JP2007210506A - Anti-theft system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-theft system for a vehicle, capable of preventing malfunction caused by an inclination sensor. <P>SOLUTION: In the anti-theft device 5 for a vehicle, alarm is given when the inclination sensor 13 to detect inclination change in the vehicle 2 detects inclination change more than prescribed to an initial value. It comprises a tire pneumatic pressure sensor 11 to detect tire pneumatic pressure, and in a case where lowering of the tire pneumatic pressure by a prescribed value or more is detected by the tire pneumatic pressure sensor 11, the inclination sensor 13 is disabled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle theft prevention device that prevents theft of a vehicle, and more particularly, to a vehicle theft prevention device that detects an abnormality of a vehicle by a tilt sensor that detects the tilt of the vehicle.

  An anti-theft device for a vehicle that ensures the security by monitoring the state of the vehicle with various sensors and listening to an alarm when an abnormality is recognized or transmitting an abnormality detection to a pre-registered service center Are known.

There are various methods for detecting theft of vehicles. For example, when a vehicle is attempted to be stolen using a tow truck, the vehicle tilts unnaturally, and this is used to detect theft. It has been proposed to do. Such an anti-theft device has a tilt sensor, for example, memorizes the tilt of the vehicle when the door is locked, and then detects the theft by detecting the change in tilt when the vehicle tilts unnaturally. (For example, refer to Patent Document 1).
JP 2003-34233 A

  However, in addition to being pulled by a tow truck during theft, the vehicle may tilt during parking, so if an abnormality of the vehicle is detected based only on the output value of the tilt sensor, the antitheft device malfunctions. There was a problem that it might end.

  In view of the above problems, an object of the present invention is to provide a vehicle antitheft device that can prevent malfunction caused by an inclination sensor.

  In order to solve the above-described problems, the present invention provides a vehicle antitheft device that detects an alarm when a tilt sensor that detects a change in vehicle tilt detects a change in tilt greater than or equal to a predetermined value relative to an initial value. It has a tire pressure sensor to detect, and when it is detected by the tire pressure sensor that the tire pressure has dropped below a predetermined value, the tilt sensor is disabled.

  According to the present invention, it is possible to prevent the tilt sensor from malfunctioning when the tire air pressure drops below a predetermined value.

  Further, in one aspect of the present invention, there is a warning state in which an alarm is heard when the inclination sensor detects a change in inclination greater than or equal to a predetermined level, and an unwarranted state in which even if there is a change in inclination greater than or equal to a predetermined level When the tire air pressure sensor detects that the tire air pressure has dropped below a predetermined level in the no-warning state, the tilt sensor is disabled in the warning state.

  According to the present invention, it is possible to prevent the tilt sensor from malfunctioning even when the tire air pressure drops below a predetermined value when the vehicle antitheft device is in an unguarded state. In this case, the tilt sensor does not enter an effective state. Dark current can be reduced.

  The present invention also relates to a tire pressure sensor for detecting tire pressure in a vehicle anti-theft device that sounds an alarm when a tilt sensor that detects a change in vehicle tilt detects a change in tilt greater than or equal to a predetermined value relative to an initial value. When the change rate of the tire air pressure detected by the tire air pressure sensor is smaller than a predetermined value, the tilt sensor is disabled.

  According to the present invention, it is possible to distinguish between omission due to omission and puncture caused by the action of a third party, so that malfunction of air omission due to omission can be prevented, and puncture caused by the action of a third party can be heard.

  The present invention also relates to a tire pressure sensor for detecting tire pressure in a vehicle anti-theft device that sounds an alarm when a tilt sensor that detects a change in vehicle tilt detects a change in tilt greater than or equal to a predetermined value relative to an initial value. And when the change of the tire pressure detected by the tire pressure sensor starts before a predetermined time or more has passed since the vehicle anti-theft device started warning, the tilt sensor is disabled. To do.

  According to the present invention, based on the time from the door lock to the start of the change in tire air pressure, it is possible to distinguish between omission due to omission and puncture due to third party action, and to prevent malfunction due to omission. Punk caused by a person's actions can be heard.

  In one embodiment of the present invention, when the change of the tire pressure detected by the tire pressure sensor is completed when the tilt sensor is disabled, the initial value of the tilt sensor is updated and returned to the enabled state. It is characterized by that.

