Engine multi-loop cooling cooperative control method and system

Abstract

The present application relates to the technical field of engine cooling control, and discloses a kind of engine multi-loop cooling collaborative control method and system.The heat exchange channel of each heat exchange unit corresponds to each cooling loop and is fluidly isolated from each other;Engine operating conditions, hot fluid state and actuator state are collected, a distribution matrix is generated, and circuit pumps, valves and air-side actuators are controlled, and heat dissipation residuals are determined based on execution response and health benchmarks.If the residuals continuously exceed the limit and meet the diagnostic admission conditions, the two cooling circuits and two heat exchange units containing the out-of-limit combination are subjected to time-limited exchange, the number of circuit distribution units and the air-side settings of the heat exchange units remain unchanged, the fault category is determined based on the residual migration of the response data before and after the exchange, and the distribution matrix is updated accordingly to implement fault-tolerant control.The present application can distinguish cooling circuits, heat exchange units and measurement consistency anomalies, ensure cooling safety, and reduce the increase in power consumption of non-discriminatory actuators caused by unknown fault locations.

Description

Technical Field

[0001] This invention relates to the field of engine thermal management control technology, specifically to an engine multi-loop cooling coordinated control method and system. Background Technology

[0002] Engines typically have multiple cooling circuits for components such as the cylinder head, cylinder block, lubricating oil heat exchanger, and turbocharged air cooler. Each cooling circuit regulates coolant circulation and heat dissipation capacity through a water pump, control valve, and heat exchange unit. Existing multi-circuit cooling systems generally control the water pump, valves, and fan separately based on the temperature of each circuit, or adjust the heat dissipation area of ​​the heat exchange unit based on a temperature threshold.

[0003] When the actual heat dissipation capacity of a cooling loop continuously decreases, temperature changes exhibit transport lag and are easily affected by load changes and switching transients. It is difficult to determine whether the anomaly originates from loop blockage, water pump or valve issues, or from dust accumulation in the heat exchange unit, insufficient airflow, or inconsistent measurement links based solely on temperature increases. When the fault location is unclear, the controller may simultaneously increase the power of both the water pump and the air-side actuator, not only increasing energy consumption but also making it difficult to rationally allocate limited heat dissipation resources for loops with high thermal safety risks. Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, the present invention provides the following technical solution: This invention provides a multi-loop cooling coordinated control method for an engine, wherein the heat exchange channels of each heat exchange unit correspond to each loop and are fluidly isolated from each other, including: S1. Collect engine operating conditions, thermofluid status and actuator status to form status data; S2. Based on the state data, generate an allocation matrix according to temperature safety, minimum flow rate, fault isolation and energy consumption priority; during steady-state allocation, each heat exchange unit is allocated to at most one cooling loop, and the loop pump valve and air-side actuator are controlled according to the allocation matrix, the execution response is compared with the health benchmark, and the heat dissipation residual and its over-limit state are determined. S3. When the heat dissipation residual continuously exceeds the limit and meets the diagnostic access conditions, select two cooling circuits and two heat exchange units containing the limit-exceeding combination to be interchanged within a time limit, keeping the number of circuit allocation units and the air side setting of the heat exchange unit unchanged, and forming response data before and after the interchange; if the temperature, pressure, valve position exceeds the safe range or the flow rate is lower than the safe lower limit, stop the interchange and restore the allocation matrix. S4. After the heat dissipation residual exceeds the limit continuously, if the diagnostic access condition is not met or the exchange is terminated, the fault category is determined as an unresolved anomaly; otherwise, the fault category is determined based on the residual migration of the response data before and after the exchange. The allocation matrix is ​​updated according to the preset handling of the fault category, the control loop pump valve and air-side actuator are controlled, and the execution result is fed back to the next control cycle.

[0005] Optionally, the step of generating an allocation matrix based on the status data according to temperature safety, minimum flow rate, fault isolation, and energy consumption priority specifically includes: The difference between the corresponding temperature safety limit of the component to be cooled and the current temperature of the component to be cooled is determined as the component temperature safety margin. Based on the actuator status, available heat exchange units are determined, and feasible allocation relationships are screened in the order of component temperature safety, minimum circulation flow of the cooling circuit, fault isolation, number of switching times, and execution energy consumption. When multiple feasible allocation relationships exist, the feasible allocation relationship with the fewest switching times of the heat exchange channel valves relative to the previous control cycle is selected. When the number of switching times is the same, the feasible allocation relationship with the lowest total power consumption of the loop water pump and air-side actuator is selected. When no feasible allocation relationship exists, the available heat exchange units are preferentially allocated to the cooling circuit with the smallest temperature safety margin of the component, and the engine is derated to generate the allocation matrix.

[0006] Optionally, the control loop pump valve and air-side actuator according to the allocation matrix specifically includes: Identify the first and second coolant temperature inflection points generated at the cooling circuit outlet and the target heat exchange unit inlet respectively by the same engine natural load change. Integrate the coolant volume flow rate from the detection time of the first coolant temperature inflection point to the detection time of the second coolant temperature inflection point to obtain the effective transport volume. Determine the effective transport delay as the ratio of the effective transport volume to the average coolant volume flow rate of the current control cycle. The early start time of the target heat exchange unit is determined based on the effective transport delay, and the corresponding heat exchange channel valve and air-side actuator are controlled at the early start time. If the first coolant temperature inflection point and the second coolant temperature inflection point cannot be completely detected, the effective transport delay of the previous control cycle is used. If there is no effective transport delay of the previous control cycle, the allocation matrix is ​​executed using the calibrated transport delay.

[0007] Optionally, the comparison of the execution response with a health benchmark to determine the heat dissipation residual and its out-of-limit status specifically includes: According to the The cooling circuit flows through the first Coolant mass flow rate of each heat exchange unit Specific heat capacity of coolant Coolant inlet temperature and coolant outlet temperature ,according to Determine the heat dissipation on the coolant side ; According to the Air mass flow rate of each heat exchange unit Specific heat capacity of air Air inlet temperature and air outlet temperature ,according to Determine the heat dissipation on the air side ; Using the coolant inlet temperature, coolant mass flow rate, air mass flow rate, and ambient temperature as indexes, the desired heat dissipation is obtained from a health baseline. ,according to Determine the residual heat transfer capacity ,according to Determine the energy consistency residual The heat dissipation residual is composed of the heat transfer capacity residual and the energy consistency residual; in or If the heat dissipation residual is in an over-limit state, it is determined that the heat dissipation residual is in a non-over-limit state. The lower limit of positive heat dissipation. and The positive threshold is defined as the duration of the over-limit state reaching the calibration determination time, thus obtaining the heat dissipation residual and its over-limit state.

[0008] Optionally, the selection of two cooling circuits and two heat exchange units containing the over-limit combination is timed to be interchanged, while keeping the number of circuit allocation units and the air-side settings of the heat exchange units unchanged, forming response data before and after the interchange, specifically including: The two cooling circuits are labeled as the first cooling circuit and the second cooling circuit, and the two heat exchange units are labeled as the first heat exchange unit and the second heat exchange unit. The over-limit combination consists of the first cooling circuit and the first heat exchange unit. The combination in which the heat dissipation residual of the second cooling circuit and the second heat exchange unit does not exceed the limit is used as the reference combination. After the heat exchange channel valve position and coolant flow rate of the combination before the swapping enter the stable range, the execution response before the swapping is recorded within a preset observation period. Maintain the air-side settings of the first heat exchange unit and the second heat exchange unit respectively, control the heat exchange channel valve to switch the first cooling circuit to the second heat exchange unit, and switch the second cooling circuit to the first heat exchange unit to form an interchangeable combination; After the valve position and coolant flow rate of the heat exchange channel after the swapping combination enter a stable range, wait for the calibrated transport delay from the cooling circuit outlet to the heat exchange unit inlet, record the execution response after the swapping within the preset observation period, discard the response during the switching transition, and use the execution response before the swapping and the execution response after the swapping as the response data before and after the swapping.

[0009] Optionally, the diagnostic admission criteria are as follows: the temperature safety margin obtained by subtracting the temperature of the cooled component from the corresponding temperature safety limit of the two cooling circuits is greater than the temperature margin threshold; the engine load change rate and the component temperature rise rate are both lower than the corresponding change rate threshold; the circulation flow rate is higher than the minimum circulation flow rate; the pressure is within the safe range; there is no valve position abnormality in the heat exchange channel valve; and the actual air mass flow rate of the two heat exchange units is within the stable range. The control heat exchange channel valve adopts a switching method in which the target heat exchange channel is opened first, and the original heat exchange channel is closed after the valve position feedback of the target heat exchange channel indicates that it is fully opened and the flow rate of the corresponding cooling circuit reaches the minimum circulation flow rate. During the switching transition period of opening first and then closing, the heat exchange channels corresponding to the two cooling circuits in the same heat exchange unit and fluidly isolated from each other are opened simultaneously. The response during the switching transition period is not included in the response data before and after the switch. During the interchange, monitor component temperature, coolant flow rate, pressure, heat exchange channel valve position, actual air mass flow rate, and interchange duration. If the component temperature exceeds the corresponding temperature safety limit, the coolant flow rate is lower than the minimum circulation flow rate, the pressure or the heat exchange channel valve position exceeds the corresponding safety range, the deviation of the actual air mass flow rate from the pre-interchange reference exceeds the air flow deviation threshold, or the interchange duration reaches the calibration upper limit, restore the pre-interchange configuration and terminate the interchange.

