JP2014154043A - Electronic control device and information processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic control device capable of detecting a transient state until a microcomputer becomes abnormal.SOLUTION: An electronic control device 100 including first information processing means 12 for continuously outputting a pulse signal and second information processing means 13 for receiving the pulse signal comprises: PWM signal creation means 34 for creating a PWM signal by calculating external information acquired from the outside; pulse signal creation means 32 for, when the PWM signal creation means starts the creation of the PWM signal, setting the pulse signal to Low, and for, when the PWM signal creation means ends the creation of the PWM signal, setting the pulse signal to High, or for, when the PWM signal creation means starts the creation of the PWM signal, setting the pulse signal to Low, and for, when the PWM signal creation means ends the creation of the PWM signal, setting the pulse signal to High to create the pulse signal; and creation time measurement means 41 and 43 for monitoring the pulse signal, and for measuring creation time since the PWM signal creation means starts the creation of the PWM signal until the PWM signal creation means ends the creation of the PWM signal.

Description

  The present invention relates to an electronic control device that monitors a processing load.

  The vehicle is equipped with an ECU (Electronic Control Computer) that controls various in-vehicle devices. The ECU is equipped with a microcomputer for controlling the in-vehicle device. However, a monitoring method for monitoring the microcomputer is devised in order to restore it early when an abnormality occurs in the microcomputer (see, for example, Patent Document 1). . Patent Document 1 discloses a CPU calculation time monitoring method in which a control CPU periodically clears a value counted by a watchdog timer and detects an abnormality of the control CPU when the count value exceeds a predetermined value. Yes.

JP 2002-315346 A

  However, the microcomputer monitoring method disclosed in Patent Document 1 has a problem that an abnormality cannot be detected until an abnormality occurs in the monitoring target microcomputer. In other words, it is not possible to detect a transitional state before an abnormality occurs so that the clearing of the watchdog timer is delayed.

  An object of the present invention is to provide an electronic control device capable of detecting a transient state until a microcomputer becomes abnormal.

  The present invention is an electronic control device having first information processing means for continuously outputting a pulse signal and second information processing means for receiving the pulse signal, and calculates external information acquired from the outside. PWM signal generating means for generating a PWM signal and setting the pulse signal to Low when the PWM signal generating means starts generating the PWM signal and setting it to High when the generation is completed, or PWM signal The pulse signal creating means for creating the pulse signal by setting to Low when the creation of the signal is started and setting to High when the creation is completed, and monitoring the pulse signal, and the PWM signal creating means And a creation time measuring means for measuring a creation time from the start to the end of creation.

  It is possible to provide an electronic control device capable of detecting a transient state until the microcomputer becomes abnormal.

It is an example of the figure explaining the general | schematic characteristic of the monitoring method of the microcomputer in the motor control apparatus of this embodiment. It is an example of the block diagram of a motor control system, and an example of the figure which illustrates the calculation method of a duty typically. It is an example of a schematic block diagram of a motor control microcomputer and a monitoring microcomputer. It is an example of the figure explaining a carrier wave, a PWM signal, and a pulse output. It is an example of the flowchart figure which shows the operation | movement procedure of a motor control microcomputer. It is an example of the flowchart figure which shows the operation | movement procedure of a monitoring microcomputer. It is an example of the functional block diagram of a motor control microcomputer and a monitoring microcomputer (Example 2). It is an example of the figure explaining a carrier wave, a PWM signal, and a pulse output. (Example 2) which is an example of the flowchart figure which shows the operation | movement procedure of a motor control microcomputer. It is an example of the flowchart figure which shows the operation | movement procedure of the monitoring microcomputer (Example 2).

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is an example of a diagram for explaining the schematic features of a microcomputer monitoring method in the motor control apparatus of this embodiment. The motor control microcomputer 12 outputs a control signal for the three-phase motor to the monitoring microcomputer 13, and the monitoring microcomputer 13 continuously outputs pulses for monitoring the motor control microcomputer 12. The monitoring microcomputer 13 detects that the pulse is output (ON / OFF change is repeated within a predetermined time) and detects that the motor control microcomputer 12 is normal. Hereinafter, monitoring with pulses is referred to as “watchdog”.

  When the pulse cannot be output because the processing load of the motor control microcomputer 12 has increased, the monitoring microcomputer 13 performs fail-safe processing such as detecting and resetting the abnormality of the motor control microcomputer 12. The use of pulses for such watchdogs has been used in the past, but it has mainly been able to monitor only the presence or absence of abnormalities.