  According to the present invention, after the change of the tire air pressure is finished, the effective state is restored, and thereafter the theft can be prevented by the inclination sensor.

  It is possible to provide a vehicle antitheft device that can prevent malfunction caused by the tilt sensor.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. The vehicle antitheft device according to the present embodiment prevents a malfunction of an alarm by disabling the tilt sensor when an abnormality is detected in the tire air pressure even if the tilt of the vehicle is detected by the tilt sensor. .

  FIG. 1 shows an example of an overall configuration diagram of a vehicle antitheft system. When the antitheft device of the vehicle 2 detects an abnormality, the antitheft device transmits an abnormality detection signal to the security center 3 via the base station 4. The vehicle 2 and the base station 4 communicate using, for example, a mobile phone network or a wireless LAN, and the base station 4 and the security center 3 are connected by a network such as the Internet. The security center 3 that has received the abnormality detection signal dispatches a guard to the vehicle 2 or informs the driver that an abnormality has been detected. Moreover, the vehicle antitheft device 5 of the vehicle 4 sounds an alarm from the alarm device and checks the person who is performing the theft. The position of the vehicle 2 is known by a GPS (Global Positioning System) device.

  FIG. 2 shows an example of a functional configuration diagram of the vehicle antitheft device 5. The vehicle antitheft device 5 is controlled by a security control ECU (Electronic Control Unit) 10. When the vehicle door is locked, the security control ECU 10 initializes the sensor and then enters a warning state for detecting a vehicle abnormality, and when the door is unlocked, the sensor has a value equal to or greater than a predetermined threshold value. Even if it is detected, it becomes an unguarded state that is ignored (hereinafter, the alert state or unguarded state is referred to as a vehicle security state). When security control ECU10 will be in a warning state, each sensor will be in an effective state.

  The security control ECU 10 is a microcomputer in which a CPU, a ROM, a RAM, an NV-RAM (Non-Volatile RAM), a communication unit, and the like are connected by a bus, and the control described later is executed by the CPU executing a program stored in the ROM. Execute.

  A tire pressure sensor 11, a GPS device 12, an inclination sensor 13, a door opening / closing detection device 14 and an alarm device 15 are connected to the security control ECU 5.

  The tire air pressure sensor 11 detects the pressure and temperature of each tire and transmits them to the security control ECU 10 wirelessly. The tire pressure sensor 11 includes a pressure signal transmission circuit embedded in the tire wheel and a receiver that receives a pressure signal provided on the vehicle side.

  The GPS device 12 receives navigation messages from a plurality of GPS satellites, calculates the arrival time of radio waves, and detects the current position of the vehicle.

  The inclination sensor 13 is a sensor that detects a change in the inclination of the vehicle. The inclination sensor 13 stores the inclination of the vehicle when the door is locked as an initial value, and outputs an alarm request to the security control ECU 10 when the inclination of the vehicle changes with respect to the initial value. Therefore, the inclination sensor 13 can detect the inclination of the vehicle when the vehicle is towed. As the tilt sensor 13, a sensor using a gyro mechanism or a sensor that electrically detects a change in the level of the filled liquid is used.

  The inclination sensor 13 is in an effective state for detecting a change in inclination when the security control ECU 10 is in a warning state, and is in an invalid state in which the change in inclination is not detected by the control of the security control ECU 10 even when the security control ECU 10 is in a warning state. Transition to. Note that the tilt sensor 13 can also transition from the invalid state to the valid state.

  The door opening / closing detection device 14 is configured by a courtesy switch, a limit switch, or the like provided at the door portion, detects opening or closing of the door, and outputs an opening signal or a closing signal to the security control ECU 10. Although only the inclination sensor 13 and the door opening / closing detection device 14 are shown in FIG. 2, a vehicle abnormality is also detected when an engine start, a human intrusion, vibration, or the like is detected.

  The alarm device 15 is an output device for sounding an alarm. When the change of the inclination or the door closing signal is detected when the security control ECU 10 is in the alert state, the alarm device 15 sounds the alarm. In addition to the alarm, a hazard lamp, tail lamp or head lamp may be turned on.

  The communication device 16 uses a communication system such as GSM (Global System for Mobile Communications), TDMA (Time Division Multiple Access), CDMA (Code Division Multiple Access), PDC (Personal Digital Cellular), wireless LAN, etc. Communicate with 3.

