JPH09242864A - Electronic controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make common ECU and reduce the kinds of type by providing it with a first control program for the kind or specification of vehicle to which an actuator is connected and a second program requiring no connection thereof, and selecting one of the programs according to the signals from a self diagnosis input circuit. SOLUTION: A microcomputer 81 performs the self diagnosis of transfer clutch drive circuit 83, and based on the result, an ECU 80 itself determines whether the application is made to an automatic transmission for two-wheel drive or to an automatic transmission for four-wheel drive. By use of the shift control program corresponding to the type of automatic transmission, an optimum shift stage is calculated. A self diagnosis input circuit 84 detects that a drive circuit 83 is abnormal when the voltage on the side of collector is at high level even if the output voltage to the base of a transister 83a from a microcomputer 81. Accordingly, the common use of ECU to the vehicles with or without a specified actuator is made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control unit for a vehicle, and more particularly to an electronic control unit for a vehicle configured to be shared even if it has different control functions depending on vehicle types or specifications. is there.

[0002]

2. Description of the Related Art Generally, an electronic control unit (ECU) for various controls in a vehicle is designed separately for each vehicle type. Further, even in the same vehicle model, the control content is often different due to the difference in specifications. Therefore, the number of ECUs has tended to increase in a matrix by the number of vehicle types and the number of specifications.

In view of such a tendency, various attempts have hitherto been made to reduce the production cost by reducing the types of ECUs with respect to the number of vehicle types and specifications. For example, in Japanese Unexamined Patent Publication (Kokai) No. 5-85284, two input ports for function switching are specially provided in an ECU having all the functions corresponding to a plurality of vehicle types or specifications, and a wire harness connected to the two input ports is provided. Internally, both ports are selectively placed in an open state or a short state so that an ECU function suitable for a vehicle type or specifications can be selected.

Japanese Patent Laid-Open No. 4-36048 discloses that
Control programs and control data common to all vehicle types or specifications are configured by a non-rewritable memory such as a mask ROM, and control programs and control data different for each vehicle type or specifications are stored in EEPROM or flash ROM.
There is disclosed a method in which a microcomputer is made common by being configured with a rewritable memory such as, and the cost is reduced by applying a single microcomputer to many vehicle types or specifications.

[0005]

However, although such a conventional technique can achieve the object of reducing the number of ECUs, it is necessary to add special parts, circuits, etc. for achieving the object. , No drastic cost reduction. Particularly, in the former example, although the number of ECUs can be reduced, the number of vehicle harnesses increases and E
The identification input circuit must be additionally configured in the CU, which causes a problem of cost increase. On the other hand, in the latter example, adding a rewritable memory to the ECU causes a cost increase. Furthermore, in order to effectively reduce the number of ECUs, after mounting the ECU on the vehicle or immediately before mounting the ECU,
It is necessary to write the control program and control data according to the vehicle type or specifications in the rewritable memory,
There is a problem in that the cost of equipment or equipment for that purpose is high.

In view of the above circumstances, the present invention diverts the existing configuration to a plurality of vehicle types or specifications that require different control functions without adding or using special parts, circuits, equipment, or the like. The purpose is to drastically reduce the production cost by making the ECU common and reducing the model number.

[0007]

In order to solve the above problems and achieve the object of the present application, an electronic control unit for a vehicle of the present invention is an electronic control unit for controlling a vehicle according to various parameters, and an electronic control unit. The electronic control unit comprises an actuator connected to the output terminal of the unit,
A microcomputer, a drive circuit for giving a signal for driving an actuator to an output terminal of the electronic control unit according to an output signal of the microcomputer, and a microcomputer connected to monitor the signal provided to the output terminal of the electronic control unit. In the vehicular electronic control device including the self-diagnosis input circuit, the actuator is selectively connected to the output terminal of the electronic control unit according to the vehicle type or the specification, and the microcomputer is at least connected to the vehicle type or the actuator. It has a first control program for specifications and a second control program for vehicle models or specifications to which the actuator is not connected, and the microcomputer connects the actuator to the electronic control unit according to the signal from the self-diagnosis input circuit. Been It is configured to control the vehicle by selecting the first control program when it is determined that it is connected, and the second control program when it is determined that it is not connected. ing.

