Abstract: Disclosed is a method for establishing an engine maintenance diagnosis. The engine includes a throttle which regulates air access into an air intake system of the engine, a position sensor which measures the position of the throttle, a manifold in fluidic communication with the throttle, a pressure sensor which measures the pressure in the manifold, at least one intake valve, a richness probe which measures an oxygen level and a richness controller for modifying the proportions of air and fuel in the air-fuel mixture. The method uses two air flow measurements in order to identify a problem in the throttle or the play at the valves.

Abstract: A method for adapting to the tolerances of a system including at least one position sensor and a rotary target. When the target rotates, the sensor(s) detects (detect) a predefined singularity on the target at an instant T_i, including: acquisition of a series of n+1 instants T_0 to T_N corresponding to a rotation R of the target; determination of theoretical values Theo_i for each instant T_i while considering that the time corresponds to the time that the target takes to effect the rotation R, taking account of any acceleration during the rotation R and as a function of a position of the predefined singularities on an ideal target produced without tolerance; conversion of the time difference between Theo_i and T_i into an angular difference A_i for a corresponding singularity of the target detected by a sensor; and memory-storage of the angular differences A_i for each singularity of the target.

Abstract: Disclosed is a method for controlling combustion in an internal combustion engine including, on the one hand, an air inlet pipe provided with an air flow regulator in the pipe and, on the other hand, a single cylinder associated with the regulator, and including the following steps: determining the engine speed and/or load; and when the speed is below a predetermined value and/or the engine load is below a predetermined value, the air flow regulator in the inlet pipe is operated in such a way that the air flow is temporarily reduced during the engine cycle compared with the position that the butterfly-type throttle valve occupies during the other strokes of the engine cycle, while an intake valve that lets air from the inlet pipe into the corresponding cylinder is open.

Abstract: Disclosed is a pulley having: a shaft; a first shroud, called the fixed shroud, mounted so as to be unable to move in translation with respect to the shaft; a second shroud, called the movable shroud, mounted to be driven in rotation by the shaft but is able to move longitudinally with respect to the latter; a mechanism for mechanically controlling the longitudinal movement of the second shroud with respect to the shaft, having: —a first assembly, which is mounted on the shaft and driven in rotation by the latter, —a second assembly, which is mounted on the shaft by way of at least one torsion spring such that the relative angular position of the second assembly with respect to the shaft depends on the torque transmitted by the shaft, and —a device for locking in at least one position between the first assembly and the second assembly.

Abstract: A method for estimating pressure in an intake manifold of an indirect injection combustion engine. A pressure sensor measures pressure in the intake manifold, the intake manifold being in fluidic communication with a combustion cylinder, a piston guided in translation in the combustion cylinder and connected to a rotating crankshaft. The method includes: measuring, with the pressure sensor, a maximum pressure corresponding substantially to a maximum pressure in the intake manifold during a preceding cycle of the engine; measuring, with the pressure sensor, a minimum pressure corresponding substantially to a minimum pressure in the intake manifold during the preceding cycle of the engine; determining a pre-calculated average pressure correction factor from a crankshaft angular position and from an engine speed; and estimating the pressure in the intake manifold for the crankshaft angular position of the current engine cycle from the average correction factor and from the minimum and maximum pressures.

Abstract: A method for estimating pressure in an intake manifold of an indirect injection combustion engine. A pressure sensor measures pressure in the intake manifold, the intake manifold being in fluidic communication with a combustion cylinder, a piston guided in translation in the combustion cylinder and connected to a rotating crankshaft. The method includes: measuring, with the pressure sensor, a maximum pressure corresponding substantially to a maximum pressure in the intake manifold during a preceding cycle of the engine; measuring, with the pressure sensor, a minimum pressure corresponding substantially to a minimum pressure in the intake manifold during the preceding cycle of the engine; determining a pre-calculated average pressure correction factor from a crankshaft angular position and from an engine speed; and estimating the pressure in the intake manifold for the crankshaft angular position of the current engine cycle from the average correction factor and from the minimum and maximum pressures.

