Vehicle security apparatus and system which prevents unauthorized use of a vehicle by immobilization

A vehicle security apparatus includes an immobilizer ECU, a remote security ECU, a display, an operation unit, and a power supply control unit. The immobilizer ECU controls a drive prohibition and drive permission for an engine based on an identification signal transmitted from a key and/or a remote setting signal and a remote unsetting signal output from the remote security ECU. When a remote setting signal has been transmitted to set an immobilizer, the power supply control unit causes a power supply transition to an accessory-on state or an ignition-on state when an authorized identification signal from the key is transmitted. Thus, the remote immobilizer is enabled to be unset by the display and the operation unit.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on and incorporates herein by reference Japanese Patent Application No. 2006-104614 filed on Apr. 5, 2006.

FIELD OF THE INVENTION

The present invention relates to a vehicle security apparatus and a vehicle security system.

BACKGROUND OF THE INVENTION

Vehicle security systems are proposed to prevent unauthorized use of a stolen vehicle by immobilizing the stolen vehicle when the vehicle is stolen with its authorized (normal) key.

In the case of robbery of a vehicle having such a vehicle security system along with its authorized key, when the owner of the vehicle reports the robbery to a base station, the base station transmits a signal representing a drive prohibition request for the engine of the vehicle to the vehicle using wireless communication. Upon receipt of the signal representing a drive prohibition request, the engine is prohibited from being started (for example, JP-A-2003-146185).

In this vehicle security system, for releasing prohibition control based on a signal representing a drive prohibition request transmitted from a base station, a releasing unit may be provided in the vehicle to release the prohibition when the releasing unit is operated. In this case, power must be supplied to the releasing unit to enable the same when a user wishes to release the prohibition. However, when power is normally supplied to the releasing unit, power consumption increases.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a vehicle security apparatus and a vehicle security system, which operates with low power consumption.

According to one aspect, a vehicle security system has a vehicle security apparatus that is capable of communicating with an electronic key transmitting a unique identification signal and with a communication apparatus in a remote location transmitting drive request signals representing a drive prohibition request and a drive permission request for a vehicle driving device of a vehicle. The vehicle security apparatus comprises a key communication unit, a remote communication unit, a control unit and a releasing unit.

The key communication unit communicates with the electronic key. The remote communication unit communicates with the communication apparatus in the remote location. The control unit controls the vehicle driving device based on at least one of the identification signal transmitted to the key communication unit and the drive request signals transmitted to the remote communication unit. The releasing unit releases control over the vehicle driving device based on the drive request signal representing the drive prohibition request according to an instruction from a user. The control unit prohibits driving of the vehicle driving device upon receipt of the drive request signal representing the drive prohibition request at the remote communication unit and allows a transition of power from a power supply mounted on the vehicle such that the releasing unit can accept an instruction from the user only when the identification signal transmitted to the key communication unit is an authorized identification signal.

Alternatively, according to another aspect, the vehicle security apparatus further comprises a door lock switch detection unit, which is normally supplied with power from a power supply mounted on the vehicle and which detects an operation on a door lock switch of the vehicle. The control unit prohibits driving of the vehicle driving device upon receipt of the drive request signal representing the drive prohibition request by the remote communication unit and allows a transition of power from the power supply such that the releasing unit can accept an instruction from the user only when the door lock switch detection units detects an operation on the door lock switch of the vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 1, a vehicle security system includes a vehicle security apparatus10, an engine electronic control unit (ECU)20for an engine30, a vehicle electronic key40, a base station50, a data center60and a cellular phone70.

The vehicle security apparatus10is mounted in a vehicle. It includes an immobilizer ECU11with an antenna11a, a remote security ECU12, a communication ECU13with an antenna13a, a display14, an operation unit15, and a power supply control unit16.

The immobilizer ECU11is a part of a control unit and a releasing unit, and it is primarily comprised of a microcomputer. The ECU11includes a memory such as a ROM, RAM or EEPROM, an interface circuit or a bus line for data transfer, and the antenna11a, which allows communication with the key40. The immobilizer ECU11detects a power supply state (ignition-on state, accessory-on state, or an OFF state of a vehicle ignition switch) in the power supply control unit16.

