JPH064375B2 - Automotive air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vehicle air conditioner, and more particularly to a dynamic model of a system relating to a vehicle air conditioner.
The present invention relates to an air conditioner for a vehicle, which performs suitable feedback control from the initial stage so that the temperature in the vehicle interior becomes a set target temperature.

[Prior Art] Conventionally, an air conditioner for controlling temperature, humidity, cleanliness, and the like in the passenger compartment has been used in order to make the passenger compartment environment comfortable for passengers. In addition, the one that controls the temperature inside the vehicle is widely used. In such an automobile air conditioner, in order to widely control the temperature of blown air from low temperature to high temperature, a cooler (evaporator or the like) is arranged upstream of the air passage, and the air to be blown is first cooled. Further, it is heated by a heater (heater core or the like) to adjust the blown air to a set temperature. A series of devices that perform such ventilation, cooling and heating
Called air conditioning unit. Air conditioning units for automobile air conditioners that have been widely used in recent years include a reheat type that changes the amount of heat supplied to a heater and an air mix type that changes the proportion of air passing through the heater.

In any case, in these automobile air conditioners, the temperature inside the vehicle compartment is controlled by the amount of heat of the blown air, that is, the flow rate and temperature of the blown air. The flow rate of the blown air is determined by the blower capacity of the blower motor, etc., while its temperature is the cooling capacity of the cooler (evaporator), in other words, the capacity of the cooling system including the compressor and the heating capacity of the heater, that is, the reheat type. It depends on the circulating amount of hot water, and on the air mix type, it depends on the damper opening of the air mix damper.

When the air conditioning is started, the air conditioning apparatus detects the vehicle interior temperature and feedback-controls the temperature and flow rate of the blown air based on the deviation from the set target temperature. Therefore, the vehicle interior temperature gradually approaches the set target temperature by adjusting the amount of heat of the blown air.

Such control is disclosed in JP-A-55-47914, JP-A-55-77659 and the like.

[Problems to be Solved by the Invention] The above-described conventional device is based on feedback control based on the deviation between the vehicle interior temperature and the target temperature so that the vehicle interior temperature approaches and is maintained at the target temperature. The predictive control in which the control amount is set so as to satisfy the preset thermal parallel condition in consideration of the outside air temperature and the amount of solar radiation is adopted. Further, as the air flow rate, a simple control is performed such that the air flow rate is increased when the temperature deviation is large and the air flow rate is decreased as the deviation decreases.

Therefore, the transient responsiveness when the target temperature is changed is not always sufficient, and depending on the set target temperature, the vehicle interior temperature at that time, the capacity of the air conditioning unit, etc. There is a problem in that it may be insufficient and it may be difficult to maintain a comfortable environment for passengers.

In addition, the capacity of the air conditioning unit is determined by a combination of the air flow rate, the cooling capacity of the cooler, the heating capacity of the heater, etc., but it is not clear how to combine these for optimal control of the vehicle interior temperature. However, conventionally, it is merely determined based on the experience of the designer and the like by a simple combination like the above-described control of the air flow rate. Therefore, it has not always been possible to sufficiently bring out the capacity of the air conditioning unit.

Further, in the initial period when the control of the air conditioning unit is started, if the same control as during the steady operation of the air conditioning unit is performed, for example, the reverse control such as once separating the vehicle interior temperature from the target temperature, or the vehicle There was also a problem in that over-control was performed so that the indoor temperature rapidly approaches the target temperature.

An object of the present invention is to provide an air conditioner for a vehicle that maximizes the capacity of an air conditioning unit and controls the vehicle interior temperature from the beginning of operation of the air conditioning unit.

Configuration of the Invention [Means for Solving the Problems] The present invention has the configuration illustrated in FIG. 1 in order to solve the above problems. That is, as illustrated in FIG. 1, the air conditioning means M1 for adjusting various amounts including at least the temperature of the air blown into the vehicle interior in accordance with the control amounts of the plurality of air conditioning control elements.
Temperature setting means M2 for setting a target temperature in the vehicle compartment, and temperature detecting means M3 for detecting a vehicle interior temperature in the vehicle compartment.
And using a predetermined optimal feedback gain based on a dynamic model of the system for automotive air conditioning,
An air conditioner for a vehicle, comprising: a control means M4, which is an additional integral type optimum regulator for feedback-controlling the air conditioning means M1 so that the vehicle compartment temperature becomes the target temperature, and the air conditioning means M1. Has a determination means M5 for determining whether or not there is an initial state, and the control means M4 uses the parameters preset based on the dynamic model to control the air conditioning means M1. A state observing section M6 for estimating a state variable representing a dynamic internal state of the system from the above and the vehicle interior temperature, a factor relating to the deviation between the target temperature and the vehicle interior temperature and the deviation of the optimum feedback gain. From the above, a first feedback amount relating to the control amount to the air conditioning means M1 is calculated, and a first feedback amount for accumulating the first feedback amount is calculated. The air-conditioning unit M1 uses the sum of the second feedback amount calculated from the feedback amount calculation unit M7 and the state variable and the element relating to the state variable of the optimum feedback gain and the accumulated first feedback amount as the control amount. And a feedback control amount calculation unit M8 for outputting to the control unit M4. When the determination unit M5 determines that the determination unit M5 is in the initial state, the control unit M4 determines a plurality of predetermined units according to the operating state of the air conditioning unit M1. A vehicle air conditioner is characterized in that the control amount of the air conditioning control element is output to the air conditioning means M1.

The air conditioning means M1 substantially corresponds to the air conditioning unit described in the section [Prior Art], and is composed of at least a plurality of air conditioning control elements for adjusting various quantities including the temperature of blown air. For example, considering the temperature of the blown air as one of the various amounts of blown air, the air conditioning control element supplies the cooler, for example, an actuator that controls the cooling capacity of the evaporator, the opening degree of the air mix damper, and the heater (heater core). It is an actuator that controls the amount of heat generated.
As the actuator that controls the capacity of the cooler, there are an actuator that changes the capacity of the compressor to change its capacity, an actuator that controls the flow rate of the refrigerant, and the like.

