JP2020112104A - Internal combustion engine control device - Google Patents

Abstract

To provide an internal combustion engine control device capable of suppressing the deviation of a crank angle even when switching a signal which is a generation source of an angle clock.SOLUTION: An engine ECU 1 includes an input switching unit 112, an acquisition unit 113, and a mask edge calculation unit 114. The acquisition unit 113 acquires an interrupt request flag and a change in the number of edges of a crank signal before the input switching unit 112 switches a signal that is a generation source of an angle clock. The mask edge calculation unit 114 corrects an increase amount of the number of edges according to the necessity of executing a crank interrupt processing, which is determined according to the interrupt request flag acquired by the acquisition unit 113 and the presence or absence of a change in the number of edges of the crank signal, and calculates the number of mask edges.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to an internal combustion engine control device that generates an angle clock.

Patent Document 1 discloses an electronic control device used for controlling an engine. The electronic control device of Patent Document 1 has an angle clock generation circuit and a processor. The angle clock generation circuit outputs the angle clock generated by multiplying the edge interval of the input signal by the generation rate set by the processor. The angle clock generation circuit normally receives a crank signal and generates an angle clock based on the edge interval of the crank signal. The angle clock generation circuit receives an input of a cam signal instead of the crank signal in a predetermined situation such as an abnormality of the crank signal, and generates an angle clock based on the edge interval of the cam signal.

The software processing executed by the processor includes crank interrupt processing started based on the occurrence of an edge of the crank signal. The processor that has started the crank interrupt process calculates the current crank angle based on the number of edges and performs various controls based on the calculated crank angle.

Japanese Patent Laid-Open No. 2006-200484

In such an internal combustion engine control device, a configuration may be adopted in which the processing load of the processor is reduced by suppressing the execution frequency of interrupt processing. Specifically, a configuration is adopted in which the processor activates the crank interrupt process only when a frequency division edge generated by dividing the crank signal by a predetermined frequency division ratio occurs. In such a configuration, a predetermined number of edges (hereinafter referred to as mask edges) for which the crank interrupt processing is not activated exist between each divided edge. The crank interrupt processing started by the frequency division edge is considered to have generated a predetermined number of mask edges from the previous frequency division edge to the current frequency division edge, and the crank angle is calculated according to the number of edges and synchronized with the crank angle. Perform the process.

When the input to the angle clock generator is switched from the crank signal to the cam signal as in Patent Document 1 in the configuration for reducing the processing load described above, the crank interrupt processing is executed only by the divided edge, Changed to run. As a result, at the time of switching, there is a possibility that the relationship between the edge that started the crank interrupt process and the number of mask edges may not be maintained correctly. Therefore, the calculated crank angle may deviate from the actual crank angle.

An object of the present disclosure is to provide an internal combustion engine control device capable of suppressing a crank angle deviation even when switching a signal that is a generation source of an angle clock.

The above objective is achieved by a combination of features described in independent claims, and the subclaims define further advantageous embodiments of the present disclosure. The reference numerals in parentheses in the claims indicate the correspondence with the specific means described in the embodiments described later as one aspect, and do not limit the technical scope of the present disclosure. ..

An internal combustion engine control device of the present disclosure for achieving the above object includes an angle clock generation unit (141) that generates an angle clock based on a crank signal or a cam signal that is input from an internal combustion engine, and a current internal combustion engine. The crank angle processing unit (111) that performs processing based on the crank angle, the input switching unit (112) that switches the input to the angle clock generation unit from the crank signal to the cam signal, and the number of edges counting the edges of the crank signal are displayed. An edge counter (142) that holds the flag, a flag register (161) that holds an interrupt request flag that is a flag based on the edge of the crank signal and that requests wake-up of the crank angle processing unit, and an input switching period by the switching unit, An acquisition unit (113) that acquires the holding status of the flag register and the change in the number of edges, and a mask that calculates the number of mask edges based on the holding status of the flag register and the change in the number of edges acquired by the acquiring unit. An edge calculation unit (114).

According to the above configuration, the edge counter counts the number of edges, and the flag register holds the interrupt request flag for waking up the crank angle processing unit based on the edge. Therefore, the mask edge calculation unit can calculate the number of mask edges according to the interrupt request flag held by the flag register and the presence or absence of a change in the number of edges. Therefore, the internal combustion engine control device can suppress the deviation of the crank angle even when switching the signal that is the generation source of the angle clock.

It is a figure which shows the structure of an engine ECU. It is a figure which shows the structure of a microcomputer. It is a flowchart which shows a signal switching process. 4 is a flowchart showing a crank signal setting subroutine of FIG. 3. 6 is a timing chart showing an example of correspondence between interrupt processing and the number of mask edges. 7 is a timing chart showing another example of correspondence between interrupt processing and the number of mask edges. It is a timing chart which shows another example of correspondence of interrupt processing and a mask edge. It is a flow chart which shows a crank signal setting subroutine of a second embodiment. It is a flow chart which shows a crank signal setting subroutine of a third embodiment. It is a flowchart which shows the crank signal setting subroutine of 4th embodiment.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. In the description of each embodiment, corresponding components may be denoted by the same reference numerals and redundant description may be omitted. When only a part of the configuration is described, the above-described embodiments can be applied to other parts of the configuration. Further, not only the combination of the configurations explicitly described in the description of each embodiment, but also the configuration may be partially combined even if it is not explicitly described unless the combination causes any trouble.

<First embodiment>
The engine ECU 1 according to the first embodiment of the present disclosure shown in FIG. 1 is an electronic control device used for controlling an internal combustion engine such as a gasoline engine or a diesel engine for a vehicle, and corresponds to an “internal combustion engine control device”. The engine ECU 1 sequentially grasps the state of the internal combustion engine such as the rotation angle of the crankshaft (hereinafter referred to as crank angle) based on the detection signals from the crankshaft sensor 2 and the camshaft sensor 3, and controls the internal combustion engine.

The crankshaft sensor 2 outputs a crank signal whose voltage level varies according to the crank angle to the engine ECU 1. The crankshaft sensor 2 is, for example, a magnetic sensor, and detects a variation in magnetic field strength according to a crank angle by a crank signal rotor 5 provided on the crankshaft 4. The crank signal rotor 5 is a substantially disk-shaped magnetic member that is provided with teeth protruding on the outer periphery at predetermined angular intervals and that rotates integrally with the crankshaft 4.

