A ship distributed multi-bus controller

Abstract

This utility model discloses a distributed multi-bus controller for ships. It includes a microcontroller controller, EtherCAT slave units, a communication unit, a human-machine interface unit, and an analog signal acquisition unit. The microcontroller controller has a built-in floating-point unit, and a crystal oscillator is connected between pins 1 and 2 of the microcontroller controller. Two load capacitors are connected in parallel to ground at each end of the crystal oscillator. The EtherCAT slave unit includes an EtherCAT slave controller, an RJ45 connector, and peripheral signal conditioning circuitry. The differential transmission signal output by the EtherCAT slave controller is processed and connected to the TD1+ and TD1- pins of the RJ45 connector. The TD1+ and TD1- lines are connected to pull-up resistors and then to the VDD33TXRX1 power supply domain. Its advantages include high integration, fast communication speed, strong compatibility, avoidance of control errors caused by communication delays, high synchronization accuracy, and fast data refresh. It achieves the technical objectives of high bandwidth, low latency, and multi-protocol compatibility, solving the problems existing in traditional ship bus technology.

Description

Technical Field

[0001] This utility model relates to a ship distributed multibus controller based on EtherCAT industrial Ethernet technology, belonging to the field of ship automation control technology. Background Technology

[0002] With the rapid development of modern ship automation, the number of shipboard devices has increased dramatically. Traditional ship control systems mostly use RS485 or CAN buses for networking. However, as the amount of data increases, traditional buses are gradually showing bottlenecks in bandwidth and real-time performance. EtherCAT, due to its high speed and high real-time performance, has been introduced into the marine field. However, existing ship equipment has a large number of CAN and RS485 interfaces that cannot be directly connected to the EtherCAT network. Therefore, it is particularly important to design a distributed controller that can connect to the EtherCAT high-speed backbone network while also being compatible with traditional buses such as CAN and RS485. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a ship distributed multi-bus controller based on EtherCAT that can realize distributed connection of ship equipment, with high integration, fast communication speed and strong compatibility.

[0004] To address the aforementioned technical issues, this utility model provides a ship distributed multi-bus controller, comprising a microcontroller controller, an EtherCAT slave unit connected to the microcontroller controller, a communication unit, a human-machine interface unit, and an analog acquisition unit for acquiring continuously changing signals from shipboard sensors. The microcontroller controller has a built-in floating-point arithmetic unit capable of performing fast Fourier transforms and digital filtering on data from the ship's electric propulsion system or main engine monitoring. A crystal oscillator is connected between pins one and two of the microcontroller controller, with two load capacitors connected in parallel to ground at each end of the crystal oscillator. The PD, PE, PF, and PG ports of the microcontroller controller output an FSMC bus for parallel data transmission with the EtherCAT slave controller. The EtherCAT slave unit includes an EtherCAT slave controller, an RJ45 connector, and peripheral signal conditioning circuitry. The differential transmission signal output by the EtherCAT slave controller is processed and connected to the TD1+ and TD1- pins of the RJ45 connector. The TD1+ and TD1- lines are connected to pull-up resistors and to the VDD33TXRX1 power supply domain.

[0005] The microcontroller's pin 3 is connected to a reset circuit, which is an RC delay reset circuit consisting of a pull-up resistor and a ground filter capacitor.

[0006] The microcontroller has multiple sets of power supply pins, and decoupling capacitors are arranged near each set of power supply pins. The VDDA pin of the microcontroller is isolated from the digital power supply through a ferrite bead.

[0007] The communication unit includes two MAX485ESA transceivers, each with an RS485 interface. In addition to connecting to TX / RX, the microcontroller is also connected to the RE and DE pins of each MAX485ESA transceiver via pins.

[0008] Both MAX485ESA transceivers have pull-up and pull-down bias resistors on their A and B lines, and each of the two MAX485ESA transceivers has a 0.1uF capacitor connected to its VCC pin.

[0009] The microcontroller controller is also connected to a human-computer interaction unit.

[0010] The microcontroller, EtherCAT slave unit, communication unit, analog signal acquisition unit, and human-machine interaction unit are all powered by DC power.

[0011] The TD1+ and TD1- lines are connected to pull-up resistors and connected to the VDD33TXRX1 power domain.

