A crane hook vertical control system and control method thereof

Abstract

A crane hook vertical control system includes a boom, a pulley, a wire rope, a hook, a controller, a tension sensor, an inclination sensor, a variable amplitude mechanism, a slewing mechanism, a lifting mechanism, a crane tower and a control platform; the top of the boom is provided with a pulley that rotates with it, the bottom of the boom rotates with the crane tower, the variable amplitude mechanism is in transmission with the boom, the bottom of the crane tower rotates with the top of the crane chassis, the crane tower is provided with a lifting mechanism, the lifting mechanism is provided with a tension sensor, the tension sensor is used to measure the tension received by the wire rope, the lifting mechanism is fixedly connected to the hook through the wire rope, and the inclination sensor is provided on the wire rope near the hook. This design can not only automatically control the boom to adjust its position to avoid the hook swinging after lifting, but also can adopt electric drive or hydraulic drive to meet different needs.

Description

Technical Field

[0001] The present invention relates to a crane control system, in particular to a crane hook vertical control system and a control method thereof, and is specifically applicable to a crane hook vertical control system and a control method thereof for preventing the hook from swinging after lifting. Background Art

[0002] A crane refers to a multi-action lifting machinery that lifts heavy objects vertically and moves them horizontally within a certain range. The crane bears the lifting load through the boom and wire rope and drives the load to move vertically or horizontally. The crane changes the direction of the wire rope through the pulley at the top of the boom so that the wire rope can lift the goods upward. During the lifting process of the crane, if the goods to be lifted are not directly under the pulley, the wire rope for lifting the goods will form an angle with the vertical line passing through the pulley, and the goods cannot be lifted vertically, which will cause the wire rope to swing back and forth, causing safety hazards and even major accidents.

[0003] At present, in order to avoid accidents, cranes often use manual inspection or video monitoring systems to detect the inclination of the wire rope. The manual inspection method provides crane workers with manual hooks and guides crane operators to adjust the boom position. The video monitoring system collects cargo swing information through cameras and automatically adjusts the boom position. Although these two monitoring systems can prevent cargo swing by detecting the inclination of the wire rope, they still have the following defects:

[0004] 1. Although the manual detection method can realize the anti-sway detection function at a low cost, the vision of the crane operator during the manual detection process is limited by the human field of vision and cannot guide the crane operator to reach the most suitable position. At the same time, the crane, especially the large-tonnage crane, is prone to cause personal injury to the crane operator during operation.

[0005] 2. The camera of the video surveillance system generates wire rope inclination information through images. The camera lens is easily affected by weather, resulting in unclear vision.

[0006] 3. Although the video surveillance system can automatically monitor the inclination of the wire rope, the camera lens is easily contaminated by fog, rain, snow, etc., and requires atmospheric maintenance. The camera lens is located at a high place and is difficult to maintain, resulting in increased maintenance costs. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art, such as high maintenance cost and poor monitoring effect, and to provide a single-layer steel wire rope drum which is easy to operate and has low production cost.

[0008] To achieve the above objectives, the technical solution of the present invention is:

[0009] A crane hook vertical control system and control method thereof, the control system comprising: a boom, a pulley, a steel wire rope, a hook, a controller, a tension sensor, an inclination sensor, a luffing mechanism, a slewing mechanism, a lifting mechanism and a crane tower; a pulley rotatably matched with the boom is arranged on the top of the boom, the bottom of the boom is connected to the crane tower, the bottom of the boom is rotatably matched with the crane tower, the rotating shaft of the boom is arranged horizontally, the luffing mechanism is transmission matched with the boom, the slewing mechanism is transmission matched with the bottom of the crane tower, the bottom of the crane tower is rotationally matched with the top of the crane chassis, the crane tower is arranged with a lifting mechanism, the lifting mechanism is provided with a tension sensor, the tension sensor is used to measure the tension of the steel wire rope, one end of the steel wire rope is fixedly connected to the lifting mechanism, the other end of the steel wire rope is fixedly connected to the hook after passing through the pulley, the lifting mechanism is transmission matched with the hook through the steel wire rope, and the inclination sensor is arranged on the steel wire rope near the hook;

[0010] The tension signal input end of the controller is connected to the signal output end of the tension sensor, the inclination signal input end of the controller is connected to the signal output end of the inclination sensor, and the control end of the controller is respectively connected to the luffing mechanism, the slewing mechanism and the lifting mechanism signal;

[0011] The control method comprises the following steps:

[0012] Step 1: Power-on self-check, turn on the system so that the hook is perpendicular to the ground under the influence of gravity, and the system automatically establishes a spatial rectangular coordinate system, the XOY plane of the spatial rectangular coordinate system is a horizontal plane, and the origin of the spatial rectangular coordinate system is the position O where the inclinometer is located. At this time, the X-axis of the spatial rectangular coordinate system coincides with the first axis of the inclinometer, the Y-axis of the spatial rectangular coordinate system coincides with the second axis of the inclinometer, and the Z-axis of the spatial rectangular coordinate system is set vertically to the ground. After the spatial rectangular coordinate system is established, the operator adjusts the inclinometer sensor bracket so that the X-axis of the spatial rectangular coordinate system coincides with the projection of the boom on the XOY plane. At this time, the power-on self-check step is completed;

[0013] Step 2: Hang and pick up the cargo. The operator connects the hook to the cargo to be picked up. After the hook is connected to the cargo to be picked up, the operator operates the controller to start working. The controller sends a lifting signal to drive the lifting mechanism to start working. After the lifting mechanism starts working, it reels in the wire rope and drives the hook to rise through the wire rope. After the hook rises, it provides upward pulling force to the cargo to be picked up. At this time, the tension sensor continuously detects the tension of the wire rope. When the tension sensor detects that the tension of the wire rope is greater than the empty hook weight of the hook, the lifting mechanism stops working and the system enters the third step of detection.

