Engine water temperature control method and device

Abstract

The present invention discloses an engine water temperature control method and device, comprising the following steps: designing an objective function in an MPC controller that includes tracking of the actual water temperature against a target water temperature and the fan's accessory power consumption, so as to optimize fan energy consumption while ensuring the engine water temperature does not exceed a thermal protection temperature; acquiring vehicle operating data, inputting the operating data into the MPC controller, and outputting a fan target speed; and controlling the engine water temperature based on the fan target speed. This application enables reasonable planning of the fan's target speed, allowing the fan to operate more frequently in a low speed range while ensuring the engine water temperature does not exceed the temperature, thereby reducing fan accessory power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle thermal management, and in particular to an engine water temperature control method and device. Background Art

[0002] Engine water temperature control is a crucial aspect of an automotive engine management system, ensuring the engine operates within the optimal temperature range under varying operating conditions. Maintaining engine water temperature within this range is crucial for extending engine life and ensuring vehicle performance.

[0003] The engine cooling system primarily consists of a water pump, thermostat, fan, radiator, radiator, water jacket in the engine block and cylinder head, and auxiliary devices. Heat loss from combustion within the engine cylinders is caused by exhaust gas loss, a small cooling water cycle, a large cooling water cycle, and heat dissipation from the cylinder block and cylinder head. Because engine heat generation and dissipation are complex processes, the engine cooling system typically uses water temperature as a control target.

[0004] Water temperature exhibits the characteristics of a high-inertia hysteresis system. This is because controlling engine water temperature involves multiple complex physical processes, including heat generation, transfer, and heat dissipation. During operation, the engine generates a large amount of heat, primarily through the combustion process, which is then dissipated through various pathways, including the exhaust system and the water circulation system. Due to the physical characteristics of these processes, changes in water temperature exhibit a certain hysteresis, meaning that the increase or decrease in water temperature is not instantaneous, but rather requires a period of accumulation or dissipation. Furthermore, water temperature control is affected by a variety of factors, such as the efficiency of the cooling system, ambient temperature, and engine load, all of which increase the complexity of water temperature control and cause it to exhibit high inertia and hysteresis characteristics.

[0005] While existing PID control methods can keep engine temperature within the thermal protection threshold, they cannot address the fan power consumption issues caused by system lag. Therefore, resolving the water temperature control lag and reducing fan power consumption are pressing technical challenges. Summary of the Invention

[0006] The main purpose of the present invention is to provide an engine water temperature control method and device, which can reasonably plan the target speed of the fan, and allow the fan to operate more in the low speed range under the premise that the engine water temperature does not exceed the temperature, thereby achieving the purpose of reducing the power consumption of fan accessories.

[0007] In a first aspect, the present application provides an engine water temperature control method, wherein the method comprises the steps of:

[0008] Design an objective function in the MPC controller that includes the tracking of the actual water temperature against the target water temperature and the fan's auxiliary power consumption, so that the fan's energy consumption is optimized while the engine water temperature does not exceed the thermal protection temperature.

[0009] Acquire vehicle operating data, input the operating data into the MPC controller, and output a fan target speed;

[0010] The water temperature of the engine is controlled based on the target fan speed.

[0011] In conjunction with the first aspect above, as an optional implementation, an objective function is designed in the MPC controller, and the optimal energy consumption of the fan is determined based on the engine water temperature without overheating through the objective function, wherein the design of the objective function includes: tracking of the actual water temperature against the target water temperature and the power consumption of the fan;

[0012] The objective function expression is: J(z k )=J y (z k )+J uF (z k ), where k is the current control moment, z k is the decision variable vector of the gradient descent method;

[0013] Among them, J y (z k ) is the tracking of the actual water temperature to the target water temperature, and its expression is: Among them, i is the prediction period, P is the prediction step size, is the weight of the actual water temperature tracking the target water temperature in the i-th prediction period, r(k+i|k) is the output reference value of the i-th prediction period, and y(k+i|k) is the predicted water temperature value of the i-th period;

[0014] J uF (z k ) is the power consumption of the fan, and its expression is: Where WiF is the weight of the fan power consumption of the control quantity in the i-th prediction period, a is the set value, u F (k+i|k) is the control quantity of the i-th prediction period.