[0010] Optionally, determining the fault category based on the residual migration of the response data before and after the swap specifically includes: The residual heat exchange capacity and residual energy consistency of each allocation combination in the execution response before and after the swap are compared according to the correspondence between cooling loops and heat exchange units, wherein the indices of the first cooling loop and the second cooling loop are 1 and 2, respectively, and the indices of the first heat exchange unit and the second heat exchange unit are 1 and 2, respectively. Any allocation combination before and after the interchange satisfies When the heat exchange channel valve position feedback is normal, the coolant flow rate and pressure are within the corresponding stable range, and the actual air mass flow rate is within the stable range, the fault category is determined to be measurement inconsistency abnormality. All allocation combinations before and after the interchange satisfy the following conditions. And the residual heat transfer capacity after the interchange satisfies and When the fault is identified, it is determined to be a heat exchange unit malfunction. All allocation combinations before and after the interchange satisfy the following conditions. And the residual heat transfer capacity after the interchange satisfies and Furthermore, when the coolant flow rate or pressure of the first cooling circuit exceeds the corresponding stable range, the fault category is determined to be a cooling circuit abnormality. If none of the aforementioned conditions are met, the fault category is determined to be an unresolved anomaly, and the fault category is obtained.

[0011] Optionally, updating the allocation matrix according to the preset handling of the fault category specifically includes: When the fault category is heat exchange unit abnormality, the abnormal heat exchange unit is placed into the disabled set, and fault handling constraints are generated based on the disabled set; When the fault category is cooling circuit abnormality, maintain the minimum circulation flow of the abnormal cooling circuit and control engine derating to generate fault handling constraints; When the fault category is measurement inconsistency anomaly, the fault location results and active interchange of the residual migration are stopped. The maximum value among multiple redundant temperature measurements of the same cooled component is used as the conservative control temperature and the engine is derated to generate fault handling constraints. When the fault category is unresolved anomaly, priority is given to ensuring the cooling circuit with the smallest difference between the corresponding temperature safety limit and the temperature of the cooled component, and the engine is derated to generate fault handling constraints. The allocation matrix is ​​updated based on the fault handling constraints to generate the updated allocation matrix.

[0012] The present invention also provides an engine multi-loop cooling coordinated control system for implementing the above-mentioned engine multi-loop cooling coordinated control method, comprising: The status acquisition module is used to collect engine operating conditions, thermofluid status, and actuator status to form status data. The collaborative allocation module is used to generate an allocation matrix based on the state data, according to temperature safety, minimum flow rate, fault isolation and energy consumption priority. During steady-state allocation, each heat exchange unit is allocated to at most one cooling loop. The module controls the loop pumps and valves and air-side actuators according to the allocation matrix, compares the execution response with the health benchmark, and determines the heat dissipation residual and its over-limit status. The interchange identification module is used to select two cooling circuits and two heat exchange units containing the over-limit combination for timed interchange when the heat dissipation residual continuously exceeds the limit and meets the diagnostic access conditions, while keeping the number of circuit allocation units and the air-side setting of the heat exchange unit unchanged, and forming response data before and after the interchange; if the temperature, pressure, valve position exceeds the safe range or the flow rate is lower than the safe lower limit, the interchange is stopped and the allocation matrix is ​​restored. The fault classification and fault tolerance control module is used to determine the fault category as unresolved anomaly when the diagnostic access conditions are not met or the exchange is terminated after the heat dissipation residual continuously exceeds the limit; otherwise, the fault category is determined based on the residual migration of the response data before and after the exchange; the allocation matrix is ​​updated according to the preset handling of the fault category, the control loop pump valve and air-side actuator are controlled, and the execution result is fed back to the next control cycle.

[0013] Beneficial effects The technical solution provided by this invention has the following beneficial effects: 1. By setting up heat exchange channels in each heat exchange unit that correspond to different cooling circuits and are fluidly isolated from each other, and by implementing time-limited interchange of two cooling circuits and two heat exchange units containing over-limit combinations while keeping the number of circuit allocation units and the air-side settings of the heat exchange units unchanged, the heat load, air-side conditions and the number of heat exchange resources before and after the interchange are kept comparable, while avoiding the interconnection of coolant in different cooling circuits. Thus, it is possible to distinguish whether the abnormality comes from the cooling circuit or the heat exchange unit based on the physical object followed by the abnormal residual.

[0014] 2. By identifying and integrating the temperature inflection points formed at the cooling circuit outlet and the target heat exchange unit inlet by natural load changes, the effective transport delay is determined. Combined with valve position and flow stability judgment, equal-length observation window, transport delay waiting and switching transition data elimination, the execution response before and after the switch corresponds to each other in time position and steady state, thereby reducing the interference of coolant transport lag and heat exchange channel switching transient on residual migration judgment.

[0015] 3. By combining the heat exchange capacity residual and the energy consistency residual into the heat dissipation residual, and by utilizing whether the energy consistency residual exceeds the limit and the opposite threshold relationship between the heat exchange capacity residuals of different loop-heat exchange unit combinations after interchange, mutually exclusive judgment conditions for measurement consistency anomalies, heat exchange unit anomalies, and cooling loop anomalies are formed; cases that do not meet the already located conditions are determined as unresolved anomalies, avoiding the same set of responses being classified into multiple fault categories at the same time.

[0016] 4. By directly converting fault categories into fault handling constraints such as disabled sets, minimum circulating flow maintenance, conservative temperature control, and engine derating, and updating the allocation matrix for the next control cycle accordingly, the limited available heat exchange resources are prioritized to protect high-risk loops with smaller temperature safety margins. When multiple feasible allocation relationships exist, the number of heat exchange channel valve switching times and the total power consumption of actuators are taken into account, which can reduce the situation where the power of the loop water pump and air-side actuators is indiscriminately increased due to unclear fault locations. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating an application scenario provided by the present invention; Figure 2 A schematic diagram illustrating the steps of a multi-loop cooling coordinated control method for an engine provided by the present invention; Figure 3 This invention provides an overall flowchart of a multi-loop cooling coordinated control method for an engine. Figure 4 This is a schematic diagram of the loop-heat exchange unit allocation matrix and interchangeable observation data structure provided by the present invention; Figure 5 This invention provides a schematic diagram of the structure of an engine multi-loop cooling coordinated control system. Figure 6 A comparison diagram of the residual migration of heat exchange capacity before and after swapping under abnormal heat exchange unit and abnormal cooling circuit conditions provided by the present invention; Figure 7 The graph shows the variation of fault classification accuracy with engine load rate under different observation window processing strategies provided by this invention. Figure 8 This invention provides a comparison chart of temperature safety margin and total actuator power consumption under different control strategies for some heat exchange unit malfunctions. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, this embodiment is applied to an engine cooling system having at least two cooling circuits and at least two addressable heat exchange units. The components to be cooled may include the cylinder head, high-temperature exhaust gas recirculation component, cylinder block, lubricating oil heat exchanger, turbocharged air cooler, or other engine components that require temperature control.

[0020] Each cooling circuit is equipped with an electronic water pump, a circuit control valve, a bypass pipeline, a coolant temperature sensor, a coolant flow sensor, and a pressure or differential pressure sensor. Each heat exchange unit has a heat exchange channel corresponding to each cooling circuit and fluidly isolated from each other, and each heat exchange channel is equipped with a heat exchange channel valve. Therefore, different cooling circuits can be connected to the same heat exchange unit, but the coolants from different cooling circuits will not mix.

[0021] Each selectable loop-heat exchange unit combination has a coolant inlet temperature measurement point immediately upstream of the corresponding heat exchange channel and a coolant outlet temperature measurement point immediately downstream. When using a common inlet or common outlet manifold temperature sensor, the controller maps the common sensor data to the currently active loop-heat exchange unit combination based on the current allocation matrix, heat exchange channel valve positions, and effective transport delay. During valve switching transitions or when the mapping relationship is not unique, the corresponding data is marked as invalid and not included in the heat dissipation residual calculation.

[0022] Each heat exchange unit is equipped with an air inlet temperature sensor, an air outlet temperature sensor, and an air mass flow sensor. The air inlet temperature measurement point is located on the windward side of the heat exchange core, and the air outlet temperature measurement point is located on the leeward side of the heat exchange core. The air-side actuator can be a zoned fan, an adjustable damper, or a combination of both.

[0023] For components requiring conservative temperature control, at least two independent temperature measurement channels should be provided. These two channels should use different sensor identifiers and input interfaces, preferably located in the high-temperature region of the component being cooled and near the coolant outlet, respectively. The controller will only take the maximum value of the temperature measurement that has passed range, update time, and electrical diagnostic verification; if only one channel is valid, the measurement value of that channel will be used; if all channels are invalid, active switching will cease, the control will provide the maximum permissible cooling capacity using the pump valves and air-side actuators, and an emergency derating request will be sent to the engine controller.

