Active diffuser angle control method, system and device based on fuzzy control and storage medium

Abstract

The invention discloses an active diffuser angle control method, system and device based on fuzzy control and a storage medium, and belongs to the technical field of automobiles, and the method comprises the steps that 1, an aerodynamic vehicle body six-degree-of-freedom model of a vehicle is established, and an aerodynamic six-component influence model and stress analysis of a diffuser on the vehicle are obtained; 2, determining the output of the controller as the angle of the diffuser according to the working principle and property of the diffuser, and fuzzifying the angle; 3, determining that the input of the controller is the difference value between the expected acceleration and the slip rate of the front and rear tires, and fuzzifying the difference value; 4, formulating a fuzzy control rule; according to the control method, the fuzzy control rule can be designed according to the effect of the diffuser on the vehicle under different driving conditions, the angle of the diffuser can be adjusted under different conditions, and the effects of improving the aerodynamic performance of the vehicle, improving the energy consumption of the vehicle and improving the operation stability of the vehicle are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of automobile technology, and in particular relates to a control method, system, device and storage medium for an active diffuser angle based on fuzzy control. Background Art

[0002] In recent years, vehicle aerodynamic components have become a major focus of vehicle aerodynamic research. The diffuser at the rear of the vehicle is one of the aerodynamic components. Reasonable use of the diffuser can effectively improve vehicle energy consumption and improve vehicle handling. However, a fixed diffuser cannot be adjusted as the vehicle's state changes. An active diffuser can adjust the state of the diffuser according to different driving scenarios, thereby achieving different aerodynamic characteristics in different situations, improving vehicle energy consumption, and increasing driving stability and safety. Summary of the invention

[0003] In view of the above-mentioned defects in the prior art, the present invention provides a control method, system, device and storage medium for an active diffuser angle based on fuzzy control, which can design fuzzy control rules according to the effect of the diffuser on the vehicle under different driving conditions, realize the adjustment of the diffuser angle under different conditions, and obtain the effect of improving the vehicle's aerodynamic performance, improving the vehicle's energy consumption and handling stability.

[0004] The present invention is achieved through the following technical solutions:

[0005] In a first aspect, the present invention provides a method for controlling an active diffuser angle based on fuzzy control, which specifically comprises the following steps:

[0006] Step 1: Establish a six-degree-of-freedom model of the vehicle's aerodynamic body, and derive the diffuser's aerodynamic six-component force influence model and force analysis on the vehicle;

[0007] Step 2: According to the working principle and properties of the diffuser, the output of the controller is determined to be the angle of the diffuser, and the angle is fuzzified;

[0008] Step 3: Determine the controller input as the difference between the desired acceleration and the front and rear tire slip rates, and fuzzify it;

[0009] Step 4: Formulate fuzzy control rules.

[0010] Furthermore, in step 1, the aerodynamic force and aerodynamic moment of the active diffuser on the vehicle body in the X, Y, and Z directions are respectively:

[0011] F AeroX =-F Drag (0-1)

[0012] F AreoY =0 (0-2)

[0013] F Areoz -F Down (0-3)

[0014] M AreoX =0 (0-4)

[0015] M AreoY =F Drag HkD Down l (0-5)

[0016] M AreoZ =0 (0-6)

[0017] Among them, F AeroX 、F AeroY 、F AeroZ are the aerodynamic forces in the X, Y, and Z directions, M AeroX 、M AeroY 、M AeroZ are the aerodynamic moments around X, Y, and Z, respectively, and F Down is the downforce generated by the active diffuser, F Drag is the air resistance generated by the active diffuser, h is the height distance from the active diffuser action point to the vehicle's center of mass, and l is the longitudinal distance from the active diffuser action point to the vehicle's center of mass.

