Crane operation tail end positioning control method and system

Abstract

The invention discloses a crane operation tail end positioning control method and system. The method comprises the steps that whether tail end positioning control is started or not is judged through a tail end positioning start-stop judgment unit; if not, the instruction output by the handle is subjected to slope amplitude limiting processing through the slope amplitude limiting unit and then serves as first input; the first instruction is subtracted from the speed instruction after slope amplitude limiting processing through a speed instruction selection unit, and then speed control is conducted through a speed control unit; if so, subtracting the current position data from the tail end target position, then adjusting the position through the position adjusting unit, and taking the obtained result as a second input; and subtracting the second instruction from the second input through the speed instruction selection unit, performing speed control through the speed control unit, and running to a target position according to the control speed. The problem of accurate positioning of the tail end during manual operation of the crane can be solved, a target position can be reached at a time, and swinging of a heavy object can be eliminated.

Description

Technical Field

[0001] This invention relates to the field of crane control technology, and more specifically to a crane end-of-line positioning control method and system. Background Technology

[0002] When a crane is manually operated by a driver, its task is generally to lift heavy objects from one point in space to another. During this process, the driver needs to control the speed of multiple mechanisms of the crane to complete the lifting task and observe the trajectory of the heavy object while these mechanisms are operating, preventing collisions with obstacles within the object's travel range. In short, the driver's tasks are spatial target location (hereinafter referred to as end-point positioning) and obstacle avoidance.

[0003] Generally, obstacle avoidance doesn't require highly precise operation. Whether it's autonomous lifting within the driver's line of sight or lifting under command outside the line of sight, as long as the driver or commander is focused, they can make the correct obstacle avoidance maneuvers to ensure a safe distance between the load and the obstacle—a distance typically measured in meters or more. However, end-point positioning requires precise operation, generally requiring accuracy below ten centimeters. This is especially true for the slewing and luffing mechanisms of boom cranes, or the trolley and crane mechanisms of gantry cranes. The operation of these mechanisms causes the load to sway, requiring the driver to manually eliminate these swaying movements and reach the target position. This usually involves repeated adjustments near the target position, which takes even longer for novice or experienced drivers operating new cranes. Furthermore, for cranes with large inertia, such as the slewing mechanism of tower cranes, there is a significant time lag between the driver's control commands and the mechanism's movement, making precise positioning even more difficult. Repeated adjustments near the target position not only reduce operational efficiency but also consume a significant amount of the driver's energy during the process.

[0004] Therefore, how to provide a method and system for positioning control at the end of crane operation is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a crane end-of-line positioning control method and system, which realizes precise positioning of the crane end-of-line, reaches the target position in one go, and can eliminate the swaying of the load.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A crane end-of-travel positioning control method, comprising: S1: The end-positioning start / stop judgment unit determines whether the end-positioning control is started; S2: If not started, the end positioning start / stop judgment unit controls the speed command selection unit to select the first input and the control angle attenuation selection unit selects the first command; The command output by the handle is processed by the ramp limiting unit and then used as the first input; After subtracting the first command from the speed command after the slope limiting process by the speed command selection unit, the speed is controlled by the speed control unit. The vehicle moves towards the target position according to this controlled speed and then returns to S1. If started, the end-positioning start / stop judgment unit controls the speed command selection unit to select the second input, and the control angle attenuation selection unit selects the second command: The current position data is subtracted from the terminal target position, and the position is adjusted by the position adjustment unit before being used as the second input. The second input is subtracted from the second command by the speed command selection unit, and the speed is controlled by the speed control unit to move to the target position.

[0007] Preferably, determining whether end-point positioning control is activated specifically includes: Determine if there is a speed command output from the handle; determine if the foot switch is pressed; and determine if the absolute value of the end-effector target position minus the current position data is less than the end-effector positioning interval threshold. If the handle does not output a speed command, the foot switch is pressed, and the absolute value of the end target position minus the current position data is less than the end positioning interval threshold, the end positioning control is activated. If at least one of the following conditions is met: the handle outputs a speed command, the foot switch is not pressed, and the absolute value of the end target position minus the current position data is not less than the end positioning interval threshold, then the end positioning control is not activated.

