JP3322692B2 - Vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner for controlling an intake door so that the amount of outside air introduced is increased as much as possible.

[0002]

2. Description of the Related Art A conventional technique of this kind is disclosed in
The one described in JP-A-222918 is known. This technology determines the introduction ratio of the inside and outside air based on the evaporator blowout temperature (the temperature of the blown air immediately after passing through the evaporator) and the operation state of the refrigeration cycle, and controls the opening of the intake door so that the introduction ratio becomes the same To do.

[0003]

However, the intake door control at an accurate timing corresponding to the excess or deficiency of the cooling power cannot be performed only by using the evaporator outlet temperature and the operating state of the refrigeration cycle as input elements.

Accordingly, an object of the present invention is to provide an air conditioner for a vehicle capable of performing intake door control at an accurate timing corresponding to excess or deficiency of the cooling power in consideration of the above circumstances.

[0005]

According to a first aspect of the present invention, there is provided an air conditioner for a vehicle, which controls the opening degree of an intake door as shown in FIG. In the vehicular air conditioner for adjusting the introduction ratio of the air and sending the adjusted air into the vehicle interior through the evaporator 13 in the refrigeration cycle, the evaporator air temperature detection means 1 for detecting the air temperature (Te) of the evaporator 13 is provided. Evaporator outlet temperature change rate calculating means 2 for calculating a change rate (d / dt · Te) of the evaporator outlet temperature (Te) detected by the detecting means 1, and evaporator outlet temperature (Te) detected by the detecting means 1. And the evaporator outlet temperature change rate (d / dt ·
Te), the target opening (θ ′) of the intake door 11 is fuzzy-inferred based on the fuzzy inference means 3 and the target opening (θ ′) inferred by the fuzzy inference means 3. And an intake door drive control means 4 for controlling the drive of the intake door 11.

In order to solve the above-mentioned problems, the vehicle air conditioner according to the second aspect of the present invention controls the opening ratio of the intake door 11 to reduce the introduction ratio of the inside air and the outside air, as shown in FIG. An evaporator target outlet temperature for calculating a target outlet temperature (Te ') of the evaporator according to the heat load in the vehicle in a vehicle air conditioner that sends the adjusted air into the vehicle interior via the evaporator 13 in the refrigeration cycle. A computing means 5 and an evaporator outlet temperature detecting means 1 for detecting the outlet temperature (Te) of the evaporator 13
And the deviation (ΔTe = Te−Te ′) between the evaporator target outlet temperature (Te ′) calculated by the evaporator target outlet temperature calculator 5 and the evaporator outlet temperature (Te) detected by the evaporator outlet temperature detector 1. A deviation calculating means 6 for calculating, a deviation change rate calculating means 7 for obtaining a change rate (d / dt · ΔTe) of the deviation (ΔTe) calculated by the deviation calculating means 6, and a deviation calculated by the deviation calculating means 6 ( Intake door opening degree fuzzy inference means 8 for fuzzy inferring the target opening degree (θ ') of the intake door 11 on the basis of the deviation change rate (d / dt · ΔTe) calculated by the deviation change rate calculation means 7. And an intake door drive control means 4 for controlling the drive of the intake door 11 so as to attain the target opening (θ ′) inferred by the fuzzy inference means 8. To have.

[0007]

In the vehicle air conditioner according to the first aspect of the present invention, the fuzzy inference means 3 sets the target opening θ 'of the intake door 11 based on the evaporator outlet temperature Te and the rate of change d / dt · Te of the outlet temperature. Fuzzy inference. That is, in this case, the antecedent variable (input) of the fuzzy inference is the evaporator outlet temperature Te and the rate of change d / dt · Te of the outlet temperature.
And the consequent variable (output) is the intake door target opening θ
1 '. Then, the intake door 11 is set to have the inferred intake door target opening θ ′ (= θ1 ′).
Control.

The fuzzy inference outputs an inference result in accordance with fuzzy rules determined based on empirical rules and the like, and the procedure of the method is as follows, for example.

