System and method for active engine mount diagnostics

Abstract

The present invention relates to systems and methods for engine active mount diagnostics. Methods and systems are provided for identifying degradation of an engine active mount coupled to a vehicle engine. By correlating a monitored vibration pattern with a selected active mount operating mode, the condition of the engine active mount can be differentiated. Timely diagnosis of the engine active mount can improve the health of the engine active mount and prevent noise, vibration and harshness (NVH) issues.

Description

Technical Field

[0001] The present invention generally relates to methods and systems for diagnosing an active engine mount coupled to an engine. Background Art

[0002] Engines have historically used solid rubber mounts to isolate vibrations from the engine compartment and chassis, with the rubber naturally absorbing vibrations from the engine. However, in performance and high-end cars, if the rubber is too compliant, certain vehicle maneuvers can result in high loads, and this can add stress to joints in the vehicle, such as those in the exhaust system. Therefore, adjustable active engine mounts have been developed that can be controlled to vary the dampening characteristics depending on engine load.

[0003] As an example, the engine active mount can be configured to be soft (e.g., suppression mode) at engine idle to absorb unexpected vibrations. However, at higher engine speeds, the engine active mount can be configured to be stiffened (e.g., stiffening mode) to limit unexpected engine motion, which can prevent, for example, stress on the exhaust header. Therefore, the engine active mount can achieve low noise, vibration and harshness (NVH) at idle, and can further reduce NVH and prevent unexpected stress under high loads. For example, over time, the engine active mount may degrade due to aging of the engine active mount. As a result, unexpected engine vibrations may not be effectively absorbed. Further, if the unexpected vibrations are not properly absorbed / suppressed, engine performance may be reduced, resulting in reduced fuel economy and an overall decrease in engine efficiency. Summary of the invention

[0004] The inventors herein have recognized these problems and have developed systems and methods that at least partially address the above problems. In one example, a condition of an active engine mount may be monitored and diagnosed by a method for a vehicle, the method comprising: in response to a request to monitor the active engine mount, using torque from an electric motor to rotate an engine driving the vehicle without being supplied with fuel, while selectively deactivating engine valves and / or cutting off fuel supply to engine cylinders, while adjusting the active engine mount; and indicating degradation of the active engine mount based on an amount of vehicle chassis vibration during rotation. In this way, degradation of the active engine mount may be reliably identified and promptly addressed.

[0005] As an example, an autonomous or hybrid vehicle system may include an engine and a transmission coupled to a vehicle chassis via an engine active mount. The engine active mount may be a vacuum-regulated engine mount that counteracts engine vibrations by operating in a first suppression mode during an engine idle condition and in a second reinforcement mode at higher engine speed / load conditions to reduce the intensity of engine vibrations. Specifically, during a vehicle stationary condition, vehicle / engine vibrations may be induced by a non-combustion mode or a degraded combustion mode. Inducing vehicle vibrations via a non-combustion mode may include rotating the engine without being supplied with fuel while selectively deactivating valves of engine cylinders (i.e., selectively activating a variable displacement engine (VDE) mode in a cyclic manner). Alternatively, vehicle vibrations may be induced by cutting off fuel supply to one or more preselected engine cylinders to stimulate a degraded combustion event (i.e., misfire). The controller may then adjust the engine active mount to operate in a first suppression mode or a second reinforcement mode for a duration during the initiation period, and may simultaneously monitor engine vibration patterns via one or more vibration sensors for a duration. If the monitored vibration pattern is within a threshold when operating in the first mode, and the monitored vibration pattern is above a threshold when operating in the second mode, it is indicated that the active engine mount is functioning as desired. However, if the monitored vibration is within the threshold for both operating modes, it may be inferred that the active engine mount is stuck in the suppress mode. Alternatively, if the monitored vibration is above the threshold for both operating modes, it may be inferred that the active engine mount is stuck in the enhance mode.

[0006] In this way, the active engine mount can be accurately and reliably diagnosed, thereby enabling better prediction of engine mount degradation. The technical effect of adjusting the active engine mount to a selected operating mode while inducing vehicle vibration and monitoring the vibration pattern after adjustment is that the actual operating state of the active engine mount can be better identified. By timely diagnosing the active engine mount, the active engine mount health status can be improved, thereby reducing undesirable NVH-related problems and improving engine performance.

[0007] It should be understood that the above summary is provided to introduce in a simplified form a selection of concepts that 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 uniquely defined by the appended claims. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1An example vehicle powertrain including one or more active engine mounts is shown.

[0009] Figure 2 Show Figure 1 An example schematic layout of a variable displacement engine (VDE) for a vehicle powertrain.

[0010] Figure 3 Shows connection to Figure 1 An external view of an example active engine mount for a vehicle powertrain.

[0011] Figure 4 A cross-sectional view of an example active engine mount including a separator structure and a decoupler element is shown.

[0012] Figure 5 is a high level flow chart illustrating an example routine for diagnosing active engine mounts.

[0013] Figure 6 An example lookup table for diagnosing an active engine mount condition is shown.

[0014] Figure 7 An example timeline for performing an engine active mount diagnostic is depicted. DETAILED DESCRIPTION

[0015] The following description relates to a method for diagnosing a vehicle (eg Figure 1 The vehicle system may include an engine system, such as a four-cylinder engine capable of operating in a variable displacement engine (VDE) mode (e.g., Figure 2 The engine system may be supported in the vehicle by a plurality of active engine mounts that may be adjusted to at least two operating modes, such as to a first suppression mode and to a second reinforcement mode, to isolate undesirable noise, vibration and harshness (NVH) from the vehicle chassis, such as Figure 3-Figure 4 The controller may be configured to execute control routines such as Figure 5 The controller may be further configured to select a vehicle from a lookup table (such as Figure 6 ) determines whether the engine active mount is functioning as expected or is stuck in one of the operating modes (eg, the inhibit mode or the boost mode). Figure 7 , showing a predetermined engine active mount diagnostic. In this way, the noise, vibration and harshness (NVH) performance of the vehicle can be improved by reliably diagnosing the engine active mount.

[0016] refer to Figure 1, an example embodiment of a vehicle system 100 is shown from a top view. The vehicle system 100 includes a vehicle body 103 having a front end labeled “front” and a rear end labeled “rear”. The vehicle system 100 may include a plurality of wheels 135. For example, Figure 1 As shown, vehicle system 100 may include a first pair of wheels adjacent a front end of the vehicle and a second pair of wheels adjacent a rear end of the vehicle.

[0017] In some examples, the vehicle system 100 can be a hybrid vehicle system with multiple torque sources available to one or more vehicle wheels 135. In one example, the vehicle system 100 can be a full hybrid system, where the vehicle is driven only by the engine and generator, or only by the electric motor, or a combination thereof. Alternatively, an auxiliary or mild hybrid embodiment can also be used, where the engine is the primary source of torque and the electric motor selectively increases torque during certain conditions (such as during a gas-on event). In another example, the vehicle system 100 can be an autonomous vehicle.

[0018] In the example shown, the vehicle system 100 includes an internal combustion engine (such as engine 10) coupled to a transmission 137. The engine 10 and the transmission 137 may be referred to herein in combination as a vehicle powertrain 110 or powertrain 110. The powertrain 110 may be configured in various ways, including being configured as a parallel, series, or series-parallel hybrid vehicle. It should be understood that other vehicle components coupled to one or more of the engine and / or transmission 137 may also be included in the vehicle powertrain 110 without departing from the scope of the present invention. For example, the engine 10 may include an engine intake 196 and an engine exhaust (not shown). The engine intake may include a throttle 197 for controlling the amount of intake air to the engine 10. In one example, the throttle 197 may be electrically controlled via a controller such as controller 12. In another example, the throttle 197 may be mechanically coupled to an accelerator pedal 181.

[0019] In the depicted example, the transmission 137 can be a gearbox, a planetary gear system, or other type of transmission. The transmission 137 can further include a generator 24 and an electric motor 26. The generator 24 and the electric motor 26 can also be referred to as electric machines because each can operate as a motor or a generator. Torque is output from the transmission 137 via a power transmission gear (not shown), a torque output shaft (not shown), and a differential and axle assembly (not shown) for driving the vehicle wheels 135.

[0020] The generator 24 is drivably connected to the electric motor 26 so that each of the generator 24 and the electric motor 26 can be operated using electrical energy from an electrical energy storage device (here described as a battery 58). In some embodiments, an energy conversion device such as an inverter can be connected between the battery and the motor to convert the DC output of the battery into an AC output used by the motor. However, in alternative embodiments, the inverter can be configured in the electric motor. The electric motor 26 can be operated in a regenerative mode, that is, as a generator, to absorb energy from the vehicle movement and / or the engine and convert the absorbed kinetic energy into an energy form suitable for storage in the battery 58.

[0021] The vehicle system 100 is depicted as having a front wheel drive (FWD) transmission, where the engine 10 drives the front wheels via half shafts 109 and 111. In another embodiment, the vehicle system 100 may have a rear wheel drive (RWD) transmission, which drives the rear wheels via a drive shaft (not shown) and a differential (not shown) located on a rear axle 131. In other examples, the vehicle system 100 may include a four wheel drive transmission.

[0022] The engine 10 and the transmission 137 can be at least partially supported by a frame or chassis 105, which in turn can be supported by a plurality of wheels 135. Thus, vibrations and motions from the engine 10 and the transmission 137 can be transmitted to the frame 105. The frame 105 can also provide support to the body and other internal components of the vehicle system 100, so that vibrations from the operation of the engine can be transmitted to the interior or cabin of the vehicle system 100. In order to reduce the transmission of vibrations to the interior or cabin of the vehicle system 100, the engine 10 and the transmission 137 can be mechanically coupled to a corresponding engine active mount 133 via a plurality of members 139. As discussed herein, an engine active mount can refer to any type of engine active mount that can change its damping characteristics. For example, such an active mount can be controlled or adjusted to be relatively soft (e.g., adjusted to a damping mode) at engine idle to absorb undesirable vibrations, but can be controlled or adjusted to be strengthened (e.g., adjusted to a strengthening mode) at higher engine speeds and loads to limit undesirable engine motions. As an example, engine manifold vacuum may be selectively applied to an active engine mount to change the characteristics of the active engine mount. Figure 4 Such examples are discussed in more detail. Thus, active engine mounts as discussed herein may involve vacuum regulated engine mounts, active motor mounts that counteract engine vibrations by commanding reverse vibrations to reduce the intensity of engine vibrations, magnetorheological mounts that may contain small iron particles suspended in a fluid such that when an electric current or magnetic field is applied to the fluid, the iron particles align and effectively increase the viscosity of the fluid, and the like.