[0014] Step 3: Detect the inclination data, set the contact point between the wire rope and the pulley as point A, and the line segment of the wire rope OA segment projected onto the XOY plane as OA'. The inclination sensor continuously detects the inclination of the wire rope and sends the inclination data to the controller. After receiving the inclination data, the controller calculates the coordinates of point A' in the spatial rectangular coordinate system as (X, Y,), and then enters the fourth step of adjustment;

[0015] Step 4: Adjust the lifting posture. The controller sends a corresponding signal according to the current coordinates of point A (X, Y,) to drive the slewing mechanism and the luffing mechanism to work:

[0016] a) When X>, the controller sends a signal to drive the slewing mechanism to work, and the slewing mechanism drives the crane tower to rotate left.

[0017] b) When X<, the controller sends a signal to drive the slewing mechanism to work, and the slewing mechanism drives the crane tower to rotate to the right.

[0018] c) When X=, the slewing mechanism does not work.

[0019] d) When Y>, the controller sends a signal to drive the luffing mechanism to work, and the luffing mechanism drives the boom to increase its elevation angle.

[0020] e) When Y <, the controller sends a signal to drive the luffing mechanism to work, and the luffing mechanism drives the boom to reduce its elevation angle.

[0021] f) When Y=, the luffing mechanism does not work.

[0022] When the slewing mechanism and the luffing mechanism are working, the tension sensor continuously detects the tension on the wire rope. When the tension sensor detects that the tension on the wire rope is less than or equal to the deadweight of the wire rope and the hook, the slewing mechanism and the luffing mechanism stop working, and at the same time the controller sends a signal to drive the lifting mechanism to start working to reel in the wire rope until the tension sensor detects that the tension on the wire rope is greater than the empty hook weight of the hook. At this time, the slewing mechanism and the luffing mechanism continue to work. When the X value and the Y value are less than the safety threshold of the crane, the adjustment step is completed, and the lifting operation can be carried out safely at this time.

[0023] The control system further comprises a control platform, a display signal input terminal of the control platform is connected to a display signal output terminal of the controller, and a control signal output terminal of the control platform is connected to a control signal input terminal of the controller.

[0024] The luffing mechanism, slewing mechanism and lifting mechanism are all motor-driven execution structures. The luffing signal input end of the luffing mechanism is connected to the luffing signal output end of the controller via a data bus, the slewing signal input end of the slewing mechanism is connected to the slewing signal output end of the controller via a data bus, the lifting signal input end of the lifting mechanism is connected to the lifting signal output end of the controller via a data bus, the controller is connected to the control platform signal via the data bus, and the luffing mechanism is fixedly connected to the top end of the boom via an luffing wire rope.

[0025] The luffing mechanism, slewing mechanism and lifting mechanism are all hydraulically driven execution structures. The luffing signal input end of the luffing mechanism is connected to the luffing signal output end of the controller through a control line, the slewing signal input end of the slewing mechanism is connected to the slewing signal output end of the controller through a control line, the lifting signal input end of the lifting mechanism is connected to the lifting signal output end of the controller through a control line, the controller is connected to the control platform signal through a data bus, and the luffing mechanism is fixedly connected to the middle part of the boom through a hydraulic cylinder.

[0026] The inclination sensor is a dual-axis inclination sensor, and the distance between the inclination sensor and the hook is less than 1 meter.

[0027] The inclination sensor is sleeved on the steel wire rope through an inclination sensor bracket, and the inclination sensor bracket is rotationally matched with the steel wire rope.

[0028] The control method further includes a tension sensor calibration step, which is performed by an operator during the crane installation phase or the crane maintenance phase. The tension sensor calibration step is as follows:

[0029] The operator operates the control platform to manually input the empty hook weight, where the empty hook weight is the tension detected by the tension sensor when the hook is flush with the top of the cargo to be lifted. After the operator inputs the empty hook weight, the operator operates the controller to enter the calibration step and performs the second preparation step, the third detection step and the fourth adjustment step. At the same time, the operator observes the working condition of the crane. When the cargo to be lifted is lifted off the ground during the operation of the crane or the lifting mechanism does not start working and reel in the wire rope after the wire rope is in a slack state in the fourth adjustment step, it indicates that the tension sensor is faulty and needs to be replaced. The tension sensor calibration step is completed when the crane completes the second step of hanging cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture.

[0030] The control method further includes a tilt sensor calibration step, which is performed by an operator during the crane installation phase or the crane maintenance phase. The tilt sensor calibration step is as follows:

[0031] The operator operates the controller to enter the calibration step and keeps the hook vertically downward. The operator operates the controller to calibrate the inclination signal sent by the inclination sensor to degrees. After the operator calibrates the inclination signal of degrees, the operator operates the controller to input the crane safety threshold. After the operator inputs the crane safety threshold, the operator operates the crane to perform the second preparation step, the third detection step and the fourth adjustment step to calibrate the crane safety threshold. The operator observes the working condition of the crane. When the X value and Y value do not decrease during the operation of the luffing mechanism and the slewing mechanism in the fourth adjustment step, it indicates that the inclination sensor is faulty and needs to be replaced. The inclination sensor calibration step is completed when the crane completes the second step of hanging and picking up the cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. In a crane hook vertical control system of the present invention, a tilt sensor is arranged on the wire rope, which can detect the tilt information of the wire rope and send it to the controller. The controller calculates the coordinates of the hook through the tilt information, and then controls the adjustment position of the boom to ensure that the wire rope is in a vertical state, and avoids the goods driving the wire rope to swing during the lifting process, causing safety accidents. Therefore, the design can obtain the hook coordinates through the tilt sensor, and then control the adjustment position of the boom, effectively improving the safety of the system.