Therefore, the motor control microcomputer 12 of the present embodiment outputs a watchdog pulse when the motor is not rotationally driven (mode 1 described later), and when the motor is rotationally driven (mode 2 described later). ) Transmits the following three pieces of information by pulses.
(i) Processing load information (H time)
(ii) CPU load margin
(iii) Frequency of Carrier Wave As shown in FIG. 1B, the motor control microcomputer 12 sets the cycle of the carrier wave as one cycle of the pulse. Further, since the motor control microcomputer 12 performs inverter control of the PWM signal for each carrier wave cycle (for example, calculates the duty), the PWM signal cycle and the pulse cycle are synchronized. Therefore, the motor control microcomputer 12 raises the pulse at the start timing of the inverter control, and lowers the pulse when the inverter control ends. For this reason, when the processing load of inverter control becomes high, the time for which the pulse maintains H (hereinafter referred to as H time) becomes long. The monitoring microcomputer 13 acquires (i) processing load information by H time.

  Since the pulse rises every carrier wave period, one pulse period is from the rising edge of the pulse to the next rising edge. The monitoring microcomputer 13 monitors the rising edge of the pulse and (iii) acquires the frequency of the carrier wave. (iii) The remainder obtained by removing H time from the carrier wave period is (ii) CPU load margin.

  As described above, the monitoring microcomputer 13 can monitor the transient processing load of the motor control microcomputer 12 without any abnormality in the motor control microcomputer 12 by using a signal line that has been conventionally used. When the processing load increases, fail-safe such as reducing the load before resetting becomes possible.

[Inverter control]
FIG. 2A is an example of a block diagram of a control system of the motor 15, and FIG. 2B is an example of a diagram for schematically explaining a duty calculation method. The motor control microcomputer 12 is connected to the HV-ECU 11, and is connected to the inverter 14 and the motor 15 via the monitoring microcomputer 13. The inverter 14 is a PWM control type, and has a configuration in which switch elements such as six power MOSFETs and IBGT are bridge-connected. The inverter 14 converts the applied voltage into a three-phase AC voltage and supplies it to the stator coils for the U, V, and W phases of the motor 15. The V-phase and W-phase current values (actual currents) Iv and Iw supplied from the inverter 14 to the motor 15 are fed back to the motor control microcomputer 12. The U-phase current value is obtained by calculation.

  The motor 15 is, for example, a three-phase AC motor, and exhibits the driving force of the vehicle alone or with the engine. The motor is not limited to an AC motor, and may be any motor that is PWM controlled such as a DC motor. The motor 15 is provided with a sensor capable of detecting the number of rotations such as a Hall element. For example, the rotation angle θ detected by the Hall element is output to the motor control microcomputer 12. The motor control microcomputer 12 calculates the rotation speed of the motor 15 from the rotation angle θ.

The HV-ECU 11 determines a current command value of the motor 15 based on the driver's accelerator pedal operation amount detected by an accelerator pedal stroke sensor or the like and the vehicle speed detected by the vehicle speed sensor, and outputs it to the motor control microcomputer 12. Information output from the HV-ECU 11 or the like corresponds to external information in the claims. Alternatively, the motor control microcomputer 12 may determine the current command value. The current command value indicates the amplitude and phase (frequency) of the fundamental wave in the coordinate system of the current flowing through the motor 15. Since the fundamental wave is a sine wave, the waveform in an arbitrary carrier wave period is known.
The frequency of the carrier wave is constant unless an explicit instruction is given, and a fixed voltage is repeatedly generated at a fixed cycle. Therefore, for each carrier wave period, the fundamental wave is expressed numerically to determine the amplitude and phase of the fundamental wave, and the numerically expressed fundamental wave and the carrier wave are compared. As shown in the figure, the duty of the PWM signal is from the start point of the carrier wave cycle to the intersection of the carrier wave and the fundamental wave.

  The motor control microcomputer 12 compares the current value corresponding to the duty with the actual current to calculate the difference, generates a PWM control voltage (PWM signal) for each phase that eliminates the difference, and the switching element of the inverter 14 by the PWM control voltage ON / OFF control. The inverter 14 applies an output voltage to the stator coil of the motor 15. As a result, the motor 15 rotates at a rotational speed corresponding to the frequency of the fundamental wave. Hereinafter, the control of the motor control microcomputer 12 including the calculation of the duty is referred to as inverter control.

  In such inverter control, the processing load increases due to frequent interruptions associated with an increase in the number of motor revolutions and changes in the vehicle status, and sudden changes in the driver's accelerator pedal operation. If the processing load increases extremely, the CPU operating speed may decrease due to a temperature rise or the like, and a phenomenon that the output of the PWM signal is not in time can occur. In the present embodiment, the monitoring microcomputer 13 can monitor the transient state of the motor control microcomputer 12 before such basic performance is impaired because the processing load increases.