[0023] As depicted, engine 10 and transmission 137 are mechanically coupled to member 139 at four locations and to four engine active mounts 133 via member 139. In other alternative embodiments, different numbers of members and engine active mounts may be used without departing from the scope of the present disclosure.

[0024] View 150 depicts a view of vehicle system 100 viewed from the front end of vehicle system 100. Control system 15 including controller 12 may at least partially control engine 10 and vehicle system 100. Controller 12 may be configured to control the vehicle system 100 from the front end of vehicle system 100. Figure 1 Various sensors 13 receive signals and use Figure 1 The various actuators 81 of the controller are used to adjust the engine operation based on the received signals and the instructions stored in the memory of the controller. As an example, the vehicle system 100 may include sensors dedicated to indicating the occupancy state of the vehicle, such as a seat load cell 189, a door sensing technology 190 and / or an onboard camera 191.

[0025] In some examples, the control system 15 may communicate with a remote engine start receiver 192 (or transceiver) that receives a wireless signal 195 from a key fob 194 having a remote start button 193. In other examples (not shown), the remote engine start may be initiated via a cell phone or smartphone-based system where the user's cell phone sends data to a server and the server communicates with the vehicle to start the engine.

[0026] Control system 15 and controller 12 may send control signals to actuator 81, in addition to other actuators of engine 10 and Figure 1 In addition to the transmission 137 not shown in the figure, the actuator 81 may also include a fuel injector 66 connected to the cylinder 30. For illustrative purposes, only one cylinder 30 and one fuel injector 66 are shown. However, it will be appreciated that the engine 10 may include multiple cylinders and multiple fuel injectors. In some embodiments, each cylinder of the engine 10 may include a spark plug 188 for initiating combustion. In response to an ignition advance signal from the controller, in a selected operating mode, the control system 15 may provide an ignition spark to the cylinder 30 via the spark plug 188. However, in some embodiments, the spark plug 188 may be omitted, such as in cases where the engine 10 can initiate combustion by automatic ignition or by injecting fuel, as in the case of some diesel engines. Further, the engine 10 may be a multi-cylinder engine capable of operating in a variable displacement engine (VDE) mode, as will be referred to in detail. Figure 2 Described in more detail.

[0027] The vehicle system 100 may include one or more fuel storage tanks 185 for storing fuel on the vehicle. For example, the fuel storage tank 185 may store one or more liquid fuels, including but not limited to gasoline, diesel, and alcohol fuels. In some examples, the fuel may be stored on the vehicle as a mixture of two or more different fuels. For example, the fuel storage tank 185 may be configured to store a mixture of gasoline and ethanol (e.g., E10, E85, etc.) or a mixture of gasoline and methanol (e.g., M10, M85, etc.), whereby these fuels or fuel mixtures may be delivered to the engine 10. Other suitable fuels or fuel mixtures may be supplied to the engine 10, where they may be burned at the engine to produce an engine output. For example, the engine output may be used to propel the vehicle.

[0028] In some embodiments, control system 15 may receive an indication of the level of fuel stored in fuel storage tank 185 via fuel level sensor 187, also referred to herein as fuel level indicator (FLI) 187. The level of fuel stored at fuel storage tank 185 (e.g., as identified by fuel level sensor 187) may be communicated to a vehicle operator, for example, via a fuel gauge or an indication in a vehicle instrument panel (not shown).

[0029] Fuel storage tank 185 may be coupled to a fuel pump system 186. Fuel pump system 186 may include one or more pumps for pressurizing fuel delivered to injectors of engine 10, such as exemplary injector 66 shown. As discussed, while only a single injector 66 is shown, additional injectors are provided for each cylinder. As depicted, fuel level sensor 187 may include a float connected to a variable resistor. Alternatively, other types of fuel level sensors may be used.

[0030] The controller 12 may receive input data from 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 routines. In one example, the controller 12 may be a conventional microcomputer including: a central processing unit (CPU), input / output (I / O) ports, read-only memory (ROM), random access memory (RAM), keep-alive memory (KAM), and a conventional data bus. The controller 12 may receive various signals from sensors coupled to the powertrain 110, including a measurement of intake mass air flow (MAF) from a mass air flow sensor (not shown); an engine coolant temperature (ECT) from a temperature sensor coupled to a cooling sleeve (not shown); a surface ignition sensing signal (PIP) from a Hall effect sensor (not shown) coupled to a crankshaft (not shown); and a throttle position TP from a throttle position sensor 197 and an absolute manifold pressure signal MAP from a sensor (not shown). Engine speed signal RPM is generated by controller 12 from signal PIP in a conventional manner, and manifold pressure signal MAP from a manifold pressure sensor provides an indication of vacuum or pressure in the intake manifold. During stoichiometric operation, this sensor can give an indication of engine load. Furthermore, this sensor, along with engine speed, can provide an estimate of charge (including air) inducted into the cylinder. In one example, the engine speed sensor may produce a predetermined number of equally spaced pulses every revolution of the crankshaft. Controller 12 may receive signals from Figure 1 The signals of various sensors are used Figure 1 Various actuators such as throttle 197, fuel injector 66, spark plug 188, etc. are controlled to regulate engine operation based on signals received and instructions stored in the memory of the controller.

[0031] In another example, the engine 10 can be at least partially controlled by a control system including the controller 12 and by input from a vehicle operator 180 or an autonomous controller via an input device 181. In one example, the input device 181 includes an accelerator pedal and an accelerator pedal position sensor 182 for generating a proportional pedal position signal PP. Similarly, the control system 15 can receive an indication of operator-requested vehicle braking via the human operator 180 or the autonomous controller. For example, the control system 15 can receive sensory feedback from a brake pedal position sensor 157 that communicates with the brake pedal 156. In some examples, the vehicle system 100 can include an antilock brake system (ABS) 113. The ABS can include, for example, a wheel speed sensor 114. The ABS can further include at least two hydraulic valves (not shown) within a brake hydraulic device (not shown). The controller 12 can monitor the rotational speed of each wheel, and in response to detecting a wheel rotating significantly slower than the other wheels, the ABS 113 can be controlled to reduce the hydraulic pressure to the brake 115 at the affected wheel, thereby reducing the braking force on the wheel. Alternatively, in response to detecting a wheel rotating significantly faster than the other wheels, the ABS 113 can be controlled to increase the hydraulic pressure to the brake at the affected wheel, thereby increasing the braking force on the wheel. In further cases, as will be discussed in detail below, the ABS 113 can command an increase in brake pressure at one or more wheels in order to perform an engine active mount test diagnostic routine. Here, increasing the brake pressure at one or more wheels via the ABS 113 can be referred to as activating one or more wheel brakes. For example, the ABS 113 can activate one or more wheel brakes in order to strengthen the vehicle frame and mechanically couple it to the engine to perform an engine active mount diagnostic routine, as will be discussed in reference Figure 5 Described in detail.

[0032] In one example, the autonomous controller may include a user interface device (not shown), a navigation system (not shown), at least one autonomous driving sensor (not shown), and an autonomous mode controller (not shown). The user interface device may be configured to present information to a vehicle occupant in the case where the vehicle occupant may be present. However, it is understood that under certain conditions, the vehicle may be operated autonomously without a vehicle occupant. The information presented may include audible information or visual information. In addition, the user interface device may be configured to receive user input. In some possible methods, the user interface device may include a touch display screen. The navigation system may be configured to determine the current position of the vehicle using, for example, a global positioning system (GPS) receiver, which is configured to triangulate the position of the vehicle relative to a satellite or a land-based transmitter tower. The navigation system may be further configured to develop a route from the current position to a selected destination, and to display a map and present driving instructions to the selected destination via, for example, a user interface device. The autonomous driving sensor may include any number of devices configured to generate signals that help navigate the vehicle. Examples of autonomous driving sensors may include radar sensors, lidar sensors, visual sensors (e.g., cameras), vehicle-to-vehicle infrastructure networks, and the like. When the vehicle system 100 is operating in autonomous mode, the autonomous driving sensors may enable the vehicle to "see" the road and vehicle surroundings, and / or steer around various obstacles. The autonomous driving sensors may be configured to output sensor signals to, for example, an autonomous mode controller.

[0033] In another example, the autonomous mode controller can be configured to control one or more subsystems when the vehicle is operated in an autonomous mode. Examples of subsystems that can be controlled by the autonomous mode controller can include brake subsystems, suspension subsystems, steering subsystems, and powertrain subsystems. The autonomous mode controller can control any one or more of these subsystems by outputting signals to a control unit associated with the subsystem. In one example, the brake subsystem can include an anti-lock braking subsystem that is configured to apply a braking force to one or more of the wheels (e.g., wheels 135). As discussed herein, applying a braking force to one or more of the vehicle wheels can be referred to as activating the brakes. In order to autonomously control the vehicle, the autonomous mode controller can output appropriate commands to the subsystems. The commands can cause the subsystems to operate according to the driving characteristics associated with the selected drive mode. For example, the driving characteristics can include how the vehicle actively accelerates and decelerates, how much space the vehicle leaves with the vehicle in front, how often the autonomous vehicle changes lanes, and the like.

[0034] Vehicle system 100 may further include an air conditioning (A / C) system 199, which may include an A / C compressor 198. In some examples, the A / C compressor and the A / C system may be electronically controlled, for example, via controller 12. However, in other examples, A / C compressor 198 may be mechanically controlled, for example, via coupling to an engine crankshaft (not shown).

[0035] The vehicle system 100 may further include an electronic parking brake system 151. For example, the electronic parking brake system may be used in conjunction with a vehicle controller to engage or release the electronic parking brake(s) 152.

[0036] With respect to the vehicle system 100, noise, vibration and harshness (NVH) may be generated during engine operation, transmission operation, during engine operating mode transitions, etc. In addition, NVH may be generated due to driving over rough (e.g., uneven) surfaces. The engine active mount 133 may be designed to suppress vehicle noise and vibration over a wide frequency range, or alternatively may be designed to suppress a specific range of vibration frequencies. In this way, NVH induced by multiple different sources may all be suppressed by a common engine active mount 133.

