JPH06137206A - Electronic control device for engine - Google Patents

Abstract

PURPOSE:To enhance redundancy against abnormality by calculating the opening of a throttle valve on the basis of the tread-in amount of an accelerator pedal by respective CPUs both for opening calculation use and for throttle valve control use, and at the time of abnormality of the CPU for opening calculation use or the like, by controlling the opening by the CPU for throttle valve control use. CONSTITUTION:In an electronic control device 5 for an engine, both a CPU 51 for fuel control use for controlling a fuel injection device 22 and a CPU 52 for throttle valve control use for controlling a pulse motor 31 by which an intake throttle valve is driven so as to be opened or closed are arranged respectively, and these CPUs are connected to each other by a bus bar 53. On the basis of the detection signal from an accelerator sensor 4, the opening signal of the pulse motor 31 is calculated by the fuel control CPU 51, and also the opening signal for alternate use is calculated by the throttle valve control CPU 52. Thereafter, when an abnormality is caused in the fuel control CPU 51 itself or in the storing part 54 for storing opening signal therefrom, the opening signal for alternate use is output from the throttle valve control CPU 52 to the pulse motor 31.

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 having a throttle valve control CPU that outputs an opening signal to an actuator that opens and closes a throttle valve provided in an intake pipe of an engine.

[0002]

2. Description of the Related Art In a conventional engine electronic control unit, a CPU for controlling a throttle valve inputs detection signals from an accelerator sensor for detecting the amount of depression of an accelerator pedal and various other sensors for detecting the state of the engine. A large number of input ports for high-precision A /
A D conversion unit is provided, and the CPU for controlling this throttle valve
Inside, an opening signal output to the actuator is calculated based on these detection signals converted by the A / D converter.

[0003]

SUMMARY OF THE INVENTION In the above conventional configuration,
When an abnormality such as a failure occurs in the throttle valve control system including the CPU for controlling the throttle valve, there arises a problem that the throttle valve opening cannot be controlled in conjunction with the accelerator operation performed by the driver. .

Incidentally, when such an abnormality occurs, a means for setting the opening of the throttle valve to a predetermined fixed value separately from the throttle valve control system including the CPU for controlling the throttle valve. It is conceivable that the vehicle is maintained so that the vehicle travels, but if the throttle valve opening is fixed in this way, the vehicle speed does not change even when the accelerator pedal is depressed and the vehicle travels. The driver's will cannot be reflected.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an electronic control unit for an engine, in which redundancy with respect to an abnormality of the throttle valve control system is enhanced.

[0006]

In order to achieve the above object, the invention of claim 1 is for controlling a throttle valve for outputting an opening signal to an actuator for opening and closing a throttle valve provided in an intake pipe of an engine. In the electronic control device having the CPU, an opening degree calculation CPU for calculating the opening degree of the throttle valve based on at least the depression amount of the accelerator pedal and outputting the calculated opening degree signal to the throttle valve control CPU is provided. At the same time, the CPU for controlling the throttle valve stores an alternative opening calculating means for calculating an alternative signal of the opening signal based on the depression amount of the accelerator pedal, and an opening signal from the CPU for calculating the opening. It is characterized in that a storage section and an alternative drive means for outputting the alternative signal to the actuator as an opening signal when the storage section is abnormal are provided.

According to a second aspect of the present invention, at least the accelerator is provided in an electronic control device including a throttle valve control CPU that outputs an opening signal to an actuator that opens and closes a throttle valve provided in an intake pipe of an engine. A CPU for opening calculation that calculates the opening of the throttle valve based on the amount of depression of the pedal and outputs it as an opening signal to the CPU for controlling the throttle valve.
The throttle valve control CPU is provided with an alternative opening calculation means for calculating an alternative signal of the opening signal based on the depression amount of the accelerator pedal, and an opening signal from the CPU for opening calculation. A storage unit that stores the data, and an auxiliary drive unit that determines an abnormality of the opening signal stored in the storage unit based on the alternative signal and outputs the alternative signal to the actuator as the opening signal when the opening signal is abnormal are provided. It is characterized by that.

Further, the invention of claim 3 is an electronic control device comprising a CPU for controlling a throttle valve for outputting an opening signal to an actuator for opening and closing a throttle valve provided in an intake pipe of an engine. Abnormality detection means for detecting an abnormality in at least one of the valve control CPU and the actuator, and auxiliary control for changing the upper limit value of the engine speed based on the depression amount of the accelerator pedal when the abnormality detection means detects the abnormality. CPU for auxiliary control including means
Is provided.

