Method and apparatus for controlling an electrically driven trailer

Abstract

The application discloses a control method and equipment of an electrically driven trailer, and belongs to the technical field of electrically driven trailer control. The method is applied to an electrically driven trailer. The function domains of the electrically driven trailer include multiple ones in an auxiliary driving function domain, an energy recovery function domain, a power connection and gear execution function domain, and a high-voltage driving enable function domain. The method comprises the following steps: if the current enable state of the function domain represents a function unlimited state, monitoring trailer operation data and trailer operation data; if it is determined that the function domain does not satisfy the safety enable condition corresponding to the function domain according to the trailer operation data and the trailer operation data, migrating the current enable state of the function domain to a target enable state, wherein the target enable state is at least one of multiple different limited degree function limited states; and performing function limitation processing on the function domain based on the target enable state. The method can improve the safety of the electrically driven trailer.

Description

Technical Field

[0001] This application belongs to the field of electric drive trailer control technology, and in particular relates to a control method and equipment for an electric drive trailer. Background Technology

[0002] With the development of electrification and energy-saving and emission-reduction technologies in commercial vehicles, the technical approach of introducing electric drive and regenerative braking at the trailer end has been gradually adopted to improve the power, economy, and energy utilization efficiency of vehicle-trailers. Based on this, electric drive trailers are typically equipped with components such as power batteries, drive motors, motor controllers, electric drive axles, trailer vehicle controllers, high-voltage power distribution systems, and regenerative braking systems. These components can provide auxiliary drive during tractor operation and recover energy during braking or coasting.

[0003] Currently, the fault handling for electric trailers adopts the same vehicle-level fault handling solution as for ordinary new energy vehicles. This means that the severity of the fault is determined based on the vehicle's signals, and uniform restriction measures are taken for the entire vehicle according to the severity of the fault. However, electric trailers are different from ordinary new energy vehicles. Electric trailers are not independently driven vehicles, and some of their functions are affected by the tractor. If the fault handling solution for ordinary new energy vehicles is simply adopted, it will be difficult to fully cover the unique safety issues of electric trailers, thereby affecting the safety of electric trailers. Summary of the Invention

[0004] The embodiments of this application provide a control method and device for an electric-driven trailer, which can at least improve the safety of the electric-driven trailer to a certain extent.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0006] According to a first aspect of the embodiments of this application, a control method for an electric drive trailer is provided, applied to an electric drive trailer. The functional domain of the electric drive trailer includes multiple of the following: auxiliary drive functional domain, energy recovery functional domain, power connection and gear shifting functional domain, and high-voltage drive enabling functional domain. The control method for the electric drive trailer includes: If the current enabled state of a functional domain represents an unrestricted state, then monitor the tractor operating data and trailer operating data. If it is determined from the tractor operation data and trailer operation data that the functional domain does not meet the corresponding safety enabling conditions, then the current enabling state of the functional domain will be migrated to the target enabling state, wherein the target enabling state is at least one of a variety of functionally restricted states with different degrees of restriction. Functional domains are subject to functional restrictions based on the target enable state.

[0007] In some embodiments, transitioning the current enabled state of a functional domain to a target enabled state includes: Based on at least one of the following: unmet sub-conditions in the security enable conditions corresponding to the functional domain, duration of non-compliance with the security enable conditions, and degree of deviation from the security enable conditions, the current enable state of the functional domain is migrated to the target enable state.

[0008] In some embodiments, the functional domain is an auxiliary driver functional domain, and the security enable conditions corresponding to the auxiliary driver functional domain include: The following conditions must be met: reliable tractor operation data; effective driving intention of the tractor; acceleration intensity of the tractor exceeding the preset intensity threshold; main and trailer attitude within the allowable attitude range of auxiliary drive; speed consistency between the tractor and trailer; controllable trailer motor controller; allowable battery discharge power exceeding the preset drive demand power threshold; controllable trailer clutch; controllable trailer power connection actuator; and trailer not in braking state.

[0009] In some embodiments, the control method for an electrically driven trailer further includes: If the tractor's operating data meets the preset credibility judgment conditions, then the tractor's operating data is determined to be credible. The preset credibility judgment conditions include one or more of the following: timeout judgment condition, boundary crossing judgment condition, jump judgment condition, counter stability judgment condition, valid bit judgment condition, and logic conflict judgment condition.

[0010] In some embodiments, multiple functional restriction states with different levels of restriction include a restricted enable state, a temporary exit state, and a locked state with progressively increasing restriction levels. Functional restriction processing of the functional domain is performed based on the target enable state, including: If the target enable state is a restricted enable state, then reduce the upper limit of the auxiliary drive torque or reduce the upper limit of the auxiliary drive torque change rate. If the target enable state is temporarily off, then the auxiliary drive request command is blocked and the auxiliary drive target torque is set to zero; If the target enable state is locked, then control the electric drive trailer to enter neutral or de-energize.

[0011] In some embodiments, the functional domain is an energy recovery functional domain, and the safety enable conditions corresponding to the energy recovery functional domain include: The tractor braking status is reliable, the trailer electronic braking system (EBS) status is reliable, the trailer battery management system (BMS) status is reliable, the trailer anti-lock braking system (ABS) trigger status is not triggered, the battery's allowable charging power is greater than the preset recovery power threshold, the motor controller's allowable recovery torque and the trailer's electronic stability control system function are not triggered.

[0012] In some embodiments, multiple functionally restricted states with different levels of restriction include a restricted enable state and a temporary exit state with progressively increasing levels of restriction. Functional restriction processing of the functional domain is performed based on the target enable state, including: If the target enable state is a restricted enable state, then reduce the upper limit of the recovery torque or the upper limit of the recovery torque change rate. If the target enable state is temporarily off, reduce the recovery torque and set the recovery target torque to zero.

[0013] In some embodiments, the functional domain is the power connection and gear shifting functional domain, and the safety enabling conditions corresponding to the power connection and gear shifting functional domain include: The trailer clutch is reliable, the trailer is in neutral, the power connection actuator is in normal condition, and when the trailer power system includes a multi-speed electric drive axle, the motor speed, trailer speed, and the speed corresponding to the target gear of the multi-speed electric drive axle meet the preset synchronization conditions.

[0014] In some embodiments, multiple functionally restricted states with different levels of restriction include a temporary exit state and a locked state with progressively increasing levels of restriction. Functional restriction processing of the functional domain is performed based on the target enable state, including: If the target enable state is temporarily off, then gear engagement or power connection is prohibited, and the electric drive trailer is controlled to enter neutral. If the target enable state is locked, then the high voltage of the control electric drive trailer is de-energized.

[0015] In some embodiments, the functional domain is a high-voltage drive enable functional domain, and the safety enable conditions corresponding to the high-voltage drive enable functional domain include: The trailer BMS status and communication are normal, the trailer vehicle controller status and communication are normal, the high voltage system status and communication are normal, the trailer insulation status is normal, the trailer is not in a prohibited driving state, and the trailer drive enable feedback command and drive enable request command are consistent.

[0016] In some embodiments, multiple functionally restricted states with different degrees of restriction include a locked state, and the transition from the current enabled state of a functional domain to a target enabled state includes: Transition the current enabled state to the locked state.

[0017] In some embodiments, functional domains are subject to functional restriction processing based on target enable states, including: If the target enable state is locked, the high voltage of the electric drive trailer is de-energized, and auxiliary drive and energy recovery are prohibited.

