DE4206013C1 - Automatic air conditioning for motor vehicles - taking outside temp. into consideration, measured via an external temp. probe on cyclic basis - Google Patents

Abstract

The method involves reading the outside temperature sensor value (TAF) via the control system on a cyclic basis and then either using the inbuilt delay function of probes (1) or the value as read, forming a simply damped value compared with the outside temp. as measured and using for system control. If no delay function is used then a delay method (2) is employed to provide a damped outside temperature value (TEGAF) which thus follows the outside measured value with slight delay (T1). A delay method is used (3) to convert the damped value (TEGAF) to a powerfully damped outside value (TSGAF) to follow the outside measured value at appreciable delay. Finally the powerfully damped value (TSGAF) is used as conditioning control basis. ADVANTAGE - Allows for outside temp. in on-line control system for max. user comfort.

Description

The invention relates to a method according to the preamble of Claim 1.

Such a method is known (DE 31 42 643 C2). Not considered remains with this procedure u. a. that heating the outside temperature sensor when the vehicle is stationary or Jumps in temperature when ignition is ON after briefly switching off the vehicle is not taken into account, so that no more Signal of the actual prevailing outside temperature, but an outside temperature signal heated by the vehicle waste heat is taken into account in the climate control.

The object of the invention is therefore the generic method with a view to a more harmonious regulation, that a calm climate control and thus a gain in comfort is achieved.

According to the invention, this object is achieved with a generic Method with the characterizing features of claim 1 solved by smoothing the outside temperature sensor values is made.  

Special training and further developments of the method according to the invention are characterized by the features of the subclaims.

Embodiments of the method according to the invention described below in the drawing. It shows

Fig. 1 is a flow chart with regard to the delay of the measured outside the sensor value,

Fig. 2a and Fig. 2b characteristics of the strongly damped outside sensor value with increasing and decreasing outside temperature and

Fig. 3a to Fig. 3c exemplary characteristics of the highly damped outside temperature sensor value with respect to the vehicle speed and the outside temperature.

Basically, the outside sensor value T _AF measured by an outside temperature sensor 1 is read in every second by a 10 bit AD converter of the control. The computing range of the sensor 1 extends from -40 ° C to + 60 ° C, so that the resolution is therefore approx. 0.1 ° C. All valid outside sensor values outside this calculation range are set to the limit values. All of the numerical values also mentioned below are examples and can be varied, for example depending on the vehicle type.

With due to its own constructional slight delay of the sensor 1 - for example with a damping time T₁ of 30 to 60 seconds. - The outdoor sensor value provided by this and read in by the control provides a simply damped outdoor sensor value T _{EG AF} for the measured outdoor sensor value T _AF Regulation represents what is symbolized in Fig. 1 by the dashed line.

If, on the other hand, a delay-free sensor 1 is used, a single-damped outside sensor value T _{EG AF is} formed in the control from the measured and read-in outside sensor value T _AF according to a delay method in a first attenuator 2 , such that the outside sensor value T _{AF is} read with a slight delay - Damping time T₁ - follows.

The purpose of this first damping measure is simple temperature jumps or tips to eliminate.

This simply damped outside sensor value T _{EG AF} then represents the initial value for the formation of a strongly damped outside sensor value T _{SG AF} , which is relevant for the climate control. The strongly damped outside sensor value at the output of a second damping element 3 follows the secondly read outside sensor value with a damping in the range of a maximum of 15 minutes, a minimum of 5 minutes, depending on whether rising or falling temperatures are read. Here, an attenuation time T₂ of approx. 15 min. And a falling attenuation time T₃ of approx. 5 min. Are automatically set in the attenuator 3 for rising, simply damped outside sensor values, so that the ones shown in FIGS . 2a and 2b are shown Curves of T _{SG AF} result, whereby the unit jump should represent a temperature jump of 20 K.

The determination of whether there are rising or falling outside temperature values is done by subtracting the current simply damped outside sensor value T _{EG AF} from the currently heavily damped outside sensor value T _{SG AF} , whereby the damping time T₃ if the result is positive (falling outside temperature) and the damping time if the result is negative (rising outside temperature) T₂ is used in the attenuator 3 .

special cases

Generally, the regulation of the vehicle when the ignition is OFF the heavily damped outside sensor value is saved.

After a subsequent ignition-ON for the simple and the strongly damped outside sensor value based on start values following criteria:

If the cooling water temperature T _{W of} the vehicle is greater than z ° C, e.g. 40, the starting point for both the simple and the heavily damped outside sensor value is the heavily damped outside sensor value stored at the ignition-OFF time. If, on the other hand, the cooling water temperature T _{W is} less than or equal to z ° C, the outdoor sensor value read in at the ignition-ON time is set as the starting value for both the simple and the strongly damped outdoor sensor value.

In addition, the heavily damped outside sensor value is not updated continuously, but is recorded when the speed V _{F of} the vehicle is less than or equal to y km / h, y for example 30. An update takes place again only after a delay time T _F , for example 1 minute, has passed after the speed V _F <y km / h has been exceeded. However, both of the above criteria only apply if the outside sensor value increases or remains the same; sinking outside temperature values are always permitted and not delayed. These facts are shown in FIGS . 3a to 3c. It can be seen when the vehicle speed V _F becomes less than or equal to y km / h — time A — T _{SG AF} with increasing outside temperature T _AF ( FIG. 3 b). If, at the time BV _F, again exceeds y km / h, T _{SG AF is} additionally recorded via the delay time T _F until time C and is only updated again afterwards.

