High-precision walking displacement monitoring device for mobile hoist

Abstract

This invention discloses a high-precision mobile gate hoist displacement monitoring device belonging to the field of water conservancy engineering machinery and equipment monitoring technology. It includes a stationary scale assembly and a moving scale assembly. The stationary and moving scale assemblies achieve non-contact data interaction through magnetic induction signals, eliminating mechanical contact wear and adapting to the long-stroke, high-vibration operating conditions of gate hoists. By employing segmented, differentiated magnet spacing encoding, each segment corresponds to a unique absolute position, eliminating cumulative errors and requiring no power-on zeroing. Positioning accuracy reaches the millimeter level, meeting the precise positioning requirements of gate hoists and far surpassing the monitoring accuracy of traditional encoders and limit switches. It achieves high-precision absolute position monitoring and can flexibly adapt to mobile gate hoists with different strokes. Installation requires no modification to the original track, making it suitable for both new equipment as standard equipment and convenient for the intelligent upgrading of existing older gate hoists. Construction is convenient, cost-effective, and modular, with strong adaptability.

Description

Technical Field

[0001] This invention belongs to the field of monitoring technology for hydraulic engineering machinery and equipment, specifically involving a high-precision mobile gate hoist walking displacement monitoring device. It is particularly suitable for the walking positioning, precise stopping and safety limit monitoring of gantry and bridge mobile gate hoists in water conservancy hub projects such as reservoirs, hydropower stations and pumping stations, and is adapted to the harsh working conditions of water conservancy projects with humid, dusty and strong vibration environments. Background Technology

[0002] Mobile gate hoists are core lifting equipment in water conservancy projects for controlling the opening, closing, and maintenance of gates. The accurate monitoring and positioning of their movement directly affects gate alignment accuracy, equipment operational safety, and the efficiency of water conservancy hub scheduling. Traditional gate hoist position monitoring methods often employ encoders, limit switches, laser rangefinders, magnetic gratings, or RFID positioning. However, these methods have several drawbacks in practical water conservancy applications: encoders rely on gear transmission to collect signals, which is prone to gear wear, slippage, and missed steps over long-term operation, leading to large cumulative errors; they also require contact installation, resulting in high maintenance costs. Limit switches can only achieve point-to-point limiting and cannot achieve continuous position monitoring, resulting in extremely low accuracy. Laser rangefinders are susceptible to interference from water mist, dust, and light, exhibiting poor stability in outdoor water conservancy scenarios and are also costly. Magnetic gratings require a small sensing distance for their moving and stationary gauges, but mobile gate hoists cannot meet this minimum distance requirement due to uneven tracks and vibrations during movement. RFID tags have low positioning resolution, making them unsuitable for high-precision docking and failing to meet the stringent requirements for precise gate alignment.

[0003] In response to the characteristics of mobile gate hoists, such as long travel distance, frequent start-stop, severe vibration, and harsh hydraulic environment, there is an urgent need for a non-contact, high-precision absolute position monitoring device that is highly resistant to interference, has no cumulative error, and is easy to install. This device would address the technical pain points of existing technologies, such as low positioning accuracy, poor reliability, cumbersome maintenance, and insufficient adaptability. Therefore, we propose a high-precision travel displacement monitoring device for mobile gate hoists. Summary of the Invention

[0004] The purpose of this invention is to provide a high-precision mobile gate hoist displacement monitoring device to solve the existing problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-precision mobile gate hoist traveling displacement monitoring device, comprising a moving scale assembly and a stationary scale assembly. The moving scale assembly consists of a moving scale housing, a PCB board, and a moving scale cover plate. The PCB board is fixedly installed inside the moving scale housing and sealed by the moving scale cover plate. A main controller is installed on the PCB board, and a Hall effect device array is provided on the side of the PCB board near the stationary scale assembly.

