Vehicle anti-theft devices

Abstract

To provide an antitheft device of a vehicle capable of preventing theft of the vehicle while allowing the vehicle to be moved during a disaster or the like.SOLUTION: When it is determined that driver information does not correspond to registered information by a DMS 25, a steering control device 50 allows steering by the driver after the determination until an own vehicle M travels a set distance Dth1 and makes an EPS motor 12 generate a driving torque which inhibits steering by the driver after the vehicle has traveled the set distance Dth1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an anti-theft device for a vehicle that prevents theft by restricting the behavior of the vehicle. [Background technology]

[0002] Conventionally, various technologies have been proposed for preventing vehicle theft for automobiles and other vehicles. For example, Patent Document 1 discloses a vehicle control device (anti-theft device) that is equipped with a person authentication device equipped with a fingerprint reader that reads the fingerprints of occupants in a vehicle, compares the fingerprint data from the fingerprint reader with fingerprint data of pre-registered authorized users, and performs interference control using an electric power steering device if the occupant is not recognized as the authorized user.

[0003] Generally, when a disaster occurs, a driver must park the vehicle on the side of the road to evacuate. At that time, the driver must leave the key inside the vehicle so that a third party can move the vehicle and ensure a passage for emergency vehicles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-41384 Joint Publication Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the anti-theft device disclosed in the above-mentioned Patent Document 1, in the event of a disaster or the like, even if the key is left inside the vehicle, it becomes difficult for anyone other than the authorized user to move the vehicle.

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide an anti-theft device for a vehicle that can prevent theft of the vehicle while allowing the vehicle to move during a disaster or the like. [Means for solving the problem]

[0007] An anti-theft device for a vehicle according to one aspect of the present invention comprises a driver verification means for verifying whether driver information acquired from a driver matches pre-registered registration information, a steering torque detection means for detecting a steering torque input to a steering system by the driver, an actuator for generating a driving torque to be applied to the steering system, and a steering control means for controlling the driving torque generated by the actuator based on the steering torque, wherein when the driver verification means determines that the driver information does not match the registration information, the steering control means allows the driver to steer until the vehicle has traveled a set distance, and then causes the actuator to generate the driving torque that prohibits the driver from steering, Furthermore, a first assist torque is generated by the actuator as the driving torque when it is determined that the driver information matches the registered information, and a second assist torque smaller than the first assist torque is generated by the actuator as the driving torque from when it is determined that the driver information does not match the registered information until the host vehicle travels the set distance. do. [Effects of the Invention]

[0008] According to the vehicle theft prevention device of the present invention, it is possible to prevent vehicle theft while allowing the vehicle to move during a disaster or the like. [Brief explanation of the drawings]

[0009] [Figure 1] Schematic diagram of an electric power steering device mounted on a vehicle [Figure 2] Flowchart showing a steering control routine [Figure 3] A characteristic diagram showing an example of the steering torque-motor drive current characteristic during normal steering control. [Figure 4] A characteristic diagram showing an example of the steering torque-motor drive current characteristic during steering control with limited assist torque. [Figure 5] A characteristic diagram showing an example of the steering torque-motor drive current characteristic when steering is prohibited DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In Fig. 1, reference numeral 1 denotes an electric power steering (EPS) device mounted on a vehicle (host vehicle) M. The steering system of this EPS device 1 has a steering shaft 2. The steering shaft 2 is rotatably supported by a body frame (not shown) of the vehicle M via a steering column 3.

[0011] One end of the steering shaft 2 extends toward the driver's seat, and the other end extends toward the engine compartment. A steering wheel 4 is fixed to the end of the steering shaft 2 on the driver's seat side.

[0012] A torsion bar 2a is interposed midway along the steering shaft 2. A pinion shaft 5 is connected to the end of the steering shaft 2 that extends toward the engine room. A torque sensor 22 serving as steering torque detection means is disposed on the outer circumferential side of the torsion bar 2a.

[0013] The torque sensor 22 detects the steering torque Td input to the steering system by the driver. Specifically, the torque sensor 22 is capable of detecting the steering torque Td by detecting the displacement between the steering wheel 4 side and the pinion shaft 5 side that occurs around the axis of the steering shaft 2 due to the twisting of the torsion bar 2a.