In the fuzzy calculation, first, according to each fuzzy rule, a grade of the evaporator outlet temperature Te and the rate of change d / dt · Te of the outlet temperature, which are variables of the antecedent part, are determined by a membership function given in advance. Fuzzy label affiliation degree or membership value) and take the minimum value of both grades. This processing is called antecedent processing. Next, as consequent part processing, the output side membership function is truncated at the above grade, and the trapezoidal output obtained by truncation processing is ORed, and the center of gravity of the superimposed trapezoidal part is obtained. , The position of the center of gravity is inferred,
That is, the intake door target opening degree is set.

This inference method is disclosed, for example, in Japanese Patent Laid-Open No. 2-927.
This method uses a method known in JP-A-63-63 and the like.
As the inference method, another method may be adopted.

In the vehicle air conditioner according to the second aspect of the present invention, the fuzzy inference means 8 determines the deviation ΔTe between the target value Te ′ of the evaporator outlet temperature and the detected value Te, and the rate of change d / dt · Intake door 1 based on ΔTe
Fuzzy inference is made for the target opening of 1. That is, in this case, the antecedent variable (input) of the fuzzy inference is the deviation ΔTe and the change rate d / dt · ΔTe of the deviation, and the consequent variable (output) is the intake door target opening θ1 ′. Then, the intake door is controlled so as to reach the inferred intake door target opening.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a schematic configuration diagram of a vehicle air conditioner shown as a first embodiment. In this air conditioner, the innermost air inlet 10A and the outer air inlet 10
B is formed so as to be divided into two forks, and an intake door 11 is provided at the divided portion. By controlling the opening and closing of the intake door 11, the ratio of inside air to outside air to be introduced into the air conditioning duct 10 can be adjusted. Here, intake door 1
When the opening of the intake door 11 is “0 (%)”, the REC position (inside air introduction position) is reached, and the opening of the intake door 11 is “100”.
(%) "Is the FRESH position (outside air introduction position).

The air-conditioning duct 10 is provided with a blower fan 12, an evaporator 13, an air mix door 14, and a heater 15 in this order as going downstream. The evaporator 13 is connected to the compressor 16, the condenser 17, the receiver tank 18, and the expansion valve 19 via a pipe to constitute a refrigeration cycle.

The air mix door 14 adjusts the ratio of air passing through the heater 15 and air not passing through the heater 15 in accordance with the degree of opening. Then, the air that has passed through the heater 15 and the air that has not passed through the heater 15 are mixed downstream of the heater 15 to adjust the temperature, and are blown into the vehicle from the outlet.

The rear end of the air conditioning duct 10 is provided with a defrost outlet 2 for blowing air toward the inner surface of the windshield.
1, a vent outlet 22 for blowing air toward the occupant's face, and an outlet 23 for blowing air toward the foot of the occupant.
Mode doors 24, 25, 2, 1
6 are provided. And these mode doors 24,
By selectively opening and closing 25 and 26, the blowing mode can be changed.

The above-mentioned intake door 11, air mix door 14, and mode doors 24-26 are respectively controlled to open and close by actuators (not shown). Further, the compressor 16 is driven by a force transmitted from the engine,
Drive is controlled by intermittently connecting and disconnecting the electromagnetic clutch 16B. The drive of each of these actuators, the blower fan 12, and the electromagnetic clutch 16B of the compressor 16 is controlled by the control unit 50.

The control unit 50 includes a drive circuit for driving the actuators, the blower fan 12, the electromagnetic clutch 16B, etc., a microcomputer for supplying a control signal to each drive circuit, and an A / D converter connected to the microcomputer. And a multiplexer.

The A / D converter in the control unit 50 includes a potentiometer 51 for detecting the opening of the air mix door 14, a solar radiation sensor 52 for detecting the amount of solar radiation entering the vehicle cabin, and an external air temperature. An outside air temperature sensor 53 for detecting, an inside air temperature sensor 54 for detecting a representative temperature in the vehicle compartment, and a temperature setting device 55 for setting a temperature in the vehicle compartment.
And a duct sensor (evaporator temperature detecting means) 56 for detecting the outlet temperature of the evaporator 13 and a potentiometer 57 for detecting the opening position of the intake door 11, and data from each sensor, potentiometer, etc. are input to the microcomputer. It is supposed to be.

