiment of the present application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various processes of the above-mentioned crane speed control method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0121] The processor is the processor in the computer device in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0122] An embodiment of the present application also provides a computer program product, including a computer program, which implements the speed control method of the crane when executed by a processor.

[0123] The processor is the processor in the computer device in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0124] The embodiment of the present application further provides a chip, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned crane speed control method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0125] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0126] The embodiment of the present application also provides a crane, which can apply the speed control method of the crane. Exemplarily, the crane includes at least a sensor, an encoder, and a lifting mechanism. Exemplarily, the crane can also include an electrical control system, which is communicatively connected to the computer device.

[0127] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0128] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the relevant technology, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0129] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0130] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0131] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A speed control method for a crane, characterized in that: The method comprises: Obtain the actual position and end position of the controlled object of the crane at the current moment; Determining a planned speed of the controlled object based on the actual position at the current moment and the end position; According to the actual speed of the controlled object fed back at the last moment, the planned speed is corrected to obtain the command speed at the current moment; The command speed at the current moment is subjected to gear discretization processing to obtain a target gear; the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment; The target gear is sent to the actuator of the crane, so that the actuator controls the controlled object to move according to the gear speed corresponding to the target gear; the position after the movement is used as the actual position of the controlled object at the next moment.

2. The method according to claim 1, characterized in that The determining the planned speed of the controlled object based on the actual position at the current moment and the end position includes: determining a remaining distance between the actual position and the end position; The remaining distance and the position proportional coefficient are integrated to obtain an intermediate value, and the first-order derivative of the intermediate value is used as the planning speed.

3. The method according to claim 1, characterized in that The step of correcting the planned speed according to the actual speed of the controlled object fed back at the previous moment to obtain the command speed at the current moment includes: Determine the speed difference between the actual speed and the planned speed according to the actual speed of the controlled object fed back at the last moment; The speed difference and the speed proportional coefficient are integrated to obtain the command speed at the current moment.

4. The method according to claim 1, characterized in that: Before sending the target gear position to the actuator of the crane, the method further includes: Acquiring a release length of the controlled object and determining a safety gear position corresponding to the release length; When the target gear position exceeds the safety gear position, the target gear position is re-determined as the safety gear position.

5. The method according to claim 1, characterized in that Before sending the target gear position to the actuator of the crane, the method further includes: Determining a gear switching frequency from a target gear at a previous moment to a target gear at a current moment; When the gear switching frequency exceeds a preset threshold, determining a smaller value between the target gear at the previous moment and the target gear at the current moment; The target gear position at the current moment is redetermined as the smaller value.

6. The method according to claim 1, characterized in that Before sending the target gear position to the actuator of the crane, the method further includes: Determine the preset upper and lower gear limits; In the case where the target gear position is higher than the upper limit gear position, re-determining the target gear position as the upper limit gear position; and / or When the target gear position is lower than the lower limit gear position, the target gear position is re-determined as the lower limit gear position.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: Calibrate multiple preset gears of the crane to obtain a gear speed table; the gear speed table records the multiple preset gears and the gear speed ranges corresponding to the multiple preset gears respectively; The step of performing gear discretization processing on the command speed at the current moment to obtain a target gear comprises: The gear speed table is searched according to the command speed at the current moment to obtain a matching preset gear, and the matching preset gear is used as the target gear.

8. A speed control device for a crane, characterized in that: include: An acquisition module is used to acquire the actual position and the terminal position of the controlled object of the crane at the current moment; A position module, used to determine the planned speed of the controlled object based on the actual position at the current moment and the end position; A speed module, used to correct the planned speed according to the actual speed of the controlled object fed back at the previous moment, to obtain the command speed at the current moment; A gear module, used to discretize the command speed at the current moment to obtain a target gear; the gear speed corresponding to the target gear is used as the actual speed of the controlled object at the next moment; The output module is used to send the target gear to the actuator of the crane, so that the actuator controls the controlled object to move according to the gear speed corresponding to the target gear; the position after the movement is used as the actual position of the controlled object at the next moment.

9. A crane, characterized in that: The crane comprises the speed control device of the crane according to claim 8.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the speed control method of the crane according to any one of claims 1 to 7 is implemented.

Images