JPH05302544A - Electronic control unit - Google Patents

Abstract

PURPOSE:To greatly reduce a processing load relating to an arithmetic unit by independently executing various processes relating to interruption of input/ output. CONSTITUTION:In the case of an on-vehicle electronic control unit 1 of this practical example, a detection signal from the first sensor 17, serving as a detecting means, is converted into a specified detection data in accordance with a LAN protocol by an input/output ECU5, serving as an input processing means, and stored. Arithmetic ECUs 7 to 11, serving as control quantity arithmetic means, receiving the detection data through a LAN circuit 3 serving as a communication line, are only required to calculate a control quantity of a control objective equipment based on the received detection data. Further, a control quantity data as the arithmetic result is stored by the input/output ECU5 serving as an output processing means and converted into a specified control signal to feed it to the control objective equipment. That is, in the arithmetic ECUs 7 to 11, a processing load is greatly reduced by obviating the necessity for executing an input/output process relating to interruption or the like from the first sensor 17.

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 controlling controlled equipment via a communication line.

[0002]

2. Description of the Related Art Conventionally, as an electronic control device of this type, for example, there is an on-vehicle electronic control device 101 shown in FIG. The in-vehicle electronic control unit 101 performs data communication as an in-vehicle LAN and is connected to the LAN line 103.
Electronic control circuits (first control ECU 105, second control E
CU107, 3rd control ECU109, ..., nth control ECU111), the sensor which sends the detection signal to each control ECU105-111 (the 1st sensor 113, the 2nd sensor 11).
5, third sensor 117, ..., Nth sensor 119),
An actuator (first actuator 12) as a device to be controlled by each of the control ECUs 105 to 111 or a part thereof
1, second actuator 123, third actuator 1
, ..., The nth actuator 127) and the like.

Each of the control ECUs 105 to 111 has actuators 121 to 121 based on the processing procedure illustrated in FIG.
The control of 127 is performed. That is, an interrupt is started by using a signal sent from the sensors 113 to 119 as a trigger (S20
1) Add processing such as data conversion to the sent signal (S2
03), a calculation is performed based on the processed detection data (S205), and a control signal is generated from the calculation result and sent to the actuators 121 to 127 (S207).

For example, when the first sensor 113 is a rotation speed sensor that generates a pulse signal in response to the rotation of the crankshaft, the first control ECU 105 starts an interrupt process by using the pulse signal sent as a trigger, and the pulse It is converted into the engine speed by measuring the time of the interval. The converted engine rotation speed is used as detection data together with the intake air amount obtained from other sensors, for example, for calculation of control amount data such as fuel injection amount and fuel injection timing.
The fuel injection amount and the fuel injection timing as the control amount data are converted into a predetermined control signal and used for controlling the actuator 121 such as an injector. At that time, the above interruption is constantly occurring. In-vehicle electronic control unit 1
01 is each control ECU 105 through the LAN line 103
Data is exchanged between the 111 as necessary.

[0005]

However, in such a conventional on-vehicle electronic control unit 101, when the sensors 113 to 119 frequently interrupt the control ECUs 105 to 111, the control ECUs 105 to 111 perform a large number of input processes according to the interrupt frequency. Will be executed within a unit time and will be subject to a high load. That is, there is a problem that other processing (for example, processing for calculating control amount data of the actuators 121 to 127) is delayed due to execution of interrupt processing (input processing) having high priority. For example, when the engine rotation speed becomes high, the frequency of the pulse output from the first sensor 113 as the rotation speed sensor becomes high accordingly, and interrupts to the first control ECU 105 become frequent. Therefore, the first control ECU 105 receives a high load due to the interrupt processing, and the calculation of the control amount data is delayed.

Even when a control signal is sent from the control ECUs 105 to 111 to the actuators 121 to 127,
There is a case where interrupt processing (output processing) having a high priority is executed in accordance with a timer interrupt or the like, and in that case, a high load will be applied. The present invention has been made in view of these problems, and an object of the present invention is to significantly reduce the processing load of an arithmetic device by independently executing various processes for input / output interrupts.

