DE10024704A1 - Method of controlling vehicle engine during clutch operations, increases e.g. engine speed - Google Patents

Abstract

The desired magnitude (speed, power, torque etc.) producing a control signal during operation of the slipping clutch has a value increased relative to the value in at least one other operational state. An Independent claim is included for corresponding control equipment.

Description

State of the art

The invention relates to a method and a device to control the drive unit of a vehicle.

A procedure is known from DE 34 26 697 C3, after which the speed of the drive unit is predetermined setpoint is regulated. To do the different Loads on the drive unit in the operating state of the ech idling (interrupted power flow) and operation stands with closed power flow in the idle range Rech It is intended to carry the desired speed of rotation number regulator to raise when the power flow in the drive train is established between the engine and the output. It will be the The speed is increased when a gear is engaged and the clutch is closed. Although the be written procedure with existing power flow and in real idle with an interrupted power flow an improvement speed control reached; however, the over gait state, especially the state of a grinding Coupling, not considered enough. The well-known Re Success is therefore not yet optimal.  

From DE 195 17 673 (US Patent 5 765 527) is known in certain operating conditions, preferably when idling, a specified torque reserve via the ignition angle put. In addition, the efficiency, which is outside the we at least an operating state in an optimal range is held by changing air supply accordingly drove and ignition angle worsened. With the same Torque of the drive unit is increased by increasing the air supply and pulling the ignition angle open the possibility net, quick jumps in torque by changing the ignition kels can also be realized in a torque-increasing direction.

Advantages of the invention

The procedure described below will Transition from a state with an interrupted power flow to optimized a state with closed power flow. In particular is special due to the temporary increase in the target value of the active regulation, especially the empty target speed, or by the temporary increase the torque reserve during the transition from open to grinding the operation of the clutch and during the grinding Be drove the problem of speed undershoots when starting or when the vehicle creeps, in particular with the accelerator pedal released, effectively avoided. This rotation undershoot, especially when starting or crawling special vehicles with automated manual transmissions occur and result in loss of comfort or to the off the engine can go, especially when driving testify to having a reduced idle speed. The application at Ottomoto is therefore particularly advantageous ren, especially with direct injection.

Furthermore, when starting or crawling the vehicle Slipping clutch due to the disturbance of the clutch motor  unwanted body vibrations generated mentes. By the measures mentioned will significantly improve the Driving comfort, especially lowering this body vibrations and an improvement in the acoustics in grinding achieved the operation of the clutch.

It is particularly advantageous that the transition of the clutch state from "open" to "dragging" by detecting the Coupling path is exactly recognizable.

Advantageously, a consumption disadvantage in the empty run through the measures mentioned through the temporal loading limit these measures to the operating area of the Slipping condition of the clutch avoided.

A further improvement in comfort is achieved when in the transition from the grinding to the completely closed Clutch, increasing the setpoint or increasing the Torque reserve filtered temporally to the value before the start lifting is carried back.

Improving driving comfort and avoiding or Reduction of speed undershoots when starting and / or creep of the vehicle by raising the target value and / or increase in the torque reserve is sufficient because through the free travel of the clutch until the A sufficient coupling torque on the drive unit Advance in time available after actuation of the clutch stands. For this reason, it is not necessary that Coupling torque generated during start-up outside the start to keep driving. This is also the moment reserve ve reduced with clutch open. The described pre hensweise thus shows an improved behavior in Be drive state with sliding clutch without consumption or fear other disadvantages.  

Further advantages result from the following Be writing of exemplary embodiments or from the dependent ones Claims.

drawing

The invention is explained below with reference to the embodiments shown in the drawing. It shows:
Fig. 1 is a flowchart a of an idle speed controller, while in Fig. 2, the procedure according to the invention using this preferred embodiment is shown as a flow chart. The mode of operation of the described embodiment is illustrated in FIG. 3 by time diagrams.

