Abstract: The device operates by correcting the opening of an additional air control valve (13) as a function of the error E=N.sub.c -N between a set-point speed (N.sub.c) and the actual speed (N), and of the time derivative (E') of this error. The correction is a function of the deviation between the actual state of the engine (E, E') and the locus of the ideal states of the engine, defined by the pairs of specific values (E, E') which correspond to the states of the engine which allow the set-point speed (N.sub.c) to be regained without correcting the nominal opening of the valve (13). The device includes means (16, 17, 18) for outputting signals representing the error and its derivative to controllers (19, 19') whose outputs (.DELTA.u.sub.1, .DELTA.u.sub.2) are combined linearly by means (20, 20', 24) which output a signal (.DELTA.u) for correcting the nominal control of the opening of the valve (13), as a function of the aforementioned deviation.

Abstract: The speed of an internal combustion engine is monitored during the entry thereof into low-idle speed operation. The engine speed can thereby be slaved to a predetermined reference point value. When a predetermined engine condition occurs which is considered to require the engine to switch to idling speed, the set speed of the engine is forced downwardly according to a predetermined time law. The set speed thereby shifts towards the predetermine idling speed.

Abstract: Fuel vapors leaving the fuel tank of a motor vehicle are recovered with a filter cartridge inserted between the tank and the intake manifold of the engine. An atmospheric connection duct of the cartridge can be selectively connected to the intake partial vacuum with a pneumatic distributor. The leaktightness of the device is thereby tested.

Abstract: A method and device for verifying the operating condition of a system for recovering vapors from a vehicle fuel tank. A vapor cartridge is insulated from the outside air and the vapor circuit of the recovery system is connected, on the one hand, to the intake port of the engine and, on the other hand, to an outlet line for the exhaust gases from the engine. The device selectively activates insulation and connection valves to sweep the cartridge with exhaust gas. Richness in oxygen of the air-fuel mixture supplied to the engine is then measured and compared with a predetermined value in order to deduce the presence of a break in the vapor circuit when the predetermined value is exceeded.

Abstract: The instantaneous energy of the pinging phenomenon is measured, a quantity (R.sub.i) dependent on the instantaneous value of this same measurement is calculated, a sliding average value (R.sub.m) of the quantity (R.sub.i) weighted by a forget factor is calculated and a correction (R.sub.A) of the ignition advance angle is calculated from an inference engine marshalling "fuzzy" logic rules enabling the membership class of (R.sub.a) to be established from those of (R.sub.i) and of (R.sub.m).

Abstract: The process and device are for detecting combustion irregularities in an internal combustion engine. The process consists in measuring the time intervals between the angular positions of the crankshaft, in grouping these time differences in sets of samples corresponding to each combustion phase, in calculating from each set a critical parameter that is representative of the variation in the instantaneous speed at the moment of combustion, and in comparing this parameter with a fault threshold in order to make a combustion diagnosis. Diagnosis at medium and high speeds is thus possible.

Abstract: A second spark is triggered, after a first ignition spark. The initiation overvoltage of the second spark is detected. The overvoltage and the occurrence or the non-occurrence of a failure of ignition of the air/fuel mixture prior to the second spark is deduced, according to whether the overvoltage is greater or less than a predetermined threshold voltage. Application to the protection of a chamber containing an oxidation, reduction catalyst for the exhaust gases of the engine.

Abstract: An oxygen sensor, whose output signal switches between two levels, is arranged in the gas flow leaving the catalytic converter. During regulation at a stabilized speed, the injection time suitable for ensuring stoichiometry of the air/fuel mixture is determined. During a predetermined time interval a time variation of symmetric deviation, whose amplitude and shape is predetermined about a base injection time chosen from the determined injection time, is imposed on the injection time. The base injection time used during successive time intervals is modified progressively and in a monotonic manner so as to center the deviation of the injection time on that of the oxygen storage capacity of the catalytic converter. Catalyst efficiency is evaluated from an oscillation of this signal.

Abstract: An apparatus for controlling a suspension system disposed between a wheel and a body of an automotive vehicle, has a device for adjusting a response of the suspension system to mechanical excitations transmitted by the body and/or the wheels. A first controller is sensitive to a vertical speed and a vertical acceleration of the vehicle body, for developing a first virtual control signal of the adjusting device which is suitable for optimizing a ride of the vehicle. A second controller is sensitive to a deflection of the wheel and a vertical speed of the wheel relative to the ground, for developing a second virtual control signal of the adjusting device which is suitable for optimizing contact between the wheel and the ground. A supervising device is sensitive to the first and second virtual control signals for developing a real control signal which is applied to the adjusting device for adjusting the response of the suspension system as a function of a predetermined behavior strategy.

