JP2844891B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device in which a detection signal from a single sensor is shared by two control units.

B. Conventional Technology An air conditioner that controls air conditioning in a vehicle cabin based on a signal from a water temperature sensor that detects an engine cooling water temperature is known (see Nissan New Model Manual U12-2 (October 1989)). .

For this water temperature sensor, a thermal transmitter whose resistance changes in proportion to the ambient temperature is used. As shown in FIG. 9, a power supply Vb is supplied to this water temperature sensor Th1 via a resistor R1 from a combination meter 1 containing various instruments of a vehicle provided on a dashboard, and a resistance value of the water temperature sensor TH1 is provided. Is converted into a voltage value proportional to the cooling water temperature. The voltage signal indicating the cooling water temperature is
It is supplied to a water temperature meter M1 in the combination meter 1 and an air conditioning control circuit 2 for controlling air conditioning in the vehicle compartment. The water temperature meter M1 displays the temperature of the cooling water of the engine according to this signal, and the air conditioning control circuit 2 performs the low water temperature activation control of the blower fan based on the cooling water temperature signal. That is, when the engine cooling water temperature is about 50 ° C. or less, the blower fan is turned off for a predetermined time, and after a predetermined time when the cooling water temperature rises, the blower fan is started to gradually increase the air volume, and suddenly when the cooling water temperature is low. Prevent cold air from blowing into the cabin. Therefore, the cooling water temperature signal becomes unnecessary for the air conditioning control circuit 2 after the cooling water temperature reaches 50 ° C. after the start of the engine.

C. Problems to be Solved by the Invention However, in the above-described conventional apparatus, when an abnormality occurs in the air conditioning control circuit 2, for example, the resistance value of the signal input circuit decreases, and an abnormal current flows from the power supply Vb to the air conditioning control circuit 2. If the water temperature flows into or the abnormal voltage is applied to the water temperature signal line L1 from the air conditioning control circuit 2, there is a problem that an error occurs in the water temperature display of the water temperature meter M1 sharing the water temperature signal of the water temperature sensor Th1.

An object of the present invention is to, when a detection signal of a single sensor is shared by a plurality of control units, an input circuit of the detection signal is cut off when the detection signal exceeds a valid condition range for the control unit, It is an object of the present invention to provide a vehicle control device which does not affect other control units when an abnormality occurs.

D. Means for Solving the Problems The present invention will be described with reference to FIG. 1 which is a claim correspondence diagram. According to the invention of claim 1, the detection signal of a single sensor 201 is transmitted to a plurality of control units 202A and 202B. A first control unit 202A that is applied to a shared vehicle control device and controls a control target using a signal in a predetermined range among detection signals output from the sensor 201; and a sensor 201 and a first control unit 202A. The above-described object is achieved by providing a shut-off unit 203 provided between the first control unit 202A and the first control unit 202A when the detection signal is out of the predetermined range.

Further, in the vehicle control device according to claim 2, the first control unit 202A is a vehicle air conditioner, the sensor 201 is a water temperature sensor for detecting an engine cooling water temperature,
The 203 shuts off the engine coolant temperature signal from the vehicle air conditioner 202A when the vehicle air conditioner 202A detects that the engine coolant temperature signal exceeds a predetermined value.

E. Operation The shutoff means 203 shuts off the detection signal output from the sensor 201 to the first control unit 202A when the detection signal from the sensor 201 is out of the predetermined range.

Further, the shut-off means 203 of the vehicle control device of claim 2 is
When the vehicle air conditioner 202A, which is the first control unit, detects that the detection signal from the water temperature sensor 201 for detecting the engine coolant temperature exceeds a predetermined value, the detection signal is cut off from the vehicle air conditioner 202A. I do.

F. Embodiment FIG. 2 is a block diagram showing the overall configuration of an embodiment in which the vehicle control device according to the present invention is applied to an air conditioner.
It should be noted that the same components as those in FIG. 9 showing the conventional example are denoted by the same reference numerals, and the description will focus on the differences.

In this embodiment, a case will be described in which the water temperature signal from the above-described water temperature sensor Th1 is shared by the vehicle air conditioner 10, the combination meter 1, and the engine control circuit 11.

