JPS58177706A - Preventing method of misoperation in controller for vehicle air conditioning device - Google Patents

Abstract

PURPOSE:To prevent misoperation in an air conditioning device through a microcomputer, by handling memory data before a change as a regular preset temperature signal in case of the change in the memory data of RAM or the like when an interruption instruction is not given. CONSTITUTION:A signal H to an interruption instruction input terminal INT, that is, at off time of switches 2, 3, data of addresses D1, D2 in a memory unit 9 are arithmetically compared, if the decision is not equal, awrite of new data to the address D1 is stopped while the data of the address D2 is transferred to the address D1. In consequence, the data before a change is continuously output from the address D1, on the basis of the preceding data, an air mixing door or the like is controlled to display data contents by display devices 12, 13. In this way, in case of no interruption signal, the data in the address D1 should never be changed at normal time, here the data is compared to prevent misoperation. Thus the necessity for a complicated trouble is eliminated, and error control can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing malfunction of a control device for a vehicle air conditioner, and particularly to a control device using a central processing unit consisting of a computer.

Recently, the set temperature signal of the temperature setting section, the inside air temperature signal from the inside air temperature sensor, the outside air temperature signal from the outside air sensor, etc. are compared and calculated, and based on the overall signal obtained as a result of this calculation, the According to a set program, the opening of the air mix door that adjusts the mixing ratio of warm air and cold air, the rotation speed of the blower that introduces outside or inside air, and the operation of the compressor are automatically controlled. A central processing unit consisting of a microcomputer is increasingly being adopted as a device for performing this processing. This central processing unit receives the set temperature signal from the temperature setting section and stores it in a RAM (random access memory), and this stored data and
The internal air temperature signal and the external air temperature signal are compared, for example, subtracted, to calculate the above-mentioned overall signal. Further, the device causes the data display device to display data of the set temperature signal stored in the RAM. Therefore, the occupant can change the set temperature value by operating the temperature setting section while visually viewing the contents of this display device. That is, when the temperature setting section is operated, the stored data of the set temperature signal in the RAM is changed in accordance with the manipulated variable, the display contents of the display device that displays the stored contents are also changed, and the control variables of the air mix door etc. are also changed. It will be changed. Note that the central processing unit takes in the set temperature signal of the temperature setting section only when an interrupt command signal is given, and takes in and processes other signals at other times.

However, in the conventional vehicle air conditioner using the central processing unit mentioned above, the central processing unit malfunctions due to noise generated from control equipment such as motors, fluctuations in power supply voltage, etc., and an interrupt command signal is not given. The data stored in the RAM changes even though it is not changed, and the air mix door, compressor, blower, etc. are controlled by this changed data, making it impossible to perform proper air conditioning. The display device also displays this data, which has the disadvantage that the displayed content becomes data other than the set content.

Therefore, an object of the present invention is to handle the stored data before the change as a normal set temperature signal when the data stored in a storage device such as a RAM fluctuates when no interrupt command is given. This will be explained in detail using an example.

FIG. 1 is a block diagram showing an embodiment of the method for preventing malfunction of a control device for a vehicle air conditioner according to the present invention, and in the figure, 1 is a temperature setting section comprising an up switch 2 and a down switch 3. , an output signal S1 which becomes "0" when the up switch 2 is on is obtained from the connection point with the resistor 4, and this output signal 81 is sent via the resistor 5 to the central processing unit 60 (input capo) consisting of a microcomputer. 6a. Further, an output signal S2 which becomes "0" when the down switch 3 is on is obtained from the connection point with the resistor 7, and this output signal S2 is inputted to the input port via the resistor 8. When the output signal Bl is input, the arithmetic processing unit 6 sequentially increases the data corresponding to the set temperature signal while the output signal S is input,
This data is written to a predetermined address D of the storage device 9 consisting of RAM. Also, when the output signal S2 is input,
The above data is sequentially decreased and stored at address D of the storage device 9. Furthermore, when any data is written, it is inputted to the interrupt command input terminal NT in the address D and the other address D2 after a set time delay.
When both switches 2 and 3 are off, the output of the NAND circuit 10 becomes 10'', and the signals S, . . . S2 are not taken in. 11 is a noise absorbing capacitor.

