Method and system for performing a diagnosis on a variable geometry compressor for an internal combustion engine

Abstract

Engine operating procedures, comprehensive: Adjusting the flow of air through a compressor and into a motor without redirecting at least some of the air flowing through the compressor from an outlet of the compressor to an inlet of the compressor, in response to a request to perform a diagnosis of the flow through the compressor and the pressure at the compressor, wherein the air flowing through the compressor is adjusted in an airflow path of the motor via a flow control device.

Description

AREA

[0001] This description relates to a method and a system for performing diagnostics on the operation of a variable geometry compressor for an internal combustion engine. The methods and systems can be particularly useful for compressors that include a device for adjusting the geometry of a compressor's flow channel. BACKGROUND AND BRIEF

[0002] A turbocharger may include a device for adjusting the airflow through the turbocharger compressor. Specifically, the turbocharger may include a wastegate or adjustable vanes that regulate the flow of exhaust gas through the turbocharger turbine, thereby increasing or decreasing the turbocharger compressor speed and adjusting the compressor flow. While adjusting the turbocharger turbine speed to control the airflow through the turbocharger compressor can be effective, the turbine speed cannot be changed instantaneously due to the inertia of the compressor fan and the turbine fan. Consequently, the airflow through the compressor may not follow a desired compressor flow pattern as precisely as desired.

[0003] One way to adjust the airflow through the compressor is to redirect some of the airflow from the compressor outlet back to the compressor inlet, thereby reducing the overall airflow through the compressor. However, redirecting airflow through a compressor requires a bypass duct outside the compressor and an actuator to adjust the flow through that duct. Furthermore, the bypass duct can alter the airflow dynamics through the compressor, potentially increasing motor noise. Additionally, the compressor bypass duct and bypass valve make it difficult to determine whether the compressor is operating correctly or if there might be a problem with the bypass duct and / or valve.Therefore, it would be desirable to provide a way to control the airflow through a compressor and to diagnose whether the airflow through the compressor is set as desired. Documents US 2013 / 0255648A1 and DE 102015121099A1 describe diagnostic routines for a turbocharger and the recirculation valve of a compressor, respectively.

[0004] The object of the present invention is to provide an engine operating method and system for improved diagnostics.

[0005] This problem is solved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims.

[0006] The inventors of the present invention have recognized the aforementioned problems and have developed a motor operating method comprising: adjusting the air flowing through a compressor and into a motor without returning air from an outlet of the compressor to an inlet of the compressor, in response to a requirement to perform a diagnosis on the flow through the compressor, wherein the air flowing through the compressor is adjusted via a flow control device in an airflow path of the motor, wherein the flow control device in the airflow path is a vane, a flow control sleeve, or a compressor housing flow control valve.

[0007] By adjusting the airflow through a compressor via a flow control device in an engine's airflow path in response to a request to perform a diagnostic check of the compressor flow, it is possible to diagnose the compressor operation without diverting at least part of the flow through a compressor bypass circuit. Furthermore, the engine can be maintained at a constant speed and load while a diagnostic check of the compressor is performed by continuing to adjust the position of a throttle valve in response to the request to perform a diagnostic check of the compressor flow. This makes it possible to diagnose both a compressor and a compressor flow control device that directly controls the airflow through the compressor.

[0008] The present description can offer several advantages. In particular, the approach can provide improved diagnostics for compressor flow control devices. Furthermore, the approach can provide a way to disrupt an airflow actuator to perform diagnostics on a compressor flow without disturbing vehicle occupants. Finally, the approach can be applied to gasoline or diesel engines that incorporate a turbocharger or a crankshaft-driven compressor.

[0009] The aforementioned advantages, as well as further advantages and features of the present description, will readily become apparent from the following detailed description, whether considered on its own or in conjunction with the accompanying drawings.

[0010] It is understood that the foregoing summary is provided to introduce, in simplified form, a selection of concepts that are further described in the detailed description. It is not intended to identify important or essential features of the claimed subject matter, the scope of which is defined solely in the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that eliminate the disadvantages mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The advantages described here become more fully apparent from reading an example of an embodiment, referred to here as the detailed description, either on its own or with reference to the drawings, in which the following applies: Fig. Figure 1 is a schematic representation of an engine that includes a turbocharger; the Fig. Figures 2A-2C show cross-sections of exemplary turbocharger compressors; Fig. 3 is a likely operating procedure for performing a diagnosis on a compressor; and the Fig. Figures 4A-4C show an exemplary procedure for performing a diagnosis on a variable flow compressor. DETAILED DESCRIPTION

[0012] The present invention relates to providing a diagnostic operation for an engine that includes a variable-flow compressor. The compressor can be contained in a turbocharger or a compressor driven by the crankshaft. An exemplary turbocharged engine is shown in Fig. Figure 1 shows three different turbochargers and their compressors. Fig. 2A-2C is shown. The airflow through the compressors can be adjusted via a compressor flow control device located in the compressor housing. The compressor can be adjusted via the [unclear text - likely a control device or feature] in [unclear text - likely a control device or feature]. Fig. 3. The process shown is based on the procedure from the Fig. 4A-4C a diagnosis will be performed.