Description of exemplary embodiments

Fig. 1 shows the flowchart of a conventional speed controller, which runs in a microcomputer 10 of a control unit for controlling the drive unit of a vehicle. There is a setpoint image 12 to form the target idle speed Nsoll is provided, which are fed via input lines 14 to 18 from measuring devices 20 to 24, signals representing the operating variables or derived from the operating variables of the drive unit and / or the vehicle. Depending on at least one of the supplied operating variables, the target idling speed is determined in accordance with a characteristic curve, a table, a characteristic diagram or calculation steps. Typical operating variables are engine temperature, gear position, battery voltage, etc. Furthermore, a signal is supplied from a corresponding measuring device, which represents the clutch travel. The measuring device is, depending on the design, a displacement sensor for the actuation path of the clutch pedal or a displacement sensor which determines the path of a movable element of the clutch, on the basis of which an open, sliding or closed clutch can be detected. Depending on at least one of these variables, the setpoint image 12 forms the setpoint speed Nsetpoint and outputs it to a comparison point 26 . This is also supplied with the actual speed Nact, which is detected by a speed sensor 30 via line 28 . In the linkage point 26 , the deviation of the actual speed Nact from the target speed Nsoll is preferably formed by forming differences. The control deviation Δ is fed to the controller 32 , which generates an output signal τ in accordance with a predetermined control strategy, which leads via the output line 34 to an electrically actuatable control element 36 . This affects the speed of the drive unit. Depending on the example, 32 different strategies are implemented in the controller. An example of this is a controller with a proportional, integral and / or differential component. In the preferred exemplary embodiment, the actuating element 36 influences the air supply or filling of an internal combustion engine. In other exemplary embodiments, the ignition and / or the amount of fuel is alternatively or additionally adjusted by the controller 32 . In the case of diesel engines, the controller affects the amount of fuel, in engines with direct petrol injection in shift operation also on the amount of fuel, in the case of electric motors, the control current.

In another embodiment, there is improvement the function of idle control also an effect degree deterioration made at idle, the Air supply increased and the ignition angle to keep the Torque is adjusted late. This creates over the ignition angle a torque reserve that allows through Firing angle early a very quick change in torque to be able to realize in an elevating sense.  

A pure idle speed controller is described above ben. The procedure described below is not with such speed controllers, but also with controllers that regulate a different size of the drive unit, for example, their filling, the air mass supplied, de ren torque, their power, etc. In a corresponding manner a setpoint is also determined for these controller concepts, which is set by regulatory intervention. The successor Procedure described using a speed setpoint assign accordingly in other embodiments applied to other setpoint values.

With such controllers, starting or crawling of the Vehicle lead to speed drops, in extreme cases Engine stalls. The reason for this behavior is that Reduced idle speed for reasons of consumption. Further kick due to the disturbance occurring when the clutch is closed Coupling torque in this operating state undesired Ka vibrations on the vehicle, which significantly improve driving comfort compromise. These effects occur particularly with automa manual transmissions and internal combustion engines with gasoline direct injection.

As is known from the prior art mentioned at the outset, a torque reserve is set in today's solutions, to the torque build-up in an internal combustion engine dynami to make it harder. Rapid torque changes are therefore first through this torque reserve using ignition angle ver position caught. Since the static torque reserve in follow the deterioration in efficiency Ver disadvantages in use and due to the need manoeuvrable retardation due to the ignition angle limit or the lambda limit cannot be increased arbitrarily can be higher torque requirements through the clutch not caught and lead to a drop in speed when starting  drive. This occurs increasingly with automated gear shifting gearboxes (ASG) or gearboxes with automated clutch on. This is because the creep torque in the autom manual transmission (ASG) open when the brake is released is switched. So the disturbance torque already occurs at losge left accelerator pedal. The idle controller has this interference intercept moment. The start is made for the manual transmission usually with the accelerator pedal depressed. The driver request The gift is therefore greater than the torque loss of the internal combustion engine machine. The excess moment is therefore before Closing the clutch present, which intercepted the Mo ment requirement improved by the clutch.

