Engine water temperature control method and device

Abstract

The invention discloses an engine water temperature control method and device, and the method comprises the steps: designing a target function containing the tracking of the actual water temperature on the target water temperature and the accessory power consumption of a fan in an MPC controller, so as to control the optimal energy consumption of the fan on the premise that the engine water temperature does not exceed the thermal protection temperature; acquiring vehicle operation data, inputting the operation data into the MPC controller, and outputting a target rotating speed of a fan; and controlling the water temperature of the engine based on the fan target rotating speed. According to the method, the target rotating speed of the fan can be reasonably planned, on the premise that the water temperature of the engine does not exceed the temperature, the fan can more run in a low-rotating-speed area, and the purpose of reducing the power consumption of fan accessories can be achieved.

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 very important aspect of the automotive engine management system, which ensures that the engine can operate within the optimal temperature range under different working conditions. Maintaining the engine water temperature within the appropriate range is crucial to extending the engine life and ensuring vehicle performance.

[0003] The engine cooling system mainly consists of a water pump, a thermostat, a fan, a radiator, a water tank, a water jacket in the engine block and cylinder head, and auxiliary devices. The heat loss generated by combustion in the engine cylinder is caused by exhaust loss, a small cooling water cycle, a large cooling water cycle, and heat dissipation in the cylinder block and cylinder head. Since the heat generation and heat dissipation of the engine is a complex process, the engine cooling system usually uses water temperature as a control target.

[0004] The water temperature has the characteristics of a large inertia hysteresis system. This is because the control of the engine water temperature involves multiple complex physical processes, including the generation, transfer and heat dissipation of heat. The engine generates a large amount of heat during operation, which is mainly generated through the combustion process and then dissipated through various channels, including the exhaust system, water circulation system, etc. Due to the physical characteristics of these processes, there is a certain hysteresis in the change of water temperature, that is, the increase or decrease of water temperature is not completed instantly, but requires a period of accumulation or dissipation. In addition, the control of water temperature is also affected by many factors, such as the efficiency of the cooling system, ambient temperature, engine load, etc., which increase the complexity of water temperature control and make it show large inertia and hysteresis characteristics.

[0005] Although the existing PID control method can satisfy the engine temperature control within the thermal protection threshold range, it cannot solve the fan accessory power consumption problem caused by system lag. Therefore, how to solve the water temperature control hysteresis problem and reduce the fan power consumption is a technical problem that needs to be solved urgently. 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 a low speed area 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 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;

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

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

[0011] In combination with the first aspect, as an optional implementation method, an objective function is designed in the MPC controller, and the optimal energy consumption of the fan is determined by the objective function under the premise that the engine water temperature does not exceed the temperature, 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;

[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 length, is the weight of the actual water temperature in the ith prediction period to the target water temperature tracking, r(k+i|k) is the output reference value of the ith prediction period, and y(k+i|k) is the predicted water temperature value of the ith 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 i-th prediction cycle control quantity, a is the set value, u F (k+i|k) is the control quantity of the i-th prediction period.

[0015] In combination with the first aspect above, as an optional implementation method, 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 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: the engine speed, the engine torque, the ambient temperature and the vehicle speed, and the measurement output includes: the actual measurement value of the engine water temperature.

[0018] In combination 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 setting 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 method, 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, as an optional implementation method, the basic target water temperature is obtained by checking the MAP using the engine speed and torque;

[0024] The basic target water temperature is corrected according to the current vehicle speed and the 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 speed of the fan 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 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 exceeding the thermal protection temperature of the engine water temperature;

[0030] A processing module, which is used to obtain vehicle operation data, input the operation data into the designed MPC controller, and output a fan target speed;

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

[0032] The present application provides an engine water temperature control method and device, wherein the method includes the following steps: designing an objective function in the 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 engine water temperature does not exceed the thermal protection temperature, and the fan's energy consumption is optimally controlled; obtaining vehicle operation data, and inputting the operation data into the MPC controller, and outputting the fan target speed; and controlling the engine water temperature based on the fan target speed. The present application can reasonably plan the fan's target speed, and under the premise that the engine water temperature does not exceed the temperature, allow the fan to operate more in the low speed zone, which can achieve the purpose of reducing the fan accessory power consumption.

