A double-redundancy intelligent CAN network system and networking method for a steering device

Abstract

The application discloses a kind of steering instrument dual-redundancy intelligent CAN network system and networking method, system includes two-way CAN net of hot backup each other, when the work of each steering function module is normal, only with the main road branch of this CAN bus connection is on; Intelligent module is connected between the two-way CAN bus, the intelligent module is suitable for real-time detection whether each steering function module fails, when detecting that there is fault steering function module on two-way CAN bus, and no one is the same on two-way CAN bus steering function failure module, the main road branch of all fault steering function modules on one-way CAN bus is disconnected, while the main road branch of corresponding normal steering function module with the same function on another CAN bus is disconnected, and the branch of from road is on.The application automatically selects perfect module from two-way CAN net by intelligent algorithm and re-networking and putting into operation, without manual intervention, degree of automation is high, guarantee the safety of ship navigation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of marine equipment, and particularly relates to a double-redundancy intelligent CAN network system for a steering instrument and a networking method. BACKGROUND

[0002] Chinese application 201510568255.2 discloses a steering compass display device based on double-redundancy CAN network with alarm function, Chinese application 201510569459.8 discloses a rudder alarm system on an automatic steering instrument and its alarm process, and Chinese utility model patent 201720116630.4 discloses a marine follow-up steering device. The double-redundancy CAN networks in the three applications are two completely independent routes, and the two routes of CAN networks are hot backups for each other. This network structure can switch to another route of CAN network when a fault occurs in one route of CAN network, thereby maintaining work.

[0003] However, when a fault occurs in the modules of both routes of CAN network, the steering instrument cannot work normally even if it is switched to another route of CAN network, and can only be steered through an emergency mode, which is very unsafe, increases the work burden of the crew, is very inconvenient, and must be repaired in time. Under the current epidemic background, maintenance personnel often cannot repair the ship in time, and the crew generally do not have repair skills. Since the steering instrument is the core equipment of the ship, long-term failure to repair and use it normally will bring great safety hazards.

[0004] Of course, if the modules that fail in the two routes of CAN network of the steering instrument are different, the intact module in one route of CAN network can theoretically replace the faulty module in the other route of CAN network, thereby piecing together a complete set of equipment to maintain operation. However, it is inevitable that the crew without repair skills will make mistakes when replacing and re-networking, especially when the ship is sailing, and the equipment cannot be replaced by power-off. SUMMARY

[0005] The present application aims to overcome the deficiencies in the prior art. When the modules that fail in the two routes of CAN network are different, the intact module is automatically selected from the two routes of CAN network by an intelligent algorithm to re-network and put into operation without human intervention, which is highly automated and ensures the safety of ship navigation.

[0006] To achieve the above object, in a first aspect, the application provides a double-redundancy intelligent CAN network system for a steering device, comprising two CAN networks which are hot backups of each other, each CAN network comprising a CAN bus and N steering function modules, each steering function module being connected to the two CAN buses through a main branch and a slave branch of a switching circuit, when each steering function module is working normally, only the main branch connected to the local CAN bus is turned on, and an intelligent module is connected between the two CAN buses, the intelligent module is adapted to detect whether each steering function module has a fault in real time, when it is detected that there are fault steering function modules on both CAN buses, and none of the fault steering function modules on one CAN bus is the same as the fault steering function modules on the other CAN bus, the main branch of all the fault steering function modules on one CAN bus is disconnected through the corresponding switching circuit, and the main branch of the normal steering function module with the same function on the other CAN bus is disconnected through the corresponding switching circuit, and the slave branch is turned on, so as to reconstitute a set of normal steering function modules to run on one CAN network.

[0007] Further, a master-backup selection unit is integrated in the intelligent module, the master-backup selection unit is adapted to select one of the two CAN networks as a master network to run when each steering function module is working normally.

[0008] Further, the master-backup selection unit is also adapted to select the other CAN network as the master network to run when there is a fault steering function module in one of the two CAN networks.

[0009] Further, a mode selection unit is integrated in the intelligent module, the mode selection unit is adapted to select any one of three steering modes, i.e. automatic, follow-up and emergency.

