A Redundancy Control Method and System for SSI Sensors Based on CAN FD Bus

Abstract

The present invention provides a redundant control method and system for SSI sensors based on the CAN FD bus. The master control module outputs a downstream CAN FD message through the CAN FD bus. A number of SSI sensor control devices respectively receive the downstream CAN FD message through their CAN FD bus transceiver interfaces. The CAN FD data unpacking module unpacks the downstream CAN FD message to obtain the data field. The SSI sensor configuration module analyzes the data field to obtain the configuration parameters for a specific SSI sensor, and the SSI sensor data transmission module drives the SSI sensor to operate. The SSI sensor data transmission module collects the measurement result feedback data of the SSI sensor. The CAN FD data packetizing module packetizes the measurement result feedback data to establish an upstream CAN FD message. The upstream CAN FD message is uploaded to the CAN FD bus, and finally the master control module receives the upstream CAN FD message, thereby realizing the real-time control and measurement data acquisition functions for the SSI sensors.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic communication, and particularly relates to a redundant control method and system for SSI sensors based on the CAN FD bus. Background Art

[0002] An SSI (Synchronous Serial Interface) sensor is a sensor device that adopts synchronous serial interface technology and has advantages such as fast signal transmission speed and convenient connection. Therefore, it is widely used in operations such as digital signal processing fields, control and measurement systems, and signal integrity testing. Along with the booming development of fields such as automotive electronics, driverless, and industrial automation, the requirements for the speed and accuracy of measurement and control operations of SSI sensor control systems are getting higher and higher.

[0003] In the prior art, a conventional SSI sensor control system constructed through a serial interface has relatively low communication rate and data throughput. For example, the highest communication rate is limited by the CAN bus protocol and is less than 1 Mbps, which greatly limits the efficient application of the SSI sensor control system in scenarios of high-precision, high-frequency data acquisition and real-time control requirements. At the same time, in a traditional SSI sensor control system, each SSI sensor usually needs to be configured separately. When the SSI sensor control system is for large-scale deployment, 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 the CAN FD bus to solve the technical problems that in the prior art, the communication rate and data throughput of conventional SSI sensor control methods and systems are relatively low, and the unified configuration and management of multiple groups of SSI sensors cannot be achieved.

[0005] To solve the above problems, the technical solution of the present invention is as follows: A redundant control method for SSI sensors based on the CAN FD bus includes the following steps:

[0006] S1: The master control module outputs a downstream CAN FD message through a single CAN FD bus. Several SSI sensor control devices redundantly connected to the CAN FD bus respectively receive the downstream CAN FD message through their CAN FD bus transceiver interfaces and transmit it to the CAN FD data unpacking module;

[0007] S2: The CAN FD data unpacking module unpacks the downstream CAN FD message, obtains the data field of the downstream CAN FD message, and transmits the data field to the SSI sensor configuration module;

[0008] S3: The SSI sensor configuration module parses the data field of the downstream CAN FD message, determines whether the target object of the downstream CAN FD message is correct. If it is correct, it obtains the configuration parameters for a specific SSI sensor, and drives the SSI sensor to operate through the SSI sensor data transmission module;

[0009] S4: Within 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 packet assembly module;

[0010] S5: The CAN FD data packet assembly module assembles the measurement result feedback data of the SSI sensor to construct an upstream CAN FD message, and the upstream CAN FD message is uploaded to the CAN FD bus through the CAN FD bus transceiver interface;

[0011] S6: The main control module receives the upstream CAN FD messages output by several of the SSI sensor control devices in the CAN FD bus.

[0012] Preferably, the data fields of the downstream CAN FD message and the upstream CAN FD message include a frame header, a data type, a control / feedback data payload, and a CRC check code. Among them, the frame header is provided with an identifier area, and the identifier area includes a priority field and a frame ID, and the frame ID corresponds to the device ID of the SSI sensor.