Abstract: Disclosed is a method for managing a piston pump using a computer of a vehicle, the pump including a guide, a piston slidably mounted in the guide, and a solenoid, suitable for moving the piston, the method including, as long as the fuel pressure in the compression chamber of the pump is below a predetermined pressure threshold, a step of the computer controlling the solenoid in order to move the piston to its high position, and a step of the computer detecting that the predetermined pressure threshold has been exceeded when the current value, measured after a predetermined period, is greater than or equal to a predetermined reference value so that the computer ceases to control the solenoid.

Abstract: Disclosed is a method for regulating the speed of an engine which drives a disengageable device. The regulation of the engine speed is effected in accordance with a first mode when the disengageable device is disengaged and in accordance with a second mode when the disengageable device is engaged. The determination is effected by: —estimating the resistive torque exerted on the engine by the disengageable device; -changing a binary value from a first value representative of the disengaged state to a second value representative of the engaged state when the estimated resistive torque is higher than a first predetermined threshold for a first predetermined period of time; and —changing the binary value from the second value to its first value when, for a second predetermined period of time, the estimated resistive torque is lower than a second threshold possibly equal to the first threshold.

Abstract: Disclosed is a solution to the use of a speed limiter in a motorcycle that has a high capacity for acceleration, including a method for limiting the speed of a motorcycle using precise parameters of speed, acceleration and required engine torque and a single control button to manage the smart activation and deactivation of the limiter and to input new speed limits Vlim in a simple way. It thus allows the use of a speed-limiting system in a motorcycle that has a high power/weight ratio by avoiding the sources of interference with the riding and the effects liable to jeopardize its stability.

Abstract: Disclosed is a method for controlling a speed of a vehicle combustion engine, the engine including at least one combustion chamber, into which a mixture of air and fuel is injected, and an air box, configured to inject the air into the combustion chamber and having an air flow rate controlled by a regulating butterfly valve, the regulating butterfly valve having a variable angular position, controlled by a predetermined position of an actuator. The method includes the steps of evaluating a so-called “load” resistant torque resulting from a plurality of external loads applied to the engine, determining, from the calculated load resistant torque, a position of the actuator, so as to determine an angular position of the regulating butterfly valve, and controlling the position of the actuator, so as to control the engine speed.

Abstract: A method for controlling an internal combustion engine with a crankshaft position sensor, intake air pressure sensor and fresh air intake throttle valve, includes: determining the engine's rotational speed based on the crankshaft position derivative relative to time; determining the intake air pressure for a first crankshaft position corresponding to 180° before top dead center; determining the intake air pressure for a second crankshaft position corresponding to 390° before top dead center; determining an atmospheric pressure learning pressure threshold based on the engine's rotational speed; determining whether the difference between the intake air pressures for the first and second crankshaft positions is below the atmospheric pressure learning pressure threshold; if so, commanding atmospheric pressure learning by applying a first-order filter to the intake air pressure for the second crankshaft position; and controlling the internal combustion engine as a function of the learned atmospheric pressure value

Abstract: A method for controlling an air-cooled internal combustion engine (ICE) of a motor vehicle controlled by an electronic control unit, includes: activating the electronic control unit; zeroing stored values of temperature of the ICE and the filtered filtering coefficient; in one iteration, —determining whether the ICE is operating, determining a filtering coefficient and a temperature setpoint, —determining a filtered filtering coefficient based on the filtering coefficient and the stored filtered filtering coefficient value, —determining temperature of the ICE according to the coefficient, temperature setpoint and stored temperature of the ICE, —determining whether the ICE is moving and whether the difference between engine temperature and admitted air temperature is below a threshold, ? if not, storing the filtered filtering coefficient and the temperature of the ICE, then beginning a new iteration, and ? if so, transmitting a signal authorizing the shutdown of the electronic control unit.

