Vehicular electronic control apparatus

• US 6,732,044 B2
• Filed: 08/06/2002
• Issued: 05/04/2004
• Est. Priority Date: 02/20/2002
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hashimoto, Kohji, Nakamoto, Katsuya
• Primary Examiner(s): Vo, Hieu T.
• Application Number:
  US10/212,045
• Publication Number:
  US 20030158649A1
• Time in Patent Office: 637 Days
• Field of Search: 701/114, 701/115, 701/102, 701/1, 701/29, 701/43
• US Class Current: 701/114
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue

Abstract

A core integrated circuit device has a microprocessor. A first ancillary integrated circuit device has an indirect parallel input circuit that receives low-speed digital signals parallel, and the first ancillary integrated circuit device outputs the received digital signals serially to the core integrated circuit device. A second ancillary integrated circuit device has a multi-channel A/D converter that receives analog signals parallel and converts those into digital signals, and the second ancillary integrated circuit device outputs the digital signals serially to the core integrated circuit device. The core integrated circuit device generates control signals based on the received signals and outputs the control signals to control object devices.

Claims

1. A vehicular electronic control apparatus comprising:

a core integrated circuit device including a microprocessor,

a first ancillary integrated circuit device for receiving low-speed digital signals connected to the core integrated circuit device in such manner that serial communication is performed with each other and

a second ancillary integrated circuit device for receiving analog signals connected to the core integrated circuit device in such manner that serial communication is performed with each other,

wherein the core integrated circuit device includes;

a direct parallel input circuit and a direct parallel output circuit for inputting and outputting signals from and to control object devices,

a first parent station serial/parallel converter and a second parent station serial/parallel converter,

a first nonvolatile memory to which control programs that serve to control the control object devices are written from an external tool, and

a first RAM for computation, and

the microprocessor of the core integrated circuit device to which the direct parallel input circuit, the direct parallel output circuit, the first and second parent station serial/parallel converters, the first nonvolatile memory, and the first RAM are bus-connected;

the first ancillary integrated circuit device includes;

a first child station serial/parallel converter connected to the first parent serial/parallel converter of the core integrated circuit device in such a manner that serial communication is performed with each other, and

an indirect parallel input circuit for receiving the low-speed digital signals in parallel, and

the first ancillary integrated circuit device outputs the digital signals received by the indirect parallel input circuit to the core integrated circuit device through the first child station serial/parallel converter, and

the second ancillary integrated circuit device includes;

a second child station serial/parallel converter connected to the core integrated circuit device in such a manner that serial communication is performed with each other, and

a multi-channel analog-to-digital converter for receiving the analog signals parallel and for converting the received analog signals into digital signals, and

the second ancillary integrated circuit device outputs the digital signals converted by the multi-channel analog-to-digital converter to the core integrated circuit device through the second child station serial/parallel converter, and

wherein the core integrated circuit device generates control signals based on the input signals received from the control object devices, the digital signals received from the first ancillary integrated circuit device, and the digital signals received from the second ancillary integrated circuit device, and outputs the generated control signals to the control object devices.

2. The vehicular electronic control apparatus according to claim 1, wherein the first ancillary integrated circuit device further includes an indirect parallel output circuit for outputting control signals generated by the core integrated circuit device to the control object devices.

3. The vehicular electronic control apparatus according to claim 1, wherein the microprocessor generates a watchdog signal,

wherein the core integrated circuit device further includes first mutual monitoring means for performing a time out check and a sum check based on the digital signals received from the first ancillary integrated circuit device and the digital signals received from the second ancillary integrated circuit device,

and wherein at least one of the first ancillary integrated circuit device and the second ancillary integrated circuit device further includes second mutual monitoring means for resetting the microprocessor when a pulse width of the watchdog signal generated by the microprocessor has exceeded a prescribed value.

4. The vehicular electronic control apparatus according to claim 3, wherein at least one of the first ancillary integrated circuit device and the second ancillary integrated circuit device further includes a sub-microprocessor that generates a watchdog signal, and wherein the first mutual monitoring means includes a runaway monitoring program that serves to reset the sub-microprocessor when a pulse width of the watchdog signal generated by the sub-microprocessor has exceeded a prescribed value.

