DE102004005728A1 - Process to regulate the acceleration of an automotive piston engine with torque converter - Google Patents

Abstract

A process regulates the operation of an automotive piston engine (10) linked via a torque converter (20) to a gearbox (30). A motor operating parameter is set that then reduces the torque change, and effects a time delay in a subsequent increase in torque.

Description

The The invention relates to a method and a device for controlling a drive unit of a vehicle according to the preamble of the independent claims 1 and 7th

at Vehicles with a gearbox that uses a torque converter, for example, via a hydrodynamic torque converter, connected to a motor, can at the transition from Push to train operation and vice versa in the transition from train operation to Push operation load changes occur. At a load change can be through the relaxation strained components, eg. As the drive shafts, as well as by the voltage relaxed components or any existing loose in the Powertrain rotational shocks between the components of the powertrain arise. These one or more times occurring Bumps takes the driver of the vehicle both tactile and acoustically true. In addition, jerky vibrations of the drive train are excited, the to another impairment driving comfort.

From the DE 100 18 551 A1 is a method for controlling a drive unit of a vehicle with an actuating element for influencing the power known, wherein starting from the position of an operating element, a power-determining signal can be predetermined, and the control of the actuating element is dependent on a filtered power-determining signal. The signal is filtered with a filter that has at least a high pass and a low pass, which are connected in parallel. Through this filter state changes between thrust and train can be carried out very quickly. Due to the rapid change of state, a spontaneous vehicle reaction to the driver's specification can be realized. The damping of the shock when hitting the new plant position causes a significant reduction in noise during the load change process, a reduction in the load impact during load changes due to small changes in driver specification and a reduced excitation of the drive train to bucking. Regulations that are used at the point of load change are difficult to apply and there is also a risk of instability.

task It is the object of the present invention to provide a method and an apparatus for the control of a drive unit of a vehicle, that one easy application possible and that instability is practical be excluded. Filtering should be avoided as far as possible be a delayed one Responsiveness to driver specifications should be avoided.

Advantages of the invention

These Task is in a method and a device for control a drive unit of a vehicle having the features of independent claims 1 and 7 solved.

The basic idea The invention is the engine torque at a detected load change to adjust to the loss moment and in conjunction with a progressive To increase the torque in the direction of the driver's specification. Under Loss moment is the sum of the moments caused by engine friction, the drive of ancillaries, etc., in short, the moments that are not for the Propulsion of the vehicle available stand, understood. A load change therefore always occurs when the difference between the engine torque and the lost torque the Sign changes.

at an advantageous embodiment the occurrence of a load change is then assumed when the difference between the torque converter input speed and the torque converter output speed is equal to zero. A load change is in other words by a slip detected at the torque converter, where slip here is the difference of Torque converter input speed and torque converter output speed means.

at another advantageous embodiment is the load change detection by at least one torque sensor performed.

at another embodiment the load change detection is performed by at least one flow or Pressure sensor in your torque converter.

Preferably becomes the torque-time characteristic of the engine to the torque converter delivered torque after adjustment to the loss torque set so that a specifiable maximum temporal gradient is not exceeded.

A advantageous embodiment of the proceedings doing a tangled Waveform before, the maximum temporal gradient corresponds to this case of a parable.

alternative are also other characteristics of the gradient, z. B. ramped Gradientenverläufe possible.

Purely In principle, instead of a slope limitation, the signal waveform also by a filter higher Order, in particular an order greater than or equal to 2, shown become.

drawing

Further Advantages and features are the subject of the following description as well as the graphic representation of embodiments of the invention.

In show the figure:

1 a block diagram of a known from the prior art drive unit of a vehicle;

2 schematically a flow chart of a method making use of the invention;

3 the speed and the torque at a load change transition from overrun to traction and

4 the speed and the torque at a load change transition from the train operation to the overrun operation.