[0014] Meanwhile, a steering gear box 6 extending in the vehicle width direction is disposed in the engine compartment. A rack shaft 7 is inserted and supported in this steering gear box 6 so that it can move back and forth freely. A rack (not shown) formed on this rack shaft 7 is meshed with a pinion formed on the pinion shaft 5. As a result, the steering system of the EPS device 1 is configured as a rack-and-pinion steering mechanism.

[0015] The left and right ends of the rack shaft 7 each protrude from an end of the steering gearbox 6. Front knuckles 9 are connected to the left and right ends of the rack shaft 7 via tie rods 8. The front knuckles 9 rotatably support left and right wheels 10L, 10R as steered wheels, and are supported on the vehicle frame so that they can be steered. That is, when the steering wheel 4 is operated, the steering shaft 2 and the pinion shaft 5 are rotated. When the rack shaft 7 is moved left and right by the rotation of the pinion shaft 5, the front knuckles 9 are rotated about a kingpin shaft (not shown). As a result, the left and right wheels 10L, 10R are steered left and right.

[0016] An electric power steering motor (EPS motor) 12 serving as an actuator is connected to the pinion shaft 5 via an assist transmission mechanism 11, which is a reduction gear mechanism such as a worm gear. The EPS motor 12 is an electric motor, for example, a DC brushless motor having a stator fixed to a case and a rotor that rotates inside the stator. Rotation of the rotor of the EPS motor 12 is converted into axial movement of the rack shaft 7 via the assist transmission mechanism 11. This enables the EPS motor 12 to generate drive torque that is applied to the steering system of the EPS device 1.

[0017] A steering control device 50 is connected to the EPS motor 12 via a motor drive unit 20 .

[0018] Signals from sensors such as a torque sensor 22, a vehicle speed sensor 24 that detects a vehicle speed V, and a driver monitoring system (DMS) 25 that performs face authentication of the driver are input to the steering control device 50. Signals from switches such as an ignition switch 26 are also input to the steering control device 50. Furthermore, an alarm device 51 equipped with, for example, a display, a speaker, etc. is connected to the steering control device 50.

[0019] Here, the DMS 25 performs, for example, facial authentication of the driver. To this end, the DMS 25 has a camera (not shown) arranged on a dashboard or the like so as to face the face of the driver seated in the driver's seat. The DMS 25, for example, recognizes the driver's face from an image captured by the camera and acquires feature points of the recognized driver's face as driver information (driver's facial recognition information). The DMS 25 also compares the acquired driver information with registration information previously registered by a user. Then, if the comparison results in a match between the recognized driver's face and the user-registered driver's face, the DMS 25 determines that the driver seated in the driver's seat is a legitimate driver (registered driver). In this way, in this embodiment, the DMS 25 functions as a driver comparison means.

[0020] The steering control device 50 controls the driving of the EPS motor 12 via the motor driving unit 20 .

[0021] Specifically, when the DMS 25 determines that the driver information matches the registered information, the steering control device 50 refers to, for example, a preset first map to calculate a first motor drive current I1. This first motor drive current I1 is a current for causing the EPS motor 12 to generate a first assist torque in response to the driver's steering as a drive torque.

[0022] 3, the first map is a three-dimensional map for calculating the first motor drive current I1 based on the steering torque Td and the vehicle speed V. Based on this first map, the steering control device 50 calculates the first motor drive current I1 so that the larger the steering torque Td (absolute value) is, the greater the drive torque (absolute value) is in the steering direction of the driver, and so that the smaller the vehicle speed V is, the greater the drive torque (absolute value) is in the steering direction of the driver.

[0023] The first motor drive current I1 calculated in this manner is output to the EPS motor 12 via the motor drive unit 20. As a result, the EPS motor 12 generates a drive torque (first assist torque) according to the first motor drive current I1.

[0024] Furthermore, when the DMS 25 determines that the driver information does not match the registered information, the steering control device 50 refers to, for example, a preset second map to calculate a second motor drive current I2 until the host vehicle M travels the set distance Dth1. This second motor drive current I2 is a current for causing the EPS motor 12 to generate a second assist torque in response to the steering of the driver.