The temperature setting means M2 is for setting a target temperature in the vehicle compartment. For example, it may be a temperature setting device operated by a driver. Further, for example, a predetermined target temperature may be set based on the deviation from the vehicle outside temperature.

The temperature detecting means M3 is for detecting the vehicle interior temperature. For example, a thermistor temperature sensor or the like may be used.
Further, for example, a thermocouple or the like having a better response can be used.

The determination means M5 is for determining whether or not the air conditioning means M1 is in the initial stage, which is the start time of control. For example, realized as a discrete logic circuit, the air conditioning means M1
It can also be configured to detect the start of control. Further, for example, a well-known CPU, ROM, RAM, and other peripheral circuit elements may be provided to determine the initial time of the air conditioning means M1 according to a predetermined processing procedure.

The control means M4 is an additional integral type optimum regulator that includes a state observing section M6, a first feedback amount calculating section M7, and a feedback control calculating section M8 and performs feedback control with the vehicle interior temperature as the target temperature. The control means M4 is usually a ROM, RAM using a microprocessor.
It is realized as a logical operation circuit configured with peripheral elements such as, and input / output circuits, and according to a pre-stored processing procedure,
Based on the target temperature set by the temperature setting means M2 and the vehicle interior temperature detected by the temperature detecting means M3, the air conditioning means M1 is fed back with optimum feedback predetermined based on a dynamic model of the system relating to vehicle air conditioning. It is configured to perform control by the control amounts of a plurality of air conditioning control elements determined by the gain.

By the way, the method of constructing the additional integral optimum regulator as described above is detailed in, for example, Katsuhisa Furuta, “Linear System Control Theory” (Showa 51) Shokoido, etc. Will be given.
In addition, in the following explanation Another system has been generated by the conversion or the like from the system, wherein the state observer (hereinafter, referred to as an observer) that the amount covered in, that y ^* of such symbol ^* is the target value, respectively Shows.

In the control of the controlled object, here the system related to the vehicle interior temperature, the dynamic behavior of this controlled object is It is known from modern control theory that it is described as. Where equation (1) is the state equation, equation (2) From the quantities of blown air adjusted by means M1 It is a vector of quantities. It should be noted that in the system for air conditioning for automobiles handled by the present invention, this output vector is It will be treated as a la amount y (k). Also, equation (1),
(2) is described in a discrete system, and the subscript k indicates that it is the value at the present time, and k-1 indicates that it is the value at the time of sampling one time before.

Air conditioning for automobiles, here controlling the temperature inside the vehicle Shows information about the history of the system that is necessary and sufficient for predicting the future influence of the control system. Therefore, a dynamic model of the system in which the temperature inside the vehicle compartment (the temperature inside the vehicle compartment) where air conditioning is performed by the air conditioning means M1 behaves according to the amount of blown air becomes clear, and equations (1) and (2) are given. Vector Will be. Since the control means M4 of the present invention is not a mere regulator for a system whose target value is always constant, but a servo system whose target value is constantly changing, it is necessary to expand the system. This will be described later.

By the way, it is difficult to theoretically and accurately obtain a dynamic model of a complex object such as air conditioning for an automobile, and it is necessary to experimentally determine it in some form. This is a so-called system identification method for model building. When the automobile air conditioner is operated in a predetermined state, it is assumed that a linear approximation holds in the vicinity of the state, The model is constructed according to the output equation of equation (2). Therefore, even when the dynamic model related to the operation is non-linear as in this example, linear approximation can be performed by separating into a plurality of steady operating states, and each dynamic model Can be determined. In this case, with respect to the controlled variable and the vehicle interior temperature, perturbations are extracted from each reference set value at a steady point when linear approximation is performed, and various amounts are calculated using the perturbed components. It is necessary to add the calculated value to each of the reference set values and use it as a controlled variable.

Here, if the controlled object can construct a model physically relatively easily, system identification is performed by a method such as a frequency response method or a spectrum analysis method, and a dynamic system model (here, vector It is difficult to create a physical model with a good approximation to some extent in a controlled object of a multidimensional system such as the air conditioning system for automobiles mentioned above. In this case, the least squares method, the auxiliary variable method, or the online identification method, etc. To build a dynamic model.

And the vehicle interior temperature y (k) and its target temperature y ^* (k) The controlled variable of (k) is theoretically optimally determined.

Usually, in an air conditioner for an automobile, as various quantities directly related to the control of the vehicle interior temperature, for example, the amount of air blown by a blower motor that affects the vehicle interior temperature, that is, the amount of the air flow that contributes to the vehicle interior temperature Use the converted value or the amount that the air mix damper opening affects the cabin temperature Most of these quantities cannot be observed directly. Therefore, in such a case, a portion (state observing unit M6) called a state observing device (observer) is formed in the control means M4, and the vehicle interior temperature and the control amounts of various amounts of blown air are used to control this vehicle. For air conditioning You can This is the so-called observer in modern control theory, and various observers and their design methods are known. These are described in detail in, for example, "Mechanical System Control" by Katsuhisa Furuta (1984), Ohmsha, Ltd., etc., and the applicable control object, here, the minimum dimension observer and finite setting according to the mode of the air conditioner for automobiles. It should be designed as an observer.

The system to be controlled by the control means M4 is a servo system in which the target temperature changes stepwise by the temperature setting means M2. That is, the target temperature changes depending on, for example, a driver's operation or a request from an automatic air conditioner or the like. Generally, in the control of a servo system, it is necessary to control so that the output of the controlled object follows a given target input without a steady deviation.
Therefore, it is necessary to include an integral of an appropriate order in the transfer function. In the present invention, since it is assumed that the target temperature changes stepwise, the first-order integration may be taken into consideration. Therefore, the control means M4 calculates the first feedback amount related to the control amount to the air conditioning means M1 from the element relating to the deviation between the target temperature and the vehicle interior temperature and the deviation of the predetermined optimum feedback gain. A first feedback amount calculation unit M7 that accumulates the first feedback amount is provided, and the target control system is expanded to a servo system.

