Method and system for pump control

Abstract

Method for a supercharged power engine, comprising the following: Combining intake manifold airflow and / or intake manifold pressure with throttle valve inlet pressure into an aggregated intake pressure, and Adjusting an operating parameter in response to compressor pumps, whereby the pumping is determined based on the aggregated suction pressure and further based on suction temperature.

Description

Field of the invention

[0001] This description relates generally to methods and systems for controlling a vehicle engine to improve the detection and mitigation of compressor surge. State of the art / brief description

[0002] A turbocharger can be used to increase the power output of an internal combustion engine. The turbocharger accomplishes this by pressurizing intake air, thereby increasing the mass of air delivered to each of the engine's combustion chambers during the intake stroke. The increased air mass supports the combustion of a correspondingly larger amount of fuel delivered to each combustion chamber, providing increased power relative to naturally aspirated engines of similar displacement. In a motor vehicle, a turbocharged engine can provide increased fuel economy by maintaining a higher power-to-weight ratio than a naturally aspirated engine of similar output and by recovering internal energy from the exhaust gas to drive the turbocharger's compressor. Additionally, the use of a turbocharger allows a given power output to be achieved with a smaller or downsized engine.The combination of derating the engine, turbocharging, and delivering fuel via direct injection has therefore resulted in significant improvements in the part-load fuel economy of gasoline-fueled engines while maintaining or exceeding the power output of conventional naturally aspirated engines.

[0003] However, a turbocharger compressor is prone to surge. Surging occurs when the pressure ratio in the turbocharger compressor (namely, the ratio of discharge pressure to intake pressure) is too high compared to the airflow through the turbocharger compressor. Turbocharger compressor surge (TCS) is a dynamic instability mode that can generate airflow and self-excited, large-amplitude pressure oscillations in the air mass flow. Surging can lead to unwanted noise and noise, vibration, and harshness (NVH) problems. In addition, surge can limit the engine's torque capacity and impact the durability of the compressor's materials. Surging can, for example, induce undesirable stresses in the turbocharger and intake, including excessive torsional loading on the turbocharger shaft.Continued or excessive TCS can therefore reduce the longevity of the turbocharger and / or the machine with which it is coupled.

[0004] Various attempts have been made to enable early detection of surge so that it can be remedied in a timely manner. An exemplary approach for implementing surge detection is shown by Shu et al. in US 8 516 815 B2 and DE 10 2010 007 444 A1. There, transient surge triggered by transient torque conditions such as tip-outs, etc., is detected by processing (e.g., low-pass filtering) a manifold pressure estimated by a pressure sensor and / or the mass air flow estimated by a manifold airflow sensor over a range of frequencies. The processed output is compared to a threshold value to enable faster and more precise detection of surge, thereby improving surge mitigation.

[0005] Further prior art is disclosed in the documents DE 10 2014 105 181 A1, which relates to a method for avoiding over-dilution of an intake air charge of an engine, and EP 1 323 927 A1, which relates to a method for detecting compressor surges of a turbocharger.

[0006] However, the inventors of the present invention have recognized potential problems with such an approach. As one example, the signal processing fails to account for the thermodynamics of the pressure waves. The thermodynamics and chemical conditions of the engine can therefore affect the pressure and airflow outputs of the sensor, distorting the surge detection results. In particular, parameters such as absolute pressure, temperature, humidity, and charge composition (including the amount of recirculated exhaust gas or EGR) can affect the processed output, leading to erroneous surge detection (e.g., failure to detect surge or false detection of surge). On the other hand, it can be difficult and computationally expensive to calibrate each engine to compensate for the varying thermodynamic conditions.A surge line on a compressor map can therefore be calibrated more conservatively to ensure safe and robust operation across a fleet of vehicles. Furthermore, based on operating conditions, there may be engine actuators that correlate with the surge frequency. Actuators such as an intake throttle or EGR valve can excite the pressure response in the same frequency band as that of surge, making it difficult to distinguish their effect on engine pressure from that of surge. Furthermore, the detection of surge in response to pressure estimation may change with changes in driver demand due to non-minimum phase (NMP) behavior. The NMP behavior of pressure may be erroneously flagged as surge during selected transients, such as tip-in.

[0007] In one example, some of the problems described above may be at least partially addressed by a method for detecting surge in a boosted engine, comprising: combining manifold pressure and / or manifold flow with throttle valve inlet pressure into an aggregate intake pressure and adjusting an engine operating parameter in response to compressor surge, wherein surge is determined based on the aggregate intake pressure and further based on intake temperature. Thus, compressor surge may be identified earlier and more reliably, thereby improving surge mitigation.

[0008] As one example, an aggregate intake pressure may be calculated by combining at least two pressure and / or flow measurements before and after the intake throttle for the purpose of detecting surge. Specifically, the aggregate pressure is then filtered with a bandpass frequency corresponding to the surge frequency range. Alternatively, filtered (e.g., bandpass filtered or lowpass filtered) values ​​of manifold pressure (MAP) or manifold airflow (MAF) may be combined with throttle inlet pressure (TIP) into the aggregate intake pressure. The filter cutoff (or passband) is adjusted based on engine operating conditions, such as temperature, to account for the variation of a surge frequency band in which surge oscillations can be expected.Surge intensity is then calculated from the aggregated intake pressure using conventional wave theory, taking into account the manifold temperature (at the time of the MAP measurement) and / or boost temperature (at the time of the TIP measurement). An amplitude of peak pressure oscillations, for example, is determined. If the surge intensity is higher than a surge threshold, it is further determined whether any actuator events have occurred that impacted the TIP response in the same frequency band as that of the surge. If yes, the effect of the actuators on the TIP response is separated from that of the surge, and the intensity is re-evaluated relative to the threshold. A surge mitigating action, such as temporarily opening a compressor recirculation valve, is then triggered based on the actuator-corrected surge intensity being greater than the surge threshold.

[0009] The technical effect of correlating the intensity of intake manifold pressure waves with one or more available engine parameters is to enable more precise detection of surge and faster surge mitigation. Specifically, by comparing a filtered output from a throttle valve inlet pressure sensor with a baseline adjusted based on the thermodynamic and chemical conditions of the engine, the NMP effect on a throttle valve inlet pressure signal is reduced, allowing more precise detection of the onset of surge. Noise contributions from actuators that produce a TIP response in the surge frequency band can also be reduced. Furthermore, a more aggressive surge line can be calibrated on a compressor map.