[0013] With reference to Fig. 1 is an internal combustion engine 10 comprising a plurality of cylinders, one of which is in Fig. As shown in Figure 1, the engine is controlled by an electronic engine control unit 12. The engine 10 consists of a cylinder head 35 and block 33, which include a combustion chamber 30 and cylinder walls 32. A piston 36 is positioned within the cylinder and moves back and forth via a connection to the crankshaft 40. A flywheel 97 and a ring gear 99 are coupled to the crankshaft 40. A starter 96 (e.g., a low-voltage electric machine (operated at less than 30 volts)) includes a pinion shaft 98 and a pinion 95. The pinion shaft 98 can selectively drive the pinion 95 so that it engages the ring gear 99. The starter 96 can be mounted directly on the front or rear of the engine. In some examples, the starter 96 can selectively supply torque to the crankshaft 40 via a belt or chain. In one example, the starter motor 96 is in a basic state when it is not engaged with the engine crankshaft.According to the illustration, the combustion chamber 30 communicates with an intake manifold 44 and an exhaust manifold 48 via a corresponding intake valve 52 and exhaust valve 54. The intake and exhaust valves can each be operated by an intake cam 51 and an exhaust cam 53, respectively. The position of the intake cam 51 can be determined by an intake cam sensor 55. The position of the exhaust cam 53 can be determined by an exhaust cam sensor 57. The intake valve 52 can be selectively switched on and off by a valve activation device 59. The exhaust valve 54 can be selectively switched on and off by a valve activation device 58. The valve activation devices 58 and 59 can be electromechanical devices.

[0014] As shown, a fuel injection device 66 is positioned such that it injects fuel directly into the cylinder 30, a process known to those skilled in the art as direct injection. The fuel injection device 66 supplies liquid fuel proportionally to the pulse width from the controller 12. The fuel is supplied to the fuel injection device 66 by a fuel system (not shown) comprising a fuel tank, a fuel pump, and a fuel distributor (not shown). In one example, a two-stage high-pressure fuel system can be used to generate higher fuel pressures.

[0015] Furthermore, it is shown that the intake manifold 44 is connected to the turbocharger compressor 162 and the engine air intake 42. In other examples, the compressor 162 may be a supercharger. A shaft 161 mechanically couples the turbocharger turbine 164 to the turbocharger compressor 162. The optional electronic throttle 62 sets a position of the throttle valve 64 to control the airflow from the compressor 162 to the intake manifold 44. The pressure in the charge chamber 45 can be referred to as the throttle inlet pressure, since the inlet of the throttle 62 is located within the charge chamber 45. The throttle outlet is located in the intake manifold 44. In some examples, the throttle 62 and the throttle valve 64 can be positioned between the intake valve 52 and the intake manifold 44 in such a way that the throttle 62 is an intake port throttle.A compressor return valve 47 can be opened to return compressor flow from the compressor inlet to the compressor outlet. Alternatively, the compressor return valve 47 can be closed to prevent air from being recirculated around the compressor 162. The wastegate 163 can be adjusted via the control unit 12 to allow exhaust gases to selectively bypass the turbine 164 in order to control the speed of the compressor 162. The pressure at the compressor 162 can be determined via a pressure sensor 41. An air filter 43 cleans the air entering the engine air inlet 42. The throttle 62 is positioned downstream of the compressor 162 in the direction of the airflow into the engine 10.

[0016] A distributorless ignition system 88 provides a spark to the combustion chamber 30 via a spark plug 92 in response to the control unit 12. A wideband lambda (Universal Exhaust Gas Oxygen - UEGO) sensor 126 is, according to the illustration, coupled to the exhaust manifold 48 upstream of a catalytic converter 70. Alternatively, the UEGO sensor 126 can be replaced by a binary lambda sensor.

[0017] In one example, catalyst 70 can contain multiple catalyst honeycomb bodies. In another example, multiple emission control devices, each containing multiple honeycomb bodies, can be used. In one example, catalyst 70 can be a three-way catalyst.

[0018] Control 12 is in Fig. 1 is represented as a conventional microcomputer, including: a microprocessor unit 102, an input / output connector 104, a read-only memory 106 (e.g., non-volatile memory), a random access memory 108, a keep-alive memory 110, and a conventional data bus.According to the diagram, in addition to the signals discussed previously, the control unit 12 receives various signals from sensors coupled to the engine 10, including: an engine coolant temperature (ECT) from a temperature sensor 112 coupled to a cooling sleeve 114; a position sensor 134 coupled to an accelerator pedal 130 to detect a force exerted by a human foot 132; a position sensor 154 coupled to a brake pedal 150 to detect a force exerted by a human foot 132; a measurement of the engine manifold pressure (MAP) from the pressure sensor 122 coupled to the intake manifold 44; an engine position sensor from a Hall effect sensor 118 that detects the position of the crankshaft 40; and a measurement of the mass of air entering the engine from a sensor 120. and a measurement of the throttle position from a sensor 68.Atmospheric pressure can also be detected for processing by the controller 12 (sensor not shown). In a preferred aspect of the present description, the motor position sensor 118 generates a predetermined number of evenly spaced pulses with each revolution of the crankshaft, from which the motor speed (RPM) can be determined.