The crankshaft sensor 2 is provided at a position facing the teeth of the crank signal rotor 5, and detects a change in magnetic field strength caused by the passage of the teeth as the crank signal rotor 5 rotates. The teeth of the crank signal rotor 5 are provided every 10 degrees except for a part of the outer circumference, for example. As a result, the rising edges of the crank signal occur at substantially equal angular intervals every 10 degrees rotation of the crankshaft 4 except for a part of the outer circumference.

The cam shaft sensor 3 outputs to the engine ECU 1 a cam signal whose voltage level varies according to the rotation of the cam shaft 6 of the internal combustion engine. The cam shaft sensor 3 is, for example, a magnetic sensor similar to the crank shaft sensor 2 and detects a change in magnetic field strength due to passage of teeth of a cam signal rotor 7 provided on the cam shaft 6. The camshaft 6 rotates at a speed half that of the crankshaft 4, and makes one rotation every two rotations of the crankshaft 4, that is, one combustion cycle of the internal combustion engine.

The teeth of the cam signal rotor 7 are provided with uneven angular widths and intervals. As a result, the rising and falling edges of the cam signal occur at uneven angular intervals as the cam shaft 6 rotates. Although one camshaft sensor 3 is shown as an input to the engine ECU 1 in FIG. 1, the number of camshaft sensors 3 can be appropriately changed according to the number of camshafts 6 of the internal combustion engine, a control algorithm, and the like. ..

The engine ECU 1 is an electronic control device that includes an input circuit 10, an output circuit 20, and a microcomputer 100. The input circuit 10 is a circuit for fetching the crank signal and the cam signal input from the crankshaft sensor 2 and the camshaft sensor 3 into the microcomputer 100. The input circuit 10 shapes, for example, the waveforms of the crank signal and the cam signal into a binary rectangular wave shape and inputs them to the microcomputer 100.

The output circuit 20 is a circuit that outputs a drive signal to a control target of the engine ECU 1, such as an injector or an igniter, based on the determination by the microcomputer 100. For example, the output circuit receives a drive signal output instruction for each control target from the microcomputer 100 and outputs the drive signal to the corresponding control target.

As shown in FIG. 2, the microcomputer 100 is a microcomputer including a storage unit 101 such as a semiconductor memory and a processor core 110 such as a CPU. The storage unit 101 corresponds to a non-transitional and substantive storage medium that non-temporarily records software executed by the processor core 110. The microcomputer 100 includes various peripheral function circuits including a timer array unit 120 and an interrupt controller 160, in addition to the storage unit 101 and the processor core 110 described above. The various peripheral function circuits, the storage unit 101, and the processor core 110 are connected to each other via an internal bus. The processor core 110 realizes various functions for controlling the internal combustion engine in cooperation with peripheral function circuits and the like by executing various kinds of processing defined by software stored in the storage unit 101.

The timer array unit 120 is a peripheral function circuit configured of a large number of logic circuits and the like and providing various timer functions. The timer array unit 120 includes an edge detection timer 130, an angle clock generation timer 140, and an output timer 150.

The edge detection timer 130 is a timer that detects an edge generated in the crank signal and the cam signal input to the microcomputer 100 and inputs the detected edge to the angle clock generation timer 140. The edge detection timer 130 includes a crank edge detection unit 131, a cam edge detection unit 132, and a channel selection unit 133.

The crank edge detection unit 131 is a channel that is configured to include, for example, a shift register or the like, and that receives an input of a crank signal from the input circuit 10. The crank edge detection unit 131 detects any of the rising edges, the falling edges, or both edges of the crank signal edges. The crank edge detection unit 131 of the present embodiment detects a rising edge and outputs a crank edge signal indicating whether or not a rising edge has been detected. The crank edge signal is a pulsed signal that temporarily changes the voltage level when a rising edge is detected. The pulse width of the crank edge signal, that is, the period during which the voltage level is temporarily changed corresponds to one cycle of the operation clock of the microcomputer 100.

Here, one cycle of the operation clock is set to be sufficiently shorter than the interval between the rising edges at the maximum rotation speed of the internal combustion engine, that is, the shortest time required to rotate the crankshaft by 10 degrees. For example, one cycle is set to be less than a few tenths of the shortest time. Therefore, each pulse of the crank edge signal has a one-to-one correspondence with the rising edge of the crank signal. Therefore, the number of pulses of the crank edge signal matches the number of rising edges of the crank signal. The crank edge detection unit 131 notifies the interrupt controller 160 of the detection of the rising edge each time the rising edge is detected.

The cam edge detection unit 132 is a channel configured to include a shift register or the like, for example, and receives a cam signal input from the input circuit 10. The cam edge detection unit 132 detects, for example, both a rising edge and a falling edge of the cam signal, and outputs a cam edge signal indicating the presence or absence of detection. The cam edge signal is a pulsed signal whose voltage level is temporarily changed when a rising or falling edge is detected. The pulse width of the cam edge signal corresponds to one cycle of the operation clock, like the crank signal.

The channel selection unit 133 is a circuit configured to include a multiplexer, for example, and selects a channel of a signal input to the angle clock generation timer 140. The channel selection unit 133 switches the channel to be selected according to the selection signal from the processor core 110. That is, the channel selection unit 133 switches a circuit of the crank edge detection unit 131 and the cam edge detection unit 132, which is connected to the angle clock generation timer 140 and inputs a signal, according to an instruction from the processor core 110. When the crank signal is normal, the channel selection unit 133 selects the crank signal channel, that is, the crank edge detection unit 131, as the input to the angle clock generation timer 140.

The angle clock generation timer 140 is a timer for generating an angle clock. The angle clock is a signal for estimating the transition of the crank angle at intervals smaller than the rising edge interval of the crank signal. The angle clock is set so that the transition of the crank angle can be estimated with a resolution of 1/16 degree, for example.

Specifically, the angle clock is a pulse-shaped signal that is output each time the crank angle is estimated to have changed once, and is output with a pulse width corresponding to one cycle of the operation clock. However, the pulse of the angle clock can be integrated with the preceding and succeeding pulses to have a pulse width corresponding to a plurality of cycles of the operation clock when correcting the shortening of the pulse interval due to the rapid acceleration. The angle clock generation timer 140 includes an angle clock generation unit 141, an edge counter 142, and a frequency division compare unit 143.

