Abstract: A target command generator for use in a control system for an automatic transmission having a simple planetary gearset in series with a multiple-ratio gearset, the target command generator providing input for a controller for the simple planetary gearset to achieve synchronized control of pressure operated friction elements of the gearsets to effect smooth swap-shifts during an overall transmission ratio change.

Abstract: A shift control ECU includes the steps of storing a position of a shift lever; starting a count-up timer when the shift lever comes to a neutral position; and recognizing a driver's request for the neutral position when a count-up timer value attains TN(1) if the stored shift lever position is a home position and when a count-up timer value attains TN(2) if the stored shift lever position is not the home position. Here, TN(1) is set to be smaller than TN(2).

Abstract: A shift control apparatus for controlling shifting actions of a step-variable automatic transmission for a vehicle, which has a plurality of selectable groups of forward-drive positions having respective different sets of speed ratios, each one of the selectable groups of forward-drive positions including at least one high-speed position each having a speed ratio which is different from that of each high-speed position of any other of the selectable groups, the shift control apparatus including a drive-force-increase determining portion operable to determine whether it is necessary to increase a drive force of the vehicle with the automatic transmission placed in any high-speed position, and a drive-position-group selecting portion operable to select one of the selectable groups of forward-drive positions which includes the at least one high-speed position each having the speed ratio higher than that of each high-speed position of any other of the selectable groups, when the drive-force-increase determining p

Abstract: A shift control system for a V-belt type continuously variable transmission is provided. The shift control system comprises a controller programmed to store an actual transmission ratio of the continuously variable transmission at stop of an associated vehicle drive source, and inhibit, at restart of the vehicle drive source, an initializing operation for returning an operational position of the shift actuator to a standard position when the actual transmission ratio is more on a high-speed side than a predetermined transmission ratio. A shift control method is also provided.

Abstract: An electronic control system includes two speed sensors connected to a microcontroller that is configured to read the sensors and perform the process of determining the gear ratio of a vehicle gearbox. The process includes calculating (several times) which of at least two gear ratios the gearbox is engaged in, then adding up the number of times each of the gear ratios was calculated, and then selecting the gear ratio that was calculated the most times as the true gear ratio.

Abstract: When shifting the gear position into a target gear position from a current gear position, some gear position different from said current gear position is used as one distributing gear position. The control unit controls the pressing load of a synchromesh of one distributing gear position to make at least part of the rotation torque from the drive power source transfer by the friction. Thereby it makes at least part of the rotation torque transferred by a synchromesh of the current gear position decrease. And then it moves the synchromesh of said current gear position to a disengaging position not meshed with said idle gear. Thereafter another gear position different from said target gear position and said one distributing gear position is used as another distributing gear position.

Abstract: There is provided an engine torque control apparatus that is comprised of a torque-down amount calculating section to which the throttle valve opening and the engine speed are inputted and which calculates the torque-down amount based on the inputted values, an inertia correction amount calculating section that calculates the correction amount for inertia of each component part (inertia discharged torque), a friction correction amount calculating section that calculates the correction amount for friction generated by a belt CVT (friction discharged torque), a torque-down amount correcting section that corrects the torque-down amount based on the calculated correction amounts, and an engine torque control section that controls engine torque.

Abstract: In a hydraulic system for an automatic transmission, a method for automatically draining fluid from an oil cooler and related hydraulic lines when power is off to prevent fluid leakage, escape and outflow when they are disconnected from the system. A control system includes a source of relatively high pressure when power is on, an oil cooler, fluid circuit lines for supplying transmission oil to the cooler, a source of low pressure for containing fluid, such as an oil sump, and a valve hydraulically connected to the circuit, high pressure source, and low pressure source, the valve having a first state at which a hydraulic connection through the valve between the circuit and the source of low pressure is closed when power is on, and a second state at which a hydraulic connection through the valve between the circuit and the low pressure source is open when power is off.

Abstract: A slip control system of a lockup torque converter includes a pre-compensator that pre-compensates for a target slip-rotation speed to produce a target slip-rotation speed correction value. A feedback compensator is provided to feedback-control an engagement capacity of a lock-up clutch based on a deviation between the target slip-rotation speed correction value and an actual slip-rotation speed to bring the actual slip-rotation speed closer to the target slip-rotation speed. Also provided is a dead-time processing section that compensates for the target slip-rotation speed correction value to reflect a dead time of dynamic characteristics peculiar to the slip control system in the target slip-rotation speed correction value. The dead-time compensated output is fed to the feedback compensator. The dead time is variable in accordance with a predetermined dead time characteristic.