[0037] The engine active mounts 133 can be operably connected to the controller 12 and can adjust their damping characteristics to counteract vibrations generated from the engine and / or transmission upon receiving signals from the controller 12. In one example, the change in damping characteristics can be achieved by actively damping by changing the effective mount stiffness. In another example, the damping characteristics can be changed by actively damping an actuated mass that is capable of generating a reaction force to the sensed vibrations. Here, the engine active mounts 133 can filter vibrations received from the engine and / or transmission and provide a reaction force that will negate the unfiltered vibrations. For example, the engine active mounts 133 can be controlled via the controller 12 to a first configuration or first mode (e.g., a damping mode) for idle operation, and a second configuration or mode (e.g., a boost mode) for operation at higher engine speeds and loads. As will be discussed below with respect to Figure 5 As discussed in further detail, the active engine mount diagnostic routine may be periodically executed to determine whether the engine active mount is functioning as desired.

[0038] As mentioned above, Figure 1 Only one cylinder of a multi-cylinder engine is shown. Thus, each cylinder may similarly include its own set of intake / exhaust valves, fuel injector(s), spark plug, etc. Any number of cylinders and a variety of different cylinder configurations may be included in engine 10, such as V-6, I-4, I-6, V-12, opposed 4, and other engine types.

[0039] Now go to Figure 2 , shows a schematic diagram of a multi-cylinder engine system 200 capable of operating in a variable displacement engine (VDE) mode. For example, the multi-cylinder engine system 200 may include Figure 1 The engine 10. It should be understood that Figure 1 Engine system components introduced in are similarly numbered and are not reintroduced.

[0040] In the depicted example, the engine 10 is a V8 engine having a first cylinder group 215A and a second cylinder group 215B, each cylinder group having four cylinders, namely cylinders A1-A4 in cylinder group 215A and cylinders B1-B4 in cylinder group 215B. Cylinders A1-A4 of cylinder group 215A and cylinders B1-B4 of cylinder group 215B may include selectively deactivatable intake valves (not shown) and selectively deactivatable exhaust valves (not shown). Cylinder valves may be deactivated via hydraulically actuated tappets or via a cam profile switching (CPS) mechanism, wherein a cam lobe without lift is used for the deactivated valve. Other mechanisms for valve deactivation may also be used. The engine 10 has an intake manifold 244 with a throttle 262 and an exhaust manifold 248 coupled to an emission control system 270. The emission control system 270 may include one or more catalysts and air-fuel ratio sensors (not shown).

[0041] During selected conditions, such as when the full torque capacity of the engine is not required, one or more cylinders in the first cylinder group 215A and the second cylinder group 215B can be selectively used for deactivation (also referred to as VDE operating mode herein). This can include selectively deactivating one or more cylinders on only the first group 215A, one or more cylinders on only the second group 215B, or one or more cylinders on each of the first and second groups. The number and identification of the cylinders deactivated on each group can be symmetrical or asymmetrical. Specifically, one or more cylinders in the selected cylinder group can be deactivated by closing the corresponding fuel injectors while maintaining the operation of the intake and exhaust valves, so that air can continue to be pumped through the cylinders. Although the fuel injectors of the deactivated cylinders are closed, the remaining enabled cylinders continue to perform combustion, and the fuel injectors are in an active and operating state. In order to meet the torque requirements, the engine produces the same amount of torque on those cylinders where the injectors remain enabled. In other words, the remaining active cylinders operate at a higher average cylinder load. This requires a higher manifold pressure, thereby reducing pumping losses and improving engine efficiency. Additionally, the lower effective surface area exposed to combustion (from only the activated cylinders) reduces engine heat losses, thereby increasing the thermal efficiency of the engine.

[0042] In one example, based on a drop in torque demand, one or more cylinders may be selectively deactivated. Further, cylinders may be grouped for deactivation in a firing order based on the position of the cylinders along the cylinder block on the cylinder banks, and the deactivation history of the cylinders. As an example, cylinders from different cylinder banks (e.g., cylinder banks 215A and 215B) may be grouped together for deactivation. For example, during a first VDE condition, cylinders A1, B1, A4, and B4 may be deactivated, while during a second VDE condition, cylinders A2, B2, A3, and B3 may be deactivated. In an alternative example, a first VDE pattern may include cylinders with different identifications and quantities than a second VDE pattern.

[0043] Engine 10 may be operated on a variety of substances, which may be delivered via fuel system 272. Engine 10 may be operated by including controller 12 (e.g., Figure 1 The controller 12 may be controlled at least in part by a control system of the engine 10. The controller 12 may be controlled by sensors 13 (similar to Figure 1 Sensors 13) receive various signals and send control signals to various actuators 81 (similar to Figure 1 Actuator 81). In addition, controller 12 may receive indications of cylinder knock or pre-ignition from one or more knock sensors distributed along the cylinder block. When included, the plurality of knock sensors may be distributed symmetrically or asymmetrically along the cylinder block. Further, the one or more knock sensors may include an accelerometer, an ion sensor, or an in-cylinder pressure sensor.

[0044] Now go to Figure 3 , shows an external view of an example engine active mount 300. It will be appreciated that such examples are intended to be illustrative and not limiting. The engine active mount 300 may be Figure 1 An example of an active engine mount 133 is shown within the vehicle system 100 of FIG. 100. When configured in a vehicle system on flat ground (e.g., Figure 1 When the engine active mount 300 is in a vehicle system 100 located at a position, the engine active mount 300 can be oriented in a generally vertical direction. However, in other configurations, the engine active mount 300 can be oriented at an inclined angle relative to the vertical. However, as used herein, the terms "upper / upper portion" and "lower / lower portion" can refer to the respective ends of arrow 398, which indicate a directional axis specific to the engine active mount. That is, arrow 398 provides a reference for the relative positioning of the components that make up the engine active mount 300, rather than providing a reference for the orientation of the engine active mount 300 within the vehicle system. In addition, the upper end of the engine active mount can refer to the end that is closer to the head of arrow 398, and the lower end of the engine active mount can refer to the end that is closer to the tail of arrow 398.

[0045] The engine active mount 300 includes an upper outer housing 302 having a central opening 312 formed in a top surface thereof. The upper outer housing 302 may be formed of a rigid material such as metal or a hard plastic. The central opening 312 is configured to receive a fastener or bolt 306 that is inserted from a first elastomeric member or primary rubber element (not shown, but see Figure 4 ) extends outwardly for fastening to a component of a vehicle powertrain (e.g., Figure 1 The bolt 306 may be formed of a rigid material such as steel or aluminum.

[0046] The upper end of the bolt 306 can be configured to rotate around the gap of the central opening 312, while the lower end (not shown) can be embedded in the first elastomeric member of the active engine mount, and thus the lower end of the bolt can remain relatively stationary compared to the upper end of the bolt. In another example, the bolt 306 can extend outward from a bearing member (not shown) partially encapsulated in the first elastomeric member of the housing, and can be configured to transmit vibration to the first elastomeric member via the bearing member.

[0047] The bolts 306 may be coupled to a rigid upper bracket 339 via fasteners 340. It should be appreciated that the upper bracket 339 may be similar to Figure 1 The upper bracket 339 may be formed of one of metal or hard plastic. The distal portion 338 of the upper bracket 339 may be coupled to a vehicle powertrain component via fasteners in a manner known in the art (e.g., coupled to a powertrain component at a flange attached thereto).

[0048] The lower outer shell 304 can be fastened (eg, mechanically coupled) to the upper shell 302. The lower outer shell 304 can be formed of a rigid material such as one of metal or hard plastic. Figure 1 The connection of the outer shell to the outer shell 105 can be achieved via a plurality of lower brackets. In this way, the outer shell can remain structurally rigid (e.g., substantially incompressible), and any vibration absorbed from the vehicle powertrain or vehicle frame can be transferred to the first elastomeric member within the outer shell, which is configured to dampen the vibration.

[0049] Figure 3Shown in the figure are a first lower bracket 332 and a second lower bracket 334. It should be understood that, without departing from the scope of the present invention, additional brackets may also be attached to the lower outer shell 304 in a manner similar to the first lower bracket 332 and the second lower bracket 334. The lower bracket may be formed of a metal such as steel. However, other materials may be used to form the lower bracket without departing from the scope of the present invention. The first lower bracket 332 is shown as being integrally formed with the lower outer shell 304. Bolts (not shown) may couple the first lower bracket 332 (e.g., mechanically) to the vehicle frame via holes 382. The second lower bracket 334 is shown as being attached to the lower outer shell 304 (but not integrally formed therewith) and may similarly be coupled to the vehicle frame via holes 384.

[0050] Figure 4 Shows active engine mounts (e.g. Figure 1 Active engine mount 133 or Figure 2 The cross-sectional view 400 of the active engine mount 200 is shown. It can be understood that Figure 4 The engine active mount depicted at is intended to be illustrative and not limiting. As used herein, the terms "upper / upper portion" and "lower / lower portion" may refer to the respective ends of arrow 498. It will be appreciated that arrow 498 may provide a reference for the relative positioning of components within the engine active mount.

[0051] The engine active mount assembly may include an outer housing 402 (e.g., similar to Figure 3 The upper outer housing 302 is sized to receive a first elastomeric member 404, which is generally shaped as a frustoconical body and is primarily made of an elastomeric material, such as a resilient rubber common in the art. Bolts 406 (e.g., similar to Figure 3 Bolts 306 at the ends of the first elastomeric member 404 extend outwardly from the first elastomeric member for fastening to a powertrain or engine (not shown) in a manner known in the art. In the depicted example, bolts 406 and at least a lower portion of a metal load bearing member 408 are encapsulated within the first elastomeric member 404. Additionally, a lower peripheral portion of the first elastomeric member may include a reinforcement, such as a metal reinforcement 410, molded within the first elastomeric member to increase rigidity and support. In this manner, vibrations and / or displacements from the powertrain may be transferred to the first elastomeric member 404 of the active engine mount.