The immobilizer ECU11outputs drive signals representing drive prohibition and drive permission for the engine30to the engine ECU20based on a remote set signal and a remote unset signal output from the remote security ECU12. The operation of outputting the drive prohibition and drive permission to the engine ECU20are referred to as setting and unsetting of an immobilizer function or setting and unsetting of an immobilizer. The operations of outputting the drive signals representing a drive prohibition and drive permission to the engine ECU20based on a remote set signal and a remote unset signal output from the remote security ECU12are hereinafter referred to as setting and unsetting of a remote immobilizer function or setting and unsetting of a remote immobilizer.

That is, the immobilizer ECU11sets the immobilizer by outputting a drive signal representing a drive prohibition to the engine ECU20to prohibit the engine30from being started. The immobilizer ECU11unsets the immobilizer by outputting a drive signal representing drive permission to the engine ECU20to allow the engine30to be started.

When the remote immobilizer is set, the immobilizer ECU11outputs the drive signal representing a drive prohibition to the engine ECU20to keep the engine30prohibited from being started even if an identification signal is transmitted from the authorized key40. When the remote immobilizer is unset (when the setting of the remote immobilizer is released), the immobilizer ECU11outputs the drive signal representing drive permission to the engine ECU20to allow the engine30to be started if the identification signal is transmitted from the authorized key40.

Further, the immobilizer ECU11has a state of waiting for the remote immobilizer function to be set (standby state) that is a state, in which the ECU11has received only a remote set signal output from the remote security ECU12. The state of waiting for the remote immobilizer function is referred to as a remote immobilizer standby state.

The immobilizer ECU11controls the transition of power supply in the power supply control unit16based on the identification signal transmitted from the key40and the remote set signal and remote unset signal output from the remote security ECU12, i.e., based on the set and unset states of the immobilizer, the set and unset states of the remote immobilizer, and the identification signal transmitted from the key40.

The vehicle key40may be a portable card key. The key40includes a communication device unit (not shown) having a unique identification signal (ID code), and the communication device unit transmits a response signal including an identification signal in response to a call signal from the antenna11a. The antenna11ais provided in the vicinity of a vehicle key slot (not shown) for starting the engine30, and a switch (not shown) is provided in the key slot. The switch is turned on by inserting the key40in the key slot, and communication is established between the communication device unit of the key40and the antenna11a.

The call signal from the antenna11amay be transmitted at predetermined time intervals, or the call signal may alternatively be transmitted when a start/stop switch (not shown) is pressed.

The remote security ECU12is a part of the control unit, and it is primarily comprised of a microcomputer. The ECU12includes a memory such as a ROM, RAM or EEPROM and an interface circuit or bus line for data transfer. The remote security ECU12outputs the remote reset signal and remote unset signal output from the communication ECU13, which will be described later, to the immobilizer ECU11. The remote set signal is the drive request signal, which represents a drive prohibition request for a driving device of a vehicle. The remote unset signal is the drive request signal, which represents a drive permission request for a driving device of a vehicle.

The communication ECU13is a remote communication unit, and it is primarily comprised of a microcomputer. The ECU13includes a memory such as a ROM, RAM or EEPROM, an interface circuit or bus line for data transfer, and the antenna13awhich communicates with the base station50corresponding to the communication apparatus in a remote location, which is away from the security apparatus10. The communication ECU13outputs a remote set signal and a remote unset signal transmitted from the base station50to the remote security ECU12. It is sufficient that the communication ECU13has the capability of connection with a wireless telephone line or an internet line, and a mobile telephone may be used as the ECU13.

The display14and the operation unit15are parts of a releasing unit, which are enabled for display of images and input operations when power is supplied from the power supply control unit16. The display14includes a display screen like a liquid crystal display panel and a backlight. Based on an image signal output from the immobilizer ECU11, the display14displays information (images) associated with unsetting of the remote immobilizer i.e., information (images) for releasing control based on the remote set signal. A display used in a navigation device may be used as the display14.

