A tower crane remote control system for realizing remote control data interaction by using RS485 communication

Abstract

This invention discloses a tower crane remote control system that uses RS485 communication for remote control data interaction, specifically relating to the field of tower crane remote control technology. It includes: a ground-based centralized control center equipped with a ground ring network main controller; several tower cranes, each equipped with a tower crane ring network node controller; and a two-core communication bus that connects the ground ring network main controller and all tower crane ring network node controllers in series, forming a physically closed RS485 redundant ring network. The ground ring network main controller manages ring network tokens and performs data interaction according to the token protocol. When the ring network is interrupted, it automatically switches the communication path to maintain the connection. This invention achieves self-healing capability and high reliability through the RS485 redundant ring network, overcomes the technical obstacles of using RS485 in ring networks through signal shaping circuits, and ensures priority transmission of emergency data by combining a token preemption mechanism. It has the advantages of low cost, high reliability, and good security.

Description

Technical Field

[0001] This invention relates to the field of tower crane remote control technology, and more specifically, to a tower crane remote control system that uses RS485 communication to achieve remote control data interaction. Background Technology

[0002] Tower cranes, commonly known as tower cranes, are vertical transportation equipment frequently used on construction sites. Their remote control systems are crucial for achieving unmanned operation and multi-tower collaboration. Currently, remote control of tower cranes mainly adopts the following two technical solutions: One solution is a wireless remote control system based on industrial radios or 4G / 5G public networks. This solution transmits the tower crane's operating status data to the ground control center via a wireless network and issues operation commands to the tower crane for execution. However, this solution has the following drawbacks in practical applications: First, it relies on the coverage of public network base stations, which can easily lead to communication interruptions in signal blind spots or network congestion, posing a safety hazard. Second, the cost of 5G modules and data traffic is high, increasing the cost of equipment deployment and operation. Finally, the latency of wireless communication is uncertain, making it difficult to meet the high real-time control requirements of tower crane emergency stops, collision avoidance, and other control scenarios. Another solution is a wired control system based on the RS485 bus. The RS485 bus is widely used in industrial control due to its strong anti-interference capability, long transmission distance, and low cost. In existing technologies, the RS485 bus is mostly used for data acquisition within a single tower crane, such as connecting sensors to the tower crane's main control PLC or establishing a point-to-point connection between the ground monitoring platform and a single tower crane. However, this application method still has the following shortcomings: On the one hand, the star or bus topology lacks physical layer redundancy design. Once a section of the line fails or a node fails, the entire communication link will be interrupted. On the other hand, the communication mechanism adopts the traditional master-slave query / response mode without priority distinction. When multiple tower cranes report data at the same time or in case of an emergency, it is impossible to guarantee the real-time priority transmission of critical data. In addition, data interaction between tower cranes must be relayed through the ground central server, resulting in a large delay in collision avoidance calculation, which is difficult to meet the safety requirements of group tower crane operations.

[0003] Therefore, how to provide a tower crane remote control system that is highly reliable, has low latency, low cost, and is suitable for multi-tower operations is a technical problem that urgently needs to be solved by those skilled in the art. In view of this, the present invention provides a tower crane remote control system that uses RS485 communication to realize remote control data interaction. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a tower crane remote control system that uses RS485 communication to realize remote control data interaction, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a tower crane remote control system that uses RS485 communication to realize remote control data interaction, comprising: Ground control center, wherein the ground control center is equipped with a ground ring network main controller; Several tower cranes, each equipped with a tower crane ring network node controller; And a two-core communication bus, which connects the ground ring network main controller and all tower crane ring network node controllers in series in sequence, and closes the connection end to form a physical layer closed RS485 redundant ring network. The tower crane ring network node controller includes a signal shaping and adaptive transceiver circuit, which is used to suppress signal reflection in the RS485 redundant ring network and automatically identify the data flow direction to avoid self-excited oscillation of the ring network. The ground ring network main controller and the tower crane ring network node controller execute a dynamic priority token interaction protocol. The token has a priority identifier field embedded in it, which is used to identify the priority of the data to be transmitted. When the tower crane ring network node controller detects that the local tower crane is in an emergency state, it preempts the token and inserts the emergency data frame into the data stream to transmit it to the ground ring network main controller. Any two tower crane ring network node controllers establish a peer-to-peer communication link through an RS485 redundant ring network to directly exchange their real-time operating attitude data for tower crane group anti-collision calculation. The ground ring network main controller is used to manage ring network tokens and interact with the ring network node controllers of each tower crane according to the token protocol. When the RS485 redundant ring network is interrupted, the ground ring network main controller automatically switches the communication path to maintain the communication connection in the non-interrupted area.