[0034] 2. In a vertical control system of a crane hook of the present invention, the displacement of the crane boom in the vertical and horizontal directions is controlled by the luffing mechanism and the slewing mechanism, and the retraction and release of the wire rope is controlled by the lifting mechanism. A weight sensor is provided on the lifting mechanism, and the weight sensor can detect the tension on the wire rope, ensure that the wire rope is straightened during the adjustment process to provide accurate inclination information, and avoid safety accidents caused by direct lifting of goods. Therefore, this design can detect the tension on the wire rope through the weight sensor, ensure the accuracy of system detection and effectively improve safety.

[0035] 3. The luffing mechanism, slewing mechanism and lifting mechanism in the vertical control system of the crane hook of the present invention can be electric drive mechanisms or hydraulic drive mechanisms. The electric drive mechanism has a larger power and is suitable for large cranes, while the hydraulic drive mechanism has a lower cost when used on small and medium-sized cranes. Therefore, the design can adopt electric drive or hydraulic drive to meet different needs and effectively improve the scope of application of the system.

[0036] 4. In a crane hook vertical control system of the present invention, the inclination sensor is arranged on the wire rope through the inclination sensor bracket, and the inclination sensor bracket is rotated with the wire rope. By rotating the inclination sensor bracket, the axial direction of the inclination sensor can be matched with the direction of the spatial rectangular coordinate system, thereby improving the detection accuracy of the system and reducing the calculation difficulty of the controller. Therefore, the design can adjust the axial direction of the inclination sensor, effectively improving the detection accuracy of the system and reducing the calculation difficulty of the controller.

[0037] 5. In the control method of the vertical control system of a crane hook of the present invention, the weight and inclination information are detected by the weight sensor and the inclination sensor and sent to the controller, and the controller processes the weight and inclination information and drives the luffing mechanism and the slewing mechanism to work according to the processing results, so as to adjust the position of the boom to ensure the vertical lifting of the goods. Therefore, the design can automatically adjust the position of the boom to ensure the vertical lifting of the goods, avoid manual detection by the crane worker, effectively improve the detection effect, and improve safety at the same time.

[0038] 6. The control method of a crane hook vertical control system of the present invention includes a calibration step. The calibration step can calibrate the accuracy of each sensor and actuator in the system by detecting the correspondence between the sensor detection signal and the actual state, and the operator can eliminate the system error according to the result to improve the accuracy of the instrument or system. Therefore, the calibration step in this design can eliminate the system error, calibrate the system accuracy, and effectively improve the detection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the present invention.

[0040] Figure 2 It is a control signal schematic diagram of the motor actuator of the present invention.

[0041] Figure 3 It is a control signal schematic diagram of the hydraulic actuator of the present invention.

[0042] Figure 4 It is a control flow chart of the present invention.

[0043] Figure 5 It is a schematic diagram of the spatial rectangular coordinate system in the present invention.

[0044] Figure 6 It is a control flow chart of the calibration step of the present invention.

[0045] In the figure: boom 1, pulley 2, wire rope 3, hook 4, controller 5, weight sensor 6, inclination sensor 7, luffing mechanism 8, slewing mechanism 9, lifting mechanism 10, crane tower 11, control platform 12. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0047] See also Figures 1 to 6 A crane hook vertical control system, the control system comprising: a boom 1, a pulley 2, a wire rope 3, a hook 4, a controller 5, a tension sensor 6, an inclination sensor 7, a luffing mechanism 8, a slewing mechanism 9, a lifting mechanism 10 and a crane tower 11;

[0048] The top of the boom 1 is provided with a pulley 2 that rotates with it, the bottom of the boom 1 is connected to the crane tower 11, the bottom of the boom 1 rotates with the crane tower 11, the rotating axis of the boom 1 is arranged horizontally, the luffing mechanism 8 is transmission-coordinated with the boom 1, the slewing mechanism 9 is transmission-coordinated with the bottom of the crane tower 11, the bottom of the crane tower 11 rotates with the top of the crane chassis, a lifting mechanism 10 is arranged on the crane tower 11, a tension sensor 6 is arranged on the lifting mechanism 10, the tension sensor 6 is used to measure the tension exerted on the wire rope 3, one end of the wire rope 3 is fixedly connected to the lifting mechanism 10, the other end of the wire rope 3 is fixedly connected to the hook 4 after passing through the pulley 2, the lifting mechanism 10 is transmission-coordinated with the hook 4 through the wire rope 3, and the inclination sensor 7 is arranged on the wire rope 3 near the hook 4;

[0049] The tension signal input end of the controller 5 is connected to the signal output end of the tension sensor 6, the inclination signal input end of the controller 5 is connected to the signal output end of the inclination sensor 7, and the control end of the controller 5 is respectively connected to the amplitude variation mechanism 8, the slewing mechanism 9 and the lifting mechanism 10.

[0050] The control system further comprises a control platform 12 , a display signal input terminal of the control platform 12 is connected to a display signal output terminal of the controller 5 , and a control signal output terminal of the control platform 12 is connected to a control signal input terminal of the controller 5 .

