13 results about "Mean effective pressure" patented technology

The invention relates to a shared bicycle brake pad abrasion monitoring system and a monitoring method thereof, and aims to solve the problems that in the prior art, shared bicycle brake pad abrasion monitoring is high in cost and low in precision, and abnormal abrasion cannot be detected, and accurate monitoring is achieved through a multi-parameter correction model of brake frequency statistics and pressure distribution perception. A microswitch is arranged on a brake pedal, three film pressure sensors are arranged on a brake pad steel backing, a brake pressure value, an average effective pressure Pavg and a pressure distribution difference delta P are synchronously collected, a wear estimation model is built by combining working condition data such as temperature and vehicle speed, and a material coefficient k, a vehicle speed correction coefficient f (v) and a temperature correction coefficient g (T) are adopted for multi-dimensional correction, so that the wear estimation precision is improved. And calculating the accumulated abrasion loss and predicting the residual thickness. Accurate recognition of abnormal wear such as eccentric wear and block falling is achieved by analyzing a delta P threshold value and Pavg mutation characteristics, parameter customization of brake pads made of different materials is supported, and a graded early warning function is achieved.

The invention relates to a cooperative control method and system for lean-burn emission of a marine low-zero carbon fuel engine. The method comprises the steps that real-time in-cylinder pressure and temperature data are collected, and an in-cylinder pressure curve and an in-cylinder temperature curve are obtained through time sequence alignment, filtering denoising and interpolation fitting processing; extracting time sequence data based on the curve, calculating average effective pressure and peak temperature in a cylinder to determine a current load interval, and marking a risk tag sequence; calculating the generation rate of the nitrogen oxides and the particulate matters by matching with reaction condition parameters, and extracting reverse variation characteristics to obtain strong mutual exclusion correlation of the nitrogen oxides and the particulate matters; and based on the associated starting model, predicting and controlling the output oil injection quantity and the air inflow adjusting quantity, calculating the transient time sequence lag quantity through a dynamic lag model, and after superposition, calibrating through a combustion phase matching algorithm to generate an oil injection timing and air inlet valve opening control instruction after transient adjustment. The method is adaptive to the combustion characteristics of low-zero-carbon fuel, emission contradictions are accurately captured, transient emission peak values are avoided, and multi-pollutant collaborative control is achieved.

The present invention discloses a method and system for modeling an engine model based on the Modelica language. The method includes: reading external engine ECU instruction information; calculating the current engine mean effective pressure and the ideal output torque according to the engine power parameter characteristics and the ECU instruction information; calculating the engine external torque output value by combining the engine ideal output torque, temperature and dynamic correction coefficient; establishing an external interaction interface, and performing dynamic balance and thermodynamic balance calculations in combination with the engine external torque output value to obtain the engine model. Among them, the external interaction interface includes a thermal interface and a flange interface. The thermal interface is used for connecting the engine to the cooling components, and the flange interface is used for connecting the engine to the load components. The present invention establishes an engine model based on the Modelica language, realizes comprehensive analysis of the dynamic speed and torque conditions during the engine operation process, and simultaneously analyzes the economic, environmental protection and other characteristics of the engine during this process.

The application discloses a lean-burn engine control method, device and engine system. The lean-burn engine control method comprises the following steps: obtaining a current torque and a target torque; when the current torque is less than the target torque, obtaining an average effective pressure and an excess air coefficient; when the average effective pressure is in a first pressure range and the excess air coefficient is in a first coefficient range, adjusting an ignition angle, increasing air content and combustible content in a cylinder, and increasing the current torque to the target torque. By using the above technical scheme, the current torque can be increased, the thermal efficiency can be ensured to be high, and the combustion center can be prevented from changing, the ignition angle can be prevented from being large, and the lean-burn engine can be prevented from being damaged by knocking.

