Driving through high water risk mitigation

Abstract

The present invention relates to risk mitigation of driving through high water levels. Methods and systems are provided for estimating the real-time water level of a vehicle and using the estimation results to execute one or more vehicle control strategies. In one example, a method may include adjusting a valve in a fuel system of the vehicle in response to the water level passed by the vehicle. In this way, water can be prevented from being drawn into the vehicle fuel system.

Description

Technical Field

[0001] The present description generally relates to methods and systems for estimating the depth of water through which a vehicle is traveling and using the estimation to execute one or more vehicle control strategies. Background Art

[0002] Land-based vehicles often travel through water. Some vehicles, such as off-road vehicles, may be designed to travel through a specified depth of water, known as a maximum wading depth, and may include appropriately sealed closures in preparation to prevent water damage to the vehicle cabin and vehicle electronics. Encountering a water level exceeding the maximum wading depth may pose a risk of engine damage. In the event of a vehicle wading, the driver of the vehicle may generally not be aware of the precise depth of water the vehicle is about to enter or has traveled through.

[0003] Therefore, various attempts have been made to determine the wading depth of a vehicle. One example method shown by Clarke et al. in US2015 / 0046032 A1 discloses a vehicle system that determines the likelihood of a vehicle entering a wading situation. By employing a remote ranging sensor to detect the presence and depth of water in which the vehicle is traveling, the system can take preventive measures to prepare the vehicle for possible wading. Among other things, vehicle operation can be adjusted to activate the internal combustion engine from an electric-only drive mode, suspend a stop-start fuel economy mode, and / or actuate a ride height adjustment.

[0004] However, the inventors herein have recognized potential problems with such systems. As an example, an off-road vehicle designed to travel through limited wading depths may encounter water levels above the maximum wading depth, such as when traveling through a flooded area or during a flash flood, or when backing into a body of water, such as during a boat launching process. In addition, even with the precautions described above, water may enter the evaporative emission control system in a vehicle traveling through high water levels. For example, during a purge operation, water may enter the fuel system and ultimately the engine via the vent port. During the vehicle's purge mode, a fuel vapor canister equipped with an adsorbent may allow the adsorbed vapors to be purged by fresh air, which is drawn into the canister via the canister vent port and the vent line inlet, and the fuel-air mixture may be purged from the canister into the engine intake manifold for use as fuel. In the event that water enters the evaporative emission control system, if the water is allowed to contact the adsorbent material, the adsorbent will no longer function to adsorb fuel vapors. In addition, due to the vacuum in the intake manifold, water may be drawn into the combustion cylinders via the canister purge valve, thereby causing a water seal condition. Summary of the invention

[0005] In one example, the above problem can be solved by a method for a vehicle, the method comprising adjusting a valve in a fuel system of the vehicle in response to a water level passed by the vehicle. The valve in the fuel system that is adjusted can be a canister purge valve or a canister vent valve. In this way, the method can shut off the fuel vapor purge when the vehicle is traveling in high water to prevent water from being drawn into the fuel vapor canister and entering the engine intake manifold, thereby preventing degradation of the fuel vapor canister and preventing engine water lock.

[0006] As an example, a proximity sensor may be employed to detect the depth of water during forward travel. The proximity sensor may be used to estimate the distance to an object when the vehicle is in reverse gear and the sensor is facing horizontally (e.g., a reverse sensor). The sensor may be repurposed and adjusted to a vertically facing position to detect the distance to the nearest surface during forward travel of the vehicle. In the event that the vehicle is traveling through high water, the proximity sensor may estimate the distance to the water and calculate the water level (e.g., the depth / height of the water above the ground) that the vehicle is traveling through. If it is determined that the water level is above a first threshold, the water level may be high enough so that water may be introduced into the evaporative emission control system, and therefore as a precaution, the purge operation may be disabled by closing the canister purge valve (CPV) and / or closing the canister ventilation valve (CVV). Additionally, determining that the water level is above a second threshold may indicate that the water level is high enough to be introduced into the engine air intake. Therefore, as a precaution, the engine may be strategically shut down to prevent water locks.

[0007] Thus, by suspending the purge operation when the vehicle is in water exceeding a first water level threshold, and further by shutting down the engine when the water level exceeds a second threshold, the risk of water being drawn into the evaporative emission control system and the engine air intake can be mitigated. Additionally, the need for additional sensors and / or equipment is eliminated by using the proximity sensor as a back-up sensor during reverse travel and by repurposing the existing proximity sensor to be oriented vertically to detect the distance to the nearest ground in real time during forward travel. The proximity sensor, when oriented vertically, can provide a reliable estimate of the proximity to the nearest surface (e.g., the distance from the sensor to the water for a vehicle traveling in water), in response to which the fuel vapor purge can be disabled. In this way, vehicle components (specifically, the evaporative emission control system and the engine air intake system) can be prepared and protected from water degradation, and maintenance costs can be eliminated in advance.

[0008] It should be understood that the above summary is provided to introduce some concepts in a simplified form, which are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the appended claims. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic depiction of an internal combustion engine and associated evaporative emissions control system for a hybrid vehicle is shown.

[0010] FIG. 2A to FIG. 2B Detailed side view showing different locations of proximity sensors.

[0011] Figure 3 To have Figure 2A and Figure 2B Schematic diagram of a vehicle with proximity sensors positioned to detect various detection thresholds.

[0012] Figure 4 A flow chart illustrating a method for controlling vehicle operation in response to detecting water via proximity sensor output is shown.

[0013] Figure 5 A graph depicting engine operating parameters for a vehicle traveling through water is shown. DETAILED DESCRIPTION

[0014] The following description relates to a method for operating a system included in a vehicle (e.g., Figure 1 Systems and methods for an engine in a hybrid electric vehicle (as shown in FIG. ). Figure 1 The vehicle shown in FIG. 1 may include a fuel system and an evaporative emission control system. The vehicle may also include a proximity sensor located on the vehicle body, such as Figure 2A and Figure 2B A proximity sensor can be used as a remote sensor and determine the distance to a nearby surface. Generally, the proximity sensor can be horizontally oriented and during reverse travel of the vehicle can be configured to horizontally estimate the proximity when approaching a nearby object, while during forward travel of the vehicle the proximity sensor can be vertically oriented and can vertically estimate the proximity to the nearest surface. For example, when Figure 1 When the vehicle is driven on the ground, the proximity sensor can detect the proximity to the ground surface, and when the vehicle is driven through water, the proximity sensor can detect the proximity to the water surface. Under conditions where the vehicle can be driven through water, the controller of the vehicle can be configured to obtain the proximity sensor output data and determine the water level based on the sensor output. The controller can then compare the determined water level with the water level. Figure 3The water level thresholds may indicate when the estimated water level may be high enough to be introduced through the fuel vapor canister vent line or the engine air intake. Figure 1 The controller may also be configured to execute a control program (e.g., Figure 4 ), to control one or more vehicle operations in response to the estimated water level, such as Figure 5 If the estimated water level is above the first threshold but not above the second threshold, water may be introduced into the evaporative emission control system, so as a precaution, the controller may disable the purge operation of the fuel vapor canister. Additionally, in response to the estimated water level being above the second threshold, the controller may shut down the engine to prevent water from being introduced into the engine air intake.

[0015] Now turning to the attached figure, Figure 1 An example internal combustion engine of a hybrid vehicle 5 with a fuel system 118 and an evaporative emission control system 151 is illustrated. In some examples, the vehicle 5 may be a hybrid vehicle with multiple torque sources that may be used for one or more wheels 55. In other examples, the vehicle 5 is a conventional vehicle with only an engine, or an electric vehicle with only (one or more) motors. In the example shown, the vehicle 5 includes an engine 110 and a motor 52. The motor 52 may be a motor or a motor / generator. When one or more clutches 56 are engaged, the crankshaft (not shown) of the engine 110 and the motor 52 are connected to the wheels 55 via a transmission 54. In the depicted example, a first clutch 56 is disposed between the crankshaft and the motor 52, and a second clutch 56 is disposed between the motor 52 and the transmission 54. The controller 112 may send a signal to the actuator of each clutch 56 to engage or disengage the clutch to connect or disconnect the crankshaft with the motor 52 and components connected thereto, and / or to connect or disconnect the motor 52 with the transmission 54 and components connected thereto. The transmission 54 may be a gearbox, a planetary gear system, or another type of transmission. The powertrain can be configured in a variety of ways, including as a parallel, series, or series-parallel hybrid vehicle.