[0007]

The present invention, which has been made to achieve the above object, has the following constitution. That is,
The invention according to claim 1 (hereinafter referred to as the first invention) is shown in FIG.
As illustrated in (a), the operating conditions of various controlled devices are detected, the control amount is calculated based on the operating conditions,
In an electronic control device that executes control of a corresponding controlled device according to the control amount, a communication line for data transmission, a detection unit that detects an operating condition of the controlled device, and a latest detection from the detection unit. Input processing means for receiving a signal, converting the detection signal into predetermined detection data, and outputting the detection data to the communication line as necessary, and input processing means for executing the series of processes through the communication line. The control amount calculating means for receiving the detection data from the means and calculating the control amount of the controlled object device based on the detection data, reduces the load of interrupt processing in the control amount calculating means. The gist is an electronic control device characterized by the above.

The invention according to claim 2 (hereinafter referred to as the second invention) is, as illustrated in FIG. 3 (b), the electronic control device according to claim 1 and further, via the communication line, The control amount data as a calculation result sent from the control amount calculation means is stored, the control amount data is converted into a predetermined control signal, and a series of output processing for outputting the control signal to the control target device is executed. The gist of an electronic control device is characterized in that the load of interrupt processing in the control amount calculation means is further reduced by providing the output processing means.

The invention according to claim 3 (hereinafter referred to as the third invention) is, as illustrated in FIG. 3 (c), the electronic control device according to claim 2, wherein the input processing means and the output processing are performed. The electronic control device is characterized in that the means and the means are configured as one input / output processing means.

[0010]

In the electronic control unit of the first aspect of the invention configured as described above, the latest detection signal sent from the detection means is converted into predetermined detection data by the input processing means and, if necessary, is sent to the communication line. Is output. Since this series of input processing does not require complicated control, only the input processing can be executed by, for example, a simple logic circuit. Therefore, the input processing means can execute only a series of input processing even if the interrupt from the detection means becomes frequent. The control amount calculation means may read the detection data stored in the input processing means via the communication line as needed, and calculate the control amount of the control target device based on the received detection data. Further, even if the control amount calculation means is configured to receive an interrupt from the input processing means and receive the detection data, the interrupt frequency is greatly reduced. Therefore, the control amount calculation means does not receive interrupts for input frequently, and does not receive high load due to interrupts due to input processing.

In the case of the electronic control device of the second invention, in addition to the operation of the first invention, the control amount data as the calculation result by the control amount calculation means is stored by the output processing means and converted into a predetermined control signal. After that, it is sent to the controlled device. Since this output processing does not require complicated control, only the output processing can be executed by a simple logic circuit or the like. The control amount calculation means may send the control amount data at the calculation end timing, and does not receive the timer interrupt for output. Further, even if the timer interrupt is configured to be received, the interrupt frequency is greatly reduced. Therefore, the control amount calculation means does not receive interrupts for output frequently and does not receive high load for output processing.

In the case of the electronic control unit of the third invention, the input processing and the output processing executed in the second invention are executed by one input / output processing means. Since the input processing and the output processing do not require complicated control, the input / output processing can be executed by using, for example, one CPU or the like. At that time, even if the input / output unit is configured to receive an interrupt of the input / output process, the input process and the output process to be executed do not receive a heavy load, so that the I / O unit is not heavily loaded. The control amount calculation means may read the detection data stored in the input / output processing means as needed, calculate the control amount of the controlled device based on the received detection data, and send it as the control amount data. Therefore, the control amount computing means does not receive interrupts for input / output frequently, and does not receive high load for input / output processing.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an in-vehicle electronic control device 1 of an embodiment to which the present invention is applied.

The on-vehicle electronic control unit 1 includes fuel injection control, ignition timing control, knock control, idle speed control, diagnostics, transmission control, suspension control, absorber damping force control, vehicle height control, constant speed running control, steering. Air flow meter, crank angle sensor, water temperature sensor, intake air temperature sensor, throttle opening sensor, oxygen concentration sensor, vehicle speed sensor, steering sensor, vehicle height sensor,
Wheel speed sensor, room temperature sensor, solar radiation sensor, outside air temperature sensor, engine water temperature sensor, and other sensor signals required for control, start switch, clutch switch,
This is executed based on some switch signals necessary for control among the switch signals of the air conditioner switch and the like.
The control processes described above are well known, and therefore detailed description thereof will be omitted. As shown in FIG. 1, the vehicle-mounted electronic control unit 1 includes a LAN line 3, an input / output ECU 5, and n arithmetic ECUs (first arithmetic ECU 7, second arithmetic ECU 9, ...
.., nth arithmetic ECU 11), switch 13, two sensors (first sensor 17, second sensor 19), three actuators (first actuator 21, second actuator 23, third actuator 25), etc. Has been done.

