Centralized controller of hoist type crane

Abstract

The invention discloses a hoist type crane integrated controller, and relates to the related field of crane operation control. The main control unit is respectively connected with the switching value input and output unit, the analog quantity acquisition unit, the encoder acquisition unit, the RS485 communication unit and the Ethernet communication unit; the switching value input and output unit is used for receiving and outputting a switching value signal to realize basic operation control; and the RS485 communication unit and the Ethernet communication unit are used for realizing information interaction with external equipment. According to the centralized controller of the hoist type crane, by integrating the main control unit, the switching value input and output unit, the analog quantity acquisition unit, the encoder acquisition unit and the two communication units, traditional scattered relay / PLC control and independent functional modules are integrated, and the problems that modules of different manufacturers are poor in compatibility, complex in wiring and low in integration level are effectively solved; centralized management of crane operation is achieved, and the stability, safety and expandability of the system are improved.

Description

Technical Field

[0001] This invention relates to the technical field of centralized controllers for cranes, specifically a centralized controller for hoist cranes. Background Technology

[0002] In modern industrial production systems, cranes, as key material handling equipment, are widely used in ports, construction, manufacturing, logistics, and many other fields. Their performance directly affects production efficiency and operational safety. Hoist cranes, as a common type, play a vital role in various industrial scenarios due to their compact structure and ease of operation. However, traditional hoist cranes have many control problems, necessitating an advanced centralized controller to optimize their operation.

[0003] Currently, most hoist cranes use relay logic or PLC logic control, which has low integration and relatively complex wiring and function implementation. To solve the above problems, one can refer to the crane controller and crane including the controller disclosed in the existing patent (Chinese patent application number CN202010087852.4, application date 2020-02-12). This controller, through the cooperation of components such as an up button, a down button, a magnet, and a Hall sensor, can control the motor's up movement according to the degree of button pressing. This invention addresses the limitation of speed control stages in electric cranes using inverter-driven motors by reducing operating speed and enabling multi-speed control. It also references existing technology (Chinese patent application number CN94248356.1, application date 1994-12-21) which discloses a portable electric hoist controller with high reliability, long lifespan, low maintenance rate, and good arc extinguishing effect, thus extending the lifespan of its matching motor. After installation and trial on 30 electric hoists, its working lifespan was increased from 3-5 days to approximately 90 days. The monthly downtime for electric hoist maintenance has been reduced from 200 hours to 13 hours. This utility model does not change the original structure of the electric hoist, is easy to modify, and can be applied to all motor forward and reverse control circuits. Finally, referring to the prior art (Chinese patent application number CN202020349627.9, application date 2020-03-19), by setting up a data processing module, PT thermistor monitoring channel, operation command monitoring module, thermal switch monitoring channel, limit signal input detection module, control relay, overload monitoring module, pulse input detection module, data storage module, current monitoring module, voltage monitoring module, phase sequence monitoring module, power monitoring module, wide area network communication module, local area network communication module, status indicator, power processing module, USB interface, communication interface, and display module, it can simultaneously realize the functions of electric hoist monitoring, control, multi-machine network operation, fault diagnosis, and data recording. It can realize the traditional monitoring and control functions of European-style electric hoists, and at the same time realize the remote monitoring of electric hoists. Combined with the cloud service platform, it can effectively realize the monitoring and maintenance functions of electric hoists.

[0004] Although the above devices have a certain degree of integration, wiring and functions, additional functional modules are required to realize the standard functions, such as overload limiters, overspeed protection devices, encoder acquisition units, etc. Since the functional modules come from different manufacturers, compatibility problems are likely to occur.

[0005] Therefore, we proposed a centralized controller for hoist cranes to solve the problems mentioned above. Summary of the Invention

[0006] The purpose of this invention is to provide a centralized controller for hoist cranes, in order to solve the problem mentioned in the background art that the hoist crane controllers currently on the market require additional functional modules to achieve standard functions, such as overload limiters, overspeed protection devices, encoder acquisition units, etc., and the functional modules come from different manufacturers, which can easily lead to compatibility issues.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a centralized controller for a hoist crane includes a main control unit; the main control unit is connected to a digital input / output unit, an analog signal acquisition unit, an encoder acquisition unit, an RS485 communication unit, and an Ethernet communication unit, respectively, for integrating signals from each unit and realizing the crane's logic control, safety protection, and data processing; the digital input / output unit is used to receive and output digital signals to realize basic operation control; the analog signal acquisition unit is used to acquire analog signals of weight and current; the encoder acquisition unit is used to acquire position and speed signals of the hoisting mechanism; the RS485 communication unit and the Ethernet communication unit are used to realize information interaction with external devices.

