Abstract: A throttle may include a throttle gear 5 is fastened to a throttle shaft 2. A relief lever 9 is pivotally mounted on the throttle shaft 2. A return spring 11 is adapted to urge the relief lever 9 in a valve closing direction with respect to a throttle body 1. A first contact means 20a is provided on the throttle body 1 and the relief lever 9 and the throttle body 1 contacts the relief lever 9 when the relief lever 9 pivots to a predetermined pivot position B in the valve closing direction. A relief spring 10 is adapted to urge the throttle gear 5 in a valve opening direction with respect to the relief lever 9. A second contact means 20b is provided on the throttle gear 5 and the relief lever 9 and the relief lever 9 contacts the throttle gear 5 when the throttle gear 5 pivots to the predetermined pivot position B in the valve opening direction. The predetermined pivot position B is preferably an initial or standby throttle valve position.

Abstract: A throttle valve control apparatus of an engine is constructed so that the poorer the response of the throttle valve, the larger the value of a control signal given as a control signal for opening of the throttle valve, whereby the speediness of control and response of the throttle valve are improved. The engine throttle valve control apparatus has means for comparing a target opening which is a control target of the throttle valve and a real opening which obtained by a sensor or the like, and obtaining a corrected target opening of the throttle valve by a map or computing, corresponding to a difference obtained as the result of the comparison.

Abstract: A powertrain control method for an internal combustion engine responsive to an accelerator pedal input, the engine having a throttle responsive to a commanded throttle position. The method comprises the steps of determining the engine speed, determining the accelerator pedal position, and generating a desired throttle position value as a function of at least the accelerator pedal position and engine speed. If the commanded throttle position is greater than the desired throttle position value, the commanded throttle position is limited to the desired value.

Abstract: A control system for an automotive vehicle is capable of realizing superior control precision and response ability by an intake air flow rate control on the basis of a fuel injection amount which is, in turn, derived on the basis of a target torque even in lean-burn condition. The control system controls at least one of vehicle speed, a vehicular distance, driving wheel speed, slip ratio toward a target value, derives a target torque of an engine on the basis of the target value, a fuel injection amount for the engine on the basis of the target torque of the engine, a target air supply amount to the engine on the basis of the fuel injection amount derived by the vehicle condition control means and an actual air supply amount of the engine. The control system controls the actual air supply amount toward the target air supply amount.

Abstract: A throttle control system including a throttle body, an air intake coupled to the throttle body providing air flow to the throttle body, a fuel supply apparatus coupled to the throttle body, where the air intake and the fuel supply apparatus, in conjunction, provide a combustible fuel-air mixture, a throttle plate coupled to the throttle body, an actuator coupled to the throttle plate to move the throttle plate within the throttle body to control at least the air flow to the throttle body, and a fuzzy logic controller controlling the actuator position and speed to provide for a desired air flow.

Abstract: In an adaptive speed control system for a vehicle, a method and system for automatically adjusting a selected following interval for the vehicle based on driving conditions is provided. The method includes determining a driving surface coefficient of friction based on a driven wheel speed of the vehicle, and adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction. The system includes a receiver capable of receiving a signal indicative of a driven wheel speed of the vehicle, and a controller capable of determining a driving surface coefficient of friction based on the driven wheel speed, and capable of adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction.

Abstract: A system and method for controlling a powertrain using multiple position sensors for electronic airflow control include comparing values corresponding to position signals generated by each of the sensors to upper and lower thresholds to determine if each signal is within a first range, and comparing at least one pair of values corresponding to the signals to generate at least one difference value which is compared to a corresponding difference threshold.

Abstract: An engine control method for improving air-fuel ratio control controls airflow when fuel injector limits are reached. The method includes a transient fuel model to calculate a required fuel injection amount based on actual cylinder air charge and feedback from an exhaust sensor. When the required fuel injection amount is outside an operable range, for example, less than zero, airflow is controlled to prevent deviations of exhaust air-fuel ratio. Otherwise, airflow is controlled to provide a desired engine torque. Alternatively, a minimum allowable airflow is determined based on a minimum achievable fuel flow. Then, airflow is prevented from falling below this minimum allowable airflow. The method is particularly useful in preventing rich excursions during rapid decreases in desired engine torque, such as during a driver tip-out.