The control unit 50 includes an air conditioner switch (A / C SW) 61 for performing at least an ON / OFF operation of the compressor, and an intake door 11.
Is connected to an operation unit 60 having a switch 62 for manually setting the opening degree of the camera, so that signals can be mutually transmitted and received.

Next, the contents of control performed by the control unit 50 of the air conditioner will be described. Here, only the contents of the intake door control will be described.

When the control routine shown in FIG. 4 starts, in step 102, a REC fixing instruction (an instruction to fix to the inside air introduction position) by a manual switch.
It is determined whether or not is issued. If the REC fixing instruction has been issued, the determination is YES, and step 12 is performed.
0, and sets the intake door target opening θ ′ to “0 (REC
Position) ".

If the REC fixing instruction has not been issued,
Next, in step 104, it is determined whether or not a FRESH fixing instruction (an instruction to fix to the outside air introduction position) is issued. If FRESH fixed instruction is issued, judgment is Y
ES is reached and the routine proceeds to step 122, where the target intake door opening degree θ ′ is set to “100 (FRESH position)”.

If the FRESH fixing instruction has not been issued, then in step 106 the air conditioner switch (A / C
SW) is OFF or not. If it is OFF, the process proceeds to step 122. If it is not OFF, the process proceeds to step 108, where the detection value of the duct sensor, that is, the evaporator outlet temperature Te is read. Then, step 110
In, it is determined whether the detected evaporator outlet temperature Te is lower than a predetermined low temperature, for example, lower than 2 ° C., and if it is lower than 2 ° C. (in the case of YES), the routine proceeds to step 122.

The detected evaporator outlet temperature Te is 2 ° C.
In the above case, the process proceeds to step 112, where the value of Te is set to E1
And put. In step 114, the rate of change d / dt · Te of the evaporator outlet temperature is obtained, and this value is set as E2. Then, using the values of E1 and E2 as input variables, the target opening θ1 ′ of the intake door 11 is fuzzy inferred. The method of inference will be described later.

After inferring the intake door target opening θ1 ′, the routine proceeds to step 124, where the inferred value θ1 ′ is set as the intake door target opening θ ′. Then, when the intake door target opening degree θ ′ is obtained in each of steps 120, 118, and 122 according to the respective conditions, the process proceeds to step.

In step 124, a signal from the potentiometer 57 for detecting the opening position of the intake door 11, that is, the intake door opening θ and the target opening θ ′.
(Θ−θ ′), and this is set as K. Next, at step 126, it is determined whether or not the absolute value of the deviation K is 5 (%) or less. That is, it is checked whether the error is within the error range of the target opening.

If it is out of the error range, that is, step 1
If the determination at 26 is NO, at step 128, it is determined whether K is correct. If K is positive (YES),
That is, the detected opening θ is larger than the target opening θ ′ (FR
When it is on the ESH side), at step 130, the intake door 11 is driven to the REC side, and further controlled so that the intake door 11 approaches the target opening.

On the other hand, when K is negative (NO), that is, when the detected opening θ is smaller than the target opening θ ′ (on the REC side), the intake door 11 is driven to the FRESH side in step 132. Then, control is performed such that intake door 11 approaches the target opening. When the detected opening degree θ converges to the target opening degree θ ′ and falls within the error range, the determination in step 126 becomes YES, the process proceeds to step 134, and the drive of the intake door 11 is stopped.

In the above processing, the fuzzy inference in step 116 is performed according to the procedure shown in the flowchart of FIG. That is, in this process, the antecedent variables E1 and E2 are the evaporator outlet temperature “Te” and the outlet temperature change rate “d / dt · Te”, respectively, and the consequent variable is the intake door target opening θ1 ′ (each The individual value for each rule is represented by Ti). In this fuzzy inference, 28 fuzzy rules as shown in the table of FIG. 6 are set based on the results obtained by empirical rules or experiments. here,
Each code (fuzzy label) has the following meaning. PL: Large in the positive direction PM: Medium in the positive direction PS: Small in the positive direction ZR: Almost "0" NS: Small in the negative direction NM: Medium in the negative direction NL: Large in the negative direction

For example, one rule is that the evaporator blowing temperature (E1 = Te) is low (PS) and the rate of change of the blowing temperature (E2 = d / dt · Te) is large in the positive direction (P
L) At that time, the intake door target opening Ti is set to almost zero (ZR), that is, REC.