[0013] Preferably, in S2, the CAN FD data unpacking module unpacks the downstream CAN FD message to obtain its data field, which further includes the following steps:

[0014] S21: A predefined set of generating polynomials are respectively configured in the main control module and each of the SSI sensor control devices;

[0015] S22: The main control module performs a binary exclusive-OR division operation on the binary expression of the control data payload in the downstream CAN FD message to be sent and the generating polynomial. The remainder obtained by the binary exclusive-OR division is defined as the CRC check code and added to the downstream CAN FD message;

[0016] S23: The CAN FD data unpacking module performs a binary exclusive-OR division operation again on the binary overall expression of the control data payload and the CRC check code in the received downstream CAN FD message and the generating polynomial. If the remainder of the calculation result of the binary exclusive-OR division is 0, the CRC check passes. If the remainder of the calculation result of the binary exclusive-OR division is non-zero, the CRC check fails, and the CAN FD data unpacking module discards the current downstream CAN FD message.

[0017] 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, and further includes the following steps:

[0018] 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, and 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;

[0019] If the frame ID is non-0, the current downlink CAN FD message is a downlink unicast CAN FD message. 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 controlled by it. If there is a match, the SSI sensor configuration module obtains the configuration parameters in the control data payload of the current downlink unicast CAN FD message. If all are different, the SSI sensor configuration module terminates obtaining the configuration parameters in the control data payload of the current downlink unicast CAN FD message;

[0020] The configuration parameters include the sampling frequency, data resolution, revolution resolution, sampling frame gap, and encoding method for configuring the operation of the SSI sensor.

[0021] Preferably, the SSI sensor data transmission module is connected to the SSI sensor through an SSI interface. In S3, the SSI sensor data transmission module drives the operation of the SSI sensor, and further includes the following steps:

[0022] S32: The SSI sensor data transmission module generates corresponding configuration commands based on the configuration parameters and transmits the configuration commands to the SSI sensor through the SSI interface;

[0023] S33: After receiving the configuration command, the SSI sensor uploads an acknowledgment response to the SSI sensor data transmission module.

[0024] Preferably, the priority field is the high bit of the identifier area, and the frame ID is the low bit of the identifier area. Among them, 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;

[0025] When multiple groups of frame IDs and multiple groups of priority fields are configured in the frame header of a downlink CAN FD message, different frame IDs have corresponding relationships with the corresponding priority fields according to their ranking order. After the measurement result feedback data packet of the SSI sensor corresponding to the device ID and the frame ID is constructed to form an uplink CAN FD message, the frame ID corresponding to the device ID and the priority field corresponding to the frame ID also exist in the frame header of the uplink CAN FD message;

[0026] Based on the CAN FD bus arbitration mechanism, in the CAN FD bus, the uplink CAN FD message upload order of multiple groups of the SSI sensor control devices 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 priority 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.

[0027] Preferably, any one of the SSI sensors is built-in with a 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 constructed by the measurement result feedback data packet output by the SSI sensor.

[0028] Preferably, in S5, the CAN FD data packet module packets the measurement result feedback data of the SSI sensor to construct an uplink CAN FD message, which further includes the following steps:

[0029] S51: The SSI sensor status monitoring module collects the abnormal condition feedback data of the SSI sensor in real time through the SSI sensor data transmission module;

[0030] S52: The CAN FD data packet module packets the measurement result feedback data and the abnormal condition feedback data of the SSI sensor as a whole to construct an uplink CAN FD message.

[0031] Preferably, the data type of the downlink CAN FD message adopts the SDO data type, and the SDO data type supports the online modification function of the configuration parameters in the downlink CAN FD message. The data type of the uplink CAN FD message adopts the PDO data type, and the PDO data type supports the real-time transmission function of the uplink CAN FD message.