The angle clock generation unit 141 is a circuit that generates an angle clock by multiplying the pulse interval of the input signal to the angle clock generation timer 140 according to a predetermined generation ratio. The generation rate is a numerical value indicating the ratio of the angular interval in which a pulse is generated in the input signal with respect to the angular interval of the output angle clock, and is set according to the instruction from the processor core 110. For example, when the crank edge signal is input to the angle clock generation unit 141, 160 times is set as the generation magnification except for a part of the crank angle range. When a cam edge signal is input to the angle clock generation unit 141, an individual numerical value is set as a generation rate for each pulse interval. For example, when a certain pulse interval corresponds to 30° rotation of the cam shaft, that is, corresponds to 60° rotation of the crankshaft, 960 times the pulse interval is set as the generation magnification.

The angle clock generation unit 141 measures by counting the pulse interval of the input signal as the number of operation clocks generated between the pulses. The angle clock generation unit 141 updates the pulse interval of the angle clock in the period until the next pulse is generated, for example, every time a pulse occurs in the input signal. The pulse interval is set to a value obtained by dividing the number of operating clocks counted from the immediately preceding pulse by the generation rate. The angle clock generation unit 141 counts the number of operation clocks, for example, and generates a pulse of the angle clock and resets the count each time the set pulse interval matches.

The edge counter 142 is a counter that measures the number of edges of the crank signal. The edge counter 142 measures the number of rising edges by counting up each time a pulse is generated in the crank edge signal, for example. The upper limit of the number that can be counted by the edge counter 142 is set to be equal to or higher than the frequency division ratio described later.

The frequency division compare unit 143 is a circuit for detecting a part of the rising edges of the crank signal as a frequency division edge and notifying it to the interrupt controller 160. In other words, the frequency division compare unit 143 exerts a function of using an edge other than the frequency division edge as a mask edge that does not notify the interrupt controller 160. The dividing edges are selected from the rising edges at intervals of 30 degrees, for example.

The frequency division compare unit 143 includes, for example, a register that holds the number of edges corresponding to the next frequency division edge. When the number of pulses counted by the edge counter 142 matches the number of edges held in the register, the frequency division compare unit 143 notifies the interrupt controller 160 of the generation of the frequency division edge. The number of edges corresponding to the next frequency division edge is newly written in the register by the crank interrupt processing described later executed by the notification. The number of newly written edges is the value obtained by adding the ratio of the angular interval of the dividing edge to the angular interval of the rising edge (hereinafter, the dividing ratio) to the number of edges before rewriting, except for some crank angle ranges. Becomes Between the dividing edges, there are mask edges with a dividing ratio of -1.

The output timer 150 is a timer having a function of instructing the output circuit 20 to output a drive signal. The output timer 150 includes an angle counter and an output period register. The angle counter is a counter for counting the numerical value of the estimated current crank angle. The angle counter counts up each time a pulse of the angle clock is generated, for example.

The output period register is a register for holding an output period, that is, a crank angle range for outputting a drive signal to each control target. The output period register has, for each control target, an area for holding a numerical value indicating the start and end timings of the output of the drive signal set by the processor core 110. When the count value of the angle counter matches the value held by the output period register, the output timer 150 instructs the output circuit 20 to start or stop the output of the drive signal to the corresponding drive target.

Due to the control of the timer array unit 120, the function of the processor core 110 includes the function of the crank angle processing unit 111.

The crank angle processing unit 111 is a function performed by the processor core 110 that is executing the crank interrupt process among the processes included in the software stored in the storage unit 101. The crank interrupt process is a type of interrupt process performed according to an interrupt request from the interrupt controller 160. The crank interrupt process is performed every time a specific crank angle is reached in synchronization with the transition of the crank angle. In other words, the crank angle processing unit 111 is a function of the processor core 110 that wakes up each time a specific crank angle is reached.

The crank interrupt process is executed according to the occurrence of the rising edge of the crank signal. More specifically, in the normal state, it is executed every time a frequency division edge occurs. However, the normal state means a state in which the crank edge signal is input as the input signal to the angle clock generation timer 140. When the cam edge signal is input as the input signal to the angle clock generation timer 140, it is executed every time the rising edge is generated.

Each time the crank interrupt process is executed, the current crank angle is calculated by adding the amount of change in the crank angle from the previous execution to the crank angle calculated in the previous startup. The amount of change in the crank angle depends on the number of edges generated in the crank signal from the previous execution to the current execution. That is, the number of edges since the previous execution×10 degrees is the amount of change in the crank angle from the previous execution.

For example, in the normal state, two mask edges have occurred in addition to the frequency division edge for which the crank interrupt processing has been executed, so that three edges from the previous execution have occurred. Therefore, the crank angle processing unit 111 calculates the crank angle by adding 30 degrees to the previous crank angle each time it is executed.

When the input signal to the angle clock generation timer 140 is the cam edge signal, no edge other than the edge for which the interrupt processing has been executed has occurred, so the number of edges from the previous execution is 1. Therefore, the crank angle processing unit 111 calculates the crank angle by adding 10 degrees to the previous crank angle each time it is executed.

Further, when a specific numerical value is calculated as the number of mask edges, the crank angle processing unit 111 corrects the amount of change according to the calculated number of mask edges and calculates the crank angle. That is, the crank angle processing unit 111 calculates the number obtained by adding 1 to the number of mask edges×10 degrees as the amount of change from the previous execution. Therefore, the change amount when a specific numerical value is calculated as the number of mask edges increases as the number of mask edges increases.

When the current crank angle is calculated, the crank interrupt process moves to execution of a process associated with the crank angle. The process associated with the crank angle, in other words, the process executed in synchronization with the crank angle includes, for example, a fuel injection process matched to the combustion cycle. The crank interrupt process includes a process of setting the crank angle at which the crank interrupt process is to be executed next by writing the number of edges corresponding to the next frequency division edge into the register of the frequency division compare unit 143.

The interrupt controller 160 is a peripheral function circuit having a function of managing whether or not to execute various interrupt processes set in software executed by the processor core 110, the priority order, and the like. The interrupt controller 160 receives the interrupt request transmitted from the inside and outside of the microcomputer 100, and causes the processor core 110 to execute a corresponding interrupt process. The interrupt controller 160 is provided with a register for holding that an interrupt request has been received for each interrupt process.