[0016] The electric machine 52 receives electrical power from the traction battery 58 to provide torque to the wheels 55. The electric machine 52 may also operate as a generator to provide electrical power to charge the battery 58, such as during braking operations.

[0017] The engine system 108 may include an engine 110 having a plurality of cylinders 130. The engine 110 includes an engine intake 123 and an engine exhaust 125. The engine intake 123 includes a throttle 162 fluidly coupled to an engine intake manifold 144 via an intake passage 142. The engine exhaust 125 includes an exhaust manifold 148 leading to an exhaust passage 135, which delivers exhaust gas to the atmosphere. The engine exhaust 125 may include one or more emission control devices 170, which may be mounted in the exhaust in a close coupled state. The one or more emission control devices may include a three-way catalyst, a lean NOx trap, a diesel particulate filter, an oxidation catalyst, etc. It should be appreciated that other components may be included in the engine, such as various valves and sensors.

[0018] The fuel system 118 may include a fuel tank 120 coupled to a fuel pump system 121. The fuel pump system 121 may include one or more pumps for pressurizing fuel delivered to injectors (e.g., the example injector 166 shown) of the engine 110. Although only a single injector 166 is shown, additional injectors may be provided for each cylinder. It should be appreciated that the fuel system 118 may be a non-return type fuel system, a return type fuel system, or various other types of fuel systems. The fuel tank 120 may include a temperature sensor 146 disposed therein.

[0019] A fuel level sensor 103 may be included in the fuel tank 120 to determine the amount of fuel in the fuel tank. For example, the fuel level sensor 103 may include an arm 101 coupled to a float 102. In the present example, the position of the float 102 on the top surface of the fuel volume may be used to determine the fuel level in the fuel tank. The emission control system 151 may include a fuel vapor canister 122 that may be used to capture and store fuel vapors. For example, vapors generated in the fuel system 118 may be transmitted to an evaporative emission control system 151 including a fuel vapor canister 122 via a vapor recovery line 131 before being purged to the engine intake 123. The fuel vapor canister 122 may include a buffer or loading port 141 to which the fuel vapor recovery line 131 is coupled. In the depicted example, the fuel system 118 includes a single canister. However, in an alternative example, one or more canisters may be provided.

[0020] The vapor recovery line 131 may be coupled to the fuel tank 120 via one or more conduits and may include one or more valves for isolating the fuel tank under certain conditions. For example, the vapor recovery line 131 may be coupled to the fuel tank 120 via one or more or a combination of conduits 171, 173, and 175. Additionally, in some examples, one or more fuel tank isolation valves may be included in the recovery line 131 or in conduits 171, 173, or 175. Among other functions, the fuel tank isolation valve may allow the fuel vapor canister of the emission control system to be maintained at a low pressure or vacuum without increasing the fuel evaporation rate of the tank (which would otherwise occur if the fuel tank pressure is reduced). For example, conduit 171 may include a grade ventilation valve (GVV) 187, conduit 173 may include a fill limit ventilation valve (FLVV) 185, conduit 175 may include a stratified ventilation valve (GVV) 183, and / or conduit 131 may include an isolation valve 153. In addition, in some examples, the recovery line 131 may be coupled to the fuel filling system 119. In some examples, the fuel filling system 119 may include a fuel cap 105 for blocking the fuel filling system and the atmosphere. The fuel filling system 119 is coupled to the fuel tank 120 via a fuel filling pipe or throat 111. In addition, a fuel cap locking mechanism 145 may be coupled to the fuel cap 105. The fuel cap locking mechanism may be configured to automatically lock the fuel cap in a closed position so that the fuel cap cannot be opened. For example, when the pressure or vacuum in the fuel tank is greater than a threshold, the fuel cap 105 may remain locked via the locking mechanism 145. In response to a fuel filling request (e.g., a request initiated by a vehicle operator), the fuel tank may be decompressed, and the fuel cap may be unlocked after the pressure or vacuum in the fuel tank drops below a threshold. The fuel cap locking mechanism 145 may be a latch or a clamping device that prevents the removal of the fuel cap when engaged. The latch or clamping device may be locked electrically, for example by a solenoid, or may be locked mechanically, for example by a pressure diaphragm.

[0021] A fuel tank pressure transducer (FTPT) 191 or fuel tank pressure sensor may be included between fuel tank 120 and fuel vapor canister 122 to provide an estimate of the fuel tank pressure. The fuel tank pressure transducer may alternatively be located in vapor recovery line 131, purge line 128, vent line 127, or other locations within emission control system 151 without affecting its engine off leak detection capabilities. As another example, one or more fuel tank pressure sensors may be located within fuel tank 120.

[0022] The fuel vapor canister 122 may be filled with a suitable adsorbent to temporarily capture fuel vapors (including vaporized hydrocarbons) during fuel tank refill operations and "running losses" (that is, fuel that vaporizes during vehicle operation). In one example, the adsorbent used is activated carbon. The emission control system 151 may also include a canister vent path or vent line 127 that may transfer gases out of the canister 122 via a canister vent port 195 and to the atmosphere via a vent line inlet 193 while storing or capturing fuel vapors from the fuel system 118.

[0023] Vent line inlet 193 may also allow fresh air to be drawn into vent line 127 and into canister 122 via canister vent port 195 when stored fuel vapors are purged from fuel system 118 to engine intake 123 via purge line 128 and canister purge valve (CPV) 161. For example, purge valve 161 may be normally closed but may be opened under certain conditions such that vacuum from engine intake 144 is provided to the fuel vapor canister for purging. In some examples, vent line 127 may include an air filter 159 disposed therein, upstream of canister 122.

[0024] In some examples, the vent line inlet 193 may allow air and vapor to flow between the canister 122 and the atmosphere, which may be further regulated by a canister ventilation valve (CVV) 129 coupled within the vent line 127 and a canister ventilation port 195 fluidly coupled to the CVV 129 and the vent line 127 on the canister housing where the vent line is coupled to the canister. When included, the canister ventilation valve 129 may be a normally open valve so that the fuel tank isolation valve 153 (FTIV) may control the ventilation of the fuel tank 120 to the atmosphere. When included, the CVV may be opened during fuel vapor storage operations (e.g., during fuel tank filling and when the engine is not running) so that air stripped of fuel vapor after having passed through the canister may be pushed out to the atmosphere. Likewise, during a purge operation (e.g., during canister regeneration and when the engine is running), the CVV may be opened to allow fresh air to flow through the vent line inlet to strip fuel vapor stored in the canister. In some examples, CVV 129 may be a solenoid valve, wherein the opening or closing of the valve is performed via actuation of a canister ventilation solenoid. Specifically, the canister ventilation valve may be closed after actuation of the canister ventilation solenoid. In some examples, CVV 129 may be configured as a latchable solenoid valve. In other words, when the valve is placed in a closed configuration, closing it does not require additional current or voltage pressure to latch closed. For example, the valve may be closed with a 100ms pulse and then opened with another 100ms pulse at a later point in time. In this way, the battery power required to maintain the CVV closed is reduced. Specifically, the CVV may be closed when the vehicle is stopped, thereby maintaining the battery power while maintaining the fuel emission control system isolated from the atmosphere. In addition, FTIV 153 may be a normally closed valve, which allows fuel vapor to be discharged from the fuel tank 120 to the fuel vapor canister 122 when opened. The fuel vapor may then be discharged to the atmosphere, or purged to the engine intake 123 via the canister purge valve 161.

[0025] By selectively adjusting the various valves and solenoids, fuel system 118 may be operated in a variety of modes by controller 112. For example, fuel system may be operated in a fuel vapor storage mode (e.g., during a fuel tank fill operation and when the engine is not combusting air and fuel) where controller 112 may open isolation valve 153 while closing canister purge valve 161 to direct fill vapors into canister 122 while preventing fuel vapors from being directed into the intake manifold.