[0032] Based on the same concept, the present invention further provides an SSI sensor redundancy control system based on the CAN FD bus, which executes the SSI sensor redundancy control method based on the CAN FD bus as described in any one of the above, and is provided with a number of SSI sensor control devices that can be redundantly configured. The SSI sensor control devices are electrically connected to a single CAN FD bus and corresponding SSI sensors respectively. Any one of the SSI sensor control devices includes:

[0033] A CAN FD bus transceiver interface, which is used to receive the downstream CAN FD message output through the CAN FD bus and send the upstream CAN FD message to the CAN FD bus;

[0034] A CAN FD data unpacking module, which is used to unpack the downstream CAN FD message and obtain the data field of the downstream CAN FD message;

[0035] An SSI sensor configuration module, which is used to parse and obtain the configuration parameters for a specific SSI sensor according to the data field of the downstream CAN FD message;

[0036] An SSI sensor data transmission module, which is used to drive the SSI sensor to operate according to the configuration parameters of the downstream CAN FD message and collect the measurement result feedback data of the SSI sensor;

[0037] An SSI sensor status monitoring module, which is used to collect the abnormal condition feedback data of the SSI sensor;

[0038] A CAN FD data packet assembly module, which is used to packet-assemble the measurement result feedback data and the abnormal condition feedback data of the SSI sensor to form an upstream CAN FD message.

[0039] Due to the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0040] The present invention provides an SSI sensor redundancy control method and system based on the CAN FD bus, which integrates the CAN FD communication bus protocol and the SSI sensor protocol. Users can directly remotely control the SSI encoder and collect measurement data 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 redundancy control system are effectively improved.

[0041] Meanwhile, in the invention, several SSI sensor control devices with redundant configurations are connected to the same CAN FD bus. Based on the setting of the downstream CAN FD messages in the CAN FD bus, it is possible to separately configure a specific SSI sensor or uniformly configure all SSI sensors in the SSI sensor redundancy control system, thereby simplifying the configuration process of redundant SSI sensors and improving the flexibility and efficiency of SSI sensor control.

[0042] In addition, the invention also separately provides an SSI sensor status monitoring module in each SSI sensor control device to detect the abnormal status of each SSI sensor, ensuring that the SSI sensor redundancy control system can quickly and effectively discover and locate the abnormal working conditions of the SSI sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Flowchart of a method for redundant control of SSI sensors based on CAN FD bus provided by the invention;

[0044] Figure 2 Schematic structural diagram of the SSI sensor control device provided by the invention;

[0045] Figure 3 Schematic structural diagram of a redundant control system for SSI sensors based on CAN FD bus provided by the invention. SPECIFIC EMBODIMENTS

[0046] The following further elaborates in detail a method and system for redundant control of SSI sensors based on CAN FD bus proposed by the invention in combination with the drawings and specific embodiments. The advantages and features of the invention will be clearer according to the following description and claims.

[0047] First Embodiment

[0048] Refer to Figures 1 - 3 , this embodiment provides a method for redundant control of SSI sensors based on CAN FD bus, which is used to enable SSI sensors through a single CAN FD bus to achieve high-precision and high-frequency data acquisition and real-time control functions, and to achieve integrated and flexible configuration for multiple groups of redundant SSI sensors. The specific steps are as follows:

[0049] S1: The master 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 respectively receive the downstream CAN FD messages through their CAN FD bus transceiver interfaces and transmit the downstream CAN FD messages to their CAN FD data unpacking modules.

[0050] S2: After the CAN FD data unpacking module of the SSI sensor control device receives the downlink CAN FD message, it 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.

[0051] S3: After the SSI sensor configuration module of the SSI sensor control device receives the data field of the downlink CAN FD message, it 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 downlink CAN FD message is the SSI sensor connected and controlled by this SSI sensor control device. If the target object of the current downlink CAN FD message matches the SSI sensor connected and controlled by this 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 downlink 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.

[0052] S4: It is set that the main control module outputs a control signal to a certain SSI sensor control device, then the SSI sensor control device drives the SSI sensor operation connected and controlled by it, 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 operation, the SSI sensor will output 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 packet assembly module.