The interrupt controller 160 is provided with a frequency division flag register 161a and an edge flag register 161b as flag registers 161 for holding interrupt flags for executing crank interrupt processing.

The condition for switching the flag of the frequency division flag register 161a is set so that the crank interrupt process is executed every time the frequency division edge is generated among the rising edges of the crank signal. The frequency division flag register 161a is set to ON indicating that an interrupt request has been made, for example, when a frequency division edge occurs. The frequency division flag register 161a is cleared to have been requested and is set to OFF when the flag is used for executing the crank interrupt process.

The interrupt request by the frequency division flag register 161a is switched to an invalid state when the input signal to the angle clock generation timer 140 is a cam edge signal. That is, the frequency division flag register 161a is not used for executing the crank interrupt process when the input signal is the cam edge signal even when the interrupt flag is in the on state.

The flag switching condition of the edge flag register 161b is set so that the crank interrupt process is executed each time a rising edge in the crank signal occurs. The edge flag register 161b is set to ON indicating that an interrupt request has been made, for example, when a pulse occurs in the crank edge signal. Further, the edge flag register 161b is cleared to have been requested and is set to OFF when used for executing the crank interrupt process.

The interrupt request by the interrupt flag of the edge flag register 161b is set to the invalid state in the normal state. That is, the edge flag register 161b is not used for executing the crank interrupt process in the normal state even when the interrupt flag is on.

As a function related to switching of an input signal to the angle clock generation timer 140, the functions of the processor core 110 include a function as an input switching unit 112, an acquisition unit 113, and a mask edge calculation unit 114.

The input switching unit 112 is a function exhibited by the processor core 110 that has executed a signal switching process for switching the input signal to the angle clock generation timer 140. The signal switching process is a process of switching the input signal to the angle clock generation timer 140, which is executed when it is determined that a predetermined input switching condition is satisfied, such as when an abnormality in the crank signal is detected. .. The period during which the signal switching process is executed corresponds to the input switching period.

Whether the input switching condition is satisfied or not, that is, the crank signal abnormality detection is periodically executed. When the crank signal is abnormal, signal switching processing is executed to cause the processor core 110 to perform the function as the input switching unit 112. The signal switching process is set to have a higher priority than, for example, the crank interrupt process, and makes the execution of the crank interrupt process wait until the execution is completed. Further, during the execution of the signal switching process, the cycle of the operation clock of the microcomputer 100 is sufficiently shorter than the edge interval, so that only one edge of the crank signal is generated or not generated. That is, a plurality of edges do not occur during execution of the signal switching process.

The input switching unit 112 outputs a switching signal for the selected channel to the channel selection unit 133 and performs a switching instruction process for switching the input signal from the crank edge signal to the cam edge signal. When the input switching condition is satisfied, the input switching unit 112 causes the acquisition unit 113 to acquire various information and then performs the switching instruction process.

The input switching unit 112 performs a process of changing the setting of the valid or invalid state of the interrupt request flag held by the flag register 161 before the switching instruction process. More specifically, the input switching unit 112 performs an invalidation process for changing the interrupt request of the frequency division flag register 161a from the valid state to the invalid state. The input switching unit 112 also performs an activation process for changing the interrupt request of the edge flag register 161b from the invalid state to the valid state. Further, the input switching unit 112 performs a clear process of clearing the flag of the edge flag register 161b before switching to the cam edge signal.

The acquisition unit 113 is a function exhibited by the processor core 110 that has executed the acquisition process. The acquisition process is a part of the crank signal side setting process related to signal switching, which is set as a subroutine of the signal switching process.

The acquisition unit 113 acquires the status of holding the interrupt flag in the flag register 161 and the change in the number of edges of the edge counter 142 before switching the input signal by the input switching unit 112. Specifically, the above information is acquired during the period from the start of the current signal switching process to the switching of the input signal.

More specifically, in the flag register 161, a flag acquisition process for acquiring the state of the interrupt flag held by the frequency division flag register 161a is performed. The acquisition unit 113 also acquires twice the number of edges counted by the edge counter 142. The acquisition unit 113 performs the edge number acquisition process for acquiring the edge number once each before and after the flag acquisition process. Hereinafter, the number of edges acquired by the edge number acquisition process before the flag acquisition process corresponding to the first edge number acquisition process will be referred to as the previous edge number. The acquisition of the number of front edges is performed before the flag is cleared by the input switching unit 112. Further, the number of edges acquired by the edge number acquisition process before the flag acquisition process corresponding to the second edge number acquisition process is referred to as the rear edge number. The acquisition of the number of trailing edges is performed after the flag is cleared by the input switching unit 112.

The mask edge calculation unit 114 is a function performed by the processor core 110 that has executed the mask edge calculation process. The mask edge calculation process is a part of the setting process on the crank signal side related to signal switching, which is set as a subroutine of the signal switching process.

The mask edge calculation unit 114 calculates the number of mask edges according to the switching of the input signal. When switching the input signal, the number of mask edges may temporarily become a number different from the frequency division ratio −1 due to a change in the execution condition of the crank interrupt process. The mask edge calculation unit 114 calculates the number of mask edges in which such a temporary change is corrected.

The mask edge calculation unit 114 calculates the number of mask edges based on the interrupt flag holding status acquired by the acquisition unit 113 and the change in the number of edges. As described above, the mask edge is an edge that has not been used in crank interrupt processing without being notified to the interrupt controller 160 among the generated edges. Therefore, the number of mask edges is calculated by determining the amount of increase in the number of edges since the immediately preceding crank interrupt process and determining whether or not the edge used in the process needs to be subtracted from the amount of increase.

The amount of increase in the number of edges indicates the number of edges generated in the crank signal since the immediately preceding crank interrupt process. The mask edge calculation unit 114 calculates the amount of increase in the number of edges by subtracting the number of edges at the time of the immediately preceding crank interrupt processing from the number of rear edges.

The edge to be subtracted from the increase amount in calculating the mask edge is an edge to be used for executing the crank interrupt process, among the edges counted as the increase amount. That is, among the edges that have occurred before the acquisition of the number of trailing edges, the edges that have occurred after the start of the input change processing and have not yet executed the requested crank interrupt processing. Therefore, the mask edge calculation unit 114 determines whether or not the subtraction is necessary by determining whether or not the interrupt processing is required to be executed in the period from the start of the input change processing to the acquisition of the number of rear edges.