Abstract: A microcomputer produces to a drive circuit drive command signals for starting to drive and braking a motor so that the position of a throttle valve is controlled to a target position. A current supplied to the motor is limited not to exceed a first current limitation value at the time of motor drive start and braking. When the current limitation continues for a predetermined time period, the current is further limited not to exceed a second current limitation value. The microcomputer detects switching of motor current supply direction. When the current supply direction is switched, a reset command signal is produced to reset a timer operation for a current limitation continuation determination.

Abstract: A powertrain control method for an internal combustion engine responsive to an accelerator pedal input, the engine having at least one fuel injector responsive to a commanded fuel signal. The method comprises the steps of determining the engine speed, determining the accelerator pedal position, and generating a desired fuel quantity value as a function of the accelerator pedal position and engine speed. If the commanded fuel signal is greater than the desired fuel quantity value, the commanded fuel signal is limited to the desired value.

Abstract: A powertrain control method for an internal combustion engine having a throttle responsive to a throttle position command. The method comprises the steps of determining the engine speed, determining the actual throttle position, and generating a desired throttle position value. In one aspect of the invention, the desired throttle position value is generated as a function of the actual throttle position and engine speed. In particular, the throttle position divided by the engine speed can be resolved to a single constant. As such, a simplified powertrain control monitor can be obtained by comparing the throttle position divided by engine speed to a predetermined constant. If the throttle position is greater than the desired throttle position value, the commanded throttle position is limited to the desired value.

Abstract: An apparatus of controlling an electronically controllable throttle valve for car has a sensor for detecting the opening of the throttle valve and a microcomputer. A throttle valve opening command value is delivered in the form of a digital signal under the control of the microcomputer. The digital command value signal is converted into an analog signal and on the basis of the analog signal and a detected throttle opening, a motor connected to the throttle valve is driven to control the opening thereof.

Abstract: In the event that a throttle position sensor fails, a method is provided which allows a pseudo throttle position sensor value to be calculated as a function of volumetric efficiency, pressure, volume, temperature, and the ideal gas constant. This is accomplished by first determining an air per cylinder (PAC) value and then calculated the mass air flow into the engine as a function of the air per cylinder (APC) value. The mass air flow is then used, as a ratio of the maximum mass air flow at maximum power at sea level for the engine, to calculate a pseudo throttle position sensor value. That pseudo TPS (BARO) value is then used to select an air/fuel target ratio that allows the control system to calculate the fuel per cycle (FPC) for the engine.

Abstract: A method for controlling an engine having both an electronically controlled inlet device, such as an electronic throttle unite, and an electronically controlled outlet device, such as a variable cam timing system is disclosed. The method of the present invention achieves cylinder air charge control that is faster than possible by using an inlet device alone. In other words, the method of the present invention controls cylinder air charge faster than manifold dynamics by coordination of the inlet and outlet device. This improved control is used to improve various engine control functions.

Abstract: To actuate a throttle valve, a first driving device is provided to drive the throttle valve only in a small throttle opening range, and a second driving device is provided to drive the throttle valve in a throttle opening range other than the small throttle opening range against a spring by using a throttle wire. The first driving device has a rotor and a magnetomotive force source. A magnet is provided on the rotor. Three pole pieces are provided on a peripheral edge facing the rotor. Pole pieces opposite to each other in polarity produced by the magnetomotive force source are connected by connecting magnetic paths.

Abstract: An electronic throttle control system is described where a throttle position sensor has multiple slopes depending on the operating region. At low throttle positions, a greater slope, and thus a greater sensitivity is provided, thereby increasing control resolution. At greater throttle positions, a lower slope, and thus lower sensitivity is provided. In this way, an output signal that varies across the entire operating region of the throttle is provided for monitoring and control, while improved performance at low throttle angles can be simultaneously achieved. A method for learning a transition region is also desribed.

Abstract: In an adaptive speed control system for a vehicle, a method and system for automatically adjusting a selected following interval for the vehicle based on driving conditions is provided. The method includes determining a driving surface coefficient of friction based on a driven wheel speed of the vehicle, and adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction. The system includes a receiver capable of receiving a signal indicative of a driven wheel speed of the vehicle, and a controller capable of determining a driving surface coefficient of friction based on the driven wheel speed, and capable of adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction.

