JPH04266516A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To furnish an air conditioner for car which can carry out stable control regardless of dispersion of temperature control characteristics of a heater unit by providing a fuzzy infererence means. CONSTITUTION:A fuzzy infererence means to infer the control input of a temperature adjustment means to minimize a difference between blow-out air necessary to make temperature in a car room near to desired temperature and maintain it and executed blow-off temperature is provided, and in the case when blow-out temperature changes due to various causes, the control input of the temperature adjustment means is decided in accordance with inference of the fuzzy inference means.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning control system for a vehicle that can more stably control the temperature inside a vehicle.

0002

2. Description of the Related Art Conventional vehicle air conditioners, as disclosed in Japanese Patent Publication No. 62-30931, use a temperature control member such as an air mix door that changes the mixing ratio of cold air and warm air to control the air inside the vehicle. It has a structure that adjusts the temperature of the air that is blown out, and feeds back the output from a sensor that detects the actual temperature inside the vehicle, and feedback controls the amount of operation of the temperature adjustment member so that the temperature inside the vehicle is maintained at the desired value. However, this configuration allows the temperature inside the vehicle to be controlled.

0003

[Problems to be Solved by the Invention] By the way, in order to stably control the temperature inside the vehicle cabin using such a conventional feedback control method, it is necessary to tune the control characteristics of the warm-air heater unit to suit the unit. However, there were problems in that it required a large number of man-hours and increased costs. This is because the temperature control characteristics of the heater unit not only differ depending on the blowout mode and suction mode, but also differ between each unit. Therefore, even if tuning is performed, in order to control the cabin temperature smoothly and stably, complex unit characteristic values must be stored in memory and control calculations must be performed while referring to these data. It has the complexity of not having to be done. An object of the present invention is to provide a vehicle air conditioning control device that can solve the above-mentioned problems in the prior art.

0004

[Means for Solving the Problems] In order to solve the above problems, as shown in FIG. 1, the device of the present invention detects a heat load in a vehicle air conditioning control device for controlling the temperature inside a vehicle interior. a target blowout temperature calculation means for calculating a target blowout temperature of the blowout air necessary to approach and maintain the temperature in the vehicle interior to a desired temperature in response to the output from the heat load detection means; and a blowout temperature detection means for detecting the actual temperature of the blowout air. The output indicating the target outlet temperature calculated by the target outlet temperature calculating means and the output indicating the outlet temperature detected by the outlet temperature detecting means are given to the fuzzy inference means. The fuzzy inference means is for inferring the operation amount of the temperature adjusting means that minimizes the difference between the target blowing temperature and the actual blowing temperature. The output of the fuzzy inference means is given to the manipulated variable determining means, which determines the manipulated variable of the temperature regulating means.

[0005]

[Effect] When the blowout temperature fluctuates due to various factors,
The temperature control means is operated according to the inference of the fuzzy inference means, and extremely fine and stable control can be obtained.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a ventilation duct, and an intake door 2 is provided at the inlet end of the ventilation duct to adjust the amount of air taken into and from the vehicle interior. 3 is a blower rotated by a blower motor 4; 5 is a cooling unit; 6 is a heater core; 7 is an air mix door that functions as a temperature control member for adjusting the temperature of the air blown from the ventilation duct 1; The positioning operation is performed by the door motor 8. A differential door 9, a vent door 10, and a foot door 11 are provided at the outlet end of the ventilation duct 1 in order to determine the blowing direction of the blowing air. By opening and closing these doors by known means, the desired blowing air can be controlled. Air can be blown out in mode.

[0008] In this configuration, in order to make the temperature inside the vehicle reach a desired temperature and maintain it at that temperature,
For the purpose of controlling the blower 4 and the air mix door 7, an air conditioning control device according to the invention, indicated relatively at 20, is provided.

In the air conditioning control device 20, 21 is a setting device that outputs a setting signal SA indicating a set temperature (Tset) that is a desired vehicle interior temperature, and 22 is a sensor that detects a room temperature Tr in the vehicle interior and displays the detection result. A room temperature sensor 23 outputs a room temperature signal SB indicating the outside temperature Ta, and an outside temperature sensor 24 outputs an outside temperature signal SC representing the detection result.
is a solar radiation sensor that detects the solar radiation amount Q and outputs a solar radiation signal SD indicating the detection result.

These signals SA to SD are converted into digital data DA, DB, DC, and DD by an analog/digital converter (A/D) 25, respectively, and are input to a microcomputer 26.

The microcomputer 26 includes a central processing unit (CPU) 27 and a read-only memory (ROM) 28.
The ROM 28 has a known configuration comprising a random access memory (RAM) 29 and a control program for temperature control based on fuzzy inference, and a membership function to be described later.

[0012] In order to detect the temperature of the blown air, in the embodiment,
It has a first sensor 30 provided near the vent door 10 and a second sensor 31 provided near the foot door 11. The first sensor 30 detects the vent outlet temperature (Tv
) is output, and the second sensor 3
1 outputs a heat temperature signal SF indicating the heat blowing temperature (Th). These temperature signals SE, SF are each converted into digital format by an analog-to-digital converter (A/D) 32, and the digitized vent temperature data DE and heat temperature data DF are input to the microcomputer 26.

Based on the input data DA to DF, a first control signal S1 for controlling the blower and a second control signal S2 for controlling the air mix door, which are obtained by executing a control program to be described later, are sent to the microcomputer 26. These control signals S1 and S2 are supplied to the first and second drive circuits 33 and 34.