[0008] Preferably, the main control unit uses an STM32F1 series microcontroller with a main frequency of 72MHz. This microcontroller enables functions such as anti-sway operation, lifting position calculation, overspeed protection, lifting weight limit, overcurrent protection, operational logic control, safety data monitoring, and USB data export. Anti-sway operation is achieved by controlling the speed of the trolley and crane frequency converters through a built-in anti-sway control algorithm. Lifting position calculation is based on encoder-collected information, and overspeed protection is implemented by determining the lifting mechanism's operating speed based on encoder data. The STM32F1 series microcontroller supports online programming, allowing for upgrades to anti-sway algorithms and other functions according to actual needs. It possesses multi-tasking capabilities, enabling efficient processing of multiple control commands simultaneously. This facilitates future function expansion and upgrades, improving equipment performance without hardware replacement. Multi-tasking ensures orderly operation of various control functions, avoiding command congestion and improving operational efficiency. The anti-sway function reduces cargo swaying and lowers the risk of cargo falling. Precise lifting position calculation facilitates accurate loading and unloading of goods.

[0009] Preferably, the main control unit further includes a storage unit comprising a ferroelectric memory FM24CL16B and a general-purpose EEPROM. The ferroelectric memory FM24CL16B is used to store frequently read and written data such as encoder signals and weight signals, and the data is not lost when power is off. The general-purpose EEPROM is used to store setting parameters. The storage unit has data encryption function to prevent tampering of critical operating data and setting parameters; it supports automatic data backup, and can quickly restore data when a memory fails; it ensures data security and integrity, and avoids equipment failure or safety accidents caused by data tampering; the data backup function improves the system's fault tolerance and reduces downtime and losses caused by data loss.

[0010] Preferably, the digital input / output unit includes a digital input unit and a digital output unit. The digital input unit uses AC36V or AC48V AC power input, transmits signals after bridge rectification and optocoupler isolation, and can be configured with forward, reverse, high-speed, fault, and limit functions. The digital output unit uses an RT314042 high-power relay, which can directly drive an external contactor and has active output. Its contacts are connected to the AC power supply. The digital input unit can flexibly configure the response sensitivity of the input signal through software to adapt to the signal characteristics of different external devices. The digital output unit has overvoltage protection to prevent damage to the relay from excessive external voltage. This improves the compatibility of the digital input / output unit with different external devices and reduces the difficulty of device matching. Overvoltage protection extends the service life of the relay, reduces the number of repairs and replacements, and lowers maintenance costs.

[0011] Preferably, the analog signal acquisition unit includes an overload limiter circuit and a current transformer acquisition circuit; the overload limiter circuit is used to acquire the crane weight sensor signal, and the current transformer acquisition circuit is used to acquire the crane system current signal; the analog signal acquisition unit has signal filtering and amplification functions, which can effectively filter out external interference signals and amplify weak sensor signals; it can monitor the working status of the acquisition circuit in real time, and issue an alarm signal in time when the circuit fails; it improves the accuracy and stability of analog signal acquisition, and provides a reliable basis for subsequent safety protection and logic control; the circuit fault alarm facilitates timely troubleshooting and avoids protection failure caused by abnormal signal acquisition.

[0012] Preferably, the overload limiter circuit uses a TM771 124-bit ADC chip and a CA-IS3721 digital isolator; the current transformer acquisition circuit uses a CA-IS1306 isolated ADC chip and a filter circuit, the filter circuit consisting of R13, R15, and C21; the TM771 124-bit ADC chip supports multiple sampling rate adjustments, and the sampling frequency can be adjusted according to the rate of weight change; the CA-IS3721 digital isolator and CA-IS1306 isolated ADC chip have high isolation voltage, which can effectively resist strong electromagnetic interference; the flexible sampling rate adjustment allows weight acquisition to maintain both accuracy and efficiency; the high isolation performance ensures that the chip works normally in complex electromagnetic environments, improves the reliability of analog signal acquisition, and ensures the accuracy of overload limiting and overcurrent protection.

