JP2005067353A - Anti-theft device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce failures of refusing a person registered in the image in an anti-theft device using a face authentication technique. <P>SOLUTION: A smart key system is used as a primary authentication, and a face authentication system is used as a secondary authentication. At a point of time when an occupant approaches to an automobile, the primary authentication by a smart key is performed. A signal for setting a face authentication threshold value of the face authentication system to be a low value if the result of the primary authentication is satisfactory or a signal for setting the face authentication threshold value to be high value if the result is unsatisfactory is transmitted from a smart key control circuit 1 to a face authentication circuit 3. The face authentication circuit 3 sets a decision threshold value of the face authentication by the signal from the smart key control circuit 1. After the occupant gets on the automobile, a face image of the occupant is acquired by a camera 2. In the face authentication circuit 3, the secondary authentication is performed by a comparison of the acquired face image and a face image stored in advance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle antitheft device that performs user verification using a face authentication system.

  2. Description of the Related Art Conventionally, as a vehicle antitheft device, there is a device that performs user verification using a biological feature or characteristic of a user (person) such as an iris pattern of a pupil (for example, see Patent Document 1).

On the other hand, there is a face authentication system as an entrance / exit management system for an office or the like. (For example, refer nonpatent literature 1).
JP 2000-168502 A OMRON, “Face Authentication System”, [online], [Search July 30, 2003], Internet, <URL: http://www.society.omron.co.jp/faceid/>

  As a vehicle antitheft device, a device that performs user verification using a face authentication system is conceivable. That is, if the face authentication technology is applied to a vehicle and the engine start is permitted / not permitted based on the face authentication result, an effect such as prevention of theft of the vehicle can be expected.

  However, if the face authentication technology is applied to a vehicle, there is a possibility that even a person who is registered as an image may be rejected for the following reasons.

  The face authentication technology, for example, compares a registered image with an acquired image using a shading pattern around a face part such as an eye, mouth, or nose as a determination element, and the degree of coincidence between both images is a predetermined determination threshold value. The user verification is performed by determining whether or not it exceeds. For this reason, when the registered image and the acquired image have different face orientations, there are many different portions between the registered image and the acquired image.

  The face authentication technology is premised on image acquisition under an ideal illumination environment. For this reason, for example, when the image cannot be acquired under the same lighting environment as the registered image, such as when the entire face is too bright due to illumination or only half of the face is exposed to light due to the evening sun in the evening, the registered image This is because there are many different parts between the acquired image and the acquired image.

  In addition, when face authentication technology is applied to a vehicle, it is conceivable to use an infrared camera as the image acquisition means. However, since sunlight also includes infrared rays, the above-mentioned is also true when infrared cameras are used. A problem occurs.

  In view of the above points, an object of the present invention is to reduce inconveniences in which an image registered person is rejected in a vehicle antitheft device using face authentication technology.

  In order to achieve the above object, according to the first aspect of the present invention, the ID code authentication control means (1) for collating the ID code of the key (4) having a unique ID code with a pre-registered ID code; Face authentication that compares the face image of an occupant input from the outside with a pre-registered face image, and permits engine start when the degree of coincidence of both face images exceeds a determination threshold Control means (3), the ID code authentication control means (1) outputs the ID code authentication result to the face authentication control means (3), and the face authentication control means (3) receives the input ID code. The determination threshold value is changed according to the authentication result.

  Specifically, as shown in claim 3, when the ID code matches the registered ID code, the determination threshold is set to the first determination threshold, and the ID code is registered. If the ID code does not match, the determination threshold is set to a second determination threshold higher than the first determination threshold.

  In this way, if the ID code matches the registered ID code, the determination threshold value for face authentication is set low, so that the person himself / herself is compared with the case where user verification is performed only by face authentication. Can be reduced.