[0008] Preferably, the angle attenuation selection unit selects the output value 0 as the first instruction; The angle attenuation selection unit calculates the current swing angle of the load using the virtual angle calculation unit based on the actual speed value of the motor. Then, it multiplies the current swing angle of the load with the swing attenuation coefficient given by the swing attenuation coefficient unit and uses this as the second instruction.

[0009] Preferably, after speed control is performed via the speed control unit, the system further includes: The motor torque value is output after speed control is performed by the speed control unit. The motor torque value is used to generate the actual motor speed value after passing through the motor kinematic model unit; The actual speed value of the motor is used to generate the current position data after passing through the integral model unit.

[0010] A crane end-of-line positioning control system, comprising: End-point positioning start / stop determination unit: used to determine whether end-point positioning control is started; Speed ​​command selection unit: used to receive control from end-positioning start / stop unit and select first input or second input. Specifically, when end-positioning control is not started, the command output by the handle is selected as the first input after being slope-limited by the slope limiting unit. When end-positioning control is started, the command is selected as the second input after subtracting the current position data from the end target position and adjusting the position by the position adjustment unit. Angle attenuation selection unit: used to receive control from the end-positioning start / stop unit and select the first command or the second command; Ramp limiting unit: Used to perform ramp limiting processing on the commands output by the handle; Position adjustment unit: used to adjust the position of the target position by subtracting the current position data from the target position. Speed ​​control unit: used to control speed by subtracting the first command from the speed command output by the handle after ramp limiting when the end-positioning control is not started, and to control speed by subtracting the second command from the second input when the end-positioning control is started.

[0011] Preferably, it also includes an end-positioning interval determination unit, used to determine whether the absolute value of the end target position minus the current position is less than the end-positioning interval threshold; The end-point positioning start / stop determination unit determines whether end-point positioning control is started, specifically including: Determine if there is a speed command output from the handle; determine if the foot switch is pressed; and determine if the absolute value of the end-effector target position minus the current position data is less than the end-effector positioning interval threshold. If the handle does not output a speed command, the foot switch is pressed, and the absolute value of the end target position minus the current position data is less than the end positioning interval threshold, the end positioning control is activated. If at least one of the following conditions is met: the handle outputs a speed command, the foot switch is not pressed, and the absolute value of the end target position minus the current position data is not less than the end positioning interval threshold, then the end positioning control is not activated.

[0012] Preferably, it also includes a virtual angle calculation unit and a sway attenuation coefficient unit; The virtual angle calculation unit is used to calculate the current swing angle of the weight based on the actual speed value of the motor. The sway attenuation coefficient unit is used to set the sway attenuation coefficient; The angle attenuation selection unit multiplies the current swing angle of the weight obtained by the virtual angle calculation unit with the swing attenuation coefficient given by the swing attenuation coefficient unit and uses it as the second instruction. The angle attenuation selection unit selects the output value 0 as the first instruction.

[0013] Preferably, it also includes an electric motor kinematic model unit and an integral model unit; The motor kinematic model unit is used to calculate the actual speed value of the motor by calculating the motor torque value output after speed control by the speed control unit; The integral model unit is used to integrate the actual speed value of the motor to generate the current position data.

[0014] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a crane end-of-line positioning control method and system, which can solve the problem of accurate end-of-line positioning when the crane is manually operated. It can switch to automatic operation within a few meters of the target point where the load is lifted by the crane, reach the target position in one go, and eliminate the swaying of the load. Attached Figure Description

[0015] 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.

[0016] Figure 1 The present invention provides a flowchart of a crane operation end positioning control method.

[0017] Figure 2 The present invention provides a structural block diagram of a crane operation end positioning control system.

[0018] Figure 3 A schematic diagram of the crane system provided by the present invention.

[0019] Figure 4 The structural block diagram of the bridge gantry crane provided by the present invention.

[0020] Figure 5 The structural block diagram of the boom crane provided by the present invention.

[0021] Figure 6 The present invention provides a structural block diagram of a crane electrical control system equipped with a human-machine interactive touch screen and operated via a linkage table, handle, and foot switch.

[0022] Figure 7 The present invention provides a structural block diagram of a crane electrical control system operated via a control panel, handle, and foot switch without a human-machine interface touchscreen.

