Crane and control method thereof

Abstract

The embodiment of the present application provides a crane and a control method thereof, wherein the crane comprises a driving motor, a control unit, a storage unit and a working unit; the driving motor is used for providing power for the working unit, and outputs a pulse signal corresponding to a position change of the working unit under the action of the power provided by the driving motor; the control unit is used for receiving and counting a first pulse number of the pulse signal, modifying a second pulse number corresponding to a position of the working unit before the position change occurs based on a level change of the pulse signal and the first pulse number, and controlling the position of the working unit based on a comparison result of the modified second pulse number and a running limit pulse number stored in the storage unit in advance. The crane provided by the embodiment of the present application can realize stroke limiting without using additional equipment, and resource consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of crane control technology, specifically to a crane and its control method. Background Technology

[0002] Cranes, as material lifting and handling equipment, are widely used in industrial production, warehousing and logistics, construction and other scenarios. Travel limit is the core function of safe operation of cranes. It is necessary to accurately limit the extreme positions of the crane's lifting and lowering to prevent safety accidents such as equipment collisions and material falling caused by overtravel. At the same time, precise distance control can improve the operating accuracy and efficiency of cranes.

[0003] In related technologies, stroke limits (limiting the crane's lifting and lowering limits) are achieved by adding extra equipment. However, this method increases resource waste due to the need for additional equipment. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a crane and its control method to reduce resource waste rate.

[0005] In a first aspect, embodiments of the present invention provide a crane, comprising: Drive motor, control unit, storage unit, and working unit; The drive motor is used to provide power to the working unit and to output the pulse signal corresponding to the position change of the working unit under the power it provides; The control unit is used to receive and count the first pulse count of the pulse signal, modify the second pulse count corresponding to the position of the working unit before the position change based on the level change of the pulse signal and the first pulse count, and control the position of the working unit based on the comparison result between the modified second pulse count and the pre-stored operating limit pulse count in the storage unit.

[0006] In a second aspect, embodiments of the present invention provide a control method for a crane, applied to a control unit of the crane as described in the first aspect, comprising: Receive and count the first pulse count of the pulse signal; Based on the level change of the pulse signal and the first pulse count, the second pulse count corresponding to the position of the working unit before the position change occurs is modified; The position of the working unit is controlled based on the comparison between the modified second pulse number and the pre-stored operating limit pulse number in the storage unit of the crane.

[0007] The crane provided in this embodiment of the invention includes: a drive motor, a control unit, a storage unit, and a working unit; the drive motor is used to provide power to the working unit and output a pulse signal corresponding to the position change of the working unit under the power provided; the control unit is used to receive and count a first pulse number of the pulse signal, modify a second pulse number corresponding to the position of the working unit before the position change based on the level change of the pulse signal and the first pulse number; and control the position of the working unit based on the comparison result between the modified second pulse number and the operating limit pulse number pre-stored in the storage unit.

[0008] The crane provided in this embodiment of the invention includes a drive motor, a control unit, a storage unit, and a working unit. The drive motor provides power to the working unit and simultaneously outputs a pulse signal corresponding to a position change of the working unit under the provided power. That is, while providing power to the working unit, the drive motor also monitors the position change of the working unit and outputs the position change as an electrical signal, i.e., a pulse signal. The control unit receives and counts a first pulse count of the pulse signal, modifies a second pulse count corresponding to the position of the working unit before the position change based on the level change of the pulse signal and the first pulse count, and controls the position of the working unit based on a comparison between the modified second pulse count and a pre-stored operating limit pulse count in the storage unit. As can be seen, the crane provided in this embodiment of the invention can convert the position change of the working unit into a pulse signal and output it through a drive motor that provides power to the working unit. The control unit can receive the pulse signal, count the first pulse number of the pulse signal, and then modify the second pulse number based on the level change and the first pulse number. The second pulse number corresponds to the position of the working unit before the position change. The control unit compares the second pulse number with the pre-stored operating limit pulse number and controls the position of the working unit based on the comparison result. In other words, the crane provided in this embodiment of the invention can limit the working unit based on the electrical signal converted from the position change of the crane. This process uses the original crane components without adding any additional equipment, thus improving resource utilization and reducing resource waste. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0010] Figure 1This is a schematic diagram of a crane provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a working unit provided in an embodiment of the present invention; Figure 3 This is yet another structural schematic diagram of a working unit provided in an embodiment of the present invention; Figure 4 Another structural schematic diagram of the working unit provided in the embodiment of the present invention; Figure 5 This is a flowchart illustrating the control method for a crane provided in an embodiment of the present invention. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Cranes, as material lifting and handling equipment, are widely used in industrial production, warehousing and logistics, construction and other scenarios. Travel limit is the core function of safe operation of cranes. It is necessary to accurately limit the extreme positions of the crane's lifting and lowering to prevent safety accidents such as equipment collisions and material falling caused by overtravel. At the same time, precise distance control can improve the operating accuracy and efficiency of cranes.

