JP2018156450A - Control system, control device, monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To temporarily transmit a signal without waiting for the elapse of a certain time in a system for transmitting a signal at regular intervals. SOLUTION: A control device transmits a control signal at regular intervals, a temporary execution unit that transmits a temporary control signal at a timing different from that of the periodic execution unit, and a temporary execution unit that transmits a control signal. It is provided with a timing changing unit for changing the timing at which the periodic execution unit transmits the control signal and causing the periodic execution unit to transmit the control signal at regular intervals after the temporary execution unit transmits the control signal. The monitoring device includes a communication unit that receives a control signal, an abnormality detection unit that detects an abnormality when the communication unit does not receive a control signal in each of a plurality of time slots, and a time when the control signal is received a plurality of times. The slot is set as a plurality of reception time slots, and a temporary processing unit is provided which sets a correction reference time based on the second reception time of a control signal in the plurality of reception time slots and sets the reference time as the correction reference time. [Selection diagram] Fig. 2

Description

  The present invention relates to a control system, a control device, and a monitoring device.

  There is known a system in which a plurality of devices are connected via a network, which transmits a signal at regular intervals and performs various processes using information received by the device that has received the signal. Patent Document 1 is an electronic control unit that monitors failures of a plurality of nodes, and monitors the presence / absence of communication of a plurality of nodes at substantially constant time intervals when the plurality of nodes transmit a message one or more times. Communication interruption detection means for recording a node in which communication is not detected within a substantially fixed time together with rank information in which communication is not detected, and the communication interruption detection means detects communication within the substantially fixed time every predetermined period. An electronic control unit is disclosed that records the rank information and nodes that are not.

JP 2012-86601 A

  In principle, in a system in which a signal is transmitted at regular time intervals, it may be desired to transmit a signal temporarily without waiting for a certain time.

A monitoring system according to a first aspect of the present invention is a control system including a control device that transmits a control signal and a monitoring device that receives the control signal, and the control device transmits the control signal at regular intervals. A periodic execution unit for transmitting, a temporary execution unit for temporarily transmitting the control signal at a timing different from that of the periodic execution unit, and when the temporary execution unit transmits the control signal, the periodic execution unit transmits the control signal. A timing changing unit that changes the timing of the temporary execution unit and transmits the control signal to the periodic execution unit at regular intervals after the temporary execution unit transmits the control signal, and the monitoring device includes the control signal A communication unit that receives a reference time, a periodic processing unit that sets a plurality of time slots that are divided by the predetermined time from a preset reference time, An abnormality detection unit that detects an abnormality when the communication unit does not receive the control signal in each of the time slots, and a plurality of times when the communication unit receives the control signal multiple times in any of the plurality of time slots. A correction reference time is set based on a second reception time of the control signal in the plurality of reception time slots, with a time slot in which the control signal has been received a plurality of times as a plurality of reception time slots, and the reference time is corrected And a temporary processing unit serving as a reference time.
The control device according to the second aspect of the present invention includes a periodic execution unit that transmits a control signal at regular intervals, a temporary execution unit that temporarily transmits the control signal at a timing different from the periodic execution unit, and the temporary When the execution unit transmits the control signal, the periodic execution unit changes the timing at which the control signal is transmitted, and the temporary execution unit transmits the control signal to the periodic execution unit at regular intervals. A timing changing unit that transmits a signal.
A monitoring device according to a third aspect of the present invention includes a communication unit that receives a control signal, a periodic processing unit that sets a plurality of time slots that are divided by a predetermined time from a preset reference time, An abnormality detection unit that detects an abnormality when the communication unit does not receive the control signal in each of the plurality of time slots; and the communication unit receives the control signal a plurality of times in any of the plurality of time slots. Setting a reference time to be corrected based on a second reception time of the control signal in the plurality of reception time slots, with a time slot in which the control signal has been received a plurality of times as a plurality of reception time slots, A temporary processing unit that sets the correction reference time.

  According to the present invention, in principle, in a system that transmits a signal at regular intervals, a signal can be transmitted temporarily without waiting for a certain period of time.

Overall configuration diagram of a vehicle 2 equipped with a control system 1 Configuration diagram of control system 1 The schematic diagram explaining a communication timing. 3A is a diagram illustrating communication timing when there is no temporary communication, and FIG. 3B is a diagram illustrating communication timing when there is temporary communication. The schematic diagram explaining a time slot. FIG. 4A shows a time slot when the front wheel reference time is not changed, and FIG. 4B shows a time slot when the front wheel reference time is changed. A flowchart showing the operation of the periodic command execution unit 110 Flowchart showing operation of temporary command execution unit 120 A flowchart showing the operation of the command timing changing unit 130 A flowchart showing the operation of the abnormality detection unit 210 A flowchart showing the operation of the regular slot processing unit 220 Flowchart showing operation of temporary slot processing unit 230 The schematic diagram which shows the communication amount per time. 11A shows a case where no temporary control signal is output, FIG. 11B shows a case where a temporary control signal is output and the next control signal is output as usual, and FIG. 11C shows a temporary control signal. When a signal is output and the output of the next control signal is changed by the command timing changing unit 130 The figure which shows the condition where the abnormality detection part 210 erroneously detects abnormality when the front wheel reference time is not changed. The figure which shows calculation of the correction reference time in the modification 1. The figure which shows calculation of the correction reference time in the modification 3.

-Embodiment-
Hereinafter, an embodiment of the control system will be described with reference to FIGS.
(Vehicle configuration)
FIG. 1 is an overall configuration diagram of a vehicle 2 on which a control system 1 is mounted. The vehicle 2 includes a control system 1, an obstacle sensor 91 that detects an obstacle, a collision prevention calculation device 92, a brake pedal signal output device 95 associated with a brake pedal operated by a driver of the vehicle 2, a front wheel A braking device 96, a rear wheel braking device 97, a front wheel rotation sensor 98, and a rear wheel rotation sensor 99 are provided. The control system 1 includes a command ECU 100, a front wheel braking ECU 200, and a rear wheel braking ECU 300. When the user turns on the ignition key switch of the vehicle 2, power is supplied to each of the above-described devices mounted on the vehicle 2, and operation starts almost simultaneously.

  The obstacle sensor 91 is, for example, a laser range finder, an ultrasonic sensor, or an image sensor. The obstacle sensor 91 acquires the ambient environment information of the vehicle 2 at a high frequency, and outputs the sensor information to the collision prevention calculation device 92. The collision prevention arithmetic device 92 is, for example, an electronic control device, and includes a CPU, a ROM, and a RAM (not shown). The collision prevention calculation device 92 calculates the possibility of collision with an obstacle based on information input from the obstacle sensor 91 and the like, and immediately outputs an emergency stop command to the command ECU 100 when it is determined that there is a possibility of collision. . The collision prevention calculation device 92 does not output any instruction to the command ECU 100 when determining that there is no possibility of collision. The brake pedal signal output device 95 is an electronic control device that outputs to the command ECU 100 the amount of depression of the brake pedal by the driver's operation. The brake pedal signal output device 95 always outputs the depression amount of the brake pedal immediately.

  The front wheel braking device 96 is a braking device provided on the front wheels of the vehicle 2, for example, a disc brake. The front wheel braking device 96 operates based on the operation command of the front wheel braking ECU 200. For example, when a hydraulic circuit (not shown) operates according to the operation command of the front wheel braking ECU 200, the brake pad that constitutes the front wheel braking device 96 is pressed against the brake rotor. Give rise to The rear wheel braking device 97 is a braking device provided on the rear wheel of the vehicle 2 and is the same as the front wheel braking device 96 except that it operates based on an operation command of the rear wheel braking ECU 300. Front wheel rotation sensor 98 detects the number of rotations of the front wheel and outputs it to command ECU 100. Rear wheel rotation sensor 99 detects the number of rotations of the rear wheel and outputs it to command ECU 100. The front wheel rotation sensor 98 and the rear wheel rotation sensor 99 output more frequently than the regular communication cycle of the control system 1 described later.

(Control system configuration)
FIG. 2 is a configuration diagram of the control system 1. The command ECU 100, the front wheel braking ECU 200, and the rear wheel braking ECU 300 all communicate with each other at a predetermined periodic communication cycle, but immediately after the control system 1 receives a signal from the collision prevention arithmetic device 92 or the brake pedal signal output device 95. Communication takes place. In this embodiment, the regular communication cycle is assumed to be 10 ms. Although described in detail later, the front wheel braking ECU 200 performs feedback control using a control signal received from the command ECU 100 and outputs an operation command to the front wheel braking device 96. The rear wheel braking ECU 300 performs feedback control using the rear wheel control signal received from the front wheel braking ECU 200, and outputs an operation command to the rear wheel braking device 97. The periodic communication cycle is a cycle determined based on the characteristics of the device or the like targeted by this feedback control. For example, the feedback control can be set to a control cycle shorter than the regular communication cycle, but the following two problems may occur. First, it is overcorrected as having no control effect, which may increase the settling time. Secondly, the next control amount is determined before the change in the manipulated variable is sufficiently reflected in the observed amount, thereby increasing the power consumption. Further, for example, if the feedback control is a control cycle longer than the regular communication cycle, problems such as extension of settling time and divergence of responses occur.

(Configuration of command ECU)
Command ECU 100, front wheel brake ECU 200, and rear wheel brake ECU 300 are all electronic control units (ECUs), each of which includes a CPU, a ROM, and a RAM that incorporate a timer function. A function described later is realized by the CPU developing and executing a program stored in the ROM on the RAM. However, some or all of the functions described later may be realized by a hardware circuit.

  Command ECU 100 includes a regular command execution unit 110, a temporary command execution unit 120, a command timing change unit 130, and a first communication unit 140. Command ECU 100 receives signals from collision prevention calculation device 92, brake pedal signal output device 95, front wheel rotation sensor 98, and rear wheel rotation sensor 99. The command reference time is stored in a RAM (not shown) of the command ECU 100. The command reference time is referred to by the regular command execution unit 110 and is rewritten by the command timing change unit 130. The command reference time may be represented by Greenwich Mean Time, but in the present embodiment, the command reference time is represented by an elapsed time after the ignition key switch of the vehicle 2 is turned on. The initial value of the command reference time is set to “0.000 seconds”, which is the time at startup.

  The regular command execution unit 110 outputs a control signal to the front wheel braking ECU 200 every time the regular communication cycle elapses. For example, the periodic command execution unit 110 determines whether or not the current time is a time when an integral multiple of the periodic communication cycle has elapsed from the command reference time, and outputs a control signal when an affirmative determination is made. This control signal includes the output of the front wheel rotation sensor 98 and the output of the rear wheel rotation sensor 99 necessary for the front wheel braking ECU 200 and the rear wheel braking ECU 300 to perform feedback control.

  When the temporary command execution unit 120 receives a signal from at least one of the collision prevention calculation device 92 and the brake pedal signal output device 95, the temporary command execution unit 120 immediately outputs a control signal to the front wheel braking ECU 200. The command timing changing unit 130 rewrites the command reference time stored in the RAM to the current time when the temporary command execution unit 120 outputs a control signal. Thereby, the timing at which the periodic command execution unit 110 transmits the control signal is changed, and the temporary command execution unit 120 transmits the control signal at regular intervals after the temporary command execution unit 120 transmits the control signal. . The timing at which the periodic command execution unit 110 performs communication will be described later with reference to FIG. The first communication unit 140 is, for example, a CAN (Controller Area Network) interface device, and communicates with the front wheel braking ECU 200.

(Configuration of front wheel braking ECU)
The front wheel braking ECU 200 includes an abnormality detection unit 210, a regular slot processing unit 220, a temporary slot processing unit 230, a second communication unit 240, and a front wheel control unit 250. The front wheel reference time is stored in the RAM of the front wheel braking ECU 200. The front wheel reference time is referred to by the regular slot processing unit 220 and rewritten by the temporary slot processing unit 230. The front wheel reference time may be represented by Greenwich Mean Time, but in the present embodiment, the front wheel reference time is represented by an elapsed time after the ignition key switch of the vehicle 2 is turned on. The initial value of the front wheel reference time is set to “0.005 seconds”, which is a time at which a predetermined time, for example, half of the regular communication cycle has elapsed since the time of activation.

  Abnormality detection unit 210 determines that an abnormality has occurred when no control command is received from command ECU 100 in a certain period determined by regular slot processing unit 220 and temporary slot processing unit 230. In the present embodiment, each period in which the abnormality detection unit 210 detects an abnormality is referred to as a “time slot”. The abnormality detection unit 210 receives the start time of each time slot from the regular slot processing unit 220, and sets a period from the start time of one time slot to the start time of the next time slot as one time slot. A specific example of the time slot will be described later with reference to FIG. The operation of the abnormality detection unit 210 when the abnormality detection unit 210 detects an abnormality is not particularly limited in the present embodiment. For example, the abnormality detection unit 210 transmits an abnormality to another device (not shown) built in the vehicle 2. Alternatively, the front wheel braking device 96 may be operated.

The regular slot processing unit 220 divides the time slot from the front wheel reference time stored in the RAM and passes the regular communication cycle to the abnormality detection unit 210. Specifically, the regular slot processing unit 220 sets each time obtained by adding an integer multiple of the regular communication cycle to the front wheel reference time as a time slot delimiter, so that the regular slot processing unit 220 is divided at regular communication cycles from the front wheel reference time. Set a time slot that is a specific period. For example, TS (N), which is the start time of the Nth time slot, is expressed as in Equation 1, where the front wheel reference time is FT and the regular communication cycle PT.
TS (N) = FT + PTxN (1)

  When the second communication unit 240 receives the control signal a plurality of times in any time slot, the temporary slot processing unit 230 sets the correction reference time based on the second reception time in the time slot. Hereinafter, a time slot in which the second communication unit 240 receives the control signal a plurality of times is referred to as a “multiple reception time slot”. A specific method for determining the correction reference time is as follows. That is, the correction reference time is set so that the second reception time in the plurality of reception time slots becomes the middle time of the newly set time slot. Then, the temporary slot processing unit 230 rewrites the front wheel reference time stored in the RAM with the corrected reference time. As a result of this rewriting, the start time of the time slot output by the regular slot processing unit 220 thereafter is based on the rewritten front wheel reference time.

  If there is no delay in the transmission, transmission, and reception of the control signal in setting the correction reference time, it may be set to be immediately after the start of the newly set time slot or just before the end of the time slot. However, it is conceivable that a slight delay occurs due to other processing inside the command ECU 100 and the front wheel braking ECU 200 and a problem with the communication path. In such a case, it is cumbersome to determine that there is an abnormality every time. Therefore, the correction reference time is set so that the control signal is received at the middle time of the time slot so that this does not occur.

  The second communication unit 240 is, for example, a CAN interface, and communicates with the command ECU 100 and the rear wheel braking ECU 300. The front wheel control unit 250 calculates the distribution of braking force between the front wheels and the rear wheels based on the control signal received from the command ECU 100. The front wheel control unit 250 controls the braking force of the front wheels based on the calculation result, and outputs a rear wheel control signal to the rear wheel braking ECU 300 to control the braking force of the rear wheels. The calculation of the above-described braking force distribution by the front wheel control unit 250 and the output of the rear wheel control signal to the rear wheel braking ECU 300 are executed immediately upon reception of the control signal from the command ECU 100. The front wheel control unit 250 performs feedback control using the output of the front wheel rotation sensor 98 included in the control signal for controlling the braking force of the front wheels. In this feedback control, an operation command to the front wheel braking device 96, for example, the pressure of the hydraulic pressure supplied to the front wheel braking device 96 is used as an operation amount, the rotation number of the front wheel is used as a control amount, and the output of the front wheel rotation sensor 98 is used as a feedback amount. Is.

  The rear wheel braking ECU 300 includes a third communication unit 340 and a rear wheel control unit 350. The third communication unit 340 is a CAN interface, for example, and communicates with the front wheel braking ECU 200. When the third communication unit 340 receives a rear wheel control signal from the front wheel braking ECU 200, the rear wheel control unit 350 controls the rear wheel braking device 97 based on the rear wheel control signal. The rear wheel control unit 350 performs feedback control using the output of the rear wheel rotation sensor 99 included in the rear wheel control signal for controlling the braking force of the rear wheel. In this feedback control, an operation command to the rear wheel braking device 97, for example, the pressure of the hydraulic pressure supplied to the rear wheel braking device 97 is used as an operation amount, the number of rotations of the rear wheel is used as a control amount, and the output of the rear wheel rotation sensor 99 is output. The amount of feedback.

(Communication timing)
FIG. 3 is a schematic diagram illustrating communication timing. FIG. 3A is a diagram illustrating communication timing in an initial state, that is, when there is no temporary communication, and FIG. 3B is a diagram illustrating communication timing when there is temporary communication and the communication timing is changed. In FIG. 3, time has passed from the left to the right in the figure, and a small scale represents 1 ms. In FIG. 3, white squares indicate communication timings scheduled from the beginning, and hatched squares indicate changed communication timings. In FIG. 3, the length of the square in the time direction indicating the communication timing is 1 ms. However, for convenience of drawing, the actual communication length is not limited to this.

  In the initial state shown in FIG. 3A, the command reference time is “0.000 seconds”. Since the regular communication cycle is 10 ms, regular communication is scheduled at 56.120 seconds, 56.130 seconds, 56.140 seconds, and 56.150 seconds, which are times when an integral multiple of 10 ms has elapsed from the command reference time ( Reference numerals 311 to 314). Here, when the command ECU 100 receives a signal from the collision prevention calculation device 92 at 56.133 seconds, the temporary command execution unit 120 immediately outputs a control signal (reference numeral 321) as shown in FIG. Then, since the command timing changing unit 130 rewrites the command reference time to “56.133 seconds” that is the current time, the time at which the regular command execution unit 110 performs regular communication thereafter is 56.143 seconds (reference numeral 322). 56.153 seconds (reference numeral 323),. That is, when temporary communication is performed, regular communication is performed each time the regular communication cycle elapses from the time when the temporary communication was performed.

(Time slot)
FIG. 4 is a schematic diagram for explaining a time slot, and a figure showing the time slot is added to FIG. FIG. 4A is a diagram showing a time slot when the front wheel reference time is not changed, that is, a time slot when the front wheel reference time is changed, and FIG. 4B is a diagram showing a time slot when the front wheel reference time is changed. In FIG. 4, the time has passed from the left to the right in the figure, and the small scale represents 1 ms. In FIG. 4, symbols such as reference numerals 411 to 414 obtained by rotating the opening or closing of the square brackets by 90 degrees indicate time slot periods. For example, the time slot 412 is a period after 56.125 seconds and less than 56.135 seconds. Although there is a space between the time slots 411 to 414 for convenience of illustration, each period is continuous without a break.

  In the initial state shown in FIG. 4A, the front wheel reference time is “0.005 seconds”. And since the regular communication cycle is 10 ms, the times that are an integral multiple of 10 ms from the front wheel reference time are 56.115 seconds, 56.125 seconds, 56.135 seconds, 56.145 seconds, 56.155 seconds, etc. Slot separator. When the time slot is set in this way, if the control signal is received at the timing indicated by the white square in FIG. 4A, the control signal is received in each time slot. No abnormality is detected.

  In FIG. 4B, the front wheel braking ECU 200 receives the control signal twice in the time slot 412. Therefore, the correction reference time is determined so that the second reception time of 56.133 seconds becomes the middle time of the newly set time slot. Specifically, 56.128 seconds, which is the time obtained by subtracting 5 ms, which is half the regular communication period, from 56.133 seconds, which is the second reception time, is determined as the correction reference time. Then, time slots 421 to 423 are set with 56.138 seconds and 56.148 seconds, which are times when an integral multiple of 10 ms has elapsed from the correction reference time, as new time slot breaks. As described with reference to FIG. 3, when temporary communication is performed, the transmission timing of the control signal after that of the command ECU 100 changes. However, as described with reference to FIG. 4, the front wheel braking ECU 200 has a timing on the transmission side. Monitoring can be continued in response to changes.

-flowchart-
(Operation of the periodic command execution unit)
FIG. 5 is a flowchart showing the operation of the regular command execution unit 110. An execution subject of each step shown below is a CPU (not shown) provided in the command ECU 100. The periodic command execution unit 110 executes step S511 when the operation starts. In step S511, the CPU determines whether or not an integral multiple of the regular communication cycle has elapsed since the command reference time. If the CPU makes an affirmative determination in this determination, it proceeds to step S512, and if it makes a negative determination, it executes step S511 again. In step S512, the CPU outputs a control signal to the front wheel braking ECU 200 and returns to step S511.

(Operation of temporary command execution unit)
FIG. 6 is a flowchart showing the operation of the temporary command execution unit 120. An execution subject of each step shown below is a CPU (not shown) provided in the command ECU 100. Temporary command execution unit 120 executes step S521 when the operation starts. In step S521, the CPU determines whether or not a signal has been received from the collision prevention calculation device 92. If an affirmative determination is made, the CPU proceeds to step S522, and if a negative determination is made, the CPU proceeds to step S523. In step S522, the CPU outputs a control signal to front wheel braking ECU 200 and returns to step S521. In step S523, it is determined whether a signal has been received from the brake pedal signal output device 95. If an affirmative determination is made, the process proceeds to step S522, and if a negative determination is made, the process returns to step S521.

(Operation of command timing change unit)
FIG. 7 is a flowchart showing the operation of the command timing changing unit 130. An execution subject of each step shown below is a CPU (not shown) provided in the command ECU 100. The command timing changing unit 130 executes step S531 when the operation starts. In step S531, the CPU determines whether or not the temporary command execution unit 120 has output a control signal. If an affirmative determination is made, the CPU proceeds to step S532. If a negative determination is made, the CPU executes step S531 again. In step S532, the command reference time stored in the RAM (not shown) is rewritten to the current time, and the process returns to step S531. Thereby, in the subsequent processing, the timing at which the periodic command execution unit 110 transmits the control signal in step S512 of FIG. 5 is changed. That is, when the command timing changing unit 130 executes the process of step S532, the time at which the temporary command executing unit 120 transmits the control signal is set as the subsequent command reference time, and is periodically updated every time the regular communication cycle elapses from that time. The command execution unit 110 transmits a control signal. As a result, the timing at which the periodic command execution unit 110 transmits the control signal is changed from that before the control signal is transmitted from the temporary command execution unit 120. In this way, the command timing changing unit 130 changes the timing at which the periodic command execution unit 110 transmits the control signal.

(Abnormality detection unit operation)
FIG. 8 is a flowchart showing the operation of the abnormality detection unit 210. An execution subject of each step shown below is a CPU (not shown) provided in the front wheel braking ECU 200. When the abnormality detection unit 210 starts its operation, it executes Step S601 and Step S603 in parallel. In step S <b> 601, the CPU determines whether time information has been received from the regular slot processing unit 220. If it is determined that the time information has been received, the process proceeds to step S602. If it is determined that the time information has not been received, step S601 is executed again. In step S602, the CPU stores the time information in the RAM as the start time of the next time slot, and returns to step S601. As described above, the processing in steps S601 to S602 is to update the start time of the next time slot using the received time information. If the processing after step S603 is considered as the main processing, it can be said that the processing of steps S601 to S602 is to update the start time of the next time slot in the background.

  In step S603, the CPU determines whether or not a control signal has been received from the command ECU 100. If an affirmative determination is made, the CPU proceeds to step S604, and if a negative determination is made, the CPU proceeds to step S607. Note that affirmative determination is made in step S603 when it is determined that the control signal is received for the first time in any time slot. In step S604, the start time of the next time slot stored in the RAM is referred to, and it is determined whether or not the current time has reached the start time of the next time slot. If the CPU makes a positive determination in step S604, it returns to step S603, and if it makes a negative determination, the CPU proceeds to step S605. The case where step S604 is positively determined is a case where a control signal is received just before the end of the time slot and it is determined that there is no abnormality.

  In step S605, it is further determined whether a control signal has been received. In other words, in step S605, it is determined whether or not a control signal is received for the second time in the current time slot. If the CPU makes a positive determination in step S605, it proceeds to step S606, and if it makes a negative determination, it proceeds to step S605. The case where a negative determination is made in this step is a case where the control signal is received at least once in the current time slot and the end of the time slot is awaited. In step S606, since the CPU has received the second control signal, the CPU notifies the temporary slot processing unit 230 and returns to step S604.

  In step S607, which is executed when a negative determination is made in step S603, it is determined whether or not the current time has reached the start time of the next time slot. If the CPU makes a positive determination in step S607, it returns to step S603, and if it makes a negative determination, it proceeds to step S608. In step S608, since the start time of the next time slot has been reached without receiving a control signal, an alert, that is, a warning is output, and the process returns to step S603.

(Operation of regular slot processor)
FIG. 9 is a flowchart showing the operation of the regular slot processing unit 220. An execution subject of each step shown below is a CPU (not shown) provided in the front wheel braking ECU 200. The periodic slot processing unit 220 executes step S611 when the operation starts. In step S611, the CPU sets the calculation time to zero and the loop counter i to “1”, and proceeds to step S612. In step S612, the CPU determines whether or not the current time has exceeded the calculated time. If an affirmative determination is made, the process proceeds to step S613, and if a negative determination is made, step S612 is executed again. In step S613, the CPU calculates the calculated time as a value obtained by adding i times the regular communication cycle to the front wheel reference time. In the subsequent step S614, the CPU increments the loop counter i, that is, increases “1”. In subsequent step S615, by outputting the calculation time calculated in step S613 to the abnormality detection unit 210, a time slot during which the abnormality detection unit 210 performs abnormality detection is set, and the process returns to step S612. This calculated time information is received by the abnormality detection unit 210 in step S601 of FIG. 8 as described above.

(Operation of temporary slot processor)
FIG. 10 is a flowchart showing the operation of the temporary slot processing unit 230. An execution subject of each step shown below is a CPU (not shown) provided in the front wheel braking ECU 200. The temporary slot processing unit 230 executes step S621 when the operation starts. In step S621, the CPU determines whether a notification has been received from the abnormality detection unit 210. If an affirmative determination is made, the CPU proceeds to step S622, and if a negative determination is made, the CPU executes step S621 again. In subsequent step S622, the CPU calculates the correction reference time as a time obtained by subtracting half of the regular communication cycle from the current time. In subsequent step S623, the CPU rewrites the front wheel reference time stored in the RAM (not shown) to the correction reference time calculated in step S622. In the subsequent step S624, the CPU outputs an operation command to the regular slot processing unit 220 and returns to step S621.

-Operation example of the anomaly detector-
An operation example of the abnormality detection unit 210 will be described with reference to FIG. When the time slot 412 starting from 56.125 seconds starts, 56.135 seconds are stored in the RAM as the start time of the next time slot. In the time slot 412, since the control signal is not received until 56.130 seconds from the start time, the determinations of S603: NO and S607: NO are repeated. Since the first control signal is received at 56.130 seconds, S603: YES is determined, and since it is not yet the start time of the next time slot, it is determined S604: NO. Since the next control signal has not been received yet, S605 is determined as NO, and the process returns to S604. That is, S604: NO and S605: NO are repeated until 56.133 seconds. Then, since the second control signal is received at 56.133 seconds, S604: NO, S605: YES are determined, and S606 is executed to notify the temporary slot processing unit 230.

  Receiving this notification, the temporary slot processing unit 230 calculates the corrected reference time as 56.128 seconds (S622 in FIG. 10) and rewrites the front wheel reference time (S623). Further, the temporary slot processing unit 230 outputs an operation command to the regular slot processing unit 220 (S624). Then, the periodic slot processing unit 220 starts the operation in response to this operation command (S616 of FIG. 9: YES), and calculates the start time of the next time slot as 56.138 seconds using the rewritten front wheel reference time. (S613). Then, the regular slot processing unit 220 outputs this time to the abnormality detection unit 210.

  The abnormality detection unit 210 receives the time output from the regular slot processing unit 220 in steps S601 to S602 operating in parallel with step S603 and the subsequent steps, and stores it as the start time of the next time slot. Therefore, immediately before the execution of step S606, the start time of the next time slot was 56.135 seconds. However, the execution of step S606 triggered the execution of the next time slot to 56.138 seconds. It is done. Therefore, when the execution of step S606 is completed, the abnormality detection unit 210 repeats the determination of S604: NO and S605: NO until 56.138 seconds. Then, an affirmative determination is made in step S604 at 56.138 seconds, and the process returns to step S603.

  Thereafter, the periodic slot processing unit 220 determines that the previous calculation time has been exceeded (FIG. 9, S612: YES), calculates the next calculation time as 56.148 seconds, and outputs it to the abnormality detection unit 210 (S615). . This time is stored as the start time of the next time slot (FIG. 8, S602). In FIG. 4B, since the control signal is not received at 56.138 seconds, the abnormality detection unit 210 makes a negative determination in S603 and is updated to 56.148 seconds as described above, and the start time of the next time slot Has not been reached, a negative determination is made in S607 and the process returns to S603.

According to the embodiment described above, the following operational effects can be obtained.
(1) The command ECU 100 includes a periodic command execution unit 110 that transmits a control signal at regular intervals, a temporary command execution unit 120 that transmits a control signal temporarily at a different timing from the periodic command execution unit 110, and a temporary command execution. When the unit 120 transmits a control signal, the periodic command execution unit 110 changes the timing at which the control signal is transmitted, and the temporary command execution unit 120 transmits the control signal to the periodic command execution unit 110 at regular intervals after transmitting the control signal. And a command timing changing unit 130 that transmits the command.

  Therefore, the command ECU 100 can output the control signal at regular intervals starting from the temporary communication timing when the control signal is temporarily output. In the present embodiment, since this control signal includes an observation amount used for feedback control, even when a temporary control signal is output by an emergency brake or the like, the feedback loop can be appropriately functioned immediately after that. . Therefore, in principle, in the control system 1 in which the command ECU 100 transmits a control signal at regular time intervals, it is possible to transmit the control signal from the command ECU 100 without waiting for the lapse of the constant time. If a temporary control signal is output temporarily and then the next control signal is output at the conventional timing, the following problems occur. In other words, the control amount is determined based on the control signal temporarily output, but if the control signal is output at the conventional timing, the next control amount is determined in a state where the observation amount does not change sufficiently, and the power consumption Increases the settling time and the settling time.

  Specifically, using FIG. 3, when a control signal is temporarily output at the timing of reference numeral 321, if the control signal is output at the timing of reference numeral 313 as in the past, the control signal is output based on the control signal of reference numeral 321. The effect of the manipulated variable is not fully reflected in the observed quantity. However, since the command ECU 100 includes the command timing changing unit 130, the next control signal is output at the timing indicated by reference numeral 322. That is, the command ECU 100 can output a control signal including an observation amount that sufficiently reflects the influence of the operation amount. When the output is omitted once at the conventional timing and the control signal is output at the timing of 314 after the timing of 321, the interval at which the observation amount is obtained becomes long and feedback control of the front wheel control unit 250 is performed. Adversely affect.

  Further, the command ECU 100 does not output the next control signal until the time corresponding to the regular communication cycle has elapsed after the temporary control signal is output by the operation of the command timing changing unit 130. Peaks can be reduced. In general, when a control signal is temporarily output, some problem occurs, or active computation is performed to avoid the problem. Therefore, when the communication path between the command ECU 100 and the front wheel brake ECU 200 is shared with other devices, for example, when a plurality of devices including the command ECU 100 and the front wheel brake ECU 200 are connected to the same CAN, a temporary control signal In the vicinity of the timing at which is output, the CAN communication band is compressed. Here, if the command ECU 100 outputs the control signal at the conventional timing, it is not desirable because it further compresses the communication band that is already compressed by another device. However, since the command ECU 100 includes the command timing changing unit 130, the next control signal that temporarily outputs the control signal is after the time corresponding to the regular communication cycle has elapsed, and therefore, compression of the communication band can be suppressed. .

  FIG. 11 is a schematic diagram showing the amount of communication per hour. 11A shows a case where no temporary control signal is output, FIG. 11B shows a case where a temporary control signal is output and the next control signal is output as usual, and FIG. 11C shows a temporary control signal. A case where a signal is output and the output of the next control signal is changed by the command timing changing unit 130 is shown. In FIG. 11, open squares indicate communication timings that are scheduled from the beginning, squares hatched with diagonal lines indicate the timings of communications performed temporarily, horizontal hatches indicate the timings of changed communications, Dashed squares indicate the timing at which communication is no longer performed due to the change.

  In the case of FIG. 11A where there is no temporary control signal output, the peak of traffic per hour is TF1. In the case of FIG. 11B in which a temporary control signal is output but the next control signal is output as usual, the communication amount of the temporary control signal and the communication amount of the next control signal are combined to indicate a broken line. As shown, the peak of the traffic volume per time becomes TF2 larger than TF1. However, in the case of FIG. 11C in which the output of the next control signal is changed by the command timing changing unit 130 even if a temporary control signal is output, the peak of the traffic volume per time is suppressed to TF1.

(2) The front wheel braking ECU 200 includes a second communication unit 240 that receives a control signal, and a plurality of time slots that are divided at regular intervals from a front wheel reference time that is preset and stored in a RAM (not shown). And a periodic slot processing unit 220 for setting an abnormality, and an abnormality detection unit 210 for detecting an abnormality when the second communication unit 240 does not receive a control signal in each of a plurality of time slots. Further, when the second communication unit 240 receives the control signal a plurality of times in any time slot, the front wheel braking ECU 200 sets the time slot in which the control signal has been received a plurality of times as a plurality of reception time slots, and the plurality of reception times. A temporary slot processing unit 230 that calculates a calculated time based on the second reception time of the control signal in the slot (step S613 in FIG. 9) and rewrites the calculated front wheel reference time stored in the RAM with the calculated time.

  Therefore, the front wheel braking ECU 200 not only outputs a control signal every fixed time, but also outputs an instruction ECU 100 that outputs a control signal every fixed time starting from the temporary communication timing when the control signal is temporarily output. Can be confirmed at regular intervals. Therefore, in principle, in the control system 1 in which the command ECU 100 transmits a control signal at regular time intervals, it is possible to transmit the control signal from the command ECU 100 without waiting for the lapse of the constant time. If the front wheel braking ECU 200 does not include the temporary slot processing unit 230 and the front wheel reference time is not changed, the abnormality detection unit 210 may erroneously detect an abnormality. In other words, due to the difference between the command reference time and the front wheel reference time and a slight communication delay, control is performed once in the time slot set by the front wheel braking ECU 200 despite the command ECU 100 operating normally. There is a case where no signal is received and it is erroneously detected that a problem has occurred in the command ECU 100. This will be described in detail below.

  FIG. 12 is a diagram illustrating a situation in which the abnormality detection unit 210 erroneously detects an abnormality when the front wheel reference time is not changed. The symbols in FIG. 12 are the same as those in FIGS. However, a broken line in FIG. 12 indicates a combination of a time slot and a control signal recognized by the abnormality detection unit 210. For example, the abnormality detection unit 210 recognizes that the control signal indicated by reference numeral 721 has been received in the time slot 710. In this example, since the front wheel reference time is not changed, the time slot is fixed. That is, time slots 710 to 715 in FIG. 12 are divided into 56.125 seconds, 56.135 seconds, 56.145 seconds,.

  In the example shown in FIG. 12, the instruction ECU 100 outputs a temporary control signal indicated by reference numeral 723 by the temporary instruction execution part 120 for a while after the periodic instruction execution part 110 outputs the control signal indicated by reference numeral 722. Since this extraordinary control signal was received at 56.144 seconds, the abnormality detection unit 210 determines that two control signals have been received in the time slot 711. However, since the front wheel reference time is not changed, The separator is not changed. On the other hand, in the command ECU 100, the command reference time is rewritten by the operation of the command timing changing unit 130, and the output timing of the regular control signal is changed. As a result, when the second communication unit 240 receives the next control signal output by the periodic command execution unit 110 in 56.154 seconds, the abnormality detection unit 210 recognizes that the control signal has been received in the time slot 712. Subsequently, when the control signal output next by the periodic command execution unit 110 is received at 56.165 seconds due to communication delay, the abnormality detection unit 210 recognizes the control signal in association with the time slot 714. That is, the abnormality detection unit 210 determines that the control signal has never been received in the time slot 713 in spite of a slight communication delay, and detects an error. In addition, since the control signal indicated by reference numeral 727 is also slightly delayed, the abnormality detection unit 210 determines that the control signal has never been received in the time slot 715 and detects an error.

  As described above, if the front wheel braking ECU 200 does not include the temporary slot processing unit 230, the abnormality detection unit 210 detects that the periodic control signal after the temporary control signal is output by the command ECU 100 is slightly delayed. An abnormality is detected. However, since the front wheel braking ECU 200 includes the temporary slot processing unit 230, such a problem does not occur, and the operation abnormality of the command ECU 100 can be appropriately monitored.

(3) The temporary slot processing unit 230 calculates the second reception time in the plurality of reception time slots so as to be the middle time in the time slot newly set as a period divided every predetermined time from the calculation time. Set the time. In other words, the time obtained by subtracting half of the regular communication period from the second reception time in the plurality of reception time slots is set as the calculation time. Therefore, it is possible to suppress the error detection of the abnormality detection unit 210 when the periodic control signal is slightly delayed.

(4) The control system 1 includes a command ECU 100 and a front wheel braking ECU 200. The control system 1 can perform appropriate feedback control without outputting the next control signal until the regular communication cycle elapses even when the control signal is temporarily output, and further responds to changes in the output timing of the control signal. Monitoring can be performed.

(Modification 1)
In the embodiment described above, the temporary slot processing unit 230 sets the correction reference time so that the second reception time in the plurality of reception time slots is the middle time of the newly set time slot. Therefore, even if transmission of the control signal by the command ECU 100 is slightly delayed, the abnormality detection unit 210 has an advantage of not detecting an abnormality. However, in other words, when the delay is allowed up to half the period of the regular communication cycle, or when the command ECU 100 suddenly stops operation, half the period of the regular communication period has elapsed since the time when the control signal should be transmitted. Only after it can be judged abnormal. There may be applications in which such control signal delays and abnormality detection delays are not allowed. In such an application, the operation of the temporary slot processing unit 230 is changed as follows.

That is, the temporary slot processing unit 230 may calculate the correction reference time T2 as shown in the following Expression 2. Hereinafter, an allowable control signal delay and an allowable abnormality detection delay are referred to as “periodic control allowable delay time”.
T2 = R2 + TL-T1 (2)
In Equation 2, R2 is the second reception time in a plurality of reception time slots, TL is an allowable delay time for cycle control, and T1 is a periodic communication cycle.

FIG. 13 is a diagram illustrating calculation of the correction reference time in the first modification. The example shown in FIG. 13 is a modification of FIG. 4B, and the points not particularly described are the same as those in FIG. 4B. In the time slot 412, the second control signal indicated by hatching was received at 56.133 seconds. If the allowable delay time TL is 3 ms at this time, the periodic communication cycle is 10 ms. Therefore, in the above equation 2, R2 = 56.133, TL = 0.003, T1 = 0.010, and the corrected reference time T2 is expressed by the following equation 3 It is calculated as follows.
T2 = 56.133 + 0.003-0.010 = 56.126 (3)

  According to the first modification, the correction reference time can be determined based on the allowable delay time of the cycle control, and the abnormality detection unit 210 can appropriately detect the abnormality.

(Modification 2)
In the embodiment described above, the temporary slot processing unit 230 sets the time obtained by subtracting half of the regular communication period from the second reception time in the plurality of reception time slots. However, a time obtained by adding half the regular communication cycle to the second reception time in the plurality of reception time slots may be used as the calculation time. That is, “−” included in the expression in step S622 of FIG. 10 may be changed to “+”. In this case, the variable i is initialized with zero instead of “1” in step S617 of FIG.

(Modification 3)
The temporary slot processing unit 230 may set the correction reference time to a time that is later than the first reception time in the multiple reception time slots and earlier than the second reception time of the control signal. Further, the plurality of reception time slots may be shortened, and the end time of the plurality of reception time slots may be used as the correction reference time, and the next time slot may be started from the correction reference time. In this case, all the time slots are continuous in time.

  FIG. 14 is a diagram illustrating calculation of the correction reference time in the third modification. The example shown in FIG. 14 is a modification of FIG. 4B, and the points not particularly described are the same as those in FIG. 4B. In the time slot 412 which is a plurality of reception time slots, the control signal is received at 56.130 seconds and 56.133 seconds. The temporary slot processing unit 230 sets the correction reference time to a time later than the first reception time in the multiple reception time slots and earlier than the second reception time of the control signal. For example, a time that is earlier than the second reception time by a predetermined time, or a time at which the first reception time and the second reception time are divided at a predetermined ratio. Furthermore, considering the regular communication cycle, for example, a time earlier than the second reception time may be set by a quarter of the regular communication cycle.