[0019] During operation, each cylinder in the engine 10 typically goes through a four-stroke cycle: The cycle includes the intake stroke, the compression stroke, the power stroke, and the exhaust stroke. During the intake stroke, the exhaust valve 54 generally closes and the intake valve 52 opens. Air is drawn into the combustion chamber 30 via the intake manifold 44, and the piston 36 moves toward the bottom of the cylinder to increase the volume within the combustion chamber 30. The position at which the piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g., when the combustion chamber 30 has reached its maximum volume) is typically referred to by those skilled in the art as bottom dead center (BDC).

[0020] During the compression stroke, the intake valve 52 and the exhaust valve 54 are closed. The piston 36 moves towards the cylinder head to compress the air within the combustion chamber 30. The point at which the piston 36 is closest to the cylinder head at the end of its stroke (e.g., when the combustion chamber 30 has its smallest volume) is typically referred to by those skilled in the art as top dead center (TDC). In a process subsequently referred to as injection, fuel is introduced into the combustion chamber. In a process subsequently referred to as ignition, the injected fuel is ignited by known ignition means, such as the spark plug 92, resulting in combustion.

[0021] During the power stroke, the expanding gases push the piston 36 back to bottom dead center (BDC). The crankshaft 40 converts piston movements into torque of the crankshaft. Finally, during the exhaust stroke, the exhaust valve 54 opens to release the burnt air-fuel mixture to the exhaust manifold 48, and the piston returns to top dead center (TDC). It should be noted that the above is merely an example and that the timing of the opening and / or closing of the intake and exhaust valves can vary, for example, to provide positive or negative valve overlap, late closing of the intake valve, or various other examples.

[0022] Fig. Figure 2A is a cross-section of a first exemplary turbocharger, which includes a variable geometry compressor. The turbocharger includes a turbine 164, a compressor 162, and a shaft 161, as shown in Figure 2A. Fig. Figure 1 shows exhaust gas from the engine 10 flowing into an exhaust duct 212 and around a turbine wheel 210. The exhaust gases pass through the turbine wheel and expand, causing the turbine wheel 210 to rotate, which in turn rotates the shaft 161 and the compressor wheel 208. The engine exhaust gases exit the exhaust duct outlet 214 in the direction indicated by arrow 215. A turbine housing 211 surrounds and holds the turbine wheel 210.

[0023] Filtered air enters the compressor 162 via a compressor inlet 216 and flows in the direction of arrow 202. The compressor wheel 208 rotates and compresses the air entering the inlet 216. The compressor wheel 208 directs the compressed air to a compressor nozzle 209. The compressor nozzle 209 is a variable nozzle, which varies its cross-sectional area to modify the flow through the nozzle, and has an annular shape. The nozzle 209 regulates the airflow from the compressor wheel 208 to the charge air outlet 203. The cross-sectional area of ​​the nozzle 209 can be increased or decreased by adjusting the position of a flow control sleeve 207, which also has an annular shape. The flow control sleeve 207 can move in the direction indicated by arrow 201. The position of the flow control sleeve 207 can be adjusted via an actuator 206, which can be coupled to the flow control sleeve via a linkage 218.The compressor flow control actuator 206 can be hydraulically, electrically, or pneumatically operated. Moving the flow control sleeve 207 to the left with respect to arrow 201 closes the nozzle 209 and reduces the airflow through the compressor. Moving the flow control sleeve 207 to the right with respect to arrow 201 opens the nozzle 209 and increases the airflow through the compressor. Thus, the flow control sleeve 207 can directly control (e.g., increase or decrease) the airflow from the compressor inlet 216 to the compressor charge air outlet 203 without recirculating air around the compressor wheel 208. The flow control sleeve 207 and the nozzle 209 are located in the compressor housing 213.

[0024] It will now be on Fig. Reference is made to Figure 2B, which shows a cross-section of a second exemplary turbocharger incorporating a variable geometry compressor. The turbocharger includes a turbine 164, a compressor 162, and a shaft 161, as shown in Figure 2B. Fig. Figure 1 shows exhaust gas from the engine 10 flowing into an exhaust duct 212 and around a turbine wheel 210. The exhaust gases pass through the turbine wheel and expand, causing the turbine wheel 210 to rotate, which in turn rotates the shaft 161 and the compressor wheel 208. The engine exhaust gases exit the exhaust duct outlet 214 in the direction indicated by arrow 215. A turbine housing 211 surrounds and holds the turbine wheel 210.

[0025] Filtered air enters the compressor 162 via a compressor inlet 216 and flows in the direction of arrow 202. Air enters the compressor housing 213 via a plurality of inlet channels 221, 222, and 223 within the compressor housing 213. The compressor housing flow control valve 220 adjusts the opening area of ​​the inlet channels 221, 222, and 223 to control the airflow into the compressor 162. The position of the housing flow control valve 220 is adjustable via a compressor housing actuator 225, which can be hydraulically, electrically, or pneumatically operated. The compressor housing flow control valve 220 can be a rotary valve, a slide valve, or another known type of flow control valve. The compressor wheel 208 rotates and compresses the air entering the inlet 216. The compressor wheel 208 directs compressed air to the compressor nozzle 209, and compressed air exits the compressor 162 at the compressor charge air outlet 203.Thus, the compressor housing flow control valve 220 can control (e.g., increase or decrease) the air flowing into the compressor inlet 216 to control the airflow through the compressor 162 and the compressor charge air outlet 203, without recirculating air around the compressor wheel 208. The compressor housing flow control valve 220 and the inlet channels 221, 222, and 223 are located in the compressor housing 213.