[0018] Furthermore, step 2 specifically includes the following contents:

[0019] Assume that the angle of the diffuser is AoD, and its adjustable range is [-30°, 30°]. The value of the fuzzy domain is [-30, 30]. Its fuzzy subset is set to {NL (negative large), NM (negative medium), NS (negative small), 0, PS (positive small), PM (positive medium), PL (positive large)}; the membership function of the angle AoD fuzzy set adopts Gaussian and joint Gaussian membership functions, and the distribution is set as follows: Among them, the two fuzzy subsets NL and PL adopt the joint Gaussian membership distribution function, and their parameters are as follows:

[0020] NL:y=gauss2mf(x,[1-30 2-25]);

[0021] PL:y=gauss2mf(x,[2 25 1 30]);

[0022] Among them, gauss2mf represents the double Gaussian mixture function, and the parameters in brackets are the parameters of the double Gaussian mixture function;

[0023] The other subsets use Gaussian membership distribution functions with the following parameters:

[0024] NM:y=gaussmf(x,[2.5-17]);

[0025] NS:y=gaussmf(x,[2-8]);

[0026] 0:y=gaussmf(x,[2 0]);

[0027] PS:y=gaussmf(x,[2 8]);

[0028] PM:y=gaussmf(x,[2.5 17]);

[0029] Gaussmf represents a Gaussian function, where the values ​​in the brackets are the parameters of the Gaussian function.

[0030] Furthermore, in step 3, the expected acceleration Acc of the vehicle exp It is calculated from the accelerator pedal opening and the brake pedal opening. The specific calculation method is as follows:

[0031] Acc exp =Pd Gas -Pd Brake

[0032] Among them, Pd Gas is the accelerator pedal opening, Pd Brake is the brake pedal opening, the range is [0,1]; the expected acceleration Acc exp The range is [-1,1], the fuzzy domain takes the value [-1,1], and its fuzzy subsets are set to {BL (reduce), BM (reduce medium), BS (reduce), 0, GS (increase), GM (increase medium), GL (increase)}, Acc exp The membership function distribution of the fuzzy set is set as follows: Among them, the two subsets BL and GL use mixed Gaussian membership distribution functions, and the specific parameters are as follows:

[0033] BL:y=gauss2mf(x,[1-1 0.1-0.85]);

[0034] GL:y=gauss2mf(x,[0.1 0.85 1 1]);

[0035] Other subsets use Gaussian membership functions, and the specific parameters are as follows:

[0036] BM:y=gaussmf(x,[0.06-0.5]);

[0037] BS:y=gaussmf(x,[0.06-0.25]);

[0038] 0:y=gaussmf(x,[0.05 0]);

[0039] GS:y=gaussmf(x,[0.06 0.25]);

[0040] GM:y=gaussmf(x,[0.06 0.5]).

[0041] Furthermore, in step 3, the difference S between the front and rear tire slip rates is F&R The specific calculation formula is as follows:

[0042] S F&R =max{S RL ,S RR}-{S FL ,F FR}

[0043] Where S RL ,S RR is the slip rate of the two rear wheels, S FL ,F FR is the slip rate of the two front wheels.

[0044] S F&R The range of is [-1,1], the fuzzy domain takes the value [-1,1], and its fuzzy subset is set to {FL (front large), FM (front middle), FS (front small), 0, RS (back small), RM (back middle), RL (back large)}; S RF& The membership function distribution of the fuzzy subsets is set as follows: The FL and RL subsets use a mixed Gaussian membership distribution function, and the specific parameters are as follows:

[0045] FL:y=gauss2mf(x,[0.6-1 0.06-0.5]);

[0046] RL:y=gauss2mf(x,[0.06 0.5 0.6 1]);

[0047] Other subsets use Gaussian membership functions, and the specific parameters are as follows:

[0048] FM:y=gaussmf(x,[0.05-0.3]);

[0049] FS:y=gaussmf(x,[0.04-0.15]);

[0050] 0:y=gaussmf(x,[0.04 0]);

[0051] RS:y=gaussmf(x,[0.04 0.15]);

[0052] RM:y=gaussmf(x,[0.05 0.3]);

[0053] Furthermore, in step 4, fuzzy rules are formulated according to the properties and effects of the tail wing.