  The service center 3 provides the driver with various services for the vehicle 2. The service center 3 is a computer including a CPU, a ROM, a RAM, a storage device, a communication device, and the like, and communicates with the vehicle 2 via the network 1. The ROM and the storage device store an OS and a program, and the CPU executes the program to notify the driver's portable terminal of an abnormality detection or request the vehicle 2 to dispatch a guard. .

  FIG. 3 is a flowchart showing a processing procedure for the security control ECU 10 to prevent an alarm malfunction in this embodiment. The flowchart of FIG. 3 starts when the door of the vehicle 2 is locked, for example.

  The security control ECU 10 repeatedly determines whether or not the vehicle is on alert (S11). If the vehicle is on alert (Yes in S11), the security control ECU 10 determines whether or not the tilt sensor 13 is in an effective state (S12). If the tilt sensor 13 is not in the valid state, the process returns to step S11.

  When the inclination sensor 13 is in the valid state (Yes in S12), the security control ECU 10 determines whether or not the tire air pressure is smaller than a predetermined abnormality determination threshold value (S13). The case where the tire pressure is smaller than the abnormality determination threshold refers to a case where it can be determined that the tire pressure is abnormally decreased due to puncture or the like.

  If the tire air pressure is not smaller than the abnormality determination threshold value (No in S13), since the inclination sensor 13 is in an effective state, it is determined whether or not the vehicle inclination has changed with respect to the initial inclination value of the inclination sensor 13 (S14). .

  If the vehicle inclination has changed (Yes in S14), the security control ECU 10 detects an abnormality and sounds an alarm (S15). If the vehicle inclination has not changed (No in S14), the process goes to step S11. Repeat the return error detection.

  When the tire air pressure is smaller than the abnormality determination threshold value (Yes in S13), the security control ECU 10 disables the tilt sensor 13 until the warning state is reached (S16). That is, when the tire air pressure is smaller than the abnormality determination threshold value, it can be determined that the tire air pressure is lower than an appropriate pressure, so the inclination sensor 13 is disabled. Thus, it is determined that the vehicle is tilted by towing even though the vehicle is tilted due to a decrease in tire pressure, and the alarm is prevented from malfunctioning. Note that if the vehicle is in an unwarranted state such as when the door is unlocked, the tilt sensor 13 does not need to be disabled, so the security control ECU 10 shifts the tilt sensor 13 to the enabled state.

  FIG. 4 is a diagram showing the tire pressure, the vehicle security state, and the state of the tilt sensor 13. 4A shows the relationship between time and tire pressure, for example, when the vehicle is parked, FIG. 4B shows the security state of the vehicle by the security control ECU 10, and FIG. 4C shows the state of the tilt sensor. Each is shown.

  In the security state of the vehicle, the alert state is a state in which an alarm is heard if there is an abnormality in the vehicle, the alert preparation state is a state in which the output value of the sensor is ignored, and the alert preparation state is performed by initializing each sensor. It is in a state.

  In the state of the tilt sensor, the valid standby state is a state in which the initial tilt of the tilt sensor is calculated, the valid state is a state in which an alarm sound is requested if there is a change in the tilt, and the invalid state is a tilt state. Even if there is a change in the state, it is not detected. These states of the inclination sensor 13 are changed by the security control ECU 10.

  In FIG. 4A, time t0 is the time when the door is locked. When the door is locked, the security control ECU 10 is in a warning preparation state until the connected sensors are initialized and the initialization is completed. Moreover, the inclination sensor 13 initialized by the security control ECU 10 holds the inclination of the vehicle when the door is locked as an initial value.

  When the initialization of the security control ECU 10 is completed, the security control ECU 10 automatically enters a warning state (t1). The inclination sensor 13 transitions to an effective state when the security control ECU 10 enters a warning state. When the inclination of the vehicle changes in the effective state, the inclination sensor 13 requests the security control ECU 10 to sound an alarm.

