JPH0321515A - Car airconditioner - Google Patents

Abstract

PURPOSE:To enhance the response by installing a calculating means to calculate the control amount when it is judged that the actual intra-coupe air temp. is near the target air temp. and performing the calculation of the control amount through the operation where differential calculation on the deviation is excluded. CONSTITUTION:An airconditioner is provided wtih a temp. sensing means 1 to sense the actual intra-coupe air temp. and a setting means to set the target air temp. for inside the coupe. A calculating means 3 calculates the control amount about the deviation between the actual air temp. and target air temp. through a specified operation incl. at least proportional and differential calculations, and in accordance with the calculated control amount, an adjusting means 4 adjusts the amount of heat supplied inside the car. Also a judging means 5 is furnished to judge whether and how the actual air temp. due to the airconditioner is approaching the target air temp., and when it is judged as approaching, the abovementioned calculating means 3 calculates the control amount with the operation where differential calculation is excluded in the specified calculational operation as mentioned above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a vehicle air conditioner that automatically controls vehicle interior temperature to approach a control target temperature.

[Conventional technology]

Conventionally, in the field of automatic control, it has been known to add differential calculations to suppress fluctuations in controlled variables, and even in vehicle air conditioning systems, as shown in Japanese Patent Laid-Open No. 57-175415, Some devices are equipped with a circuit that performs differential calculations to suppress temperature fluctuations and improve stability.

[Problems to be Solved by the Invention] However, in devices such as air conditioners for vehicles, which are subject to many fluctuations in usage conditions and conditions, that is, disturbances, etc., there are many temperature fluctuations, and even if this differential calculation circuit is provided, Uncontrollable temperature fluctuations may occur. In this case, although the indoor temperature is controlled to converge to the control target temperature by controlling the temperature of the device, there is a problem in that the responsiveness is worsened by the action of the differential calculation circuit.

The present invention has been made in view of the above-mentioned problems, and has excellent stability and a response that can quickly converge to the set temperature, which is the control target temperature, even if temperature fluctuations, that is, overshoot or undershoot, occur in the vehicle interior. The purpose of the present invention is to provide a vehicle air conditioner with excellent performance.

[Means to solve the problem]

In order to achieve the above object, the present invention has a detection stage 1 for detecting the actual air temperature in the vehicle interior, and a setting stage 2 for setting the target air temperature in the vehicle interior, as shown in FIG. , a calculation means 3 for calculating a control amount by predetermined calculation processing including at least proportional and differential calculations with respect to the deviation between the actual air temperature and the target air temperature; and a calculation control amount by the calculation means 3. In a vehicle air conditioner equipped with a control stage 4 that adjusts the amount of heat supplied to the vehicle interior according to the amount of heat supplied to the vehicle interior, the state in which the actual air temperature in the vehicle interior approaches the target air temperature by the vehicle air conditioner A determining means 5 is provided for determining the approaching state, and when the determining means 5 determines the approaching state, the calculating means 3 calculates the control amount by a calculation process excluding the differential calculation in the predetermined calculation process. Adopt technical means.

[Action and effect]

Therefore, depending on the outputs from the detection means 1 and the setting means 2, the determination means 5 determines whether the actual air temperature in the vehicle interior is approaching the target air temperature, and when it is approaching the target air temperature, the calculation means 3 In the predetermined arithmetic processing, a control amount is calculated by the arithmetic processing that is removed by the differential calculation regarding the deviation, and the g11 node means 4 adjusts the amount of heat supplied to the passenger compartment in accordance with the control amount.

Therefore, when in the approaching state, no differential calculation is involved and there is an excellent effect of excellent responsiveness.

On the other hand, in the non-approach state, differential calculations are included, so there is an excellent effect of excellent stability against temperature fluctuations.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described.

FIG. 1 shows the structure of a known vehicle air conditioner to which the present invention is applied. In the air duct 10 of this air conditioner, there are an inside/outside air switching door 20, a blower 30, an evaporator 40, a heater 50, etc. ．． An air mix damper 60 and outlet switching doors 70, 80 are arranged. The outside air switching door 20 is set to the outside air mode when the inlet 1l of the air duct 10 is opened, and the air duct l-
Introduce outside air into the chamber. On the other hand, when the recirculation port 12 of the air duct 10 is opened, the inside air mode is set, and the air inside the vehicle compartment l3 is recirculated to the air duct 10. The blower 30 sucks air from the inlet 11 or the recirculation port 12, and sends it to the evaporator 40 as an air flow having a flow i1W depending on the rotation speed of the air. Note that the rotation speed of the blower 30 is controlled by a control circuit 90. The evaporator 40 cools the airflow from the blower 30 using a refrigeration cycle including an electromagnetic clutch 41 and a compressor 42, and applies the cooled airflow to the air ξx damper 60 as a cooling airflow.

Note that the electromagnetic clutch 4l is driven under the control of the control circuit 90 to selectively connect the compressor 42 to the internal combustion engine E.

The heater 50 receives cooling water from the cooling device of the internal combustion engine E and warms the cooling air flow sent from the evaporator 40.