[0026] As another example, the fuel system may be operated in a fuel fill mode (e.g., when a vehicle operator requests a fuel tank fill), wherein the controller 112 may open the isolation valve 153 while maintaining the canister purge valve 161 closed to depressurize the fuel tank before allowing fuel to be added to the fuel tank. Thus, the isolation valve 153 may remain open during the fill operation to allow the fill vapor to be stored in the canister. After the fill is complete, the isolation valve may be closed. Additionally, if misfueling is detected (e.g., when diesel fuel is dispensed into a gasoline fuel tank), the controller 112 may be configured to actively close the isolation valve 153. By sealing the fuel tank in response to an indication of misfueling, further addition of incorrect fuel to the fuel tank is prevented in advance.

[0027] As yet another example, the fuel system may be operated in a canister purge mode (e.g., after the emission control device light-off temperature has been reached and while the engine is combusting air and fuel), where controller 112 may open canister purge valve 161 while closing isolation valve 153. In this context, vacuum generated by the intake manifold of the operating engine may be used to draw fresh air through vent line 127 and through fuel vapor canister 122 to purge stored fuel vapors into intake manifold 144. In this mode, purged fuel vapors from the canister are combusted in the engine. Purging may continue until the amount of stored fuel vapors in the canister is below a threshold.

[0028] The controller 112 may include a portion of a control system 114. The control system 114 is shown as receiving information from a plurality of sensors 116 (various examples of which are described herein) and sending control signals to a plurality of actuators 181 (various examples of which are described herein). As an example, the sensors 116 may include an exhaust gas sensor 137 located upstream of the emission control device 170, a temperature sensor 133, a pressure sensor 191, and a canister temperature sensor 143. Other sensors such as pressure, temperature, air-fuel ratio, and composition sensors may be coupled to various locations in the vehicle system 5. As another example, the actuators may include a throttle 162, a fuel tank isolation valve 153, a canister purge valve 161, and a canister ventilation valve 129. The control system 114 may include the controller 112. The controller may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on instructions or code programmed therein corresponding to one or more programs. In this document with respect to Figure 4 A sample control program is described.

[0029] The undesirable evaporative emissions detection routine may be intermittently performed by the controller 112 on the fuel system 118 and / or the evaporative emissions system 151 to confirm the absence of undesirable evaporative emissions in the fuel system and / or the evaporative emissions system. Thus, the evaporative emissions detection routine may be performed while the engine is off (engine off test) using engine off natural vacuum (EONV) generated due to changes in temperature and pressure at the fuel tank after the engine is shut down and / or using supplemental vacuum from the vacuum pump. Alternatively, the evaporative emissions detection routine may be performed while the engine is running by operating the vacuum pump and / or using engine intake manifold vacuum.

[0030] FIG. 2A to FIG. 2B Detailed side views 200, 220 of a proximity sensor 202 coupled to a vehicle 5 are schematically shown. The proximity sensor 202 may be positioned at the rear of the vehicle body, such as on the rear bumper, below the rear bumper, or, for example, optionally on the rear license plate. In another example, one or more proximity sensors may be positioned at the rear of the vehicle 5 and / or optionally at the front of the vehicle 5. The proximity sensor 202 may optionally be located on one or more of a front subframe, a bumper beam, an engine compartment bulkhead, a suspension knuckle, or other similar components. In one example, only one proximity sensor may be positioned on the vehicle, while in other examples, more than one sensor may be provided, which may be positioned and arranged in different ways.

[0031] In one example, the proximity sensor 202 may be an ultrasonic sensor that is capable of remotely sensing an obstacle or surface near the vehicle. In other examples, an electromagnetic sensor, an optical sensor, a capacitive sensor, or other proximity determination sensor may be used. In one example, the proximity sensor may be used as a parking distance control (PDC) sensor or a back-up sensor to warn the driver of an obstacle during parking. When used as an ultrasonic back-up sensor, the proximity sensor 202 may be a remote sensing device (e.g., a non-contact sensor) that may determine the presence and proximity of an obstacle relative to the vehicle. In an example where the vehicle is traveling in water, the proximity sensor may detect the presence of water and the proximity of water before the vehicle is traveling in water, such as when the vehicle is about to enter a flooded area. These remote sensors may be acoustic transducers that transmit pulsed ultrasonic beams that may be detected as signals after being reflected from an object (e.g., an obstacle in the vehicle's path or the surface of water through which the vehicle may pass), and may be further used to calculate proximity.

[0032] FIG. 2A to FIG. 2BA proximity sensor 202 is shown positioned at the rear of a vehicle body, such as on a rear bumper of a vehicle 5. The proximity sensor may be mounted with a spring (not shown), wherein the spring may be coupled to an actuator of the proximity sensor 202. The actuator of the sensor 202 may include an electromechanical device, such as a solenoid 204 including a plunger 210. Electrical energy for actuating the solenoid 204 may be converted into mechanical movement of the plunger 210. The solenoid 204 with the plunger 210 may be mounted on top of a curved rear surface of the sensor 202 using a ball point contact 208. The proximity sensor 202 may be configured to be adjusted to two positions, such as a horizontal facing position and a vertical facing position. Figure 2A The vertical facing position shown in FIG. 2 may be the default position of the proximity sensor. In this position, the vehicle's controller may de-energize the solenoid 204 so that the plunger 210 may be in a retracted state, wherein the torsion spring hinge 212 is relaxed, such as Figure 2A When the proximity sensor is oriented vertically, the proximity sensor may estimate the proximity to the nearest vertical (e.g., ground) surface, such as the distance or height from the sensor to the nearest surface. In one example, the nearest surface may be the ground on which the vehicle is traveling, while in another example, when the vehicle is in water, the nearest surface may be the surface of the water.

[0033] The proximity sensor 202 is positioned at the rear of the vehicle and can sense proximity in two sensing directions that are perpendicular to each other (e.g., a vertical direction when the sensor is oriented vertically to measure proximity to a nearby ground surface and a horizontal direction when the sensor is oriented horizontally to measure proximity to a nearby object). In this example, the sensor 202 may include a sensing axis 212, where the sensing axis may be an axis extending through the sensor and parallel to the direction in which the sensor measures proximity (e.g., the sensing axis is parallel to the sensor's radiated acoustic axis, which may represent the center path / directivity of sound waves radiated from the sensor). When the sensor is in a position such as Figure 2A When the sensor 202 is actuated to the vertically oriented default position shown in FIG. 1 , the sensing axis 212 may have an orientation perpendicular to a horizontal reference plane (e.g., the ground on which the vehicle is located / driving). Figure 2B When the proximity sensor 202 is in the horizontal facing position as seen in FIG. 1 , the sensing axis 212 may be oriented parallel to a horizontal reference plane (e.g., the ground). Under conditions such as those described in detail below, the proximity sensor 202 may be actuated to a position such as the horizontal facing position as seen in FIG. Figure 2B. To adjust the position of the sensor 202 from a vertical orientation to a horizontal orientation, the controller may send a signal to actuate the solenoid. When energized, the solenoid 204 may cause the plunger 210 to move away from the solenoid and exert a downward force on the ball-point contact 208. The plunger may then force the ball-point contact 208 to rotate the sensor, thereby adjusting the sensor 202 to a horizontal orientation position, wherein the torsion spring hinge 212 is deflected (e.g., subjected to torque). When oriented horizontally, the proximity sensor 202 may continue to function as a remote sensor (e.g., a parking distance control (PDC) sensor or a reverse sensor), albeit horizontally to estimate the proximity distance to an object.

[0034] When the vehicle is in forward gear or any gear except reverse gear, the sensor can be in Figure 2A , which may be the default position of the sensor. In this position, the proximity sensor 202 may be used as a remote sensor to estimate the proximity to the nearest surface. Under normal driving conditions, the nearest surface may be the ground on which the vehicle is traveling. In the case where the vehicle is traveling through high water or encountering water while driving, the proximity sensor may estimate the distance to the water (e.g., water is the nearest surface). In other words, the proximity sensor 202 may sense the distance from the height at which the sensor is mounted to the water surface. The controller of the vehicle 5 may store the height information of the sensor in a memory. As an example, at the time of manufacturing, the height of the sensor above the ground may be stored in the memory of the control system 114. During engine operation, the height of the sensor from the ground may change in response to, for example, changes in tire pressure or changes in passenger load weight. In this case, the controller may obtain the distance output from the proximity sensor 202 and adjust and update the height of the sensor above the ground accordingly. In the case where the vehicle is traveling through water, the proximity sensor may estimate the distance to the water and output the data to the controller. The controller can then estimate the height of the water based on the difference in the distance output from sensor 202 when the vehicle is traveling on dry ground compared to when the vehicle is traveling through water. In addition, the controller can include height information for other engine components relative to the location of the proximity sensor on the vehicle. For example, the height of the proximity sensor above the ground for the engine air intake system and the evaporative emission control system relative to the height of the proximity sensor can be stored in the memory of the controller. Thus, the controller can not only estimate the distance from the proximity sensor to the water, but can additionally estimate the proximity of other engine components to the water, such as the distance from the engine air intake to the water and the distance from the evaporative emission system to the water.