As a membership function expressing the above label for each variable, FIGS.
The one shown in (c) is used. The function of (a) is a membership function of the input variable E1 (evaporator outlet temperature Te), the function of (b) is a membership function of the input variable E2 (evaporator outlet temperature change rate d / dt · Te), and the function of (c). The function is a membership function of the output variable Ti (intake door target opening). The unit of the input variable E1 in the antecedent part is ° C., and the unit of E2 is deg / sec.

Steps 202 and 204 of fuzzy inference
In step 206, according to the fuzzy rules described above,
The intake door target opening degree θ1 ′ is calculated using a MIN-MAX rule known in Japanese Patent No. 92763 or the like. The flow is as follows. First, the grade Wi of the antecedent variables E1, E2 is determined by the input side membership function for each rule (step 202), and then, for each rule grade, by the output side membership function, Calculate intake door target opening Ti which is a consequent part output (step 2)
04). Then, the output of the consequent part obtained for each rule is ORed to obtain the center of gravity, and the position of the center of gravity is set as the intake door target opening degree θ1 ′ which is the final inference result.

As described above, the intake door target opening is
Fuzzy inference is performed based on the evaporator outlet temperature and the rate of change, and the opening control of the intake door is executed based on the inference result. it can.

Next, a second embodiment of the present invention will be described. FIG. 8 is a schematic configuration diagram of a vehicle air conditioner shown as a second embodiment. In this air conditioner, a variable displacement compressor is used as the compressor 16 'in the refrigeration cycle, and control of the compressor displacement is performed by the control unit 50'. The rest of the hardware configuration is exactly the same as that of the second embodiment shown in FIG.

Variable capacity compressor 1 used here
6 'is a swash plate type variable displacement compressor. In the compressor 16 ', the capacity is determined by the inclination angle of the swash plate (oscillating plate), the inclination angle of the swash plate is determined by the pressure in the crank chamber, and the pressure in the crank chamber is substantially opened by the solenoid valve 16A. Depends on the degree. That is, the compressor capacity decreases when the supply current Isol to the solenoid valve 16A is increased, and the compressor capacity increases when the supply current to the solenoid valve 16A is reduced. Here, the supply current Isol to the solenoid valve 16A is limited to a predetermined range, and the capacity is 0% at MAX and 100% at 0. This variable displacement compressor 16 '
As in the first embodiment, it is driven by the force transmitted from the engine, and is driven and controlled by connecting and disconnecting the electromagnetic clutch 16B.

The contents of control in the air conditioner of the second embodiment will be described. Here, only the contents of the intake door control will be described.

When the control routine shown in FIG. 9 starts, in step 102, a REC fixing instruction (instruction to be fixed to the inside air introduction position) by a manual switch.
It is determined whether or not is issued. If the REC fixing instruction has been issued, the determination is YES, and step 12 is performed.
0, and sets the intake door target opening θ ′ to “0 (REC
Position) ".

If the REC fixing instruction has not been issued,
Next, in step 104, it is determined whether or not a FRESH fixing instruction (an instruction to fix to the outside air introduction position) is issued. If FRESH fixed instruction is issued, judgment is Y
ES is reached and the routine proceeds to step 122, where the target intake door opening degree θ ′ is set to “100 (FRESH position)”.

If the FRESH fixing instruction has not been issued, then in step 106 the air conditioner switch (A / C
SW) is OFF or not. If it is OFF, the process proceeds to step 122. If it is not OFF, the process proceeds to step 108, where the detection value of the duct sensor, that is, the evaporator outlet temperature Te is read. Up to this point, the control flow is the same as that of the first embodiment.

Next, in step 510, a deviation ΔTe between the detected evaporator outlet temperature Te and the evaporator target outlet temperature Te ′ calculated by another routine is obtained, and is set as E1. The evaporator target outlet temperature Te 'is a value calculated in accordance with the in-vehicle heat load obtained from the set temperature, the in-vehicle temperature, the outside air temperature, the amount of solar radiation, and the like.

