Grab ship unloader man-machine anti-collision system and method based on UWB technology

Abstract

The invention discloses a grab ship unloader man-machine anti-collision system and method based on the UWB technology, and the system comprises a UWB positioning unit which comprises UWB labels, a UWB base station and a UWB positioning server, the UWB labels are installed at the top of a cabin cleaning machine and safety helmets worn by personnel in a cabin, and send nanosecond pulse signals to the surroundings in real time; the PLC control unit comprises a PLC module and a switch, the PLC module receives real-time positioning data, transmitted by the UWB positioning unit, of the cabin cleaning machinery and personnel and then monitors the collision risk of the cabin cleaning machinery and personnel in the grab bucket descending process in real time, and the mechanism control unit comprises a lifting opening and closing frequency converter and a lifting opening and closing motor. And after receiving the lifting opening and closing control instruction transmitted by the PLC control unit, the lifting opening and closing frequency converter controls the operation action of the lifting opening and closing motor. The system eliminates the risk hidden danger that the grab bucket hits and touches the cabin cleaning machine, and improves the safety and reliability of bulk cargo wharf operation. According to the UWB technology-based man-machine anti-collision system of the grab ship unloader, the market core competitiveness of grab ship unloader products is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of grab ship unloader control, and particularly to a human-machine anti-collision system and method for grab ship unloaders based on UWB technology. Background Art

[0002] As an important ship unloading equipment in bulk cargo terminals, grab ship unloaders have increasingly growing demands for intelligence and digitization in recent years. Currently, intelligent grab ship unloaders generally use image recognition methods for positioning detection of the cabin cleaning machinery during the cabin cleaning stage, and then achieve anti-collision protection for it. However, for the personnel working in the cabin, there is no matching positioning detection and anti-collision protection scheme. In addition, the positioning accuracy of image recognition technology is relatively low, and it is greatly affected by dust and light, unable to effectively ensure the safe and reliable operation of the equipment. Therefore, a precise positioning and anti-collision protection scheme for the cabin cleaning machinery and personnel during the cabin cleaning stage of grab ship unloaders is needed. Summary of the Invention

[0003] According to the problems existing in the prior art, the present invention discloses a human-machine anti-collision system for grab ship unloaders based on UWB technology.

[0004] The UWB positioning unit includes UWB tags, UWB base stations, and a UWB positioning server. The UWB tags are installed on the top of the cabin cleaning machinery in the cabin and on the safety helmets worn by the personnel in the cabin, and send nanosecond-level pulse signals to the surrounding in real time, and transmit the detection data to the UWB positioning server in the form of TCP / IP protocol. The UWB positioning server calculates the real-time position information of the UWB tags in the cabin by using the obtained pulse data of the UWB tags in the cabin and combining the installation position data of the UWB base stations, and outputs the obtained data in the form of TCP / IP protocol.

[0005] The PLC control unit includes a PLC module and a switch. After receiving the real-time positioning data of the cabin cleaning machinery and personnel in the cabin transmitted by the UWB positioning unit, the PLC module monitors the collision risk of the cabin cleaning machinery and personnel during the grab lowering process in real time, and outputs control instructions for the hoisting and opening / closing motors of the grab ship unloader in the form of Profinet protocol through the switch.

[0006] The mechanism control unit includes a hoisting frequency converter, an opening / closing frequency converter, and a hoisting and opening / closing motor. After receiving the hoisting and opening / closing control instructions transmitted by the PLC control unit, the hoisting frequency converter and the opening / closing frequency converter control the operation actions of the hoisting and opening / closing motors.

[0007] Furthermore, there are four UWB base stations, which are respectively installed at the midpoint position of the left boom, the midpoint position of the right boom, the middle position of the boom end, and the middle position of the sea side of the front shoulder beam. The UWB positioning server is installed in the PLC room.

[0008] Further, the arrangement of 4 UWB base stations completely covers the ship unloading operation area of the grab ship unloader. The positioning detection area is divided according to the three-dimensional control positions of the 4 UWB base stations, and the UWB tag pulse signals on the hold cleaning machinery and personnel in the cabin are received, and the detection data is transmitted to the UWB positioning server.

[0009] Further, the UWB positioning server calculates the real-time positions of the UWB tags in the hold by receiving the detection data of the 4 UWB base stations, and then obtains the real-time positions of the hold cleaning machinery and personnel in the hold.