[0015] In conjunction with the first aspect above, as an optional implementation, weight values ​​of sub-items of the objective function are set, wherein the sub-items include: fan power consumption and tracking of the actual water temperature against the target water temperature;

[0016] According to different control requirements, the weight value of each sub-item of the objective function is adjusted.

[0017] In combination with the first aspect above, as an optional implementation method, the prediction model in the MPC controller is configured to output the fan target speed, which includes: configuring the manipulated variables, interference quantities and measurement outputs, wherein the manipulated variables include: the speed of the electronically controlled silicone oil fan, the interference quantities include: engine speed, engine torque, ambient temperature and vehicle speed, and the measurement output includes: the actual measurement value of the engine water temperature.

[0018] In conjunction with the first aspect above, as an optional implementation, constraints are imposed on the manipulated variables, the changes in the manipulated variables, and the predicted temperature;

[0019] The manipulated variable constraints include: setting the minimum speed of the electronically controlled silicone oil fan to the idle speed and the maximum speed to the product of the drive speed ratio and the engine speed;

[0020] The change constraints of the manipulated variables include: designing constraint values ​​for the fan speed increase rate and decrease rate according to the meshing characteristics of the electronically controlled silicone oil fan;

[0021] The predicted temperature constraint includes: the designed predicted water temperature must not exceed the thermal protection temperature of the engine.

[0022] In combination with the first aspect above, as an optional implementation, the operating data includes: vehicle speed, engine speed, engine torque, ambient temperature, fan speed and target water temperature.

[0023] In combination with the first aspect above, as an optional implementation method, the basic target water temperature is obtained by querying the MAP using the engine speed and torque;

[0024] The basic target water temperature is corrected according to the current vehicle speed and ambient temperature to calculate the target water temperature.

[0025] In combination with the first aspect above, as an optional implementation, the determined target speed of the silicone oil fan is input into the vehicle thermal management control system;

[0026] The vehicle thermal management control system uses PI to control the actual fan speed through feedback values ​​of the target fan speed and the actual fan speed to adjust the water temperature of the engine.

[0027] In combination with the first aspect above, as an optional implementation method, the objective function designs the prediction time domain and the prediction control output step size according to the water temperature hysteresis characteristics.

[0028] In a second aspect, the present application provides an engine water temperature control device, the device comprising:

[0029] A design module is used to design an objective function in the MPC controller that includes the tracking of the actual water temperature to the target water temperature and the fan's auxiliary power consumption, so that the fan's energy consumption is optimized while the engine water temperature does not exceed the thermal protection temperature;

[0030] a processing module configured to obtain vehicle operating data, input the operating data into the designed MPC controller, and output a target fan speed;

[0031] A control module is configured to control the water temperature of the engine based on the target fan speed.

[0032] This application provides an engine water temperature control method and device, which includes the following steps: designing an objective function in an MPC controller that includes tracking of the actual water temperature against the target water temperature and the fan's accessory power consumption, so that the fan's energy consumption is optimized while the engine water temperature does not exceed the thermal protection temperature; obtaining vehicle operating data, inputting the operating data into the MPC controller, and outputting a fan target speed; and controlling the engine water temperature based on the fan target speed. This application can reasonably plan the fan's target speed, allowing the fan to operate more frequently in a low speed range while the engine water temperature does not exceed the temperature, thereby achieving the goal of reducing the fan's accessory power consumption.

[0033] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0035] Figure 1 This is a flow chart of an engine water temperature control method provided in an embodiment of the present application;

[0036] Figure 2 This is a schematic diagram of an engine water temperature control device provided in an embodiment of the present application;

[0037] Figure 3 This is a schematic diagram of engine water temperature control provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0039] Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Some of the blocks shown in the drawings are functional entities that do not necessarily correspond to physically or logically separate entities.

[0040] The embodiments of the present application are further described in detail below with reference to the accompanying drawings.

[0041] Reference Figure 1 , Figure 1 The figure shows a flow chart of an engine water temperature control method provided by the present invention, as shown in FIG. Figure 1 As shown, the method includes the steps of:

[0042] Step S101: Design an objective function in the MPC controller that includes the tracking of the actual water temperature to the target water temperature and the fan's accessory power consumption, so that the fan's energy consumption is optimally controlled without the engine water temperature exceeding the thermal protection temperature.