Abstract: The invention is directed to a method and an arrangement for controlling an operating variable of a motor vehicle wherein the controller has at least one changeable parameter. This parameter of the controller is changed in dependence upon the operating range of the actuator, which is driven by the controller, and/or the magnitude of the change of the desired value.

Abstract: The disclosed control apparatus and method of an engine of the present invention calculates a target engine torque using an operation amount of an accelerator, converting the target engine torque into a first opening area of a throttle valve, calculates a required air amount at the time of idling, converting the required air amount into a second opening area of the throttle valve, calculates a target total opening area of the throttle valve by adding the first opening area and the second opening area of the throttle valve, calculates a target opening degree of the throttle valve in correspondence to the target total opening area, and outputs the target opening degree to the throttle valve controller which controls an opening degree of the throttle valve.

Abstract: The present invention provides a method and apparatus for controlling the speed of an engine. The engine has an associated turbo charger and a throttle. The method includes the steps of determining an actual speed of the engine, establishing a desired speed of the engine, determining an overspeed condition exists in response to said desired speed and said actual speed, and determining a throttle command in response to the desired and actual engine speed.

Abstract: There is provided in accord with the present invention a work vehicle comprising a vehicle support structure upon which a plurality of wheels are rotatably mounted and which structure supports an engine having a fuel injection system operatively coupled to at least two of the wheels. The engine is provided with an engine speed control system in electrical communication with the engine and comprising a controller operatively connected to the fuel injection system with the controller receiving feedback signals from an engine transducer to control engine speed in response to an actuator operatively connected to a potentiometer. The potentiometer is electrically connected to the controller and responsive, proportionately, to the movement of the actuator.

Abstract: A throttle valve controller includes a motor, a throttle valve driven by the motor, an accelerator sensor for setting a target position of the throttle valve, a throttle sensor for detecting the actual position of the throttle valve, a position control circuit for controlling the motor in accordance with a difference between the target position and the actual position of the throttle valve, a friction compensating circuit for compensating a positional error due to friction force affecting the throttle valve, and a driver for driving the motor with repetition of a control period in accordance with the position control circuit and the friction compensating circuit. The friction compensating circuit may compensate the positional error due to friction force during a control period together with the position control circuit. The motor may generate compensated torque in accordance with the friction force that affects the throttle valve.

Abstract: A manifold valve controller (30, 32) designed to be embedded within the casing (24) of a throttle actuator in a manifold valve assembly for a gas fueled internal combustion engine. The controller (30, 32) senses the current position and current velocity of the valve (14) and calculates a rest position of the valve (14) if the valve commenced deceleration from its current position and velocity. The controller (30, 32) then compares the calculated rest position with a demanded position for the manifold valve (14) in order to determine whether the current position or the rest position exceeds the demanded position The controller (30, 32) then accelerates or decelerates the valve (14) to the demanded position as required, based on the comparison A feedback position sensor such as a potentiometer (22) provides the means for sensing the current position and velocity of the valve (14).

Abstract: The present invention relates to a method and an apparatus for controlling a car equipped with an automatic transmission having a lockup clutch. According to the control method of the present invention, when the lockup clutch is in the lockup state, a variation of a generated torque is detected. When the range of the torque variation detected exceeds a predetermined value, an engine torque is reduced by controlling the engine, and the automatic transmission is controlled to compensate for a reduction of the driving torque due to a reduction of the engine torque. Thus, the speed change ratio is changed to the low gear side.

Abstract: The throttle valve control device of this invention controls a throttle based on outputs of a position sensor including a first sensor and a second sensor which detect a position of a same object, wherein the output of the first sensor and the output of the second sensor change opposite to each other depending on a change in the position of the object, and the throttle valve control device determines the position sensor abnormal when a variation in the output of the first sensor is equal to or greater than a first threshold value and a variation in the output of the second sensor is equal to or greater than a second threshold value.

Abstract: The invention is directed to a method and an arrangement for controlling an operating variable of a motor vehicle wherein the controller has at least one changeable parameter. This parameter of the controller is changed in dependence upon the operating range of the actuator, which is driven by the controller, and/or the magnitude of the change of the desired value.