[0010] Further, the PLC module receives the positioning data of the hold cleaning machinery and personnel detected by the UWB positioning unit, and controls the mechanism control unit to prevent the grab mechanism from hitting the hold cleaning machinery and personnel in the hold.

[0011] Further, the switch is used for data transmission between the PLC module, the UWB positioning unit and the mechanism drive unit.

[0012] A control method for a grab ship unloader human-machine anti-collision system based on UWB technology includes:

[0013] S1: 4 UWB base stations on the grab ship unloader are used to receive in real time the pulse signals sent by the UWB tags carried by the hold cleaning machinery and personnel in the hold, and send them to the UWB positioning server;

[0014] S2: After the UWB positioning server obtains the data transmitted by the 4 UWB base stations, it performs real-time positioning detection on the UWB tags in the hold;

[0015] Where the three-dimensional space coordinates of the UWB tag are (x, y, z), and the actual three-dimensional coordinate values corresponding to the actual installation positions of the 4 UWB base stations are (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), (x4, y4, z4) respectively. The following method is used to calculate the actual three-dimensional coordinate values of the UWB tag:

[0016] S 12 = c×(T1 - T 发送 ) - c×(T2 - T 发送 );

[0017] S 23 = c×(T2 - T 发送 ) - c×(T3 - T 发送 );

[0018] S 34 = c×(T3 - T 发送 ) - c×(T4 - T 发送 );

[0019] S 41 = c×(T4 - T 发送 ) - c×(T1 - T 发送 );

[0020]

[0021]

[0022] where S 12 is the distance difference between the UWB tag and Base Station 1# and Base Station 2#, S 23 is the distance difference between the UWB tag and Base Station 2# and Base Station 3#, S 34 is the distance difference between the UWB tag and Base Station 3# and Base Station 4#, S 41 is the distance difference between the UWB tag and Base Station 4# and Base Station 1#, c is the speed of light value, T1 is the time value when Base Station 1# receives the UWB tag pulse signal, T2 is the time value when Base Station 2# receives the UWB tag pulse signal, T3 is the time value when Base Station 3# receives the UWB tag pulse signal, T4 is the time value when Base Station 4# receives the UWB tag pulse signal, and T 发送 is the time value when the UWB tag emits the pulse signal. Solve the above equations to obtain the actual three-dimensional coordinate values (x, y, z) of the UWB tag;

[0023] S3: The UWB positioning server transmits the calculated real-time position of the UWB tag to the PLC module;

[0024] S4: When the PLC module determines that there is a risk of collision between the grabbing point where the grab bucket descends and the UWB tag in the cabin, the PLC module sends control commands to the hoisting frequency converter and the opening and closing frequency converter to prohibit the hoisting and opening and closing motors from descending, so as to avoid collisions between the grab bucket and the cabin cleaning machinery and personnel. The method for determining the collision risk is as follows:

[0025] When S 机械风险距离 < S 抓斗区域 + S 清舱机械区域 ), it is determined that there is a risk of collision between the grab bucket and the cabin cleaning machinery, and the descent is prohibited;

[0026] where S 机械风险距离 is the distance value from the center point of the grab bucket's target material taking operation point to the UWB tag of the cabin cleaning machinery, S 抓斗区域 is the self-safe distance value of the grab bucket with the center point of the grab bucket as the midpoint, and S 清舱机械区域 is the self-safe distance value of the cabin cleaning machinery with the center point of the cabin cleaning machinery as the center;

[0027] When S 人员风险距离 < S 抓斗区域 + S人员区域 When it is determined that there is a risk of the grab hitting the personnel in the same cabin, the descent is prohibited;

[0028] Among them, S 人员风险距离 is the distance value from the center point of the grab's target material-taking operation point to the UWB tag of the personnel in the cabin, and S 抓斗区域 is the self-safety distance value of the grab with the center point of the grab as the midpoint, and S 人员区域 is the self-safety distance value of the cabin cleaning personnel with the center point of the personnel in the cabin as the center;

[0029] S5: Keep the function of the anti-collision system for the grab ship unloader and the operator activated until the ship unloading operation is completed.

