Active monitoring and diagnosing method for steer-by-wire bilateral controller

Abstract

The invention discloses a steer-by-wire bilateral controller activity monitoring and diagnosing method, which comprises the following steps that: S1, a bilateral controller generates a verification PWM (Pulse Width Modulation) signal as a heartbeat signal according to the own activity state and sends the heartbeat signal to an opposite side, and meanwhile, specifies the real-time activity state of a microcontroller represented by different heartbeat signals; s2, calculating a bilateral heartbeat activity state according to the heartbeat signal within a specified window time; S3, calculating and waiting for a far side heartbeat activity state, determining waiting time according to the far side heartbeat activity state, completing power-on synchronization and starting a periodic task; s4, when a power supply is cut off, calculating and waiting for a far-side activity state in the periodic circulation task, determining waiting time according to different far-side heartbeat activity states, and completing power-off synchronization; wherein the bilateral controller presets a master side frequency and a slave side frequency, master-slave judgment is carried out by calculating the heartbeat frequency of the bilateral controller, and the heartbeat frequency of the bilateral controller is correspondingly adjusted when the master-slave relation is switched. According to the invention, active monitoring and diagnosis of the steer-by-wire bilateral controller can be comprehensively and reliably realized.

Description

Technical Field

[0001] This invention relates to the automotive field, and in particular to a method for monitoring and diagnosing the activity of a steer-by-wire dual-sided controller. Background Technology

[0002] With the rapid development of intelligent driving technology, the safety performance of steer-by-wire systems, as core actuators, has received high attention from the industry. To meet increasingly stringent safety requirements, steer-by-wire systems generally adopt a dual-redundancy architecture design. This architecture includes two sets of microcontrollers, two sets of sensor units, and a six-phase motor. Through the cooperation and synchronous output of the master and slave microcontrollers, coordinated steering control is achieved, thereby reducing steering failure rate.

[0003] In a dual-redundant control system, the coordinated operation of both microcontrollers is crucial for ensuring normal system operation, while the bilateral activity monitoring and diagnostic function directly determines the reliability of the coordinated control. Without an effective activity monitoring and diagnostic mechanism, if either microcontroller malfunctions, the system cannot detect and respond in a timely manner, potentially leading to erroneous coordinated control outputs. This could result in dangerous accidents such as lane departure and collisions, seriously threatening the safety of drivers and pedestrians.

[0004] While existing technologies offer monitoring solutions for redundant systems, most current monitoring methods rely solely on the communication link status to determine microcontroller activity without incorporating real-time feedback from hardware signals, resulting in insufficient reliability of diagnostic results. Furthermore, the lack of synchronous design for system power-on and power-off processes can easily lead to asynchrony between master and slave microcontroller states. Additionally, when bilateral communication fails, the master-slave role determination cannot be effectively maintained, potentially resulting in abnormal "dual master" or "dual slave" operating conditions that affect system stability and security.

[0005] In summary, the existing redundancy systems have the following technical problems that need to be addressed: 1. Existing monitoring methods rely solely on the status of the communication link without considering hardware signal feedback, resulting in insufficient reliability of microcontroller activity diagnosis results and an inability to detect abnormal failures of the microcontroller in a timely and accurate manner. 2. The lack of synchronous design for the power-on and power-off process of the system makes it easy for the master and slave microcontrollers to become out of sync, affecting the stability of the system during startup and shutdown; 3. When bilateral communication fails, the master-slave role judgment cannot be effectively maintained, which can easily lead to abnormal working conditions of "dual master" or "dual slave", resulting in errors in the collaborative control output; 4. The activity characterization of the microcontroller under different working states (static, high-load operation, etc.) is not accurate enough, and there is a lack of dynamic monitoring mechanism adapted to different working conditions.

[0006] Therefore, there is an urgent need for a design method that can comprehensively and reliably realize the activity monitoring and diagnosis of the dual-sided microcontroller for steer-by-wire. Summary of the Invention

[0007] The summary of this invention introduces a series of simplified concepts, all of which are simplifications of existing technologies in the field, and will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0008] The technical problem to be solved by the present invention is to provide a method for comprehensively and reliably monitoring and diagnosing the activity of a dual-sided controller for steer-by-wire.