[0010] It is understood that the above 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 key or essential features of the claimed subject matter, the scope of which is defined solely by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address any disadvantages noted above or in any part of this disclosure. Short description of the drawings Fig. 1 shows an example supercharged machine system configuration. Fig. Figure 2 shows a high-level flow diagram of an example routine for detecting pumps while reducing the noise contribution from actuators and NMP effects on pressure. Fig. Figure 3 shows an example block diagram of a pumping intensity algorithm used to detect pumping. Fig. Figure 4 shows an example processing of wave intensity during a pumping event. Fig. Figure 5 shows an example of NMP behavior in TIP. Fig. Figure 6 shows an example of adjusted pump intensity after considering the NMP behavior of the TIP during tip-in and tip-out events. Detailed description

[0011] The following description relates to systems and methods for controlling pumps in a supercharged machine system, such as the Fig. 1. A control device may be configured to execute a control routine, such as the exemplary routine of Fig. 2, to combine a plurality of pressures upstream and downstream of an intake throttle valve to determine an aggregate pressure and to determine pumping intensity based on the aggregate pressure following correction for NMP pressure behavior and noise contribution from the engine actuators. A block diagram of the pumping intensity determination and assessment is shown in Fig. 3. Example processing of the TIP and MAP for detecting pumping is shown with reference to the Fig. 4 to 6. This improves the detection of pumping, allowing for earlier reduction.

[0012] Fig. 1 schematically shows aspects of an exemplary engine system 100 having an engine 10. In the illustrated embodiment, the engine 10 is a boosted engine coupled to a turbocharger 13 including a compressor 114 driven by a turbine 116. Specifically, fresh air is introduced along an intake passage 42 into the engine 10 via the air cleaner 112 and flows to the compressor 114. The compressor may be any suitable intake air compressor, such as an electric motor-driven or driveshaft-driven supercharger compressor. However, in the engine system 10, the compressor is a turbocharger compressor mechanically coupled to the turbine 116 via a shaft 19, with the turbine 116 being driven by expanding engine exhaust. In one embodiment, the turbocharger may be a twin-scroll device.In another embodiment, the turbocharger may be a variable geometry turbocharger (VGT), wherein the turbine geometry is actively varied as a function of engine operating conditions.

[0013] As in Fig. 1, the compressor 114 is coupled to the throttle valve 20 through the charge air cooler (CAC) 18 (also referred to here as the intercooler). The throttle valve 20 is coupled to the engine intake manifold 22. From the compressor, the compressed air flow flows through the charge air cooler 18 and the throttle valve to the intake manifold. The charge air cooler can be, for example, an air-to-air or water-to-air heat exchanger. Fig. 1, the pressure of the air charge within the intake manifold 22 is sensed by a manifold air pressure (MAP) sensor 124. In some embodiments, the intake manifold may further include a manifold air flow (MAF) sensor for estimating the airflow charge within the intake manifold.

[0014] One or more sensors may be coupled to an inlet of a compressor 114. For example, a temperature sensor 45 may be coupled to the inlet to estimate a compressor inlet temperature. As another example, compressor inlet temperature sensor 57 may be coupled to the inlet to estimate a pressure of the air charge entering the compressor. Still other sensors may include, for example, air-fuel ratio sensors, humidity sensors, flow sensors, etc. In other examples, one or more compressor inlet conditions (such as humidity, pressure, temperature, etc.) may be inferred based on engine operating conditions.

[0015] Still other sensors may be coupled to the air intake system upstream or downstream of the compressor and upstream and downstream of the intake throttle valve 20. For example, a throttle valve inlet pressure sensor 58 may be provided downstream of the compressor 114 and upstream of the throttle 20 to provide an estimate of the boost pressure delivered to the engine.

[0016] During select conditions, such as during tip-out when transitioning from engine operation with boost to engine operation without boost, compressor surge may occur. This is due to reduced flow through the compressor as the throttle closes during tip-out. The reduced forward flow through the compressor can cause surge and degrade turbocharger performance. Additionally, surge can lead to NVH issues, such as undesirable noise from the engine intake system. To reduce compressor surge, at least a portion of the air charge compressed by compressor 114 may be recirculated via the compressor inlet. This allows excess boost pressure to be substantially immediately relieved and flow through the compressor to be boosted. This results in a desirable drop in pressure ratio across the compressor.The compressor recirculation system may include a recirculation passage 60 (also referred to herein as a compressor bypass) for recirculating compressed air from the compressor outlet downstream of the charge air cooler 18 to the compressor inlet. In alternative examples, the compressor recirculation system may additionally or alternatively include a recirculation passage for recirculating compressed air from the compressor outlet upstream of the charge air cooler to the compressor inlet. The compressor recirculation stream delivered to the compressor inlet from downstream of the CAC 18 may therefore be a cooler recirculation stream (e.g., at a lower temperature) than a recirculation stream delivered from upstream of the CAC 18.

[0017] The recirculation passage 60 may include a compressor recirculation valve (CRV) 62 (also called a compressor bypass valve here) for adjusting an amount of recirculation flow returned to the compressor inlet from downstream of the compressor. The recirculation valve 62, in one example, may be a single variable on / off valve. Alternatively, the CRV 62 may be a continuously variable valve, with a position of the valve constantly variable from a fully closed position to a fully open position and any position in between. In some embodiments, the CRV 62 may normally be partially open during boosted engine operation to provide some surge margin. Here, the partially open position may be a default valve position. Then, the opening of the valve may be increased in response to an indication of surge.For example, the valve may be adjusted from the partially open default position to a fully open position via an actuator receiving signals from the engine controller 12. A degree of opening of the valve during these conditions may be based on the surge cue (e.g., compressor ratio, compressor flow rate, a pressure differential across the compressor, etc.). In alternative examples, the CRV 62 may be held closed during boosted engine operation (e.g., during peak power conditions) to improve boost response and peak power. The valve may then be opened (e.g., partially or fully open) in response to a surge cue.

[0018] In addition to opening the CRV 62, or instead of opening the CRV 62, the pumping margin during a tip-out may be improved via a wastegate actuator 92. In particular, the wastegate actuator 92 may be actuated to open based on a signal from the engine controller 12 to dump at least some exhaust pressure from upstream of the turbine to a location downstream of the turbine via the wastegate 90. By reducing the exhaust pressure upstream of the turbine, the turbine speed may be reduced.

[0019] The intake manifold 22 is coupled to a series of combustion chambers 30 through a series of intake valves (not shown). The combustion chambers are further coupled to the exhaust manifold 36 via a series of exhaust valves (not shown). In the depicted embodiment, a single exhaust manifold 36 is shown. However, in other embodiments, the exhaust manifold may include a plurality of exhaust manifold sections. Configurations with multiple exhaust manifold sections may allow for the flow from different combustion chambers to be directed to different locations in the engine system.

[0020] In one embodiment, both the exhaust and intake valves may be electronically actuated or controlled. In another embodiment, both the exhaust and intake valves may be cam-actuated or controlled. Whether electronically or cam-actuated, the timing of the exhaust and intake valve opening and closing can be adjusted as needed for a desired combustion and emissions control performance.