[Configuration example]
FIG. 3A shows an example of a schematic configuration diagram of the motor control microcomputer 12 and the monitoring microcomputer 13. The motor control microcomputer 12 and the monitoring microcomputer 13 operate as one ECU (electronic control unit) housed in one housing. However, even if the motor control microcomputer 12 and the monitoring microcomputer 13 are one chip, there is no change in that the monitoring function can monitor the motor control function by a pulse. Even if the motor control microcomputer 12 and the monitoring microcomputer 13 are stored in separate ECUs (housings), one can monitor the other.

  The motor control microcomputer 12 includes a CPU 21, a RAM 22, a ROM 23, and an input / output interface 24 connected to the bus. The monitoring microcomputer 13 has a CPU 26, a RAM 27, a ROM 28, and an input / output interface 25, but further has an input / output interface 29 for transmitting a PWM signal to the inverter 14. In addition, although the motor control microcomputer 12 and the monitoring microcomputer 13 have a general configuration in the microcomputer, illustration is omitted.

  The input / output interfaces 24 and 25 are connected to each other by one pulse line 51, six PWM signal lines 52, and one or more fail-safe signal lines 53. The pulse line 51 is a line for providing a watch dog function and transmitting a pulse for the monitoring microcomputer 13 to monitor the motor control microcomputer 12. The six PWM signal lines 52 are lines through which PWM signals for turning on / off the two U-phase switch elements, the two V-phase switch elements, and the two W-phase switch elements are transmitted. The fail-safe signal line 53 is a line for the control microcomputer 13 to perform control for reducing the processing load of the motor control microcomputer 12 or for resetting the motor control microcomputer 12. For example, the fail-safe signal line 53 may be a line that is provided for each type of control and notifies H or L. For example, in the control for reducing the processing load, a single pulse (H → L) notifies that the processing load is reduced by a predetermined amount. In the reset control, the motor control microcomputer 12 is reset by L → H (high active) or H → L (low active). Alternatively, the fail safe signal line 53 may be a serial line, and a single line may correspond to all types of control.

  The input / output interfaces 25 and 29 in the monitoring microcomputer 13 are connected by six PWM signal lines. The CPU 26 monitors the state of the six PWM signal lines 52. Under normal conditions, the CPU 26 does not process the PWM signal, and the monitoring microcomputer 13 passes the PWM signal as it is. When the PWM signal cannot be confirmed, the CPU 26 turns off the switch 54 for the PWM signal and stops outputting the PWM signal to the inverter 14. If the PWM signal cannot be confirmed, there is a possibility that some abnormality has started to occur in the motor control microcomputer 12, so that it is possible to prevent the motor control from being performed in such an abnormal state.

  FIG. 3B shows an example of a functional block diagram of the motor control microcomputer 12 and the monitoring microcomputer 13. The motor control microcomputer 12 includes a carrier wave generation unit 31 that generates a carrier wave, a pulse generation unit 32 that generates a pulse, an inverter control unit 34 that generates a PWM signal, and a carrier frequency control unit 33 that controls the frequency of the carrier wave. have. The monitoring microcomputer 13 includes a pulse monitoring unit 41 that monitors pulses, a PWM signal monitoring unit 42 that monitors PWM signals, a processing load determination unit 43 that determines the processing load of the motor control microcomputer 12, and the motor control microcomputer 12. A fail-safe unit 44 that performs fail-safe control is provided. These will be described later.

The motor control microcomputer 12 and the monitoring microcomputer 13 have two operation modes: mode 1 in which the motor 15 is stopped (no PWM signal is output) and mode 2 in which the motor 15 is in operation.
Mode 1: Watchdog mode Mode 2: Abnormal monitoring mode of this embodiment The motor control microcomputer 12 and the monitoring microcomputer 13 determine whether the mode is 1 or 2 based on whether a PWM signal is output. Hereinafter, functions in mode 2 will be mainly described.

[About monitoring contents]
FIG. 4 is an example of a diagram illustrating a carrier wave, a PWM signal, and a pulse signal. Since the carrier wave is generated by the carrier wave generator 31 in the motor control microcomputer 12, the carrier wave is not output to the monitoring microcomputer 13. The PWM signal and the pulse are generated by the motor control microcomputer 12 and output to the monitoring microcomputer 13. Although the PWM signal is transmitted through each of the six PWM signal lines 52, the monitoring microcomputer 13 focuses on one PWM signal synchronized with the pulse signal.

