Method for adjusting the radiator grille latches of a vehicle based on the vehicle speed and the direction of adjustment of the radiator grille latches

Abstract

Power engine process, which includes the following: Setting a motor (202) coupled to radiator grille latches (114) based on a direction of movement of the radiator grille latches (114), a target opening of the radiator grille latches (114) and a vehicle speed.

Description

[0001] A vehicle grille is typically located at a front portion of a vehicle and may be configured to provide an opening through which intake air is received from outside the vehicle, such as a grille opening or a bumper opening. Such intake air may then be directed to an engine compartment of the vehicle to assist the vehicle's cooling system in cooling the engine, transmission, and other such engine compartment components. Such airflow over the grille may add drag when the vehicle is in motion. Accordingly, grilles may include grille shutters to block such airflow and consequently reduce drag and improve fuel economy.Closed grille shutters can also provide faster powertrain warm-up, which can improve fuel economy due to reduced friction and enhance the performance of the passenger compartment heater. However, closed grille shutters also reduce airflow through the radiator and other cooling components. As a result, engine temperatures, such as engine coolant temperature (ECT), can increase. Consequently, operation of the grille shutters may include increasing or decreasing the opening of the grille shutters based on engine cooling requirements and vehicle driving conditions.

[0002] An exemplary approach for adjusting grille shutters to increase fuel economy is shown by Kerns et al. in US Pat. No. 8,311,708 B2. Therein, the vehicle's grille shutters are adjusted in response to the engine temperature and a non-driven vehicle condition. For example, if the engine temperature is above a threshold temperature or the vehicle is decelerating, the grille shutters may be opened.

[0003] However, backlash in the grille shutter system can result in differences between a commanded position of the grille shutters and the actual resulting position of the grille shutters. For example, an engine may adjust the grille shutters through a series of gears. However, the gears may contain an amount of backlash that results in reduced grille shutter positioning accuracy. A single map or relationship between the target position of the grille shutters and the commanded position of the grille shutters can be used to adjust the grille shutters to a position close to the target position. This relationship can change based on the direction of movement of the grille shutters (e.g., opening or closing), thereby resulting in reduced grille shutter position control.

[0004] US 2013 / 0 110 356 A1 relates to a control device for opening / closing a roller shutter of a vehicle, which is arranged at a front part of the vehicle in order to introduce ambient air into an engine room through a front opening.

[0005] US 2013 / 0 338 870 A1 describes a system and method for performing a diagnosis of an active grille closure system of a vehicle.

[0006] JP S61 - 218.713 A describes a radiator ventilation air quantity regulator for improving fuel consumption by controlling the amount of cooling air introduced into a radiator and reducing the driving resistance of a vehicle during high-speed operation.

[0007] US 2011 / 0 288 717 A1 discloses a vehicle system comprising a first sensor providing first data indicating at least one of the vehicle speed and the ambient temperature, and a roller shutter control module, the first sub-module, providing a first amount of change for an opening amount of one of the roller shutters based on the first data.

[0008] US 2010 / 0 147 611 A1 describes a motor vehicle with an outside air introduction assembly which serves to introduce outside air into a radiator in an engine cooling system while driving.

[0009] DE 22 16 585 A relates to a cooling device for a motor vehicle and in particular to a cooling device which has a fan guide body which ensures a sufficient air flow rate through a radiator.

[0010] In one example, the issues described above may be addressed by a method for adjusting a motor coupled to the grille shutters based on a direction of movement of the grille shutters, a desired opening of the grille shutters, and a vehicle speed. In this way, a position error between a commanded position of the grille shutters and the resulting position of the grille shutters may be reduced, thereby increasing vehicle fuel economy while providing adequate engine cooling.

[0011] As one example, unique opening and closing maps (or relationships) may be stored within a memory of an engine controller. The unique opening and closing maps may include a commanded percentage opening or a commanded percentage closure (depending on the selected map) corresponding to a desired percentage opening or a desired percentage closure at a current vehicle speed. In one example, the map may be stored in a lookup table within the controller's memory. The opening and closing map for determining the commanded position of the grille shutters may be determined based on a desired engine position relative to a current or previous desired engine position. For example, if there is a difference between the desired engine position (based on the desired position of the grille shutters) and the current (e.g.,B. If the actual engine position is greater than an engine increment, the controller may use the opening map to determine the commanded position of the grille shutters. However, if instead a difference between the current engine position and the desired engine position is greater than an engine increment, the controller may use the closure map to determine the commanded position of the grille shutters. In this way, determining the commanded position of the grille shutters based on both the desired position of the grille shutters as well as the vehicle speed and direction of movement of the grille shutters may result in an actual position of the grille shutters that is closer to the commanded position of the grille shutters. As a result, fuel economy may be increased along with the accuracy of engine temperature control.

[0012] It should be understood that the above summary is provided to introduce, in simplified form, a selection of the concepts further described in the detailed description. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that eliminate all of the disadvantages noted above or in any part of this disclosure. Fig. 1 shows a schematic diagram of a grille closure system, an engine, and associated components in a vehicle. Fig. 2 shows an example of a location of a CAC, radiator, and engine within a vehicle with respect to the grille shutters and associated ambient airflow. Fig. Figure 3 shows a schematic grille closure system of a vehicle. Fig. 4 shows a diagram of different positions of the grille closure wings. Fig. 5 shows a method for adjusting the grille shutters based on a direction of movement of the grille shutters. Fig. 6 shows example position maps for determining a commanded position of the grille shutters.

[0013] The following description relates to systems and methods for adjusting the grille shutters of a vehicle to improve cooling for an engine system, such as the one in Fig. 1. The grille shutters of the vehicle may be positioned in a grille of a front portion of a vehicle, as shown in Fig. 2. A percentage opening of the grille shutters may be adjusted based on engine operating conditions to increase or decrease cooling airflow to the engine. Specifically, an engine controller may communicate a commanded position of the grille shutters to a motor coupled to the grille shutters, such as the one shown in Fig. 3 shown engine. The engine can then adjust the grille shutters to the commanded position. In Fig. 4 shows various positions of the grille shutters relative to an opening angle of the grille shutters. In some cases, the actual resulting position of the grille shutters after adjusting the grille shutters may be different from the commanded position of the grille shutters (resulting in a position error). This position error may be due to backlash in the grille shutter system and may change based on the vehicle speed and the direction of movement of the grille shutters (e.g., whether the grille shutters are opening or closing). Fig. 5 shows a method for adjusting the grille shutters based on the direction of movement of the grille shutters (e.g., the direction of adjustment of the grille shutters). In Fig. 6 shows various opening and closing maps for determining the commanded position of the grille shutters.

[0014] Fig. 1 shows an exemplary embodiment of a grille closure system 110 and an engine system 100 in a motor vehicle 102, illustrated schematically. The engine system 100 may be included in a vehicle, such as a road vehicle, among other vehicle types. While exemplary applications of the engine system 100 are described with respect to a vehicle, it should be recognized that various types of engines and vehicle propulsion systems may be used, including passenger cars, trucks, etc.

[0015] In the illustrated embodiment, the engine 10 is a supercharged engine coupled to a turbocharger 13 including a compressor 14 driven by a turbine 16. Specifically, fresh air is introduced into the engine 10 along an intake passage 42 via an air cleaner 11, flowing to the compressor 14. The compressor may be any suitable intake air compressor, such as an engine-driven or driveshaft-driven supercharger compressor. In the engine system 100, the compressor is shown as a turbocharger compressor mechanically coupled to the turbine 16 via a shaft 19, with the turbine 16 driven by the expanding engine exhaust. In one embodiment, the compressor and turbine may be coupled within a twin-scroll turbocharger.In another embodiment, the turbocharger may be a variable geometry turbocharger (VGT), wherein the turbine geometry is actively varied as a function of engine speed and other operating conditions.