Next, at step 512, the rate of change of the deviation d / dt · ΔTe is determined, and this value is set as E2. Then, the process proceeds to step 514. In step 514, it is determined whether the compressor displacement control signal Isol is larger than the minimum ("0") and smaller than the maximum, that is, whether it is neither the minimum nor the maximum. In the case of NO, that is, when the capacity is minimum or maximum, it means that the evaporator temperature cannot be controlled by the compressor capacity control.Therefore, a step is taken to control the evaporator temperature by the intake door control. Proceed to 516
Intake door target opening is fuzzy inferred based on E1 and E2. Then, the value θ1 ′ obtained by fuzzy inference in step 118 is set as the intake door target opening degree θ ′.
If the compressor displacement control signal Isol is in an intermediate range that is neither minimum nor maximum, that is, if the evaporator temperature can be controlled by the compressor displacement control, step 516 is passed and the intake door target opening θ1 ′ is finally set. Is fixed to the value calculated in step 516. Subsequent processes are the same as those in the first embodiment, and the same reference numerals are given to the respective steps, and the description is omitted.

In the above processing, the fuzzy inference in step 516 is performed according to the procedure shown in the flowchart of FIG. That is, in this processing, the antecedent variables E1 and E2 are set to the target value Te ′ of the evaporator outlet temperature and the detected value Te, respectively.
Of the deviation “ΔTe” and the rate of change of the deviation “d / dt · ΔT
e ", and the consequent variable is the intake door target opening change amount Ti. In this fuzzy inference, 49 fuzzy rules as shown in the table of FIG. 11 are set based on the results obtained through empirical rules or experiments.

For example, one rule is that the deviation (E1 = ΔT
e) is small (PS) and the rate of change of the deviation (E2 = d
/ Dt · ΔTe) is large in the positive direction (PL),
The intake door target opening change amount Ti is set to a middle position (N
M).

Then, as a membership function expressing the above label for each variable, FIG.
(B) and (c) are used. The function of (a) is a membership function of the input variable E1 (deviation ΔTe), and the function of (b) is the input variable E2 (change rate d / d of deviation).
The function of (c) is a membership function of the output variable Ti (intake door target opening change amount). The unit of the input variable E1 in the antecedent part is deg, and the unit of E2 is deg / sec.

Steps 602 and 604 of fuzzy inference
At 606, the MIN-
The target opening change amount Δθ1 ′ of the intake door is calculated using the MAX rule. First, the antecedent variable E is calculated by the input membership function for each rule.
1, the grade Wi of E2 is obtained (step 502), and then the intake door target opening variation Ti, which is the output of the consequent part, is calculated for each rule grade by the output side membership function (step 504). . Then, the output of the consequent part obtained for each rule is ORed to obtain the center of gravity, and the position of the center of gravity is set as the intake door target opening change amount Δθ1 ′ which is the final inference result. Then, this intake door target opening change amount Δθ1 ′ is added to the previous intake door target opening θ1 ′ to obtain the present intake door target opening θ1 ′ (step 608).

As described above, the intake door target opening change amount is fuzzy inferred based on the deviation between the target value and the detected value of the evaporator outlet temperature and the change rate of the deviation, and the intake door target opening amount is determined based on the inference result. , The intake door control can be performed at an appropriate timing with respect to the excess or deficiency of the cooling power. Moreover, in the case of this embodiment, the deviation ΔTe and its change rate d / dt · Δ
Since Te is used as an input variable, it is possible to cope with a change in the target value Te ′ of the evaporator outlet temperature.
In the control of the embodiment, the control of the evaporator outlet temperature is first performed by controlling the capacity of the compressor, and after the capacity is out of the range of the capacity control, the intake door is controlled by fuzzy inference. The switching frequency is kept low and stable control is performed.

[0047]

As described above, according to the first aspect of the present invention, the opening degree of the intake door is controlled by using the temperature of the evaporator blowout and the rate of change thereof as input, so that it is possible to accurately determine whether the cooling power is excessive or insufficient. Intake door control can be performed at a timing. In addition, since the intake door target opening for the evaporator outlet temperature and its change rate is fuzzy inferred, the intake door control can be performed with an accurate response simply by reflecting the control conditions etc. in the fuzzy rules and membership functions. it can. Also, since this fuzzy inference can be performed with simple rules and function operations,
It does not require complicated control logic, can be easily handled by an existing microcomputer, and does not cause a cost increase. In addition, since the only element directly detected and input is the evaporator blowout temperature, the detector can be simplified.