[0013] Preferably, the encoder acquisition unit includes an EL0631 signal isolator and a 74LVC2T45 conversion chip; the EL0631 signal isolator has a maximum transmission rate of 10MHz and is used to isolate encoder signals; the 74LVC2T45 conversion chip is used to convert 5V signals to 3.3V signals and transmit them to the main control unit; the EL0631 signal isolator has over-signal protection function, automatically cutting off transmission when the input signal exceeds the normal range; the 74LVC2T45 conversion chip supports bidirectional signal conversion, which can adapt to the signal output types of different encoders; it prevents abnormal signals from damaging the main control unit and extends the service life of the equipment; bidirectional signal conversion improves the versatility of the encoder acquisition unit, which can be adapted to various models of encoders, reducing the difficulty of equipment selection. Preferably, the RS485 communication unit has two independent interfaces, which can work in host mode and slave mode respectively, and adopts isolation protection and surge protection design, which is suitable for big data communication, frequency converter control, dual-machine collaboration, and large screen display scenarios.

[0014] Preferably, the Ethernet communication unit adopts an RJ-45 interface, supports the standard Ethernet protocol, and can achieve high-speed, high-stability signal transmission for transmitting signals with high requirements. The Ethernet communication unit supports remote diagnostics and remote control functions, allowing parameter modification and fault diagnosis of the controller via the network. It has network flow control functions to avoid data congestion affecting the transmission of critical signals. The remote function reduces the labor and time costs of equipment maintenance and facilitates rapid response to equipment failures. Network flow control ensures priority transmission of critical signals, guarantees the real-time performance and reliability of high-requirement signal transmission, and meets the needs of remote monitoring and intelligent management.

[0015] Preferably, the overcurrent protection is achieved through feedback of the current operating current from the current transformer. When the actual operating current exceeds the rated operating current, the protection logic is activated and an alarm signal is issued. The safety data monitoring can record and save the crane's operating status in real time, providing support for later data traceability. The USB data export can export historical operating data to external devices such as USB flash drives and computers through the USB transmission interface of the processing chip. The overcurrent protection has a multi-level early warning function, issuing different levels of early warning signals according to the degree to which the current exceeds the rated value. The safety data monitoring allows for customization of the data recording period and content, meeting the data analysis needs of different users. Multi-level early warning enables users to take measures in advance to avoid overcurrent faults and reduce the risk of equipment damage. Customizable data recording improves the flexibility of data monitoring, facilitating targeted data analysis and equipment optimization. USB data export facilitates offline data analysis and archiving, providing strong support for equipment maintenance and management.

[0016] Compared with existing technologies, the beneficial effects of this invention are as follows: This hoist crane centralized controller integrates main control, digital input / output, analog signal acquisition, encoder acquisition, and two types of communication units, consolidating traditionally distributed relay / PLC control and various independent functional modules into one unit. This effectively solves the problems of poor compatibility between modules from different manufacturers, complex wiring, and low integration. Simultaneously, thanks to the multi-functional design of the core unit, dedicated storage and data processing mechanisms, and efficient communication interfaces, it achieves centralized management of crane operation, improves system stability, security, and scalability, reduces equipment procurement, installation, and maintenance costs, and facilitates operational data traceability and functional expansion. Specific details are as follows:

[0017] 1. By integrating the STM32F1 series microcontroller into the main control unit, safety functions such as overload limiting, overspeed protection, and overcurrent protection are directly linked with the encoder acquisition and analog signal acquisition units, avoiding the protection lag caused by signal transmission delays or compatibility issues in traditional distributed modules. For example, the overload limiter circuit uses the TM771 124-bit high-precision ADC chip and CA-IS3721 isolator to accurately acquire weight signals and transmit them to the main control unit in real time. Combined with built-in protection logic, it can quickly trigger protection actions. The current transformer acquisition circuit uses a filter circuit and an isolated ADC chip to ensure stable current signal feedback. In case of overcurrent, it can immediately activate protection and alarm, greatly reducing the risk of safety accidents.

[0018] 2. Compared to traditional cranes that require separate modules such as overload limiters and overspeed protection devices, this controller integrates digital input / output and encoder acquisition functions into one unit, reducing the number of wires and interface adaptations required for modules from different manufacturers. The digital input / output unit directly uses AC36V / AC48V power, eliminating the need for additional power conversion equipment. The encoder acquisition unit uses an EL0631 isolator and signal conversion chip, eliminating the need for additional overspeed protection equipment. This simplifies the electrical layout, reduces the cost of equipment procurement, installation, and subsequent maintenance, and also reduces potential failure points caused by module dispersion.