[0024] The controller and engine controller operate independently. The engine controller sends engine load, speed, fuel injection quantity, operating mode, and planned operating condition change times to the controller. The controller sends derating requests to the engine controller and receives derating confirmations. The status sensor group provides thermofluid status and actuator feedback to the controller. The controller outputs control commands to the electric water pump, loop control valve, heat exchange channel valve, and air-side actuators.

[0025] The controller includes a processor, volatile memory, non-volatile memory, analog input interfaces, digital input / output interfaces, and a vehicle communication interface. For 0–5V analog sensors, the sensing signal is filtered and limited before being converted into a digital signal by a 12-bit analog-to-digital converter. Communication-type sensors and actuators transmit messages with timestamps and validity flags via the vehicle communication bus. The preferred underlying sampling period is 20ms, and the cooperative control period is 100ms. If the timestamp difference between any two data points participating in the same residual calculation is greater than 40ms, that set of residuals will not be calculated in this control cycle.

[0026] In this embodiment, with Indicates the cooling circuit index, in This represents the heat exchange unit index. The allocation matrix is ​​denoted as... ,in, Indicates the first The cooling circuit is assigned to the first... One heat exchange unit, This indicates that the allocation relationship has not yet been formed. During steady-state allocation, the following conditions are met:

[0027] That is, each heat exchange unit is assigned to at most one cooling loop. During the short switching transition period of opening and then closing, two heat exchange channels in the same heat exchange unit that are fluidly isolated from each other can be opened simultaneously, but this state is not considered a steady-state allocation state, and its response is not included in the diagnostic observation window.

[0028] When a cooling circuit corresponds to multiple components being cooled, the temperature safety margin of that cooling circuit is:

[0029] in, For the first A collection of components cooled by a cooling circuit. For the first Temperature safety limits for each cooled component This represents the current temperature of the component being cooled. Therefore, matrix generation, diagnostic access, and fault handling are all based on the component with the smallest temperature safety margin in this cooling loop.

[0030] This implementation distinguishes between two temperature margin thresholds. The fault-tolerant control temperature safety margin threshold is denoted as... The preferred temperature is 4℃, used for matrix allocation feasibility assessment and engine derating assessment; the diagnostic access temperature margin threshold is denoted as... The preferred temperature is 6°C, which is used to determine whether there is an additional safety margin for performing an active swap. This allows the active switching to use more stringent temperature safety conditions than normal fault-tolerant control.

[0031] like Figure 2 As shown, the method of this embodiment includes the following steps.

[0032] S1. Collect engine operating conditions, thermofluid status and actuator status to form status data; In this step, the controller obtains data from the engine controller, status sensor group, and actuator feedback according to a unified clock, performs range, timestamp, update cycle, and valid status verification on the data, forms status data for collaborative allocation and exchange identification, and then passes the status data to the next step.

[0033] Engine operating conditions should include at least engine speed, engine load, fuel injection quantity, operating mode, derating status, and the time of planned operating condition changes. Thermal fluid status should include at least the temperature of the cooled components, coolant inlet temperature, coolant outlet temperature, coolant mass flow rate or volumetric flow rate, coolant pressure, air inlet temperature, air outlet temperature, actual air mass flow rate, and ambient temperature. Actuator status should include at least the electronic water pump command and feedback, loop control valve command and feedback, heat exchange channel valve command and feedback, fan speed, and adjustable damper opening.

[0034] Each status data record includes a data identifier, physical quantity value, unit, sampling time, validity flag, data source, and calibration version. The data identifier consists of the device type, cooling circuit index, heat exchange unit index, and measurement location. Data for which the heat exchange unit index is not needed is set to null. Data that exceeds the sensor range, timestamp, timestamp, communication verification, or sensor self-diagnosis fails is marked as invalid.

[0035] S2. Based on the state data, generate an allocation matrix according to temperature safety, minimum flow rate, fault isolation and energy consumption priority; during steady-state allocation, each heat exchange unit is allocated to at most one cooling loop, and the loop pump valve and air-side actuator are controlled according to the allocation matrix, the execution response is compared with the health benchmark, and the heat dissipation residual and its over-limit state are determined. This step involves the controller reading status data, the allocation matrix from the previous control cycle, and the execution results. It first forms an allocation matrix that meets temperature safety, minimum flow rate, and fault isolation conditions. Then, the control loop pumps, valves, and air-side actuators execute the allocation matrix. The controller compares the stable execution response with the corresponding health baseline to form the heat dissipation residual and out-of-limit status for each active loop-heat exchange unit combination, and transmits this information to subsequent interchangeability identification processing.

[0036] The process of generating an allocation matrix based on the status data, according to temperature safety, minimum flow rate, fault isolation, and energy consumption priority, specifically includes: The difference between the corresponding temperature safety limit of the component to be cooled and the current temperature of the component to be cooled is determined as the component temperature safety margin. Based on the actuator status, available heat exchange units are determined, and feasible allocation relationships are screened in the order of component temperature safety, minimum circulation flow of the cooling circuit, fault isolation, number of switching times, and execution energy consumption. When multiple feasible allocation relationships exist, the feasible allocation relationship with the fewest switching times of the heat exchange channel valves relative to the previous control cycle is selected. When the number of switching times is the same, the feasible allocation relationship with the lowest total power consumption of the loop water pump and air-side actuator is selected. When no feasible allocation relationship exists, the available heat exchange units are preferentially allocated to the cooling circuit with the smallest temperature safety margin of the component, and the engine is derated to generate the allocation matrix.

[0037] Specifically, the controller enumerates all elements that satisfy the conditions in a fixed order, based on the heat exchange unit index and the cooling circuit index. and The candidate matrix. Heat exchange units that are placed in the disabled set, have communication failures, abnormal heat exchange channel valves, or air-side actuator failures are unavailable, and all their corresponding matrix elements are fixed to 0.

[0038] To determine whether the candidate matrix can meet the minimum circulation flow rate, a hydraulic calibration table is established for each cooling loop and its possible heat exchange channel valve state vectors. The heat exchange channel valve state vectors record the open or closed state of each channel sequentially according to the heat exchange unit index. The hydraulic calibration table uses the electronic water pump speed command and coolant temperature as continuous indices and the heat exchange channel valve state vectors as discrete indices, outputting the predicted circulation volumetric flow rate, predicted pressure, and water pump power consumption.

[0039] The hydraulic calibration table is established under the condition that the cooling circuit is confirmed to be free of blockages and leaks, and that the pumps and valves are functioning normally. The electronic water pump speed command is divided into grids at 10% of the rated speed, and the coolant temperature is divided into grids at 10°C. Each grid point obtains at least three stable measurement windows, using the smallest circulating volumetric flow rate as the conservative predicted flow rate and the maximum water pump power consumption as the conservative predicted power consumption. The calibration table saves the circuit index, valve state vector, grid axis, output value, validity flag, calibration version, and checksum. Online calibration only uses linear interpolation when adjacent grids are valid and the input is within the calibration domain; extrapolation beyond the domain is prohibited. Candidate matrices without corresponding valid hydraulic calibration data are deleted.

[0040] To evaluate the temperature safety before the newly assigned matrix stabilizes, a short-time prediction margin is used:

[0041] in, For the first The maximum effective temperature rise rate of the component being cooled corresponding to each cooling circuit, in °C / s; The predicted time domain from the current moment until the new allocation relationship takes effect includes the heat exchange channel valve action time, effective transport delay, air-side actuator response time, and a 0.5s control margin.

[0042] If the candidate matrix uses an unavailable heat exchanger, the predicted circulation flow rate is lower than the minimum circulation flow rate, the predicted pressure exceeds the safe range, the fault isolation constraint is violated, or any cooling loop is involved. If the candidate matrix is ​​not found, it will be deleted. After completing the above filtering, feasible allocation relationships are obtained.

[0043] When multiple feasible allocation relationships exist, they are no longer sorted a second time based on temperature margin. Instead, the unique result is determined strictly according to the following order: 1. The number of switching times of heat exchange channel valves relative to the allocation matrix of the previous control cycle is from least to most; 2. When the number of switching times is the same, the predicted total power consumption of the electric water pump and air-side actuator is from least to most; 3. When the total power consumption is the same, the binary code of the allocation matrix formed by prioritizing the cooling circuit index and then the heat exchange unit index is from least to most.

[0044] Therefore, temperature safety, minimum flow rate, and fault isolation are used to determine the feasible set, while the number of switching operations and execution energy consumption are used to select the result from the feasible set, consistent with the aforementioned priority order.

[0045] For example, if the first cooling circuit contains two components to be cooled, with temperature safety limits of 105℃ and 120℃ respectively, and current temperatures of 98℃ and 111℃ respectively, then the temperature safety margin for the first cooling circuit is 7℃. The temperature safety margin for the second cooling circuit is 9℃. If the temperature rise rates of the two circuits are 0.20℃ / s and 0.10℃ / s respectively, and the prediction time domain is 5s for both, then the predicted temperature safety margins are 6℃ and 8.5℃ respectively, both not lower than... .

[0046] If the number of valve switching required to maintain the current allocation relationship is 0 and the total power consumption is 2.3kW, and the number of valve switching required for the cross allocation relationship is 4 and the total power consumption is 2.1kW, and both allocation relationships meet the conditions of temperature safety, minimum flow rate and fault isolation, then the current allocation relationship with 0 valve switching times is selected, and this result is not changed due to the lower power consumption of the cross allocation relationship.