[0051] The luffing mechanism 8, slewing mechanism 9 and lifting mechanism 10 are all motor-driven execution structures. The luffing signal input end of the luffing mechanism 8 is connected to the luffing signal output end of the controller 5 via a data bus, the slewing signal input end of the slewing mechanism 9 is connected to the slewing signal output end of the controller 5 via a data bus, the lifting signal input end of the lifting mechanism 10 is connected to the lifting signal output end of the controller 5 via a data bus, the controller 5 is connected to the control platform 12 signal via a data bus, and the luffing mechanism 8 is fixedly connected to the top end of the boom 1 via a luffing wire rope.

[0052] The luffing mechanism 8, slewing mechanism 9 and lifting mechanism 10 are all hydraulically driven execution structures. The luffing signal input end of the luffing mechanism 8 is connected to the luffing signal output end of the controller 5 through a control line, the slewing signal input end of the slewing mechanism 9 is connected to the slewing signal output end of the controller 5 through a control line, the lifting signal input end of the lifting mechanism 10 is connected to the lifting signal output end of the controller 5 through a control line, the controller 5 is connected to the control platform 12 signal through a data bus, and the luffing mechanism 8 is fixedly connected to the middle part of the boom 1 through a hydraulic cylinder.

[0053] The inclination sensor 7 is a dual-axis inclination sensor, and the distance between the inclination sensor 7 and the hook 4 is less than 1 meter.

[0054] The inclination sensor 7 is sleeved on the steel wire rope 3 through an inclination sensor bracket, and the inclination sensor bracket is rotatably matched with the steel wire rope 3 .

[0055] A control method for a crane hook vertical control system, characterized in that:

[0056] The control method comprises the following steps:

[0057] Step 1: Power-on self-check, turn on the system so that the hook 4 is perpendicular to the ground under the influence of gravity, and the system automatically establishes a spatial rectangular coordinate system, the XOY plane of the spatial rectangular coordinate system is a horizontal plane, and the origin of the spatial rectangular coordinate system is the position O where the inclination sensor 7 is located. At this time, the X-axis of the spatial rectangular coordinate system coincides with the first axis of the inclination sensor 7, the Y-axis of the spatial rectangular coordinate system coincides with the second axis of the inclination sensor 7, and the Z-axis of the spatial rectangular coordinate system is set vertically to the ground. After the spatial rectangular coordinate system is established, the operator adjusts the inclination sensor bracket so that the X-axis of the spatial rectangular coordinate system coincides with the projection of the boom 1 on the XOY plane. At this time, the power-on self-check step is completed;

[0058] Step 2: Hanging and picking up the cargo, the operator connects the hook 4 to the cargo to be picked up, and after the hook 4 is connected to the cargo to be picked up, the operator operates the controller 5 to start working, and the controller 5 sends a lifting signal to drive the lifting mechanism 10 to start working. After the lifting mechanism 10 starts working, it reels in the wire rope 3 and drives the hook 4 to rise through the wire rope 3. After the hook 4 rises, it provides an upward pulling force to the cargo to be picked up. At this time, the tension sensor 6 continuously detects the tension of the wire rope 3. When the tension sensor 6 detects that the tension of the wire rope 3 is greater than the empty hook weight of the hook 4, the lifting mechanism 10 stops working and the system enters the third detection step;

[0059] Step 3: Detect the inclination data, set the contact point between the wire rope 3 and the pulley 2 as point A, and the line segment of the wire rope segment OA projected onto the XOY plane as OA'. The inclination sensor 7 continuously detects the inclination of the wire rope 3 and sends the inclination data to the controller 5. After receiving the inclination data, the controller 5 calculates the coordinates of point A' in the spatial rectangular coordinate system as (X, Y, 0), and then enters the fourth step of adjustment;

[0060] Step 4: Adjust the lifting posture. The controller 5 sends a corresponding signal according to the current coordinates of point A (X, Y, 0) to drive the slewing mechanism 9 and the luffing mechanism 8 to work:

[0061] a) When X>0, the controller 5 sends a signal to drive the slewing mechanism 9 to work, and the slewing mechanism 9 drives the crane tower 11 to rotate left.

[0062] b) When X < 0, the controller 5 sends a signal to drive the slewing mechanism 9 to work, and the slewing mechanism 9 drives the crane tower 11 to rotate right.

[0063] c) When X=0, the slewing mechanism 9 does not work.

[0064] d) When Y>0, the controller 5 sends a signal to drive the luffing mechanism 8 to work, and the luffing mechanism 8 drives the boom 1 to increase its elevation angle.

[0065] e) When Y < 0, the controller 5 sends a signal to drive the luffing mechanism 8 to work, and the luffing mechanism 8 drives the boom 1 to reduce its elevation angle.

[0066] f) When Y=0, the luffing mechanism 8 does not work.

[0067] When the slewing mechanism 9 and the luffing mechanism 8 are working, the tension sensor 6 continuously detects the tension on the wire rope 3. When the tension sensor 6 detects that the tension on the wire rope 3 is less than or equal to the deadweight of the wire rope 3 and the hook 4, the slewing mechanism 9 and the luffing mechanism 8 stop working, and at the same time the controller 5 sends a signal to drive the lifting mechanism 10 to start working to reel in the wire rope 3 until the tension sensor 6 detects that the tension on the wire rope 3 is greater than the empty hook weight of the hook 4. At this time, the slewing mechanism 9 and the luffing mechanism 8 continue to work. When the X value and the Y value are less than the safety threshold of the crane, the adjustment step is completed, and the lifting operation can be carried out safely at this time.

