Automatic initialization method for ship unloader

Abstract

An automatic initialization method for a ship unloader, comprising: mounting a weighing sensor, a pressure sensor, a magnetic limit sensor and a laser ranging sensor on a ship unloader; determining, on the basis of the weighing sensor, whether a grab is off the ground, if so, determining, by means of the magnetic limit sensor, whether a trolley is located at a starting position, if so, driving the grab to descend until the weight measured by the weighing sensor drops to zero; in this case, initializing a grab lifter encoder to zero, and calibrating a lifting-lowering stroke; correcting the deviation of a trolley encoder by means of the laser ranging sensor, and calibrating the transverse traveling range of the trolley; and lifting the grab to the top, determining, by means of the pressure sensor, whether the grab is in a fully open state, if so, initializing a grab encoder, and calibrating the opening-closing stroke range of the grab. Compared with the prior art, the automatic initialization method for a ship unloader avoids the influence of visual inspection errors, avoids initialization problems caused by driver negligence, and reduces the working intensity of personnel.

Description

An automatic initialization method for a ship unloader Technical Field

[0001] This invention relates to the field of ship unloader control technology, and in particular to an automatic initialization method for a ship unloader. Background Technology

[0002] Currently, most bulk cargo terminals use bridge-type grab unloaders for material handling. To ensure the safety of unloading operations, since the beginning of this century, the unloaders have been controlled by PLC + frequency converter. At the same time, initialization is set for grab operation safety protection. Initialization is an important tool that uses an encoder installed on the hoisting opening and closing motor to calculate and measure the speed and position of the grab traction wire rope. If the encoder is not initialized for a long time, it will accumulate drift, which will cause the trolley and grab to move beyond the specified travel range, resulting in an accident.

[0003] Due to recent significant changes in personnel allocation, ship unloader operators have gradually transitioned from in-house staff to outsourced teams. These outsourced personnel exhibit varying levels of skill, proficiency, and adherence to standardized procedures when operating the ship unloader. Operators frequently fail to initialize the trolley grab bucket before operating the machine, leading to accumulated offsets in the grab bucket encoder values ​​during prolonged coal unloading. This results in the grab bucket failing to move even when it is in a normal operating position, impacting unloading efficiency and increasing the workload of maintenance personnel and management's diagnostic capabilities.

[0004] As shown in Figure 1, the initialization steps for existing well-known ship unloader manufacturers are as follows:

[0005] After the operator gets on the machine and closes the brakes, they turn on the initialization knob, then raise the grab bucket to a visually acceptable working height, move the trolley to the top of the land side, and click the trolley initialization button to complete the calibration of the trolley's lateral and vertical travel ranges. Next, open the grab bucket, visually check that it is fully open, and click the grab bucket open initialization button. Then, close the grab bucket, reduce the closing speed as it is about to close completely, and visually check that it is closed before clicking the grab bucket close initialization button to complete the calibration of the grab bucket's opening and closing travel ranges. Finally, turn off the initialization knob to complete the initialization operation of the entire trolley and grab bucket.

[0006] The initialization process of the aforementioned ship unloader requires constant visual inspection to determine whether each step has been completed. Relying on manual labor for each step means that the accuracy of the initialization process cannot be guaranteed, and the labor cost is high. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art, which requires visual inspection to determine whether each step has been completed, relies on manual operation of each step, cannot guarantee the accuracy of the initialization process, and has high labor costs, and to provide an automatic initialization method for a ship unloader.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] An automatic initialization method for a ship unloader includes the following steps:

[0010] S0: Install a weighing sensor on the guide wheel pin of the ship unloader to monitor the wire rope, install a pressure sensor on the grab bucket to determine the opening and closing of the grab bucket, install a magnetic limit sensor on the main beam of the ship unloader to limit the starting position of the trolley, and install a laser rangefinder on the main beam of the ship unloader to measure the position of the trolley.

[0011] S1: During the initialization process, the load cell determines whether the grab bucket is not on the ground. If it is, step S2 is executed; otherwise, the grab bucket is raised or lowered until the load cell detects that the grab bucket is off the ground.

