SSI sensor redundancy control method and system based on CAN FD bus

Abstract

The invention provides an SSI sensor redundancy control method and system based on a CAN FD bus, a main control module outputs a downlink CAN FD message through the CAN FD bus, a plurality of SSI sensor control devices receive the downlink CAN FD message through CAN FD bus transmit-receive interfaces of the SSI sensor control devices, a CAN FD data unpacking module unpacks the downlink CAN FD message to obtain a data field, and the data field is sent to the CAN FD bus. The SSI sensor configuration module analyzes the data field to obtain configuration parameters for a specific SSI sensor, the SSI sensor data transmission module drives the SSI sensor to work, the SSI sensor data transmission module collects measurement result feedback data of the SSI sensor, the CAN FD data packing module packs the measurement result feedback data to establish an uplink CAN FD message, and the uplink CAN FD message is transmitted to the SSI sensor configuration module. And the uplink CAN FD message is uploaded to the CAN FD bus, and finally the uplink CAN FD message is received by the main control module, so that the real-time control and measurement data acquisition functions aiming at the SSI sensor are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic communications, and in particular relates to a SSI sensor redundancy control method and system based on a CAN FD bus. Background Art

[0002] SSI (Synchronous Serial Interface) sensor is a sensor device that uses synchronous serial interface technology. It has the advantages of fast signal transmission speed and convenient connection, so it is widely used in digital signal processing, control and measurement systems, and signal integrity testing. With the vigorous development of automotive electronics, unmanned driving, industrial automation and other fields, the speed and accuracy requirements for measurement and control operations of SSI sensor control systems are getting higher and higher.

[0003] In the prior art, the communication rate and data throughput of the conventional SSI sensor control system constructed through a serial interface are relatively low. For example, the maximum communication rate is limited by the CAN bus protocol and is less than 1Mbps, which greatly limits the efficient application of the SSI sensor control system in high-precision, high-frequency data acquisition and real-time control scenarios. At the same time, in the traditional SSI sensor control system, each SSI sensor usually needs to be configured separately. When the SSI sensor control system is deployed on a large scale, it is difficult to uniformly configure and control multiple sensors, and it is difficult to monitor the operating status of all SSI encoders in real time. Summary of the invention

[0004] The present invention aims to provide a redundant control method and system for SSI sensors based on a CAN FD bus, so as to solve the technical problem that the conventional SSI sensor control method and system have low communication rate and data throughput and cannot realize unified configuration and management of multiple groups of SSI sensors in the prior art.

[0005] To solve the above problems, the technical solution of the present invention is: a SSI sensor redundancy control method based on CAN FD bus, comprising the following steps: S1: The main control module outputs a downlink CAN FD message through a single CAN FD bus, and a plurality of SSI sensor control devices redundantly connected to the CAN FD bus receive the downlink CAN FD message through their CAN FD bus transceiver interfaces respectively, and transmit the message to the CAN FD data unpacking module; S2: the CAN FD data unpacking module unpacks the downlink CAN FD message, obtains the data field of the downlink CAN FD message, and transmits the data field to the SSI sensor configuration module; S3: The SSI sensor configuration module parses the data field of the downstream CAN FD message to determine whether the target object of the downstream CAN FD message is correct. If correct, the configuration parameters for the specific SSI sensor are obtained, and the SSI sensor operation is driven by the SSI sensor data transmission module; S4: In a single measurement cycle, the SSI sensor data transmission module collects the measurement result feedback data of the SSI sensor and transmits it to the CAN FD data packaging module; S5: the CAN FD data packetization module packets the measurement result feedback data of the SSI sensor to form an uplink CAN FD message, and the uplink CAN FD message is uploaded to the CAN FD bus through the CAN FD bus transceiver interface; S6: The main control module receives uplink CAN FD messages output by the plurality of SSI sensor control devices in the CAN FD bus.

[0006] Preferably, the data fields of the downlink CAN FD message and the uplink CAN FD message include a frame header, a data type, a control / feedback data payload and a CRC check code, wherein the frame header is provided with an identifier area, the identifier area includes a priority field and a frame ID, and the frame ID corresponds to the device ID of the SSI sensor.

[0007] Preferably, in S2, the CAN FD data unpacking module unpacks the downlink CAN FD message to obtain its data field, further comprising the following steps: S21: A set of predefined generating polynomials are respectively configured in the main control module and each of the SSI sensor control devices; S22: the main control module performs a binary XOR division operation on the binary expression of the control data payload in the downlink CAN FD message to be sent and the generating polynomial, and the remainder obtained by the binary XOR division is defined as a CRC check code, and is added to the downlink CAN FD message; S23: The CAN FD data unpacking module performs a binary XOR division operation on the binary integral expression of the control data payload and the CRC check code in the received downlink CAN FD message and the generating polynomial again. If the remainder of the calculation result of the binary XOR division is 0, the CRC check passes; if the remainder of the calculation result of the binary XOR division is non-0, the CRC check fails, and the CAN FD data unpacking module discards the current downlink CAN FD message.