[0010] Further, the switching circuit comprises a relay and a CAN isolation transceiver, the coil of the relay is connected to the GPIO port of the controller in the intelligent module, the data transceiver end of the CAN isolation transceiver is connected to the data transceiver end of the corresponding steering function module, the bus end of the CAN isolation transceiver is connected to one CAN bus through a pair of normally open contacts of the relay and to the other CAN bus through a pair of normally closed contacts of the relay.

[0011] Further, the intelligent module is adapted to periodically receive the heartbeat packets sent by each steering function module, and to judge whether each steering function module has a fault according to whether the heartbeat packets are received within a preset time, if not, it is determined that a fault has occurred, and if yes, it is determined to be valid.

[0012] Further, the intelligent module is provided with two storage areas of steering function module validity state variables, each of the steering function module validity state variables is a binary parameter with N bits, one of the steering function module validity state variables corresponds to N steering function modules in one CAN network, and the other steering function module validity state variable corresponds to N steering function modules in another CAN network; the validity state of each steering function module includes two states of validity and failure, which are represented by different values of binary bits, each state bit in the steering function module validity state variable represents the validity state of one steering function module, when the validity state of the steering function module changes, the corresponding state bit in the steering function module validity state variable changes; if any steering function module fails, a value is assigned to the corresponding validity state variable, and if any steering function module is valid, another value is assigned to the corresponding validity state variable.

[0013] Further, the intelligent module is adapted to count the number of faulty steering function modules on each CAN bus according to the validity state variables of the steering function modules, and select the CAN bus with fewer faulty steering function modules to re-network.

[0014] Further, when the intelligent module detects that all the faulty steering function modules are repaired, the intelligent module is adapted to restore the two hot standby CAN networks to an independent operation mode.

[0015] Further, the message data of each heartbeat packet includes two state bits, which represent the initially allocated CAN network and the currently located CAN network, and each state bit includes two values, one of which represents one of the two hot standby CAN networks, and the other represents the other CAN network; when the intelligent module receives two heartbeat packets of the same steering function module in the same period, it is determined that the steering function module that has failed has been repaired, at this time, it is further determined whether the two state bits in the heartbeat packet message data of the steering function module are consistent, if not, a switching instruction is sent to the steering function module to restore it to the initial CAN network, and the initial CAN network state bit in the heartbeat packet message data is restored to the initial setting value.

[0016] In a second aspect, the application provides a networking method for a double-redundant intelligent CAN network of a steering instrument, which is based on two CAN networks that are hot backups of each other, and each steering function module on the two CAN networks is adapted to switch between the two CAN networks; when it is detected that there are faulty steering function modules on both CAN networks, and none of the faulty steering function modules on one CAN network is the same as the faulty steering function modules on the other CAN network, all the faulty steering function modules on one CAN network are disconnected, and the corresponding normal steering function modules on the other CAN network that have the same functions are put into the CAN network, so as to recombine a set of normal steering function modules to operate on one CAN network.

[0017] Further, whether each steering function module is faulty is determined according to whether a heartbeat packet of each faulty steering function module is received within a preset time, and if not, it is determined that the steering function module is faulty, and if yes, it is determined that the steering function module is valid.

[0018] Further, the number of faulty steering function modules on each CAN network is counted, and the CAN network with fewer faulty steering function modules is selected to re-network.

[0019] Further, when all the faulty steering function modules are repaired, the two CAN networks that are hot backups of each other are restored to an independent operation mode.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] 1. Firstly, some standby lines are added on the basis of a traditional double-redundant CAN network, each module belonging to the first CAN network is connected to the second CAN network through a group of standby lines, and vice versa, each module belonging to the second CAN network is connected to the first CAN network through a group of standby lines, when there are N modules on each CAN network, only 2N groups of standby lines need to be added; then a CAN network switching circuit is added to each module, and the main line and the standby line are connected to the switching circuit; finally, an intelligent module is added, and the two CAN networks are connected to the intelligent module, so that double-redundant CAN network intelligent networking can be realized, when there is no module with the same function in the multiple modules that are faulty in the two CAN networks, the intelligent module can calculate which modules need to be switched, and send a switching instruction to the modules, so that the steering instrument automatically selects a set of available modules in the two CAN networks at the cost of the least number of module switching, recombines a complete set of modules on the same CAN network, and maintains the normal operation of the steering instrument. No manual intervention is required throughout the process, even if a fault occurs during the navigation of the ship, intelligent networking can be quickly realized, an available module set can be selected, and the safe and reliable navigation of the ship can be ensured.