[0009]

By providing a CPU for calculating the opening degree separately from the CPU for controlling the throttle valve, when an abnormality occurs in the storage unit built in the CPU for calculating the opening degree or the CPU for controlling the throttle valve, An alternative signal calculated in the CPU for controlling the throttle valve is output to the actuator so that the opening of the throttle valve can be drive-controlled according to the operation of the accelerator pedal.

When an abnormality occurs in the throttle valve control CPU or actuator and the throttle valve cannot be driven, the fuel supply amount is controlled to limit the engine speed to some extent. However, it is not possible to reflect the driver's will by merely limiting the engine speed, and there is a risk of so-called upswing. Therefore, a separately provided CPU for auxiliary control sets the upper limit value of the engine speed. This has been changed to prevent the engine from blowing up, and this upper limit value is changed according to the amount of depression of the accelerator pedal so that the vehicle speed can be changed in conjunction with the driver's operation on the accelerator pedal.

[0011]

1 and 2, reference numeral 1 denotes an engine controlled by an electronic control unit 5 according to the present invention, which sucks air from an air cleaner 21 through an intake pipe 2 and supplies an appropriate amount to this intake air. Fuel is injected from the nozzle 22 to fill the cylinder. A throttle valve 3 for increasing or decreasing the intake passage area is provided in the middle of the intake pipe 2, and the opening degree of the pulse motor 31 is an actuator connected to the throttle valve 3.
The angle sensor 32 attached to the throttle valve 3 detects the actual opening degree. Reference numeral 23 is an intake negative pressure sensor for detecting the pressure in the intake pipe line 2. An accelerator sensor (AP sensor) that outputs a depression amount signal AP proportional to the depression amount of the accelerator pedal 41 to the accelerator pedal 41 operated by the driver D.
4 is attached.

The drive control of the pulse motor 31 and the fuel injection amount from the nozzle 22 are performed by the electronic control unit 5, and the electronic control unit 5 controls the fuel supply amount to the engine 1. A CPU 51 for fuel control and a CPU 52 for throttle valve control that controls the opening and closing of the throttle valve 3 are stored. DPRA capable of bidirectional data exchange in the CPU 52 for controlling the throttle valve
Built-in M (Dual Port Random Access Memory) 54, CPU 51 for fuel control and DPRAM
The bus line 53 is connected to the bus line 54.

A depression amount signal from the accelerator sensor 4 and an actual opening signal of the throttle valve 3 from the angle sensor 32 are input to both the fuel control CPU 51 and the throttle valve control CPU 52. Then, the CPU 51 for fuel control
In addition, the intake negative pressure sensor 23, a rotation sensor 61 for detecting the number of revolutions of the engine 1, and a vehicle speed sensor 6 for detecting the vehicle speed.
2, atmospheric pressure sensor 63 for detecting atmospheric pressure, engine 1
Various sensors such as a water temperature sensor 64 for detecting the cooling water temperature are connected, and a control signal is output to the nozzle 22 based on the fuel supply amount calculated based on these various detection signals. These various detection signals are input from an input port (not shown) of an input unit in the CPU 51 for fuel control and converted into digital signals by an A / D conversion unit (not shown).

The opening signal TH output to the pulse motor 31 is calculated based on the detection signals from various sensors including AP from the accelerator sensor 4. Therefore, the opening degree signal TH is configured to be calculated by the CPU 51 for fuel control, and various detection signals used for calculating the fuel supply amount are shared. The opening signal TH calculated by the fuel control CPU is sent to the DPRAM via the bus line 53.
It is output to 54. On the other hand, in the CPU 52 for controlling the throttle valve, the substitute signal THAP corresponding to the opening signal for driving the pulse motor 31 is also calculated based on AP. The CPU 52 for controlling the throttle valve has a high-precision A /
Since the D converter is not provided, the alternative signal THAP can only roughly control the pulse motor 31 than the opening signal TH calculated by the fuel control CPU 51.

When the opening signal TH is transferred to the DPRAM 54, it is first determined whether the DPRAM 54 is normal (S1), as shown in FIG. This determination method may be a conventionally used method. For example, in the case of this embodiment, the number of bytes to be transferred is 15, two of these bytes are set for sum check, and the remaining 13 bytes are used for data. Set and set the 13-byte sum value for the data written in this byte for sum check and the DPR
The sum value of the data transferred to the OM 54 is compared, and if the two sum values match, the DPRAM 54 is determined to be normal, and if they do not match, it is determined to be abnormal. When it is determined that the DPRAM 54 is normal, in order to determine whether the fuel control CPU 51 is normal, the TH from the fuel control CPU 51 and a predetermined amount α from the substitute signal THAP are used. A comparison is made with a large value, and if TH exceeds this value, it is determined that TH is abnormal (S2), and instead of TH calculated by the fuel control CPU 51, it is calculated by the throttle valve control CPU 52. The alternative signal THAP is output to the pulse motor 31 to auxiliary drive the pulse motor 31 (S3). still,
Even when it is determined in S1 that the DPRAM 54 is abnormal, the alternative signal THAP is output to the pulse motor 31 to drive the pulse motor 31 in an alternative manner.
(S3).