[0012] S2: Determine whether the trolley is in the starting position through the magnetic limit sensor. If yes, proceed to step S3; otherwise, move the grab bucket horizontally until the magnetic limit sensor detects that the trolley is in the starting position.

[0013] S3: Drive the grab bucket down until the weight detected by the weighing sensor drops to zero;

[0014] S4: Initialize the encoder of the grab bucket elevator to zero point and calibrate the lifting stroke of the grab bucket elevator; measure the change in the position of the trolley through the laser range sensor, correct the deviation of the trolley encoder, and calibrate the lateral range of the trolley.

[0015] S5: Raise the grab bucket to the top, and then use the pressure sensor to determine whether the grab bucket is in the open position. If it is, proceed to step S6; otherwise, drive the grab bucket to open until the pressure sensor determines that the grab bucket is in the open position.

[0016] S6: With the grab bucket in the fully extended position, initialize the grab bucket encoder and calibrate the grab bucket's opening and closing stroke range.

[0017] S7: Complete the initialization of the trolley and grab bucket.

[0018] Further, in step S1, determining whether the grab bucket is just off the ground based on the weighing sensor specifically involves: measuring the distance between the grab bucket's support leg and the trolley guide wheel after the grab bucket is placed on the ground, calculating the weight of the steel wire rope corresponding to this distance and the weight of the grab bucket, and using this as a conditional trigger value; when the weight detected by the weighing sensor reaches the conditional trigger value, it is determined that the grab bucket is just off the ground.

[0019] Furthermore, in step S5, during the process of driving the grab bucket to open, the pressure sensor determines that when the grab bucket is about to open to the correct position, the opening speed of the grab bucket is reduced until it reaches the correct position.

[0020] Furthermore, the pressure sensor is a clamping force sensor.

[0021] Furthermore, both the magnetic limit sensor and the laser rangefinder are installed at the tail of the main beam of the unloader.

[0022] Furthermore, the method also includes: when the unloader operator finishes his work, driving the trolley to the location of the magnetic limit sensor and lowering the grab bucket to the ground.

[0023] Furthermore, the initialization process is performed after the unloader operator gets on the machine and closes the brakes.

[0024] Furthermore, the method is executed by a PLC controller.

[0025] Furthermore, the method is executed by a PLC controller, which is connected to a weighing sensor, a pressure sensor, a magnetic limit sensor, and a laser rangefinder.

[0026] Furthermore, the method also includes: programming the process of steps S1-S7 into a program to run in the PLC controller.

[0027] Furthermore, the PLC controller is the controller for the ship unloader.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] (1) This invention uses a magnetic limit sensor to fix the initial position of the trolley and a laser rangefinder to measure the position of the trolley for correction, thereby calibrating the encoder of the trolley; by setting a load cell on the wire rope, the length of the wire rope when the grab bucket is placed on the ground and the weight of the grab bucket are used as trigger values ​​to determine that the grab bucket is almost touching the ground, and then the wire rope continues to descend until the value of the load cell is 0. This is the bottom position during the descent of the grab bucket. At this time, the wire rope does not slack, thereby ensuring that the encoder starting position is consistent each time it is initialized, and achieving accurate calibration of the grab bucket lifting stroke; by setting a pressure sensor on the grab bucket, the opening and closing stroke of the grab bucket is calibrated by detecting the opening position of the grab bucket.

[0030] (2) The above solution greatly reduces the cumulative encoder offset caused by driver negligence, which leads to the failure of the trolley grab bucket to move in a normal working position during coal unloading; reduces the error in the initial calibration range of the trolley grab bucket caused by visual deviation of different drivers; and reduces the workload of maintenance personnel.