[0026] It will now be on Fig. Reference is made to Figure 2C, which shows a cross-section of a third exemplary turbocharger incorporating a variable geometry compressor. The turbocharger includes a turbine 164, a compressor 162, and a shaft 161, as shown in Figure 2C. Fig. Figure 1 shows exhaust gas from the engine 10 flowing into an exhaust channel 212 and around a turbine wheel 210. The exhaust gases pass through the turbine wheel and expand, causing the turbine wheel 210 to rotate, which in turn rotates the shaft 161 and the compressor wheel 208. The engine exhaust gases exit the exhaust channel outlet 214 in the direction indicated by arrow 215. A turbine housing 211 surrounds and supports the turbine wheel 210.

[0027] Filtered air enters the compressor 162 via a compressor inlet 216 and flows in the direction of arrow 202. The compressor wheel 208 rotates and compresses the air entering the inlet 216. The compressor wheel 208 directs the compressed air to a compressor nozzle 209. The compressor nozzle 209 is a variable nozzle, which varies its cross-sectional area to modify the flow through the nozzle, and has an annular shape. The nozzle 209 regulates the airflow from the compressor wheel 208 to the charge air outlet 203. The nozzle contains a plurality of circumferentially spaced vanes 250. Each vane 250 is fixed by a pin (not shown) that is rotatable. Each vane 250 can rotate, allowing the corresponding vane to rotate around the pin, thereby setting the vane angle. Each pin includes a rod (not shown) that engages a ring (not shown) which can rotate about its axis.The blades 250 rotate when the ring is turned by an actuator 255. The angles of the blades change as they rotate to vary the cross-sectional area of ​​the nozzle 209. The compressor flow control actuator 255 can be hydraulically, electrically, or pneumatically operated. Thus, the flow control blades 250 can directly control (e.g., increase or decrease) the air flowing from the compressor inlet 216 to the compressor charge air outlet 203 without recirculating air around the compressor wheel 208. The blades 250 and the nozzle 209 are located in the compressor housing 213.

[0028] Thus, the system enables the Fig. 1-2C, a system comprising: an engine; a turbocharger coupled to the engine, comprising a compressor, a turbine, and an airflow control device in a compressor housing; a controller comprising instructions stored in non-volatile memory for adjusting the airflow control device in response to a request to perform diagnostics on an airflow through the compressor without recirculating air through the compressor. The system includes: wherein the airflow control device is a vane, and further comprising additional instructions for adjusting the airflow control device in further response to a change in the engine airflow greater than a threshold.The system comprises: wherein the airflow control device is an airflow control sleeve, and further comprising additional instructions for adjusting the airflow control device in response to a change in engine speed greater than a threshold. The system comprises: wherein the airflow control device is a compressor casing flow control valve, and further comprising additional instructions for adjusting the airflow control device in response to the engine speed being greater than a first threshold and the engine speed being less than a second threshold. The system further comprises a throttle located in an air duct of the engine at a point downstream of the compressor. The system further comprises instructions for adjusting the position of the throttle in response to a request to perform diagnostics on an airflow through the compressor.

[0029] It will now be on Fig. Reference is made to section 3, which describes a likely operating procedure for performing a diagnosis on a compressor. The procedure is based on... Fig. 3 can be derived from the procedure Fig. 4A-4C in conjunction with the system consisting of the Fig. 1-2C will be provided. The procedure is performed for a motor that operates at constant speed and load throughout the procedure.

[0030] The first diagram from the top in Fig. Figure 3 is a diagram showing the diagnostic state of the compressor flow as a function of time. The vertical axis represents the diagnostic state of the compressor, and a compressor diagnostic is performed when curve 302 is at a higher level near the arrow on the vertical axis. No compressor diagnostic is performed when curve 302 is near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right.

[0031] The second diagram from the top in Fig. Figure 3 is a diagram showing the flow requirement of a compressor flow control device as a function of time. The flow requirement of the compressor flow control device regulates the flow through the compressor. The compressor flow control device can be a sleeve, blades, or a compressor flow control valve, as shown in the following. Fig. Figures 2A-2C are shown. The flow requirement of the compressor flow control device is indicated by curve 304 and increases in the direction of the arrow on the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0032] The third diagram from the top in Fig. Figure 3 is a diagram of the actual flow through the compressor as a function of time. The actual compressor flow increases in the direction of the arrow on the vertical axis and is represented by curve 306. The horizontal line 308 represents a threshold compressor flow, which is compared to the actual flow through the compressor between times T1 and T2. The horizontal line 310 represents a threshold compressor flow, which is compared to the actual flow through the compressor between times T3 and T4. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0033] The fourth diagram from the top in Fig. Figure 3 is a diagram of the exhaust gas flow through a turbine that drives the compressor. The exhaust gas flow rate is represented by the curve 312. The exhaust gas flow rate increases in the direction of the arrow on the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0034] The fifth diagram from the top in Fig. Figure 3 is a diagram showing the position of the engine intake throttle (e.g., 62 from Fig. 1) as a function of time. The position of the intake throttle is represented by curve 314. The degree of opening of the intake throttle increases in the direction of the arrow on the vertical axis. The intake throttle is fully closed when curve 314 is at the level of the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0035] The sixth diagram from the top in Fig. Figure 3 is a diagram showing the compressor's wear condition over time. The vertical axis represents compressor wear, and the compressor is considered worn when the wear level is at a higher level near the arrow on the vertical axis. The compressor is not worn when the wear level is at a lower level near the horizontal axis. Figure 316 depicts the compressor's wear conditions. The horizontal axis represents time, and time increases from the left to the right side of the figure.