[0030] Due to the adoption of the above technical solution, a grab ship unloader anti-collision system and method for the operator based on UWB technology provided by the present invention provides users with precise positioning and anti-collision protection for the cabin cleaning machinery during the cabin cleaning operation of the grab ship unloader, eliminates the risk of the grab hitting the cabin cleaning machinery, and improves the safety and reliability of the operation of the bulk cargo terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is the structural block diagram of the grab ship unloader anti-collision system for the operator based on UWB technology of the present invention

[0033] Figure 2 It is the layout diagram of the grab ship unloader anti-collision system for the operator based on UWB technology of the present invention

[0034] Figure 3 It is the wiring diagram of the UWB positioning unit in the present invention

[0035] Figure 4 It is the wiring diagram of the PLC control unit in the present invention

[0036] Figure 5 It is the wiring diagram of the mechanism control unit in the present invention

[0037] Figure 6 It is the spatial schematic diagram of the UWB positioning tag and base station of the grab ship unloader in the present invention

[0038] Figure 7 It is the illustration of the risk of the grab hitting the cabin cleaning machinery and personnel in the same cabin in the present invention

[0039] Figure 8 Control Flow Chart of Man-Machine Anti-Crushing and Collision System for Grab Unloader Based on UWB Technology in the Present Invention Specific Embodiments

[0040] To make the technical solutions and advantages of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention:

[0041] As Figure 1 shown, a man-machine anti-crushing and collision system for a grab unloader based on UWB technology includes three parts: a UWB positioning unit, a PLC control unit, and a mechanism control unit.

[0042] Among them, the UWB positioning unit consists of UWB tags installed on the tank cleaning machine, UWB tags installed on the safety helmets worn by personnel, UWB base stations installed at four positions: the midpoint of the left boom, the midpoint of the right boom, the middle of the boom end, and the middle of the sea side of the front shoulder beam, and a UWB positioning server installed in the PLC room. The layout of the 4 UWB base stations can fully cover the ship unloading operation area of the grab unloader. The positioning detection area is divided according to the three-dimensional control positions of the 4 UWB base stations, and the pulse signals of the UWB tags on the tank cleaning machine and personnel in the cabin are received, and the detection data is transmitted to the UWB positioning server; the UWB tag is used to send nanosecond-level pulse signals to the surrounding for easy reception by the UWB base station; the UWB positioning server obtains the real-time positions of the UWB tags in the cabin through algorithm processing of the detection data received from the 4 UWB base stations, and then obtains the real-time positions of the tank cleaning machine and personnel in the cabin. The PLC control unit consists of a PLC module and a switch installed in the PLC room. Among them, the PLC module controls the mechanism control unit by receiving the positioning data of the tank cleaning machine and personnel in the cabin detected by the UWB positioning unit to avoid the grab mechanism from crushing and colliding with the tank cleaning machine and personnel in the cabin; the switch is used for data transmission between the PLC module, the UWB positioning unit, and the mechanism drive unit. The mechanism drive unit consists of a hoisting frequency converter and an opening and closing frequency converter installed in the electrical room, and a hoisting and opening and closing motor installed in the machine room. Among them, the hoisting frequency converter and the opening and closing frequency converter control the operation of the hoisting and opening and closing motors by receiving the control instructions of the PLC control unit; the hoisting and opening and closing motors drive the grab mechanism to perform corresponding upward and downward movements.

[0043] Embodiment

[0044] The man-machine anti-crushing and collision system for a grab unloader based on UWB technology is composed of three parts: a UWB positioning unit U1, a PLC control unit U2, and a mechanism control unit U3. The system architecture diagram is as Figure 1 shown.

[0045] As Figure 3As shown in the figure, the UWB positioning unit U1 consists of a UWB tag, a UWB base station, and a UWB positioning server. The UWB tags are installed on the top of the hold cleaning machinery in the hold and on the safety helmets worn by the personnel in the hold. They are powered by lithium batteries and the UWB tags send nanosecond-level pulse signals to the surrounding area in real time. The 4 UWB base stations installed on the grab ship unloader receive the pulse signals of the UWB tags in the hold in real time and transmit the detection data to the UWB positioning server in the form of the TCP / IP protocol. The UWB positioning server uses the obtained pulse data of the UWB tags in the hold and combines with the installation position data of the 4 UWB base stations to calculate the real-time position value of the UWB tags in the hold and transmits it to the PLC module via the switch in the PLC control unit U2 in the form of the TCP / IP protocol.