[0013] In related technologies, cranes often use three-phase asynchronous motors as their power source. When using a three-phase asynchronous motor as the power source, the travel limit can be implemented in the following two ways: The first method is the physical microswitch control method. In this method, physical microswitches are installed at the lifting limit position and the lowering limit position of the crane, and corresponding mechanical triggering structures are used to trigger the physical microswitches. When the crane moves to the limit position (including the lifting limit position and the lowering limit position), the mechanical triggering structure triggers the physical microswitches, and the physical microswitches send out electrical signals to cut off the motor drive circuit and realize the travel limit.

[0014] However, this approach requires additional physical components such as microswitches and mechanical triggering structures, which not only increases the structural complexity of the crane but also raises material and assembly / debugging costs. Furthermore, these physical components are prone to wear, loosening, and jamming during long-term use, which can lead to limit signal failure and reduce the reliability of travel limit.

[0015] The second method is encoder + PLC (Programmable Logic Controller) control: An incremental encoder is connected to the output shaft of the three-phase asynchronous motor. The incremental encoder follows the output shaft of the three-phase asynchronous motor and converts the rotation of the output shaft of the three-phase asynchronous motor into pulse signals and transmits them to the PLC. The PLC calculates the crane's running distance and position by accumulating the number of pulses of the pulse signals. When the position of the working unit is detected to reach the limit position, the PLC issues a command to control the three-phase asynchronous motor to stop running, that is, the working unit stops running, so as to realize the travel limit and distance control.

[0016] However, in this approach, both the incremental encoder and the PLC are additional high-cost electronic components, which significantly increases the overall manufacturing cost of the crane and is not suitable for large-scale application of low- to mid-range crane products. Furthermore, the incremental encoder needs to be mechanically connected to the three-phase asynchronous motor, which increases the mechanical assembly process. The programming and debugging of the PLC also place higher demands on the professional skills of the technicians, increasing production and maintenance costs.

[0017] It is evident that, since the three-phase asynchronous motor does not have the functions of position detection and pulse output, the implementation of travel limit and distance control in the above two methods requires the addition of external components and the completion of corresponding structural / circuit / program debugging. Due to the need for additional equipment, the resource waste rate increases.

[0018] To address the above problems, embodiments of the present invention provide a crane, the structural schematic of which is shown below. Figure 1 As shown, Figure 1 This is a structural schematic diagram of a crane provided in an embodiment of the present invention.

[0019] Please refer to Figure 1 The crane 1 includes: The drive motor 10, control unit 11, storage unit 12, and working unit 13 are included.

[0020] The drive motor 10 is used to provide power to the working unit 13 and to output the pulse signal corresponding to the position change of the working unit 13 under the action of the power it provides; The control unit 11 is used to receive and count the first pulse number of the pulse signal, modify the second pulse number corresponding to the position of the working unit 13 before the position change based on the level change of the pulse signal and the first pulse number, and control the position of the working unit 13 based on the comparison result between the modified second pulse number and the pre-stored operating limit pulse number in the storage unit 12.

[0021] In order to enable the drive motor 10 to provide power to the working unit 13 while also outputting pulse signals to reflect the position change of the working unit 13, the drive motor 10 may be, for example, a brushless direct current motor (BLDC) with built-in Hall effect devices.

[0022] A brushless DC motor with built-in Hall effect sensors has the Hall sensor directly installed inside the motor to detect the rotor position in real time and achieve electronic commutation. This replaces the carbon brushes and commutator of a traditional brushed motor, resulting in a longer lifespan, lower noise, and higher efficiency.

[0023] The brushless DC motor with built-in Hall effect components includes a stator, a rotor, Hall effect sensors, and a driver. The core of the stator is a three-phase winding, which generates a magnetic field when energized in stages. The rotor is equipped with permanent magnets and is driven to rotate by the magnetic field generated by the three-phase winding of the stator. Three Hall effect sensors are respectively installed on the three-phase winding. The Hall effect sensors are used to sense the magnetic pole position of the rotor in real time and output an electrical signal (Hall effect pulse signal) reflecting the change in rotor position to the driver. The driver is used to switch the energizing sequence of the three-phase winding of the stator according to the Hall effect signal, so that the magnetic field generated by the three-phase winding of the stator continues to rotate forward. The rotating magnetic field continuously pulls the rotor equipped with permanent magnets, so that the brushless DC motor can operate smoothly and continuously.