Abstract: The accelerator opening degree detection apparatus of the present invention includes: an accelerator pedal position sensor for detecting a position of an accelerator pedal; and a calculating section for calculating an accelerator opening degree based on an output of the accelerator pedal position sensor.

Abstract: The present invention relates to an apparatus and a method for limiting the vehicle speed of a working vehicle which can provide a smooth traveling condition during vehicle speed limit, and which can set a vehicle speed limit suited to environmental conditions. To this end, a vehicle speed control device (10) judges a vehicle speed limit traveling period when a vehicle speed signal is equal to or greater than a vehicle speed limit value, to calculate a corrected depressing stroke signal by a control gain based on a deviation value between the vehicle speed signal and the vehicle speed limit value so that the deviation value becomes smaller to output to an engine control device (40), and judges an accelerated traveling period, when the vehicle speed signal is smaller than the vehicle speed limit value and the corrected depressing stroke signal is larger than a depressing stroke signal, to output the depressing stroke signal to the engine control device (40).

Abstract: A stepping motor control apparatus for controlling a stepping motor to drive a fluid flow control valve in an engine includes an operation state monitoring unit for monitoring the operation state of the engine; a step position monitoring unit for monitoring a step position of the stepping motor; a first motor drive direction-determining unit for determining the motor drive direction during normal operations of the stepping motor as determined by a target step position and the present step position of the stepping motor; a second motor drive direction-determining unit for determining the motor drive direction during anomalous operations of the stepping motor; a drive pulse-rate determining unit for determining the pulse generation rate to drive the stepping motor; and a drive unit for driving the stepping motor at the pulse generation rate determined by the drive pulse-rate determining unit.

Abstract: The present invention provides a method and apparatus for determining a fuel command for an fuel system. The present invention provides a method for determining a fuel command for an engine. The method includes determining a desired and actual engine speed, comparing the desired and actual engine speeds, and controlling the air/fuel mixture flow into the intake manifold of the fuel system in response to the comparison. The inlet pressure and temperature within the manifold are then determined. A fuel command is determined in response to the manifold air pressure and temperature. The fuel command is then modified in response to the comparison of the desired and actual engine speeds.

Abstract: A throttle control apparatus which is adapted to be disposed near the accelerator pedal of a vehicle includes an electric motor, and an operational member which is operatively connected to the output shaft of the electric motor for abutting against the accelerator pedal in order to swing the accelerator pedal during operation of the motor. The motor is positioned within a housing and is operatively connected to the operational member by way of interengaging gears located in the housing and a rotation shaft extending through the housing. To facilitate the mounting of the housing on the vehicle dashboard, a two-piece bracket can be employed.

Abstract: An internal combustion engine is provided with a first pedal position sensor and a second pedal position sensor measuring the position of an accelerator pedal. An emergency running mode of the internal combustion engine is actuated if a failure of either the first or the second pedal position sensor is detected. In the emergency running mode, a rise in the rotational speed or in the travel speed within a prescribed time interval is limited to a prescribed rise value.

Abstract: Pulsations which falsify an output signal of an air mass meter occur at low and medium rotational speeds in a unit that supplies air to an internal combustion engine. A method for adjusting the load of the internal combustion engine limits an opening angle of an electromotively adjustable throttle valve to a rotational speed-dependent opening value which includes an opening base value that is between a lower and an upper limit value. In the case of the lower limit value, the full load of the engine is reached. In the case of the upper limit value, pulsations of the air in an intake duct upstream of the throttle valve do not yet occur.

Abstract: The throttle control device of this invention for controlling a throttle based on outputs of a position sensor including a first sensor and a second sensor which detect a position of a same object includes: a judgment section for judging whether or not the position sensor is abnormal by comparing a difference between the output of the first sensor and the output of the second sensor with a predetermined threshold value; and a change section for changing the predetermined threshold value depending on at least one of the output of the first sensor and the output of the second sensor.

Abstract: A throttle valve control device is provided which includes a throttle valve mounted in an intake pipe of an internal combustion engine, an actuator which drives the throttle valve so as to change an opening of the throttle valve, an operating condition sensor which detects operating conditions of the internal combustion engine, an accelerator sensor which detects an accelerator pedal position that represents an amount by which an accelerator pedal is depressed by a driver, and a control unit for controlling the throttle valve.