[0047] When no feasible allocation relationship exists, available heat exchange units are allocated in ascending order of current temperature safety margin; if the temperature safety margins are the same, priority is given to those with smaller cooling circuit indices. Simultaneously, a derating request is sent to the engine controller to gradually reduce the allowable engine load until a feasible allocation matrix is ​​regained. If the engine controller does not return a derating confirmation within 200ms, the controller maintains the highest available cooling capacity and repeatedly sends the derating request; if the temperature of the cooled components continues to rise to the temperature safety limit, an engine safety shutdown request is sent.

[0048] The control loop pump valves and air-side actuators according to the allocation matrix specifically include: Identify the first and second coolant temperature inflection points generated at the cooling circuit outlet and the target heat exchange unit inlet respectively by the same engine natural load change. Integrate the coolant volume flow rate from the detection time of the first coolant temperature inflection point to the detection time of the second coolant temperature inflection point to obtain the effective transport volume. Determine the effective transport delay as the ratio of the effective transport volume to the average coolant volume flow rate of the current control cycle. The early start time of the target heat exchange unit is determined based on the effective transport delay, and the corresponding heat exchange channel valve and air-side actuator are controlled at the early start time. If the first coolant temperature inflection point and the second coolant temperature inflection point cannot be completely detected, the effective transport delay of the previous control cycle is used. If there is no effective transport delay of the previous control cycle, the allocation matrix is ​​executed using the calibrated transport delay.

[0049] Specifically, the controller first performs five-point median filtering on the engine load, cooling circuit outlet temperature and target heat exchange unit inlet temperature, and then performs least-squares linear fitting on the filtering result using a sliding window with a length of 0.5s, using the slope of the fitted line as the rate of change of the corresponding signal.

[0050] When the absolute value of the engine load change rate reaches 2% / s of the rated load and the change direction remains continuous for 300 ms, a natural load change event is identified and an event number is generated. Before this event occurs, the absolute value of the coolant temperature change rate should not exceed 0.02℃ / s. After the event occurs, when the absolute value of the cooling circuit outlet temperature change rate reaches 0.05℃ / s and the temperature change direction corresponding to the load change direction remains continuous for three sampling cycles, the moment when the condition is first met is determined as the first coolant temperature inflection point detection moment. .

[0051] exist Within the subsequent 0.5–8 s time window, candidates for the second coolant temperature inflection point are determined from the inlet temperature sequence of the target heat exchange unit using the same rules. The temperature change direction of the second inflection point should be the same as that of the first inflection point. When multiple candidates exist, the normalized correlation coefficients of the temperature change sequences 0.5 s before and after each inflection point are calculated, and the candidate with the highest correlation coefficient is selected; if the correlation coefficients are the same, the candidate with the earlier detection time is selected. If the maximum correlation coefficient is lower than 0.80, this pairing is invalid.

[0052] Let the effective detection time of the second coolant temperature inflection point be... The coolant volume flow rate is The effective transport volume is then determined using the trapezoidal integral of adjacent flow samples.

[0053] Taking the 100ms control period in which the second coolant temperature inflection point is confirmed as the current control period, the arithmetic mean of all effective coolant volumetric flow rate samples within this control period is denoted as... The effective transport delay is determined according to the following formula:

[0054] The number of valid flow samples in the current control period is less than three. The effective transport delay is invalid if the flow rate is below the minimum circulation flow rate, the valve position mapping is not unique during the integration period, or any flow sample is invalid. The effective transport delay should be within the range of 0.5 to 8 seconds; if it exceeds this range, it is also considered invalid.

[0055] Each allocation matrix command that needs to be scheduled for execution includes the matrix version, generation time, and target effective timestamp. When the engine controller provides the planned operating condition change time, that time is used as... If no future planning time is provided, the command generation time of the current control cycle shall be used as the time. The controller executes immediately without claiming that it has been completed and enabled in advance.

[0056] The time from receiving the opening command to the valve position feedback reaching 95% of the target opening degree is recorded as (the time is not specified in the original text). The time from when the air-side actuator receives the command to when the actual air mass flow rate enters the range of ±5% of the target value and remains there for 0.5 seconds is recorded as _____. Both are calibrated separately under healthy system conditions after system assembly, and stored in partitions according to ambient temperature and power supply voltage. The larger conservative value among adjacent valid partitions is taken online. The actuator combination response time is:

[0057] The early activation time is:

[0058] The actual command time is:

[0059] in, This is the current control moment. If... The controller immediately activates the corresponding heat exchange channel valve and air-side actuator, and records the "insufficient lead time" status; the response before the combination enters a steady state is not used for diagnosis.

[0060] For example, if the effective transport volume is 5.4L and the average volumetric flow rate during the control cycle in which the second inflection point is confirmed is 2.7L / s, then the effective transport delay is 2s. If , If the advance activation time is 97.6s, then when the current time is 98.0s, the controller immediately executes and records that the advance time of 0.4s is insufficient.

[0061] If two inflection points cannot be fully detected or the effective transport delay calculation is invalid, the effective transport delay of the most recent one under the same calibration version for the same loop-heat exchange unit combination shall be used. If such a historical value does not exist, the calibrated transport delay of the corresponding combination shall be used.

[0062] The comparison between the execution response and the health benchmark to determine the heat dissipation residual and its out-of-limit status specifically includes: According to the The cooling circuit flows through the first Coolant mass flow rate of each heat exchange unit Specific heat capacity of coolant Coolant inlet temperature and coolant outlet temperature ,according to Determine the heat dissipation on the coolant side ; According to the Air mass flow rate of each heat exchange unit Specific heat capacity of air Air inlet temperature and air outlet temperature ,according to Determine the heat dissipation on the air side ; Using the coolant inlet temperature, coolant mass flow rate, air mass flow rate, and ambient temperature as indexes, the desired heat dissipation is obtained from a health baseline. ,according to Determine the residual heat transfer capacity ,according to Determine the energy consistency residual The heat dissipation residual is composed of the heat transfer capacity residual and the energy consistency residual; in or If the heat dissipation residual is in an over-limit state, it is determined that the heat dissipation residual is in a non-over-limit state. The lower limit of positive heat dissipation. and The positive threshold is defined as the duration of the over-limit state reaching the calibration determination time, thus obtaining the heat dissipation residual and its over-limit state.

[0063] Specifically, a four-dimensional health calibration table was established for each loop-heat exchange unit combination, indexed by coolant inlet temperature, coolant mass flow rate, air mass flow rate, and ambient temperature. The health calibration table was generated under bench conditions where the engine and cooling system were confirmed to be fault-free.

[0064] During calibration, only samples with stable heat exchange channel valve positions, unique combination mappings, stable coolant and air mass flow rates, valid sensors, and cooled component temperatures not approaching safety limits were used. Coolant inlet temperature was divided into grids at 5°C intervals, coolant mass flow rate at 0.2 kg / s intervals, air mass flow rate at 0.1 kg / s intervals, and ambient temperature at 5°C intervals. At least five independent 10-second stable observation windows were collected for each grid point. The median of the median heat dissipation on the coolant side of each observation window was used as the expected heat dissipation for that grid point. Grid points with insufficient sample sizes were invalidated.

[0065] Each health calibration table stores the loop index, heat exchange unit index, grid axis, expected heat dissipation, valid flags, number of samples, calibration version, and checksum. During online calculation, four-dimensional linear interpolation is used only when the current input is within the calibration domain and all 16 adjacent four-dimensional grid points are valid. If the input is outside the calibration domain, the adjacent grid is invalid, the checksum is incorrect, or the health baseline version is inconsistent with the control software version, extrapolation will not be performed, and the active interchange diagnostics for that combination will not be initiated.

[0066] The health calibration table is updated only in maintenance calibration mode, and requires that heat exchange units, cooling circuits, and sensors all pass health checks. During normal operation, out-of-limit data is not used to update the health baseline to prevent the incorporation of gradually developing faults into the health baseline.

[0067] The heat dissipation on both the coolant and air sides is calculated using time-aligned samples within the same 100ms control cycle. When using a common manifold temperature sensor, the corresponding effective transport delay should also be waited for, and the valve position mapping should be confirmed to be unique. If the timestamp difference exceeds 40ms, the switching transition flag is true, or any input is invalid, the residual record for that cycle will be null, and the timing will be reset to zero for consecutive over-limit operations.

[0068] Preferably, , , The continuous limit violation detection time is 3 seconds. or At that time, it will be treated as if no limit has been exceeded. Only when strictly met... or It has just entered the over-limit state.

[0069] For example, when the coolant mass flow rate is 0.5 kg / s, the coolant specific heat capacity is 3800 J / (kg·℃), the inlet temperature is 96℃, and the outlet temperature is 88℃, the heat dissipation on the coolant side is 15.2 kW. If the heat dissipation on the air side is 15.68 kW and the expected heat dissipation under healthy conditions is 18 kW, then... Approximately -0.156, It is approximately -0.031. Therefore, the heat transfer capacity residual exceeds the limit, while the energy consistency residual does not.