Abstract: A method and apparatus for adjusting the torque output of a power train of a motor vehicle. An engine is connected to the input end of a continuously variable belt-type transmission. The output end of the belt-type transmission is operably connected to the drivable wheels of a motor vehicle. Open-loop torque control for the power train of the motor vehicle is effected based on specific operating states of the power train and the mechanical tension acting on the belt of the continuously variable belt-type transmission.

Abstract: A mechatronic transmission arrangement for motor vehicles that comprises a transmission housing (1) is disclosed including a mechatronic component (2), and a sensor arrangement (4) accommodated therein. The latter is mounted in a manner that permits its position to change with regard to the mechatronic housing (3). A position adjusting device (13) operates between the sensor arrangement (4) and the transmission housing (1) while passing through the mechatronic housing (3). After adjusting, the sensor arrangement (4) can be fixed by means of a fixing device (18).

Abstract: An objective method is provided for selecting gear ratios for use in a motor vehicle transmission having multiple selectable gears. The method includes selecting gear ratios for a specific application includes calculating a low gear ratio, and a high gear ratio based upon vehicle parameters and performance requirements. The total ratio spread is determined by dividing the low gear ratio by the high gear ratio. Using the total ratio spread, a geometric sequence is created with a plurality of terms, such that each of the terms respectively represent the ratio steps between the gears. Lastly, each gear ratio is divided by its respective ratio step plus one to find the gear ratio for the next gear. This method provides an objective method for selecting gear ratios, such that the steps between each of the ratios are uniformly progressive.

Abstract: A control method for an automatic transmission in which a first and a second control system are provided and regulate the transmission ratio respectively in automatic and in manual mode. The method comprises the stages of activating the first control system and automatically setting a transmission ratio, detecting the presence of a manual command from an operator to modify the transmission ratio in use, performing the manual command from the operator by modifying the transmission ratio set automatically, silencing the first control system for a predetermined time interval such that the transmission ratio set following the manual command is not modified following any automatic gear change request from the first control system, and attributing the control of the automatic transmission to the first control system.

Abstract: A downshift control method for an automatic transmission, which transmission is normally downshifted, to increase a gear ratio, when a vehicle throttle is opened more than a preset value. The method includes a step of selecting a slip-determining threshold on the basis of an instantaneous steering angle of a vehicle. The method also includes steps of detecting a perceived rear wheel speed Vs, and averaging a number of rear wheel speeds Vs to derive an average vehicle speed Va. The normal downshift procedure is overridden, and the automatic transmission is prevented from downshifting, if a difference between the perceived rear wheel speed and the average vehicle speed exceeds the slip-determining threshold T, and the rear wheels are determined to be slipping.

Abstract: A torque variation control device for a vehicle which has a motor providing rotational torque to a drive shaft of a vehicle, a motor control means controlling the motor based on drive torque, and a rotational velocity detection means detecting a rotational velocity of the drive shaft or a rotational shaft of the motor. The device has a feature that the device includes a torque variation detection means detecting a torque variation of the vehicle caused by a variation of the rotational velocity, and a compensation torque setting means setting compensation torque in an opposite phase relative to the torque variation.

Abstract: A side-slip velocity estimation module for a vehicle stability enhancement control system includes a side-slip acceleration estimation module that determines an estimated side-slip acceleration of a vehicle. A limited-frequency integrator integrates the estimated side-slip acceleration to determine an estimated side-slip velocity of the vehicle. A reset logic module clears an output of the limited-frequency integrator when a first condition occurs. The first condition is one of a straight-driving condition, a speed condition, and a sensor bias condition. The estimated side-slip velocity is compared to a desired side-slip velocity to produce a side-slip control signal. The side-slip control signal is combined with a yaw rate control signal to produce an actuator control signal. The actuator control signal is received by one of at least one brake actuator and a rear-wheel steering actuator to create a yaw moment to correct a dynamic behavior of the vehicle.