[0008] Preferably, the downlink CAN FD message includes a downlink unicast CAN FD message and a downlink broadcast CAN FD message. In S3, the SSI sensor configuration module determines whether the target object of the downlink CAN FD message is correct, further comprising the following steps: S31: the SSI sensor configuration module determines whether the frame ID in the current downlink CAN FD message is 0. If it is only 0, the current downlink CAN FD message is a downlink broadcast CAN FD message. The SSI sensor configuration modules of all the SSI sensor control devices respectively obtain the configuration parameters in the control data payload of the current downlink broadcast CAN FD message. If the frame ID is not 0, the current downlink CAN FD message is a downlink unicast CAN FD message, and the SSI sensor configuration modules of all the SSI sensor control devices respectively determine whether any frame ID in the current downlink unicast CAN FD message is the same as the device ID of the SSI sensor connected and controlled thereto; if they are the same, the SSI sensor configuration module obtains the configuration parameters in the control data payload of the current downlink unicast CAN FD message; if they are all different, the SSI sensor configuration module terminates obtaining the configuration parameters in the control data payload of the current downlink unicast CAN FD message; The configuration parameters include sampling frequency, data resolution, circle resolution, sampling frame interval and encoding method for configuring the SSI sensor operation.

[0009] Preferably, the SSI sensor data transmission module is connected to the SSI sensor via an SSI interface, and in S3, the SSI sensor data transmission module drives the SSI sensor to operate, further comprising the following steps: S32: The SSI sensor data transmission module generates a corresponding configuration command based on the configuration parameters, and transmits the configuration command to the SSI sensor through the SSI interface; S33: After receiving the configuration command, the SSI sensor uploads a confirmation response to the SSI sensor data transmission module.

[0010] Preferably, the priority field is used as the high bit of the identifier area, and the frame ID is used as the low bit of the identifier area, wherein the smaller the value of the priority field is, the higher the message priority is; the smaller the frame ID is, the higher the message priority is, and the priority of the priority field is higher than the priority of the frame ID; When a plurality of sets of frame IDs and a plurality of sets of priority fields are configured in the frame header of the downlink CAN FD message, different frame IDs correspond to the corresponding priority fields according to their ranking order. When the measurement result feedback data group output by the SSI sensor corresponding to the device ID and the frame ID is packaged to form an uplink CAN FD message, the frame header of the uplink CAN FD message also has a frame ID corresponding to the device ID and a priority field corresponding to the frame ID. Based on the CAN FD bus arbitration mechanism, in the CAN FD bus, the upload order of multiple groups of uplink CAN FD messages of the SSI sensor control device is automatically scheduled according to different priority fields and frame IDs. When the priority fields in multiple groups of uplink CAN FD messages are different, the uplink CAN FD message with a higher priority field is sent first; when the priority fields in multiple groups of uplink CAN FD messages are the same, the uplink CAN FD message with a higher frame ID priority is sent first.

[0011] Preferably, any of the SSI sensors has a built-in corresponding measurement threshold. Within a single measurement cycle, when the measurement result feedback data output by the SSI sensor exceeds the measurement threshold, a high priority priority field is automatically configured in the frame header of the uplink CAN FD message formed by the measurement result feedback data package output by the SSI sensor.

[0012] Preferably, in S5, the CAN FD data packaging module packages the measurement result feedback data of the SSI sensor to form an uplink CAN FD message, further comprising the following steps: S51: The SSI sensor status monitoring module collects abnormal operating condition feedback data of the SSI sensor in real time through the SSI sensor data transmission module; S52: The CAN FD data packaging module packages the measurement result feedback data and the abnormal operating condition feedback data of the SSI sensor as a whole to form an uplink CAN FD message.

[0013] Preferably, the data type of the downlink CAN FD message adopts the SDO data type, which supports the online modification function of the configuration parameters in the downlink CAN FD message, and the data type of the uplink CAN FD message adopts the PDO data type, which supports the real-time transmission function of the uplink CAN FD message.