The vehicle air conditioner 10 has a water temperature signal of 50 ° C. as described above.
The low water temperature start control of the blower fan is performed in the following cases. Therefore, when the water temperature exceeds 50 ° C., this water temperature signal becomes unnecessary, and the water temperature signal line L1 is cut off as described later. Also,
The engine control circuit 11 performs well-known ignition control, fuel injection control, and the like based on the water temperature signal. At this time, 90 ℃
High accuracy is required for the above water temperature signal. Further, the combination meter 1 displays the temperature of the cooling water of the engine with the water temperature meter M1 based on the water temperature signal as described above. Usually, the temperature range in which the display accuracy of the water thermometer M1 is required is about 70 ° C. or more.

As shown in FIG. 2, a vehicle air conditioner 10 according to the present invention includes a variable displacement compressor 13 driven by an engine 12, a condenser 14, an evaporator 15, a liquid tank 16,
Cooling unit of compression refrigeration cycle consisting of expansion valve 17
It has 100. When the suction pressure Ps exceeds the set pressure Pr, the variable displacement compressor 13 increases the inclination angle to increase the refrigerant discharge capacity.The set pressure Pr is controlled by the solenoid current Isol supplied from the air conditioning control circuit 18. Controlled. Further, the evaporator 15 is provided with an outside air inlet 19a.
In addition, it is disposed in an air conditioning duct 19 having an inside air inlet 19b.

Each of the inlets 19a and 19b is provided with an inside / outside air switching door 20 for controlling the flow rate of air introduced into the air conditioning duct 19. Furthermore, as is well known, a blower fan
21, a heater unit 22, and an air mix door 23 are provided, and a vent door 24 and a foot door 25 for adjusting the amount of air blown out from a vent outlet 19c and a foot outlet 19d provided in the air conditioning duct 19 are provided. Also,
A defroster door 26 is provided at a defroster outlet 19e provided in the air conditioning duct 19.

The air-conditioning control circuit 18 includes a microcomputer and its peripheral parts, executes a control program described later to control the air-conditioning of the vehicle interior, and when the temperature of the engine cooling water exceeds 50 ° C. When an abnormality is detected in 10, the transistor Tr1 is turned off to shut off the water temperature signal line L1. The air-conditioning control circuit 18 has a water temperature sensor Th1 for detecting an engine cooling water temperature Tw, an outside air temperature T
Outside temperature sensor Th2 for detecting amb, inside temperature sensor Th3 for detecting vehicle interior temperature Tinc, solar sensor Pd1 for detecting solar radiation Qsun, suction temperature for detecting air temperature downstream of the evaporator (hereinafter referred to as suction temperature) Tint Sensor Th4, expansion valve 17
A refrigerant temperature sensor Th5, which is provided on the outlet side of the tube, and detects a refrigerant temperature Tref, and an air mix door opening sensor PBR, which detects the opening of the air mixing door, are connected to each other. Information is entered. The air conditioning control circuit 18 includes an air conditioner switch SW.
1. The blower fan switch SW2, the temperature setting switch SW3 for setting the set temperature Tptc, the ignition switch SW4, the defroster switch SW5, and the economy switch SW6 are also connected.

Further, the air conditioning control circuit 18 includes various actuators such as an intake door actuator, an air mix door actuator, a vent door actuator, a foot door actuator, and a defroster door actuator.
The blower fan control circuit 27 is connected to the blower fan control circuit 27, and the blower fan 21 is connected to the blower fan control circuit 27. Further, a solenoid control valve (not shown) of the above-described variable displacement compressor 13 is connected.

FIGS. 3A to 3D are flowcharts showing a control program executed by the air-conditioning control circuit 18. FIG. The operation of the air conditioner will be described with reference to this flowchart.

In step S1, various control parameters used in this control program are initialized. In the normal auto mode, for example, set temperature Tptc to 25 ℃,
Initially set the engine cooling water temperature Tw to 25 ° C. Step S2
Then, various information is input from each sensor.

Next, in step S3, the outside air temperature Tamb obtained from the outside air temperature sensor Th2 is processed to a value Tamb 'corresponding to the actual outside air temperature, excluding the influence from other heat sources. Steps
In S4, the solar radiation amount information as the amount of light from the solar radiation sensor Pd1 is processed into a value Qsun 'as a heat amount suitable for subsequent conversion. In step S5, a value obtained by correcting the set temperature Tptc set by the temperature setting switch SW3 according to the outside air temperature Tamb.
Process to Tptc '.

In step S6, for example, Tptc ', Tinc, Tamb', and Qsu by the method disclosed in JP-A-63-81995.
The target outlet temperature T0 is calculated based on n ′, and the opening X of the air mix door is calculated according to the deviation between the target outlet temperature T0 and the suction temperature Tint. Next steps
In S7, the variable displacement compressor 13 is controlled as follows. That is, as shown in FIG.
Classified into control zones A to D according to mb ', and as shown in FIG. 4 (b), according to the setting state of the air conditioner switch SW1, the defroster switch SW5, and the economy switch SW6, a well-known state is set according to each control zone. Various compressor controls are performed.