Therefore, the vehicle type or the specification in which the vehicle in which the ECU is mounted uses a certain actuator to perform the control using the monitoring result of the existing self-diagnosis input circuit without adding a new circuit or device. Whether or not there is is easily determined, and the control program is appropriately selected according to the determination result. That is, the ECU can be shared by a vehicle equipped with a specific control actuator and a vehicle not equipped with it, and the ECU model can be reduced to reduce the production cost.

Further, the present invention is applied to share the ECU for controlling the shift of the automatic transmission among a plurality of vehicle types or specifications. Particularly, in an automatic transmission in which a transfer clutch for four-wheel drive can be selectively incorporated, the ECU is applied by detecting whether or not a control solenoid for operating the transfer clutch is connected to the ECU. It is determined whether an automatic transmission for a two-wheel drive vehicle or an automatic transmission for a four-wheel drive vehicle incorporating a transfer clutch is selected, and an appropriate automatic transmission control program corresponding to each is selected. is there.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5, an example in which the present invention is applied to the sharing of an electronic control unit for an automatic transmission will be described. In particular, the electronic control unit for automatic transmission that incorporates the control of the transfer clutch that enables four-wheel drive can also be applied as the electronic control unit for automatic transmission in a two-wheel drive vehicle that does not have a transfer clutch. The case will be described. Although FIG. 2 shows an automatic transmission for a four-wheel drive vehicle, since it includes all the essential components of an automatic transmission for a two-wheel drive vehicle, the present invention is provided for convenience. A detailed configuration of both automatic transmissions will be described with reference to the drawings.

First, in FIG. 2, reference numeral 1 indicates a torque converter case of an automatic transmission, and reference numeral 2 indicates a differential case. The transmission case 3 is joined to the rear ends of the torque converter case 1 and the differential case 2, and the transfer case 4 is joined to the rear ends of the transmission case 3. An oil pan 5 is attached to the lower part of the transmission case 3.

Reference numeral 10 is an engine, and a crankshaft 11 of the engine 10 is connected to a torque converter 13 provided with a lockup clutch 12 arranged in the Turkish converter case 1. Torque converter 13
The power of the engine 1 is transmitted to the input shaft 14 of the automatic transmission mechanism 30 arranged in the transmission case 3. The power transmitted to the input shaft 14 is shifted by the automatic transmission mechanism 30, and then the output shaft 15 outputs a pair of reduction gears 17 arranged in the transfer case 4.
18 and is further transmitted from the front drive shaft 16 arranged in parallel to the input shaft 14 and the output shaft 15 to the front wheels via the front differential device 19.

Further, only in the case of an automatic transmission of a four-wheel drive vehicle, a transfer clutch 51 composed of a hydraulic multi-plate clutch is connected to the rear stage of the reduction gear 17,
By selectively energizing the hydraulic pressure in accordance with a transfer clutch control signal from an electronic control unit (ECU) 80 described later, the power transmission path is selectively connected and released. The power of the engine via the transfer clutch 51 is configured to be transmitted from the rear drive shaft 20 to the rear wheels via the propeller shaft 21 and the rear differential device 22, which enables four-wheel drive.

The automatic transmission mechanism for a two-wheel drive vehicle and an automatic transmission for a four-wheel drive vehicle have the same structure. In the automatic transmission mechanism 30, first, the input shaft 14 is the sun gear 3 of the rear planetary gear 32.
2a, the ring gear 31 of the front planetary gear 31
b and the carrier 32c of the rear planetary gear 32 are connected to the output shaft 15. A first one-way clutch 34 and a forward clutch 35 are provided in series between the coupling element 33 and the ring gear 32b that are integral with the carrier 31c of the front planetary gear 31, and the coupling element 33 and the case side that is a fixing member are provided. A second one-way clutch 36 and a low reverse brake 37 are provided in parallel between and. An overrunning clutch 38 is bypassed between the connecting element 33 and the ring gear 32b. A band brake 40 is provided on the connecting element 39 integrated with the sun gear 31a, and a high clutch 43 is provided between the connecting element 41 integrated with the input shaft 14 and the connecting element 42 integrated with the carrier 31c. Is provided. Furthermore, the connecting element 3
A reverse clutch 44 is provided between 9 and 41.