Further, the control means M4 uses the sum of the accumulated first feedback amount and the second feedback amount calculated from the above-mentioned state variable and the element relating to the above-mentioned state variable of the optimum feedback gain as the control amount, and the air-conditioning means M1.
It has a feedback control amount calculation unit M8 for outputting to the control unit, and determines the control amount as an additional integral type optimum regulator.

Next, the optimum feedback gain will be described. In the optimum regulator to which the integral amount is added as described above, it is clarified how to obtain the control input (here, the control amount of various amounts of blown air of the system for air conditioning of the vehicle) that minimizes the evaluation function J. Therefore, the optimal feedback gain is also the solution of the Riccati equation and the state equation (1) and the output equation (2). It is known that it can be obtained from the weight parameter matrix (see above). Here, the weight parameter is initially given arbitrarily, and the evaluation function J changes the weight that restricts the behavior of various amounts of blown air in the system that performs air conditioning for a vehicle. It is possible to determine an optimum value by giving an arbitrary weighting parameter and performing a simulation by a large computer, changing the weighting parameter by a predetermined amount and repeating the simulation from the obtained behavior of various amounts of blown air. As a result, the optimal fee Therefore, the control means M4 is configured as an additional integral type optimum regulator by using a dynamic model of a system for air conditioning for a vehicle, which is determined in advance by system identification or the like, and an observer inside the regulator is provided. All are decided in advance by simulation.

Although it was explained as a quantity that represents the internal state of the system that performs air conditioning for automobiles, this is a variable quantity that corresponds to the actual physical quantity,
For example, it may be the rotation speed of the blower motor, the opening degree of the air mix damper, or the like, or may be designed as a vector quantity composed of various quantities that have been directly related to the vehicle interior temperature as described above.

Further, the control means M4 is configured to output each reference set value at the steady point in the case of performing the above-described linear approximation to the air conditioning means M1 as a control amount when the determination means M5 determines that it is in the initial state. ing.

[Operation] In the vehicle air conditioner of the present invention configured as described above, the control means M4 causes the vehicle interior temperature detected by the temperature detection means M3 to become the target temperature set by the temperature setting means M2. Thus, the air conditioning means M1 is feedback-controlled.

Further, in the control means M4, the state observing unit M6 uses the preset parameters based on the dynamic model of the system relating to the air conditioning of the vehicle, and sets the control amounts of the plurality of air conditioning control elements to be the control inputs. , A state variable representing the internal state of the system is estimated from the vehicle interior temperature detected by the temperature detection means M3, and the first feedback amount calculation unit M7
From the deviation between the vehicle interior temperature detected by the temperature detecting means M3 and the target temperature set by the temperature setting means, and the optimum feedback gain deviation preset based on the dynamic model of the system, The feedback amount of 1 is calculated and this first feedback amount is accumulated. Then, the feedback control amount calculation unit M8
, A second feedback amount is calculated from the state variable estimated by the state observing unit M6 and the element related to the state variable of the optimal feedback gain, and the second feedback amount and the first feedback amount calculating unit M7 are calculated. The sum of the first feedback amount accumulated at
It is calculated as a control amount of 1.

Further, in the automobile air conditioner of the present invention, the determination means M5 determines whether or not the air conditioning means M1 is in the initial state, and the determination means M5 determines that the air conditioning means M1 is in the initial state. Then, the control means M4 outputs a predetermined control amount to the air conditioning means M1 according to the operating conditions of the air conditioning means M1.

That is, in the automobile air conditioner of the present invention,
When the air conditioning means M1 is in the initial stage, that is, when the air conditioning control is started, the air conditioning control is performed with a control amount that is predetermined according to the operating conditions of the air conditioning means M1. Feedback control is executed with a control amount based on the deviation from the room temperature.

Therefore, according to the vehicle air conditioner of the present invention, at least the temperature of the blown air is optimally adjusted by the air conditioning means M1 immediately after the start of control, and thereafter, at least the temperature of the blown air is promptly adjusted by the air conditioning means M1 without delay in response. It will be controlled to the target temperature.

That is, the state variable obtained by the state observation unit M6 is
Since the information about the history of the system necessary and sufficient for predicting the influence on the future of the system related to the air conditioning for automobiles is included, the feedback control amount calculation unit M8 outputs the control to the air conditioning unit M1 after the control is started. It is possible to determine the control amount while predicting how the system behaves depending on the amount, and this control amount optimally controls multiple air conditioning control elements to control the vehicle interior temperature to the target temperature with extremely high responsiveness. You will be able to do it.

[Embodiment] Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 is a system configuration diagram of an automobile air conditioner in one embodiment of the present invention, FIG. 3 is a control system diagram showing a control model of a system that performs automobile air conditioning, and FIG. 4 is used for explaining system identification. FIG. 5 is a block diagram, FIG. 5 is a signal flow diagram thereof, FIG. 6 is a block diagram showing the structure of the observer, and FIG. 7 is a vehicle interior temperature control process executed by an electronic control circuit in one embodiment of the present invention. Which is shown in this order.

In FIG. 2, the air conditioning unit 1 is configured as an air mix type centering around a blower motor 3, an evaporator 5, a heater core 7, an air mix damper 9, and the like. A passenger compartment temperature sensor 12 for detecting a passenger compartment temperature TR, a temperature setter 14 and the like are arranged in the passenger compartment 10. The air conditioning unit 1 is controlled by the electronic control circuit 20.