-Motor control microcomputer The carrier wave generator 31 repeatedly generates a carrier wave at a reference frequency. The frequency of the carrier wave can be adjusted in the range between the lower limit and the upper limit for noise countermeasures and the like. Although it is a sawtooth shape in the figure, it may be a triangular wave.

  The inverter control unit 34 performs inverter control for each cycle in synchronization with the carrier wave cycle. For example, the CPU 21 wakes up the inverter control unit 34 when the rising edge or the falling edge of the carrier wave is interrupted. As described above, the inverter control unit 34 calculates the duty and outputs a PWM signal. Since the inverter control unit 34 calculates the duty of the next cycle, the duty calculated in the i-th cycle is reflected in the PWM signal of the i + 1-th cycle. Further, there may be no correlation between the processing load and the duty of the PWM signal (even if the inverter control takes a long time, the duty does not increase).

Moreover, the inverter control part 34 of a present Example notifies control start to the pulse production part 32, when inverter control is started (for example, immediately after waking up). By obtaining this notification, the pulse creating unit 32 sets the pulse signal line to H. Further, the inverter control unit 34 notifies the pulse generation unit 32 of the end of control when the inverter control of one carrier wave cycle is completed. By obtaining this notification, the pulse creating unit 32 sets the pulse signal line to L. Therefore, the pulse becomes H at the start of the carrier wave period, and becomes L when the inverter control ends. Therefore, H time means the time required for inverter control, and the monitoring microcomputer 13 can estimate the processing load of the motor control microcomputer 12 from the pulse. The setting of L and H may be reversed. In this case, the monitoring microcomputer 13 may determine the processing load from the time of the L state of the pulse.
The carrier frequency control unit 33 reduces the frequency of the carrier wave in response to a request from the fail safe unit 44. Thereby, the processing load of the motor control microcomputer 12 can be reduced.

Monitoring microcomputer The pulse monitoring unit 41 of the monitoring microcomputer 13 monitors the pulse, for example, notifies the processing load determination unit 43 that the rising edge of L → H has been detected, and detects that the falling edge of H → L has been detected. The determination unit 43 is notified. As a result, the processing load determination unit 43 acquires the following three pieces of information.
(i) Processing load information
(ii) CPU load margin
(iii) Carrier wave frequency
(i) is the time from the detection of the rise to the detection of the fall, and represents the inverter control time (that is, the processing load). (iii) is the time from the rising detection to the next rising detection, and represents the frequency (and period) of the carrier wave. (ii) is the time from the detection of falling to the detection of rising, and represents the margin of CPU load from the end of inverter control to the start of the next inverter control. In this way, the processing load determination unit 43 can monitor the processing load of the motor control microcomputer 12, the margin of the CPU load, and the frequency of the carrier wave. Note that (iii) the frequency of the carrier wave can also be acquired from the rising edge of the PWM signal.

  Further, the PWM signal monitoring unit 42 monitors the PWM signal and notifies the processing load determination unit 43 that, for example, the rising edge of L → H has been detected. Thereby, the processing load determination part 43 can detect the frequency (period) of a carrier wave similarly to (iii). The frequency of the carrier wave detected from the pulse and the frequency of the carrier wave detected from the PWM signal are the same except for errors.

Therefore, the processing load determination unit 43 can further acquire the following information.
(iv) PWM signal abnormality monitoring One PWM signal (one rectangular wave) should be formed in one carrier wave cycle. Therefore, the processing load determination unit 43 determines whether or not a PWM signal is detected within one carrier wave period. For example, if a time sufficiently longer than the period of the carrier wave is targeted, it is monitored whether the rising and falling edges of the PWM signal are detected. If the target is a time slightly shorter than the period of the carrier wave, it is monitored whether at least one of the rising edge and the falling edge of the PWM signal is detected.

  If the processing load determination unit 43 determines that the processing load has increased from (i) and (ii), the processing load determination unit 43 requests the fail safe unit 44 for fail safe. In this case, the fail safe unit 44 requests the carrier frequency control unit 33 to lower the frequency of the carrier wave. Since the frequency of inverter control is reduced by lowering the frequency of the carrier wave, the processing load on the motor control microcomputer 12 can be reduced.

  If the processing load determination unit 43 determines from (iv) that the PWM signal is abnormal, the processing load determination unit 43 requests the fail safe unit 44 for fail safe. In this case, the fail safe unit 44 turns off the switch 54 on the monitoring microcomputer 13 side to stop the output to the inverter 14.

  As described above, the motor control device 100 according to the present embodiment can reduce the processing load before the motor control microcomputer 12 becomes in a state that needs to be reset due to an abnormality.