[0068] The control method further includes a calibration step of the tension sensor 6, which is performed by an operator during the crane installation phase or the crane maintenance phase. The calibration step of the tension sensor 6 is as follows:

[0069] The operator operates the control platform 12 to manually input the empty hook weight of the hook 4, where the empty hook weight of the hook 4 is the tension detected by the tension sensor 6 when the hook 4 is flush with the top height of the cargo to be lifted; after the operator inputs the empty hook weight of the hook 4, the operator operates the controller 5 to enter the calibration step and performs the second preparation step, the third detection step and the fourth adjustment step. At the same time, the operator observes the working condition of the crane. When the cargo to be lifted is lifted off the ground during the operation of the crane or the lifting mechanism 10 does not start working and reel in the wire rope 3 after the wire rope 3 is in a relaxed state in the fourth adjustment step, it indicates that the tension sensor 6 is faulty and needs to be replaced; the calibration step of the tension sensor 6 is completed when the crane completes the second step of hanging cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture.

[0070] The control method further includes a calibration step of the inclination sensor 7, which is performed by an operator during the crane installation phase or the crane maintenance phase. The calibration step of the inclination sensor 7 is as follows:

[0071] The operator operates the controller 5 to enter the calibration step and keeps the hook 4 vertically downward. The operator operates the controller 5 to calibrate the inclination signal emitted by the inclination sensor 7 to be 0 degrees. After the operator calibrates the inclination signal of 0 degrees, the operator operates the controller 5 to input the crane safety threshold. After the operator inputs the crane safety threshold, the operator operates the crane to perform the second preparation step, the third detection step and the fourth adjustment step to calibrate the crane safety threshold. The operator observes the working condition of the crane. When the X value and the Y value do not decrease during the operation of the luffing mechanism 8 and the slewing mechanism 9 in the fourth adjustment step, it indicates that the inclination sensor 7 is faulty and needs to be replaced; when the crane completes the second step of hanging and picking up the cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture, the calibration step of the inclination sensor 7 is completed.

[0072] The principle of the present invention is described as follows:

[0073] The present invention provides an upward pulling force to the steel wire rope 3 through the lifting mechanism 10, and at the same time the weight of the cargo itself provides a downward pulling force to the steel wire rope 3. The two work together to straighten the steel wire rope 3. The steel wire rope 3 can accurately reflect its own inclination in the straightened state. At this time, the inclination information of the steel wire rope 3 can be detected by the inclination sensor 7.

[0074] The present invention sets the hook 4 as the coordinate origin of the spatial rectangular coordinate system, and calculates the line segment projection of the wire rope 3 in the straight state on the XOY plane through the inclination information of the wire rope 3. The projection point of the pulley 2 on the XOY plane is obtained through the projection information of the wire rope 3. The distance between the projection point of the pulley 2 and the X-axis and Y-axis of the spatial rectangular coordinate system is the deviation distance between the hook 4 and the pulley 2 in the horizontal direction. The controller drives the amplitude variation mechanism 8 and the slewing mechanism 9 to work according to the deviation distance information to reduce the deviation distance until the deviation distance between the hook 4 and the pulley 2 in the horizontal direction is less than the preset crane safety threshold. At this time, lifting can prevent the cargo from causing the wire rope 3 to swing.

[0075] In the present invention, the controller 5 is connected to each execution structure signal through a data bus. The controller 5 outputs a pulse-adjustable periodic square wave pulse signal. When the pulse width of the square wave changes, the corresponding execution structure starts to work, and the working amplitude of the execution structure is proportional to the change of the pulse width. Example

[0076] A crane hook vertical control system and a control method thereof, the control system comprising: a boom 1, a pulley 2, a wire rope 3, a hook 4, a controller 5, a tension sensor 6, an inclination sensor 7, a luffing mechanism 8, a slewing mechanism 9, a lifting mechanism 10 and a crane tower 11; the top of the boom 1 is provided with a pulley 2 that rotates with it, the bottom of the boom 1 is connected to the crane tower 11, the bottom of the boom 1 rotates with the crane tower 11, the rotating axis of the boom 1 is horizontally arranged, the luffing mechanism 8 is in transmission cooperation with the boom 1, the slewing mechanism 9 is in transmission cooperation with the bottom of the crane tower 11, the bottom of the crane tower 11 rotates with the top of the crane chassis, the crane tower A lifting mechanism 10 is arranged on 11, and a tension sensor 6 is arranged on the lifting mechanism 10. The tension sensor 6 is used to measure the tension exerted on the wire rope 3. One end of the wire rope 3 is fixedly connected to the lifting mechanism 10, and the other end of the wire rope 3 is fixedly connected to the hook 4 after passing through the pulley 2. The lifting mechanism 10 is matched with the hook 4 through the wire rope 3, and the inclination sensor 7 is arranged on the wire rope 3 near the hook 4; the tension signal input end of the controller 5 is connected to the signal output end of the tension sensor 6, and the inclination signal input end of the controller 5 is connected to the signal output end of the inclination sensor 7. The control end of the controller 5 is respectively connected to the amplitude variation mechanism 8, the slewing mechanism 9 and the lifting mechanism 10.