Abstract: It is an object of the present invention to provide a controlling apparatus for throttle valve that detects a throttle open degree enabling more appropriate controls by removing ill effects of multiplexing an idle control in controlling data. The idle control amount is canceled by subtracting the idle target open degree from the detected throttle open degree. Further, in order to correct differences of the detected data due to a response delay of the throttle valve, the previous measured value is regarded as the detected throttle open degree when the response delay occurs.

Abstract: An engine management system comprising engine control unit (17) which receives throttle position signals from at least two throttle position sensors (15); compares the signals; selects a preferred signal in response to a discrepancy between the signals; and operates the engine using that preferred signal.

Abstract: A governor for an internal combustion engine suitable for speed regulation of engines driving loads of such character that the power requirements vary more within a recurring cycle than between such cycles is provided by the current invention. Means are provided for speed detection, designation of a number of fixed positions within the load cycle, setting of a power control to specific positions, and memory to store representations of load cycle positions and engine power control positions. A microprocessor computes an engine power control position at each load cycle position and applies the power control position to the engine by controlling the engine power control means.

Abstract: A speed governing system for an internal combustion engine includes an internal combustion engine having an inlet manifold, an exhaust manifold, and at least one variable volume combustion chamber disposed therebetween. The apparatus also includes a fuel and air delivery control system having an air delivery mechanism responsive to a sensor control signal for affecting engine operation, a fuel delivery mechanism responsive to input from an operator for affecting engine operation, and a sensor responsive to engine operating conditions for supplying the sensor control signal. The apparatus also has an exhaust gas recirculation system including an exhaust gas recirculation conduit and an exhaust gas recirculation control valve, the control valve being controllably regulated in response to the sensor control signal in order to adjust air/fuel ratio. A method for governing operating speed of an internal combustion engine is also disclosed.

Abstract: A feedback calculator and a controller are disclosed which energize a throttle valve driver so that a vehicle speed Vs may be brought into coincidence with a target vehicle speed Vo which is instructed by a driver. The feedback calculator calculates a target acceleration AT on the basis of a vehicle speed Vs and a target speed Vo, and also detects a running acceleration Aa of the vehicle and calculates a deviation of the running acceleration Aa with respect to the target acceleration AT, Ad=AT-Aa. It chooses a high gain G when the deviation Ad is positive and its change dAd is also positive, and chooses a low gain G when the deviation Ad is negative and its change dAd is also negative, thus deriving a controlled variable D having a magnitude which depends on the deviation Ad and the gain G. The controller energizes the throttle valve driver in accordance with the controlled variable D, thus driving the throttle valve for opening or closing at a rate which depends on the controlled variable D.

Abstract: In a valve actuator arrangement for an internal combustion engine, a valve structure having a valve body and a rotary valve axle is provided, an electric motor structure having a generally disc shaped body fixed on one end of said valve axle so as to be integrally pivoted with the valve axle is provided, a permanent magnet fixed on the disc-shaped body is provided, a fixing member fixed on the one end of the valve axle is provided, and a pair of windings to form a pair of coils whose winding directions are mutually opposite to each other are wound around the fixing member so that a direction of a magnetic flux developed between each of the pair of windings and the permanent magnet is parallel to the valve axle.

Abstract: The throttle control device of this invention controls a throttle based on outputs of a position sensor including a first sensor and a second sensor which detect a position of a same object, wherein, when an abnormality is detected in one of the first sensor and the second sensor, throttle control is continued based on the output of the other sensor in which no abnormality is detected, and the throttle control is discontinued when the detection of the abnormality in one of the first sensor and the second sensor continues for a first predetermined time, and when an abnormality is detected in both the first sensor and the second sensor, throttle control is continued based on the output of one of the first sensor and the second sensor, and the throttle control is discontinued when the detection of the abnormality in both the first sensor and the second sensor continues for a second predetermined time which is shorter than the first predetermined time.

Abstract: A programmable interface which connects to an engine control device and allows convenient entry of engine performance limitation data such as maximum allowable vehicle speed and engine RPM's. Such entered data is stored and processed so as to interface with existing and/or modified engine controllers to produce the desired vehicle performance limitations. Programmable data entry devices include an alphanumeric keypad, a wireless remote keypad, a keychain unit, and an encoded ignition key. Wireless transfer of data can be achieved through RF or light transmitters/receivers, or active and passive transponders/interrogators. Once processed, the data can be used, for instance, to alter or generate pulse trains which control ignition spark, fuel injection, or carburetion.