[0043] Specifically, an objective function is designed in the MPC controller, and the optimal energy consumption of the fan is determined based on the engine water temperature without overheating. The design of the objective function includes: tracking the actual water temperature to the target water temperature and the power consumption of the fan;

[0044] The objective function expression is: J(z k )=J y (z k )+J uF (z k ), where k is the current control moment, z k is the decision variable vector of the gradient descent method;

[0045] Among them, J y (z k ) is the tracking of the actual water temperature to the target water temperature, and its expression is: Among them, i is the prediction period, P is the prediction step size, is the weight of the actual water temperature tracking the target water temperature in the i-th prediction cycle, r(k+i|k) is the output reference value of the i-th prediction cycle, and y(k+i|k) is the predicted water temperature value of the i-th cycle, where y is the predicted water temperature. Specifically, collect the operating data of the commercial vehicle, including vehicle speed, engine speed, engine torque, ambient temperature, fan speed, and water temperature. This operating data needs to include vehicle speed (0-90km / h), engine speed (500-2600rpm / min), engine torque (-300Nm-2500Nm), ambient temperature (10℃-45℃), fan speed (0-2300rpm / min), and water temperature (10℃-105℃). The ranges given above are all reference ranges and can be adjusted according to the specific engine model and vehicle model.

[0046] Using the Identification Toolbox in MATLAB, we developed a dynamic model for water temperature. The model is as follows: x(k+1) = Ax(k) + Bu(k); y(k) = Cx(k) + Du(k), where x represents the system state variable for engine water temperature, A, B, C, and D represent the parameter matrix, and u represents the vector of vehicle speed, engine speed, engine torque, ambient temperature, and fan speed. y represents the predicted engine water temperature.

[0047] Where, A=[0.9981 -0.01372 -0.00825 -0.0041650.005744 0.8885 -0.2046 -0.04946 -0.002967 0.08225 0.7124 -0.2246-0.007192 0.006945 -0.03385 0.9285].

[0048] B=[8.162e-07-5.683e-06 8.363e-09 -1.565e-08 5.948e-082.697e-06 -4.472e-05 8.25e-07 -1.083e-06 6.997e-071.075e-05 6.67e-05 -2.995e-07 -4.248e-06 5.681e-06-3.321e-06 2.525e-05 -1.445e-08 -3.582e-07 8.872e-07].

[0049] C=[-1450 -2.096 -3.316 -0.6278].

[0050] D=[0 0 0 0 0].

[0051] J uF (z k) is the power consumption of the fan, and its expression is: Where WiF is the weight of the fan power consumption of the control quantity in the i-th prediction period, a is the set value, u F (k+i|k) is the control quantity of the i-th prediction period.

[0052] The objective function design also includes designing a prediction time domain and a predictive control step size based on the large hysteresis characteristics of the water temperature. It is understood that designing the prediction time domain and predictive control step size can save computing resources.

[0053] In one embodiment, the weight values ​​of each sub-item of the objective function are set, wherein the sub-items include: fan power consumption and tracking of the actual water temperature to the target water temperature; the weight values ​​of each sub-item of the objective function are adjusted according to different control requirements. It is understandable that, for example, when the constraint on the manipulated variable target speed needs to be strengthened, the weight value of each sub-item of the objective function can be increased. When it is necessary to reduce The same applies to the output water temperature. Specifically, weights for each sub-item of the objective function are set based on the MPC controller's control performance requirements. To increase the penalty for changes in the manipulated variable, increase the weight of the manipulated variable change rate restriction term.

[0054] It should be noted that the design of the MPC controller includes the design of the prediction model, the design of the objective function, the design of the controller constraints and the optimization solver.

[0055] Among them, the design of the MPC controller also includes the design of a prediction model, which includes configuring the prediction model in the MPC controller to output the fan target speed, which includes: configuring manipulated variables, interference quantities and measurement outputs, wherein the manipulated variables include: the speed of the electronically controlled silicone oil fan, the interference quantities include: engine speed, engine torque, ambient temperature and vehicle speed, and the measurement output includes: the actual measurement value of the engine water temperature.