Abstract: An automatic shift controller for a vehicle which controls a gear-shifting mechanism to engage one of several gear trains. A sub-clutch connects and disconnects so that one of the gear trains, other than a first-speed gear train and a reverse gear train, is engaged or disengaged. By use of a controller, 1) when the vehicle is parked, then the reverse gear is engaged, the main clutch is engaged, and the sub-clutch is disengaged, and 2) when preparation for engine start-up is started in a state wherein the vehicle is parked, then the main clutch is disengaged and the sub-clutch is engaged.

Abstract: A side-slip velocity estimation module for a vehicle stability enhancement control system includes a side-slip acceleration estimation module that determines an estimated side-slip acceleration of a vehicle. A limited-frequency integrator integrates the estimated side-slip acceleration to determine an estimated side-slip velocity of the vehicle. The limited-frequency integrator includes a feedback loop which incorporates a cutoff frequency for the integrator.

Abstract: In a method and apparatus for diagnosing a malfunction in a clutch actuator of a motor vehicle, the actual position of the clutch actuator is measured by a position sensor. Simultaneously, an estimated position of the clutch actuator is calculated by an emulation unit that emulates the function of the clutch actuator. Malfunctions of the clutch-actuator are diagnosed by comparing the actual, measured position to the estimated position.

Abstract: A method for the performance of the gear disengagement in a servo-controlled manual gear change, according to which an oscillation is generated with respect to the angular speed of a primary shaft of the gear change by abruptly opening the relative clutch and the disengagement of the gear is performed around the maximum amplitude of an oscillation half-wave, when this oscillation has caused the angular speed of the primary shaft to be relatively close to the angular speed that the primary shaft has to assume to carry out the engagement of the subsequent gear.

Abstract: Operating range of feedback in CVT ratio control has been extended by use of stabilized values as an actual value of CVT ratio. The actual value of CVT ratio is derived from first and second pulse train signals provided by input and output speed sensors. Updating of rotational speed of the input member is repeated at intervals governed by the first pulse train. Updating of rotational speed of the output member is repeated at intervals governed by the second pulse train. Updating of an old value of a ratio between the latest value of the rotational speed of the input member and the latest value of the rotational speed of the output member to a new value thereof is repeated each time immediately after the rotational speeds of the input and output members have been updated since the latest updating of an old value of the ratio.

Abstract: A center differential limiting control unit calculates and sets a vehicle speed, a target difference in a rotational speed between front and rear axle shafts, a control start difference in the rotational speed, and an actual difference in the rotational speed, respectively. Then, when the actual difference is large than the control start difference, it is determined that a front and rear axle shaft control start condition is established, and front and rear axle shaft differential limiting torque is calculated according to the actual difference and the target difference. In contrast, when the actual difference is smaller than the control start difference, it is determined that the front and rear axle shaft control start condition is not established, and an integral term in the front and rear axle shaft limiting torque and control is set to 0.

Abstract: A method is described for operating an automatic transmission in which a command for changing a current ratio of the automatic transmission is generated when achieving preset operating states of the vehicle automatically or by manual input in a manual shifting mode, the activated manual shifting mode being preferred to an automatic shifting mode. The manual shifting mode is quit when a current vehicle speed is less than a threshold value, or when a longitudinal acceleration of the vehicle is within a defined range, a lateral acceleration is less than a threshold value and a driver type evaluation counter is less than a limiting value.

Abstract: A vehicular automatic shift control unit for executing a cooperative shift control (an upshift inhibition and a downshift) of an automatic transmission based on an information associated with a road condition around a vehicle or a road condition in front of the vehicle, is provided with judging means for judging whether a vehicle exists in a predetermined area including a branch point of the road during execution of the cooperative shift control, and gear ratio maintaining control means for maintaining a gear ratio of the automatic transmission if it is judged that the vehicle exists in the predetermined area.

Abstract: An objective method is provided for selecting gear ratios for use in a motor vehicle transmission having multiple selectable gears. The method includes selecting gear ratios for a specific application includes calculating a low gear ratio, and a high gear ratio based upon vehicle parameters and performance requirements. The total ratio spread is determined by dividing the low gear ratio by the high gear ratio. Using the total ratio spread, a geometric sequence is created with a plurality of terms, such that each of the terms respectively represent the ratio steps between the gears. Lastly, each gear ratio is divided by its respective ratio step plus one to find the gear ratio for the next gear. This method provides an objective method for selecting gear ratios, such that the steps between each of the ratios are uniformly progressive.

