Control device of vehicle and control method of vehicle

Abstract

A control device of a vehicle controls a cooling air control apparatus configured to control a flow rate of cooling air introduced to a radiator and an aerodynamic performance control apparatus configured to control an aerodynamic performance of the vehicle, based on output signals of a vehicle speed sensor configured to detect a vehicle speed and a water temperature sensor configured to detect a cooling water temperature, respectively. At this time, the control device of the vehicle changes a control state of one of the cooling air control apparatus and the aerodynamic performance control apparatus, considering a control state of the other of the cooling air control apparatus and the aerodynamic performance control apparatus.

Description

Technical Field

[0001] This invention relates to a vehicle control device and a vehicle control method for coordinating the control of an active air intake grille and a variable air dam. Background Technology

[0002] In recent years, automobiles have sometimes been equipped with active air intake grilles that control the flow of cooling air by changing the opening of the front grille, and variable air dams installed on the lower front of the vehicle body to suppress lift generation. Japanese Patent Application Publication No. 63-195921 (Patent Document 1) proposes a technology that integrates the active air intake grille and the air dam, and coordinates the control of such an active air intake grille and air dam. In this proposed technology, during low-speed driving where engine heat is high due to climbing hills, the opening of the front grille is increased to ensure cooling performance, and the air dam is raised to ensure ground clearance in case of rough road conditions. Furthermore, in this proposed technology, during high-speed driving where engine heat is low and cooling air is easily introduced, the opening of the front grille is reduced and the air dam is lowered to ensure aerodynamic performance.

[0003] Existing technical documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 63-195921 Summary of the Invention

[0005] The technical problem that the invention aims to solve

[0006] However, in the technology proposed in Patent Document 1, the opening of the front grille increases at low speeds, which may result in excessive cooling airflow, such as when the engine is cold, making it difficult to ensure preheating performance. Furthermore, in this proposed technology, since the opening of the front grille decreases at high speeds, insufficient cooling airflow may occur, such as under high loads, making it difficult to ensure cooling performance.

[0007] Therefore, the purpose of this invention is to provide a vehicle control device and a vehicle control method that can coordinate the control of the active air intake grille and the variable air dam by taking into account not only aerodynamic performance but also cooling performance.

[0008] Technical solutions for solving technical problems

[0009] The vehicle's control unit, based on the output signals of a vehicle speed sensor configured to detect vehicle speed and a coolant temperature sensor configured to detect coolant temperature, controls a cooling air control device configured to control the flow rate of cooling air introduced to the radiator and an aerodynamic performance control device configured to control the vehicle's aerodynamic performance. At this time, the vehicle's control unit considers the control state of one of the cooling air control device and the aerodynamic performance control device and changes the control state of the other of the two devices accordingly.

[0010] Invention Effects

[0011] According to the present invention, by coordinating the control of the active air intake grille and the variable air dam mounted on the vehicle, the aerodynamic performance and cooling performance of the vehicle can be ensured simultaneously. Attached Figure Description

[0012] Figure 1 This is a schematic structural diagram showing an example of the front of a vehicle.

[0013] Figure 2 This is an illustrative diagram showing an example of the variation characteristics of cooling airflow and air resistance based on an active air intake grille.

[0014] Figure 3 This is an illustrative diagram illustrating an example of the changing characteristics of the flow rate, downforce, and air resistance of cooling air based on an air dam.

[0015] Figure 4 This is an explanatory diagram showing an example of the internal structure of an electronic control device.

[0016] Figure 5 This is a flowchart illustrating an example of vehicle control processing.

[0017] Figure 6 This is a flowchart illustrating an example of vehicle control processing.

[0018] Figure 7 This is a flowchart representing an example of a subroutine used to execute high-speed mode.

[0019] Figure 8 This is an explanatory diagram illustrating an example of the control states for each mode.

[0020] Figure 9 This is a flowchart representing an example of a subroutine used to execute the warm-up mode.

[0021] Figure 10 This is a flowchart representing an example of a subroutine used to execute the cooling mode.

[0022] Figure 11 This is a flowchart representing an example of a subroutine used to execute aerodynamic modes.

[0023] Figure 12 This is an explanatory diagram illustrating an example of the control modes of the active air intake grille and air dam, corresponding to vehicle speed and cooling requirements.

[0024] Figure 13 This is an illustration of an example of control measures in case of a fully closed active grille shutter malfunction.

[0025] Figure 14This is an illustration of an example of control when the active grille shutters are fully open in a faulty configuration.

[0026] Figure 15 This is an illustrative diagram illustrating an example of control measures in the event of a dam failure.

[0027] Figure 16 This is an illustrative diagram illustrating an example of control measures in the event of a dam deployment failure.

[0028] Figure 17 This is an explanatory diagram illustrating an example of control during emergency braking. Detailed Implementation

[0029] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.

[0030] Figure 1 This describes the general structure of the front of a vehicle such as an automobile that can be implemented according to this embodiment.

[0031] A radiator 120 for cooling coolant (not shown) and an electric fan (radiator fan) 130 for actively controlling the cooling airflow through the radiator 120 are respectively arranged in the front part of the engine compartment 110 located in front of the vehicle 100. Additionally, a front grille 150 for directing cooling air into the engine compartment 110 is formed in front of the front bumper 140 of the vehicle 100. Here, the front grille 150 has, for example, a plurality of openings 150A extending in the left-right direction of the vehicle 100.