[0012] The advantages of this utility model are: (1) By setting up a single-chip microcontroller and an EtherCAT slave controller connected to the single-chip microcontroller and setting up the corresponding physical layer interface circuit, the single-chip microcontroller can access the ship automation network through the EtherCAT slave unit. It can collect and convert the data of the ship's field CAN and RS485 heterogeneous devices using the communication unit. After processing by the single-chip microcontroller, the data is uploaded to the master station. The single-chip microcontroller can also display the operating status and network parameters in real time through the OLED display module and indicator lights of the human-machine interaction unit. It can perform real-time high-speed interaction on the operating data of the ship's distributed devices to ensure the coordinated work of the ship's power and auxiliary systems. It has high integration, fast communication speed, and strong compatibility, avoiding control errors caused by communication delay. It has high synchronization accuracy and fast data refresh, which can effectively solve the problems of insufficient bandwidth and complex wiring of traditional ship bus. It achieves the technical goal of high bandwidth, low latency and multi-protocol compatibility, and solves the problems existing in traditional ship bus technology.

[0013] (2) The communication unit includes a CAN interface circuit, an RS485 interface circuit and a USB communication circuit, which integrates CAN, RS485 and USB interfaces, and solves the problem of interconnection between different devices. Attached Figure Description

[0014] Figure 1This is a schematic diagram of the principle of the ship distributed multi-bus controller of this utility model; Figure 2-1 This is a circuit diagram of the microcontroller controller unit (upper part) of this utility model; Figure 2-2 This is a circuit diagram of the lower half of the single-chip microcomputer controller unit of this utility model; Figure 3-1 This is a schematic diagram of the LAN9252 circuit in the EtherCAT slave unit of this utility model; Figure 3-2 This is a schematic diagram of the HR911205C circuit in the EtherCAT slave unit of this utility model; Figure 3-3 This is a schematic diagram of the EEPROM circuit in the EtherCAT slave unit of this utility model; Figure 4-1 This is a schematic diagram of the CAN circuit in the communication unit of this utility model.

[0015] Figure 4-2 This is a schematic diagram of the RS485 bus circuit in the communication unit of this utility model. Detailed Implementation

[0016] The ship distributed multi-bus controller of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] As shown in the figure, this utility model constructs a ship distributed multi-bus controller with a microcontroller as the core, integrating EtherCAT high-speed Ethernet communication, CAN bus communication, RS485 bus communication, and a human-machine interface. It includes a microcontroller, an EtherCAT slave unit connected to the microcontroller, a communication unit, and an analog signal acquisition unit for acquiring continuously changing signals from shipboard sensors. The analog signal acquisition unit includes a signal conditioning circuit and an analog-to-digital converter interface. The analog signal acquisition unit utilizes the 12-bit ADC integrated on the STM32F407ZET6 chip to acquire voltage or current signals. The EtherCAT slave unit is key to achieving the "distributed" and "high-speed" characteristics. The EtherCAT slave unit includes an EtherCAT slave controller chip (LAN9252), a network isolation transformer integrated socket (HR911205C), and peripheral signal conditioning circuitry. Specifically, an RJ45 connector of model HR911205C can be used. This connector integrates a network transformer, which provides electrical isolation and impedance matching, effectively isolating high-voltage surges and common-mode interference in the ship's electrical network. The slave unit uses a LAN9252 chip in conjunction with an EEPROM to achieve millisecond-level real-time communication with the upper-layer master station; In this embodiment, the microcontroller controller uses the STM32F407ZET6 chip with a main frequency of up to 168MHz. The microcontroller controller has a built-in floating-point unit (FPU) capable of performing Fast Fourier Transform (FFT) and digital filtering on data in ship electric propulsion systems or main engine monitoring. A crystal oscillator with a frequency of 8MHz is connected between the microcontroller controller's crystal oscillator connection pins (pins 23 and 24 in the figure). Two load capacitors with a capacitance of 22pF are connected in parallel to ground at each end of the crystal oscillator to start oscillation and maintain frequency stability, ensuring the accuracy of the system clock. This is crucial for the synchronization accuracy of the EtherCAT distributed clock. The microcontroller controller's reset pin (pin 25) is connected to a reset circuit. This reset circuit is an RC delay reset circuit composed of pull-up resistors and ground-filtering capacitors to prevent false resets caused by power fluctuations. The microcontroller controller has multiple sets of power supply pins. Each power supply pin of the controller is equipped with a 0.1uF decoupling capacitor to filter out high-frequency noise and ensure the purity of the MCU core voltage. The VDDA pin is isolated from the digital power supply via a ferrite bead to improve ADC acquisition accuracy. The PD, PE, PF, and PG ports of the microcontroller are brought out to form the FSMC bus for parallel data transmission with the EtherCAT slave controller LAN9252. FSMC can significantly improve data throughput. PB8 and PB9 pins are configured as CAN1_RX and CAN1_TX, connecting to the CAN transceiver; PA9, PA10, PB10, and PB11 pins are configured as USART interfaces, connecting to the RS485 transceiver; PA13 and PA14 are connected to the SWD debug port; the differential transmit signals (TXP / TXN) output by the EtherCAT slave controller are processed and connected to the TD1+ and TD1- pins of the RJ45 connector. Figure 3-2 (Pin 1 and pin 2 shown in the diagram).