[0022] The CAN network switching circuit has a simple structure. By adjusting the voltage level of the main controller's GPIO port, the relay coil is activated / released. The two normally open contacts of the relay are connected to the first CAN network, and the two normally closed contacts are connected to the second CAN network. This simple circuit has a fast response speed, enabling rapid re-networking. The shorter the time, the safer the ship.

[0023] 3. The intelligent networking algorithm operates quickly. It first calculates the number of faulty modules on each CAN network and selects the CAN network with the fewest faulty modules. It then identifies the faulty module on that CAN network and sends a switchover command to a module with the same function on another CAN network, causing it to switch to the new CAN network. The faster the algorithm, the faster the networking, and the safer the ship.

[0024] 4. When the faulty module recovers, the intelligent networking algorithm switches it back to the original CAN network, ensuring the independence of the two CAN networks. In other words, when all modules are functioning normally, or when only one CAN network has a faulty module, the two CAN networks operate independently, regardless of the number of faulty modules on that network. If both CAN networks have faulty modules, and the faulty modules have different functions, the network will be re-formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an architectural diagram of an embodiment of the system of the present invention;

[0026] Figure 2 A flow chart of an embodiment of the method of the present invention;

[0027] Figure 3 FIG. 1 is a schematic diagram of a switching circuit in one embodiment of the system / method of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 As shown, the steering control system has two internal CAN networks, each of which houses multiple steering modules, including the automatic control module, follow-up control module, emergency steering module, compass display module, serial-to-CAN module, rudder angle feedback module, and alarm module. Each module also has a CAN network switching circuit and an intelligent module connected to both CAN networks.

[0030] On the basis of traditional CAN network, a CAN network switching circuit is added to each module, and a smart module is connected to two CAN networks. The smart module decides which CAN network each device should be connected to through the heartbeat packet of each device on the two CAN networks.

[0031] Each module has an initial assigned CAN value when it is first added to the CAN network, 0 for the first CAN network and 1 for the second CAN network. A jumper cap is used to determine whether a circuit is connected or not. The master chip reads the voltage at the back end of the jumper cap through a GPIO port. If the voltage is low, it is the first CAN network, otherwise it is the second CAN network. Each module sends a heartbeat packet to the smart module every second. The lowest two bits of the data in the heartbeat packet represent the initial assigned CAN network and the current CAN network of the module, respectively. When the smart module receives the heartbeat packet of a device module on the CAN network, it indicates that the device is not malfunctioning. If no heartbeat packet is received for 5 consecutive seconds, the device is considered to be malfunctioning. When there is only one device malfunctioning in the two CAN networks, the smart module does not take any action. The alarm module displays the fault code and prompts the user to switch to the other CAN network. At the same time, there is also an audible and visual alarm. When multiple modules malfunction in the two CAN networks, the smart module executes an intelligent networking algorithm to calculate the modules that need to be switched from one CAN network to the other. The algorithm calculates the minimum number of modules that need to be switched based on the current malfunctioning modules.

[0032] When the malfunctioning module recovers, the smart module will also calculate to restore the two CAN networks to independent operation mode. After the malfunctioning device recovers, it needs to be restored to the original initial CAN network. When the smart module receives two heartbeat packets from the same device in one second, it indicates that there are two identical modules in the CAN network. The lowest bit and the second lowest bit of the data in the heartbeat packet of the device are compared. If they are not consistent, the device is sent a switching instruction to restore it to the initial CAN network. At the same time, the lowest bit in the heartbeat packet is restored to the initial set value.

