WO2006048062A1

WO2006048062A1 - Method and device for the thermal protection for at least one drive in a vehicle

Info

Publication number: WO2006048062A1
Application number: PCT/EP2005/008342
Authority: WO
Inventors: Tobias Gerlach; Holger Martin; Attila Pado; Michael Riedle
Original assignee: Daimlerchrysler Ag; Leopold Kostal Gmbh & Co. Kg
Priority date: 2004-11-04
Filing date: 2005-08-02
Publication date: 2006-05-11
Also published as: DE102004053850A1

Abstract

The invention relates to a method for thermal protection of at least one drive (1) in a vehicle (3) and to an associated device for carrying out said method. The invention is characterised in that a current motor temperature of the controlled drive (1) which is converted into an energy value is determined, the current energy value converted by the motor temperature is compared to a predetermined first threshold value, a cooling function is activated if the determined energy value exceeds the predetermined first threshold value and/or if the drive (1) is no longer controlled. After terminating the current control of the drive (1), an additional control of the drive (1) is prevented until the current motor temperature defined by the cooling function, which is determined by the recorded motor energy and a predetermined cooling characteristic, reaches or exceeds a predetermined threshold value, and the cooling function is deactivated according to current vehicle conditions.

Description

Method and device for temperature protection for at least one drive in a vehicle

The invention relates to a method for temperature protection for at least one drive in a vehicle according to the Oberbe¬ handle of claim 1 and an associated apparatus for performing the method.

DE 102 60 106 A1 describes a method for protecting semiconductor output stages of an electric drive, which are controlled via a microcontroller and driver, with a specification of the setpoint voltage of the electric drive via a setpoint generator, starting from a first temperature of the semi-conductor output stages. A second temperature is estimated within a thermal protection routine depending on the load state of the electric drive within a microcontroller in various evaluation routines such as "stalling", "adjustment", "linear drive." The first temperature is modified by an event dependent estimated temperature change electric drive is carried out in a cooling behavior simulating its Auswerteroutine "cooling" taking into account the ambient temperature and the transient thermal behavior of the semiconductor amplifiers and their environment characterizing sizes. The object of the invention is to provide a cost-effective method for temperature protection for at least one drive in a vehicle and to provide an associated device for carrying out the method.

The invention achieves this object by providing a method for temperature protection for at least one drive in a vehicle having the features of patent claim 1 and by an associated apparatus for carrying out the method having the features of patent claim 10.

Advantageous embodiments and further developments of the invention are specified in the dependent claims.

According to the invention, the method for temperature protection of at least one drive in a vehicle comprises the steps: determining a current engine temperature of the driven drive, which is converted in the form of an energy value, comparing the current energy value converted from the engine temperature with a predefinable first threshold, activating a cooling function, If the determined energy value exceeds the predetermined first threshold value or if the drive control is terminated, wherein after completion of the current control of the drive further control of the drive is prevented until the current determined by the cooling function engine temperature, which from the recorded motor energy and a predetermined cooling characteristic is determined, reaches or falls below a predetermined threshold, and wherein the cooling function is deactivated in dependence on the current vehicle state. By taking into account the state of the vehicle when deactivating the cooling function, quiescent current requirements for the temperature protection of the drive can be taken into account in an advantageous manner.

In an embodiment of the method according to the invention, the cooling function is deactivated in a first vehicle state when an estimated from the recorded engine energy engine temperature reaches or falls below a currently measured ambient temperature. By taking into account the ambient temperature during the deactivation can be dispensed with an external time information, which is provided for example on a bus.

In a further embodiment of the method according to the invention, the cooling function is deactivated in a second vehicle state when a predetermined period has expired and / or the determined engine temperature reaches or falls below a first threshold value and / or a second threshold value. The predefinable time period is predetermined, for example, by setting a down counter, which then counts down to zero, external time information is not required.

The predefinable time period for the deactivation of the cooling function is predetermined, for example, as a function of the temperature behavior of the drive. The second threshold value is chosen such that, after reaching the threshold value, renewed activation of the drive is possible without damage. These measures advantageously ensure that after deactivation of the cooling function and the release of the drive for a further control, the drive has cooled down so far that it is at re-activation is not damaged by overheating.

The first vehicle state corresponds for example to a normal driving operation of the vehicle and the second vehicle state corresponds to a rest operation of the vehicle, preferably a parked state of the vehicle.

