JP3136844B2 - 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 for processing a plurality of physical quantities relating to a heat load required for air conditioning, such as an outside air temperature and an amount of solar radiation, in accordance with a system control theory (modern control theory) to air-condition a vehicle interior to a target temperature. The present invention relates to an air conditioner.

[0002]

2. Description of the Related Art A vehicle interior temperature set value, an actual vehicle interior temperature,
2. Description of the Related Art There is known a vehicle air conditioner that controls a blown air temperature and a blown air amount based on an outside air temperature, a solar radiation amount, and the like, and air-conditions a vehicle interior to a target temperature (for example, a Nissan service report).
(Refer to No. 578, June 1987). In this type of device,
As shown in FIG. 10, the vehicle interior temperature set value Tptc, the vehicle interior temperature Tinc, the insolation Qsun, and the outside air temperature Tam
b is input to the controller 1, and the difference between the set temperature Tptc and the actual vehicle interior temperature Tinc, the amount of solar radiation Qsun, the outside air temperature Tamb, and the set temperature Tptc are respectively multiplied by experimentally obtained control constants K10 to K13. The control command value is calculated, and the control amounts of the air conditioning unit 2, that is, the air mixing door opening X and the blower motor driving voltage Vf are determined by the computing units 1a and 1b, and the air mixing door, the blower fan, and the outlet of the air conditioning unit 2 are determined. By controlling the target blow air temperature To and the target blow air flow Ga
The air conditioning of the passenger compartment 3 is performed.

[0003]

As described above, in the conventional vehicle air conditioner, when the disturbance such as the outside air temperature Tamb or the amount of solar radiation Qsun mixed in the air conditioning control system changes,
The respective control constants K1 determined in advance for the amounts of change
The control command value of the vehicle interior temperature Tinc is calculated by multiplying by 1, K12, the air mix door opening X and the blower motor drive voltage Vf are determined based on the control command value, and the target blow air temperature To and the target blow air volume are determined. The air conditioning unit is controlled such that Ga changes the vehicle interior temperature Tinc to the set value Tptc.

However, in the conventional vehicle air conditioner, the vehicle interior temperature Tinc in a steady state is maintained at its set value Tptc, but the vehicle interior temperature Tinc in the transient state until the vehicle interior temperature Tinc reaches the set value Tptc. The temperature Tinc is determined by the blown air temperature To, the blown air amount Ga, the amount of heat in the passenger compartment, and the like, and there is a problem that the comfort of the occupant is not always satisfied.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle air conditioner capable of performing air conditioning that is comfortable for an occupant even when the vehicle interior temperature reaches a set value when the vehicle interior temperature set value is changed. It is to provide a device.

[0006]

Means for Solving the Problems The present invention will be described with reference to FIG. 1 which is a claim correspondence diagram. According to the first aspect of the present invention, a mixture of cold air and hot air in an air conditioning duct according to a door opening control amount is disclosed. Drive the air mix door to adjust the ratio,
An outlet air temperature adjusting means 100 for adjusting the temperature of the outlet air to the vehicle interior, and a blower air volume for adjusting the amount of air blowing into the interior of the vehicle by driving a blower fan provided in the air conditioning duct in accordance with a blower motor drive voltage control amount. Adjusting means 101
The present invention is applied to a vehicle air conditioner having: Then, a mathematical model is set that indicates a target value to be changed over time of the vehicle interior temperature and the occupant skin temperature when the vehicle interior temperature set value is changed, and the mathematical model is set based on the disturbance mixed into the air conditioning control system. The target value generating means 102 for generating the target vehicle interior temperature and the target skin temperature during transitional and steady states that satisfy the occupant's comfort by changing the constant of the vehicle, and detecting the vehicle interior temperature.
The occupant's skin temperature is determined based on the inside air temperature detecting means 108 and the door opening control amount and the blower motor drive voltage control amount.
Estimating means 103 for estimating the degree and an evaluation function for evaluating the comfort of the occupant are set, and the evaluation function and a target vehicle interior temperature, a target skin temperature, a skin temperature estimation value, and a vehicle interior temperature are set.
The above-mentioned object is achieved by providing a calculating means 104 for calculating a door opening control amount and a blower motor drive voltage controlling amount based on a detected value , and a linear compensating means 105 for operating the calculating means 104 linearly. Further, the vehicle air conditioner according to the present invention has an outside air temperature detecting means for detecting the temperature outside the passenger compartment and an insolation detecting means for detecting the amount of solar radiation.
The constant value of the mathematical model is changed by the target value generating means 102A based on the outside temperature detected by the outside air temperature detecting means 106 and the amount of solar radiation detected by the solar radiation amount detecting means 107. This is for generating a vehicle interior temperature and a target skin temperature.