  Further, as the ID code authentication control means (1), for example, as shown in claim 2, an ID code signal oscillated from a request signal transmitting means and a key having a unique ID code in response to the request signal ID code signal receiving means for receiving the ID code signal, and a means for checking the ID code signal received by the ID code signal receiving means with a registered ID code can be used. Specifically, for example, a smart key system (registered trademark) can be used.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
1 and 2 are sectional views of an automobile equipped with the vehicle antitheft device according to this embodiment. The vehicle antitheft device includes a smart key control circuit 1 as ID code recognition control means, a camera 2 as face image acquisition means, a control means for the camera 2 and a near-infrared illumination device (not shown), and face authentication control means. The face authentication circuit 3 is provided.

  The smart key control circuit 1 detects the approach of an occupant carrying the smart key 4 and constitutes a smart key system (SMARTKEY SYSTEM (registered trademark)). The smart key system of the present embodiment has a function of setting a determination threshold value of the face authentication circuit 3 to be described later in addition to the door unlocking function.

  Specifically, although not shown, a vehicle-side transmitter as a request signal transmitting unit and a wireless receiver as an ID code signal receiving unit are installed in the vehicle. The smart key control circuit 1 outputs a request signal to the vehicle-side transmitter and transmits the request signal from the vehicle-side transmitter. The wireless receiver receives the ID code signal including the response code from the smart key 4 that has received the request signal. Then, the ID code is discriminated / verified by the smart key control circuit 1. Thereafter, the collation result is output to the face authentication circuit 3.

  The camera 2 is arranged at a position in the automobile where a face of an occupant seated in the driver's seat can be taken. Specifically, for example, a near infrared camera 2 is used as the camera 2. Moreover, as shown in FIG. 1, the camera 2 is installed, for example in the instrument panel in an instrument panel, and is located in the deep place so that it may not stand out.

  In addition, the camera 2 can also be installed in the vicinity of the face outlet of the air conditioner in the center of the instrument panel, for example. However, since the position where the occupant's face can be taken from the front is suitable as the installation location of the camera 2, a location located in front of the driver's seat is preferable to the center of the instrument panel.

  The camera 2 acquires an occupant's face image and outputs the acquired occupant's face image to the face authentication circuit 3.

  Although not shown, a near-infrared illumination device is installed in front of the driver's seat. As the lighting device, for example, a light emitting diode can be used. Although not shown, a sensor unit for detecting the presence of an occupant is installed in the vehicle. The sensor unit includes, for example, an infrared sensor or a weight detection switch incorporated in the seat seat surface. The sensor unit outputs an occupant detection signal toward the face authentication circuit 3. The face authentication circuit 3 controls (drives) the camera 2 and the near-infrared illumination device using the signal as a trigger.

  As shown in FIG. 1, the face authentication circuit 3 is installed at a position in front of the driver. The face authentication circuit 3 can store personal face image data. The face authentication circuit 3 performs personal recognition by comparing the face image input from the camera 2 with a face image registered in advance, and if the degree of coincidence of both face images exceeds a determination threshold value. The engine is allowed to start.

  The determination threshold value of the face authentication circuit 3 is variable in conjunction with the collation result of the smart key control circuit 1.

  Next, the operation of the vehicle antitheft device will be described. FIG. 3 shows a flowchart of a face authentication threshold value setting process executed by the smart key control circuit 1, and FIG. 4 shows a flowchart of an engine start permission process executed by the face authentication circuit 3.

  First, the face authentication threshold setting process of the smart key control circuit 1 will be described with reference to FIG. Each step shown in the flowchart of FIG. 3 is always executed by the smart key control circuit 1 by power supply from the battery.

  As shown in FIG. 3, in step 101, a request signal is output to the vehicle-side transmitter, and the request signal is transmitted from the vehicle-side transmitter.

  At this time, as shown in FIG. 1, when the occupant carrying the smart key 4 approaches the vehicle, the smart key 4 receives the request signal. The smart key 4 transmits an ID code signal in response to this request signal.