[0035] Alternatively, when the vehicle is switched to the reverse driving mode, the proximity sensor 202 may be activated as shown in FIG. Figure 2B. Upon sensing that the vehicle transmission has switched to a reverse driving mode, a controller of the vehicle may actuate the solenoid. The reverse driving mode of the vehicle may be determined by a selected drive gear or other mechanism of the vehicle. When activated, the solenoid 204 may apply a mechanical force in a downward direction using the plunger 210 so that the plunger may push down on the ball point contact 208, thereby rotating the proximity sensor 202 and adjusting it to a horizontal facing position in which the torsion spring hinge 212 is deflected (e.g., subjected to torque). In this position, the proximity sensor 202 may perform the same function of remotely measuring the distance to an object. Because the proximity sensor in the horizontal facing position may measure the distance to an object or obstacle in the vehicle's path of travel, the sensor may be a park distance control (PDC) sensor or a reverse sensor that points outward from the rear of the vehicle, such as Figure 2B The sensor may also be configured to output the distance measurement to a controller, where the controller may, in one example, evaluate the measured proximity to the obstacle against a threshold range and provide a warning to the vehicle operator in one example. In another example, an onboard assessment of the presence and distance of an obstacle may be provided to the operator of the vehicle, for example, the vehicle may be equipped with a camera directly connected to the proximity sensor.

[0036] In this way, the vehicle can be adapted to use existing reverse sensors to determine the distance to water when the vehicle is traveling in high water. In one example, the proximity sensor can be actuated (e.g., horizontally) to act as a PDC sensor when reverse gear is selected, and can be deactivated once any other gear of the drive system is selected. In another example, the proximity sensor can be activated by a wading sensor (e.g., a contact sensor) that can detect the presence of water (when submerged) relative to a low water level of the vehicle. Optionally, the wading sensor can be positioned below a flooded vehicle component (e.g., an evaporative emission control system) and can automatically disable purging independent of the proximity sensor. In another example, the wading sensor can be sensitive enough to detect the presence of a small amount of water when in contact, such as during a rainfall event or during a vehicle driving through a puddle. In this context, when activated when in contact with water, the output of the wading sensor can be used by the controller to activate the proximity sensor to determine the distance to the nearest surface. The controller can then obtain a distance measurement from the proximity sensor and determine whether the vehicle is in high water. In another example, when the vehicle is in forward travel, upon detecting a rainfall event, the proximity sensor may be adjusted from a horizontally facing PDC sensor position to a vertically facing proximity sensor position. In some examples, when the vehicle reaches a predetermined speed (e.g., a highway), the controller may deactivate the vertically facing proximity sensor.

[0037] Under the above conditions, the proximity sensor may be present in a default position and oriented vertically, e.g. Figure 2AIn this position, the proximity sensor 202 can estimate the proximity to the nearest surface, as described below with reference to Figure 3 Now refer to Figure 3 , showing that Figure 2A Schematic diagram of a vehicle with a rear proximity sensor positioned to detect the distance to the nearest surface. The proximity sensor 202 may be located along the central longitudinal axis of the vehicle (eg, Figure 3 The proximity sensor 202 may be positioned at a vertical height 'h' above the vehicle body, where 'h' may correspond to the distance / height of the sensor above the horizontal reference plane (e.g., the ground surface). The proximity sensor may also include a sensing axis 212, where when the sensor is positioned such as Figure 3 When shown as vertically oriented in FIG, the proximity sensor sensing axis can be oriented vertically to a horizontal reference plane (e.g., the ground). The sensing axis 212 can also be oriented vertically to one or more water level thresholds described below. The sensor can be communicatively coupled to a controller, such as the control system 114, and can be configured to output distance information to the controller.

[0038] As previously described, for a vehicle traveling in high water, water may enter the evaporative emission control system via the vent line inlet 193 and enter the fuel vapor canister via the canister vent port 195. In this context, the fuel vapor canister filled with adsorbent may be used to purge adsorbed vapors by fresh air drawn in through the vent line inlet by opening the canister vent valve 129. Therefore, in order to estimate the water level relative to the location of the vent line inlet, the controller may include location information (e.g., vertical height / distance from the ground surface) of the vent line inlet 193. Figure 3 The height / position of the vent line inlet on the vehicle depicted by line 308 in the diagram may be measured relative to the height / position of the proximity sensor and further stored in the memory of the controller. Line 308 may also represent a first water level threshold 'th1' that, when exceeded, may allow water to enter the evaporative emission control system via the vent line inlet and enter the canister via the canister vent port, thereby potentially degrading the fuel vapor canister.

[0039] Water can also enter the internal combustion engine through the engine air intake system. Therefore, in high water driving conditions, in order to estimate the water depth relative to the location of the engine air intake, the controller may also include position information of the vehicle air intake system (e.g., vertical height / distance from the ground surface). Figure 3The height of the engine air intake depicted by line 306 in the figure may be measured relative to the height / position of the proximity sensor and stored in the memory of the controller. Line 306 may also represent a water level threshold 'th2' which, when exceeded, may allow water to enter the engine air intake, thereby damaging engine components. Optionally, the position of the engine air intake relative to the ground surface (at the vertical height shown by line 306) and the position of the ventilation duct inlet (at the vertical height shown by line 308) may also be processed and stored in the memory of the controller of the vehicle 5.

[0040] As the vehicle travels forward, the controller 112 may predict the presence of high water ahead by, for example, inferring a rainfall event from one or more onboard rain sensors and / or from a remote weather service, a GPS system, from vehicle-to-vehicle communications, and / or a personal weather station. In one example, during forward travel of the vehicle and after a rainfall event is detected, the proximity sensor may default to a vertically facing position, continuously functioning as a remote sensor and transmitting the real-time distance to the ground surface as an output to the controller. In another example, a reverse gear vehicle with an actuated horizontally facing proximity sensor may shift to another gear. In this case, the controller may automatically de-actuate the proximity sensor to a default position to face vertically. In another example, the proximity sensor may be activated by the presence of water sensed by a wading sensor (e.g., a contact sensor when submerged) that is placed at a low level relative to the vehicle.

[0041] In one embodiment, during forward travel, the vehicle may enter a body of water and the vertically facing proximity sensor 202 may perform distance measurements to the water since the water is the nearest detectable surface (h * ), and this information can be output to a controller of the vehicle 5. The location and height of the proximity sensor on the vehicle can be known to the controller. The controller can use the distance output obtained from the proximity sensor to calculate an estimated height of the water (e.g., water depth = [hh * ]). The controller may then compare the calculated water depth to one or more thresholds to assess whether the water depth through which the vehicle is traveling may cause problems to vehicle components. Specifically, the controller may first compare the calculated water depth to a first threshold 'th1', which represents the height above the ground of the ventilation duct inlet of the evaporative emission control system. If the calculated water depth is found to be equal to or higher than 'th1', the controller may infer that the water depth through which the vehicle is traveling is at or above the location of the ventilation duct inlet, and water may move into the evaporative emission control system via the open ventilation duct inlet and further into the canister via the canister ventilation port. The controller may then control the vehicle accordingly. Figure 4 Specific vehicle operations are described in detail in.

[0042] Next, the controller may compare the calculated water depth with a second threshold value 'th2', which represents the height of the engine intake above the ground. The second threshold value 'th2' may be a higher threshold value than the first threshold value 'th1', where, for example, the engine intake may be located above an evaporative emission control system in a vehicle. If the calculated water depth [hh * ] is equal to or greater than 'th2', then the controller may infer that the depth of water through which the vehicle is travelling is at or above the engine intake, such that water may enter the combustion engine through the intake.