[0021] Combustion chambers 30 can be supplied with one or more fuels, such as gasoline, alcoholic fuel blends, diesel, biodiesel, compressed natural gas, etc. Fuel can be delivered to the combustion chambers via direct injection, port injection, throttle body injection, or any combination thereof. Combustion in the combustion chambers can be initiated via spark ignition and / or compression ignition.

[0022] As in Fig. 1, exhaust gas from the one or more exhaust manifold sections is directed to the turbine 116 to drive the turbine. If reduced turbine torque is desired, a portion of the exhaust gas may instead be directed through a wastegate 90, bypassing the turbine. The combined flow from the turbine and wastegate then flows through the emissions control 170. In general, one or more emissions control devices 170 may include one or more exhaust aftertreatment catalysts configured to catalytically treat the exhaust stream and thereby reduce an amount of one or more substances in the exhaust stream. For example, an exhaust aftertreatment catalyst may be configured to X from the exhaust stream when the exhaust stream is lean, and the captured NO Xreduced when the exhaust stream is rich. In other examples, an exhaust aftertreatment catalyst may be designed to reduce NO X disproportionate or NO X selectively reduced using a reducing agent. In other examples, an exhaust aftertreatment catalyst may be configured to oxidize residual hydrocarbons and / or residual carbon monoxide in the exhaust stream. Various exhaust aftertreatment catalysts having any such functionality may be disposed in interlayers or elsewhere in the exhaust aftertreatment stages, either separately or together. In some embodiments, the exhaust aftertreatment stages may include a regenerable soot filter configured to capture and oxidize soot particulates in the exhaust stream.

[0023] All or a portion of the treated exhaust gas from emissions control 170 may be exhausted to the atmosphere via exhaust conduit 35. However, depending on operating conditions, some exhaust gas may be diverted to the engine's intake manifold to provide exhaust gas recirculation (EGR). Specifically, exhaust gas may be recirculated from the exhaust manifold to the EGR passage 50 through the EGR cooler 51 and the EGR valve 52 to the inlet of the compressor 114. The EGR valve may be opened based on a signal received from the engine controller 12 to admit a controlled amount of cooled exhaust gas to the compressor inlet for the desired combustion and emissions control performance. Thus, the engine system 10 is adapted to provide external low-pressure (LP) EGR by recirculating exhaust gas from downstream of the turbine 116 to a location upstream of the compressor 114.Rotating the compressor, in addition to the relatively long LP EGR flow path in the engine system 10, provides improved homogenization of the exhaust gases in the intake air charge. Furthermore, the arrangement of the EGR branch and mixing points provides effective cooling of the exhaust gases for increased available EGR mass and improved power. In further embodiments, the engine system may further include a high-pressure EGR flow path, with exhaust gas drawn from upstream of the turbine 116 and recirculated to the engine intake manifold downstream of the compressor 114.

[0024] The EGR cooler 51 may be coupled to an EGR passage 50 for cooling EGR delivered to the compressor. Additionally, one or more sensors may be coupled to the EGR passage 50 to provide details related to the composition and condition of the EGR. For example, a temperature sensor may be provided to provide a temperature of the EGR, a pressure sensor may be provided to determine a pressure of the EGR, a humidity sensor may be provided to determine a humidity or water content of the EGR, and an air-fuel ratio sensor 54 may be provided to estimate an air-fuel ratio of the EGR. An opening of the EGR valve may be adjusted based on engine operating conditions and EGR conditions to provide a desired amount of engine dilution.

[0025] In the depicted embodiment, the EGR passage 50 is shown as separate from the compressor return passage 60. In alternative examples, the EGR passage 50 and the compressor return passage 60 may be combined at a location upstream of the compressor inlet.

[0026] As here in the Fig. 3 and Fig. As explained in Figure 4, surge intensity estimation can be improved by combining pressure measurements from before and after the throttle (i.e., TIP and MAP, respectively) to generate an aggregate intake pressure. In particular, the NMP behavior of TIP can be better identified, thereby reducing the erroneous detection of surge due to NMP behavior of TIP. In addition, the noise contribution from engine actuators, such as an EGR valve, which generate TIP responses in the same frequency range as surge, can be better eliminated. Overall, the identification of surge is made more precise and reliable, allowing for early detection and mitigation of surge.

[0027] The engine system 100 may further include a control system 14. The control system 14 includes a controller 12 and is shown receiving information from a plurality of sensors 16 (various examples of which are described herein) and sending control signals to a plurality of actuators 81 (various examples of which are described herein). As one example, the sensors 16 may include an exhaust gas sensor 126 located upstream of the emissions control device, a MAP sensor 124, an exhaust gas temperature sensor 128, an exhaust gas pressure sensor 129, a compressor inlet temperature sensor 55, a compressor inlet pressure sensor 57, a TIP sensor 58, and an EGR sensor 54. Other sensors, such as additional pressure, temperature, air / fuel ratio, and composition sensors, may be coupled to various locations in the engine system 100.The actuators 81 may include, for example, throttle valve 20, EGR valve 52, compressor recirculation valve 62, wastegate actuator 92, and fuel injector 66. The control system 14 may include a controller 12. The controller may receive input data from the various sensors of the . Fig. 1, process the entered data and control the various actuators of the Fig. 1 to adjust machine operation based on the received signals and instructions stored in a memory of the control device. Exemplary control routines are described herein with reference to the Fig. 2 and Fig. 3. For example, the controller may send a signal to an actuator of the CRV 62 to actuate the valve to a wider open position in response to an indication from pumping.

[0028] With reference to Fig. 2, an exemplary method 200 for detecting compressor surge is shown. The method is based on a physics-based metric that uses wave intensity to determine how strong the surge oscillations are, allowing early mitigation or offline calibration of the surge line during the calibration stage. The oscillation amplitude is determined from pressure or mass flow measurements. The method improves boundary line calibration and adjustment and also allows easier online or offline detection of surges. Instructions for performing method 200 and the remaining methods included herein may be executed by a controller based on instructions stored in a memory of the controller and in conjunction with signals received from machine system sensors, such as those described above with reference to Fig. 1 described sensors. The control device can control machine actuators of the machine system, such as the sensors of the Fig. 1, use to adjust the machine operation according to the procedures described below.

[0029] At 202, the method includes estimating and / or measuring engine operating conditions, such as engine speed, driver torque demand, ambient temperature, humidity and pressure, barometric pressure, engine temperature, EGR, etc. Still other parameters may be determined, such as based on the output of corresponding sensors. These include, for example, intake manifold pressure (MAP), manifold air flow (MAF), compressor inlet pressure (CIP), compressor inlet temperature (CIT), throttle valve inlet pressure (TIP), or boost pressure, throttle charge temperature (TCT), air charge temperature (ACT), intake air temperature (IAT), etc.