[0053] S5: The CAN FD data packet assembly module performs packet assembly processing on the measurement result feedback data of the SSI sensor, constructs an uplink CAN FD message, and the uplink CAN FD message is transmitted to the CAN FD bus transceiver interface and uploaded to the CAN FD bus.

[0054] S6: The main control module receives the uplink CAN FD messages output by several SSI sensor control devices in the CAN FD bus, and realizes the function of obtaining the measurement result feedback data of several SSI sensors.

[0055] Next, the specific steps and functions of a redundant control method for SSI sensors based on the CAN FD bus provided in this embodiment will be further described in detail:

[0056] In this embodiment, the data fields of the downlink CAN FD message and the uplink CAN FD message both include at least a frame header, a data type, control / feedback data payloads, and a CRC check code. Among them, an identifier area is provided in the frame header, and 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 the 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 payloads. The control / feedback data payloads record control data and feedback data respectively. The CRC check code is used to implement the security verification of the downlink CAN FD message.

[0057] Preferably, in this embodiment, in S2, the CAN FD data unpacking module unpacks the downlink CAN FD message to obtain its data field, and further includes a CRC check step:

[0058] S21: A predefined generating polynomial is configured in the main control module and each SSI sensor control device.

[0059] S22: Before the main control module sends the downlink CAN FD message, the main control module first performs a binary exclusive-OR division operation on the binary expression of the control data payload in the downlink CAN FD message and the generating polynomial, defines the remainder obtained by the binary exclusive-OR division as the CRC check code, and adds it to the downlink CAN FD message, and transmits it to the SSI sensor control device together with the control data payload.

[0060] S23: When the CAN FD data unpacking module unpacks the downlink CAN FD message, the control data payload and the CRC check code are obtained. Subsequently, the binary overall expression of the control data payload and the CRC check code in the downlink CAN FD message is performed a binary exclusive-OR division operation with the generating polynomial again. If the remainder of the calculation result of the binary exclusive-OR 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 downlink CAN FD message and the data is legal. On the contrary, if the remainder of the calculation result of the binary exclusive-OR division is non-0, the CRC check fails, proving that the content of the control data payload has changed during the transmission of the downlink CAN FD message and the data is illegal. The SSI sensor control device discards the current downlink CAN FD message.

[0061] In one embodiment, after receiving the upstream CAN FD message output by the SSI sensor control device, the main control module can also perform CRC check on the upstream CAN FD message. That is, the SSI sensor data transmission module performs binary exclusive OR division operation on the binary expression of the data fed back according to the measurement result of the SSI sensor and the generating polynomial to obtain a set of CRC check codes, and adds them to the upstream CAN FD message. After receiving the upstream CAN FD message, the main control module performs CRC check with reference to step S23. If the CRC check passes, it proves that the content of the feedback data payload has not been changed during the transmission of the upstream CAN FD message and the data is legal. On the contrary, if the CRC check fails, it proves that the content of the feedback data payload has changed during the transmission of the upstream CAN FD message and the data is illegal. The main control module discards the current upstream CAN FD message.

[0062] It should be noted 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 as 17 bits or 21 bits. A higher-order generating polynomial bit number can significantly improve the error monitoring ability of the CRC check step, that is, effectively improve the security performance of the SSI sensor redundancy control system based on the CAN FD bus.

[0063] Preferably, in this embodiment, the downstream CAN FD message includes a downstream unicast CAN FD message and a downstream broadcast CAN FD message. In S3, the SSI sensor configuration module determines whether the target object of the downstream CAN FD message is correct, which further includes the following steps:

[0064] S31: After the SSI sensor configuration module obtains the frame ID data in the downstream CAN FD message, it judges 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, the 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.