The operation unit15is a part of a releasing unit. The operation unit15may be a transparent touch panel provided on the display surface of the display screen of the display14, and the unit allows operations to be performed according to images displayed on the display screen of the display14.

The information (images) associated with the unsetting of the remote immobilizer includes, for example, an input screen for a request for unsetting of the remote immobilizer and an input screen for an authentication number for unsetting of the remote immobilizer. The operations according to images displayed on the display screen of the display14include the operation of inputting the request for unsetting and the operation of inputting the authentication number.

In this embodiment, the releasing unit will be described using an example of the unit including the display14and the operation unit15(touch panel). For example, the releasing unit may have operation switches provided around the display14or provided on an overhead module, and the unit may alternatively be a joy stick provided on a center console. Further, the releasing unit may be a voice recognition device for determining whether the voice pronounced by a user satisfies a predetermined condition or not or a biological information determination device for determining whether biological information of a user (such as a fingerprint or voiceprint) satisfies a predetermined condition or not.

The power supply control unit16is a part of the control unit, and it is primarily comprised of a microcomputer. The control unit may include a memory such as a ROM, RAM or EEPROM or an interface circuit or bus line for data transfer. The power supply control unit16is connected to a battery (not shown), which is an on-vehicle power supply. The control unit switches power supply transitions based on instructions from the immobilizer ECU11to switch the state of power supply to each part of vehicle equipment (such as the display14, the control unit15, and the engine ECU20).

The engine ECU20is primarily comprised of a microcomputer. It includes a memory such as a ROM, RAM or EEPROM or an interface circuit or bus line for data transfer. The engine ECU20allows a starter motor, a fuel injection device, and an ignition device to start operating based on a start signal from an ignition switch (not shown) only when the immobilizer ECU11has unset the immobilizer, that is, only when the drive signal representing drive permission for the engine30has been output. As a result, fuel is injected into the engine30with the starter motor rotated and ignited by the ignition plug. The engine30is thus started (driving is enabled).

The engine ECU20disables the starter motor, the fuel injection device, and the ignition device to start operating, when the immobilizer ECU11has set the immobilizer, that is, when the drive signal representing the drive prohibition for the engine30has been output. Thus, the engine ECU20does not allow the engine30to be started (driving is prohibited).

The base station50is the communication apparatus in a remote location. The base station can communicate with the communication ECU13and the cellular phone70on a wireless basis. The base station50is connected to the data center60, which manages a multiplicity of pieces of vehicle information. In the vehicle security system, when a vehicle is stolen, the user (or owner) of the vehicle communicates with the base station50using the cellular phone70to report the robbery to the data center60. Upon receipt of the report of robbery, the data center60outputs a remote set signal to the base station50. Upon receipt of the remote set signal, the base station50transmits the remote set signal to the vehicle (communication ECU13).

When the stolen vehicle is found, the user of the vehicle communicates with the base station50using the cellular phone70to report to the data center60that the stolen vehicle has been found. When it is reported that the stolen vehicle has been found, the data center60outputs a remote unset signal to the base station50to unset the remote immobilizer. Upon receipt of the remote unset signal, the base station50transmits the remote unset signal to the vehicle (communication ECU13).

The vehicle security system can unset the remote immobilizer by transmitting a remote unset signal from the base station50or using the display14and the operation unit15. Thus, the remote immobilizer can be unset even when the stolen vehicle is in a place out of reach of a radio wave (remote unset signal).

Operations of the present embodiment will now be described with reference to a time chart shown inFIG. 2.

It is assumed here that the vehicle is stolen along with the key40by an unauthorized person, who is not authorized to use the vehicle, and the key40is inserted in the key slot to drive the engine30and the vehicle. Then, the immobilizer ECU11checks whether the key40is the authorized one or not based on the identification signal transmitted from the key40. When it is determined that the key40is the authorized one, the immobilizer is unset as shown in the period from a starting point (left end) up to a time point A in (c) ofFIG. 2. Therefore, the power supply of the vehicle enters an ignition state (represented by IG in the figure) to allow the vehicle to be driven as shown in the periods from the starting points up to the points (a) and (b) inFIG. 2, when the unauthorized person turns the ignition switch on using the key40, and the vehicle is freely used by the unauthorized person.