The air mix damper 60 is connected to a rod 62 of a servo mork 61, and when the servo motor 6l rotates by inputting a control signal from a control circuit 90 to move the rod 62 upward or downward, its opening degree Ar It functions to decrease or increase according to the upward or downward movement of the rod 62. As a result, part of the cooling airflow from the evaporator 40 is applied to the heater 50 according to the opening degree Ar of the air mix damper 60, while the remaining part of the cooling airflow from the evaporator 40 is applied to the heater 50. The air outlet switching door 70 is mixed with the warmed air stream to form a mixed air stream.
sent to. In this case, the air 5x damper 60 has a minimum opening degree when the rod 62 is at the upper moving end in the figure, and the entire cooling airflow from the evaporator 40 is directly applied to the outlet switching door 70. do. On the other hand, when the rod 62 is at the lower moving end, the air ξx damper 60 has the maximum opening degree, and the entire cooling air flow from the evaporator 40 is applied to the heater 50.

The outlet switching door 70 is operatively connected to a servo motor 71, and when the servo motor 71 is at the home position, it is maintained at the home position (indicated by the solid line in FIG. 1) and moves inside the air duct 10. The mixed air flow flowing through the air duct 10
The air is blown into the vehicle compartment 13 through the air outlet l4. This means that the outlet switching door 70 is placed in the heat mode. The outlet switching door 70 cooperates with the switching door 80 to blow out the mixed air flow from the outlet 14.15 of the air duct 10 into the vehicle interior 13 or from the outlet 16 of the air duct 10 into the vehicle interior 13. It all works. This means that the switching door 70.80 is placed in vent mode, pie level mode or defroster mode. Note that the switching door 70 is operated by a servo motor 71.
The switching door 80 is rotated downward in response to a command from the control circuit 90 and placed in vent mode, pie level mode, or defroster mode. It is placed under vent mode, pie level or defroster mode. Note that the mode setting by switching the air outlet or the above-mentioned inside/outside air switching mode can be controlled according to the mode setting by the passenger setting the mode setting device 94 provided in the passenger compartment 13, or by controlling the mode setting by the control circuit. Automatically controlled at 90.

The control circuit 90 is constituted by a microcomputer and includes internal temperature sensors 91 . It is connected to an opening sensor 92, a temperature setting device 93, and the mode setting device 94 mentioned above. The interior temperature sensor 91 is disposed within the vehicle interior l3, detects the actual temperature Tr within the vehicle interior 13, and generates a signal corresponding to this interior temperature Tr.

The opening sensor 92 is operatively connected to the rod 62 that is moved up and down by the servo motor 61, and detects the actual opening Ar of the air ξx damper 60.
Generates a signal corresponding to The temperature setting device 93 is located in the vehicle compartment 13.
A desired set temperature Tset is selected by the passenger's manual operation and is generated as a temperature setting signal.

Further, a predetermined control program is stored in the microcomputer, and according to the control program, the most suitable opening SW of the air damper 60 is calculated, and compared with the actual opening Ar from the opening sensor 92. The control amount of the air mix damper 60 is determined. That fall?
The servo motor 61 is driven by a control signal corresponding to the amount of B, and the opening degree of the air mix damper 60 is controlled.
The temperature within 3 is regulated.

Next, the operation of this embodiment will be explained using the control flowchart shown in FIG. Note that this control flowchart is an example in which the present invention is applied to the initial temperature adjustment operation of a vehicle air conditioner.

When the switch of the air conditioner (not shown) is turned on in FIG. 1, first, in step 200, output values from the inside temperature sensor 91, opening sensor 92, temperature setting device 93, mode setting device 94, etc. are input. Ru. In the next step 201, it is determined whether the set temperature Tset and the room temperature T are equal.

If YES here, the process advances to step 207, and after the room temperature Tr is controlled by normal PID control, step 207 follows.
Return to 0. That is, as is well known, the optimum opening degree SW of the air mix damper 60 is determined by the following equation, and the opening degree of the air mix damper 60 is controlled.

Here, the subscript n indicates the value at the current sampling time, and n-1 indicates the value at the previous sampling time. In addition, e n = T StTn T re
is the deviation between the set temperature T$ETn and the room temperature T r n,
θ is the sample time, K is the proportional gain, T1 is the integration time,
T, is the differential time.

On the other hand, when the determination in step 201 is NO, the process proceeds to step 202, and it is determined whether the blowout mode is the vent mode or the heater mode according to the output value from the mode setting device 94. In the vent mode, the process proceeds to step 204, where a comparison is made between the room temperature T and the set temperature TSET. T
r > T s t r If the determination is NO, it is determined that the room temperature has not yet reached the set temperature and is falling, and the process proceeds to step 207. Conversely, if YES, the room temperature is undershooting with respect to the set temperature Tsit. After making a determination, the process proceeds to step 205.

Further, when the blowing mode is the heater mode in step 202, the process proceeds to step 203, where it is determined whether T,>T SET. Here, if T,<T,,T and the determination is No, it is determined that the setting has not been reached and the room temperature is still rising, and step 207
On the other hand, if YES, it is determined that the room temperature T, is overshooting the set temperature T'sz'r, and step 20
Proceed to step 5.