In the air conditioning unit 1, the air taken in through the inside / outside air switching damper 21 by the blower motor 3 is once cooled by passing through the evaporator 5, and then a part of the air is heated again through the heater core 7 to reheat the heater core. 7
And is blown out into the passenger compartment 10. The ratio of the air passing through the heater core 7 and the air not passing through the heater core 7 is controlled by the opening degree of the air mix damper 9. The evaporator 5 is provided with a compressor 22 and a conduit for circulating a refrigerant, and the electronic control circuit 20 controls the capacity of the compressor 22 to control the cooling capacity thereof. The control of the capacity of the compressor 22, which uses an on-vehicle engine (not shown) as a power source, is performed by an actuator (not shown) that is built in the compressor 22 and controls the opening area of the passage that connects the high pressure chamber of the compressor 22 to the low pressure chamber. This is done by changing the flow rate of the refrigerant. The electronic control circuit 20 controls the drive voltage of the actuator to control the cooling capacity. Hereinafter, the drive voltage of the built-in actuator will be simply referred to as the drive signal (drive voltage) of the compressor 22.

The heater core 7 is configured to circulate engine cooling water (warm water) (not shown), and a certain amount of heat is supplied to the heater core 7 when the engine warm-up is completed. Further, the air mix damper 9 is configured such that the damper actuator 24 controls the damper opening degree.

The electronic control circuit 20 includes a well-known CPU 30, ROM 32, R
Input port 36, output port 38, mainly AM34
Etc. are connected to each other via a common bus 40, and are configured as a logical operation circuit. The input port 36 inputs the vehicle interior temperature TR from the vehicle interior temperature sensor 12 and the target temperature TR ^* from the temperature setter 14 as electrical signals corresponding to respective amounts. The output port 38 outputs a drive signal VB for driving the blower motor 3, a drive signal VC for the compressor 22, a drive signal VD for the damper actuator 24, and the like.

The electronic control circuit 20 includes a temperature setter 14 and a vehicle interior temperature sensor 12 according to a program stored in advance in the ROM 32.
The blower motor 3, compressor 22, damper actuator 24, etc. are feedback-controlled by drive signals (VB, VC, VD, etc.) based on signals (TR ^* , TR, etc.) input from The control model used will be described below. In particular, state equation (1) by system identification, output equation Based on this, observer design and feedback It Incidentally, FIG. 3 is a diagram showing a control system, and does not show a hardware configuration. The control system shown in FIG. 3 is actually realized as a discrete system by executing the series of programs shown in the flowchart of FIG.

As shown in FIG. 3, the target temperature TR ^* is first set by the target temperature setting unit P1. In this embodiment, the temperature setter 14 corresponds to the target temperature setting unit P1.

The integrator P2 calculates the optimum feedback gain to be described later based on the deviation between the target temperature TR ^* and the vehicle interior temperature TR. The accumulated values are multiplied to obtain the first feedback amount, which is the deviation accumulated value ZTRB (k), ZTRC (k), ZTRD.
(K) is calculated.

The perturbation extractor P3 measures the vehicle interior temperature TRa in the vehicle interior temperature TRa in a state in which steady air conditioning is performed.
Extract the perturbations from. As described above, this is because the state of air conditioning by the automobile air conditioner is linearly approximated in the vicinity of a plurality of steady air-conditioning states in order to perform the linear approximation to the nonlinear model. This is due to the construction of a dynamic model for this system, which is regarded as a continuous range of Therefore, the vehicle interior temperature TR is once set to a predetermined perturbation δTR (= TR-T from the steady state).
It is treated as Ra). Drive voltage VB of the blower motor 3 that determines the control amount of the air conditioning unit 1, that is, various amounts of blown air, which are obtained by the integrator P2, the observer P4, and the feedback amount determination unit P5, the compressor 2
The drive voltage VC of 2 and the drive voltage VD of the damper actuator 24 that determines the opening degree of the air mix damper 9 are also treated as perturbations δVB, δVC, δVD.

The observer P4 is a state variable expressing the internal state of the air conditioner from the perturbation component δTR of the vehicle interior temperature and the perturbation components δVB, δVC, δVD of the control amount. It is something.

The feedback amount determination unit P5 estimates the state. And the second feedback amount calculated by
And the deviation cumulative value that is the first feedback amount calculated by the above equation are added to obtain the perturbation amount δVB (k), δV of the control amount.
C (k) and δVD (k) are calculated.

The perturbations δVB (k), δVC (k), δVD (k) of the control amount calculated by the feedback amount determining unit P5 are
It is a perturbation component from the control amount corresponding to the steady operating state of the air conditioner selected by the perturbation component extraction unit P3. For this reason, the reference set value adding unit P6 causes the reference set values VBa, VCa, VDa corresponding to the above-mentioned steady operation state.
Are the perturbations δVB (k), δVC (k), δVD
In addition to (k), the controlled variables VB, VC,
The VD is calculated.

The initial determination unit P7 determines whether the control of the air conditioning unit 1 is in the initial period.

When it is determined that it is in the initial stage, the integrator P described above is used.
The first feedback amount calculated by 2 is set to a value equal to the second feedback amount, and the positive and negative signs are set to opposite values. By this process, in the initial stage, the feedback amount determination unit P5 cancels the first feedback amount and the second feedback amount,
The perturbations of the controlled variable are all zero. Therefore, the control amount at the initial time is set to the reference set values VBa, VCa, VDa. This is because there is no accumulated deviation value of the operation state up to that time at the initial stage of the control on the air conditioning unit 1. For this reason, the state calculated based on the uncertainty In order to stabilize the control at the initial stage, the reference amount set in advance corresponding to the steady operating state is used as the control amount.

Although the configuration of this control system has been briefly described above, the drive voltage VB of the blower motor 3, the drive voltage VC of the compressor 22, and the drive voltage VD of the damper actuator 24 are taken as examples as the operating conditions of the air conditioner. In an automotive air conditioner having these air-conditioning units 1 of the air mix type, these quantities are
It depends on the fact that it is a basic quantity related to the control of R.
Therefore, in this embodiment, the air conditioner is regarded as a multi-input system with three inputs and one output. If the automotive air conditioner is a reheat type, other multidimensional control models can be used as necessary, such as replacing the opening of the water valve that changes the flow rate of hot water circulating in the heater core with one of the control variables. Just make it.

The hardware configuration of the vehicle air conditioner and the configuration of the control system in the case of taking a 3-input 1-output system as a device for controlling this output have been described above. Therefore, next we will build a dynamic model by actual system identification, design the observer P4, and To do.

