DE102006050957A1 - Motor vehicle drive, has control unit provided with fault check devices and integrators, where deactivation signal is emitted for deactivation of accentuation of specification of torque, if check devices and integrators recognize error - Google Patents

Abstract

The drive has an engine, a gear and a control unit (1), where reference specification (Msoll) of engine torque increased by an accentuation is described by the control unit during gear change process in a direction of larger transmission. The control unit is provided with fault detection devices (10, 14) and integrators (12, 15). A deactivation signal is emitted for deactivation of the accentuation of the reference specification of the engine torque, if the fault check devices and the integrators recognize an error. An independent claim is also included for a method for operation of a motor vehicle drive.

Description

The The invention relates to a motor vehicle drive, with a motor, a transmission and a control unit and a method of operation a motor vehicle drive.

In a power shift transmission may continue during a shift Torque from the engine of the motor vehicle to driven Transmit vehicle wheels become. In a downshift have to Speeds of the prime mover and the transmission can be increased. For a driver is the switchback completed when the speed of the prime mover is a synchronous speed reached a target corridor. This is true even if within the gearbox the downshift not quite finished yet. The synchronous speed of the target gear, So the gear back in the switched is, is the speed of the prime mover and a transmission input shaft, which after completion of the circuit at the current speed of the motor vehicle.

The for the increase The necessary energy is no longer available for the drive of the motor vehicle available, leaving it without further action while the downshift to a collapse of the torque on the driven vehicle wheels and thus comes to the collapse of the acceleration of the motor vehicle.

The DE 42 04 401 A1 describes a device and a method for performing a downshift in a power shift transmission of a motor vehicle. In a partial section of the downshift, a clutch associated with an original gear is brought into a slipping state, and subsequently the output torque of the engine is increased. This leads to an increase in the rotational speed of the drive machine without simultaneous loss of torque to the driven vehicle wheels.

From the DE 10 2004 046 066 A1 a device for performing a downshift in a power shift transmission is known, which allows fast downshifts. The device brings in a partial section of the downshift a clutch associated with an original gear in a slipping state and then increases the output torque of the prime mover. This leads to an increase in the rotational speed of the drive machine without simultaneous loss of torque to the driven vehicle wheels. The device is intended to reduce a transferable torque of a controllable starting clutch arranged between the drive machine and the transmission, at least in a second subsection of the downshift, at least to such an extent that the starting clutch is operated slipping.

From the publication DE 44 38 714 A1 is a monitoring concept for monitoring control units of a motor vehicle drive known. This is a method and a device for controlling the drive power of a vehicle with a microcomputer having at least two mutually independent planes, wherein a first level performs the control functions and a second level performs the monitoring functions. A third level is a control level which controls the surveillance level and thus the microcomputer.

task The invention is the failure safety during a gear change operation to increase a motor vehicle drive.

These The object is achieved by a Motor vehicle drive with the features of claim 1 and a method for operating a motor vehicle drive with the features of Claim 8 solved.

According to the invention Task solved by the control unit has an error detection device, by a shutdown signal for switching off the increase of the target value of the Engine torque is output, if the error detection device detects an error. If an error is detected, for example not all conditions for a gear change process towards a larger translation are met or the information supplied to the error detection device inconsistent are, so there is no torque increase. This will have potential harmful effects an unfounded or faulty torque increase avoided.

In an embodiment is the error detection device designed as an integrator, with the increase of the target specification of the engine torque over the Time is integrable and through which a mistake is recognizable and a Shutdown signal for switching off the increase can be output, if the boost integral thus formed exceeds a definable limit.

In order to can be detected if the torque boost is not completed properly or too high. If such an error is detected, a shutdown signal for Shutdown of the boost output. The did not finish properly or too high torque increase will be switched off and thus possible damage prevented.

In one embodiment, the error is identification device designed as a plausibility device, in the information on a gear change with the information of a speed sensor can be checked for plausibility, and by an error recognizable and a shutdown signal for switching off the increase of the target specification of the engine torque can be output if the information supplied to it is implausible. This prevents that implausible information leads to a torque increase.

In an embodiment then the plausibility checker detects an error if no gear change operation is in the direction of a larger translation. A momentum increase should only for the case of a gear change operation towards a larger translation permissible be. This condition becomes a torque boost for everyone else Cases and especially for a gear shift towards a smaller gear ratio prevented. This serves to avoid consequential damage.

In an embodiment the control unit has a functional level for performing control functions on, in which the error detection device is arranged. The Control unit as a two-level monitoring concept or three-level surveillance concept perform elevated the safety and the quality the supervised Information and the operations performed from this information.

In one embodiment, the control unit has a function monitoring level for carrying out monitoring functions, in which a further fault detection device is arranged, by which a switch-off signal for switching off the increase in the target specification of the engine torque to the functional level of the control unit ( 1 ) is outputable when the device detects an error. The functional monitoring level monitors the functional level. To do this, it performs the same checks that have already been performed at the functional level. In this way, the safety of the tests is increased and errors of the functional level can be detected.