[0032] An active air intake grille 160 is disposed behind (on the rear) of the front grille 150 and in front of the radiator 120 disposed in the engine compartment 110, and configured to control the flow rate of cooling air introduced into the radiator 120. The active air intake grille 160 has the same number of blades 160A as the openings 150A of the front grille 150, and an actuator 160B, such as an electric motor, that rotates the blades 160A about a rotation axis extending in the left-right direction. In this embodiment, the front grille 150 has three openings 150A, and therefore three blades 160A are disposed accordingly. The blades 160A are mounted to allow the openings 150A of the front grille 150 to rotate between fully open (maximum opening area: 100%) and fully closed (minimum opening area: 0%). Furthermore, the actuator 160B is configured to cause the blades 160A to rotate continuously or intermittently about a rotation axis extending in the left-right direction between fully open and fully closed. Here, the active air intake grille 160 is cited as an example of a cooling air control device.

[0033] like Figure 2As shown, the active air intake grille 160 changes the flow rate of cooling air introduced into the radiator 120 and the air resistance of the vehicle 100 based on the rotation angle (grille opening) of the blades 160A relative to the fully closed position. Figure 2 In one example shown, the cooling airflow and air resistance gradually increase as the grille opening increases from fully closed (0%) to fully open (100%). It should be noted that this variation is just one example, and may vary depending on the shape of the opening 150A of the front grille 150, the shape of the blades 160A, etc.

[0034] A variable air dam 170 is disposed at the lower front part of the vehicle 100, specifically at the lower part of the front bumper 140. This air dam is configured to suppress lift generation and control the aerodynamic performance of the vehicle 100 by varying the amount of protrusion downwards from the vehicle 100. The air dam 170 includes: a skirt 170A, the base of which is fixed to a rotating shaft extending in the left-right direction; and an actuator 170B, such as an electric motor, configured to rotate the skirt 170A about the rotating shaft. Here, the actuator 170B is configured to continuously or intermittently rotate the skirt 170A from a forward-retracted position (rotation angle 0°) towards the front of the vehicle to a rearward-retracted position (rotation angle 180°) towards the rear of the vehicle. Furthermore, the skirt 170A is configured such that, in both the forward and rearward-retracted positions, its surface is retracted parallel to the longitudinal direction of the vehicle 100. Here, air dam 170 is cited as an example of an aerodynamic performance control device.

[0035] like Figure 3 As shown, as the skirt 170A rotates from the front retracted position to the rear retracted position, the air dam 170 causes changes in the flow rate of the cooling air introduced into the radiator 120, the downforce of the vehicle 100, and the air resistance of the vehicle 100. Figure 3In one example, the cooling airflow gradually increases as the front end of the skirt panel 170A rotates from a front-retracted position to a rear-retracted position, then to a forward-extended position (rotated 45°), and gradually decreases as the front end of the skirt panel 170A rotates back to a rear-retracted position. Downforce gradually increases as the front end of the skirt panel 170A rotates from a front-retracted position to a forward-extended position (rotated 45°), then gradually decreases as the front end of the skirt panel 170A rotates back to a fully extended position (rotated 45°), then gradually increases as the front end of the skirt panel 170A rotates back to a rear-extended position (rotated 45°), and gradually decreases as the front end of the skirt panel 170A rotates back to a rear-retracted position. Air resistance gradually increases as the front end of the skirt panel 170A rotates from a front-retracted position to a fully extended position, and gradually increases as the skirt panel 170A rotates back to a rear-retracted position. Here, the forward deployment position is between the front retracted position and the fully deployed position (rotation angle 0° to 90°), and the rearward deployment position is between the fully deployed position and the rear retracted position (rotation angle 90° to 180°). It should be noted that this characteristic is just one example, and may vary, for example, depending on the installation position and shape of the skirt 170A of the air dam 170.

[0036] At a designated location on the active air intake grille 160, as an example of the opening degree of the active air intake grille 160, a grille opening degree sensor 180 is installed, configured to detect the rotation angle θgs of the blades 160A relative to the fully closed position. Additionally, at a designated location on the air dam 170, as an example of the operating state of the air dam 170, an air dam opening degree sensor 190 is installed, configured to detect the rotation angle θad of the skirt 170A from its forward retracted position to its rearward retracted position. The output signals of both the grille opening degree sensor 180 and the air dam opening degree sensor 190 are input to an electronic control unit (ECU) 200, which contains a microcomputer (not shown).

[0037] In the electronic control unit 200, in addition to the output signals of the grille opening sensor 180 and the air dam opening sensor 190, the output signals of the vehicle speed sensor 210, the coolant temperature sensor 220, the external gas temperature sensor 230, and the refrigerant pressure sensor 240 are also input. The vehicle speed sensor 210 is configured, for example, to detect the vehicle speed VSP based on the rotational speed of the output shaft of a transmission (not shown). The coolant temperature sensor 220 is configured, for example, to detect the temperature (water temperature) Tw of the coolant flowing in the water jacket formed in an engine (not shown). The external gas temperature sensor 230 is configured, for example, installed inside the front bumper 140, to detect the external gas temperature To around the vehicle 100. The refrigerant pressure sensor 240 is configured, for example, installed at a designated location in the refrigerant circuit of an air conditioner (not shown), to detect the pressure Pr of the refrigerant circulating in the refrigerant circuit.

[0038] like Figure 4 As shown, the electronic control device 200 includes a processor 200A, a non-volatile memory 200B, a volatile memory 200C, a communication circuit 200D, an input / output circuit 200E, and an internal bus 200F that connects them to enable communication between them.

[0039] Processor 200A is an electronic component that executes the instruction set specified in an application program, such as a CPU (Central Processing Unit). Non-volatile memory 200B is a semiconductor storage element that retains data even when the power supply is cut off, such as EEPROM (Electrically Erasable Programmable Read Only Memory) or Flash ROM (Read Only Memory). Volatile memory 200C is a semiconductor storage element whose data is lost when the power supply is cut off, such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory).