More specifically, the mask edge calculation unit 114 determines whether or not the interrupt flag of the frequency division flag register 161a acquired by the acquisition unit 113 is ON, or when the number of front edges and the number of rear edges are different. Judge that execution of interrupt processing is required. The mask edge calculation unit 114 determines that the crank interrupt process does not need to be executed when the interrupt flag is off and the number of front edges and the number of rear edges match.

When the mask edge calculation unit 114 determines that the crank interrupt process needs to be executed, the mask edge calculation unit 114 subtracts the corresponding edges to calculate the number of mask edges. That is, the number obtained by subtracting 1 from the amount of increase in the number of edges is determined as the number of mask edges. Even when the interrupt flag is on and the number of front edges and the number of rear edges are different, the mask edge calculation unit 114 determines that the crank interrupt process should be executed only once, and subtracts 1 from the crank interrupt process. When the mask edge calculation unit 114 determines that the crank interrupt process does not need to be executed, the mask edge calculation unit 114 calculates the number of mask edges without subtracting the edges. That is, the amount of increase in the number of edges is determined as the number of mask edges.

The mask edge calculation unit 114 executes the crank interrupt process according to the determined necessity of execution, for example, by rewriting the interrupt flag held in the edge flag register 161b. That is, when the mask edge calculation unit 114 determines that the execution is required, the mask edge calculation unit 114 rewrites the edge flag register 161b to ON. With the edge flag register 161b rewritten to be ON, the crank interrupt process is forcibly executed after the completion of the switching process.

The mask edge calculation unit 114 does not rewrite the interrupt flag of the edge flag register 161b when it is determined that the execution is not necessary. That is, the edge flag register 161b remains in the state cleared by the input switching unit 112. When the edge flag register 161b which has not been rewritten is turned on in accordance with the edge generated after clearing, the crank interrupt processing is executed independently of the signal switching processing. The crank interrupt process calculates the crank angle according to the temporary mask edge number calculated by the mask edge calculation unit 114 only when it is first executed after the completion of the signal switching process.

[Operation of processor core 110]
The operation of the processor core 110 will be described with reference to the flowcharts of FIGS. 3 and 4. The processor core 110 periodically executes the process shown in FIG. 3 from S101 as the signal switching process during the control of the internal combustion engine.

In S101, it is determined whether or not the crank signal is abnormal. If it is determined that an abnormality has occurred, it is necessary to switch the input signal to the angle clock generation timer 140 to the cam signal, and the process proceeds to S102. If it is determined that no abnormality has occurred, the processing shown in FIG. 3 is terminated. The input switching period starts from S101.

In S102, the crank signal setting subroutine shown in FIG. 4 is executed in order to make various settings for the crank signal when switching to the cam signal. In the crank signal setting subroutine, the processing shown in FIG. 4 is executed from S110.

In S110, the interrupt controller 160 enables the crank interrupt processing by the edge flag register 161b. That is, as the validation process, a process for validating the execution of the crank interrupt process for each edge detection of the crank signal is executed.

In S111, the current number of edges is acquired from the edge counter 142. That is, as the first edge number acquisition process, a process of acquiring the number of front edges which is the number of edges before the flag is acquired from the frequency division flag register 161a is executed. Edges generated thereafter are detected as a change in the number of edges regardless of whether they correspond to frequency division edges, and the crank interrupt process is executed. Therefore, this process can be said to be a process for canceling the frequency division of the edge that generates the interrupt request.

In S112, as the clearing process, a process of clearing the interrupt request flag held by the edge flag register 161b is executed. That is, even if the edge before this processing turns on the interrupt request flag of the edge flag register 161b, it does not affect the execution of the crank interrupt processing after the completion of the signal switching processing.

In S113, as flag acquisition processing. Processing for acquiring the interrupt request flag held by the frequency division flag register 161a is executed. That is, it is acquired whether or not a frequency division edge has occurred during the period from the start of the current signal switching process to this process.

In S114, the current number of edges is acquired again from the edge counter 142. That is, as the second edge number acquisition process, a process of acquiring the rear edge number, which is the number of edges after the flag is acquired from the frequency division flag register 161a, is executed.

In S115, it is determined whether it is necessary to execute the crank interrupt process. That is, it is determined whether the flag acquired from the frequency division flag register 161a is on or there is a difference between the number of front edges and the number of rear edges. If the flag is on or there is a difference in the number of edges, it is determined that an edge for executing the crank interrupt process has occurred, that is, execution is required, and the process proceeds to S116. If the flag is off and the numbers of edges match, it is determined that the crank interrupt process does not need to be executed, and the process proceeds to S118.

In S116, the interrupt request flag held by the edge flag register 161b is turned on. That is, when the signal switching process is completed, the crank interrupt process for the generated edges is forcibly executed once.

In S117, the number obtained by subtracting 1 from the amount of increase in the number of edges is determined as the number of mask edges. That is, the number of mask edges is calculated by subtracting the number of edges for which the crank interrupt process is performed in S116 from the increase amount of the number of edges.

In S118, the amount of increase in the number of edges is determined to be the number of mask edges. That is, since the execution of the crank interrupt process is not reserved, the increase amount of the edge number itself is calculated as the mask edge number.

In step S119, the interrupt request by the interrupt flag of the frequency division flag register 161a is changed to a non-permitted state, the subroutine of FIG. 4 is terminated, and the process returns to the process of FIG. That is, after this process, the frequency division flag register 161a is not treated as a valid interrupt request even when the interrupt flag is on, and is not used for executing the crank interrupt process.

Returning to the processing of FIG. 3, the processing proceeds to S103. In the process of S103, various settings are made for the cam signal when switching to the cam signal.

In S104, the channel selection unit 133 is caused to switch the input signal to the angle clock generation timer 140 to the cam signal. The input switching period is completed in S104.

In S105, it is determined whether the interrupt request flag of the edge flag register 161b is turned on. That is, it is determined whether or not the crank interrupt process is reserved in S116 or an edge has occurred after the number of rear edges is acquired. If it is on, the process proceeds to S106 to execute the crank interrupt process. If it is off, the processing shown in FIG. 4 is terminated and the execution of the crank interrupt processing is waited until the next edge is generated.

In S106, crank interrupt processing is executed. That is, the crank angle is calculated based on the number of mask edges calculated in S117 or S118.

