Abstract: A plurality of intake air amount control systems are provided for diagnosing a failure of each intake air amount control system. At the failure of any of them, a fail-safe control is performed using a normal intake air amount control system.

Abstract: A required fuel amount for an engine is calculated at a predetermined calculation cycle. A fuel injection amount to be injected from an upstream injection valve and a fuel injection amount to be injected from a downstream injection valve are then calculated. After fuel injection on the basis of the calculated fuel injection amounts, a lack of fuel delivered by the fuel injection amounts immediately before re-calculation of a required fuel amount at the calculation cycle until the end of an intake stroke (end of an intake valve opening period), is calculated by subtracting the fuel injection amounts from the re-calculated required fuel amount. The calculated lack of fuel amount is injected from the downstream injection valve during the intake stroke, e.g., in stages 6 and 7.

Abstract: In a vane type valve timing control apparatus, when an amplitude of a rotation phase of a cam shaft with respect to a crank shaft is above a predetermined value, a target value for the rotation phase is forcibly changed to a maximum advance angle and a maximum delay angle, so that oil of an advance angle side hydraulic chamber and a delay angle side hydraulic chamber is discharged together with air.

Abstract: A plurality of cam sensors are provided for outputting cylinder judgment signals and the output number of cylinder judgment signals between reference crank angle positions are counted for each cam sensor, to thereby perform cylinder judgment based on combination of the output number of the counted cylinder judgment signals.

Abstract: In a variable valve mechanism that changes an opening characteristic of an engine valve by a rotation force of a direct current motor, an electric current to be supplied to the direct current motor is forcibly lowered by providing restriction to a control signal of a power transistor that supplies the electric current to the direct current motor, or providing restriction to a change speed of target value of the opening characteristic, when an engine temperature is high.

Abstract: The present invention enables reliable shift to a fail-safe processing upon detection of failure by RAM diagnosis. To this end, the diagnosis result of the RAM diagnosis is doubly stored, as flags, into mutually different two addresses of the RAM; and a fail-safe processing is conducted based on the doubly stored diagnosis result flags when at least one of the flags indicates existence of failure. Otherwise, the diagnosis result of the RAM diagnosis is stored, as a flag, into a predetermined register; and a fail-safe processing is conduced based on the diagnosis result flag stored in the register such that the fail-safe processing is conducted when the flag indicates existence of failure.

Abstract: A required fuel amount for an engine is calculated at a predetermined calculation cycle. A fuel injection amount to be injected from an upstream injection valve and a fuel injection amount to be injected from a downstream injection valve are then calculated. After fuel injection on the basis of the calculated fuel injection amounts, a lack of fuel delivered by the fuel injection amounts immediately before re-calculation of a required fuel amount at the calculation cycle until the end of an intake stroke (end of an intake valve opening period), is calculated by subtracting the fuel injection amounts from the re-calculated required fuel amount. The calculated lack of fuel amount is injected from the downstream injection valve during the intake stroke, e.g., in stages 6 and 7.

Abstract: A photochemical hole burning medium is composed of a material in which a rare earth complex and a reducing agent is dispersed in a solid matrix. The rare earth complex may be at least one complex selected from the group consisting of a europium (III) crown ether complex, a europium (III) polyether complex, and a europium (III) cryptand complex.

Abstract: In an internal combustion engine provided with a variable valve operating apparatus which variably changes a valve operating characteristic of at least one of intake and exhaust valves, a reference intake pipe pressure and a reference fresh air ratio corresponding to a reference operating condition of the variable valve operating apparatus are computed based on the detection value of the engine operating condition, a fresh air ratio correction amount corresponding to an operating condition of the variable valve operating apparatus is computed based on the detection value of the intake pipe pressure and the reference intake pipe pressure, the reference fresh air ratio is corrected based on the computed fresh air ratio correction amount to compute a final fresh air ratio, and an operating amount of the control object in the internal combustion engine is computed based on the final fresh air ratio to operate the control object.

Abstract: Calculating an acceleration corrective in response to a subtle change in a throttle action by utilizing first and second rate-of-change calculators to calculate rates of change D&thgr;THA, D&thgr;THB of a throttle opening in preceding first and second periods (second period>first period) per a predetermined crankshaft rotational angle). A maximum value updater updates a stored value in a maximum value memory with a greater one of past and present maximum rates of change D&thgr;TH of the throttle opening, based on a compared result from a comparator. Points in a plurality of cycles read from a point calculator based on the maximum rate of change D&thgr;TH of the throttle opening are added together and inputted to a corrective value calculator.

Abstract: To change a fuel injection quantity to follow a throttle opening change in a low load region. A first calculator calculates a basic injection time using a throttle opening and an engine rotational speed. A second calculator calculates a basic injection time using an intake pipe negative pressure and the engine rotational speed. A selector selects the first calculator when the load is higher, and selects the second calculator when the load is lower. If the rate of change of the throttle opening is greater than a reference value, then a switcher sets the selector to select the first calculator. Thus, if the rate of increase of the throttle opening is greater than the reference value even when the load is low, the first calculator is selected.