[0014] Based on the same concept, the present invention also provides an SSI sensor redundant control system based on a CAN FD bus, which executes the SSI sensor redundant control method based on a CAN FD bus as described in any one of the above, and is provided with a plurality of redundantly configurable SSI sensor control devices, wherein the SSI sensor control devices are electrically connected to a single CAN FD bus and a corresponding SSI sensor, respectively, and any of the SSI sensor control devices comprises: A CAN FD bus transceiver interface, the CAN FD bus transceiver interface is used to receive downlink CAN FD messages output through the CAN FD bus, and send uplink CAN FD messages to the CAN FD bus; A CAN FD data unpacking module, wherein the CAN FD data unpacking module is used to unpack a downlink CAN FD message and obtain a data field of the downlink CAN FD message; An SSI sensor configuration module, the SSI sensor configuration module is used to parse and obtain configuration parameters for a specific SSI sensor according to a data field of a downlink CAN FD message; An SSI sensor data transmission module, the SSI sensor data transmission module is used to drive the SSI sensor operation according to the configuration parameters of the downlink CAN FD message, and collect the measurement result feedback data of the SSI sensor; An SSI sensor status monitoring module, the SSI sensor status monitoring module is used to collect abnormal operating condition feedback data of the SSI sensor; A CAN FD data packaging module is used to package the measurement result feedback data of the SSI sensor and the abnormal working condition feedback data to form an uplink CAN FD message.

[0015] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: The present invention provides an SSI sensor redundant control method and system based on a CAN FD bus, which integrates the CAN FD communication bus protocol with the SSI sensor protocol. Users can directly remotely control the SSI encoder and measure data acquisition functions through the CAN FD bus. Based on the high data transmission rate of the CAN FD bus, the communication rate and data throughput of the SSI sensor redundant control system are effectively improved.

[0016] At the same time, in the invention, several redundantly configured SSI sensor control devices are connected to the same CAN FD bus. Based on the setting of the downstream CAN FD message in the CAN FD bus, a specific SSI sensor can be configured individually, or all SSI sensors in the SSI sensor redundant control system can be configured uniformly, thereby simplifying the configuration process of redundant SSI sensors and improving the flexibility and efficiency of SSI sensor control.

[0017] In addition, the present invention also separately provides an SSI sensor status monitoring module in each SSI sensor control device to detect abnormal status of each SSI sensor, thereby ensuring that the SSI sensor redundant control system can quickly and effectively discover and locate abnormal operating conditions of the SSI sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of a SSI sensor redundancy control method based on a CAN FD bus provided by the present invention; Figure 2 A schematic diagram of the structure of the SSI sensor control device provided by the present invention; Figure 3 The present invention provides a structural schematic diagram of a SSI sensor redundant control system based on a CAN FD bus. DETAILED DESCRIPTION

[0019] The following is a further detailed description of a SSI sensor redundancy control method and system based on a CAN FD bus proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0020] First embodiment See also Figure 1-Figure 3 This embodiment provides a SSI sensor redundancy control method based on a CAN FD bus, which is used to enable SSI sensors to achieve high-precision, high-frequency data acquisition and real-time control functions through a single CAN FD bus, and to achieve integrated and flexible configuration for multiple groups of redundant SSI sensors, and specifically includes the following steps: S1: The main control module outputs downstream CAN FD messages through a single CAN FD bus. Several SSI sensor control devices redundantly connected to the CAN FD bus receive the downstream CAN FD messages through their CAN FD bus transceiver interfaces respectively, and transmit the downstream CAN FD messages to their CAN FD data unpacking modules.

[0021] S2: After receiving the downlink CAN FD message, the CAN FD data unpacking module of the SSI sensor control device unpacks the downlink CAN FD message respectively, thereby obtaining the data field of the downlink CAN FD message, and further transmits the data field of the downlink CAN FD message to the SSI sensor configuration module.

[0022] S3: After receiving the data field of the downstream CAN FD message, the SSI sensor configuration module parses the data field respectively. The SSI sensor configuration module of each SSI sensor control device first determines whether the target object of the current downstream CAN FD message is the SSI sensor connected and controlled by the SSI sensor control device. If the target object of the current downstream CAN FD message matches the SSI sensor connected and controlled by the SSI sensor control device, the SSI sensor configuration module further obtains the configuration parameters for configuring the SSI sensor operation in the data field of the current downstream CAN FD message, and transmits the configuration parameters to the SSI sensor data transmission module in the form of registers. The SSI sensor data transmission module drives the SSI sensor operation based on the configuration parameters.

[0023] S4: Set the main control module to output a control signal to a certain SSI sensor control device, then the SSI sensor control device drives the SSI sensor connected to it to operate, and finally the main control module receives the feedback data output by the SSI sensor, which is a complete measurement cycle. In a single measurement cycle, after the SSI sensor data transmission module drives the SSI sensor to operate, the SSI sensor will output the measurement result feedback data to the SSI sensor data transmission module, that is, the SSI sensor data transmission module collects the measurement result feedback data of the SSI sensor in real time and transmits it to the CAN FD data packaging module.

[0024] S5: The CAN FD data packetization module packages the measurement result feedback data of the SSI sensor to form an uplink CAN FD message. The uplink CAN FD message is transmitted to the CAN FD bus transceiver interface and uploaded to the CAN FD bus.