The invention relates to a torque precision verification method for a whole vehicle engine. The torque precision verification method comprises the steps of obtaining universal characteristic data of a median engine in a warm-up state; the median engine is formed by assembling a plurality of parts with first intake and exhaust parameters meeting design conditions, and second intake and exhaust parameters after assembly meet assembly conditions; under the first intake and exhaust parameters and the second intake and exhaust parameters, the intake and exhaust performance of the median engine is optimal; in the warm-up state, the working efficiency of the median engine is optimal; the universal characteristic data is used for reflecting the operation performance of the engine under different working conditions; based on the actually measured torque and the actually measured average effective pressure IMEP in the universal characteristic data, establishing a mapping relation among the IMEP, the rotating speed and the torque; the actually measured torque comprises torques of the median engine at different rotating speeds; and the torque in the mapping relation is used as a verification reference, and the torque precision of the engine under different whole vehicle working conditions is verified.

A method for controlling engine combustion noise, comprising the steps of: calculating an engine combustion noise target value by a controller; measuring a cylinder pressure after fuel combustion depending on a main injection timing and a pilot injection fuel quantity based on the calculated engine combustion noise target value; calculating an engine combustion noise index (CNI) by converting the measured cylinder pressure into a cylinder pressure level; and controlling a feedback pilot injection in which the CNI is used in variable injection control while controlling the main injection timing and the pilot injection fuel quantity, characterized in that the cylinder pressure level is expressed as a noise (dB)-frequency (Hz) diagram by signal processing of the measured cylinder pressure using an FFT.the CNI is calculated using a noise (dB)-frequency (Hz) diagram of the cylinder pressure level, and a reference value of a mean effective pressure (BMEP) is used in the pilot injection control, the CNI is calculated as an uncorrected engine combustion noise prediction value without correcting the CNI at the reference value or less and then used in the variable injection control, and the CNI is calculated as a corrected engine combustion noise prediction value by correcting it at the reference value or more and then used in the variable injection control.

The invention relates to the field of hydrogen internal combustion engines, in particular to a VGT opening calibration method for a hydrogen internal combustion engine. The method comprises the steps that the rotating speed, the initial average effective pressure and the initial VGT opening degree of the hydrogen internal combustion engine are determined and calibrated; the average effective pressure is increased, the VGT opening degree is adjusted, and when the first preset excess air coefficient is determined, the first calibrated VGT opening degree is obtained; the average effective pressure is increased, the VGT opening degree is adjusted, and when it is determined that the average effective pressure is smaller than the first preset excess air coefficient and the air inlet pressure is not smaller than 2 bar, the second calibrated VGT opening degree is obtained; determining a preset number of VGT opening values based on the second calibrated VGT opening; when it is determined that the highest effective heat efficiency corresponding to the preset number of VGT opening values is a second calibrated VGT opening and is smaller than a second preset excess air coefficient, VVT setting is switched; and the average effective pressure is increased, the VGT opening degree is adjusted, and when it is determined that the hydrogen internal combustion engine has the abnormal combustion phenomenon, the third calibrated VGT opening degree is obtained. Different loads are considered, and the VGT opening degree under the full working condition of the hydrogen internal combustion engine can be calibrated.

This invention relates to a method of reducing abnormal combustion events in a hydrogen fueled internal combustion engine during operation of the engine including: (i) providing a lubricating oil composition to the hydrogen fueled internal combustion engine; (ii) providing fuel comprising hydrogen to the internal combustion engine; and (iii) combusting the fuel in the hydrogen fueled internal combustion engine; wherein the lubricating oil composition: 1) includes one or more zinc dihydrocarbyl dithiophosphate compounds that provide more than 0.01 mass% zinc, and less than 0.08 mass% of phosphorus, or alternatively greater than or equal to 0.10 mass % and less than 0.40 mass % of phosphorus, based upon the weight lubricating oil composition, and 2) exhibits reduced pre-ignition at a given engine speed (rpm) whilst operating at maximum BMEP for that given engine speed (rpm), as compared to the same composition except that the concentration of the zinc dihydrocarbyl diphosphate compounds is such that the mass % phosphorus present in the lubricating oil composition is not within the specified ranges.