In order to avoid such a situation, when the vehicle is stolen, the authorized user of the vehicle communicates with the base station50using the cellular phone70to report the robbery to the data center60. Upon receipt of the robbery report, the data center60outputs a remote set signal to the base station50. Upon receipt of the remote set signal, the base station50transmits the remote set signal to the vehicle (communication ECU13) as shown at the point A in (d) ofFIG. 2to request setting of the remote immobilizer.

The communication ECU13receives the remote set signal through the antenna13a. The communication ECU13outputs the received remote set signal to the remote security ECU12. The remote security ECU12outputs the received remote set signal to the immobilizer ECU11.

When a remote set signal has been output by the remote security ECU12, the immobilizer ECU11keeps the immobilizer unset for a period, during which the immobilizer is unset based on the identification signal from the key40. Specifically, the immobilizer ECU11keeps the immobilizer unset as shown in the periods from the points A to the points B in (c) and (d) ofFIG. 2to put the remote immobilizer in the standby state, thereby prohibiting the engine ECU20from outputting a drive signal representing a drive prohibition for the engine30.

Therefore, even when the vehicle stops or the power supply enters the accessory-on state or off state as shown between the points A and B in (a) and (b) ofFIG. 2, the immobilizer ECU11keeps the immobilizer unset and outputs a drive signal representing drive permission to the engine ECU20. The vehicle is therefore in a drivable state.

The vehicle is traveling or on a traveling lane in most cases when a drive signal representing drive permission for the engine30is output to the engine ECU20based on the identification signal from the key40. Therefore, the immobilizer ECU11keeps the immobilizer unset and outputs a drive signal representing drive permission to the engine ECU20, when a remote set signal is output during the period in which the immobilizer is unset based on an identification signal from the key40. As a result, the engine30can be prevented from being prohibited from starting when the vehicle is on a traveling lane, thus preventing the vehicle from disturbing the flow of traffic. That is, the drive prohibition on the engine30can be prevented in case that the engine30of the stolen vehicle has stalled or has been stopped at a red traffic light, it is therefore possible to prevent the vehicle from disturbing the flow of traffic.

Since the immobilizer ECU11keeps the immobilizer unset and outputs a drive signal representing drive permission to the engine ECU20as thus described when the remote set signal is output during the period in which the immobilizer is unset based on the identification signal from the key40, the engine30can be prevented from being prohibited from starting even in the case of a malfunction of the remote immobilizer such as erroneous transmission of a remote unset signal.

Preferably, when the immobilizer is kept unset and the remote immobilizer is kept in the standby state as shown in the periods from the points A to the points B in (c) and (d) ofFIG. 2, the immobilizer ECU11cancels the standby state of the remote immobilizer when a remote unset signal is output from the remote security ECU12.

Described next are situations, in which a drive prohibition is placed on the engine30by the immobilizer ECU11, and in which the immobilizer function of the remote immobilizer function is set by the immobilizer ECU11.

After the immobilizer ECU11has put the remote immobilizer in the standby state according to the remote set signal received from the base station50through the remote security ECU12as shown in the period from the point A to the point B in (d) ofFIG. 2, the ECU11sets the immobilizer and the remote immobilizer when the vehicle enters a parking state in which the key40is removed from the key slot as shown between the points B and C in (e) ofFIG. 2and the power supply is in the off state as shown in (a) and (b) ofFIG. 2. That is, when the immobilizer ECU11determines that there is no identification signal from the key40, which occurs because the key40has been removed from the key slot, and determines that the authorized key40is not inserted in the key slot, the ECU11sets the immobilizer and the remote immobilizer. When the immobilizer is set, the immobilizer ECU11outputs a drive signal representing a drive prohibition to the engine ECU20to prohibit the engine30from being started.

During a period in which the immobilizer and the remote immobilizer are set (e.g., the periods starting at the points B in (c) and (d) ofFIG. 2), the immobilizer ECU11does not unset the immobilizer and keeps the immobilizer set even if the authorized key40is inserted in the key slot. The purpose is to prevent unauthorized use of the vehicle from being continued by an unauthorized person.