[0043] In another embodiment, during forward travel of the vehicle in water, the controller may obtain a distance from the water (e.g., water is the nearest detectable surface) from a vertically facing proximity sensor, and may compare the output of the proximity sensor to one or more distance thresholds. In this context, a first threshold distance may indicate a distance from the proximity sensor to an engine intake, and a second threshold distance may indicate a distance from the proximity sensor to a ventilation line inlet of an evaporative emission control system. For example, in response to a distance from the water being greater than the first threshold distance but less than the second threshold distance, the controller may close the canister ventilation valve. The controller may further shut down the engine (and, at least in some examples, continue to propel the vehicle with the electric motor) in response to the distance being less than the first threshold distance. The second threshold distance may be a longer distance than the first threshold distance, wherein the engine intake may be positioned higher than the evaporative emission control system relative to the ground.

[0044] In yet another embodiment, during forward travel of the vehicle through water, the controller may obtain a proximity sensor output of a distance from the water (e.g., water is the nearest detectable surface) and may compare the proximity sensor output to one or more distance thresholds, where the distance thresholds are different from the previous embodiments. In one example, in response to the distance from the water being less than a first threshold distance and greater than a second threshold distance, the controller may disable the fuel vapor purge. In this context, the first threshold distance may indicate a distance from the proximity sensor to a vent line inlet of an evaporative emission control system, and the second threshold distance may indicate a distance from the proximity sensor to an engine intake. The controller may further shut down the engine in response to the distance being less than the second threshold. The first threshold may be a higher threshold than the second threshold, indicating that the engine intake is positioned above the evaporative emission control system.

[0045] The controller may then specifically control vehicle operation to prepare the vehicle and protect the vehicle from ingesting water, as described below. Figure 4 Described in detail in.

[0046] Figure 4A flow chart illustrating a method 400 for controlling vehicle operation in response to detecting water from a proximity sensor output is shown. Instructions for implementing the method 400 included herein may be provided by the controller 112 based on instructions stored on a memory of the controller and in conjunction with sensors of the engine system (e.g., as described above with reference to FIG. 1 ). Figure 1 and Figure 2A as well as Figure 2B The controller may use a signal received from a sensor described above, such as proximity sensor 202, to perform a proximity sensor operation. According to the method described below, the controller may use an engine actuator of the engine system to adjust engine operation (e.g., solenoid 206 coupled to proximity sensor 202 and configured to adjust the position of the proximity sensor).

[0047] At 402, the method includes estimating and / or measuring engine operating conditions. These conditions may include, for example, transmission drive gear (e.g., forward or reverse), engine speed, torque demand, boost level, engine temperature, exhaust temperature, atmospheric pressure, fuel composition, particulate filter load, etc. Estimating engine operating conditions may optionally include inferring rainfall events by a variety of methods, as described below. At 404, method 400 determines whether the vehicle is traveling in reverse. The reverse travel of the vehicle may be determined by the selected drive gear or other mechanism of the vehicle. When the answer at 404 is yes (e.g., when the vehicle is in reverse gear), method 400 moves to 406 to actuate the proximity sensor from a vertical facing position to a horizontal facing position to detect proximity to an object. For example, the proximity sensor may be a reverse sensor or a PDC sensor of the vehicle, which may determine the distance to an obstacle when actuated to a horizontal facing position. In this article, when the sensor 202 is actuated to a horizontal facing position, the sensing axis 212 may be oriented parallel to a horizontal reference plane (e.g., the ground). In one example, the proximity sensor may output the distance measurement to a controller, and the controller may in turn provide an onboard assessment to a driver of the vehicle.

[0048] At 408, the vehicle may purge fuel vapors when instructed. In one example, a purge of the fuel vapor canister may be instructed when a canister load exceeds a threshold, such as when the amount of stored fuel vapor in the canister is at or near the canister's absorption capacity. Herein, the controller may implement the purge of the fuel vapor canister by opening a canister purge valve and a canister vent valve. The vacuum generated by the intake manifold during engine operation may be used to draw fresh air through the canister vent port and through the fuel vapor canister, thereby purging the stored fuel vapor into the intake manifold to be combusted.

[0049] Method 400 may continue to 410 to perform a fuel system leak test when indicated. A leak test may be indicated under the following conditions: when the vehicle speed is within a predetermined range, if the leak check program has not yet been run on the current trip, the powertrain load is within a predetermined range, etc. In one example, a leak detection test may include using a vacuum from an internal combustion engine to reduce the pressure inside the fuel tank and close the canister ventilation valve to the atmosphere. When the reduced pressure is maintained for a specific period of time, the fuel system may be determined to be leak-free. In another example involving a hybrid electric vehicle, the vehicle may be operated in an all-electric mode (based on battery power) with very little use of the associated internal combustion engine. Leak detection in such a vehicle may use energy from the battery to cause a temperature change inside the fuel tank (e.g., heating the fuel). In this example, a first temperature may be measured by a temperature sensor, after which heat may be transferred to the fuel system and a second temperature is measured. The integrity of the fuel system may be verified by measuring the temperature of the fuel flowing out of the fuel system and comparing the measured value with a predetermined value. Alternatively, the integrity of the fuel system may be checked by inducing pressure in the fuel system by pumping air into the fuel tank and isolating the fuel system from the atmosphere (e.g., by closing a canister vent valve). If the pressure in the system measured by the pressure sensor increases at an expected rate, the fuel system is inferred to be sealed, and if the pressure rises below the expected value for a sealed system, a leak is determined. In some examples, the leak test may be repeated. In this way, the integrity of the fuel system may be determined by measuring temperature and pressure and comparing the measured values ​​to predetermined values. Signaling the presence of a leak may then be performed in an appropriate manner, such as by illuminating an indicator at the dashboard of the vehicle. Instructions for one or more methods of leak detection may be stored in a memory of the controller.

[0050] Returning to method 400, at 404, method 400 determines whether the vehicle is traveling in reverse. When the answer at 404 is no (e.g., when the vehicle is in any gear except reverse), method 400 moves to 412 to return the proximity sensor from the horizontally facing position to the vertically facing position. When the sensor is vertically facing, sensing axis 212 may be oriented perpendicular to a horizontal reference plane (e.g., the ground). In one example, the controller may return the proximity sensor to a default vertically facing position in response to the vehicle switching out of a reverse driving mode. For example, the controller may send a signal to de-energize the solenoid actuator, thereby deactivating the plunger of the solenoid actuator to remove the force from the ball joint, thereby returning the sensor to the vertically facing default position, such as Figure 2A. In another example, the proximity sensor may be adjusted from a horizontal facing position to a vertical facing position upon detecting a rainfall event during forward travel of the vehicle (e.g., the vehicle is not traveling in reverse). Detection of a rainfall event may be based on information obtained, for example, from a rain sensor. In one example, the rain sensor may be an onboard rain sensor configured to provide an indication of a rainfall event and a rainfall level to the controller 112. Such a sensor may be used to optically detect moisture and may be combined with an existing wiper system of the vehicle, for example, in one example, the sensor may be mounted on a wiper blade. In another example, a rain detection optical sensor may be mounted in contact with the inside of the windshield, such as near a rearview mirror or alternatively mounted to a bracket in an upper center portion of the windshield, integrated with an automatic light sensor to sense the presence of moisture on the windshield. In other examples, a humidity sensor may also be used. Additionally or alternatively, detection of a rainfall event may be based on information received from a remote device (e.g., a device of a weather service (such as a weather report from a weather service)), a GPS system, from vehicle-to-vehicle communications, and / or a personal weather station. In one example, a combination of methods may be used to infer rainfall events.