[0056] It also includes constraints on manipulated variables, changes in manipulated variables and predicted temperatures; the manipulated variable constraints include: designing the minimum speed of the electronically controlled silicone oil fan to be idle speed, and designing the maximum speed to be the product of the drive speed ratio and the engine speed (i.e., engine speed × drive speed ratio); the manipulated variable change constraints include: designing constraint values ​​for the fan speed increase rate and decrease rate based on the engagement characteristics of the electronically controlled silicone oil fan (i.e., the fan target speed change rate range is -300rpm / s, 300rpm / s); the predicted temperature constraints include: designing the predicted water temperature not to exceed the engine's thermal protection temperature (e.g., 105°C).

[0057] It's understood that the engine water temperature prediction model inputs are: engine speed, engine torque, ambient temperature, vehicle speed, and fan speed; the output is the predicted water temperature value. The prediction model can take the form of a transfer function or a linear state-space model. In the engine water temperature model predictive control, the manipulated variable (required fan speed) is designed to be the speed of the electronically controlled silicone oil fan. Observable disturbances (interference quantities) include: engine speed, engine torque, ambient temperature, vehicle speed, etc. The measurable output is the measured engine water temperature value.

[0058] Constraints for designing the MPC controller: Manipulated variables: The minimum speed of the electronically controlled silicone oil fan is idle speed, and the maximum speed is the speed ratio multiplied by the engine speed.

[0059] The change constraints of the manipulated variables; the fan speed increase rate and decrease rate limits. The change constraints of the manipulated variables can be given different constraint values ​​according to the characteristics of the electronically controlled silicone oil fan, which engages quickly and disengages slowly.

[0060] Predicted water temperature maximum constraint: The predicted water temperature must not exceed the engine's thermal protection temperature.

[0061] In one embodiment, the target engine water temperature must be determined before designing the MPC controller. It is understood that the target engine water temperature must be determined by comprehensively considering engine speed, engine torque, vehicle speed, and ambient temperature. Engine speed and torque represent engine load, and vehicle speed affects engine cooling: as vehicle speed increases, headwind removes some heat, thereby lowering engine temperature and regulating the water temperature. Ambient temperature also affects the temperature rise of the engine water temperature. In particular, when ambient temperature is high, the target water temperature should be appropriately lowered to avoid engine overtemperature protection.

[0062] In one embodiment, a base target water temperature is obtained by querying a MAP using engine speed and torque; the base target water temperature is then corrected based on the current vehicle speed and ambient temperature to calculate the target water temperature. It is understood that the base target water temperature is obtained by querying a MAP using engine speed and torque, and the target water temperature is corrected by vehicle speed, with the target water temperature being appropriately increased at higher vehicle speeds, and the target water temperature being corrected by ambient temperature, with the target water temperature being lowered as the ambient temperature increases.

[0063] Among them, the optimization solution is to use the gradient descent method to solve the control quantity when the objective function of MPC is minimum: that is, the target speed of the fan.

[0064] It is understandable that designing the objective function and constraints in the MPC controller can reasonably plan the target speed of the fan. On the premise that the engine water temperature does not exceed the temperature, the fan can be operated more in the low speed area, which can achieve the purpose of reducing the power consumption of the fan accessories.

[0065] Step S102: Acquire vehicle operating data, input the operating data into the MPC controller, and output the fan target speed.

[0066] Specifically, the operating data includes vehicle speed, engine speed, engine torque, ambient temperature, fan speed, and target water temperature. The operating data is input into the designed MPC control to obtain the fan target speed.

[0067] Step S103: Control the water temperature of the engine based on the fan target speed.

[0068] Specifically, a gradient descent method can be used to solve for the control variable at the minimum value of the MPC objective function: the target fan speed. The determined target speed of the silicone oil fan is input into the vehicle thermal management control system. The vehicle thermal management control system uses the PI control to control the actual fan speed based on feedback from the target fan speed and the actual fan speed to regulate the engine water temperature.