[0009] To solve the above-mentioned technical problems, the present invention provides a method for monitoring and diagnosing the activity of a steer-by-wire dual-sided controller, comprising the following steps: S1, the dual-side controller generates a verification PWM signal as a heartbeat signal based on its own activity state and sends it to the other side, while specifying the real-time activity state of the microcontroller represented by different heartbeat signals; S2, calculate bilateral cardiac activity status based on heartbeat signals within a specified window time. S3, after the microcontroller is initialized, calculates and waits for the remote heartbeat activity state, determines the waiting time based on the remote heartbeat activity state, completes power-on synchronization and starts the cycle task; S4, when the microcontroller is preparing to shut down and cut off the power, it calculates and waits for the activity status of the remote side in the periodic loop task, determines the waiting time according to the different heartbeat activity status of the remote side, and completes the power-off synchronization. The bilateral controller has preset master and slave frequencies. It determines the master-slave relationship by calculating the heartbeat frequency of the bilateral controller and adjusts its own heartbeat frequency accordingly when switching between master and slave.

[0010] Preferably, in a further improved method for monitoring and diagnosing the activity of the dual-side controller for steering-by-wire, in step S1, two PWM hardware interfaces are configured, one for sending and the other for receiving PWM signals from the local microcontroller. The local microcontroller generates a PWM signal of a corresponding frequency based on its own activity state and sends it as a heartbeat signal to the other side. At the same time, it receives the heartbeat signal from the remote microcontroller to monitor the activity state of the remote side.

[0011] Preferably, the method for monitoring and diagnosing the activity of the steer-by-wire dual-side controller is further improved by setting four heartbeat activity states: Off, Prepare, Wake, and Reset, which respectively characterize the real-time activity state of the microcontroller during system power-on, power-off, and operation.

[0012] Preferably, the method for monitoring and diagnosing the activity of the steer-by-wire dual-side controller is further improved, and the calculation of the heartbeat activity state includes: 1) Set the window time Twindow and obtain the far edge counter value at the start of the window time; 2) When the window time ends, obtain the counter value of the other far edge; 3) Calculate the difference between the two edge counter values ​​and convert it to frequency; 4) Compare the calculated frequency with the standard frequency to check frequency stability; 5) Set the stabilization time and wait for the edge counter to stabilize or time out; 6) If the edge counter is stable during the stabilization period, update the far-edge heartbeat activity status based on the matching result of the calculated frequency and the standard frequency; if the frequency cannot be stabilized or does not match the standard frequency during the stabilization period, report the fault and set the far-edge activity status to Unknown.

[0013] Preferably, in the further improved method for monitoring and diagnosing the activity of the steer-by-wire dual-side controller, the window time ranges from 1 millisecond to 5 milliseconds, preferably 2 milliseconds, and the anti-shake time ranges from 10 milliseconds to 30 milliseconds, preferably 20 milliseconds.

[0014] Preferably, the method for monitoring and diagnosing the activity of the steer-by-wire dual-side controller is further improved by dividing the heartbeat activity state into Initial, Alive, and NotAlive states. The calculation of the heartbeat activity state includes: Check if there is a timeout fault in the UART communication status of the two-sided controllers. If a timeout occurs, the remote controller is determined to be in an inactive NotAlive state. If the UART communication is normal or the heartbeat activity of the remote controller is not in an unknown state, the remote controller is determined to be in an active Alive state. In the Alive state, the bilateral UART communication status and the remote heartbeat activity status are continuously monitored. If the UART communication times out and the remote heartbeat activity is in the Unknown state, the remote side is determined to be in the NotAlive state and a fault is set. The fault can be recovered when the remote side recovers its active state. In the inactive NotAlive state, the bilateral UART communication status and the remote heartbeat activity status are continuously monitored. If the UART communication is normal or the remote heartbeat activity is not in the Unknown state, the remote side is determined to be in the active Alive state.

[0015] Preferably, in a further improved method for monitoring and diagnosing the activity of the steer-by-wire dual-side controller, the power-on synchronization includes: When the remote activity is in the Prepare state, the waiting time is Tpoweron; When the remote activity is in an unknown state, the waiting time is Texception1; When the remote activity is not in the Prepare or Unknown state, power-on synchronization is completed directly.