[0070] S3. When the heat dissipation residual continuously exceeds the limit and meets the diagnostic access conditions, select two cooling circuits and two heat exchange units containing the limit-exceeding combination to be interchanged within a time limit, keeping the number of circuit allocation units and the air side setting of the heat exchange unit unchanged, and forming response data before and after the interchange; if the temperature, pressure, valve position exceeds the safe range or the flow rate is lower than the safe lower limit, stop the interchange and restore the allocation matrix. This step involves the controller generating a unique diagnostic task from consecutive out-of-limit combinations and valid reference combinations. When the diagnostic entry conditions are met, the controller maintains the air-side settings of each of the two heat exchange units and performs a timed interchange by first opening the target heat exchange channel and then closing the original heat exchange channel, generating response data before and after the interchange in the stable observation window. When any safe exit condition is met, the controller restores the original allocation matrix and outputs an interchange abort status.

[0071] The selection of two cooling circuits and two heat exchange units containing the over-limit combination involves a time-limited interchange while maintaining the number of circuit allocation units and the air-side settings of the heat exchange units unchanged, generating response data before and after the interchange. Specifically, this includes: The two cooling circuits are labeled as the first cooling circuit and the second cooling circuit, and the two heat exchange units are labeled as the first heat exchange unit and the second heat exchange unit. The over-limit combination consists of the first cooling circuit and the first heat exchange unit. The combination in which the heat dissipation residual of the second cooling circuit and the second heat exchange unit does not exceed the limit is used as the reference combination. After the heat exchange channel valve position and coolant flow rate of the combination before the swapping enter the stable range, the execution response before the swapping is recorded within a preset observation period. Maintain the air-side settings of the first heat exchange unit and the second heat exchange unit respectively, control the heat exchange channel valve to switch the first cooling circuit to the second heat exchange unit, and switch the second cooling circuit to the first heat exchange unit to form an interchangeable combination; After the valve position and coolant flow rate of the heat exchange channel after the swapping combination enter a stable range, wait for the calibrated transport delay from the cooling circuit outlet to the heat exchange unit inlet, record the execution response after the swapping within the preset observation period, discard the response during the switching transition, and use the execution response before the swapping and the execution response after the swapping as the response data before and after the swapping.

[0072] When multiple combinations exceed limits simultaneously and consecutively, the controller establishes a candidate set of consecutive limits and sorts them in order according to the following conditions: 1. Temperature safety margin of the cooling circuit in which the limit-exceeding combination is located, from small to large; 2. Duration of consecutive limits exceeding limits, from long to short; 3. Normalized limit severity, from large to small; 4. Cooling circuit index, from small to large; 5. Heat exchange unit index, from small to large.

[0073] The normalization severity of exceeding the limit is:

[0074] The first combination after sorting is taken as the combination that exceeds the limit in this case.

[0075] The reference combination should have different cooling circuit indexes and heat exchange unit indices from the over-limit combination, and simultaneously meet the following requirements: current actual allocation, residual not exceeding limits, consistent health baseline version, valid data, normal heat exchange channel valves, and normal air-side actuators.

[0076] When multiple reference combinations exist, first select the combination with the larger temperature safety margin for the corresponding cooling circuit. When the temperature safety margins are the same, calculate the normalized operating condition distance between the reference combination and the combination exceeding the limit:

[0077] in, and These represent the average engine load within the observation window corresponding to the over-limit combination and the reference combination, respectively. and The average coolant inlet temperature, and Average coolant mass flow rate, and This is the average air mass flow rate. Preferably, Take 100% of the rated load. , , The above normalization scales are saved with each calibration version and are all positive values.

[0078] choose The smallest combination is used as the reference combination; If the distances are the same, the reference cooling circuit index and the reference heat exchange unit index are used sequentially. If any distance input is invalid, the combination is not considered a reference combination. If no reference combination exists, no swapping is performed, and it is directly identified as an unresolved exception.

[0079] Let the over-limit combination be The reference combination is Before the interchange, the following conditions must be met:

[0080] Execute after swapping:

[0081]

[0082] The other elements in the allocation matrix remain unchanged. Therefore, the first and second cooling loops each reduce one original allocation unit and increase one target allocation unit, while the number of allocation units in both cooling loops remains unchanged.

[0083] The controller executes only one active diagnostic task at any given time. The unique identifier for a diagnostic task consists of the start control cycle number, the index of the over-limit cooling loop, and the index of the over-limit heat exchange unit, and stores the reference combination, health baseline version, pre-exchange allocation matrix, and safety parameter version. When a new consecutive over-limit combination appears during the diagnostic process, it is added to the diagnostic queue.

[0084] Before dequeuing a task, the consecutive violation status, current allocation relationship, health baseline version, and diagnostic admission conditions are re-verified. If the consecutive violation has disappeared, the allocation relationship has changed, the version is inconsistent, or the diagnostic admission conditions are not met, the task is deleted and the reason for failure is recorded; otherwise, the reference combination is determined again according to the above rules before execution.

[0085] The diagnostic admission criteria are as follows: the temperature safety margin obtained by subtracting the temperature of the cooled component from the corresponding temperature safety limit of the two cooling circuits is greater than the temperature margin threshold; the engine load change rate and the component temperature rise rate are both lower than the corresponding change rate threshold; the circulation flow rate is higher than the minimum circulation flow rate; the pressure is within the safe range; there is no valve position abnormality in the heat exchange channel valve; and the actual air mass flow rate of the two heat exchange units is within the stable range. The control heat exchange channel valve adopts a switching method in which the target heat exchange channel is opened first, and the original heat exchange channel is closed after the valve position feedback of the target heat exchange channel indicates that it is fully opened and the flow rate of the corresponding cooling circuit reaches the minimum circulation flow rate. During the switching transition period of opening first and then closing, the heat exchange channels corresponding to the two cooling circuits in the same heat exchange unit and fluidly isolated from each other are opened simultaneously. The response during the switching transition period is not included in the response data before and after the switch. During the interchange, monitor component temperature, coolant flow rate, pressure, heat exchange channel valve position, actual air mass flow rate, and interchange duration. If the component temperature exceeds the corresponding temperature safety limit, the coolant flow rate is lower than the minimum circulation flow rate, the pressure or the heat exchange channel valve position exceeds the corresponding safety range, the deviation of the actual air mass flow rate from the pre-interchange reference exceeds the air flow deviation threshold, or the interchange duration reaches the calibration upper limit, restore the pre-interchange configuration and terminate the interchange.

[0086] Specifically, after the engine load and component temperature are filtered by five-point median, least-squares linear fitting is performed using samples within the most recent 1-second sliding window. The fitting slopes are used as the engine load change rate and component temperature rise rate, respectively. The engine load change rate is taken as the absolute value, and the component temperature rise rate is taken as the largest positive temperature rise rate among all cooled components corresponding to the two cooling circuits.

[0087] The preferred settings for diagnostic admission parameters are as follows: The temperature safety margin for both cooling circuits is strictly greater than [a certain value]. ℃; The engine load change rate is strictly lower than 12% / s of the rated load; The component's temperature rise rate must be strictly below 0.25℃ / s; The circulating volumetric flow rate of both cooling circuits is strictly higher than 1.8 L / s; The coolant pressure is in the range of 80–250 kPa, including the endpoints. The error between the valve position feedback and the command opening in the heat exchange channel shall not exceed 3 percentage points; The actual air mass flow rate of the two heat exchange units deviates from the target value by no more than 5%.

[0088] The heat exchanger channel valve position, coolant flow rate, pressure, and actual air mass flow rate are all determined using the most recent 2-second stability window. In addition to a feedback error not exceeding 3 percentage points, the absolute value of the least squares fitted change rate of the heat exchanger channel valve position should also not exceed 0.5 percentage points / second. The coefficients of variation for coolant flow rate, pressure, and actual air mass flow rate should each not exceed 2%. A value of zero, fewer than ten samples, or invalid data within any window indicates that the system has not entered a stable range.

[0089] The diagnostic criteria are not met when the temperature safety margin is 6℃, the engine load change rate is 12% / s, the component temperature rise rate is 0.25℃ / s, or the circulation flow rate is 1.8L / s. The corresponding conditions are considered met when the pressure is 80kPa or 250kPa, the valve position feedback error is 3 percentage points, the air mass flow rate deviation is 5%, and the coefficient of variation is 2%.

[0090] Before the switchover, after all stable conditions are met continuously for 2 seconds, a 10-second pre-switch observation begins. During the switchover, the target heat exchange channel valve is first opened to more than 95% of its target opening degree; only after the target valve position feedback is in place and the corresponding cooling circuit flow rate reaches 1.8 L / s is the original heat exchange channel valve closed. The time period from the start of the target channel's operation to the original channel's complete closure is the switchover transition period. All responses during this period are marked with a transition indicator and are not included in the diagnostic data.

[0091] After the swap, once the valve position and coolant flow rate have returned to a stable range, wait for the corresponding calibration transport delay before starting observations 10 seconds after the swap. The sample size, sampling period, and statistical methods for the observation windows before and after the swap are the same.

[0092] The valve position safety error during the interchange is set at 5 percentage points. The interchange shall be terminated if the valve position feedback error is strictly greater than 5 percentage points for 200 ms consecutively. The interchange shall also be terminated immediately if the temperature of the cooled component is strictly greater than the corresponding temperature safety limit, the circulation flow rate is strictly less than 1.8 L / s, the pressure is strictly less than 80 kPa or strictly greater than 250 kPa, the deviation of the actual air mass flow rate from the reference before the interchange is strictly greater than 5%, or the total interchange time reaches 30 s.