[0024] Therefore, based on the above discussion, when the drive motor 10 in the embodiment of the present invention is a brushless DC motor, the aforementioned pulse signal is a Hall pulse signal. More specifically, the pulse signal can be, for example, a three-channel Hall pulse signal output by three Hall sensors disposed on the rotor inside the brushless DC motor, used to reflect changes in rotor position.

[0025] It is known that the core of the stator can also be a single-phase winding, a two-phase winding, or a five-phase winding, a seven-phase winding, etc. The number of Hall sensors can also be two, four or more. In the case of a DC brushless motor of the same specifications, the more Hall sensors there are, the more accurate the rotor speed detected.

[0026] The control unit 11 in this embodiment of the invention can be, for example, an MCU (Microcontroller Unit). An MCU, commonly known as a microcontroller, is a small embedded control core that integrates a CPU (Central Processing Unit), memory, and peripheral interfaces on a single chip. It is designed specifically for control scenarios and has functions such as pulse signal reception, data processing, and motor drive control.

[0027] The pulse signal received by the control unit 11 is a segment of pulse signal, and the number of pulses in this segment of pulse signal refers to the number of pulses contained in this segment of pulse signal.

[0028] In one embodiment, the operating limit pulse count includes a lower limit pulse count and an upper limit pulse count; the lower limit pulse count indicates the number of pulses when the working unit 13 is at its limit position where it can move downwards; the upper limit pulse count indicates the number of pulses when the working unit 13 is at its limit position where it can move upwards.

[0029] The second pulse count can be stored in the control unit 11, for example. In the case where the control unit 11 is an MCU, a pulse accumulation variable is set in the MCU. The pulse accumulation variable can receive and accumulate the number of Hall pulses corresponding to the Hall pulse signal output by the Hall element (Hall sensor) in the brushless DC motor in real time.

[0030] The crane 1 provided in this embodiment of the invention includes a drive motor 10, a control unit 11, a storage unit 12, and a working unit 13. The drive motor 10 provides power to the working unit 13 and outputs a pulse signal corresponding to the position change of the working unit 13 under the power it provides. That is, while providing power to the working unit 13, the drive motor 10 also monitors the position change of the working unit 13 and outputs the position change of the working unit 13 as an electrical signal, i.e., a pulse signal. The control unit 11 receives and counts the first pulse count of the pulse signal, modifies the second pulse count corresponding to the position of the working unit 13 before the position change based on the level change of the pulse signal and the first pulse count, and controls the position of the working unit 13 based on the comparison result between the modified second pulse count and the pre-stored operating limit pulse count in the storage unit 12. As can be seen, the crane 1 provided in this embodiment of the invention can convert the position change of the working unit 13 into a pulse signal and output it through the drive motor 10 that provides power to the working unit 13. The control unit 11 can then receive the pulse signal, count the first pulse number, and modify the second pulse number based on the level change and the first pulse number. The second pulse number corresponds to the position of the working unit 13 before the position change. The control unit 11 compares the second pulse number with the pre-stored operating limit pulse number and controls the position of the working unit 13 based on the comparison result. In other words, the crane 1 provided in this embodiment of the invention can limit the working unit 13 based on the electrical signal converted from the position change of the crane 1. This process uses the original components of the crane 1 without adding any additional equipment, thus improving resource utilization and reducing resource waste.

[0031] In one embodiment, the control unit 11 is configured to modify the second pulse number corresponding to the position of the working unit 13 before the position change, based on the level change of the pulse signal and the first pulse number, including: Based on the level change of the pulse signal, the running direction of the working unit 13 is determined; based on the running direction of the working unit 13 and the first pulse number, the second pulse number corresponding to the position of the working unit 13 before the position change is modified.

[0032] Taking the aforementioned brushless DC motor as an example, the rotor of the brushless DC motor rotates synchronously with its motor shaft to provide power to the working unit 13. When the motor shaft rotates forward, the working unit 13 moves upward, and when the motor shaft rotates in reverse, the working unit 13 moves downward. Therefore, the running direction of the working unit 13 can be determined by judging the rotation direction of the motor shaft. Since the rotor rotates synchronously with the motor shaft (because the rotor and the motor shaft are rigidly connected), the running direction of the working unit 13 can be determined by judging the rotation direction of the rotor.