[0051] Returning to method 400, at 414, the method may estimate the distance to the nearest surface based on the output of the proximity sensor. The proximity sensor in a default position facing vertically may determine the proximity to the ground surface on which the vehicle is traveling. In the event that the vehicle encounters high water, the proximity sensor may estimate the vertical height of the sensor above the water (e.g., the height of the sensor above the water level if water is the nearest surface). At 416, method 400 may calculate the water depth based on the proximity sensor output. As previously described with reference to Figure 3 As explained above, the controller may obtain a distance output from the proximity sensor. The controller may calculate the distance output based on the output of the proximity sensor when the vehicle is traveling on dry ground (h) and the output of the proximity sensor when the vehicle is traveling in water (h * ) to calculate the water depth. The controller may then compare the calculated water depth to the first and second thresholds. Specifically, at 418, method 400 may determine whether the water depth is above the first threshold and below the second threshold. Figure 3As described in , the first water level threshold 'th1' may represent a height on the vehicle, which, when exceeded, may introduce water into the evaporative emission control system via the ventilation line inlet. The second water level threshold 'th2' may represent another height on the vehicle, which, when exceeded, may allow water to enter the engine intake device. In one example, the first and second thresholds may be absolute non-zero positive thresholds, which are stored in the memory of a controller (e.g., controller 112). If the water depth is above the first threshold but below the second threshold (e.g., yes at 418), then method 400 may move to 420 to disable purging. The purging operation may be disabled by closing the canister purge valve and / or the canister ventilation valve at 422. The closure of the canister ventilation valve may be a precautionary measure, which may prevent water from entering the fuel vapor canister under the condition that water may enter via the ventilation line inlet. Therefore, degradation of the canister may be avoided. The closure of the canister purge valve may be an additional precautionary measure, in which the controller may ensure that any water that may have been allowed to enter the fuel vapor emission system can be prevented from being sucked into the engine intake manifold and entering the combustion engine. In this way, vehicle operation may be appropriately controlled to inhibit water from entering the evaporative emission control system. Additionally, any fuel system leak detection test currently being performed or scheduled to be performed may be paused and / or delayed when the water depth is greater than the first threshold. For example, closing of a canister vent valve and / or a canister purge valve may disrupt leak detection, and / or the presence of water near or around fuel system components may confuse test results, making them unreliable. Method 400 then returns.

[0052] Returning to 418, method 400 may determine whether the water depth is above a first threshold but below a second threshold. If the water depth is above the first threshold but not above the second threshold (e.g., no at 418), method 400 proceeds to 424 to determine whether the water depth is above the first threshold and above the second threshold. In one example, the water depth through which the vehicle travels may gradually increase, such as when the vehicle travels through a flooded area. If the water depth is determined to be not greater than the first and second thresholds (e.g., no at 424), method 400 infers that the water level through which the vehicle travels may not be high enough to enter the engine and / or fuel system via the engine intake or via the evaporative emission control system. Therefore, method 400 proceeds to 408 to purge fuel vapor when indicated, and then proceeds to 410 to perform a fuel system leak test when indicated. However, if the water depth is determined to be above the first and second thresholds (e.g., yes at 424), method 400 moves to 426 to shut down the engine. An estimated water depth above the second threshold (e.g., a water level above both the first and second thresholds) may allow water to be introduced into the engine intake system. Therefore, as a precautionary measure, the controller may intentionally shut down the internal combustion engine to prevent water sealing and degradation of engine components. The internal combustion engine may be shut down by fuel cutoff in one example, by engine throttle control in another example, or by a combination of such methods. In one example, the threshold th1 may represent the height at which the evaporative emission control system ventilation duct inlet is installed on the vehicle, or the first threshold th1 may represent the height of the vehicle below the evaporative emission control system ventilation duct inlet. For example, when the first threshold th1 is the vehicle height below the evaporative emission control system ventilation duct inlet, the first threshold th1 may be set to be 10% lower than the height of the ventilation duct inlet (for example, the threshold may represent 90% of the height of the ventilation duct inlet relative to the ground). Similarly, the threshold th2 may represent the height at which the engine intake device is installed on the vehicle, or the second threshold th2 may represent the height on the vehicle below the engine intake device. For example, when the second threshold th2 is the vehicle height below the engine intake device, the second threshold th2 may be set to be 10% lower than the height of the engine intake device (for example, the second threshold may represent 90% of the height of the engine intake device relative to the ground). By comparing the water depth to a threshold value indicative of a water sensitive vehicle component or positioned below a component, sufficient time may be provided to perform a vehicle control operation. In this manner, vehicle operation may be controlled to inhibit water from entering the combustion engine. Method 400 may proceed to 428 to optionally propel the vehicle with an electric motor (or maintain propulsion by the electric motor if the vehicle is already in electric mode). In another embodiment, the controller may compare the distance output of the proximity sensor to a distance threshold value, the distance threshold value including a first threshold distance indicating the distance of the proximity sensor from the engine intake.The controller may further shut down the engine (and in some examples propel the vehicle with an electric motor) in response to the measured distance being less than a first threshold. As previously described, the vehicle may be a hybrid electric vehicle, which includes an electric motor and an internal combustion engine. Preventively shutting down the internal combustion engine by the controller may convert vehicle operation to an electric operating mode, in which an electric motor powered by a battery may be used for vehicle propulsion. In some examples, when the vehicle switches to or maintains an electric mode in response to a water depth greater than a second threshold, vehicle operating parameters may be adjusted to extend the duration that the vehicle may be propelled in the electric mode. For example, the vehicle torque may be reduced by reducing the vehicle torque limit to extend the range in which the vehicle may be propelled by the electric motor. In another example, selected vehicle operations may be disabled to extend battery life and / or prevent water from being drawn into the vehicle heating and cooling system, such as shutting down an air conditioning condenser, temporarily disabling cabin heating or cooling, shutting down a front grille shutter, etc. Then, method 400 returns.

[0053] Therefore, by executing Figure 4 The controller may also warn the vehicle operator and further provide the operator with recommendations to perform Figure 4 The vehicle control operations discussed in.

[0054] Now go to Figure 5, a graph 500 depicting engine operating parameters of a vehicle traveling in water is shown. The horizontal axis (x-axis) represents time and the vertical axis shows the corresponding values ​​of the engine parameters operating at times t0 to t4. The first graph from the top shows the operating state of the internal combustion engine of the vehicle, wherein line 506 depicts the engine which may be burning (on) or shut down (off). The second graph shows the water depth that can be calculated based on the distance measurement value obtained by the proximity sensor of the vehicle when the vehicle may encounter water. In this graph, line 508 depicts the water level or water depth that varies with time, and dashed lines 502 and 504 show the first and second thresholds (th1 and th2), which respectively represent the height on the vehicle corresponding to the ventilation line inlet and the engine intake device connected to the evaporative emission control system. The measured water level exceeding the first and / or threshold value may cause the vehicle operation to be controlled to prevent water from entering the vehicle system mentioned above. The third graph from the top shows the location of a proximity sensor such as sensor 202 on the vehicle, which in one example can alternate between a vertical orientation and a horizontal orientation in response to a selected transmission gear of the vehicle. Line 510 in the third graph indicates that the location of the proximity sensor is vertical or horizontal. The fourth graph from the top includes line 512, which shows the state of a canister purge valve such as CPV 161, which can alternate between an open state and a closed state. The CPV can be opened to allow fuel vapors to be purged into the combustion engine, and can be closed when the load on the fuel vapor canister is below a threshold load. In addition, when there is a risk of water ingestion, the CPV can be closed to prevent water from being ingested into the combustion engine. The fifth graph from the top includes line 514, which shows the state of a canister vent valve such as CVV 129, which can operate similarly to the CPV in an open state and a closed state. A CVV coupled to a vent line of an evaporative emission control system can be opened during a fuel vapor purge to allow vapors adsorbed by the fuel vapor canister to be purged by fresh air drawn in through the valve. When high water levels may be introduced into the exhaust system via the vent line inlet, the CVV may close, thereby preventing water from entering the fuel vapor canister. The sixth graph from the top includes line 516 showing vehicle gear, where the transmission may be in forward drive or reverse drive, but it should be understood that other vehicle drive gears are possible.

[0055] During the time period t0 to t1, the vehicle with the combustion engine on (e.g., line 506 in the first graph) may be traveling in reverse gear, as can be seen by line 516 in the sixth graph. The vehicle may be traveling on a ground surface without detectable water during t0 to t1, as shown by line 508. When the vehicle is in reverse gear, the proximity sensor may be actuated by the controller to assume a horizontal facing position, as shown by line 510 in the third graph. When the water depth (e.g., no water is detected during t0 to t1) is below the first and second diagnostic thresholds, in one example, the canister vent valve may be opened to draw fresh air through the vent line inlet and perform a purge of fuel vapors in the carbon canister, as shown by line 514 in the fifth graph. During this time period, the canister purge valve may be closed because the fuel vapor load in the fuel vapor canister is less than the threshold load, as shown by line 512 in the fourth graph.

