| Mass air flow estimation based on manifold absolute pressure -> Monitor Keywords |
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Mass air flow estimation based on manifold absolute pressureRelated Patent Categories: Data Processing: Vehicles, Navigation, And Relative Location, Vehicle Control, Guidance, Operation, Or Indication, With Indicator Or Control Of Power Plant (e.g., Performance), Internal-combustion Engine, Digital Or Programmed Data ProcessorMass air flow estimation based on manifold absolute pressure description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060069490, Mass air flow estimation based on manifold absolute pressure. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to estimating mass air flow through a throttle of a vehicle, and more particularly to estimating mass air flow based on manifold absolute pressure. BACKGROUND OF THE INVENTION [0002] Internal combustion engines (ICE's) are controlled based on a manifold absolute pressure (MAP) and mass air flow (MAF) signals that are generated by MAP and MAF sensors, respectively. A controller controls emissions and engine performance characteristics of the ICE based on the MAP and MAF signals. For example, critical engine parameters, such as air-to-fuel (A/F) ratio, can be adjusted by knowing the mass of air available for combustion. [0003] MAF sensors are commercially available and have been used with ICE's to provide the required MAF information. MAF sensors, however, are relatively expensive as compared to other sensors implemented with the ICE. Therefore, alternative techniques for determining MAF into the ICE have developed. Two conventional techniques include a speed density technique and a throttle position technique. The speed density technique determines MAF based on MAP, engine speed and intake air temperature. The throttle position technique determines MAF based on throttle position and engine speed. [0004] Although the conventional techniques eliminate the need for a MAF sensor, they are less accurate than desired. These inaccuracies result from an incorrect estimation of MAF during throttle transient conditions. During throttle transient conditions, a finite amount of time is required to calculate MAF and adjust fuel input. MAF can change dramatically due to the dynamic nature of the ICE during this time. Even during static conditions, the conventional techniques result in cycle-to-cycle measurement variations. More specifically, air flow pulsations that occur as the ICE draws air into the cylinders and delays in processing sensor information result in such cycle-to-cycle variations. SUMMARY OF THE INVENTION [0005] Accordingly, the present invention provides a control system that determines a mass air flow through a throttle of an internal combustion engine (ICE) having an intake manifold. The control system includes a calculator that calculates an estimated mass air flow based on a throttle position and an adaptation module that determines an adjustment value. The adjustment value is based on the estimated mass air flow, an estimated manifold absolute pressure and a measured manifold absolute pressure. A multiplier multiplies the estimated mass air flow by the adjustment value to determine the mass air flow. [0006] In one feature, the control system further includes a calculator that calculates the estimated manifold absolute pressure. [0007] In another feature, the control system further includes an engine speed sensor that generates an engine speed signal and an intake manifold temperature sensor that generates an intake manifold temperature signal. The estimated manifold absolute pressure is based on the engine speed signal and the intake manifold temperature signal. [0008] In another feature, the control system further includes a multiplier that calculates an adjustment input as a product of the estimated mass air flow and a manifold absolute pressure error. The manifold absolute pressure error is determined as a difference between the estimated manifold absolute pressure and the measured manifold absolute pressure. [0009] In still another feature, the adaptation module is an integrator that integrates an adjustment input that is based on the estimated mass air flow and a manifold absolute pressure error. The adaptation module integrates the adjustment input and multiplies the adjustment input by a gain. [0010] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: [0012] FIG. 1 is a schematic illustration of an internal, combustion engine (ICE) system according to the present invention; [0013] FIG. 2 is a flowchart illustrating mass air flow estimation according to the present invention; and [0014] FIG. 3 is a flowchart illustrating steps of the mass air flow estimation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0015] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module and/or device refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, or other suitable components that provide the described functionality. [0016] Referring now to FIG. 1, a vehicle 10 includes an internal combustion engine 12 having an intake manifold 14. A throttle 16 regulates air flow into the intake manifold 14. More particularly, a throttle blade 18 is articulated based on a driver input (not shown) to regulate air flow through the throttle 16. The intake manifold 14 directs air flow into cylinders 20 of the engine 12. Although a single cylinder 20 is shown, it can be appreciated that the engine 12 can include multiple cylinders (e.g., 2, 3, 4, 5, 6, 8, 10 and 12). Air flowing into the cylinders 20 is mixed with fuel and the mixture is combusted therein to drive pistons (not shown) producing drive torque. [0017] A control system regulates operation of the engine based on the sensorless control of the present invention. More specifically, a controller 22 monitors and regulates engine operation based on processing several inputs according to the sensorless control. The controller 22 generally includes software-based processing. [0018] A throttle position sensor 24 generates a throttle position signal (THR.sub.POS) and a manifold absolute pressure (MAP) sensor 26 generates a MAP signal (MAP.sub.MEAS), which are received by the controller 22. An intake manifold temperature sensor 28 generates an intake manifold temperature signal (T.sub.MAN) and an engine speed sensor 30 generates an engine speed signal (RPM), which are received by the controller 22. An ambient pressure sensor 32 generates an ambient pressure signal (P.sub.AMB) that is received by the controller 22. The controller 22 processes the various signals according to the sensorless control and generates at least one command signal based thereon. Engine operation is controlled based on the at least one command signal. [0019] Referring now to FIG. 2, the sensorless control of the present invention will be described in detail. In step 100, control calculates an estimated mass air flow (MAF.sub.EST) based on THR.sub.POS. More particularly, a throttle area (A.sub.THROTTHLE) is determined based on THR.sub.POS. A.sub.THROTTLE can be determined from a look-up table based on THR.sub.POS or can be calculated by processing THR.sub.POS through a mathematical model of the throttle 16. MAF.sub.EST is calculated based on the following equation: MAF EST = P AMB A THROTTLE T MAN [ 71.821 ( MAP MEAS P AMB ) 1.7074 - ( MAP MEAS P AMB ) 1.7083 ] Control determines an adjusted mass air flow (MAF.sub.ADJ) based on MAF.sub.EST and an adjustment factor (ADJ) in step 102. In step 104, control operates the vehicle based on MAF.sub.ADJ. More particularly, control can manipulate engine operation parameters based on MAF.sub.ADJ to produce desired drive torque or emissions. Continue reading about Mass air flow estimation based on manifold absolute pressure... Full patent description for Mass air flow estimation based on manifold absolute pressure Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Mass air flow estimation based on manifold absolute pressure patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Mass air flow estimation based on manifold absolute pressure or other areas of interest. ### Previous Patent Application: Motor vehicle control using a dynamic feedforward approach Next Patent Application: Control device for internal combustion engine Industry Class: Data processing: vehicles, navigation, and relative location ### FreshPatents.com Support Thank you for viewing the Mass air flow estimation based on manifold absolute pressure patent info. IP-related news and info Results in 0.29581 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry 174 |
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