  As shown in FIG. 4A, the tire air pressure gradually decreases and becomes smaller than the abnormality determination threshold at time t2. When the tire air pressure becomes smaller than the abnormality determination threshold, the inclination sensor 13 may detect an abnormal inclination change in the vehicle. For this reason, the security control ECU 10 shifts the tilt sensor 13 to the invalid state. Therefore, after time t2, the tilt sensor 13 can be prevented from malfunctioning, and the tilt sensor 13 is in an invalid state, but the security control ECU 10 detects that an abnormality is detected by another sensor (for example, the door opening / closing detection device 14). An alarm can be heard.

  When the door is unlocked (t3), the security control ECU 10 enters an unwarranted state and shifts the tilt sensor 13 to an effective standby state.

  According to the vehicle antitheft device 5 of the present embodiment, malfunction due to a decrease in tire air pressure can be prevented.

  In the present embodiment, a case where the tire air pressure decreases during an unwarranted state or during alert preparation will be described. FIG. 5 is a flowchart showing a processing procedure for the security control ECU 10 to prevent an alarm malfunction in this embodiment. The flowchart of FIG. 5 starts from a state before the door is locked.

  The security control ECU 10 repeatedly determines whether or not the vehicle is on alert (S21). If the vehicle is on alert (Yes in S21), the security control ECU 10 determines whether or not the tilt sensor 13 is in an effective standby state (S22). If the tilt sensor 13 is not in the effective preparation state (No in S22), the process returns to step S21.

  When the inclination sensor 13 is in the valid standby state (Yes in S22), the security control ECU 10 determines whether or not the tire air pressure is already smaller than a predetermined abnormality determination threshold value in the case of no warning (S23).

  If the tire pressure is already smaller than the predetermined abnormality determination threshold (Yes in S23), the tilt sensor 13 is disabled (S24).

  Similarly, when the tire air pressure becomes smaller than a predetermined abnormality determination threshold value (Yes in S25), the inclination sensor 13 is disabled (S24).

  When the tire air pressure does not become smaller than the predetermined abnormality determination threshold value (No in S25), the process returns to step S21, and the inclination sensor 13 continues the effective standby state.

  FIG. 6 is a diagram showing the tire pressure, the security state of the vehicle, and the state of the tilt sensor 13. As shown in FIG. 6A, in this embodiment, when the security control ECU 10 is in an unguarded state, the tire air pressure becomes smaller than the abnormality determination threshold value (t1). That is, the door is not locked at time t1. If the door is not locked, the tilt sensor 13 is in a valid standby state (or invalid state) for transitioning to a valid state.

  When the door is locked at time t2, the security control ECU 10 enters a warning preparation state, and when initialization or the like ends, the security control ECU 10 enters a warning state (t3). Further, when the door is locked, the security control ECU 10 puts the tilt sensor 13 into an invalid standby state (t2). The invalid standby state is a state in which the security control ECU 10 transitions to an invalid state when the security control ECU 10 transitions to a warning state even if the calculation of the initial value of the slope is finished and the valid state can be entered. In addition, after a door lock, it is good also as an invalid state immediately instead of an invalid standby state.

  When the door is unlocked (t4), the security control ECU 10 enters an unwarranted state, and the tilt sensor 13 transitions to an effective standby state.

  When the antitheft device of the present embodiment detects an abnormality in the tire air pressure before entering the alert state, the inclination sensor 13 remains in the invalid standby state or the invalid state until the door is unlocked and enters the no alert state. Therefore, malfunction due to the tilt sensor 13 can be prevented. Such a situation may occur when the tire air pressure decreases during running or when the vehicle is stopped and before the door is locked. Therefore, in the alert state, the tilt sensor 13 is in an invalid state (it is not necessary to detect the tire air pressure), so that dark current (current at ignition off) can be reduced.

  In this embodiment, based on how the tire pressure changes, alarms are prevented from malfunctioning due to omissions (spontaneous pressure reduction such as looseness of tire valves and caps), and third party actions (for example, An anti-theft device that sounds an alarm for puncture caused by mischief is explained. The change in the tire pressure is calculated by the security control ECU 10 based on the change in the tire pressure over the past several times.

  FIG. 7 is a flowchart showing a processing procedure for the security control ECU 10 to prevent an alarm malfunction in this embodiment.

  The security control ECU 10 repeatedly determines whether or not the vehicle is on alert (S31). If the vehicle is on alert (Yes in S31), the security control ECU 10 determines whether or not the tilt sensor 13 is in an effective state (S32). If the tilt sensor 13 is not in the valid state, the process returns to step S11.