[0023] Figure 8This is a structural block diagram of a crane electrical control system operated by a remote controller, as provided by the present invention.

[0024] Figure 9 The simulation waveform diagram provided for this invention shows the waveforms in the first row as the speed setpoint of the handle command (dashed line) and the automatic speed setpoint of the end-positioning (solid line), the waveforms in the second row as the position waveforms of the end-positioning (solid line) and the position waveforms of the handle command (dashed line), and the waveforms in the third row as the swing angle waveform of the weight. Detailed Implementation

[0025] 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.

[0026] First, let's introduce the composition of the crane device corresponding to the method of this invention. A crane is generally equipped with an operating system 1 and an electrical control system 2, used to control the operation of the crane's drive mechanism 3, such as... Figure 3 As shown.

[0027] Crane mechanisms are generally classified into hoisting mechanisms, translation mechanisms (trolley, gantry, luffing mechanism), and slewing mechanisms. Figure 4 The image shows a bridge crane 21, whose trolley translation mechanism and hoisting mechanism are represented by 22, the load is 23, and the trolley translation mechanism is 24. Figure 5 The image shows a boom crane 31, whose trolley translation mechanism and hoisting mechanism are represented by 32, the load is 33, and the slewing mechanism is 34.

[0028] The electrical control system 2 is generally composed of low-voltage components, PLC, frequency converter, and detection devices. The operating system 1 generally has two modes: operation by the driver on the crane via a control panel, handle, and foot switch, and operation by the driver under the crane via a remote control.

[0029] The first mode is as follows Figure 6 As shown, the operator is located in the operator's cab on the crane, sitting in seat 42. Using the handle 43 on the control panel 41, the operator issues commands to control the frequency converters of the corresponding mechanisms, driving the hoisting mechanism, translation mechanism (trolley, gantry, luffing), and slewing mechanism. Other crane controls (such as fault reset and emergency stop) and signal displays (torque, weight, limit) are generally implemented through the human-machine interface touchscreen 47 and buttons and indicator lights 44 on the control panel. 45 defines the function labels for each button or indicator light. When the operator's hands are used to operate the mechanisms, if simultaneous commands are required, the system is equipped with a foot switch 46 for foot control.

[0030] Some basic configurations do not have a touchscreen for human-computer interaction, such as Figure 7 As shown, the operator is located in the operator's cab on the crane, sitting in seat 42. He issues commands using handle 43 on the control panel 41 to control the frequency converters of the corresponding mechanisms, driving the hoisting mechanism, translation mechanism (trolley, gantry, luffing), and slewing mechanism. Other crane controls (such as fault reset and emergency stop) and signal displays (torque, weight, limit) are generally implemented using buttons and indicator lights 44 on the control panel. 45 contains function definition labels for each button or indicator light. When the operator's hands are used to operate the mechanisms, if simultaneous commands are required, the system is equipped with a foot switch 46 for foot control.

[0031] In the second mode, the remote control typically uses only buttons for control, without any signal display. For example... Figure 8 As shown, the driver uses button 62 on remote control 61 to issue commands to control the frequency converters of the corresponding mechanisms to drive the hoisting mechanism, translation mechanism (trolley, gantry, luffing), and slewing mechanism, as well as to reset faults and initiate emergency stops for the entire electronic control system. Signal display functionality is not available. 63 contains the function definition labels for each button.

[0032] This invention discloses a crane end-of-line positioning control method, such as... Figure 1 As shown, it includes: S1: The end-positioning start / stop judgment unit determines whether the end-positioning control is started; S2: If not started, it means that we have not yet approached the target position. The end positioning start / stop judgment unit controls the speed command selection unit to select the first input and the control angle decay selection unit selects the first command. The command output by the handle is processed by the ramp limiting unit and then used as the first input; The speed command after the slope limiting process is subtracted from the first command by the speed command selection unit, and then the speed is controlled by the speed control unit. The motor moves towards the target position according to this speed control and returns to S1. The speed control unit inputs not only the data after the slope limiting process is subtracted from the first command, but also the actual speed value of the motor. If activated, it indicates that the target position is being approached. The end-positioning start / stop judgment unit controls the speed command selection unit to select the second input, and the control angle attenuation selection unit selects the second command. The position is adjusted by subtracting the current position from the target position and then used as the second input. The second input is subtracted from the second command by the speed command selection unit, and the speed is controlled by the speed control unit. The load moves to the target position at this controlled speed, eliminating any swaying of the load during the process. The speed control unit receives not only the data obtained by subtracting the second command from the second input, but also the actual motor speed.