[0046] As Figure 4 shown in the figure, the PLC control unit U2 consists of a PLC module and a switch. After the PLC module obtains the real-time positioning data of the hold cleaning machinery and personnel transmitted by the UWB positioning server, it monitors the risk of collision of the hold cleaning machinery and personnel during the lowering of the grab in real time and transmits it to the hoisting frequency converter and the opening and closing frequency converter in the mechanism drive unit U3 in the form of the Profinet protocol, and then drives the hoisting and opening and closing motors to realize the anti-collision of the hold cleaning machinery and personnel of the grab ship unloader. The switch is used for data transmission between the PLC module and the hoisting frequency converter, the opening and closing frequency converter in the mechanism drive unit U3, and the image processing server in the image recognition unit U1.

[0047] As Figure 5 shown in the figure, the mechanism control unit U3 consists of a hoisting frequency converter, an opening and closing frequency converter, and hoisting and opening and closing motors. After the hoisting frequency converter and the opening and closing frequency converter obtain the hoisting and opening and closing control instructions in the PLC control unit U2, they drive the hoisting and opening and closing motors to perform corresponding running actions in the form of hard wiring to realize the anti-collision of the hold cleaning machinery and personnel of the grab ship unloader.

[0048] The specific control method of the grab ship unloader man-machine anti-collision system based on UWB technology is as follows:

[0049] Step 1: When the hold cleaning machinery and personnel enter the cabin, the function of the grab ship unloader man-machine anti-collision system based on UWB technology is activated;

[0050] Step 2: The 4 UWB base stations on the grab ship unloader receive the pulse signals sent by the UWB tags carried by the hold cleaning machinery and personnel in the hold in real time and send them to the UWB positioning server;

[0051] Step 3: After the UWB positioning server obtains the data transmitted by the 4 UWB base stations, it performs real-time positioning detection on the UWB tags in the hold. Refer to Figure 6Spatial schematic diagram of the UWB positioning tag and base station of the grab unloader, and the specific data processing method is described as follows:

[0052] According to the three-dimensional space coordinates (x, y, z) of the UWB tag, the actual three-dimensional coordinate values corresponding to the actual installation positions of the 4 UWB base stations are (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), and (x4, y4, z4) respectively, and how to calculate the UWB tag coordinates is described.

[0053] S 12 = c×(T1 - T 发送 ) - c×(T2 - T 发送 );

[0054] S 23 = c×(T2 - T 发送 ) - c×(T3 - T 发送 );

[0055] S 34 = c×(T3 - T 发送 ) - c×(T4 - T 发送 );

[0056] S 41 = c×(T4 - T 发送 ) - c×(T1 - T 发送 );

[0057]

[0058] Among them, S 12 is the distance difference between the UWB tag and the 1# base station and the 2# base station, S 23 is the distance difference between the UWB tag and the 2# base station and the 3# base station, S 34 is the distance difference between the UWB tag and the 3# base station and the 4# base station, S 41 is the distance difference between the UWB tag and the 4# base station and the 1# base station, c is the value of the speed of light, T1 is the time value when the 1# base station receives the UWB tag pulse signal, T2 is the time value when the 2# base station receives the UWB tag pulse signal, T3 is the time value when the 3# base station receives the UWB tag pulse signal, T4 is the time value when the 4# base station receives the UWB tag pulse signal, and T 发送 is the time value when the UWB tag emits the pulse signal. Solve the above equations to obtain the actual three-dimensional coordinate values (x, y, z) of the UWB tag.

[0059] Step 4: The UWB positioning server transmits the calculated real-time position of the UWB tag to the PLC module;

[0060] Step 5: When the PLC module determines that there is a risk of collision between the grab during its descent and the UWB tag in the cabin, the PLC module sends control commands to the hoist frequency converter and the opening / closing frequency converter to prohibit the hoist and opening / closing motors from descending, so as to avoid collision accidents between the grab and the hold cleaning machinery and personnel in the cabin. Refer to Figure 7 The diagram showing the risk of collision between the grab and the hold cleaning machinery and personnel in the cabin is used to specifically illustrate the method for determining the collision risk:

[0061] When S 机械风险距离 <S 抓斗区域 +S 清舱机械区域 , it is determined that there is a risk of collision between the grab and the hold cleaning machinery in the cabin, and the descent is prohibited;

[0062] Where S 机械风险距离 is the distance value from the center point of the grab's target material taking operation point to the UWB tag of the hold cleaning machinery, S 抓斗区域 is the self - safety distance value of the grab with the center point of the grab as the mid - point, and S 清舱机械区域 is the self - safety distance value of the hold cleaning machinery with the center point of the hold cleaning machinery as the center.