[0069] It's important to note that the thermal management cooling system for commercial vehicle engines primarily consists of a mechanical water pump, a wax thermostat, an electronically controlled silicone oil fan, and a radiator. The power consumption of the electronically controlled silicone oil fan is strongly correlated with the fan speed. The power consumption difference between low and high fan speeds is significant.

[0070] Reference Figure 2 , Figure 2 FIG. 1 is a schematic diagram of an engine water temperature control device provided by the present invention, as shown in FIG. Figure 2 As shown, the device includes:

[0071] Design module 201: It is used to design an objective function in the MPC controller that includes the tracking of the actual water temperature to the target water temperature and the fan's auxiliary power consumption, so as to control the fan's energy consumption to the optimal level without exceeding the thermal protection temperature of the engine water temperature.

[0072] Processing module 202 is used to obtain vehicle operation data, input the operation data into the designed MPC controller, and output the fan target speed.

[0073] The control module 203 is configured to control the water temperature of the engine based on the target fan speed.

[0074] Furthermore, in a possible embodiment, a design module is configured to design an objective function in the MPC controller, and determine the optimal energy consumption of the fan based on the engine water temperature without overheating, wherein the design of the objective function includes: tracking of the actual water temperature to the target water temperature and the power consumption of the fan;

[0075] The objective function expression is: J(z k)=J y (z k )+J uF (z k ), where k is the current control moment and k is the decision variable vector of the gradient descent method;

[0076] Among them, J y (z k ) is the tracking of the actual water temperature to the target water temperature, and its expression is: Among them, i is the prediction period, P is the prediction step size, is the weight of the actual water temperature tracking the target water temperature in the i-th prediction period, r(k+i|k) is the output reference value of the i-th prediction period, and y(k+i|k) is the predicted water temperature value of the i-th period;

[0077] J uF (z k ) is the power consumption of the fan, and its expression is: Where WiF is the weight of the fan power consumption of the control quantity in the i-th prediction period, a is the set value, u F (k+i|k) is the control quantity of the i-th prediction period.

[0078] Furthermore, in a possible embodiment, a module is designed for setting weight values ​​of sub-items of the objective function, wherein the sub-items include: fan power consumption and tracking of actual water temperature against target water temperature;

[0079] According to different control requirements, the weight value of each sub-item of the objective function is adjusted.

[0080] Furthermore, in a possible implementation, the design module is also used to configure the prediction model in the MPC controller to output the fan target speed, which includes: configuring the manipulated variables, interference quantities and measurement outputs, wherein the manipulated variables include: the speed of the electronically controlled silicone oil fan, the interference quantities include: engine speed, engine torque, ambient temperature and vehicle speed, and the measurement output includes: the actual measurement value of the engine water temperature.

[0081] Furthermore, in a possible implementation, the design module is further configured to constrain the manipulated variables, the changes in the manipulated variables, and the predicted temperature;

[0082] The manipulated variable constraints include: setting the minimum speed of the electronically controlled silicone oil fan to the idle speed and the maximum speed to the product of the drive speed ratio and the engine speed;

[0083] The change constraints of the manipulated variables include: designing constraint values ​​for the fan speed increase rate and decrease rate according to the meshing characteristics of the electronically controlled silicone oil fan;

[0084] The predicted temperature constraint includes: the designed predicted water temperature must not exceed the thermal protection temperature of the engine.

[0085] Furthermore, in a possible implementation manner, the processing module further includes an acquisition module, which is used for the operating data including: vehicle speed, engine speed, engine torque, ambient temperature, fan speed and target water temperature.

[0086] Furthermore, in a possible implementation, the processing module is further configured to obtain a basic target water temperature by querying a MAP using the engine speed and torque;

[0087] The basic target water temperature is corrected according to the current vehicle speed and ambient temperature to calculate the target water temperature.

[0088] Furthermore, in a possible implementation manner, the control module is further configured to input the determined target speed of the silicone oil fan into the vehicle thermal management control system;

[0089] The vehicle thermal management control system uses PI to control the actual fan speed through feedback values ​​of the target fan speed and the actual fan speed to adjust the water temperature of the engine.

[0090] Furthermore, in a possible implementation manner, the design module is also used to design the prediction time domain and the prediction control output step size according to the water temperature hysteresis characteristics of the objective function.