In the automatic transmission mechanism 30, the forward clutch 35, the low reverse brake 37, the overrunning clutch 38, the band brake 40, the high clutch 43, the reverse clutch 44, and the hydraulic pressure generated by the hydraulic control unit 46 having various valves are used. To selectively connect and release. As a result, the gear ratio determined by the operating states of the front planetary gears 31 and the rear planetary gears 32 changes, and four forward gears and one reverse gear are performed. The shift operation in the automatic transmission mechanism 30 is achieved by selectively driving the solenoid group 47 in the hydraulic control unit 46 by a shift control signal from the ECU 80 to operate various valves.

On the other hand, as shown in FIG. 3, the hydraulic control unit 46 in the automatic transmission for a four-wheel drive vehicle includes a pilot valve 48 for variably adjusting the transfer clutch pressure acting on the transfer clutch 51 and a transfer control valve. 49 and 4WD solenoids 50 are provided. The line pressure adjusted from the discharge pressure of the oil pump 45 by a line pressure adjusting valve (not shown) to an appropriate pressure according to the traveling state is adjusted by the pilot valve 48 to a constant pilot pressure. ECU 8 described later
The pilot pressure is adjusted to a transferee pressure by a 4WD solenoid 50 as an actuator whose duty is controlled by 0 depending on the traveling state. Both the line pressure and the transfer duty pressure are guided to the transfer control valve 49, and this line pressure is converted into a transfer clutch pressure by the action of the transfer duty pressure and acts on the transfer clutch 51. Thus, the 4WD controlled by the ECU 80
By adjusting the transfer clutch pressure to an arbitrary value in accordance with the ratio between the ON state and the OFF state of the solenoid 50, that is, the magnitude of the duty ratio, the engaging force of the transfer clutch 51, in other words, the torque to the rear wheels. The distribution is continuously and variably controlled.

Next, the structure of the ECU 80 will be described. The ECU 80 mainly includes a CPU, RA (not shown).
M, a backup RAM, a ROM 810 and the like, and a shift control solenoid group 47 according to the control output of the microcomputer 81 and the microcomputer 81.
Drive circuit 82 for individually driving the transfer clutch drive circuit 83 for transmitting a drive signal to the 4WD solenoid 50 as an actuator for operating the transfer clutch 51 for a four-wheel drive vehicle, and a self-diagnosis of the transfer clutch drive signal in the microcomputer 81. A self-diagnosis input circuit 84 and a lamp drive circuit 85 for driving the indicator lamp 52 for indicating whether the ECU 80 is applied to the automatic transmission for two-wheel drive vehicle or the automatic transmission for four-wheel drive vehicle are provided. There is.

The microcomputer 81 performs self-diagnosis of the transfer clutch drive circuit 83, and based on the result, whether the ECU 80 itself is applied to an automatic transmission for two-wheel drive or an automatic transmission for four-wheel drive. Determine if it is applied. Then, a shift control program corresponding to the determined type of automatic transmission is used to calculate the optimum shift speed according to various engine operating parameters and vehicle running parameters. The microcomputer 81 outputs a shift signal to the solenoid group 47 via the drive circuit 82 in order to obtain the calculated shift speed.

Further, when the microcomputer 81 determines that the ECU 80 is applied to an automatic transmission for four-wheel drive, it executes a transfer clutch control program to control the engagement state of the transfer clutch 51. . First, the microcomputer 81 calculates the optimum fastening force of the transfer clutch 51 according to various engine operating parameters and vehicle running parameters, that is, the optimum torque distribution to the rear wheels. And the duty ratio (ON / OFF ratio) required to obtain this optimum fastening force
A duty signal (ON / OFF) having the above is output from the output port 81a to the transfer clutch drive circuit 83.