As a result, the first drive circuit 33 outputs the first
A blower drive signal K1 necessary to obtain the air volume according to the control signal S1 is output, and the blower motor 3 is driven according to this blower drive signal K1. On the other hand, the second drive circuit 34
A door drive signal K2 necessary for obtaining the operating amount of the air mix door 7, that is, the opening degree according to the second control signal S2 is output, and the positioning operation of the air mix door 7 by the door motor 8 is controlled by the door drive signal K2. It is carried out according to the following.

Next, the operation of the air conditioning control device 20 will be explained with reference to the flowchart of the control program shown in FIG.

In step 41, each input data is read, and then in step 42, the temperature inside the vehicle is brought close to the set temperature Tset and maintained there using a known calculation formula shown therein. A necessary target blowout temperature value Xm is calculated. Here, A to E are constants and can be determined as appropriate.

In the next step 43, a first control is performed to control the blower 4 in accordance with the characteristics shown in step 43 so that the air flow rate is obtained in accordance with the target blowout temperature value Xm obtained in step 44. A signal S1 is output, and the blower motor 3 for driving the blower 4 is controlled accordingly.

Next, the process proceeds to step 44, where the difference F between the target air outlet temperature value Xm and the actual air outlet temperature value Xr in the passenger compartment is calculated.
and the amount of change ΔF of the difference F per unit time is calculated. Here, the blowout temperature value Xr is calculated from the vent and heat temperature data DE and DF.

In step 45, the following rule (
According to 1) to (5), the grade of the antecedent in each rule is calculated.

(1) IF F=ZO AND ΔF=
PB, THEN Δθ=PB (2) IF
F=ZO AND ΔF=ZO, THEN Δθ
=ZO (3) IF F=ZO AND
ΔF=NB, THEN Δθ=NB (4) I
F F=NB AND ΔF=ZO, THEN
Δθ=NB (5) IF F=PB AN
D ΔF=ZO, THEN Δθ=PB

0021
That is, the membership functions defined in FIGS. 4 and 5 are determined in consideration of empirical rules, experimental data, and other useful information, and are inputted into the ROM 28 in advance as digital data. In the illustrated embodiment, the values are large in the negative direction (NB), appropriate (ZO
), positively larger (PB) are defined. Therefore, nine combinations are possible, but
Here are the rules (1) for five of them.
-(5) only are defined.

A state in which these rules are applied is schematically shown in FIG. In FIG. 7, the horizontal axis is time, the vertical axis is the value of the difference F, and the curved line represents the change in the difference F over time.

Therefore, for example, regarding rule (1), if F=5 and ΔF=0.5, the grade for F would be 0.44 and the grade for ΔF would be 0.46. Therefore, the grade of the antecedent part for rule (1) is 0.44.

In this way, the remaining rules (2) to (
Regarding 5), the grade is determined in the same way.

In step 46, the manipulated variable Δθ is determined from the grade determined in step 45 based on the output membership function shown in FIG. 6 for determining the manipulated variable Δθ of the air mix door 7.

To explain using the above example, rules (2) to (
The grades for 5) are 0, 0, 0, 0, respectively.
Therefore, the shaded part in Figure 6 is based on these rules (
Conclusions according to 1) to (5) will be shown. Based on this, the position of the center of gravity is calculated, which gives the operation amount (displacement amount) Δθa of the air mix door according to the inference result.

In step 47, a second control signal S for controlling the air mix door 7 according to the value of Δθa is
2 is output and the next step 48 is entered. Step 48
Then, other necessary controls are executed, and then the execution of this program ends.

According to the above configuration, the required blowing temperature value Xm
Using the difference F between and the actual blowout temperature value Therefore, extremely appropriate vehicle room temperature control can be achieved.

[0029]

According to the present invention, as described above, fuzzy inference is performed by using the difference between the required blowout temperature and the actual blowout temperature, and the adjustment position of the temperature adjustment member is controlled based on the result of this inference. As a result, it is possible to perform more fine-grained temperature control than with conventional control, and the usability can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for explaining the configuration of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart of a control program executed in the microcomputer of FIG. 2;

FIG. 4 is a diagram showing membership functions for fuzzy inference used for control.

FIG. 5 is a diagram showing membership functions for fuzzy inference used for control.

FIG. 6 is a diagram showing membership functions for fuzzy inference used for control.

FIG. 7 is an explanatory diagram for explaining application of control rules for fuzzy inference.

[Explanation of symbols]

7 Air mix door 20 Air conditioning control device 21 Setting device 22 Internal temperature sensor 23 Outside temperature sensor 24 Solar radiation sensor 26 Microcomputer 30 First sensor 31 Second sensor

Claims (1)

[Claims] 1. A vehicle air conditioning control device for controlling a vehicle air conditioner equipped with a temperature adjustment means for regulating the temperature inside a vehicle, comprising: a heat load detection means for detecting a heat load; A target outlet temperature calculation means for calculating a target outlet temperature of the outlet air necessary to maintain the temperature in the passenger compartment close to a desired temperature in response to the output from the heat load detecting unit; In response to the blowout temperature detection means to be detected, the target blowout temperature calculation means, and the blowout temperature detection means, the operation amount of the temperature adjustment means is inferred so as to minimize the difference between the target blowout temperature and the actual blowout temperature. An air conditioning control device for a vehicle, comprising: fuzzy inference means; and operation amount determination means for determining the operation amount of the temperature adjustment means in response to the fuzzy inference means.