[Operation procedure]
FIG. 5 is an example of a flowchart showing an operation procedure of the motor control microcomputer 12. The procedure of FIG. 5 is repeatedly executed for each carrier wave period.

  First, the motor control microcomputer 12 determines whether or not a PWM signal is output, and determines the operation mode of the motor control microcomputer 12 (S10). Whether or not the PWM signal is output is apparent depending on whether or not the motor control microcomputer 12 is generating the PWM signal, but may be determined by monitoring the PWM signal.

  When the PWM signal is not output and the mode is 1 (No in S10), the pulse creating unit 32 periodically switches the setting of the pulse to H or L (S80). That is, the duty of the pulse is fixed in a range of 10 to 90%, for example.

  When the PWM signal is output and in the mode 2 (Yes in S10), the inverter control unit 34 determines whether or not the cycle of the carrier wave has been started based on the carrier wave (S20).

  When the carrier wave period is started (Yes in S20), the inverter control unit 34 notifies the pulse generation unit 32 of the start of control, and the pulse generation unit 32 sets the pulse to H (S30).

  Thereafter, the inverter control unit 34 performs inverter control (S40).

  When the inverter control is completed, the inverter control unit 34 notifies the pulse generation unit 32 of the end of the control, so the pulse generation unit 32 sets the pulse to L (S50).

  The carrier frequency control unit 33 determines whether there is a fail-safe request from the monitoring microcomputer 13 at an arbitrary timing (S60).

  And when there exists a fail safe request | requirement (Yes of S60), the carrier frequency control part 33 reduces the processing load of CPU21 by lowering | hanging the frequency of a carrier wave (S70).

FIG. 6 is an example of a flowchart showing the operation procedure of the monitoring microcomputer 13.
First, the monitoring microcomputer 13 determines whether there is a PWM signal output and determines the operation mode of the monitoring microcomputer 13 (S110).

  When there is no PWM signal output and the mode is 1 (No in S110), the processing load determination unit 43 monitors the abnormality of the motor control microcomputer 12 from the pulse interval monitored by the pulse monitoring unit 41 (S200).

  When there is an output of the PWM signal and the mode 2 is selected (Yes in S110), the processing load determination unit 43 determines whether or not the pulse rising detection is acquired from the pulse monitoring unit 41 (S120).

  When the pulse rising detection is acquired (Yes in S120), the processing load determination unit 43 starts the timer 1, stops the timer 2, and starts again (S130). Timer 1 is a timer that measures the H time, and timer 2 is a timer that measures the period of the carrier wave.

  Next, the processing load determination unit 43 determines whether or not the pulse falling detection is acquired from the pulse monitoring unit 41 (S140).

  When the pulse falling detection is acquired (Yes in S140), the processing load determination unit 43 stops the count of the timer 1 (S150). Thereby, (i) processing load information is obtained. In addition, since (iii) the frequency of the carrier wave is known by the timer 2 in step S130, (ii) the CPU load margin is obtained.

  The processing load determination unit 43 performs fail-safe control 1 if necessary by comparing the H time with a predetermined value (S160). The fail safe control 1 is a fail safe that reduces the processing load of the motor control microcomputer 12.

  Next, the processing load determination unit 43 determines whether or not the count value of the timer 2 has exceeded a threshold value (S170). This threshold value is slightly shorter than the carrier wave cycle obtained in S130. You may determine dynamically from the period of a carrier wave.

  Therefore, when the count value of the timer 2 exceeds the threshold value (Yes in S170), the PWM signal should be detected, so the processing load determination unit 43 detects the rise or fall of the PWM signal from the PWM signal monitoring unit 42. (S180). For example, a flag that turns ON when the rising edge of the PWM signal is detected or falls is set (OFF after the reference).

  When the PWM signal is not detected, the processing load determination unit 43 performs fail-safe control 2 (S190). The fail safe control 2 is a fail safe that stops the output of the PWM signal to the inverter 14.

  As described above, the motor control apparatus 100 according to the present embodiment can monitor the processing load and the like even if there is no abnormality in the motor control microcomputer 12 by using pulses conventionally used. It is possible to perform an appropriate fail safe that does not increase.

  In the present embodiment, a motor control apparatus 100 that can further transmit arbitrary data using pulses will be described. In the present embodiment, the components denoted by the same reference numerals in the first embodiment perform the same functions, and therefore, only the main components of the present embodiment may be mainly described.

  FIG. 7 shows an example of a functional block diagram of the motor control microcomputer 12 and the monitoring microcomputer 13 of this embodiment. The motor control microcomputer 12 newly has a data preparation unit 35, and the monitoring microcomputer 13 has a data reception unit 45. The data preparation unit 35 processes arbitrary data for transmission and outputs it to the pulse generation unit 32. The data receiving unit 45 receives data from the pulse monitored by the pulse monitoring unit 41 according to the communication protocol.