Abstract: In an internal combustion engine equipped with a variable valve operating mechanism that performs a valve timing control and a valve lift amount control of at least one of an intake valve and an exhaust valve, target values of the valve timing and the valve lift amount set based on an engine operating condition are limited by a limit value to limit a control range of one of the valve timing and the valve lift amount in accordance with a control state of the other of the valve timing and the valve lift amount, so that the valve timing and the valve lift amount are controlled based on the respective target values one of which has been limited as above.

Abstract: The apparatus comprises two accelerator position sensors and two throttle position sensors, and when one out of said two accelerator position sensors or said two throttle position sensors fails to operate, a limitation is added to the increase in accelerator position for the output characteristics of the accelerator position sensor. Thereby, the vehicle is enabled to travel at a minimum speed necessary without excessively increasing the engine output. When one of the two throttle position sensors fails to operate, the fuel injection quantity may be set based on the detection value of the accelerator position, which enables the vehicle to be driven by approximately the desired speed without excessively increasing the engine output.

Abstract: In electronically controlling the opening of a throttle valve mounted in an intake system of an engine, the opening is controlled through a sliding mode control, based on a control amount including a control amount portion proportional to the switching function and a control amount portion corresponding to a nonlinear spring torque of a return spring urging said throttle valve in a direction to reduce the throttle valve opening. According to this constitution, the response characteristic of the control unit is maintained while restraining overshoot, enabling the opening to converge to the target opening promptly while sliding along a switching plane. Further, since said control amount includes the control amount portion corresponding to the nonlinear spring torque of the return spring, uncertainty element is reduced, to thereby perform a high response control.

Abstract: To enable accurate detection of the alternative ambient pressure when the correction of fuel supply is carried out by the used of the value of the ambient pressure substituted by the negative pressure in the inlet pipe. The difference between the calculated alternative ambient pressure and the estimated ambient pressure (offset) is set as a plurality of functions of the number of engine revolutions and the throttle opening, and stored in the area determination section with a plurality of areas divided by each offset value. In which area the condition of the engine resides is determined from the number of engine revolution and the throttle opening and the offset corresponding to the area is supplied. The calculation section calculates the calculation base value by the use of the negative pressure PB and the offset. When the relationship between the calculated base value and the last determined alternative ambient pressure is constant, the alternative ambient pressure is renewed by the calculation base value.

Abstract: In an electronically controlled fuel injection apparatus of a speed density type, a new air intake efficiency correction value for correcting an intake pressure is calculated based on the intake pressure, an engine rotation speed, and an advance angle amount of valve timing.

Abstract: Calculating an acceleration corrective in response to a subtle change in a throttle action by utilizing first and second rate-of-change calculators to calculate rates of change D&thgr;THA, D&thgr;THB of a throttle opening in preceding first and second periods (second period > first period) per a predetermined crankshaft rotational angle). A maximum value updater updates a stored value in a maximum value memory with a greater one of past and present maximum rates of change D&thgr;TH of the throttle opening, based on a compared result from a comparator. Points in a plurality of cycles read from a point calculator based on the maximum rate of change D&thgr;TH of the throttle opening are added together and inputted to a corrective value calculator.

Abstract: To change a fuel injection quantity to follow a throttle opening change in a low load region. A first calculator calculates a basic injection time using a throttle opening and an engine rotational speed. A second calculator calculates a basic injection time using an intake pipe negative pressure and the engine rotational speed. A selector selects the first calculator when the load is higher, and selects the second calculator when the load is lower. If the rate of change of the throttle opening is greater than a reference value, then a switcher sets the selector to select the first calculator. Thus, if the rate of increase of the throttle opening is greater than the reference value even when the load is low, the first calculator is selected.

Abstract: To allow an engine having an intake duct for drawing running air to produce a high output by performing appropriate fuel injection depending on dynamic pressure variations. A vehicle speed corrective coefficient calculator calculates a fuel corrective coefficient KVPLS based on a vehicle speed VPLS, and a throttle corrective coefficient calculator calculates a corrective coefficient KV&thgr;TH based on a throttle opening &thgr;TH. A corrective coefficient multiplier multiplies the fuel corrective coefficient KVPLS and the corrective coefficient KV&thgr;TH, thus calculating a vehicle speed fuel adjustment corrective coefficient KVAF. An injection time calculator calculates a basic injection time TiM based on the throttle opening &thgr;TH and an engine rotational speed Ne, and also calculates a fuel injection time Ti by reading the vehicle speed fuel adjustment corrective coefficient KVAF and correcting the basic injection time TiM.

Abstract: In a vane type variable valve timing control apparatus, a neutral control value for retaining a rotation phase of a cam shaft is set in accordance with a target rotation phase, and the supply and discharge of oil to respective hydraulic chambers is performed at a balance corresponding to a change in an urging force of a resilient body for urging the vane.