[0025] S6: The main control module receives the uplink CAN FD message output by several SSI sensor control devices in the CAN FD bus, and realizes the function of obtaining the feedback data of the measurement results of several SSI sensors.

[0026] The specific steps and functions of the SSI sensor redundancy control method based on the CAN FD bus provided in this embodiment will be further described below: In this embodiment, the data fields of the downlink CAN FD message and the uplink CAN FD message at least include a frame header, a data type, a control / feedback data payload, and a CRC checksum, wherein an identifier area is provided in the frame header, the identifier area includes a priority field and a frame ID, the frame ID corresponds to the device ID of the SSI sensor, and is used to identify the target object and source object of the downlink CAN FD message and the uplink CAN FD message. The data type is used to define the specific format of the control / feedback data payload. The control / feedback data payload records the control data and the feedback data, respectively. The CRC checksum is used to implement the security verification of the downlink CAN FD message.

[0027] Preferably, in this embodiment, in S2, the CAN FD data unpacking module unpacks and processes the downlink CAN FD message to obtain its data field, and further includes a CRC check step: S21: A predefined generating polynomial is configured in the main control module and each SSI sensor control device.

[0028] S22: Before the main control module sends the downlink CAN FD message, the main control module first performs a binary XOR division operation on the binary expression of the control data payload in the downlink CAN FD message and the generating polynomial, defines the remainder of the binary XOR division as a CRC check code, and adds it to the downlink CAN FD message, which is transmitted to the SSI sensor control device together with the control data payload.

[0029] S23: After the CAN FD data unpacking module unpacks and processes the downstream CAN FD message, it obtains the control data payload and the CRC check code, and then performs a binary XOR division operation on the binary overall expression of the control data payload and the CRC check code in the downstream CAN FD message and the generating polynomial again. If the remainder of the calculation result of the binary XOR division is 0, the CRC check passes, proving that the content of the control data payload has not been changed during the transmission of the downstream CAN FD message and the data is legal. On the contrary, if the remainder of the calculation result of the binary XOR division is not 0, the CRC check fails, proving that the content of the control data payload has been changed during the transmission of the downstream CAN FD message and the data is illegal, and the SSI sensor control device discards the current downstream CAN FD message.

[0030] In one embodiment, after the main control module receives the uplink CAN FD message output by the SSI sensor control device, it can also perform a CRC check on the uplink CAN FD message, that is, the SSI sensor data transmission module performs a binary XOR division operation on the binary expression of the feedback data of the SSI sensor measurement result and the generating polynomial to obtain a set of CRC check codes, and add them to the uplink CAN FD message. After the main control module receives the uplink CAN FD message, it refers to step S23 to perform a CRC check. If the CRC check passes, it proves that the feedback data payload content of the uplink CAN FD message has not been changed during the transmission process, and the data is legal. On the contrary, if the CRC check fails, it proves that the feedback data payload content of the uplink CAN FD message has been changed during the transmission process, and the data is illegal, and the main control module discards the current uplink CAN FD message.

[0031] It is worth noting that since the CAN FD bus supports a larger data field and a more flexible data transmission rate, in this embodiment, the number of bits of the generating polynomial can be selected to be 17 bits or 21 bits. A higher-order generating polynomial number can significantly improve the error monitoring capability of the CRC verification step, that is, effectively improve the safety performance of the SSI sensor redundant control system based on the CAN FD bus.

[0032] Preferably, in this embodiment, the downlink CAN FD message includes a downlink unicast CAN FD message and a downlink broadcast CAN FD message. In S3, the SSI sensor configuration module determines whether the target object of the downlink CAN FD message is correct, further comprising the following steps: S31: After the SSI sensor configuration module obtains the frame ID data in the downstream CAN FD message, it determines the value of the frame ID. If the frame ID is only 0, the current downstream CAN FD message is a downstream broadcast CAN FD message, that is, a downstream CAN FD broadcast message sent by the current main control module through the CAN FD bus, which is used to control all SSI sensors to perform the same measurement action. Therefore, in this embodiment, the SSI sensor configuration modules of all SSI sensor control devices respectively parse and obtain the configuration parameters in the control data payload of the current downstream broadcast CAN FD message.