  FIG. 8 is an example of a diagram illustrating the carrier wave, the PWM signal, and the pulse output. This embodiment is different from the first embodiment in that there are three blocks, a start block S, a data block D, and a processing load block L from the beginning of the pulse.

The motor control microcomputer carrier wave generator 31 may be the same as that of the first embodiment, but the pulse generator 32 generates a pulse based on the cycle of the carrier wave. That is, the pulse generator 32 starts H output before the inverter controller 34 starts inverter control. The start timing of the H output is Z time before the start point of the carrier wave period. Specifically, it is only necessary to start the H output by counting that "carrier wave cycle-Z time" elapses with a timer or the like from the start of the carrier wave cycle. Note that the Z time is ahead because the monitoring microcomputer 13 detects the start point of the data block at the rising edge of the PWM signal. In this sense, the PWM signal of this embodiment substitutes a clock signal for data transmission / reception.

  The pulse generator 32 maintains the H output for X hours. The X time may be a time shorter than the Z time since the monitoring microcomputer 13 can confirm the start block. To simplify the control, X time = Z time can be set.

  The data preparation unit 35 outputs a predetermined amount of data to the pulse generation unit 32 in advance, or outputs the data bit by bit to the pulse generation unit 32 in synchronization with the operation clock of the motor control microcomputer 12. As will be described later, any data may be transmitted. In this embodiment, it is assumed that 8 bits (1 byte) of data is transmitted in one cycle of the carrier wave (the size of the data block is 1 byte).

There are the following two modes for data transmission.
A. A mode in which each bit of one byte is given a meaning and the state of the motor control microcomputer 12 is notified depending on whether each bit is “1” or “0”. In the case of mode A in which more than one byte of data is transmitted by dividing it into a plurality of carrier wave periods, a maximum of eight types of information can be transmitted in one byte. In the case of mode B, the data preparation unit 35 prepares a data block (synchronization frame) of, for example, “00000000” before transmitting the data in order to notify the monitoring microcomputer 13 of the beginning of the data. Thereafter, even if the data to be transmitted is “00000000”, it is not set to “00000000”, so that bit 8 is fixed to “1”. For example, when “00000001” is transmitted, “10000001” is transmitted, when “00000010” is transmitted, “10000010” is transmitted, and when “00000011” is transmitted, “10000011” is transmitted. Therefore, the monitoring microcomputer 13 receives the data by interpreting the lower 7 bits as, for example, an ASCII code.

  Further, in order to notify the end of a group of data, the data preparation unit 35 prepares “00000000” again. Therefore, the first “00000000” to “00000000” is a group of data. When there is no data to be transmitted, for example, random data or “11111111” is transmitted as data other than “00000000”.

The data prepared by the data preparation unit 35 is error information, for example, and includes the following contents.
er1. A drop in the voltage of the microcomputer power supply system has been detected (there is a risk that the CPU may malfunction)
er2. Inverter 14 voltage error, microcomputer A / D conversion function or current sensor error detected (component error necessary for PWM signal creation)
er3. Log of control state of motor control microcomputer 12 without being limited to error information The motor control microcomputer 12 can transmit various information to the monitoring microcomputer 13 in this way.

  The pulse generation unit 32 sets the pulse to H until the inverter control unit 34 notifies the end of control following the insertion of the data block. That is, if the data block is “11111111”, the start block, the data block, and the processing load block become one rectangular wave. If the inverter control unit 34 notifies the end of control before the data block has been transmitted, there is no processing load block. Therefore, also in this embodiment, the start block rises by Z time earlier, and (i) the inverter control processing load can be notified in the time from the rise of the pulse (start block) to the fall of the pulse. The same applies to (ii) CPU load margin and (iii) carrier wave frequency.

-Monitoring microcomputer 13
The pulse monitoring unit 41 of the monitoring microcomputer 13 monitors the pulse and notifies the processing load determination unit 43 that, for example, the rise of L → H has been detected. In addition, since the data block may include L bits, the processing load determination unit 43 is notified that the falling edge of H → L has been detected after ignoring the bit string having a length of “Z time + 1 byte”. As a result, the processing load determination unit 43 acquires the following four pieces of information.
(i) Processing load information
(ii) CPU load margin
(iii) Carrier wave frequency
(iv) Monitoring the abnormality of the PWM signal The period of the carrier wave may be the time from the rising edge of the pulse to the next rising edge, but since the position of the period is shifted forward by Z time, not only the period of the carrier wave, To synchronize including the position, the carrier wave frequency is corrected for Z time. Even without such correction, (iv) it is possible to monitor the abnormality of the PWM signal.