[0030] At 204, it may be determined whether surge detection is enabled. In the present example, surge detection may be enabled during a wide range of operating conditions, including tip-in events and tip-out events of a driver accelerator pedal. In other words, surge may be assessed based on pressure (and / or airflow) metrics during both an increase in torque demand following pressing a driver accelerator pedal and a decrease in torque demand following releasing the driver accelerator pedal.

[0031] If surge detection is not enabled, such as during steady-state conditions, the method includes maintaining the position of one or more engine actuators, such as a compressor recirculation valve (CRV) coupled in a bypass to the compressor, an exhaust wastegate actuator, and an EGR valve, at 206. Then, the method ends and closes.

[0032] If surging detection is enabled, the method includes, at 208, combining the throttle valve inlet pressure (TIP) and the manifold air pressure (MAP) into an aggregate intake pressure. In other words, two measurements before and after the throttle valve are combined for the purpose of surging detection. Combining the throttle valve inlet pressure (TIP) and the manifold air pressure (MAP) into an aggregate intake pressure may include combining a weighted value of the throttle valve inlet pressure (TIP) with a weighted value of the manifold air pressure (MAP) into the aggregate intake pressure. The weighting may be based on the respective temperatures of the combined charges. For example, weighting MAP may be based on a manifold air charge temperature, while weighting TIP may be based on the throttle valve charge (or boost) temperature.In an alternative example, the controller may combine MAP and TIP into the aggregate intake pressure and then adjust the aggregate pressure based on temperature, particularly based on both a weighted air charge temperature and a weighted boost temperature. It will be appreciated that in alternative examples, the estimated manifold airflow (MAF) may be combined with the throttle valve inlet pressure (or flow) to determine an aggregate intake pressure or aggregate intake airflow, with the detection of surge then being based on the flow-based aggregate intake pressure or aggregate intake airflow.

[0033] The inventors recognized that using throttle valve inlet pressure (or MAP) alone to detect surge works well for some engine configurations but not well for others. For example, the approach may provide more accurate results in an inline engine than in a V-engine. This difficulty arises from the non-minimum phase (NMP) response of TIP to changes in driver demand. NMP behavior, common in complex systems, typically results when two processes competing with each other at different time scales act on a given measurement. In the engine airway system, NMP behavior arises for the following reasons: During a tip-in event, the throttle opens, causing TIP to drop and manifold pressure (MAP) to suddenly rise.Increasing MAP causes engine flow and, consequently, increased turbocharger power, leading to an increase in TIP. Consequently, as illustrated in mapping 500 of the . Fig. As shown in Figure 5, the TIP (represented by a solid line) initially drops rapidly and then rises slowly, while the MAP (represented by a dashed line) gradually increases. The initial drop in TIP indicates NMP behavior. In terms of the physics of the process, it is caused by competing dynamics of port filling (fast dynamics) and turbocharger spool-up (slow dynamics). A similar situation arises during a tip-out event. When the driver performs a tip-out, the TIP initially rises and then falls, indicating NMP behavior.

[0034] The inventors have recognized that the NMP behavior of the TIP may contain energy in the surge frequency (e.g., around 8 Hz) depending on the boost pressure and intake volume of the engine (such as in the case of a 3.5L V6 engine). In such a system, a surge detection method based on TIP signal processing may falsely mark the NMP behavior as surge. As described herein with reference to Fig. As explained in Section 6, the approach can correctly identify surges during tip-outs. However, the NMP behavior can be incorrectly marked as surges during tip-ins.

[0035] To address this problem, the present method reduces the NMP effect of the signal by combining TIP and MAP (or MAF) into an aggregate intake pressure. Specifically, the aggregate intake pressure is determined as a weighted sum of the measured TIP and MAP (or MAF).

[0036] To define the aggregate intake pressure, the pressure in the combined charge and intake volume is defined as follows: mT=mi+mb VT=Vi+Vb TT=mimi+mbTi+mbmi+mbTb where m is the mass, V is the volume, and T is the temperature. The subscript i is the intake, the subscript b is the boost, and the subscript T are the aggregate values. These equations state that the volume of a hypothetical aggregate plenum is the sum of two volumes, the gas mass in the new volume is the total mass of gases, and the new temperature is given by a weighted average of temperatures assuming adiabatic mixing.

[0037] Using the ideal gas law (PV = mRT), the new aggregate intake pressure P T be shown to be given by the following: PT=PbVbVi+Vb+PiViVi+Vb

[0038] This aggregate pressure indicates the pressure that would be reached if the intake and charging volumes were combined and the gases were heated to the temperature T T By executing the surge detection algorithm of the present routine on the aggregated intake pressure, the non-minimum phase behavior can be significantly reduced during both tip-ins and tip-outs. False marking of tip-ins as surges can also be reduced. In other words, by detecting surges using the aggregated values ​​of intake pressure P T and temperature T T -values ​​instead of just the temperature and pressure upstream of the throttle valve, the detection of pumps can be improved.

[0039] It should be appreciated that when using the ideal gas law mentioned above, R is assumed to be constant. However, it can actually be variable and depend, for example, on humidity and EGR (such as EGR percentage, dilution, or flow). In alternative examples, the equation for determining the aggregate intake pressure P T be changed accordingly to take this into account.

[0040] An example of reducing erroneous pump marking by taking NMP behavior into account is described with reference to the mapping 600 of the Fig. 6. Plotter representation 602 maps TIP, plotter representation 604 maps a pumping intensity calculated using only TIP, while plotter representation 606 maps an adjusted pumping intensity calculated using both TIP and MAP, and intake temperature to account for NMP behavior. The pumping intensities are compared to the pumping threshold 605. The mapping maps two tip-out events at t1 and t3 and a single tip-in event at t2.

[0041] In plotter representation 604, when the unadjusted pumping intensity is compared to the pumping threshold, pumping is correctly identified during tip-out events. However, the NMP behavior of the TIP during a tip-in event is erroneously marked as pumping. In comparison, in plotter representation 606, when the adjusted pumping intensity is compared to the pumping threshold, pumping is correctly identified during tip-out events, and the NMP behavior of the TIP during the tip-in event is not marked as pumping. In other words, pumping is more reliably identified.

[0042] Under Return to Fig. 2, the method includes, at 210, processing the aggregated intake pressure through one or more filters. The one or more filters may be, for example, a low-pass filter and a band-pass filter. Further, a passband (or cutoff frequency or passband) of one or more filters may be adjusted based on engine operating conditions. The filter may therefore be configured to pass selected frequencies (of the aggregated intake pressure) that are indicative of surge while reducing (or blocking) the passband of frequencies (of the aggregated intake pressure) that are outside the surge range. The selected frequencies that pass through the filter include a range of frequencies that are variable and change with engine operating conditions, such as temperature.The temperature for adjusting the shutdown frequency may include a manifold air charge temperature and / or a compressor inlet temperature. The temperature for adjusting the shutdown frequency may further include a weighted average of the manifold air charge temperature and / or the compressor inlet temperature.