According to the invention, it is dependent on the transition of the coupling tion state from completely open to the clutch state or grinding the target specification of the controller, in particular the target speed, and / or the torque reserve without delay enlarged. Due to the sudden increase in control deviation of the controller is the control variable of the control element and there with the controlled size in time for the correction of the Coupling torque increased at the grinding point. This applies before especially for the filling, which is opened in good time by early opening the throttle valve is raised. The detection of the transition the coupling state takes place on the coupling path, e.g. B. at Hand switch based on the clutch pedal travel. The clutch away other movable parts of the clutch can be detected become. The increase in speed or Torque of the drive unit during the grinding Coupling operation has the advantage in addition to the starting aid a reduction in the tendency to vibrate the body when Crawl. The dome is in this operating state generally also in the grinding operating state. Due to the increased excitation frequency due to the speed the vibration amplitude is significantly reduced because  the excitation outside the critical resonance range of the Body is.

The increase described is withdrawn if the Be drive state of the sliding clutch is exited (for open or closed coupling). Compared to a stati increase with the temporary increase during the operating state of the sliding clutch Consumption not increased when clutch is open. Besides, will poor efficiency (retarded ignition timing at homogeneous λ = 1 operation) avoided with the clutch open, because the torque reserve outside of this operating state everything in idle, can be reduced. Is the clutch completely closed, the increase in the target size is obtained approximately the momentary reserve preferably temporally tert withdrawn.

A preferred embodiment of the procedure described above is based on the flow chart of FIG . This flowchart outlines a computer program which is run through at predetermined time intervals, preferably depending on the number of revolutions. In the first step 100 , the variables relevant below are read in, actual speed nest and clutch travel Skup. Then, in step 102 , the clutch path is used to check whether the clutch is open. This is ascertained, for example, by the fact that the clutch travel Skup is compared with a predetermined limit value, when it is exceeded or fallen short of an open clutch can be assumed. If the clutch is accordingly opened, then in step 103 it is checked whether a flag FLAG is set to the value 1. This mark is set when a transition from the open to the closed clutch or vice versa has been recognized for the first time. If the mark is at the value 1, then this means that the open clutch was recognized for the first time after a transition state, so the mark is set to the value 0 in step 104 and, according to step 105, the desired speed from the clutch operating state for the looping state predetermined setpoint Nsoll2 to the value Nsoll1 according to a predetermined time function. The same applies to the increased torque reserve in the operating state with a sliding clutch. If the mark is not set to the value 1 (step 103 ), then in step 107 the setpoint Nsetpoint intended for the real idle operation and the reserve REST provided for the real idle operation are specified as the setpoint Nsetpoint. In a preferred exemplary embodiment, these values are dependent on farm size. After step 107 , the output signal of the idle controller DMLLR is determined in step 106 in accordance with the specified control strategy on the basis of the selected setpoint Nset and the actual value Nact and the specified torque reserve REST is set by appropriate control of filling and ignition angle.

If it was determined in step 102 that the clutch is not open, then a check is made in step 108 to determine whether the clutch is closed. This also takes place on the basis of the coupling path, which is compared with a second limit value, the undershoot or overshoot of which a closed clutch can assume. If the clutch is closed, it is checked in step 110 whether a flag FLAG is set to the value 1. This mark is set when a transition from the open to the closed clutch or vice versa has been recognized for the first time (see step 118 ). If the mark is at the value 1, this means that the closed clutch was recognized for the first time after a transition state, so the mark is set to the value 0 in step 112 and, according to step 114, the setpoint speed from that for the sliding operating state of the clutch predefined setpoint Nsoll2 is reduced to the value Nsoll1 in accordance with a predefined time function. The same applies to the increased torque reserve in the operating state with a sliding clutch. Step 114 follows step 106 .

If step 110 has shown that the brand does not have the value 1, this means that the operating state of the vehicle is outside the area of the sliding clutch, so that according to step 116 the values as idle control setpoint or as reserve according to step 104 RES1 and Nsoll1 can be specified. Step 106 then follows, in which the output signal of the idle controller is calculated when the controller is active and, if seen before, the torque reserve is set.

If step 108 has shown that the clutch is not closed, the clutch is in the sliding operating state. This means that the flag FLAG is set to the value 1 in step 118 and the target speed Nsetpoint is suddenly set to the increased value Nsetpoint2 provided for this operating state in accordance with step 120 . The same applies to the torque reserve, which is set to the RES2 value. This is followed by step 106 with the calculation of the output signal of the controller or the setting of the torque reserve. After step 106 , the program is ended and it is run through again with the next time interval.