The transfer clutch drive circuit 83 is a PN
A P-type transistor 83a is provided, the base of which is connected to the output port 81a of the microcomputer 81 via the resistor 83b. Also, the transistor 83
The collector of a is connected to the output terminal 80a of the ECU 80, and the emitter is grounded. Therefore, this ECU
When the 80 is applied to an automatic transmission for a four-wheel drive vehicle, the 4WD solenoid 50 is connected to the output terminal 80a of the ECU 80.
Is connected in series with a 12V power supply, and the duty signal from the microcomputer 81 is turned on to output port 81a.
When the output voltage at is high level (5 V), the transistor 83a is turned on and the 4WD solenoid 50 is energized. On the other hand, when the duty signal is OFF, output port 8
When the output voltage at 1a is low level (0V), the transistor 83a is turned off and the 4WD solenoid 50 is de-energized. When the ECU 80 is applied to an automatic transmission for a two-wheel drive vehicle, since the 4WD solenoid 50 is not used, the output terminal 80a is naturally used.
Is open with no connection.

On the other hand, in the self-diagnosis input circuit 84,
Transistor 83 of transfer clutch drive circuit 83
The voltage on the collector side of a is adjusted in level by the resistors 84a and 84b and stabilized by the Zener diode 84c, and then the input port 81 of the microcomputer 81.
given to b. The microcomputer 81 diagnoses the transfer clutch drive circuit 83 by a self-diagnosis program described later. Specifically, when the output voltage from the microcomputer 81 to the base of the transistor 83a is at a high level (5V) and the collector side voltage detected by the self-diagnosis input circuit 84 is at a low level (0V), or When the output voltage to the base of the transistor 83a is low level (0V) and the collector side voltage detected by the self-diagnosis input circuit 84 is high level (5V), the drive circuit 83 is determined to be normal. . Further, when the output voltage from the microcomputer 81 to the base of the transistor 83a is at high level (5V), but the collector side voltage is at high level (5V), the drive circuit 83 determines that it is abnormal. The self-diagnosis program also determines whether or not the 4WD solenoid 50 is connected to the ECU 80, which is required for the purpose of sharing the ECU 80 according to the present invention. That is, when the output voltage from the microcomputer 81 to the base of the transistor 83a is low level (0V) and the collector side voltage is low level (5V), the 4WD solenoid 50 is connected to the output terminal 80a of the ECU 80. If not, it is determined that the output terminal is open.

On the other hand, the lamp drive circuit 85 includes a PNP type transistor 85a. The transistor 85a is
The output port 8 of the microcomputer 81
It is turned on when a high level signal from 1c is given, and the indicator lamp 52 connected to its collector via the output terminal 80b of the ECU 80 is turned on. In addition,
When the ECU 80 is applied to an automatic transmission for a four-wheel drive vehicle, the display lamp 52 is turned on when the driver presses the 2WD switch provided in the vehicle compartment to force the two-wheel drive state. It may be replaced by a 2WD lamp.

Since the ECU 80 of the present invention can be shared by an automatic transmission for a two-wheel drive vehicle and an automatic transmission for a four-wheel drive vehicle, the ROM 810 of the microcomputer 81 stores both automatic transmissions. In addition to the gear shift control program commonly used in the vehicle, the gear shift control program not commonly used and the transfer clutch 5 used only in the automatic transmission for a four-wheel drive vehicle
All necessary programs for both sides, such as one control program, are stored in advance.

Next, referring to the flow charts shown in FIGS. 4 and 5, the 2WD executed to share the ECU 80 between the two-wheel drive automatic transmission and the four-wheel drive automatic transmission. The / 4WD identification program will be described.
FIG. 4 shows a self-diagnosis program of a transfer clutch drive signal which is executed at predetermined time intervals after a key switch (not shown) is turned on and the microcomputer 81 is initialized, and FIG. 5 is executed by utilizing the self-diagnosis result. 2W
9 shows a D / 4WD identification program. Note that these self-diagnosis program and 2WD / 4WD identification program are EC
It is stored in the ROM 810 of the U80.