The central processing unit 6 reads the data written in the address D1 of the storage device 9 and outputs it from the output ports A and B, and displays the middle digit display 12 and the first digit display 13.
This data and the inside air output from an inside air temperature sensor, an outside air temperature sensor, etc. (not shown) are displayed in decimal on the display device 30 consisting of the following.

It calculates the outside air temperature signal and outputs control signals for controlling the air mix door drive circuit 14, the compressor [movement circuit (electromagnetic crust drive circuit) 15, and the blower drive circuit 16] based on the overall signal calculated thereby. Capo) 0
．． Output from D and E.

Here, in the present invention, as shown in FIG. When the data at address D2 is compared with the data at address D2, and it is determined that the two data are not equal, writing of new data to address D of the storage device 9 is stopped, and the data at address D2 is transferred to address D, Move to.

Therefore, the data before the change in the address D of the storage device 9 continues to be output, the air mix door etc. are controlled based on the previous data, and the contents of the data are displayed on the displays 12 and 13. As described above, according to the present invention, if no interrupt command signal is input to the interrupt command input terminal NT, it is impossible for the data at address D1 to change during normal operation, and therefore the data at address D is changed to address D2. must be equal to the data in Therefore, the present invention performs the above comparison control to prevent malfunctions when no interrupt compensation is provided.

Note that due to fluctuations in the data at address D1, address D
The data at address D2 also changes, but since the data at address D2 is changed with a delay from the data at address D1, the data at address D2 changes at the time the data at address D1 changes.
Since the previous data is still written in 2, comparison control as in this embodiment can be performed. Therefore, according to the present invention, the air mix door and the like are not controlled by the new data that has changed, preventing malfunctions of these devices, and preventing incorrect data from being displayed.

Such an operation program for the central processing unit 6 is stored in advance in a ROM (read only memory), and the device 6 performs operations in accordance with this program. In addition,
Data not stored by the above operations will be lost.

As explained above, according to the present invention, when an interrupt command is given, the data of the set temperature signal from the temperature setting section is written into the storage device, the contents of the written data are displayed on the data display device, and In a vehicle air conditioning system consisting of a central processing unit that controls the opening degree of the air mix door based on this data, the previous data written in the storage device when no interrupt command is given, and the new data to be written. When it is determined that the two data are not equal, writing of the new data is stopped, the opening degree of the air mix door is controlled based on the data that has already been written, and the contents of the data are Since the data is displayed on the data display device, even if the written data fluctuates due to disturbances, it is possible to eliminate the disadvantages of incorrect control of the air mix door or the like and incorrect data being displayed on the data display device. Therefore, when incorrect data is displayed on the data display device, the driver does not have to go through the trouble of correcting the data by operating the temperature setting section, and safety during driving can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a method for preventing malfunction of a control device for a vehicle air conditioner according to the present invention, and FIG. 2 is a flowchart for explaining the present invention in detail. 1...Temperature setting section, 6...Central processing unit, 9.
...Storage device, 12.13...Display device, 14...Air mix door drive circuit, 15...Compressor drive circuit, 16...Prower drive circuit.

Claims (2)

[Claims] (1) A central processing unit that writes the data of the set temperature signal corresponding to the operation amount of the temperature setting unit into the storage device when an interrupt command is given, reads out the contents of this written data, and displays it on the data display device. In a vehicle air conditioner equipped with this device, when an interrupt command is not given, new data written to the storage device is compared with data written before this data is written, and both data are compared. A method for preventing malfunction of an air conditioner for a vehicle, characterized in that when the data is not equal, the previous data is displayed on a data display device. (2) The central processing unit controls an air mix door drive circuit, a blower drive circuit for introducing inside air and outside air, and a compressor drive circuit that constitute a vehicle air conditioner based on data read from the storage device. A method for preventing malfunction of a control device for a vehicle air conditioner as described above.