[0052] As mentioned above about Figure 3As discussed, the first elastomeric member is housed within the upper outer housing 402 such that the bolt 406 extends through the central opening 412 in the restrictor. The lower surface 405 of the first elastomeric member 404 forms a portion of the first or upper fluid chamber 416 of the engine mount, i.e., the high pressure side. The first fluid chamber 416 can be filled with a hydraulic fluid (e.g., ethylene glycol). The remainder of the first fluid chamber 416 is defined by an inertial track assembly 420. It will be appreciated that the inertial track assembly 420 may also be referred to herein as a partition structure. An outer portion of the upper surface of the partition structure (indicated by reference numeral 422) abuts against and sealingly engages the first elastomeric member 404 to seal the first fluid chamber 416. A second outer portion of the partition structure along the lower surface (indicated by reference numeral 424) is sealingly engaged by a second elastomeric member 430 (rubber boot or diaphragm) and in particular an upper peripheral portion 432 thereof. The lower surface 424 of the separator structure 420 combines with the second elastomeric member 430 to form a second or lower fluid chamber 450. The second fluid chamber may also be filled with a hydraulic fluid (e.g., ethylene glycol). The second elastomeric member 430 is protected by a diaphragm cover 434, which is preferably formed of a material that is more rigid than the elastomeric diaphragm and is cooperatively engaged (e.g., mechanically coupled) with the lower outer housing 440. When the lower outer housing 440 is fastened to the upper housing, the lower peripheral edge of the first elastomeric member 404 and the peripheral portion 432 of the second elastomeric member sealingly engage the opposing sides or faces 422, 424 of the separator structure 420, respectively.

[0053] The partition structure and operation of a typical engine mount 400 will be briefly described. As noted, the first fluid chamber 416 and the second fluid chamber 450 are fluidly coupled together by the partition structure 420. The partition structure 420 includes a channel plate 401, a decoupler 460 (e.g., a compliant membrane), a first fluid track 470 (e.g., an idle track), a second fluid track 475 (e.g., a riding track), and a vacuum chamber 465. The vacuum chamber 465 can be coupled to the partition structure such that the vacuum chamber can be defined by a channel in the channel plate 401, and wherein segments of the vacuum chamber are defined by the decoupler 460. The vacuum chamber 465 can be fluidly coupled to a vacuum source or atmospheric pressure source via a conduit 480. Vacuum (e.g., intake manifold vacuum) can be provided to the vacuum chamber 465 via a vacuum line (not shown) by any available vehicle vacuum source. A solenoid valve (e.g., a three-way solenoid valve) can control the amount of vacuum in the vacuum line. In one example, a first pressure 447 (e.g., atmospheric pressure) or a second pressure 448 (e.g., vacuum) can be applied to the vacuum chamber 465 via controlling the two-way valve 446. For example, the controller 12 can command the two-way valve 446 so that the first pressure or the second pressure can be transmitted to the vacuum chamber 465 according to vehicle operating conditions, which will be discussed in further detail below. More specifically, the controller 12 can send a signal to the two-way valve 446 to actuate the valve to connect the first pressure 447 to the vacuum chamber 465, or to connect the second pressure 448 to the vacuum chamber 465.

[0054] When the vacuum chamber 465 is at atmospheric pressure (e.g., a first pressure), the decoupler 460 can move freely. In addition, when the vacuum chamber 465 is at atmospheric pressure, the first vacuum-actuated valve 455 is located in an upper position within the channel plate 401, so that the first fluid track 470 is closed. When in this configuration, the decoupler 460 can be ventilated in response to vibration or displacement, and can only allow fluid flow between the first fluid chamber 416 and the second fluid chamber 450 via the second fluid track 475. Therefore, when the vacuum chamber 465 is at atmospheric pressure, the engine mount 400 represents a decoupled engine mount function. This configuration of the engine active mount 400 can be referred to as a second or enhanced mode of engine active mount operation.

[0055] Alternatively, applying a vacuum to the vacuum chamber 465 may be used to force the decoupler 460 against the channel plate 401 (indicated by arrow 486), and may also position the first vacuum-actuated valve in a lower position indicated by arrow 485. Thus, the first fluid rail 470 is opened, and the decoupler 460 is not allowed to move or ventilate. Thus, since the first fluid rail 470 represents the path of least resistance through the inertial track assembly 420, fluid flow between the first fluid chamber 416 and the second fluid chamber 450 occurs via the first fluid rail 470, thereby providing a soft engine mount for idle mode operation. In other words, with the vacuum chamber 465 coupled to the second pressure 448 (e.g., vacuum), the active engine mount 400 may be understood to be operating in a first or inhibited mode of engine active mount operation.

[0056] Further, the controller 12 (similar to Figure 1 and Figure 2 The controller 12 described in the foregoing may be configured to monitor the vehicle powertrain (eg Figure 1 As an example, when relatively low frequencies are generated (e.g., low amplitude torque pulses during engine idle conditions), the controller can apply a vacuum to the vacuum chamber 465 such that the engine active mount operates in a first suppression mode. In another example, when high frequency vibrations are detected (e.g., during rapid acceleration and / or high engine load conditions), the controller can apply a first atmospheric pressure to the vacuum chamber 465 such that the engine active mount operates in a second enhancement mode. In this manner, the engine active mount can isolate a wide range of vibration frequencies and amplitudes generated by the vehicle powertrain under different engine operating modes.

[0057] Figure 3 and Figure 4An example configuration of relative positioning of various components is shown. If shown as directly contacting each other or directly connected, then at least in one example, these elements can be referred to as direct contact or direct connection respectively. Similarly, at least in one example, the elements shown to be adjacent or adjacent to each other can be adjacent or adjacent to each other respectively. As an example, components arranged in coplanar contact with each other can be referred to as coplanar contact. As another example, in at least one example, the elements spaced apart from each other with only intervals and no other components therebetween can be referred to as such. As another example, the elements shown as above / below each other, on each other's sides or on each other's left / right can be referred to as such relative to each other. Further, as shown in the figure, in at least one example, the topmost element or the topmost point 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 figure and used to describe the positioning of the elements of the figure relative to each other. Thus, in one example, the element shown above other elements is vertically positioned above other elements. As yet another example, the shapes of elements depicted in the drawings may be referred to as having those shapes (e.g., such as circular, straight, flat, curved, rounded, chamfered, angled, etc.). Further, in at least one example, elements shown crossing each other may be referred to as crossing elements or crossing each other. Further, in one example, an element shown as being within another element or an element shown as being outside another element may be referred to as such.

[0058] As mentioned above, ( Figure 1-Figure 2The engine 10 of the present invention can be operated in a VDE mode or a non-VDE (full cylinder ignition) mode. Further, a portion of the cylinders of the engine can be disabled during a selected condition, wherein the selected condition can be defined by parameters such as engine speed / load conditions. In addition, the controller can disable the selected cylinder by sealing the intake valve and exhaust valve of the cylinder. Noise, vibration and discomfort (NVH) problems may occur during the engine operating mode conversion from VDE mode to non-VDE mode, and vice versa, and in order to provide fuel economy benefits and reduced NVH, the engine 10 can be mainly operated in, for example, a balanced ignition three-cylinder or uniform ignition VDE mode. In another example, the conversion between the VDE mode and the non-VDE mode can involve alternating between a four-cylinder (V4) operating mode and an eight-cylinder (V8) operating mode. Therefore, when switching from the V4 mode to the V8 mode, the previously deactivated cylinders can be activated and all cylinders can be ignited. Conversely, when switching from the V8 mode to the V4 mode, the selected cylinders can be deactivated. In one example, the first four cylinders in the firing order may be deactivated, while the last four cylinders in the firing order may be fired. However, during the transition between non-VDE to VDE mode, engine vibrations due to torsional vibrations may be experienced. For example, when switching from non-VDE mode to VDE mode, the engine may provide the same output with fewer cylinders fired, and therefore torque fluctuations may occur due to fewer firing events and lower firing frequencies, which may result in increased engine vibrations. Since the engine active mount is configured to absorb vibrations from the engine, this increase in engine vibrations may not typically be detected by the vehicle operator. In order to ensure that the engine active mount functions as desired, the engine active mount health may be monitored by periodically executing an engine active mount diagnostic routine. In this way, unexpected engine NVH issues may be avoided and vehicle performance may be improved.

[0059] therefore, Figure 1-Figure 4The components are such that a vehicle system includes: an engine including one or more cylinders; an electric motor device coupled to a battery; a transmission coupled to at least the engine; one or more engine active mounts configured to isolate engine vibrations from a vehicle chassis; one or more vibration sensors configured to monitor vehicle chassis vibrations; and a controller. The controller may include computer readable instructions stored on a non-transitory memory for: inducing vehicle vibrations when the engine is in an idle condition by rotating the engine without fuel using a motor while selectively deactivating one or more valves of the engine cylinders; when the vibrations are induced, during the inducing, adjusting the engine active mount to a first dampening mode for a first predetermined duration, then adjusting the engine active mount to a second enhancing mode during a second predetermined duration, and then returning the engine active mount to the first dampening mode during a third predetermined duration; monitoring an amount of vehicle chassis vibrations during the adjusting; and indicating degradation of the engine active mount based on the amount of chassis vibrations monitored in each operating mode. In one example, the one or more vibration sensors configured to monitor vehicle chassis vibrations may include one or more of: a fuel level sensor configured to monitor the level of fuel slosh in a fuel tank that provides fuel to an engine; and a vibration sensor coupled to a suspension system of the vehicle. In another example, the vehicle system may further include: an anti-lock braking system for increasing or decreasing hydraulic pressure to one or more vehicle wheel brakes; a parking brake system for providing a variable braking force on a wheel; and wherein the controller further stores instructions including: commanding the transmission to operate in a drive mode; commanding or maintaining application of wheel brakes; and commanding the parking brake system to provide full braking force. In one example, the controller may further store instructions in the non-transitory memory that, when executed, cause the controller to: indicate that one or more engine active mounts are stuck in a first suppression mode in response to vehicle vibrations monitored via one or more vibration sensors when the vibrations during each of the first, second, and third predetermined durations are less than a threshold; and indicate that the engine active mounts are stuck in a second reinforcement mode in response to vibrations monitored via one or more vibration sensors when the vibrations during each of the first, second, and third predetermined durations are above a threshold.

[0060] Go to Figure 5 , shows a high level example routine 500 for performing engine mount diagnostics. The routine may be executed by the controller based on instructions stored in the memory of the controller and in conjunction with sensors from the engine system (such as those described above). Figure 1 and Figure 4The controller may use signals received from sensors (described in the examples) to execute instructions for performing method 500 and other methods included herein. According to the methods described below, the controller may use engine actuators of the engine system to adjust engine operation.