[0036] At time T0, the compressor is not worn and is not undergoing any compressor diagnostics. The compressor flow control device is set to a lower stage, and the actual flow through the compressor is at a low stage. The exhaust gas flow rate through the turbine driving the compressor is at a lower-medium stage. The throttle is positioned at a medium stage.

[0037] At time T1, compressor flow diagnostics are activated, as indicated by the compressor flow diagnostic state transitioning from a lower to a higher stage. The compressor flow control device is instructed to increase the flow through the compressor, as indicated by the increased demand for the compressor flow control device. The actual airflow through the compressor increases shortly after time T1 to a value greater than the threshold value of 308. The exhaust gas flow through the turbine remains constant, and the throttle inlet position is reduced to partially close the throttle, so that the airflow to the engine remains constant despite the increasing compressor flow. There is no indication that the compressor wear state indicates that the airflow through the compressor is at an expected level.

[0038] At time T2, the compressor flow diagnostics are deactivated, as indicated by the compressor flow diagnostic state transitioning from a higher to a lower stage. The compressor flow control device is instructed to reduce the flow through the compressor, as indicated by the decrease in the required action of the compressor flow control device. The actual airflow through the compressor drops to a value below the threshold value of 308 shortly after time T2. The exhaust gas flow through the turbine remains constant, and the throttle inlet position is increased to partially open the throttle, so that the airflow to the engine remains constant despite the decrease in compressor flow. There is no indication that the compressor wear state indicates that the airflow through the compressor is at an expected level.Thus, the compressor flow diagnostics for an initial throughput through the compressor are complete, and the compressor behaves as desired.

[0039] At time T3, a second compressor flow diagnostic is activated, indicated by the compressor flow diagnostic state transitioning from a lower stage to a higher stage, with the higher stage being greater than the higher stage at time T1. The compressor flow control device is instructed to increase the flow through the compressor, indicated by the increased demand for the compressor flow control device. The actual airflow through the compressor increases shortly after time T3 to a value less than the threshold value of 310. The exhaust gas flow through the turbine remains constant, and the throttle inlet position is reduced to partially close the throttle, so that the airflow to the engine remains constant despite the increasing compressor flow rate.Initially, it cannot be determined that the compressor's wear condition indicates that the airflow through the compressor is at an expected level. However, as time approaches T2, it becomes apparent that the compressor's wear condition indicates compressor wear.

[0040] At time T4, the compressor flow diagnostics are deactivated, as indicated by the compressor flow diagnostic state transitioning from a higher to a lower stage. The compressor flow control device is instructed to reduce the flow through the compressor, as indicated by the decrease in the required compressor flow control. The actual airflow through the compressor drops to a value below the threshold of 310 shortly after time T4. The exhaust gas flow through the turbine remains constant, and the throttle inlet position is increased to partially open the throttle, so that the airflow to the engine remains constant despite the decreasing compressor flow. It should also be noted that the compressor wear condition indicates that the airflow through the compressor was not at an expected level.Thus, the compressor flow diagnostics for a second flow velocity through the compressor are complete, and if the compressor is not behaving as expected, compressor wear is indicated. Measures can be taken to mitigate compressor wear when it is indicated. For example, motor speed and load can be limited below threshold values. Furthermore, the exhaust gas flow through the turbine can be limited to reduce the likelihood of further compressor wear.

[0041] It will now be referred to as Fig. Reference is made to sections 4A-4C, which present an exemplary flowchart for a procedure for performing a diagnosis on a compressor of an engine. The procedure from the Fig. 4A-4C can be integrated into the system from the Fig. 1-2C be included and interact with it. Furthermore, at least parts of the process can be derived from the Fig. 4A-4C may be included as executable instructions stored in non-volatile memory, while other parts of the procedure may be carried out via a controller that converts operating states of devices and actuators in the physical world.

[0042] In procedure 402, a procedure 400 determines vehicle operating conditions. Vehicle operating conditions may include, but are not limited to, vehicle speed, engine airflow, ambient temperature, manifold absolute pressure (MAP), engine load, and driver-demand torque. Procedure 400 may determine the above conditions via in Fig. 1. Determine the sensors and actuators shown. Procedure 400 transitions to 404.

[0043] In procedure 404, procedure 400 assesses whether the engine airflow or air throughput into the engine is greater than a first threshold and less than a second threshold. The thresholds can be empirically determined in advance and stored in a memory of the control unit. If procedure 400 assesses that the engine airflow is greater than the first threshold and less than the second threshold, the answer is yes, and procedure 400 proceeds to 406. Otherwise, the answer is no, and procedure 400 proceeds to 450.