In an embodiment of the method according to the invention, after the activation of the drive, the current energy value is estimated periodically starting from an energy start value, to which a calculated power-dependent energy supply is added.

In a further embodiment of the method according to the invention, the energy start value is formed from the currently measured ambient temperature or from an engine temperature stored after the last activation of the drive, a temperature offset being added to the ambient temperature.

If the vehicle is at rest for an extended period of time, for example longer than one day, then the currently measured ambient temperature is taken into account in the calculation of the energy start value. Otherwise, the motor temperature stored after the last actuation of the drive is taken into account in the calculation of the energy start value.

In a further embodiment of the method according to the invention, an associated motor current is determined for calculating the power-dependent energy supply from an engine period, which is multiplied by the associated motor voltage. The engine period corresponds to the reciprocal of the engine speed. By implementing the method of the invention in a control unit to hardware components allow for temperature ^¬ temperature protection save and improve the behavior of the drive in Reversierfall a drive. The method according to the invention is advantageously functional with and without time information from a bus system and can therefore also be implemented relatively inexpensively.

The inventive device for carrying out the method comprises an evaluation and control unit for determining a current engine temperature of the driven drive, which is implemented in the form of an energy value, for activating and executing a cooling function when the determined energy value exceeds a predetermined first threshold or the control of the drive is completed, and for deactivating the cooling function as a function of the current vehicle state, and means for determining the current vehicle state and the ambient temperature, wherein the drive is locked or released via an associated switch. The switch can be embodied, for example, as a semiconductor switch or as a relay.

Advantageous embodiments of the invention are illustrated in the drawings and will be described below.

Showing:

1 is a flowchart of a first part of a

Method for temperature protection for at least one drive in a vehicle, Fig. 2 is a flowchart of a second part of the

Method for temperature protection for at least one drive in a vehicle, 3 is a flowchart of a partial method for

Determining a current energy value from FIG. 1,

4 is a diagram showing characteristics for a cooling function,

Fig. 5 is a diagram illustrating a current-motor period characteristic, and

Fig. 6 is a block diagram of an apparatus for

Implementation of the method of FIGS. 1 and 2.

As can be seen from FIG. 6, the device for carrying out the method for temperature protection of at least one drive 1 in a vehicle 3 comprises an evaluation and control unit 2, which comprises, for example, a microprocessor, not shown, for determining a current engine temperature T _{M of} the controlled one Drive 1, which is converted in the form of an energy value W _E , for activating and executing a cooling function F _κ , when the determined energy value W _E exceeds a predetermined first threshold value Sl or when the drive of the drive 1 is completed, and for deactivating the Cooling function F _κ as a function of the current vehicle state, and means 5, 6 for determining the current vehicle state and the Umge¬ ambient temperature T _A , wherein the drive 1 is blocked or released via a zugeord¬ Neten switch 4. The switch 4 may be designed, for example, as a semiconductor switch and / or as a relay.

As can be seen in FIGS. 1 and 2, in the method according to the invention for temperature protection of at least one drive 1 controlled by an evaluation and control unit 2 via a switch 4 in a vehicle 3, after activation of the drive 1 in step S100 in step S200 a current energy value W _{E of} the drive 1, starting determined by a starting value W _s . The step S200 is described below in more detail with reference to FIG. 3. In step S300, the determined energy value W _{E is} compared with a predefinable first threshold value S1, which, for example, represents a maximum permissible amount of energy which the drive 1 can absorb without being damaged. If the comparison in step S300 reveals that the predefined threshold value has not yet been reached, then in step S350 it is checked whether there is another activation request. If there is another activation, then the method returns to the starting point and the current energy value W _{E is} determined again in step S200. Before the repetition of step S200, a waiting time can be predetermined, which is implemented, for example, by a correspondingly programmed counter. If the comparison in step 300 reveals that the determined energy value W _E exceeds the predefined first threshold value S1, then in step S400 the drive 1 is blocked for further activation. A cooling function F _κ is then activated in step S500. The cooling function F _κ is also activated when it is detected as checked at the step S350 that no further control of the drive 1 is present. Subsequently, the current vehicle state is determined in step S600 by evaluating the signals of the means 5, 6 for determining the current vehicle state.

