DE10059563A1 - Controlling steering for motor vehicle involves determining torque loss dependent on power steering required servo torque from steering angle - Google Patents

Abstract

The method involves determining the demand value for a torque applied to a shaft in the drive train taking into account a torque loss and controlling actuating elements of the drive depending on the demand value. The torque loss (TQLOSS) depends on a servo torque (TQSERVO) required to be provided for a power steering system and is determined depending on a steering angle (STA). An Independent claim is also included for an arrangement for controlling a drive for a motor vehicle.

Description

The invention relates to a method and an apparatus for Controlling a drive, in particular an internal combustion engine ne, a motor vehicle according to the preamble of independency gene claims.

DE 196 12 455 A1 describes a method for controlling a Internal combustion engine known. A setpoint is a Torque applied to a shaft of the drive train determined taking into account a loss torque. The loss torque takes into account friction and pump ver loss of the internal combustion engine with a temperature correction and the load caused by an air conditioning compressor acts on the internal combustion engine. The setpoint of the torque then is controlled by appropriate control of Stell structure, such as B. a throttle valve in the intake tract Internal combustion engine or injectors or spark plugs set. A lead torque is generated via the air path set future torque requests one Idle control, an anti-slip control or a kata analyzer protection function or a driving stability control taken into account. By adjusting the ignition accordingly This torque can then be applied when it actually does will be set very quickly. It is essential Lich to calculate the requested torque exactly, so the running behavior of the internal combustion engine on the one hand very com is fortunate and on the other hand consumption and emissio are as low as possible.

The object of the invention is the known method or to further develop the known device so that the Laufver keeping the drive of the motor vehicle becomes more comfortable, and  at the same time, consumption and emissions are lower the.

The task is solved by the characteristics of the independent Claims. Advantageous developments of the invention are marked in the subclaims.

The invention is based on the finding that a servo steering has a significant impact on the torque of the on Drive of a motor vehicle that has a drive train is delivered. The relative influence is at internal combustion seem particularly weighty when the engine is idling ne. By taking the servo torque into account The quality is thus determined by determining the setpoint value of the torque the determination of the target value of the torque clearly verbes sert.

The servo torque is particularly easy to determine depending on a steering angle. This is the case with many modern ones Vehicles are possible without additional sensors Lich, because more and more vehicles via a driving stability Have control to which a steering angle sensor is assigned.

In a further embodiment of the invention, the servo Torque depending on an electrical current and / or egg ner voltage determined. So the servo torque can be particularly be determined precisely because current and voltage are direct define the sizes of an electrically operated Power steering pump or one directly by means of electrical Power steering drive powered power steering whose leis characterize tung.

Embodiments of the invention are based on the schematic rule drawings explained in more detail. Show it:

Fig. 1, an internal combustion engine with a control device in a motor vehicle,

Fig. 2 is a block diagram of the control device.

An internal combustion engine ( FIG. 1) comprises an intake tract 1 with a throttle valve 10 and an engine block 2 , which has a cylinder 20 and a crankshaft 23 . A piston 21 and a connecting rod 22 are assigned to the cylinder 20 . The connecting rod 20 is coupled with the piston and the crankshaft.

A cylinder head 3 is provided in which a valve train is arranged with at least one inlet valve 30 and one outlet valve 31 . The valve train comprises at least one camshaft, not shown, with a transmission device which transmits the cam lift to the intake valve 30 or the exhaust valve 31 . Devices for adjusting the valve lift times and the valve lift curve can also be seen before. Alternatively, an electromechanical actuator can also be provided, which controls the course of the valve lift of the intake or exhaust valve 30 , 31, optionally without a camshaft.

An injection valve 33 and a spark plug 34 are also introduced in the cylinder head 3 . The injection valve is arranged so that the fuel is metered directly into the combustion chamber of the cylinder 20 . Alternatively, the injection valve can also be arranged in the intake tract 1 . The internal combustion engine is shown in FIG. 4 with a cylinder Darge. However, it can also comprise several cylinders. An exhaust tract 4 with a catalyst 40 and an oxygen probe is also assigned to the internal combustion engine.

The internal combustion engine is installed in a motor vehicle which has a power steering 5 .

Furthermore, a control device 6 is provided, to which sensors are assigned, which record different measured variables and each determine the measured value of the measured variable. The control device 6 determines one or more steep signals depending on at least one measured variable, each of which controls an actuator.