[0065] If the frame ID is non-zero, the current downlink CAN FD message is a downlink unicast CAN FD message, that is, the current master control module sends a downlink CAN FD broadcast message through the CAN FD bus, which is only used to control a specific group or several groups of SSI sensors to perform the same measurement action. Among them, when the downlink CAN FD broadcast message is only used to control a group of SSI sensors, the frame ID is only a 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 the frame IDs of different fields respectively 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 downlink unicast CAN FD message is the same as the device ID of the SSI sensor connected and controlled by it. If there is a match, it proves that the SSI sensor connected and controlled by this SSI sensor control device is the target object of the current downlink unicast CAN FD message. Therefore, its SSI sensor configuration module parses and obtains the configuration parameters in the control data payload of the current downlink unicast CAN FD message. On the contrary, if they are all different, it proves that the SSI sensor connected and controlled by this SSI sensor control device is not the target object of the current downlink unicast CAN FD message. Therefore, its SSI sensor configuration module terminates obtaining the configuration parameters in the control data payload of the current downlink unicast CAN FD message. Thus, the master control module can achieve unified control of all SSI sensors or separate control of specific SSI sensors.

[0066] Specifically, in this embodiment, the configuration parameters include parameters such as sampling frequency, data resolution, revolution resolution, sampling frame interval, and encoding method 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 revolution resolution is used to determine the number of rotation revolutions that the SSI sensor (such as an incremental encoder) can measure. The sampling frame interval is used to determine the sampling period of the SSI sensor. The encoding method is used to determine the data encoding format of the SSI sensor.

[0067] Preferably, in this embodiment, the SSI sensor data transmission module is connected to the SSI sensor through the SSI interface, so as to enable the SSI sensor data transmission module to send configuration parameters to the SSI sensor and receive the measurement result feedback data output by the SSI sensor.

[0068] In S3, the SSI sensor data transmission module drives the SSI sensor to operate, which further includes the following steps:

[0069] 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.

[0070] S32: After the SSI sensor receives the configuration command, it uploads an acknowledgement response to the SSI sensor data transmission module, and then the SSI sensor performs a measurement action based on the configuration command.

[0071] Further, in this embodiment, in S4, the SSI sensor data transmission module collects the measurement result feedback data of the SSI sensor in real time, which specifically includes the following steps:

[0072] 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 synchronizing 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 it to form a complete measurement value, ensuring the synchronization and accuracy of the measurement result feedback data transmission.

[0073] Preferably, in this embodiment, the priority field is the high bit of the identifier area, and the frame ID is the low bit of the identifier area. Among them, the smaller the value of the priority field, the higher the priority of the message; the smaller the frame ID, the higher the priority of the message, and the priority of the priority field is higher than that of the frame ID. That is, in a single message, the priority of the priority field needs to be considered first, and then the priority of the frame ID. Similarly to the frame ID, in a single downstream CAN FD message, multiple groups of priority fields can also exist, and the number of priority fields is the same as that of the frame ID. When multiple groups of frame IDs and multiple groups of priority fields are configured in the frame header of the downstream CAN FD message, different frame IDs have corresponding relationships with the corresponding priority fields according to their ranking order, that is, multiple groups of frame IDs and multiple groups of priority fields are pairwise corresponding according to their respective ranking orders. After the measurement result feedback data packet constructed by the SSI sensor corresponding to the device ID and the frame ID forms an upstream CAN FD message, the frame header of the upstream CAN FD message also has a frame ID corresponding to the device ID and a priority field corresponding to the frame ID.

[0074] Based on the CAN FD bus arbitration mechanism, in the CAN FD bus, the upload order of the uplink CAN FD messages of multiple groups of SSI sensor control devices can be automatically scheduled according to different priority fields and frame IDs. Specifically, the uplink CAN FD messages implement a first-come, first-served transmission mechanism. When 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, then the uplink CAN FD message with a higher priority field priority is sent first; when 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, then 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 priority field or frame ID can be preferentially uploaded and preferentially obtained by the main control module, realizing the efficient propagation and sequential response of the CAN FD messages.

[0075] It should be noted that in this embodiment, the situation where the priority fields and frame IDs in multiple groups of downlink CAN FD messages or uplink CAN FD messages are exactly the same should be avoided.