[0061] At 505, engine operating conditions may be estimated, measured, and / or inferred. These may include, for example, vehicle speed, vehicle position, etc.; various engine conditions, such as engine state, engine load, engine speed, A / F ratio (air-fuel ratio), etc.; various fuel system conditions, such as fuel level, fuel type, fuel temperature, etc.; various evaporative emission system conditions, such as fuel vapor canister load, fuel tank pressure, etc.; and various environmental conditions, such as ambient temperature, humidity, barometric pressure, etc.

[0062] At 510, it may be determined whether conditions are met for performing an engine active mount test. For example, the conditions met may include an engine start condition. The conditions met for engine active mount diagnosis may further include an indication that the vehicle is in an idle mode, in which the engine is running but the vehicle is not in motion (i.e., at rest). Further, the conditions met for engine active mount diagnosis may include a predetermined time period that has passed since a prior engine active mount diagnosis was performed. In some examples, the predetermined time period may include 30 days, or less than 30 days. In other examples, the predetermined time period may include greater than 30 days but less than 60 days. In a further example, the predetermined time period may include greater than 60 days. Such examples are intended to be illustrative and not intended to be limiting.

[0063] Further, satisfying the conditions for an active engine mount diagnostic may additionally or alternatively include an indication of a remote start event. For example, a vehicle operator may initiate an active engine mount diagnostic via a key fob (e.g., Figure 1 A remote start event is initiated by a remote control key 194, which can transmit a wireless signal (e.g., Figure 1 The wireless signal 195) is sent to the remote engine start receiver (eg Figure 1 A remote engine start receiver 192) is provided to initiate engine activation so that the engine begins to burn air and fuel.

[0064] In some examples, conditions satisfied for an active engine mount diagnostic may additionally or alternatively include an indication that the vehicle is unoccupied. Figure 1 The controller 12 can interpret the data from the seat load unit (e.g. Figure 1 Seat load cells 189), door sensing technology (e.g. Figure 1 Door sensing technology 190) and / or vehicle-mounted camera(s) (e.g. Figure 1In some examples, method 500 may include disabling or suspending an engine active mount diagnostic if the vehicle is indicated as occupied. Additionally, if it is indicated that the vehicle is occupied during the diagnostic process, the diagnostic routine may be suspended or paused and may be resumed when the vehicle is not occupied. Further, it will be appreciated that in some examples, an engine active mount diagnostic may be performed even if the vehicle is indicated as occupied.

[0065] If conditions for active mount testing are not indicated to be met, method 500 may proceed to 515 where current vehicle operating conditions are maintained and the engine active mount diagnostic routine is not performed. Method 500 may then end.

[0066] If the conditions for performing an engine active mount diagnostic are indicated, method 500 may then proceed to 520 where the vehicle is commanded to "drive" with the wheel brakes activated. More specifically, method 500 may include commanding the transmission to a drive operating mode, or if already in drive mode, maintaining the transmission in drive mode. Additionally, at 520, method 500 may include commanding the transmission to a drive mode of operation, such as via an anti-lock braking system (e.g., Figure 1 The controller may be configured to command depression of a brake pedal. When the vehicle transmission is configured in a drive mode and the brake pedal is depressed or the brakes are actuated, the vehicle frame (e.g., Figure 1 The vehicle frame 105) can be reinforced and mechanically coupled to the engine (e.g. Figure 1 In some examples, method 500 may further include a vehicle controller communicating with (e.g., sending a signal to) an electronic parking brake system to engage the electronic parking brake (e.g., Figure 1 152). Engaging the electronic parking brake can be used to further mechanically couple the vehicle frame to the engine.

[0067] At 525, vehicle vibration is induced in either a non-combustion mode (step 526) or a degraded combustion mode (step 528). At 526, the non-combustion mode includes spinning the engine without being supplied with fuel and operating the engine periodically in a VDE and non-VDE mode, while at 528, the degraded combustion mode includes cutting off fuel to preselected engine cylinders to provoke a misfire condition. The decision to induce vehicle vibration via the non-combustion mode or the degraded combustion mode may be predetermined by a vehicle controller, such as may be set by a vehicle manufacturer. In another example, method 500 may include inducing vehicle vibration via the non-combustion mode immediately followed by inducing vehicle vibration via the degraded combustion mode, or vice versa.

[0068] In another example, the controller may be further configured to determine whether the vehicle is operating in an electric-only mode (e.g., a plug-in hybrid electric vehicle) or in a gasoline mode. If the vehicle is operating in an electric-only mode, the vehicle vibration may be induced by a non-combustion mode (i.e., by spinning the engine without fuel and periodically operating the engine in VDE and non-VDE modes).

[0069] Alternatively, if the vehicle is operating in gasoline mode, the method can preview the trip route and if there is sufficient opportunity for the vehicle to operate in downhill deceleration fuel cut-off (DFSO) mode, vehicle vibration can be induced via the non-combustion mode. Otherwise, vehicle vibration can be induced via the degraded combustion mode. The non-combustion mode is more suitable for inducing vehicle vibration because it can minimize the disturbance to the air-fuel ratio and it provides a less intrusive vehicle vibration inducing strategy for the on-board control system. Further, the vibration patterns from these two modes can then be combined and analyzed by the vehicle controller.

[0070] In one example, by rotating the engine without being supplied with fuel and operating the engine periodically in VDE and non-VDE modes, initiating the vehicle via a non-combustion mode can include operating the motor / generator using the vehicle battery power as the sole source of torque, while prohibiting the supply of fuel to all cylinders. Further, the torque from the electric motor / generator of the vehicle can be used to rotate the engine at increasing and decreasing speeds. For example, the engine can rotate at a first higher speed in a first duration and at a second lower speed in a second duration, while commanding the engine to operate periodically in VDE mode and non-VDE mode in a cyclic manner. In another example, the engine speed can be changed by operating the motor / generator to a higher / lower current value. Further, operating the engine in VDE mode and non-VDE mode can include selectively sealing and opening the intake and exhaust valves of one or more engine cylinders. The conversion between VDE mode and non-VDE mode can affect manifold pressure, engine airflow, engine torque output and engine power, which in turn can generate engine vibration.

[0071] In another example, inducing engine vibration by inducing a degraded combustion mode by cutting fuel to preselected engine cylinders to induce a misfire condition may include injecting fuel into a fuel injector (e.g., Figure 1 The system may further include a control module 60 that sends a command to a fuel injector 66 of the engine and actuates the fuel injector to cease injecting fuel to a preselected engine cylinder. In one example, the preselected engine cylinder may include a cylinder that, when fuel injection to the cylinder is terminated, causes the greatest amount of vibration to be transmitted to the vehicle frame. In other words, degraded combustion may be induced in the preselected cylinder such that engine mechanical vibrations (a result of degraded combustion when fuel injection to the preselected cylinder is terminated) are transmitted to the vehicle frame in a predictable manner. More specifically, vibrations from the engine and transmitted to the vehicle frame may correspond to degraded combustion events such that degraded combustion events may be associated with increased vibrations. In one example, an electronically controlled throttle (e.g., Figure 1 The throttle valve 197) may be adjusted to a wider angle or more open position so that more intake air may be directed to the engine for combustion. In yet another example, combustion may be initiated early in the remaining activated cylinders so that engine knock may occur, which further increases engine vibration. In another example, the controller may be configured to adjust the engine speed (RPM) during initiation to increase and decrease the engine speed in a cyclic manner over the duration of the engine active mount diagnostic. By varying the engine speed up and down in a cyclic manner over the duration of the engine active mount test diagnostic, vehicle vibration may be increased. In yet another example, the compressor may be periodically enabled and disabled (e.g., Figure 1 A / C compressor 198) and A / C system (e.g. Figure 1A / C system 199). For example, during the duration of the engine active mount diagnostic routine, the A / C compressor can be enabled for a first predetermined duration and then disabled for a second predetermined duration, for example. By cycling the A / C compressor between on and off conditions, vehicle vibration can be increased.

[0072] Once vehicle vibration is induced, the method proceeds to 530 where the engine active mount is commanded to operate in a first mode (e.g., a dampening mode) and the resulting pattern of vehicle frame vibration is recorded. In one example, the vibration may be monitored via a fuel level sensor or a fuel level indicator located within the fuel tank. More specifically, the vehicle vibration may be monitored based on fuel sloshing in the fuel tank, where the fuel sloshing may be determined via the fuel level sensor or the fuel level indicator. In another example, the vehicle vibration may be monitored as a vibration amplitude within a specific frequency range as monitored via an active suspension sensor coupled to the vehicle suspension system.

[0073] Operating the active engine mount in the first suppression mode is expected to suppress vehicle vibrations such that little or no vibration amplitude exceeding a threshold value may be recorded. For example, the vibration threshold value may be a predetermined number set by the vehicle manufacturer. In another example, the vehicle controller may remain aware of and update the vibration threshold value when the active engine mount functions as intended.

[0074] At 535, it may be determined whether the first predetermined duration has elapsed. If the first predetermined duration has not elapsed, the method 500 may return to 530 where the engine active mount may continue to operate in the first mode and continue to record the resulting vibration pattern in the first operating mode until the first predetermined duration has elapsed. If the first predetermined duration has elapsed, the method may proceed to 540.

[0075] The engine active mount is commanded to operate in a second operating mode (i.e., enhanced mode) and the resulting pattern of vehicle frame vibrations is recorded at 540. In enhanced mode, vehicle vibrations may be expected to be significant or substantially undamped, such that vehicle vibrations recorded via the fuel level indicator and / or active suspension sensors may have a vibration amplitude above a threshold vibration amplitude.

[0076] Commanding the engine to be actively mounted to the second mode at 540 may include commanding the engine to be actively mounted to the second mode for a second predetermined duration. In some examples, the second predetermined duration may be different from the duration of the first predetermined duration. In another example, the second predetermined duration may be the same as the first predetermined duration.

[0077] At 545, it may be determined whether the second predetermined duration has elapsed. If the second predetermined duration has not elapsed, the method 500 may return to 540, where the engine active mount may remain in the second mode and the resulting pattern of vehicle frame vibration may continue to be recorded until the second predetermined duration has elapsed. If the second predetermined duration has elapsed, the method may proceed to 550.

[0078] At 550, method 500 may include commanding the engine active mount to operate in the first suppression mode. Thus, when the engine active mount is configured in the first mode, the resulting pattern of vehicle frame vibration may be recorded again via the vehicle controller. The first operating mode may be returned to within a third predetermined time period. In some examples, the third predetermined duration may be the same or substantially the same as the first predetermined duration and / or the second predetermined duration. In another example, the third predetermined duration may not be the same duration as the first predetermined duration or the second predetermined duration.