[0031] (3) The present invention uses a pressure sensor on the grab bucket to determine whether the grab bucket is fully opened. At the same time, during the opening process, the grab bucket is controlled to decelerate when it is about to be fully opened by the opening and closing weighing sensor, which can prevent damage to the grab bucket and the opening and closing pressure sensor. Attached Figure Description

[0032] Figure 1 is a schematic diagram of the original car initialization steps provided in the background art of the present invention;

[0033] Figure 2 is a structural schematic diagram of a bridge-type grab unloader provided in an embodiment of the present invention;

[0034] Figure 3 is a flowchart illustrating an automatic initialization method for a ship unloader provided in an embodiment of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0038] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Example 1

[0040] As shown in Figures 2 and 3, this embodiment provides an automatic initialization method for a ship unloader, including the following steps:

[0041] S0: Install a weighing sensor on the guide wheel pin of the ship unloader to monitor the wire rope, install a pressure sensor on the grab bucket to determine the opening and closing of the grab bucket, install a magnetic limit sensor on the main beam of the ship unloader to limit the starting position of the trolley, and install a laser rangefinder on the main beam of the ship unloader to measure the position of the trolley.

[0042] S1: During the initialization process, the load cell determines whether the grab bucket is not on the ground. If it is, step S2 is executed; otherwise, the grab bucket is raised or lowered until the load cell detects that the grab bucket is off the ground.

[0043] S2: Determine whether the trolley is in the starting position through the magnetic limit sensor. If yes, proceed to step S3; otherwise, move the grab bucket horizontally until the magnetic limit sensor detects that the trolley is in the starting position.

[0044] S3: Drive the grab bucket down until the weight detected by the weighing sensor drops to zero;

[0045] S4: Initialize the encoder of the grab bucket elevator to zero point and calibrate the lifting stroke of the grab bucket elevator; measure the change in the position of the trolley through the laser range sensor, correct the deviation of the trolley encoder, and calibrate the lateral range of the trolley.

[0046] S5: Raise the grab bucket to the top, and then use the pressure sensor to determine whether the grab bucket is in the open position. If it is, proceed to step S6; otherwise, drive the grab bucket to open until the pressure sensor determines that the grab bucket is in the open position.

[0047] S6: With the grab bucket in the fully extended position, initialize the grab bucket encoder and calibrate the grab bucket's opening and closing stroke range.

[0048] S7: Complete the initialization of the trolley and grab bucket.

[0049] Specifically, in step S0, a magnetic limit sensor and a laser rangefinder are installed at the tail end (landside) of the main beam of the unloader; a weighing sensor for the lifting wire rope is installed on the guide wheel pin of the trolley; and an opening pressure sensor is installed on the grab bucket body.

[0050] In step S1, determining whether the grab bucket is just off the ground based on the weighing sensor specifically involves: measuring the distance between the grab bucket's support leg and the trolley guide wheel after the grab bucket is placed on the ground, calculating the weight of the steel wire rope corresponding to this distance and the weight of the grab bucket, and using this as a conditional trigger value; when the weight detected by the weighing sensor reaches the conditional trigger value, it is determined that the grab bucket is just off the ground.

[0051] In other words, in steps S1-S4, an important condition for initializing the encoder of the trolley grab bucket is that the starting position of the trolley grab bucket must be basically the same each time it is initialized. Therefore, this solution sets a magnetic limit sensor to first fix the trolley in a preliminary position. After the grab bucket is placed on the ground, a laser range sensor is used to correct the deviation during initialization.

[0052] The load cell installed on the trolley is used to measure whether the wire rope is fully slack and not over-feeded after the grab bucket is placed on the ground. First, the distance from the grab bucket's support leg to the trolley's guide wheel is measured after the grab bucket is placed on the ground. The weight of the wire rope at this length is calculated and added to the weight of the grab bucket, and this is set as the conditional trigger value. When the trolley moves to the magnetic limit, the load cell starts to work. As the grab bucket continues to descend, the weight read by the load cell will increase continuously with the elongation of the wire rope until the grab bucket is almost close to the ground. At this point, the weight read by the load cell will be exactly the conditional trigger value. Then, as the wire rope continues to descend, the value read by the load cell will decrease until it reaches 0, at which point the descent of the grab bucket will immediately stop.

[0053] At this point, the grab bucket is positioned exactly on the ground. The output of the grab bucket elevator is initialized at this time to calibrate the grab bucket encoder.

[0054] Preferably, in step S5, during the process of driving the grab bucket to open, the pressure sensor determines that when the grab bucket is about to open to the correct position, the opening speed of the grab bucket is reduced until it reaches the correct position.