The LAN line 3 is a communication line for performing data communication between a plurality of control devices distributed in the vehicle, and is a well-known vehicle LAN line.
Here, the input / output ECU 5, the arithmetic ECUs 7 to 11, the second ECU
Data communication between the sensor 19 and the third actuator 25 is performed via the LAN line 3.

The input / output ECU 5 functions as an input processing unit and an output processing unit, and is a logic circuit having an input processing unit and an output processing unit. The input processing unit converts the latest signal sent from the switch 13, the first sensor 17 and the like into a predetermined digital signal according to the LAN protocol and stores the converted digital data as detection data. For example, when the first sensor 17 is a rotation speed sensor, the pulse signal transmitted in synchronization with the rotation of the crankshaft is converted into the engine rotation speed by measuring the time of the pulse interval and stored. The stored detection data is
It is sent to the arithmetic ECUs 7 to 11 via the LAN line 3.

The output processing unit stores control amount data and the like as the calculation results of the calculation ECUs 7 to 11 sent via the LAN line 3. The stored control amount data is converted into a predetermined control signal and sent to the actuators 21, 23 and the like. For example, when the first actuator 21 is an injector for fuel injection control, the control amount data such as the fuel injection amount and the fuel injection timing sent as the calculation result is stored, and the control amount data is subjected to a predetermined control by the output processing unit. It is converted into a signal and sent to the injector as the first actuator 21. The input / output ECU 5 can also be realized as one input / output processing unit by combining the input processing and the output processing by using the CPU processing.

The calculation ECUs 7 to 11 function as control amount calculation means, and are electronic control devices having a CPU inside. The arithmetic ECUs 7 to 11 execute arithmetic processing of control amounts for the actuators 21, 23, 25 and the like as control target devices based on the detection data of the switch 13, the sensors 17, 19 and the like that detect the driving conditions of the vehicle. The processes to be executed include, for example, fuel injection control, ignition timing control, knock control, idle speed control, diagnosis, transmission control, suspension control, absorber damping force control, vehicle height control, constant speed running control, steering control, skid control. Some of the controls.

The switch 13, the sensors 17 and 19 fulfill some functions as a detecting means for detecting the operating conditions of the on-vehicle control equipment. The switch 13 is, for example, a start switch, a clutch switch, an air conditioner switch, or the like. The signal from the switch 13 is sent to the input / output ECU 5. The sensors 17 and 19 are, for example, air flow meter, crank angle sensor, water temperature sensor, intake air temperature sensor, throttle opening sensor, oxygen concentration sensor, vehicle speed sensor, steering sensor, vehicle height sensor, wheel speed sensor, room temperature sensor, solar radiation sensor. , Outside air temperature sensor, engine water temperature sensor, etc.
The detection signal from the first sensor 17 is sent to the input / output ECU 5. The second sensor 19 is internally provided with an interface circuit as an input processing means, and the detection signal is directly LA
It is sent to the arithmetic ECUs 7 to 11 via the N line 3.

The actuators 21 to 25 are devices to be controlled using a power supply circuit such as a solenoid and a stepping motor. The actuators 21 to 25 are, for example, injectors, igniters (ignition modules), idle speed control valves, electromagnetic spill valves, and the like. The actuators 21 and 23 have input / output E
A predetermined operation is realized based on the control signal sent from the CU 5. The third actuator 25 is internally provided with an interface circuit as an output processing means, and a control signal is directly sent from the arithmetic ECUs 7 to 11 via the LAN line 3.

Next, the input / output ECU 5 and the arithmetic ECU 7
The processing executed by each of 11 to 11 will be described based on a flowchart. It is assumed that data communication is performed between the input / output ECU 5 and the arithmetic ECUs 7 to 11 based on a well-known processing procedure in the vehicle-mounted LAN.