[0033] It is to 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 A flow chart of an engine water temperature control method provided in an embodiment of the present application;

[0036] Figure 2 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] Here, exemplary embodiments will be described in detail, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

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

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

[0041] Reference Figure 1 , Figure 1 FIG. 1 is 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 comprises 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 by the objective function under the premise that the engine water temperature does not exceed the temperature, 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;

[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 length, is the weight of the actual water temperature of the ith prediction period to the target water temperature tracking, r(k+i|k) is the output reference value of the ith prediction period, y(k+i|k) is the predicted water temperature value of the ith period, where y is the predicted water temperature. Specifically, the operating data of commercial vehicles are collected, including vehicle speed, engine speed, engine torque, ambient temperature, fan speed, and water temperature. The 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, a dynamic model of water temperature is obtained. The dynamic model of water temperature is as follows: x(k+1)=Ax(k)+Bu(k); y(k)=Cx(k)+Du(k), where x is the system state quantity of engine water temperature, A, B, C, D are parameter matrices, and u is a vector composed of vehicle speed, engine speed, engine torque, ambient temperature, and fan speed. y is the predicted engine water temperature.

[0047] Among them, 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 i-th prediction cycle control quantity, a is the set value, u F (k+i|k) is the control quantity of the i-th prediction period.

[0052] The design of the objective function also includes: the objective function designs the prediction time domain and the prediction control step size according to the characteristics of the large hysteresis of the water temperature. It can be understood that the design of the prediction time domain and the prediction 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 target water temperature by the actual 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 is true for the output water temperature. That is, the weight values ​​of each sub-item of the objective function are set according to the control performance requirements of the MPC controller. If you need to increase the penalty for the manipulated variable change, you can increase the weight of the restriction item of the manipulated variable change rate.

[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 according to the electronically controlled silicone oil fan meshing characteristics (i.e., the fan target speed change rate ranges from -300rpm / s to 300rpm / s); the predicted temperature constraints include: designing the predicted water temperature not to exceed the thermal protection temperature of the engine (e.g., 105°C).

[0057] It can be understood that the prediction model input of engine water temperature is: engine speed, engine torque, ambient temperature, vehicle speed, fan speed, and the output is the predicted value of water temperature. The prediction model can be in the form of a transfer function or a linear state space model. In the model prediction control of engine water temperature, the designed manipulated variable (fan demand speed) is the speed of the electronically controlled silicone oil fan. Observable interference (interference quantity): engine speed, engine torque, ambient temperature, vehicle speed, etc. Measurable output: engine water temperature measurement 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] Change constraints of manipulated variables; fan speed increase rate and decrease rate limits. Change constraints of manipulated variables can be given different constraint values ​​according to the characteristics of the electric-controlled silicone oil fan that engages quickly and disengages slowly.

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

[0061] In one embodiment, the target water temperature of the engine needs to be designed before designing the MPC controller. It is understandable that the target water temperature of the engine needs to comprehensively consider the engine speed, engine torque, vehicle speed, and ambient temperature settings. The engine speed and torque represent the load of the engine, and the vehicle speed will affect the cooling of the engine: when the vehicle speed increases, the oncoming wind will take away some heat, thereby reducing the temperature of the engine and adjusting the water temperature. The ambient temperature will also affect the temperature rise of the engine water temperature. In particular, when the ambient temperature is high, the target water temperature should be appropriately lowered to avoid engine over-temperature protection.

[0062] In one embodiment, the basic target water temperature is obtained by checking the MAP using the engine speed and torque; the basic target water temperature is corrected according to the current vehicle speed and ambient temperature to calculate the target water temperature. It can be understood that the basic target water temperature is obtained by checking the MAP using the engine speed and torque, the vehicle speed corrects the target water temperature, the higher the vehicle speed, the higher the target water temperature can be appropriately increased, the ambient temperature corrects the target water temperature, the higher the ambient temperature, the lower the target water temperature.

[0063] Among them, the optimization solution, that is, the gradient descent method is used 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. Under the premise that the engine water temperature does not exceed the temperature, the fan can be operated more in the low speed area, thereby achieving the purpose of reducing the power consumption of the fan accessories.

[0065] Step S102: Acquire vehicle operation data, input the operation 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: Controlling the water temperature of the engine based on the fan target speed.

[0068] Specifically, the gradient descent method can be used to solve the control quantity when the objective function of MPC is at its minimum value: that is, the target speed of the fan. The determined target speed of the silicone oil fan is input to the vehicle thermal management control system; the vehicle thermal management control system uses PI to control the actual speed of the fan through the feedback value of the target fan speed and the actual fan speed to adjust the water temperature of the engine.

[0069] It should be noted that the thermal management cooling system of commercial vehicle engines mainly 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 related to the fan speed. The power consumption of the fan is greatly different when it is running at a low speed and when it is running at a high speed.

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

[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 auxiliary power consumption of the fan, so that the energy consumption of the fan is optimally controlled without exceeding the thermal protection temperature of the engine water temperature.

[0072] Processing module 202: It 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 used to control the water temperature of the engine based on the fan target speed.

[0074] Further, in a possible implementation manner, a design module is used to design an objective function in the MPC controller, and through the objective function, the optimal energy consumption of the fan is determined 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 length, is the weight of the actual water temperature in the ith prediction period to the target water temperature tracking, r(k+i|k) is the output reference value of the ith prediction period, and y(k+i|k) is the predicted water temperature value of the ith 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 i-th prediction cycle control quantity, a is the set value, u F (k+i|k) is the control quantity of the i-th prediction period.