[0033] In a brushless DC motor, taking the brushless DC motor with three Hall sensors as an example, the pulse signal is a three-channel Hall pulse signal output by the three Hall sensors installed on the rotor of the brushless DC motor, used to reflect the change of rotor position. When the rotor rotates forward, the order of the pulse signal level changes of the three Hall sensors is 100→110→010→011→001→101; when the rotor rotates in reverse, the order of the pulse signal level changes of the three Hall sensors is 100→101→001→011→010→110.

[0034] Conversely, the operating direction of the working unit 13 can be determined based on the level changes of the pulse signals. For example, when the order of the pulse signal level changes output by the three Hall sensors is 100→110→010→011→001→101, it can be determined that the rotor of the brushless DC motor is rotating forward and the motor shaft is rotating forward, thus determining that the operating direction of the working unit 13 is upward; when the order of the pulse signal level changes output by the three Hall sensors is 100→101→001→011→010→110, it can be determined that the rotor of the brushless DC motor is rotating in reverse and the motor shaft is rotating in reverse, thus determining that the operating direction of the working unit 13 is downward.

[0035] First, the running direction of the working unit 13 is determined. Then, based on the determined running direction and the first pulse number, the second pulse number is modified. In essence, the second pulse number directly corresponds to the current position of the working unit 13. Therefore, the second pulse number is modified when the position of the working unit 13 changes. Thus, this method of modifying the second pulse number corresponding to the current position of the working unit 13 can make the second pulse number corresponding to the current position of the working unit 13 change in real time, and the recorded value has high accuracy.

[0036] The pulse signals output by the Hall effect sensors of the brushless DC motor as the rotor rotates are equidistant and synchronous. The number of the first pulses of the pulse signal is linearly proportional to the angle / number of rotations of the rotor of the brushless DC motor. The number of rotations of the motor shaft of the brushless DC motor (which rotates synchronously with the rotor, so the number of rotations of the rotor is the same as the number of rotations of the motor shaft) is in a fixed transmission ratio relationship with the operating displacement of the working unit 13 of the crane 1 (the distance between the position before the position change and the position after the position change).

[0037] Please refer to Figure 2 , Figure 2 The present invention provides a schematic diagram of the working unit 13 in the embodiment of the invention. In the crane 1, the working unit 13 includes: a hook 130 and a wire rope 131; wherein, the hook 130 is used to suspend, hook, and carry the materials / lifting tools to be lifted, and can move up and down along the wire rope 131.

[0038] exist Figure 2 In this diagram, a coordinate axis is established with the wire rope 131 as the X-axis and B as the origin, using meters as the unit. The coordinates of position B are (0), and the coordinates of position A can be, for example, (6). The distance between A and B is 6m. Position A is the upper limit position of the hook 130 on the wire rope 131, and position B is the lower limit position of the hook 130 on the wire rope 131. The operating displacement of the working unit 13 refers to the operating displacement of the hook 130 on the wire rope 131. If the hook 130 moves from point B to point A on the wire rope 131, its operating displacement is 6m.

[0039] Please continue to refer to this. Figure 2 Alternatively, a coordinate system can be established with the wire rope 131 as the X-axis, B as the origin, and the number of rotations of the rotor in the brushless DC motor as the unit. In this coordinate system, the coordinate of A could be, for example, (5000), meaning that the rotor in the brushless DC motor needs to rotate 5000 times during the process of the hook 130 moving from the origin B to A. The coordinate of B could be, for example, (0), meaning that the rotor in the brushless DC motor does not need to rotate during the process of the hook 130 moving from the origin B to the origin B. Figure 2As can be seen from the image, the hook 130 is located at the lower limit position of the wire rope 131, which is the origin B of the X-axis coordinate.

[0040] Please continue to refer to Figure 2 Alternatively, a coordinate system can be established with the wire rope 131 as the X-axis, B as the origin, and the number of pulses as the unit. In this coordinate system, the coordinate of A can be, for example, (90000). This means that during the process from B to A, the Hall sensor in the brushless DC motor outputs a pulse signal based on the number of rotor rotations, and the number of pulses in this pulse signal is 90000. The coordinate of B is (0), meaning that during the process from B to B, the Hall sensor in the brushless DC motor outputs a pulse signal based on the number of rotor rotations, and the number of pulses in this pulse signal is 0, i.e., no pulse signal is output. It can be seen that in this coordinate system, 90000 is the upper limit pulse count of the working unit 13, and 0 is the lower limit pulse count of the working unit 13.