When a remote set signal has been transmitted to set the immobilizer as indicated by the points C and E in (e) ofFIG. 2, the immobilizer ECU11checks whether the key is the authorized key40or not from the identification signal transmitted by the key40. When it is determined that the key is the authorized key40(key state: YES in (e) ofFIG. 2), power supply control unit16causes a power supply transition to an accessory-on state or an ignition-on state with the immobilizer and the remote immobilizer kept set.

When such a power supply transition to the accessory-on state or the ignition-on state takes place as thus described, the display14and the operation unit15are enabled for display of images and for input operations. Specifically, when the power supply transition to the accessory-on state or the ignition-on state takes place, the remote immobilizer enters a state in which it can be unset by the display14and the control unit15. Even when such a power supply transition to the accessory-on state or the ignition-on state takes place as thus described or even when the key is determined to be the authorized key40, the immobilizer is kept set at least until the remote immobilizer is unset.

Further, the system may be arranged so that a power supply transition to the accessory-on state takes place if the key is determined to be the authorized key40and the start/stop switch (not shown) is pressed, or when a brake pedal (not shown) is stepped on and the key is determined to be the authorized key40, and the start/stop switch (not shown) is pressed, a power supply transition to the ignition-on state takes place. Alternatively, a power supply transition to the accessory-on state may take place when the start/stop switch (not shown) is pressed once when the key is determined to be the authorized key40, and a power supply transition to the ignition-on state may take place when the start/stop switch (not shown) is pressed again within a predetermined time after the first press.

Described further is a situation in which starting of the engine30is allowed by the immobilizer ECU11, that is, the immobilizer ECU11unsets the immobilizer function and the remote immobilizer function.

First, unsetting of the functions using the base station50will be described. For example, when a stolen vehicle has been found and the authorized user of the vehicle can get in the vehicle, the authorized user of the vehicle communicates with the base station50using the cellular phone70to report to the data center60that the vehicle has been found. Upon receipt of the report that the vehicle has been found, the data center60outputs a remote unset signal to the base station50. Upon receipt of the remote unset signal, the base station50transmits the remote unset signal to the vehicle (communication ECU13) to make a remote immobilizer unset request.

The communication ECU13receives the remote unset signal through the antenna13a. The communication ECU13outputs the received remote unset signal to the remote security ECU12. The remote security ECU12outputs the received remote unset signal to the immobilizer ECU11.

When the remote unset signal is output from the remote security ECU12, the immobilizer ECU11unsets the remote immobilizer. During a period in which the immobilizer is set based on the identification signal from the key40, the immobilizer ECU11preferably keeps the immobilizer set even when the remote unset signal is output from the remote security ECU12to unset the remote immobilizer. That is, the immobilizer ECU11keeps the immobilizer set even if the remote immobilizer is unset, and keeps outputting a drive signal representing a drive prohibition to the engine ECU20. The vehicle is therefore disabled from traveling without the authorized key40.

It is assumed that the immobilizer is unset concurrently with unsetting of the remote immobilizer. When the immobilizer is unset by the unsetting of the remote immobilizer, the immobilizer ECU11outputs a drive signal representing drive permission to the engine ECU20, which is not desired. Therefore, the vehicle becomes drivable without the authorized key40in the slot when the immobilizer is unset by the unsetting of the remote immobilizer. Therefore, as described in the present embodiment, the immobilizer ECU11keeps outputting a drive signal representing a drive prohibition to the engine ECU20even when a remote unset signal is output from the remote security ECU12to unset the remote immobilizer during the period in which the immobilizer is set based on the identification signal from the key40. Thus, unauthorized use of the vehicle can be prevented from being continued by an unauthorized person.

When the key40is inserted in the key slot with the remote immobilizer unset, the immobilizer ECU11checks whether the key is an authorized key40or not from the identification signal transmitted from the key40, and unsets the immobilizer when the key is determined to be an authorized one.