Description of the embodiments

A drive unit of a vehicle, shown in FIG 1 , has a motor 10 , z. As an internal combustion engine, on the over a crankshaft 12 with a torque converter 20 connected is. The torque converter 20 is via a transmission input shaft 22 with a gear 30 connected. The gear 30 is about an axis 32 with a wheel 40 connected. It is understood that this must be considered as a schematic representation only. In practice, the transmission output shaft 32 for example, connected via one or more differential gear with the wheel axles. At the crankshaft 12 , which may also be referred to as a torque converter input shaft, is a speed sensor 14 provided, the speed of the crankshaft 12 detected. At the transmission input shaft 22 , which may also be referred to as a torque converter output shaft, is also a speed sensor 24 arranged, the speed of the transmission input shaft 22 detected. The signals of the speed sensors 14 and 24 become a control device 50 supplied and processed in a manner described in more detail below. The control device 50 allows via a schematically illustrated control line 54 the control of actuators for influencing the of the engine 10 to the torque converter 20 delivered torque.

A method of controlling the in 1 shown drive unit of a vehicle is described below in connection with 2 and 3 described. First, in a step S210, it is determined whether there is a load change. This is done, for example, by checking whether the crankshaft speed or torque converter input speed n ₁₂ and the torque converter output speed or transmission input speed n _{22 are the} same (step S210). Another way (not shown) to detect a load change, is to close due to the measured or otherwise determined flow and / or pressure conditions in the torque converter to a load change. When there is a load change, there is no slip on the torque converter 20 in front. In a viscous torque transmission, as in a hydrodynamic torque converter 20 is present, no moment is transmitted in this state. In a load change detected in this way, the torque M _mot output by the engine is now adjusted by driving an actuating element for influencing the torque output by the engine so that it _loses a loss torque M within predeterminable limits S M S _≦ M _{mot ≦} M _loss + S (step S220). The sum of the moments is termed the moment M loss _loss thereby, which are not due to engine friction, the drive of auxiliary units and the like for propelling the vehicle. Then, the engine torque in a manner to be described in more detail below a torque-time curve M = f (t) is increased (step S230), so that it is a predetermined by the driver of the vehicle engine torque M _FV (see 3 . 4 ) approaches.

The above in connection with 2 described method will be described below with reference to 3 explained in more detail.

In the upper graph of the 3 For example, torque converter input speed n ₁₂ and torque converter output speed n _{22 are} plotted against time. In a coasting mode of the vehicle designated I, the torque converter output speed n _{22 is} greater than the torque converter input speed n ₁₂ . The torque converter input speed n ₁₂ , the crankshaft speed of the engine 10 is followed, in terms of its timing substantially the torque converter output speed n ₂₂ , but with a smaller value.

At a time t ₁ , the driver now gives a torque value M _FV (see the lower diagram of FIG 3 ) in front. The crank mechanism of the engine 10 is now accelerated with a rising moment so nigt that the crankshaft or torque converter input speed n ₁₂ increases. This results in a spontaneous response, as in 3 , upper and lower diagram. Have as soon as the torque converter input rotational speed n ₁₂ and the torque converter output speed n ₂₂ assumed the same value n ₁₂ = n _22, which is detected in step S210, control elements are for influencing of the engine 10 output torque is controlled so that that of the engine 10 output torque of the loss torque M _loss within predeterminable limits ± S corresponds to: _miss M - S ≤ M ≤ M _{mot loss} + S, as shown in the lower half of 3 is shown; the barriers + S are shown here schematically and not to scale. In this state, no torque is transmitted by the hydraulic torque converter. This time t ₂ is assumed to be the time of the load change and the resulting load impact. Starting from the loss _torque M set in this _way , the output _{torque of} the motor M _mot is then subsequently increased taking into account a predefinable, maximum permissible gradient. The increase in the output torque is limited, for example parabolic, so that a in 3 shown tangent torque-time curve results, with which the engine torque M _{mot is} increased so that it approaches the driver predetermined torque value M _MV . As a result, a "gentle" flipping of the engine and drive train is effected in a designated with II train operation of the vehicle, thus reducing the occurrence of a load shock.

In 4 is a load change transition from train operation in the overrun mode of the vehicle shown.

In the lower diagram of the 4 the torque is plotted against time, in the upper graph, the torque converter input speed n ₁₂ and the torque converter output speed n ₂₂ are shown.

Of the Train operation of the vehicle is in these graphs in the III designated area, whereas the push operation in illustrates the area designated by IV area of the graphs is.