[0056] At time t1, the vehicle may shift gears, such as from reverse gear to forward gear (line 516) with the combustion engine running (line 506). In response, the controller may automatically actuate the proximity sensor to assume its default position and face vertically (as shown by line 510) to detect the distance from the ground, as previously described with reference to FIG. Figure 2A As explained. During t1 to t2, the vertically facing proximity sensor may estimate the distance to the nearest surface. In one example, the nearest surface may be the ground on which the vehicle is traveling. In another example, the vehicle may encounter driving in water, so the proximity sensor may measure the distance to the water. The controller of the vehicle may obtain the distance output from the proximity sensor in real time and may calculate the water depth. For example, during t1 to t2, the calculated water depth as shown by line 508 may be lower than the first and second thresholds. Therefore, the CVV may be in an open position (as shown by line 514) to continue to allow fresh air to enter the ventilation line and enter the fuel vapor filter canister for fuel vapor purging and / or fuel system leak checks when indicated. In addition, engine operation may cause the fuel vapor load of the fuel vapor filter canister to exceed the threshold load. Therefore, the CPV may be actuated from the previous closed position (t0 to t1) to the open position (t1 to t2), as shown by line 512.

[0057] At time t2, the depth of water through which the vehicle may be traveling may exceed a first threshold (th1) but not exceed a second threshold (th2), depicted by line 508 being above dashed line 502 but not above dashed line 504. At this point, the vehicle may be traveling forward (line 516) with the engine on (line 506) and the proximity sensor facing vertically to estimate the distance to the water. In one example, threshold th1 may be based on the height at which the evaporative emission control system vent line inlet is mounted on the vehicle, but may be a height measured below the evaporative emission control system vent line inlet so that sufficient time may be allowed to protect and prepare the vehicle when water is introduced. The water depth above the first threshold during t2 to t3 may provide a likelihood of water being introduced into the evaporative emission control system via the vent line inlet and further via the CVV and into the canister (see FIG. 5 ). Figure 1 ). Therefore, during this time period, the CVV may be closed (as indicated by line 514) to inhibit water from entering the evaporative emission control system and damaging the fuel vapor filter canister. As an additional precautionary measure, the CPV may also be closed (as indicated by line 512) to prevent any water that is undesirably introduced into the emission control system from entering the internal combustion engine via the CPV.

[0058] In one example, the vehicle may continue to drive forward through water of increasing depth. At time t3, the depth of water through which the vehicle may drive may exceed the first and second thresholds (th1 and th2), depicted by line 508 above dashed lines 502 and 504. At this point, the vehicle may drive forward (line 516), with the proximity sensor facing vertically to estimate the distance from the water. In one example, threshold th2 may be based on the vehicle height at which the engine intake is installed, but may be a height measured below the engine intake so that sufficient time may be allowed to protect and prepare the vehicle when water is introduced. The depth of water above the first and second thresholds during t3 to t4 is likely to introduce water into the evaporative emission control system and the engine intake. Therefore, after determining that the water depth exceeds the second threshold, during the time period t3 to t4, the CPV and CVV may remain closed (as shown by lines 512 and 514) to prevent water from entering the evaporative emission control system, and further, the internal combustion engine of the vehicle may be shut down (turned off) (as shown by line 506) to avoid water from entering the engine intake.

[0059] In this way, in a vehicle system employing a proximity sensor such as an ultrasonic PDC sensor, changing the purpose of the proximity sensor by adjusting its position from a horizontal orientation to a vertical orientation and vice versa may allow not only obstacles in the path of the vehicle to be determined, but also the depth of water through which the vehicle is traveling. Additionally, upon detecting that the water level exceeds a predetermined threshold, vehicle components that may be at risk of water introduction may be appropriately disabled. For example, by suspending the purge operation when the vehicle is at a high water level as determined by a first threshold and by further shutting down the engine when the water level is higher as determined by a second threshold, the risk of water ingestion into the evaporative emission control system and the engine air intake may be mitigated.

[0060] The technical effect of monitoring the water level in real time with a proximity sensor is that vehicle operation can be controlled in advance to prevent water from being introduced into the evaporative emission control system and the engine intake system. In this way, at-risk vehicle components can be prepared and protected from water damage in advance, and maintenance costs can be avoided.

[0061] Figure 2A and Figure 2B An example configuration with relative positioning of various components is shown. If shown as directly contacting or directly connecting each other, then at least in one example, such elements can be referred to as directly contacting or directly connecting, respectively. Similarly, at least in one example, elements shown as being adjacent or adjacent to each other can be adjacent or adjacent to each other, respectively. As an example, the placement of components that are coplanarly contacted with each other can be referred to as coplanar contact. As another example, in at least one example, elements that are positioned to be separated from each other, with only space between them and no other components can be referred to as such. As another example, elements shown as being above / below each other, on opposite sides of each other, or on the left / right side of each other can be referred to as such relative to each other. In addition, as shown in the accompanying drawings, in at least one example, the topmost element or the vertex of an element can be referred to as the "top" of a component, and the bottommost element or the bottommost point of an element can be referred to as the "bottom" of a component. As used herein, top / bottom, upper / lower, above / below can be relative to the vertical axis of the accompanying drawings, and are used to describe the positioning of elements in the accompanying drawings relative to each other. Therefore, in one example, an element shown as being above other elements is vertically positioned above other elements. As yet another example, shapes of elements depicted within the drawings may be referred to as having those shapes (e.g., such as being rounded, straight, flat, curved, rounded, chamfered, angled, etc.). Additionally, in at least one example, elements shown as intersecting each other may be referred to as intersecting elements or intersecting each other. Furthermore, in one example, an element shown as being within another element or shown as being outside another element may be referred to as such.

[0062] A method includes adjusting a valve in a fuel system of a vehicle in response to a water level through which the vehicle passes. In a first example of the method, adjusting the valve includes adjusting a position of a fuel vapor canister purge valve positioned intermediate a fuel vapor canister and an engine. A second example of the method optionally includes the first example, and further includes wherein adjusting the valve includes adjusting a position of a fuel vapor canister vent valve positioned intermediate a fuel vapor canister and the atmosphere. A third example of the method optionally includes one or more or both of the first and second examples, and further includes measuring a water level during forward travel of the vehicle based on outputs from one or more proximity sensors positioned on the vehicle. A fourth example of the method optionally includes one or more or each of the first to third examples, and further includes measuring a distance between the vehicle and one or more objects approaching the vehicle during reverse travel of the vehicle based on outputs from one or more proximity sensors. A fifth example of the method optionally includes one or more or each of the first to fourth examples, and further includes wherein adjusting the valve in response to the water level includes closing the valve in response to the water level exceeding a first threshold level. A sixth example of the method optionally includes one or more or each of the first to fifth examples, and further includes shutting down an engine of the vehicle in response to the water level exceeding a second threshold level greater than the first threshold level. The seventh example of the method optionally includes one or more or each of the first to sixth examples, and further includes propelling the vehicle with the electric motor in response to shutting down the engine. The eighth example of the method optionally includes one or more or each of the first to seventh examples, and further includes where the valve is a canister vent valve, the canister vent valve fluidly coupling the fuel vapor canister to the atmosphere, and further includes, when the water level is below a first threshold level, opening the canister vent valve, and in response to the load on the fuel vapor canister reaching a threshold load, opening the canister purge valve to pass fresh air through the canister vent valve and the fuel vapor canister, and passing the fresh air-fuel vapor mixture to the engine through the canister purge valve. The ninth example of the method optionally includes one or more or each of the first to eighth examples, and further includes delaying the fuel system leak test until the water level drops below the threshold level.

[0063] In the above example, adjusting a valve in a fuel system of a vehicle in response to a level of water that the vehicle is passing through may include measuring the water level with a proximity sensor and determining that the vehicle is passing through a level of water greater than a first threshold level, wherein the first threshold level represents the height of a fresh air inlet of the fuel system. In response to determining that the vehicle is passing through water, wherein the water level is greater than the first threshold, adjusting a valve in the fuel system. The example may include measuring the water level with a proximity sensor and determining from the measurement that the vehicle is passing through a level of water greater than a second threshold level, wherein the second threshold level represents the height of a fresh air intake of the engine. In response to determining that the vehicle is passing through water, wherein the water level is greater than the second threshold, the engine of the vehicle may be shut down.