[0006] Preferably, the emergency state includes at least one of the following: wind speed exceeding limit state, torque exceeding limit state, or emergency stop triggered state.

[0007] Preferably, the two-core communication bus is an armored shielded twisted pair cable, laid along the standard sections of the tower crane and the ground of the construction site.

[0008] Preferably, the tower crane ring network node controller is connected to the tower crane main control PLC, which is used to collect tower crane sensor data and control the tower crane actuators.

[0009] Preferably, the tower crane sensor data includes at least one of weight data, amplitude data, height data, or wind speed data.

[0010] Preferably, when the ground ring network main controller sends control commands to the target tower crane, it sends the control commands to the RS485 redundant ring network in the form of broadcast frames; The tower crane ring network node controller of the target tower crane receives control commands based on the address code and forwards them to the corresponding tower crane main control PLC to execute the corresponding actions.

[0011] The technical effects and advantages of this invention are as follows: 1. This invention achieves high reliability and self-healing capability of the tower crane remote control system by constructing a physically closed RS485 redundant ring network. The ground ring network main controller and all tower crane ring network node controllers are connected in series sequentially via a two-core communication bus and closed at both ends. When a break occurs in the ring network, the ground ring network main controller automatically switches the communication path, and the ring network degenerates into a chain network. Communication between nodes in non-breakpoint areas and between nodes and the ground ring network main controller can still be maintained. Compared with the existing technology that relies on 5G / 4G public networks or single-link 485 communication, this invention achieves redundant backup of communication links at the physical level, avoiding the interruption of the entire network communication due to a single point of failure, and significantly improving the operational reliability of the system in complex construction site environments. 2. This invention solves the technical obstacles of using RS485 in closed loop networks by combining signal shaping and adaptive transceiver circuits with a dynamic priority token interaction protocol, and realizes high-priority transmission of emergency data. On the one hand, the signal shaping and adaptive transceiver circuits shape the waveform of the bus signal and automatically identify the data flow direction, effectively suppressing signal reflection and self-excited oscillation in the RS485 closed loop network, ensuring the stability of the loop network communication. On the other hand, the token has an embedded priority identifier field. When the tower crane is in an emergency state such as wind speed exceeding the limit, torque exceeding the limit, or emergency stop triggering, the tower crane loop network node controller can actively seize the token and insert the emergency data frame into the data stream with the highest priority, transmitting it to the ground control center within milliseconds. Compared with the conventional alarm reporting mechanism in the prior art, this invention ensures the real-time reliable transmission of critical safety data in emergency situations, greatly improving the inherent safety of tower crane operations. 3. This invention achieves peer-to-peer communication between tower crane nodes through an RS485 redundant ring network, providing a low-latency data interaction foundation for anti-collision of multiple tower cranes. It also offers significant cost advantages. The ring network node controllers of any two tower cranes can directly exchange real-time operational attitude data via the ring network for tower crane group anti-collision calculations, without needing to be relayed through the ground ring network main controller. Compared to existing technologies that rely on central server forwarding, the peer-to-peer communication mode significantly reduces data transmission latency, making anti-collision response faster. Furthermore, this invention uses low-cost two-core armored shielded twisted-pair cable as the transmission medium, eliminating the need for 5G / 4G public network base station coverage. This avoids the impact of public network signal blind spots and network congestion on the control link, and significantly reduces equipment deployment and operating costs, making it particularly suitable for complex construction site environments involving multiple tower cranes. Attached Figure Description

[0012] Figure 1 This is a system diagram of the present invention.

[0013] The attached diagram is labeled as follows: 100, Ground Control Center; 110, Ground Ring Network Main Controller; 200, Tower Crane; 210, Tower Crane Ring Network Node Controller; 300, Two-Core Communication Bus. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Example 1

[0015] This embodiment provides a tower crane remote control system that uses RS485 communication to realize remote control data interaction. The system includes: a ground control center 100, several tower cranes 200, and a two-core communication bus 300.