Further, the data receiving unit 45 can further acquire the following information.
(v) Data Contents The data receiving unit 45 detects the head of the data block by detecting the rising edge of the PWM signal notified by the PWM signal monitoring unit 42. The data receiving unit 45 extracts 7 bits from the top of the data block from the pulse (8 bits may be extracted from the pulse and the 8th bit may be deleted).

  For example, when the fail safe unit 44 receives error information of ex1 (abnormality of the microcomputer power supply), the fail safe unit 44 shortens the predetermined value compared with the H time. If there is an abnormality in the microcomputer power supply, there is a high possibility that the CPU will be affected, so the processing load on the motor control microcomputer 12 can be reduced early. For example, when ex2 error information (abnormality of parts necessary for PWM signal creation) is received, the fail safe unit 44 stops outputting the PWM signal. When there is an abnormality in the parts necessary for creating the PWM signal, the control can be stopped by assuming that the reliability of the PWM signal is low.

[Operation procedure]
FIG. 9 is an example of a flowchart showing an operation procedure of the motor control microcomputer 12. The procedure of FIG. 9 is repeatedly executed for each carrier wave period. S210 and S300 are the same as those in the first embodiment.

  In the case of mode 2, the pulse generating unit 32 determines whether or not the time is Z time before the carrier wave cycle by using the carrier wave cycle and a timer (S220).

  When the time is Z time before the start of the carrier wave cycle (Yes in S220), the pulse generating unit 32 sets the pulse to H and holds it for X time (S230). When the X time and the Z time are not equal, the pulse generating unit 32 sets the pulse to H or L until the carrier wave period starts. When the carrier wave cycle is started, the inverter control unit 34 performs inverter control.

  The pulse creation unit 32 sets the 1-byte data prepared by the data preparation unit 35 as a pulse (S240).

  Next, the pulse generator 32 sets H to the pulse (S250). If the end of control in the next S260 is notified before setting 1-byte data in a pulse, H in S250 is not set.

  The pulse generating unit 32 maintains the pulse at H until the inverter control unit 34 notifies the pulse generating unit 32 of the end of control (S260).

  When the inverter control is completed, the inverter control unit 34 notifies the pulse generation unit 32 of the end of the control, so the pulse generation unit 32 sets the pulse to L (S270).

  The carrier frequency control unit 33 determines whether there is a fail-safe request from the monitoring microcomputer 13 at an arbitrary timing (S280).

  If there is a fail-safe request (Yes in S280), the carrier frequency control unit 33 reduces the processing load on the CPU by lowering the frequency of the carrier wave (S290).

  FIG. 10 is an example of a flowchart showing the operation procedure of the monitoring microcomputer 13. Steps S410 and S530 are the same as those in the first embodiment.

  When there is an output of the PWM signal and in the mode 2, the processing load determination unit 43 determines whether or not the pulse rising detection is acquired from the pulse monitoring unit 41 (S420).

  When the rising edge detection is acquired (Yes in S420), the processing load determination unit 43 starts the timer 1, stops the timer 2, and starts again (S430). Timer 1 is a timer that measures the H time, and timer 2 is a timer that measures the period of the carrier wave.

  Next, the processing load determination unit 43 determines whether or not the PWM signal rising edge detection has been acquired from the PWM signal monitoring unit 42 (S440). Thereby, the head of a data block can be specified.

  When the rising edge detection of the PWM signal is acquired (Yes in S440), the data receiving unit 45 extracts a data block from the pulse (S450).

  The data receiving unit 45 receives a group of error information and the like, determines the error content, and requests the fail safe control 3 from the fail safe unit 44 if necessary (S460). The fail-safe control 3 includes early determination of abnormality and stop of the PWM signal.

  Next, the processing load determination unit 43 determines whether or not pulse falling detection has been acquired from the pulse monitoring unit 41 (S470). As described above, the trailing edge until the end of the data block is ignored.

  When the pulse falling detection is acquired (Yes in S470), the processing load determination unit 43 stops the count of the timer 1 (S480). Thereby, (i) processing load information is obtained. In addition, since (iii) the frequency of the carrier wave is known by the timer 2 in step S430, (ii) the CPU load margin is obtained.

  The processing load determination unit 43 performs fail-safe control 1 if necessary by comparing the H time with a predetermined value (S490). The fail safe control 1 is a fail safe that reduces the processing load of the motor control microcomputer 12.

