84 results about "Mean effective pressure" patented technology

A method and apparatus for accurately determining TTX: in a cylinder of an internal combustion engine. Gas pressure is measured in the cylinder relative to crank angle, giving rise to a curve of gas pressure with crank angle. An offset is found by first computing the angular position of an inflexion point of the compression pressure curve measured as a function of the crank angle, and then computing the offset as the difference between the angular position of a piston in the cylinder and a theoretical value for said angular position of the piston dependent on a known or measured flywheel angle. The value of TDC corrected by the offset is then used to calculate a value of work output such as the indicated Mean Effective Pressure (IMEP) which may be used for diagnostic and/or control purposes.

A system and method for identifying the cylinders having the lowest (“weakest”) and highest (“strongest”) Indicated Mean Effective Pressure (IMEP) utilizes engine speed derivative and/or higher order derivative values typically available in an engine control module by virtue of the need to detect misfire. A delta parameter is calculated that is indicative of the difference between the engine speed derivatives and/or higher order derivatives for the “weakest” and the “strongest” cylinders. Control action is then taken to balance the cylinders, based on the delta parameter, by first increasing torque for the “weakest” cylinder, by at least one increasing spark advance, increasing fuel, decreasing dilution (EGR) or slowing decay of fuel control on cold start. Once the weakest cylinder has been balanced, the control action is then directed to increasing torque of the new “weakest” cylinder.

A control apparatus which is capable of ensuring both high-level stability and accuracy of control, even when controlling a controlled object having extremal characteristics or a controlled object a controlled object model of which cannot be represented. The control apparatus 1 includes a cooperative controller 30, an onboard model analyzer 40, and a model corrector 60. The model corrector 60 calculates the model correction parameter matrix θ, so as to correct the controlled object model defining the relationship between the intake opening angle θlin and the exhaust reopening angle θrbl and the indicated mean effective pressure Pmi. The onboard model analyzer 40 calculates first and second response indices RI1 and RI2 representative of correlations between θlin, θrbl, and Pmi, based on the controlled object model corrected using θ. The cooperative controller 30 calculates the θlin and θrbl such that Pmi is caused to converge to a target value Pmi_cmd, and determines an increasing/decreasing rate and increasing/decreasing direction of θlin and θrbl according to RI1 and RI2.

A method for determining the optimum fuel injection timing angle in a CI engine provided with means disposed in one or more cylinders for measuring Indicated Mean Effective Pressure. The pressure level during the power stroke of a piston is a direct correlate of engine torque being generated, and the timing of fuel injection can increase or decrease the amount of torque. Thus, maximum torque can be obtained by optimizing the timing of fuel injection. An algorithm in the ECM varies the timing of fuel injection in a narrow range until a IMEP maximum is achieved, which timing is then retained and employed until the engine operating conditions change. Thus, the invention can optimize fuel economy by optimizing the torque obtained from each injection of fuel into the cylinders.

The present invention relates to a method for monitoring combustion stability of an internal combustion engine equipped with a crankshaft, an intake manifold and at least one cylinder, including the following steps: determining the absolute deviation e of indicated mean effective pressure p_ind or indicated torque T_ind with respect to their actual set point, i.e., with respect to actual indicated mean effective pressure set point p_ind,setpt or actual indicated torque set point T_ind,setpt, namely Δp_ind or ΔT_ind, or alternatively determining the relative change Δe in said deviation between two consecutive combustion cycles k, k+1 of said at least one cylinder, i.e., determining (Δp_ind,k+1−p_ind,k) or (ΔT_ind,k+1−ΔT_ind,k) or determining the relative change Δe in angular acceleration ω′ of the crankshaft between two consecutive combustion cycles k, k+1, i.e., (Δω′_k+1−Δω′_k), and comparing said determinated deviation e or said change Δe with a predetermined engine operating point dependent threshold e_threshold or Δe_threshold in order to decide if the combustion is stable or not by means of the following inequalities: |e|>e_threshold or |Δe|>Δe_threshold means combustion is not stable, |e|≦e_threshold or |Δe|≦Δe_threshold means combustion is stable. The method is preferably applied to homogeneous charge combustion ignition engines (HCCI).