[0093] When restoring the original configuration before the swap, first reopen the original target channel before the swap, confirm that the valve position is in place and the circulation flow rate reaches the minimum circulation flow rate, and then close the channel activated during the swap. Maintain the safe pump speed and the air-side settings before the swap during the restoration. If any critical sensor fails, timestamp exceeds the limit, or the assigned mapping is not unique, perform the same restoration operation according to the conservative principle and identify it as an unresolved anomaly.

[0094] S4. After the heat dissipation residual exceeds the limit continuously, if the diagnostic access condition is not met or the exchange is terminated, the fault category is determined as an unresolved anomaly; otherwise, the fault category is determined based on the residual migration of the response data before and after the exchange. The allocation matrix is ​​updated according to the preset handling of the fault category, the control loop pump valve and air-side actuator are controlled, and the execution result is fed back to the next control cycle.

[0095] This step involves the controller taking the diagnostic task status, pre- and post-swap response data, and safety abort status as inputs. Following a fixed sequence, it determines a unique fault category, writes the corresponding fault handling constraints into the matrix solution process of the next control cycle, and outputs derating commands for pumps, valves, air-side actuators, and the engine. Actuator feedback and the engine controller's derating confirmation together form the execution result of the next control cycle.

[0096] The determination of the fault category based on the residual migration of the response data before and after the swap specifically includes: The residual heat exchange capacity and residual energy consistency of each allocation combination in the execution response before and after the swap are compared according to the correspondence between cooling loops and heat exchange units, wherein the indices of the first cooling loop and the second cooling loop are 1 and 2, respectively, and the indices of the first heat exchange unit and the second heat exchange unit are 1 and 2, respectively. Any allocation combination before and after the interchange satisfies When the heat exchange channel valve position feedback is normal, the coolant flow rate and pressure are within the corresponding stable range, and the actual air mass flow rate is within the stable range, the fault category is determined to be measurement inconsistency abnormality. All allocation combinations before and after the interchange satisfy the following conditions. And the residual heat transfer capacity after the interchange satisfies and When the fault is identified, it is determined to be a heat exchange unit malfunction. All allocation combinations before and after the interchange satisfy the following conditions. And the residual heat transfer capacity after the interchange satisfies and Furthermore, when the coolant flow rate or pressure of the first cooling circuit exceeds the corresponding stable range, the fault category is determined to be a cooling circuit abnormality. If none of the aforementioned conditions are met, the fault category is determined to be an unresolved anomaly, and the fault category is obtained.

[0097] Specifically, the median of each residual within the effective observation window before and after the swap is taken as the classification residual. The residuals used for comparison must belong to the same diagnostic task, the same health baseline version, and the same safety parameter version. During classification, measurement consistency anomalies are identified first, followed by heat exchange unit anomalies and cooling circuit anomalies, and finally, pending anomalies are identified.

[0098] For example, before the swap , After the swap , If none of the energy consistency residuals exceed the limit, then the negative limit-exceeding residuals migrate with the first heat exchange unit, thus determining that the first heat exchange unit is abnormal.

[0099] For example, before the swap , After the swap , If the flow rate or pressure of the first cooling circuit exceeds the stable range, the negative over-limit residual will migrate with the first cooling circuit, thus determining that the first cooling circuit is abnormal.

[0100] If the absolute value of the energy consistency residual before and after the swap is 0.14, and the valve position, coolant flow rate, pressure, and actual air mass flow rate are all within a stable range, then because 0.14 is greater than... If the measurement consistency is abnormal, it will be prioritized and the location of the circuit or heat exchange unit will no longer be determined based on the residual heat exchange capacity.

[0101] The step of updating the allocation matrix according to the preset handling of the fault category specifically includes: When the fault category is heat exchange unit abnormality, the abnormal heat exchange unit is placed into the disabled set, and fault handling constraints are generated based on the disabled set; When the fault category is cooling circuit abnormality, maintain the minimum circulation flow of the abnormal cooling circuit and control engine derating to generate fault handling constraints; When the fault category is measurement inconsistency anomaly, the fault location results and active interchange of the residual migration are stopped. The maximum value among multiple redundant temperature measurements of the same cooled component is used as the conservative control temperature and the engine is derated to generate fault handling constraints. When the fault category is unresolved anomaly, priority is given to ensuring the cooling circuit with the smallest difference between the corresponding temperature safety limit and the temperature of the cooled component, and the engine is derated to generate fault handling constraints. The allocation matrix is ​​updated based on the fault handling constraints to generate the updated allocation matrix.

[0102] Fault handling constraints include fault category, fault object index, generation time, health baseline version, safety parameter version, validity flag, and retention status. Fault handling constraints are written to non-volatile memory. After the controller is powered off and restarted, the valid constraints are read and restored first, and then the allocation matrix calculation is performed to prevent the restart from bypassing the disabled or derating state of the heat exchange unit.

[0103] When a heat exchange unit malfunctions, all matrix elements of the corresponding heat exchange unit are fixed to 0. When a cooling circuit malfunctions, a pump / valve command capable of maintaining a circulation flow rate of at least 1.8 L / s is selected using a hydraulic calibration table, and an engine derating request is made. When measurement consistency is abnormal, invalid channels are eliminated from at least two independent temperature channels of the same cooled component, and the maximum value of the remaining valid measurements is taken. When unresolved anomalies occur, the cooling circuit is maintained in order of increasing temperature safety margin.

[0104] Fault handling constraints can only be lifted under maintenance authorization status. Before lifting, the faulty object must complete three consecutive health verifications, each lasting 60 seconds; within the three verification windows, all relevant sensors must be effective, residuals must not exceed limits, pump and valve feedback must be normal, and temperature safety margins must not be lower than [a certain value]. At a certain temperature, the controller receives a maintenance release command. If any verification window fails to meet the conditions, the health verification count is reset to zero, but the fault handling constraints remain in place.

[0105] like Figure 3 As shown, the current control cycle sequentially completes status data acquisition, allocation matrix generation and coordinated control, heat dissipation residual determination, and continuous limit violation judgment. If there are no continuous limit violations, the execution results are directly fed back to the next control cycle; if there are continuous limit violations, the diagnostic access conditions are verified, and a time-limited swap is implemented if they are met. If no valid response data before and after the swap is generated, it is determined as an unresolved anomaly; when valid data is generated, the fault category is determined based on residual migration and energy consistency residuals. For each fault category, fault handling constraints are generated, the allocation matrix is ​​updated, and fault-tolerant control is executed.

[0106] like Figure 4 As shown, the allocation matrix is ​​arranged with cooling loops as rows and heat exchange units as columns. The combination residual record for each activity combination includes the combination index, coolant-side heat dissipation, air-side heat dissipation, expected heat dissipation, heat exchange capacity residual, energy consistency residual, and out-of-limit status. The swap observation record includes the allocation relationship before swap, the allocation relationship after swap, stable valve position, stable flow rate, actual air mass flow rate, preset observation duration, calibrated transport delay, and switching transition data removal flags. The diagnostic and control record includes residual migration results, fault categories, fault handling constraints, and the updated allocation matrix.

[0107] This embodiment also provides an engine multi-loop cooling coordinated control system. For example... Figure 5As shown, the dashed box represents the controller boundary. The status acquisition module, cooperative allocation module, interchange identification module, and fault classification and fault-tolerant control module are located inside the controller; the engine controller, status sensor group, cooling circuit, heat exchange unit array, and corresponding actuators are located outside the controller.

[0108] An engine multi-loop cooling coordinated control system, the system being used to implement the above method, and the system comprising: The status acquisition module is used to collect engine operating conditions, thermofluid status, and actuator status to form status data. The collaborative allocation module is used to generate an allocation matrix based on the state data, according to temperature safety, minimum flow rate, fault isolation and energy consumption priority. During steady-state allocation, each heat exchange unit is allocated to at most one cooling loop. The module controls the loop pumps and valves and air-side actuators according to the allocation matrix, compares the execution response with the health benchmark, and determines the heat dissipation residual and its over-limit status. The interchange identification module is used to select two cooling circuits and two heat exchange units containing the over-limit combination for timed interchange when the heat dissipation residual continuously exceeds the limit and meets the diagnostic access conditions, while keeping the number of circuit allocation units and the air-side setting of the heat exchange unit unchanged, and forming response data before and after the interchange; if the temperature, pressure, valve position exceeds the safe range or the flow rate is lower than the safe lower limit, the interchange is stopped and the allocation matrix is ​​restored. The fault classification and fault tolerance control module is used to determine the fault category as unresolved anomaly when the diagnostic access conditions are not met or the exchange is terminated after the heat dissipation residual continuously exceeds the limit; otherwise, the fault category is determined based on the residual migration of the response data before and after the exchange; the allocation matrix is ​​updated according to the preset handling of the fault category, the control loop pump valve and air-side actuator are controlled, and the execution result is fed back to the next control cycle.