[0006] The stationary scale assembly consists of a stationary scale body, coding blocks, a large permanent magnet, a small permanent magnet, and a stationary scale support. The stationary scale assembly adopts a segmented modular design, composed of several standard stationary scale sections sequentially spliced ​​together. Each section of the stationary scale assembly contains one or more sets of coding blocks, and each set of coding blocks contains a large permanent magnet and a small permanent magnet to form a stationary scale section of fixed length, facilitating transportation and installation. The stationary scale assembly and the moving scale assembly achieve long-distance non-contact data interaction through unipolar magnetic induction signals, avoiding the limitation of small sensing distance when using bipolar magnetic induction signals for coding. There is no mechanical contact wear, making it suitable for the long-stroke, high-vibration operating conditions of the hoist. The stationary scale assembly is fixedly installed along the entire length of the mobile hoist's traveling track, while the moving scale assembly is correspondingly installed at the bottom of the hoist's traveling trolley, moving synchronously with the hoist. A constant non-contact induction gap is maintained between the stationary and moving scales to ensure stable transmission of the magnetic field signal.

[0007] Preferably, the internal structure of the coding block is a differentiated coding magnet group, where the magnetic field width of the large permanent magnet is greater than that of the small permanent magnet. The spacing between the large and small permanent magnets in each coding block group is different, forming a unique magnetic field coding sequence through the differentiated spacing, thus constituting an absolute position coding system. Each stationary scale section corresponds to a unique absolute position on the hoist track, with no coding repetition, completely avoiding position identification confusion. The stationary scale section does not require power supply, operates passively, and has extremely high stability. The bottom of the stationary scale section is equipped with a track fixing buckle, which can be directly snapped and fixed to the side wall of the hoist traveling track or a special bracket next to the track. The installation does not require damage to the track structure and is compatible with the intelligent transformation of existing hoist equipment.

[0008] Preferably, the effective length of the moving ruler assembly is greater than the length of the coding block, and the Hall effect device array on the PCB board can cover at least one section of the coding block to avoid interruption of coding recognition due to crossing sections during walking, thus ensuring the continuity of position monitoring.

[0009] Preferably, the Hall device array consists of multiple linear Hall elements evenly arranged along the length of the moving scale assembly to form a multi-channel magnetic field sensing area. This area can simultaneously acquire the magnetic field width signal and relative position signal of the large permanent magnet and the small permanent magnet, accurately identify the spacing characteristics of the large permanent magnet and the small permanent magnet within the stationary scale section, and analyze the corresponding absolute position code.

[0010] Preferably, the PCB board is also equipped with a signal processing control module and a data transmission module. The signal processing control module has a built-in microprocessor for receiving the magnetic field signal transmitted by the Hall array, performing filtering, amplification, encoding and parsing operations to quickly determine the current absolute travel position of the hoist. The data transmission module uses wired RS485 or wireless LoRa / 4G modes to transmit the real-time position data to the hoist control room's central control system or PLC control system, realizing real-time position display, overspeed warning, precise stopping control and safety limit protection.

[0011] Preferably, each group of the coding blocks uses engineering plastic as support, and is assembled in sequence and installed on a stainless steel static ruler bracket to form a standard static ruler section. The static ruler bracket needs to be made of austenitic stainless steel or non-ferromagnetic materials such as copper or aluminum to prevent interference with the working distance of the permanent magnet.

[0012] Preferably, the magnetic poles of the large permanent magnet and the small permanent magnet in each group of coding blocks are in the same direction, which increases the sensing distance and effectively avoids the influence of iron debris on the track.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. By adopting segmented differential magnet spacing encoding, each segment corresponds to a unique absolute position, with no cumulative error and no need for power-on zeroing. The positioning accuracy can reach the millimeter level, meeting the precise stopping and alignment requirements of the gate hoist. It is far superior to the monitoring accuracy of traditional encoders and limit switches, achieving high-precision monitoring of absolute position. It can be flexibly adapted to mobile gate hoists with different strokes. Installation does not require modification of the original track. It is suitable for standard configuration of new equipment and also facilitates the intelligent upgrading and transformation of existing old gate hoists. It is convenient to construct, low in cost, segmented and modular, and highly adaptable.

[0014] 2. By adopting a passive permanent magnet design for the stationary scale component and a non-contact Hall array for the moving scale, there is no mechanical transmission wear. It is unaffected by harsh hydraulic working conditions such as water mist, dust, humidity, vibration, and dirt. It has a long service life and stability far exceeding that of laser and photoelectric monitoring devices. It is non-contact and wear-free, with strong anti-interference capabilities. The stationary scale operates passively, requiring no power supply and having no vulnerable parts. The moving scale is sealed and protected, making it waterproof and dustproof. It requires no daily maintenance, significantly reducing the workload and cost of operation and maintenance of the gate hoist position monitoring system.