[0063] When S 人员风险距离 <S 抓斗区域 +S 人员区域 , it is determined that there is a risk of collision between the grab and the personnel in the cabin, and the descent is prohibited;

[0064] Where S 人员风险距离 is the distance value from the center point of the grab's target material taking operation point to the UWB tag of the personnel in the cabin, S 抓斗区域 is the self - safety distance value of the grab with the center point of the grab as the mid - point, and S 人员区域 is the self - safety distance value of the hold cleaning personnel with the center point of the personnel in the cabin as the center.

[0065] Step 6: Keep the function of the anti - collision system between the grab ship unloader and humans activated until the ship unloading operation is completed.

[0066] Embodiment

[0067] Taking the 1800t / h grab ship unloader and a 50,000 - ton bulk carrier as an example, the control process of the anti - collision system between the grab ship unloader and humans based on image recognition technology is described. As Figure 7As shown: After the hold cleaning machinery and personnel enter the hold, the function of the anti-collision system for the grab ship unloader and personnel based on UWB technology is activated; the 4 UWB base stations on the grab ship unloader start to receive in real time the pulse signals sent by the UWB tags carried by the hold cleaning machinery and personnel in the hold, and send them to the UWB positioning server; after the UWB positioning server obtains the data transmitted by the 4 UWB base stations, it conducts real-time positioning detection on the UWB tags in the hold; then, the UWB positioning server transmits the real-time position of the UWB tags calculated to the PLC module; when the PLC module determines that there is a risk of collision between the grabbing point where the grab descends and the UWB tags in the hold, the PLC module sends control commands to the hoist frequency converter and the opening and closing frequency converter to prohibit the hoist and the opening and closing motors from descending, so as to avoid the grab colliding with the hold cleaning machinery and personnel in the hold; keep the function of the anti-collision system for the grab ship unloader and personnel activated until the ship unloading operation is completed.

[0068] An anti-collision system and method for a grab ship unloader and personnel based on UWB technology disclosed by the present invention provides users with precise positioning and anti-collision protection for hold cleaning machinery during the hold cleaning operation stage of the grab ship unloader, eliminates the risk of the grab colliding with the hold cleaning machinery, and improves the safety and reliability of the operation of the bulk cargo terminal. The anti-collision system for the grab ship unloader and personnel based on UWB technology greatly increases the core competitiveness of the grab ship unloader product in the market. At the same time, a single set of anti-collision system for the grab ship unloader and personnel based on UWB technology has certain economic benefits.

[0069] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A man-machine anti-collision and anti-smashing system for a grab unloader based on UWB technology, characterized in that Including: A UWB positioning unit, including a UWB tag, a UWB base station and a UWB positioning server. The UWB tag is installed on the top of the hold cleaning machine in the hold and on the safety helmets worn by the personnel in the hold, and sends nanosecond-level pulse signals to the surrounding area in real time, and transmits the detection data to the UWB positioning server in the form of the TCP / IP protocol. The UWB positioning server calculates the real-time position information of the UWB tag in the hold by using the obtained pulse data of the UWB tag in the hold and combining the installation position data of the UWB base station, and outputs the obtained data in the form of the TCP / IP protocol; A PLC control unit, including a PLC module and a switch. After the PLC module receives the real-time positioning data of the hold cleaning machine and personnel in the hold transmitted by the UWB positioning unit, it monitors the collision risk of the hold cleaning machine and personnel in the hold during the lowering process of the grab, and outputs control instructions for the hoisting and opening / closing motors of the grab ship unloader in the form of the Profinet protocol through the switch; A mechanism control unit, including a hoisting frequency converter, an opening / closing frequency converter and a hoisting and opening / closing motor. After the hoisting frequency converter and the opening / closing frequency converter receive the hoisting and opening / closing control instructions transmitted by the PLC control unit, they control the running actions of the hoisting and opening / closing motors.

2. The anti-collision system for grab ship unloader and human based on UWB technology according to claim 1, characterized in that: There are four UWB base stations, which are respectively installed at the midpoint position of the left boom, the midpoint position of the right boom, the middle position of the boom end and the middle position of the sea side of the front shoulder beam. The UWB positioning server is installed in the PLC room.

3. The anti-collision system for grab unloader between human and machine based on UWB technology according to claim 2, wherein: Among them, the layout of the 4 UWB base stations completely covers the ship unloading operation area of the grab ship unloader. The positioning detection area is divided according to the three-dimensional control positions of the 4 UWB base stations, and the pulse signals of the UWB tags on the hold cleaning machine and personnel in the hold are received, and the detection data is transmitted to the UWB positioning server.