First, we build a dynamic model of an automobile air conditioner.
FIG. 4 is a diagram in which a system of an air conditioner which is normally operated as a system of three inputs and one output is described by transfer functions G1 (z) to G3 (z). In addition, z indicates z conversion of the sample value of the input / output signal, and G1 (z) to G3 (z) have an appropriate order. It is obtained in the vicinity of a certain reference motion of a sample value system with a constant period and is linearly approximated.

If the control system is a system with three inputs and one output, and there is interference in various input and output, like the air conditioner of the present embodiment, it is extremely difficult to determine a physical model. Becomes In such a case, the transfer function can be obtained by a kind of simulation called system identification.

The method of system identification is described in detail in, for example, Setsuo Sagara et al., "System Identification" (1981), The Society of Instrument and Control Engineers, etc., but here the identification is performed by the least squares method.

The air conditioning unit 1 is steadily operated in a predetermined state, the perturbations δVC and δVD of the drive voltage of the compressor 22 and the damper actuator 24 are both set to 0, and the perturbation δVB of the drive voltage of the blower motor 3 is controlled by an appropriate test signal.
At this time, the data of the perturbation component δVB of the drive voltage of the blower motor 3 as the input and the perturbation component δTR of the vehicle interior temperature as the output are sampled N times. The input data series {u (i)} = {δVBi}, the output data series {y (i)} = {δTRi} (where i = 1, 2,
3, ... N). At this time, the system can be regarded as one input and one output, and the transfer function G1 (z) of the system is G1 (z) = B (z ^-1 ) / A (z ^-1 ) ... (3) That is, G1 (Z) = (b0 + b1 * z- ¹ + ... + bnz- ⁿ ) / (1 + a1 * z- ¹ + a2 * z- ² + ... + an * z- ⁿ ) ... (4). Here, z ⁻¹ is a unit transition operator and means z ⁻¹ · x (k) = x (k−1).

The transfer function G1 (z) of the system can be obtained by defining the parameters a1 to an and b0 to bn of the equation (4) from the input / output data series {u (i)} and {y (i)}. In system identification by the method of least squares, these parameters a1 to an and b0 to bn are Is set to be the minimum. In this embodiment, n = 1,
Each parameter was calculated. In this case, the signal flow diagram of the system is as shown in Fig. 5, and the state variable quantity is x1.
Taking (k), the state / output equation is as follows: x1 (k + 1) = z.x1 (k) =-a1.x1 (k) + b1.u (k) ... (6) y (k) = It is expressed as x1 (k) ... (7). Therefore, it is regarded as a system with one input and one output. Becomes

By the same method, transfer functions G2 (z), G3 Is required. Therefore, from these system parameters, the system parameters of the original 3-input 1-output multidimensional system, that is, the state equation (1), the output equation It

In this way, the dynamic module of this embodiment was obtained by system identification. This dynamic model is based on the air conditioning unit 1
Is operated in a predetermined state, a linear approximation is established in the vicinity of this state. Therefore, the transfer functions G1 (z) to G3 (z) are obtained by the above method for a plurality of steady air-conditioning states, and Will be established during.

Next, a method of designing the observer P4 will be described. There are Gopinas design methods in the design of the observer, and Katsuhisa Furuta and Akira Sano "Basic System Theory" (1978).
Although detailed in Corona, etc., this embodiment is designed as a minimum order observer.

The observer P4 is a perturbation component (δTR) of the temperature inside the vehicle and a perturbation component (δVB, δVC, δ) of the air-conditioned interior.
VD) and inside of the air conditioning unit 1 (K) is the actual state change in the control of this system. It is assumed that (k) is configured as the following equation (9) based on the state equation (1) and the output equation (2).

is there. By transforming from equations (1), (2), and (9), (That is, the drive voltage of the blower motor 3 [VB (k) (That is, here as the scalar quantity y (k) it can.

FIG. 6 is a block diagram showing the structure of the minimum dimension observer. Configure the observer like this, Then, using equation (11), I will keep it.

As described above, the Gopinus design method is known as a specific design method of such a minimum-dimensional observer, and in this embodiment, this is used to determine a certain steady operating state of the air conditioning unit 1. Got

Here is the state required by the observer ΔTB (k), δTC (k), δ
We are considering TD (k). The variable δTB (k) is a variable δTC, which is a perturbation amount of the vehicle interior temperature affected by the drive voltage VB that controls the flow rate of the blown air of the blower motor 3.
Similarly, (k) shows the perturbation of the actual temperature inside the vehicle, which is affected by the drive voltage VC of the compressor 22, as a variable δTD.
(K) respectively means perturbations of the vehicle interior temperature that are also affected by the damper actuator 24.

Is represented as

Since the method to be obtained is detailed in, for example, “Linear System Control Theory” (supra), the detailed explanation is omitted here and only the result is shown.

Control input for air conditioning unit 1 For some output y (k) = TR (k) around a stationary point, And an optimal control input that minimizes the following evaluation function J, The control problem as an additional integral type optimum regulator for the control system of No. 1 will be solved.

Shows the number of samplings when the control start time is 0. This is a so-called quadratic form expression.

Is the solution. Incidentally, here, the meaning of the evaluation function J of the equation (19) is as a control input to the air conditioning unit 1. Is intended to minimize the deviation of the control output y (k), here the vehicle interior temperature TR (k) from the target value TR (k) ^* , while restricting the movement of Can be changed. Therefore, the dynamic model, that is, the matrix, of the air conditioning unit 1 that has already been obtained. Is calculated from equations (12) and (13).

As described above, the optimum feedback gain is calculated based on the deviation between the target temperature TR ^* and the vehicle interior temperature TR. Digit accumulated values are accumulated to obtain deviation accumulated values ZTRB (k), ZTRC (k), ZTRD which are first feedback amounts.
Calculate (k). Next, state estimation 1 to 3, j = 1 to 3) to calculate a second feedback amount, and the first feedback amount is added to the calculated value, the control of the air conditioning unit 1 is performed. δVC (k) and δVD (k) are obtained.