[0016] As in Fig. 1, the compressor 14 is coupled to a throttle valve 20 through a charge air cooler (CAC) 18. The CAC may, for example, be an air-to-air or an air-to-water heat exchanger. The throttle valve 20 is coupled to the engine intake manifold 22. The hot compressed air charge from the compressor enters the inlet of the CAC 18, cools as it moves through the CAC, and then exits to pass through the throttle valve to the intake manifold. Ambient airflow 116 from outside the vehicle may enter the engine 10 through a grille 112 in a front portion of the vehicle and may pass over the CAC to assist in cooling the charge air. Condensation may form and accumulate in the CAC when the ambient air temperature decreases or during humid or rainy weather conditions when the charge air is cooled below the dew point of water.If the charge air contains recirculated exhaust gases, the condensate may become acidic and corrode the CAC housing. The corrosion can lead to leaks between the air charge, the atmosphere, and possibly the coolant in the case of water-to-air coolers. Additionally, condensate may accumulate at the bottom of the CAC and then be sucked into the engine all at once during acceleration (or pedal application), increasing the possibility of engine misfire. In one example, the cooling ambient airflow moving through the CAC may be controlled by the grille shutter system 110 so that condensate formation and engine misfire events are reduced.

[0017] In the Fig. In the embodiment shown in Figure 1, the pressure of the air charge within the intake manifold is sensed by a manifold air pressure (MAP) sensor 24, and boost pressure is sensed by a boost sensor 124. A compressor bypass valve (not shown) may be coupled in series between the inlet and outlet of the compressor 14. The compressor bypass valve may be a normally closed valve configured to open under select operating conditions to vent excess boost pressure. For example, the compressor bypass valve may be open during conditions of decreasing engine speed to prevent compressor surge.

[0018] The intake manifold 22 is coupled to a series of combustion chambers 31 by a series of intake valves (not shown). The combustion chambers are further coupled to the exhaust manifold 36 via a series of exhaust valves (not shown). In the illustrated embodiment, a single exhaust manifold 36 is shown. However, in other embodiments, the exhaust manifold may include multiple exhaust manifold sections. Configurations including multiple exhaust manifold sections may allow effluent from different combustion chambers to be routed to different locations in the engine system. A universal exhaust gas oxygen (UEGO) sensor 126 is shown coupled to the exhaust manifold 36 upstream of the turbine 16. Alternatively, the UEGO sensor 126 may be replaced with a dual-state exhaust gas oxygen sensor.

[0019] As in Fig. 1, exhaust gas is directed from one or more exhaust manifold sections to the turbine 16 to drive the turbine. If reduced turbine torque is desired, some exhaust gas may instead be directed through a wastegate (not shown) and bypass the turbine. The combined flow from the turbine and wastegate then flows through an emission control device 70. Generally, one or more emission control devices 70 may include one or more exhaust aftertreatment catalysts configured to catalytically treat the exhaust flow and thereby reduce an amount of one or more substances in the exhaust flow.

[0020] All or a portion of the treated exhaust gas from the emission control device 70 may be vented to the atmosphere via an exhaust conduit 35. However, depending on operating conditions, some exhaust gas may instead be diverted to the EGR passage 51, through the EGR cooler 50, and the EGR valve 52 to the inlet of the compressor 14. In this manner, the compressor is configured to admit exhaust gas bled from a location downstream of the turbine 16. The EGR valve may be opened to admit a controlled amount of cooled exhaust gas to the compressor inlet for desired combustion and emission control performance. In this manner, the engine system 100 is configured to provide external low-pressure EGR (LP-EGR). The rotation of the compressor, in addition to the relatively long LP-EGR flow path in the engine system 100, provides excellent homogenization of the exhaust gas into the intake air charge.Furthermore, the arrangement of the EGR takeoff and mixing points provides effective cooling of the exhaust gas for increased available EGR mass and improved performance. In further embodiments, the EGR system may be a high-pressure EGR system with an EGR passage 51 connecting from a location upstream of the turbine 16 to a location downstream of the compressor 14.

[0021] The motor vehicle 102 further includes a cooling system 104 that circulates a coolant through the internal combustion engine 10 to absorb the waste heat and that distributes the heated coolant via the coolant lines 82 and 84 to the radiator 80 and / or the heater core 90. In particular, Fig. 1, the cooling system 104 is coupled to the engine 10 and circulates engine coolant from the engine 10 via an engine-driven water pump 86 to the radiator 80 and back to the engine 10 via the coolant line 82. The engine-driven water pump 86 may be coupled to the engine via a front end accessory drive (FEAD) 88 and rotated via a belt, chain, etc., in proportion to engine speed. Specifically, the engine-driven water pump 86 circulates coolant through passages in the engine block, engine head, etc., to absorb engine heat, which is then transferred to the ambient air via the radiator 80.In an example where the engine-driven water pump 86 is a centrifugal pump, the pressure generated (and resulting flow) may be proportional to the speed of the crankshaft, which in the example is shown in FIG. Fig. 1 is directly proportional to engine speed. In another example, a motor-controlled pump may be used that can be adjusted independently of engine rotation. The temperature of the coolant (e.g., engine coolant temperature, ECT) may be controlled via a thermostatic valve 38 located in cooling line 82, which may be held closed until the coolant reaches a threshold temperature.

[0022] The engine system 100 may include an electric fan 92 to direct cooling airflow to the CAC 18, the engine cooling system 104, or other components of the engine system. In some embodiments, the electric fan 92 may be an engine cooling fan. The engine cooling fan may be coupled to the radiator 80 to maintain airflow through the radiator 80 when the vehicle 102 is moving slowly or is stopped while the engine is running. The speed or direction of rotation of the fan may be controlled by a controller 12. In one example, the engine cooling fan may also direct cooling airflow to the CAC 18. Alternatively, the electric fan 92 may be coupled to an engine accessory drive system driven by the engine crankshaft. In other embodiments, the electric fan 92 may act as a dedicated CAC fan.In this embodiment, the electric fan may be coupled to the CAC or located at a location to direct airflow directly to the CAC. In yet another embodiment, there may be two or more electric fans. For example, one may be coupled to the radiator for cooling the engine (as shown), while the other may be coupled elsewhere to direct cooling air directly to the CAC. In this example, the two or more electric fans may be controlled separately (e.g., at different speeds) to provide cooling to their respective components.

[0023] Coolant may flow through coolant line 82, as described above, and / or through coolant line 84 to heater core 90, where heat may be transferred to passenger compartment 106, with the coolant flowing back to engine 10. In some examples, engine-driven water pump 86 may operate to circulate coolant through both coolant lines 82 and 84.

[0024] Fig. 1 further shows a control system 28. The control system 28 may be communicatively coupled to various components of the engine system 100 to perform the control routines and actions described herein. For example, as shown in Fig. 1, the control system 28 may include an electronic digital controller 12. The controller 12 may be a microcomputer including a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values, a random access memory, a hold memory, and a data bus. As illustrated, the controller 12 may receive input from a plurality of sensors 30 that may include the user inputs and / or the sensors (such as a transmission gear position, an accelerator pedal input (e.g., a pedal position), a brake input, a transmission automatic shift lever position, vehicle speed, engine speed, mass air flow through the engine, boost pressure, ambient temperature, ambient humidity, intake air temperature, fan speed, etc.), the cooling system sensors (such asThe controller 12 may include sensors (such as engine coolant temperature, fan speed, passenger compartment temperature, ambient humidity, etc.), CAC 18 sensors (such as CAC inlet air temperature and pressure, CAC outlet air temperature and pressure, etc.), and others. Additionally, the controller 12 may receive data from a GPS 34 and / or an in-vehicle communications and entertainment system 26 of the vehicle 102.