[0077] The control method comprises the following steps:

[0078] Step 1: Power-on self-check, turn on the system so that the hook 4 is perpendicular to the ground under the influence of gravity, and the system automatically establishes a spatial rectangular coordinate system, the XOY plane of the spatial rectangular coordinate system is a horizontal plane, and the origin of the spatial rectangular coordinate system is the position O where the inclination sensor 7 is located. At this time, the X-axis of the spatial rectangular coordinate system coincides with the first axis of the inclination sensor 7, the Y-axis of the spatial rectangular coordinate system coincides with the second axis of the inclination sensor 7, and the Z-axis of the spatial rectangular coordinate system is set vertically to the ground. After the spatial rectangular coordinate system is established, the operator adjusts the inclination sensor bracket so that the X-axis of the spatial rectangular coordinate system coincides with the projection of the boom 1 on the XOY plane. At this time, the power-on self-check step is completed;

[0079] Step 2: Hanging and picking up the cargo, the operator connects the hook 4 to the cargo to be picked up, and after the hook 4 is connected to the cargo to be picked up, the operator operates the controller 5 to start working, and the controller 5 sends a lifting signal to drive the lifting mechanism 10 to start working. After the lifting mechanism 10 starts working, it reels in the wire rope 3 and drives the hook 4 to rise through the wire rope 3. After the hook 4 rises, it provides an upward pulling force to the cargo to be picked up. At this time, the tension sensor 6 continuously detects the tension of the wire rope 3. When the tension sensor 6 detects that the tension of the wire rope 3 is greater than the empty hook weight of the hook 4, the lifting mechanism 10 stops working and the system enters the third detection step;

[0080] Step 3: Detect the inclination data, set the contact point between the wire rope 3 and the pulley 2 as point A, and the line segment of the wire rope segment OA projected onto the XOY plane as OA'. The inclination sensor 7 continuously detects the inclination of the wire rope 3 and sends the inclination data to the controller 5. After receiving the inclination data, the controller 5 calculates the coordinates of point A' in the spatial rectangular coordinate system as (X, Y, 0), and then enters the fourth step of adjustment;

[0081] Step 4: Adjust the lifting posture. The controller 5 sends a corresponding signal according to the current coordinates of point A (X, Y, 0) to drive the slewing mechanism 9 and the luffing mechanism 8 to work:

[0082] a) When X>0, the controller 5 sends a signal to drive the slewing mechanism 9 to work, and the slewing mechanism 9 drives the crane tower 11 to rotate left.

[0083] b) When X < 0, the controller 5 sends a signal to drive the slewing mechanism 9 to work, and the slewing mechanism 9 drives the crane tower 11 to rotate right.

[0084] c) When X=0, the slewing mechanism 9 does not work.

[0085] d) When Y>0, the controller 5 sends a signal to drive the luffing mechanism 8 to work, and the luffing mechanism 8 drives the boom 1 to increase its elevation angle.

[0086] e) When Y < 0, the controller 5 sends a signal to drive the luffing mechanism 8 to work, and the luffing mechanism 8 drives the boom 1 to reduce its elevation angle.

[0087] f) When Y=0, the luffing mechanism 8 does not work.

[0088] When the slewing mechanism 9 and the luffing mechanism 8 are working, the tension sensor 6 continuously detects the tension on the wire rope 3. When the tension sensor 6 detects that the tension on the wire rope 3 is less than or equal to the deadweight of the wire rope 3 and the hook 4, the slewing mechanism 9 and the luffing mechanism 8 stop working, and at the same time, the controller 5 sends a signal to drive the lifting mechanism 10 to start working to reel in the wire rope 3 until the tension sensor 6 detects that the tension on the wire rope 3 is greater than the empty hook weight of the hook 4. At this time, the slewing mechanism 9 and the luffing mechanism 8 continue to work. When the X value and the Y value are less than the safety threshold of the crane, the adjustment step is completed, and the lifting operation can be carried out safely at this time;

[0089] The control system also includes a control platform 12, a display signal input end of the control platform 12 is connected to a display signal output end of the controller 5, and a control signal output end of the control platform 12 is connected to a control signal input end of the controller 5; the luffing mechanism 8, the slewing mechanism 9 and the lifting mechanism 10 are all motor-driven execution structures, the luffing signal input end of the luffing mechanism 8 is connected to the luffing signal output end of the controller 5 via a data bus, the slewing signal input end of the slewing mechanism 9 is connected to the slewing signal output end of the controller 5 via a data bus, the lifting signal input end of the lifting mechanism 10 is connected to the lifting signal output end of the controller 5 via a data bus, the controller 5 is connected to the control platform 12 signal via a data bus, and the luffing mechanism 8 is fixedly connected to the top of the boom 1 via an luffing wire rope. The luffing mechanism 8, slewing mechanism 9 and lifting mechanism 10 are all hydraulically driven execution structures. The luffing signal input end of the luffing mechanism 8 is connected to the luffing signal output end of the controller 5 through a control line, the slewing signal input end of the slewing mechanism 9 is connected to the slewing signal output end of the controller 5 through a control line, the lifting signal input end of the lifting mechanism 10 is connected to the lifting signal output end of the controller 5 through a control line, the controller 5 is connected to the control platform 12 signal through a data bus, and the luffing mechanism 8 is fixedly connected to the middle part of the boom 1 through a hydraulic cylinder; the inclination sensor 7 is a dual-axis inclination sensor, and the distance between the inclination sensor 7 and the hook 4 is less than 1 meter; the inclination sensor 7 is mounted on the wire rope 3 through an inclination sensor bracket, and the inclination sensor bracket rotates with the wire rope 3. Example

[0090] Embodiment 2 is substantially the same as Embodiment 1, except that:

[0091] The control method further includes a calibration step of the tension sensor 6, which is performed by an operator during the crane installation phase or the crane maintenance phase. The calibration step of the tension sensor 6 is as follows:

[0092] The operator operates the control platform 12 to manually input the empty hook weight of the hook 4, where the empty hook weight of the hook 4 is the tension detected by the tension sensor 6 when the hook 4 is flush with the top height of the cargo to be lifted; after the operator inputs the empty hook weight of the hook 4, the operator operates the controller 5 to enter the calibration step and performs the second preparation step, the third detection step and the fourth adjustment step. At the same time, the operator observes the working condition of the crane. When the cargo to be lifted is lifted off the ground during the operation of the crane or the lifting mechanism 10 does not start working and reel in the wire rope 3 after the wire rope 3 is in a relaxed state in the fourth adjustment step, it indicates that the tension sensor 6 is faulty and needs to be replaced; the calibration step of the tension sensor 6 is completed when the crane completes the second step of hanging cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture. Example