[0016] The ground control center 100 is located in the ground control room, which is equipped with a ground ring network main controller 110. The ground ring network main controller 110 is the control core of the entire system. It is responsible for managing the ring network tokens and interacting with each tower crane 200 according to the token protocol. The ground control center 100 is also equipped with equipment such as an operator's seat and a video splicing server for operators to monitor and control the tower crane 200 in real time. Each tower crane 200 is equipped with a tower crane ring network node controller 210. This tower crane ring network node controller 210 serves as a communication and control node at the tower crane 200 end. It is responsible for data interaction with the ground ring network main controller 110 and connecting with the tower crane 200's own control system. Specifically, the tower crane ring network node controller 210 is connected to the tower crane 200's main control PLC. The tower crane 200's main control PLC is used to collect tower crane 200 sensor data and control the tower crane 200's actuators. The tower crane 200's sensor data includes, but is not limited to, at least one of weight data, amplitude data, height data, or wind speed data. The tower crane 200's actuators include hoisting mechanisms, slewing mechanisms, luffing mechanisms, etc. The two-core communication bus 300 is the physical transmission medium. It is preferably made of armored shielded twisted pair cable and laid along the standard section of the tower crane 200 and the ground of the construction site to enhance anti-interference ability and mechanical strength. The two-core communication bus 300 connects the ground ring network main controller 110 and all tower crane ring network node controllers 210 in series in sequence, and closes the connection end to form a physical layer closed RS485 redundant ring network.

[0017] At the communication protocol level, the ground ring network main controller 110 and the tower crane ring network node controller 210 execute a dynamic priority token interaction protocol. The core of this protocol is that the ground ring network main controller 110 generates a ring network token, which is circulated in the RS485 redundant ring network. The token has an embedded priority identifier field, which is used to identify the priority of the data to be transmitted. Only the node holding the token has the right to send data to the ring network, thereby avoiding conflicts caused by multiple nodes sending data at the same time.

[0018] When the system is working normally, the tokens are passed between the nodes in a predetermined order. When the ring network node controller of a certain tower crane 200 needs to send data, it waits for the token to arrive, acquires the token, loads the data frame onto the ring network, and then releases the token to allow it to continue to be transmitted.

[0019] The system in this embodiment has redundant communication capability. Since the two-core communication bus 300 forms a closed ring network structure at the physical layer, when a break occurs in the RS485 redundant ring network, such as when a section of the line is cut due to a construction accident, the ground ring network main controller 110 can detect the break location and automatically switch the communication path. At this time, the ring network degenerates into a chain network, but the communication between nodes in the non-break area and between nodes and the ground ring network main controller 110 can still be maintained, thereby realizing the self-healing capability of the system and significantly improving the reliability of the system. Example 2

[0020] This embodiment further defines the structure of the tower crane ring network node controller 210 based on embodiment 1; The tower crane ring network node controller 210 includes a signal shaping and adaptive transceiver circuit, which is connected to a two-core communication bus 300 to suppress signal reflection in the RS485 redundant ring network and automatically identify the data flow direction to avoid self-excited oscillation of the ring network. Since RS485 buses are typically designed for master-slave bus topologies rather than closed-loop network topologies, when multiple nodes are connected end-to-end to form a closed loop, signal propagation in the loop is prone to reflection and superposition, and may even cause self-excited oscillation, leading to communication failure. This embodiment addresses this by setting up signal shaping and adaptive transceiver circuits to shape the waveform of the signals on the bus, remove reflected noise, and dynamically adjust the transmission and reception directions to ensure stable and unidirectional logical transmission of signals in the ring network, thereby overcoming the technical obstacles of using RS485 in closed-loop networks. Example 3

[0021] This embodiment further defines the data processing mechanism under emergency conditions based on embodiment 1 or embodiment 2. When the tower crane ring network node controller 210 detects that the local tower crane 200 is in an emergency state through the tower crane 200 main control PLC connected to it, such as detecting at least one of the states of wind speed exceeding the limit, torque exceeding the limit, or emergency stop triggering, the node controller immediately starts the emergency preemption mechanism without waiting for the current token holder to release the token. Specifically, the tower crane ring network node controller 210 ignores the current token holder, actively seizes the token, and inserts the frame containing emergency data, i.e. the emergency data frame, into the data stream with the highest priority, and immediately transmits it to the ground ring network main controller 110. After receiving the emergency data frame, the ground ring network main controller 110 immediately triggers an alarm or takes corresponding safety measures, ensuring that critical data in emergency situations can be delivered to the ground control center 100 within milliseconds, greatly improving the system's security. Example 4