[0079] At 555, method 500 may include indicating whether the third predetermined duration has elapsed. If at 555 the third predetermined duration has not elapsed, method 500 may return to 550 and may include continuing to maintain the engine active mount in the first mode and may further include continuing to record the resulting pattern of vehicle frame vibration. Otherwise, the method may proceed to 560 where the third predetermined duration may be determined based on the vehicle frame vibration. Figure 6 The table depicted in is used to determine the condition of the active engine mount, which will be further described below.

[0080] As an example, based on the vibration patterns recorded during the first, second, and third durations, the controller may be configured to detect whether the vibration pattern exceeds a threshold in a selected engine active mount operating mode. For example, the vibration thresholds for each selected operating mode may be pre-set by the vehicle manufacturer and updated into the vehicle memory, and during the engine active mount diagnostic routine, the controller may compare the values ​​between the recorded vibrations to the vibration thresholds. If the vibration pattern falls within the threshold, then it may be inferred that the engine active mount is functioning as desired. However, if the vibration is not within the threshold, then it may be inferred that the engine active mount is not functioning as desired. In one example, Figure 6 The table depicted in may consist of three potential results of an engine active mount diagnostic, which may include an indication that the engine active mount is functioning as desired or not functioning as desired. As an example, indicating that the engine active mount is not functioning as desired may further include indicating that the engine active mount is stuck in the first inhibit mode or the second enhance mode.

[0081] At 565, based on Figure 6Based on the diagnostic results of the test, it can be determined whether the engine active mount is functioning as expected. In response to the indication that the engine active mount is functioning as expected, method 500 can proceed to 575 and can include updating vehicle operating parameters. Updating the vehicle operating parameters at 575 can include storing the results of the test diagnostic at the controller.

[0082] Alternatively, at 565, if the engine active mount is not functioning as desired, method 500 may proceed to 570 where it is indicated that the engine active mount is not functioning as desired. For example, at 570, method 500 may include indicating that the engine active mount is stuck in the first inhibited mode, or that the engine active mount is stuck in the second enhanced mode. The method may further include updating vehicle operating parameters. For example, updating vehicle operating parameters at 570 may include storing the results of the test diagnostic at the controller. More specifically, the vehicle operating parameters may be updated based on (from Figure 6 The updating of the vehicle operating parameters may further include setting a flag at the controller, or setting a diagnostic trouble code (DTC). Further, updating the vehicle operating parameters may include illuminating a malfunction indicator light (MIL), thereby alerting the vehicle operator (if present) that the vehicle needs to be serviced. In one example, updating the vehicle operating parameters may include limiting the maximum engine speed in response to the indication that the engine active mount is stuck in the second enhanced mode.

[0083] Now go to Figure 6 , Table 600 shows potential results of the engine active mount test diagnostic routine. In one example, Figure 6 The table can be used as Figure 5600 may be performed as part of a routine of , such as at 560. In some examples, table 600 may include a lookup table and may be stored at a vehicle controller. Table 600 may be indexed based on potential results (AC) and their corresponding diagnostic results, where result A corresponds to an engine active mount functioning as desired, potential result B corresponds to an active mount being stuck in a first mode (e.g., a dampened mode), and result C corresponds to an active mount being stuck in a second mode (e.g., an enhanced mode). Recorded patterns of vehicle vibrations during a first predetermined duration 630 in which the engine active mount is configured as a first mode, recorded patterns of vehicle vibrations during a second predetermined duration 640 in which the engine active mount is configured as a second mode, and recorded patterns of vehicle vibrations during a third predetermined duration 650 in which the engine active mount is configured as a first mode may be compared to results AC to diagnose the condition of the engine active mount. In one example, the magnitude of vehicle frame vibrations may be indicated via a fuel level indicator and / or an active suspension sensor, and the magnitude of the vibrations may be compared to a threshold vibration level at the end of each predetermined duration. If the magnitude of the vehicle frame vibration exceeds the threshold, a "yes" answer is recorded, and if the magnitude of the vehicle frame vibration does not exceed the threshold, a "no" answer is recorded.

[0084] In one example, if the vibration amplitude recorded by the controller during a first predetermined duration when the engine active mount is operating in the first suppression mode is less than a threshold (“No” in column 630), and the vibration amplitude recorded during a second predetermined duration when the engine active mount is operating in the second enhancement mode is above the threshold (“Yes” in column 640), and is below the threshold during a third predetermined duration when the engine active mount is operating in the first suppression mode (“No” in column 650), the controller may output an “A” as a diagnostic result associated with the engine active mount functioning as desired.

[0085] In another example, if the vibration amplitude recorded by the controller during a first predetermined duration when the engine active mount is operating in the first suppression mode is less than a threshold (“No” in column 630), and the vibration amplitude recorded during a second predetermined duration when the engine active mount is operating in the second enhanced mode is higher than the threshold (“No” in column 640), and the vibration amplitude recorded during a third predetermined duration when the engine active mount is operating in the first suppression mode is lower than the threshold (“No” in column 650), the controller may output “B” as a diagnostic result associated with the engine active mount being stuck in the first suppression mode.

[0086] In yet another example, if the vibration amplitude recorded by the controller during a first predetermined duration when the engine active mount is operating in the first suppression mode is less than a threshold (“Yes” in column 630), and the vibration amplitude recorded during a second predetermined duration when the engine active mount is operating in the second enhanced mode is above the threshold (“Yes” in column 640), and is below the threshold during a third predetermined duration when the engine active mount is operating in the first suppression mode (“Yes” in column 650), the controller may output “C” as a diagnostic result associated with the engine active mount being stuck in the second enhanced mode.

[0087] Reference now Figure 7 , showing an example engine active mount diagnostic. Examples include inducing vehicle vibration via a non-combustion mode (between t1 and t5) and via a degraded combustion mode (between t6 and t9). Map 700 depicts an engine active mount operating mode at curve 703, a degraded combustion mode indication at 705, an engine speed (RPM) at curve 707, a VDE mode indication at 709, and engine vibration at curve 711. Map 700 further depicts an indication of whether the engine active mount is functioning as desired at curve 740. All graphs are depicted along the x-axis over time. Time markers t1-t9 depict important time points during fuel system calibration.

[0088] Prior to the engine active mount diagnostic routine, between t0 and t1, the vehicle may be moving (plot 707), and therefore it may be determined that conditions for performing the engine active mount diagnostic routine are not met. When conditions for performing the engine active mount diagnostic are not met, fuel is maintained to the engine cylinders (not shown). Accordingly, a degraded combustion mode (plot 705) or a VDE mode (plot 709) is not indicated.

[0089] At t1, the vehicle stops, with the engine remaining running. Since the vehicle is stationary, it can be determined that the conditions for performing the engine active mount diagnostic routine are met. Further, in response to an instruction to perform the engine active mount diagnostic routine, the controller can be configured to command activation of the wheel brakes, and the brake pedal can be maintained depressed so that the braking force of the vehicle can be increased. Further, the vehicle transmission can be maintained in motion, or commanded by the controller to drive. Further, the electric parking brake can be commanded to engage. In addition, the controller can decide to induce vehicle vibration via the first non-combustion mode. As a result, fuel injection to all cylinders can be prohibited, and the controller can command the engine to rotate without being supplied with fuel. Further, the engine RPM begins to cycle between an increased RPM and a decreased RPM. For example, the engine RPM can increase to a first predetermined RPM and then decrease to a second predetermined RPM, and such a cycle can continue throughout the duration of the engine active mount diagnostic routine, as indicated by curve 707. Additionally, the controller may activate the VDE mode via the non-combustion mode in a periodic manner throughout the duration of the engine active mount diagnostic routine, as shown by plot 709 .

[0090] Between t2 and t3, with the engine active mount configured in the first suppression mode (curve 703), vehicle frame vibrations, such as patterns of vehicle frame vibrations, are recorded. As indicated, three VDE on / off patterns are indicated between times t2 and t3, however, such an example is illustrative and more than three VDE on / off patterns may occur between times t2 and t3. The time period between times t2 and t3 may be understood to include the first predetermined duration, as described above in Figure 5-Figure 6 The vehicle / engine vibration pattern (as indicated at curve 711) is indicated as being above threshold 710 during this period, and thus for a first predetermined duration (e.g., Figure 6 During the period, the answer "yes" is updated into the controller memory.

[0091] At t3, the active engine mount switches from the first mode to the second enhanced mode. Between times t3 and t4, with the active engine mount configured in the second mode, a pattern of vehicle frame vibration is recorded by the vehicle controller. As discussed above, the time period between times t3 and t4 may be understood to include a second predetermined time period. As indicated by curve 711, the vehicle / engine vibration pattern during this period is indicated as being above threshold 710, and thus for a second predetermined duration (e.g., Figure 6 During the period, the answer "yes" is updated into the controller memory.

[0092] At time t4, the engine active mount switches from the second mode back to the first mode. Between time t4 and t5, with the engine active mount configured in the second mode, a pattern of vehicle frame vibration is recorded by the vehicle controller. Similar to the above, three VDE on / off patterns are indicated between time t4 and t5. As discussed above, the time period between time t4 and t5 can be understood to include a third predetermined time period. The vehicle / engine vibration pattern during this period, as indicated by curve 711, is indicated as being above threshold 710, and thus for a third predetermined duration (e.g., Figure 6 During column 650 of FIG. 11 , the answer “yes” is updated into the controller memory.

[0093] At t5, the engine active mount diagnostics for vehicle vibrations induced via non-combustion modes are completed. The controller may now query a lookup table to determine if the engine active mount is functioning as expected. In one example, the lookup table may include Figure 6 . The controller may retrieve the "answer" stored in the memory during the first, second, and third predetermined time periods. In the depicted example, since "yes" is indicated for all predetermined time periods, a result C may be provided by the controller. As a result, the controller may determine that the engine active mount is not functioning as desired, and specifically, the engine active mount is stuck in the second enhanced mode. In response to the engine active mount being stuck in the enhanced mode, an error flag may be set. In one example, an error flag counter may be updated simultaneously, and once the number of error flags exceeds a threshold, an indication may be provided to the vehicle operator to service or repair the engine active mount. In one example, a diagnostic trouble code (DTC) may be indicated. Alternatively, a malfunction indicator light (MIL) may be illuminated.