[0018] In some embodiments, the multiple functionally restricted states with different levels of restriction include a restricted enable state and a temporary exit state with progressively increasing levels of restriction. The method further includes: If the target enable state is a temporary exit state and the functional domain meets the first recovery condition, then it will transition from the temporary exit state to the restricted enable state. If the functional domain meets the second recovery condition and the functional domain meets the corresponding security enable condition within a preset time period, it will transition from the restricted enable state to the unrestricted function state.

[0019] According to a second aspect of the embodiments of this application, a control device for an electric drive trailer is provided, including a processor and a memory. The memory stores computer program instructions that can be executed by the processor. When the processor executes the computer program instructions, it implements the steps of the method described in any of the first aspects above.

[0020] In this application, the functional domains of the electric drive trailer are divided into multiple domains, including auxiliary drive, energy recovery, power connection and gear shifting, and high-voltage drive enable. For each functional domain, when the current enable state of the functional domain represents an unrestricted state, the system combines the tractor's operating data and the trailer's operating data to determine whether each functional domain meets the corresponding safety enable conditions. This allows for a comprehensive assessment of whether any safety issues exist in each functional domain. When a functional domain does not meet the safety enable conditions, its current enable state is migrated to a target enable state where the function is restricted. Based on the target enable state, the corresponding functions of the functional domain are subject to targeted restrictions. This avoids the safety risks caused by applying uniform restrictions to the entire vehicle, thereby improving the safety of the electric drive trailer.

[0021] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 An architecture diagram of a control system for an electric-driven trailer according to some embodiments of this application is shown; Figure 2 A flowchart illustrating a control method for an electric-driven trailer according to some embodiments of this application is shown; Figure 3 A schematic diagram of the structure of a control device for an electric-driven trailer according to some embodiments of this application is shown; Explanation of icon numbers: 1-Tractor; 2-Main-trailer communication interface module; 3-Trailer vehicle controller; 4-Judgment unit; 5-Trailer operation data acquisition module; 6-Functional domain state machine control unit; 7-Auxiliary drive execution module; 8-Energy recovery execution module; 9-Power connection and gear execution module; 10-High voltage drive enable module; 11-Alarm recording module. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0025] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0026] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0027] To enable those skilled in the art to better understand this application, the application scenarios involved in this application will be briefly described first.

[0028] This application applies to electric-drive trailers. Unlike ordinary new energy vehicles, electric-drive trailers are not independently driven vehicles; some of their functions are affected by the tractor. Simply applying the fault handling solutions for ordinary new energy vehicles, determining the severity of the fault solely based on the vehicle's signals, and then imposing uniform restrictions on the entire vehicle according to the severity of the fault, would be insufficient to fully cover the unique safety issues of electric-drive trailers. For example, when the main-trailer articulation angle or the draw pin angle is too large, continued auxiliary drive output by the trailer may exacerbate the instability of the main-trailer posture, even increasing the risk of folding, understeer, or fishtailing. Such situations are usually best handled by limiting torque or temporarily disengaging the auxiliary drive. During gear shifting or power connection, the trailer may experience brief periods of neutral or power disconnection. If the tractor continues to accelerate, it may cause a missynchronization between the trailer's motor speed, vehicle speed, and the target gear, resulting in problems such as gear grinding, inability to engage the target gear, or power connection shock. Furthermore, when the tractor does not indicate a driving intention or is in a state of... When stationary, if the trailer experiences motor drive output due to controller malfunction, drive enable malfunction, upgrade process malfunction, or other reasons, it may create unexpected drive risks. Such situations are considered high-risk and uncontrollable, requiring the trailer to enter a safety lockout state. When the trailer speed or wheel speed exceeds the tractor speed, continued auxiliary drive output by the trailer may cause the trailer to push the tractor, reducing the coordination between the tractor and trailer. Such situations should be handled by limiting torque or temporarily disengaging auxiliary drive, and should not be simply equated with system failure. When the braking force is large and the trailer's Anti-lock Braking System (ABS) is activated, if the trailer simultaneously maintains high energy recovery torque, it may affect the ABS's control over wheel slip ratio, which is detrimental to braking stability. Therefore, energy recovery should be disengaged promptly when ABS is activated or braking stability control intervenes. When the tractor's transmitted signal experiences timeout, boundary violation, jump, or logical conflict, if the trailer continues to output drive or recover torque according to normal logic, it may cause mis-drive, mis-recovery, or uncoordinated braking between the main and trailer power systems.

[0029] Based on this, the inventors proposed a safety control scheme that differs from the fault classification and handling of ordinary new energy vehicles. This scheme divides the functional domain of the electric drive trailer into multiple domains, including auxiliary drive functional domain, energy recovery functional domain, power connection and gear execution functional domain, and high-voltage drive enable functional domain. Based on the safety enable conditions of different functional domains, tractor operation data, and trailer operation data, it determines whether the function of each functional domain should continue to work, whether functional restrictions are required, and the degree of restriction.

[0030] Figure 1 An architecture diagram of a control system for an electric-driven trailer according to some embodiments of this application is shown. Figure 1As shown, the control system of the electric drive trailer may include a tractor 1, a main-trailer communication interface module 2, a trailer vehicle controller 3, a trailer operation data acquisition module 5, an auxiliary drive execution module 7, an energy recovery execution module 8, a power connection and gear execution module 9, a high-voltage drive enable module 10, and an alarm recording module 11. The trailer vehicle controller 3 may include a judgment unit 4 and a functional domain state machine control unit 6.

[0031] Among them, the main trailer communication interface module 2 is used to receive the tractor's operation data transmitted from the tractor to the trailer.

[0032] The main mount communication interface module 2 includes, but is not limited to, the main mount electrical connector, bus communication interface, discrete signal acquisition interface, electronic braking system (EBS) communication interface, ABS communication interface, interface power supply detection circuit, interface grounding detection circuit, and communication status monitoring circuit.

[0033] The tractor operating data may include one or more of the following: tractor wheel speed, tractor vehicle speed, tractor acceleration intensity (determined by accelerator pedal opening), tractor braking intensity (determined by brake pedal opening), tractor lighting data, steering wheel angle, ABS trigger status, EBS braking request or braking data, ignition or power-on status, communication validity flag, message counter, timestamp or refresh flag, and other data used to determine the tractor's driving intention and vehicle status.

[0034] The tractor unit's lighting data can include brake light data, turn signal data, reversing light data, hazard warning light data, or other lighting data related to driving intent. The trailer's overall controller can use this lighting data as supplementary information, along with acceleration intensity, braking intensity, steering wheel angle, and vehicle speed, to determine the tractor unit's driving intent and current driving conditions.

[0035] The trailer controller 3 can be used to receive tractor operation data and trailer operation data, and perform status verification, functional domain state transition, function limitation, and recovery control.

[0036] The trailer operation data acquisition module 5 is used to collect trailer operation data, which may include one or more of the following: tow pin rotation angle, main-trailer articulation angle, trailer wheel speed, estimated trailer speed, motor speed, actual motor output torque, motor target torque, battery state of charge (SOC), battery allowable discharge power, battery allowable charging power, battery temperature, battery management system (BMS) status, motor controller status, high voltage system status, clutch status, neutral status, gear or shift status, power connection actuator status, trailer ABS trigger status, trailer braking pressure or braking status, trailer yaw rate, trailer longitudinal acceleration, trailer lateral acceleration, trailer attitude, and other data used to determine the trailer's motion status, power system status, or braking stability status.