Abstract: Although there are various combinations of engine speed and transmission state that correspond to a selected vehicle speed and load, there is one combination that best achieves a predetermined criteria. The present invention relates to a vehicle including a control system that electronically controls engine speed and transmission state in order to best achieve the predetermined criteria, such as fuel economy. There is an electronic control module including a power train algorithm that is in control communication with the transmission and the engine. The predetermined criteria is achieved by establishing a limited engine speed range that is less than an entire engine speed range, and restricting engine speed, via the power train algorithm, to the limited engine speed range. The power train algorithm is also operable to determine a combination of the engine speed, within the limited engine speed range, and transmission state that corresponds to a selected vehicle speed and the predetermined criteria.

Abstract: A transmission electronic control unit includes an operation detection section for detecting the operation state of a transmission, a pulse width control section for controlling the pulse width of a current flown into a linear solenoid for operating the transmission, a constant current control section for controlling the current flown into the linear solenoid to a constant value, and an energization control section. The energization control section is responsive to detection output of the operation detection section, for performing switch control between the operation of the constant current control section and the operation of the pulse width control section so that the constant current control section energizes the linear solenoid when the operation of the transmission is placed in a constant state and that the pulse width control section energizes the linear solenoid when the operation of the transmission is not placed in the constant state.

Abstract: In a method for controlling a drive unit, a driver command value is formed while considering the current transmission ratio and the drive unit is controlled in dependence upon the driver command value. In addition, a predicted driver command value is determined in dependence upon transmission ratios other than the current transmission ratio. In addition, the minimum and maximum possible values are considered in the formation of the driver command value. A correction of the driver command value is undertaken in dependence upon the difference between minimum possible torque and minimum requested torque or between maximum possible torque and maximum requested torque.

Abstract: A low cost control apparatus of a contact mechanism resolving a disadvantage caused when a contact body is moved to make contact with a contacted body by an actuator. A synchronizing mechanism, which a coupling sleeve rotatably and integrally provided with an input shaft is pushed against a synchronizer ring disposed between the coupling sleeve and a synchronized gear, thereby synchronizing rotational speeds of both the components to engage them, is modeled as a collision between an inertia system object and an elastic system object. A computation coefficient (VPOLE, f in FIG. 9) of a switching function for sliding mode control having a deviation between an actual position of the coupling sleeve (Psc, d in FIG. 9) and a target position (Psc_cmd, e in FIG. 9) as a state variable is changed depending on the actual position (Psc), and thereby changing a control ability of the model against a disturbance.

Abstract: A method of changing gear in an automated transmission system of a motor vehicle having a multi-ratio gearbox with an input shaft and an output shaft, a take-up clutch located between the input shaft and an output shaft of an engine, a number of pairs of intermeshing gears.

Abstract: A method for control of operation of shifting elements for an automatic transmission. Each cycle of the control for similar controls are configured to shift in an overlapping manner during operation of the automatic transmission.

Abstract: In a method and apparatus for diagnosing a malfunction in a clutch actuator of a motor vehicle, the actual position of the clutch actuator is measured by a position sensor. Simultaneously, an estimated position of the clutch actuator is calculated by an emulation unit that emulates the function of the clutch actuator. Malfunctions of the clutch-actuator are diagnosed by comparing the actual, measured position to the estimated position.

Abstract: The invention relates to an arrangement and a method for determining the transmission ratio of a continuously variable transmission having a drive end and an output end. A signal, which represents the transmission ratio, is computed in dependence upon a primary rpm of the drive end and a secondary rpm of the output end which are transmitted to the arrangement. A fault signal is generated which is dependent upon the instantaneous primary rpm and/or the instantaneous secondary rpm and indicates whether a value for the transmission ratio is to be outputted as the signal representing the transmission ratio. This value is computed from the detected instantaneous values for the primary rpm and the secondary rpm.

Abstract: The present invention comprises a vehicle speed monitoring device which enables a driver to enter a speed tolerance profile that represents the driver's personal travel speed preferences and which alerts the driver when the vehicle speed falls outside the speed tolerance profile. Specifically, the speed tolerance profile consists of a number of speed tolerance ranges, each associated with a particular posted speed limit. As the vehicle travels through various map zones, the applicable posted speed limit is determined using a customized GPS map. The device determines the vehicle location, speed and the posted speed limit and then compares the vehicle speed using a running average to see whether vehicle speed is within the driver's speed tolerance profile and if not, the device provides the driver with a visual and/or audible warning according to the driver's operational preferences.