[0007]

[Function] Based on disturbances such as the outside air temperature and the amount of solar radiation mixed into the air-conditioning control system, the constants of the mathematical model of the target vehicle interior temperature and the target skin temperature are changed, and the transient and steady state conditions satisfy the occupant's comfort. Obtain the target vehicle interior temperature and target skin temperature, and estimate the target vehicle interior temperature, target skin temperature, and skin temperature.
A door opening control amount and a blower motor drive voltage control amount are calculated based on the constant value and the detected vehicle interior temperature value , and the air mixing door and the blower fan are driven based on these control amounts to perform air conditioning in the vehicle interior.

[0008]

FIG. 2 is a block diagram showing the configuration of one embodiment. It is to be noted that the same reference numerals are given to the same devices as those in FIG. In the figure, 4 is a solar radiation sensor for detecting the amount of solar radiation Qsun, and 5 is an outside air temperature Tam.
b is an outside air temperature sensor for detecting b, and 6 is a vehicle interior temperature set value T
It is a room temperature setting device for setting ptc. Reference numeral 7 denotes a controller composed of a microcomputer and its peripheral components. The controller 7 includes a reference model 71, an observer 72, a linear compensator 73, and an optimum regulator 74. The solar radiation amount Qsun, the outside air temperature Tamb, and the vehicle interior temperature set value are provided. Tp
tc, the control amount based on the vehicle interior temperature Tinc, etc., that is, the air mix door opening X and the blower driving voltage V
f is calculated, and the air conditioning unit 2 is controlled. The air conditioning unit 2 is an actuator 2 that opens and closes the air mix door.
1 and its drive circuit 22, a blower motor 24 and its drive circuit 25, and the like.

The reference model 71 has a vehicle interior temperature set value Tp.
A mathematical model indicating a target value to be changed with time of the vehicle interior temperature Tinc and the occupant skin temperature Tf when tc is changed is set, and the outside air temperature Ta to be mixed into the air conditioning control system is set.
The constant of the mathematical model is changed based on disturbances such as mb and the amount of solar radiation Qsun to generate a target vehicle interior temperature Tinc ^* and a target skin temperature Tf ^* that satisfy the comfort of the occupant.
The target vehicle interior temperature Tinc ^* and the target skin temperature Tf ^* determine a comfortable air-conditioning temperature in a steady state, and at the same time, provide a comfortable feeling for the occupant even during a transition until reaching the target temperature. It determines the degree of change of the temperature.

A mathematical model of the target vehicle interior temperature Tinc ^* and the target skin temperature Tf ^* that satisfies the occupant's comfort during the transient and steady states is set as follows.

## EQU00001 ## dTinc ^* / dt = Ar1.Tinc ^* + Br1.Tptc (1)

DTf ^* / dt = Ar2 · Tf ^* + Br2 · Tptc (2) where Ar1, Ar2, Br1, and Br2 are constants.

The constants Ar1, Ar2, Br1, and Br2 of the mathematical models shown in the above equations (1) and (2) are set as follows based on the outside air temperature Tamb and the amount of solar radiation Qsun.

Ar1 = α1 · Tamb + β1 · Qsun + γ1 (3)

## EQU00004 ## Br1 = .alpha.2.Tamb + .beta.2.Qsun + .gamma.2 (4)

Ar5 = α3 · Tamb + β3 · Qsun + γ3 (5)

## EQU6 ## Br2 = α4.Tamb + β4.Qsun + γ4 (6) where α1 to α4, β1 to β4, and γ1 to γ4 are coefficients.

FIG. 3 is a time chart showing the result of air conditioning by the vehicle air conditioner (solid line) and the result of air conditioning by the conventional vehicle air conditioner (dashed line) according to the present invention.
Indicates a time when the set temperature Tptc is lowered at time t1,
(B) shows the case where the set temperature Tptc is increased at time t2. In the conventional vehicle air conditioner, the transient change of the vehicle interior temperature Tinc when the set temperature Tptc is changed is determined by the control amount of the controller 1, and the transient does not always satisfy the comfort of the occupant. In the air conditioner of the present invention, the target vehicle interior temperature Tinc ^* and the target skin temperature Tf ^* according to the time change and the environmental change are determined in the reference model 71. The air conditioning temperature that suits the feeling is set.