In step 205, the change in Murotan Tr is ΔT14=T r
It is determined whether the slope of a T r n − + has been reversed, that is, has shifted from negative to positive or from positive to negative.

When the determination in step 205 is YES, STEP 20
Proceed to step 6, and the optimum opening SW of the air ξtx damper 60 is set to P.
I control equation (the differential term in equation 1 is determined, the room temperature T, is adjusted, and the process returns to step 200. On the other hand, when the determination in step 205 is NO, the process proceeds to step 207, PID control is performed, and step 200 Return to

The effects of this embodiment will be explained using FIG. 3, which shows a control characteristic diagram when the room temperature rises in the heater mode.

In the figure, curve a shows the characteristics of this embodiment, and curve b shows the characteristics of the conventional one.

If the room temperature T, has not risen to the setting 7MTsEt, that is, in state A, the determination at step 203 in FIG. 2 becomes No, and the room temperature is adjusted by normal PID control at step 207. In other words, P to include the differential term
The proportional gain of the ID control can be large, the room temperature can be controlled to rise sharply, and overshoot after reaching the set temperature can be suppressed.

In addition, in state B where the room temperature T, exceeds the setting '/HTsEr and overshoots, the determination in step 205 in FIG. 2 is No, and in step 207 the PI
D control is performed. Therefore, even if overshoot occurs, the overshoot is suppressed to a small level by the action of the differential term of PID control that attempts to suppress state changes, and its peak value is close to the set temperature, reducing passenger discomfort caused by overshoot. be able to.

In state C, where the overshoot peak point converges to the set temperature, the determination at step 205 in FIG. 2 is YES, and the room temperature is set to gJ1 by the PI control at step 206. In other words, temperature control is performed in a direction that eliminates the deviation between the room temperature and the set temperature due to the action of the integral term that tries to eliminate the deviation between the set temperature and the room temperature, and the differential term that tries to suppress the state change. Since the temperature does not include the room temperature, the time for convergence to the set temperature of the room temperature is shorter than that of the conventional method.

That is, as described above, in this embodiment, overshoot can be suppressed and even if overshoot occurs, the temperature can be quickly brought to the set temperature.

Conversely, even in the vent mode, undershoot can be similarly suppressed, and even if undershoot occurs, the temperature can be quickly converged to the set temperature.

In addition, in the above embodiment, in step 201, T,=T SE
For example, the room temperature Tr is determined as the set value T.
Whether it is within a predetermined range based on SET (TsE
r-α≦T,≦T. E, +α) may be determined.

Further, in the above embodiment, the control characteristics are shown as a control method for overshoot or undershoot at the beginning of startup of the vehicle air conditioner, but when the room aT is set at the set temperature T. This method can also be applied when the control characteristics fluctuate due to external disturbances even when T is stable. That is, when changing from a stable state, the fluctuation is suppressed by the differential term by PID control, and when attempting to return to a stable state, control is performed to quickly converge to a stable state by PI control that does not include a differential term.

Further, in the above embodiment, in order to control the indoor temperature to the set temperature, only the indoor temperature was detected, but as is known, the outside temperature. Evaporator outlet temperature, heater water temperature,
solar radiation. It can also be applied to systems that add compensation for air volume, etc.

In that case, the set temperature T527 in the above embodiment may be replaced with the target temperature T stt with the various compensations added above.

It is also applicable to control that does not include an integral term. This may be such that the controls in steps 206 and 207 in FIG. 2 are, for example, P control and PD control, respectively.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a vehicle air conditioner, Fig. 2 is a control flowchart showing an embodiment of the present invention, Fig. 3 is a diagram explaining control characteristics of the embodiment shown in Fig. 2, and Fig. 4 is a basic composition diagram of the present invention. l...Detection means, 2...Setting means, 3...Calculation means, 4...Adjustment means, 5...Discrimination means, 10...
Air duct, 13... Vehicle interior, 40... Evaporator, 50... Heater, 60... Air ξx damper,
61... Servo motor, 62... Rod, 90...
・Control circuit, 91...Inside temperature sensor. 92... Opening sensor. 93...Temperature setting device, 94...Mode setting device.

Claims (1)

[Scope of Claims] Detection means for detecting the actual air temperature in the vehicle interior, setting means for setting a target air temperature in the vehicle interior, and regarding the deviation between the actual air temperature and the target air temperature. , a vehicle comprising calculation means for calculating a control amount by a predetermined calculation process including at least proportional and differential calculations, and adjustment means for adjusting the amount of heat supplied to the passenger compartment in accordance with the calculation control amount by the calculation means. In an air conditioner for a vehicle, a determining means is provided for determining a state in which the actual air temperature in the vehicle interior approaches the target air temperature by the vehicle air conditioner, and when the determining means determines the approaching state, , wherein the calculation means calculates the control amount by a calculation process excluding the differential calculation in the predetermined calculation process.