If a first vehicle state is detected in step S600, which corresponds, for example, to a normal driving operation of the vehicle 3, then branching is made to node 10 in FIG. 2 and, for example, from the determined energy value W _E and a predetermined drive-dependent cooling characteristic curve W _K2 (in step S700). see Fig. 4), which depicts the cooling behavior of the associated drive 1, the current engine temperature T _M determined. In step S800, it is checked whether the current engine temperature T _M determined in step S700 has reached or falls below the first threshold value S1. If the comparison in step S800 is positive, then the drive 1 is released in step S900 for a renewed activation. If the comparison in step S800 is negative, then steps S700 to S800 are repeated, whereby a waiting time can be specified before the repetition. In step S100, the current ambient temperature T _{A is} measured, for example with a temperature sensor 6. In step S1100 it is checked whether the determined current engine temperature T _{M is} lower than the measured current ambient temperature T _A. If the comparison in step S1100 shows that the current engine temperature T _{M is} not lower than the measured current ambient temperature T _A , then after a renewed determination of the current engine temperature T _M , the method returns to step S 1000 in step 1200 and the current value again becomes Outside temperature T _A determined. Before the step S1200, a waiting time can be given, which is implemented, for example, by a correspondingly programmed counter. If the comparison in step 1100 shows that the current engine temperature T _{M is} lower than the measured current ambient temperature T _A , then the current engine temperature T _M and the current outside temperature T _A are stored in step S1800, and then in step S1900 the cooling function F _κ disabled.

If a second vehicle state is detected in step S600, which corresponds, for example, to a resting operation of the vehicle 3, preferably a parked state of the vehicle 3, then it is checked in step S1300 whether the current engine temperature is less than or equal to a second threshold S2, which is smaller than that first threshold Sl is. If the check in step S1300 is affirmative, then in step S1330, in step S900, the drive is released again if it was previously disabled. Then, branching is made to the node 30 in FIG. If the check at step S1300 is negative, then a follow-up period TN, in step S1350 is started for which the associated control unit to perform the cooling function F _κ least still remains activated before it enters an idle state. Then, branching is made to the node 20 in FIG. As can be seen from FIG. 2, it is checked after the node 20 in step S1400 whether the predefinable time period TN has expired. If the time period TN has not yet expired, then in step S1500, analogous to step S700, for example from the current energy value W _E and the predetermined drive-dependent cooling characteristic curve W _K2 , the current engine temperature T _{M is} determined. In step S1600 it is checked whether the current engine temperature T _M falls below the first threshold value Sl. If the comparison in step S1600 reveals that the current engine temperature T _M has not yet reached the first threshold value S1, then the system jumps back to the node 20 and the step S1400 is repeated. Before the repetition of step S1400, for example, a waiting time can be predetermined, which is converted, for example, by a correspondingly programmed counter. If the comparison S1600 reveals that the current engine temperature T _{M is} below the first threshold value S 1, the drive is released again in step S 1700, analogously to steps S 900, and then jumped back to node 20 and the step S 1400 is repeated. In addition, a programmable waiting time can be provided before the return. If it is determined in step S1400 that the predetermined time period TN has elapsed, then the system branches to node 30. At node 30, the method continues with step S1800 and the current engine temperature T _M and the current outside temperature T _A are stored. The cooling function F _κ is then deactivated in step S1900. The pre-defined time period TN and the predetermined first and second threshold values S1 and S2 are selected such that after the release of the drive 1 a renewed activation of the drive 1 without damage is possible.

As can be seen from FIG. 3, in step S200 the current energy value W _{E is} periodically estimated on the basis of an energy start value W ₈ , to which a calculated power-dependent energy supply W _{z is} added in a step S230. The current energy value is then output in step S260. The energy start value W ₅ is formed from a currently measured ambient temperature T _A or from a motor temperature T _M stored after the last actuation of the drive 1, wherein in step S210 the measured ambient temperature T _A , which is provided by a bus system, for example, a temperature offset T _{0 is} added. The temperature offset serves as Sicherheits¬ impact. In the subsequent step S220, the temperature determined in step 210 is converted by means of an associated characteristic curve into the corresponding energy start value W ₃ . The currently measured ambient temperature T _A is taken into account in the calculation of the energy start value W _s , in particular after a longer period of time, for example of one day, has expired.

For calculating the power-dependent energy supply W _z , in step S240 by means of a corresponding characteristic (see FIG. 5) determines an associated motor current I from an engine period MP, which motor is multiplied by the associated motor voltage U for the power calculation in step S250. From the calculated power P and a time period, the power-dependent power supply W _{z is} calculated, which is summed up in step S230.