[0016] Preferably, in a further improved method for monitoring and diagnosing the activity of the steer-by-wire dual-side controller, the power-on synchronization includes: The waiting time for Tpoweron ranges from 5 to 15 seconds, with 10 seconds being preferred. The waiting time Texception1 ranges from 200 milliseconds to 700 milliseconds, with 500 milliseconds being preferred.

[0017] Preferably, in a further improved method for monitoring and diagnosing the activity of the steer-by-wire dual-side controller, the power-down synchronization includes: When the remote activity state is neither a restarted Rest nor an unknown state, the waiting time Tpoweroff is applied. When the remote activity is in the Unknown state, the waiting time is Texception2.

[0018] Preferably, the improved steer-by-wire dual-side controller activity monitoring and diagnostic method has a waiting time Tpoweroff ranging from 100 seconds to 140 seconds, preferably 120 seconds. The waiting time Texception2 ranges from 100 milliseconds to 500 milliseconds, with 300 milliseconds being preferred.

[0019] This invention can achieve at least the following technical effects; 1. Existing technologies do not incorporate hardware signal feedback and rely solely on the communication link status. When there is transient interference or delay in the communication link, the active status of the microcontroller is easily misjudged. Furthermore, the lack of accurate signal sampling and stability verification mechanisms makes it impossible to effectively filter interference signals, resulting in insufficient reliability of diagnostic results.

[0020] This invention employs a dual judgment mechanism of "heartbeat signal (hardware PWM signal) + UART communication status": heartbeat signals of different frequencies are sent through the PWM hardware interface to characterize the microcontroller's activity status, and this, combined with the UART communication status, jointly determines the remote heartbeat activity status. Compared to existing methods that rely solely on the communication link, this dual judgment mechanism allows for mutual verification, effectively avoiding misjudgments caused by single-link failures. Simultaneously, steps such as window sampling and debouncing verification are designed to accurately calculate and verify the stability of the PWM frequency, ensuring the accuracy of activity status judgment. Therefore, it can detect microcontroller malfunctions promptly and accurately, improving the reliability of activity diagnosis.

[0021] 2. Existing technologies do not have a dedicated power-on and power-off synchronization mechanism for the dual-redundancy architecture of the steer-by-wire system, and do not consider the impact of different remote activity states on synchronization, resulting in inconsistent start-stop rhythms of the master and slave microcontrollers and easy desynchronization of states.

[0022] This invention designs a synchronization mechanism for the power-on and power-off processes. Different waiting times are set based on the remote endpoint's heartbeat activity state (Prepare, Unknown, etc.) to ensure that the master and slave microcontrollers are in the same state during startup and shutdown. During power-on, the system waits for the remote endpoint to reach the corresponding activity state before starting the periodic task; during power-off, it waits for the remote endpoint to complete the state transition before cutting off the power. This avoids startup failures or shutdown anomalies caused by state asynchrony, ensuring the stability of the system during startup and shutdown.

[0023] 3. Existing technology relies on bilateral communication to transmit master-slave role information. When communication fails, the basis for role judgment is lost, and the master-slave relationship cannot be maintained, which leads to abnormal working conditions of "dual master" or "dual slave".

[0024] This invention predefines specific heartbeat frequencies (fMaster, fSlave) for the master and slave sides, and determines master / slave status by calculating the bilateral heartbeat frequencies. When bilateral communication fails, it eliminates the need to rely on the communication link to transmit master / slave role information; instead, it directly identifies master / slave status through the frequency of the hardware PWM signal. Simultaneously, it synchronously adjusts its own heartbeat frequency during master / slave relationship switching to avoid role conflicts. Therefore, even with communication failure, it can still maintain normal master / slave role determination. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and various details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "combined" to another element, the element can be directly connected or combined to the other element, or there may be intermediate elements. The difference is that when an element is referred to as "directly connected" or "directly combined" to another element, there are no intermediate elements. Example

[0026] This invention provides a method for monitoring and diagnosing the activity of a dual-sided steering steer controller, comprising the following steps: S1, the dual-side controller generates a verification PWM signal as a heartbeat signal based on its own activity state and sends it to the other side, while specifying the real-time activity state of the microcontroller represented by different heartbeat signals; S2, calculate bilateral cardiac activity status based on heartbeat signals within a specified window time. S3, after the microcontroller is initialized, calculates and waits for the remote heartbeat activity state, determines the waiting time based on the remote heartbeat activity state, completes power-on synchronization and starts the cycle task; S4, when the microcontroller is preparing to shut down and cut off the power, it calculates and waits for the activity status of the remote side in the periodic loop task, determines the waiting time according to the different heartbeat activity status of the remote side, and completes the power-off synchronization. The bilateral controller has preset master and slave frequencies. It determines the master-slave relationship by calculating the heartbeat frequency of the bilateral controller and adjusts its own heartbeat frequency accordingly when switching between master and slave.