[0094] Alternatively, the controller may combine vibration pattern data of vehicle vibrations induced via non-combustion mode and degraded combustion mode. Thus, at t6, the VDE mode indication is disabled (curve 709), and the degraded combustion mode is enabled (curve 705). Further, the fuel supply to the preselected engine cylinder is cut off. More specifically, a command may be sent from the controller to a fuel injector configured to deliver fuel to the preselected cylinder, thereby commanding the fuel injector to stop delivering fuel to the preselected cylinder. Similar to inducing vibrations via the non-combustion mode, as shown at curve 707, the engine RPM begins to cycle between increased RPM and reduced RPM during the degraded combustion mode. Further, the spark to the engine cylinders not including the preselected cylinders may be advanced to increase vehicle vibrations. In addition, the engine throttle may be commanded to a more open position so that a greater intake air flow may be provided to the engine, which may further increase vehicle vibrations. In addition, the A / C compressor may be cycled on and off during the duration of the engine active mount test diagnostic to generate more RPM turbulence.

[0095] Thus, between times t6 and t7, with the engine active mount configured in the first suppression mode (curve 703), vehicle frame vibrations, such as vehicle frame vibration patterns, are recorded. As indicated, three degraded combustion events are indicated between times t6 and t7. The time period between times t6 and t7 may be understood to include the first predetermined time period. As indicated by curve 711, the vehicle / engine vibration pattern during this period is indicated as being above threshold 710, and thus is recorded for a first predetermined duration (e.g., Figure 6 During the period, the answer "yes" is updated into the controller memory.

[0096] At t7, the active engine mount switches from the first mode to the second enhanced mode (curve 703). Between times t7 and t8, with the active engine mount configured in the second mode, a pattern of vehicle frame vibration is recorded by the vehicle controller. As discussed above, the time period between times t7 and t8 can be understood to include a second predetermined time period. As indicated by curve 711, the vehicle / engine vibration pattern during this period is indicated as being above threshold 710, and thus is recorded for a second predetermined duration (e.g., Figure 6 During the period, the answer "yes" is updated into the controller memory.

[0097] At time t8, the engine active mount switches from the second mode back to the first mode (curve 703). Between time t8 and t9, with the engine active mount configured in the second mode, a pattern of vehicle frame vibration is recorded by the vehicle controller. Similar to the above, three degraded combustion modes / events are indicated between time t8 and t9. As discussed above, the time period between time t8 and t9 can be understood to include a third predetermined time period. As shown by curve 711, the vehicle / engine vibration pattern during this period is indicated as being above threshold 710, and thus for a third predetermined duration (e.g., Figure 6 During column 650 of FIG. 11 , the answer “yes” is updated into the controller memory.

[0098] At t9, the engine active mount diagnostics in which vehicle vibrations are induced via degradation mode are completed. The controller can now query the lookup table to determine whether the engine active mount is functioning as expected. In one example, the lookup table may include Figure 6 . The controller may retrieve the "answer" stored in the memory during the first, second, and third predetermined periods of the degraded combustion mode. In another example, the controller may also retrieve the "answer" previously stored during the engine active mount diagnostic via the non-combustion mode (i.e., the vibration pattern recorded during time t1-t5). In the depicted example, the engine active mount diagnostic routine is performed via the non-combustion mode and the degraded combustion mode. In addition, since "yes" is indicated for all predetermined durations (t1-t5 for the non-combustion mode and t6-t9 for the degraded combustion mode), a result C is provided. As a result, the controller may determine that the engine active mount is not functioning as expected, and specifically, the engine active mount is stuck in the second enhanced mode. In response to the engine active mount being stuck in the enhanced mode, an error flag may be set. In one example, an error flag counter may be updated simultaneously, and once the number of error flags exceeds a threshold, an indication may be provided to the vehicle operator to service or repair the engine active mount. In one example, a diagnostic trouble code (DTC) may be indicated. Alternatively, a malfunction indicator light (MIL) may be illuminated.

[0099] Alternatively, the controller may compare the results gathered from running the engine active mount diagnostic via the non-combustion mode and the degraded combustion mode, and if the "answers" provided are not similar between the two modes, a third diagnostic routine may be executed to ensure the accuracy of the diagnostic results.

[0100] In this manner, engine active mount diagnostics may be performed with improved accuracy. In some examples, testing may be performed on an autonomously driven vehicle, such that a diagnosis may be made as to whether the engine active mount is functioning as desired even in situations in which a vehicle operator or other occupants may not be present. However, such examples are not intended to be limiting, and engine active mount test diagnostics may additionally or alternatively be performed on vehicles that are not configured for autonomous driving, such as conventional gasoline (or other fuel blend) vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and the like.

[0101] The technical effect is to recognize that for a vehicle with an actively controllable engine mount, engine vibrations can be easily induced under stationary conditions, such as engine idle conditions, by rotating the engine without being supplied with fuel and periodically activating the VDE mode or cutting off the fuel supply to preselected engine cylinders. In the case of inducing engine vibrations, vehicle chassis vibrations can be monitored in cases where the induced vibrations are expected to be suppressed and in cases where the induced vibrations are expected not to be suppressed. By monitoring whether the induced vibrations are suppressed while controlling the engine active mount to both a suppression mode and an enhancement mode, it can be determined whether the engine active mount is functioning as expected, whether it is stuck in the suppression mode, or whether it is stuck in the enhancement mode. By periodically determining whether the engine active mount is functioning as expected, any NVH issues can be quickly detected and promptly addressed.

[0102] An example method for a vehicle includes: in response to a request to monitor an active engine mount, using torque from an electric motor to rotate an engine driving the vehicle without fuel while selectively deactivating engine valves and / or cutting off fuel supply to engine cylinders while adjusting the active engine mount; and indicating degradation of the active engine mount based on an amount of vehicle chassis vibration during rotation. In the previous example, additionally or optionally, the amount is an amplitude within a specified frequency range. In any or all of the previous examples, additionally or optionally, using motor torque to rotate the engine without fuel while selectively deactivating valves of engine cylinders further includes: commanding a fuel injector configured to provide fuel to stop injecting fuel into the engine cylinders; rotating the engine at increasing speeds and decreasing speeds in a cyclic manner; periodically sealing and opening all intake valves and exhaust valves associated with (one or more) deactivated cylinders. In any or all of the previous examples, additionally or optionally, selectively cutting off fuel injection to the cylinder further includes: commanding a fuel injector configured to provide fuel to a preselected engine cylinder to stop injecting fuel to the preselected engine cylinder; and increasing vehicle chassis vibration by one or more of the advance sparks in one or more remaining cylinders, the remaining cylinders including cylinders that do not include the preselected cylinder, providing sparks to one or more remaining cylinders via one or more spark plugs; increasing and decreasing the speed of the engine in a cyclic manner; turning on a compressor for a vehicle air conditioning system for a duration and turning off the compressor for another duration in a cyclic manner; and commanding an intake throttle configured to enable air to be introduced into the engine to a predetermined angle. In any or all of the previous examples, additionally or optionally, adjusting the engine active mount further includes: adjusting the engine active mount to a first suppression mode for a first predetermined duration, then adjusting the engine active mount to a second enhancement mode for a second predetermined duration, and then returning to adjusting the engine active mount to the first suppression mode for a third predetermined duration; and wherein adjusting the engine active mount includes adjusting the engine active mount to the first suppression mode at idle conditions to absorb unwanted chassis vibrations, and adjusting the engine active mount to the second enhancement mode at higher engine speeds and loads to reduce unwanted engine motions.In any or all of the previous examples, additionally or optionally, indicating degradation of the engine active mount further includes: determining whether vibrations from the vehicle chassis monitored via one or more vibration sensors are associated with an increase in vibration during adjustment of the engine active mount to the first mode and the second mode; in response to the monitored vibrations not being associated with increased vibrations in the first mode, but wherein the monitored vibrations are associated with increased vibrations in the second mode, indicating that the engine active mount is functioning as desired; in response to the monitored vibrations not being associated with increased vibrations in the first mode, and wherein the monitored vibrations are not associated with increased vibrations in the second mode, indicating that the engine active mount is stuck in the first mode; in response to the monitored vibrations being associated with increased vibrations in the first mode, and wherein the monitored vibrations are also associated with increased vibrations in the second mode, indicating that the engine active mount is stuck in the second mode. In any or all of the previous examples, additionally or optionally, determining whether vibrations from the vehicle chassis monitored via one or more vibration sensors are associated with increased vibrations further includes: in response to the vibrations monitored being above a threshold vibration level within a time threshold of the increased vibrations, indicating that the vibrations monitored via the one or more vibration sensors are associated with increased vibrations. In any or all of the previous examples, additionally or optionally, the amount of vehicle chassis vibrations is measured based on fuel sloshing in a fuel tank that provides fuel to an engine, wherein the level of fuel sloshing is indicated via a fuel level sensor. In any or all of the previous examples, additionally or optionally, the amount of vehicle chassis vibrations is measured based on signals received by one or more vibration sensors coupled to a vehicle suspension system. In any or all of the previous examples, the method additionally or optionally further includes: commanding or maintaining application of one or more wheel brakes of one or more wheels of the vehicle, commanding or maintaining engagement of an electronic parking brake of one or more wheels of the vehicle, and maintaining a vehicle transmission in a drive operating mode configurable to at least a parking mode, a drive mode, and a reverse mode. In any or all of the previous examples, additionally or optionally, the adjusting includes adjusting when the engine is at idle. In any or all of the previous examples, additionally or optionally, the vehicle is a hybrid vehicle.