In Fig. 3, the operation of the above procedure is shown using time diagrams. In Fig. 3a, the time course of the target speed (drawn by) and the actual speed (dashed) is shown. Fig. 3b shows the time course of the torque reserve, while in Fig. 3c the course of the clutch path Skup is set.

The illustration shows a vehicle with automated manual transmission (ASG) or automated clutch. First, the vehicle is in a real idle state. The setpoint speeds Nsetpoint and the reserve RES1 have therefore been set up to the time T0, the clutch being opened and the actual speed setpoint Nist being set to the setpoint speed. At time T0, the open state of the clutch is left and the sliding operating state of the clutch is entered. This means that at time T0 both the reserve ( FIG. 3b) and the target speed ( FIG. 3a) are suddenly increased. At time T1, the closed state of the clutch is recognized, which leads to a time limitation of the increased values at the corresponding times according to FIGS . 3a and 3b. As shown in Fig. 3a (dash-dotted line), if the measure described were to be dispensed with, a speed undershoot would be observed when the clutch entered the sliding operating state, which the idle speed controller regulates with difficulty. In contrast, the idle speed is increased when using the procedure described, it being important to note that the speed control is taken over by the accelerator pedal at time T1, since the vehicle is starting. A more comfortable start without speed undershoot is thus achieved.

In general, a setpoint (torque reserve value and / or target value (target speed)) during the duration of the loading drive state of the sliding clutch compared to the value in another operating state (open and / or closed coupling) increased. This increase results in one Embodiment only compared to the real idle state (open clutch), because when the clutch is closed a wide re increase in value takes place.  

The operating point "sliding clutch" is not only on Coupling path recognized, but also predicted. That is, if the clutch travel ver fully open the value for clutch allows, the condition of the clutch is already recognized. This has the advantage that the setpoint increase (suddenly increased control deviation) or an increase in torque reserve can be placed over the slow air path, because at this point the clutch is not yet a moment (Disturbance variable for idle control) transmits. The momenter increase or torque reserve is now via the air path (slow moment path) poses and represents a moment reserve for the time at which the clutch travel Grinding point reached. Before reaching the grinding point the excess torque with retarded ignition angle (quick torque path) destroyed (idle control). On the grinding The moment can be used to compensate the clutch interference torque over the fast torque path (ignition angle direction early). Advantage of this control: The Torque reserve with poor efficiency due to late Firing angle only works as long as the clutch is out of condition moved open to the grinding point.

Claims (8)

1. A method for controlling the drive unit of a vehicle, a control signal being generated as a function of a setpoint which controls at least one control element influencing an output size of the drive unit, the setpoint being influenced as a function of the clutch condition, characterized in that the setpoint during the duration of the operating state of the sliding clutch has an increased value compared to the value in at least one other operating state. 2. The method according to claim 1, characterized in that the setpoint is a setpoint, preferably a setpoint number, target torque, target power, target filling or Target air mass, and / or a torque set to be set serve above the ignition angle. 3. The method according to any one of the preceding claims, since characterized by that the operating state of the Slipping clutch determined based on the clutch path or if the clutch travel is "fully open" leaves.   4. The method according to claim 3, characterized in that the clutch travel by measuring the clutch pedal travel or by measuring the path of another moving one Part of the clutch is determined. 5. The method according to any one of the preceding claims characterized by that after leaving the state of the sliding clutch the increased target size made to measure given a predetermined time function, in particular one Filter function, is reduced from the increased value. 6. The method according to any one of the preceding claims, since characterized in that the control variable by a Idle speed controller is determined, which the An Control variable depending on the target speed and the actual speed determined. 7. The method according to any one of the preceding claims characterized in that the moment reserve by Er heights of the filling of the internal combustion engine and spa pulls the ignition angle of the internal combustion engine is set. 8. Device for controlling the drive unit of a driving stuff, with a control unit, which according to a Setpoint is a control signal for an output variable the control element influencing the drive unit, wherein the control unit the operating state of a clutch determination of the drive unit and the target size changed depending on the clutch condition, characterized records that the control unit the operating state of the sliding clutch detects and during the duration this operating state the setpoint compared to one other operating condition increased.