[0033] If the frame ID is not 0, the current downlink CAN FD message is a downlink unicast CAN FD message, that is, the downlink CAN FD broadcast message sent by the current main control module through the CAN FD bus is only used to control a specific group or groups of SSI sensors to perform the same measurement action. Among them, when the downlink CAN FD broadcast message is only used to control one group of SSI sensors, the frame ID is only one group of fields, that is, corresponding to a single device ID. When the downlink CAN FD broadcast message is used to control multiple groups of SSI sensors at the same time, the frame ID has multiple groups of fields, and frame IDs with different fields correspond to different device IDs. Therefore, in this embodiment, the SSI sensor configuration modules of all SSI sensor control devices respectively determine whether any frame ID in the current downstream unicast CAN FD message is the same as the device ID of the SSI sensor connected and controlled by it. If there is a same, it proves that the SSI sensor connected and controlled by the SSI sensor control device is the target object of the current downstream unicast CAN FD message, so its SSI sensor configuration module parses and obtains the configuration parameters in the control data payload of the current downstream unicast CAN FD message. On the contrary, if all are different, it proves that the SSI sensor connected and controlled by the SSI sensor control device is not the target object of the current downstream unicast CAN FD message, so its SSI sensor configuration module stops obtaining the configuration parameters in the control data payload of the current downstream unicast CAN FD message. In this way, the master control module can uniformly control all SSI sensors, or individually control specific SSI sensors.

[0034] Specifically, in this embodiment, the configuration parameters include parameters such as sampling frequency, data resolution, number of revolutions resolution, sampling frame gap, and encoding mode for configuring the operation of the SSI sensor. The sampling frequency is used to determine the number of times the SSI sensor collects data per unit time, the data resolution is used to determine the measurement accuracy of the SSI sensor, the number of revolutions resolution is used to determine the number of revolutions that the SSI sensor (such as an incremental encoder) can measure, the sampling frame gap is used to determine the sampling period of the SSI sensor, and the encoding mode is used to determine the data encoding format of the SSI sensor.

[0035] Preferably, in this embodiment, the SSI sensor data transmission module is connected to the SSI sensor via an SSI interface, so that the SSI sensor data transmission module sends configuration parameters to the SSI sensor and receives measurement result feedback data output by the SSI sensor.

[0036] In S3, the SSI sensor data transmission module drives the SSI sensor operation, further comprising the following steps: S32: The SSI sensor data transmission module generates corresponding configuration commands based on various configuration parameters, and transmits the configuration commands to the SSI sensor through the SSI interface.

[0037] S32: After receiving the configuration command, the SSI sensor uploads a confirmation response to the SSI sensor data transmission module, and the SSI sensor then performs a measurement action based on the configuration command.

[0038] Furthermore, in this embodiment, the SSI sensor data transmission module in S4 collects the measurement result feedback data of the SSI sensor in real time, which specifically includes the following steps: During the two-way communication between the SSI sensor data transmission module and the SSI sensor, the SSI sensor data transmission module generates a clock signal for synchronous data transmission. Based on the frequency of the clock signal, the SSI sensor data transmission module reads the measurement result feedback data output by the SSI sensor bit by bit and combines them to form a complete measurement value, ensuring the synchronization and accuracy of the measurement result feedback data transmission.

[0039] Preferably, in this embodiment, the priority field is used as the high bit of the identifier area, and the frame ID is used as the low bit of the identifier area, wherein the smaller the value of the priority field is, the higher the message priority is; the smaller the frame ID is, the higher the message priority is, and the priority of the priority field is higher than the priority of the frame ID, that is, in a single message, the priority of the priority field must be considered first, and then the priority of the frame ID. Similar to the frame ID, in a single downlink CAN FD message, there may also be multiple groups of priority fields, and the number of priority fields is consistent with the number of frame IDs. When multiple groups of frame IDs and multiple groups of priority fields are configured in the frame header of the downlink CAN FD message, different frame IDs correspond to the corresponding priority fields according to their ranking order, that is, multiple groups of frame IDs and multiple groups of priority fields correspond to each other according to their respective ranking orders. When the measurement result feedback data group output by the SSI sensor corresponding to the device ID and the frame ID is constructed to form an uplink CAN FD message, the frame header of the uplink CAN FD message also has a frame ID corresponding to the device ID and a priority field corresponding to the frame ID.

[0040] Based on the CAN FD bus arbitration mechanism, in the CAN FD bus, the upload order of multiple groups of uplink CAN FD messages of SSI sensor control devices can be automatically scheduled according to different priority fields and frame IDs. Specifically, the uplink CAN FD message implements a first-send-first-transmit transmission mechanism. At the same time point, if there are multiple groups of uplink CAN FD messages uploaded to the CAN FD bus, and the priority fields of the multiple groups of uplink CAN FD messages are different, the uplink CAN FD message with a higher priority field is sent first; at the same time point, if there are multiple groups of uplink CAN FD messages uploaded to the CAN FD bus, and the priority fields of the multiple groups of uplink CAN FD messages are the same, the uplink CAN FD message with a higher frame ID priority is sent first, thereby ensuring that the uplink CAN FD message with a high priority field or frame ID can be uploaded first and obtained by the main control module first, thereby realizing efficient propagation and sequential response of CAN FD messages.