[0037] The auxiliary drive execution module 7 can be used to control the auxiliary drive according to the control commands of the trailer's overall controller. This module may include a power battery, BMS, high-voltage power distribution unit, motor controller, drive motor, electric drive axle, reducer, drive shaft, drive enable circuit, torque output control circuit, etc. It can be understood that the auxiliary drive functional domain is the set of functions corresponding to the auxiliary drive execution module.

[0038] The energy recovery execution module 8 can be used to control the drive motor to enter the power generation state when the trailer meets the conditions for entering energy recovery, thereby realizing braking energy recovery. This module may include a motor controller, drive motor, power battery, BMS, high-voltage power distribution unit, recovery torque control unit, battery rechargeable power calculation unit, and braking state interface. It can be understood that the energy recovery functional domain is the set of functions corresponding to the energy recovery execution module.

[0039] The power connection and gear shifting module 9 can be used to control the power connection status between the trailer's electric drive system and the wheels. This module may include a clutch, neutral gear mechanism, gear shifting mechanism, gear position sensor, neutral confirmation switch, clutch status sensor, electric drive axle, reducer, and related execution control circuits. It can be understood that the power connection and gear shifting functional domain is the set of functions corresponding to the power connection and gear shifting module.

[0040] In embodiments where the electric drive axle has a multi-gear structure, the power connection and gear execution module is also used to perform target gear engagement, gear shift synchronization, and gear status confirmation; in embodiments where the electric drive axle has a single-gear structure, gear shift synchronization detection may not be performed.

[0041] The high-voltage drive enable module 10 can be used to control whether the trailer's high-voltage drive system allows the motor controller to provide drive output conditions. This module may include a BMS, a high-voltage power distribution unit, a high-voltage relay, an insulation monitoring unit, a high-voltage interlock circuit, a drive enable circuit, and a high-voltage power-off control circuit. It can be understood that the high-voltage drive enable functional domain is the set of functions corresponding to the high-voltage drive enable module.

[0042] The alarm recording module 11 is used to record information such as event type, triggering condition, confirmation time, functional domain status, state transition path and recovery process when the functional domain enters a restricted, exit or locked state. It can also output alarm information or fault codes to the driver, instrument, remote monitoring platform or maintenance and diagnostic equipment. The alarm recording module can also be used to record drive prohibition states during upgrade, maintenance or debugging to prevent the trailer from having unexpected drives during software maintenance, remote upgrade or debugging.

[0043] Figure 2 A flowchart illustrating a control method for an electrically driven trailer according to some embodiments of this application is shown. Figure 2 As shown, a control method for an electrically driven trailer is provided. Taking the application of this method to the trailer's overall controller as an example, the method may include the following steps: Step 201: If the current enabled state of the functional domain represents an unrestricted function, then monitor the tractor operation data and trailer operation data. Step 202: If it is determined from the tractor running data and trailer running data that the functional domain does not meet the corresponding safety enabling conditions, then the current enabling state of the functional domain is migrated to the target enabling state, wherein the target enabling state is at least one of a variety of functionally restricted states with different degrees of restriction. Step 203: Perform functional restriction processing on the functional domain based on the target enable state.

[0044] The enabling states of a functional domain can include an unrestricted state and various restricted states with different degrees of restriction. In some embodiments, the unrestricted state is also referred to as the normal enabling state, and the various restricted states with different degrees of restriction include a restricted enabling state with increasing levels of restriction, a temporary exit state, and a locked state. The meanings of each enabling state are shown in Table 1 below: Table 1

[0045] In step 201, the trailer vehicle controller can monitor each functional domain according to a preset detection cycle to determine the current enabling state of the functional domain. The detection cycles of different functional domains can be the same or different. The specific detection cycle can be set according to the trailer control cycle, communication message cycle and actuator response characteristics. This application does not impose any restrictions on this.

[0046] The trailer controller can obtain the tractor's operating data through the main-trailer communication interface module. The tractor's operating data includes, but is not limited to, tractor wheel speed, tractor vehicle speed, tractor acceleration intensity, tractor braking intensity, tractor light status, steering wheel angle, ABS trigger status, EBS status, communication validity flag, message counter, and timestamp.

[0047] The trailer controller acquires trailer operating data through the trailer operating data acquisition module. The trailer operating data includes, but is not limited to, the towing pin angle, the main trailer articulation angle, the trailer wheel speed, the estimated trailer speed, motor data, battery data, BMS status, motor controller status, high voltage system status, clutch status, neutral status, gear or shift status, power connection actuator status, trailer ABS trigger status, and trailer braking pressure or braking status.

[0048] The trailer controller can preprocess the tractor and trailer operating data. Preprocessing includes, but is not limited to, filtering, de-jittering, amplitude limiting, time synchronization, unit conversion, missing value marking, signal refresh status recording, message counter verification, and storage of current and historical values.

[0049] In step 202, if it is determined from the tractor running data and trailer running data that the functional domain does not meet the corresponding safety enable conditions, the trailer vehicle controller can migrate the current enable state of the functional domain to the target enable state.

[0050] Understandably, different functional domains have different safety enable conditions. The trailer controller can determine whether a functional domain meets the corresponding safety enable conditions based on the tractor's operating data and the trailer's operating data. If a functional domain does not meet the corresponding safety enable conditions, when the tractor's operating data and the trailer's operating data meet different conditions, the trailer controller can either transition the functional domain's enable state from the normal enable state to a restricted enable state, a temporary deactivation state, or a locked state all at once, or it can transition from the normal enable state to the restricted enable state, then from the restricted enable state to the temporary deactivation state, and finally from the temporary deactivation state to the locked state.

[0051] During the state transition process, the current enabled state of the functional domain can be transitioned to the target enabled state based on at least one of the following: unmet sub-conditions in the security enable conditions corresponding to the functional domain, duration of non-compliance with the security enable conditions, and degree of deviation from the security enable conditions.

[0052] In some embodiments, the safety enabling conditions corresponding to the auxiliary drive functional domain include: reliable tractor operating data, the tractor having a valid driving intention, the tractor's acceleration intensity being greater than a preset intensity threshold, the main and trailer attitudes being within the allowable attitude range of the auxiliary drive, the tractor and trailer meeting the speed consistency condition, the trailer motor controller being controllable, the battery's allowable discharge power being greater than a preset drive demand power threshold, the trailer clutch being controllable, the trailer power connection actuator being controllable, and the trailer not being in a braking state.

[0053] The auxiliary drive functional domain mainly focuses on whether the tractor's operating data is reliable, whether the tractor-trailer posture is safe, and whether the tractor-trailer speeds are consistent.

[0054] The reliability of the tractor operation data can be determined in the following way: if the tractor operation data meets the preset reliability judgment conditions, then the tractor operation data is determined to be reliable. The preset reliability judgment conditions include one or more of the following: timeout judgment conditions, boundary judgment conditions, jump judgment conditions, counter stability judgment conditions, valid bit judgment conditions, and logic conflict judgment conditions.