The sensors are a pedal position sensor 71 , which detects a pedal position PV of the accelerator pedal 7 , a throttle valve position sensor 11 , which detects an opening degree of the throttle valve 10 , an air mass meter 12 , which detects an air mass flow MAF, and / or an intake manifold pressure sensor 13 , which detects an intake manifold pressure detected in the intake tract 1 , a temperature sensor 14 which detects an intake air temperature TAL, a speed sensor 24 which detects a rotational speed N of the crankshaft 23 , a temperature sensor 25 which detects a coolant temperature TCO, a temperature sensor 26 which detects an oil temperature TOlL detects, a steering angle sensor 51 that detects a steering angle STA, a pressure difference sensor 52 that detects a pressure difference Δp before and after a power steering pump, an ammeter that detects an electrical current through an electric actuator of a power steering, a voltmeter 54 that detects a Voltage through the electric actuator of an electric ch operated power steering. Depending on the embodiment of the invention, any subset of the sensors mentioned or additional sensors may be present.

The actuators each include an actuator and an actuator. The actuator is an electromotive drive, an electromagnetic drive or another drive known to those skilled in the art. The actuators are designed as a throttle valve 10 , as an injection valve 33 , as a spark plug 34 or as a device for adjusting the valve lift of the intake or exhaust valves 30 , 31 . In the following, reference is made to the actuators with the respectively assigned actuator Be.

The control device 6 is preferably designed as an electronic engine control. However, it can also comprise several control devices which are connected to one another in an electrically conductive manner, for. B. via a bus system.

The function of the part of the control device 6 relevant to the invention is described below with reference to the block diagram with reference to FIG. 2.

A loss torque TQ_LOSS is dependent in block B1 determined from several torque contributions. A first spin Torque contribution for the loss torque TQ_LOSS is from egg Map KF1 depends on the air mass flow MAF and the Speed N determines and takes into account pump and friction losses of the internal combustion engine. A second torque trag takes temperature-dependent losses into account and is reduced dependent on the oil temperature TOIL and the coolant temperature TCO determined from a map KF2. Another torque ment contribution takes into account the load requirement of a compress sors of an air conditioning system and becomes a further map KF3 depending on a load value ACC_LOAD of the air conditioning compressor and a speed N determined.

A servo torque is determined in a block B2, which takes into account the torque requirement of the power steering 5 . The servo torque TQ_SERVO can be determined particularly easily as a function of the steering angle STA from a map and preferably corrected by means of a power correction factor that depends on the speed N. The map takes into account the increased torque requirement of the servo near the stops of the Power steering.

He can follow the servo torque even more precisely if the time derivative of the steering angle, i.e. the steering angle speed STA_V, is also taken into account when determining the servo torque TQ_SERVO. The torque requirement of a pump in a hydraulic power steering system 5 is dependent on the delivery pressure of the pump. The closer the steering angle is to the steering stop, the more power the pump has to deliver. This relationship is then preferably stored in the map depending on the steering angle and preferably also depending on the steering angle speed.

The servo torque TQ_SERVO can still when the vehicle is moving can be determined more precisely, even if measurands that Lateral acceleration of the vehicle and / or the vehicle characterize speed, be taken into account.

If a sensor is provided on the power steering 5 , which detects a variable representing the pressure difference before and after the power steering pump, such as. B. the pressure difference Δp, the servo torque TQ_SERVO can also be determined simply as a function of the pressure difference Δp. Is against the hydraulic pump of the power steering 5 driven by an electric drive or the power steering 5 is a steering operated directly by means of an electric drive, the servo torque TQ_SERVO can also directly from the electrical quantities current I and voltage U, which by the electric drive flow or fall off, be determined. An extremely precise calculation of the servo torque TQ_SERVO is thus possible, since these variables characterize the torque required by the power steering 5 directly. An even more precise determination of the servo torque is possible in this case if the steering angle and / or the steering angle speed are also taken into account.

In a block B3 it is dependent on the loss torque TQ_LOSS and other sizes, such as the speed, a minimum and a maximum torque TQ_MIN, TQ_MAX er averages that to a shaft of the drive train minimal or can be at most at the respective time. The exact he The averaging of the minimum and maximum torque is in the  DE 196 12 455 A1, the content of which is hereby described is involved.

In block B4, a requested torque TQI_REQ determined depending on the minimum and the maximum TQ_MIN, TQ_MAX, the loss torque TQ_LOSS and the driver representative sizes, such as driving Pedal value PV in connection with the speed or a position worth CRU of a cruise control. The investigation of the requested torque TQI_REQ is in detail in the DE 196 12 455 A1, the content of which is hereby described is involved.

In block B5, a quickly adjustable torque TQI_FAST is determined depending on the requested torque TQI_REQ. In a block B6, control signals INJ, IGN for the injection valve 33 and for the ignition are then determined.

In block B7, one to be set via the air path Torque TQI_SLOW determined. In addition to the requested torque TQI_REQ lead torque of the empty running control, for catalyst heating, for driving stability control gelation, for catalyst protection and a lead torque of Power steering TQ_V_SERVO considered.