Abstract: A pedal side drive mechanism which is rotatable relative to a throttle shaft in both opening and closing directions is provided at one end of the throttle shaft. The throttle shaft opens and closes a throttle valve. A motor side drive mechanism, which is rotatable relative to the throttle shaft in both opening and closing directions, is provided at the other end of the throttle shaft. The pedal side drive mechanism and the motor side drive mechanism are able to be driven independently without interfering with each other, in both of the opening and closing directions of the throttle shaft. Accordingly, driving of the throttle can be performed using either the accelerator pedal or the motor, and functions including fail-safe measures or a limp home mode can be accomplished using a simple structure.

Abstract: A vehicle speed control system provides adaptive compensation for compliance in a linking mechanism between a throttle control member and a throttle which creates hysteresis in throttle movement. The system has a vehicle speed sensor, an actuator having an output linked to the throttle control member, an actuator position signal generator and a control responsive to the vehicle speed sensor and the actuator position signal generator for positioning the actuator in closed loop control with a major loop in response to vehicle speed and a minor loop in response to actuator position.

Abstract: On one side of a valve shaft, there are provided an accelerator drum connected to an accelerator pedal by an accelerator wire, a return spring for urging the accelerator drum in a valve closing direction, and an accelerator sensor for detecting rotation of the accelerator drum and transmitting a detected signal to a host system. On the other side of the valve shaft, there are provided a large-diameter gear and an opening sensor. An armature of a solenoid clutch is attached to the gear and held on a motor shaft via a slide bearing. Thus, the motor, the solenoid clutch and the throttle valve are arranged into a U-shaped form for interconnection through four gears.

Abstract: The process assures the correction of the control of an actuator acting on the speed 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. A correction (.DELTA.u) for the control of the actuator is derived from the addition of first (.DELTA.u.sub.1) and second (.DELTA.u.sub.2) partial corrections which are functions of the speed error (E) and the time derivative (E') of this error, respectively. These corrections are defined as a function of the relative position of the value of the error, or of the error derivative, with respect to at least two predetermined values of the error (or the derivative of the error), each of which has an associated predetermined value of the partial correction .DELTA.u.sub.1 (or .DELTA.u.sub.2).

Abstract: A throttle body for use in the air intake system of an internal combustion engine having an idle speed control. The throttle body assembly (10) includes a throttle plate (18) mounted to a throttle shaft (16), which is, in turn, mounted to a throttle control lever (20). A bearing member (30) is coupled to the throttle control lever (20). A motor (32) is mounted relative to the throttle body and includes an idle control cam (36) mounted to the motor shaft (34) so that the bearing (30) rests on the cam (36). A circuit (40) actuates the motor (32). This arrangement provides a variable idle stop for the throttle plate (18) where the cam (36) is directly controlled by the motor (32). The motor size is minimized by providing an overdrive function that overdrives the motor (32) during transitional phases, to obtain fast response time and high resolution of idle control.

Abstract: An engine power train control method and control apparatus for a vehicle having an engine and an automatic transmission is capable of quickly changing an air-fuel ratio to meet the requirements for exhaust gas without producing shocks and without reducing engine torque. An air-fuel ratio command value is varied stepwise for transition between an air-fuel ratio for lean-burn operation and a stoichiometric air-fuel ratio, and at the same time, the period following the completion of the stepwise variation of the air-fuel ratio command value, a basic fuel amount fed to the engine is varied stepwise from a value determined according to the air amount and an engine speed to a value determined according to a position of an accelerator pedal of the vehicle and the engine speed. In this way, shocks do not occur and the operability is improved, because the engine torque remains substantially constant through the air-fuel ratio transition.

Abstract: The invention is directed to a method and an arrangement for controlling an internal combustion engine. An electronic adjustment of a power adjusting unit for influencing the supply of air is provided. The adjustment of this power adjusting unit as well as a value representing the load of the engine are detected. For monitoring purposes, the variable representing the load and the adjustment value of the power adjusting unit are compared to each other. The maximum position of the power adjusting unit is limited in dependence upon the load and/or the engine rpm in such a manner that the range of high loads is not reached.