[0055] Specifically, the timeout judgment condition can be that the tractor's operating data is refreshed within a preset time window; the boundary judgment condition can be that the tractor's operating data does not exceed the physically reasonable range; the jump judgment condition can be that the rate of change of each state value in the tractor's operating data does not exceed the preset rate of change; the counter stability judgment condition can be that the message counter is continuous and does not repeat; the valid bit judgment condition can be that the communication valid flag is valid; and the logical conflict judgment condition can be that there is no contradiction between acceleration intensity and braking intensity, vehicle speed and wheel speed, braking intensity and ABS status, light status and braking status, light status and steering status, tractor speed and trailer wheel speed, estimated values ​​of tractor wheel speed and trailer speed, and no obvious inconsistency between the acceleration or braking intensity of the tractor and the wheel speed of the trailer.

[0056] By judging the reliability of the tractor's operating data, it is possible to prevent the trailer from continuing to output unreasonable drive or recover torque when the tractor's wheel speed, vehicle speed, acceleration intensity, braking intensity, lights, steering wheel angle, and ABS status are unreliable. By judging the attitude of the tractor and trailer and the speed consistency between the tractor and trailer, the auxiliary drive function can be restricted or disengaged in a timely manner when the attitude of the tractor and trailer is unfavorable or the speed is inconsistent, thereby improving the safety of the trailer.

[0057] During implementation, the presence of a tractor with a valid driving intention can be determined based on the tractor pedal signal in the tractor's operating data. The tractor-trailer attitude refers to the articulation angle between the trailer and the tractor, which can be determined by the towing pin angle or estimated by a combination of steering wheel angle and speed. The trailer motor controller can be determined to be controllable when the motor controller is in normal condition. The trailer clutch can be determined to be controllable when the trailer clutch is in normal condition. The trailer power connection actuator can be determined to be controllable when the trailer power connection actuator is in normal condition.

[0058] Understandably, if the tractor's operating data and the trailer's operating data meet all the conditions corresponding to the auxiliary drive functional domain, then the auxiliary drive functional domain is determined to meet the safety enabling conditions; otherwise, the auxiliary drive functional domain is determined not to meet the safety enabling conditions.

[0059] The state transition rules for the auxiliary driver functional domain can be referenced as follows: 1. The unmet sub-condition in the safety enabling conditions is that the tractor's driving intention is unreliable. Detection period: can be set to be consistent with the communication message period of the main device, typically 10ms to 50ms.

[0060] Testing conditions: The tractor and trailer have established a communication connection, the auxiliary drive function domain is in S0 or S1 state, and the trailer is receiving data such as tractor wheel speed, tractor speed, acceleration intensity, braking intensity, light status, and steering wheel angle.

[0061] Confirmation conditions: The tractor vehicle speed, tractor wheel speed, acceleration intensity, braking intensity, or steering wheel angle exceeds the time limit, goes out of bounds, jumps, message counter is abnormal, valid bit is abnormal, or logic conflict occurs, and continues to exceed the first confirmation time.

[0062] State transition rules: When the data related to the tractor's driving intention (tractor speed, tractor wheel speed, acceleration intensity, braking intensity, or steering wheel angle) is abnormal for a short time, the enabling state of the auxiliary drive functional domain switches from S0 to S1; when the data related to the tractor's driving intention is abnormal for a continuous period, the enabling state of the auxiliary drive functional domain switches from S1 to S2; when multiple data related to the tractor's driving intention are abnormal at the same time, causing the trailer to be unable to confirm the tractor's driving intention, and there is a risk of unexpected driving, abnormal drive enabling, or uncontrollable actuator, the auxiliary drive functional domain switches from state S0, S1, or S2 to state S3.

[0063] 2. The sub-condition that is not met in the safety enable condition is that the main mount's attitude is not within the range of the auxiliary drive's allowed attitude. Detection period: can be set to 10ms to 20ms.

[0064] Detection conditions: The auxiliary drive functional domain is in state S0 or S1 and the main mount attitude can be determined.

[0065] Confirmation conditions: The master attitude exceeds the first attitude threshold and continues to exceed the second confirmation time; or exceeds the second attitude threshold and continues to exceed the second confirmation time.

[0066] State transition rules: When the master attitude exceeds the first attitude threshold, the auxiliary drive functional domain switches from state S0 to state S1; when the master attitude exceeds the second attitude threshold, the auxiliary drive functional domain switches from state S1 to state S2.

[0067] 3. The unmet sub-condition in the safety enabling conditions is that the tractor and trailer do not meet the speed consistency condition. Detection period: can be set to 10ms to 20ms.

[0068] Detection conditions: The tractor vehicle speed or tractor wheel speed is reliable, the trailer wheel speed or estimated trailer speed is valid, and the auxiliary drive functional domain is in state S0 or S1.

[0069] Confirmation conditions: The trailer speed is greater than the tractor speed, and the speed difference exceeds the first speed difference threshold and continues to exceed the third confirmation time; or the speed difference exceeds the second speed difference threshold and continues to exceed the third confirmation time.

[0070] State transition rules: When the speed difference exceeds the first speed difference threshold, the auxiliary drive function domain switches from S0 to S1; when the speed difference exceeds the second speed difference threshold, the auxiliary drive function domain switches from S1 to S2.

[0071] In some embodiments, the safety enabling conditions corresponding to the energy recovery functional domain include: reliable tractor braking status, reliable trailer EBS status, reliable trailer BMS status, trailer ABS trigger status is not triggered, battery allowable charging power is greater than the preset recovery power threshold, motor controller allowable recovery torque, and trailer body electronic stability control system function is not triggered.

[0072] The energy recovery functional domain primarily focuses on the reliability of braking status, EBS status, BMS status, and battery charging capacity. The tractor braking status can include both the tractor braking intensity and the tractor brake light status.

[0073] Understandably, if the tractor operating data and trailer operating data meet all the conditions corresponding to the energy recovery functional domain, then the energy recovery functional domain is determined to meet the safety enabling conditions; otherwise, the energy recovery functional domain is determined not to meet the safety enabling conditions.

[0074] The state transition rules for the energy recovery functional domain can be referenced as follows: 1. The unmet sub-condition in the safety enabling condition is that the tractor braking state or EBS state is unreliable. Detection period: can be set from 10ms to 50ms.

[0075] Detection conditions: The energy recovery functional domain is in state S0, S1, or S2, and the trailer is receiving information about the tractor's braking intensity, tractor brake light status, and EBS status.

[0076] Confirmation conditions: The tractor braking strength, tractor brake light status, EBS status, or brake request signal timeout, out-of-bounds, jump, valid bit abnormality, or logic conflict occurs and continues for more than the fourth confirmation time.

[0077] State transition rules: If braking-related data (tractor braking intensity, tractor brake light status, EBS status, brake request signal) is temporarily unreliable, the energy recovery function domain switches from S0 to S1; if braking-related data is continuously unreliable, the energy recovery function domain switches from S1 to S2; if braking-related data is unreliable and there is also uncontrollable recovery actuator or high-voltage system malfunction, the energy recovery function domain can switch to S3 together with the high-voltage drive enable function domain.

[0078] 2. The sub-conditions that are not met in the safety enabling conditions are: the trailer ABS is not in the triggered state or the trailer braking stability is affected by the regenerative torque. Detection period: can be set to 10ms.

[0079] Testing conditions: The energy recovery functional domain is in state S0 or S1, and the trailer is in braking or coasting recovery mode.

[0080] Confirmation conditions: The trailer's ABS is detected as triggered, or the trailer's braking stability is affected by regenerative torque. For ABS trigger status, confirmation can be made immediately after a single effective trigger.