[0076] In another embodiment, any SSI sensor can be built-in with corresponding measurement thresholds. 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. In the frame header of the uplink CAN FD message constructed by packetizing the measurement result feedback data group output by the SSI sensor, a high-priority priority field will be automatically configured. This embodiment is applicable to both downlink broadcast CAN FD messages and downlink unicast CAN FD messages.

[0077] Through reasonable priority management, it can be ensured that the key measurement result feedback data of the SSI sensor is preferentially fed back, improving the real-time performance and reliability of the system.

[0078] Preferably, in this embodiment, in S5, the CAN FD data packetizing module packetizes the measurement result feedback data of the SSI sensor to construct an uplink CAN FD message, which further includes the following steps:

[0079] S51: The SSI sensor status monitoring module collects the abnormal working condition feedback data of the SSI sensor in real time through the SSI sensor data transmission module. The abnormal working condition feedback data includes abnormal communication status, abnormal measurement data, etc.

[0080] S52: The CAN FD data packet module packs the measurement result feedback data of the SSI sensor and the abnormal condition feedback data as a whole to construct an uplink CAN FD message. An SSI sensor status monitoring module is additionally set to obtain the measurement result feedback data of the SSI sensor, facilitating the main control module to timely detect the abnormal status of the SSI sensor, locate and take relevant measures, avoiding measurement data errors or system failures caused by SSI sensor failures, and thus improving the stability and reliability of the system.

[0081] Preferably, in this embodiment, the data type of the downlink CAN FD message adopts the SDO data type. The SDO data type supports the online modification function of the configuration parameters in the downlink CAN FD message. That is, during the transmission of the downlink 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, it requests to modify the control data payload content in the downlink CAN FD message. After receiving the SDO write request, the SSI sensor control device will update the control data payload content in the downlink CAN FD message, and there will be no abnormal jump situations such as configuration parameter garbling or clearing. The data type of the uplink CAN FD message adopts the PDO data type. The PDO data type supports the real-time transmission function of the uplink CAN FD message, which is applied to high-frequency data update requirements to ensure the real-time performance and stability of the system.

[0082] In summary, this embodiment provides a redundant control method for SSI sensors based on the CAN FD bus. Based on a single CAN FD bus for several redundantly connected SSI sensors, it realizes overall unified configuration or separate configuration for specific SSI sensors, 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, it effectively improves the communication rate and data throughput of the SSI sensor redundant control system.

[0083] Second Embodiment

[0084] Based on the same concept, referring to Figures 2 - 3 , this embodiment provides a redundant control system for SSI sensors based on the CAN FD bus, which is used to execute a redundant control method for SSI sensors based on the CAN FD bus as described in the first embodiment. In this embodiment, there are several SSI sensor control devices that can be redundantly configured. The SSI sensor control devices are respectively electrically connected to a single CAN FD bus and a group of specific SSI sensors. The SSI sensor control device specifically includes:

[0085] CAN FD bus transceiver interface, which is electrically connected to the CAN FD bus and the CAN FD data unpacking module, is used to receive the downstream CAN FD message output through the CAN FD bus and send the upstream CAN FD message to the CAN FD bus.

[0086] CAN FD data unpacking module, which is electrically connected to the CAN FD bus transceiver interface and the SSI sensor configuration module, is used to unpack the downstream CAN FD message and obtain the data field in the downstream CAN FD message.

[0087] SSI sensor configuration module, which is electrically connected to the CAN FD data unpacking module and the SSI sensor data transmission module, is used to parse and obtain the configuration parameters for specific SSI sensors according to the data field of the downstream CAN FD message.

[0088] SSI sensor data transmission module, which is respectively electrically connected to the SSI sensor configuration module, the SSI sensor, the SSI sensor status monitoring module and the CAN FD data packet assembly module, is used to generate a configuration command to drive the SSI sensor to operate according to the configuration parameters of the downstream CAN FD message and collect the measurement result feedback data of the SSI sensor.