The lead torque TQ_V_SERVO of the power steering 5 is determined in a block B8. The lead torque of the power steering can be determined particularly easily depending on the steering angle STA. A particularly precise value of the storage torque of the power steering 5 is obtained if the steering angle speed STA_V is also taken into account, since this gives a particularly precise estimate of the speed at which the steering angle moves towards one of its end stops.

Used to determine the lead torque of the power steering the pressure difference Δp used, so it is particularly before  partial if the time derivative of the pressure difference is there is taken into account, since this in turn is a measure of the fast approaching the end stops of the steering angle is.

Alternatively or additionally, the lead torque of the power steering can also be determined depending on the current by an electric drive of the power steering 5 and the voltage that drops at an electric servo drive of the power steering.

The lead torque TQ_V_SERVO of the power steering 5 is preferably only built up shortly before the end positions of the steering angle are reached, since this ensures that the emissions increase only briefly due to a reduction in the ignition angle.

Depending on the torque to be set via the air path TQI_SLOW then becomes a throttle valve in block B9 signal determined with which the throttle valve is controlled. Alternatively or additionally, a can also be in block B9 Control signal for another the air supply to the cylinders the actuator influencing the actuator is determined become. The torque to be set via the air path TQI_SLOW is activated by means of appropriate control of the spark plug ze about the quickly adjustable torque TQI_FAST so greatly reduced that it requested torque TQI_REQ equivalent.

By taking into account the servo torque TQ_SERVO and the lead torque TQ_V_SERVO of the power steering 5 , the idle control is relieved of control interventions particularly when idling, which leads to a significant increase in the control quality during idle.

Instead of training the drive as an internal combustion engine can the drive also as an electric motor or a fuel  cell or another drive known to those skilled in the art for Motor vehicles be trained.

Claims (10)

1. A method for controlling a drive of a motor vehicle, in which a setpoint of a torque that is present on a shaft of the drive train is determined taking into account loss torque (TQ_LOSS) and actuators of the drive are controlled depending on the setpoint of the torque, thereby characterized in that the lost torque (TQ_LOSS) depends on a servo torque (TQ_SERVO) that has to be provided for a power steering ( 5 ) and that is determined depending on a steering angle (STA). 2. The method according to claim 1, characterized in that the servo torque (TQ_SERVO) depends on a steering angle Speed (STA_V). 3. The method according to any one of the preceding claims, characterized in that the servo torque (TQ_SERVO) depends on the speed (N) of the crankshaft ( 23 ) of the drive 4. The method according to any one of the preceding claims, characterized characterized that the drive as an internal combustion engine is formed and that a lead torque that over a Actuator for the air path of the internal combustion engine turned on is dependent on a servo lead torque (TQ_V_SERVO) is determined, which depends on the steering angle (STA) and / or the steering angular velocity (STA_V). 5. Method for controlling a drive of a motor vehicle, at which a setpoint of a torque that is on a shaft of the powertrain is determined under consideration loss torque (TQ_LOSS) and actuators of the drive depending on the setpoint of the torque are controlled, characterized by that the loss torque (TQ_LOSS) depends on a Ser vo torque (TQ_SERVO), that for a power steering drive  must be made available and that depending on one electrical current (I) and / or a voltage (U) determined that flows through the power steering drive or on this falls off. 6. The method according to claim 5, characterized in that the drive is an internal combustion engine and that a curtain te torque, which has an actuator for the air path of the Internal combustion engine is set depending on a Ser Vo lead torque (TQ_V_SERVO) is determined, that from depends on the electrical current (I) and / or the voltage (U) 7. The method according to any one of claims 5 or 6, characterized ge indicates that the servo lead torque (TQ_V_SERVO) depends on the steering angle (STA) and / or the steering angle speed (STA_V). 8. method for controlling a drive of a motor vehicle, at which a setpoint of a torque that is on a shaft of the powertrain is determined under consideration loss torque (TQ_LOSS) and actuators of the drive depending on the setpoint of the torque are controlled, characterized by that the loss torque (TQ_LOSS) depends on a Ser vo torque (TQ_SERVO), which is used for power steering for ver must be made and that depending on one Pressure difference before and after a power steering pump rep representative size is determined. 9. The method according to claim 8, characterized in that the size representing the pressure difference is the pressure difference reference (Δp). 10. Device for controlling a drive of a motor vehicle stuff with means for determining a target value of a rotation moments that abut a shaft of the drive train, un  taking into account a loss torque (TQ_LOSS) and Means for controlling actuators of the drive dependent from the nominal value of the torque, characterized in that that the loss torque depends on a servo Torque (TQ_SERVO), which is available for power steering must be made and that depends on an electri 's current (I) and / or a voltage (U) by the Power steering drive flows or drops on it, and / or a steering angle (STA) is determined.