Abstract: In a motor vehicle transmission, gears representing different transmission ratios are engaged by applying a force to an actuator output element that couples a selected gear to a rotary shaft. A synchronizing device blocks the coupling of the gear to the shaft until at least an approximate synchronization of rpm-rates has been achieved. A synchronization threshold position corresponding to the blocked condition of the actuator element is stored in a memory of a controller device. The controller device periodically performs an automatic adaptation of the stored value for the synchronization threshold position.

Abstract: Drive unit for motor vehicles, comprising an engine and an automated friction clutch arranged between the engine and its gearbox, the engagement and disengagement of the clutch being controlled by a servo unit, which is controlled by a control computer to which, from various sensors there are fed values of engine speed, rotational speed of the input shaft of the gearbox, the position of the servo unit and the position of the gearsift lever. Points on a torque curve are stored in the memory of the control computer, the curve showing the torque as a function of the servo position (the clutch position). The computer is furthermore programmed to calibrate the servo unit to a pulling position, which provides a predetermined desired value of the torque, and to check, with a certain regularity, the actual value of the torque in the pulling position and, if needed, the adjust the actual value towards the desired value by changing the position of the servo unit.

Abstract: A method for estimating deceleration of a wheeled vehicle during a transmission gear shift. A first input signal indicative of an engine torque and a second signal indicative of an input shaft rotational speed are used to predict the expected vehicle deceleration during a transmission ratio shift to a target gear ratio. An expected vehicle deceleration value is outputted to a shift decision control unit for implementing a transmission gear shift.

Abstract: In solenoid control method and apparatus for an automatic transmission, a current signal varied in a stepwise manner is caused to pass through a filter having a predetermined transfer function, the current signal being inputted to a solenoid to drive a control valve by which a working oil pressure on at least one frictional element of the automatic transmission is controlled by reducing the working oil pressure to release the frictional element and the filter passed current signal is inputted to the solenoid to drive the control valve. The solenoid control method and apparatus described above are applicable to a change-over shift operation.

Abstract: The trunnion (23) of a vehicle toroidal continuously variable transmission is displaced by a step motor (52) via a control valve (56) and oil pressure servo cylinder (50) in order to vary a speed ratio of the transmission. A controller (80) calculates a target value (z*) of a control variable (z) based on an accelerator pedal depression amount (APS) and output disk rotation speed (&ohgr;co) (S5). Further, a time-variant coefficient (f) showing the relation between the trunnion displacement (y) and variation rate ({dot over (&phgr;)}) of the gyration angle (&phgr;) of the power roller, is calculated (S10). The error between the speed change response of the transmission and a target linear characteristic can be decreased by determining a command value (u) to the step motor (52) under a control gain determined based on a time differential ({dot over (f)}) of the coefficient (f) (S20).

Abstract: A method is proposed for controlling an automatic transmission driven by a prime mover in which a shift from a first transmission ratio to a second transmission ratio occurs in the form of a pull upshift or push downshift or a pull downshift or push upshift by a first clutch opening and a second clutch closing and an electronic transmission control device controls, via electromagnetic valves, the pressure curve of the first and of the second clutch during the shifting operation. The shifting operation is divided into various shifting phases, an engine intervention taking place in the load-transfer (LÜ) of the gradient-setting phase (GE), the sliding phase (GL), the gradient-reduction phase (GA) and the closing phase (S), an engine torque and/or a characteristic value that determines the engine torque being transferred from the transmission control device to an engine control device of the prime mover.

Abstract: A method for controlling gear shifting of a transmission in a vehicle. The transmission is supplied with electric power from a battery or an alternator and drives an actuator to shift gear ranges of the transmission. The transmission has an output shaft that becomes difficult to rotate if a predetermined range is selected when the engine stops running. The method includes determining whether a gear range differing from the predetermined range is selected when the vehicle stops traveling, and forcibly shifts the gear range to the predetermined range when a gear range differing from the predetermined range is selected by driving the actuator with electric power supplied from the alternator.

Abstract: A device controls the operating conditions of a self-propelled vehicle. The device includes a first device for controlling the travelling speed of the self-propelled vehicle, and a second device for controlling the output speed of an internal combustion engine. The first and second devices are separate from each other.