[0019] 3. The main control unit is equipped with a ferroelectric memory FM24CL16B and a general-purpose EEPROM, which are used to classify and store frequently read / write data and set parameters, respectively, ensuring that data such as operating status and fault records are stably saved and not lost when power is off. Historical data can be directly exported via USB interface, and with the high-speed transmission capability of Ethernet communication unit, it is convenient for users to monitor or trace the crane's operating status in real time, providing data support for equipment maintenance and optimization. In addition, the two independent interfaces of RS485 communication unit and Ethernet interface support flexible docking with external devices such as frequency converters and large screen displays. Combined with the expandable logic control of the main control unit, functions such as remote monitoring and multi-machine collaboration can be added according to actual needs without large-scale hardware modification, improving the adaptability and service life of the equipment. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the hoist-type overall operating circuit of the present invention;

[0021] Figure 2 This is a schematic diagram of the circuit associated with the controller functional modules of the present invention;

[0022] Figure 3 This is a schematic diagram of the main control unit circuit of the present invention;

[0023] Figure 4 This is a schematic diagram of the storage cell circuit of the present invention;

[0024] Figure 5 This is a schematic diagram of the switch input unit circuit of the present invention;

[0025] Figure 6 This is a schematic diagram of the switch output unit circuit of the present invention;

[0026] Figure 7 This is a schematic diagram of the overload limiter circuit of the present invention;

[0027] Figure 8 This is a schematic diagram of the current transformer acquisition circuit of the present invention;

[0028] Figure 9This is a schematic diagram of the encoder acquisition unit circuit of the present invention. Detailed Implementation

[0029] 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.

[0030] Please see Figures 1-9 The present invention provides the following technical solution: a centralized controller for hoist cranes.

[0031] Example 1: This example adopts a modular integrated design, which can be referred to in the appendix. Figure 1 and attached Figure 2 Each functional unit is electrically connected through internal wiring on the PCB board. The selection and layout of the core components are as follows:

[0032] Main control unit: The core processor is an STM32F103RCT6 microcontroller (72MHz clock frequency). This chip has a built-in 32-bit ARM Cortex-M3 core, 128KB flash memory and 20KB RAM, and can run anti-shake algorithm, logic control and data processing programs at the same time. A 16MHz external crystal oscillator is configured around the chip to ensure clock stability, and electromagnetic interference is reduced by the ground plane design of the 4-layer PCB board.

[0033] Storage Unit: The FM24CL16B ferroelectric memory connects to the microcontroller via an I²C bus, and its read / write lifespan reaches [missing information]. The first type of EEPROM is specifically designed to store high-frequency data updated more than 10 times per second, such as the encoder's real-time pulse count and instantaneous load value. The second type is a standard EEPROM (AT24C64, 64Kbit) connected via the I²C bus, used to store factory-set parameters such as rated lifting capacity, overspeed threshold, and communication baud rate, with a read / write lifespan of up to [missing information]. This meets the needs of long-term use.

[0034] Interface module layout: The digital input / output units and analog acquisition units are all arranged on the edge of the PCB board. The RT314042 relay (contact capacity 10A / 250VAC) of the digital output unit has a separate heat dissipation pad. The ADC chip of the analog acquisition unit has reserved space around it for a π-type filter circuit to reduce the impact of power supply noise.

[0035] Example 2: This example optimizes the circuit design and working principle of each functional unit based on Example 1. See the appendix for details. Figure 3 -Appendix Figure 9 .

[0036] Digital input / output unit

[0037] Digital input circuit: Adopting a wide voltage input design of AC36V / AC48V, external signals are first connected via terminal blocks and converted to DC (approximately 50V) by a KBPC1010 bridge rectifier. Then, the signal is divided and current-limited by resistors R4 (10KΩ) and R10 (10KΩ) to drive a PC817 optocoupler for isolation. The optocoupler output is connected to the microcontroller's GPIO port (3.3V level). For example, when the "forward" button is pressed, the input circuit is activated, the optocoupler's secondary winding conducts, and the microcontroller detects a low-level signal, interpreting it as a forward command. This circuit supports 16 configurable inputs, which can be defined via software for functions such as "high-speed," "limit," and "fault reset."