[0025] The in-vehicle communications and entertainment system 26 may communicate with a wireless communication device 40 using various wireless protocols, such as wireless networks, cell tower transmissions, and / or combinations thereof. The data obtained by the in-vehicle communications and entertainment system 26 may include real-time and predicted weather conditions. Weather conditions, such as temperature, precipitation (e.g., rain, snow, hail, etc.), and humidity, may be obtained through various wireless communication device applications and weather forecast websites. The data obtained by the in-vehicle communications and entertainment system may include current and predicted weather conditions for both the current location and future locations along a planned travel route.In one embodiment where the in-vehicle communications and entertainment system includes a GPS, the current and future weather data may be correlated with the current and future travel routes displayed on the GPS. In an alternative embodiment where the vehicle system includes a dedicated GPS 34, both the GPS and the in-vehicle communications and entertainment system may communicate with the wireless communication device 40 and with each other to transmit current and future weather data for current and future travel routes. In one example, the entertainment system may access various weather maps stored on the Internet or other cloud computing systems. The stored weather maps may include rain, humidity, precipitation, and / or temperature information, provided, for example, as contour maps.In one example, wireless communication device 40 may forward the real-time humidity data to the in-vehicle communication and entertainment system 26 and / or the GPS 34, which is then forwarded to the controller 12. The controller 12 compares the received humidity data to threshold values ​​and determines the appropriate settings for the engine's operating parameters. In one example, these settings may include adjusting the grille shutter system 110. For example, if the humidity is greater than a defined threshold, one or more of the grille shutters may be closed.

[0026] In other embodiments, the presence of rain may be inferred from other signals or sensors (e.g., rain sensors). In one example, rain may be inferred from an on / off signal from the vehicle's windshield wipers. Specifically, in one example, when the windshield wipers are on, a signal may be sent to controller 12 to indicate rain. The controller may use this information to predict the likelihood of condensation forming in the CAC and adjust vehicle actuators, such as electric fan 92 and / or grille shutter system 110.

[0027] Additionally, the controller 12 may communicate with various actuators 32, which may include engine actuators (such as fuel injectors, an electronically controlled intake air throttle plate, spark plugs, etc.), cooling system actuators (such as air handling valves and / or blow-off valves in the passenger compartment air conditioning system, etc.), and others. In some examples, the storage medium may be programmed with computer-readable data representing processor-executable instructions to perform both the methods described below and other variations that are anticipated but not specifically listed.

[0028] As noted here, the amount of waste heat transferred from the engine to the coolant can vary with operating conditions, thereby affecting the amount of heat transferred to the airflows. For example, if the engine output torque or fuel flow is reduced, the amount of waste heat generated can be proportionally reduced.

[0029] The motor vehicle 102 further includes a grille 112 that provides an opening (e.g., a grille opening, a bumper opening, etc.) for receiving ambient airflow 116 through or near the front of the vehicle and into the engine compartment. Such ambient airflow 116 may then be used by the radiator 80, the electric fan 92, and other components to keep the engine and / or transmission cool. The ambient airflow 116 may further remove heat from the vehicle's air conditioning system and may improve the performance of turbocharged / supercharged engines equipped with a CAC 18 that reduces the temperature of the air entering the intake manifold / engine. In one example, the electric fan 92 may be adjusted to further increase or decrease airflow to the engine components.In another example, a dedicated CAC fan may be included in the engine system and used to increase or decrease airflow to the CAC.

[0030] Fig. 2 shows an example of the locations of the CAC 18, the radiator 80, the electric fan 92, and the engine system 100 within a vehicle 102 with respect to the grille closure system 110 and the associated ambient airflow 116. Other components under the hood (the fuel system, the batteries, etc.) may also benefit from the cooling airflow. Consequently, the grille closure system 110 may assist the cooling system 104 in cooling the internal combustion engine 10. In one example, as shown in Fig. 2, the grille shutter system 110 may be a dual active grille shutter system including two groups of one or more grille shutters 114 configured to adjust the amount of airflow received by the grille 112. In another example, the grille shutter system 110 may be an active grille shutter system including only one group of one or more grille shutters 114.

[0031] The grille shutters 114 may cover a frontal area of ​​the vehicle, e.g., spanning from just under the hood to the lower part of the bumper. By covering the front of the vehicle, aerodynamic drag is reduced and the ingress of outside cooling air to the radiator 80 and the CAC 18 is reduced. In some embodiments, all of the grille shutters 114 may be moved in coordination by the controller. In other embodiments, the grille shutters may be divided into groups, and the controller may adjust the opening / closing of each area independently. For example, a first group of grille shutters 204 may be positioned in front of the radiator, while a second group of grille shutters 206 may be positioned in front of the CAC 18.

[0032] As in Fig. 2, the first group of grille shutters 204 is positioned vertically above the second group of grille shutters 206 with respect to a surface upon which the vehicle 102 sits. As such, the first group of grille shutters 204 may be referred to as the upper grille shutters, while the second group of grille shutters 206 may be referred to as the lower grille shutters. An amount of opening of the first group of grille shutters 204 controls an amount of ambient airflow 216 moving toward the radiator 80, while an amount of opening of the second group of grille shutters 206 controls an amount of ambient airflow moving toward the CAC 18. As such, the upper grille shutters may largely affect vehicle drag and engine cooling, while the lower grille shutters affect CAC cooling.

[0033] In some examples, each group of grille shutters may include the same number of grille shutters 114, while in other examples, one group of grille shutters may include more than the other. In one embodiment, the first group of grille shutters 204 may include multiple grille shutters, while the second group of grille shutters 206 includes one grille shutter. In an alternative embodiment, the first group of grille shutters may include only one grille shutter, while the second group of grille shutters includes multiple grille shutters. In alternative embodiments, all of the grille shutters 114 may be included as a group, where an amount of opening of one group of grille shutters 114 may affect vehicle aerodynamic drag, engine cooling, and CAC cooling.

[0034] The grille shutters 114 are movable between an open position and a closed position and can be maintained in both positions or in multiple intermediate positions thereof. In other words, the opening of the grille shutters 114 can be adjusted so that the grille shutters 114 are partially open, partially closed, or cycled between an open position and a closed position to provide airflow to cool the components in the engine compartment. The open position can be referred to as a maximum amount of opening (or a maximum percentage of opening) such that the grille shutters are fully open. An amount of opening of the grille shutters 114 or the group of grille shutters (e.g.,The opening percentage (e.g., the first group of grille shutters 204 or the second group of grille shutters 206) may be designated by a percentage. For example, when the grille shutters are halfway between an open and a closed position, the grille shutters may be 50% open. When the grille shutters are opened to the maximum percentage opening (e.g., an upper threshold amount of opening), the grille shutters may be 100% open.

[0035] The grille shutters 114 (e.g., the upper grille shutters) may be actuated by a motor 202. The motor 202 may be operatively coupled to the control system 28. As an example, the controller 12 may be communicatively connected to the grille shutter system 110 and may have information stored therein to adjust the opening of the grille shutters 114. The controller 12 may send signals to the motor 202 for adjusting the grille shutter system 110. These signals may include commands to increase or decrease the opening of the upper grille shutters. For example, the controller 12 may command the motor 202 to open the upper grille shutters 30% open. The motor 202 may be coupled to one or more grille shutters 114. For example, the motor 202 maybe coupled to a first grille shutter 114, wherein the first grille shutter is mechanically connected to the remaining grille shutters 114. In another example, the motor 202 may be coupled to each grille shutter 114 or each group of grille shutters. Further, in some examples, the grille shutter system 110 may include more than one motor for controlling more than one group or more than one individual grille shutter.