  In step 102, the wireless receiver receives the signal, and the smart key control circuit 1 determines / verifies the ID code. Thus, when the passenger approaches the automobile, the primary authentication is performed by collating the ID code with the smart key 4.

  In step 103, it is determined whether or not the received ID code matches the ID code registered in advance. If they match, the primary authentication is OK and the process proceeds to step 104. If they do not match, the primary authentication is NG and the process proceeds to step 105.

  In step 104, a signal for unlocking the door is output to a door ECU (not shown), and a signal for setting the collation determination threshold value of the face authentication circuit 3 to the first determination threshold value. Is output to the face authentication circuit 3.

  On the other hand, in step 105, a signal for setting the collation determination threshold value of the face authentication circuit 3 to the second determination threshold value is output toward the face authentication circuit 3. In this step, a signal for unlocking the door is not output.

  As described above, in steps 104 and 105, a signal for setting the collation determination threshold value of the face authentication circuit 3 is transmitted from the smart key control circuit 1 to the face authentication circuit 3. Then, the face authentication circuit 3 sets the collation determination threshold value to the first determination threshold value or the second determination threshold value according to the signal from the smart key control circuit 1.

  In step 102, the ID code signal from the smart key 4 is not received by the wireless receiver unless the passenger carrying the smart key 4 approaches. However, in this embodiment, even when the ID code is not received, in step 103, it is processed as the primary authentication NG. That is, if the occupant does not have the smart key 4, the process in step 105 is always performed.

  From the above, when the occupant has the smart key 4, the occupant unlocks the door by sitting on the driver's seat by touching the door handle. At this time, a determination threshold value for face authentication described later is a first determination threshold value. On the other hand, when the occupant does not have the smart key 4, the occupant unlocks the door by means other than the smart key 4 and does not perform ID code collation, and sits in the driver's seat. At this time, the determination threshold value for face authentication is the second determination threshold value.

  Next, the engine start permission process executed by the face authentication circuit 3 will be described with reference to FIG. In step 106, when the sensor unit detects the occupant's boarding, an occupant detection signal is output from the sensor unit to the face authentication circuit 3.

  In step 107, the lighting device and the camera 2 are operated by the activation signal from the face authentication circuit 3, and an occupant's face image is acquired by the camera 2 as shown in FIG. Then, the face image is output from the camera 2 toward the face authentication circuit 3.

  In step 108, the face authentication circuit 3 performs secondary authentication by comparing the face image input from the camera 2 with the face image registered in advance. This secondary authentication is performed by, for example, how many elements that divide the face image match in both face images.

  In step 109, the face authentication circuit 3 determines whether the degree of matching between the registered face image and the acquired face image exceeds a determination threshold value. This determination is executed based on the threshold value set in the determination threshold value setting process shown in FIG.

  Here, the determination threshold value of the face authentication circuit 3 is set to the first determination threshold value when the primary authentication is OK, and is set to the second determination threshold value when the primary authentication is NG. Has been.

  Of the first determination threshold value and the second threshold value, the first threshold value is lower than the second threshold value. This is because, in general, it is a legitimate user who has the smart key 4, and when the ID codes match, the person who is the legitimate user is avoided as much as possible. Moreover, the reason why the second determination threshold value is higher is that it is desired to prohibit the start of the engine if it is an occupant other than the authorized user.

  For example, in both face images, assuming that the plurality of elements obtained by dividing the face image are all coincident, 100%, the first determination threshold is set to 70%, and the second determination threshold is set to 90%. %.

  If the degree of coincidence of both face images exceeds the determination threshold value, that is, if the secondary authentication is OK, the face authentication circuit 3 permits the engine to be started in step 112.

  On the other hand, if the degree of coincidence does not exceed the determination threshold value, that is, if the secondary authentication is NG, the engine authentication is not permitted by the face authentication circuit 3 in step 110. In this case, in step 111, an occupant is taught an operation method for obtaining a good face image by voice or character display, and prompts the occupant to perform another authentication operation. For example, an occupant is taught how to operate the camera 2 such as facing the front and pressing a button. This is because it is considered that even if the person who is a legitimate user, the secondary authentication is NG, a good face image cannot be obtained.