Abstract: An entry into an acceleration phase of the vehicle is detected, the ignition advance of the engine is then reduced to a predetermined value (a.sub.L) and the advance is maintained at this value for a predetermined time interval (.DELTA.t) which is a function of the selected gear ratio (r) of a gearbox placed on the output side of the engine.Application to a vehicle propelled by an internal-combustion engine associated with an ignition- and injection-control computer.

Abstract: The dynamic behaviour of the engine (1) is monitored and the existence of misfires is deduced from the detection of irregularities in this behaviour induced by these misses. According to the invention, forces transmitted between the engine (1) and the chassis (2) of the vehicle in which it is installed are sensed, the amplitude of these forces is compared to a predetermined threshold value, from the exceeding of this threshold the application to the engine of external forces is deduced and the detection (8) of possible misfires is inhibited when these external forces are applied to the engine (1) when the load of the latter is lower than a predetermined load value. Application is to the protection of a catalytic converter.

Abstract: The mean oxygen richness (S.sub.o) of the exhaust gases is measured during a first engine operating phase during which the device for injection of air is active and the mean oxygen richness (S.sub.1) of the air/exhaust gases mixture is measured during a second consecutive phase during which this device is inactive and the operating condition of the device is diagnosed by comparing the difference (S.sub. -S.sub.1) in the oxygen richnesses measured during these two phases, with an expected value of this difference. Application to an engine equipped with a catalytic chamber for oxidation-reduction of the exhaust gases.

Abstract: The device comprises (a) an external impedance (R.sub.ext) connected up between a voltage source (E) for powering the circuit and a pin (4) connected to a high-impedance input (3) of the logic part of this circuit, (b) a branch of the analogue circuit, connected up between this pin (4) and the earth of the circuit and, (c) a circuit (5) transmitting logic signals and connected up to this pin (4) by a logic output (6) which offers a high impedance in one of its two logic states, a specified current being established in the said pin when the said output is in the high-impedance state.Application to the limitation, regulation, directing or measuring of the current in a load outside the integrated circuit.

Abstract: A sensor for measuring dielectric constant or resistivity of a flowing liquid, and especially of fuel mixtures for determining alcohol content, includes an inner tube through which the liquid flows, an outer sleeve about the inner tube in coaxial relation, holes in the inner tube to provide fluid communication at two locations to the space between the tube and the sleeve, and a partial restriction in the tube to divert some of the fluid flow into the space between the tube and the sleeve. The tube forms the inner electrode of a capacitor and the sleeve forms the outer electrode of the capacitor to measure dielectric constant. The ends of the sleeve are sealed in liquid tight fashion.

Abstract: According to the invention, a) from the position of an accelerator pedal actuated by the driver, a value is extracted of a power (P.sub.d) requested by this driver, b) in various vehicle operating phases, a base power (P.sub.b) absorbed by the vehicle over and above the power possibly required to move the latter is calculated, and c) the quantities of air and of fuel admitted into the engine are controlled in such a way as to drive the power (P.sub.m) which it delivers to the sum of the requested (P.sub.d) and base (P.sub.b) powers.

Abstract: A circuit for measuring current in a power MOS transistor (M0) comprises second (M1) and third (M2) transistors in series of the same type and same technology as, but having a smaller surface than, the power transistor and arranged in parallel on the latter. The two series transistors have their gates connected to the gate of the power transistor. The current in transistor (M2) which is connected to the reference electrode of the power transistor is measured.

Abstract: In a method and device for fastening an electronic circuit substrate onto a support, a looped line of an adhesive product in the viscous state is deposited on one of the surfaces of the substrate or the support to be fastened to one another. The surfaces are placed opposite each other in order to establish a space defined by the line of adhesive product and areas of the opposing surfaces inside the line. A reduced pressure is applied to the space by a suction device so as to squash the line of adhesive product between the two surfaces to be assembled, in order to spread the viscous adhesive product in a layer with a uniform thickness, and the layer formed in this way is dried. The method and device are applied to the fastening of electronic circuit substrates in protective casings.