[0041] It is known that the three coordinate systems mentioned above are only different in units, all with the steel wire rope 131 as the X-axis and B as the origin. However, in reality, any point on the steel wire rope 131 can be used as the origin of the coordinate system to realize the present invention, so the present invention does not limit this.

[0042] It should be noted that in the above coordinate system, the coordinates of different units at the same position have a corresponding relationship. Taking point A as an example, the coordinates of point A in the three coordinate systems are (6), with the unit being m, (5000), with the unit being r, and (90000), with the unit being 1. The actual physical meaning of these three coordinates is: During the process of the hook 130 of the working unit 13 moving from point B of the wire rope 131 to point A of the wire rope 131, the rotor (motor shaft) of the DC brushless motor rotates 5000 times. Based on the rotor rotating 5000 times, the Hall sensor outputs a Hall pulse signal. The number of pulses in this Hall pulse signal is 90000. This process moves 6m.

[0043] In the aforementioned brushless DC motor with Hall effect sensors, the number of Hall pulses per revolution = the number of stator pole pairs × 6, and the total number of pulses = the number of rotor revolutions × the number of Hall pulses per revolution. In other words, the total number of pulses in a Hall pulse signal segment = the number of rotor revolutions × the number of stator pole pairs × 6.

[0044] The stator pole pair number refers to the number of pole pairs of the magnetic field generated by the three-phase windings of the stator. The number of pole pairs of the magnetic field corresponds to the number of permanent magnets installed on the rotor. If there are 6 permanent magnets installed on the rotor, and each permanent magnet corresponds to a single N pole or a single S pole, then the number of pole pairs of the magnetic field is 3, and the number of pole pairs of the stator is 3. The number of pole pairs of the stator can be, for example, 1, 2, or 3.

[0045] When the number of pole pairs of the stator is 3, the total number of pulses of a Hall pulse signal is equal to the number of rotations of the rotor × 18. Taking point A as an example, when the rotor rotates 5000 times from point B to point A, the number of pulses of the Hall pulse signal output by the Hall sensor is 5000 × 18 = 90000.

[0046] That is, during the process of the working unit 13 moving from point A to point B, the operating displacement of the working unit 13 is 6m, the rotor of the DC brushless motor rotates 5000r (revolutions), and the number of Hall pulse signals output by the Hall sensor is 90000.

[0047] Therefore, in the three coordinate systems, the three different coordinates of the same point have a corresponding relationship.

[0048] In one embodiment, the control unit 11 is configured to modify the second pulse number corresponding to the position of the working unit 13 before the position change, based on the running direction of the working unit 13 and the first pulse number, including: When the working unit 13 runs upward, the second pulse number is added to the first pulse number to obtain the modified second pulse number; when the working unit 13 runs downward, the second pulse number is subtracted from the first pulse number to obtain the modified second pulse number.

[0049] This calculation method is relatively simple and intuitive, and can be easily implemented, improving the availability of crane 1.

[0050] Please refer to Figure 3 , Figure 3 This is another structural schematic diagram of the working unit 13 provided in an embodiment of the present invention. Figure 3 In the diagram, the hook 130 is located at position C, and the coordinates of position C can be, for example, (1.8m, 1500r, 27000). This means that during the process of the hook 130 moving from position B to position C on the wire rope 131, the running displacement of the hook 130 is 1.8m, and the rotor of the DC brushless motor needs to rotate 1500r. Based on detecting the rotor rotation of 1500r, the Hall sensor outputs a Hall pulse signal with 27000 pulses.

[0051] Please refer to Figure 4 , Figure 4 This is another structural schematic diagram of the working unit 13 provided in an embodiment of the present invention. Figure 4In the diagram, the hook 130 is located at position D, and the coordinates of position D can be, for example, (3.9m, 3250r, 58500). This means that during the process of the hook 130 moving from position B to position D on the wire rope 131, the running displacement of the hook 130 is 3.9m, the rotor of the DC brushless motor needs to rotate 3250r, and the Hall sensor outputs a Hall pulse signal with 58500 pulses based on detecting the rotor rotation of 3250r.