[0033] The automatic control module, the follow-up control module, the emergency steering module, the sub-compass display module, the serial port to CAN module, the rudder angle feedback module and the alarm module are first added to the CAN network, and each has an initial assigned CAN value, 0 for the first CAN network and 1 for the second CAN network. A jumper cap is used to determine whether a circuit is connected or not, and the master control chip reads the voltage at the back end of the jumper cap through a GPIO port. If the voltage is low, it is the first CAN network, otherwise it is the second CAN network. Each module sends a heartbeat packet to the intelligent module every second, and the lowest two bits of the data in the heartbeat packet represent the initial assigned CAN network of the current module and the CAN network in which the current module is located. When the intelligent module receives the heartbeat packet of the device module on the CAN network, it indicates that the device is not faulty. If no heartbeat packet is received for 5 consecutive seconds, it is considered that the device is faulty. When only one device in the two-way CAN network is faulty, the intelligent module does not take any action, and the alarm module displays the fault code and prompts the user to switch to the other CAN network through the man-machine interface, accompanied by sound and light alarm. When multiple non-same modules in the two-way CAN network are faulty, the intelligent module executes the intelligent networking algorithm to calculate the modules to be switched from one CAN network to the other CAN network, and sends a switching instruction to the modules. The algorithm calculates the number of modules that need to be switched based on the current faulty modules.

[0034] Each module switches to a specific CAN network through the CAN network switching circuit according to the switching instruction sent by the intelligent module.

[0035] The intelligent networking algorithm flow chart is shown in Figure 2 , and the specific process is as follows:

[0036] (1) Assuming that there are N devices on each CAN network, two N-bit variables CAN1Flag and CAN2Flag are selected for the first CAN network and the second CAN network, respectively. Each binary bit of the variable represents the validity of each module in the CAN network (1 valid, 0 invalid). The lowest bit of the variable is the automatic control module, the next lowest bit is the follow-up control module, and so on.

[0037] (2) When the intelligent module receives the heartbeat packet of each module, the corresponding module in CAN1Flag or CAN2Flag is set to 1, and if no heartbeat packet is received for five consecutive seconds, it is set to 0.

[0038] (3) The intelligent module calculates the or value tempXor = CAN1Flag + CAN2Flag once every second. If the or value is not 2 N -1, it means that the same module in the two-way CAN network is faulty, the alarm module issues a sound and light alarm, and returns to step (2) to wait for the faulty device to recover. Otherwise, the CAN network with the least number of faulty devices is selected.

[0039] (4) In order to find the CAN network with the least number of device faults, it is necessary to compare the binary bit 0 of CAN1Flag and CAN2Flag, because the number of faulty devices is less than that of non-faulty devices, so the number of 0 in the variables CAN1Flag and CAN2Flag is more than that of 1. First, the two values are inverted, that is, CAN1Flag_Not = ~CAN1Flag, CAN2Flag_Not = ~CAN2Flag, and the number of 0 in CAN1Flag and CAN2Flag is found, which is equivalent to finding the number of 1 in CAN1Flag_Not and CAN2Flag_Not. The value is ANDed with the value after the value is reduced by 1, so that the rightmost bit 1 is removed, until the number is 0, and the number of times of the loop is the number of 1. The specific code is as follows:

[0040]

[0041]

[0042] The traditional method is to shift without stopping, judge whether it is 1 or 0, and if it is 0, it will not stop accumulating, which needs to be looped N times, and when N is very large, the calculation amount will be very large. The method adopted by the present application is that the number of times of the loop is the number of 0, as described above, in practical application, the number of 0 in the variable is much less than the number of 1, so the efficiency is higher.