[0081] State transition rule: The energy recovery functional domain directly switches from state S0 or S1 to state S2.

[0082] By promptly disengaging energy recovery when the trailer's ABS is not activated or when the trailer's braking stability is affected by the regenerative torque, the impact of the regenerative torque on the anti-lock braking system can be avoided.

[0083] 3. The sub-condition that is not met in the safety enabling conditions is that the battery's allowable charging power is less than the preset recycling power threshold. Detection period: can be set to 50ms~100ms.

[0084] Detection conditions: The energy recovery function domain is in state S0, S1 or S2, and the trailer BMS provides feedback on the battery's allowable charging power or charging limit status.

[0085] Confirmation conditions: The battery's allowable charging power is less than the preset recycling power threshold, the BMS data is unreliable, and this condition persists for more than the fifth confirmation time.

[0086] State transition rules: When the battery's allowable charging power is less than the preset recovery power threshold, the energy recovery function domain switches from state S0 to state S2; when the BMS communication is severely abnormal and affects the high voltage safety judgment, the high voltage drive enable function domain can enter state S3.

[0087] In some embodiments, the safety enable conditions corresponding to the power connection and gear execution functional domain include: the trailer clutch is in a reliable state, the trailer is in neutral, the power connection actuator is in a normal state, and when the trailer power system includes a multi-speed electric drive axle, the motor speed, the trailer speed, and the speed corresponding to the target gear of the multi-speed electric drive axle meet preset synchronization conditions.

[0088] It is understandable that shift synchronization detection is only required if the trailer power system includes a multi-speed electric drive axle; if the trailer power system includes a single-speed electric drive axle, then shift synchronization detection is not required.

[0089] If the tractor's operating data and the trailer's operating data meet all the conditions corresponding to the power connection and gear execution functional domain, then the power connection and gear execution functional domain is determined to meet the safety enabling conditions; otherwise, the power connection and gear execution functional domain is determined not to meet the safety enabling conditions.

[0090] The state transition rules for the power connection and gear shifting functional domains can be referenced as follows: 1. The sub-condition that is not met in the safety enabling conditions is that the trailer is in neutral or the power connection actuator is in an abnormal state. Detection period: can be set from 10ms to 50ms.

[0091] Testing conditions: The vehicle is powered on, and the trailer's overall controller can detect the neutral or power connection status.

[0092] Confirmation conditions: The neutral state cannot be confirmed, the power connection status is abnormal, or the power connection actuator is uncontrollable, and this condition persists for more than the sixth confirmation time.

[0093] State transition rules: When the neutral state cannot be reliably confirmed or the power connection state is abnormal, the power connection and gear execution function domain switches from state S0 to state S2; when the power connection cannot be disconnected or the neutral state cannot be confirmed at all, the power connection and gear execution function domain switches to state S3.

[0094] 2. The sub-condition that is not met in the safety enabling conditions is that the motor speed and the speed corresponding to the target gear of the multi-speed electric drive bridge do not meet the preset synchronization condition. Detection cycle: can be set to 10ms or the same as the shift control cycle.

[0095] Detection conditions: There is an auxiliary drive request, and the trailer needs to perform a gear shifting or gear changing action.

[0096] Confirmation conditions: The difference between the motor speed and the speed corresponding to the target gear exceeds the synchronization threshold and continues to exceed the seventh confirmation time; or the tractor continues to accelerate, causing the synchronization window to fail to form.

[0097] State transition rules: When the speed difference exceeds the synchronization threshold and is continuously confirmed, the functional domain switches from state S0 to state S2; the functional domain only enters state S3 when the shift actuator is uncontrollable, the gear feedback is abnormal and the neutral state cannot be confirmed.

[0098] In some embodiments, the safety enable conditions corresponding to the high-voltage drive enable function domain include: trailer BMS status and communication are normal, trailer vehicle controller status and communication are normal, high-voltage system status and communication are normal, trailer insulation status is normal, trailer is not in a prohibited drive state, and trailer drive enable feedback instruction is consistent with drive enable request instruction.

[0099] The high-voltage drive enable functional domain mainly focuses on BMS, trailer vehicle controller, high-voltage system, insulation, contactor, drive status, etc.

[0100] If the tractor running data and trailer running data meet all the conditions corresponding to the high-voltage drive enable functional domain, then the high-voltage drive enable functional domain is determined to meet the safety enable conditions; otherwise, the high-voltage drive enable functional domain is determined not to meet the safety enable conditions.

[0101] The state transition rules for the high-voltage drive enable functional domain can be referenced as follows: 1. The sub-conditions that are not met in the safety enabling conditions are: the trailer drive enable feedback command and the drive enable request command are inconsistent; the trailer vehicle controller is in an abnormal state; or the trailer is in a prohibited driving state. Detection period: can be set to 10ms or the same as the driver enable monitoring period.

[0102] Testing conditions: The trailer is powered on, and the trailer's overall controller can obtain drive enable commands, drive enable feedback, target motor torque, and actual motor torque.

[0103] Confirmation conditions: The trailer drive enable feedback command and the drive enable request command are inconsistent; the motor target torque is zero but the actual torque is not zero; the trailer vehicle controller is uncontrollable; or the vehicle is in a prohibited drive state but the drive enable is abnormally turned on.

[0104] State transition rule: The high-voltage drive enable functional domain directly switches from state S0, S1 or S2 to state S3.

[0105] 2. The unmet sub-condition in the safety enabling condition is an abnormal state of the high-voltage system or an abnormal state of the trailer insulation. Detection period: can be set to 50ms~100ms.

[0106] Testing conditions: The trailer is in a state of high voltage power-on, driving, energy recovery, or auxiliary drive, and the status of the BMS, high voltage power distribution unit, insulation monitoring unit, or contactor can be obtained.

[0107] Confirmation criteria: Abnormal trailer insulation, abnormal contactor status, abnormal high-voltage interlock, serious BMS malfunction, abnormal high-voltage voltage, or unreliable high-voltage system status are detected and persist for more than the eighth confirmation time. For serious high-voltage safety risks, direct confirmation is possible.

[0108] State transition rule: The high-voltage drive enable function domain switches from state S0, S1 or S2 to state S3.

[0109] In step 203, the trailer vehicle controller can perform functional restriction processing on the functional domain based on the target enable state.

[0110] It is understandable that when the target enable state is in a functionally restricted state with different degrees of restriction, the vehicle controller's operation for functional restriction processing of the functional domain and the subsequent recovery operation will also be different.

[0111] It should be noted that when the functional domain enters the locked state, the trailer enters the safe state by shifting to neutral or by cutting off the high voltage, and does not automatically return to the temporary exit state, restricted enable state, or normal enable state through the control program.

[0112] In some embodiments, the functional restriction processing for the auxiliary drive functional domain includes: if the target enable state is a restricted enable state, then reducing the upper limit of the auxiliary drive torque or reducing the upper limit of the auxiliary drive torque change rate; if the target enable state is a temporary exit state, then blocking the auxiliary drive request command and setting the auxiliary drive target torque to zero; if the target enable state is a locked state, then controlling the electric drive trailer to enter neutral or de-energize.

[0113] Taking the unmet sub-condition of the safety enabling condition being that the tractor's driving intention is unreliable as an example, the function restriction handling method can be referred to as follows: In S1 state, reduce the upper limit of the auxiliary drive torque or reduce the upper limit of the auxiliary drive torque change rate; in S2 state, set the auxiliary drive target torque to zero and prohibit new auxiliary drive requests; in S3 state, control the electric drive trailer to enter neutral state or execute high voltage power-off, and record high-level events.