[0040] The communication circuit 200D is a device used for communication with other electronic control devices via in-vehicle networks such as CAN (Controller Area Network), and is composed of, for example, a CAN transceiver. The input / output circuit 200E is a device that reads analog or digital signals from various sensors or switches and outputs analog or digital drive signals to actuators, and is composed of, for example, an A / D converter, a D / A converter, or a D / D converter. The internal bus 200F is a path for exchanging data between devices, including an address bus for transmitting addresses, a data bus for transmitting data, and a control bus for timing or exchanging control information via the address bus or data bus for actual input / output.

[0041] Furthermore, the electronic control unit 200 receives output signals from the grille opening sensor 180, air dam opening sensor 190, vehicle speed sensor 210, coolant temperature sensor 220, external gas temperature sensor 230, and refrigerant pressure sensor 240 via the input / output circuit 200E. Additionally, the electronic control unit 200 performs prescribed calculations on these output signals to determine the operating parameters of the actuators 160B of the active air intake grille 160 and 170B of the air dam 170, and outputs these operating parameters to the actuators 160B and 170B via the input / output circuit 200E. At this time, the electronic control unit 200 determines the active air intake grille opening based on the output signal of the grille opening sensor 180, and determines the air dam operating angle (operation state) based on the output signal of the air dam opening sensor 190. The control functions of the electronic control unit 200 over the active air intake grille 160 and air dam 170 are described in detail below.

[0042] Figure 5 and Figure 6 This describes an example of vehicle control processing that is repeatedly executed by the processor 200A of the electronic control unit 200 at predetermined intervals upon activation of the electronic control unit 200. It should be noted that the processor 200A of the electronic control unit 200 executes the vehicle control processing according to an application program pre-stored in the non-volatile memory 200B. Furthermore, for the sake of simplicity, the processor 200A of the electronic control unit 200 will be referred to as "electronic control unit 200" below.

[0043] Here, the electronic control device 200 is configured to change the control state of the other of the active air intake grille 160 and air dam 170 by performing vehicle control processing and taking into account the control state of one of the active air intake grille 160 and air dam 170.

[0044] In step 100 (in Figure 5In the (abbreviated as "S100", the same applies below), the electronic control device 200, as an example of vehicle information indicating the vehicle's driving status, inputs the output signals of the vehicle speed sensor 210, water temperature sensor 220, external gas temperature sensor 230, and refrigerant pressure sensor 240.

[0045] In step 110, the electronic control unit 200 determines whether the vehicle speed VSP input from the vehicle speed sensor 210 is above a predetermined speed. Here, the predetermined speed is a threshold used to determine whether the wind generated by the high-speed travel of the vehicle 100 could potentially damage the blades 160A of the active air intake grille 160; for example, it can be set to 130 km / h. If the electronic control unit 200 determines that the vehicle speed VSP is above the predetermined speed (yes), the process proceeds to step 160. Conversely, if the electronic control unit 200 determines that the vehicle speed VSP is below the predetermined speed (no), the process proceeds to step 120.

[0046] In step 120, the electronic control unit 200 determines whether the water temperature Tw input from the water temperature sensor 220 is below a first predetermined water temperature. Here, the first predetermined water temperature is a threshold used to determine whether the engine preheating of the vehicle 100 is complete, and can be set to, for example, 95°C. If the electronic control unit 200 determines that the water temperature Tw is below the first predetermined water temperature (yes), the process proceeds to step 170. On the other hand, if the electronic control unit 200 determines that the water temperature Tw is higher than the first predetermined water temperature (no), the process proceeds to step 130.

[0047] In step 130, the electronic control unit 200 determines whether the water temperature Tw input from the water temperature sensor 220 is higher than or equal to a second predetermined water temperature, which is higher than a first predetermined water temperature. Here, the second predetermined water temperature is one of the thresholds used to determine whether the engine of the vehicle 100 needs to be cooled; for example, it can be set to 97°C. If the electronic control unit 200 determines that the water temperature Tw is higher than or equal to the second predetermined water temperature (yes), the process proceeds to step 180. On the other hand, if the electronic control unit 200 determines that the water temperature Tw is lower than the second predetermined water temperature (no), the process proceeds to step 140.

[0048] In step 140, the electronic control unit 200 determines whether the external gas temperature To, input from the external gas temperature sensor 230, is above a predetermined temperature. Here, the predetermined temperature is one of the thresholds used to determine whether cooling of the engine of the vehicle 100 is necessary; for example, it can be set to 35°C. If the electronic control unit 200 determines that the external gas temperature To is above the predetermined temperature (yes), the process proceeds to step 180. Conversely, if the electronic control unit 200 determines that the external gas temperature To is below the predetermined temperature (no), the process proceeds to step 150.

[0049] In step 150, the electronic control unit 200 determines whether the refrigerant pressure Pr input from the refrigerant pressure sensor 240 is above a predetermined pressure. Here, the predetermined pressure is one of the thresholds used to determine whether the engine load has increased due to the use of the air conditioner, thus requiring cooling of the engine of the vehicle 100; for example, it can be set to 1.5 MPa. If the electronic control unit 200 determines that the refrigerant pressure Pr is above the predetermined pressure (yes), the process proceeds to step 180. On the other hand, if the electronic control unit 200 determines that the refrigerant pressure Pr is below the predetermined pressure (no), the process proceeds to step 190.

[0050] In step 160, since the vehicle is traveling at a high speed (VSP) above the specified speed, the electronic control unit 200 calls a subroutine for executing the high-speed mode (details described later). Afterwards, the electronic control unit 200 terminates the vehicle control processing in this control loop.

[0051] In step 170, since the vehicle speed VSP is less than the specified speed and the coolant temperature Tw is below the first specified coolant temperature, the electronic control unit 200 calls a subroutine to execute a preheating mode that prioritizes engine preheating performance (details described later). Afterward, the electronic control unit 200 terminates the vehicle control processing in this control cycle.