[0054] In a second aspect, the present invention provides a control system for an active diffuser angle based on fuzzy control, comprising:

[0055] Establish a module for establishing a six-degree-of-freedom model of the vehicle's aerodynamic body, and derive the six-component force model and force analysis of the diffuser on the vehicle's aerodynamics;

[0056] A determination module, used for determining the output of the controller as the angle of the diffuser according to the working principle and properties of the diffuser, and fuzzifying it;

[0057] A fuzzy module determines the controller input as the difference between the desired acceleration and the front and rear tire slip rates, and fuzzifies it;

[0058] The formulation module is used to formulate fuzzy control rules.

[0059] In a third aspect, the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for controlling an active diffuser angle based on fuzzy control as described in any one of the embodiments of the present invention is implemented.

[0060] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for controlling an active diffuser angle based on fuzzy control as described in any one of the embodiments of the present invention.

[0061] Compared with the prior art, the advantages of the present invention are as follows:

[0062] The present invention provides a control method, system, device and storage medium for an active diffuser based on fuzzy control. When a car is driving in different driving environments, the angle of the diffuser is controlled according to the running state of the vehicle and the operation of the driver, so that the vehicle can achieve the best air performance in the current state and obtain a balanced improvement in energy consumption and improved handling performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0064] Figure 1 A control flow chart of a control method for an active diffuser angle based on fuzzy control according to the present invention;

[0065] Figure 2 The aerodynamic six-component force model and diffuser influence force diagram adopted by the invention;

[0066] Figure 3 It is the surface diagram of the input-output relationship of the fuzzy controller;

[0067] Figure 4 This is a comparison diagram of the longitudinal speed during the acceleration process of straight-line driving when the active diffuser is in effect and the longitudinal speed without the diffuser;

[0068] Figure 5 It is a comparison diagram of the trajectories with and without active diffuser under double lane change conditions;

[0069] Figure 6 The yaw angular velocity comparison diagram with and without active diffuser under double lane change conditions;

[0070] Figure 7 This is a schematic diagram of the structure of an electronic device in Example 3 of the present invention. DETAILED DESCRIPTION

[0071] In order to clearly and completely describe the technical solution and its specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings of the specification:

[0072] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0075] Example 1

[0076] A method for controlling the angle of a vehicle active diffuser based on fuzzy control comprises the following steps:

[0077] Step 1: Establish a six-degree-of-freedom model of the vehicle's aerodynamic body, and derive the diffuser's aerodynamic six-component force influence model and force analysis on the vehicle;

[0078] Step 2: According to the working principle and properties of the diffuser, the output of the controller is determined to be the angle of the diffuser, and the angle is fuzzified;

[0079] Step 3: Determine the controller input as acceleration request, front and rear wheel slip rate, and fuzzify them;

[0080] Step 4: Design fuzzy control rules and fuzzy controller;

[0081] In the step 1:

[0082] The vehicle aerodynamic six-component force model is as follows Figure 2 As shown in the figure, the forces and moments shown in the figure are all generated by air action, among which F AeroX 、F AeroY 、F AeroZ are the aerodynamic forces in the X, Y, and Z directions, M AeroX 、M AeroY 、M AeroZ are the aerodynamic moments around X, Y, and Z, respectively, and F Down is the downforce generated by the active diffuser, F Drag is the air resistance generated by the active diffuser, h is the height distance from the active diffuser action point to the vehicle's center of mass, and l is the longitudinal distance from the active diffuser action point to the vehicle's center of mass.

[0083] According to the influence of the active diffuser on the six aerodynamic forces, the aerodynamic force and aerodynamic moment of the active diffuser on the vehicle body in the x, y, and z directions are:

[0084] F AeroX =-F Drag (0-7)

[0085] F AreoY =0 (0-8)

[0086] F Areoz =-F Down (0-9)

[0087] M AreoX =0 (0-10)

[0088] M AreoY =F Drag HkD Down l (0-11)

[0089] M AreoZ =0 (0-12)