[Summary of First Embodiment]
According to the first embodiment described above, the edge counter 142 counts the number of edges. In addition, the flag register 161 holds an interrupt request flag that is turned on when an edge occurs and that wakes up the crank angle processing unit 111. Therefore, the mask edge calculation unit 114 can calculate the number of mask edges according to the amount of change in the number of edges generated from the crank interrupt process immediately before detected as the change in the number of edges and the interrupt request flag held by the flag register 161. Become. Therefore, the engine ECU 1 can suppress the deviation of the calculated crank angle even when switching the signal that is the generation source of the angle clock.

That is, the mask edge calculation unit 114 calculates the number of mask edges by subtracting the edge from the change amount when executing the crank interrupt processing in accordance with the turning on of the interrupt request flag or the change in the number of edges.

When the crank interrupt processing is not executed because the interrupt request flag is off and the number of edges has not changed, the mask edge calculation unit 114 calculates the number of mask edges without subtracting the executed edge from the change amount. .. As described above, the mask edge calculation unit 114 calculates the number of mask edges by subtracting the executed edges according to the necessity of executing the crank interrupt process. Therefore, the mask edge calculation unit 114 can calculate the number of mask edges in synchronization with the presence/absence of execution of the crank interrupt process.

In addition, in the present embodiment, the crank angle processing unit 111, which is woken up by the reservation by the mask edge calculation unit 114 or the edge after the signal switching process, uses the crank angle calculated based on the number of mask edges calculated by the mask edge calculation unit 114. To correct. Therefore, in the engine ECU 1, the deviation of the crank angle used for various processes is suppressed, and the deterioration of control accuracy is further suppressed.

Further, in the present embodiment, the acquisition unit 113 acquires the interrupt request flag held by the frequency division flag register 161a as a holding status, and acquires the number of edges before and after acquiring the holding status as the number of front edges and the number of rear edges, respectively. Further, when the interrupt request of the frequency division flag register 161a is turned on, or when the number of front edges and the number of rear edges are different, the mask edge calculation unit 114 executes crank interrupt processing and calculates the amount from the edge increase amount. Subtract. As a result, the mask edge calculation unit 114 can calculate the number of mask edges in synchronization with the presence/absence of execution of the crank interrupt process, even when an edge occurs during the execution period of the signal switching process.

Calculation of the number of mask edges synchronized with the presence or absence of execution of the crank interrupt process will be described in detail with reference to FIGS. FIGS. 5 to 7 show examples of correspondence between the edge causing the crank interrupt process and the number of mask edges when the edge occurs during the execution period of the signal switching process. In addition, among the edges of the crank signal, the arrow indicates the edge generated at the crank angle corresponding to the frequency division edge. A straight line that is not an arrow indicates an edge that does not correspond to a frequency division edge (hereinafter, a non-frequency division edge). A dashed arrow extending from each edge indicates that the edge is an edge that has executed interrupt processing.

FIG. 5 shows the operation when an edge corresponding to the frequency division edge occurs during the execution period of the signal switching process. The edge corresponding to the frequency division edge can be detected as the flag being turned on when it occurs before the flag of the frequency division flag register 161a is acquired, and the edge when it occurs from the front edge number acquisition to the rear edge number acquisition. It can be detected as a change in the number. Therefore, the frequency division edge causes the interrupt processing even when it occurs from the start of the signal switching processing to the acquisition of the number of rear edges. Therefore, the number of mask edges is calculated without including this edge.

6 and 7 show the operation in the case where the non-divided edge occurs during the execution period of the signal switching process. The non-frequency-divided edge cannot be detected using the flag of the frequency-division flag register 161a, but can be detected by the change in the number of edges. Therefore, the non-frequency-divided edge that has occurred until the acquisition of the number of front edges is included in the number of mask edges without causing interrupt processing. On the other hand, the non-frequency-divided edge generated during the period from the acquisition of the number of front edges to the acquisition of the number of rear edges is not a frequency-divided edge but is used for generating interrupt processing. Therefore, the non-divided edges generated in this period are not included in the number of mask edges.

It should be noted that the number of edges determined by the mask edge calculation unit 114 increases regardless of whether the edges generated after the acquisition of the number of rear edges during the signal switching process is the divided edges or the non-divided edges. Not included in the quantity. Therefore, the edge generated during this period is not referred to by the mask edge calculation unit 114 in determining whether or not to subtract from the increase amount, and the crank interrupt process is executed independently.

Further, the mask edge calculation unit 114 reserves the execution of the crank interrupt processing by the ON writing to the edge flag register 161b that is cleared before the acquisition of the number of trailing edges. As a result, the mask edge calculation unit 114 causes the crank interrupt process to be executed only once even if the mask edge calculation unit 114 has been rewritten to ON due to the occurrence of an edge from the clearing of the edge flag register 161b to the acquisition of the number of rear edges. Therefore, the mask edge calculation unit 114 can suppress the deviation between the number of edges and the number of executions.

In addition, the mask edge calculation unit 114 compares the number of front edges acquired before the clearing process with the number of trailing edges after the clearing process to determine whether or not to execute the interrupt process. Contrary to the configuration of the present embodiment, when the configuration for determining the necessity by comparing the number of trailing edges with the number of front edges acquired after the clearing process is adopted, the result of the determination of necessity by the mask edge calculation unit 114, The state of the edge flag register 161b may be different. Specifically, when a non-divided edge occurs between the clearing process and the acquisition of the number of front edges, the non-divided edge does not turn on the frequency division flag register 161a, and the difference between the number of front edges and the number of rear edges is calculated. Does not occur. Therefore, this non-frequency-divided edge is used by the mask edge calculation unit 114 to turn on the edge flag register 161b, even though it is determined by the mask edge calculation unit 114 that crank interrupt processing is not required to be executed and is included in the number of mask edges.

In contrast to this concern, in the present embodiment, the mask edge calculation unit 114 determines the crank based on the difference between the number of front edges and the number of rear edges, regardless of when an edge occurs from the clearing process to the acquisition of the number of rear edges. It can be determined that execution of interrupt processing is required. Therefore, the mask edge calculation unit 114 detects the edge even if it is a non-frequency-divided edge, and matches the state of the edge flag register 161b, which has been rewritten to ON, with the result of the determination as to whether or not to execute the crank interrupt process. sell. Therefore, even if the flag of the edge flag register 161b is rewritten after clearing, the mask edge calculation unit 114 can suppress the deviation between the number of edges and the number of executions.