[0064] In one example, the vehicle may be operated in a first mode, wherein the first mode includes passing water having a water level above a first threshold. The first mode also includes adjusting a valve in a fuel system. In one example, the vehicle may be operated in a second mode, wherein the second mode includes passing water having a water level above a second threshold. After operating in the second mode, the engine may be shut down.

[0065] A method for a vehicle includes, in response to detecting a rainfall event and while the vehicle is traveling forward, actuating an actuator of a proximity sensor to tilt the proximity sensor from a horizontal facing position to a vertical facing position, estimating a distance to a ground surface on which the vehicle is located based on an output from the proximity sensor, disabling a fuel vapor purge in response to the distance being less than a first threshold and greater than a second threshold, and shutting down an engine of the vehicle in response to the distance being less than the second threshold. In a first example of the method, when the proximity sensor is in the vertical facing position, the proximity sensor is angled toward the ground on which the vehicle is located, and the method further includes, when the vehicle is traveling in reverse, actuating the actuator to move the proximity sensor back to the horizontal facing position, and estimating a distance to an object approaching the vehicle based on the output from the proximity sensor. A second example of the method optionally includes the first example, and further includes wherein disabling the fuel vapor purge includes one or more of closing a canister vent valve and closing a canister purge valve. A third example of the method optionally includes one or more or both of the first and second examples, and further includes wherein detecting a rainfall event includes detecting a rainfall event based on one or more of information received from a remote device and an output from an onboard rain sensor.

[0066] In the above example, the vehicle may be operated in a first mode, the first mode including operation in forward travel. The first mode may also include actuating an actuator of the proximity sensor to tilt the proximity sensor from a horizontal facing position to a vertical facing position. In the first mode, a distance from a ground surface on which the vehicle is located is estimated based on an output from the proximity sensor. In the first mode, the distance is less than a first threshold and greater than a second threshold. In the first mode, fuel vapor purge is disabled. The vehicle may be operated in a second mode, the second mode including operation in forward travel. The second mode may also include actuating an actuator of the proximity sensor to tilt the proximity sensor from a horizontal facing position to a vertical facing position. In the second mode, a distance from a ground surface on which the vehicle is located is estimated based on an output from the proximity sensor. In the second mode, the distance is less than a second threshold. After operating in the second mode, the engine of the vehicle is turned off.

[0067] A system for a vehicle includes an engine, an electric motor, a fuel system including a fuel vapor canister coupled to a fuel tank and coupled to the engine, a vent valve fluidly coupling the fuel vapor canister to atmosphere, a proximity sensor positioned on a body of the vehicle, and a controller storing instructions executable to: measure a distance between the proximity sensor and a surface detectable by the proximity sensor when the proximity sensor is in a first position; in response to the distance being greater than a first threshold distance but less than a second threshold distance, close the canister vent valve; and in response to the distance being less than the first threshold distance, shut down the engine and propel the vehicle with the electric motor. In a first example of the system, the instructions are executable to notify a vehicle operator that an object is positioned within a threshold distance behind the vehicle based on output from the proximity sensor when the proximity sensor is in a second position. A second example of the system optionally includes the first example, and further includes a solenoid actuator coupled to the proximity sensor and configured to move the proximity sensor from a first position to a second position, the first position being a vertically facing position, wherein a sensing axis of the proximity sensor is perpendicular to the ground on which the vehicle is located, and the second position being a horizontally facing position, wherein a sensing axis of the proximity sensor is parallel to the ground on which the vehicle is located. A third example of the system optionally includes one or more or both of the first and second examples, and further includes wherein the instructions are executable to energize the solenoid actuator to move the proximity sensor to the second position in response to the vehicle being operated in reverse gear. A fourth example of the system optionally includes one or more or each of the first to third examples, and further includes wherein the instructions are executable to reduce the vehicle torque limit in response to the distance being less than a first threshold distance. A fifth example of the system optionally includes one or more or each of the first to fourth examples, and further includes wherein the proximity sensor includes an ultrasonic sensor positioned on a rear bumper of the vehicle.

[0068] Note that the example control and estimation procedures included herein can be used with various engine and / or vehicle system configurations. The control methods and procedures disclosed herein can be stored as executable instructions in a non-transitory memory and can be executed by a control system including a controller combined with various sensors, actuators and other engine hardware. The specific procedures described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc. Therefore, the various actions, operations and / or functions described can be performed in the order shown, performed in parallel, or omitted in some cases. Similarly, the processing sequence is not required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. Depending on the specific strategy used, one or more of the actions, operations and / or functions shown can be repeatedly performed. In addition, the described actions, operations and / or functions can graphically represent the code in the non-transitory memory of a computer-readable storage medium programmed into the engine control system, wherein the actions are performed by executing instructions in a system including various engine hardware components combined with an electronic controller.

[0069] It should be appreciated that the configurations and procedures disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered limiting, as many variations are possible. For example, the above-described techniques can be applied to V-6, I-4, I-6, V-12, opposed 4, 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 properties disclosed herein.

[0070] The accompanying claims specifically point out certain combinations and subcombinations believed to be novel and non-obvious. The claims may refer to "an" element or a "first" element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amendment of the existing claims or by presentation of new claims in this or a related application. Such claims, whether broader, narrower, the same or different in scope than the original claims, are deemed to be included in the subject matter of the present disclosure.

Claims

1. A method for a vehicle, the method comprising: Adjusting a valve connected to a fuel vapor canister in a fuel system of the vehicle in response to a water level passed by the vehicle, wherein adjusting the valve in response to the water level includes closing the valve in response to the water level exceeding a first threshold level, shutting down an engine of the vehicle in response to the water level exceeding a second threshold level greater than the first threshold level, and propelling the vehicle with an electric motor in response to shutting down the engine. 2 . The method of claim 1 , wherein adjusting the valve comprises adjusting a position of a fuel vapor canister purge valve positioned intermediate the fuel vapor canister and the engine. 3 . The method of claim 1 , wherein adjusting the valve comprises adjusting a position of a fuel vapor canister vent valve positioned intermediate the fuel vapor canister and atmosphere. 4 . The method of claim 1 , further comprising measuring the water level during forward travel of the vehicle based on output from one or more proximity sensors positioned on the vehicle. 5 . The method of claim 4 , further comprising measuring a distance between the vehicle and one or more objects proximate to the vehicle during reverse travel of the vehicle based on output from the one or more proximity sensors.

6. The method of claim 1 , wherein the valve is a canister vent valve that fluidly couples a fuel vapor canister to atmosphere, and further comprising, when the water level is below the first threshold level: opening the canister vent valve; and In response to a load on the fuel vapor canister reaching a threshold load, a canister purge valve is opened to route fresh air through the canister vent valve and the fuel vapor canister and route a fresh air-fuel vapor mixture to the engine through the canister purge valve. 7 . The method of claim 1 , further comprising delaying a fuel system leak test until the water level drops below the first threshold level.

8. A system for a vehicle, the system comprising: engine; Electric motor; a fuel system including a fuel vapor canister coupled to a fuel tank and to the engine; a vent valve fluidly coupling the fuel vapor canister to atmosphere; a proximity sensor positioned on a body of the vehicle; and A controller storing instructions executable to: measuring a distance between the proximity sensor and a surface detectable by the proximity sensor when the proximity sensor is in a first position; In response to the distance being greater than a first threshold distance but less than a second threshold distance, closing the canister vent valve; as well as In response to the distance being less than the first threshold distance, the engine is shut down and the vehicle is propelled using the electric motor.

9. The system of claim 8, wherein the instructions are executable to notify a vehicle operator that an object is positioned within a threshold distance range behind the vehicle based on output from the proximity sensor when the proximity sensor is in the second position.

10. The system of claim 9, further comprising a solenoid actuator coupled to the proximity sensor and configured to move the proximity sensor from the first position to the second position, wherein the first position is a vertically facing position in which a sensing axis of the proximity sensor is perpendicular to the ground on which the vehicle is located, and the second position is a horizontally facing position in which the sensing axis of the proximity sensor is parallel to the ground on which the vehicle is located.

11. The system of claim 10, wherein the instructions are executable to energize the solenoid actuator to move the proximity sensor to the second position in response to the vehicle being operated in reverse gear.

12. The system of claim 8, wherein the instructions are executable to reduce a vehicle torque limit in response to the distance being less than the first threshold distance, and wherein the proximity sensor comprises an ultrasonic sensor positioned on a rear bumper of the vehicle.

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