[0018] Furthermore, to optimize signal quality, pull-up resistors are connected to the TD1+ and TD1- lines, both with a resistance of 49.9Ω and a precision of 1%, and are connected to the VDD33TXRX1 power domain. This termination matching design is to match the 100Ω characteristic impedance of the Ethernet cable, minimizing signal reflection. Simultaneously, an LC filter circuit consisting of an inductor and a capacitor is connected in series on the signal lines to suppress high-frequency EMI noise. The RD1+ (pin 3) and RD1- (pin 6) of the RJ45 connector are a receiving differential pair, also connected to the receiving end of the PHY chip via impedance matching resistors and an LC filter. The center tap of the RJ45 connector is connected to the chassis ground (EARTH) via a high-voltage capacitor, providing a low-impedance discharge path for common-mode noise. The RJ45 interface integrates LED indicators; LED1+ and LED1- are connected to the GPIO0 pin of the LAN9252 via current-limiting resistor R15, respectively. As indicator lights, the LEDs are constantly lit when the network cable connection is normal; when data transmission occurs, the LEDs flash, allowing the engineer to visually determine network connectivity.

[0019] Furthermore, the communication unit mainly includes a CAN interface circuit and an RS485 interface circuit, integrating CAN and RS485. It is equipped with a CAN transceiver to achieve protocol communication with marine diesel engine and generator set controllers, and an RS485 transceiver to achieve half-duplex communication with Modbus RTU devices such as level transmitters and temperature and humidity sensors. As shown on the left side of Figure 4, it is designed with two CAN communication interfaces, each using a TJA1050 high-speed CAN transceiver. The TTL level signals (CAN1_TX / RX) output by the STM32 are connected to the TXD and RXD pins of the TJA1050. The TJA1050 converts the logic levels to the differential levels (CANH and CANL) required by the CAN bus. A terminating resistor with a resistance of 120Ω is connected in parallel between CANH and CANL. This is the end-matching resistor required by the CAN bus standard, used to absorb signal reflection energy. In practical applications, if this controller is not a bus end node, this resistor can be disconnected using a jumper cap.

[0020] As shown on the right side of Figure 4, it uses two MAX485ESA transceivers, each with an RS485 interface. RS458 is typically half-duplex communication; therefore, in addition to connecting TX / RX, the microcontroller also connects to the RE (receive enable) and DE (transmit enable) pins of each MAX485ESA transceiver via pins. Typically, RE and DE are shorted and controlled by a single GPIO pin: high level for transmit, low level for receive. Furthermore, to prevent uncertain voltage levels when the bus is idle, pull-up and pull-down bias resistors are designed on the A and B pins of the two MAX485ESA transceivers, respectively. Figure 4-2As shown, resistor R32 is pulled up to 5V, and resistor R40 is pulled down to GND. Resistor R36 is the terminating resistor. Similarly, the second 485 interface also has bias resistors R44 and R47 and a terminating resistor R45. A 0.1uF capacitor is connected to the VCC pins of U6A and U6B to ensure stable power supply to the 485 transceiver. The microcontroller is responsible for scheduling the data flow of the CAN, RS485, and USB interfaces, and performing logic checks and fault diagnosis.