[0109] The status acquisition module includes a data acquisition unit, a time synchronization unit, a validity verification unit, and a sensor position mapping unit. The data acquisition unit obtains engine operating conditions, thermofluid status, and actuator feedback through an analog input interface or vehicle communication interface. The time synchronization unit converts the input to the controller's unified clock. The validity verification unit outputs status data with a validity flag. The sensor position mapping unit determines the corresponding activity combination of the common manifold sensors based on the allocation matrix, valve position, and effective transport delay. If mapping fails, the status acquisition module outputs an invalid data status to the cooperative allocation module and the interchange identification module.

[0110] The collaborative allocation module includes a temperature safety margin calculation unit, a candidate matrix enumeration unit, a hydraulic calibration table lookup unit, a feasibility screening unit, a matrix sorting unit, an effective transport delay calculation unit, a health baseline storage unit, a residual calculation unit, and an actuator command unit. The collaborative allocation module receives status data and fault handling constraints, and outputs the allocation matrix, pump / valve commands, air-side commands, heat dissipation residuals, and out-of-limit states. Actuator commands are sent via a digital drive interface, a pulse-width modulation interface, or a vehicle communication interface, and the execution feedback returns to the status acquisition module.

[0111] The interchange identification module includes a continuous over-limit timing unit, a diagnostic task sequencing unit, a reference combination selection unit, a diagnostic access judgment unit, an interchange state machine, a stable observation window management unit, and a safety rollback unit. The interchange state machine includes at least the following states: standby, pre-interchange observation, opening the target channel, confirming the target flow, closing the original channel, waiting for calibration transport delay, post-interchange observation, recovery, and abort. Each state only proceeds to the next state when the corresponding valve position, flow rate, time, and safety conditions are met; otherwise, it enters the recovery or abort state.

[0112] The fault classification and fault-tolerant control module includes a residual migration comparison unit, a fault category determination unit, a disabled set management unit, a redundant temperature processing unit, a derating request unit, a constraint persistence unit, and an allocation matrix update unit. This module receives response data before and after the exchange or unresolved abnormal states, outputs fault categories and fault handling constraints, feeds the constraints back to the cooperative allocation module, and sends a derating or shutdown request to the engine controller through the vehicle communication interface.

[0113] The aforementioned modules can be implemented by the controller processor executing programs stored in non-volatile memory, or by a combination of microcontrollers, programmable logic devices, or corresponding functional circuits. Modules exchange status data, allocation matrices, diagnostic tasks, response data, and fault handling constraints through versioned data records in shared memory or internal message queues.

[0114] To verify the feasibility of the method, the following conditions can be set up on an engine thermal management test bench or in a hardware-in-the-loop system: reduced heat exchange capacity of the heat exchange unit, increased flow resistance in the cooling loop, and measurement link deviation faults. Different control strategies are implemented using the same engine load, ambient temperature, initial coolant temperature, residual threshold, and fault injection level.

[0115] like Figure 6 As shown in (a), under abnormal heat exchange unit conditions, the residual heat exchange capacity of the first cooling loop-first heat exchange unit combination exceeds the limit before the swap. After the swap, the residual exceeding the limit is transferred to the second cooling loop-first heat exchange unit combination, while the first cooling loop-second heat exchange unit combination does not exceed the limit. This result indicates that the exceeding state migrates with the first heat exchange unit, supporting the classification of abnormal heat exchange units.

[0116] like Figure 6 As shown in (b), under abnormal cooling circuit conditions, the residual heat exchange capacity of the first cooling circuit-first heat exchange unit combination exceeds the limit before the swap. After the swap, the residual exceeding the limit is transferred to the first cooling circuit-second heat exchange unit combination, while the second cooling circuit-first heat exchange unit combination does not exceed the limit. Combined with the flow rate or pressure of the first cooling circuit exceeding the stable range, it can be determined that the limit-exceeding state migrates with the first cooling circuit, supporting the classification of cooling circuit abnormalities.

[0117] like Figure 7 As shown, without transport delay compensation and while retaining transitional data, the fault classification accuracy decreases rapidly with increasing engine load change rate. Compensation for transport delay alone or removal of transitional data improves classification accuracy. Simultaneously employing transport delay waiting, stability determination, equal-length observation windows, and removal of transitional data results in high classification accuracy within the diagnostic threshold. When the engine load change rate reaches 12% / s, active diagnosis ceases, consistent with the strict less-than relationship in the diagnostic threshold conditions.

[0118] like Figure 8 As shown in (a), the horizontal axis represents the degree of heat dissipation loss of the heat exchange unit, and the vertical axis represents the minimum temperature safety margin. The "temperature margin threshold" marked in the figure corresponds to the fault-tolerant control temperature safety margin threshold of this embodiment. ℃, does not correspond to the diagnostic admission temperature margin threshold. ℃. When the heat exchange unit's heat dissipation capacity loss is 50%, the minimum temperature safety margin for conventional independent temperature threshold control is approximately 2.5℃, while the minimum temperature safety margin for fault-tolerant redistribution control after fault classification is approximately 5.6℃. The former is lower than The latter is higher than .

[0119] like Figure 8 As shown in (b), the horizontal axis represents the degree of heat dissipation capacity loss of the heat exchange unit, and the vertical axis represents the total power consumption of the electric water pump and the air-side actuator. When the heat dissipation capacity loss is 50%, the total power consumption of the actuator under conventional independent temperature threshold control is approximately 4.0 kW, and the total power consumption of the actuator under fault-tolerant redistribution control after fault classification is approximately 3.15 kW. After reaching the feasible distribution boundary shown in the figure, the controller no longer maintains the original load but enters the engine derating branch.

[0120] When the number of cooling loops and heat exchange units is greater than two, an over-limit combination and a reference combination are still selected according to the aforementioned deterministic rules. Only the four matrix elements corresponding to two cooling loops and two heat exchange units are replaced at a time, while other matrix elements remain unchanged. After completing the current task, the tasks in the queue are re-verified and processed sequentially, without executing multiple active swapping tasks simultaneously.

[0121] The heat exchange unit can be a multi-channel heat exchange core with multiple isolated heat exchange channels, or it can be an isolated heat exchange module that is physically parallel and shares an air-side duct. When using a shared air-side duct, each heat exchange unit is still equipped with separate air inlet temperature, air outlet temperature, and branch air mass flow rate measurement points to ensure that the air-side heat dissipation of each heat exchange unit can be determined separately.

[0122] The coolant mass flow rate can be directly measured by a mass flow sensor, or it can be obtained by multiplying the coolant volumetric flow rate by the coolant density at the corresponding temperature. When using the latter method, the coolant density is obtained from a temperature-density calibration table with a version; if the input exceeds the calibration range, the heat dissipation residual for that cycle is not calculated.

[0123] The health baseline preferably adopts the aforementioned four-dimensional health calibration table. When changing the calibration grid interval, stable observation window length, or interpolation, the four types of indices—coolant inlet temperature, coolant mass flow rate, air mass flow rate, and ambient temperature—should remain unchanged, and the common constraints of health status sampling, in-calibration interpolation, version verification, cross-domain disabling, and prohibition of updates during faults should be maintained.

[0124] The aforementioned threshold and time parameters constitute a preferred parameter set, which can be adjusted through bench calibration based on engine heat capacity, cooling circuit volume, pump and valve response time, and the allowable temperature range of the cooled components. After adjustment, the versions of the hydraulic calibration table, health baseline, safety parameters, and control software should be linked and saved. Active swapping should be stopped and conservative cooling and engine derating should be maintained if versions are inconsistent.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-loop cooling coordinated control method for an engine, characterized in that, Each heat exchange unit's heat exchange channels correspond to its respective loop and are fluidly isolated from each other, including: S1. Collect engine operating conditions, thermofluid status and actuator status to form status data; S2. Based on the state data, generate an allocation matrix according to temperature safety, minimum flow rate, fault isolation and energy consumption priority; during steady-state allocation, each heat exchange unit is allocated to at most one cooling loop, and the loop pump valve and air-side actuator are controlled according to the allocation matrix, the execution response is compared with the health benchmark, and the heat dissipation residual and its over-limit state are determined. S3. When the heat dissipation residual continuously exceeds the limit and meets the diagnostic access conditions, select two cooling circuits and two heat exchange units containing the limit-exceeding combination to be interchanged within a time limit, keeping the number of circuit allocation units and the air side setting of the heat exchange unit unchanged, and forming response data before and after the interchange; if the temperature, pressure, valve position exceeds the safe range or the flow rate is lower than the safe lower limit, stop the interchange and restore the allocation matrix. S4. After the heat dissipation residual exceeds the limit continuously, if the diagnostic access condition is not met or the exchange is terminated, the fault category is determined as an unresolved anomaly; otherwise, the fault category is determined based on the residual migration of the response data before and after the exchange. The allocation matrix is ​​updated according to the preset handling of the fault category, the control loop pump valve and air-side actuator are controlled, and the execution result is fed back to the next control cycle.