In an embodiment becomes the integral of the boost the time is formed and an error is detected when this raising integral exceeds a definable limit. In this way, an erroneously too large increase can be detected.

In an embodiment the boost integral becomes independent from the presence of a gear change operation continuously formed and an error is detected if this raise integral is a definable Exceeds limit. This can be used to detect if the increase has not been completed.

In an embodiment an error is detected when the time required for the gear change exceeds a definable maximum period of time. It is typical provided that the period of time for a gear change and thus the raising period in the range of 1-3 seconds. If the gear change lasts too long, there is an error. This can be recognized this way.

In an embodiment becomes after detection of an error, a shutdown signal for shutdown the increase of the engine torque output as an error reaction. In order to In case of error, the inventive method is terminated or canceled.

Further Advantages and embodiments will become apparent from the dependent claims and the description. The figure shows a schematic Representation of an embodiment a control device of a motor vehicle drive according to the invention.

One Motor vehicle drive usually has a Engine out, over a starting element is connected to a transmission. It can the Engine as an internal combustion engine, electric machine or hybrid drive be educated. As a starting element between engine and transmission For example, a manual clutch, an automatic clutch or a transducer may be provided. The illustrated invention is also for Motor vehicle drives suitable without starting element, such as for one Hybrid drive with an internal combustion engine, one or more electric machines and a power split transmission with two planetary gear sets.

The gear shift of the transmission is in a control unit 1 supervised. In the figure, such a control unit 1 shown. The control unit shown in FIG 1 has a functional level 2 and a functional monitoring level 3 on.

In the functional level 2 is formed from a driver request torque Msoll_Fahrer and a speed information and information about a shift request a target torque Msoll for the engine of the motor vehicle.

This is done by a speed sensor 4 the information collected by him a switching function device 5 the functional level 2 to. Typically, the speed sensor detects 4 the input speed or the output speed of the transmission. It may also be provided to detect the engine speed. It can also be provided several speed sensors, the different speeds to capture.

The switching function device 5 detects the incoming information of the speed sensor 4 and calculates a speed. In addition, the switching function device receives 5 via data lines, not shown Information about the operating state of the gearbox. This includes information about the current transmission gear and about a possible shift request. From these incoming data, it is determined whether a switching operation should be carried out and under which boundary conditions this switching operation should be performed. As boundary conditions are defined, for example, start and duration of the shift, current transmission gear, target gear, whether up or downshifting, as well as the target speed at the location of the speed detection. This information is sent to a moment calculator 6 passed.

Except the information of the switching function device 5 becomes the moment calculator 6 via a data transmission device 9 the driver request torque Msoll_Fahrer to led. The torque calculator calculates from this information 6 the increase in the setpoint Msoll for the engine torque required for a pleasant shift. The determined value for the increase of the moment is sent to an adder 7 output.

The adder 7 is also via the data transmission device 9 the driver request torque Msoll_Fahrer to led. the adder 7 sums the driver request torque Msoll_Fahrer and the increase of the moment to a raised target torque Msoll of the engine. This desired torque Msoll is given by the adder 7 via a data line 8th out.

The switching function device 5 also gives their information to a plausibility checker 10 the functional level 2 further. In the plausibility checker 10 the plausibility of incoming information is checked. For example, it is checked whether the shift request to that of the speed sensor 4 captured information fits. It is checked whether the actual speed is smaller than the (by one tolerance increased) target speed. It is also checked whether after a definable time since the downshift, the actual speed has risen by a definable value or more. If one of these checks does not lead to the desired result, the plausibility checker indicates 10 an error signal via a Boolean operator 11 at the moment calculator 6 further.

The Boolean operator 11 In the embodiment shown in the figure, it is designed such that it transmits an error signal if one of its inputs receives an error signal.

Receives the moment calculator 6 from the Boolean operator 11 an error signal, a torque increase Mplus is output with the value zero.

The of the moment calculator 6 output torque increase Mplus also becomes one in the function level 2 arranged integrators 12 fed. The integrator 12 integrates the values supplied to it for the torque increase Mplus over time and compares the result with a stored or calculated limit value. If the integral exceeds the limit value, then the integrator outputs 12 an error signal via a Boolean operator 11 at the moment calculator 6 continue and the moment calculator 6 outputs a torque boost Mplus with the value zero.

The control unit shown in FIG 1 also has a functional monitoring level 3 on. All in the functional level 2 formed and calculated values are independent of the functional level 2 also in the function monitoring level 3 formed or calculated. This serves to monitor the functional level 2 ,

The speed sensor 4 carries its information also a calculation device 13 the functional monitoring level 3 to. The calculation device 13 detects the incoming information of the speed sensor 4 and calculates the speed. This information is provided by the calculation device 13 to a plausibility checker 14 the functional monitoring level 3 further.