First, in step S100 of the self-diagnosis program shown in FIG. 4, the output port 8 of the microcomputer 81 for controlling the driving of the 4WD solenoid 50.
The signal output from 1a is checked. In the case of an automatic transmission of a four-wheel drive vehicle, the 4WD solenoid 50 is duty-controlled as described above, and the microcomputer 8
A high level (5V) that turns on the transistor 83a and energizes the 4WD solenoid 50 at the output port 81a of 1
And a low level (0V) voltage that turns off the transistor 83a and deenergizes the 4WD solenoid 50 are alternately energized. Therefore, when the ECU 80 is used in an automatic transmission for a four-wheel drive vehicle and when the high level voltage of the duty signal is applied to the output port 81a, the process proceeds to step S101 and the self-diagnosis input circuit 84 to the input port 81 of the microcomputer 81
The level of the signal applied to b is checked. Here, when the voltage on the collector side of the transistor 83a of the transfer clutch drive circuit 83 applied to the input port 81b is at the low level, the transistor 83a is normally turned on and the 4WD solenoid 50 is driven in step S102. Determine that On the other hand, if the collector side voltage is at high level, step S10
In FIG. 3, although the signal for turning on the transistor 83a is output, since it is not actually turned on, it is determined that the drive circuit 83 is in failure.

On the other hand, in step S100, the ECU
When 80 is used in an automatic transmission for a four-wheel drive vehicle and when the low level voltage of the duty signal is applied to the output port 81a, or the ECU 80
Is used in an automatic transmission for a two-wheel drive vehicle, the program proceeds to step S104 and step S101.
Similarly, the level of the signal applied from the self-diagnosis input circuit 84 to the input port 81b of the microcomputer 81 is checked. Here, when the voltage on the collector side of the transistor 83a of the transfer clutch drive circuit 83, which is applied to the input port 81b, is at the high level, the transistor 83a is turned off in step S102, and the power supply voltage is supplied via the 4WD solenoid 50. It is detected and judged to be normal. On the other hand, when the voltage on the collector side is low level, it is determined in step S105 that the output terminal 80a of the ECU 80 is not connected to the 4WD solenoid 50 and the power source, that is, the output terminal is open.

Next, the two-wheel drive / four-wheel drive identification program will be described with reference to FIG. First, step S200
Then, in the self-diagnosis program of the transfer clutch drive signal shown in FIG. 5, the output terminal 8 of the ECU 80 is
It is determined whether it is determined that the 4WD solenoid 50 is not connected to 0a and the output terminal is open. If it is determined that the output terminal is open, it is determined in step S201 that the ECU 80 is used as an automatic transmission ECU for a two-wheel drive vehicle, and thereafter, in step S202, the two-wheel drive vehicle is operated. The control program necessary for controlling the automatic transmission for vehicle is selected, and in step S203, the 2WD in the vehicle compartment is selected.
Turn on the lamp. On the other hand, if it is not determined that the output terminal is open, in step S204, it is determined that the ECU 80 is used as the automatic transmission ECU for the four-wheel drive vehicle, and thereafter in step S205, the ECU 80 is used for the four-wheel drive vehicle. The control program necessary for controlling the automatic transmission and the transfer clutch control program peculiar to the four-wheel drive vehicle are selected, and the 2WD lamp in the vehicle interior is turned off in step S206.

As described above, the same automatic transmission ECU is operated by 4W.
The embodiment of the circuit configuration for sharing between the four-wheel drive vehicle having the D solenoid and the two-wheel drive vehicle not having the D solenoid and the identification program for distinguishing the two-wheel drive vehicle from the four-wheel drive vehicle has been described. It is not limited to this. In particular, the transfer clutch drive circuit may have any circuit configuration as long as it drives the 4WD solenoid in response to a control signal from the microcomputer, and the self-diagnosis input circuit also determines the output voltage of the transfer clutch drive circuit. Any circuit configuration may be used as long as it can be detected. FIG. 6 shows another example. In this case, when the output voltage from the microcomputer to the transistor of the transfer clutch drive circuit is at high level and the self-diagnosis input is at low level, the 4WD solenoid is connected.
It is determined that the vehicle is a wheel drive vehicle, and if the self-diagnosis input is high level, it is determined that the vehicle is a two wheel drive vehicle because the 4WD solenoid is not connected. Note that, in FIG. 6, parts corresponding to the respective constituent elements shown in FIG. 1 are denoted by the same reference numerals.