Next, in step S8, outlet control is performed. That is, in the normal auto air conditioner mode, the outlet is selected as shown in FIG. 5 according to the target outlet temperature T0 calculated in step S6. Further, in step S9,
Perform suction port control. That is, in the normal auto air-conditioning mode, outside air is always introduced when the compressor 13 is turned off, and when the compressor 13 is turned on, the sixth air is supplied according to the air mix door opening X calculated in step S6. Select the inlet as shown.

Next, from step S10 in FIG. 3 (b) to FIG. 3 (d)
In step S31, the air volume of the blower fan 21 is controlled.

First, in step S10, it is determined whether or not the blower fan switch SW2 is turned off. If the blower fan switch SW2 is turned off, the process proceeds to step S11 to stop the blower fan 21 and proceeds to step S32. If the blower fan switch SW2 is turned on, the process proceeds to step S12 to turn on the transistor Tr1 so that the engine cooling water temperature signal can be input to the air conditioning control circuit 18. In the following step S13, it is determined whether or not the mode is the auto mode, and if it is the auto mode, the process proceeds to step S16,
If the mode is the manual mode, the process proceeds to step S14. In step S14, since the water temperature signal is unnecessary in the manual mode, the transistor Tr1 is turned off.
Then, the blower fan 21 is driven by outputting a fan voltage corresponding to the fan speed set by the blower fan switch SW2. Thereafter, the process proceeds to step S32.

At step S16, it is determined whether or not the defroster switch SW5 is turned on.
Proceed to step 5, otherwise proceed to step S17. Steps
In S17, it is determined whether or not the vent outlet 19c is selected. If the vent is being discharged, the process proceeds to step S23, and if not, the process proceeds to step S18. In step S18, it is determined whether or not the engine cooling water temperature exceeds 50 ° C. If it has, the process proceeds to step S22; otherwise, the process proceeds to step S19. Further, in step S19, it is determined whether or not the target blowout temperature T0 calculated in the above step is lower than the predetermined temperature K1, and if it is lower, the process proceeds to step S20 to perform low water temperature start control; otherwise, the process proceeds to step S24. Start air volume control is performed. Note that the predetermined temperature K1 may be set to a temperature at which the occupant does not feel cold even when the blower fan 21 is activated when the engine coolant temperature is 50 ° C. or lower.

When the low water temperature start control is selected, in step S20, the start delay time t1 of the blower fan 21 corresponding to the target blow temperature T0.
In the following step S21, the blower fan 21 is started after the start is delayed by the start delay time t1, and the blower fan 21 is gradually accelerated to a speed at which the target air volume can be obtained.
Thereby, the cold air does not blow out from the outlet and does not give the occupant any discomfort. After performing the low water temperature start control in step S21, the process proceeds to step S32.

If it is determined in step S18 that the water temperature Tw exceeds 50 ° C., the transistor Tr1 is turned off and the water temperature signal input circuit is shut off in step S22 because the water temperature signal is unnecessary. Next, proceeding to step S23, it is determined whether or not the startup has been completed up to the fan speed at which the target air volume can be obtained by the low water temperature startup control or the startup air volume control described later. Is performed, and if the activation is completed, the process proceeds to step S25.

When the starting air volume control is selected, the fan voltage applied to the motor of the blower fan 21 is gradually increased in step S24, and the blower fan 21 is accelerated until the target air volume is reached. Thereby, the feeling at the time of starting the fan is improved.

Next, after turning off the transistor Tr1 in step S25,
Proceeding to step S26, a constant for air volume control described later is set. Next, in step S27, it is determined whether or not venting is being performed. If venting is being performed, the process proceeds to step S28, and if not, step S28 is skipped. In step S28, the control parameter β is calculated according to the amount of solar radiation Qsun ', and in the following step S29, the fan voltage Vf is calculated from the target blowing temperature T0, the parameter β, and the constants L, M, N, P. Further, in step S30, a control parameter α is calculated in accordance with the outside air temperature Tamb ', and in step S31,
The fan voltage Vf 'for obtaining the target air volume is calculated from the fan voltage Vf and the control parameters α and β. Then, the voltage Vf ′ is applied to the motor of the blower fan 21 to drive the blower fan 21.