[0033] In this embodiment, determining whether end-point positioning control is activated specifically includes: Determine if there is a speed command output from the handle; determine if the foot switch is pressed; and determine if the absolute value of the end-effector target position minus the current position data is less than the end-effector positioning interval threshold. If the handle does not output a speed command, the foot switch is pressed, and the absolute value of the end target position minus the current position data is less than the end positioning interval threshold, the end positioning control is activated. If at least one of the following conditions is met: the handle outputs a speed command, the foot switch is not pressed, and the absolute value of the end target position minus the current position data is not less than the end positioning interval threshold, then the end positioning control is not activated.

[0034] In this embodiment, the angle attenuation selection unit selects the output value 0 as the first instruction; The angle attenuation selection unit calculates the current swing angle of the load using the virtual angle calculation unit based on the actual speed value of the motor. Then, it multiplies the current swing angle of the load with the swing attenuation coefficient given by the swing attenuation coefficient unit and uses this as the second instruction.

[0035] In this embodiment, after speed control is performed by the speed control unit, the method further includes: The motor torque value is output after speed control is performed by the speed control unit. The motor torque value is used to generate the actual motor speed value through the motor kinematic model unit, thereby enabling the updating of the actual motor speed value; The actual speed value of the motor is used to generate the current position data after passing through the integral model unit.

[0036] like Figure 9As shown, the simulation of the operating waveform of a mechanism using the method of this invention demonstrates the operation of such a mechanism, which can be either a translation mechanism or a slewing mechanism of a crane. The initial position of the mechanism is 0, and the end-positioning target position is 35°. First, the speed of the mechanism is controlled by a handle command. The operator does not actively suppress the swaying, and it can be seen that the load sways with varying amplitudes during the time period controlled by the handle command. When the mechanism is at approximately position 28° and the time is approximately 40°, the operator initiates end-positioning control. It can be seen that the speed setpoint of the handle command gradually decreases to 0, and the automatic speed setpoint of the end-positioning, under the control of the aforementioned algorithm, drives the mechanism to the end-positioning target position 35°, at which point the speed setpoint becomes 0, and the swaying angle of the load also becomes 0. That is, the mechanism automatically stops after reaching the end-positioning target position, and the swaying of the load is eliminated.

[0037] This invention discloses a crane end-of-line positioning control system, such as... Figure 2 As shown, it includes: End-point positioning start / stop judgment unit 73: used to determine whether end-point positioning control is started; Speed ​​command selection unit 77: used to receive control from end-positioning start / stop unit 73 and select the first input or the second input. Specifically, when end-positioning control is not started, the command output by handle 43 is selected as the first input after being slope-limited by ramp limiting unit 75. When end-positioning control is started, the command is selected as the second input after subtracting the current position Pos_Fck from the end target position Pos_Ref and adjusting the position by position adjustment unit 76. Angle attenuation selection unit 78: used to receive control from the end positioning start / stop unit and select the first command or the second command; Ramp limiting unit 75: Used to perform ramp limiting processing on the commands output by handle 43; Position adjustment unit 76: used to adjust the position by subtracting the current position Pos_Fck from the end target position Pos_Ref; Speed ​​control unit 79: When the end-positioning control is not activated, it performs speed control by subtracting the first command from the speed command output by the handle 43 after ramp limiting processing. The speed control unit receives not only the data after subtracting the first command from the ramp-limited speed command, but also the actual motor speed value. When the end-positioning control is activated, it performs speed control by subtracting the second command from the second input. The speed control unit receives not only the data after subtracting the second command from the second input, but also the actual motor speed value.