[0036] Fig. 3 shows a schematic 300 of the grille shutter system 110, which includes the motor 202 and a single grille shutter 114 of a group of grille shutters. Specifically, the schematic 300 shows that the motor 202 is indirectly coupled to the grille shutter 114 through a series of shafts and gears. The motor 202 is coupled to a first rotatable shaft 302 at a first end of the first shaft 302. A second end of the first shaft 302 is coupled to a first gear 304. When the first shaft 302 rotates in a direction shown by arrow 306, the first gear 304 rotates. As such, the first shaft 302 and the first gear 304 rotate together about a central axis of the first shaft 302. Further, the motor 202 actuates the first shaft 302 to rotate it to a plurality of positions.

[0037] The single grille shutter 114 may be referred to as a vane. The diagram 300 shows a front view of the grille shutter vane 114 (relative to the front of the vehicle). As such, airflow from outside the vehicle may be directed into a plane of the side. The grille shutter vane 114 may be coupled to a second shaft 308 at a first end of the second shaft 308. A second end of the second shaft 308 is coupled to a second gear 310. The first gear 304 is connected to the second gear 310 such that rotation of the first gear 304 causes rotation of the second gear 310. Specifically, the first gear 304 includes a plurality of teeth offset from a plurality of teeth of the second gear 310. As such, the teeth of the first gear 304 fit between the teeth of the second gear 310, while the teeth of the second gear 310 fit between the teeth of the first gear 304.As shown in diagram 300, as the first gear 304 rotates in a first direction indicated by arrow 306, the second gear consequently rotates in a second direction indicated by arrow 312. The second direction is opposite to the first direction. As a result of the rotation of the first shaft 302, the grille shutter blade 114 rotates with the rotation of the second gear 310 and the second shaft 308.

[0038] In alternative embodiments, the Fig. 3 may have additional gears and / or shafts that couple the motor 202 to the grille shutter wing 114. Furthermore, additional mechanical components (in addition to those shown in Fig. 3) may be included in the grille shutter system 110 to translate the movement of the motor 202 into coordinated movement and rotation of the grille shutter blade 114.

[0039] In one example, motor 202 may be a stepper motor. As such, motor 202 may only move first shaft 302 to a finite number of positions. Further, motor 202 may have a minimum amount it must move with each actuation. For example, motor 202 may only move in six-degree increments. In another example, motor 202 may move in increments of a different number of degrees. As such, motor 202 may have a finite number of motor positions, where a desired position of the grille shutters after moving the grille shutters with motor 202 may not align with an actual resulting position of the grille shutters. Instead, motor 202 may move the grille shutters to the closest available position to the commanded position of the grille shutters.

[0040] Upon receiving a command from a controller, the motor 202 rotates the first shaft 302 to a position corresponding to the commanded position of the grille shutters. In one example, the command may be a motor position offset from the commanded position of the grille shutters. In another example, the command may be the commanded position of the grille shutters having a corresponding motor position. The commanded position of the grille shutters may be a percentage open (or percentage closed) or an opening angle (e.g., a degree of opening). For example, 0% open may correspond to a grille shutter angle of 0 degrees, measured from a vertical axis of the grille shutter, as shown in Fig. 4 and will be explained further below. As discussed above, the commanded position of the grille shutters may not correspond to an exact motor position. Consequently, the motor 202 may actuate the grille shutter 114 to the position closest to the commanded position. Although in Fig. 4 that the motor 202 is coupled to a single grille shutter 114, in some embodiments the motor 202 may be coupled to additional grille shutters. Furthermore, the Fig. 4 may be mechanically connected (e.g., via a connection) to additional grille closures positioned vertically above and / or below the grille closure 114. Rotating the grille closure 114 shown in Fig. 4, as such, can rotate the other connected grille shutters by the same amount. In this way, the motor 202 can adjust multiple grille shutters 114 or groups of grille shutters together and parallel to each other.

[0041] A position sensor 314 may be coupled to the grille shutter system 110 to provide feedback of an actual position of the grille shutter blade to a controller (such as the controller shown in Fig. 1 shown controller 12). As shown in Fig. 4, the position sensor 314 is positioned with the second shaft 308 closer to the end of the second shaft 308 that is coupled to the grille shutter blade 114. However, in alternative embodiments, the position sensor 314 may be positioned in a different position on the second shaft 308, the first shaft 302, or the grille shutter blade 114. The output of the position sensor 314 may be a feedback position of the grille shutters.

[0042] In some cases, the feedback position of the grille shutters may be different than the commanded position, resulting in a position error. As discussed above, the actual position of the grille shutter blades may be different than the commanded position of the grille shutter blades due to available motor increments not exactly matching the desired blade angle. Additionally, a position error may result from backlash. As discussed above, the first gear 304 and the second gear 310 have teeth that are interconnected between the teeth of the opposing gear. In some examples, the teeth of the gears may be slightly smaller than the gap between adjacent teeth. As a result, when the two gears are interconnected, there may be an amount of gap between the interconnected teeth of the two gears.This space or gap between the mating teeth can cause some slippage or backlash in the gears. For example, if the mating teeth are not positioned relative to each other when a first of the two gears begins to move, the teeth of the first gear may move a distance before contacting the mating teeth of the second gear and subsequently begin to move the second gear. Consequently, the first gear may move a first amount before the second gear begins to rotate. As a result, the grille shutter vane 114 may move the target minus the first amount, resulting in a position that is different from the commanded position.

[0043] Backlash may occur to a greater extent when a direction of movement of the grille shutters 114 is changed. For example, backlash may occur when transitioning from opening to closing or from closing to opening of the grille shutters. Consequently, depending on the direction of movement of the grille shutters, the effect of the backlash on the position of the grille shutters may be different. Further details on determining the commanded position of the grille shutters to account for the backlash, the direction of movement (i.e., increasing or decreasing the opening percentage), and additional operating conditions, such as vehicle speed, are described below with reference to Fig. 5-6.

[0044] Fig. 4 shows exemplary positions of the grille shutters for a single grille shutter wing 114. Specifically, the diagram 400 shows a side view of a grille shutter wing 114 (such as the one shown in Fig. 3). The grille closure wing 114 rotates about a central axis of the wing and the second shaft 308, as shown in Fig. 3. The diagram 400 shows a pivot point 408 of the grille shutter blade 114. The grille shutter blade 114 rotates between a fully open and a fully closed position defined by a vertical axis 410 and a lateral axis 412 of the grille shutters.

[0045] A first position of the grille shutters is shown at 402. The first position of the grille shutters is a closed position in which the grille shutters are fully closed, thereby preventing airflow through the grille from entering the vehicle. The percentage open when the grille shutters are fully closed is 0%. Likewise, the percentage closed when the grille shutters are fully closed is 100%. The grille shutter blade 114 is aligned with the vertical axis 410 such that an angle between the grille shutter blade 114 and the vertical axis 114 is approximately 0°. This angle may be referred to as the open angle. In other embodiments, the fully closed position of the grille shutters may be slightly greater than 0° (e.g., 5°) to allow for overlapping of adjacent grille shutters.A force 414 acts on an outer side of the grille shutter blade 114, with the force 414 resulting from airflow pushing against the blades as a vehicle (in which the grille shutters are installed) moves in a forward direction. Consequently, the force 414 increases as the speed of the vehicle (the vehicle speed, VS) increases. The force 414 is further based on the percentage opening, with the force 414 being greatest at 0% opening (the fully closed position shown at 402) and smallest at the maximum percentage opening (the fully open position shown at 406). In this way, the force acting on the outer side of the grille shutter blade 114 is a function of the vehicle speed and the percentage opening, with the force increasing as the vehicle speed increases and the percentage opening decreases.