According to the second aspect of the present invention, the opening degree of the intake door is controlled by inputting the deviation between the target value and the detected value of the evaporator outlet temperature and the rate of change of the deviation. In addition to the same effects as the invention, the invention can be applied to a device for changing the evaporator target outlet temperature.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the invention of claim 1;

FIG. 2 is a block diagram showing the gist of the invention of claim 2;

FIG. 3 is a block diagram showing a schematic configuration of a first embodiment of the present invention.

FIG. 4 is a flowchart showing a control operation of the embodiment.

FIG. 5 is a flowchart showing details of an intake door target opening calculation step in the flowchart.

FIG. 6 is a table showing fuzzy rules used for fuzzy inference shown in the flowchart of FIG. 5;

7A and 7B show membership functions used in the fuzzy inference, wherein FIG. 7A shows a membership function of an antecedent variable E1 (evaporator outlet temperature Te), and FIG. 7B shows an antecedent variable E2 (evaporator outlet temperature). Change rate d / dt · T
e) is a membership function, and (c) is a membership function of a consequent variable (intake door target opening θ1 ′).

FIG. 8 is a block diagram showing a schematic configuration of a second embodiment of the present invention.

FIG. 9 is a flowchart showing a control operation of the embodiment.

FIG. 10 is a flowchart showing details of an intake door target opening calculation step in the flowchart.

FIG. 11 is a table showing fuzzy rules used for fuzzy inference shown in the flowchart of FIG. 10;

12A and 12B show membership functions used in the fuzzy inference. FIG. 12A shows a membership function of an antecedent variable E1 (deviation ΔTe between a target value and a detected value of an evaporator outlet temperature), and FIG. A membership function of the part variable E2 (the rate of change of the deviation d / dt · ΔTe), and (c) is a membership function of the consequent variable (the target opening degree change Δθ1 ′ of the intake door).

[Explanation of symbols]

 1 evaporator outlet temperature detecting means 2 evaporator outlet temperature change rate calculating means 3 intake door target opening fuzzy inference means 4 intake door drive control means 5 evaporator target outlet temperature calculating means 6 deviation calculating means 7 deviation change rate calculating means 8 intake door target Opening fuzzy inference means 11 Intake door 13 Evaporator 50 Control unit

Claims (2)

(57) [Claims] 1. An air conditioner for a vehicle, wherein the rate of introduction of inside air and outside air is adjusted by controlling an opening degree of an intake door, and the adjusted air is sent into a vehicle interior via an evaporator in a refrigeration cycle. Evaporator outlet temperature detecting means for detecting the outlet temperature of the evaporator, evaporator outlet temperature change rate calculating means for calculating the rate of change of the evaporator outlet temperature detected by the detecting means, evaporator outlet temperature detected by the detecting means, and the calculating means Fuzzy inference means for fuzzy inference of the target opening of the intake door based on the evaporator blow-out temperature change rate calculated by the estimator; and driving the intake door to achieve the target opening inferred by the fuzzy inference means. Control means for controlling an intake door drive, Apparatus. 2. An air conditioner for a vehicle, wherein the degree of introduction of inside air and outside air is adjusted by controlling an opening degree of an intake door, and the adjusted air is sent into a vehicle interior through an evaporator in a refrigeration cycle. Evaporator target outlet temperature calculating means for calculating the target outlet temperature of the evaporator according to the load; evaporator outlet temperature detecting means for detecting the outlet temperature of the evaporator; and evaporator target outlet temperature calculated by the evaporator target outlet temperature calculating means. Deviation calculating means for calculating a deviation between the evaporator outlet temperature and the evaporator outlet temperature detected by the evaporator outlet temperature detecting means; deviation changing rate calculating means for obtaining a change rate of the difference calculated by the deviation calculating means; Based on the calculated deviation and the deviation change rate calculated by the deviation change rate calculation means. Fuzzy inference means for fuzzy inference of the target opening of the door; and intake door drive control means for driving and controlling the intake door so as to attain the target opening inferred by the fuzzy inference means. Characteristic vehicle air conditioner.