[0078] Further, in a possible implementation, a module is designed to set weight values ​​of each sub-item of the objective function, wherein the sub-items include: fan power consumption and tracking of actual water temperature to 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 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: the engine speed, the engine torque, the ambient temperature and the 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 also used 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 setting 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 also 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 manner, 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 the 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 speed of the fan 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 FIG. 1 is a schematic diagram of engine water temperature control provided by the present invention, as shown in FIG. Figure 3 As shown:

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

[0093] Among them, the prediction model: the prediction model input of the engine water temperature is: engine speed, engine torque, ambient temperature, vehicle speed, fan speed, and the output is the water temperature prediction value. The prediction model can be in the form of a transfer function or a linear state space model. In the model predictive control of the engine water temperature, the designed manipulated variable (fan demand speed) is the speed of the electronically controlled silicone oil fan.

[0094] Constraints for designing MPC controller:

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

[0096] Change constraints of manipulated variables: fan speed increase rate, decrease rate limit. Change constraints of manipulated variables can be given different constraint values ​​according to the characteristics of fast engagement and slow disengagement of the electric-controlled silicone oil fan.

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

[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] The weight values ​​of each sub-item of the objective function are set according to the control performance requirements of the MPC controller. If you need to increase the penalty for the manipulated variable change, you can increase the weight of the restriction item of the manipulated variable change rate.

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

[0103] In one embodiment, the designed MPC algorithm has an objective function including tracking of the actual water temperature against the target water temperature and the fan's accessory power consumption. Under the premise that the water temperature does not exceed the thermal protection temperature, the fan's power consumption is controlled to be minimum, thereby achieving the purpose of reducing fuel consumption and fan noise.

[0104] According to the cab noise test data, when the fan runs at a speed of 200-2300rpm / min, the noise is 57-70db. When the fan speed is 200-2300rpm / min, the fan's accessory power consumption is 20W-42kw. Therefore, fan control optimization is of great significance to reducing engine fuel consumption and noise. The optimization direction of the two (noise and power consumption) is also the same, and the fan is operated in the medium and low speed range as much as possible.

[0105] It can be understood that the design of the MPC controller includes: objective function and constraint design. Specifically, by collecting the vehicle's 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. Under 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 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 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. When the computer program is executed by the processor, the steps of each of the above method embodiments can be implemented. 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 capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, 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. 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, the computer-readable medium does 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, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (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, etc. The processor is the control center of a computer device, and uses various interfaces and lines to connect various parts of the entire computer device.

[0110] The memory can be used to store computer programs and / or modules. The processor realizes 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 an application required for at least one 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 devices.

[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 in combination with software and hardware. Moreover, 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 disk storage and optical storage, etc.) that contain 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 generate 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 capable of directing a computer or other programmable data processing device to operate 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 A 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 operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0115] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also 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 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; Acquire vehicle operation data, input the operation data into the MPC controller, and output a fan target speed; The water temperature of the engine is controlled based on the fan target speed.

2. The method according to claim 1, characterized in that The objective function designed in the MPC controller includes tracking of the actual water temperature to the target water temperature and the auxiliary power consumption of the fan, including: An objective function is designed in the MPC controller, and the optimal energy consumption of the fan is determined by the objective function under the premise that the engine water temperature does not exceed the temperature, 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: 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; 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 length, and W i y is the weight of the actual water temperature in the ith prediction period to the target water temperature tracking, r(k+i|k) is the output reference value of the ith prediction period, and y(k+i|k) is the predicted water temperature value of the ith period; 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 i-th prediction cycle control quantity, a is the set value, u F (k+i|k) is the control quantity of the i-th prediction period.

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

4. 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 variables, the disturbance variables and the measured outputs, wherein the manipulated variables include: the speed of the electronically controlled silicone oil fan, the disturbance variables include: the engine speed, the engine torque, the ambient temperature and the vehicle speed, and the measured output includes: the actual measured value of the engine water temperature.

5. The method according to claim 4, 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 setting 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.

6. The method according to claim 1, characterized in that The obtaining of vehicle operation data comprises: The operating data includes: vehicle speed, engine speed, engine torque, ambient temperature, fan speed and target water temperature.

7. The method according to claim 6, characterized in that include: Use engine speed and 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 the ambient temperature to calculate the target water temperature.

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

9. 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.

10. 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 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 exceeding the thermal protection temperature of the engine water temperature; A processing module, which is used to obtain vehicle operation data, input the operation data into the designed MPC controller, and output a fan target speed; A control module is used to control the water temperature of the engine based on the fan target speed.

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