[0041] It is worth noting that, in this embodiment, it should be avoided that there are multiple groups of downlink CAN FD messages or the priority field and the frame ID in the uplink CAN FD message are completely consistent.

[0042] In another embodiment, any SSI sensor may have a corresponding measurement threshold built in. Within a single measurement cycle, when the measurement result feedback data output by the SSI sensor exceeds the measurement threshold, it proves that the object detected by the SSI sensor may have abnormal movement. The frame header of the uplink CAN FD message formed by the measurement result feedback data group output by the SSI sensor will be automatically configured with a high priority priority field. This embodiment can be applied to both downlink broadcast CAN FD messages and downlink unicast CAN FD messages.

[0043] Through reasonable priority management, it can ensure that the key measurement result feedback data of the SSI sensor is fed back with priority, thus improving the real-time performance and reliability of the system.

[0044] Preferably, in this embodiment, in S5, the CAN FD data packetization module packets the measurement result feedback data of the SSI sensor to form an uplink CAN FD message, further comprising the following steps: S51: The SSI sensor status monitoring module collects abnormal operating condition feedback data of the SSI sensor in real time through the SSI sensor data transmission module. The abnormal operating condition feedback data includes abnormal communication status, abnormal measurement data, etc.

[0045] S52: The CAN FD data packetization module packages the measurement result feedback data of the SSI sensor and the abnormal working condition feedback data as a whole to form an uplink CAN FD message. The SSI sensor status monitoring module is additionally set to obtain the measurement result feedback data of the SSI sensor, so that the main control module can timely detect the abnormal state of the SSI sensor and locate and take relevant measures to avoid measurement data errors or system failures caused by SSI sensor failures, thereby improving the stability and reliability of the system.

[0046] Preferably, in this embodiment, the data type of the downstream CAN FD message adopts the SDO data type, and the SDO data type supports the online modification function of the configuration parameters in the downstream CAN FD message, that is, during the transmission of the downstream CAN FD message, the main control module can send an SDO write request to the SSI sensor control device through the CAN FD bus, for example, requesting to modify the control data payload content in the downstream CAN FD message. After receiving the SDO write request, the SSI sensor control device will update the control data payload content in the downstream CAN FD message, and will not generate abnormal jumps such as garbled characters and clearing of configuration parameters. The data type of the upstream CAN FD message adopts the PDO data type, and the PDO data type supports the real-time transmission function of the upstream CAN FD message, and is applied to high-frequency data update requirements to ensure the real-time and stability of the system.

[0047] In summary, this embodiment provides an SSI sensor redundant control method based on the CAN FD bus, which realizes overall unified configuration of several redundantly connected SSI sensors based on a single CAN FD bus, or realizes separate configuration for specific SSI sensors, thereby effectively improving the configuration flexibility and efficiency of the SSI sensor redundant control system, and based on the high data transmission rate of the CAN FD bus, effectively improving the communication rate and data throughput of the SSI sensor redundant control system.

[0048] Second embodiment Based on the same idea, see Figure 2-Figure 3 This embodiment provides an SSI sensor redundant control system based on a CAN FD bus, which is used to execute a SSI sensor redundant control method based on a CAN FD bus as described in the first embodiment. In this embodiment, a plurality of redundantly configurable SSI sensor control devices are provided. The SSI sensor control devices are electrically connected to a single CAN FD bus and a group of specific SSI sensors, respectively. The SSI sensor control devices specifically include: The CAN FD bus transceiver interface is electrically connected to the CAN FD bus and the CAN FD data unpacking module, and is used to receive downlink CAN FD messages output through the CAN FD bus, and send uplink CAN FD messages to the CAN FD bus.

[0049] The CAN FD data unpacking module is electrically connected to the CAN FD bus transceiver interface and the SSI sensor configuration module, and is used to unpack the downstream CAN FD message and obtain the data field in the downstream CAN FD message.

[0050] The SSI sensor configuration module is electrically connected to the CAN FD data unpacking module and the SSI sensor data transmission module, and is used to parse and obtain configuration parameters for a specific SSI sensor according to the data field of the downlink CAN FD message.

[0051] SSI sensor data transmission module: The SSI sensor data transmission module is electrically connected to the SSI sensor configuration module, the SSI sensor, the SSI sensor status monitoring module and the CAN FD data packaging module respectively, and is used to generate configuration commands to drive the SSI sensor operation according to the configuration parameters of the downlink CANFD message, and to collect the measurement result feedback data of the SSI sensor.

[0052] The SSI sensor status monitoring module is electrically connected to the SSI sensor data transmission module and the CAN FD data packaging module, and is used to collect abnormal operating condition feedback data of the SSI sensor through the SSI sensor data transmission module.

