Abstract: A plant controller includes a feedback controller configured to calculate a control input provided to a plant so that a control output of the plant matches a target value. The feedback controller includes a controller transfer function that is a transfer function of the feedback controller. The controller transfer function is expressed by a product of an inverse transfer function of a transfer function of a control target model obtained by modeling the plant and a disturbance sensitivity correlation function defined using a sensitivity function. The sensitivity function indicates sensitivity of a disturbance to be applied to the plant with respect to the control output. The sensitivity function is defined by using a response characteristic parameter that indicates a response characteristic of the plant.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine includes an air-fuel ratio sensor having an output characteristic which is nonlinear with respect to the air-fuel ratio of exhaust gas. An output deviation converter is configured to convert an output deviation to a first predetermined value if an output value of the air-fuel ratio sensor is on a richer side of a predetermined target value and to a second predetermined value if the output value is on a leaner side of the target value. A control input calculator is configured to calculate a control input to feedback-control the output value of the air-fuel ratio sensor such that the output deviation converted by the output deviation converter is to be zero. An air-fuel ratio controller is configured to control the air-fuel ratio of exhaust gas using the control input calculated by the control input calculator.

Abstract: An air-fuel ratio control apparatus for an internal-combustion engine includes an air-fuel-ratio sensor, a control-input calculator, an air-fuel-ratio controller, and a gain calculator. The air-fuel-ratio sensor is disposed in an exhaust channel in the internal-combustion engine and is configured to detect an air-fuel ratio in exhaust gas. The control-input calculator is configured to calculate a control input in accordance with an output value of the air-fuel-ratio sensor. The air-fuel-ratio controller is configured to perform a feedback control using the control input such that the output value of the air-fuel-ratio sensor reaches a target value. The gain calculator is configured to calculate a gain in accordance with the output value when the output value is leaner than the target value. The gain is to be used in calculating the control input.

Abstract: An air-fuel ratio control system for an internal combustion engine, which, at the resumption of air-fuel ratio feedback control, is capable of setting the initial value of an integral term of the feedback control to a value properly learned in preceding feedback control, thereby enabling improvement of control accuracy. To feedback-control the output value of an O2 sensor to a target value, a target air-fuel ratio is calculated. During the feedback control, when it is determined that a predetermined condition in which it is estimated that exhaust gas air-fuel ratio upstream of the catalyst is excellently reflected on an exhaust gas air-fuel ratio at a location midway or downstream of the catalyst is satisfied, an adaptive law input calculated immediately before interruption of the feedback control is updated and stored as the initial value of an integral term for the following execution of the feedback control.

Abstract: An air bypass valve failure detecting device outputs an opening command to an air bypass valve when a throttle valve suddenly closes, thereby prevent surging from occurring in a second intake passage between a turbocharger and a throttle valve. When the opening command is outputted to the air bypass valve, failure detection for the air bypass valve is permitted only if an intake air quantity of an engine immediately before a closing command is changed to the opening command is equal to or larger than a predetermined value. Thus, it is possible to prevent the failure detecting device from erroneously determining that the air bypass valve is normal although valve closing failure of the air bypass valve has occurred. This is because, when the intake air quantity is smaller than the predetermined value, surging does not occur in the second intake passage even if the valve closing failure of the airy bypass valve has occurred.

Abstract: When an engine load QC is equal to or larger than a predetermined value, an acceleration-state determiner determines that a turbine is in an acceleration state, and a supercharging-pressure-control-state determiner determines that supercharging-pressure controller (a bypass valve, a wastegate, and a variable flap) of a turbocharger are in a maximum supercharging pressure control state (a closed valve state), i.e., when a delay coefficient ? of the turbocharger calculated by a delay-coefficient calculator on the basis of an actual supercharging pressure ?c and a convergent value ?c* of a supercharging pressure calculated by a convergent-value calculator indicates a value peculiar to the turbocharger, a failure of the supercharging-voltage controller is determined on the basis of the delay coefficient ?.