[0093] Embodiment 3 is substantially the same as Embodiment 2, except that:

[0094] The control method further includes a calibration step of the inclination sensor 7, which is performed by an operator during the crane installation phase or the crane maintenance phase. The calibration step of the inclination sensor 7 is as follows:

[0095] The operator operates the controller 5 to enter the calibration step and keeps the hook 4 vertically downward. The operator operates the controller 5 to calibrate the inclination signal emitted by the inclination sensor 7 to be 0 degrees. After the operator calibrates the inclination signal of 0 degrees, the operator operates the controller 5 to input the crane safety threshold. After the operator inputs the crane safety threshold, the operator operates the crane to perform the second preparation step, the third detection step and the fourth adjustment step to calibrate the crane safety threshold. The operator observes the working condition of the crane. When the X value and the Y value do not decrease during the operation of the luffing mechanism 8 and the slewing mechanism 9 in the fourth adjustment step, it indicates that the inclination sensor 7 is faulty and needs to be replaced; when the crane completes the second step of hanging and picking up the cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture, the calibration step of the inclination sensor 7 is completed.

Claims

1. A method for vertically controlling a crane hook, characterized in that: The control method is based on the following control structure: A boom (1), a pulley (2), a steel wire rope (3), a hook (4), a controller (5), a tension sensor (6), an inclination sensor (7), a luffing mechanism (8), a slewing mechanism (9), a lifting mechanism (10) and a crane tower (11); the top of the boom (1) is provided with a pulley (2) rotatably matched with the boom, the bottom of the boom (1) is connected to the crane tower (11), the bottom of the boom (1) is rotatably matched with the crane tower (11), the rotating shaft of the boom (1) is arranged horizontally, the luffing mechanism (8) is transmission matched with the boom (1), the slewing mechanism (9) is transmission matched with the bottom of the crane tower (11), the bottom of the crane tower (11) is rotatably matched with the top of the crane chassis, and the lifting mechanism (10) is provided on the crane tower (11). The lifting mechanism (10) is provided with a tension sensor (6), and the tension sensor (6) is used to measure the tension applied to the wire rope (3). One end of the wire rope (3) is fixedly connected to the lifting mechanism (10), and the other end of the wire rope (3) is fixedly connected to the hook (4) after passing through the pulley (2). The lifting mechanism (10) is transmission-coordinated with the hook (4) through the wire rope (3), and the inclination sensor (7) is arranged on the wire rope (3) near the hook (4); the tension signal input end of the controller (5) is connected to the signal output end of the tension sensor (6), and the inclination signal input end of the controller (5) is connected to the signal output end of the inclination sensor (7). The control end of the controller (5) is signal-connected to the variable amplitude mechanism (8), the slewing mechanism (9) and the lifting mechanism (10) respectively; The control method comprises the following steps: Step 1: Power-on self-check. Turn on the system so that the hook (4) is perpendicular to the ground under the influence of gravity. The system automatically establishes a spatial rectangular coordinate system. The XOY plane of the spatial rectangular coordinate system is a horizontal plane. The origin of the spatial rectangular coordinate system is the position O where the inclination sensor (7) is located. At this time, the X axis of the spatial rectangular coordinate system coincides with the first axis of the inclination sensor (7), the Y axis of the spatial rectangular coordinate system coincides with the second axis of the inclination sensor (7), and the Z axis of the spatial rectangular coordinate system is set perpendicular to the ground. After the spatial rectangular coordinate system is established, the operator adjusts the inclination sensor bracket so that the X axis of the spatial rectangular coordinate system coincides with the projection of the boom (1) on the XOY plane. At this time, the power-on self-check step is completed. Step 2: To hang the cargo, the operator connects the hook (4) to the cargo to be hung. After the hook (4) is connected to the cargo to be hung, the operator operates the controller (5) to start working. The controller (5) sends a lifting signal to drive the lifting mechanism (10) to start working. After the lifting mechanism (10) starts working, it reels in the steel wire rope (3) and drives the hook (4) to rise through the steel wire rope (3). After the hook (4) rises, it provides an upward pulling force to the cargo to be hung. At this time, the tension sensor (6) continuously detects the tension of the steel wire rope (3). When the tension sensor (6) detects that the tension of the steel wire rope (3) is greater than the empty hook weight of the hook (4), the lifting mechanism (10) stops working and the system enters the third detection step. Step 3: Detect the inclination data, set the contact point between the steel wire rope (3) and the pulley (2) as point A, and project the line segment of the steel wire rope segment OA onto the XOY plane as OA'. The inclination sensor (7) continuously detects the inclination of the steel wire rope (3) and sends the inclination data to the controller (5). After receiving the inclination data, the controller (5) calculates the coordinates of point A' in the spatial rectangular coordinate system as (X, Y, 0), and then enters the fourth step of adjustment; Step 4: Adjust the lifting posture. The controller (5) sends a corresponding signal according to the current coordinates of point A (X, Y, 0) to drive the slewing mechanism (9) and the luffing mechanism (8) to work: a) When X>0, the controller (5) sends a signal to drive the slewing mechanism (9) to work, and the slewing mechanism (9) drives the crane tower (11) to rotate leftward. b) When X<0, the controller (5) sends a signal to drive the slewing mechanism (9) to work, and the slewing mechanism (9) drives the crane tower (11) to rotate rightward. c) When X=0, the rotary mechanism (9) does not work. d) When Y>0, the controller (5) sends a signal to drive the luffing mechanism (8) to work, and the luffing mechanism (8) drives the boom (1) to increase its elevation angle. e) When Y < 0, the controller (5) sends a signal to drive the luffing mechanism (8) to work, and the luffing mechanism (8) drives the boom (1) to reduce its elevation angle. f) When Y=0, the luffing mechanism (8) does not work. When the slewing mechanism (9) and the luffing mechanism (8) are working, the tension sensor (6) continuously detects the tension on the wire rope (3). When the tension sensor (6) detects that the tension on the wire rope (3) is less than or equal to the deadweight of the wire rope (3) and the hook (4), the slewing mechanism (9) and the luffing mechanism (8) stop working, and at the same time the controller (5) sends a signal to drive the lifting mechanism (10) to start working to reel in the wire rope (3) until the tension sensor (6) detects that the tension on the wire rope (3) is greater than the empty hook weight of the hook (4). At this time, the slewing mechanism (9) and the luffing mechanism (8) continue to work. When the X value and the Y value are less than the safety threshold of the crane, the adjustment step is completed, and the lifting operation can be carried out safely.