[0090] Step 2: According to the properties of the active diffuser, the output of the control strategy is determined to be the angle of the diffuser. The angle of the diffuser is AoD, and its adjustable range is [-30°, 30°]. The value of the fuzzy domain is [-30, 30]. Its fuzzy subset is set to {NL (negative large), NM (negative medium), NS (negative small), 0, PS (positive small), PM (positive medium), PL (positive large)}; the membership function of the angle AoD fuzzy set adopts Gaussian and joint Gaussian membership functions, and the distribution is set as follows: The two fuzzy subsets NL and PL adopt the joint Gaussian membership distribution function, and their parameters are as follows:

[0091] NL:y=gauss2mf(x,[1-30 2-25]);

[0092] PL:y=gauss2mf(x,[2 25 1 30]);

[0093] The other subsets use Gaussian membership distribution functions with the following parameters:

[0094] NM:y=gaussmf(x,[2.5-17]);

[0095] NS:y=gaussmf(x,[2-8]);

[0096] 0:y=gaussmf(x,[2 0]);

[0097] PS:y=gaussmf(x,[2 8]);

[0098] PM:y=gaussmf(x,[2.5 17]);

[0099] Step 3: There are two inputs, one of which is the vehicle's expected acceleration Acc exp , which is calculated from the accelerator pedal opening and the brake pedal opening. The specific calculation method is as follows:

[0100] Acc exp =Pd Gas -Pd Brake

[0101] Among them, Pd Gas is the accelerator pedal opening, Pd Brake is the brake pedal opening, ranging from [0,1]. Expected acceleration Acc exp The range is [-1,1], the fuzzy domain takes the value [-1,1], and its fuzzy subsets are set to {BL (reduce), BM (reduce medium), BS (reduce), 0, GS (increase), GM (increase medium), GL (increase)}, Acc exp The membership function distribution of the fuzzy set is set as follows: the two subsets BL and GL use a mixed Gaussian membership distribution function, and the specific parameters are as follows:

[0102] BL:y=gauss2mf(x,[1-1 0.1-0.85]);

[0103] GL:y=gauss2mf(x,[0.1 0.85 1 1]);

[0104] Other subsets use Gaussian membership functions, and the specific parameters are as follows:

[0105] BM:y=gaussmf(x,[0.06-0.5]);

[0106] BS:y=gaussmf(x,[0.06-0.25]);

[0107] 0:y=gaussmf(x,[0.05 0]);

[0108] GS:y=gaussmf(x,[0.06 0.25]);

[0109] GM:y=gaussmf(x,[0.06 0.5]);

[0110] Step 4: Another input is the difference S between the front and rear tire slip rates F&R , the specific calculation formula is as follows:

[0111] S F&R =max{S RL ,S RR}-{S FL ,F FR}

[0112] Where S RL ,S RR is the slip rate of the two rear wheels, S FL ,F FR is the slip rate of the two front wheels.

[0113] S F&R The range of is [-1,1], the fuzzy domain takes the value [-1,1], and its fuzzy subset is set to {FL (front large), FM (front middle), FS (front small), 0, RS (back small), RM (back middle), RL (back large)}; S RF& The membership function distribution of the fuzzy subsets is set as follows: The FL and RL subsets use a mixed Gaussian membership distribution function, and the specific parameters are as follows:

[0114] FL:y=gauss2mf(x,[0.6-1 0.06-0.5]);

[0115] RL:y=gauss2mf(x,[0.06 0.5 0.6 1]);

[0116] Other subsets use Gaussian membership functions, and the specific parameters are as follows:

[0117] FM:y=gaussmf(x,[0.05-0.3]);

[0118] FS:y=gaussmf(x,[0.04-0.15]);

[0119] 0:y=gaussmf(x,[0.04 0]);

[0120] RS:y=gaussmf(x,[0.04 0.15]);

[0121] RM:y=gaussmf(x,[0.05 0.3]);