[0043] It will be appreciated that in some examples, the filter output can be ignored during a tip-in event, including at frequencies indicative of pumping, to reduce the likelihood of false pumping markers.

[0044] At 212, the method includes calculating a surge intensity. The calculated surge intensity is then used to detect surges. Calculating the surge intensity includes, at 214, applying a recursive estimation using the filtered aggregated intake pressure as the input. This approach relies on system identification, where a model of the system is adaptively identified online, and no a priori information about the system is required. The obtained model of the pressure signal is used to detect surges and can also be used to predict future pressure values.

[0045] Calculating the surge intensity may additionally or alternatively comprise, at 216, estimating an amplitude and / or intensity of peak pressure oscillations of the aggregated intake pressure after passing through the filter(s). This approach is based on the wave intensity of the pressure oscillations and is explained below. The surge intensity, as determined by this approach, captures the energy carried by the pressure wave (the potential surge wave) and therefore directly measures the magnitude of the surge. This approach takes into account the thermodynamics of the pressure waves, including thermodynamics and chemical states. By basing the detection of surge on the surge intensity, the method becomes applicable to diverse types of machines and simplifies calibration.

[0046] Therefore, to quantify compressor surge, an expression for the power transferred by the pressure oscillations is derived using conventional wave theory. Consider, for example, a one-dimensional compression wave, such as in the intake path of an engine. The wave causes a displacement of the air molecules represented as ξ (x, t), where x is the coordinate and t is time. A mass element between position x and x + δx is therefore displaced by ξ (x, t) and stretched by δξ. The resulting volume change is δV = Aδξ, where A is the cross-sectional area. The mass of the element is δm = ρA δx, where ρ is the density. Assume small displacements (such as those where δξ / δx << 1), ideal gas, and that the process is isentropic (where PV Y is constant), the pressure variation δP: δP=−γP¯∂ξ∂x

[0047] Where Y is the specific heat ratio for the gas and P is the mean pressure. The voltage is F(x)= ⌣−AδP and the net force on the mass element is ∂F∂xδx. Newton’s second law for the mass element then results in the wave equation: ∂2ξ∂t2=1c2∂2ξ∂x2 where c=γP¯ρ is the wave speed (speed of sound). The power transmitted by the wave is ultimately given by equation (4) as follows: P=−F(x)∂ξ∂t=−γAP¯∂ξ∂t∂ξ∂x

[0048] It was observed that pressure oscillations during compressor surge lie within a narrow frequency band. These observations motivated the investigation of a harmonic described by equation (5): ξ(x,t)=ξ0 sin(k(x−ct)) where ξ0 is the amplitude and k is the wavenumber. For this harmonic, the pressure fluctuation (1) has the amplitude: P0=γξ0kP=ρξ0c2k and by equation (4) the average power is: =<AρcP02cos2(k(x−ct))> =A2ρcP02

[0049] The intensity I of the wave, defined as the transmitted power per unit area, is then: I= A=12ρcP02

[0050] An alternative intensity expression based on the mass flow is derived here by noting that the mass flow variation is δW=ρ∂V∂t=ρA∂ξ∂t.

[0051] For the harmonic (5) the flow amplitude is therefore: W0=ρξ0Ack

[0052] And, by comparing (6) and (7), the intensity is: I=12ρcP02=c2ρA2W02.

[0053] Overall, if the sound speed c and the density ρ are known, the intensity of the harmonic compression wave can be calculated from Eq. (8) based on data for the oscillation amplitude of the pressure or the mass flow.

[0054] An algorithm for calculating (e.g. online or offline, on-board or off-board) the intensity of compressor surge based on Eq. (8) is then formulated below and at Fig. 3. As described herein with reference to Fig. As explained in Figure 3, by using MAP and TIP as well as the equations described above, the pumping intensity of a pumping compression wave can be determined and used to reliably detect pumping. A block diagram 300 for the pumping intensity algorithm is therefore shown in Fig. 3. The equations and parameters associated with each block of the block diagram 300 and as discussed above (such as equations (1) through (8) as well as the parameters described above and below, such as P, W, c, ρ, Y, R, T, I, A, f1, f2, Ỹ and P, etc.) are given in parentheses.

[0055] The pressure during pumping is therefore approximated as a (single) harmonic: P=P¯−P0cos(k(x−ct)) with amplitude P0 around an average pressure P. The aim is to calculate the intensity for oscillations in the frequency band in which pumping occurs.

[0056] The oscillation amplitude P0 or W0 is calculated using bandpass filtering and peak detection logic. The cutoff frequencies for the filter, (f1, f2), are selected such that f1 < 1 / T0 < f2, where 1 / T0 is the observed pumping frequency for the particular machine configuration used (for example, based on the number of cylinders in the machine, whether the machine is an inline or V-machine, etc.). The filter output Ỹ is fed into peak detection logic, which measures the maximum and minimum amplitude over a moving window of length T w , takes the minimum of these values ​​at each sample, and applies a low-pass filter with time constant τ for smoothing. The logic is designed to capture peaks while attenuating asymmetric signals, such as non-oscillatory machine dynamics in the passband (f1, f2). The window length is selected such that T w ≥ T0.

[0057] The speed of sound c from equation (3), and the density ρ from the ideal gas law, ρ=P¯RT are calculated from measured or estimated thermodynamic states and properties. For example, for air γ ≈ 1.4 and R≈287JkgK. The mean pressure P is obtained by low-pass filtering with cut-off frequency f0 < f1.

[0058] The intensity is calculated from Eq. (8). If the mass flow amplitude is used, the area A can be calculated from the pipe diameter. To detect pumps, the intensity is fed by the detection logic with hysteresis using threshold values ​​(L, U).

[0059] While the block diagram 300 of the Fig. 3 depicts the algorithm, in the mapping 400 the Fig. Figure 4 illustrates the pumping algorithm with data. The inputs to the algorithm are the measured or estimated pressure P, the temperature T, gas properties (Y, R), and optionally the mass flow W to determine W0. The parameters (f0, f1, f2, T w , τ, L, U) and, when using mass flow measurements, A.

[0060] From Eq. (8), it can be seen that an intensity threshold for detecting surge is equivalent to a scaled threshold for the square of the amplitude of the pressure or mass flow, where the scaling is performed using the thermodynamic conditions as captured by the density ρ and speed of sound c. Scaling can be significant, for example, given that the density downstream of the compressor in automotive engines varies by more than a factor of two during normal operating conditions. Using surge intensity therefore provides a way to advantageously exploit the physics involved to simplify threshold selection and adaptation for varying operating conditions and engine configurations.