4. The anti-collision system for grab ship unloader and human based on UWB technology according to claim 2, characterized in that: The UWB positioning server obtains the real-time position of the UWB tag in the hold by receiving the detection data of the 4 UWB base stations, and then obtains the real-time position of the hold cleaning machine and personnel in the hold.

5. The anti-collision system for grab ship unloader and human based on UWB technology according to claim 2, wherein: The PLC module receives the positioning data of the hold cleaning machine and personnel in the hold detected by the UWB positioning unit, and controls the mechanism control unit to avoid the grab mechanism from colliding with the hold cleaning machine and personnel in the hold.

6. The anti-collision system for grab ship unloader and human based on UWB technology according to claim 5, characterized in that: The switch is used for data transmission between the PLC module, the UWB positioning unit and the mechanism drive unit.

7. A control method for the human-machine anti-collision and anti-smashing system of a grab unloader based on UWB technology, using the human-machine anti-collision and anti-smashing system of the grab unloader according to any one of claims 1-5, characterized in that Including: S1: Four UWB base stations on the grab ship unloader are used to receive the pulse signals sent by the UWB tags carried by the hold cleaning machine and personnel in the hold in real time, and send them to the UWB positioning server; S2: After the UWB positioning server obtains the data transmitted by the 4 UWB base stations, it performs real-time positioning detection on the UWB tags in the hold; Among them, the three-dimensional space coordinates of the UWB tag are (x, y, z), and the actual three-dimensional coordinate values corresponding to the actual installation positions of the 4 UWB base stations are (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), (x4, y4, z4) respectively. The following method is used to calculate the actual three-dimensional coordinate values of the UWB tag: S 12 = c×(T1 - T 发送 ) - c×(T2 - T 发送 ); S 23 = c × (T2 - T 发送 ) - c × (T3 - T 发送 ); S 34 = c×(T3 - T 发送 ) - c×(T4 - T 发送 ); S 41 = c×(T4 - T 发送 ) - c×(T1 - T 发送 ); Where S 12 is the distance difference between the UWB tag and Base Station 1 and Base Station 2, S 23 is the distance difference between the UWB tag and Base Station 2 and Base Station 3, S 34 is the distance difference between the UWB tag and Base Station 3 and Base Station 4, S 41 is the distance difference between the UWB tag and Base Station 4 and Base Station 1, c is the speed of light value, T1 is the time value when Base Station 1 receives the UWB tag pulse signal, T2 is the time value when Base Station 2 receives the UWB tag pulse signal, T3 is the time value when Base Station 3 receives the UWB tag pulse signal, T4 is the time value when Base Station 4 receives the UWB tag pulse signal, T 发送 is the time value when the UWB tag emits the pulse signal. Solve the above equations to obtain the actual three-dimensional coordinate values (x, y, z) of the UWB tag; S3: The UWB positioning server transmits the calculated real-time position of the UWB tag to the PLC module; S4: When the PLC module determines that there is a risk of impact between the grabbing point where the grab descends and the UWB tag in the cabin, the PLC module sends control commands to the hoisting frequency converter and the opening / closing frequency converter to prohibit the hoisting and opening / closing motors from descending, so as to avoid impact accidents between the grab and the cabin cleaning machinery and personnel. The method for determining the impact risk is as follows: When S 机械风险距离 <S 抓斗区域 +S 清舱机械区域 When it is, it is judged that there is a risk of impact between the grab and the hold cleaning machinery in the same hold, and lowering is prohibited; Where S 机械风险距离 is the distance value from the center point of the grab target material taking operation point to the UWB tag of the hold cleaning machine, S 抓斗区域 is the self-safety distance value of the grab with the center point of the grab as the midpoint, S 清舱机械区域 is the self-safety distance value of the hold cleaning machine with the center point of the hold cleaning machine as the center; When S 人员风险距离 <S 抓斗区域 +S 人员区域 When it is determined that there is a risk of the grab hitting the personnel in the same cabin, the lowering is prohibited; Among which S 人员风险距离 is the distance value from the center point of the grab target material taking operation point to the UWB tag of the personnel in the hold, S 抓斗区域 is the self - safety distance value of the grab with the center point of the grab as the mid - point, S 人员区域 is the self - safety distance value of the hold - cleaning personnel with the center point of the personnel in the hold as the center; S5: Keep the function of the anti-impact system for the grab ship unloader activated until the ship unloading operation is completed.

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