[0046] At 404, a second position of the grille shutters is shown. The second position of the grille shutters is an intermediate position in which the grille shutter blade 114 is partially open (or partially closed). The opening angle 416 is defined between the vertical axis 410 and a blade axis 418 of the grille shutter blade 114. In one example, the opening angle 416 may be about 36°, such that the percentage opening of the grille shutters is about 40%. In another example, the opening angle may be about 9°, such that the percentage opening of the grille shutters is about 10%. In some examples, the controller may also determine a percentage closure of the grille shutters. For example, the percentage closure of the grille shutters may be 100 minus the percentage opening. In the example where the percentage open is 40%, the percentage closed is 60%.The partially open grille shutter blade 114 allows ambient airflow 116 to flow around the blade, through the opening created by the partially open grille shutter blade 114, and into the vehicle and toward the engine. The force 414 acting on the grille shutter blade 114 (the force perpendicular to the front of the blade) may decrease as the percentage opening and the opening angle 416 increase.

[0047] A third position of the grille shutters is shown at 406. The third position of the grille shutters is a fully open position, thereby allowing maximum ambient airflow 116 to enter the vehicle and engine compartment through the grille. Consequently, the fully open position may be referred to herein as a maximum opening or a maximum percentage opening. When the grille shutters are fully open, the opening angle is approximately 90°, with the percentage opening being 100%. The force 414 on the outside of the grille shutter blade 114 may have little effect on the resulting position of the grille shutters because the blades are fully open. Further, upon reaching the maximum percentage opening of 100% (and an opening angle of 90°), the grille shutter blade 114 may contact an end stop 420.The end stop 420 may be coupled to a support structure (e.g., an outer frame) of the grille shutter system 110. The end stop 420 may be positioned along a lateral axis of at least one grille shutter wing 114 of a group of grille shutters. As such, at least one grille shutter wing 114 of the group of grille shutters may contact the end stop 420 upon reaching the maximum percentage open of 100%. In response to the grille shutter wing 114 contacting the end stop, the controller may detect a stall current. Thus, detecting the stall current may verify that the grille shutters are at the maximum percentage open.

[0048] In this way, the grille shutter blades 114 of a grille shutter system 110 can be adjusted to multiple positions between 0% open (the fully closed position) and 100% open (the maximum percentage open or fully open position). A motor can actuate the grille shutters to different positions based on the commanded position of the grille shutters.

[0049] The system according to the Fig. 1-4 provides a system including grille shutters positioned in a front portion of a vehicle, a motor coupled to the grille shutters and operable to adjust a position of the grille shutters, and a controller having a memory and computer-readable instructions stored therein for adjusting the motor based on a commanded percentage opening of the grille shutters, wherein the commanded percentage opening is based on a particular direction of movement of the grille shutters, a desired opening of the grille shutters, and a current vehicle speed. The computer-readable instructions include instructions for determining the particular direction of movement of the grille shutters based on a comparison between a desired motor position and a previous desired motor position, wherein the desired motor position corresponds to the commanded percentage opening.

[0050] An opening map may be stored in the controller's memory, wherein the computer-readable instructions further include instructions for looking up the commanded percentage opening of the grille shutters within the opening map when the grille shutters move in an opening direction. A closure map may also be stored in the controller's memory, wherein the computer-readable instructions further include instructions for looking up the commanded percentage opening of the grille shutters within the closure map when the grille shutters move in a closing direction.

[0051] A target position of the grille shutters (a target percentage opening) may be based on engine operating conditions, such as engine coolant temperature (ECT), drive conditions, pedal position, CAC efficiency, CAC temperature, and / or vehicle speed. A motor coupled to the grille shutters may adjust the grille shutters based on a command received from the controller. However, if the controller sends the target position of the grille shutters to the motor, the resulting (actual) position of the grille shutters may be different. For example, if the target percentage opening is 40%, the actual resulting position of the grille shutters after the motor adjustment may be 20% (or a percentage other than 40%).

[0052] As discussed above, the actual measured position of the grille shutter blade (e.g., measured by the position sensor) may be significantly different from the commanded blade position due to backlash in the grille shutter blade mechanism. This difference (position error) may be significant enough to adversely affect fuel economy. If the controller instead commands the grille shutters to open a greater amount than desired, the resulting grille shutter position may be closer to the target grille shutter position, thereby reducing the grille shutter position error and increasing fuel economy. For example, if the target percentage opening is 40%, the commanded percentage opening may be 65%. The engine may then actuate the grille shutters to open them 65%.However, the resulting position of the grille shutters can be approximately 40%. Thus, the commanded position of the grille shutters can be different from the target position of the grille shutters.

[0053] The commanded position of the grille shutters may be based on the desired position of the grille shutters and additional operating conditions that may change the final position of the grille shutters. For example, as described above, backlash in the grille shutter system may cause a position error of the grille shutters. In some examples, the backlash of the grille shutters may be quantified and then used to generate a map or relationship between the commanded percentage opening of the grille shutters and the desired percentage opening of the grille shutters. Specifically, a map of the commanded percentage openings corresponding to the desired percentage openings may be stored in a memory of the controller in the form of a lookup table or map (as in Fig. 6 and discussed further below). In another example, the controller may use a relationship between the desired percent opening and the commanded percent opening (e.g., in the form of a position translator function) to translate a desired percent opening into a commanded percent opening. In some examples, the relationship or map may translate the commanded position into counts (positions) of the stepper motor. In another example, the corresponding motor positions may be stored within a lookup table or map.

[0054] However, using only a single map or only a single relationship between the desired percentage opening and the commanded percentage opening may still result in a position error (e.g., a difference between the commanded and the actual resulting position of the grille shutters). As introduced above, the backlash and achievable engine positions may differ depending on whether the grille shutters are moving in an opening direction (e.g., an increasing percentage opening) or in a closing direction (e.g., a decreasing percentage opening). For example, when moving from a closed position to an open position, the position error of the grille shutters may increase for openings smaller than a threshold (e.g., 30%).This may be due to initial backlash when transitioning to moving in an opening direction. However, when moving from the open to the closed position, the position error may be reduced for openings smaller than the threshold (e.g., 30%) because the backlash may have already been corrected by the time the grille shutters reach the smaller opening angles.

[0055] Consequently, the position error of the grille shutters may be related to the direction of movement of the grille shutter blades. The position error of the grille shutters may further be related to the vehicle speed. As discussed above, a force acting against the outside of the grille shutter blade (e.g., the surface closest to the outside of the vehicle) may result in blade hysteresis, or a change in the blade position from the commanded position. For example, as the force increases, the grille shutter blade may be pushed away from the target percentage opening. The force may increase with increasing vehicle speed and decreasing grille shutter angle (e.g., a decreasing percentage opening). Consequently, the position error of the grille shutters may be a function of the vehicle speed, the percentage opening of the grille shutters, and the direction of movement (e.g.,of opening or closing) the grille locks.