[0061] It will be appreciated that mass airflow estimation can be used in alternative examples, such as using mass airflow sensors, to detect surges. This can provide several advantages, as MAF does not exhibit the NMP behavior seen in TIP response. Therefore, as discussed with reference to Fig. 3, the left branch of the surge detection routine may start with the pressure P or the current W. A pressure estimation may therefore still be required for the right branch of the surge detection routine to dynamically scale the surge threshold.

[0062] Under Return to Fig. 2 at 218, the method includes updating a surge threshold of the engine based on thermodynamic and chemical states of the engine. Specifically, the surge threshold is adjusted to account for changes in absolute pressure, temperature, and gas composition. For example, the surge threshold is adjusted based on EGR (such as an EGR amount, an EGR flow, or an EGR percentage). The surge threshold may additionally be adjusted based on ambient humidity.

[0063] At 220, the method includes comparing the calculated surge intensity to the updated surge threshold. If the surge intensity is not greater than the threshold, the routine continues to 226, where it is indicated that no surge exists. Additionally, in response to the indication of no surge, the position of one or more actuators of the engine is maintained. For example, the position of the EGR valve, the CRV, and the wastegate is maintained.

[0064] If the surge intensity is higher than the threshold, at 222, prior to confirming surge, the method further includes applying a correction to account for the operation of actuators that generate a response in the surge frequency band. Specifically, in response to operation of an engine actuator at the selected frequencies indicative of surge, the method further includes processing the filtered aggregate intake pressure based on a change in throttle valve inlet pressure resulting from operation of the engine actuator. The engine actuator may be at least one of an intake throttle valve, an exhaust gas recirculation valve, a compressor recirculation valve, and a driver accelerator pedal.

[0065] The surge detection method of the present disclosure focuses on the frequency range most consistent with surge. However, the inventors have recognized that other disturbances may be present in the same frequency band. They may corrupt the results of the surge detection method and require special attention to enable robust surge detection. The closed-loop combination of throttle valve and exhaust gas recirculation (EGR) may excite the TIP response in the same frequency band as that of surge. To address this, the surge detection method is updated to consider engine control parameters such that their impact on the TIP response can be separated from that of surge. Example actuators that may correlate with surge frequency include the throttle valve, the EGR valve, a compressor recirculation valve (CRV), and driver accelerator pedal movements.Although the wastegate actuator can also excite the TIP response, the bandwidth for the wastegate response is much lower than typical surge frequencies. Consequently, the wastegate actuator cannot be considered a noise factor for sensing surge. Additional factors (not attributable to actuators) that can affect the closed-loop system in the selected surge frequency range include poor engine calibration, which can cause instabilities and numerical instabilities involving nonlinear lookup tables and jumping. In particular, nonlinear lookup tables involving parameters such as engine speed, engine load, and intake and exhaust cam positions can jump from index to index within the same frequency band as surge, affecting the TIP response through fluctuations in engine mass airflow.

[0066] If the wave intensity calculation based on TIP measurements suggests that surge is occurring (at 220), the correction at 222 first eliminates the effect of any actuators that may stimulate the TIP response in the same frequency range. This increases robustness for detecting surge, enables faster recovery from surge events, and allows for more aggressive calibration of the boundary line on the compressor map.

[0067] To eliminate the effect of actuators that may correlate with the pumping frequency, a virtual pressure value (or sensor) can be used within the pumping detection algorithm. In the case of the throttle valve and EGR flow, the pressure signal p is given by p=mRTV where m, V and T represent mass, volume and temperature respectively and R is the universal gas constant. The mass is a combination of compressor m c , throttle valve m thr and AGR m egr .

[0068] Defining a virtual pressure sensor or a pressure value, p¯=p−RTV(mthr+megr) which can be calculated from measured and / or estimated values ​​available in the engine control device, can eliminate the effects of throttle valve and EGR. In particular, since m = m c + m thr + m egr , one has p¯=RTVmc which only involves the mass quantity associated with the compressor. Other actuators that correlate with the pumping frequency (CRV, etc.) can be treated similarly.

[0069] To eliminate the effect of non-actuator factors that may correlate with the surge frequency, a frequency at which sensitive nonlinear machine controller lookup tables jump from index to index is monitored and compared to the frequency range of interest for surge detection. If the two frequencies overlap, the surge detection threshold level can be temporarily increased to reduce erroneous detection of a surge event.

[0070] An exemplary illustration of the processing of the pressure signals to estimate the pumping intensity and subsequent detection of pumps is shown with reference to the mapping 400 of the Fig. 4. The upper plot depicts a TIP (P) measured during a tip-out event at curve 402 (solid line). A nominal pressure (such as a low-pass filtered pressure) P based on the measured TIP is simultaneously shown at curve 403 (dashed line). The second plot depicts a band-pass filtered value of the pressure P at curve 404 (solid line). An amplitude of the filtered pressure (P0) is simultaneously shown at curve 405 (dashed line). The lower plot depicts the intensity of the associated pressure wave (the "pumping intensity") at curve 406.

[0071] At 224, the method includes confirming that a real surge event has occurred. Specifically, the surge intensity is again compared to the surge threshold after eliminating the effects of interfering actuators (such as the EGR valve and throttle valve). If, after eliminating the effect of the interfering actuators, the surge intensity is not greater than the threshold, at 226, it is indicated that no surge is occurring. Additionally, in response to indicating no surge, the position of one or more actuators of the engine is maintained. For example, the position of the EGR valve, the CRV, and the wastegate is maintained.

[0072] If, after eliminating the effect of the interfering actuators, the surge intensity is higher than the threshold, it is indicated at 228 that real surge is occurring. Additionally, the method includes adjusting an operator parameter of the engine in response to the indication of compressor surge, where surge is determined based on aggregate intake pressure and intake temperature. The position of one or more engine actuators is adjusted to adjust the operating parameter. The position of the EGR valve, CRV, and wastegate is adjusted. By way of example, an opening of the CRV is increased by an actuator based on signals received from the controller. As another example, an opening of the wastegate is increased by an actuator based on signals received from the controller.As yet another example, an opening of the EGR valve is increased by an actuator based on signals received from the controller.

[0073] It will be appreciated that although the method here illustrates the detection of surges based on processing measured air pressure signals (such as MAP and TIP), it is understood that in alternative examples, the detection of surges may be based on measured airflow signals, such as MAF.

[0074] As a result of the approach of capturing pumps of the Fig. 2 clearly shows how the pumping intensity increases when the pressure signal indicates pumping oscillations, improving the correlation with pumping. Additionally, the pumping intensity can be greater than zero during tip-in events, even when no visible pumping is present. The detection relies on a filter (e.g., a bandpass filter) to isolate the relevant signal, which is affected if energy is present in the specified passband from non-pumping machine dynamics. By using a threshold on the intensity to detect pumping, non-pumping events can be correctly classified and distinguished from pumping events. Additionally, pumping thresholds can be calibrated more aggressively (i.e., the thresholds can be lowered).The low thresholds allow the controller to detect a short pump oscillation during a tip-out while avoiding erroneous detections during a tip-in.