[0025] 4, the second map is a three-dimensional map for calculating the second motor drive current I2 based on the steering torque Td and the vehicle speed V. Based on this second map, the steering control device 50 calculates the second motor drive current I2 so that the drive torque (absolute value) increases in the steering direction of the driver as the steering torque Td (absolute value) increases, and so that the drive torque (absolute value) increases in the steering direction of the driver as the vehicle speed V decreases. However, the second motor drive current I2 (absolute value) is a value that is relatively smaller than the first motor drive current I1 (absolute value) calculated for the same steering torque Td and vehicle speed V.

[0026] The second motor drive current I2 calculated in this manner is output to the EPS motor 12 via the motor drive unit 20. As a result, the EPS motor 12 generates a drive torque (second assist torque) according to the second motor drive current I2.

[0027] Furthermore, when the DMS 25 determines that the driver information does not match the registered information, after the host vehicle M has traveled a set distance Dth1, the steering control device 50 refers to, for example, a preset third map to calculate a third motor drive current I3. This third motor drive current I3 is a current for causing the EPS motor 12 to generate an inhibiting torque against the steering by the driver.

[0028] 5, the third map is a three-dimensional map for calculating the third motor drive current I3 based on the steering torque Td and the vehicle speed V. Based on this third map, the steering control device 50 calculates the third motor drive current I3 so that the larger the steering torque Td (absolute value), the greater the drive torque (absolute value) is in the opposite direction (inhibition side) to the steering direction of the driver, and so that the larger the vehicle speed V, the greater the drive torque (absolute value) is in the opposite direction (inhibition side) to the steering direction of the driver.

[0029] The third motor drive current I3 calculated in this manner is output to the EPS motor 12 via the motor drive unit 20. As a result, the EPS motor 12 generates a drive torque (inhibition torque) according to the third motor drive current I3.

[0030] In this way, in this embodiment, the steering control device 50 realizes the function as a steering control means.

[0031] Next, the steering control executed by the steering control device 50 will be described with reference to the flowchart of the steering control routine shown in Fig. 2. This routine is executed repeatedly, for example, at set time intervals.

[0032] When the routine starts, the steering control device 50 checks in step S101 whether the ignition switch 26 is turned on.

[0033] Then, in step S101, if it is determined that the ignition switch 26 is turned off, the steering control device 50 exits the routine as is.

[0034] On the other hand, if it is determined in step S101 that the ignition switch 26 is turned on, the steering control device 50 proceeds to step S102 and reads the driver verification result performed in the DMS 25.

[0035] Then, when the process proceeds from step S102 to step S103, the steering control device 50 checks whether the driver verified in the DMS 25 matches a registered driver, that is, whether the driver information matches the registered information.

[0036] Then, in step S103, if it is determined that the driver information matches the registered information, the steering control device 50 proceeds to step S104 and clears the accumulated travel distance D of the host vehicle M, which will be described later.

[0037] In the following step S105, the steering control device 50 performs the first steering assist control and then exits the routine. That is, the steering control device 50 refers to a preset first map (see FIG. 3) and calculates a first motor drive current I1 based on the steering torque Td and the vehicle speed V. Then, the steering control device 50 outputs the calculated first motor drive current I1 to the EPS motor 12 via the motor drive unit 20 and then exits the routine.

[0038] On the other hand, if it is determined in step S103 that the driver information does not match the registered information, the steering control device 50 proceeds to step S106 and calculates the distance traveled (accumulated distance traveled) D of the vehicle M since it was determined that the driver information does not match the registered information, for example, based on the vehicle speed V.

[0039] In the following step S107, the steering control device 50 checks whether the cumulative traveling distance D is equal to or greater than a preset first threshold value (set distance) Dth1. The first threshold value Dth1 is set to approximately several hundred meters.

[0040] Then, if it is determined in step S107 that the cumulative travel distance D is less than the first threshold value Dth1, the steering control device 50 proceeds to step S108 and checks whether the cumulative travel distance D is equal to or greater than a preset second threshold value Dth2. Note that the second threshold value Dth2 is set to a distance that is, for example, about several tens of meters shorter than the first threshold value Dth1.

[0041] Then, if it is determined in step S108 that the accumulated travel distance D is equal to or greater than the second threshold value Dth2, the steering control device 50 proceeds to step S109, outputs an alarm through the alarm device 51, and then proceeds to step S110. Here, the alarm output in step S109 is a warning to notify the driver that steering of the vehicle M will be prohibited. For example, the steering control device 50 outputs a message such as "You will soon be unable to steer this vehicle. Please stop the vehicle in a safe place" through the alarm device 51 by voice or image.