[0038] Digital output circuit: Each output is controlled by the GPIO port of STM32F103, which controls the ULN2003 Darlington transistor array to drive the RT314042 relay. One end of the normally open contact of the relay is connected to an AC36V / AC48V power supply, and the other end is output through a terminal block. When the relay is energized, it directly supplies power to the external contactor coil without additional wiring. When the "lifting" command is executed, the microcontroller controls the corresponding relay to energize the contactor coil and start the lifting mechanism.

[0039] Overload limiter circuit: The mV-level signal output by the weight sensor is connected via a shielded wire and sent to the TM7711 24-bit ADC chip (conversion rate adjustable from 10Hz to 80Hz); the SPI interface of the TM7711 is connected to the microcontroller through a CA-IS3721 digital isolator (isolation voltage 2500Vrms) to ensure electrical isolation between the sensor side and the control side; the microcontroller converts the ADC reading into the actual weight (e.g., 10000LSB corresponds to 5t), and issues a warning when the weight exceeds 90% of the rated value, and immediately cuts off the lifting output when the weight exceeds 110%.

[0040] Current transformer acquisition circuit: The AC current output from the through-type current transformer (100A / 5A ratio) is converted into a 0-500mV AC signal by the sampling resistor R14 (0.1Ω / 1W). The signal is then filtered out by a second-order low-pass filter circuit (cutoff frequency 1kHz) composed of R13 (1KΩ), R15 (1KΩ) and C21 (100nF) to remove high-frequency noise before being sent to the CA-IS1306 isolated ADC chip (24-bit resolution). The digital signal output by the chip is directly transmitted to the microcontroller and converted into the actual current value (e.g., 500mV corresponds to 100A). If the current exceeds 120% of the rated current for 3 consecutive seconds, the overcurrent protection is triggered.

[0041] Encoder Acquisition Unit: The A and B phase pulse signals of the incremental encoder (e.g., 1024 lines) of the hoisting mechanism are connected via terminal blocks. Electrical isolation is first achieved through an EL0631 optocoupler isolator (transmission rate up to 10MHz). The isolated 5V pulse signal is converted to 3.3V by a 74LVC2T45 level converter chip (withstand voltage 5.5V) and connected to the encoder interface of the microcontroller's TIM2 and TIM3 timers. The microcontroller calculates the hoisting height by counting the number of pulses and the running speed by the pulse frequency. When the speed exceeds 120% of the rated value, the overspeed protection is activated, cutting off the hoisting output and triggering an alarm.

[0042] Communication unit

[0043] RS485 Communication: The SP3485 transceiver is used, with two independent loops. Each loop is connected to the microcontroller's UART interface through an ISO7740 isolation chip (isolation voltage 2500Vrms). An external TVS diode is used for surge protection (10kV electrostatic discharge protection). Interface 1 is set to master mode (address 0x01) for connecting to the frequency converter. Interface 2 is set to slave mode (address 0x02) for connecting to the touch screen and supports the Modbus-RTU protocol.

[0044] Ethernet communication: Employs the W5500 hardware TCP / IP chip, connecting to the microcontroller via an SPI interface. The RJ-45 interface integrates a network transformer, supporting 10 / 100Mbps auto-sensing. This interface connects to the factory's SCADA system, enabling real-time uploading of operating load data, location data, and current data, and receiving remote control commands (such as emergency stops). Communication latency is ≤10ms.

[0045] Example 3: This example demonstrates the software flow and core algorithm in detail. Please refer to the appendix for details. Figure 1 -Appendix Figure 9 The main program flow is as follows: After the microcontroller is powered on, it first initializes the peripherals (GPIO, ADC, timer, communication interface), reads the configuration parameters in the EEPROM, and then enters the main loop (10ms cycle): ① Acquire the status of digital input; ② Read analog quantities (weight, current) and encoder data; ③ Execute the anti-shake algorithm and protection logic; ④ Update the output status; ⑤ Record the running data; ⑥ Respond to communication commands.

[0046] Anti-sway control algorithm: Based on the matching relationship between the trolley's running speed and the swing period of the suspended load, the algorithm calculates the ideal deceleration curve by collecting the trolley's position (s) and speed (v) through the encoder: v(t) = v0 - k × s(t), where k is a proportional coefficient (dynamically adjusted according to the load length). The command is sent to the frequency converter via RS485, causing the trolley to decelerate according to the curve, controlling the swing amplitude within ±5°.