Although the flow shown in FIG. 3 is executed in the CPU 52 for controlling the throttle valve, the CPU 51 for controlling the fuel
The flow shown in FIG. 4 is also executed inside. In the fuel control CPU 51, it is first determined whether or not the accelerator sensor 4 is abnormal (S4). If the accelerator sensor 4 is abnormal, the driver's operation on the accelerator pedal 41 cannot be detected. In order to regulate the upper limit of the rotation speed, the rev limit value NL set in advance is replaced with a predetermined fixed value Na (for example, 2000 rpm), and the engine 1
The number of rotations of was not increased above Na (S
5). If the accelerator sensor 4 is normal,
When an abnormality occurs in at least one of the throttle valve control CPU 52 and the pulse motor 31, an abnormality is detected by using a flag F set to 1 and it is determined whether or not the flag F is 1 ( S6), if the flag F is 1,
The engine 1 is supplementarily controlled by replacing the NL with an alternative value Nb that changes according to the stepping signal AP (S7).

This Nb is set so as to increase as the stepping signal AP increases as shown in FIG. 5, for example. Therefore, when the driver depresses the accelerator pedal 41, the rev limit value also rises and the driver can drive without impairing the traveling performance, and the engine speed does not rise above Nb.

[0018]

As is apparent from the above description, the engine can be controlled in conjunction with the accelerator operation performed by the driver even when an abnormality such as a failure occurs in any of the throttle valve control systems.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an engine to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of an electronic control device of the present invention.

FIG. 3 is a process flow chart when an abnormality occurs, which is executed in the CPU for controlling the throttle valve.

FIG. 4 is a flow chart of processing executed when an abnormality occurs in the fuel control CPU.

FIG. 5 is a table showing the relationship between the accelerator pedal depression amount and the engine speed upper limit regulation value.

[Explanation of symbols]

1 engine 2 intake pipe 3 throttle valve 4 accelerator sensor 5 electronic control unit 31 pulse motor 41 accelerator pedal 51 C for fuel control
PU 52 CPU 54 for controlling throttle valve DPRAM

Claims (3)

[Claims] 1. An electronic control device comprising a throttle valve control CPU for outputting an opening signal to an actuator for opening and closing a throttle valve provided in an intake pipe of an engine, based on at least a depression amount of an accelerator pedal. A CPU for controlling the throttle valve as an opening signal by calculating the opening of the throttle valve
And an alternative opening calculation means for calculating an alternative signal of the opening signal on the basis of the depression amount of the accelerator pedal, and a CPU for opening control for outputting the opening An electronic control unit for an engine, comprising: a storage unit that stores an opening degree signal from a CPU for use in a vehicle; and an alternative drive unit that outputs the alternative signal to the actuator as an opening degree signal when the storage unit is abnormal. . 2. An electronic control device comprising a throttle valve control CPU that outputs an opening signal to an actuator that opens and closes a throttle valve provided in an intake pipe of an engine, based on at least a depression amount of an accelerator pedal. A CPU for controlling the throttle valve as an opening signal by calculating the opening of the throttle valve
And an alternative opening calculation means for calculating an alternative signal of the opening signal on the basis of the depression amount of the accelerator pedal, and a CPU for opening control for outputting the opening For storing the opening signal from the CPU for use in the actuator, and an abnormality of the opening signal stored in the storage unit based on the alternative signal, and when the abnormality of the opening signal occurs, the alternative signal is used as the opening signal for the actuator. An electronic control unit for an engine, which is provided with an auxiliary drive means for outputting to. 3. An electronic control device comprising a throttle valve control CPU that outputs an opening signal to an actuator that opens and closes a throttle valve provided in an intake pipe of an engine, wherein the throttle valve control CPU and actuator are provided. Auxiliary control means for detecting an abnormality in at least one of the above, and an auxiliary control means for changing the upper limit regulation value of the engine speed based on the depression amount of the accelerator pedal when the abnormality detection means detects an abnormality. An electronic control unit for an engine, which is provided with a CPU for the engine.