2. A method for controlling a crane hook vertically according to claim 1, characterized in that: The control structure further comprises: a control platform (12), a display signal input end of the control platform (12) being connected to a display signal output end of the controller (5), and a control signal output end of the control platform (12) being connected to a control signal input end of the controller (5).

3. A method for controlling the verticality of a crane hook according to claim 2, characterized in that: In the control structure, the luffing mechanism (8), the slewing mechanism (9) and the lifting mechanism (10) are all motor-driven execution structures; the luffing signal input end of the luffing mechanism (8) is connected to the luffing signal output end of the controller (5) via a data bus; the slewing signal input end of the slewing mechanism (9) is connected to the slewing signal output end of the controller (5) via a data bus; the lifting signal input end of the lifting mechanism (10) is connected to the lifting signal output end of the controller (5) via a data bus; the controller (5) is signal-connected to the control platform (12) via the data bus; and the luffing mechanism (8) is fixedly connected to the top end of the boom (1) via a luffing steel wire rope.

4. A method for controlling the verticality of a crane hook according to claim 2, characterized in that: In the control structure, the luffing mechanism (8), the slewing mechanism (9) and the lifting mechanism (10) are all hydraulically driven execution structures; the luffing signal input end of the luffing mechanism (8) is connected to the luffing signal output end of the controller (5) via a control line; the slewing signal input end of the slewing mechanism (9) is connected to the slewing signal output end of the controller (5) via a control line; the lifting signal input end of the lifting mechanism (10) is connected to the lifting signal output end of the controller (5) via a control line; the controller (5) is connected to the control platform (12) via a data bus signal; and the luffing mechanism (8) is fixedly connected to the middle part of the boom (1) via a hydraulic cylinder.

5. A method for controlling a crane hook vertically according to any one of claims 1 to 4, characterized in that: In the control structure, the inclination sensor (7) is a dual-axis inclination sensor, and the distance between the inclination sensor (7) and the hook (4) is less than 1 meter.

6. A method for controlling the verticality of a crane hook according to claim 5, characterized in that: In the control structure, the inclination sensor (7) is sleeved on the steel wire rope (3) via an inclination sensor bracket, and the inclination sensor bracket and the steel wire rope (3) are rotatably matched.

7. A method for controlling the vertical movement of a crane hook according to claim 6, characterized in that: The control method further comprises a tension sensor (6) calibration step, wherein the tension sensor (6) calibration step is performed by an operator during a crane installation phase or a crane maintenance phase, and the tension sensor (6) calibration step is as follows: The operator operates the control platform (12) to manually input the empty hook weight of the hook (4), wherein the empty hook weight of the hook (4) is the tension detected by the tension sensor (6) when the hook (4) is flush with the top of the cargo to be lifted. After the operator inputs the empty hook weight of the hook (4), the operator operates the controller (5) to enter the calibration step and performs the second preparation step, the third detection step and the fourth adjustment step. At the same time, the operator observes the working condition of the crane. When the cargo to be lifted is lifted off the ground during the operation of the crane or the lifting mechanism (10) does not start working and reel in the wire rope (3) after the wire rope (3) is in a slack state in the fourth adjustment step, it indicates that the tension sensor (6) is faulty and needs to be replaced. When the crane completes the second step of hanging cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture, the calibration step of the tension sensor (6) is completed.

8. A method for controlling the vertical movement of a crane hook according to claim 7, characterized in that: The control method further comprises a tilt sensor (7) calibration step, wherein the tilt sensor (7) calibration step is performed by an operator during a crane installation phase or a crane maintenance phase, and the tilt sensor (7) calibration step is as follows: The operator operates the controller (5) to enter the calibration step and keeps the hook (4) vertically downward. The operator operates the controller (5) to calibrate the inclination signal emitted by the inclination sensor (7) to be 0 degrees. After the operator calibrates the inclination signal of 0 degrees, the operator operates the controller (5) to input the crane safety threshold. After the operator inputs the crane safety threshold, the operator operates the crane to perform the second preparation step, the third detection step and the fourth adjustment step to calibrate the crane safety threshold. The operator observes the working condition of the crane. When the X value and the Y value do not decrease during the operation of the luffing mechanism (8) and the slewing mechanism (9) in the fourth adjustment step, it indicates that the inclination sensor (7) is faulty and needs to be replaced. When the crane completes the second step of hanging and picking up the cargo, the third step of detecting the inclination data and the fourth step of adjusting the lifting posture, the calibration step of the inclination sensor (7) is completed.

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