By repeating the above simulation until the characteristics are obtained, the optimum feedback gain is obtained. Was asked for.

As mentioned above, the dynamic model of the control system of the air conditioning unit 1 is constructed by the system identification by the least squares method, the design of the minimum dimensional observer, and the optimal feedback network Inside the control circuit 20, the actual control is performed using only the result.

Then, next, the vehicle interior temperature control processing which the electronic control circuit 20 actually performs will be described with reference to the flowchart of FIG. In the following description, the amount handled in actual processing is added with the subscript (k), and the amount handled the previous time is added with the subscript.
(k-1) is attached.

After the air conditioner is activated, the CPU30
Value of the initial flag FS indicating that this processing is the first time, clearing the internal register of
After initialization processing such as resetting to step 100 is performed in step 100, steps 110 to 250 described later are repeatedly executed according to a procedure stored in the ROM 32 in advance. In this vehicle interior temperature control process, First, in step 110, the output signal of the vehicle interior temperature sensor 12 is input through the input port 36, and the vehicle interior temperature T
Read R (k). Similarly, in step 120, the output signal of the temperature setter 14 is input to set the target temperature T
A process of reading R ^* (k) is performed. This step 120
The above process functions as the target temperature setting unit P1 shown in FIG.

In the following step 130, the deviation between the vehicle interior temperature TR (k) read in step 110 and the target temperature TR ^* (k) read in step 120 is e (k) = TR ^* (k).
-Determine as TR (k).

In the following step 140, when the dynamic model of the air conditioning unit 1 is constructed from the vehicle interior temperature TR (k) read in step 110, the steady operating state of the air conditioning unit 1 taken as a range in which linear approximation is established The closest state among these (hereinafter, this is the steady point TRa, VBa, VCa, V
Called Da). In step 150, the vehicle interior temperature TR (k) read in step 110
Is calculated for the perturbation component δTR (k) from the steady point determined in step 140. Regarding this perturbation component, it is assumed that the values at the time when this control processing was executed last time, including δTR (k-1), are stored. The processing in steps 140 and 150 functions as the perturbation component extraction unit P3 in FIG.

In the following step 160, the parameters in the observer corresponding to the current operating state of the air conditioning unit 1 are set. Etc. are selected.

Next, in step 170, the deviation e (k-1) previously calculated in step 130 is added to the step A value is multiplied by an element relating to the deviation and accumulated deviations ZTRB (k), ZTRC (k), ZTRD (k) are calculated as follows. Here, ZTRB (k-1), ZTRC (k-1), ZTRD at the initial stage
The values of (k-1) are all set to 0 in step 100. Further, the reason that e (k-1) is used as the deviation is that the calculation time delay in this processing is taken into consideration. The processes of the above step 130 and this step 170 function as the integrator P2 in FIG.

ZTRB (k) = ZTRB (k-1) + F14 · T · e (k-1) ZTRC (k) = ZTRC (k-1) + F24 · T · e (k-1) ZTRD (k) = ZTRD (k -1) + F34 · T · e (k-1) The following steps 180 and 190 are state estimation. , (13), [δTB (k) δTC (k) δT
D (k)] ^T is required. That is, of the In step 180, W1 (k), W2
(K), W1 (k) = P11 · W1 (k-1) + P12 · W2 (k-1) + M11 · δVB (k-1) + M12 · δVC (k-1) + M13 · δVD (k-1) + M14 ・ δTR (k-1) W2 (k) = P21 ・ W1 (k-1) + P22 ・ W2 (k-1) + M21 ・ δVB (k-1) + M22 ・ δVC (k-1) + M23 ・ δVD (k -1) + M24δTR (k-1), and in the following step 190, using the result of step 180, the state estimator is δTB (k) = C11W1 (k) + C12W2 (k) + D1δTR (k) δTC (k) = C21 · W1 (k) + C22 · W2 (k) + D2 · δTR (k) δTD (k) = δTR (k) −δTB (k) −δTC (k) Be done. Step 180 here
Used in δVB (k-1), δVC (k-1), δVD (k-
As described above, 1), δTR (k-1), etc. are values when the present control processing was executed last time.

(K), that is, a perturbation component δVD (k) of the drive voltage of the damper actuator 24 that controls the opening degree of the air mix damper 9.
The temperature perturbation δTD (k) that affects the vehicle interior temperature perturbation δTR (k) is calculated by δTR (k) −δTB
What is calculated as (k) −δTC (k) is that the perturbation component δTR (k) of the vehicle interior temperature is measured (step 1
Therefore, the calculation is facilitated in consideration of the improvement of the processing speed. The processing of steps 180 and 190 functions as the observer P4 of FIG.

Next, at step 200, it is judged whether or not it is the initial time based on the value of the initial time flag FS. Since the initial flag FS has been reset to the value 0 in step 100 described above, the process proceeds to step 210. The process of step 200 functions as the initial determination unit P7 in FIG.

In step 210, which is executed only at the initial stage, a process of setting the deviation accumulated value as follows is performed.

ZTRB (k) =-{F11.delta.TB (k) + F12.delta.TC (k) + F13.delta.TD (k) ZTRC (k) =-{F21.delta.TB (k) + F22.delta.TC (k) + F23.delta.TD (k) ZTRD (k) =-{F31.delta.TB (k) + F32.delta.TC (k) + F33.delta.TD (k) After that, the initial state flag FS is set to the value 1 and the routine proceeds to step 220.

In the initial case, following step 210 above,
If it is not the initial time, step 220 is executed after step 200. In step 220, the state estimation amount calculated in steps 180 and 190 above Optimal feedback gain selected in step 160 Further, the deviation cumulative value calculated in step 170 or step 210 is added to add the perturbation component δVB (k) of the drive voltage of the blower motor 3, the perturbation component δVC (k) of the drive voltage of the compressor 22, and the damper actuator 24. A process of calculating the perturbation component δVD (k) of the drive voltage is performed. That is, the following calculation is executed.