FIG. 4 is a control block diagram showing the structure of the observer 72. In the following, symbols and the like in the control block diagram are displayed according to a general notation of system control (modern control), and description thereof will be omitted. In the figure, reference numeral 72a denotes a system to be actually controlled.
Assume a linear time-invariant system (fixed coefficient system) with o.

The observer 72 has a pre-identified estimated model of the control target system 72a. The observer 72 has a measurable vehicle interior temperature Yo (= Tinc) and a vehicle interior temperature estimated value Yo ^S output from the previously identified estimated model. Deviation (Yo-Y
o ^S ) is fed back to estimate the unmeasurable or difficult-to-measure vehicle body temperature Tm, blown air volume Ga, air mix door opening Xmm (not shown), etc. shown in FIG. 5, and based on these estimated values. Occupant skin temperature Tf
Is estimated. Here, the air mix door opening Xmm
Is the actual opening of the air mix door driven by the drive circuit 22 and the actuator 21 according to the air mix door opening control amount X.

The equation of state of the system 72a to be controlled,
The output equation is expressed as follows.

DXo / dt = Ao · Xo + Bo · U (7)

## EQU00008 ## where Yo = Tinc = Co.Xo (8) where Xo is a state variable vector, and Xo = [T
m, Tinc, Ga, Xmm] ^T and U are control command value vectors.

The body temperature Tm estimated by the previously identified estimation model, when the blowing air volume Ga and the air mix door Xo ^S estimates of the state variables Xo opening X mm, the estimation model can be expressed by the following equation.

DXo ^S / dt = Ao · Xo ^S + Bo · U (9)

## EQU10 ## where Yo = Tinc ^S = Co × Xo ^S (10) where Xo ^S = [Tm ^S , Tinc ^S , Ga ^S , Xm
m ^{S] T,} Tm ^S is the estimated value of the vehicle body temperature Tm, Tinc ^S is the estimated value of the vehicle interior temperature Tinc, estimates of Ga ^S is blowing air volume Ga, Xmm ^S is the estimated value of er mix door opening Xmm .

The estimation errors eo (= Xo ^S -X) of the state variables caused by fluctuations in the coefficient matrices Ao and Bo and disturbances
In order to converge o) to 0, feedback is added to the estimation model as shown in FIG.
2 is expressed as follows.

Equation 11] ^{dXo S / dt = Ao · Xo} S + Bo · U + F · (Yo-Yo S) ·· (11) where, F is a feedback coefficient Matorisukusu.

Incidentally, the system to be controlled in the air conditioner is non-linear, and it is difficult to make the optimum regulator 74 described later to perform non-linear operation. Therefore, linearization compensation is performed by the linear compensator 73. The linear compensator 73 corresponds to FIG.
As shown in (a), it is constituted by nonlinear state feedback and nonlinear state feedforward. That is,

U = f (X, t) + g (X, t) · U (12) where U = [u1, u2] ^T , where u1 is a control command for determining the blower motor drive voltage Vf. The value u2 is a control command value for determining the air mix door opening X. Also, f
(X, t) is a nonlinear feedback function, g (X, t)
Is a non-linear feedforward function. According to equation (12), U to Y are linearized and converted as in the following equation (FIG. 6B).

DY / dt = A1 · Y + B1 · U (13) Here, A1 and B1 are coefficient matrices.

The optimal regulator 74 has a reference model 71
In order to follow the target value, the optimum value of the control constant for achieving both the response and the stability is calculated using the evaluation function J, and the control amount is determined. The evaluation function J is represented by the following equation.

J = ∫ ｛W1 · (ΔTinc) ² + W2 · (ΔTf) ² + W3 · (du1 / dt) ² + W4 · (du2 / dt) ² ｝ dt (14) where ΔTinc is a car The deviation between the room temperature Tinc and its target value Tinc ^* , ΔTf is the deviation between the occupant's skin temperature Tf and its target value Tf ^*, and du1 / dt is the rapid difference in the change in the control command value that determines the blower motor drive voltage Vf. Is a time differential value indicating a sharp difference in a change in a control command value for determining the air mix door opening X, and W1, W2, W3, and W4 are weighting coefficients. ∫ indicates an integration operation from 0 to ∞.

In the above equation (14), ΔTf represents a local thermal sensation at a portion where solar radiation or blowing wind hits, and du1 / d
t and du2 / dt are blower noise, blowing air volume,
It indicates the feeling of change in the outlet temperature. These ΔTinc, ΔT
f, du1 / dt and du2 / dt are main parameters that affect the comfort of the occupant. In order to comprehensively evaluate the feeling of comfort, first, weighting factors W1, W of the parameters are used.
2, W3 and W4 are determined.