The present disclosure provides an internal combustion engine having an engine housing with at least one cylinder that has diameter less than about 3 inches. A fuel injector is provided and disposed at least partially within the at least one cylinder, and includes a plurality of outlet orifices having a diameter between about 50 microns and about 110 microns. The disclosure further provides a method of operating an internal combustion engine. The method includes the steps of rotating an engine crank shaft of the engine at a speed greater than about 5000 revolutions per minute, injecting a quantity of fuel into each of the cylinders, and burning at least every fourth piston stroke a sufficient quantity of the injected fuel to yield a brake mean effective pressure of at least about 200 lbs. per square inch.

A method of controlling ignition timing of an engine. In the control method, final ignition timing for performing ignition is calculated by adding a variation component to a set ignition timing. According to the final ignition timing, an indicated average effective pressure of an in-cylinder pressure detected when ignition is performed is calculated. An ignition timing characteristic curve indicating the correlation between the indicated average effective pressure and the variation component is estimated and optimal ignition timing is calculated from the characteristic curve. Feedback control for converging the set ignition timing to the optimal ignition timing is then performed. Consequently, the ignition timing is controlled to an optimal ignition timing corresponding to a current operational state of the engine.

The invention relates to a fuel self-adaptation control method for a flexible fuel engine. The fuel self-adaptation control method comprises the steps that a gasoline and diesel mixing flexible fuel engine combustion closed-loop control system which comprises an engine electronic control unit, a flexible fuel compression-ignition engine, a piezoresistive cylinder pressure sensor and a fuel self-adaptation control unit is arranged, wherein the fuel self-adaptation control unit comprises a power performance self-adaptation control module, an economical efficiency optimizing self-adaptation control module and a mean effective pressure calculating module; an IMEP and an PMEP are obtained by the mean effective pressure calculating module and are transmitted to the power performance self-adaptation control module, and meanwhile, the IMEP is transmitted to the economical efficiency optimizing self-adaptation control module; a new fuel-injection amount is obtained by the power performance self-adaptation control module and is transmitted to the engine electronic control unit, and the self-adaptation control is carried out on fuel power performance by the engine electronic control unit; a fuel-injection time corrected value is obtained by the economical efficiency optimizing self-adaptation control module and is transmitted to the engine electronic control unit, and the optimized self-adaptation control is carried out on fuel economical efficiency by the engine electronic control unit.

The invention provides a piston group cylinder sleeve friction force wireless measuring method and an implement device, which belong to the technical field of an internal combustion engine. The wireless measuring device comprises strain gauges, a wireless sending module, a receiving antenna, a pressure sensor, a charge amplifier, a photoelectric encoder, a signal acquisition module and a computer. The train gauges are attached to the two sides of the middle portion of a connection rod, and is connected with the wireless sending module; the receiving antenna extends into an engine cylinder through a signal hole in an engine oil pan; and the receiving antenna is connected with the signal acquisition module. The piston group cylinder sleeve friction force wireless measuring method and device are provided on the basis of a mean effective pressure indication method (IMEP), and thus the problem that in the wired measuring process, the connecting rod is always in a high-velocity motion state with a bent axle under the working condition of an engine, and it is necessary to design a special line-leading device to lead out a signal line, however, the line can be damaged easily, and the measuring system is disabled. The measuring method and device are reasonable in design, simple in structure and suitable for optimization design of a piston group cylinder sleeve friction force measuring system.

The invention belongs to the technical field of automobile control, and provides an electronic water pump control method, which comprises the following steps that an ECU (Electronic Control Unit) calculates indicated mean effective brake pressure according to an engine estimation model if an engine runs; if the indicated mean effective brake pressure is lower than first pressure, an electronic water pump does not work; if the indicated mean effective brake pressure is not lower than the first pressure and not higher than second pressure, the electronic water pump works, and practical temperature after inter-cooling is detected; if the practical temperature is higher than target temperature, rotating speed of the electronic water pump is regulated by adopting closed loop control until an absolute value of a difference between the practical temperature and the target temperature is lower than a preset value; if the indicated mean effective brake pressure is higher than the second pressure, the electronic water pump works at rated rotating speed. According to the method, the ECU calculates the indicated mean effective brake pressure according to the engine estimation model, and the indicated mean effective brake pressure is compared with a minimum load threshold of the indicated mean effective brake pressure to control the electronic water pump to ensure that a booster and an inter-cooler work at optimal temperature, save energy resources and improve economy of fuel.