[0022] This embodiment further limits the data interaction between tower cranes 200 based on embodiment 1 or embodiment 2; Any two different tower crane ring network node controllers 210 can establish a peer-to-peer communication link through an RS485 redundant ring network. This means that the first tower crane ring network node controller 210 and the second tower crane ring network node controller 210 can directly exchange their real-time operating attitude data without going through the ground ring network main controller 110. The real-time operating attitude data includes information such as the slewing angle, amplitude, height, and load of the tower crane 200. These directly interactive real-time operating attitude data are used for anti-collision calculations of the tower crane 200 group. When the working ranges of two or more tower crane 200s overlap, they can independently perform anti-collision calculations by directly obtaining each other's position and attitude information, or they can perform collaborative control at the tower crane 200 main control PLC level. Compared with the traditional solution that relays through a central server, this peer-to-peer communication method has lower latency, better real-time performance, and faster anti-collision response. Example 5

[0023] This embodiment further defines the control command issuance process based on embodiment 1 or embodiment 2; When an operator issues control commands via a control seat at the ground control center 100, such as sending a hoisting command to a target tower crane 200, the ground ring network main controller 110 first generates a control command frame containing the address code of the target tower crane 200, and then sends the control command to the RS485 redundant ring network in the form of a broadcast frame. Since all tower crane ring network node controllers 210 on the ring network can receive the broadcast frame, only the ring network node controller of the target tower crane 200 with the matching address code will receive the control command. After parsing the command, the ring network node controller of the target tower crane 200 forwards the command to the corresponding tower crane 200 main control PLC. The tower crane 200 main control PLC controls the corresponding actuator to perform corresponding actions according to the command, such as driving the hoisting motor to run.

[0024] Through the above methods, the tower crane 200 remote control system of the present invention constructs an industrial control local area network with high reliability, low latency, self-healing capability, and emergency priority, which effectively solves the problems of signal interruption and uncertain delay that may exist in the prior art when relying on public network communication, and is particularly suitable for complex construction site environments where multiple tower cranes are operated.

[0025] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tower crane remote control system that uses RS485 communication to achieve remote control data interaction, characterized in that: include: Ground control center (100), wherein the ground control center (100) is equipped with a ground ring network main controller (110); Several tower cranes (200), each of which is equipped with a tower crane ring network node controller (210); And a two-core communication bus (300), which connects the ground ring network main controller (110) and all tower crane ring network node controllers (210) in series and closes at both ends to form a physical layer closed RS485 redundant ring network; The tower crane ring network node controller (210) includes a signal shaping and adaptive transceiver circuit, which is used to suppress signal reflection in the RS485 redundant ring network and automatically identify the data flow direction to avoid self-excited oscillation of the ring network. The ground ring network main controller (110) and the tower crane ring network node controller (210) execute a dynamic priority token interaction protocol. The token has a priority identifier field embedded in it, which is used to identify the priority of the data to be transmitted. When the tower crane ring network node controller (210) detects that the local tower crane (200) is in an emergency state, it preempts the token and inserts the emergency data frame into the data stream to transmit it to the ground ring network main controller (110). Any two tower crane ring network node controllers (210) establish a peer-to-peer communication link through an RS485 redundant ring network to directly exchange their real-time operating attitude data for tower crane (200) group anti-collision calculation. The ground ring network master controller (110) is used to manage ring network tokens and interact with each tower crane ring network node controller (210) according to the token protocol. When the RS485 redundant ring network is interrupted, the ground ring network master controller (110) automatically switches the communication path to maintain the communication connection in the non-interruption area.

2. The tower crane remote control system according to claim 1, characterized in that: The emergency state includes at least one of the following: wind speed exceeding limit, torque exceeding limit, or emergency stop triggered state.

3. The tower crane remote control system according to claim 1, characterized in that: The two-core communication bus (300) is an armored shielded twisted pair cable, which is laid along the standard section of the tower crane (200) and the ground of the construction site.

4. The tower crane remote control system according to claim 1, characterized in that: The tower crane ring network node controller (210) is connected to the tower crane (200) main control PLC. The tower crane (200) main control PLC is used to collect tower crane (200) sensor data and control the tower crane (200) actuator.

5. The tower crane remote control system according to claim 1, characterized in that: The tower crane (200) sensor data includes at least one of weight data, amplitude data, height data, or wind speed data.

6. The tower crane remote control system according to claim 1, characterized in that: When the ground ring network main controller (110) sends control commands to the target tower crane (200), it sends the control commands to the RS485 redundant ring network in the form of broadcast frames. The tower crane ring network node controller (210) of the target tower crane (200) receives the control command according to the address code and forwards it to the corresponding tower crane (200) main control PLC to execute the corresponding action.

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