[0089] SSI sensor status monitoring module, which is electrically connected to the SSI sensor data transmission module and the CAN FD data packet assembly module, is used to collect the abnormal working condition feedback data of the SSI sensor through the SSI sensor data transmission module.

[0090] CAN FD data packet assembly module, which is electrically connected to the CAN FD bus transceiver interface, the SSI sensor data transmission module and the SSI sensor status monitoring module, is used to assemble the measurement result feedback data and the abnormal working condition feedback data of the SSI sensor as a whole to construct an upstream CAN FD message.

[0091] In addition, there is also a single main control module, which is electrically connected to several 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 the feedback data of each SSI sensor to realize the centralized management, dynamic adjustment, status monitoring and coordinated communication functions of the SSI sensor redundancy control system.

[0092] In summary, this embodiment provides an SSI sensor redundancy control system based on the CAN FD bus, which integrates the CAN FD communication bus with several SSI sensors. Users can directly perform remote control, measurement data acquisition, and operation status monitoring functions on the SSI encoder through the CAN FD bus, and achieve 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.

[0093] The above has described in detail the embodiments of the present invention in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and its equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. A redundant control method for SSI sensors based on the CAN FD bus, characterized in that It includes the following steps: S1: The master control module outputs a downstream CAN FD message through a single CAN FD bus. A number of SSI sensor control devices redundantly connected to the CAN FD bus respectively receive the downstream CAN FD message through their CAN FD bus transceiver interfaces and transmit it to the CAN FD data unpacking module; S2: The CAN FD data unpacking module unpacks the downstream CAN FD message, obtains the data field of the downstream CAN FD message, and transmits the data field to the SSI sensor configuration module; S3: The SSI sensor configuration module analyzes the data field of the downstream CAN FD message, determines whether the target object of the downstream CAN FD message is correct. If it is correct, it obtains the configuration parameters for a specific SSI sensor and drives the SSI sensor to operate through the SSI sensor data transmission module; S4: Within 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 packet assembly module; S5: The CAN FD data packet assembly module assembles the measurement result feedback data of the SSI sensor, constructs an upstream CAN FD message, and the upstream CAN FD message is uploaded to the CAN FD bus through the CAN FD bus transceiver interface; S6: The master control module receives the upstream CAN FD messages output by a number of the SSI sensor control devices in the CAN FD bus.

2. The redundant control method of the SSI sensor based on the CAN FD bus according to claim 1, wherein, The data fields of the downstream CAN FD message and the upstream CAN FD message include a frame header, a data type, a control / feedback data payload, and a CRC check code. Among them, the frame header is provided with an identifier area, and 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 redundancy control method for the SSI sensor based on the CAN FD bus according to claim 2, wherein In S2, the CAN FD data unpacking module unpacks the downstream CAN FD message to obtain its data field, which further includes the following steps: S21: A predefined set of generating polynomials are respectively configured in the master control module and each of the SSI sensor control devices; S22: The master control module performs a binary exclusive OR division operation on the binary expression of the control data payload in the downstream CAN FD message to be sent and the generating polynomial. The remainder obtained by the binary exclusive OR division is defined as the CRC check code and added to the downstream CAN FD message; S23: The CAN FD data unpacking module performs a binary exclusive OR division operation again on the binary overall expression of the control data payload and the CRC check code in the received downstream CAN FD message and the generating polynomial. If the remainder of the calculation result of the binary exclusive OR division is 0, the CRC check passes. If the remainder of the calculation result of the binary exclusive OR division is non-zero, the CRC check fails, and the CAN FD data unpacking module discards the current downstream CAN FD message.

4. The redundant control method for SSI sensors 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, and further includes 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, then 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 non-0, then the current downlink CAN FD message is a downlink unicast CAN FD message. 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 by it. If there is a match, then the SSI sensor configuration module obtains the configuration parameters in the control data payload of the current downlink unicast CAN FD message. If all are different, then 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 the sampling frequency, data resolution, revolution resolution, sampling frame gap, and encoding method for configuring the operation of the SSI sensor.