[0122] Step 5: The main impact of the active diffuser on the aerodynamics of the vehicle is to provide additional downforce and change the drag coefficient. The main factor affecting the downforce and drag is the angle of the diffuser. Considering that the drag provided by the diffuser can increase the acceleration during braking, it will generate additional drag during the acceleration phase, thereby reducing the acceleration performance. Therefore, the acceleration request value, that is, the difference between the throttle and the brake, is considered when the fuzzy rule is formulated, so that when the driver brakes, the diffuser angle is increased to provide additional drag to help braking; when the driver accelerates, the diffuser angle is reduced to reduce the impact of additional drag on the acceleration process. At the same time, the downforce provided by the diffuser can provide additional downforce when the wheels slip, helping the vehicle to stabilize; therefore, when the front and rear slip rates of the vehicle change, the angle of the diffuser can be adjusted to change the downforce and Y-axis torque, increase the downforce of the front and rear wheels, and thus improve the stability of the vehicle. According to the above settings and the control logic of the diffuser, the fuzzy control rules for the angle of the active diffuser are shown in the table; the first row represents different values ​​of the expected acceleration, and the first column is the difference between the front and rear wheel slip rates. These two values ​​are the inputs of the fuzzy control. When the values ​​of the two inputs are determined, the intersection of the two inputs in the table corresponds to an output value. Fuzzy control is to obtain the output based on the rules of this table and the input values.

[0123] Table 1 Fuzzy control rules for active diffuser angle

[0124]

[0125] Figure 4 This is a simulation comparison diagram of the working condition of suddenly applying the brakes during acceleration. The two curves represent the speed change diagrams of the two vehicles. The solid line represents the vehicle without a diffuser, and the dotted line represents the vehicle with a diffuser. Except for the diffuser, the other parameters of the two vehicles are the same. As shown in the figure, the braking force is applied at the fifteenth second, and the vehicle begins to decelerate. The vehicle with an active diffuser decelerates faster during the braking process, has a greater acceleration, and has significantly better braking performance than the vehicle without a diffuser.

[0126] Figure 5 The following is a diagram of the trajectory changes of the vehicles during driving. The two vehicles are driving at the same speed and the same steering wheel angle operation is performed on the two vehicles. From the trajectory diagram, it can be seen that the vehicle without diffuser skids after the second direction change and cannot return to the normal trajectory, and the vehicle loses control; while the vehicle with diffuser does not skid or lose control and returns to the normal trajectory. This shows that the vehicle with an active diffuser has better handling performance than the vehicle without an active diffuser.

[0127] Figure 6The following is a diagram of the change in the yaw rate of the vehicle during driving. The two vehicles are driving at the same speed and the same steering wheel angle operation is performed on the two vehicles. The yaw rate represents the stability of the vehicle. It can be seen from the figure that after the vehicle makes a steering operation, the yaw rate of the vehicle with an active diffuser finally tends to be stable, while the yaw rate of the vehicle without an active diffuser cannot return to a stable value and the vehicle loses control. This shows that the handling stability of the vehicle with an active diffuser is better than that of the vehicle without an active diffuser.

[0128] Example 2

[0129] This embodiment provides a control system for an active diffuser angle based on fuzzy control, including:

[0130] Establish a module for establishing a six-degree-of-freedom model of the vehicle's aerodynamic body, and derive the six-component force model and force analysis of the diffuser on the vehicle's aerodynamics;

[0131] A determination module, used for determining the output of the controller as the angle of the diffuser according to the working principle and properties of the diffuser, and fuzzifying it;

[0132] A fuzzy module is used to determine the controller input as the difference between the desired acceleration and the front and rear wheel slip rates, and fuzzify it;

[0133] The formulation module is used to formulate fuzzy control rules.

[0134] The specific control process of the fuzzy controller is to fuzzify the input data, and then output according to the input and fuzzy control rules. According to the fuzzification setting of the output, the specific output value is obtained to realize the entire control process. Therefore, the entire fuzzy controller will produce an output based on the input. This output is obtained by the fuzzification of the input and output and the fuzzy rules we designed. The formulation of fuzzy rules is based on the properties and effects of the tail, which can be expressed as a table. After the fuzzification of input and output and the formulation of fuzzy rules are completed, the design of the fuzzy controller is completed.