[0053] The CAN FD data packetization module is electrically connected to the CAN FD bus transceiver interface, the SSI sensor data transmission module and the SSI sensor status monitoring module, and is used to package the measurement result feedback data and the abnormal working condition feedback data of the SSI sensor to form an uplink CAN FD message.

[0054] In addition, a single main control module is provided, which is electrically connected to a number of SSI sensor control devices and SSI sensors through a single CAN FD bus. The main control module is used to output control signals to the SSI sensors and receive feedback data from each SSI sensor to achieve centralized management, dynamic adjustment, status monitoring and coordinated communication functions of the SSI sensor redundant control system.

[0055] In summary, this embodiment provides an SSI sensor redundant control system based on the CAN FD bus, which integrates the CAN FD communication bus with a number of SSI sensors. Users can directly remotely control the SSI encoder, collect measurement data, and monitor the operating status through the CAN FD bus, thereby achieving high-speed and high-precision measurement and control operations for the SSI sensor control system in the fields of automotive electronics, unmanned driving, industrial automation, etc.

[0056] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A SSI sensor redundancy control method based on CAN FD bus, characterized in that: The steps include: S1: The main control module outputs a downlink CAN FD message through a single CAN FD bus, and a plurality of SSI sensor control devices redundantly connected to the CAN FD bus receive the downlink CAN FD message through their CAN FD bus transceiver interfaces respectively, and transmit the message to the CAN FD data unpacking module; S2: the CAN FD data unpacking module unpacks the downlink CAN FD message, obtains the data field of the downlink CAN FD message, and transmits the data field to the SSI sensor configuration module; S3: The SSI sensor configuration module parses the data field of the downstream CAN FD message to determine whether the target object of the downstream CAN FD message is correct. If correct, the configuration parameters for the specific SSI sensor are obtained, and the SSI sensor operation is driven by the SSI sensor data transmission module; S4: In a single measurement cycle, the SSI sensor data transmission module collects the measurement result feedback data of the SSI sensor and transmits it to the CAN FD data packaging module; S5: the CAN FD data packetization module packets the measurement result feedback data of the SSI sensor to form an uplink CAN FD message, and the uplink CAN FD message is uploaded to the CAN FD bus through the CAN FD bus transceiver interface; S6: The main control module receives uplink CAN FD messages output by the plurality of SSI sensor control devices in the CAN FD bus.

2. The SSI sensor redundancy control method based on the CAN FD bus according to claim 1, characterized in that: The data fields of the downlink CAN FD message and the uplink CAN FD message include a frame header, a data type, a control / feedback data payload and a CRC check code, wherein the frame header is provided with an identifier area, the identifier area includes a priority field and a frame ID, and the frame ID corresponds to the device ID of the SSI sensor.

3. The SSI sensor redundancy control method based on the CAN FD bus according to claim 2, characterized in that: In S2, the CAN FD data unpacking module unpacks the downlink CAN FD message to obtain its data field, further comprising the following steps: S21: A set of predefined generating polynomials are respectively configured in the main control module and each of the SSI sensor control devices; S22: the main control module performs a binary XOR division operation on the binary expression of the control data payload in the downlink CAN FD message to be sent and the generating polynomial, and the remainder obtained by the binary XOR division is defined as a CRC check code, and is added to the downlink CAN FD message; S23: The CAN FD data unpacking module performs a binary XOR division operation on the binary integral expression of the control data payload and the CRC check code in the received downlink CAN FD message and the generating polynomial again. If the remainder of the calculation result of the binary XOR division is 0, the CRC check passes; if the remainder of the calculation result of the binary XOR division is non-0, the CRC check fails, and the CAN FD data unpacking module discards the current downlink CAN FD message.

4. The SSI sensor redundancy control method based on the CAN FD bus according to claim 2, characterized in that: The downlink CAN FD message includes a downlink unicast CAN FD message and a downlink broadcast CAN FD message. In S3, the SSI sensor configuration module determines whether the target object of the downlink CAN FD message is correct, further comprising the following steps: S31: the SSI sensor configuration module determines whether the frame ID in the current downlink CAN FD message is 0. If it is only 0, the current downlink CAN FD message is a downlink broadcast CAN FD message. The SSI sensor configuration modules of all the SSI sensor control devices respectively obtain the configuration parameters in the control data payload of the current downlink broadcast CAN FD message. If the frame ID is not 0, the current downlink CAN FD message is a downlink unicast CAN FD message, and the SSI sensor configuration modules of all the SSI sensor control devices respectively determine whether any frame ID in the current downlink unicast CAN FD message is the same as the device ID of the SSI sensor connected and controlled thereto; if they are the same, the SSI sensor configuration module obtains the configuration parameters in the control data payload of the current downlink unicast CAN FD message; if they are all different, the SSI sensor configuration module terminates obtaining the configuration parameters in the control data payload of the current downlink unicast CAN FD message; The configuration parameters include sampling frequency, data resolution, circle resolution, sampling frame interval and encoding method for configuring the SSI sensor operation.