[0044] In procedure 406, procedure 400 assesses whether the engine speed is greater than a third threshold and less than a fourth threshold. These thresholds can be empirically determined in advance and stored in the controller's memory. If procedure 400 assesses that the engine speed is greater than the third threshold and less than the fourth threshold, the answer is yes, and procedure 400 proceeds to 408. Otherwise, the answer is no, and procedure 400 proceeds to 450.

[0045] In procedure 408, procedure 400 assesses whether the ambient air temperature is greater than a fifth threshold and less than a sixth threshold. These thresholds can be empirically determined in advance and stored in the controller's memory. If procedure 400 assesses that the engine airflow is greater than the fifth threshold and less than the sixth threshold, the answer is yes, and procedure 400 proceeds to 410. Otherwise, the answer is no, and procedure 400 proceeds to 450.

[0046] At step 410, procedure 400 assesses whether the engine MAP is greater than a seventh threshold and less than an eighth threshold. These thresholds can be empirically determined in advance and stored in the control unit's memory. If procedure 400 assesses that the engine MAP is greater than the seventh threshold and less than the eighth threshold, the answer is yes, and procedure 400 proceeds to step 412. Otherwise, the answer is no, and procedure 400 proceeds to step 450.

[0047] At 412, procedure 400 assesses whether the engine load is greater than a ninth threshold and less than a tenth threshold. The thresholds can be empirically determined in advance and stored in a memory of the control unit. If procedure 400 assesses that the engine load is greater than the ninth threshold and less than the tenth threshold, the answer is yes, and procedure 400 proceeds to 414. Otherwise, the answer is no, and procedure 400 proceeds to 450.

[0048] In example 414, procedure 400 has satisfied a set of preconditions for performing a diagnostic check on an engine compressor operation. Procedure 400 then limits the driver-demand torque (e.g., torque requested by a human driver via an accelerator pedal) to less than a threshold. For example, procedure 400 may limit the driver-demand torque to less than 50% of the available driver-demand torque. However, in some examples, if the accelerator pedal position exceeds a threshold, procedure 400 may increase the driver-demand torque to match the accelerator pedal position and suspend the engine compressor diagnostic check. Procedure 400 then proceeds to 416 after the driver-demand torque has been limited.

[0049] In 416, method 400 adjusts the flow through the compressor by means of a flow control device. The flow control device can be located inside the compressor and it adjusts the flow through the compressor without recirculating air from the compressor outlet to the compressor inlet. However, in some examples, some of the air from the compressor inlet to the compressor outlet may be recirculated while the diagnostic procedure is being performed. The flow control device can be the devices from the Fig. 2A-2C and other known compressor flow-adjusting devices are included. The compressor flow is adjusted without altering the exhaust gas flow through the turbine or the rotational speed of the compressor wheel. The compressor flow rate can be set to a variety of different flow rates by adjusting a position or state of the compressor flow-adjusting device. Method 400 transitions to 418 after an adjustment of the air flowing through the compressor has been ordered.

[0050] In procedure 400, shown in 418, an engine throttle position is set in response to the air compressor flow diagnostic request and the increase in the commanded airflow through the compressor. The throttle position is set to substantially maintain the engine airflow (for example, varying by less than 15%). If the compressor flow rate is increased, for example, the throttle may be partially closed to maintain the engine airflow. The throttle position may be set in response to the pressure ratio at the throttle to substantially maintain the engine airflow, so that engine speed and torque are substantially maintained (for example, varying by less than 15%). Procedure 400 then proceeds to 420.

[0051] At step 420, procedure 400 assesses whether the airflow through the compressor is greater than an eleventh threshold and less than a twelfth threshold. The airflow through the compressor can be determined using an airflow sensor or a pressure sensor. If procedure 400 assesses that the airflow through the compressor is greater than an eleventh threshold and less than a twelfth threshold, the answer is yes, and procedure 400 proceeds to step 422. Otherwise, the answer is no, and procedure 400 proceeds to step 430.

[0052] In procedure 422, procedure 400 assesses whether a desired number of airflows through the compressor has been determined under current conditions. For example, it may be desirable to adjust the airflow through the compressor to five different rates for the current engine operating conditions. If the desired number of compressor airflows has been determined, the answer is yes, and procedure 400 proceeds to 424. Otherwise, the answer is no, and procedure 400 proceeds to 440.

[0053] At 424, procedure 400 adjusts the airflow through the compressor and the motor throttle position to baseline conditions or values ​​for the current engine speed and load. The airflow through the compressor and the throttle position are reset to baseline positions to improve engine efficiency and performance. Procedure 400 then terminates.

[0054] At step 440, procedure 400 sets the compressor flow rate by adjusting the position of the compressor flow control device. In one example, the airflow through the compressor can be increased in incremental steps from a small value to a larger value. Procedure 400 returns to step 416 after the compressor airflow has been set.

[0055] At 430, procedure 400 outputs a compressor wear indicator. This output can be a displayed value or an indicator light to inform vehicle occupants. Procedure 400 then transitions to 432.

[0056] At 432, procedure 400 stops engine operation to reduce the likelihood of further compressor wear. In one example, engine speed and load can be limited. In other examples, exhaust gas flow through the turbine can be limited to limit the compressor speed. The exhaust gas flow through the turbine can be limited by adjusting the position of a wastegate or by adjusting blade positions or other devices to change the turbine geometry. Procedure 400 terminates.