[0114] Taking the example that the sub-condition of the safety enable condition is that the main mount attitude is not within the allowable attitude range of the auxiliary drive, the function limitation handling method can be referred to as follows: In the S1 state, the upper limit of the auxiliary drive torque is gradually reduced according to the attitude risk level, and the rate of change of the auxiliary drive torque is limited; in the S2 state, the target torque of the auxiliary drive is set to zero, new auxiliary drive requests are prohibited, but high voltage power-down is not performed.

[0115] Taking the unmet sub-condition in the safety enabling condition as an example that the tractor and trailer do not meet the speed consistency condition, the function restriction handling method can be referred to as follows: In S1 state, reduce the upper limit of the auxiliary drive torque; in S2 state, set the auxiliary drive target torque to zero and prohibit the auxiliary drive output; if there is a braking request at the same time, the energy recovery functional domain and braking stability condition should be used to determine whether restricted recovery is allowed.

[0116] In some embodiments, the functional limitation processing for the energy recovery functional domain includes: if the target enable state is a restricted enable state, then reducing the upper limit value of the recovery torque or the upper limit value of the recovery torque change rate; if the target enable state is a temporary exit state, then reducing the recovery torque and setting the recovery target torque to zero.

[0117] Taking the example of a sub-condition that is not met in the safety enabling conditions, namely, the tractor braking state or the EBS state is unreliable, the function limitation handling method can be referred to as follows: In the S1 state, reduce the upper limit of the regenerative torque; in the S2 state, quickly reduce the regenerative torque to zero and prohibit the generation of regenerative torque based on the unreliable braking state; in the S3 state, execute high voltage power-off.

[0118] Taking the unmet sub-conditions in the safety enabling conditions as an example, such as the trailer ABS being in the triggered state or the trailer braking stability being affected by the regenerative torque, the functional restriction handling method can be referred to as follows: quickly reduce the regenerative torque to zero, prohibit energy recovery from participating in the current braking process, and prioritize ensuring that the ABS or braking stability control adjusts the wheel slip state.

[0119] Taking the unmet sub-condition of the safety enabling condition, which is that the battery's allowable charging power is less than the preset recovery power threshold, as an example, the function limitation processing method can be referred to as follows: In state S1, the recovery torque is limited to the range corresponding to the battery's allowable charging power; in state S2, the recovery target torque is set to zero; record the battery limitation state and the recovery exit state.

[0120] In some embodiments, the functional restriction processing for the power connection and gear execution functional domain includes: if the target enable state is a temporary disengagement state, then gear engagement or power connection is prohibited, and the electric drive trailer is controlled to enter neutral; if the target enable state is a lock-up state, then the electric drive trailer is controlled to de-energize.

[0121] Taking the unmet sub-condition of the safety enabling condition being the abnormal state of the trailer in neutral or the abnormal state of the power connection actuator as an example, the function restriction handling method can be referred to as follows: In S2 state, gear engagement or power connection is prohibited, and the electric drive trailer is controlled to enter the neutral state; in S3 state, high voltage is cut off.

[0122] Taking the example that the sub-conditions of the safety enable conditions are not met, namely that the motor speed and the speed corresponding to the target gear of the multi-gear electric drive bridge do not meet the preset synchronization conditions, the function restriction handling method can be referred to as follows: In S2 state, gear engagement is prohibited, neutral is maintained, and auxiliary drive output is prohibited; in S3 state, high voltage power-off is performed.

[0123] In some embodiments, the functional restriction processing for the high-voltage drive enable functional domain includes: if the target enable state is a locked state, controlling the high voltage of the electric drive trailer to be de-energized and disabling auxiliary drive and energy recovery.

[0124] Taking the unmet sub-conditions in the safety enable conditions as an example, such as the trailer drive enable feedback command and drive enable request command being inconsistent, the trailer vehicle controller being in an abnormal state, or the trailer being in a prohibited drive state, the function restriction handling method can be referred to as follows: In S3 state, execute high voltage power down, prohibit auxiliary drive and energy recovery, and output a high-level alarm.

[0125] Taking the unmet sub-condition of the safety enabling condition being an abnormal high-voltage system state or an abnormal trailer insulation state as an example, the function restriction handling method can be referred to as follows: In S3 state, turn off drive enable, execute high-voltage power-off, disable auxiliary drive and energy recovery functions, and record high-level faults.

[0126] After the functional limitation is handled, for states S0, S1, and S2, the functional domain can adopt a step-by-step transition mechanism. For state S3, it needs to be re-detected after the trailer is powered on and will not automatically transition to other states.

[0127] In some embodiments, if the target enable state is a temporary exit state and the functional domain meets the first recovery condition, then the state transitions from the temporary exit state to the restricted enable state; if the functional domain meets the second recovery condition and the functional domain meets the corresponding security enable condition within a preset time period, then the state transitions from the restricted enable state to the unrestricted function state.

[0128] The first recovery condition may include: the tractor's operating data refreshes normally for multiple consecutive detection cycles; key data such as tractor speed, tractor wheel speed, acceleration intensity, braking intensity, and steering wheel angle have no timeouts, out-of-bounds errors, jumps, or logical conflicts; the difference between the tractor speed and trailer speed is less than the speed recovery threshold; the estimated results of the towing pin angle, main-trailer articulation angle, or attitude fall back to within the recovery threshold; the ABS trigger state is released, and the wheel slip ratio returns to normal; the battery's allowable charging power and allowable discharging power meet the limited recovery requirements; the motor controller is controllable, and the actual torque is consistent with the target torque; and the neutral state or power connection state is reliable.

[0129] During the implementation process, after the first recovery condition mentioned above is met and the recovery confirmation time is reached, the functional domain can transition back from state S2 to state S1.

[0130] The second recovery condition may include: all safety enabling conditions corresponding to the functional domain are met; the tractor's operating data is reliable; the speed consistency between the main and trailer meets the requirements for normal operation; the attitude of the main and trailer is within the safe range; the braking stability is normal; and the feedback from the neutral gear, power connection actuator, and high-voltage system is normal.

[0131] During implementation, after the second recovery condition is met and the S1, S2 or S3 state transition is not triggered again within the preset observation window, the trailer vehicle controller gradually increases the upper limit of the auxiliary drive torque or recovery torque according to the preset slope until the functional domain is restored to the S0 state.

[0132] After the functional domain enters the S3 state and is powered on again, the trailer controller re-performs state checks, which include at least: whether the tractor's operating data is reliable; whether the tractor wheel speed, tractor vehicle speed, acceleration intensity, braking intensity, and steering wheel angle are effective; whether the estimated results of the draw pin angle, main trailer articulation angle, or attitude are within the allowable range; whether the actual motor torque is zero; whether the drive enable feedback command and control command are consistent; whether the neutral state is reliable; whether the high-voltage system status is normal; whether the communication between the BMS, MCU, and high-voltage system is normal; whether the ABS status and EBS status are normal; and whether the power connection actuator is controllable. After power-on, if all safety enable conditions are met, the corresponding functional domain can enter the S0 state.