[0038] In this embodiment, an end positioning interval determination unit 74 is also included, which is used to determine whether the absolute value of the end target position Pos_Ref minus the current position Pos_Fck is less than the end positioning interval threshold Pos_Threshold. The end-point positioning start / stop judgment unit 73 determines whether the end-point positioning control is started, specifically including: Determine if there is a speed command output from handle 43, determine if foot switch 46 is pressed, and determine if the absolute value of the end-target position Pos_Ref minus the current position Pos_Fck is less than the end-position positioning interval threshold Pos_Threshold. If the handle 43 does not output a speed command, the foot switch 46 is pressed, and the absolute value of the end target position Pos_Ref minus the current position Pos_Fck is less than the end positioning interval threshold Pos_Threshold, the end positioning control is activated. If at least one of the following conditions is met: the handle 43 outputs a speed command, the foot switch 46 is not pressed, and the absolute value of the end target position minus the current position data is not less than the end positioning interval threshold, then the end positioning control is not activated.

[0039] In other words, the commands from the handle 43, the foot switch 46, and the signals from the end-positioning interval judgment unit 74 are all input into the end-positioning start / stop judgment unit 73.

[0040] In this embodiment, a virtual angle calculation unit 712 and a swing attenuation coefficient unit 710 are also included; The virtual angle calculation unit 712 is used to calculate the current swing angle of the weight based on the actual speed value of the motor. The sway attenuation coefficient unit 710 is used to set the sway attenuation coefficient; The angle attenuation selection unit 78 processes the current position data through the virtual angle calculation unit 712 to obtain the current swing angle of the weight, and multiplies it with the swing attenuation coefficient given by the swing attenuation coefficient unit 710 to obtain the second instruction. Angle attenuation selection unit 78 selects the output value 0 as the first instruction.

[0041] In this embodiment, the system also includes an electric motor kinematics model unit 711 and an integral model unit 713; The motor kinematic model unit 711 is used to calculate the motor torque value output after speed control by the speed control unit 79 to generate the actual motor speed value, thereby realizing the update of the actual motor speed value; The integral model unit 713 is used to integrate the actual speed value of the motor to generate the current position data.

[0042] In this embodiment, the position adjustment unit 76 can be a proportional control, a proportional + integral control, or a proportional + derivative control. The output of the position adjustment unit 76 is a speed command responsible for controlling the speed to reach the position, and this command enters the speed command selection unit 77.

[0043] To achieve end-point positioning control, this invention must also provide the driver with a method to input the target position. A simple implementation method is for the driver's target position to be directly derived from the current position of the crane's load. For example, in a certain scenario, the driver needs to operate the load to a certain position in space. When the driver operates the load to that position for the first time, that position can be set as a target position.

[0044] The specific setup method is as follows: For an electronic control system with a human-computer interaction touchscreen, a virtual button for "Save Current Location as Target Location" can be set on the touchscreen 47. After pressing the button, a dialog box can be used to set the name of the current location. After setting and saving, a virtual button with the named location name can be generated on the touchscreen 47. Multiple target locations can be set using the same method, generating virtual buttons for multiple target locations.

[0045] When a driver needs to enable the end-point positioning function, they can select the corresponding virtual button according to the target location requirement. The virtual button can be pressed and different colors will indicate that it has been selected.

[0046] During the lifting of a heavy object from the starting position to the target position, the driver is responsible for operating the crane's lifting, traversing, or slewing mechanisms before reaching the end-positioning area. The driver is also responsible for ensuring the heavy object avoids any obstacles along the path. Once within the end-positioning area (determined by the driver based on the set end-positioning range value and visual distance estimation, or automatically by the control system based on the set end-positioning range value and the difference between the current position of each mechanism and the target position; the control system can notify the driver via voice, touchscreen display, or buzzer upon confirmation of entry), the end-positioning function is activated by a switch, and the crane mechanism's handle 43 is released. In a system equipped with a control console and handle, this switch can be a foot switch 46 located in front of the control console and under the driver's feet, or an additional button on the handle 43. This switch must be pressed continuously from activation to deactivation of the end-positioning function; otherwise, the system will deactivate the end-positioning function upon release and will only accept commands from the handle 43. For an electronic control system that only has a control panel and lacks a human-machine interface touchscreen, the method for setting the target position is as follows: When the load is already at the target position, switch the "Memory Position / Normal Operation" switch on the control panel 41 to "Memory Position." Then, select an "Enable / Disable" switch as the enable switch for the target position. After a period of time, such as 3 seconds, the system will memorize the current position as the target position into the PLC or frequency converter. If the system has a voice module, it can announce "Position memorization successful" to notify the driver that the setting is complete. If there is no voice module but a buzzer is present, it can sound once to notify the driver that the setting is complete. Next to this "Enable / Disable" switch, text indicating the target position can be written in a laser-engraved format to notify the driver. Multiple target positions can be set using the same method; the number of target positions depends on the number of similar "Enable / Disable" switches on the control panel 41.