  When the inclination sensor 13 is in the valid state (Yes in S32), the security control ECU 10 determines whether or not the tire air pressure change rate is smaller than a predetermined threshold (S33). Usually, when the puncture is performed by a third party, the rate of change of the tire pressure is large, and when the puncture is caused by omission, the rate of change of the tire pressure is often small. Therefore, if the rate of change in tire pressure is monitored, it can be determined whether or not it is due to the action of a third party.

  If the change rate of the tire air pressure is smaller than the predetermined threshold (Yes in S33), the security control ECU 10 disables the inclination sensor 13 until the warning state is reached (S36). That is, when the change rate of the tire air pressure is smaller than a predetermined threshold value, it is determined that the air has been lost due to omission and the inclination sensor 13 is disabled. As a result, it is determined that the vehicle is tilted by traction even though the vehicle is tilted due to the natural pressure drop of the tire, and the alarm is prevented from malfunctioning. Note that if the vehicle is in an unwarranted state such as when the door is unlocked, the tilt sensor 13 does not need to be disabled, so the security control ECU 10 shifts the tilt sensor 13 to the enabled state.

  In determining whether the change rate of the tire air pressure is smaller than a predetermined threshold value, a state where the slope is almost zero is excluded. Therefore, in this case, since the tilt sensor 13 continues to be in an effective state, traction by the tow truck can be detected.

  When the change rate of the tire pressure is not smaller than the abnormality determination threshold (No in S33), it is determined whether there is an alarm request from the inclination sensor 13 (S34). If there is an alarm request from the inclination sensor 13, the vehicle inclination has changed greatly with respect to the initial vehicle inclination, so the security control ECU 10 detects an abnormality and sounds an alarm (S35).

  FIG. 8 is a diagram illustrating changes in tire air pressure due to third party actions and changes in tire air pressure due to omissions. FIG. 8 shows changes over time in tire air pressure from the time t0 when the door is locked.

  When the change rate of the tire air pressure is small (line A), it is determined that the air is lost due to omission, and the tilt sensor 13 is disabled. Therefore, malfunction can be prevented even if the vehicle is tilted with respect to the initial value. If the change rate of the tire pressure is large (after time t2 on line B), it is determined that the puncture is caused by a third party action, and the tilt sensor 13 continues to be in an effective state. Can be heard. Further, as described above, when the vehicle is pulled by a tow truck or the like between times t1 and t2 on line B, an alarm can be heard by the alarm request from the inclination sensor 13.

  According to the present embodiment, it is possible to discriminate between air loss due to omission and puncture due to third party action, and prevent malfunction of air loss due to omission, and puncture due to third party action can be heard.

  In this example, based on the time from the door lock to the start of tire pressure change, it is distinguished from omission due to omission and puncture due to third party action, preventing malfunction of air omission due to omission. The anti-theft device that can be heard by puncturing the alarm is explained.

  FIG. 9 is a flowchart showing a processing procedure for the security control ECU 10 to prevent an alarm malfunction in this embodiment.

  The security control ECU 10 repeatedly determines whether or not the vehicle is on alert (S41). If the vehicle is on alert (Yes in S41), the security control ECU 10 determines whether or not the tilt sensor 13 is in an active state (S42). If the tilt sensor 13 is not valid, the process returns to step S41.

  When the inclination sensor 13 is in the valid state (Yes in S42), the security control ECU 10 determines whether the change in tire air pressure has started after the predetermined time T has elapsed after the door lock (S43).

  In the case of puncture due to omission, it is considered that the change in tire pressure starts after the door is locked. Therefore, based on the time when the change of the tire air pressure starts, it can be determined whether or not there is air loss due to omission.

  If the tire air pressure has not started after the elapse of T time (No in S43), the security control ECU 10 disables the tilt sensor 13 until the warning state is reached (S46). That is, since the change in the tire air pressure is proceeding gradually, it is determined that the air is inadvertently removed and the inclination sensor 13 is disabled. As a result, it is determined that the vehicle is tilted by traction even though the vehicle is tilted due to the natural pressure drop of the tire, and the alarm is prevented from malfunctioning. Note that if the vehicle is in an unwarranted state such as when the door is unlocked, the tilt sensor 13 does not need to be disabled, so the security control ECU 10 shifts the tilt sensor 13 to the enabled state.