2. The method according to claim 1, characterized in that, The process of generating an allocation matrix based on the status data, according to temperature safety, minimum flow rate, fault isolation, and energy consumption priority, specifically includes: The difference between the corresponding temperature safety limit of the component to be cooled and the current temperature of the component to be cooled is determined as the component temperature safety margin. Based on the actuator status, available heat exchange units are determined, and feasible allocation relationships are screened in the order of component temperature safety, minimum circulation flow of the cooling circuit, fault isolation, number of switching times, and execution energy consumption. When multiple feasible allocation relationships exist, the feasible allocation relationship with the fewest switching times of the heat exchange channel valves relative to the previous control cycle is selected. When the number of switching times is the same, the feasible allocation relationship with the lowest total power consumption of the loop water pump and air-side actuator is selected. When no feasible allocation relationship exists, the available heat exchange units are preferentially allocated to the cooling circuit with the smallest temperature safety margin of the component, and the engine is derated to generate the allocation matrix.

3. The method according to claim 1, characterized in that, The control loop pump valves and air-side actuators according to the allocation matrix specifically include: Identify the first and second coolant temperature inflection points generated at the cooling circuit outlet and the target heat exchange unit inlet respectively by the same engine natural load change. Integrate the coolant volume flow rate from the detection time of the first coolant temperature inflection point to the detection time of the second coolant temperature inflection point to obtain the effective transport volume. Determine the effective transport delay as the ratio of the effective transport volume to the average coolant volume flow rate of the current control cycle. The early start time of the target heat exchange unit is determined based on the effective transport delay, and the corresponding heat exchange channel valve and air-side actuator are controlled at the early start time. If the first coolant temperature inflection point and the second coolant temperature inflection point cannot be completely detected, the effective transport delay of the previous control cycle is used. If there is no effective transport delay of the previous control cycle, the allocation matrix is ​​executed using the calibrated transport delay.

4. The method according to claim 1, characterized in that, The comparison between the execution response and the health benchmark to determine the heat dissipation residual and its out-of-limit status specifically includes: According to the The cooling circuit flows through the first Coolant mass flow rate of each heat exchange unit Specific heat capacity of coolant Coolant inlet temperature and coolant outlet temperature ,according to Determine the heat dissipation on the coolant side ; According to the Air mass flow rate of each heat exchange unit Specific heat capacity of air Air inlet temperature and air outlet temperature ,according to Determine the heat dissipation on the air side ; Using the coolant inlet temperature, coolant mass flow rate, air mass flow rate, and ambient temperature as indexes, the desired heat dissipation is obtained from a health baseline. ,according to Determine the residual heat transfer capacity ,according to Determine the energy consistency residual The heat dissipation residual is composed of the heat transfer capacity residual and the energy consistency residual; in or If the heat dissipation residual is in an over-limit state, it is determined that the heat dissipation residual is in a non-over-limit state. The lower limit of positive heat dissipation. and The positive threshold is defined as the duration of the over-limit state reaching the calibration determination time, thus obtaining the heat dissipation residual and its over-limit state.

5. The method according to claim 4, characterized in that, The selection of two cooling circuits and two heat exchange units containing the over-limit combination involves a time-limited interchange while maintaining the number of circuit allocation units and the air-side settings of the heat exchange units unchanged, generating response data before and after the interchange. Specifically, this includes: The two cooling circuits are labeled as the first cooling circuit and the second cooling circuit, and the two heat exchange units are labeled as the first heat exchange unit and the second heat exchange unit. The over-limit combination consists of the first cooling circuit and the first heat exchange unit. The combination in which the heat dissipation residual of the second cooling circuit and the second heat exchange unit does not exceed the limit is used as the reference combination. After the heat exchange channel valve position and coolant flow rate of the combination before the swapping enter the stable range, the execution response before the swapping is recorded within a preset observation period. Maintain the air-side settings of the first heat exchange unit and the second heat exchange unit respectively, control the heat exchange channel valve to switch the first cooling circuit to the second heat exchange unit, and switch the second cooling circuit to the first heat exchange unit to form an interchangeable combination; After the valve position and coolant flow rate of the heat exchange channel after the swapping combination enter a stable range, wait for the calibrated transport delay from the cooling circuit outlet to the heat exchange unit inlet, record the execution response after the swapping within the preset observation period, discard the response during the switching transition, and use the execution response before the swapping and the execution response after the swapping as the response data before and after the swapping.

6. The method according to claim 5, characterized in that, The diagnostic admission criteria are as follows: the temperature safety margin obtained by subtracting the temperature of the cooled component from the corresponding temperature safety limit of the two cooling circuits is greater than the temperature margin threshold; the engine load change rate and the component temperature rise rate are both lower than the corresponding change rate threshold; the circulation flow rate is higher than the minimum circulation flow rate; the pressure is within the safe range; there is no valve position abnormality in the heat exchange channel valve; and the actual air mass flow rate of the two heat exchange units is within the stable range. The control heat exchange channel valve adopts a switching method in which the target heat exchange channel is opened first, and the original heat exchange channel is closed after the valve position feedback of the target heat exchange channel indicates that it is fully opened and the flow rate of the corresponding cooling circuit reaches the minimum circulation flow rate. During the switching transition period of opening first and then closing, the heat exchange channels corresponding to the two cooling circuits in the same heat exchange unit and fluidly isolated from each other are opened simultaneously. The response during the switching transition period is not included in the response data before and after the switch. During the interchange, monitor component temperature, coolant flow rate, pressure, heat exchange channel valve position, actual air mass flow rate, and interchange duration. If the component temperature exceeds the corresponding temperature safety limit, the coolant flow rate is lower than the minimum circulation flow rate, the pressure or the heat exchange channel valve position exceeds the corresponding safety range, the deviation of the actual air mass flow rate from the pre-interchange reference exceeds the air flow deviation threshold, or the interchange duration reaches the calibration upper limit, restore the pre-interchange configuration and terminate the interchange.

7. The method according to claim 5, characterized in that, The determination of the fault category based on the residual migration of the response data before and after the swap specifically includes: The residual heat exchange capacity and residual energy consistency of each allocation combination in the execution response before and after the swap are compared according to the correspondence between cooling loops and heat exchange units, wherein the indices of the first cooling loop and the second cooling loop are 1 and 2, respectively, and the indices of the first heat exchange unit and the second heat exchange unit are 1 and 2, respectively. Any allocation combination before and after the interchange satisfies When the heat exchange channel valve position feedback is normal, the coolant flow rate and pressure are within the corresponding stable range, and the actual air mass flow rate is within the stable range, the fault category is determined to be measurement inconsistency abnormality. All allocation combinations before and after the interchange satisfy the following conditions. And the residual heat transfer capacity after the interchange satisfies and When the fault is identified, it is determined to be a heat exchange unit malfunction. All allocation combinations before and after the interchange satisfy the following conditions. And the residual heat transfer capacity after the interchange satisfies and Furthermore, when the coolant flow rate or pressure of the first cooling circuit exceeds the corresponding stable range, the fault category is determined to be a cooling circuit abnormality. If none of the aforementioned conditions are met, the fault category is determined to be an unresolved anomaly, and the fault category is obtained.

8. The method according to claim 7, characterized in that, The step of updating the allocation matrix according to the preset handling of the fault category specifically includes: When the fault category is heat exchange unit abnormality, the abnormal heat exchange unit is placed into the disabled set, and fault handling constraints are generated based on the disabled set; When the fault category is cooling circuit abnormality, maintain the minimum circulation flow of the abnormal cooling circuit and control engine derating to generate fault handling constraints; When the fault category is measurement inconsistency anomaly, the fault location results and active interchange of the residual migration are stopped. The maximum value among multiple redundant temperature measurements of the same cooled component is used as the conservative control temperature and the engine is derated to generate fault handling constraints. When the fault category is unresolved anomaly, priority is given to ensuring the cooling circuit with the smallest difference between the corresponding temperature safety limit and the temperature of the cooled component, and the engine is derated to generate fault handling constraints. The allocation matrix is ​​updated based on the fault handling constraints to generate the updated allocation matrix.

9. A multi-loop cooling coordinated control system for an engine, characterized in that, The system is used to implement the method of any one of claims 1 to 8, and the system comprises: The status acquisition module is used to collect engine operating conditions, thermofluid status, and actuator status to form status data. The collaborative allocation module is used to generate an allocation matrix based on the state data, according to temperature safety, minimum flow rate, fault isolation and energy consumption priority. During steady-state allocation, each heat exchange unit is allocated to at most one cooling loop. The module controls the loop pumps and valves and air-side actuators according to the allocation matrix, compares the execution response with the health benchmark, and determines the heat dissipation residual and its over-limit status. The interchange identification module is used to select two cooling circuits and two heat exchange units containing the over-limit combination for timed interchange when the heat dissipation residual continuously exceeds the limit and meets the diagnostic access conditions, while keeping the number of circuit allocation units and the air-side setting of the heat exchange unit unchanged, and forming response data before and after the interchange; if the temperature, pressure, valve position exceeds the safe range or the flow rate is lower than the safe lower limit, the interchange is stopped and the allocation matrix is ​​restored. The fault classification and fault tolerance control module is used to determine the fault category as unresolved anomaly when the diagnostic access conditions are not met or the exchange is terminated after the heat dissipation residual continuously exceeds the limit; otherwise, the fault category is determined based on the residual migration of the response data before and after the exchange; the allocation matrix is ​​updated according to the preset handling of the fault category, the control loop pump valve and air-side actuator are controlled, and the execution result is fed back to the next control cycle.

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