[0015] 3. By designing the length of the moving ruler to be greater than the length of the coding block, seamless coding can be achieved when traveling across sections, and position signals can be continuously output throughout the entire process. It has the dual functions of continuous position monitoring and precise stopping limit, improving the safety and efficiency of the hoist operation, and ensuring continuous monitoring without interruption. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the static ruler structure of the present invention; Figure 3 This is a schematic diagram of the movable ruler structure of the present invention; Figure 4 This is a schematic diagram of the PCB board structure of the present invention.

[0017] In the diagram: 1. Moving scale assembly; 101. Moving scale housing; 102. PCB board; 103. Main controller; 104. Electrical contacts; 105. Hall effect device array; 106. Moving scale cover plate; 2. Stationary scale assembly; 201. Encoding block; 202. Large permanent magnet; 203. Small permanent magnet; 204. Stationary scale support; 205. Stationary scale body. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The following modifications will follow the above approach, paying attention to the changes made to the numerical codes. Please see Figure 1-4 This invention provides a technical solution for a high-precision mobile gate hoist displacement monitoring device, comprising a moving scale assembly 1 and a stationary scale assembly 2. The moving scale assembly 1 consists of a moving scale housing 101, a PCB board 102, and a moving scale cover plate 106. The PCB board 102 is fixedly installed inside the moving scale housing 101 and sealed by the moving scale cover plate 106. A main controller 103 is installed on the PCB board 102. A Hall effect device array 105 is provided on the side of the PCB board 102 near the stationary scale assembly 2. The overall length of the moving scale assembly 1 is 512mm, which is greater than the 500mm of the coding block. The moving scale is equipped with a Hall effect array 105 consisting of 256 linear Hall elements, evenly distributed along the length of the moving scale, with a sensing gap of 2mm. The moving scale is fixed to the bottom of the hoist trolley and moves synchronously with the trolley. The Hall effect array 105 collects magnetic field signals in real time. The signal processing module quickly analyzes the magnet spacing code, matches it with the position database, and outputs the current moving position of the trolley in real time. The data is transmitted to the PLC in the control room to realize real-time position display. When it reaches the preset stopping position of the gate, it automatically triggers a deceleration and stopping command with a positioning error of ≤±2mm. The stationary scale assembly 2 consists of a stationary scale body 205, coding blocks 201, a large permanent magnet 202, a small permanent magnet 203, and a stationary scale support 204. The stationary scale assembly 2 adopts a segmented modular design, composed of several standard stationary scale sections spliced ​​together sequentially. Each section of the stationary scale assembly 2 contains one or more sets of coding blocks 201. Each set of coding blocks 201 contains a large permanent magnet 202 and a small permanent magnet 203 to form a stationary scale section of fixed length, facilitating transportation and installation. The stationary scale assembly 2 and the moving scale assembly 1 achieve long-distance non-contact data interaction through a single-pole magnetic induction signal, avoiding the limitation of small sensing distance when using bipolar magnetic induction signal encoding. It eliminates mechanical contact wear and is suitable for the long-stroke, high-vibration operating conditions of the hoist. The stationary scale assembly 2 is fixedly installed along the entire length of the mobile hoist's traveling track. Component 1 is installed at the bottom of the hoist's traveling trolley and moves synchronously with the hoist. A constant non-contact sensing gap is maintained between the stationary and moving gauges to ensure stable transmission of the magnetic field signal. The total length of the stationary gauge assembly track is 50m. The stationary gauge assembly 2 is divided into 25 standard stationary gauge sections, each 2m long. Each stationary gauge section contains 4 sets of continuous coding blocks. The coding block 201 contains a large permanent magnet 202 with a width of 10mm and a small permanent magnet 203 with a width of 2mm. The spacing between the large permanent magnet 202 and the small permanent magnet 203 in each coding block 201 is set to 15mm, 18mm, 21mm...492mm, with 160 different spacings, forming 160 unique absolute position codes, corresponding to a range of 0-80m, covering the 50m travel distance monitoring needs of the track.