Immobilizers may be unset by way of the display14and the control unit15in the following manner. When a remote set signal has been transmitted to the immobilizer ECU11to set the immobilizers (the immobilizer and the remote immobilizer have been set) as indicated by the points C and E in (e) ofFIG. 2, a power supply transition to the accessory-on state or ignition-on state at the power supply control unit16enables operations of the display14and the operation unit15such as display of images and input operations.

The immobilizer ECU11displays images relating to unsetting of the remote immobilizer (e.g., a screen for inputting a request for unsetting of the remote immobilizer or a screen for inputting an authentication number for unsetting of the immobilizer) on the display screen of the display14. When an operation associated with the images relating to unsetting of the remote immobilizer (e.g., an operation of inputting a request for unsetting or an operation of inputting an authentication number) is performed in this state, the immobilizer ECU11unsets the remote immobilizer.

During a period in which the immobilizer is set based on the identification signal from the key40, the immobilizer ECU11keeps the immobilizer set even when the operation associated with images relating to unsetting of the remote immobilizer displayed on the display screen of the display14is performed at the operation unit15. Even if the remote immobilizer is unset, the immobilizer ECU11keeps the immobilizer set to keep outputting a drive signal representing a drive prohibition to the engine ECU20. The vehicle is therefore disabled from traveling without the authorized key40.

As thus described, when a remote set signal has been transmitted to set the immobilizers (the immobilizer and the remote immobilizer have been set), the power supply control unit16causes a power supply transition to the accessory-on state or the ignition-on state, which allows a reduction in power consumption.

Although the embodiment has been described with reference to an example in which a remote set signal and a remote unset signal are transmitted from the base station50, it is possible to transmit a remote set signal and a remote unset signal from any communication apparatuses in a remote location, which transmits drive request signals representing a drive prohibition request and a drive permission request for the vehicle engine30.

The immobilizer ECU11may control the locking and unlocking of a steering wheel80based on the identification signal transmitted from the key40. Specifically, the immobilizer ECU11locks the steering wheel80when the authorized identification signal is not transmitted from the key40and unlocks the steering wheel80when the authorized identification signal is transmitted from the key40. When a remote set signal has been transmitted to set the immobilizers (the immobilizer and the remote immobilizers have been set), the unlocking of the steering wheel80maybe prohibited, although the power supply control unit16causes a power supply transition to the accessory-on state or the ignition-on state.

The present embodiment has been described with reference to an example in which the power supply control unit16causes a power supply transition to the accessory-on state or the ignition-on state in response to transmission of the authorized identification signal from the key40when a remote set signal has been transmitted to set the immobilizers (the immobilizer and the remote immobilizers have been set). Alternatively, the power supply transition may be caused based on an operation on a door lock switch. In general, power is normally supplied to a door lock switch detection unit90for detecting an operation on the door lock switch. Therefore, a reduction in power consumption can be also achieved by allowing the power supply transition to the accessory-on state or the ignition-on state at the power supply control unit16only when the door lock switch detection unit90detects an operation on the door lock switch of the vehicle after a remote set signal has been transmitted to set the immobilizers (the immobilizer and the remote immobilizer have been set).

The present embodiment has been described with reference to an example, in which the power supply control unit16causes a power supply transition to the accessory-on state or the ignition-on state in response to transmission of the correct identification signal from the key40when a remote set signal has been transmitted to set the immobilizers (the immobilizer and the remote immobilizers have been set). Alternatively, the power supply transition may be such that power is supplied only to the display14and the operation unit15without turning the accessory and ignition on. A further reduction in power consumption can thus be achieved by this power supply transition such that power is supplied only to the display14and the operation unit15without turning the accessory and ignition on.

Although the present embodiment has been described with reference to an example, in which the cellular phone70is used for communication with the base station50, a stationary telephone set at home may alternatively be used.

In the resent embodiment, the vehicle security apparatus10includes the immobilizer ECU11, the antenna11a, the remote security ECU12, the communication ECU13, and the antenna13a. It is however possible that the apparatus10may be a controller that includes a key communication unit for communication regarding the key40, a remote communication unit for communication with the base station50, and a control unit for controlling the engine30by prohibiting or permitting the starting of the same based on an identification signal transmitted to the key communication unit and a remote set signal and a remote unset signal transmitted to the remote communication unit.