5. The vehicular electronic control apparatus according to claim 3, wherein the first ancillary integrated circuit device further includes;

an abnormality storage circuit for storing information indicating an abnormality detected by the first mutual motoring means and the second mutual motoring means,

a power detection circuit for resetting the abnormality storage circuit when detecting application of power to the vehicular electronic control apparatus, and

a logic circuit for opening a load power relay that is connected to a power circuit for the control object device while the information indicating the abnormality is stored in the abnormality storage circuit.

6. The vehicular electronic control apparatus according to claim 5, wherein the core integrated circuit device further includes automatic control means for controlling a control object device according to a control program that is stored in the first nonvolatile memory, and wherein the first ancillary integrated circuit device includes automatic control monitoring means for monitoring the control object device according to a control program that is stored in a second nonvolatile memory.

7. The vehicular electronic control apparatus according to claim 6, wherein:

the second ancillary integrated circuit device receives first and second target values as double-system analog values having the same value, first and second detection values that are obtained by detecting operation of the control object device and correspond to the first and second target values, respectively, and the second ancillary integrated circuit device includes a monitoring output circuit for outputting the second target value and the second detection value,

the first ancillary integrated circuit device includes a monitoring input circuit that is connected to the monitoring output circuit,

the automatic control means of the core integrated circuit device controls the control object device based on the first target value and the first detection value that are supplied from the second ancillary integrated circuit device, and

the automatic control monitoring means of the first ancillary integrated circuit device compares an output of an approximated transfer function of an actuator system of the control object device that is produced when the second target value obtained from the monitoring input circuit is input to the approximated transfer function, with the second detection value obtained from the monitoring input circuit, and the automatic control monitoring means generates a control error signal if a resulting comparison deviation is greater than a prescribed value and thereby sets the abnormality storage circuit.

8. The vehicular electronic control apparatus according to claim 1, wherein each of input circuit sections of the indirect parallel input circuit of the first ancillary integrated circuit device includes an input interface section and a variable filter circuit,

the input interface section includes;

a noise filter having a small-capacitance capacitor and a large-resistance series resistor that is connected to a small-resistance bleeder resistor as a load of an input switch and

a level judgment comparator having a hysteresis function, and

the variable filter circuit includes;

an input determination flip-flop circuit that is set when a large part of consecutive level judgment results that have been sampled at a prescribed period and stored are true, and that is reset when the large part of consecutive level judgment results are false and

a constant setting register in which at least one of the sampling period and the number of set/reset logical judgment points is stored as a filter constant.

9. The vehicular electronic control apparatus according to claim 8, wherein the variable filter circuit further includes a reversible counter for reversibly counting clock signal depending on an output logical level of the level judgment comparator, and wherein the input determination flip-flop is set when a current value of the reversible counter has reached a setting value, and is reset when the current value of the reversible counter has become 0.

10. The vehicular electronic control apparatus according to claim 8, wherein the first ancillary integrated circuit device further includes an input interface section and a variable threshold circuit that are provided in a front stage of the direct parallel input circuit of the core integrated circuit device,

the input interface section includes;

a noise filter having a small-capacitance capacitor and a large-resistance series resistor that is connected to a small-resistance bleeder resistor as a load of an input switch, and

the variable threshold circuit includes;

a level judgment comparator having a hysteresis function, and

a constant setting register in which a setting value of a judgment level of the level judgment comparator is stored.

11. The vehicular electronic control apparatus according to claim 8, wherein control constants including at least one of the filter constants of the variable filter circuits and threshold constants of the variable threshold circuits and a constant transfer program that is executed by the microprocessor and serves to transfer the control constants to the constant setting registers are stored in the first nonvolatile memory of the core integrated circuit device.