Abstract: Disclosed is a method for detecting the clogging of an air filter including the following steps when the cross section for the passage of air in an intake tract is greater than a predetermined passage cross section: measuring a pressure in the intake tract at the end of a phase of admitting air into a cylinder; measuring a pressure in the intake tract at the end of an exhaust phase in a cylinder; and determining that the air filter is clogged by comparison between at least one pressure measured during a pressure measurement at the end of the phase of admitting air into a cylinder and, on the other hand, a pressure measured during a pressure measurement at the end of the exhaust phase, the filter being estimated to be clogged when the comparison yields a value higher than a predetermined value.

Abstract: A method for measuring the flow rate MAF of cool air entering an intake manifold of a two-stroke engine, the intake manifold being located between a throttle body and an intake system. The method uses a specific prediction model depending on whether the two-stroke engine is subject, on the one hand, to a light load and, on the other hand, to a medium or heavy load. The model suitable for the load is selected using a predetermined threshold and two absolute pressure measurements taken at the intake manifold at crankshaft angles of rotation around top dead center and bottom dead center. Next, a pressure quotient is formed for each model which will be used to deduce the flow rate of cool air entering the intake manifold.

Abstract: A method for measuring the flow rate MAF of cool air entering an intake manifold of a two-stroke engine, the intake manifold being located between a throttle body and an intake system. The method uses a specific prediction model depending on whether the two-stroke engine is subject, on the one hand, to a light load and, on the other hand, to a medium or heavy load. The model suitable for the load is selected using a predetermined threshold and two absolute pressure measurements taken at the intake manifold at crankshaft angles of rotation around top dead center and bottom dead center. Next, a pressure quotient is formed for each model which will be used to deduce the flow rate of cool air entering the intake manifold.

Abstract: Process for calculating the torque of an internal combustion engine having electronic injection. The method includes having a cogged target with an indexed reference rotating before a fixed sensor. The defects of the target are corrected by distinguishing the combustion interval of the target from the reference. A term assigned to each interval is $g(b)i which is determined in the absence of combustion from the measurement of the engine torque which is proportional to the pressure in the commutator represented by the equation Ci=K.Pcoll=&agr;(&Sgr;N+$g(b)i)N2 where Ci is the engine torque, Pcoll is the pressure, N is the engine power, K is the proportionality factor and &agr; is a constant term.

Abstract: A method for detecting a misfire in at least one truck or motor vehicle internal combustion engine cylinder by analysing the values (Cg, n, i) of a quantity (Cg) characteristic of combustion and generated by observing the rotation of the crankshaft to detect the occurrence of a misfire. According to the method, misfire detection is suspended for a predetermined time when the analysis of said values (Cg, n, i) reveals anomalies originating in the transmission power line between the drive shaft and the vehicle wheels.

Abstract: This method includes detecting the passage before a sensor of each of the teeth of the inertial flywheel of an engine; measuring the time of passage d.sub.i of each of these teeth; constituting a measurement horizon extending on both sides of the angular range of the explosions; dividing this measurement horizon into eight sets of teeth of equal length of which six are for the angular range of the explosions; measuring the passage times of these eight sets and in assigning them a rank in the measurement horizon du.sub.+1, du.sub.0, . . . , du.sub.5, du.sub.+1 ; calculating the period of the explosions T=du.sub.0 +du.sub.+1 +du.sub.2 +du.sub.3 +du.sub.4 +du.sub.5 ; calculating a term Q.sub.c =2du.sub.0 -du.sub.-1 -du.sub.3 -du.sub.+1 +2du.sub.5 ; calculating a term D.sub.c =p.multidot.Q.sub.c where p=.pi./2.sqroot.3, a constant stored in a memory; and calculating the desired torque using the relation Cg.sub.c =A.multidot.D.sub.c /T.sup.3 +B/T.sup.2 in which A and B are constants stored in a memory.