  If the change in tire pressure has started after the elapse of time T (Yes in S43), it is determined whether there is an alarm request from the tilt sensor 13 (S44). When there is an alarm request from the inclination sensor 13, the change in tire air pressure is started by the action of a third party and the inclination changes greatly with respect to the initial inclination of the vehicle, so the security control ECU 10 detects an abnormality. The alarm is heard (S45).

  FIG. 10 is a diagram illustrating changes in tire air pressure due to third party actions and changes in tire air pressure due to omissions. FIG. 10 shows the change over time in tire air pressure with the door lock time t0 as the origin. Further, a predetermined time after the door is locked is indicated by T.

  If the change in tire air pressure has started before the predetermined time T (line A), it is determined that the air has been lost due to omission, and the tilt sensor 13 is disabled. Operation can be prevented.

  If the change in tire pressure starts after a predetermined time T (after time t1 on line B), it is determined that the puncture is caused by a third party action, and the tilt sensor 13 continues to be in an effective state. An alarm can be heard when tilted. Further, when the vehicle is pulled by a tow truck or the like between times t0 and t1 on line B, an alarm can be heard when the tilt sensor 13 detects a change in tilt.

  According to the present embodiment, based on the time from the door lock to the start of the change in tire air pressure, it is possible to distinguish between omission due to omission and puncture due to third party action, and prevent malfunction due to omission. Punk by tripartite action can be heard.

  In this embodiment, when the rate of change of the tire air pressure becomes smaller than a predetermined threshold, it is determined that the vehicle has finished tilting, and the anti-theft performance is ensured by returning the tilt sensor that has been disabled to the enabled state. The anti-theft device will be described.

  FIG. 11 is a flowchart showing a processing procedure in which the security control ECU 10 prevents an alarm malfunction due to a change in tire air and ensures the antitheft performance.

  The security control ECU 10 repeatedly determines whether or not the vehicle is on alert (S51). If the vehicle is on alert (Yes in S51), whether or not the inclination sensor 13 has automatically transitioned to an invalid state due to an abnormality in tire air pressure. Is determined (S52). Since the transition to the invalid state is controlled by the security control ECU 10, it is already known whether or not the transition to the invalid state has been made automatically. If it is not automatically changed to the invalid state (No in S52), the process returns to Step S51.

  When the state is automatically changed to the invalid state (Yes in S52), the security control ECU 10 determines whether the change rate of the tire air pressure is smaller than a predetermined threshold value (S53). The predetermined threshold value is a threshold value for determining whether or not the change in tire air pressure has ended.

  If the change rate of the tire pressure is not smaller than the predetermined threshold (No in S53), the vehicle is still tilted.

  When the change rate of the tire air pressure is smaller than the predetermined threshold (Yes in S53), the security control ECU 10 updates the reference value of the tilt sensor and returns the tilt sensor to the valid state (S54). By updating the reference value of the tilt sensor 13, the initial value of the tilt sensor 13 becomes the tilt value after the change in air pressure is completed. Further, since the tilt sensor 13 is in an effective state, an alarm can be heard when pulled by a tow truck or the like.

  FIG. 12 is a view showing the tire pressure, the vehicle security state, and the state of the tilt sensor 13. 12A shows the relationship between time and tire pressure when the vehicle is parked, for example, FIG. 12B shows the security state of the vehicle by the security control ECU 10, and FIG. 12C shows the state of the tilt sensor. Each is shown.

  As shown in FIG. 12A, the change in tire air pressure starts from time t1 and ends at time t3. Further, it is assumed that the tire air pressure becomes smaller than the abnormality determination threshold at time t2. Moreover, as shown in FIG.12 (b), the security state of a vehicle is a warning state consistently after time t0.

  The tilt sensor 13 is in a valid state until time t2, but since the tire air pressure becomes smaller than the abnormality determination threshold at time t2, the security control ECU 10 shifts the tilt sensor 13 to an invalid state. When the change in tire air pressure ends at time t3 and the rate of change becomes smaller than a predetermined threshold value at time t4, the security control ECU 10 returns the tilt sensor 13 to the valid state. The initial value of the tilt sensor 13 is also updated.