FIG. 2A-1 shows an input process in the input / output ECU 5. When the input / output ECU 5 is composed of a logic circuit, when the latest detection signal from the first sensor 17 is received, it is converted into digital data according to the LAN protocol and the converted digital data is stored as detection data (S51). ). If the input / output ECU 5 is configured as CPU processing, the first sensor 1
The detection signal sent from 7 is used as a trigger to execute the interrupt processing of S51. Input / output ECU 5 is a logic circuit or CP
As the processing executed in the U processing, for example, a pulse synchronized with the rotation of the crankshaft is received from the first sensor 17, the interval time is measured from the received pulse, the engine rotational speed is converted, and the latest engine rotational speed is always stored. There is processing.

FIG. 2B shows the processing executed by the arithmetic ECUs 7-11. The calculation ECUs 7 to 11 input / output E
A request signal for reading the latest detection data is sent to the CU 5, and the input / output ECU 5 sends out the stored latest detection data accordingly. Operation ECU 7-11
Performs calculation based on the detection data received from the input / output ECU 5 (S71), and the input / output E is calculated at the calculation end timing.
The control amount data as the calculation result is sent to CU5. For example, the arithmetic ECU 7 reads out the latest engine rotation speed stored in the input / output ECU 5, and based on the received engine rotation speed and the detection data such as the intake air amount received by the similar configuration procedure, the fuel injection amount and the fuel injection amount. Control amount data such as timing is calculated and sent to the input / output ECU 5.

FIG. 2A-2 shows the output processing in the input / output ECU 5. When the input / output ECU 5 is formed of a logic circuit, when the control amount data from the arithmetic ECU 7 is received, the received control amount data is stored and converted into a predetermined control signal, and the first actuator 21
To (S61). When the input / output ECU 5 is configured as the processing of the CPU, the processing of S61 is executed in response to the interrupt instruction for sending the control amount data from the arithmetic ECU 7. For example, the input / output ECU 5 converts the received control amount data such as the fuel injection amount and the fuel injection timing into a predetermined control signal and sends the converted control signal to an injector as the first actuator 21 to perform fuel injection control.

In the in-vehicle LAN, a heavy load may be applied to the ECU for calculation, especially in the fuel injection control according to the engine speed and the skid control according to the vehicle speed. According to the calculation ECUs 7-1
1 does not directly receive an interrupt from the sensor signal, and the arithmetic ECUs 7 to 11 store the latest detection data (engine speed, intake air amount, etc.) stored in the input / output ECU 3 at the timing of the arithmetic processing to be executed. ) Will be received. In addition, the input / output ECU 3 to the calculation ECU 7
To 11 and interrupt the detection data to calculate ECU
Even if the method of sending to No. 7 to 11 is adopted, it may be performed when a certain predetermined time has elapsed, or when the detection signals sent from the sensors 17 to 19 change greatly, and in any case, the input processing is input / output. Since it is executed by the ECU 3, the arithmetic ECUs 7 to 11 are not heavily loaded.

Also in the output processing, for example, when a control signal is sent to the injector, according to the vehicle-mounted electronic control unit 1 of the present embodiment, the arithmetic ECUs 7 to 11 do not need to execute the interrupt processing for the timer interrupt or the like. Arithmetic ECU
7 to 11 may send the control amount data such as the fuel injection amount and the fuel injection timing to the input / output ECU 5 at the calculation end timing.
Even if the method in which the arithmetic ECUs 7 to 11 receive the timer interrupt is adopted, since the output processing is executed by the input / output ECU 3, the interrupt frequency of the arithmetic ECUs 7 to 11 does not increase and the processing load does not increase. Even when the input processing and the output processing are executed by a single CPU, the input / output processing does not require complicated control, so that a high load is not applied to this CPU. Of course, the input processing and the output processing may be configured by using a plurality of CPUs, and in this case, the CPUs can execute other processings within a range where the load does not increase. As for the data exchange method via the communication line, there are many known techniques, and any method may be used.

As described above, according to the on-vehicle electronic control unit 1 of the present embodiment, the latest signal sent from the switch 13, the first sensor 17, etc. is sent to the LA by the input / output ECU 5.
It is converted into predetermined detection data according to the N protocol and stored in the input / output ECU 5. Further, when controlling the actuators 21 and 23 which are the control target devices, the input / output ECU
5, the control amount data is stored and output processing (data conversion, signal transmission, etc.) is executed. Therefore, the calculation ECU 7
No. 11 to No need to perform input / output processing by input / output interrupts, or the number of interrupts is extremely small,
The processing load on the arithmetic ECUs 7 to 11 is significantly reduced.