[0047] Data recording and export: Key data (timestamp, load, lifting height, current, fault code) is recorded every 500ms and stored in the FM24CL16B (cyclically overwritten, retaining the most recent 100,000 records). When the USB interface detects a USB flash drive being inserted, the microcontroller exports the data in "year-month-day.csv" format via the USBOTG protocol, with each record containing 20 fields.

[0048] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 centralized controller for a hoist crane, comprising a main control unit; characterized in that: The main control unit is connected to the digital input / output unit, analog signal acquisition unit, encoder acquisition unit, RS485 communication unit, and Ethernet communication unit, respectively, to integrate the signals of each unit and realize the logic control, safety protection, and data processing of the crane; the digital input / output unit is used to receive and output digital signals to realize basic operation control; the analog signal acquisition unit is used to acquire analog signals of weight and current; the encoder acquisition unit is used to acquire the position and speed signals of the hoisting mechanism; the RS485 communication unit and Ethernet communication unit are used to realize information interaction with external devices.

2. The centralized controller for hoist cranes according to claim 1, characterized in that, The main control unit uses an STM32F1 series microcontroller with a main frequency of 72MHz. It can realize functions such as anti-sway operation, lifting position calculation, overspeed protection, lifting weight limit, overcurrent protection, operation logic control, safety data monitoring, and USB data export. Among them, anti-sway operation is achieved by controlling the operating speed of the trolley and crane frequency converters through a built-in anti-sway control algorithm; lifting position calculation is completed based on encoder data; and overspeed protection is achieved by judging the operating speed of the lifting mechanism based on encoder data.

3. The centralized controller for hoist cranes according to claim 2, characterized in that, The main control unit also includes a storage unit, which contains a ferroelectric memory FM24CL16B and a general-purpose EEPROM. The ferroelectric memory FM24CL16B is used to store data that is frequently read and written to encoder signals and weight signals, and the data is not lost when power is off. The general-purpose EEPROM is used to store setting parameters.

4. The centralized controller for hoist cranes according to claim 1, characterized in that, The digital input / output unit includes a digital input unit and a digital output unit. The digital input unit uses AC36V or AC48V AC power input, transmits signals after bridge rectification and optocoupler isolation, and is configured with forward, reverse, high-speed, fault, and limit functions. The digital output unit uses an RT314042 high-power relay, which can directly drive an external contactor and has an active output, with its contacts connected to the AC power supply.

5. The centralized controller for a hoist crane according to claim 1, characterized in that, The analog quantity acquisition unit includes an overload limiter circuit and a current transformer acquisition circuit; the overload limiter circuit is used to acquire the crane weight sensor signal, and the current transformer acquisition circuit is used to acquire the crane system current signal.

6. The centralized controller for a hoist crane according to claim 5, characterized in that, The overload limiter circuit uses a TM7711 24-bit ADC chip and a CA-IS3721 digital isolator; the current transformer acquisition circuit uses a CA-IS1306 isolated ADC chip and a filter circuit, which consists of R13, R15, and C21.

7. The centralized controller for hoist cranes according to claim 1, characterized in that, The encoder acquisition unit includes an EL0631 signal isolator and a 74LVC2T45 conversion chip; the EL0631 signal isolator has a maximum transmission rate of 10MHz and is used to isolate the encoder signal; the 74LVC2T45 conversion chip is used to convert the 5V signal to a 3.3V signal and transmit it to the main control unit.

8. The centralized controller for hoist cranes according to claim 1, characterized in that, The RS485 communication unit has two independent interfaces, which operate in master mode and slave mode respectively. It adopts isolation protection and surge protection design, and is suitable for big data communication, frequency converter control, dual-machine collaboration and large screen display scenarios.

9. The centralized controller for a hoist crane according to claim 1, characterized in that, The Ethernet communication unit uses an RJ-45 interface, supports the standard Ethernet protocol, and can achieve high-speed and high-stability signal transmission, making it suitable for transmitting signals with high requirements.

10. The centralized controller for a hoist crane according to claim 2, characterized in that, The overcurrent protection is achieved by feeding back the current operating current through a current transformer. When the actual operating current exceeds the rated operating current, the protection logic is activated and an alarm signal is issued. The safety data monitoring can record and save the crane's operating status in real time, providing support for later data traceability. The USB data export can export historical operating data to a USB flash drive or computer external device through the USB transmission interface of the processing chip.

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