[0133] When the auxiliary drive functional domain recovers from state S2, it can be executed in the following order: confirm that the tractor acceleration intensity, tractor speed, tractor wheel speed, and steering wheel angle are reliable; confirm that the tractor speed, tractor wheel speed, trailer speed, and trailer wheel speed are consistent; confirm that the estimated results of the towing pin angle, main-trailer articulation angle, or main-trailer attitude are within the recovery range; confirm that the battery's allowable discharge power meets the requirements; confirm that the execution state of the trailer's vehicle controller is controllable; confirm that the neutral or power connection state is controllable; first, restore to state S1 and test operation in a low-torque, low-power mode; after no abnormalities are observed in the observation window, restore to state S0.

[0134] When the energy recovery function domain recovers from S2, it can be executed in the following order: confirm the reliability of braking intensity, brake light status, ABS status, and EBS status; confirm that the ABS trigger status has been released; confirm that the wheel slip ratio has returned to normal; confirm that the battery's allowable charging power meets the requirements; confirm that the motor controller allows recovery; first recover to S1 state, and try to recover with a lower recovery torque; gradually increase the upper limit of recovery torque according to the preset slope; after there is no ABS triggering again, abnormal slip ratio, or abnormal braking signal in the observation window, recover to S0 state.

[0135] When the power connection and gear shifting function domain recovers from state S2, it can be executed in the following order: confirm that the actuator communication and self-test are normal; confirm that the neutral state can be identified; confirm that the power connection status is reliable; for multi-speed electric drive bridges, confirm that the motor speed and the speed corresponding to the target gear meet the synchronization condition; for single-speed electric drive bridges, do not perform gear shifting synchronization detection; allow entry into state S1 to execute restricted power connection or synchronization control; after the power connection is completed and the status is confirmed to be valid, return to state S0; if synchronization failure, neutral state cannot be confirmed, or actuator abnormality occurs again during the recovery process, re-enter state S2 or S3.

[0136] During the functional domain recovery process, the alarm logging module can record the following: the reason for exit triggering; the state transition path; the time of entering S1, S2, or S3 state; the time when the recovery conditions are met; the safety locking method corresponding to S3 state; the detection results after power-on; whether the abnormality is triggered again during the recovery process; and the functional domain state after recovery. For events that enter S3 state, fault codes or safety event records should be retained to facilitate subsequent maintenance diagnosis and operational risk analysis.

[0137] The following specific embodiments illustrate the process of functional domain state transition, functional limitation handling, and state recovery in this application: Example 1: State transition, function limitation handling, and state recovery of the auxiliary drive functional domain when the master attitude exceeds the limit. During vehicle operation, the trailer controller determines the main trailer posture. If the main trailer posture exceeds the first posture threshold, the trailer controller switches the auxiliary drive function domain from state S0 to state S1, reduces the upper limit of the auxiliary drive torque, and limits the rate of change of the auxiliary drive torque.

[0138] If the main trailer attitude parameters continue to increase and exceed the second attitude threshold, and continue to exceed the preset confirmation time, the trailer vehicle controller will switch the auxiliary drive function domain from state S1 to state S2, and prohibit the output of auxiliary drive torque.

[0139] Once the main trailer's attitude returns to within the recovery threshold and continues to meet the recovery time, the auxiliary drive functional domain enters the recovery process. The trailer's overall controller first recovers from state S2 to state S1, allowing low torque output, and then recovers to state S0 according to a preset slope.

[0140] Example 2: State transition, function limitation handling, and state recovery of the power connection and gear shift execution functional domains when the tractor accelerates too quickly, causing the power connection or gear shift synchronization conditions to be unmet. When the tractor unit sends a valid drive intention, the trailer controller determines, based on this intention, whether to perform a power connection, engage a gear, or shift gears to enter auxiliary drive mode. At this time, the trailer controller confirms the synchronization conditions for power connection or gear shifting based on trailer speed, motor speed, neutral status, power connection status, and target gear.

[0141] If the electric drive axle has a multi-gear structure and the tractor accelerates quickly, causing the difference between the motor speed and the speed corresponding to the target gear to exceed the synchronization threshold and continue for longer than the preset confirmation time, the trailer vehicle controller will switch the power connection and gear execution function domain from state S0 to state S2, keep it in neutral, and prohibit the output of auxiliary drive torque.

[0142] If the electric drive axle is a single-gear structure, shift synchronization detection will not be performed; when the power connection cannot be disconnected or the neutral position cannot be confirmed, it will enter the S3 state and perform the shift to neutral or power off the high voltage.

[0143] When the motor speed and the speed corresponding to the target gear meet the synchronization condition, and the actual gear or power connection status feedback is effective, the power connection and gear execution function domain transitions from state S2 to state S0, and the auxiliary drive function domain gradually recovers according to the low torque and limited slope method.

[0144] By keeping the trailer in neutral and prohibiting auxiliary drive torque output in scenarios where the trailer's power connection or shift synchronization conditions are not met due to excessive acceleration of the tractor, the risks of gear grinding, power connection shock, and inability to engage gears can be reduced.

[0145] Example 3: State transition, function limitation handling, and state recovery of the auxiliary drive functional domain when the trailer speed is greater than the tractor speed. During vehicle operation, the trailer controller continuously compares the tractor speed, tractor wheel speed, trailer wheel speed, and estimated trailer speed. If the trailer speed is greater than the tractor speed and the speed difference exceeds the first speed difference threshold, the trailer controller switches the auxiliary drive function domain from state S0 to state S1, reducing the upper limit of the auxiliary drive torque.

[0146] If the speed difference exceeds the second speed difference threshold and continues for more than the preset confirmation time, the trailer controller will switch the auxiliary drive function domain from state S1 to state S2, set the auxiliary drive target torque to zero, and prevent the trailer from continuing to push the tractor.

[0147] When the speed difference falls back to within the recovery threshold, and the tractor's operating data is reliable and the tractor's driving intention is clear, the trailer's overall controller first restores the auxiliary drive function domain from state S2 to state S1, and then restores it to state S0 according to the preset slope.

[0148] Example 4: State transition, functional limitation handling, and state recovery of the energy recovery functional domain when ABS is triggered During vehicle braking, the trailer controller detects that the ABS of the tractor or trailer has been triggered. At this time, even if the tractor still has a braking request, the trailer controller controls the energy recovery function domain to switch from state S0 or S1 to state S2, quickly reducing the recovered torque to zero.

[0149] Once the ABS trigger is deactivated, the wheel slip ratio stabilizes, the braking status is reliable, and the battery's allowable charging power meets requirements, the trailer's overall controller first restores the energy recovery function domain from state S2 to state S1, attempting recovery with a lower recovery torque, and then gradually increases the upper limit of the recovery torque according to a preset slope. If no ABS triggers again in the observation window, it returns to state S0.

[0150] This application embodiment divides the functional domains of an electric drive trailer into multiple domains, including an auxiliary drive functional domain, an energy recovery functional domain, a power connection and gear shifting functional domain, and a high-voltage drive enabling functional domain. For each functional domain, when the current enabling state of the functional domain represents an unrestricted state, the system combines tractor operating data and trailer operating data to determine whether each functional domain meets the corresponding safety enabling conditions. This allows for a comprehensive assessment of whether any safety issues exist in each functional domain. When a functional domain does not meet the safety enabling conditions, its current enabling state is migrated to a target enabling state with restricted functions. Based on the target enabling state, the corresponding functions of the functional domain are subject to targeted restrictions. This avoids the safety risks caused by applying uniform restrictions to the entire vehicle, thereby improving the safety of the electric drive trailer.