  According to the present embodiment, the tilt sensor 13 is disabled during the change of the tire pressure, so that malfunction can be prevented, and after the change of the tire pressure is completed, the tilt sensor 13 returns to the enabled state. Can be prevented. Since the present embodiment is a control example for returning the tilt sensor 13 in the invalid state to the valid state, it can be applied to any of the first to fourth embodiments.

  As described above, the vehicle antitheft device of the present embodiment can prevent malfunction caused by the tilt sensor by detecting the tire air pressure. That is, when the tire air pressure becomes below a predetermined value, when the rate of change of the tire air pressure is smaller than a predetermined value, and when the decrease of the tire air pressure starts in a short time after the door is locked, the inclination sensor 13 is invalidated. By setting the state, it is possible to prevent malfunction of the vehicle anti-theft device in which an alarm is accidentally heard. Moreover, since the inclination sensor 13 is returned to the effective state after the change of the tire air pressure is finished, an alarm can be heard when the tow truck is towed.

It is an example of the whole block diagram of a vehicle antitheft system. It is an example of the functional block diagram of a vehicle antitheft device. In Example 1, it is a flowchart figure which shows the process sequence which security control ECU prevents a malfunctioning of an alarm. It is a figure which shows a tire pressure, the security state of a vehicle, and the state of an inclination sensor. In Example 2, security control ECU is a flowchart figure which shows the process sequence which prevents the malfunctioning of an alarm. It is a figure which shows a tire pressure, the security state of a vehicle, and the state of an inclination sensor. In Example 3, it is a flowchart figure which shows the process sequence which security control ECU prevents a malfunctioning of an alarm. It is a figure which shows the change of the tire pressure by the action of the third party, and the change of the tire pressure by omission. In Example 4, it is a flowchart figure which shows the process sequence which security control ECU prevents a malfunctioning of an alarm. It is a figure which shows the change of the tire pressure by the action of the third party, and the change of the tire pressure by omission. It is a flowchart figure which shows the process sequence which security control ECU secures anti-theft performance while preventing the malfunction of the alarm by the air change of a tire. It is a figure which shows a tire pressure, the security state of a vehicle, and the state of an inclination sensor.

Explanation of symbols

5 Vehicle anti-theft device 10 Security control ECU
DESCRIPTION OF SYMBOLS 11 Tire pressure sensor 12 GPS apparatus 13 Inclination sensor 14 Door opening / closing detection apparatus
15 Alarm 16 Communication device

Claims (5)

In the vehicle anti-theft device for sounding an alarm when a tilt sensor that detects a change in vehicle tilt detects a change in tilt greater than or equal to a predetermined value relative to an initial value,
A tire pressure sensor for detecting tire pressure;
When the tire pressure sensor detects that the tire pressure has dropped below a predetermined value, the tilt sensor is disabled.
The vehicle antitheft device characterized by the above. When the inclination sensor detects a change in inclination greater than or equal to a predetermined level, there is a warning state to hear a warning, and an unwarranted state to ignore even if there is a change in inclination greater than or equal to a predetermined level,
When the tire air pressure sensor detects that the tire air pressure has dropped below a predetermined level in the no-warning state, the tilt sensor is disabled in the warning state.
The vehicle antitheft device according to claim 1. In the vehicle anti-theft device for sounding an alarm when a tilt sensor that detects a change in vehicle tilt detects a change in tilt greater than or equal to a predetermined value relative to an initial value,
A tire pressure sensor for detecting tire pressure;
When the change rate of the tire pressure detected by the tire pressure sensor is smaller than a predetermined value, the tilt sensor is disabled.
The vehicle antitheft device characterized by the above. In the vehicle anti-theft device for sounding an alarm when a tilt sensor that detects a change in vehicle tilt detects a change in tilt greater than or equal to a predetermined value relative to an initial value,
A tire pressure sensor for detecting tire pressure;
When the change of the tire pressure detected by the tire pressure sensor starts before a predetermined time or more has passed since the vehicle antitheft device started warning, the tilt sensor is disabled.
The vehicle antitheft device characterized by the above. When the tilt sensor is disabled,
When the change in the tire pressure detected by the tire pressure sensor is completed, the initial value of the tilt sensor is updated and returned to the valid state.
The vehicle antitheft device according to any one of claims 1 to 4.

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