[0052] Assume that work cell 13 moves from position C to position D, by Figure 3 and Figure 4 As shown, when moving from position C to position D, the operating direction of the working unit 13 is upward. The second pulse number is the pulse number corresponding to position C, which is 27000. During the process from position C to position D, the first pulse number of the Hall pulse signal output by the Hall sensor is 31500. Therefore, when the operating direction of the working unit 13 is upward, the second pulse number is added to the first pulse number to obtain the modified second pulse number, which is 58500, corresponding to the coordinate 58500 of position D.

[0053] Assume that work cell 13 moves from position D to position C, by Figure 3 and Figure 4 As shown, when moving from position D to position C, the working unit 13 moves downwards. The second pulse number is the pulse number corresponding to position D, which is 58500. During the process from position D to position C, the first pulse number of the Hall pulse signal output by the Hall sensor is 31500. Therefore, when the working unit 13 moves downwards, the second pulse number is subtracted from the first pulse number to obtain the modified second pulse number, which is 27000, corresponding to the coordinate 27000 of position C.

[0054] In one embodiment, when the working unit 13 is first in its limit position where it can move downwards, the control unit 11 is further configured to store the second pulse count in the storage unit 12 as the lower limit pulse count; when the working unit 13 is first in its limit position where it can move upwards, the control unit 11 is further configured to store the second pulse count in the storage unit 12 as the upper limit pulse count. After storing the lower limit pulse count and the upper limit pulse count in the storage unit 12, the control unit 11 is also used to save the calibration status flag; the calibration status flag is used to indicate that the lower limit pulse count and the upper limit pulse count have been stored in the storage unit 12.

[0055] Storing the maximum number of pulses during operation helps provide a data basis for subsequent determination of the position of working unit 13, which can speed up the determination process.

[0056] The storage unit 12 in this embodiment of the invention can be, for example, Flash memory, which is a non-volatile memory and whose data is not lost when power is off.

[0057] This can be achieved by manually controlling the working unit 13 to be in its extreme position where it can move downwards / upwards for the first time, or by other means; the present invention does not limit this.

[0058] Specifically, for example, at position A (the limit position where the working unit 13 can move upward) / B (the limit position where the working unit 13 can move downward), the value of the pulse accumulation variable (which stores the second pulse number) in the control unit 11 is stored in the storage unit 12 as the upper / lower limit pulse number.

[0059] In one embodiment, the control unit 11 controls the position of the working unit 13 based on a comparison between the modified second pulse number and the pre-stored operating limit pulse number in the storage unit 12, including: If the comparison result between the second pulse number and the lower limit pulse number is that the second pulse number is less than or equal to the lower limit pulse number, then the working unit 13 is controlled to stop running downwards. If the comparison between the second pulse count and the upper limit pulse count shows that the second pulse count is greater than or equal to the upper limit pulse count, then the working unit 13 is controlled to stop moving upward.

[0060] The limiting of the working unit 13 is the limiting of the position of the hook 130 in the wire rope 131. Limiting the position of the hook 130 in the wire rope 131 can ensure that the wire rope 131 is subjected to balanced force, avoid unilateral wear, kinking, and wire breakage, and extend its service life. It can also prevent load eccentricity, reduce the swaying, tipping, and slippage of the suspended object, and improve the overall stability of the hoisting. At the same time, it can prevent the hook 130 from wearing unevenly on the pulley and getting stuck in the groove, and reduce the deformation and damage of the hook 130 and the pulley block. In addition, it can also straighten the rope path, suppress the wire rope 131 from winding and tangling, make the lifting operation smoother, and reduce the probability of mechanism jamming and failure.

[0061] Please continue to refer to this. Figure 2 Position A is the limit position at which the working unit 13 can move upward, and position B is the limit position at which the working unit 13 can move downward. That is to say, the hook 130 can move between position A and position B on the wire rope 131. If the current position of the hook 130 is higher than position A, it cannot move upward anymore. If the current position of the hook 130 is lower than position B, it cannot move downward anymore.

[0062] In one embodiment, the storage unit 12 is located in the control unit 11, or the storage unit 12 is electrically connected to the control unit 11 to be controlled by the control unit 11.

[0063] In one embodiment, the control unit 11 is further configured to store the second pulse count in the storage unit 12 when a power-off signal or a power-down signal is received, so as to serve as the pulse count before power-off; Alternatively, after a first preset time interval, the second pulse count is stored in the storage unit 12 as the pulse count before power-off. When a power-off signal or power-down signal is received, the second pulse count is written back into the storage unit 12. The control unit 11 is also used to read the number of pulses before shutdown from the storage unit 12 when the power is on, and use the number of pulses before shutdown as the second number of pulses.