[0047] When the driver needs to enable the end-point positioning function, they should switch the corresponding "enable / disable" switch to "enable" according to the target location requirements.

[0048] During the lifting of a heavy object from the starting position to the target position, the driver is responsible for operating the crane's lifting, traversing, or slewing mechanisms before reaching the end-positioning area. The driver is also responsible for ensuring the heavy object avoids any obstacles along the path. Once within the end-positioning area (determined by the driver's visual estimation based on the set end-positioning range value, or automatically by the control system based on the difference between the current position and the target position of each mechanism, and notifying the driver via voice, touchscreen display, or buzzer upon entry), the end-positioning function is activated via a switch, and the crane mechanism's handle 43 is released. In a system equipped with a control console and handle, this switch can be a foot switch 46 located in front of the control console 41 at the driver's feet, or an additional button on the handle 43. This switch must be pressed continuously from activation to deactivation; otherwise, the system will deactivate the end-positioning function upon release and will only accept commands from the handle 43. For an electronic control system equipped only with a remote control, the method for setting the target position is as follows: When the load is already at the target position, simultaneously press and hold the two buttons 62 on the remote control 61 labeled "Position Memory" and "Target Position*" for a period of time, such as 3 seconds. The system will then memorize the current position as a target position into the PLC or frequency converter. If the system lacks any screen, voice, or other feedback modules, the lifting mechanism can be controlled to automatically rise a short distance and then descend a short distance back to its original position as a notification, indicating successful position memorization. Multiple target positions can be set using the same method; the number of target positions depends on the number of similar "Target Position*" buttons 62 on the remote control 61.

[0049] When the driver needs to activate the end-point positioning function, he / she should press the corresponding "target position*" button for a period of time, such as 3 seconds, according to the target position requirements. Since the driver needs to operate other mechanism buttons, it is impossible to keep pressing the button. One possible way to indicate this is to activate the brake switch of the translation mechanism twice, indicating that the end-point positioning function of the target position has been activated.

[0050] During the lifting of a heavy object from the starting position to the target position, the operator is responsible for operating the crane's lifting, traversing, or slewing mechanisms before reaching the end-positioning area. The operator is also responsible for ensuring the heavy object avoids any obstacles along the path. Once within the end-positioning area (the determination of whether the end-positioning area has been entered is made by the operator based on the set end-positioning range value and visual distance estimation during remote control operation), the end-positioning function is activated via button 62. Simultaneously, the buttons for operating the crane mechanisms can be released. This switch, when operated via remote control, must be a predefined button. This switch must be continuously pressed from activation to deactivation of the end-positioning function; otherwise, the system will deactivate the end-positioning function upon release and will only accept button commands from the crane mechanisms.

[0051] The above method for inputting the target position can also be implemented in the settings of crane control systems with manned touch screens, crane control systems without manned touch screens, and crane control systems operated by remote controls. The above implementation is just an example and is not a specific limitation.

[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for positioning control at the end of a crane's operation, characterized in that, include: S1: The end-positioning start / stop judgment unit determines whether the end-positioning control is started; S2: If not started, the end positioning start / stop judgment unit controls the speed command selection unit to select the first input and the control angle attenuation selection unit selects the first command; The command output by the handle is processed by the ramp limiting unit and then used as the first input; After subtracting the first command from the speed command after the slope limiting process by the speed command selection unit, the speed is controlled by the speed control unit. The vehicle moves towards the target position according to this controlled speed and then returns to S1. If started, the end-positioning start / stop judgment unit controls the speed command selection unit to select the second input, and the control angle attenuation selection unit selects the second command: The current position data is subtracted from the end target position, and the position is adjusted by the position adjustment unit before being used as the second input. The second input is subtracted from the second command by the speed command selection unit, and the speed is controlled by the speed control unit to move to the target position.