[0055] Preferably, the above method further includes: when the previous driver of the unloader has finished his work, driving the trolley to the location of the magnetic limit sensor and lowering the grab bucket to the ground.

[0056] The above initialization process is automatically executed after the next operator of the ship unloader gets on the machine and closes the brakes.

[0057] Preferably, the above method is executed by a PLC controller, that is, all newly added equipment signals are connected to the PLC controller, and the program is modified according to the processing flow of the above method so that it can complete the function of automatic initialization of the trolley grab bucket;

[0058] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method of automatic initialization of an unloader, characterized in that, The method comprises the following steps: S0: Pre-installing a weighing sensor for monitoring the steel wire rope on the trolley guide wheel angle pin of the ship unloader, a pressure sensor for judging the opening and closing of the grab bucket on the grab bucket, a magnetic limit sensor for limiting the starting position of the trolley on the girder of the ship unloader, and a laser ranging sensor for measuring the position of the trolley on the girder of the ship unloader; S1: In the initialization process, it is judged by the weighing sensor whether the grab bucket is on the ground, if yes, step S2 is executed, otherwise the grab bucket is lifted until the grab bucket is detected off the ground by the weighing sensor; S2: It is judged by the magnetic limit sensor whether the trolley is at the starting position, if yes, step S3 is executed, otherwise the grab bucket is horizontally moved until the trolley is detected at the starting position by the magnetic limit sensor; S3: The grab bucket is lowered until the weight detected by the weighing sensor is zero; S4: The encoder of the grab bucket lifter at this time is initialized to zero point, and the lifting stroke of the grab bucket lifter is calibrated; The change of the trolley position is measured by the laser ranging sensor, the deviation of the trolley encoder is corrected, and the horizontal range of the trolley is calibrated; S5: The grab bucket is lifted to the top, and then it is judged by the pressure sensor whether the grab bucket is in the open-to-position state, if yes, step S6 is executed, otherwise the grab bucket is driven to open until the grab bucket is in the open-to-position state detected by the pressure sensor; S6: In the open-to-position state of the grab bucket, the encoder of the grab bucket is initialized, and the opening and closing stroke range of the grab bucket is calibrated, S7: The initialization of the trolley and the grab bucket is completed.

2. A method of automatic initialization of an unloader according to claim 1, characterized in that, In step S1, whether the grab bucket is just off the ground is judged according to the weighing sensor, which is specifically: measuring the distance between the grab bucket bracket and the trolley guide wheel after the grab bucket is placed on the ground, calculating the weight of the steel wire rope corresponding to the length and the weight of the grab bucket as the condition trigger value; When the weight detected by the weighing sensor reaches the condition trigger value, it is judged that the grab bucket is just off the ground.

3. A method of automatic initialization of a ship unloader according to claim 1, characterized in that, In step S5, during the process of driving the grab bucket to open, when the grab bucket is about to reach the open-to-position state, the opening speed of the grab bucket is reduced until the open-to-position state is reached.

4. A method of automatic initialization of an unloader according to claim 1, characterized in that, The pressure sensor is a clamping force sensor.

5. A method of automatic initialization of a ship unloader according to claim 1, characterized in that, The magnetic limit sensor and the laser ranging sensor are both installed at the tail of the girder of the ship unloader.

6. A method of automatic initialization of a ship unloader according to claim 1, characterized in that, The method further comprises: when the driver of the ship unloader completes the work, the trolley is opened to the position of the magnetic limit sensor, and the grab bucket is lowered to the ground.

7. A method of automatic initialization of a ship unloader according to claim 1, characterized in that, The process of initialization is executed after the driver of the ship unloader gets on the machine and closes the switch.

8. A method of automatic initialization of a ship unloader according to claim 1, characterized in that, The method is executed by a PLC controller connected with the weighing sensor, the pressure sensor, the magnetic limit sensor and the laser ranging sensor.

9. A method of automatic start-up of a ship unloader according to claim 8, characterized in that The method further comprises: programming the processes of steps S1-S7 into a program running in the PLC controller.

10. A method of automatic initialization of an unloader according to claim 1, characterized in that, The PLC controller is the controller of the ship unloader.

Images