[0091] Reference Figure 3 , Figure 3 The figure shows the engine water temperature control schematic diagram provided by the present invention, as shown in FIG. Figure 3 As shown:

[0092] The MPC controller includes a prediction model, a predictive control objective function, constraints, and a solver.

[0093] The prediction model for engine water temperature takes as input the following: engine speed, engine torque, ambient temperature, vehicle speed, and fan speed; the output is the predicted water temperature. The prediction model can be a transfer function or a linear state-space model. In the model predictive control of engine water temperature, the manipulated variable (required fan speed) is designed to be the speed of the electronically controlled silicone oil fan.

[0094] Constraints for designing MPC controllers:

[0095] Manipulated variable: The minimum speed of the electronically controlled silicone oil fan is idle speed, and the maximum speed is the speed ratio multiplied by the engine speed.

[0096] Manipulated variable change constraints: fan speed increase rate, decrease rate limit. Manipulated variable change constraints can be given different constraint values ​​according to the characteristics of the electronically controlled silicone oil fan, which engages quickly and disengages slowly.

[0097] Predicted water temperature maximum constraint: The predicted water temperature must not exceed the engine's thermal protection temperature.

[0098] Design of objective function:

[0099] The optimization cost function of the cooling system optimization problem is to find the optimal cooling system actuator action. The designed objective function includes the tracking of the actual water temperature to the target water temperature and the power consumption of the fan.

[0100] The objective function designs the prediction time domain and the prediction control step size according to the characteristics of large hysteresis of water temperature.

[0101] Set the weights of the various sub-items in the objective function based on the control performance requirements of the MPC controller. If you need to increase the penalty for changes in the manipulated variable, increase the weight of the limit term for the manipulated variable change rate.

[0102] Optimization solver: uses the gradient descent method to solve the control variable when the MPC objective function is minimized: that is, the target speed of the fan.

[0103] In one embodiment, the designed MPC algorithm has an objective function that includes tracking the actual water temperature against the target water temperature and the fan's power consumption. Assuming the water temperature does not exceed the thermal protection temperature, the fan's power consumption is minimized, thereby reducing fuel consumption and fan noise.

[0104] According to cab noise test data, fan noise levels range from 57 to 70 decibels when operating at speeds between 200 and 2300 rpm. At these speeds, fan accessories consume 20W to 42kW of power. Therefore, optimizing fan control is crucial for reducing both engine fuel consumption and noise. The optimization objectives for both (noise and power consumption) are consistent: operating the fan within the low to medium speed range as much as possible.

[0105] It can be understood that the design of an MPC controller includes: objective function and constraint design. Specifically, by collecting vehicle operating data, including vehicle speed, engine speed, engine torque, ambient temperature, fan speed, water temperature, etc., the collected data is input into the designed MPC controller to generate the optimal control quantity through the MPC controller, and then reasonably plan the target speed of the fan. On the premise that the engine water temperature does not exceed the temperature, the fan is allowed to operate more in the low speed area, which can achieve the purpose of reducing the power consumption of fan accessories.

[0106] Based on the same inventive concept, an embodiment of the present application further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, all or part of the method steps of the above method are implemented.

[0107] The present application implements all or part of the processes in the above-mentioned method, and can also be completed by instructing related hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0108] Based on the same inventive concept, an embodiment of the present application also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program running on the processor, and when the processor executes the computer program, all or part of the method steps in the above method are implemented.

[0109] The processor may be a central processing unit (CPU), other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor. The processor is the control center of a computer device and connects various parts of the entire computer device using various interfaces and lines.

[0110] The memory can be used to store computer programs and / or modules. The processor implements various functions of the computer device by running or executing the computer programs and / or modules stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system and at least one application required for a function (such as a sound playback function, an image playback function, etc.); in addition, the memory can include a high-speed random access memory and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0111] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, servers, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer-usable program code.