Abstract: When an engine load QC is equal to or larger than a predetermined value, an acceleration-state determiner determines that a turbine is in an acceleration state, and a supercharging-pressure-control-state determiner determines that supercharging-pressure controller (a bypass valve, a wastegate, and a variable flap) of a turbocharger are in a maximum supercharging pressure control state (a closed valve state), i.e., when a delay coefficient ? of the turbocharger calculated by a delay-coefficient calculator on the basis of an actual supercharging pressure ?c and a convergent value ?c* of a supercharging pressure calculated by a convergent-value calculator indicates a value peculiar to the turbocharger, a failure of the supercharging-voltage controller is determined on the basis of the delay coefficient ?.

Abstract: An air bypass valve failure detecting device outputs an opening command to an air bypass valve when a throttle valve suddenly closes, thereby prevent surging from occurring in a second intake passage between a turbocharger and a throttle valve. When the opening command is outputted to the air bypass valve, failure detection for the air bypass valve is permitted only if an intake air quantity of an engine immediately before a closing command is changed to the opening command is equal to or larger than a predetermined value. Thus, it is possible to prevent the failure detecting device from erroneously determining that the air bypass valve is normal although valve closing failure of the air bypass valve has occurred. This is because, when the intake air quantity is smaller than the predetermined value, surging does not occur in the second intake passage even if the valve closing failure of the airy bypass valve has occurred.

Abstract: A vehicle component tamper detection system is provided capable of appropriately preventing tampering from occurring, and of facilitating and ensuring detection of such tampering when it occurs, while maintaining flexibility in layout and in manufacturing processes. The present invention omits wiring between an RFID 12 and an ECU 14 by employing a small radio frequency identification integrated circuit (RFID) to wirelessly transmit signals to a receiver 13. With this configuration, the present invention contributes to increased layout flexibility as well as a reduction in assembly steps and manufacturing costs. Furthermore, because the RFID 12 is small, the RFID 12 may be mixed in slurry and disposed at an inconspicuous portion of a detection target component 11. Subsequently, it is possible to hinder visual confirmation of the RFID 12, thereby making the tampering itself difficult.

Abstract: An ozone purifier for a vehicle is configured of an ozone purification catalyst mounted on the vehicle; a first ozone concentration detection mechanism for detecting an ozone concentration in air before its passing the ozone purification catalyst; a second ozone concentration detection mechanism for detecting an ozone concentration in air after its passing the ozone purification catalyst; a deterioration detection mechanism for using output values of the first and second ozone concentration detection mechanisms and detecting deterioration of the ozone purification catalyst; and furthermore a mechanism for calibrating the output values of the first and second ozone concentration detection mechanisms, and when detecting the deterioration of the ozone purification catalyst, the purifier calibrates the output values of the first and second ozone concentration detection mechanisms.

Abstract: A system for detecting misfire occurred in an internal combustion engine installed in a vehicle, based on a rotation signal outputted by an engine speed sensor. In the system, first and second fluctuation value of the wheel rotation speed are calculated based on a signal, outputted by a wheel speed sensor, indicating a rotation speed of the vehicle wheel, and a parameter indicative of a degree of wheel rotation speed fluctuation is calculated by multiplying the calculated first and second fluctuation values. Then, the parameter is compared with a threshold value and when the number of times the parameter was equal to or greater than the threshold value has reached a predetermined value, it is discriminated that the vehicle is under a rough road running condition that affects the misfire detection and the misfire detection is disabled. With this, it becomes possible to reliably avoid false detection of misfire while ensuring that misfire detection is not erroneously disabled when misfire does occur.

Abstract: A system for detecting misfire occurred in an internal combustion engine installed in a vehicle, based on a rotation signal outputted by an engine speed sensor. In the system, first and second fluctuation value of the wheel rotation speed are calculated based on a signal, outputted by a wheel speed sensor, indicating a rotation speed of the vehicle wheel, and a parameter indicative of a degree of wheel rotation speed fluctuation is calculated by multiplying the calculated first and second fluctuation values. Then, the parameter is compared with a threshold value and when the number of times the parameter was equal to or greater than the threshold value has reached a predetermined value, it is discriminated that the vehicle is under a rough road running condition that affects the misfire detection and the misfire detection is disabled. With this, it becomes possible to reliably avoid false detection of misfire while ensuring that misfire detection is not erroneously disabled when misfire does occur.