  If the secondary authentication is NG, repeat steps 107, 108, and 109 several times until it becomes OK, and if it still fails, teach the occupant how to obtain a good image. It can also be.

  After step 111, steps 107 and 108 are performed again. If the secondary authentication is OK in step 109, engine start is permitted in step 112.

  In the present embodiment, as described above, the determination threshold value of the face authentication circuit 3 is changed according to the primary authentication result by the smart key 4.

  That is, when the occupant approaches, if the occupant has the smart key 4, the primary authentication by the smart key control circuit 1 is OK, and the face authentication circuit 3 sets the secondary authentication verification threshold value. Set low.

  Thereby, even when an ideal face image cannot be acquired, the possibility of rejecting the person can be suppressed. As a method of reducing the rejection rate of the person in face authentication, a method of simply setting a determination threshold value low can be considered. However, this method also reduces the rejection rate of persons other than the principal, and thus the anti-theft effect is impaired. On the other hand, in this embodiment, since the smart key system is used in combination, even if the determination threshold for secondary authentication is set low, the effect of preventing theft is obtained.

  On the other hand, if the smart key 4 is not held even if the occupant approaches, the primary authentication by the smart key control circuit 1 is NG, and the face authentication circuit 3 has a high verification threshold for secondary authentication. Is set.

  Thereby, when a person other than the person gets on board, the probability (acceptance rate of others) of being OK in the secondary authentication can be kept low, and theft can be prevented with high probability. In addition, when the person gets on board, the risk of being rejected in the secondary authentication is high, but when the person is rejected in the secondary authentication, the step is to teach a good facial image acquisition procedure. It encourages re-operation. For this reason, in the second face authentication, the probability of being OK can be increased.

(Other embodiments)
In the first embodiment, the case where the smart key system is used as the primary authentication has been described. However, the present invention is not limited to this, and other devices can be used as long as the ID code of the authorized user is verified. .

  In the first embodiment, the vehicle antitheft device has been described. However, the present invention is not limited to the vehicle, and the present invention is applicable to all cases where the face authentication system is used where it is difficult to acquire an image under a good lighting environment. The invention can be applied.

Sectional drawing of the motor vehicle of the state which mounts the antitheft device in 1st Embodiment is shown. Sectional drawing of the motor vehicle of the state which mounts the antitheft device in 1st Embodiment is shown. It is a flowchart for demonstrating the face authentication threshold value setting process which a smart key control circuit performs. 6 is a flowchart for explaining an engine start permission process executed by a face authentication circuit 3;

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Smart key control circuit, 2 ... Camera, 3 ... Face authentication circuit, 4 ... Smart key.

Claims (3)

ID code authentication control means (1) for collating the ID code of the key (4) having a unique ID code with a pre-registered ID code;
Face authentication that compares the face image of an occupant input from the outside with a pre-registered face image, and permits engine start when the degree of coincidence of both face images exceeds a determination threshold Control means (3),
The ID code authentication control means (1) outputs the authentication result of the ID code to the face authentication control means (3), and the face authentication control means (3), based on the input ID code authentication result, The antitheft device for vehicles characterized by changing the judgment threshold. A request signal transmission means;
ID code signal receiving means for receiving an ID code signal transmitted from the key having the unique ID code in response to the request signal,
The antitheft device for vehicles according to claim 1, wherein the ID code authentication control means (1) collates the ID code signal received by the ID code signal receiving means with the registered ID code. . When the ID code matches the registered ID code, the face authentication control means (3) sets the determination threshold to a first determination threshold, and the ID code is registered The determination threshold value is set to a second determination threshold value that is higher than the first determination threshold value if the ID code does not match. 3. Anti-theft device for vehicles.

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