[0020] Specifically, the internal structure of the coding block 201 consists of differentiated coding magnet groups. The magnetic field width of the large permanent magnet 202 is greater than twice the magnetic field width of the small permanent magnet 203. The spacing between the large permanent magnet 202 and the small permanent magnet 203 in each group of coding blocks 201 is different, and the magnetic pole directions of the large permanent magnet 202 and the small permanent magnet 203 in each group of coding blocks 201 are the same. Through the differentiated spacing, a unique magnetic field coding sequence is formed, constituting an absolute position coding system. Each stationary scale section corresponds to a unique absolute position on the hoist track, with no coding repetition, completely avoiding position identification confusion. The stationary scale section does not require power supply, operates passively, and has extremely high stability. The bottom of the stationary scale section is equipped with a track fixing buckle, which can be directly snapped and fixed to the side wall of the hoist traveling track or a special bracket next to the track. The installation does not require damage to the track structure and is compatible with the intelligent transformation of existing hoist equipment.

[0021] Specifically, the effective length of the moving ruler assembly 1 is greater than the length of the encoding block 201, and the Hall device array on the PCB board 102 can cover at least one section of the encoding block 201, so as to avoid interruption of encoding recognition due to crossing sections during the movement and ensure the continuity of position monitoring.

[0022] Specifically, the Hall device array consists of multiple linear Hall elements evenly arranged along the length of the moving scale assembly. The Hall elements can be unipolar or bipolar to form a multi-channel magnetic field sensing area, which can simultaneously acquire the magnetic field width signal and relative position signal of the large permanent magnet 202 and the small permanent magnet 203, accurately identify the spacing characteristics of the large permanent magnet 202 and the small permanent magnet 203 within the stationary scale section, and analyze the corresponding absolute position code.

[0023] Specifically, the PCB board 102 is also equipped with a signal processing control module and a data transmission module. The signal processing control module has a built-in microprocessor, which is used to receive the magnetic field signal transmitted by the Hall array, perform filtering, amplification, encoding and analysis calculations, and quickly determine the current absolute travel position of the hoist. The data transmission module adopts wired RS485 or wireless LoRa / 4G mode to transmit the real-time position data to the central control system or PLC control system in the hoist control room, so as to realize real-time position display, overspeed warning, precise stop control and safety limit protection.

[0024] Specifically, each set of coding blocks 201 uses engineering plastic as support and is assembled in sequence and installed on stainless steel static ruler bracket 204 to form a standard static ruler section. The static ruler bracket 204 needs to be made of austenitic stainless steel or non-ferromagnetic materials such as copper and aluminum to prevent interference with the working distance of the permanent magnet.

[0025] Specifically, in each group of coding blocks, the large and small permanent magnets have the same magnetic pole direction. This increases the sensing distance while effectively avoiding the influence of iron debris on the track. (Note: If a bipolar magnet is used, the N and S poles will attract each other, reducing the sensing distance, especially when the two poles are very close. This is the fundamental reason why conventional static magnetic grid sensors have very short sensing distances. When iron debris accumulates on one side of a magnetic pole (e.g., the N pole), it will be attracted by the other pole (e.g., the S pole). In this case, the iron debris acts as a magnetic conductor, making it difficult for the moving scale to obtain effective magnetic field information. If a monopolar magnet is used, the same poles repel each other. This not only increases the effective distance of the magnetic field in the air, but when iron debris is attracted, it will "stand" on the magnet, further increasing the sensing distance between the moving and stationary scales.) In this implementation scheme, position monitoring is achieved based on the principle of magnetic induction coding recognition: the static scale assembly 2 is passively deployed, with a certain number of coding blocks 201 set in each section of the static scale. The coding blocks 201 form a unique absolute position code through the differentiated spacing between the large permanent magnets 202 and the small permanent magnets 203. When the moving scale moves synchronously with the hoist, the Hall array sensor module continuously senses the magnetic field signals of the large permanent magnets 202 and the small permanent magnets 203 in the corresponding coding block 201, identifies the difference in magnetic field width and relative spacing between the large permanent magnets 202 and the small permanent magnets 203, and converts the magnetic field analog signal into a digital coding signal. The signal processing module analyzes the coding signal, matches it with a preset coding position lookup table, and directly outputs the absolute position value of the hoist's current movement. There is no need for cumulative counting, no start-up-to-zero process, and it is not affected by the start-up and shutdown of the hoist or vibration. It achieves non-contact, high-precision, continuous and stable monitoring throughout the entire process. It should be noted that the coded blocks 201 are arranged continuously in either forward or reverse order.