[0135] Example 3

[0136] Figure 7 This is a schematic diagram of the structure of a computer device in Example 3 of the present invention. Figure 7 A block diagram of an exemplary computer device 12 suitable for use in implementing embodiments of the present invention is shown. Figure 7 The computer device 12 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0137] like Figure 7As shown, the computer device 12 is in the form of a general-purpose computing device. The components of the computer device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0138] Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures. By way of example, these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0139] The computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device 12, including volatile and non-volatile media, removable and non-removable media.

[0140] The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The computer device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 7 not shown, usually called a "hard drive"). Although Figure 7 Not shown in the figure, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present invention.

[0141] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described herein.

[0142] The computer device 12 may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), may also communicate with one or more devices that enable a user to interact with the computer device 12, and / or communicate with any device that enables the computer device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed through an input / output (I / O) interface 22. In addition, the computer device 12 in this embodiment, the display 24 does not exist as an independent individual, but is embedded in the mirror surface, and when the display surface of the display 24 is not displayed, the display surface of the display 24 and the mirror surface are visually integrated. In addition, the computer device 12 may also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN) and / or public network, such as the Internet) through a network adapter 20. As shown in the figure, the network adapter 20 communicates with other modules of the computer device 12 through a bus 18. It should be understood that although not shown in the figures, other hardware and / or software modules may be used in conjunction with the computer device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0143] The processing unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28 , for example, implementing a control method of an active diffuser angle based on fuzzy control provided by an embodiment of the present invention.

[0144] Implementation 4

[0145] Embodiment 4 of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, a method for controlling an active diffuser angle based on fuzzy control as provided in all the embodiments of the present application is implemented.

[0146] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, device, or device.

[0147] Computer-readable signal media may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0148] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0149] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0150] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A control method for active diffuser angle based on fuzzy control, characterized in that: The specific steps include: Step 1: Establish a six-degree-of-freedom model of the vehicle's aerodynamic body, and derive the diffuser's aerodynamic six-component force influence model and force analysis on the vehicle; Step 2: According to the working principle and properties of the diffuser, the output of the controller is determined to be the angle of the diffuser, and the angle is fuzzified; Step 3: Determine the controller input as the difference between the desired acceleration and the front and rear tire slip rates, and fuzzify it; Step 4: Establish fuzzy control rules.

2. The method for controlling the angle of an active diffuser based on fuzzy control according to claim 1, characterized in that: In step 1, the aerodynamic force and aerodynamic moment of the active diffuser on the vehicle body in the X, Y, and Z directions are: F AeroX =-F Drag (0-1) F AreoY ＝0 (0-2) F Areoz =-F Down (0-3) M AreoX ＝0 (0-4) M AreoY =F Drag h-F Down l (0-5) M AreoZ ＝0 (0-6) Among them, F AeroX 、F AeroY 、F AeroZ are the aerodynamic forces in the X, Y, and Z directions, M AeroX 、M AeroY 、M AeroZ are the aerodynamic moments around X, Y, and Z, respectively, and F Down is the downforce generated by the active diffuser, F Drag is the air resistance generated by the active diffuser, h is the height distance from the active diffuser action point to the vehicle's center of mass, and l is the longitudinal distance from the active diffuser action point to the vehicle's center of mass.

3. The method for controlling the active diffuser angle based on fuzzy control according to claim 1, characterized in that: Step 2 specifically includes the following: Assume that the angle of the diffuser is AoD, and its adjustable range is [-30°, 30°]. The value of the fuzzy domain is [-30, 30]. Its fuzzy subset is set to {NL (negative large), NM (negative medium), NS (negative small), 0, PS (positive small), PM (positive medium), PL (positive large)}; the membership function of the angle AoD fuzzy set adopts Gaussian and joint Gaussian membership functions, and the distribution is set as follows: Among them, the two fuzzy subsets NL and PL adopt the joint Gaussian membership distribution function, and their parameters are as follows: NL:y=gauss2mf(x,[1 -30 2 -25]); PL:y=gauss2mf(x,[2 25 1 30]); Among them, gauss2mf represents the double Gaussian mixture function, and the parameters in brackets are the parameters of the double Gaussian mixture function; The other subsets use Gaussian membership distribution functions with the following parameters: NM:y=gaussmf(x,[2.5 -17]); NS:y=gaussmf(x,[2 -8]); 0:y=gaussmf(x,[2 0]); PS:y=gaussmf(x,[2 8]); PM:y=gaussmf(x,[2.5 17]); Gaussmf represents a Gaussian function, where the values ​​in the brackets are the parameters of the Gaussian function.