[0075] Thus, surge intensity is used to characterize compressor surge in turbocharged engines, where surge can be characterized for both online and offline operation. By using an intensity metric that captures the power imparted by pressure oscillations and using conventional wave theory to characterize the oscillations, surge can be detected more quickly and reliably. Detecting surge early allows for early mitigation of surge, reducing engine durability and drivability problems caused by surge. The technical effect of correlating pressure wave intensity with other available engine parameters is that a boundary line can be calibrated more aggressively on a compressor map.Additionally, compared to surge detection approaches based on static compressor mappings, which must be tuned conservatively to be robust, the present approach, based on aggregate pressure filtered within the surge region, allows surge detection thresholds to be automatically adjusted to operating conditions. This enables the use of less conservative mitigation action to counter surge and results in higher compressor utilization.

[0076] An example method for a boosted engine includes combining manifold pressure and throttle valve inlet pressure into an aggregated intake pressure and adjusting an operating parameter in response to compressor surge, wherein surge is determined based on aggregated intake pressure and intake temperature. In another example, the foregoing example method may additionally or optionally further include processing the aggregated intake pressure via a filter. In any or all of the foregoing examples, the filter may additionally or optionally pass selected frequencies indicative of surge and reduce the passing of frequencies outside of surge.In any or all of the preceding examples, the selected frequencies passed through the filter may additionally or optionally include a range of frequencies that vary with engine operating conditions, including temperature. In any or all of the preceding examples, the temperature may additionally or optionally include a manifold air charge temperature and / or a compressor inlet temperature. In any or all of the preceding examples, the temperature may additionally or optionally include a weighted average of a manifold air charge temperature and / or a compressor inlet temperature. In any or all of the preceding examples, the filter may additionally or optionally include a low-pass filter and / or a band-pass filter, and a passband of the filter may additionally or optionally be adjusted based on engine operating conditions.In any or all of the preceding examples, the method may additionally or optionally include, during a tip-in event, ignoring an output of the filter, including at frequencies indicative of surge. In any or all of the preceding examples, the method may additionally or optionally further include, in response to operation of an engine actuator at the selected frequencies indicative of surge, processing the filtered aggregate intake pressure based on a change in throttle valve inlet pressure resulting from operation of the engine actuator. In any or all of the preceding examples, the engine actuator may include at least one of an intake throttle valve, an exhaust gas recirculation valve, a compressor recirculation valve, and a driver accelerator pedal.In any or all of the preceding examples, compressor surge is additionally or optionally determined based on a driver accelerator pedal tip-in event and / or a driver accelerator pedal tip-out event. In any or all of the preceding examples, adjusting an operating parameter additionally or optionally comprises adjusting via an actuator, wherein the actuator comprises an exhaust wastegate actuator and / or a compressor recirculation valve.

[0077] Another example method for a boosted engine includes combining manifold pressure and throttle valve inlet pressure into an aggregate pressure, adjusting the aggregate pressure based on temperature, processing the adjusted aggregate pressure through one or more filters, and indicating compressor surge based on a processed output. In the preceding example, adjusting based on temperature may additionally or optionally include adjusting based on a weighted air charge temperature and / or a weighted boost temperature, the method additionally or optionally further comprising, in response to the indication, increasing an opening of a compressor recirculation valve to increase recirculation of compressed air from downstream of a compressor to upstream of the compressor.In any or all of the preceding examples, combining additionally or optionally comprises combining during driver accelerator pedal tip-in and tip-out events. In any or all of the preceding examples, processing additionally or optionally comprises low-pass or band-pass filtering the adjusted aggregate pressure and estimating an amplitude and / or an intensity of the processed output, and indicating compressor surge based on the processed output additionally or optionally comprises indicating compressor surge based on the amplitude or intensity of the processed output being greater than a surge threshold, where the threshold is based on EGR and / or ambient humidity.In any or all of the preceding examples, the method additionally or optionally further comprises updating the processed output in response to actuation of at least one of an EGR valve, an intake throttle valve, an exhaust wastegate, and a compressor bypass valve, wherein the updating is based on an effect of the actuation on throttle valve inlet pressure in a frequency range indicative of surge.

[0078] Another exemplary engine system includes: an engine intake manifold having an intake throttle valve, a compressor for providing a compressed air charge to the intake manifold, a compressor bypass having a compressor recirculation valve for redirecting compressed air from downstream of the compressor to upstream of the compressor, a first pressure sensor coupled downstream of the throttle valve for estimating intake manifold pressure, a first temperature sensor coupled downstream of the throttle valve for estimating intake manifold air charge temperature, a second pressure sensor coupled upstream of the throttle valve for estimating throttle valve inlet pressure, a second temperature sensor coupled upstream of the throttle valve for estimating boost temperature, an EGR valve in an EGR passage for recirculating exhaust gas to the intake manifold, and a controller.The controller is configured with computer-readable instructions stored in non-transitory memory to: combine the intake manifold pressure and the throttle valve inlet pressure into an aggregated intake pressure, filter the aggregated intake pressure to select pressure signals in a selected frequency range indicative of surge, compare a peak intensity of the filtered aggregated intake pressure to a threshold to indicate compressor surge, the threshold being adjusted based on actuation of the EGR valve in the selected frequency range, and in response to the indication of compressor surge, increase an opening of the compressor recirculation valve.In the preceding example system, the controller additionally or optionally includes further instructions for adjusting the selected frequency range based on a weighted average of the manifold air charge temperature and the boost temperature. In any or all of the preceding examples, the engine system additionally or optionally further includes a driver accelerator pedal, wherein the combining, filtering, and comparing are additionally or optionally performed during both driver accelerator tip-in and driver accelerator tip-out events.

[0079] In another depiction, the example method for a boosted engine includes bandpass filtering a throttle valve inlet pressure value, estimating an amplitude or intensity of a peak pressure of the bandpass filtered throttle valve inlet pressure, and indicating compressor surge in response to the estimated amplitude / intensity relative to a threshold. The foregoing example method may additionally or optionally further include correcting the estimated amplitude or intensity based on MAP. Any or all of the foregoing examples may additionally or optionally further include correcting the estimated amplitude or intensity based on correlation with actuation of an intake throttle valve and / or an EGR valve. In any or all of the foregoing examples, the threshold may additionally or optionally be adjusted based on EGR and / or humidity.

[0080] In another further representation, an example method for a boosted engine may include combining manifold airflow and throttle valve inlet airflow (or pressure) into an aggregated intake airflow and adjusting an operating parameter in response to compressor surge, wherein surge is determined based on the aggregated intake airflow and further based on intake temperature. In another example, the foregoing example method may additionally or optionally further include processing the aggregated intake airflow through a filter to pass frequencies indicative of surge and dispass frequencies outside the expected surge range.