In the train operation of the vehicle, the torque converter output speed n _{22 is} above the torque converter input speed n ₁₂ . At a time t ₃ , the predetermined by the driver torque M _{FV changes} . The driver of the vehicle, for example, the gas back with the intention of operating the vehicle from this point in overrun operation. Accordingly occurs in the in the lower graph in 4 represented a jump of the driver predetermined torque M _FV to the value 0 on. From the time t ₃ is now the crank mechanism of the engine 10 delayed with a decreasing moment so that the crankshaft speed or torque converter input speed n ₁₂ decreases. The value of the torque converter input rotational speed n ₁₂ reaches the value of the torque converter output rotational speed n ₂₂ at time t ₄ , which is determined as a load change change (step S210). At time t ₄ is therefore - as described above - the actuator for influencing the of the engine 10 output torque is controlled so that that of the engine 10 output torque M _mot the loss torque M _loss within the limits ± S corresponds to: M _loss - S ≤ M _mot ≤ M _loss + S. In this state is determined by the hydraulic torque converter 20 no torque transmitted. Starting from the loss torque M _loss thus set, the output torque M _{mot of} the motor is then subsequently 10 taking into account a - given above - predetermined, maximum allowable gradient reduced. The reduction of the output torque M _mot , for example, parabolic, so that the in 4 shown tangent-shaped torque-time curve results, with which the engine torque M _{mot is} reduced, so that it is z. B. approaches a value predetermined by the driver. As a result, in turn, a "gentle" Umlegen the engine and the drive train from the designated III train operation in the designated IV thrust operation is possible.

Of the The advantage of the above-described method is in particular that that it is easy to apply. In the load change point, the drive train, namely a strongly nonlinear behavior. Regulations at the point of load change are used, are therefore difficult to apply and it exists the danger of instability. The method described above represents a pure control, so that instabilities are structural excluded are.

Claims (10)

Method for controlling a motor ( 10 ), a transmission ( 30 ) and one between the engine ( 10 ) and the transmission ( 30 ) arranged torque converter ( 20 ) having a drive unit of a vehicle, characterized in that at least one operating parameter of the engine ( 10 ) is set at the occurrence of a load change change such that a magnitude similar to that of the engine ( 10 ) to the torque converter ( 20 ) Torque characterized, first one of the loss torque of the engine ( 10 ) characterizing size within predeterminable limits and is subsequently increased according to a predeterminable time course. A method according to claim 1, characterized in that the occurrence of a load change change is assumed when the difference of the torque converter input speed (n ₁₂ ) and the torque converter output speed (n ₂₂ ) corresponds to a predetermined value, in particular equal to zero. Method according to claim 1, characterized in that that this Occurrence of a load change detected by detecting the torque. Method according to claim 1, characterized in that that this Occurrence of a load change by detecting the flow velocity of a hydraulic fluid and / or pressure of the hydraulic fluid is detected in the torque converter. Method according to one of the preceding claims, characterized characterized in that Size that the torque delivered by the engine to the torque converter characterized, so changed will that one specifiable maximum amount of time of the gradient is not exceeded becomes. Method according to claim 5, characterized in that that the Torque-time curve tangent form is. Device for controlling a drive unit of a vehicle with an engine, a transmission and between the engine ( 10 ) and the transmission ( 30 ) arranged torque converter ( 20 ) and at least one control device ( 50 ) for influencing that of the engine ( 10 ) and at least one means ( 14 . 24 ) for detecting a load change, characterized in that the control device ( 50 ) if the at least one means ( 14 . 24 ) detects a load change change to detect a load change, at least one operating parameter of the engine ( 11 ) is set so that a size similar to that of the engine ( 10 ) to the torque converter ( 20 ) torque output, within predeterminable limits of a size corresponding to the loss torque of the engine ( 10 ), and subsequently increased according to a predeterminable time course. Apparatus according to claim 7, characterized in that the means for detecting a load change change means ( 14 . 24 ) for detecting the speed difference of the torque converter input speed (n ₁₂ ) and the torque converter output speed (n ₂₂ ). Device according to claim 7, characterized in that that this Means for detecting a load change at least one torque sensor is. Device according to claim 7, characterized in that that this Means for detecting a load change at least one flow and / or Pressure sensor in the torque converter is.