δVB (k) = F11 · δTB (k) + F12 · δTC (k) + F13 · δTD (k) + ZTRB (k) δVC (k) = F21 · δTB (k) + F22 · δTC (k) + F23 · δTD (k) + ZTRC (k) δVD (k) = F31 · δTB (k) + F32 · δTC (k) + F33 · δTD (k) + ZTRD (k) The process of step 220 functions as the feedback amount determination unit P5 shown in FIG. . At the initial stage, since the deviation accumulated value is set in step 210, the perturbations δVB (k), δVC (k), and δVD (k) obtained from the above calculation are canceled out and all become zero. On the other hand, if it is not the initial time, the accumulated deviation value is calculated in step 170, so that the perturbations δVB (k), δVC (k), and δVD (k) become predetermined values by the above calculation.

In the following step 230, the perturbation components δVB (k), δVC (k), δVD of each drive voltage obtained in step 220.
Actual driving voltages VB (k), VC (k), VD are obtained by adding the values VBa, VCa, VDa at the steady point to (k).
The process of obtaining (k) is performed. This is a process corresponding to the reference set value adding unit P6 in FIG.

In the following step 240, the drive voltages VB (k), VC (k), VD (k) obtained in step 230 are supplied to the blower motor 3, compressor 22,
Processing for outputting to each of the damper actuators 24 is performed. In step 250, the value of the subscript K indicating the number of times of sampling, calculation and control is incremented (updated) by 1, and the process returns to step 110 and the processes of steps 110 to 250 are repeated again.

FIG. 8 shows the state of the control performed by the vehicle interior temperature control processing configured as described above in comparison with the state of the conventional simple feedback control. As a control example, the case where the target temperature TR ^* is set to 20 [° C.] and the control is started when the vehicle compartment temperature TR is 15 [° C.] is taken up. The target temperature is shown by the alternate long and short dash line P in FIG. 8, and the change in the vehicle interior temperature relative to this is plotted on the basis of the output signal of the vehicle interior temperature sensor 12, and the solid line G,
It is a broken line F and a chain double-dashed line H. A solid line G shows an example of control of the vehicle interior temperature according to the present embodiment, a broken line F shows an example of control by conventional control, and a chain double-dashed line H shows an example of control when no determination is made at the initial stage. As is clear from FIG.
According to the present embodiment, the vehicle interior temperature TR is set to the target temperature TR ^* with almost no overshoot or undershoot while realizing a quicker response (rise) than the conventional control ^.
Is able to Comparing the time during which the air conditioning system stabilizes, it can be seen that, in this example, an improvement of one digit or more is realized despite the rapid rise. Also, at the beginning When calculating, there is no accumulated deviation value in the initial stage, so Therefore, for example, as indicated by the chain double-dashed line H, the target TR ^*
There may be a problem that the control is started in the opposite direction. On the other hand, as in this embodiment, the reference set values VBa and VC at the steady point are initially set.
When the control is started based on a and VDa, as shown by the solid line G in FIG. 8, the target temperature TR ^* is rapidly approached from the initial stage. As a result, not only the vehicle interior temperature TR can be controlled to the target temperature with good responsiveness, but also the blower motor 3,
Since the compressor 22 and the damper actuator 24 are optimally controlled, wasteful energy is not consumed,
The fuel consumption is reduced and the fluctuation of the output torque of the internal combustion engine can be reduced because the compressor 22 is not controlled to be turned on and off.

This is because in the control of the present embodiment, control is performed by the electronic control circuit 20 that is an optimum integral-type regulator instead of the simple feedback control that predicts the thermal balance. That is, the model of the air conditioning system to be controlled is experimentally analyzed by system identification, and the state of the controlled object, that is, the information about the past history of the system necessary and sufficient for predicting the influence on the future is estimated. However, at the initial stage of control, the reference set value at the steady point of the model of the above system is
This is because after the control is started, the above-mentioned estimated amount is used to perform the control.

Further, in the present embodiment, the deviation accumulated values ZTRB (k), ZTR
When calculating C (k) and ZTRD (k), the deviation e (k-1) previously sampled and calculated is used as the deviation. Therefore, the electronic control circuit 20 in the discrete time system
It is possible to compensate for the calculation time delay of.

Further, in the vehicle air conditioner of the present embodiment, the design of the feedback gain in the electronic control circuit 20 for controlling the vehicle interior temperature is made extremely logically, and this is determined optimally. Therefore, unlike the conventional control device, it is not necessary to design based on the experience of the designer, actually adjust as necessary, and set the feedback gain that seems to be appropriate, which reduces the design and development man-hours and cost. Can be reduced.

In the present embodiment, the air conditioning unit 1 uses the air conditioning means M.
1, the temperature setter 14, the electronic control circuit 20, and the processing executed by the electronic control circuit 20 (step 1
20) functions as the temperature setting means M2, and includes the vehicle interior temperature sensor 12, the electronic control circuit 20, and the electronic control circuit 20.
The processing (step 110) executed by the above functions as the temperature detecting means M3. Further, the electronic control circuit 20 and the processing executed by the electronic control circuit 20 (step 1
40, 150, 160, 210) as the control means M4, the electronic control circuit 20 and the processing (step 200) executed by the electronic control circuit 20 as the determination means M5 by the electronic control circuit 20 and the electronic control circuit 20. The process executed (steps 180, 190) is the state observing section M6, and the process executed by the electronic control circuit 20 and the electronic control circuit 20 (steps 130, 170).
Functions as the first feedback amount calculation unit M7, and the electronic control circuit 20 and the processes (steps 220, 230, 240) executed by the electronic control circuit 20 function as the feedback control amount calculation unit M8.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and is applied to a reheat type air conditioner. As a matter of course, the present invention can be implemented in various modes without departing from the scope of the present invention.