[0056] Alternatively, two different maps (or relationships) between the desired percentage opening and the commanded percentage opening may be stored within the controller's memory. For example, unique position translator functions may be provided for opening and closing the grille shutters. The controller may determine the direction of movement of the grille shutters and switch between the two maps based on whether the desired percentage opening of the grille shutters is increasing (opening) or decreasing (closing). As such, the commanded position of the grille shutters may be based on the direction of movement of the grille shutters, the desired percentage opening, and the vehicle speed.

[0057] The maps or relationships of the positions of the grille shutters can be adjusted for different grille shutter systems, vehicles, suppliers, etc. For example, a backlash can be different for different vehicles and different grille shutter systems. Consequently, the positional relationships of the grille shutters can be calibrated offline prior to vehicle operation. In some examples, the positional relationships can be recalibrated and updated after a period of use to account for any deterioration or changes within the grille shutter system. Further details of adjusting the grille shutters based on the positional maps are described below with reference to Fig. 5. Furthermore, exemplary position maps are shown in Fig. 6 shown.

[0058] In this way, a motor coupled to the grille shutters is adjusted based on a direction of movement of the grille shutters, a desired opening of the grille shutters, and a vehicle speed. The method further includes adjusting the motor to the desired motor position to increase an opening of the grille shutters when a difference between a desired motor position and a current motor position is greater than a motor increment, wherein the desired motor position is based on the desired opening, the vehicle speed, and the direction of movement of the grille shutters.The method further includes adjusting the motor to the desired motor position to decrease an opening of the grille shutters when a difference between a current motor position and a desired motor position is greater than a motor increment, wherein the desired motor position is based on the desired opening, the vehicle speed, and a closing direction. The method further includes maintaining the direction of movement of the grille shutters and not adjusting the motor when an absolute value of a difference between a desired motor position and a current motor position is not greater than a motor increment.

[0059] The desired opening is based on at least one of the engine coolant temperature, the vehicle's drive conditions, the pedal position, the charge air cooler efficiency, and / or the vehicle speed. In one example, the motor is a stepper motor, wherein the stepper motor is operable to move in increments of a finite size. The method further includes adjusting the motor by a number of motor increments to achieve the desired opening, wherein the number of motor increments increases for increasing vehicle speed, a decreasing desired opening when moving in an opening direction, and an increasing desired opening when moving in a closing direction.

[0060] In Fig. 5 shows a method 500 for adjusting the grille shutters based on a direction of movement of the grille shutters. As described above, a motor coupled to the grille shutters may move the grille shutters to a desired percentage opening (or a desired percentage closure). However, the controller may send a commanded percentage opening to the motor that is different than the desired percentage opening. As such, the commanded percentage opening may be the amount of opening to achieve the desired percentage opening. Further, the direction of movement of the grille shutters may be either an opening direction in which the percentage opening of the grille shutters increases or a closing direction in which the percentage opening decreases (or the percentage closure increases).In one example, the direction of movement may be determined by comparing a desired motor position with an actual motor position. In another example, the direction of movement may be determined by comparing the desired motor position with a previous motor position (e.g., a most recently received motor position). The instructions for performing method 500 may be executed within a controller (such as the one described in . Fig. 1). The controller may execute method 500 as described below.

[0061] The method begins at 502 by estimating and / or measuring the engine operating conditions. The engine operating conditions may include the engine speed and load, the vehicle speed, the position of the grille shutters (the actual feedback position from the grille shutter position sensor), the engine coolant temperature (ECT), the pedal position, the CAC conditions (e.g., the temperature and pressure), the ambient humidity, a grille shutter motor position, etc. At 504, the method includes determining the desired position of the grille shutters. The desired position of the grille shutters may be based on the engine operating conditions, including the ECT and / or the vehicle driving condition (e.g.,whether the vehicle is powered or not) and / or pedal position and / or CAC efficiency and / or CAC temperature and / or vehicle speed. The method may further include, at 504, determining a desired motor position corresponding to the desired position of the grille shutters. The motor may be, for example, a stepper motor with a finite number of positions. The desired motor position may include a number of counts, motor positions, or motor increments by which to adjust the motor. Further, each motor increment may correspond to adjusting the grille shutters by a grille shutter angle of approximately six degrees (or another finite angle). As such, the desired motor position may be the motor position closest to the desired position of the grille shutters.

[0062] At 506, the method includes determining whether a difference between the desired motor position and the actual motor position is greater than a motor position (or a motor increment or a motor count). The actual motor position may also be referred to as the current motor position. In some examples, the actual motor position may be different than the previous desired motor position (e.g., the last value of the desired motor position) due to the motor moving in increments a set number of times. Thus, at 506, the method may additionally or alternatively include determining whether the difference between the current desired position and the previous value of the desired motor position is greater than a motor position.If the difference between the desired motor position and the actual motor position (or the difference between the desired motor position and the previous desired motor position) is greater than one motor position, the desired direction of movement of the grille shutters is the opening direction. In other words, the controller may command the motor to increase the percentage opening of the grille shutters. As a result, the method proceeds to 508 to use the grille shutter opening position map. An example of a grille shutter opening position map is shown at 602 of FIG. Fig. 6, which is further described below. In one example, at 508, the method may include transitioning from using the closure position map to using the opening position map if the grille shutters were initially moving in the closing direction. As such, the grille shutters may transition from moving in the closing direction to moving in the opening direction. Alternatively, if the grille shutters were initially moving in the opening direction, the method may include continuing to use the opening position map and continuing to adjust the grille shutters in the opening direction at 508.

[0063] At 510, the controller determines the commanded position of the grille shutters using the opening map. As such, the commanded position of the grille shutters may be based on the determined desired position of the grille shutters, a current vehicle speed, and the opening direction. At 512, the method includes translating the commanded position of the grille shutters into motor increments and then actuating the motor to adjust the grille shutters to the commanded position. At 512, the method may include, for example, adjusting the motor by increasing or decreasing the motor position by a certain number of counts or motor positions. The resulting position of the grille shutters (measured by the position sensor) may be approximately the desired position of the grille shutters determined at 504.

[0064] If, returning to 506, the difference between the desired motor position and the actual motor position is not greater than a motor position, the method proceeds to 514. At 514, the method includes determining whether a difference between the actual motor position and the desired motor position is greater than a motor position (e.g., a motor increment). Alternatively, at 514, the method may include determining whether a difference between the previous desired motor position and the current desired motor position is greater than a motor position. If the difference is greater than a motor position at 514, the desired direction of movement of the grille shutters is the closing direction. In other words, the controller may command the motor to decrease the percentage opening of the grille shutters (and increase the percentage closing of the grille shutters).As a result, the method proceeds to 516 to use a grille shutter position map. An example grille shutter position map is shown at 604 in FIG. Fig. 6, which is further described below. If the grille shutters were previously moving in an opening direction, the method at 516 may include transitioning from using the opening position map to using the closing position map. Further, the grille shutters may transition from moving in the opening direction to moving in the closing direction. However, if the grille shutters were moving in the closing direction, the closing movement direction may be maintained, and the method at 516 may include continuing to use the closing position map.

[0065] At 518, the controller determines the commanded position of the grille shutters using the shutter map. As such, the commanded position of the grille shutters may be based on the determined desired position of the grille shutters, a current vehicle speed, and the closing direction. At 512, the method includes translating the commanded position of the grille shutters into motor increments and then actuating the motor to adjust the grille shutters to the commanded position. The resulting position of the grille shutters (measured by the position sensor) may be approximately the desired position of the grille shutters determined at 504.

[0066] If, returning to 514, the difference between the actual engine position and the desired engine position is not greater than one engine position, the method continues to 520. At 520, the method includes not changing the direction of movement of the grille shutters and continuing to use the current position map. Further, at 520, the method may include not adjusting the grille shutters because the engine cannot move in partial engine increments.