[0027] Based on the above main design concept, the working process of the present invention is further explained as follows; In this embodiment, the dual-redundant steer-by-wire system includes two sets of microcontrollers (MCU A and MCU B), two sets of sensor units, and a six-phase motor. Each microcontroller is configured with two PWM hardware interfaces, which are used to send its own PWM heartbeat signal and receive the PWM heartbeat signal from the other side, respectively. At the same time, bilateral communication is realized through the UART interface.

[0028] Both MCU A and MCU B generate PWM signals of corresponding frequencies based on their own activity levels via their respective PWM transmit interfaces: the PWM frequency is lower when the system is stationary and higher when the system is under high load. MCU A receives the PWM heartbeat signal from MCU B via its PWM receive interface, monitoring MCU B's activity status in real time; similarly, MCU B receives the PWM heartbeat signal from MCU A via its PWM receive interface, achieving mutual monitoring between the two systems.

[0029] This invention defines four heartbeat activity states, each corresponding to a different stage of system operation: Off state: The microcontroller is not powered on, and there is no PWM signal output; Prepare state: During the microcontroller's power-on initialization process, a PWM signal of a specific frequency is output; Wake state: The microcontroller is in normal working state and outputs a PWM signal of the corresponding frequency according to the system load; Reset state: The microcontroller is ready to power down and outputs a PWM signal of a specific frequency.

[0030] The remote state calculation update supports two methods: synchronous update (MCU A and MCU B update the state simultaneously) and asynchronous update (MCU A and MCU B update the state independently).

[0031] Heart rate activity calculation: Heartbeat activity status update time parameter table; Calculation of cardiac activity state: The window time Twindow is set to 2 milliseconds, and the debounce time Tdebounce is set to 20 milliseconds; At the start of the window time Twindow, MCU A obtains the edge counter value C1 of MCU B through a function. When the window time Twindow ends, obtain the edge counter value C2 of MCU B; Calculate the difference ΔC = C2 - C1, and convert the difference to the PWM frequency f (unit: Hz) according to the formula f = ΔC / Twindow. The calculated frequency f is compared with the preset standard frequencies for each activity state to check whether the frequency is stable. Start the image stabilization timer and wait for Tdebounce (20 milliseconds). If the calculated frequency f remains stable and matches a certain standard frequency within Tdebounce, the heartbeat activity status of MCU B is updated to the status corresponding to that standard frequency (Off / Prepare / Wake / Reset); if the frequency is unstable or does not match a valid standard frequency within Tdebounce, a fault is reported, and the heartbeat activity status of MCU B is set to Unknown.

[0032] Among them, the edge counter update of MCU B supports synchronous and asynchronous methods, and is adapted to the remote edge state update method.

[0033] Three heartbeat activity states are defined, and the determination is made by combining the UART communication state and the remote heartbeat activity state: 1. Initial state: After the system starts up, MCU A and MCU B initially enter this state; If a timeout failure is detected in bilateral UART communication, the far side is determined to be in a NotAlive state. If bilateral UART communication is normal, or the heartbeat activity status of the far side is not in the Unknown state, then the far side is determined to be in the Alive state. 2. Alive state: The active state of MCU A and MCU B when they are working normally; Continuously monitor the bilateral UART communication status and the remote heartbeat activity status. If the UART communication times out and the remote heartbeat activity status is Unknown, determine that the remote side is in a NotAlive state and set the corresponding fault flag. If the remote UART communication is detected to have returned to normal or the heartbeat activity state is removed from Unknown, the fault flag is cleared and the remote side is determined to have returned to the Alive state. 3. NotAlive state: The remote microcontroller is in a failure state; Continuously monitor the bilateral UART communication status and the remote heartbeat activity status. If the UART communication is normal or the remote heartbeat activity status is not in the Unknown state, it is determined that the remote side has recovered to the Alive state.