[0151] Based on the same inventive concept, this application also provides a control device for an electrically driven trailer, see reference. Figure 3 The diagram shows a schematic of the structure of the control device for an electric drive trailer according to an embodiment of this application. The control device for the electric drive trailer includes one or more memories 304, one or more processors 302, and at least one computer program (computer program instruction) stored in the memory 304 and executable on the processor 302. When the processor 302 executes the computer program, it implements the method described above.

[0152] Among them, Figure 3 In this document, a bus architecture (represented by bus 300) is used. Bus 300 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 302 and memory represented by memory 304. Bus 300 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 305 provides an interface between bus 300 and receiver 301 and transmitter 303. Receiver 301 and transmitter 303 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 302 is responsible for managing bus 300 and general processing, while memory 304 can be used to store data used by processor 302 during operation.

[0153] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing computer program instructions, which, when executed by a processor, cause the processor to perform the steps of the method described above.

[0154] Based on the same inventive concept, embodiments of this application provide a computer program product, including a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0155] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0156] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0157] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0158] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing computer program instructions, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0159] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A control method for an electrically driven trailer, characterized in that, The method is applied to an electrically driven trailer, wherein the functional domains of the electrically driven trailer include multiples of an auxiliary drive functional domain, an energy recovery functional domain, a power connection and gear shifting functional domain, and a high-voltage drive enabling functional domain, and the method includes: If the current enabled state of the functional domain represents an unrestricted state, then monitor the tractor operating data and trailer operating data. If it is determined from the tractor operation data and trailer operation data that the functional domain does not meet the safety enabling conditions corresponding to the functional domain, then the current enabling state of the functional domain is migrated to the target enabling state, wherein the target enabling state is at least one of a variety of functionally restricted states with different degrees of restriction. The functional domain is subject to functional restriction processing based on the target enable state.

2. The control method for an electrically driven trailer according to claim 1, characterized in that, The step of transitioning the current enabled state of the functional domain to the target enabled state includes: Based on at least one of the following: unmet sub-conditions in the security enable conditions corresponding to the functional domain, duration of unmet security enable conditions, and degree of deviation from the security enable conditions, the current enable state of the functional domain is migrated to the target enable state.

3. The control method for an electrically driven trailer according to claim 1, characterized in that, The functional domain is an auxiliary drive functional domain, and the safety enable conditions corresponding to the auxiliary drive functional domain include: The following conditions must be met: reliable tractor operation data; effective driving intention of the tractor; acceleration intensity of the tractor exceeding the preset intensity threshold; main and trailer attitude within the allowable attitude range of auxiliary drive; speed consistency between the tractor and trailer; controllable trailer motor controller; allowable battery discharge power exceeding the preset drive demand power threshold; controllable trailer clutch; controllable trailer power connection actuator; and trailer not in braking state.

4. The control method for an electrically driven trailer according to claim 3, characterized in that, Also includes: If the tractor operation data meets the preset credibility judgment conditions, then the tractor operation data is determined to be credible. The preset credibility judgment conditions include one or more of the following: timeout judgment conditions, boundary judgment conditions, jump judgment conditions, counter stability judgment conditions, valid bit judgment conditions, and logic conflict judgment conditions.

5. The control method for an electrically driven trailer according to claim 4, characterized in that, The various functional restriction states with different levels of restriction include restricted enable state, temporary exit state, and locked state, with the restriction level increasing sequentially. The functional restriction processing of the functional domain based on the target enable state includes: If the target enabling state is the restricted enabling state, then reduce the upper limit of the auxiliary drive torque or reduce the upper limit of the auxiliary drive torque change rate. If the target enable state is the temporary exit state, then the auxiliary drive request command is blocked and the auxiliary drive target torque is set to zero; If the target enable state is the locked state, then the electric drive trailer is controlled to enter neutral or be powered down.

6. The control method for an electrically driven trailer according to claim 2, characterized in that, The functional domain is the energy recovery functional domain, and the safety enabling conditions corresponding to the energy recovery functional domain include: The tractor braking status is reliable, the trailer electronic braking system (EBS) status is reliable, the trailer battery management system (BMS) status is reliable, the trailer anti-lock braking system (ABS) is not triggered, the battery's allowable charging power is greater than the preset recovery power threshold, the motor controller's allowable recovery torque and the trailer's electronic stability control system are not triggered.

7. The control method for an electrically driven trailer according to claim 6, characterized in that, The various functional restriction states with different levels of restriction include a restricted enable state and a temporary exit state with progressively increasing restriction levels. The functional restriction processing of the functional domain based on the target enable state includes: If the target enabling state is the restricted enabling state, then reduce the upper limit of the recovery torque or the upper limit of the recovery torque change rate. If the target enable state is the temporary exit state, then reduce the recovery torque and set the recovery target torque to zero.

8. The control method for an electrically driven trailer according to claim 1, characterized in that, The functional domain is the power connection and gear shifting functional domain, and the safety enabling conditions corresponding to the power connection and gear shifting functional domain include: The trailer clutch is in a reliable state, the trailer is in neutral state, the power connection actuator is in a normal state, and when the trailer power system includes a multi-speed electric drive axle, the motor speed, the trailer speed, and the speed corresponding to the target gear of the multi-speed electric drive axle meet the preset synchronization conditions.

9. The control method for an electrically driven trailer according to claim 8, characterized in that, The various functional restriction states with different levels of restriction include a temporary exit state and a locked state with progressively increasing restriction levels. The functional restriction processing of the functional domain based on the target enable state includes: If the target enable state is the temporary exit state, then gear engagement or power connection is prohibited, and the electric drive trailer is controlled to enter neutral. If the target enable state is the locked state, then control the electric drive trailer to de-energize.

10. The control method for an electrically driven trailer according to claim 1, characterized in that, The functional domain is a high-voltage drive enable functional domain, and the safety enable conditions corresponding to the high-voltage drive enable functional domain include: The trailer BMS status and communication are normal, the trailer vehicle controller status and communication are normal, the high voltage system status and communication are normal, the trailer insulation status is normal, the trailer is not in a prohibited driving state, and the trailer drive enable feedback command and drive enable request command are consistent.

11. The control method for an electrically driven trailer according to claim 10, characterized in that, The various functionally restricted states with different degrees of restriction include a locked state, and the step of transitioning the current enabled state of the functional domain to a target enabled state includes: Transition the current enabled state to the locked state.

12. The control method for an electrically driven trailer according to claim 11, characterized in that, The functional restriction processing of the functional domain based on the target enable state includes: If the target enable state is the locked state, then the electric drive trailer is powered off under high voltage, and auxiliary drive and energy recovery are prohibited.

13. The control method for an electrically driven trailer according to claim 1, characterized in that, The various functional restriction states with different levels of restriction include a restricted enable state and a temporary exit state with progressively increasing restriction levels. The method further includes: If the target enable state is the temporary exit state and the functional domain satisfies the first recovery condition, then the system transitions from the temporary exit state to the restricted enable state. If the functional domain meets the second recovery condition and the functional domain meets the corresponding security enable condition within a preset time period, then it will transition from the restricted enable state to the unrestricted function state.

14. A control device for an electrically driven trailer, comprising a processor and a memory, characterized in that, The memory stores computer program instructions that can be executed by the processor, and when the processor executes the computer program instructions, it implements the steps of the method as described in any one of claims 1 to 13.

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