As described above, the mask edge calculation unit 114 can calculate the number of mask edges in synchronization with the execution of the crank interrupt processing by the edge, at which timing the edge occurs in the crank signal. Therefore, the crank angle processing unit 111 can suppress the deviation of the crank angle based on the calculated mask edge number.

<Second embodiment>
The second embodiment is a modification of the first embodiment. In the second embodiment, the processing of the crank signal setting subroutine shown in FIG. 8 is executed by the processor core 110 instead of the processing shown in FIG. In the process of the crank signal setting subroutine in the second embodiment shown in FIG. 8, the processes of S110 to S114 of FIG. 4 are replaced with S210 to S214.

S210 is a process corresponding to S111 of FIG. That is, in S210, the current number of edges is acquired from the edge counter 142. S210 is executed before the acquisition of the flag of the frequency division flag register 161a in S213. Therefore, the number of edges acquired in S210 corresponds to the number of front edges.

S211 is a process corresponding to S110 of FIG. That is, in S211, the interrupt controller 160 is made to enable the crank interrupt processing by the edge flag register 161b.

S212 is a process corresponding to S112 of FIG. That is, in S212, the interrupt request flag held by the edge flag register 161b is cleared.

S213 is a process corresponding to S113 of FIG. That is, in S213, the interrupt request flag held by the frequency division flag register 161a is acquired.

S214 is a process corresponding to S114 of FIG. That is, in S214, the current number of edges is acquired again from the edge counter 142. S214 is performed after the acquisition of the flag of the frequency division flag register 161a in S213. Therefore, the number of edges acquired in S214 corresponds to the number of rear edges. S214 is performed after the edge flag register 161b is cleared in S212.

[Summary of Second Embodiment]
As described above, according to the second embodiment described above, the engine ECU 1 controls the crank angle deviation based on the number of mask edges calculated by the mask edge calculation unit 114, similarly to the first embodiment. You can.

Also in the second embodiment, the mask edge calculation unit 114 determines whether to execute the crank interrupt process based on the flag of the frequency division flag register 161a and the presence/absence of the difference between the front edge number and the rear edge number. However, the number of mask edges can be corrected according to the necessity of execution. In addition, also in the second embodiment, the mask edge calculation unit 114 reserves the execution of the crank interrupt process by writing to the edge flag register 161b that is cleared between the acquisition of the number of front edges and the acquisition of the number of rear edges. To do. Therefore, also in the second embodiment, as in the first embodiment, the mask edge calculation unit 114 determines the number of mask edges in synchronization with the execution of the crank interrupt process at any timing when an edge occurs in the crank signal. It can be calculated.

<Third embodiment>
The third embodiment is another modification of the first embodiment. In the third embodiment, the processing of the crank signal setting subroutine shown in FIG. 9 is executed by the processor core 110 instead of the processing shown in FIG. In the process of the crank signal setting subroutine in the third embodiment shown in FIG. 9, the processes of S110 to S114 of FIG. 4 are replaced with S310 to S314.

S310 is a process corresponding to S110 of FIG. That is, in S310, the interrupt controller 160 is made to enable the crank interrupt processing by the edge flag register 161b.

S311 is a process corresponding to S111 of FIG. That is, in S311, the current edge number is acquired from the edge counter 142. S311 is executed before the acquisition of the flag of the frequency division flag register 161a in S312. Therefore, the number of edges acquired in S311 corresponds to the number of front edges. Further, S311 is executed before the edge flag register 161b is cleared in S313.

S312 is a process corresponding to S113 of FIG. That is, in S312, the interrupt request flag held by the frequency division flag register 161a is acquired.

S313 is a process corresponding to S112 of FIG. That is, in S313, the interrupt request flag held by the edge flag register 161b is cleared.

S314 is a process corresponding to S114 of FIG. That is, in S314, the current number of edges is acquired again from the edge counter 142. S314 is performed after the acquisition of the flag of the frequency division flag register 161a in S312. Therefore, the number of edges acquired in S314 corresponds to the number of rear edges. Further, S314 is executed after the edge flag register 161b is cleared in S313.

[Summary of Third Embodiment]
As described above, according to the third embodiment described above, the engine ECU 1 controls the crank angle deviation based on the number of mask edges calculated by the mask edge calculation unit 114, similarly to the first embodiment. You can.

Also in the third embodiment, the mask edge calculation unit 114 determines whether to execute the crank interrupt process based on the flag of the frequency division flag register 161a and the presence/absence of the difference between the front edge number and the rear edge number. It is possible to judge and correct the number of mask edges according to the necessity of execution. In addition, also in the third embodiment, the mask edge calculation unit 114 reserves the execution of the crank interrupt process by writing to the edge flag register 161b that is cleared between the acquisition of the number of front edges and the acquisition of the number of rear edges. To do. Therefore, also in the third embodiment, as in the first embodiment, the mask edge calculation unit 114 determines the number of mask edges in synchronization with the execution of the crank interrupt process at any timing when an edge occurs in the crank signal. It can be calculated.

<Fourth Embodiment>
The fourth embodiment is another modification of the first embodiment. In the fourth embodiment, the processing of the crank signal setting subroutine shown in FIG. 10 is executed by the processor core 110 instead of the processing shown in FIG. In the processing of the crank signal setting subroutine in the fourth embodiment shown in FIG. 10, the processing of S110 to S114 in FIG. 4 is replaced with S410 to S414.

S410 is a process corresponding to S111 of FIG. That is, in S410, the current number of edges is acquired from the edge counter 142. S410 is performed before the acquisition of the flag of the frequency division flag register 161a in S412. Therefore, the number of edges acquired in S410 corresponds to the number of previous edges. Further, S410 is executed before the edge flag register 161b is cleared in S413.

S411 is a process corresponding to S110 of FIG. That is, in step S411, the interrupt controller 160 enables the crank interrupt processing by the edge flag register 161b.

S412 is a process corresponding to S113 of FIG. That is, in S412, the interrupt request flag held by the frequency division flag register 161a is acquired.

S413 is a process corresponding to S112 of FIG. That is, in S413, the interrupt request flag held by the edge flag register 161b is cleared.