[0064] This means there are two ways to store the second pulse count before shutdown. One is to directly store the second pulse count in storage unit 12 when a shutdown signal or power failure signal is detected. The other is to store the second pulse count in storage unit 12 at intervals (a first preset duration) when the crane 1 is powered on, and then rewrite the second pulse count into storage unit 12 when a shutdown signal or power failure signal is detected. Replacing the first trigger method of immediately writing data upon detecting a power failure signal with a timed write + power failure rewrite method, that is, when the crane 1 is operating, the control unit 11 writes the second pulse count into the flash memory at fixed intervals (a first preset duration, for example, 1 second), while retaining the power failure rewrite function, can further improve the reliability of data storage and avoid write failures caused by sudden power failures.

[0065] The storage unit 12 stores the number of pulses before shutdown, that is, when a shutdown signal or power failure signal is detected, the second pulse number is written into the storage unit 12. This can save the number of pulses corresponding to the position of the hook 130 in the wire rope 131 before the last shutdown. Since the storage unit 12 is a non-volatile memory, the number of pulses before shutdown can also be saved after power failure. After power-on, the number of pulses before shutdown can be directly read into the pulse accumulation variable (storing the second pulse number) of the control unit 11. In this way, after power-on, the second pulse number in the control unit 11 can correspond to the position of the hook 130 in the wire rope 131, and the crane can be started directly without data verification, thus improving the working efficiency of the crane 1.

[0066] In one embodiment, the storage unit 12 includes three sectors, which respectively store the lower limit pulse count, the upper limit pulse count, and the pulse count before power-off; Alternatively, the crane 1 may include three storage units 12, which respectively store the lower limit pulse count, the upper limit pulse count, and the pulse count before shutdown.

[0067] In one embodiment, the control unit 11 is used to control the working unit 13 and the drive motor 10 to perform work, and the steps of receiving and counting the first pulse number of the changing pulse signal are performed continuously or at intervals of a second preset time.

[0068] This means that the continuous comparison method of comparing the current value with the limit value in real time under the first method can be replaced by the interval sampling comparison method. That is, the control unit 11 collects the second pulse number in the pulse accumulation variable once every fixed time (second preset duration, such as 50ms) and performs subsequent comparison steps, which can reduce the computational load of the control unit 11 and is suitable for low power crane 1 control scenarios.

[0069] Based on the same inventive concept, embodiments of the present invention also provide a crane control method, such as... Figure 5 As shown, Figure 5 This is a flowchart illustrating the control method for a crane provided in an embodiment of the present invention.

[0070] Please refer to Figure 5 The control method for the crane, applied to the control unit of the crane as described in any of the foregoing embodiments, includes the following steps: Step S501: Receive and count the first pulse number of the pulse signal; Step S502: Based on the level change of the pulse signal and the first pulse count, modify the second pulse count corresponding to the position of the crane's working unit before the position change occurred; Step S503: Based on the comparison result between the modified second pulse number and the pre-stored operating limit pulse number in the storage unit of the crane, control the position of the working unit.

[0071] The crane control method provided in this embodiment of the invention is applied to the crane described in any of the foregoing embodiments. The crane includes a drive motor, a control unit, a storage unit, and a working unit. The drive motor provides power to the working unit and outputs a pulse signal corresponding to the position change of the working unit under the power it provides. That is, while providing power to the working unit, the drive motor also monitors the position change of the working unit and outputs the position change of the working unit as an electrical signal, i.e., a pulse signal. The control unit receives and counts the first pulse count of the pulse signal, modifies the second pulse count corresponding to the position of the working unit before the position change based on the level change of the pulse signal and the first pulse count, and controls the position of the working unit based on the comparison result between the modified second pulse count and the pre-stored operating limit pulse count in the storage unit. As can be seen, the crane provided in this embodiment of the invention can convert the position change of the working unit into a pulse signal and output it through a drive motor that provides power to the working unit. The control unit can receive the pulse signal, count the first pulse number of the pulse signal, and then modify the second pulse number based on the level change and the first pulse number. The second pulse number corresponds to the position of the working unit before the position change. The control unit compares the second pulse number with the pre-stored operating limit pulse number and controls the position of the working unit based on the comparison result. In other words, the crane provided in this embodiment of the invention can limit the working unit based on the electrical signal converted from the position change of the crane. This process uses the original crane components without adding any additional equipment, thus improving resource utilization and reducing resource waste.