4. The method for controlling the angle of an active diffuser based on fuzzy control according to claim 1, characterized in that: In step 3, the expected acceleration of the vehicle Acc exp It is calculated from the accelerator pedal opening and the brake pedal opening. The specific calculation method is as follows: Acc exp =Pd Gas -Pd Brake Among them, Pd Gas is the accelerator pedal opening, Pd Brake is the brake pedal opening, the range is [0,1]; the expected acceleration Acc exp The range is [-1,1], the fuzzy domain takes the value [-1,1], and its fuzzy subset is set to {BL (reduce), BM (reduce medium), BS (reduce), 0, GS (increase), GM (increase medium), GL (increase)}, Acc exp The membership function distribution of the fuzzy set is set as follows: Among them, the two subsets BL and GL use mixed Gaussian membership distribution functions, and the specific parameters are as follows: BL:y=gauss2mf(x,[1 -1 0.1 -0.85]); GL:y=gauss2mf(x,[0.1 0.85 1 1]); Other subsets use Gaussian membership functions, and the specific parameters are as follows: BM:y=gaussmf(x,[0.06 -0.5]); BS:y=gaussmf(x,[0.06 -0.25]); 0:y=gaussmf(x,[0.05 0]); GS:y=gaussmf(x,[0.06 0.25]); GM:y=gaussmf(x,[0.06 0.5]).

5. The method for controlling the active diffuser angle based on fuzzy control according to claim 1, characterized in that: In step 3, the difference S between the front and rear tire slip rates F&R The specific calculation formula is as follows: S F&R =max{S RL ,S RR }-{S FL ,F FR } Where S RL ,S RR is the slip rate of the two rear wheels, S FL ,F FR is the slip rate of the two front wheels. S F&R The range of is [-1,1], the fuzzy domain takes the value [-1,1], and its fuzzy subset is set to {FL (front large), FM (front middle), FS (front small), 0, RS (back small), RM (back middle), RL (back large)}; S RF& The membership function distribution of the fuzzy subsets is set as follows: The FL and RL subsets use a mixed Gaussian membership distribution function, and the specific parameters are as follows: FL:y=gauss2mf(x,[0.6 -1 0.06 -0.5]); RL:y=gauss2mf(x,[0.06 0.5 0.6 1]); Other subsets use Gaussian membership functions, and the specific parameters are as follows: FM:y=gaussmf(x,[0.05 -0.3]); FS:y=gaussmf(x,[0.04 -0.15]); 0:y=gaussmf(x,[0.04 0]); RS:y=gaussmf(x,[0.04 0.15]); RM:y=gaussmf(x,[0.05 0.3]).

6. The method for controlling the angle of an active diffuser based on fuzzy control according to claim 1, characterized in that: In step 4, fuzzy rules are formulated according to the properties and effects of the tail.

7. A control system for active diffuser angle based on fuzzy control, used to implement the method according to any one of claims 1 to 6, characterized in that: include: Establish a module for establishing a six-degree-of-freedom model of the vehicle's aerodynamic body, and derive the six-component force model and force analysis of the diffuser on the vehicle's aerodynamics; A determination module, used for determining the output of the controller as the angle of the diffuser according to the working principle and properties of the diffuser, and fuzzifying it; A fuzzy module determines the controller input as the difference between the desired acceleration and the front and rear tire slip rates, and fuzzifies it; The formulation module is used to formulate fuzzy control rules.

8. A computer device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for controlling an active diffuser angle based on fuzzy control as claimed in any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, a method for controlling an active diffuser angle based on fuzzy control as described in any one of claims 1 to 7 is implemented.

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