12. The vehicular electronic control apparatus according to claim 1, wherein the first ancillary integrated circuit device further includes a second RAM for computation, a second nonvolatile memory, and a sub-microprocessor, and wherein each of input circuit sections of the indirect parallel input circuit of the first ancillary integrated circuit device includes an input interface section and a variable filter means,

the input interface section includes;

a noise filter having a small-capacitance capacitor and a large-resistance series resistor that is connected to a small-resistance bleeder resistor as a load of an input switch, and

a level judgment comparator having a hysteresis function, and

the variable filter means includes;

an input determination program that is stored in the second nonvolatile memory and executed by the sub-microprocessor, and that is set when a large part of consecutive level judgment results that have been sampled at a prescribed period and stored are true and is reset when the large part of consecutive level judgment results are false, and

wherein at least one of the sampling period and the number of set/reset logical judgment points is stored in the second RAM as a filter constant.

13. The vehicular electronic control apparatus according to claim 12, wherein control constants including at least one of the filter constants of the variable filter circuits and threshold constants of the variable threshold circuits and a constant transfer program that is executed by the microprocessor and serves to transfer the control constants to the constant setting registers are stored in the first nonvolatile memory of the core integrated circuit device, and wherein a constant reception program that serves to receive the control constants that are transferred being controlled by the constant transfer program is stored in the second nonvolatile memory.

14. The vehicular electronic control apparatus according to claim 1, wherein each of channel input circuit sections of the multi-channel analog-to-digital converter of the second ancillary integrated circuit device includes an input interface circuit and a variable filter circuit,

the input interface circuit includes a noise filter having a positive-side clip diode, a negative-side clip diode, and a small-capacitance capacitor, and

the variable filter circuit includes;

an equivalent resistor of a switched capacitor,

a capacitor connected to the equivalent resistor, and

a constant setting register in which a filter constant that determines a switching period of the switched capacitor is stored.

15. The vehicular electronic control apparatus according to claim 14, wherein the second ancillary integrated circuit device includes two multi-channel analog-to-digital converters, and wherein double-system analog sensors that are provided for the same measurement object are connected to the two multi-channel analog-to-digital converters, respectively.

16. The vehicular electronic control apparatus according to claim 14, wherein the second ancillary integrated circuit device further includes a digital conversion output circuit provided for part of the analog signals, for converting the part of the analog signals into digital signals, and wherein the first ancillary integrated circuit device further includes a monitoring digital conversion input circuit that is connected to an output of the digital conversion output circuit.

17. The vehicular electronic control apparatus according to claim 1, wherein each of channel input circuit sections of the multi-channel analog-to-digital converter of the second ancillary integrated circuit device includes an input interface circuit and a variable filter circuit,

the input interface circuit includes a noise filter having a positive-side clip diode, a negative-side clip diode, and a small-capacitance capacitor, and

the variable filter circuit includes;

a variable resistor including a selectively switched resistor,

a capacitor connected to the variable resistor, and

a constant setting register in which a filter constant that determines a resistance value of the variable resistor is stored.

18. The vehicular electronic control apparatus according to claim 1, wherein the second ancillary integrated circuit device further includes a second RAM for computation, a second nonvolatile memory, and a sub-microprocessor, and each of channel input circuit sections of the multi-channel analog-to-digital converter of the second ancillary integrated circuit device includes an input interface section and a variable filter means,

the input interface section includes a noise filter having a positive-side clip diode, a negative-side clip diode, and a small-capacitance capacitor, and

the variable filter means includes a moving average calculation program that is stored in the second nonvolatile memory and executed by the sub-microprocessor, and that calculates an average value of consecutive digital conversion values that have been sampled at a prescribed period and stored, and

wherein at least one of the sampling period and the number of moving average calculation points is stored in the second RAM as a filter constant.

19. The vehicular electronic control apparatus according to claim 1, wherein the first ancillary integrated circuit device further includes;

a second nonvolatile memory,

a second RAM for computation,

a sub-microprocessor to which the second nonvolatile memory and the second RAM are bus-connected, and

input interface circuits and a monitoring parallel input circuit that are provided in a front stage of the direct parallel input circuit of the core integrated circuit device,

each of the input interface sections includes;

a noise filter comprising a small-capacitance capacitor and a large-resistance series resistor that is connected to a small-resistance bleeder resistor as a load of an input switch, and

a level judgment comparator having a hysteresis function; and

the monitoring parallel input circuit that is a data selector that selectively bus-connects outputs of the level judgment comparators to the sub-microprocessor.