2. The crane end-of-line positioning control method according to claim 1, characterized in that, Determining whether end-point positioning control is activated specifically includes: Determine if there is a speed command output from the handle; determine if the foot switch is pressed; and determine if the absolute value of the end-effector target position minus the current position data is less than the end-effector positioning interval threshold. If the handle does not output a speed command, the foot switch is pressed, and the absolute value of the end target position minus the current position data is less than the end positioning interval threshold, the end positioning control is activated. If at least one of the following conditions is met: the handle outputs a speed command, the foot switch is not pressed, and the absolute value of the end target position minus the current position data is not less than the end positioning interval threshold, then the end positioning control is not activated.

3. The crane end-of-line positioning control method according to claim 1, characterized in that, The angle attenuation selection unit selects the output value 0 as the first instruction; The angle attenuation selection unit calculates the current swing angle of the load using the virtual angle calculation unit based on the actual speed value of the motor. Then, it multiplies the current swing angle of the load with the swing attenuation coefficient given by the swing attenuation coefficient unit and uses this as the second instruction.

4. The crane end-of-line positioning control method according to claim 1, characterized in that, Speed ​​control via the speed control unit also includes: The motor torque value is output after speed control is performed by the speed control unit. The motor torque value is used to generate the actual motor speed value after passing through the motor kinematic model unit; The actual speed value of the motor is used to generate the current position data after passing through the integral model unit.

5. A crane end-of-line positioning control system, characterized in that, include: End-point positioning start / stop determination unit: used to determine whether end-point positioning control is started; Speed ​​command selection unit: used to receive control from end-positioning start / stop unit and select first input or second input. Specifically, when end-positioning control is not started, the command output by the handle is selected as the first input after being slope-limited by the slope limiting unit. When end-positioning control is started, the command is selected as the second input after subtracting the current position data from the end target position and adjusting the position by the position adjustment unit. Angle attenuation selection unit: used to receive control from the end-positioning start / stop unit and select the first command or the second command; Ramp limiting unit: Used to perform ramp limiting processing on the commands output by the handle; Position adjustment unit: used to adjust the position of the target position by subtracting the current position data from the target position. Speed ​​control unit: used to control speed by subtracting the first command from the speed command output by the handle after ramp limiting when the end-positioning control is not started, and to control speed by subtracting the second command from the second input when the end-positioning control is started.

6. A crane end-of-line positioning control system according to claim 5, characterized in that, It also includes an end-point positioning interval determination unit, used to determine whether the absolute value of the end target position minus the current position is less than the end-point positioning interval threshold; The end-point positioning start / stop determination unit determines whether end-point positioning control is started, specifically including: Determine if there is a speed command output from the handle; determine if the foot switch is pressed; and determine if the absolute value of the end-effector target position minus the current position data is less than the end-effector positioning interval threshold. If the handle does not output a speed command, the foot switch is pressed, and the absolute value of the end target position minus the current position data is less than the end positioning interval threshold, the end positioning control is activated. If at least one of the following conditions is met: the handle outputs a speed command, the foot switch is not pressed, and the absolute value of the end target position minus the current position data is not less than the end positioning interval threshold, then the end positioning control is not activated.

7. A crane end-of-line positioning control system according to claim 5, characterized in that, It also includes a virtual angle calculation unit and a sway attenuation coefficient unit; The virtual angle calculation unit is used to calculate the current swing angle of the weight based on the actual speed value of the motor. The sway attenuation coefficient unit is used to set the sway attenuation coefficient; The angle attenuation selection unit multiplies the current swing angle of the weight obtained by the virtual angle calculation unit with the swing attenuation coefficient given by the swing attenuation coefficient unit and uses it as the second instruction. The angle attenuation selection unit selects the output value 0 as the first instruction.

8. A crane end-of-line positioning control system according to claim 5, characterized in that, It also includes motor kinematics model units and integral model units; The motor kinematic model unit is used to calculate the actual speed value of the motor by calculating the motor torque value output after speed control by the speed control unit; The integral model unit is used to integrate the actual speed value of the motor to generate the current position data.

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