[0052] In step 180, if the vehicle speed VSP is less than a specified speed, and the coolant temperature Tw is above a second specified coolant temperature (higher than a first specified coolant temperature), the external gas temperature To is above a specified temperature, or the refrigerant pressure Pr is above a specified pressure, then the electronic control unit 200 invokes a subroutine to execute a cooling mode that prioritizes engine cooling performance (details described later). Afterward, the electronic control unit 200 terminates the vehicle control processing in this control cycle.

[0053] In step 190, since none of the high-speed mode, preheating mode, and cooling mode described above are met, the electronic control unit 200 invokes a subroutine to execute the aerodynamic mode that prioritizes aerodynamic performance (details described later). Afterward, the electronic control unit 200 terminates the vehicle control processing in this control cycle.

[0054] Figure 7 This represents an example of a subroutine used to execute high-speed mode.

[0055] In high-speed mode, to prevent damage to the blades 160A of the active air intake grille 160 caused by the wind during high-speed driving, such as Figure 8As shown, the active air intake grille 160 makes the front grille 150 fully open (100% opening). In addition, in high-speed mode, considering the control state of the active air intake grille 160, the rotation angle of the skirt 170A of the air dam 170 in the rearward deployed position is changed according to the vehicle speed VSP, thereby increasing the downforce acting on the vehicle 100.

[0056] In step 161, the electronic control unit 200 inputs the vehicle speed VSP from the vehicle speed sensor 210.

[0057] In step 162, the electronic control device 200 inputs the water temperature Tw from the water temperature sensor 220.

[0058] In step 163, the electronic control unit 200 outputs a control quantity to the actuator 160B of the active air intake grille 160 to fully open the blades 160A, thus fully opening the opening 150A of the front grille 150. At this time, the electronic control unit 200 inputs the rotation angle θgs of the blades 160A from the grille opening sensor 180, thereby calculating the actual active air intake grille opening. Then, the electronic control unit 200 performs feedback control on the control quantity based on the actual active air intake grille opening to ensure that the opening 150A of the front grille 150 is fully open.

[0059] In step 164, the electronic control device 200, for example, refers to a high-speed mode mapping that sets a target air dam opening corresponding to the vehicle speed VSP input from the vehicle speed sensor 210. Figure 8 As shown, the target opening of the air dam is set such that, in the rearward deployed position, it gradually increases as the vehicle speed decreases; in short, the downward protrusion gradually increases as the vehicle speed increases. Here, a high-speed mode mapping with the target air dam opening corresponding to the vehicle speed is pre-determined, for example, through actual machine testing, simulation, etc., and stored in non-volatile memory 200B.

[0060] In step 165, the electronic control unit 200 outputs a control quantity corresponding to the target opening degree of the air dam 170 to the actuator 170B of the air dam 170, causing the skirt 170A of the air dam 170 to rotate to the target opening degree. At this time, the electronic control unit 200 inputs the rotation angle θad of the skirt 170A from the air dam opening sensor 190, and performs feedback control on the control quantity based on this rotation angle θad. Afterwards, the electronic control unit 200 returns the processing to the vehicle control processing, which is the main program.

[0061] Figure 9 This represents an example of a subroutine used to execute the warm-up mode. It should be noted that, to avoid repetition, the following is an example of... Figure 7The same processing as shown in the high-speed mode will be briefly explained. If needed, please refer to the high-speed mode instructions (the same applies below).

[0062] In preheating mode, to reduce the flow of cooling air to the radiator 120 and thus promote the preheating of the engine of the vehicle 100, such as... Figure 8 As shown, the active air intake grille 160 makes the opening of the front grille 150 fully closed (0% opening). In addition, in the preheating mode, considering the control state of the active air intake grille 160, the rotation angle of the skirt 170A of the air dam 170 in the rearward deployed position is changed according to the vehicle speed VSP, thereby increasing the downforce acting on the vehicle 100.

[0063] In step 171, the electronic control unit 200 inputs the vehicle speed VSP.

[0064] In step 172, the electronic control device 200 inputs the water temperature Tw.

[0065] In step 173, the electronic control unit 200 outputs a control quantity to the actuator 160B of the active air intake grille 160 to fully close the blades 160A, thereby fully closing the opening 150A of the front grille 150. At this time, the electronic control unit 200 inputs the rotation angle θgs of the blades 160A from the grille opening sensor 180 and performs feedback control on the control quantity based on this rotation angle θgs.

[0066] In step 174, the electronic control device 200, for example, refers to a mapping used in a preheating mode that sets a target air dam opening corresponding to the vehicle speed VSP, and sets the target air dam opening. Figure 8 As shown, the target opening of the air dam is set such that it gradually increases as the vehicle speed decreases from the rearward deployed position to the rearward retracted position; in short, as the vehicle speed increases, the downward protrusion gradually increases. Here, a mapping for the preheating mode with the target air dam opening corresponding to the vehicle speed is determined in advance, for example, through actual machine testing or simulation, and is stored in non-volatile memory 200B.

[0067] In step 175, the electronic control unit 200 outputs a control quantity corresponding to the target opening degree of the air dam 170 to the actuator 170B of the air dam 170, causing the skirt 170A of the air dam 170 to rotate to the target opening degree. At this time, the electronic control unit 200 inputs the rotation angle θad of the skirt 170A from the air dam opening sensor 190, and performs feedback control on the control quantity based on this rotation angle θad. Afterwards, the electronic control unit 200 returns the processing to the vehicle control processing, which is the main program.

[0068] Figure 10 This represents an example of a subroutine used to execute the cooling mode.

[0069] In cooling mode, to increase the airflow to the radiator 120 and improve the engine cooling performance of the vehicle 100, such as... Figure 8 As shown, the side skirt 170A of the air dam 170 is positioned in the forward-deployed position according to the vehicle speed VSP. In addition, in cooling mode, considering the control state of the air dam 170, the opening of the active air intake grille 160, which is set according to the water temperature Tw, is changed to increase the downforce acting on the vehicle 100.