Further, according to the vehicle-mounted electronic control unit 1 of this embodiment, it is possible to provide an interface circuit corresponding to the input processing means and the output processing means such as the second sensor 19 and the third actuator 25. Therefore, it becomes possible to construct a miniaturized control system. Disperse each processing unit
By miniaturizing, it becomes easy to prevent concentration of heat generated in each device.

In addition, since the processing loads on the arithmetic ECUs 7 to 11 are greatly reduced, the low-priority processing, which has been delayed until now, can be executed without delay. Therefore, the CP provided in the arithmetic ECUs 7 to 11
When selecting U, the demand for interrupt processing capability is relaxed, and an inexpensive CPU can be used.

Further, by reducing the processing load, it becomes possible to centrally execute the arithmetic processing which has been performed by a plurality of CPUs until now by one CPU. As a result, the ECU as viewed from the system can be configured in a small size and at a low cost, some of the control processes described above can be centralized and executed, and the overall control becomes easy.

In addition, a plurality of E's have been used so far by the sensor signal or the like.
The data that can be commonly used by the CUs may be stored redundantly in the respective control ECUs. However, since the input / output ECU 5 of this embodiment stores the data centrally, the memory Use efficiency improves.

The processing executed by the input / output ECU 5 does not require high-level processing such as branching based on a judgment statement or switching of calculation, and the types of the switch 13, the first sensor 17, the solenoid 15, the first actuator 21, etc. Therefore, the forms of the detection signal and the control signal do not greatly differ, so that it can be realized by a simple logic circuit (for example, a gate array) having high versatility and capable of mass production. Further, since the arithmetic processing executed by the arithmetic ECUs 7 to 11 can be realized by a simple product-sum calculation, it becomes possible to realize the pipeline processing by the digital signal processor (DSP), which enables faster and more efficient processing. Becomes

[0033]

As described in detail above, the electronic control unit according to the present invention independently executes various processes for input / output interrupts, thereby significantly reducing the processing load of the arithmetic unit.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an in-vehicle electronic control device as an embodiment of the present invention.

FIG. 2 is a flowchart showing a process executed by an input / output ECU and an arithmetic ECU.

FIG. 3 is a block diagram illustrating the configuration of the present invention.

FIG. 4 is a block diagram showing a configuration of a vehicle-mounted electronic control device as a conventional example.

FIG. 5 is a flowchart showing a process executed by a conventional control ECU.

[Explanation of Codes] 1 ... In-vehicle electronic control device, 3 ... LAN line, 5 ...
.... Input / output ECU, 7 ... First arithmetic ECU, 9 ...
2nd operation ECU, 11 ... nth operation ECU, 13 ...
・ Switch, 17 ... First sensor, 19 ... Second sensor, 21 ... First actuator, 23 ... Second
Actuator, 25 ... Third actuator

Claims (3)

[Claims] 1. Detecting the operating conditions of various controlled devices,
In an electronic control unit that calculates a controlled variable based on the operating condition and executes control of the controlled device corresponding to the controlled variable, a communication line for data transmission and an operating condition of the controlled device are displayed. An input for executing a series of processing for detecting the detection means and the latest detection signal from the detection means, converting the detection signal into predetermined detection data, and outputting the detection data to the communication line as necessary. The control means includes a processing means and a control amount calculation means for receiving the detection data from the input processing means via the communication line and calculating the control amount of the control target device based on the detection data. An electronic control device characterized in that the load of interrupt processing in the quantity calculation means is reduced. 2. The electronic control unit according to claim 1, further stores control amount data as a calculation result sent from the control amount calculation means via the communication line, and stores the control amount data in a predetermined manner. By providing an output processing means for converting the control signal into a control signal and outputting the control signal to the device to be controlled, a load of interrupt processing in the control amount calculation means is further reduced. An electronic control device characterized in that 3. The electronic control device according to claim 2, wherein the input processing means and the output processing means are configured as one input / output processing means.