[0043] (5) The number of 0 in CAN1Flag is Num1, and the number of 0 in CAN2Flag is Num2. When Num1 ≤ Num2, the first CAN is selected, otherwise the second CAN is selected. Here, in order to illustrate by example, we assume that Num1 ≤ Num2, we need to find the faulty module in the first CAN. To find the faulty module in the first CAN, we only need to find the position of 0 in CAN1Flag. The way of divide and conquer is adopted, first judge the high N / 2 bit, if it is 2 N / 2 -1, then there is no 0 in this part, otherwise there is 0, continue to judge the high N / 4 and low N / 4 of this part, and the low N / 2 bit is the same. The traditional method of shifting to judge whether it is 0 has a time complexity of O(N), and the method has a time complexity of O(logN). After finding all the positions of binary 0, send the switching instruction to the corresponding module in the second CAN. After the module switches from the second CAN to the first CAN, the lowest bit of the data in the heartbeat packet is changed to 0. At this time, the intelligent module receives the heartbeat packet of the module in the first CAN again, and when the next loop returns to step (2), the corresponding bit in CAN1Flag is also set to 1.

[0044] (6) When the faulty module recovers, the intelligent module will also restore the two CAN networks to independent operation mode through calculation. After the faulty device recovers, it is necessary to restore the device to the original initial CAN network. When the intelligent module receives two heartbeat packets from the same device in one second, it means that there are two identical modules in the network. It determines the lowest bit and the second lowest bit in the heartbeat packet message data of the device. If they are inconsistent, it sends a switching command to the device to restore the device to the initial CAN network and restore the lowest bit in the heartbeat packet to the initial setting value.

[0045] The automatic control module, follow-up control module, emergency steering module, compass display module, serial port to CAN module, rudder angle feedback module and alarm module on the CAN network switch to a specific CAN network through the CAN network switching circuit according to the switching command sent by the intelligent module.

[0046] CAN network switching circuit such as Figure 3 As shown, Figure 3 In the upper part, pins 3 and 4 of the CAN isolation transceiver CTM1051AT are connected to the CAN pins of the main control chip, and pins 6 and 7 are connected to a G5V-2 relay. When the relay is energized, pins 6 and 7 are connected to the external first CAN network, that is, the module belongs to the first CAN at this time; otherwise, when the relay returns to the initial state, pins 6 and 7 are connected to the external second CAN network, that is, the module belongs to the second CAN at this time.

[0047] Figure 3 The lower part is the control of the relay in the CAN network hardware switching. The CAN1 pin on the left is connected to a GPIO port of the main control chip. When the first CAN is selected (the jumper cap is plugged in during initialization or the switch to the first CAN command sent by the intelligent module is received), the GPIO port is set to low, that is, Figure 3 When the CAN1 pin is low, the 3rd and 4th pins of the photoelectric coupler TLP521 are turned on, and the emitter and collector of the PNP transistor are turned on. At this time, the G5V-2 relay is energized. Figure 3 As mentioned above, when the relay is closed, the CAN pin of the main control chip selects the first CAN, that is, the device module selects the first CAN. Conversely, when the GPIO port of the main control chip is set high, the device module selects the second CAN.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A dual-redundant intelligent CAN network system for steering instruments, characterized in that: The invention comprises two CAN networks serving as hot backups for each other, each CAN network comprising a CAN bus and N steering function modules, each of the steering function modules being connected to the two CAN buses via a main branch and a slave branch of a switching circuit. When the steering function modules are operating normally, only the main branch connected to the corresponding CAN bus is turned on. An intelligent module is connected between the two CAN buses, and is adapted to detect in real time whether a fault has occurred in each steering function module. When it is detected that there is a faulty steering function module on both CAN buses, and the faulty steering function module on one CAN bus is not the same as the faulty steering function module on the other CAN bus, the main branch of all the faulty steering function modules on one CAN bus is disconnected by controlling the corresponding switching circuit. At the same time, the main branch of the corresponding normal steering function module with the same function on the other CAN bus is disconnected by controlling the corresponding switching circuit, and the slave branch is turned on, so that a set of normal steering function modules are reorganized into one CAN network for operation. The intelligent module is adapted to periodically receive heartbeat packets sent by each of the steering function modules, and determine whether each of the steering function modules has a fault based on whether the heartbeat packets are received within a preset time. If no heartbeat packets are received, it is determined that a fault has occurred; if received, it is determined that the steering function module is valid; The intelligent module is preset with storage areas for two steering function module validity status variables, each of which is a binary parameter with N bits, wherein one of the steering function module validity status variables corresponds to N steering function modules in one CAN network, and the other steering function module validity status variable corresponds to N steering function modules in another CAN network; the validity status of each steering function module includes two types: valid and faulty, which are represented by binary bits with different values ​​respectively, and each status bit in each steering function module validity status variable represents the validity status of a steering function module. When the validity status of the steering function module changes, the corresponding status bit in the steering function module validity status variable to which it belongs changes accordingly; if any of the steering function modules fails, a value is assigned to the corresponding validity status variable; if any of the steering function modules is valid, another value is assigned to the corresponding validity status variable; When the intelligent module detects that all the failed steering function modules have been repaired, the intelligent module is suitable for restoring the two mutually hot backup CAN networks to an independent operation mode.