[0112] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), servers and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0113] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0114] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0115] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for controlling engine water temperature, characterized in that: include: Design an objective function in the MPC controller that includes the tracking of the actual water temperature against the target water temperature and the fan's auxiliary power consumption, so that the fan's energy consumption is optimized while the engine water temperature does not exceed the thermal protection temperature. Acquire vehicle operating data, input the operating data into the MPC controller, and output a fan target speed; controlling the water temperature of the engine based on the fan target speed; The objective function is designed in the MPC controller, and the optimal energy consumption of the fan is determined based on the engine water temperature without overheating. The design of the objective function includes: tracking of the actual water temperature to the target water temperature and the power consumption of the fan; The objective function expression is: ,in, is the current control moment, is the decision variable vector of the gradient descent method; in, The actual water temperature tracks the target water temperature, and its expression is: ,in, is the forecast period, is the prediction step length, For the The weight of the actual water temperature in each prediction period to the target water temperature tracking, For the The output reference value of the prediction cycle, For the predicted Water temperature value of each cycle; is the power consumption of the fan, which is expressed as: ,in, For the The weight of the fan power consumption controlled by the prediction cycle, is the set value, For the The control quantity for a forecast period.

2. The method according to claim 1, characterized in that Also includes: Setting weights for each sub-item of the objective function, wherein the sub-items include: fan power consumption and tracking of the actual water temperature against the target water temperature; According to different control requirements, the weight value of each sub-item of the objective function is adjusted.

3. The method according to claim 1, characterized in that Also includes: The prediction model in the MPC controller is configured to output the fan target speed, which includes: configuring the manipulated variable, the interference variable and the measurement output, wherein the manipulated variable includes: the speed of the electronically controlled silicone oil fan; the interference variable includes: the engine speed, the engine torque, the ambient temperature and the vehicle speed; the measurement output includes: the actual measurement value of the engine water temperature.

4. The method according to claim 3, characterized in that Also includes: Constraints are placed on the manipulated variables, their changes, and the predicted temperature; The manipulated variable constraints include: setting the minimum speed of the electronically controlled silicone oil fan to the idle speed and the maximum speed to the product of the drive speed ratio and the engine speed; The change constraints of the manipulated variables include: designing constraint values ​​for the fan speed increase rate and decrease rate according to the meshing characteristics of the electronically controlled silicone oil fan; The predicted temperature constraint includes: the designed predicted water temperature must not exceed the thermal protection temperature of the engine.

5. The method according to claim 1, wherein The obtaining of vehicle operation data includes: The operating data includes: vehicle speed, engine speed, engine torque, ambient temperature, fan speed and target water temperature.

6. The method according to claim 5, characterized in that include: Use engine speed and engine torque to check MAP to get the basic target water temperature; The basic target water temperature is corrected according to the current vehicle speed and ambient temperature to calculate the target water temperature.

7. The method according to claim 1, characterized in that The controlling of the water temperature of the engine based on the fan target speed includes: inputting the determined target speed of the silicone oil fan into the vehicle thermal management control system; The vehicle thermal management control system uses PI to control the actual fan speed through feedback values ​​of the target fan speed and the actual fan speed to adjust the water temperature of the engine.

8. The method according to claim 1, characterized in that The design of the objective function also includes: The objective function designs the prediction time domain and the prediction control output step size according to the water temperature hysteresis characteristics.

9. An engine water temperature control device, characterized in that: include: A design module is used to design an objective function in the MPC controller that includes the tracking of the actual water temperature to the target water temperature and the fan's auxiliary power consumption, so that the fan's energy consumption is optimized while the engine water temperature does not exceed the thermal protection temperature; a processing module configured to obtain vehicle operating data, input the operating data into the designed MPC controller, and output a target fan speed; a control module, configured to control a water temperature of the engine based on the target fan speed; The design module is further configured to design an objective function in the MPC controller, and determine the optimal energy consumption of the fan based on the engine water temperature without overheating, wherein the design of the objective function includes: tracking of the actual water temperature to the target water temperature and the power consumption of the fan; The objective function expression is: ,in, is the current control moment, is the decision variable vector of the gradient descent method; in, The actual water temperature tracks the target water temperature, and its expression is: ,in, is the forecast period, is the prediction step length, For the The weight of the actual water temperature in each prediction period to the target water temperature tracking, For the The output reference value of the prediction cycle, For the predicted Water temperature value of each cycle; is the power consumption of the fan, which is expressed as: ,in, For the The weight of the fan power consumption controlled by each prediction cycle, is the set value, For the The control quantity for a forecast period.

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