摘要:
In a method and a system for the ventilation of a fuel tank of a motor vehicle having an internal-combustion engine which has a suction pipe with a bypass containing, in particular, an idling adjuster, the fuel tank being capable of being ventilated into the open by way of a ventilation conduit having an adsorption filter and having a first valve located between the latter and a ventilation orifice, and the adsorption filter being capable of being scavenged with scavenging air which is supplied to the suction pipe by way of a scavenging-air conduit containing a second valve, to avoid disturbances of the operating conditions of the internal-combustion engine the scavenging air for the adsorption filter is branched off from the airstream flowing by way of the bypass.
摘要:
A method for determining the operability of a tank-venting system on a motor vehicle subjects the signals for the volume flow through the tank-venting valve and the signals for the pressure difference between the tank interior and the ambient to a cross-covariance analysis. The above-mentioned signals are formed by a high pass in advance of forming the cross-covariance function and the maximum or the mean value of the cross-covariance function is formed with respect to the product of the two input variables. A variance measure is formed for the signal of the volume flow through the tank-venting valve and a transfer factor is computed from the variance measure and the mean value or maximum. The tank-venting system is deemed to be operational when the transfer range lies in a pregiven region. An advantage of the method is seen in the independence of the tank-pressure changes which are not caused by volume-flow changes through the tank-venting valve. Here, changes are especially of concern which are caused by the sudden generation of vapor in the tank such as caused by sloshing fuel.
摘要:
A method and an arrangement for open-loop control and/or closed-loop control of an operating variable of an internal combustion engine is suggested with a transfer element fixing the relationship between input and output variables in the form of a characteristic curve or characteristic field such as an electrically actuable actuator, which directly or indirectly influences the operating variable of the engine of a motor vehicle and which fixes the relationship between the driving and operating variable or a variable influencing this operating variable in the form of a characteristic curve or a characteristic field. The transfer element or the characteristic curve or the characteristic field is subjected to changes. By adapting the characteristic curve or the computation instruction representing the characteristic curve or the characteristic field, these are adapted to these changes. This adaptation is performed in such a manner that at least one region of the characteristic curve or of the characteristic field is rotated about a pregiven point which lies outside of the characteristic curve and is specific to the actuator or to the engine. This point is adaptable in the context of a long-term adaptation.
摘要:
The invention is directed to a method for obtaining a value for evaluating the performance loss of a catalytic converter with the aid of a forward signal of a forward gas probe mounted forward of the catalytic converter and a rearward signal of a rearward gas probe mounted rearward of the catalytic converter, the catalytic converter being connected to an internal combustion engine. The method includes the steps of: carrying out the method during the steady-state operation of the engine; multiplying the forward signal and the rearward signal with each other to form a plurality of products; averaging the products over a plurality of oscillations of the forward signal to obtain a mean value; and, utilizing the mean value as a value for evaluating the performance loss of the catalytic converter. This correlation method can be varied in different ways and especially in that the forward-probe signal is correlated without or with phase shift with the rearward-probe signal. A cross-correlation factor or the real or imaginary component of an orthogonal correlation or other correlation values are obtained in dependence upon the nature of the correlation. These correlation values are used for evaluating the performance loss of the catalytic converter. The evaluation of the performance loss of the catalytic converter with the aid of these correlation values is very significantly more reliable than the evaluation with the aid of amplitudes or amplitude mean values of the probe signals.
摘要:
The invention relates to a method and an arrangement for checking the operability of an electric heater in motor vehicles and especially the heater of an oxygen probe which is mounted in the exhaust gas channel of an internal combustion engine. It is necessary to determine the temperature-dependent electrical resistance and the temperature of the oxygen probe heater for a precise evaluation of the operational state of the oxygen probe heater. The basic principle of the invention is based upon the consideration that the measurement of the electrical resistance of the oxygen probe heater is then carried out when the oxygen probe heater has cooled down to the ambient temperature. Whether this cool down has taken place can be determined in various ways in accordance with the invention, for example, from the cool down of the engine block or by a comparison of the engine block temperature to the intake-air temperature. The operating state of the oxygen probe heater so determined is displayed to the driver by the activation of a corresponding control device and/or, if required, read into a fault memory.
摘要:
The invention is directed to a method for lambda control of an internal combustion engine having a catalyzer and a measuring probe arrangement in front of the catalyzer for emitting a measuring signal and a testing probe arrangement behind the catalyzer for emitting a test signal. The method includes the steps of: forming a ratio between the measuring signal and the test signal at pregiven operating conditions; evaluating said ratio as an estimating quantity for the conversion rate of the catalyzer; and, modifying output values of control parameters in a pregiven controlled manner on the basis of the instantaneous values of said ratio, said output values being applicable for controlling an internal combustion engine having a new catalyzer. This method affords the advantage that it evaluates a catalyzer with the aid of the above-mentioned ratio value and controllably modifies values of control parameters in dependence upon the evaluation ratio. This leads to an especially stable control with low toxic gas discharge.
摘要:
The invention is directed to a method for protecting a catalyzer against overheating. The method includes the steps of checking whether an injection valve no longer correctly closes by means of a conventional diagnostic process. If the condition is present that an injection valve no longer correctly closes, the air/fuel mixture for all cylinders is enriched and an overrun switchoff is inhibited. The method leads to the condition that in all load ranges, the oxygen quantity reaching the catalyzer is limited so that no damaging afterburning can take place. In this way, the catalyzer is protected against overheating and the affected vehicle is not disabled.
摘要:
In operation of an internal combustion engine, an air filling (rl) in a combustion chamber is ascertained, taking into account a pressure (ps) in an intake conduit. It is proposed that the air filling (rl) be ascertained on the basis of a model (A), which as its input variables receives an rpm (nmot) of a crankshaft and a ratio of the pressure (ps) in the intake conduit (22) to an ambient pressure (pu).
摘要:
In an internal combustion engine the fuel is injected into an intake manifold. A quantity characterizing the injection quantity is a function of a predicted quantity which characterizes a predicted air charge. A setpoint quantity is used for determining the predicted quantity which characterizes a setpoint air charge.
摘要:
A method and a device for operating an internal combustion engine having exhaust-gas recirculation are provided, which make it possible to dispense with an ambient-pressure sensor. In this context, an intake-manifold pressure and an ambient pressure are modeled. The intake-manifold pressure is modeled as a function of the modeled ambient pressure. The intake-manifold pressure is also measured. The modeled intake-manifold pressure is compared to the measured intake-manifold pressure. The modeled ambient pressure is adapted as a function of the comparison result. The modeled ambient pressure is adapted only when the exhaust-gas recirculation is inactive.