The internal combustion engine (1) includes: an exhaust gas recirculation device having an exhaust gas recirculation control valve (9); a crankshaft angle sensor (11) for detecting the graphical mean effective pressure variation rate (cPi), which is an indicator of the combustion stability of the internal combustion engine (1); and a controller (10) for correcting the EGR rate of the exhaust gas recirculation device based on the combustion stability. If the graphical mean effective pressure variation rate (cPi) is less than a threshold for a specified number of cycles, the controller (10) increases the EGR rate by a specified amount. If the graphical mean effective pressure variation rate (cPi) is greater than or equal to the threshold, the EGR rate is immediately decreased.

The application discloses a cylinder early warning method and system based on indirect estimation of cylinder pressure state of an internal combustion engine, and the method collects a transient rail pressure signal in a common rail pipe through a high-frequency rail pressure sensor; according to a rail pressure drop segment feature caused by an oil injection event, an instantaneous oil injection rate curve of each cylinder varying with a crank angle is reconstructed; in a built cylinder combustion thermodynamic model, a complete cylinder pressure curve is obtained by angle-by-angle integral solution; characteristic parameters such as a highest explosion pressure, a pressure rise rate, an indicated mean effective pressure and a combustion phase are extracted from the cylinder pressure curve, and are compared with theoretical normal values or historical healthy values, so that online evaluation and fault early warning of the cylinder combustion state are realized. The application indirectly calculates the cylinder pressure through the rail pressure signal without increasing the hardware cost of the cylinder pressure sensor, establishes cross-domain quantitative correlation between the rail information and the cylinder combustion state, and has the advantages of low cost, strong universality and full-life-cycle self-adaptation.

An engine includes pistons, cylinders, a crankshaft, an intake manifold, an exhaust manifold, intake valves, exhaust valves, a fuel injector, and an Electronic Control Unit (ECU). The pistons actuate the crankshaft and are actuated by combustion reactions. Each cylinder houses a piston and contains a combustion reaction. The intake valves control a flow of a gas mixture to the cylinders. The fuel injector injects fuel into the cylinders that is combusted to create exhaust gases. The exhaust manifold includes a blowdown line and a scavenge line that deliver to a turbine and a catalytic conversion device, respectively. Each exhaust valve is disposed at a blowdown or scavenge line inlet and controls a flow of the exhaust gases to the exhaust manifold. The ECU deactivates exhaust valves associated with the blowdown line inlets when the engine operates with a Brake Mean Effective Pressure (BMEP) value less than a BMEP threshold.

The application discloses a diesel engine under-charge real-time monitoring and fault diagnosis method, which measures the parameters such as cylinder pressure and crank angle signals of the diesel engine by comprehensively applying various sensors, firstly reads or calculates the cylinder pressure at the top dead center, the maximum explosion pressure, the effective power feature and the average effective pressure, respectively, calculates the difference value of the above parameters and the threshold value of the corresponding normal working condition, respectively, and preliminarily diagnoses whether the diesel engine is under-charge; secondly, the fault degree of each parameter is judged by calculating the deviation rate of each parameter; finally, the overall fault degree is comprehensively analyzed according to the above fault degree; according to the fusion of the fault characteristic information, the typical fault characteristics are compared, so that the composite fault diagnosis of the diesel engine is realized, various characteristic information is fully utilized, the diagnosis speed and accuracy are improved, qualitative and quantitative analysis is realized, and the application of the diesel engine fault diagnosis level will be improved.

The application provides a combustion control method and system of an engine, the method comprising: obtaining a combustion fluctuation error of a plurality of combustion cycles after starting of the engine, the combustion fluctuation error being an absolute value of a difference between an actual combustion fluctuation amount determined by an average indicated mean effective pressure of a plurality of reference combustion cycles corresponding to the combustion cycle and a preset standard combustion fluctuation amount; calculating an EGR valve opening degree according to the combustion fluctuation error, a preset proportional link adjustment gain and a preset integral link adjustment gain; and controlling an actual EGR valve opening degree of the engine to be equal to the EGR valve opening degree. Based on this, the application can calculate the corresponding EGR valve opening degree in real time according to the actual operation condition of the engine, so that the application can obtain the EGR valve opening degree under various operation conditions of the engine in actual operation, and the overall performance of the EGR technology applied to the engine is improved.