2. The steering instrument dual-redundant intelligent CAN network system according to claim 1, characterized in that: The intelligent module is integrated with a primary / standby selection unit, which is adapted to select one of the CAN networks as the primary network when all the steering function modules are working normally.

3. The steering instrument dual-redundant intelligent CAN network system according to claim 2, characterized in that: The master / standby selection unit is further adapted to select another CAN network as the master network when a faulty steering function module exists in one of the CAN networks.

4. The steering instrument dual-redundant intelligent CAN network system according to claim 1, characterized in that: The intelligent module is integrated with a mode selection unit, which is suitable for selecting any one of the three steering modes: automatic, follow-up and emergency.

5. The steering instrument dual-redundant intelligent CAN network system according to claim 1, characterized in that: The switching circuit includes a relay and a CAN isolation transceiver, the coil of the relay is connected to the GPIO port of the controller in the intelligent module, the data transceiver end of the CAN isolation transceiver is connected to the data transceiver end of the corresponding steering function module, and the bus end of the CAN isolation transceiver is connected to one CAN bus through a pair of normally open contacts of the relay, and is connected to another CAN bus through a pair of normally closed contacts of the relay.

6. The steering instrument dual-redundant intelligent CAN network system according to claim 1, characterized in that: The intelligent module is suitable for counting the number of faulty steering function modules on each CAN bus according to the validity state variables of each steering function module, and selecting the CAN bus with the least number of faulty steering function modules to re-network.

7. The steering instrument dual-redundant intelligent CAN network system according to claim 1, characterized in that: The message data of each heartbeat packet includes two status bits, which respectively represent the initially allocated CAN network and the current CAN network. Each status bit includes two values, one of which represents one CAN network of the two mutually hot backup CAN networks, and the other represents the other CAN network. When the intelligent module receives two heartbeat packets of the same steering function module within the same time period, it determines that the steering function module that had a fault has been repaired. At this time, it continues to determine whether the two status bits in the heartbeat packet message data of the steering function module have the same value. If they are inconsistent, a switching instruction is sent to the steering function module to restore it to the initial CAN network, and at the same time, the initial CAN network status bit in its heartbeat packet message data is restored to the initial setting value.

8. A networking method for a steering instrument dual-redundant intelligent CAN network, characterized in that: Utilizing the dual-redundant intelligent CAN network system for steering instruments as described in any one of claims 1 to 7, based on two CAN networks that serve as hot backups for each other, each steering function module on the two CAN networks is adapted to switch between the two CAN networks; when it is detected that there are faulty steering function modules on both CAN networks, and no faulty steering function module on one CAN network is identical to a faulty steering function module on the other CAN network, all faulty steering function modules on one CAN network are disconnected, and simultaneously, corresponding normal steering function modules with the same functions on the other CAN network are put into that CAN network, so that a set of normal steering function modules are reorganized into one CAN network for operation.

9. The networking method according to claim 8, characterized in that: Whether each of the steering function modules has a fault is determined based on whether the heartbeat packet of each of the faulty steering function modules is received within a preset time. If not, it is determined that a fault has occurred. If received, it is determined that the fault is valid.

10. The networking method according to claim 8, characterized in that: Count the number of faulty steering function modules on each CAN network, and select the CAN network with fewer faulty steering function modules to re-network.

11. The networking method according to claim 8, wherein: When all faulty steering function modules are repaired, the two CAN networks serving as hot backup for each other will be restored to independent operation mode.

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