[0057] Thus, procedure 400 in 404-414 ensures that engine operating conditions are substantially constant (e.g., varying by less than 15%) to allow entry into steady-state compressor flow settings. Such conditions can be useful when the compressor flow rate is set in small quantities that may not be audible or perceptible to vehicle occupants.

[0058] At step 450, procedure 400 assesses whether the airflow through the compressor is greater than a thirteenth threshold. The airflow through the compressor can be determined using an airflow sensor or a pressure sensor. If procedure 400 assesses that the airflow through the compressor is greater than the thirteenth threshold, the answer is yes, and procedure 400 proceeds to step 452. Otherwise, the answer is no, and procedure 400 proceeds to step 470.

[0059] In procedure 452, procedure 400 assesses whether the engine speed is greater than a fourteenth threshold. If procedure 400 assesses that the engine speed is greater than the fourteenth threshold, the answer is yes, and procedure 400 proceeds to 454. Otherwise, the answer is no, and procedure 400 proceeds to 470.

[0060] Thus, procedure 400, in conjunction with 450 and 452, restricts the entry conditions for engine compressor diagnostics to more significant transient engine conditions, so that intentional disturbances of the compressor throughput are less noticeable to vehicle occupants.

[0061] At 470, procedure 400 adjusts the airflow through the compressor and the motor throttle position to baseline values ​​for the current engine speed and load. The airflow through the compressor and the throttle position are reset to baseline positions to improve engine efficiency and performance. Procedure 400 then terminates.

[0062] In device 454, method 400 adjusts the flow through the compressor via a flow control device in addition to adjusting the compressor flow rate due to transient engine operating conditions. For example, if the transient engine operating conditions require a compressor air flow rate of X grams per second, then the compressor air flow rate is commanded to an air flow rate of X+Y grams per second. The air flow control device can be located inside the compressor and it adjusts the flow through the compressor without recirculating air from the compressor outlet to the compressor inlet. The flow control device can be the devices from the Fig. 2A-2C and other known compressor flow-adjusting devices are included. The compressor airflow is adjusted, while the exhaust gas flow through the turbine can be adjusted. Method 400 transitions to 456 after an adjustment of the air flowing through the compressor has been ordered.

[0063] In procedure 400, shown in 456, the throttle position is set in response to the compressor flow diagnostic request and the increase in the commanded airflow through the compressor. The throttle position is set to provide the requested engine torque, while the airflow through the compressor is instructed to provide more airflow than is used to provide the requested engine torque under stoichiometric combustion conditions. For example, if the compressor flow rate is increased by X+Y grams / second, the throttle may be partially closed to maintain the engine airflow at X grams / second (e.g., engine airflow to provide the desired engine torque). The throttle position may be set in response to the pressure ratio at the throttle. Procedure 400 then proceeds to 458.

[0064] At 458, procedure 400 assesses whether the airflow through the compressor is greater than a fifteenth threshold and less than a sixteenth threshold. The airflow through the compressor can be determined using an airflow sensor or a pressure sensor. If procedure 400 assesses that the airflow through the compressor is greater than a fifteenth threshold and less than a sixteenth threshold, the answer is yes, and procedure 400 proceeds to 460. Otherwise, the answer is no, and procedure 400 proceeds to 480.

[0065] At 460, procedure 400 resets the airflow through the compressor and the motor throttle position to baseline states or values ​​for the current engine speed and load after the transition of engine operating conditions. The airflow through the compressor and the throttle position are reset to baseline positions to improve engine efficiency and performance. Procedure 400 then terminates.

[0066] At 480, procedure 400 outputs a compressor wear indicator. This output can be a displayed value or an indicator light to inform vehicle occupants. Procedure 400 then transitions to 482.

[0067] At 482, procedure 400 stops engine operation to reduce the likelihood of further compressor wear. In one example, engine speed and load can be limited. In other examples, exhaust gas flow through the turbine can be limited to restrict compressor speed. The exhaust gas flow through the turbine can be limited by adjusting the position of a wastegate or by adjusting blade positions or other devices to modify the turbine geometry. Procedure 400 terminates.

[0068] In this way, the airflow through a compressor can be specifically disrupted and diagnosed during steady-state conditions or transient engine operating conditions, so that vehicle occupants do not notice the ongoing diagnosis.

[0069] Thus, the procedure is derived from the Fig. 4A-4C provides an engine operating procedure, comprehensive: Adjusting the flow of air through a compressor and into an engine, without redirecting at least a portion of the air flowing through the compressor from a compressor outlet to a compressor inlet, in response to a request to diagnose the flow through the compressor and the pressure at the compressor, wherein the air flowing through the compressor is adjusted via a flow control device in an airflow path of the engine. The method comprises: wherein adjusting the air flowing through the compressor involves stepwise increasing the airflow through the compressor in response to the request to diagnose the flow through the compressor, and wherein the pressure at the compressor is a pressure change from a compressor inlet to a compressor outlet.The procedure further includes adjusting the air flowing through the compressor in response to the fact that the engine airflow is greater than a first threshold and less than a second threshold.