[0103] Another example method includes: at least partially propelling an autonomous vehicle via an engine; isolating engine vibrations from a chassis of the vehicle via one or more engine active mounts, the one or more engine active mounts being controllable to at least one suppression mode and one enhancement mode; and initiating an engine active mount diagnostic test based on predetermined conditions, the predetermined conditions including one or more of an engine idle condition, a duration of time elapsed since a previous engine active mount diagnostic, a fuel level in a fuel tank between ten percent and ninety percent of the capacity of the fuel tank, an indication of a remote engine start event; and / or an indication that the vehicle is unoccupied; during the engine mount diagnostic test, by using Torque from a motor causes the engine to rotate without being supplied with fuel while selectively deactivating valves of engine cylinders or actively inducing vehicle vibrations by cutting off fuel supply to preselected engine cylinders to induce degraded combustion in preselected engine cylinders; during an engine mount diagnostic test, adjust one or more engine active mounts to a suppression mode, followed by an enhancement mode, and then back to the suppression mode while actively inducing vehicle vibrations; and based on multiple fuel slosh events in the fuel tank caused by selectively deactivating valves and degraded combustion while the engine is rotating, indicate whether the engine active mount is functioning as expected, is stuck in the suppression mode, or is stuck in the enhancement mode. In the previous example, the method additionally or alternatively further includes: when the engine mount is adjusted to the suppression and enhancement modes, monitoring vehicle chassis vibrations via one or more vibration sensors, and wherein the monitored vibrations include vibrations caused by engine vibrations induced by deactivating and reactivating one or more valves of the engine cylinders. Additionally or alternatively in any or all of the previous examples, indicating that the active engine mount is functioning as desired includes monitoring vibrations to be suppressed below a vibration threshold during each period of the suppression mode and monitoring vibrations to be above a vibration threshold during each period of the enhancement mode.

[0104] Another example vehicle system includes: an engine including one or more cylinders; an electric motor device coupled to a battery; a transmission coupled to at least the engine; one or more engine active mounts configured to isolate engine vibrations from a vehicle chassis; one or more vibration sensors configured to monitor vehicle chassis vibrations; and a controller having computer-readable instructions stored on a non-transitory memory for: inducing vehicle vibrations when the engine is in an idle condition by rotating the engine without fuel using a motor while selectively deactivating one or more valves of the engine cylinders; when the vibrations are induced, during the induction, adjusting the engine active mount to a first suppression mode for a first predetermined duration, then adjusting the engine active mount to a second enhancement mode during a second predetermined duration, and then returning the engine active mount to the first suppression mode during a third predetermined duration; monitoring an amount of vehicle chassis vibration during the adjustment; and indicating degradation of the engine active mount based on the amount of chassis vibration monitored in each operating mode. In the previous examples, additionally or optionally, the one or more vibration sensors configured to monitor vehicle chassis vibrations further include one or more of the following: a fuel level sensor configured to monitor the level of fuel sloshing in a fuel tank that provides fuel to the engine; and a vibration sensor coupled to a suspension system of the vehicle. In any or all of the previous examples, the vehicle system additionally or optionally further includes: an anti-lock braking system for increasing or decreasing hydraulic pressure to one or more vehicle wheel brakes; a parking brake system for providing a variable braking force on the wheels; and wherein the controller further stores instructions including: commanding the transmission to operate in a drive mode; commanding or maintaining application of wheel brakes; and commanding the parking brake system to provide full braking force. In any or all of the previous examples, additionally or optionally, the controller further stores instructions in the non-transitory memory, which when executed cause the controller to: indicate that one or more engine active mounts are stuck in the first suppression mode in response to vehicle vibrations monitored via one or more vibration sensors when the vibrations during each of the first, second, and third predetermined durations are less than a threshold; and indicate that the engine active mounts are stuck in the second reinforcement mode in response to vibrations monitored via one or more vibration sensors when the vibrations during each of the first, second, and third predetermined durations are above the threshold.

[0105] Note that the exemplary control and estimation routines included here can be used with various engine and / or vehicle system configurations. The control methods and routines disclosed here can be stored as executable instructions in a non-transitory memory and can be executed by a control system including a controller in combination with various sensors, actuators and other engine hardware. The specific routines described here can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc. In this way, the various actions, operations and / or functions shown can be executed in the order shown, in parallel, or omitted in some cases. Similarly, the processing order is not necessary to achieve the features and advantages of the example embodiments described here, 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. Further, the described actions, operations and / or functions can graphically represent the code in the non-transitory memory of a computer-readable storage medium to be programmed into the engine control system, wherein the electronic controller executes instructions in a system including various engine hardware components to complete the described actions.

[0106] It should be understood that the configurations and routines disclosed herein are exemplary in nature, and these specific embodiments are not to be considered limiting, as many variations are possible. For example, the above techniques may be applied to other engine types such as V-6, I-4, I-6, V-12, opposed 4 cylinders, etc. 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.

[0107] The following claims particularly point out certain combinations and subcombinations regarded as novel and non-obvious. These claims may refer to "an" element or "a first" element or the equivalent thereof. These 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 present claims or by presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, are also deemed to be included within the subject matter of the present disclosure.

Claims

1. A method for a vehicle, comprising: In response to monitoring a request for an active engine mount, using torque from an electric motor to spin an engine driving the vehicle without being fueled while selectively deactivating engine valves and / or cutting off fuel to engine cylinders while adjusting the active engine mount; as well as indicating degradation of the engine active mount based on an amount of vehicle chassis vibration during the rotation, Wherein adjusting the active engine mount further comprises: adjusting the active engine mount to a first dampened mode for a first predetermined duration, subsequently adjusting the active engine mount to a second enhanced mode for a second predetermined duration, and then returning the active engine mount adjustment to the first dampened mode for a third predetermined duration; as well as The adjusting the active engine mount includes adjusting the active engine mount to the first suppression mode to absorb undesirable chassis vibrations at idle conditions, and adjusting the active engine mount to the second reinforcement mode to reduce undesirable engine motions at higher engine speeds and loads. 2 . The method of claim 1 , wherein the amount of vehicle chassis vibration is an amplitude within a specified frequency range.

3. The method of claim 1 , wherein using motor torque to spin the engine without fuel while selectively deactivating the engine valves of engine cylinders further comprises: commanding a fuel injector configured to provide fuel to cease injecting fuel into a cylinder of the engine; rotating the engine at increasing speeds and decreasing speeds in a cyclic manner; Intake valves and exhaust valves associated with one or more deactivated cylinders are periodically sealed and opened.

4. The method of claim 1 , wherein selectively cutting off fuel injection to the engine cylinders further comprises: commanding a fuel injector configured to provide fuel to a preselected engine cylinder to cease injecting fuel into the preselected engine cylinder; as well as increasing vehicle chassis vibrations by one or more of advancing sparks in one or more of the remaining cylinders, The remaining cylinders include cylinders excluding the preselected cylinder, and spark is provided to the one or more remaining cylinders via one or more spark plugs; increasing and decreasing the speed of the engine in a cyclic manner; Turning on a compressor for a vehicle air conditioning system for a certain duration and turning off the compressor for another certain duration in a cyclic manner; and An intake throttle configured to enable air to be introduced into the engine is commanded to a predetermined angle.

5. The method of claim 1 , wherein indicating degradation of the engine active mount further comprises: determining whether vibrations from the vehicle chassis monitored via one or more vibration sensors are associated with an increase in vibrations during said adjusting of the active engine mount to the first dampened mode and the second enhanced mode; In response to the monitored vibration not being correlated with increased vibration in the first dampened mode, but wherein the monitored vibration is correlated with increased vibration in the second enhanced mode, indicating that the active engine mount is functioning as desired; indicating that the active engine mount is stuck in the first suppression mode in response to the monitored vibration not being correlated with the increased vibration in the first suppression mode, and wherein the monitored vibration not being correlated with the increased vibration in the second enhancement mode; In response to the monitored vibration being correlated with increased vibration in the first dampened mode, and wherein the monitored vibration is also correlated with increased vibration in the second enhanced mode, it is indicated that the active engine mount is stuck in the second enhanced mode.

6. The method of claim 5, wherein determining whether vibrations from the vehicle chassis monitored via the one or more vibration sensors are associated with the increased vibrations further comprises: In response to the monitored vibration being above a threshold vibration level within a time threshold of the increased vibration, indicating that the vibration monitored via the one or more vibration sensors is associated with the increased vibration.

7. The method of claim 1, wherein the amount of chassis vibration of the vehicle is measured based on fuel sloshing in a fuel tank providing fuel to the engine, wherein the level of fuel sloshing is indicated via a fuel level sensor.

8. The method of claim 1, wherein the amount of vehicle chassis vibration is measured based on signals received by one or more vibration sensors coupled to a vehicle suspension system.

9. The method according to claim 1, further comprising: commanding or maintaining application of one or more wheel brakes to one or more wheels of said vehicle, commanding or maintaining engagement of an electronic parking brake of one or more wheels of the vehicle, and The vehicle transmission is maintained in the drive operating mode configurable into at least a park mode, a drive mode, and a reverse mode.

10. The method of claim 1, wherein said adjusting comprises adjusting while said engine is idling.

11. A vehicle system comprising: An engine comprising one or more cylinders; an electric motor device coupled to a battery; a transmission coupled to at least the engine; one or more active engine mounts configured to isolate engine vibrations from the vehicle chassis; one or more vibration sensors configured to monitor vehicle chassis vibrations; as well as A controller having computer readable instructions stored on a non-transitory memory for: inducing vehicle vibrations when the engine is in an idle condition by rotating the engine without being supplied with fuel using the electric motor assembly while selectively deactivating one or more valves of the one or more cylinders; When the vibration is induced, during the inducing, adjusting the active engine mount to a first dampening mode for a first predetermined duration, subsequently adjusting the active engine mount to a second enhancing mode for a second predetermined duration, and then returning the active engine mount adjustment to the first dampening mode for a third predetermined duration; monitoring an amount of vehicle chassis vibration during said adjusting; as well as Based on the amount of chassis vibration monitored in each operating mode, active engine mount degradation is indicated.

12. The system of claim 11, wherein the one or more vibration sensors configured to monitor vehicle chassis vibrations include one or more of: a fuel level sensor configured to monitor a level of fuel slosh in a fuel tank that provides fuel to the engine; and A vibration sensor is coupled to a suspension system of the vehicle.

13. The system of claim 11, further comprising: Anti-lock braking systems, which are used to increase or decrease hydraulic pressure to one or more vehicle wheel brakes; and a parking brake system for providing variable braking force on the wheels; The controller further stores instructions for: commanding the transmission to operate in a drive mode; commanding or maintaining application of said wheel brakes; and The parking brake system is commanded to provide full braking force.

14. The system of claim 11, wherein the controller further stores instructions in the non-transitory memory, the instructions when executed causing the controller to: indicating that the one or more engine active mounts are stuck in the first suppression mode in response to vehicle vibrations monitored via the one or more vibration sensors when the vibrations during each of the first, second, and third predetermined durations are less than a threshold; and When the vibration during each of the first, second, and third predetermined durations is above the threshold, the active engine mount is indicated to be stuck in the second enhanced mode in response to vibration monitored via the one or more vibration sensors.

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