Effect of the Invention As described in detail above, in the vehicle air conditioner of the present invention, at the start of the control when the air conditioning unit is in the initial stage, the air conditioning unit has a plurality of air conditioners for adjusting various amounts including at least the temperature of the blown air. As the control amount of the air conditioning control element, a predetermined control amount is set according to the operating conditions of the air conditioning means, and thereafter, the control amounts of the plurality of air conditioning control elements that are control inputs and the vehicle interior temperature that is the control output are set. State variable that represents the internal state of the system related to the air conditioning for the vehicle estimated by the above, the cumulative value of the first feedback amount calculated using the optimal feedback gain from the deviation between the target temperature and the vehicle interior temperature, and the state variable and the optimal The sum of the feedback gain and the second feedback amount determined by the feedback gain is set as the control amount of the air conditioning unit.

Therefore, according to the present invention, it is possible to control the vehicle interior temperature toward the target temperature from the initial stage of starting the air conditioning control, and after the control starts, even if the target temperature changes, responsiveness and It is possible to perform control while keeping the followability at a high level.

That is, in the conventional air conditioner for an automobile by PID control, the control amount is set only based on the deviation between the vehicle interior temperature and the target temperature. It is calculated as a dynamic model of output, and the control variables of multiple air conditioning control elements are calculated at the same time using state variables that contain information about the history of the system that is necessary and sufficient to predict the future impact of that control system. Therefore, after starting the control, it is necessary to clarify the dynamic model of the control system, which is how the dynamic model that controls the vehicle interior temperature behaves according to the control input (the control amount of multiple air conditioning control elements). While the control amount can be determined while changing the target temperature, the vehicle interior temperature can be quickly converged to the target temperature without causing overcontrol. .

In particular, in the air conditioner for an automobile as in the present invention, the heat load changes abruptly due to changes in the amount of solar radiation, the speed of the vehicle, the place of travel, etc., and is easily affected by these disturbance factors. In the conventional device that determines
Such a disturbance element causes response delay or hunting, and it is difficult to converge the vehicle interior temperature to the target temperature. However, according to the automobile air conditioner of the present invention, information for predicting future influence of the control system is provided. Since the controlled variable is determined using the included state variables, the controlled variable can be optimally set even when the heat load changes abruptly due to changes in the amount of solar radiation, vehicle speed, running location, etc. Air conditioning control with excellent stability can be realized.

Furthermore, since the conventional air conditioner for a vehicle using PID control can control only one input and one output, when performing air conditioning control as in the present invention, mutual interference between the respective control inputs is eliminated and each control is controlled. Although there is no choice but to make a one-to-one correspondence between inputs and control outputs and control them as a set of a plurality of controls of one input and one output, the air conditioner may be wastefully driven. Since the control amount can be optimally set in consideration of the interrelationship between the control input and the control output as described above, the operation of the air conditioning means can be minimized, and the consumption of the internal combustion engine or the like that is the drive source thereof can be minimized. It becomes possible to suppress energy, and eventually fuel efficiency of the drive source.

Furthermore, since the optimum feedback gain that is predetermined based on the dynamic model of the system for air conditioning for automobiles is used, there is an advantage that the number of man-hours for designing and developing the air conditioning apparatus can be reduced.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram conceptually illustrating the contents of the present invention, FIG. 2 is a system configuration diagram of an automobile air conditioner as one embodiment of the present invention, and FIG. Fig. 4 is a control system diagram of the system, Fig. 4 is a block diagram used to identify the model of the system, Fig. 5 is a signal flow diagram for obtaining the transfer function, and Fig. 6 is a configuration of the minimum dimension observer. 7 is a flow chart showing the control as an additional integral type optimum regulator executed in one embodiment of the present invention, and FIG. 8 compares the control characteristic of the embodiment with the state of conventional control. It is a graph. M1 ... Air conditioning means, M2 ... Temperature setting means M3 ... Temperature detection means M4 ... Control means, M5 ... Judgment means M6 ... State observation part M7 ... First feedback amount calculation part M8 ... Feedback control amount calculation part 1 ... Air conditioning unit, 3 ... Blower motor 5 ... Evaporator 9 ... Air mix damper 10 ... Passenger compartment, 12 ... Vehicle interior temperature sensor 14 ... Temperature setting device, 20 ... Electronic control circuit 22 ... Compressor 24 ... Damper actuator 30 ... CPU 32 ... ROM

Claims (2)

[Claims] 1. An air conditioning means for adjusting various quantities including at least the temperature of air blown into a vehicle compartment in accordance with control quantities of a plurality of air conditioning control elements, a temperature setting means for setting a target temperature in the vehicle interior, and the above vehicle. By using the temperature detection means for detecting the temperature inside the vehicle interior and the optimum feedback gain that is predetermined based on the dynamic model of the system for air conditioning for automobiles,
An air conditioner for a vehicle, comprising: a control means that is an additional integral type optimum regulator that feedback-controls the air conditioning means so that the vehicle interior temperature becomes the target temperature. The control means has a determining means for determining whether or not there is, and the control means uses the preset parameters based on the dynamic model to control the air-conditioning means and the vehicle interior temperature. From the state observing unit that estimates the state variable that represents the dynamic internal state of the system, and the factors related to the deviation between the target temperature and the vehicle interior temperature and the deviation of the optimum feedback gain, to the air conditioning unit. A first feedback amount calculation unit that calculates a first feedback amount related to the control amount and accumulates the first feedback amount; And a feedback control amount calculation unit that outputs the sum of the second feedback amount calculated from the above-mentioned state variable element of the optimum feedback gain and the accumulated first feedback amount to the air conditioning unit as a control amount. If the control means determines that the determination means is in the initial state, the control means outputs to the air conditioning means control amounts of a plurality of air conditioning control elements that are predetermined according to the operating state of the air conditioning means. An air conditioner for a vehicle characterized by being configured. 2. The various amounts adjusted by the air-conditioning means are composed of a blower amount of a blower motor for blowing blown air, a flow rate of a refrigerant for temporarily cooling the blown air, and a flow rate of the blown air to be reheated. The automobile air conditioner according to claim 1.