  Next, the processing load determination unit 43 determines whether or not the count value of the timer 2 has exceeded a threshold value (S500). This threshold value is slightly shorter than the carrier wave period obtained in S430. It may be determined dynamically. In this embodiment, the rising edge of the PWM signal is detected in step S440, but if it is not detected in step S440, the timer 2 exceeds the threshold value in step S500.

  Therefore, when the count value of the timer 2 exceeds the threshold value (Yes in S500), the PWM signal should be detected, so the processing load determination unit 43 detects the rising or falling edge of the PWM signal from the PWM signal monitoring unit 42. (S510).

  When the PWM signal is not detected, the processing load determination unit 43 performs fail-safe control 2 (S530). The fail safe control 2 is a fail safe that stops the output of the PWM signal to the inverter 14.

  As described above, in addition to the effects of the first embodiment, the motor control device 100 according to the present embodiment allows the motor control microcomputer 12 to transmit arbitrary data to the monitoring microcomputer 13 by a monitoring pulse.

12 Motor control microcomputer 13 Monitoring microcomputer 14 Inverter 21 CPU
51 Pulse line 52 PWM signal line 53 Fail-safe signal line 54 Switch 100 Motor controller

Claims (9)

An electronic control device comprising: first information processing means for continuously outputting a pulse signal; and second information processing means for receiving the pulse signal,
PWM signal creation means for computing external information acquired from the outside and creating a PWM signal;
When the PWM signal creation means starts creating the PWM signal, the pulse signal is set to Low and when the creation is finished, it is set to High, or when creation of the PWM signal is started, it is set to Low and the creation is finished. A pulse signal creating means for creating the pulse signal by setting it to High when
A creation time measuring means for monitoring the pulse signal and measuring a creation time from when the PWM signal creation means starts creating the PWM signal to when it finishes;
An electronic control device comprising: The PWM signal creating means creates a PWM signal for each carrier wave period,
The creation time measuring means monitors the fall or rise of the pulse signal, and the time from when the PWM signal creation means starts creating the PWM signal to the next time when the creation of the PWM signal is started is a carrier. Measure as wave period,
The electronic control device according to claim 1. The pulse signal creation means inserts data of a predetermined length into the pulse signal between the time when the PWM signal creation means starts creating the PWM signal and the time when the creation ends.
PWM signal monitoring means for monitoring the PWM signal and detecting the rising edge of the PWM signal;
A data receiving means for specifying the time when the rising edge of the PWM signal is detected as the head of the data and receiving the data;
The electronic control device according to claim 1, further comprising:   The electronic control device according to claim 1, further comprising fail-safe means for lengthening a carrier wave period when the creation time is equal to or greater than a predetermined value. PWM signal monitoring means for monitoring the PWM signal and detecting at least one of the rising edge and falling edge of the PWM signal;
Fail safe means for stopping the output of the PWM signal when the PWM signal monitoring means does not detect either the rise or fall of the PWM signal within the period of the carrier wave measured by the creation time measurement means,
The electronic control device according to claim 2, further comprising: When the PWM signal creation means has not created a PWM signal, the pulse signal creation means creates the pulse signal whose state is periodically switched,
The fail-safe means performs fail-safe processing on the PWM signal creating means when the state of the pulse signal is not switched within a predetermined time.
The electronic control device according to claim 4 or 5, wherein If the creation time is greater than or equal to a predetermined value, it has fail-safe means for increasing the period of the carrier wave,
The fail safe means changes the predetermined value according to the data received by the data receiving means.
The electronic control device according to claim 3. An information processing device that continuously outputs the pulse signal to a second information processing device that measures a creation time from the time when the information processing device receives a pulse signal to the time when it finishes creating a PWM signal. Because
PWM signal creation means for computing external information acquired from the outside and creating a PWM signal;
When the PWM signal creation means starts creating the PWM signal, the pulse signal is set to Low and when the creation is finished, it is set to High, or when creation of the PWM signal is started, it is set to Low and the creation is finished. A pulse signal creating means for creating the pulse signal by setting it to High when
An information processing apparatus comprising: PWM signal creation means for computing external information acquired from the outside and creating a PWM signal;
When the PWM signal creation means starts creating the PWM signal, the pulse signal is set to Low and set to High when the creation is finished, or set to Low when the creation of the PWM signal is started and the creation is finished. From a second information processing apparatus having pulse signal creating means for creating the pulse signal by setting it to High sometimes
Pulse signal receiving means for receiving the pulse signal;
A creation time measuring means for monitoring the pulse signal and measuring a creation time from when the PWM signal creation means starts creating the PWM signal to when it finishes;
An information processing apparatus comprising:

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