[0067] Fig. 6 shows example position maps for determining a commanded position of the grille shutters. An opening position map of the grille shutters (e.g., the opening map) 602 shows a relationship between the commanded percentage opening of the grille shutters (to achieve the desired target opening percentage) and the desired opening percentage. The desired opening percentage and the commanded opening percentage may be an amount of grille shutter opening, which may correspond to the grille shutter angle, as shown in Fig. 4. Further, the relationship between the commanded position of the grille shutters and the desired position of the grille shutters may be based on vehicle speed. The opening map 602 includes a first graphical representation 606 of the commanded percentage opening at various desired percentage openings and a first vehicle speed. The opening map 602 further includes a second graphical representation 608 of the commanded percentage opening at various desired percentage openings and a second vehicle speed, wherein the first vehicle speed is greater than the second vehicle speed.

[0068] As vehicle speed increases, a force against the outer surface of the grille shutters (the surface closer to the outside of the vehicle than to the inside of the vehicle) may increase. This may cause the grille shutters to open a smaller amount than commanded. Consequently, the commanded opening of the grille shutters may increase as vehicle speed increases. For a target percentage opening of X%, the commanded percentage opening is greater at the first, higher vehicle speed (plot 606) than at the second, lower vehicle speed (plot 608).

[0069] The opening map 602 may include multiple lines or relationships at different vehicle speeds. In one example, the opening map 602 may be stored in the controller's memory as a lookup table. In this way, for a desired percentage opening and a vehicle speed, there may be a corresponding commanded percentage opening. For example, the controller may input the desired position of the grille shutters (e.g., the percentage opening) and the vehicle speed into the lookup table and receive a corresponding commanded position of the grille shutters. In another example, a mathematical relationship (e.g., a position translator function) may be stored within the controller that can determine the commanded percentage opening based on the desired percentage opening and the vehicle speed.

[0070] A similar map, table, or relationship may be stored within the controller for determining a commanded percentage closure of the grille shutters. Specifically, Fig. 6 shows a grille shutter closure position map (e.g., a shutter map) 604 indicating a relationship between the commanded percentage closure of the grille shutters (to achieve the desired target closure percentage) and the desired closure percentage. The desired closure percentage and the commanded closure percentage may be an amount of grille shutter closure, which may correspond to the grille shutter angle, as shown in Fig.4. Additionally, in some examples, a desired percentage open may be translated into a desired percentage closed. Further, as described above, the relationship between the commanded position of the grille shutters and the desired position of the grille shutters may be based on vehicle speed. Shutter map 604 includes a first graphical representation 610 of the commanded percentage closed at various desired percentage closed and a first vehicle speed. Shutter map 604 further includes a second graphical representation 612 of the commanded percentage closed at various desired percentage closed and a second vehicle speed, wherein the first vehicle speed is greater than the second vehicle speed.

[0071] As vehicle speed increases, a force against the outer surface of the grille shutters (the surface closer to the outside of the vehicle than to the inside of the vehicle) may increase. This may cause the grille shutters to close by a smaller amount than commanded. Consequently, the commanded closure of the grille shutters may increase as vehicle speed increases. For a target percentage closure of X%, the commanded percentage closure is greater at the first, higher vehicle speed (plot 606) than at the second, lower vehicle speed (plot 608).

[0072] Similar to the opening map 602, the closure map 604 may include multiple lines or relationships at different vehicle speeds. In one example, the closure map 604 may be stored in the controller's memory as a lookup table. In this way, for a desired percentage closure and a vehicle speed, there may be a corresponding commanded percentage closure. For example, the controller may input the desired position of the grille shutters (e.g., the percentage closure) and the vehicle speed into the lookup table and receive a corresponding commanded position of the grille shutters. In another example, a mathematical relationship (e.g., a position translator function) may be stored within the controller that can determine the commanded percentage closure based on the desired percentage closure and the vehicle speed.In yet another example, the input to and / or output from the map or the input to and / or output from the relationship may be a percentage opening for the closing direction (e.g., the x- and y-axes of the closure map may be translated into corresponding opening percentages).

[0073] As described above, the motor may be a stepper motor. The controller may adjust the motor by a number of motor increments when determining the commanded position of the grille shutters from the desired position of the grille shutters using either the opening map 602 or the closing map 604. In other words, the controller may increase or decrease the motor position by the number of motor increments. For a specified desired percentage opening or closing, the corresponding commanded percentage opening or closing may increase as the vehicle speed increases. As such, the number of motor increments required to achieve the desired position of the grille shutters may increase as the vehicle speed increases.Furthermore, for a fixed vehicle speed, the difference between the target percentage opening and the commanded percentage opening may increase as the target percentage opening decreases. Consequently, when moving in the opening direction, the number of motor increments required to achieve the target percentage opening may increase with a decreasing percentage opening. Likewise, for a fixed vehicle speed, the difference between the target percentage closure and the commanded percentage closure may increase as the target percentage closure decreases. Consequently, the number of motor increments required to achieve the target percentage closure may increase with a decreasing percentage closure. As the percentage closure decreases, the percentage opening increases.Therefore, it may also be true that the number of motor increments when moving in the closing direction may increase with increasing percentage target opening when considering the shutter map 604.

[0074] As such, during a first condition when the grille shutters are moving in an opening direction, a method may include adjusting the grille shutters based on a first relationship between the position of the grille shutters and the vehicle speed. Then, during a second condition when the grille shutters are closing, the method may include adjusting the grille shutters based on a second relationship between the position of the grille shutters and the vehicle speed, where the first relationship is different than the second relationship.

[0075] The first relationship is a relationship between a commanded percentage opening of the grille shutters, the vehicle speed, and a desired percentage opening of the grille shutters. Adjusting the grille shutters during the first condition includes increasing an opening of the grille shutters by a first amount, where the first amount increases as the vehicle speed increases and the desired percentage opening decreases. The second relationship is a relationship between a commanded percentage closure of the grille shutters, the vehicle speed, and a desired percentage closure of the grille shutters. Adjusting the grille shutters during the second conditions includes decreasing an opening of the grille shutters by a second amount, where the second amount increases as the vehicle speed increases and the desired percentage closure decreases.

[0076] In one example, adjusting the grille shutters includes adjusting a stepper motor coupled to the grille shutters to a desired motor position, the desired motor position including a number of motor counts, each motor count corresponding to a six-degree change in the opening angle of the grille shutters. If a difference between the current motor position and the desired motor position is greater than one, the method may include transitioning from the opening direction to the closing direction and transitioning from adjusting the grille shutters based on the first relationship to adjusting the grille shutters based on the second relationship.The method may further include transitioning from the closing direction to the opening direction and transitioning from adjusting the grille shutters based on the second relationship to adjusting the grille shutters based on the first relationship when a difference between the desired motor position and a current motor position is greater than one. Still further, the method may include maintaining a current direction of movement of the grille shutters and not adjusting the grille shutters when an absolute value of a difference between a current motor position and the desired motor position is not greater than one.

[0077] In this way, the technical effect of the invention is achieved by adjusting the grille shutters based on a target position of the grille shutters, the direction of movement of the grille shutters, and the vehicle speed, thereby reducing the position error of the grille shutters. Reducing the position error can increase fuel economy while also providing adequate cooling for the engine system.