S414 is a process corresponding to S114 of FIG. That is, in S414, the current number of edges is acquired again from the edge counter 142. S414 is performed after the acquisition of the flag of the frequency division flag register 161a in S412. Therefore, the number of edges acquired in S414 corresponds to the number of trailing edges. Further, S414 is performed after the edge flag register 161b is cleared in S413.

[Summary of Fourth Embodiment]
As described above, according to the fourth embodiment described above, the engine ECU 1 controls the crank angle deviation based on the number of mask edges calculated by the mask edge calculation unit 114, similarly to the first embodiment. You can.

Also in the fourth embodiment, the mask edge calculation unit 114 determines whether to execute the crank interrupt process based on the flag of the frequency division flag register 161a and the presence/absence of the difference between the front edge number and the rear edge number. It is possible to judge and correct the number of mask edges according to the necessity of execution. In addition, also in the fourth embodiment, the mask edge calculation unit 114 reserves execution of crank interrupt processing by writing to the edge flag register 161b that is cleared between the acquisition of the number of front edges and the acquisition of the number of rear edges. To do. Therefore, also in the fourth embodiment, as in the first embodiment, the mask edge calculation unit 114 determines the number of mask edges in synchronization with the execution of the crank interrupt process at any timing when an edge occurs in the crank signal. It can be calculated.

<Other Embodiments>
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and the following modifications are also included in the technical scope of the present disclosure. Various modifications can be made without departing from the scope. In the following description, elements having the same reference numerals as those used up to now are the same as the elements having the same reference numerals in the previous embodiments, unless otherwise specified. Further, when only a part of the configuration is described, the above-described embodiment can be applied to the other part of the configuration.

In the above-described embodiment, the process of switching the interrupt request flag of the frequency division flag register 161a to invalid is performed after the calculation of the number of mask edges. However, if the interrupt request of the frequency division flag register 161a can be acquired, the timing of the process of switching to invalid is not limited to this and can be changed appropriately.

In the above-described embodiment, the rising edge is used as the edge of the crank signal. However, a configuration using a falling edge may be used.

1 engine ECU (internal combustion engine control unit), 111 crank angle processing unit, 112 input switching unit, 113 acquisition unit, 114 mask edge calculation unit, 142 edge counter, 141 angle clock generation unit, 161 flag register, 161a frequency division flag register , 161b Edge flag register

Claims (10)

An angle clock generation unit (141) that generates an angle clock based on the input crank signal or cam signal of the internal combustion engine,
A crank angle processing unit (111) for performing processing in synchronization with the current crank angle of the internal combustion engine;
An input switching unit (112) for switching the input to the angle clock generation unit from the crank signal to the cam signal,
An edge counter (142) for holding the number of edges counting the edges of the crank signal,
A flag register (161) for holding an interrupt request flag for requesting wake-up of the crank angle processing unit, the flag being based on the edge generation of the crank signal;
An acquisition unit (113) for acquiring the holding status of the flag register and the number of edges during the input switching period by the input switching unit;
An internal combustion engine control device comprising: a mask edge calculation unit (114) that calculates the number of mask edges based on the holding status of the flag register acquired by the acquisition unit and whether or not the number of edges has changed. When the flag register indicates that there is an interrupt request, or when the number of edges has changed, the mask edge calculation unit wakes up the crank angle processing unit and subtracts the edge that wakes up the interrupt. The internal combustion engine controller according to claim 1, wherein the mask edge number is calculated based on the edge number. When the flag register indicates that there is no interrupt request and the number of edges has not changed, the mask edge calculation unit does not wake up the crank angle processing unit, and the mask edge is calculated based on the number of edges. The internal combustion engine controller according to claim 1, wherein the number is calculated. The internal combustion engine control according to any one of claims 1 to 3, wherein the crank angle processing unit executes processing in synchronization with a crank angle calculated according to the number of mask edges calculated by the mask edge calculation unit. apparatus. The flag register has an edge flag register (161b) which is in a state indicating that an interrupt request is generated each time an edge of the crank signal is generated, and a state in which an interrupt request is generated each time a divided edge of the crank signal edges is generated. And a frequency division flag register (161a)
The input switching unit performs, during the input switching period, a validating process for validating an interrupt request of the edge flag register and a clearing process for clearing an interrupt request held by the edge flag register,
The acquisition unit, during the input switching period, a flag acquisition process that acquires the interrupt request flag of the frequency division flag register as the holding state, a first edge number acquisition process and a second edge number acquisition process that acquires the number of edges. Process and
The mask edge calculation unit determines whether there is a change between the number of edges acquired in the first edge number acquisition processing and the second edge number acquisition processing as the presence or absence of the change in the number of edges. 4. The internal combustion engine controller according to any one of 4 above. The acquisition unit executes the first edge number acquisition process before the flag acquisition process and before the clear process, and the second edge number acquisition process after the flag acquisition process and Execute after clearing process,
The internal combustion engine control device according to claim 5, wherein the mask edge calculation unit wakes up the crank angle processing unit by switching the edge flag register to a state indicating that there is an interrupt request. When the input switching period is started, the input switching unit performs the validation process,
The acquisition unit performs the first edge number acquisition process after the activation process,
The input switching unit performs the clear process after the first edge number acquisition process,
The internal combustion engine control device according to claim 5, wherein the acquisition unit performs the flag acquisition process after the clear process, and performs the second edge number acquisition process after the flag acquisition process. When the input switching period is started, the acquisition unit performs the first edge number acquisition process,
The input switching unit performs the validation processing after the first edge number acquisition processing, performs the clear processing after the validation processing,
The internal combustion engine control device according to claim 5, wherein the acquisition unit performs the flag acquisition process after the clear process, and performs the second edge number acquisition process after the flag acquisition process. When the input switching period is started, the input switching unit performs the validation process,
The acquisition unit performs the first edge number acquisition process after the activation process, performs the flag acquisition process after the first edge number acquisition process,
The input switching unit performs the clear process after the flag acquisition process,
The internal combustion engine control device according to claim 5, wherein the acquisition unit performs the second edge number acquisition process after the clear process. When the input switching period is started, the acquisition unit performs the first edge number acquisition process,
The input switching unit performs the validation processing after the first edge number acquisition processing,
The acquisition unit performs the flag acquisition process after the activation process,
The input switching unit performs the clear process after the flag acquisition process,
The internal combustion engine control device according to claim 5, wherein the acquisition unit performs the second edge number acquisition process after the clear process.

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