Also the switching function device 5 the functional level 2 gives its information (eg about the current transmission gear and about a possible shift request, whether a shift should be performed, start and duration of the shift, current gear, target gear, whether up or down to be switched, and the target speed) to the plausibility check 14 the functional monitoring level 3 further. In the plausibility checker 14 the plausibility of incoming information is checked. For example, it is checked whether the shift request to that of the speed sensor 4 captured information fits. If this is not the case, the plausibility checker indicates 14 an error signal via a Boolean operator 16 at the moment calculator 6 further. The moment calculator 6 then outputs a torque boost Mplus with the value zero.

The of the moment calculator 6 the functional level 2 output torque boost Mplus also becomes an integrator 15 the functional monitoring level 3 fed. The integrator 15 integrates the values supplied to it for the torque increase Mplus over time and compares the result with a stored or calculated limit value. If the integral exceeds the limit value, then the integrator outputs 15 an error signal via the Boolean operator 16 at the moment calculator 6 continue and the moment calculator 6 outputs a torque boost Mplus with the value zero.

In addition, that of the moment calculator 6 the functional level 2 output torque increase Mplus also an adder 18 the functional monitoring level 3 fed. The adder 18 is via a data transmission device 17 a maximum permissible limit Mzul_Fahrer for the driver request torque Msoll_Fahrer supplied. This limit value Mzul_Fahrer is added with the torque increase Mplus and results in a maximum permissible limit value Mzul of the raised setpoint torque Msetpoint of the motor.

In the embodiment of the control unit shown in FIG 1 is an adder 18 intended. The adder is calculated by the moment calculator 6 fed to the torque increase Mplus. Via the data line 17 becomes the adder 18 a value for the maximum permissible driver torque Mzul_Fahrer supplied. The adder adds the two supplied moments and thus forms a maximum permissible torque Mzul. The adder 18 gives the maximum permissible torque Mzul over a data line 19 out. The maximum permissible torque Mzul is the maximum permissible upper limit for the setpoint torque Msetpoint, which is formed from the sum of the torque increase Mplus and the driver request torque Msetpoint_driver. The setpoint torque Msetpoint is limited to the maximum permissible torque Mzul. This limitation is intended to prevent damage caused by incorrect requirements.

Claims (11)

Motor vehicle drive, with an engine, a transmission, and a control unit ( 1 ), wherein during a gear change operation in the direction of a larger translation by an increase (Mplus) increased target specification of the engine torque (Msoll) by the control unit ( 1 ), characterized in that the control unit ( 1 ) an error detection device ( 10 . 12 . 14 . 15 ), by which a switch-off signal for switching off the increase (Mplus) of the setpoint specification (Msetpoint) of the engine torque can be output if the fault detection device ( 10 . 12 . 14 . 15 ) detects an error. Motor vehicle drive according to claim 1, characterized in that the error detection device ( 12 . 15 ) is formed as an integrator, with which the increase (Mplus) of the target specification (Msoll) of the engine torque over time can be integrated and an error is recognizable if the so-formed boosting integral exceeds a definable limit. Motor vehicle drive according to claim 1, characterized in that the error detection device ( 10 . 14 ) is designed as a plausibility check device in which information about a gear change with the information of a speed sensor ( 4 ) are verifiable for their plausibility, and by which an error is recognizable if the information supplied to them is implausible. Motor vehicle drive according to claim 3, characterized in that an error by the plausibility check device ( 10 . 14 ) is recognizable if there is no gear change operation in the direction of a larger translation. Motor vehicle drive according to claim 1, characterized in that the control unit ( 1 ) a functional level ( 2 ) for performing control functions in which the error detection device ( 10 . 12 ), and a functional monitoring level ( 3 ) for performing monitoring functions for monitoring the functional level ( 2 ). Motor vehicle drive according to claim 5, characterized in that in the function monitoring level ( 3 ) for performing monitoring functions, a further error detection device ( 14 . 15 ) is arranged, by which a switch-off signal for switching off the increase (Mplus) of the target specification (Msoll) of the engine torque to the functional level ( 2 ) of the control unit ( 1 ) can be issued if the facility ( 14 . 15 ) detects an error. Motor vehicle drive according to claim 6, characterized in that in the error detection device ( 15 ) the boost integral is calculable and an error is detected when the boost integral exceeds a definable limit. A method for operating a motor vehicle drive according to one of claims 1 to 7, wherein during a gear change operation in the direction of a larger translation an increase (Mplus) of the setpoint (Msoll) of the engine torque, characterized in that the integral of the increase (Mplus) over time is formed and an error is detected if this raising integral has a definable limit exceeds. Method according to claim 8, characterized in that that the boost integral is independent of the presence of a gear change operation is continuously formed and an error is detected if this raise integral exceeds the definable limit. Method according to claim 8 or 9, characterized that an error is detected when the time required for the gear change exceeds a definable maximum period of time. Method according to one of claims 8 to 10, characterized that after detection of a fault, a shutdown signal for switching off the Increase (Mplus) of the engine torque (Msoll) output as an error reaction becomes.