If, on the other hand, the outside temperature T _{AF falls} after the time A, then T _{SG AF is} no longer recorded - time B '- but tracks the falling outside temperature with a delay ( Fig. 3c).

By taking into account the aforementioned special cases an external sensor value is determined for the climate control, which - how Tests have shown - exactly the prevailing mean outside temperature at a distance from the vehicle.

The simply damped outside sensor value is determined in the attenuator 2 , which corresponds to a PT1 attenuator, as follows:

T _{EG AF (n)} = (T _{EG AF (n-1)} 15 + T _AF ): 16

in which mean:

T _{EG AF (n)} simply damped outside sensor value at time n
T _AF measured outside sensor value every second
n 1, 2, 3,. . . (is increased every second).

The heavily damped outside sensor value is determined by means of the attenuator 3 every five seconds from the simply damped outside sensor value as follows:

• a) First, a deviation dT _{A is} determined in order to recognize whether there are rising or falling temperatures, which then determines the damping time T₂ or T₃ accordingly: dT _A = T _{EG AF (n)} - T _{SG AF (m-1} ) where mean: T _{SG AF (m)} strongly damped outside sensor value at time m
  m 1, 2, 3,. . . (increases every 5 seconds).
• b) The heavily damped outside sensor value is then determined on the basis of the deviation dT _A as follows:
  • - at constant temperatures or dT _A = 0 after,
    T _{SG AF (m)} = T _{SG AF (m-1)}
  • - with increasing temperatures or dT _A <0 every 5 seconds
    T _{SG AF (m)} = T _{SG AF (m-1)} + 0.1 ° C
  • - with falling temperatures or dT _A <0 every 5 seconds
    T _{SG AF (m)} = T _{SG AF (m-1)} -0.5 ° C.

Alternatively, in the event of larger deviations from dT _A by more than 10 K, the addition or subtraction values can be doubled: then 0.2 ° C are added for dT _A <10 K and <10 K 1 ° C for dT _A subtracted.

During the outdoor sensor value determination described above under b) includes fixed temperature jumps, can also realize a damping (smoothing) principle that no fixed Includes temperature jumps and works with PT1 elements.

Based on the deviation dT _A, the heavily damped outside sensor value would then be used

• - with increasing temperatures or dT _A <0 every 5 seconds
  T _{SG AF (m)} = (T _{SG AF (m-1)} · 127 + T _{EG AF (n)} ): 128
• - with falling temperatures or dT _A <0 every 5 seconds
  T _{SG AF (m)} = (T _{SG AF (m-1)} 31 + T _{EG AF (n)} ): 32
  be determined.

This has smoothing that does not include fixed temperature jumps the advantage that temperature jumps of any kind are always in one fixed time interval, determined by the parameters of PT1 attenuators used in the control.

Of course, other smoothing methods are also conceivable.

Claims (8)

1. A method for taking the outside temperature into account in an automatic climate control system of a vehicle that is controlled as a function of the same, the outside temperature being measured by means of a sensor and the outside sensor value being processed in the control,
characterized,
that the outside sensor value (T _AF ) is read in cyclically by the control,
whereby either due to its own inherent low delay (damping time T₁) of the sensor ( 1 ) the sensor sensor value provided and read by it compared to the measured sensor sensor value (T _AF ) represents a simply damped sensor sensor value (T _{EG AF} ) for the control
or in the case of a delay-free sensor ( 1 ) in the closed-loop control from the read measured outside sensor value (T _AF ) after a delay method ( 2 ) a simply damped outside sensor value (T _{EG AF} ) is formed in such a way that the measured outside sensor value is read with a slight delay (damping time T₁) follows
with the simply damped outside sensor value (T _{EG AF} ) after a delay method ( 3 ) a strongly damped outside sensor value (T _{SG AF} ) is formed in such a way that it follows the measured outside sensor value with a longer delay (damping time T₂ or T₃),
and the strongly damped outside sensor value (T _{SG AF} ) is then used as the basis for the climate control. 2. The method according to claim 1, characterized, that with increasing simply damped outside sensor values the Damping time T₂ is greater than the damping time T₃ when falling simply damped outside sensor values. 3. The method according to claim 2, characterized, that in the scheme a subtraction of the current simple damped outside sensor value from the current heavily damped Outside sensor value takes place and with a positive result, accordingly falling outside temperature, the damping time T₃ and at negative result, corresponding to rising outside temperature, the damping time T₂ is switched on. 4. The method according to claim 1, characterized, that the strongly damped outside sensor value at the time of ignition OFF of the vehicle is saved. 5. The method according to claim 4, characterized in that at the time of ignition ON and at a cooling water temperature T _W <z ° C of the vehicle as a starting value for both the simply damped outside sensor value and for the heavily damped outside sensor value of the stored at the time ignition OFF strongly damped Outside sensor value is set. 6. The method according to claim 1, characterized in that at the time of ignition ON and at a cooling water temperature T _W = z ° C of the vehicle as the starting value for both the simply damped outside sensor value and for the strongly damped outside sensor value, the outside sensor value read in when the ignition is ON is set . 7. The method according to claim 1, characterized in that with increasing or constant - but not with decreasing - outside sensor value, the strongly damped outside sensor value is not updated further but is held when the vehicle speed falls below V _F = y km / h. 8. The method according to claim 7, characterized in that with increasing or constant - but not with decreasing - outside sensor value, the heavily damped outside sensor value is updated again when the vehicle speed exceeds V _F <y km / h and a delay time T _{F has} passed.