When the above air volume control is completed, the process proceeds to step S32, where abnormalities of the control signal input circuit, abnormalities of the sensor itself, disconnection of the signal line, and the like are diagnosed with respect to control signals from important external devices. That is, for example, as shown in FIG. 7, an abnormality determination criterion is provided for each control signal, and if these reference values are exceeded, it is determined that there is an abnormality. In the following step S33,
As a result of the self-diagnosis, if the device is normal, the process returns to step S2, and if there is an abnormality, the process proceeds to step S34. In step S34, the transistor Tr1 is turned off to cut off the input circuit of the water temperature signal, thereby preventing the combination meter 1 and the engine control circuit 11, which share the water temperature signal, from being externally affected. In the following step S35, after turning off the auto mode of the air conditioner 10, the abnormal part is displayed on a display (not shown). Then, returning to step S2, the operation of the air conditioner is continued in the manual mode.

The operating states of the transistor Tr1 described above are summarized and shown in FIG.

As described above, the transistor Tr1 for interrupting the circuit is provided in the input circuit of the water temperature signal, and when this water temperature signal exceeds a signal level range effective for the air conditioner, that is, 50 ° C.,
Alternatively, when an air conditioner malfunctions, the transistor Tr1 is turned off to shut off the circuit, so that even if the air conditioner malfunctions, the water temperature meter M1 and the engine control circuit 11, which share the water temperature signal, are not affected, and these external devices are not affected. Operational accuracy and reliability of the device can be ensured.

In the above-described embodiment, an example in which the water temperature signal from the water temperature sensor Th1 is shared with another control unit has been described. However, the detection signal is not limited to the water temperature signal, and the present invention is not limited thereto. Can be applied. Further, the present invention can be applied to a vehicle control device in which a detection signal of a sensor is once input to another control unit and processed, and the processed signal is input to a control unit such as an air conditioner.

In the configuration of the above embodiment, the water temperature sensor Th1 is the sensor 201, the vehicle air conditioner 10 is the first control unit,
The transistors Tr1 constitute the blocking means 203, respectively.

G. Effects of the Invention As described above, according to the invention of claim 1, after the detection signal of the sensor is out of the predetermined range and becomes unnecessary in the first control unit, the sensor is switched from the first control circuit. Even if an abnormality occurs in the first control unit due to interruption, no disturbance is given to the detection signal of the sensor due to the abnormality.
Influence on other control units sharing the detection signal of the sensor is prevented.

In the second aspect, when the engine cooling water temperature from a water temperature sensor shared with another control unit exceeds a predetermined value, the water temperature signal is cut off from the vehicle air conditioner. However, other control units can continue to operate without any influence, and the reliability is improved.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims. FIG. 2 is a block diagram showing the overall configuration of the embodiment, FIGS. 3 (a) to 3 (d) are flowcharts showing an air conditioning control program, FIG. 4 (a) is a diagram showing control zones in compressor control, FIG. FIG. (B) shows the control contents for each control zone, FIG. 5 shows the outlet determined according to the target outlet temperature, and FIG. 6 determines the air mix door opening. FIG. 7 is a diagram showing an introduction state of outside air and inside air, FIG. 7 is a diagram showing abnormality determination criteria for various control signals,
FIG. 8 is a diagram showing an operation of a transistor for interrupting an input circuit, and FIG. 9 is a diagram showing a conventional example in which a water temperature signal from a water temperature sensor is shared by an air conditioning control device and a combination meter. 1: Combination meter 10: Vehicle air conditioner 11: Engine control circuit, 18: Air conditioning control circuit Tr1: Transistor, L1: Water temperature signal line Th1: Water temperature sensor, 201: Sensor 202A: First control unit (vehicle air conditioner 202B: Other control unit 203: Shut-off means

Claims (2)

(57) [Claims] 1. A vehicle control device in which a detection signal of a single sensor is shared by a plurality of control units, wherein a control target is controlled using a signal in a predetermined range among the detection signals output from the sensor. 1 control unit, and is provided between the sensor and the first control unit, and cuts off the detection signal output from the sensor to the first control unit when the detection signal is out of the predetermined range. A control device for a vehicle, comprising: 2. The vehicle control device according to claim 1, wherein said first control unit is a vehicle air conditioner, said sensor is a water temperature sensor for detecting engine coolant temperature, and said shutoff means is A vehicle control device, wherein when the vehicle air conditioner detects that the engine coolant temperature signal exceeds a predetermined value, the engine coolant temperature signal is cut off from the vehicle air conditioner.