4 shows a first characteristic W ₀ , which converts the temperature offset as energy value W ₀ . A second characteristic curve W _K i shows a real curve of a drive-dependent cooling curve, starting from an energy value W _{E of} the drive 1, the actual course of the cooling curve corresponding to a superposition of at least two e-functions. A third characteristic W _K2 shows an approximated by line segments to the real course of the characteristic curve, which is used by the inventive method for determining the current Motor¬ temperature T _M during the activated cooling function F _κ.

FIG. 5 shows a current-motor cycle characteristic curve from which the current motor current I is determined in step S240 from a current motor period MP which corresponds to the reciprocal of the motor speed. The motor current is, as already described, used to determine the power-dependent energy increase W ₂ .

Claims

claims

Method for temperature protection of at least one drive (1) in a vehicle (3), characterized by the steps:

Determining a current engine temperature (T _M ) of the driven drive (1), which is converted in the form of an energy value (W _E ),

Comparing the current energy value (W _E ) converted from the engine temperature with a predefinable first threshold value (Sl),

- activating a cooling function (F _κ) when the energy value (W _E) determined exceeds the predetermined first threshold value (Sl) and / or when the control of the drive (1) is completed,

- After completion of the current control of the drive (1) further control of the drive (1) is prevented until the current of the

Cooling function certain engine temperature (T _M ), which from the energy value (W _E ) and a predetermined Abkühlkennlinie (W _K2 ) is determined, reaches or falls below a predetermined threshold (Sl, S2), and wherein the cooling function (F _κ ) depending on current vehicle state is deactivated.

2. The method according to claim 1, characterized in that the cooling function (F _κ), is deactivated at a first vehicle condition when the engine temperature (T _M) measured has reached a currently measured ambient temperature (T _A) or below.

3. The method of claim 1 or 2, characterized in that the cooling function (F _κ ) is deactivated in a second vehicle state when a predetermined period of time (TN) has expired and / or the determined engine temperature (T _M ) a first threshold value (Sl ) and / or reaches or falls below a second threshold value (S2).

4. The method according to claim 3, characterized in that the predeterminable time period (TN) for the deactivation of the cooling function (F _κ ) depending on the temperature behavior of the drive (1) is specified, and the second threshold (S2) is selected such that a renewed control of the drive (1) without damage is possible.

5. The method according to any one of claims 2 to 4, characterized in that the first vehicle state corresponds to a driving operation of the vehicle (3) and the second vehicle state a resting operation of the vehicle (3), preferably a parked state of the vehicle (3).

6. The method according to any one of claims 1 to 5, characterized in that after the activation of the drive (1) the energy value (w _E ), starting from a power start value (W ₅ ) is estimated periodically, to which a calculated power-dependent power supply (W _z ) is added.

7. The method according to claim 6, characterized in that the energy start value (W _s ) from the currently measured ambient temperature (T _A ) or from an after the last control of the drive (1) stored engine temperature (T _M ) is formed, wherein the current Ambient temperature (T _A ) a temperature offset (T ₀ ) is added.

8. The method according to claim 7, characterized in that after a predetermined period of time (TN) in the second vehicle state, the currently measured ambient temperature (T _A ) is taken into account in the calculation of the energy start value (W _s ).

9. The method according to any one of claims 6 to 8, characterized in that for calculating the power-dependent power supply (W ₂ ) from an engine period (MP) an associated motor current (I) is determined, which is multiplied by the associated motor voltage (U).

10. Apparatus for carrying out the method for temperature protection of at least one drive (1) in a vehicle (3) according to any one of claims 1 to 9, characterized by

- An evaluation and control unit (2) for determining a current engine temperature (T _M ) of the driven drive (1), which is implemented in the form of an energy value (W _E ), for activating and executing a cooling function (F _κ ), if the determined energy value

(W _E ) exceeds a predetermined first threshold value (Sl) or when the drive of the drive (1) has ended, and for deactivating the cooling function

(F _K ) depending on the current vehicle condition, and

- means (5, 6) for determining the current vehicle status and the ambient temperature (T _A ),

- Wherein the drive (1) via an associated switch

(4) lockable or releasable.

11. The device according to claim 10, characterized in that the evaluation and control unit (2) comprises at least one microprocessor.