[0081] In yet another further representation, an example method for a boosted engine may include combining measured manifold airflow and measured throttle inlet airflow into an aggregated airflow estimate, adjusting the aggregated airflow estimate based on temperature, processing the adjusted aggregated airflow estimate through one or more filters, and indicating compressor surge based on a processed output.

[0082] It should be noted that the example control and estimation routines included herein may be used with various machine and / or vehicle system configurations. The control methods and routines disclosed herein may be stored as executable instructions in non-volatile memory and may be executed by the control system, including the controller combined with the various sensors, actuators, and other engine hardware. The specific routines described herein may represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. Therefore, various illustrated actions, operations, and / or functions may be performed in the illustrated order, in parallel, or in some cases, omitted.Likewise, the order of processing is not necessarily required to achieve the features and advantages of the embodiments described herein, but is provided for ease of illustration and description. One or more of the illustrated actions, operations, and / or functions may be performed repeatedly depending on the particular strategy employed. Furthermore, the described actions, operations, and / or functions may graphically represent code to be programmed into non-transitory memory of the computer-readable storage medium in the machine control system, wherein the described actions are performed by executing the instructions in a system including the various machine hardware components in combination with the electronic controller.

[0083] It is understood that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered limiting, as numerous variations are possible. For example, the above technology is applicable to V6, I4, I6, V12, horizontally opposed 4-cylinder, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and / or characteristics disclosed herein.

[0084] The following claims particularly point out certain combinations and subcombinations that are considered novel and non-obvious. These claims may refer to "a" element or "a first" element, or the equivalent thereof. Such claims should be construed as encompassing the inclusion 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 amending the present claims or by presenting new claims in this or a related application. Such claims, whether broader, narrower, the same, or different in scope than the original claims, are also considered to be included within the subject matter of the present disclosure.

Claims

[1] A method for a supercharged engine comprising: combining intake manifold air flow and / or intake manifold pressure with throttle valve inlet pressure into an aggregate intake pressure, and adjusting an operating parameter in response to compressor surge, wherein surge is determined based on aggregate suction pressure and further based on suction temperature. [2] The method of claim 1, further comprising processing the aggregated intake pressure via a filter. [3] The method of claim 2, wherein the filter passes selected frequencies indicative of pumping and disables the passing of frequencies outside of pumping. [4] The method of claim 3, wherein the selected frequencies passed through the filter have a range of frequencies that varies with machine operating conditions, including temperature. [5] The method of claim 4, wherein the temperature comprises a manifold air charge temperature and / or a compressor inlet temperature. [6] The method of claim 4, wherein the temperature comprises a weighted average of a manifold air charge temperature and / or a compressor inlet temperature. [7] The method of claim 2, wherein the filter comprises a low-pass filter and / or a band-pass filter, and wherein a passband of the filter is adjusted based on engine operating conditions. [8] The method of claim 3, further comprising, during a tip-in event, ignoring an output of the filter, including at frequencies indicative of pumping. [9] The method of claim 3, further comprising, in response to operation of an engine actuator (81) at the selected frequencies indicative of surge, further processing the filtered aggregate intake pressure based on a change in throttle valve inlet pressure resulting from operation of the engine actuator (81). [10] The method of claim 9, wherein the engine actuator (81) comprises an intake throttle valve (20) and / or an exhaust gas recirculation valve and / or a compressor recirculation valve (62) and / or a driver accelerator pedal. [11] The method of claim 1, wherein compressor surge is determined on a tip-in event and / or a tip-out event of a driver accelerator pedal. [12] The method of claim 1, wherein adjusting an operating parameter comprises adjusting via an actuator (81), wherein the actuator (81) comprises an exhaust wastegate actuator (92) and / or a compressor recirculation valve (62). [13] A method for a supercharged engine comprising: Combining intake manifold pressure and throttle valve inlet pressure into an aggregate pressure, Adjusting the aggregate pressure based on temperature, Processing the adjusted aggregated pressure through one or more filters, and Specify compressor pumping based on a processed aggregate pressure output. [14] The method of claim 13, wherein adjusting based on temperature comprises adjusting based on a weighted air charge temperature and a weighted boost temperature, the method further comprising, in response to the indication, increasing an opening of a compressor recirculation valve (62) to increase recirculation of compressed air from downstream of a compressor (114) to upstream of the compressor (114). [15] The method of claim 13 or 14, wherein combining comprises combining during driver accelerator pedal tip-in and tip-out events. [16] The method of claim 13, wherein processing comprises low-pass or band-pass filtering the adjusted aggregate pressure and estimating an amplitude and / or an intensity of the processed output, and wherein indicating compressor surge based on the processed output comprises indicating compressor surge based on the amplitude or intensity of the processed output being higher than a surge threshold, wherein the threshold is based on EGR and / or ambient humidity. [17] The method of claim 13, further comprising updating the processed output in response to actuation of at least one of an EGR valve (52), an intake throttle valve (20), an exhaust wastegate (90), and a compressor bypass valve (62), wherein the updating is based on an effect of the actuation on throttle valve inlet pressure in a frequency range indicative of surge. [18] Machine system (10, 100) comprising: an engine intake manifold (22) having an intake throttle valve (20), a compressor (114) for providing a compressed air charge to the intake manifold (22), a compressor bypass (60) having a compressor recirculation valve (62) for diverting compressed air from downstream of the compressor (114) to upstream of the compressor (114), a first pressure sensor (16) coupled downstream of the throttle valve (20) for estimating the intake manifold pressure, a first temperature sensor (16) coupled downstream of the throttle valve (20) for estimating the intake manifold air charge temperature, a second pressure sensor (16) coupled upstream of the throttle valve (20) for estimating the throttle valve inlet pressure, a second temperature sensor (16) coupled upstream of the throttle valve (20) for estimating the charging temperature, an EGR valve (52) in an EGR passage (50) for returning exhaust gas to the intake manifold (22), and a control device (12) having computer-readable instructions stored on a non-volatile memory for: to combine the intake manifold pressure and the throttle valve inlet pressure into an aggregated intake pressure, filter the aggregated suction pressure to select pressure signals in a selected frequency range indicative of surges, compare a peak intensity of the filtered aggregated intake pressure to a threshold to indicate compressor surge, the threshold being adjusted based on actuation of the EGR valve (52) in the selected frequency range, and in response to the indication of compressor pumps, to increase an opening of the compressor recirculation valve (62). [19] The engine system (10, 100) of claim 18, wherein the controller (12) further comprises instructions for adjusting the selected frequency range based on a weighted average of the intake manifold air charge temperature and the boost temperature. [20] The machine system (10, 100) of claim 18 or 19, further comprising a driver accelerator pedal, wherein the combining, filtering, and comparing are performed during both driver accelerator pedal tip-in and tip-out events.

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