[0034] Power-on synchronization: Power-on synchronization time parameter table; 1. The normal synchronization wait time Tpoweron is 10 seconds, and the abnormal synchronization wait time Texception1 is 500 milliseconds; 2. After MCU A completes the initialization sequence, it initiates the power-on synchronization process: Detect the heartbeat activity status of MCU B; If the heartbeat activity state of MCU B is in Prepare state, wait for Tpoweron (10 seconds) until the state of MCU B stabilizes and completes power-on synchronization, starts the cycle task, and the system enters the full-assist output state; If the heartbeat activity status of MCU B is Unknown, wait for Texception1 (500 milliseconds), and after the timeout, complete the power-on synchronization and start the periodic task; If the heartbeat activity state of MCU B is Off, Wake, or Reset, then power-on synchronization is completed directly and the cycle task is started.

[0035] The power-on synchronization process of MCU B is the same as that of MCU A.

[0036] Power-off synchronization: Power-down synchronization time parameter table; 1. The normal power-off waiting time Tpoweroff is 120 seconds, and the abnormal power-off waiting time Texception2 is 300 milliseconds; 2. When MCU A is about to shut down and disconnect the power, the power-down synchronization process is initiated in the periodic cyclic task: Detect the heartbeat activity status of MCU B; If the heartbeat activity state of MCU B is not in the Rest state or the Unknown state, then wait for Tpoweroff (120 seconds) until MCU B enters the power-down ready state, then MCU A cuts off the power and completes the power-down synchronization; If the heartbeat activity status of MCU B is Unknown, it waits for Exception2 (300 milliseconds). After the timeout, MCU A cuts off the power and completes the power-down synchronization.

[0037] The power-down synchronization process of MCU B is the same as that of MCU A.

[0038] Dual-side controller master-slave diagnostics: Master-slave heartbeat frequency table; 1. The master-side heartbeat frequency fMaster ranges from 19.3MHz to 20.6MHz, with an average value of 20MHz; the slave-side heartbeat frequency fSlave ranges from 14.3MHz to 15.6MHz, with an average value of 15MHz. 2. Master-slave judgment: After the system is powered on, MCU A and MCU B negotiate the initial master-slave roles through UART communication. Once the negotiation is successful, the master microcontroller outputs a PWM heartbeat signal according to fMaster, and the slave microcontroller outputs a PWM heartbeat signal according to fSlave. Both sides continuously monitor the PWM heartbeat frequency of the other side to verify whether the master and slave roles are consistent; When a master-slave switching requirement occurs (such as a non-fatal failure of the master-side microcontroller), the original master-side microcontroller switches the PWM frequency to fSlave, and the original slave-side microcontroller switches the PWM frequency to fMaster. The master-slave role switching is completed through frequency change, avoiding abnormal "dual master" or "dual slave" operating conditions. If bilateral UART communication fails, MCU A and MCU B maintain their original master-slave roles by detecting the PWM frequency of the other side, ensuring normal collaborative control output.

[0039] Furthermore, it should be understood that although the terms "first," "second," etc., may be used herein to describe different elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, without departing from the teachings of exemplary embodiments according to the present invention, the first element, component, region, layer, or portion discussed below may also be referred to as the second element, component, region, layer, or portion.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0043] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless explicitly defined herein, terms such as those defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and not as having an idealized or overly formal meaning.

[0044] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for monitoring and diagnosing the activity of a steer-by-wire dual-sided controller, characterized in that, Includes the following steps: S1, the dual-side controller generates a verification PWM signal as a heartbeat signal based on its own activity state and sends it to the other side, while specifying the real-time activity state of the microcontroller represented by different heartbeat signals; S2, calculate bilateral cardiac activity status based on heartbeat signals within a specified window time. S3, after the microcontroller is initialized, calculates and waits for the remote heartbeat activity state, determines the waiting time based on the remote heartbeat activity state, completes power-on synchronization and starts the cycle task; S4, when the microcontroller is preparing to shut down and cut off the power, it calculates and waits for the activity status of the remote side in the periodic loop task, determines the waiting time according to the different heartbeat activity status of the remote side, and completes the power-off synchronization. The dual-side controller has preset master-side frequency and slave-side frequency. It determines the master-slave relationship by calculating the heartbeat frequency of the dual-side controller and adjusts its own heartbeat frequency accordingly when switching between master and slave relationships.