Abstract: Given a method for controlling the trailing throttle of automotive drives, in which, assuming an automatic transmission whose control is equipped with various shift programs, the specific shift program being selected automatically as a function of the actuation of the accelerator and the transmission being in operative connection with a selector lever to be operated by the driver, for the selection of factors influencing the drag torque of the automotive drive and therefore for the drivetrain control or transmission-shift control, a specific range of a drag torque is assigned an operating mode, in which, after the system start-up and the setting of the selector lever in the permanent position for forward gear D, steps for controlling the drivetrain or the transmission are carried out individually or in combination, in each case according to the drag torque demanded, but also according to the coasting operation.

Abstract: Described is a process for the adaption of the shifting operation of an automatic transmission. Accordingly, a determination of adaption values is made relative to occurrences shifting quality in the operation of an automatic transmission, and said determined values are stored in the memory of an adaption storage and can be accessed for the control of shifting operations. The determined adaption values prior to the storage in the adaption memory are corrected in respect to a lifetime loading of the automatic transmission.

Abstract: A modular electronic control system for a geared multiple-ratio transmission wherein pressure profiles for each ratio shift actuator are used to provide seamless transitions during both positive and negative engine torque conditions to improve shift feel and responsiveness to ratio change commands. The system provides shift staging for sequenced shifts between ratios as well as for so-called “change-of-mind” shifts in which a sequence shift is interrupted as a new destination gear is introduced. A constant ratio change occurs during sequenced shifts. A change-of-mind shift can be performed directly where the new destination gear is commanded immediately. Independent pressure profiles for each clutch involved in a commanded shift are used to accommodate various types of shifts.

Abstract: An apparatus for controlling the operation of a bicycle transmission includes a shift command receiving unit that receives shift command signals corresponding to shift commands, and a shift command combining unit that combines a plurality of the shift command signals into a resultant shift command signal that would shift the bicycle transmission to the same state as if the plurality of shift commands all were executed individually. A method for controlling the operation of a bicycle transmission includes the steps of receiving shift command signals corresponding to shift commands, and combining a plurality of the shift command signals into a resultant shift command signal that would shift the bicycle transmission to the same state as if the plurality of shift commands all were executed individually.

Abstract: A shift control device is provided for a bicycle that uses shift control signals from a signal provider to operate an automatic shifting mechanism of a bicycle transmission, wherein the shift control signals correspond to a traveling condition. The shift control device comprises an override shift command unit for providing an override shift command, and a simulation unit operatively coupled to the override shift command unit for providing simulated shift control signals in response to the override shift command.

Abstract: The vehicle comprises a continuously variable transmission and traction control system (TCS) which controls a driving force. When the TCS is not operating, a controller computes a final target ratio based on a sensor detected vehicle speed. When the TCS is operating, the final target ratio is computed based on an estimated vehicle speed, and the final target ratio is limited by a speed ratio upper limiting value computed based on the sensor detected vehicle speed. The controller controls a speed change actuator so that a real speed ratio approaches the final target ratio.

Abstract: A system for adjusting a transmission ratio for a transmission built into a motor vehicle. Selection devices actuable by the driver of the vehicle are provided. With these selection devices, the driver can pregive pulses to change the transmission ratio. In a first component object, the pulse processing, pulses are detected whereupon in a second component object, the counter, count values are determined and stored in dependence upon valid pulses. In a third component object, the switch request, shift requests are determined in dependence upon count values and while considering pregivable peripheral conditions. The transmission ratio is adjusted in dependence upon the shift requests. With the defined interfaces of the objects, the exchangeability thereof is made possible whereby especially a reuse of the software is facilitated.

Abstract: An engine output for bringing the drive power of a motor vehicle to a requested value is determined as a target output. One of the lean burn and the stoichiometric burn is selected as a combustion form that achieves a best fuel consumption performance in terms of the control of the actual engine output to the target output. That is, an output value that serves as a criterion for determining whether to switch the combustion force is determined based on the minimum fuel consumption rate during the stoichiometric-burn operation and the minimum fuel consumption rate during the lean-burn operation in which the fuel consumption involved in the rich spike control is taken into account. If the target output is less than the output value, the lean-burn operation is performed. If the target output is greater than the output value, the stoichiometric-burn operation is performed.