5. The redundancy control method of the SSI sensor based on the CAN FD bus according to claim 4, wherein The SSI sensor data transmission module is connected to the SSI sensor through the SSI interface. In S3, the SSI sensor data transmission module drives the operation of the SSI sensor, and further includes the following steps: S32: The SSI sensor data transmission module generates corresponding configuration commands based on the configuration parameters and transmits the configuration commands to the SSI sensor through the SSI interface; S33: After receiving the configuration command, the SSI sensor uploads an acknowledgment response to the SSI sensor data transmission module.

6. The redundant control method for the SSI sensor based on the CAN FD bus according to 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. Among them, 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 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 have corresponding relationships with the corresponding priority fields according to their ranking order. When the measurement result feedback data packet constructed by the SSI sensor corresponding to the device ID and the frame ID forms an uplink CAN FD message, there is a frame ID corresponding to the device ID and a priority field corresponding to the frame ID in the frame header of the uplink CAN FD message; Based on the CAN FD bus arbitration mechanism, in the CAN FD bus, the upload order of the uplink CAN FD messages of multiple groups of the SSI sensor control devices is automatically scheduled according to different priority fields and frame IDs. When the priority fields in multiple uplink CAN FD messages are different, the uplink CAN FD message with a higher priority field priority is sent first; when the priority fields in multiple uplink CAN FD messages are the same, the uplink CAN FD message with a higher frame ID priority is sent first.

7. The redundancy control method for SSI sensors based on the CAN FD bus according to claim 4, characterized in that, Any one of the SSI sensors is built-in with a 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 packetizing the measurement result feedback data output by the SSI sensor.

8. The redundant control method of the SSI sensor based on the CAN FD bus according to claim 1, wherein In S5, the CAN FD data packetizing module packetizes the measurement result feedback data of the SSI sensor to construct an uplink CAN FD message, which further includes the following steps: S51: The SSI sensor status monitoring module collects the abnormal working condition feedback data of the SSI sensor in real time through the SSI sensor data transmission module; S52: The CAN FD data packetizing module packetizes the measurement result feedback data of the SSI sensor and the abnormal working condition feedback data as a whole to construct an uplink CAN FD message.

9. The redundant control method for the SSI sensor based on the CAN FD bus according to claim 2, characterized in that, The data type of the downlink CAN FD message adopts the SDO data type, and the SDO data type supports the online modification function of the configuration parameters in the downlink CAN FD message. The data type of the uplink CAN FD message adopts the PDO data type, and the PDO data type supports the real-time transmission function of the uplink CAN FD message.

10. A redundant control system for SSI sensors based on the CAN FD bus, characterized in that, Implement the SSI sensor redundancy control method based on the CAN FD bus according to any one of claims 1-9. There are several SSI sensor control devices that can be redundantly configured. The SSI sensor control devices are respectively electrically connected to a single CAN FD bus and the corresponding SSI sensors. Any one of the SSI sensor control devices includes: A CAN FD bus transceiver interface, which is used to receive the downlink CAN FD message output through the CAN FD bus and send the uplink CAN FD message to the CAN FD bus; A CAN FD data unpacking module, which is used to unpack the downlink CAN FD message to obtain the data field of the downlink CAN FD message; An SSI sensor configuration module, which is used to parse and obtain the configuration parameters for a specific SSI sensor according to the data field of the downlink CAN FD message; An SSI sensor data transmission module, which is used to drive the SSI sensor to operate according to the configuration parameters of the downlink CAN FD message and collect the measurement result feedback data of the SSI sensor. SSI sensor status monitoring module, which is used to collect abnormal working condition feedback data of the SSI sensor; CAN FD data packet assembly module, which is used to assemble the measurement result feedback data and abnormal working condition feedback data of the SSI sensor to construct an uplink CAN FD message.

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