From the above equations (1), (2), and (13), an expansion system as shown in the following equation is constructed.

DE / dt = Ae · E + Be · dU / dt (15) where E = [dY / dt, e, dXr / dt] ^T , A
e and Be are coefficient matrices, e is a deviation vector (e = Y
rY).

In equation (15), the control law that minimizes the evaluation function J is represented by the following equation.

DU / dt = K1 · dY / dt + K2 · e + K3 · dXr / dt (16) where K1, K2, and K3 are control constant matrices. The time derivative dU of the control command value vector in equation (16)
To keep / dt as small as possible and follow the target value, control constants K1, K2, and K3 are determined by the following equations.

(K1, K2, K3) = − R ⁻¹ Be ^T P (17) where R is a weight coefficient matrix, and P is a matrix solution of the following Riccati equation.

Ae ^T・ P + P ・ Ae + Q-P ・ Be ・ R ^-1・ Be ^T・ P = 0 (18) where Q is a weight coefficient matrix.

As described above, by setting the weight coefficient matrices Q and R, the control constants K1, K2 and K3 are determined according to a predetermined algorithm. By substituting the control constants K1, K2, and K3 determined by the above equation into the equation (15) and integrating, the optimal control command value vector U, that is, the control amount of the air conditioning unit 2 is determined.

U = K1 · Y + K2 · ∫edt + K3 · Xr + {U (0) −K1 · Y (0) −K3 · Xr (0)} (19) where U (0), Y ( 0) and Xr (0) are control command values, outputs, and initial values of state variables, respectively.

FIG. 7 is a control block diagram showing the configuration of the optimal regulator 74 designed in this way. FIG. 8 is a time chart showing a process of calculating the control command value of the optimal regulator 74. Optimal regulator 74
Difference, as shown at time t3 in FIG. 8, and the calculated target vehicle interior temperature Tinc ^* and the target skin temperature Tf ^* in the reference model 71, the estimated value Tf ^S of the actual cabin temperature Tinc and skin temperature Of the air-conditioning unit 2, that is, the air mix door opening X and the blower motor drive voltage Vf are determined so that the area of the air-conditioning unit 2 is minimized. That is, while ensuring responsiveness and stability under all conditions based on the evaluation function J for evaluating the comfort of the occupant, the air conditioning unit 2 is controlled so that the temperature target value of the reference model 71 conforms to the comfort of the occupant. Control. Note that the control amount calculated by the optimal regulator 74 is linearized by the linear compensator 73 as described above.

FIG. 9 is a flowchart showing a control program executed by the microcomputer of the controller 7. The microcomputer starts executing the control program when a main switch (not shown) of the air conditioner is turned on. The operation of the embodiment will be described with reference to this flowchart. In step S1, the vehicle interior temperature set value Tptc set by the room temperature setting device 6, the outside air temperature Tamb detected by the outside air temperature sensor 5, and the amount of solar radiation Qsun detected by the solar radiation sensor 4 are input to the air conditioning control system. External temperature Tamb and solar radiation Q
The constant of the mathematical model is changed based on disturbances such as sun, and the target vehicle interior temperature Tinc ^* and the target skin temperature Tf ^* at transient and steady times that satisfy the comfort of the occupant are generated. Then, those target values are output to the optimal regulator 74. In a succeeding step S2, the vehicle body temperature Tm, the blowing air amount Ga, the air mix door opening Xmm, etc., which cannot be measured by the observer 72 or are difficult to measure, are estimated.
The occupant's skin temperature Tf is predicted based on these estimated values and output to the optimal regulator 74.

In step S3, the optimal regulator 74 determines the target vehicle interior temperature Tinc ^* , the target skin temperature Tf ^* determined by the reference model 71, the estimated skin temperature Tf ^S estimated by the observer 72, and the measured vehicle temperature. Based on the room temperature Tinc, a deviation from the target value and a change amount of the control amount are calculated, and an optimum control constant for following the target value is calculated by the evaluation function J, and the air mix door opening X and the blower are calculated. Fan drive voltage Vf
Is determined and output to the linear compensator 73. In step S4, the control amount from the optimal regulator 74 is linearized by the linear compensator 73. Then, step S5
Then, the linearized control amount is output to the air conditioning unit 2.
The air conditioning unit 2 controls the drive circuit 22 according to the control amount of the air mix door opening X, opens and closes the air mix door by the actuator 21, and applies the blower fan drive voltage Vf to the blower motor 24 by the drive circuit 25. The air conditioning of the passenger compartment 3 is performed by driving the blower fan.