[0070] In step 181, the electronic control unit 200 inputs the vehicle speed VSP.

[0071] In step 182, the electronic control device 200 inputs the water temperature Tw.

[0072] In step 183, the electronic control device 200, for example, refers to a mapping used for a cooling mode that sets a grille opening corresponding to the water temperature Tw. Figure 8 As shown, the target grille opening is set to gradually increase as the vehicle speed decreases, from the middle opening to the fully open opening; in short, it gradually increases to compensate for the decrease in vehicle speed. Here, a cooling mode mapping for the target grille opening corresponding to the water temperature is set, for example, determined in advance through actual machine testing, simulation, etc., and stored in non-volatile memory 200B.

[0073] In step 184, the electronic control device 200, for example, refers to a mapping used for a cooling mode that sets a target air dam opening corresponding to the vehicle speed VSP. Figure 8 As shown, the target opening of the air dam is set such that, in the forward-deployed position, it gradually increases as the vehicle speed decreases, and in general, the downward protrusion gradually decreases as the vehicle speed increases. Here, a mapping for the cooling mode with the target air dam opening corresponding to the vehicle speed is determined in advance, for example, through actual testing, simulation, etc., and stored in non-volatile memory 200B.

[0074] In step 185, the electronic control unit 200 inputs the rotation angle θad of the skirt 170A of the air dam 170 from the air dam opening sensor 190, and corrects the target grille opening based on this rotation angle θad. Specifically, the electronic control unit 200 takes into account the increased flow rate of cooling air to the radiator 120 due to the air dam 170 being in the forward-deployed position, and corrects based on this increase in flow rate to reduce the target grille opening.

[0075] In step 186, the electronic control device 200 outputs a control quantity corresponding to the target opening degree of the air dam 170 to the actuator 170B of the air dam 170, causing the skirt 170A of the air dam 170 to rotate to the target opening degree. At this time, the electronic control device 200 inputs the rotation angle θad of the skirt 170A from the air dam opening sensor 190, and performs feedback control on the control quantity based on the rotation angle θad.

[0076] In step 187, the electronic control unit 200 outputs a control quantity corresponding to the target grille opening degree to the actuator 160B of the active air intake grille 160, causing the blades 160A of the active air intake grille 160 to rotate to the target grille opening degree. At this time, the electronic control unit 200 inputs the rotation angle θgs of the blades 160A from the grille opening sensor 180, and performs feedback control on the control quantity based on this rotation angle θgs. Afterwards, the electronic control unit 200 returns the processing to the vehicle control processing, which is the main program.

[0077] Figure 11 This represents an example of a subroutine used to execute aerodynamic modes.

[0078] In aerodynamic mode, to improve vehicle stability, such as... Figure 8 As shown, the side skirts 170A of the air dam 170 are positioned rearward according to the vehicle speed VSP, increasing the downforce acting on the vehicle 100. Furthermore, in aerodynamic mode, to maintain a constant flow of cooling air to the radiator 120 and reduce air resistance, the opening of the active air intake grille 160, set according to the water temperature Tw, is adjusted considering the control state of the air dam 170.

[0079] In step 191, the electronic control unit 200 inputs the vehicle speed VSP.

[0080] In step 192, the electronic control device 200 inputs the water temperature Tw.

[0081] In step 193, the electronic control device 200, for example, refers to a mapping used for an aerodynamic mode that sets a target grille opening corresponding to the water temperature Tw. Figure 8 As shown, the target grille opening is set to gradually decrease from a medium opening to a fully open opening as the vehicle speed decreases, in order to compensate for the reduced cooling airflow due to the decrease in vehicle speed. Here, an aerodynamic pattern mapping with a target grille opening corresponding to the water temperature is pre-determined, for example, through actual testing, simulation, etc., and stored in non-volatile memory 200B.

[0082] In step 194, the electronic control device 200, for example, refers to a mapping used for an aerodynamic mode that sets a target air dam opening corresponding to the vehicle speed VSP, and sets the target air dam opening. Figure 8 As shown, the target air dam opening is set such that, in the rearward deployed position, it gradually increases as the vehicle speed decreases; in short, the downward protrusion gradually increases as the vehicle speed increases. Here, the aerodynamic pattern mapping with the target air dam opening corresponding to the vehicle speed is determined in advance, for example, through actual testing or simulation, and stored in non-volatile memory 200B.

[0083] In step 195, the electronic control unit 200 inputs the rotation angle θad of the skirt 170A of the air dam 170 from the air dam opening sensor 190, and corrects the target grille opening based on this rotation angle θad. Specifically, the electronic control unit 200 considers the increased flow rate of cooling air due to the skirt 170A of the air dam 170 being in the rearward extended position, and makes corrections based on this increase in flow rate to reduce the target grille opening.

[0084] In step 196, the electronic control device 200 outputs a control quantity corresponding to the target opening degree of the air dam 170 to the actuator 170B of the air dam 170, causing the skirt 170A of the air dam 170 to rotate to the target opening degree. At this time, the electronic control device 200 inputs the rotation angle θad of the skirt 170A from the air dam opening sensor 190, and performs feedback control on the control quantity based on the rotation angle θad.

[0085] In step 197, the electronic control unit 200 outputs a control quantity corresponding to the target grille opening degree to the actuator 160B of the active air intake grille 160, causing the blades 160A of the active air intake grille 160 to rotate to the target grille opening degree. At this time, the electronic control unit 200 inputs the rotation angle θgs of the blades 160A from the grille opening sensor 180, and performs feedback control on the control quantity based on this rotation angle θgs. Afterwards, the electronic control unit 200 returns the processing to the vehicle control processing, which is the main program.