[0021] Furthermore, the microcontroller controller is also connected to a human-machine interface (HMI) unit and an alarm unit with a buzzer. The HMI unit has an OLED display module, a button unit, and status indicator lights for visual monitoring and manual intervention of the on-site status. The microcontroller controller is connected to the EtherCAT slave unit, communication unit, and HMI unit via a bus, and is responsible for the overall scheduling and data processing of the system. The OLED display module in the HMI unit is connected to the I2C or SPI interface of the STM32, displaying the local IP address, current operating mode, and bus communication rate in real time. The LEDs (status indicator lights) indicate power, operation, and status. The buttons are connected to the GPIO port of the STM32 for resetting and setting the slave alias address. Thus, the microcontroller controller can... The OLED display module and indicator lights display the operating status and network parameters in real time. The slave station alias setting and reset operations are performed by the button unit. The buzzer and LED unit output audible and visual alarm signals. It is equipped with OLED display, button input, ADC acquisition and buzzer alarm functions to facilitate on-site operation and maintenance. In addition, the microcontroller, EtherCAT slave unit, communication unit, analog signal acquisition unit, alarm unit and human-machine interaction unit are all powered by the power supply unit. The power supply unit is responsible for converting the external power supply of the ship to the 3.3V and 5V voltage required by the internal chips of the microcontroller. It uses a step-down chip to convert the ship's spare 24V power supply to 5V and 3.3V, providing isolated power for RS485 and CAN interfaces to ensure stable operation of the system in a 24V DC power supply environment.

[0022] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A ship distributed multi-bus controller, characterized by: The system includes a microcontroller controller, an EtherCAT slave unit connected to the microcontroller controller, a communication unit, and an analog acquisition unit for acquiring continuously changing signals from on-site sensors on the ship. The EtherCAT slave unit includes an EtherCAT slave controller, an RJ45 connector, and peripheral signal conditioning circuitry. The microcontroller controller has a built-in floating-point arithmetic unit that enables fast Fourier transform and digital filtering of data in the ship's electric propulsion system or main engine monitoring. A crystal oscillator is connected between pins 1 and 2 of the microcontroller controller, and two load capacitors are connected in parallel to ground at each end of the crystal oscillator. The PD, PE, PF, and PG ports of the microcontroller controller lead out to an FSMC bus for parallel data transmission with the EtherCAT slave controller. The differential transmission signal output by the EtherCAT slave controller is processed and connected to the TD1+ and TD1- pins of the RJ45 connector.

2. The ship distributed multi-bus controller according to claim 1, characterized in that: The microcontroller's third pin is connected to a reset circuit, which is an RC delay reset circuit consisting of a pull-up resistor and a ground filter capacitor.

3. A ship distributed multi-bus controller according to claim 1 or 2, characterized in that: The microcontroller has multiple sets of power supply pins, and decoupling capacitors are arranged near each set of power supply pins. The VDDA pin of the microcontroller is isolated from the digital power supply through a ferrite bead.

4. The ship distributed multi-bus controller according to claim 3, characterized in that: The communication unit includes two MAX485ESA transceivers, each with an RS485 interface. In addition to connecting to TX / RX, the microcontroller is also connected to the RE and DE pins of each MAX485ESA transceiver via pins.

5. The ship distributed multi-bus controller according to claim 4, characterized in that: Both MAX485ESA transceivers have pull-up and pull-down bias resistors on their A and B lines, and each of the two MAX485ESA transceivers has a 0.1uF capacitor connected to its VCC pin.

6. The ship distributed multi-bus controller according to claim 1, 2, 4 or 5, characterized in that: The microcontroller controller is also connected to a human-computer interaction unit.

7. The ship distributed multi-bus controller according to claim 6, characterized in that: The microcontroller, EtherCAT slave unit, communication unit, analog signal acquisition unit, and human-machine interaction unit are all powered by a power supply.

8. The ship distributed multi-bus controller according to claim 1, characterized in that: The TD1+ and TD1- lines are connected to pull-up resistors and connected to the VDD33TXRX1 power domain.

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