[0070] In some examples, the method further includes comparing the flow rate of air flowing through the compressor with a threshold value and indicating compressor wear in response to the flow rate being less than the threshold value. The method includes: where the flow rate through the compressor is based on an output from a mass airflow sensor. The method includes: where the flow rate through the compressor is based on a pressure in an engine air intake duct. The method includes: where the device in the airflow path is a vane. The method includes: where the device in the airflow path is a flow control sleeve. The method includes: where the device in the airflow path is a compressor casing flow control valve.

[0071] The procedure from the Fig.4A-4C further provides an engine operating procedure comprising: adjusting the air flowing through a compressor and into an engine via a flow control device in an airflow path of an engine air inlet in response to a request to perform diagnostics on the flow through the compressor; and adjusting a throttle position in response to the adjustment of the air flowing through the compressor to maintain a substantially constant engine airflow. The procedure includes: wherein adjusting the air flowing through the compressor involves increasing the airflow through the compressor, wherein adjusting the throttle position involves at least partially closing the throttle, and wherein adjusting the air flowing through the compressor involves not recirculating air from a compressor outlet to a compressor inlet.In some examples, however, the airflow can be adjusted by recirculating air from the compressor outlet to the compressor inlet.

[0072] In some examples, the method further includes comparing the air flowing through the compressor, after adjusting the air flow through the compressor in response to a request to perform a diagnostic check of the compressor flow, with a threshold value. The method further includes indicating compressor wear in response to the air flowing through the compressor being less than the threshold value after adjusting the air flow through the compressor. The method includes: where the compressor is contained within a turbocharger.

[0073] It should be noted that the exemplary control and estimation routines contained here can be used with various engine and / or vehicle system configurations.

[0074] The control methods and routines disclosed herein can be stored as executable instructions in non-volatile memory and executed by the control system, which includes the controller in combination with the various sensors, actuators, and other motor hardware. The specific routines described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. Accordingly, various illustrated operations, steps, and / or functions can be performed in the illustrated sequence or in parallel, or in some cases, omitted. Likewise, the processing sequence is not strictly necessary to achieve the features and benefits of the embodiments described herein, but is provided for the sake of clarity and description.One or more of the described processes, steps, and / or functions can be repeated depending on the specific strategy employed. Furthermore, the described processes, steps, and / or functions can graphically represent code that is to be programmed in non-volatile memory of the computer-readable storage medium within the engine control system. The described processes are carried out by executing the instructions in a system comprising the various engine hardware components in combination with the electronic control unit.

[0075] This concludes the description. Upon reading it by a person skilled in the art, many changes and modifications become apparent, without deviating from the spirit and scope of the description. For example, the present description could be advantageously used for I3, I4, I5, V6, V8, V10, and V12 engines operating on natural gas, gasoline, diesel, or alternative fuel configurations.

Claims

[1] Engine operating procedures, comprising: Adjusting the flow of air through a compressor and into a motor without redirecting at least some of the air flowing through the compressor from an outlet of the compressor to an inlet of the compressor, in response to a request to perform a diagnosis of the flow through the compressor and the pressure at the compressor, wherein the air flowing through the compressor is adjusted in an airflow path of the motor via a flow control device. [2] Method according to claim 1, wherein adjusting the air flowing through the compressor involves stepwise increasing the airflow through the compressor in response to the requirement to perform a diagnosis on the flow through the compressor, and wherein the pressure at the compressor is a pressure change from an inlet of the compressor to an outlet of the compressor. [3] Method according to claim 1, further comprising adjusting the air flowing through the compressor in further response to the fact that the motor airflow is greater than a first threshold and less than a second threshold. [4] Method according to claim 1, further comprising comparing a throughput of air flowing through the compressor with a threshold value and indicating compressor wear in response to the fact that the throughput is less than the threshold value. [5] Method according to claim 4, wherein the throughput through the compressor is based on an output from a mass airflow sensor. [6] Method according to claim 4, wherein the throughput through the compressor is based on a pressure in an engine air intake duct. [7] Method according to claim 1, wherein the device in the airflow path is a blade. [8] Method according to claim 1, wherein the device in the airflow path is a flow control sleeve. [9] Method according to claim 1, wherein the device in the airflow path is a compressor housing flow control valve. [10] System, encompassing: an engine; a turbocharger coupled to the engine, comprising a compressor, a turbine and an airflow control device in a compressor housing; a control system that includes instructions stored in non-volatile memory for adjusting the airflow control device in response to a request to perform a diagnosis on an airflow through the compressor without recirculating air through the compressor. [11] System according to claim 10, wherein the airflow control device is a vane, and further comprising additional instructions for adjusting the airflow control device in further response to a change in the engine airflow that is greater than a threshold value. [12] System according to claim 10, wherein the airflow control device is an airflow control sleeve, and further comprising additional instructions for adjusting the airflow control device in response to a change in engine speed that is greater than a threshold value. [13] System according to claim 10, wherein the airflow control device is a compressor casing flow control valve, and further comprising additional instructions for adjusting the airflow control device in response to the fact that the engine speed is greater than a first threshold and the engine speed is less than a second threshold. [14] System according to claim 10, further comprising a throttle located in an air duct of the engine at a point downstream of the compressor. [15] System according to claim 14, further comprising instructions for setting a position of the throttle in response to the request to perform a diagnosis on the airflow through the compressor.

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