5. The SSI sensor redundancy control method based on CAN FD bus as claimed in claim 4, characterized in that: The SSI sensor data transmission module is connected to the SSI sensor via an SSI interface. In S3, the SSI sensor data transmission module drives the SSI sensor to operate, further comprising the following steps: S32: The SSI sensor data transmission module generates a corresponding configuration command based on the configuration parameters, and transmits the configuration command to the SSI sensor through the SSI interface; S33: After receiving the configuration command, the SSI sensor uploads a confirmation response to the SSI sensor data transmission module.

6. The SSI sensor redundancy control method based on CAN FD bus as claimed in claim 4, characterized in that: The priority field is the high bit of the identifier area, and the frame ID is the low bit of the identifier area. The smaller the value of the priority field, the higher the message priority; the smaller the frame ID, the higher the message priority, and the priority of the priority field is higher than the priority of the frame ID; When a plurality of sets of frame IDs and a plurality of sets of priority fields are configured in the frame header of the downlink CAN FD message, different frame IDs correspond to the corresponding priority fields according to their ranking order. When the measurement result feedback data group output by the SSI sensor corresponding to the device ID and the frame ID is packaged to form an uplink CAN FD message, the frame header of the uplink CAN FD message contains a frame ID corresponding to the device ID and a priority field corresponding to the frame ID. Based on the CAN FD bus arbitration mechanism, in the CAN FD bus, the upload order of multiple groups of uplink CAN FD messages of the SSI sensor control device is automatically scheduled according to different priority fields and frame IDs. When the priority fields in multiple groups of uplink CAN FD messages are different, the uplink CAN FD message with a higher priority field is sent first; when the priority fields in multiple groups of uplink CAN FD messages are the same, the uplink CAN FD message with a higher frame ID priority is sent first.

7. The SSI sensor redundancy control method based on CAN FD bus as claimed in claim 4, characterized in that: Any of the SSI sensors has a built-in corresponding measurement threshold. Within a single measurement cycle, when the measurement result feedback data output by the SSI sensor exceeds the measurement threshold, a high priority priority field is automatically configured in the frame header of the uplink CAN FD message formed by the measurement result feedback data packet output by the SSI sensor.

8. The SSI sensor redundancy control method based on CAN FD bus according to claim 1, characterized in that: In S5, the CAN FD data packetization module packets the measurement result feedback data of the SSI sensor to form an uplink CAN FD message, further comprising the following steps: S51: The SSI sensor status monitoring module collects abnormal operating condition feedback data of the SSI sensor in real time through the SSI sensor data transmission module; S52: The CAN FD data packaging module packages the measurement result feedback data and the abnormal operating condition feedback data of the SSI sensor as a whole to form an uplink CAN FD message.

9. The SSI sensor redundancy control method based on CAN FD bus as claimed in claim 2, characterized in that: The data type of the downstream CAN FD message adopts the SDO data type, which supports the online modification function of the configuration parameters in the downstream CAN FD message. The data type of the upstream CAN FD message adopts the PDO data type, which supports the real-time transmission function of the upstream CAN FD message.

10. A SSI sensor redundant control system based on CAN FD bus, characterized in that: The SSI sensor redundant control method based on the CAN FD bus as claimed in any one of claims 1 to 9 is performed, and a plurality of redundantly configurable SSI sensor control devices are provided, wherein the SSI sensor control devices are electrically connected to a single CAN FD bus and a corresponding SSI sensor, respectively, and any of the SSI sensor control devices comprises: A CAN FD bus transceiver interface, the CAN FD bus transceiver interface is used to receive downlink CAN FD messages output through the CAN FD bus, and send uplink CAN FD messages to the CAN FD bus; A CAN FD data unpacking module, wherein the CAN FD data unpacking module is used to unpack a downlink CAN FD message and obtain a data field of the downlink CAN FD message; An SSI sensor configuration module, the SSI sensor configuration module is used to parse and obtain configuration parameters for a specific SSI sensor according to a data field of a downlink CAN FD message; An SSI sensor data transmission module, the SSI sensor data transmission module is used to drive the SSI sensor operation according to the configuration parameters of the downlink CAN FD message, and collect the measurement result feedback data of the SSI sensor; An SSI sensor status monitoring module, the SSI sensor status monitoring module is used to collect abnormal operating condition feedback data of the SSI sensor; A CAN FD data packaging module is used to package the measurement result feedback data of the SSI sensor and the abnormal working condition feedback data to form an uplink CAN FD message.

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