[0086] According to the electronic control unit 200 equipped with the aforementioned vehicle control processing, based on vehicle speed VSP, coolant temperature Tw, external gas temperature To, and refrigerant pressure Pr (examples of vehicle information), it selects any one of the following modes: high-speed mode, preheating mode, cooling mode, and aerodynamic mode. Furthermore, the electronic control unit 200 executes any one of these selected modes.

[0087] In high-speed mode, such as Figure 8As shown, the grille opening is fully open, thus suppressing the pressure of the cooling air acting on the blades 160A of the active air intake grille 160, thereby protecting the active air intake grille 160. Furthermore, in high-speed mode, as the vehicle speed decreases, the air dam opening gradually increases in the rearward-deployed position, thus ensuring downforce acting on the vehicle 100 while reducing the amount of cooling air directed towards the radiator 120, thereby reducing air resistance acting on the vehicle 100.

[0088] In preheating mode, such as Figure 8 As shown, since the grille opening is fully closed, the flow of cooling air to the radiator 120 is reduced, thus decreasing cooling performance and promoting engine preheating of the vehicle 100. Furthermore, in preheating mode, as the vehicle speed decreases, the air dam opening gradually increases from the rearward extended position to the rearward retracted position. Therefore, while ensuring downforce acting on the vehicle 100, it reduces the amount of cooling air directed to the radiator 120, thereby reducing air resistance acting on the vehicle 100.

[0089] In cooling mode, such as Figure 8 As shown, to prioritize engine cooling, the grille opening is adjusted within a range from intermediate to fully open, corresponding to the coolant temperature. In this mode, the grille opening gradually increases as vehicle speed decreases, thus compensating for the reduced airflow to the radiator 120 due to decreased vehicle speed. Furthermore, in cooling mode, since the air dam opening is in the forward-deployed position, the airflow of cooling air introduced to the radiator 120 through the air dam 170 skirt 170A increases, thereby increasing the airflow through the radiator 120. Moreover, because the cooling air introduced to the radiator 120 through the air dam 170 increases, the grille opening can be reduced accordingly, resulting in a decrease in air resistance acting on the vehicle 100.

[0090] In aerodynamic mode, such as Figure 8 As shown, to prioritize downforce acting on vehicle 100, the air dam opening is increased or decreased in the rearward-deployed position according to vehicle speed. At this time, as vehicle speed decreases, the air dam opening gradually increases; in general, the amount of downward protrusion from the front bumper 140 gradually decreases, thus suppressing the required downforce acting on vehicle 100. Furthermore, the target grille opening, set according to coolant temperature, is corrected towards the closed side based on the target air dam opening. This compensates for the increased cooling airflow due to the target air dam opening being in the rearward-deployed position, and reduces air resistance acting on vehicle 100.

[0091] Therefore, by appropriately switching the control mode of the active air intake grille 160 and air dam 170 based on vehicle information, it is possible to ensure the appropriate airflow for that mode and optimize the downforce and air resistance acting on the vehicle 100. Furthermore, by reducing air resistance, the fuel economy of the vehicle 100 can also be improved, for example.

[0092] If we categorize the high-speed mode, preheating mode, cooling mode, and aerodynamic mode according to vehicle speed and cooling requirements, then it becomes... Figure 12 The example shown here. Here, as an example, low speed is 30km / h to 50km / h, medium speed is 50km / h to 80km / h, high speed is 80km / h to 130km / h, and super high speed is above 130km / h.

[0093] At extremely high vehicle speeds, regardless of cooling requirements, the mode set according to vehicle information becomes high-speed mode. In high-speed mode, as mentioned above, the grille opening becomes fully open, and the air dam opening becomes rearward-deployed. Therefore, it is possible to increase downforce acting on the vehicle 100 while protecting the active air intake grille 160.

[0094] When cooling requirements are low and vehicle speeds are low, medium, and high, the mode set according to vehicle information becomes the preheating mode. In preheating mode, as mentioned above, the grille opening is fully closed, and the air dam opening gradually increases with increasing vehicle speed in the rearward extended position. Therefore, it is possible to increase downforce acting on the vehicle 100 while promoting engine preheating.

[0095] When cooling requirements are medium and vehicle speeds are low, medium, and high, the mode set according to vehicle information becomes the aerodynamic mode. In aerodynamic mode, as mentioned above, the grille opening ranges from a mid-opening to fully open corresponding to vehicle speed, and the air dam opening gradually increases with increasing vehicle speed in the rearward deployment position. Therefore, it is possible to improve aerodynamic performance while suppressing engine overcooling.

[0096] When cooling requirements are high and vehicle speeds are low, medium, or high, the mode set based on vehicle information becomes the cooling mode. In cooling mode, as described above, the grille opening ranges from an intermediate opening corresponding to the vehicle speed to full opening, and the air dam opening gradually increases with increasing vehicle speed in the forward-deployed position. Therefore, aerodynamic performance can be improved while ensuring engine cooling performance.

[0097] However, the active grille shutter 160 may experience either a fully closed fault (remaining fully closed) or a fully open fault (remaining fully open) due to a malfunction in the actuator 160B that rotates the blades 160A or its control system. When the active grille shutter 160 experiences a fully closed fault, the flow rate of cooling air introduced into the radiator 120 through the opening 150A of the front grille 150 decreases, resulting in insufficient cooling capacity, for example, when the vehicle 100 is driven under high load, and the engine may overheat. Conversely, when the active grille shutter 160 experiences a fully open fault, the flow rate of cooling air introduced into the radiator 120 through the opening 150A of the front grille 150 increases, resulting in excessive cooling capacity, for example, when the vehicle 100 is driven under low load, and the engine may overcool.