In the above embodiment, the external temperature and the amount of solar radiation have been described as examples of the disturbance mixed in the air conditioning control system. However, the disturbance elements are not limited to the above embodiment.

In the configuration of the above embodiment, the air mix door actuator 21 and the drive circuit 22 serve as the blow-out air temperature control means, the blower motor 24 and the drive circuit 25 serve as the blow-off air flow rate control means, and the reference model 71 serves as the target value generation means. The observer 72 constitutes estimating means, the optimal regulator 74 constitutes calculating means, the linear compensator 73 constitutes linear compensating means, the outside air sensor 5 constitutes outside temperature detecting means, and the solar radiation sensor 4 constitutes solar radiation detecting means.

[0029]

As described above, according to the present invention, a mathematical model representing a target value which is to be changed with time in the vehicle interior temperature and the occupant skin temperature when the vehicle interior temperature set value is changed is set. Then, the constants of the mathematical model are changed based on the disturbance mixed into the air conditioning control system, and the target vehicle interior temperature and the target skin temperature at the transient and steady times that satisfy the occupant's comfort are obtained . Target skin temperature, skin
The air mix door opening control amount and the blower motor drive voltage control amount are calculated based on the temperature estimation value and the vehicle interior temperature detection value , and the air mix door and the blower fan are driven and controlled according to these control amounts. In a steady state, the vehicle interior temperature is maintained at the set value, so that a comfortable vehicle interior environment can be obtained. In addition, the passenger's comfort can be satisfied even during the transition until the vehicle interior temperature reaches the set value. .

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims.

FIG. 2 is a block diagram showing a configuration of one embodiment.

FIG. 3 is a time chart showing a change in vehicle interior temperature when a set value of vehicle interior temperature is changed.

FIG. 4 is a control block diagram showing a configuration of an observer.

FIG. 5 is a diagram showing physical quantities relating to a heat load required for air conditioning control.

FIG. 6 is a control block diagram illustrating a configuration of a linear compensator.

FIG. 7 is a control block diagram showing a configuration of an optimal regulator.

FIG. 8 is a view for explaining a method of calculating a control amount in an optimal regulator.

FIG. 9 is a flowchart showing an example of a control program executed by a microcomputer of the controller.

FIG. 10 is a block diagram showing a configuration of a conventional vehicle air conditioner.

[Explanation of symbols]

 2 air conditioner unit 3 cabin 4 solar radiation sensor 5 outside temperature sensor 6 room temperature setting device 7 controller 21 air mix door actuator 22, 25 drive circuit 24 blower motor 71 reference model 72 observer 73 linear compensator 74 optimal regulator 100 blowing air temperature control means Reference Signs List 101 blow-out air volume adjusting means 102, 102A target value generating means 103 estimating means 104 calculating means 105 linear compensating means 106 outside temperature detecting means 107 solar radiation detecting means

Claims (2)

(57) [Claims] An air mixing door for controlling an air mixing door for adjusting a mixing ratio of cold air and hot air in an air conditioning duct in accordance with a door opening control amount, and an outlet air temperature adjusting means for adjusting the temperature of air blowing into a vehicle cabin; A blower motor provided in the air-conditioning duct in accordance with a blower motor drive voltage control amount, and a blower air flow rate adjusting means for adjusting a blown air flow rate into a vehicle cabin; Set a mathematical model indicating a target value to be temporally changed of the vehicle interior temperature and the occupant's skin temperature when changing, the constant of the mathematical model is changed based on disturbance mixed into the air conditioning control system, a target value generating means for generating a target passenger compartment temperature and the target skin temperature during transient and steady satisfy comfort of the passenger, and temperature detection means among which detects the passenger compartment temperature, wherein And estimating means for estimating the skin temperature before Symbol occupant based on the A opening control amount and the blower motor drive voltage control amount, sets an evaluation function for evaluating the comfort of the occupant, the target and the evaluation function Calculating means for calculating the door opening control amount and the blower motor drive voltage control amount based on the vehicle interior temperature, the target skin temperature, the skin temperature estimation value, and the vehicle interior temperature detection value; An air conditioner for a vehicle, comprising: a linear compensator that operates. 2. The vehicle air conditioner according to claim 1, further comprising: an outside air temperature detecting unit that detects a temperature outside the vehicle compartment; and an insolation amount detecting unit that detects an insolation amount. Based on the temperature outside the vehicle compartment detected by the outside air temperature detecting means and the amount of solar radiation detected by the solar radiation detecting means, the constant of the mathematical model is changed to generate a target vehicle interior temperature and a target skin temperature. An air conditioner for a vehicle, comprising: