Electric parking brake system

Abstract

To reduce power consumption while a start switch of a vehicle is turned off in an electric parking braking device configured to notify a detected abnormality.SOLUTION: An electric parking braking device 10 includes: a switch device 30; an actuator 11; and an EPB control device 20. The EPB control device 20 has a detection section M2 for detecting an abnormality of the switch device 30 and a notification instruction section M3 for outputting an instruction for controlling the notification device 92. The EPB control device 20 executes off state processing as processing when notifying the occurrence of an abnormality in the switch device 30 while a start switch 94 of a vehicle 90 is turned off. In the off state processing, the notification instruction section M3 adjusts notification time to be time when abnormality notification is continued according to a mode of an abnormality detected by the detection section M2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric parking brake device.

Background Art

[0002] Patent Document 1 discloses a parking brake device for a vehicle. The parking brake device includes warning means for warning a driver of an abnormality. The parking brake device includes a switch device whose connection is switched according to an operation when a driver operates an operating member for operating the parking brake device. The parking brake device is configured to warn a driver of an abnormality when there is an abnormality in the switch device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Situations where a driver operates an operating member of a parking brake device include, for example, a situation where the driver is about to get out of the vehicle. In such a situation, the start switch of the vehicle may be turned off. Generally, in a vehicle with the start switch turned off, the power generation device provided in the vehicle does not generate power. This is the same regardless of the type of drive source provided in the vehicle. Therefore, when an abnormality warning is given in a situation where the start switch of the vehicle is turned off, the power required for the warning is consumed from the in-vehicle battery. As a result, when a warning is given in a situation where the start switch of the vehicle is turned off, depending on the frequency of the warning and the length of time the warning continues, the power consumption from the in-vehicle battery may increase.

Means for Solving the Problems

[0005] An electric parking brake system for solving the above problems comprises a switch device whose state is switched by the operation of an operating member by the driver of the vehicle, an actuator that generates braking force on the vehicle, and a control device that controls the actuator according to the state of the switch device, wherein the control device comprises a detection unit that detects an abnormality in the switch device, and a notification instruction unit that outputs an instruction for controlling a notification device that notifies that an abnormality has occurred in the switch device, and performs an off-state processing as a process for notifying that an abnormality has occurred in the switch device while the vehicle's start switch is off, and the gist of the off-state processing is that the notification instruction unit adjusts the notification time, which is the time for which the notification of the abnormality continues according to the type of abnormality detected by the detection unit.

[0006] One example of the purpose of notifying a switch device malfunction is to prompt the driver to operate the control component. In some cases, the driver can recover from the malfunction once they recognize it, while in other cases, even with the driver's best efforts, recovery is not possible. An example of a malfunction that the driver can recover from is a malfunction caused by a stuck contact in the switch device. For example, the driver repeatedly operating the control component may resolve the stuck contact. On the other hand, an example of a malfunction that the driver cannot recover from is a malfunction caused by a broken wire in the switch device. In this case, even if the malfunction is notified, power is consumed only for the notification itself, and recovery from the malfunction cannot be expected. In other words, power may be consumed unnecessarily.

[0007] With the above configuration, the notification time, which is the duration for which an anomaly notification continues, can be adjusted according to the nature of the anomaly. This is expected to reduce unnecessary power consumption compared to a system that uniformly notifies the occurrence of an anomaly when an anomaly is detected while the vehicle's start switch is off. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of an electric parking brake system and a vehicle equipped with the electric parking brake system. [Figure 2] Figure 2 is a flowchart showing the processing flow performed by the control device of the electric parking brake system shown in Figure 1. [Figure 3] Figure 3 illustrates the adjustment of notifications made by the control device provided in the electric parking brake system shown in Figure 1. [Figure 4] Figure 4 is a timing chart showing when an abnormality is notified by the electric parking brake system shown in Figure 1. [Modes for carrying out the invention]

[0009] An embodiment of the electric parking brake system will be described below with reference to Figures 1 to 4. Figure 1 shows an electric parking brake system 10 and a vehicle 90 equipped with the electric parking brake system 10.

[0010] <Electric Parking Brake System> The electric parking brake system 10 comprises an actuator 11, an EPB control device 20 which is a control device for controlling the actuator 11, and a switch device 30.

[0011] The actuator 11 is equipped with an electric motor, for example. For instance, the electric parking brake 10 can generate braking force by pressing a friction material against a rotating body that rotates integrally with the wheel, driven by the electric motor. Alternatively, the electric parking brake 10 can release the braking force by releasing the force pressing the friction material against the rotating body, driven by the electric motor.

[0012] The EPB control device 20 is a processing circuit that controls the actuator 11. The EPB control device 20 controls the actuator 11 according to the switching state of the switch device 30. The EPB control device 20 can detect the state of the switch device 30 by performing a detection process. The detection process can also detect an abnormality in the switch device 30. The detection process is repeatedly performed at predetermined intervals. Preferably, the EPB control device 20 is configured to activate the actuator 11 to release the braking force when an abnormality in the switch device 30 is detected.

[0013] If the EPB control device 20 detects an abnormality in the switch device 30, it executes a process to notify the driver of the vehicle 90 that an abnormality has occurred. Details of the EPB control device 20 and the switch device 30 will be described later.

[0014] <Vehicle> The vehicle 90 is equipped with an operating member 91. The operating member 91 is an element that can be operated by the driver of the vehicle 90. By operating the operating member 91, the movable contacts of the switch device 30 can be driven. In other words, the operating member 91 is a switch that allows the driver to activate the electric parking brake device 10.

[0015] The operating member 91 has three operating positions: an apply position, a release position, and a neutral position. The apply position is the position where the operating member 91 is operated when the actuator 11 is activated to generate braking force. The release position is the position where the operating member 91 is operated when the actuator 11 is activated to release the braking force. The neutral position is the position where the operating member 91 is operated when the actuator 11 is not activated. For example, the neutral position is between the apply position and the release position. The initial position of the operating member 91 is the neutral position. The driver can operate the operating member 91 from the neutral position to the apply position or the release position.

[0016] The operation member 91 is, for example, an operation knob. When operating the operation member 91 to the apply position, the operation member 91 is operated in the first direction. When operating the operation member 91 to the release position, the operation member 91 is operated in a second direction different from the first direction. Additionally, the operation member 91 may be a toggle switch or a button switch. Hereinafter, operating the operation member 91 may also be referred to as an EPB operation.

[0017] The vehicle 90 includes an in-vehicle battery 99. The negative electrode 99a of the in-vehicle battery 99 is connected to the body ground, for example, the frame of the vehicle 90. The positive electrode 99b of the in-vehicle battery 99 is connected to each device provided in the vehicle 90. In FIG. 1, the wiring connecting the in-vehicle battery 99 and each device is not shown. The in-vehicle battery 99 can store, for example, the electric power generated by a power generation device provided in the vehicle 90. The power generation device can generate electricity according to the operation of a drive source provided in the vehicle 90. An example of the power generation device is an alternator that rotates in conjunction with the drive source. Another example of the power generation device is a motor generator that also serves as a drive source. The in-vehicle battery 99 can supply electric power to, for example, each device provided in the vehicle 90.

[0018] The vehicle 90 includes a start switch 94. The start switch 94 is a member that can be operated by the driver of the vehicle 90. The start switch 94 is a switch for starting the drive source of the vehicle 90. When the start switch 94 is turned on, the drive source of the vehicle 90 is configured to start. When the start switch 94 is turned off, the drive source of the vehicle 90 is configured to stop. The start switch 94 may also be referred to as an ignition switch, a power switch, a start switch, etc.

[0019] The vehicle 90 includes a notification device 92. An example of the notification device 92 is an indicator light. In this case, notification can be performed by lighting or flashing the notification device 92. Another example of the notification device 92 is, for example, a buzzer.

[0020] In addition to the EPB control device 20, the vehicle 90 further includes various processing circuits. In FIG. 1, as an example of the processing circuits included in the vehicle 90, a notification control device 93 and a drive control device 95 are shown. Further, the vehicle 90 may include one or more other control devices 97.

[0021] The notification control device 93 has a function of controlling the notification device 92. The drive control device 95 has a function of controlling the drive source of the vehicle 90. The vehicle 90 may include various sensors. An example of the various sensors is a wheel speed sensor.

[0022] The vehicle 90 may include an in-vehicle network 98. In the in-vehicle network 98, for example, each processing circuit included in the vehicle 90, various sensors included in the vehicle 90, and each device included in the vehicle 90 are connected. Each component connected to the in-vehicle network 98 can communicate with each other. For example, when the notification control device 93 receives a notification instruction signal via the in-vehicle network 98, it can operate the notification device 92 to perform a notification.

[0023] <Power saving function of each control device> Each control device such as the EPB control device 20, the notification control device 93, the drive control device 95, and the other control device 97 may have a power saving function.

[0024] As an example of the power saving function, each control device can switch between an active state and a sleep state. The active state is a state in which all functions of the control device can be executed. The sleep state is a state in which the power consumption of the control device is suppressed compared to the case where the control device is in the active state. A control device in the sleep state cannot execute processing such as arithmetic processing, except for some processing. Examples of some processing include processing for transitioning the control device from the sleep state to the active state.

[0025] The start state and the sleep state are switched, for example, as follows. When the sleep condition is satisfied while each control device is in the start state, the control device can transition from the start state to the sleep state. For example, the sleep condition is satisfied when a prescribed rest permission time has elapsed since the start switch 94 was turned off. Alternatively, the sleep condition may be configured to be satisfied when the control device receives a sleep permission signal. Also, for example, the sleep condition may be configured not to be satisfied while signals are being transmitted and received on the in-vehicle network 98.

[0026] When the wake-up condition is satisfied while each control device is in the sleep state, the control device transitions from the sleep state to the start state. For example, the wake-up condition is satisfied when the control device receives a specific signal via the in-vehicle network 98. Examples of the specific signal include a signal indicating that the drive source of the vehicle 90 has started, a signal indicating that an abnormality has occurred in the vehicle 90, etc. In the present embodiment, the signal for instructing the notification control device 93 when the EPB control device 20 detects an abnormality is an example of the above-mentioned "signal indicating that an abnormality has occurred".

[0027] Each control device may have a unique condition set as the wake-up condition. For example, the EPB control device 20 may be set such that the wake-up condition is satisfied when the operation member 91 is operated. That is, the EPB control device 20 can detect the switching state of the switch device 30 even while in the sleep state.

[0028] <EPB control device> An example of the EPB control device 20, which is a processing circuit, will be described. The EPB control device 20 includes, for example, a processor 25. The processor 25 includes a processing device such as a CPU. The processor 25 includes a storage device. For example, the storage device stores a control program executed by the processing device. The processor 25 may be connected to the in-vehicle network 98.

[0029] The processor 25 functions as various functional units by executing a control program. Figure 1 illustrates the control unit M1, detection unit M2, and notification / instruction unit M3 as functional units.

[0030] The control unit M1 can operate the actuator 11. The detection unit M2 can detect the state of the switch device 30. The notification instruction unit M3 can output instructions to control the notification device 92. For example, the notification control device 92 is controlled by the notification control device 93 upon receiving the instruction, thereby notifying that an abnormality has occurred in the switch device 30.

[0031] The EPB control device 20 performs an ON state process as a way to notify the vehicle 90's start switch 94 of an abnormality in the switch device 30 while the vehicle 90's start switch 94 is ON. For example, in the ON state process, once the notification is started, the notification continues until the start switch 94 is turned OFF.

[0032] The EPB control device 20 performs an off-state processing as a process to notify the vehicle 90's start switch 94 of an abnormality occurring in the switch device 30 while the vehicle 90's start switch 94 is off. The notification instruction unit M3 can terminate the notification instruction during the off-state processing when a reference time Ti3 has elapsed since the start of outputting the notification instruction. In other words, the reference time Ti3 is set as the time for which the abnormality notification continues when the start switch 94 is off. The length of the reference time Ti3 is set to a value calculated in advance. Furthermore, during the off-state processing, the notification instruction unit M3 adjusts the notification time, which is the time for which the abnormality notification continues, according to the type of abnormality detected by the detection unit M2. For example, the notification instruction unit M3 can adjust the notification time, which is the time for which the notification continues, by adjusting the time from when it starts outputting the notification instruction until it terminates. The notification instruction unit M3 can also make the notification time shorter than the reference time Ti3, or make the notification time longer than the reference time Ti3.

[0033] The EPB control device 20 includes a first output circuit 21, a first input circuit 23, a second output circuit 22, and a second input circuit 24. The processor 25 has four ports, each corresponding one-to-one with circuits 21-24. Each circuit 21-24 is connected to its corresponding port.

[0034] The EPB control device 20 includes a first output terminal Out1, a first input terminal In1, a second output terminal Out2, and a second input terminal In2. The first output terminal Out1 is connected to the first output circuit 21. The first input terminal In1 is connected to the first input circuit 23. The second output terminal Out2 is connected to the second output circuit 22. The second input terminal In2 is connected to the second input circuit 24. A switch device 30 is connected to the first output terminal Out1, the first input terminal In1, the second output terminal Out2, and the second input terminal In2.

[0035] In the EPB control device 20, the signal output from the first output circuit 21 is input to the first input circuit 23 or the second input circuit 24, or to both the first input circuit 23 and the second input circuit 24, via the switch device 30.

[0036] In the EPB control device 20, the signal output from the second output circuit 22 is input to the first input circuit 23 or the second input circuit 24, or to both the first input circuit 23 and the second input circuit 24, via the switch device 30.

[0037] The EPB control device 20 can detect the switching state of the switch device 30 based on the output signals output from the first output circuit 21 and the second output circuit 22, and the input signals input to the first input circuit 23 and the second input circuit 24 via the switch device 30. By detecting the switching state of the switch device 30, the operating position of the operating member 91 can be detected.

[0038] <Switching device> An example of a switch device 30 will be described. The switch device 30 includes a lock switch 30a that operates when the operating member 91 is operated to the apply position. The lock switch 30a is composed of a first lock switch SWL1 and a second lock switch SWL2.

[0039] The first lock switch SWL1 is a normally open switch. The second lock switch SWL2 is a normally closed switch. The first lock switch SWL1 and the second lock switch SWL2 are connected in parallel.

[0040] The switch device 30 includes a release switch 30b that operates when the operating member 91 is moved to the release position. The release switch 30b is composed of a first release switch SWR1 and a second release switch SWR2.

[0041] The first release switch SWR1 is a normally closed switch. The second release switch SWR2 is a normally open switch. The first release switch SWR1 and the second release switch SWR2 are connected in parallel.

[0042] The first lock switch SWL1, the second lock switch SWL2, the first release switch SWR1, and the second release switch SWR2 are in the ON state when their movable contacts and fixed contacts are in contact. The first lock switch SWL1, the second lock switch SWL2, the first release switch SWR1, and the second release switch SWR2 are in the OFF state when their movable contacts and fixed contacts are separated.

[0043] Let's explain lock switch 30a further. In the lock switch 30a, the first lock switch SWL1 and the second lock switch SWL2 operate in mechanical conjunction depending on the operating position of the operating member 91. When the lock switch 30a is activated, such that the operating member 91 is operated to the apply position, the first lock switch SWL1 is turned ON and the second lock switch SWL2 is turned OFF. On the other hand, when the lock switch 30a is not activated, the first lock switch SWL1 is turned OFF and the second lock switch SWL2 is turned ON. In other words, the lock switch 30a is structured so that either the first lock switch SWL1 or the second lock switch SWL2 is selectively turned ON.

[0044] Let's explain the release switch 30b further. In the release switch 30b, the first release switch SWR1 and the second release switch SWR2 operate in mechanical conjunction depending on the operating position of the operating member 91. When the release switch 30b is activated, such that the first release switch SWR1 is in the OFF state and the second release switch SWR2 is in the ON state. On the other hand, when the release switch 30b is not activated, the first release switch SWR1 is in the ON state and the second release switch SWR2 is in the OFF state. In other words, the release switch 30b is structured so that either the first release switch SWR1 or the second release switch SWR2 is in the ON state.

[0045] As described above, the switch device 30 has a configuration in which the lock switch 30a and the release switch 30b are each made redundant by a pair of switches. The circuit configuration of the switch device 30 will be explained.

[0046] In the switch device 30, the lock switch 30a and the release switch 30b are connected in series. Specifically, the first lock switch SWL1 and the first release switch SWR1 are connected in series. The second lock switch SWL2 and the second release switch SWR2 are connected in series.

[0047] The switch device 30 includes a first wiring 31, a second wiring 32, a third wiring 33, and a fourth wiring 34. The first wiring 31 connects the first output terminal Out1 to the first lock switch SWL1 and the first release switch SWR1. The second wiring 32 connects the second output terminal Out2 to the second lock switch SWL2 and the second release switch SWR2. The third wiring 33 connects the first input terminal In1 to the first lock switch SWL1 and the second lock switch SWL2. The fourth wiring 34 connects the second input terminal In2 to the first release switch SWR1 and the second release switch SWR2.

[0048] <Method for detecting anomalies> An example of how the EPB control device 20 detects an abnormality as part of the detection process will be described below. The EPB control device 20 can diagnose the switch device 30 by a known method of comparing the output signal and the input signal. For example, the EPB control device 20 stores the relationship between the output signal and the input signal when there is no abnormality in the switch device 30 as a predetermined pattern. The predetermined pattern includes the pattern when the operating member 91 is in the apply position, the pattern when the operating member 91 is in the release position, and the pattern when the operating member 91 is in the neutral position. Therefore, if the relationship between the output signal and the input signal does not match the predetermined pattern, the EPB control device 20 can detect that there is an abnormality in the switch device 30. At this time, the waveform of the input signal changes relative to the waveform of the output signal depending on the type of abnormality in the switch device 30. This is because the circuit configuration within the switch device 30 changes depending on the type of abnormality, which changes the signal path. For example, a break in each of the wires 31 to 34, and contact sticking in each of the switches SWL1, SWL2, SWR1, and SWR2 each show a unique pattern. In addition to wire breaks and contact sticking, the EPB control device 20 can also detect short circuits, including ground faults and ceiling faults. In other words, the EPB control device 20 can detect abnormalities occurring in the switch device 30 separately.

[0049] In the following, output signals and input signals are referred to as diagnostic signals. Diagnostic signals that conform to a specified pattern are collectively called "normal signals." That is, normal signals are signals that occur when there is no abnormality in the switch device 30. Furthermore, when a diagnostic signal is a normal signal, it is referred to as "normal." Diagnostic signals that do not conform to a specified pattern are collectively called "undefined signals." That is, undefined signals are signals that occur when there is an abnormality in the switch device 30. Furthermore, when a diagnostic signal is an undefined signal, it is referred to as "undefined."

[0050] For example, the detection unit M2 can be configured to detect the occurrence of an anomaly if the undefined signal continues for a predetermined judgment time Ti2 or longer from the time it starts receiving the undefined signal.

[0051] For example, the detection unit M2 turns on an abnormality flag when it detects an abnormality. The abnormality flag indicates that an abnormality has occurred in the switch device 30 when it is turned on. The detection unit M2 can also store information that identifies the type of abnormality detected.

[0052] <Off state processing> Figure 2 shows the flow of the off-state processing performed by the EPB control device 20. This processing routine is repeatedly executed at predetermined intervals by the EPB control device 20 while the start switch 94 is off. More specifically, this processing routine is repeatedly executed at predetermined intervals while the start switch 94 is off and the EPB control device 20 is in the activated state.

[0053] When this processing routine is started, in step S101, the detection unit M2 first determines whether or not there is an abnormality notification history. As will be described later, when the detection unit M2 instructs the system to notify of an abnormality, it updates the notification history to record that a notification has been made. The notification history is initialized, i.e., deleted, when the start switch 94 is turned on. In other words, the existence of a notification history indicates that an abnormality notification has been made one or more times between the time the start switch 94 is turned off and the time the start switch 94 is turned on again.

[0054] If there is a notification history (S101: YES), the detection unit M2 proceeds to step S110. By executing the process in step S110, the detection unit M2 terminates this processing routine without issuing a notification. As a result, the detection unit M2 limits the number of notifications issued between the time the start switch 94 is turned off and the time it is turned on again to a maximum of one.

[0055] On the other hand, if there is no notification history (S101:NO), the detection unit M2 proceeds to step S102. In step S102, the detection unit M2 determines whether or not an abnormality has occurred in the switch device 30. If there is no abnormality, i.e., the abnormality flag is turned off (S102: NO), the detection unit M2 proceeds to step S110. After that, the detection unit M2 terminates this processing routine without issuing a notification.

[0056] On the other hand, if there is an abnormality, that is, if the abnormality flag is turned on (S102:YES), the detection unit M2 proceeds to step S103. In step S103, the detection unit M2 determines whether the detected abnormality is recoverable. An example of a recoverable abnormality is a stuck contact. An example of an unrecoverable abnormality is a broken wire. If the detected abnormality is unrecoverable (S103: NO), the detection unit M2 proceeds to step S111.

[0057] In step S111, the detection unit M2 instructs the notification instruction unit M3 to send a notification. At this time, the detection unit M2 updates the notification history. Furthermore, the detection unit M2 instructs the notification instruction unit M3 to adjust the notification time. Specifically, the notification instruction unit M3 terminates the notification instruction early so that the notification time is shorter. For example, the notification instruction unit M3 terminates the notification instruction so that the notification time is shorter than the reference time Ti3. As a result, if the abnormality of the switch device 30 is an irrecoverable abnormality, the notification time is shorter compared to when the abnormality of the switch device 30 is a recoverable abnormality. After adjusting the notification time, the detection unit M2 terminates this processing routine.

[0058] On the other hand, if the abnormality is recoverable (S103: YES), the detection unit M2 proceeds to step S104. In step S104, the detection unit M2 determines whether or not the operating member 91 has been operated. If the operating member 91 is in the apply position or release position at the time the process in step S104 is being executed, the detection unit M2 determines that there has been an operation. On the other hand, if the operating member 91 is in the neutral position at the time the process in step S104 is being executed, the detection unit M2 determines that there has been no operation.

[0059] If there is an operation (S104:YES), the detection unit M2 proceeds to step S105. In step S105, the detection unit M2 determines whether the state of the operating member 91 and the operating state of the actuator 11 correspond correctly, that is, whether the states of both are in agreement. For example, if the operating member 91 is in the release position and the actuator 11 is not generating braking force, the detection unit M2 determines that the states of both are in agreement. On the other hand, if the operating member 91 is in the apply position and the actuator 11 is not generating braking force, the detection unit M2 determines that the states of both are in agreement.

[0060] If both states match (S105: YES), the detection unit M2 proceeds to step S110. After that, the detection unit M2 terminates this processing routine without issuing a notification.

[0061] On the other hand, if the states of both do not match (S105: NO), the detection unit M2 proceeds to step S106. Furthermore, if there is no operation during step S104 (S104:NO), the detection unit M2 proceeds to step S106.

[0062] In step S106, the detection unit M2 starts a determination process to obtain the period during which an undefined signal is continuously received. The determination process is performed to cause the notification instruction unit M3 to adjust the notification time according to the result of the determination process, that is, according to the reception time of the undefined signal.

[0063] When the reception time determination process begins, the detection unit M2 moves the process to step S112. In step S112, the detection unit M2 instructs the notification instruction unit M3 to send a notification. At this time, the detection unit M2 updates the notification history. Furthermore, the detection unit M2 instructs the notification instruction unit M3 to adjust the timing for ending the notification according to the result of the determination process started in step S106. As will be described in detail later, if the reception time is long, i.e., the undefined signal continues for a long time, the detection unit M2 shortens the notification time. If the reception time is short, i.e., the undefined signal ends quickly, the detection unit M2 lengthens the notification time. After adjusting the notification time, the detection unit M2 terminates this processing routine.

[0064] <Adjusting notification times> Using Figure 3, the relationship between the determination process initiated in step S106 in Figure 2 and the notification time adjusted as a result of said determination process will be explained.

[0065] For example, as shown by the solid line in Figure 3(a), suppose the undefined signal ends after a specified time Ti1 has elapsed since the undefined signal was detected. The detection unit M2 detects an anomaly after a determination time Ti2 has elapsed since the undefined signal was detected. As a result, the anomaly flag is turned on, as shown by the solid line in Figure 3(c). When the anomaly flag is turned on, notification is started by outputting a notification instruction from the notification instruction unit M3, as shown by the solid line in Figure 3(c). At this time, the notification instruction unit M3 ends the notification after a reference time Ti3 has elapsed since the notification started, i.e., since the anomaly was detected. The specified time Ti1 is set as the length of the reception time when the notification time is the reference time Ti3.

[0066] Furthermore, the length of the reception time, which is the duration of the undefined signal, can be used as an indicator to estimate how easily the system will recover from an anomaly. For example, a long reception time suggests that recovery from an anomaly is unlikely. Conversely, a short reception time suggests that recovery from an anomaly is relatively easy.

[0067] Next, we will explain an example where the undefined signal ends before the specified time Ti1 has elapsed from the time the undefined signal was detected, as shown by the dashed line in Figure 3(a). In this case, the determination process will determine that the reception time of the undefined signal is shorter than the specified time Ti1.

[0068] If the reception time of an undefined signal is shorter than the specified time Ti1, the detection unit M2 makes the notification time longer than the reference time Ti3, as shown by the dashed line in Figure 3(c). Specifically, the detection unit M2 delays the timing at which the notification instruction unit M3 terminates the notification instruction so that the notification time is longer than the reference time Ti3. In this way, the notification instruction unit M3 makes the notification time longer than the reference time Ti3 if the period during which a signal with an abnormal pattern is input is shorter than or equal to the specified time Ti1. For example, the detection unit M2 may be configured so that the notification time becomes longer the shorter the reception time of the undefined signal is compared to the specified time Ti1.

[0069] Next, as shown by the dashed line in Figure 3(a), we will explain an example where the undefined signal continues even after a specified time Ti1 has elapsed since the undefined signal was detected. In this case, the determination process will determine that the reception time of the undefined signal is longer than the specified time Ti1.

[0070] If the detection unit M2 detects that the reception time of an undefined signal is longer than the specified time Ti1, it shortens the notification time to be shorter than the reference time Ti3, as shown by the dashed line in Figure 3(c). Specifically, the detection unit M2 causes the notification instruction unit M3 to terminate the notification instruction earlier so that the notification time is shorter than the reference time Ti3. In this way, the notification instruction unit M3 shortens the notification time to be shorter than the reference time Ti3 if the period during which a signal with an abnormal pattern is input is longer than the specified time Ti1. For example, the notification instruction unit M3 can terminate the output of the notification instruction so that the notification time is the reference time Ti3 minus the shortening time Ti4. For example, the shortening time Ti4 is preset so that a longer notification time is calculated compared to the notification time shortened as a result of the processing performed in step S111 shown in Figure 2. For example, the notification instruction unit M3 may terminate the output of the notification instruction at the point when the reception time of the undefined signal becomes equal to the sum of the time obtained by subtracting the shortening time Ti4 from the reference time Ti3 and the judgment time Ti2. The reduction time Ti4 may also be a value calculated based on the length of the reception time.

[0071] <Mechanism of Action and Effects> The operation and effects of this embodiment will now be described. One example of the purpose of notifying the driver of an abnormality in the switch device 30 is to prompt the driver to operate the operating member 91. In some cases, the driver who recognizes the abnormality can recover from it, while in other cases, even if the driver takes all necessary measures, recovery from the abnormality is not possible. An example of an abnormality that the driver can recover from is an abnormality caused by the contacts of the switch device 30 becoming stuck. For example, the driver may be able to resolve the sticking of the contacts by repeatedly operating the operating member 91. On the other hand, an example of an abnormality that the driver cannot recover from is an abnormality caused by a broken wire in the switch device 30. In this case, even if the abnormality is notified, power required for notification will be consumed, and recovery from the abnormality cannot be expected. In other words, power may be consumed unnecessarily.

[0072] The electric parking brake system 10 allows the notification time, which is the duration for which an abnormality notification continues, to be adjusted according to the nature of the abnormality. This is expected to reduce unnecessary power consumption compared to a system that uniformly notifies the occurrence of an abnormality when an abnormality is detected while the vehicle's start switch 94 is off. By reducing power consumption while the start switch 94 is off, excessive discharge of the onboard battery 99 while the start switch 94 is off can be suppressed. In turn, degradation of the onboard battery 99 can be suppressed.

[0073] Using Figure 4, an example of the electric parking brake system 10 of this embodiment providing notification while the start switch 94 is off will be explained. As shown in Figure 4(a), the start switch 94 is turned off from timing t11 onwards.

[0074] As shown in Figure 4(b), the operating member 91 is operated to the apply position during the period from timing t13 to timing t14. For example, if the driver realizes after turning off the start switch 94 that they have forgotten to generate braking force from the electric parking brake 10, the EPB operation may be performed at this timing.

[0075] As shown in Figure 4(c), the EPB control device 20 transitions from the active state to the sleep state at timing t12, after the pause permission time has elapsed from the timing t11 when the start switch 94 is turned off. The EPB control device 20 transitions from the sleep state to the active state at timing t13 when the operating member 91 is operated.

[0076] As shown in Figure 4(d), an undefined signal is detected at timing t13 when the EPB operation is performed. It is assumed that this detected undefined signal indicates a recoverable abnormality pattern. The undefined signal continues until timing t16. The period from timing t13 to timing t16 is longer than the specified time Ti1. From this, it can be inferred that the detected abnormality is not irrecoverable, but rather difficult to recover from.

[0077] As shown in Figure 4(e), the abnormal flag is turned on at timing t15, after the determination time Ti2 has elapsed since the detection of the indeterminate signal at timing t13. The abnormal flag remains on from timing t15 onward.

[0078] Because the abnormality flag is turned on at timing t15, the notification of the abnormality starts from timing t15, as shown in Figure 4(f). The timing for ending the abnormality notification is adjusted by the EPB control device 20.

[0079] As shown in Figure 4(e), the abnormality flag is turned on, meaning an abnormality has been detected, and the actuator 11 releases the braking force. At this time, as shown in Figure 4(b), the operating member 91 is in the neutral position. Therefore, the EPB control device 20 determines that there is no operation of the operating member 91 (S104: NO). This allows the reception time of the undefined signal to be determined (S106). Since the reception time is longer than the specified time Ti1, the notification time is made shorter than the reference time Ti3 (S112). As a result, the notification ends at a timing t17 earlier than the time Ti3 has elapsed since the notification started.

[0080] Because the notification of the abnormality ends early at timing t17, the EPB control device 20 enters a sleep state after timing t17. This reduces power consumption.

[0081] Figure 4(g) shows the communication status of the in-vehicle network 98. As shown in Figure 4(g), communication takes place in the in-vehicle network 98 while the EPB control device 20 is running. Specifically, communication takes place during the period before timing t12 and from timing t13 to timing t17. During the period when communication is taking place in the in-vehicle network 98, other control devices besides the EPB control device 20, such as the notification control device 93, are also running. Since the notification ends at timing t17, each control device can enter a sleep state after timing t17. This reduces power consumption.

[0082] Thus, with the electric parking brake system 10, power consumption can be reduced by shortening the notification time when it is difficult to recover from an abnormality. In the electric parking brake system 10, the notification time can be extended if the switch device 30 is likely to recover from an abnormality. The longer the notification time, the more likely the driver is to notice the notification. When the driver notices the notification, they can operate the operating member 91, which may, for example, resolve a stuck contact. In this way, the electric parking brake system 10 provides more opportunities to attempt to recover from an abnormality if it is likely to recover from an abnormality.

[0083] The electric parking brake system 10 is configured to shorten the notification time if the malfunction of the switch device 30 is irreversible. By relatively shortening the notification time when recovery from the malfunction is not expected, the power consumption required for notification can be reduced. On the other hand, if recovery from the malfunction is possible, the notification time can be relatively lengthened to make the notification more easily recognizable to the driver.

[0084] By the way, if the system has not yet recovered from the malfunction despite notifications being sent after the start switch 94 was turned off, sending another notification may not lead to recovery.

[0085] Therefore, with the electric parking brake system 10, the number of notifications issued between the time the start switch 94 is turned off and the time it is turned on again is limited to a maximum of one time. This prevents notifications from being issued when recovery from an abnormality cannot be expected. As a result, power consumption while the start switch 94 is off can be reduced.

[0086] The electric parking brake system 10 is configured not to issue a notification if the state of the operating member 91 and the operating state of the actuator 11 are the same. If the two states are not the same, issuing a notification can be expected to have the following effect: that is, by prompting the driver to operate the operating member 91, the two states can be guided to be the same. On the other hand, even if there is a malfunction in the switch device 30, if the two states are the same, it is difficult for the driver to perceive the difference from when there is no malfunction. For this reason, power consumption can be reduced by not issuing a notification when the two states are the same, that is, when the actuator 11 is performing an operation corresponding to the operating position of the operating member 91. In this way, the electric parking brake system 10 can reduce power consumption by reducing the opportunities for low-priority notifications to be issued.

[0087] (Example of change) This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0088] The configuration of the switch device 30 in the above embodiment is just one example. The configuration of the switch device 30 is sufficient as long as it allows the EPB control device 20 to separately detect abnormalities occurring in the switch device 30.

[0089] The detection process in the above embodiment is just one example. Any detection process that can differentiate and detect abnormalities occurring in the switch device 30 is acceptable. • In the above embodiment, an example was shown in which each control device has a power-saving function. It is not essential that each control device has a power-saving function. If the EPB control device 20 is configured to adjust the notification time according to the type of abnormality occurring in the switch device 30, it will lead to a reduction in the power consumption required for notification.

[0090] • In the off-state processing of the above embodiment, the system is configured not to send a notification if there is a notification history. That is, the system is configured to limit the number of notifications sent between the time the start switch 94 is turned off and the time the start switch 94 is turned on again to a maximum of one. Alternatively, a notification may be sent even if there is a notification history.

[0091] In the off-state processing of the above embodiment, if the reception time of the undefined signal is shorter than the specified time Ti1, the notification time is set to be longer than the reference time Ti3. Alternatively, even if the reception time of the undefined signal is shorter than the specified time Ti1, the notification time may be set to the reference time Ti3.

[0092] • In the off-state processing of the above embodiment, the system is configured to perform a determination of the reception time, but performing the determination is not mandatory. In this case, an example of a configuration that adjusts the notification time according to the nature of the abnormality will be described. For example, when a notification is sent when the abnormality of the switch device 30 is a recoverable abnormality, the notification time is set to the first hour. Then, when a notification is sent when the abnormality of the switch device 30 is an unrecoverable abnormality, the notification time is set to the second hour, which is shorter than the first hour.

[0093] Each control device in the EPB control device 20 and the vehicle 90 may have one of the following configurations: [a] A circuit comprising one or more processors that perform various processes according to a computer program. The processor comprises a processing unit. Examples of processing units include a CPU, DSP, and GPU. The processor comprises memory. Examples of memory include RAM, ROM, and flash memory. The memory stores program code or instructions configured to cause the processing unit to perform the processes. Memory, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer. [b] A circuit comprising one or more hardware circuits that perform various processes. Examples of hardware circuits include an ASIC (Application Specific Integrated Circuit), a CPLD (Complex Programmable Logic Device), and an FPGA (Field Programmable Gate Array). [c] A circuit comprising a processor that performs a part of the various processes according to a computer program, and hardware circuits that perform the remaining parts of the various processes.

[0094] Some or all of the functions implemented by the notification control device 93 may be implemented by the EPB control device 20. [Explanation of symbols]

[0095] 10…Electric parking brake system 11… Actuator 20…EPB control device 30…Switching device 30a... Lock switch 30b…Release switch 90... Vehicles 91... Operating component 92…Notification device 94... Start switch 98…In-vehicle network 99... Car battery M1...Control Unit M2...Detection unit M3…Notification and Instruction Department

Claims

1. An electric parking brake system comprising: a switch device whose state is switched by the operation of an operating member by the vehicle driver; an actuator that generates braking force on the vehicle; and a control device that controls the actuator according to the state of the switch device, The control device is A detection unit for detecting abnormalities in the aforementioned switch device, The system includes a notification instruction unit that outputs instructions for controlling a notification device that notifies the user that an abnormality has occurred in the switch device, The off-state processing is performed as a process to notify the vehicle that an abnormality has occurred in the aforementioned switch device while the vehicle's start switch is off. In the off-state processing, the notification instruction unit adjusts the notification time, which is the duration for which the notification of the abnormality continues, according to the type of abnormality detected by the detection unit. Electric parking brake system.

2. In the off-state processing, the notification instruction unit shortens the notification time if the abnormality of the switch device is an irreversible abnormality, compared to the case where the abnormality of the switch device is a recoverable abnormality. The electric parking brake device according to claim 1.

3. The detection unit detects abnormalities based on signals input via the switch device. In the off-state processing, the notification instruction unit sets the notification time to be at least the reference time if the period during which a signal indicating an abnormal pattern is input is less than or equal to a specified time, and shortens the notification time to less than the reference time if the period during which a signal indicating an abnormal pattern is input is longer than the specified time. The electric parking brake device according to claim 1.

4. The detection unit limits the number of notifications issued between the time the start switch is turned off and the time the start switch is turned on to a maximum of one time. An electric parking brake device according to any one of claims 1 to 3.

Images