[0098] Therefore, in this embodiment, when the active grille shutter 160 experiences a complete closure failure, regardless of the mode selected based on vehicle information, it will still function as follows: Figure 13 The skirt 170A of the air dam 170 is positioned in a forward-opening position as shown. In this way, cooling airflow is directed towards the radiator 120 through the skirt 170A of the air dam 170 via a suitable gap between the active air intake grille 160 and the air dam 170, ensuring sufficient airflow for cooling.

[0099] On the other hand, when the active grille shutter 160 fails to fully open, regardless of the mode selected based on vehicle information, such as Figure 14 As shown, the skirt 170A of the air dam 170 is positioned in a rearward-extended position. This directs cooling air downwards from the vehicle 100 via the skirt 170A, reducing the flow of cooling air to the radiator 120 and suppressing engine overcooling. Furthermore, the increased downforce improves vehicle stability. It should be noted that if the active air intake grille 160 malfunctions while its opening is between fully closed and fully open, the air dam opening can be appropriately adjusted based on the current active air intake grille opening.

[0100] In summary, the electronic control device 200 is configured to adjust the protrusion of the air dam 170 according to the water temperature Tw in the event of a malfunction of the active air intake grille 160, thereby supplementing and maintaining the flow rate of cooling air introduced into the radiator 120.

[0101] It should be noted that whether the active grille shutter 160 has malfunctioned can be diagnosed, for example, by checking whether the active grille shutter 160 operates from fully closed to fully open or from fully open to fully closed after the ignition key has been turned off a specified number of times (e.g., 10 times). According to this diagnostic method, the active grille shutter 160 does not operate from fully closed to fully open whenever the ignition switch is turned off, thus reducing the number of times it operates and suppressing durability degradation.

[0102] Similar to the active grille 160, the air dam 170 may also experience a retraction malfunction, such as maintaining a fixed front or rear retracted position, or an deployment malfunction, such as maintaining a fixed center opening, due to a fault in the actuator 170B that rotates the side skirt 170A or its control system. When the air dam 170 experiences a retraction malfunction, the downward protrusion from the front bumper 140 decreases, resulting in reduced cooling airflow and increased air resistance. For example, it may be difficult to ensure adequate cooling airflow during high-load driving. Conversely, if the air dam 170 experiences a deployment malfunction, the downward protrusion from the front bumper 140 increases, thus increasing the flow of cooling air introduced to the radiator 120 through the side skirt 170A of the air dam 170. For example, excessive cooling air introduced to the radiator 120 during preheating may lead to overcooling of the engine.

[0103] Therefore, in this embodiment, when the air dam 170 experiences a storage failure, regardless of the mode selected based on the vehicle information, it will proceed as follows: Figure 15 The grille opening is reduced towards the closed side as shown. This maintains the airflow to the radiator 120 and reduces air resistance acting on the vehicle 100 by decreasing the grille opening.

[0104] On the other hand, when the air dam 170 experiences a deployment failure, regardless of the mode selected based on vehicle information, it will... Figure 16 The grille opening is reduced towards the closed side as shown. In this way, the flow rate of cooling air introduced into the radiator 120 can be maintained by reducing the flow rate of cooling air through the skirt 170A of the air dam 170, and the air resistance acting on the vehicle 100 can be reduced by reducing the grille opening.

[0105] It should be noted that the degree of reduction in blade opening can be appropriately set according to factors such as the air dam opening and water temperature. Furthermore, for example, by checking whether the air dam 170 moves from the front retracted position to the rear retracted position or vice versa after a predetermined number of ignition key disconnections (e.g., 10 times), a malfunction of the air dam 170 can be diagnosed. Using this diagnostic method, the air dam 170 does not move from the front retracted position to the rear retracted position whenever the ignition switch is disconnected, thus reducing the number of times it operates and suppressing durability degradation.

[0106] When the braking demand of vehicle 100 is high (e.g., during emergency braking), in order to suppress overheating of the service brakes and maintain braking capacity, it is preferable to simultaneously promote the cooling of the service brakes. Therefore, in this embodiment, when the braking demand of vehicle 100 is high, such as... Figure 17As shown, the grille opening is set to fully open, and the side skirt 170A of the air dam 170 is positioned in a forward-retracted position. When the grille is fully open, the airflow into the service brake increases, improving its cooling performance. Furthermore, if the side skirt 170A of the air dam 170 is in the forward-retracted position, air resistance increases, which assists the service brake. Therefore, by using the active air intake grille 160 and the air dam 170, the cooling of the service brake can be promoted, and the air resistance acting on the vehicle 100 can be increased, shortening the time and distance the vehicle 100 travels to a stop. In addition, since the side skirt 170A of the air dam 170 is retracted in the forward-retracted position, damage to the air dam 170 can also be avoided. It should be noted that in cases where the braking requirements of the vehicle 100 are high, the side skirt 170A of the air dam 170 can be retracted to the rear instead of being positioned in the forward-retracted position. It should be noted that "front storage position" and "rear storage position" are not limited to the structure where the skirt panel 170A is in a completely front storage position or a completely rear storage position, but may also include the angle to which the above-mentioned effects can be achieved.

[0107] When the vehicle 100 is parked or traveling at low speeds, if the side skirt 170A of the air dam 170 is in a fully deployed, forward-deployed, or rearward-deployed position, the front end of the side skirt 170A may come into contact with protrusions such as wheel chocks and be damaged. Therefore, in this embodiment, to ensure a clearance from protrusions when the vehicle 100 is parked, the side skirt 170A of the air dam 170 can be set to a forward-folded position, a rearward-folded position, etc., and the air dam opening can be adjusted. Here, protrusions such as wheel chocks can be detected, for example, using a known obstacle detection device.