Further, in this embodiment, the E for automatic transmission is used.
Although description has been made regarding sharing of CUs, the present invention is not limited to this, and is similarly applied to any ECU mounted in a vehicle, such as an engine control ECU and a traction control ECU. In that case, the signal to the drive circuit of the actuator and the signal from the self-diagnosis input circuit that are used in one of the multiple vehicle types or specifications that are trying to share the ECU and are not used in the other, depend on those vehicle types or specifications. Used to properly select different control programs.

[0030]

As described above, according to the electronic control unit for a vehicle of the present invention, the ECU concerned can be used by using the monitor result of the existing self-diagnosis input circuit without adding a new circuit or device. It is easily determined whether or not the installed vehicle is a vehicle type or specification for performing control using a specific actuator, and a control program is appropriately selected according to the determination result. As a result, the EC for a vehicle equipped with a specific control actuator and an
The U can be shared, and the ECU model can be reduced to reduce the production cost.

Further, when the vehicle electronic control unit according to the present invention is applied to an ECU for controlling the shift of an automatic transmission in which a transfer clutch for four-wheel drive can be selectively incorporated according to a vehicle type or specifications. By detecting whether or not the control solenoid for operating the transfer clutch is connected to the ECU, whether the automatic transmission to which the ECU is applied is for a two-wheel drive vehicle or a transfer clutch is incorporated. Whether or not it is for a wheel drive vehicle is determined, and an appropriate automatic transmission control program corresponding to each is selected. As a result, the E transmission between the automatic transmission for two-wheel drive vehicle and the automatic transmission for four-wheel drive vehicle
CU can be shared.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an example of an automatic transmission ECU to which the present invention is applied.

FIG. 2 is a skeleton diagram showing an example of a drive system of the automatic transmission according to the embodiment.

FIG. 3 is a hydraulic control circuit of the transfer clutch in the embodiment.

FIG. 4 is a flowchart showing a self-diagnosis program according to the embodiment.

FIG. 5 is a flowchart showing a program for identifying a two-wheel drive vehicle and a four-wheel drive vehicle according to the embodiment.

FIG. 6 is a circuit diagram showing another example of an automatic transmission ECU to which the present invention is applied.

[Explanation of symbols]

 30 Automatic transmission mechanism 50 4WD solenoid 51 Transfer clutch 52 Indicator lamp 80 Electronic control unit (ECU) 80a Output terminal 81 Microcomputer 83 Transfer clutch drive circuit 84 Self-diagnosis input circuit

Claims (3)

[Claims] 1. An electronic control unit for controlling a vehicle according to various parameters, and an actuator connected to an output terminal of the electronic control unit, wherein the electronic control unit is a microcomputer and the microcomputer. From a drive circuit for giving a signal for driving the actuator to an output terminal of the electronic control unit according to the output signal of the electronic control unit, and a self-diagnosis input circuit connected to the microcomputer for monitoring the signal given to the output terminal. In the vehicle electronic control device configured, the actuator is selectively connected to an output terminal of the electronic control unit according to a difference in vehicle type or specifications, and the microcomputer is at least connected to the vehicle type or specifications to which the actuator is connected. First control program for A second control program for a vehicle type or specification to which the actuator is not connected, the microcomputer determines whether the actuator is connected to an electronic control unit according to a signal from the self-diagnosis input circuit. If the vehicle is controlled, the vehicle is controlled by selecting the first control program when it is determined that the vehicle is connected and the second control program when determining that the vehicle is not connected. Electronic control unit. 2. The microcomputer controls an automatic transmission, the actuator is a solenoid for operating a four-wheel drive transfer clutch selectively incorporated in the automatic transmission, and the microcomputer is connected to the solenoid. If it is detected that the transfer clutch is installed in the automatic transmission, the automatic transmission control program for a four-wheel drive vehicle is selected. The vehicle electronic control device according to claim 1, wherein the automatic transmission control program for a two-wheel drive vehicle is selected when it is determined that the clutch is not incorporated in the automatic transmission. 3. A display lamp provided in a vehicle compartment and selectively turned on so as to distinguish between a case where it is determined that the solenoid is connected and a case where it is determined that the solenoid is not connected. The electronic control device for a vehicle according to claim 2, wherein