[0026] The positioning principle is as follows: When the moving ruler is at any position, it can obtain the sensing information of at least one large permanent magnet 202 and at least one small permanent magnet 203 in the stationary ruler. If the moving ruler obtains the information of the small permanent magnet 203 to the right of the large permanent magnet 202, the distance between the large permanent magnet 202 and the small permanent magnet 203 can be calculated to determine that the moving ruler is above the Nth coding block. If the moving ruler obtains the information of the small permanent magnet 203 to the left of the large permanent magnet 202, the distance between the large permanent magnet 202 and the small permanent magnet 203 can be calculated and the position above the N-1 (or N+1) coding block 201 can be obtained through reverse calculation. Then, the accurate position information can be obtained through the sensing information of the large permanent magnet 202 in the moving ruler array.

[0027] Since the length of the moving ruler is greater than the length of the coding block, when the hoist travels to the junction of the two coding blocks, the Hall array can simultaneously cover part of the coding of the two adjacent coding blocks, achieving seamless coding connection, avoiding position monitoring breakpoints, and ensuring the continuity of long-stroke monitoring; the differentiated magnet spacing coding design makes each stationary ruler correspond to a unique position, completely eliminating coding interference between adjacent segments, and greatly improving the accuracy and reliability of position recognition.

[0028] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-precision mobile gate hoist displacement monitoring device, comprising a moving scale assembly (1) and a stationary scale assembly (2), characterized in that: The movable ruler assembly (1) consists of a movable ruler housing (101), a PCB board (102), and a movable ruler cover plate (106). The PCB board (102) is fixedly installed inside the movable ruler housing (101) and sealed by the movable ruler cover plate (106). A main controller (103) is installed on the PCB board (102). A Hall effect device array (105) is provided on the side of the PCB board (102) near the stationary ruler assembly (2). The static ruler assembly (2) consists of a static ruler body (205), an encoding block (201), a large permanent magnet (202), a small permanent magnet (203), and a static ruler support (204). The static ruler assembly (2) adopts a segmented modular design. Each segment of the static ruler assembly (2) contains one or more sets of encoding blocks (201). Each set of encoding blocks (201) contains a large permanent magnet (202) and a small permanent magnet (203).

2. The mobile gate hoist high-precision walking displacement monitoring device according to claim 1, characterized in that: The interior of the coding block (201) is a group of differentiated coding magnets. The magnetic field width of the large permanent magnet (202) is greater than twice the magnetic field width of the small permanent magnet (203). The spacing between the large permanent magnet (202) and the small permanent magnet (203) in each group of coding blocks (201) is different. The magnetic pole directions of the large permanent magnet (202) and the small permanent magnet (203) in each group of coding blocks (201) are the same.

3. The high-precision mobile gate hoist displacement monitoring device according to claim 1, characterized in that: The effective length of the moving ruler assembly (1) is greater than the length of the coding block (201), and the Hall device array on the PCB board (102) can cover at least one section of the coding block (201).

4. The high-precision mobile gate hoist displacement monitoring device according to claim 1, characterized in that: The Hall device array consists of multiple linear Hall elements evenly arranged along the length of the moving scale assembly. The Hall elements can be either unipolar or bipolar.

5. The high-precision mobile gate hoist displacement monitoring device according to claim 1, characterized in that: The PCB board (102) is also equipped with a signal processing control module and a data transmission module, and the signal processing control module has a built-in microprocessor.

6. The high-precision mobile gate hoist displacement monitoring device according to claim 1, characterized in that: Each set of the coding blocks (201) uses engineering plastic as support and is assembled in sequence and installed on a stainless steel static ruler bracket (204) to form a standard static ruler section.

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