  In the example shown in FIG. 14, the correction reference time is set to 56.132 seconds. In accordance with this correction reference time, the time slot 412 is shortened to a time slot 412A up to 56.132 seconds. The start time of the next time slot 421B is set to 56.132 seconds.

  According to the third modification, all the time slots can be continuous without time breaks. In addition, the control signal is received at least once in each time slot, so that the operation of the abnormality detection unit 210 can be made consistent.

(Modification 4)
When the collision prevention calculation device 92 determines that there is no possibility of a collision, the collision prevention calculation device 92 may transmit the fact to the command ECU 100. In this case, command ECU 100 outputs a temporary control signal only when a signal indicating the possibility of a collision is received. The command ECU 100 temporarily outputs a control signal based on the output of the brake pedal signal output device 95 when the amount of depression of the brake pedal is greater than or equal to a predetermined amount, or the amount of change in the amount of depression is greater than or equal to a predetermined ratio. It is good only as a case. In other words, in this case, the command ECU 100 temporarily outputs a control signal when it is determined that sudden braking has been performed.

(Modification 5)
The regular command execution unit 110, the temporary command execution unit 120, and the command timing change unit 130 that constitute the command ECU 100 may be integrated into one. The abnormality detection unit 210, the regular slot processing unit 220, and the temporary slot processing unit 230 constituting the front wheel braking ECU 200 may be integrated into one, or the front wheel control unit 250 may be further integrated.

(Modification 6)
A configuration excluding the front wheel control unit 250 from the front wheel drive ECU 200, that is, an abnormality detection unit 210, a regular slot processing unit 220, a temporary slot processing unit 230, and a second communication unit 240 are monitored. A dedicated ECU may be provided. The control system 1 may not include the rear wheel control ECU 300. The rear wheel control ECU 300 may further include an abnormality detection unit 210, a regular slot processing unit 220, and a temporary slot processing unit 230.

Although the program is stored in a ROM (not shown), the program may be stored in a nonvolatile memory (not shown). Each ECU may be provided with an input / output interface (not shown), and a program may be read from another device via an input / output interface and a medium that can be used by each ECU when necessary. Here, the medium refers to, for example, a storage medium that can be attached to and detached from the input / output interface, or a communication medium, that is, a wired, wireless, or optical network, or a carrier wave or digital signal that propagates through the network. Also, part or all of the functions realized by the program may be realized by a hardware circuit or FPGA.
You may combine the modification mentioned above, respectively. Although the embodiment and the modification have been described above, the present invention is not limited to these contents. Other embodiments conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

1 ... Control system 100 ... Command ECU
110 ... Regular command execution unit 120 ... Temporary command execution unit 130 ... Command timing change unit 200 ... Front wheel braking ECU
210 ... Abnormality detection unit 220 ... Regular slot processing unit 230 ... Temporary slot processing unit 240 ... Second communication unit

Claims (6)

A control system comprising: a control device that transmits a control signal; and a monitoring device that receives the control signal,
The control device includes:
A periodic execution unit that transmits the control signal at regular intervals;
A temporary execution unit that temporarily transmits the control signal at a different timing from the periodic execution unit;
When the temporary execution unit transmits the control signal, the periodic execution unit changes the timing of transmitting the control signal, and the temporary execution unit transmits the control signal to the periodic execution unit at regular intervals. A timing changing unit for transmitting the control signal,
The monitoring device
A communication unit for receiving the control signal;
A periodic processing unit that sets a plurality of time slots that are divided by the predetermined time from a preset reference time;
An abnormality detection unit that detects an abnormality when the communication unit does not receive the control signal in each of the plurality of time slots;
When the communication unit receives the control signal a plurality of times in any one of the plurality of time slots, the time slot in which the control signal is received a plurality of times is defined as a plurality of reception time slots, and the A control system comprising: a temporary processing unit that sets a correction reference time based on a second reception time of the control signal and uses the reference time as the correction reference time. A periodic execution unit that transmits a control signal at regular intervals;
A temporary execution unit that temporarily transmits the control signal at a different timing from the periodic execution unit;
When the temporary execution unit transmits the control signal, the periodic execution unit changes the timing of transmitting the control signal, and the temporary execution unit transmits the control signal to the periodic execution unit at regular intervals. A control apparatus comprising: a timing changing unit that transmits the control signal. A communication unit for receiving a control signal;
A periodic processing unit that sets a plurality of time slots that are divided by a predetermined time from a preset reference time;
An abnormality detection unit that detects an abnormality when the communication unit does not receive the control signal in each of the plurality of time slots;
When the communication unit receives the control signal a plurality of times in any one of the plurality of time slots, the time slot in which the control signal is received a plurality of times is defined as a plurality of reception time slots, and the A monitoring apparatus comprising: a temporary processing unit that sets a correction reference time based on a second reception time of the control signal and uses the reference time as the correction reference time. The monitoring device according to claim 3,
The temporary processing unit is a monitoring device that sets the correction reference time to a time later than a first reception time of the control signal and later than a second reception time of the control signal. The monitoring device according to claim 3,
The temporary processing unit is configured such that the second reception time in the plurality of reception time slots is a middle time in a time slot newly set as a period divided by the regular processing unit from the correction reference time every fixed time. A monitoring device that sets the correction reference time to be The monitoring device according to claim 3,
When the allowable delay time of the periodic control performed based on the control signal is TL,
The temporary processing unit sets the correction reference time according to the following equation 1 when the second reception time in the plurality of reception time slots is expressed as R2, the correction reference time is expressed as T2, and the fixed time is expressed as T1. Monitoring device.
T2 = R2 + TL−T1... Formula 1

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