The present invention provides a method for easily measuring a brake mean effective pressure of a running vehicle. An air flow sensor, a λ sensor and a data collecting apparatus are mounted to the vehicle. A running speed and engine speed from the vehicle while actually running on a road surface, and output of the air flow sensor an the λ sensor are inputted to the data collecting apparatus. Specific fuel consumption is obtained from an intake air amount and ratio of excessive air in exhaust gas. Output of an engine is obtained from a relation between the specific fuel consumption and the engine speed.

The invention relates to a system and a method for estimating torque output of a homogeneous charge compression ignition engine, and concretely provides a control system for a homogeneous charge compression ignition (HCCI) engine including a fuel requirement estimation module, a torque estimation module, and a torque control module. The fuel requirement estimation module estimates a fuel requirement of the HCCI engine based on a desired indicated mean effective pressure (IMEP) of cylinders in the HCCI engine. The torque estimation module estimates a torque output of the HCCI engine based on the estimated fuel requirement. The torque control module adjusts the torque output of the HCCI engine based on the estimated torque output and a desired torque output.

A method of determining and controlling misfire in an engine. The method and device sense combustion pressure in a combustion chamber of an engine while the engine is operated; calculate MFB (a ratio of the amount of combustion heat at a specific point of time to the total amount of combustion heat), MFB50 (a point of time at which the amount of combustion heat is 50% of the total amount of combustion heat), MFB50 COV (Coefficient of Variation), IMEP (Indicated Mean Effective Pressure) and IMEP COV, from the combustion chamber; set a desired MFB50; and determine that there is misfire when a crank angle is delayed at 5 degrees or more, the MFB50 COV is 20% or more, or the IMEP COV is 20% or more, by comparing the calculated MFB50 with the desired MFB50; and then advance an injection time such that the MFB follows the desired MFB.

A method and a control system that includes a window module that determines a piston position window, a mean effective pressure determination module that generates a mean effective pressure with in-cylinder pressure signals within the piston position window and an engine control module that controls the engine using the mean effective pressure.

To prevent a reduction in engine load detection accuracy due to variations in reluctor size within mass production tolerances, an engine control unit includes a pulse generator PC that detects a reluctor to output crank pulses. An angular velocity calculating unit calculates a first crank angular velocity on the basis of an interval between two crank pulses output in a predetermined section near compression top dead center TDC, and detects near overlap top dead center OLP the same reluctor used for calculating the first crank angular velocity to calculate a second crank angular velocity on the basis of an interval between generated two crank pulses. An engine load estimating unit calculates, as an engine load, a difference between the first crank angular velocity and the second crank angular velocity. The engine load is indicated mean effective pressure over a whole cycle including negative work done by the engine.

Premixed engines including dual fuel engines can experience abnormal combustion characteristics including misfire, pre-ignition and knock. A method for detecting and mitigating abnormal combustion in an engine comprises sensing frequency components of an acoustic signal associated with a combustion chamber during a combustion cycle, the frequency components representative of at least one of a normal and an abnormal combustion characteristic; determining an in-cylinder pressure signal as a function of the acoustic signal; calculating as functions of the in-cylinder pressure signal at least one of a knock index, a gross indicated mean effective pressure and a start of combustion timing; detecting the abnormal combustion characteristic is at least one of (a) a misfire event when the gross indicated mean effective pressure is less than a predetermined mean effective pressure value; (b) a pre-ignition event when the start of combustion timing is advanced of a start of ignition timing; and (c) an engine knock event when the knock index is greater than a predetermined knock value; and performing a mitigation strategy for the detected abnormal combustion characteristic.