[0072] The foregoing describes multiple embodiments of the present invention. The optional methods described in each embodiment can be combined and cross-referenced without conflict, thereby extending to a variety of possible embodiments. These can all be considered as embodiments disclosed or made public by the present invention.

[0073] While the embodiments of the present invention have been disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A crane, characterized in that include: Drive motor, control unit, storage unit, and working unit; The drive motor is used to provide power to the working unit and to output the pulse signal corresponding to the position change of the working unit under the power it provides; The control unit is used to receive and count the first pulse count of the pulse signal, modify the second pulse count corresponding to the position of the working unit before the position change based on the level change of the pulse signal and the first pulse count, and control the position of the working unit based on the comparison result between the modified second pulse count and the pre-stored operating limit pulse count in the storage unit.

2. Crane according to claim 1, characterized in that The control unit is configured to modify the second pulse number corresponding to the position of the working unit before the position change, based on the level change of the pulse signal and the first pulse number, including: The operating direction of the working unit is determined based on the level change of the pulse signal; Based on the operating direction of the working unit and the first pulse number, the second pulse number corresponding to the position of the working unit before the position change is modified.

3. Crane according to claim 2, characterized in that The control unit is used to modify the second pulse number corresponding to the position of the working unit before the position change, based on the running direction of the working unit and the first pulse number, including: When the working unit is running in the upward direction, the second pulse number is added to the first pulse number to obtain the modified second pulse number; when the working unit is running in the downward direction, the second pulse number is subtracted from the first pulse number to obtain the modified second pulse number.

4. Crane according to claim 3, characterized in that The operating limit pulse count includes: lower limit pulse count and upper limit pulse count; the lower limit pulse count is used to indicate the number of pulses when the working unit is at its limit position where it can move downwards; the upper limit pulse count is used to indicate the number of pulses when the working unit is at its limit position where it can move upwards.

5. Crane according to claim 4, characterized in that The control unit controls the position of the working unit based on a comparison between the modified second pulse number and the pre-stored operating limit pulse number in the storage unit, including: If the comparison result between the second pulse number and the lower limit pulse number is that the second pulse number is less than or equal to the lower limit pulse number, then the working unit is controlled to stop running downwards. If the comparison between the second pulse count and the upper limit pulse count shows that the second pulse count is greater than or equal to the upper limit pulse count, then the working unit is controlled to stop moving upwards.

6. The crane of claim 4, wherein, When the working unit is first in its limit position where it can move downwards, the control unit is also used to store the second pulse count in the storage unit as the lower limit pulse count; when the working unit is first in its limit position where it can move upwards, the control unit is also used to store the second pulse count in the storage unit as the upper limit pulse count. After storing the lower limit pulse count and the upper limit pulse count into the storage unit, the control unit is also used to save the calibration status flag; the calibration status flag is used to indicate that the lower limit pulse count and the upper limit pulse count have been stored into the storage unit.

7. The crane of claim 1, wherein, The storage unit is located within the control unit, or the storage unit is electrically connected to the control unit to be controlled by the control unit.

8. The crane of claim 1, wherein, The control unit is also used to store the second pulse count in the storage unit when a power-off signal or a power-down signal is received, so as to serve as the pulse count before power-off; Alternatively, after a first preset time interval, the second pulse count is stored in the storage unit as the pulse count before power-off. When a power-off signal or power-down signal is received, the second pulse count is written back into the storage unit. The control unit is also configured to read the number of pulses before shutdown from the storage unit when the power is on, and use the number of pulses before shutdown as the second number of pulses.

9. A crane according to claim 4 or 8, characterised in that The storage unit includes three sectors, which respectively store the lower limit pulse count, the upper limit pulse count, and the pulse count before power-off; Alternatively, the crane may include three storage units, which respectively store the lower limit pulse count, the upper limit pulse count, and the pulse count before shutdown.

10. The crane of claim 1, wherein, The control unit is used to control the working unit and the drive motor to perform work, and the steps of receiving and counting the first pulse number of the changing pulse signal are performed continuously or at intervals of a second preset time.

11. A control method of a crane, characterized by, A control unit applied to the crane as described in any one of claims 1-10, comprising: Receive and count the first pulse count of the pulse signal; Based on the level change of the pulse signal and the first pulse count, the second pulse count corresponding to the position of the crane's working unit before the position change occurs is modified. The position of the working unit is controlled based on the comparison between the modified second pulse number and the pre-stored operating limit pulse number in the storage unit of the crane.

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