[0078] It is noted that the exemplary control and estimation routines included herein may be used with various engine and / or vehicle system configurations. The control methods and routines disclosed herein may be stored as executable instructions in non-transitory memory. The specific routines described herein may represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. As such, the various acts, operations, and / or functions illustrated may be performed in the illustrated order, executed in parallel, or in some cases, omitted.Likewise, the order of processing is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but is provided for ease of illustration and description. One or more of the illustrated acts, operations, and / or functions may be performed repeatedly depending on the particular strategy employed. Furthermore, the described acts, operations, and / or functions may graphically represent code to be programmed into the non-transitory memory of the computer-readable storage medium in the engine control system.

[0079] It is understood that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, as numerous variations are possible. For example, the above technique may be applied to V-6, I-4, I-6, V-12, horizontally opposed four, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations and other features, functions, and / or characteristics disclosed herein.

[0080] The following claims particularly set forth certain combinations and subcombinations that are considered novel and non-obvious. These claims may refer to "a" element or "a first" element, or the equivalent thereof. Such claims should be understood to include the inclusion of one or more such elements and neither require nor exclude two or more such elements. Further combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by presenting new claims in this or a related application.Such claims, whether broader in scope than, narrower than, equal to, or different in scope from the original claims, are also considered to be included within the subject matter of the present disclosure. List of reference symbols 10 Power machine 11 Air filter 12 controllers 13 turbochargers 14 Compressor 16 turbines 18 Intercooler (CAC) 19 Wave 20 throttle valve 22 intake manifold 24 Manifold air pressure sensor (MAP sensor) 26 Communication and entertainment system 28 Tax system 30 sensors 31 combustion chambers 32 actuators 34 GPS 35 Outlet line 36 exhaust manifold 38 Thermostatic valve 40 wireless communication device 42 Inlet channel 50 EGR cooler 51 EGR channel 52 EGR valve 70 Exhaust gas purification device 80 coolers 82, 84 coolant lines 86 Water pump 88 Front End Accessory Drive (FEAD) 90 heating core 92 electric fan 100 power machine systems 102 Motor vehicle 104 Cooling system 106 Passenger compartment 110 Grille locking system 112 Radiator grille 114 Radiator grille closure (wing) 116 Ambient air flow 124 boost pressure sensor 126 Exhaust gas oxygen sensor (UEGO sensor) 202 engine 204 first group of grille closures 206 second group of grille locks 300 scheme 302 first rotating shaft 304 first gear 306 Arrow 308 second wave 310 second gear 312 Arrow 314 Position sensor 400 scheme 402 first position of the grille locks 404 second position of the grille locks 406 third position of the grille locks 408 Pivot point 410 vertical axis 412 side axis 414 Force 416 opening angle 418 wing axis 420 end stop 500 Procedures for adjusting the grille locks 502 - 520 process steps 602 opening map 604 Shutter characteristic map percentage opening at first 606 Vehicle speed percentage opening at second 608 Vehicle speed percentage closure at a first 610 Vehicle speed percentage closure at a second 610 vehicle speed

Claims

[1] Engine process comprising: Adjusting a motor (202) coupled to grille shutters (114) based on a direction of movement of the grille shutters (114), a desired opening of the grille shutters (114), and a vehicle speed. [2] The method of claim 1, further comprising setting the motor (202) to a desired motor position to increase an opening of the grille shutters (114) when a difference between the desired motor position and a current motor position is greater than a motor increment, wherein the desired motor position is based on the desired opening, the vehicle speed, and the direction of movement of the grille shutters (114). [3] The method of claim 1, further comprising adjusting the motor (202) to a desired motor position to decrease an opening of the grille shutters (114) when a difference between a current motor position and the desired motor position is greater than a motor increment, the desired motor position being based on the desired opening, vehicle speed, and a closing direction. [4] The method of claim 1, further comprising maintaining the direction of movement of the grille shutters (114) and not adjusting the motor (202) when an absolute value of a difference between a desired motor position and a current motor position is not greater than a motor increment. [5] The method of claim 1, wherein the desired opening is based on at least one of an engine coolant temperature, drive conditions of the vehicle (102), pedal position, charge air cooler efficiency, and vehicle speed. [6] The method of claim 1, wherein the motor (202) is a stepper motor, the stepper motor operable to move in increments of a finite size. [7] The method of claim 6, further comprising adjusting the motor (202) by a number of motor increments to achieve the desired opening, wherein the number of motor increments increases for increasing vehicle speed, a decreasing desired opening when moving in an opening direction, and an increasing desired opening when moving in a closing direction. [8] Engine process comprising: during a first condition when grille shutters (114) are moving in an opening direction, adjusting the grille shutters (114) based on a first relationship between a position of the grille shutters (114) and a vehicle speed; and during a second condition when the grille shutters (114) are moving in a closing direction, adjusting the grille shutters (114) based on a second relationship between the position of the grille shutters (114) and the vehicle speed, wherein the first relationship is different than the second relationship. [9] The method of claim 8, wherein the first relationship is a relationship between a commanded percentage opening of the grille shutters (114), the vehicle speed, and a desired percentage opening of the grille shutters (114). [10] The method of claim 9, wherein adjusting the grille shutters (114) during the first condition includes increasing an opening of the grille shutters (114) by a first amount, the first amount increasing with increasing vehicle speed and decreasing desired percentage opening. [11] The method of claim 8, wherein the second relationship is a relationship between a commanded percentage closure of the grille shutters (114), the vehicle speed, and a target percentage closure of the grille shutters (114). [12] The method of claim 11, wherein adjusting the grille shutters (114) during the second condition includes decreasing an opening of the grille shutters (114) by a second amount, the second amount increasing with increasing vehicle speed and decreasing target percent closure. [13] The method of claim 8, wherein adjusting the grille shutters (114) includes adjusting a stepper motor coupled to the grille shutters (114) to a desired motor position, the desired motor position including a number of motor counts, each motor count corresponding to a six-degree change in the opening angle of the grille shutters (114). [14] The method of claim 13, further comprising transitioning from the opening direction to the closing direction and transitioning from adjusting the grille shutters (114) based on the first relationship to adjusting the grille shutters (114) based on the second relationship when a difference between a current engine position and the desired engine position is greater than one. [15] The method of claim 13, further comprising transitioning from the closing direction to the opening direction and transitioning from adjusting the grille shutters (114) based on the second relationship to adjusting the grille shutters (114) based on the first relationship when a difference between the desired engine position and a current engine position is greater than one. [16] The method of claim 13, further comprising maintaining a current direction of movement of the grille shutters (114) and not adjusting the grille shutters (114) when an absolute value of a difference between a current engine position and the desired engine position is not greater than one. [17] System comprising: Grille shutters (114) positioned in a front portion of a vehicle (102); a motor (202) coupled to the grille shutters (114) and operable to adjust a position of the grille shutters (114); and a controller (12) having a memory and computer-readable instructions stored therein for adjusting the motor (202) based on a commanded percentage opening of the grille shutters (114), wherein the commanded percentage opening is based on a particular direction of movement of the grille shutters (114), a desired opening of the grille shutters (114), and a current vehicle speed. [18] The system of claim 17, wherein the computer-readable instructions include instructions for determining the particular direction of movement of the grille shutters (114) based on a comparison between a desired motor position and a previous desired motor position, the desired motor position corresponding to the commanded percentage opening. [19] The system of claim 17, wherein an opening map (602) is stored in the memory of the controller (12), and wherein the computer-readable instructions further include instructions for looking up the commanded percentage opening of the grille shutters (114) within the opening map (602) when the grille shutters (114) move in an opening direction. [20] The system of claim 17, wherein a shutter map (604) is stored in the memory of the controller (12), and wherein the computer-readable instructions further include instructions for looking up the commanded percentage opening of the grille shutters (114) within the shutter map (604) when the grille shutters (114) move in a closing direction.

Images