[0108] Furthermore, when the vehicle 100 is traveling at low speeds, if the air dam 170 is retracted or deployed based on whether the vehicle speed exceeds a certain threshold, the air dam 170 will repeatedly retract and deploy at speeds near the threshold, potentially reducing its durability. Therefore, in this embodiment, a lag can be provided between the retraction and deployment points of the air dam 170. Additionally, when the vehicle speed is below a certain threshold, the air dam 170 may not be deployed and may be retracted to a forward or rearward storage position.

[0109] It should be noted that those skilled in the art can readily understand that new implementation methods can be generated by omitting a part of the technical ideas of the various embodiments described above, or by appropriately combining a part of the technical ideas, or by replacing a part of the technical ideas with known technologies.

[0110] Explanation of reference numerals in the attached figures

[0111] 100: Vehicle; 120: Radiator; 140: Front bumper; 150: Front grille; 160: Active grille (cooling air control device); 160A: Blade; 160B: Actuator; 170: Air dam (aerodynamic performance control device); 170A: Skirt; 170B: Actuator; 200: Electronic control unit; 210: Vehicle speed sensor; 220: Coolant temperature sensor.

Claims

1. A vehicle control device, based on output signals from a vehicle speed sensor configured to detect vehicle speed and a coolant temperature sensor configured to detect coolant temperature, respectively controls a cooling air control device and an aerodynamic performance control device, wherein the cooling air control device is configured to control the flow rate of cooling air introduced into a radiator, and the aerodynamic performance control device is configured to control the aerodynamic performance of the vehicle. The vehicle's control device is configured to change the control state of the other of the cooling air control device and the aerodynamic performance control device by considering the control state of the latter.

2. The vehicle control device according to claim 1, The cooling air control device is an active air intake grille capable of continuously or intermittently changing the opening degree of the front grille from fully open to fully closed. The aerodynamic performance control device is a variable air dam installed at the lower front of the vehicle and capable of continuously or periodically changing the amount of protrusion downwards from the vehicle.

3. The vehicle control device according to claim 2, The active air intake grille has blades that are rotatable about a rotation axis extending in the left-right direction of the vehicle. And an actuator that causes the blades to rotate about the rotation axis from fully open to fully closed of the front grille. The air dam has: a skirt that can rotate about a rotation axis extending in the left-right direction around the lower part of the front bumper; And an actuator that causes the skirt to rotate about the rotation axis between the front and rear retracted positions of the vehicle.

4. The vehicle control device according to claim 3, When the vehicle is traveling at a speed higher than a specified speed, the front grille is fully opened by the active air intake grille, and taking into account the control state of the active air intake grille, the rotation angle of the skirt of the air dam, which is set to be deployed towards the rear of the vehicle, is changed according to the vehicle speed.

5. The vehicle control device according to claim 3, The vehicle control device is configured to, while prioritizing the preheating performance of the engine mounted on the vehicle, fully close the opening of the front grille via the active air intake grille, and, taking into account the control state of the active air intake grille, change the rotation angle of the skirt of the air dam, which is set to be deployed towards the rear of the vehicle, according to the vehicle speed.

6. The vehicle control device according to claim 3, The vehicle control device is configured to, while prioritizing the cooling performance of the engine mounted on the vehicle, adjust the skirt of the air dam to be deployed in a forward-facing state according to the vehicle speed, and, taking into account the control state of the air dam, change the opening degree of the active air intake grille, which is set according to the coolant temperature.

7. The vehicle control device according to claim 3, The vehicle control device is configured to, while prioritizing the aerodynamic performance of the vehicle, adjust the skirt of the air dam to be deployed towards the rear of the vehicle based on the vehicle speed, and, taking into account the control state of the air dam, change the opening of the active air intake grille, which is set according to the coolant temperature.

8. The vehicle control device according to claim 2, The vehicle's control device is configured to, in the event of a malfunction in either the active air intake grille or the air dam, control the other of the active air intake grille and the air dam to compensate for the malfunction in either the active air intake grille or the air dam.

9. The vehicle control device according to claim 2, The vehicle's control device is configured to, in the event of a malfunction in the active air intake grille, adjust the protrusion of the air dam according to the coolant temperature to maintain the flow rate of cooling air introduced into the radiator.

10. The vehicle control device according to claim 2, The vehicle's control device is configured to, in the event of a malfunction in the air dam, change the opening of the active air intake grille according to the coolant temperature to maintain the flow rate of cooling air introduced into the radiator.

11. The vehicle control device according to claim 2, The vehicle's control device is configured to, in the event of a malfunction in the air dam, change the opening of the active air intake grille according to the vehicle speed to maintain the flow rate of cooling air introduced into the radiator.

12. The vehicle control device according to claim 3, The vehicle control device is configured to, when the vehicle has high braking requirements, fully open the active air intake grille and rotate the skirt of the air dam to the front retracted position or the rear retracted position.

13. The vehicle control device according to claim 3, The vehicle's control device is configured to rotate the skirt of the air dam to the rear storage position when the vehicle is parked.

14. A method for controlling a vehicle, The vehicle's control unit, based on the output signals of a vehicle speed sensor configured to detect vehicle speed and a coolant temperature sensor configured to detect coolant temperature, controls a cooling air control device and an aerodynamic performance control device, respectively. The cooling air control device is configured to control the flow rate of cooling air introduced into the radiator, and the aerodynamic performance control device is configured to control the vehicle's aerodynamic performance. The vehicle's control device considers the control state of one of the cooling air control device and the aerodynamic performance control device to change the control state of the other of the two devices.

15. The vehicle control method according to claim 14, The cooling air control device is an active air intake grille that can continuously or periodically change the opening of the front grille from fully open to fully closed. The aerodynamic performance control device is a variable air dam installed at the lower front of the vehicle and capable of continuously or periodically changing the amount of protrusion downwards from the vehicle.

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