2. The method for monitoring and diagnosing the activity of a steer-by-wire dual-sided controller as described in claim 1, characterized in that: When implementing step S1, two PWM hardware interfaces are configured, which are used for sending and receiving PWM signals from the local microcontroller. The local microcontroller generates a PWM signal of the corresponding frequency according to its own activity state and sends it to the other side as a heartbeat signal. At the same time, it receives the heartbeat signal from the remote microcontroller to monitor the activity state of the remote side.

3. The method for monitoring and diagnosing the activity of a steer-by-wire dual-sided controller as described in claim 2, characterized in that: Four heartbeat activity states are set: Off, Prepare, Wake, and Reset, which respectively represent the real-time activity state of the microcontroller during system power-on, power-off, and operation.

4. The method for monitoring and diagnosing the activity of a steer-by-wire dual-side controller as described in claim 1, characterized in that... Heart rate activity calculation includes: 1) Set the window time Twindow and obtain the far edge counter value at the start of the window time; 2) When the window time ends, obtain the counter value of the other far edge; 3) Calculate the difference between the two edge counter values ​​and convert it to frequency; 4) Compare the calculated frequency with the standard frequency to check frequency stability; 5) Set the stabilization time and wait for the edge counter to stabilize or time out; 6) If the edge counter remains stable during the stabilization period, update the far-edge heartbeat activity status based on the matching result of the calculated frequency and the standard frequency; If the frequency cannot be stabilized or does not match the standard frequency within the stabilization time, report the fault and set the remote activity status to Unknown.

5. The method for monitoring and diagnosing the activity of a steer-by-wire dual-sided controller as described in claim 1, characterized in that: The window time ranges from 1 millisecond to 5 milliseconds, and the anti-shake time ranges from 10 milliseconds to 30 milliseconds.

6. The steer-by-wire dual-side controller activity monitoring and diagnostic method as described in claim 4, characterized in that: Heartbeat activity states are divided into Initial, Alive, and NotAlive states. The calculation of heartbeat activity states includes: Check if there is a timeout fault in the UART communication status of the two-sided controllers. If a timeout occurs, the remote controller is determined to be in an inactive NotAlive state. If the UART communication is normal or the heartbeat activity of the remote controller is not in an unknown state, the remote controller is determined to be in an active Alive state. In the Alive state, the bilateral UART communication status and the remote heartbeat activity status are continuously monitored. If the UART communication times out and the remote heartbeat activity is in the Unknown state, the remote side is determined to be in the NotAlive state and a fault is set. The fault can be recovered when the remote side recovers its active state. In the inactive NotAlive state, the bilateral UART communication status and the remote heartbeat activity status are continuously monitored. If the UART communication is normal or the remote heartbeat activity is not in the Unknown state, the remote side is determined to be in the active Alive state.

7. The method for monitoring and diagnosing the activity of a steer-by-wire dual-side controller as described in claim 3, characterized in that, The power-on synchronization includes: When the remote activity is in the Prepare state, the waiting time is Tpoweron; When the remote activity is in an unknown state, the waiting time is Texception1; When the remote activity is not in the Prepare or Unknown state, power-on synchronization is completed directly.

8. The method for monitoring and diagnosing the activity of a steer-by-wire dual-side controller as described in claim 7, characterized in that, The power-on synchronization includes: The wait time for Tpoweron ranges from 5 to 15 seconds; The waiting time Texception1 ranges from 200 milliseconds to 700 milliseconds.

9. The method for monitoring and diagnosing the activity of a steer-by-wire dual-side controller as described in claim 3, characterized in that, The power-down synchronization includes: When the remote activity state is neither a restarted Rest nor an unknown state, the waiting time Tpoweroff is applied. When the remote activity is in the Unknown state, the waiting time is Texception2.

10. The method for monitoring and diagnosing the activity of a steer-by-wire dual-sided controller as described in claim 9, characterized in that: The waiting time Tpoweroff ranges from 100 seconds to 140 seconds; The waiting time for Texception2 ranges from 100 milliseconds to 500 milliseconds.