[0042] On the other hand, if it is determined in step S108 that the cumulative travel distance D is less than the second threshold value Dth2, the steering control device 50 proceeds directly to step S110.

[0043] When the process proceeds from step S108 or step S109 to step S110, the steering control device 50 performs the second steering assist control and then exits the routine. That is, the steering control device 50 refers to a preset second map (see FIG. 4) and calculates the second motor drive current I2 based on the steering torque Td and the vehicle speed V. Then, the steering control device 50 outputs the calculated second motor drive current I2 to the EPS motor 12 via the motor drive unit 20 and then exits the routine.

[0044] Furthermore, if it is determined in step S107 that the accumulated travel distance D is equal to or greater than the first threshold value Dth1, the steering control device 50 proceeds to step S111, performs steering prohibition control, and then exits the routine. That is, the steering control device 50 refers to a preset third map (see FIG. 5) and calculates a third motor drive current I3 based on the steering torque Td and the vehicle speed V. Then, the steering control device 50 outputs the calculated third motor drive current I3 to the EPS motor 12 via the motor drive unit 20, and then exits the routine.

[0045] According to this embodiment, when the DMS 25 determines that the driver information does not match the registered information, the steering control device 50 allows the driver to steer from the time of the determination until the host vehicle M has traveled a set distance Dth1, and causes the EPS motor 12 to generate a drive torque that prohibits the driver from steering after the host vehicle M has traveled the set distance Dth1. This allows the EPS device 1 to function as an anti-theft device that prevents the vehicle M from being stolen while allowing the vehicle M to move in the event of a disaster or the like.

[0046] That is, even if the DMS 25 determines that the driver sitting in the driver's seat is not a registered user driver, the steering control device 50 allows steering until the host vehicle M travels the set distance Dth1, thereby enabling a third party other than the authorized user to move the vehicle M in the event of a disaster, etc. Then, after traveling the set distance Dth1, steering by anyone other than the authorized user is prohibited, thereby making it possible to reliably prevent theft of the vehicle M.

[0047] In this case, when the steering control device 50 determines in the DMS 25 that the driver information does not match the registered information, the steering control device 50 suppresses the assist torque generated by the EPS motor 12 compared to when the DMS 25 determines that the driver information matches the registered information, thereby preventing theft and encouraging careful driving when a third party is driving the vehicle M.

[0048] Furthermore, the prohibition of steering by the driver is realized by generating an interference torque in the opposite direction to the steering torque as a driving torque by the EPS motor 12, so that steering by a third party can be appropriately prohibited.

[0049] Furthermore, the steering control device 50 issues a warning to the driver before the disturbing torque is generated, thereby enabling the driver to evacuate the vehicle M to a safe place before the disturbing torque makes the vehicle M unsteerable.

[0050] Furthermore, by performing driver verification based on face recognition information acquired by the DMS 25, driver verification can be achieved without forcing the driver seated in the driver's seat to perform any special authentication operations.

[0051] In the above-described embodiment, the DMS 25 and the steering control device 50 are configured with a well-known microcomputer equipped with a CPU, RAM, ROM, non-volatile storage unit, etc., and its peripheral devices, and the ROM stores programs to be executed by the CPU, fixed data such as data tables, etc. Note that all or part of the functions of the processor may be configured with logic circuits or analog circuits, and the processing of various programs may be realized by electronic circuits such as FPGAs.

[0052] The invention described in the above embodiments is not limited to these embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. For example, in the above embodiments, an example in which driver authentication (matching) is performed by facial recognition is described, but the present invention is not limited to this, and fingerprint authentication, etc., can also be used.

[0053] Furthermore, if the stated problem can be solved and the stated effect can be obtained even if some of the constituent elements are deleted from all the constituent elements shown in the above form, the configuration from which these constituent elements are deleted can be extracted as an invention. [Explanation of symbols]

[0054] 1...EPS device 2... Steering axis 2a ... Torsion bar 3... Steering column 4 … Steering wheel 5 ... Pinion shaft 6... Steering gearbox 7 ... Rack shaft 8... tie rod 9... Front knuckle 10L,10R … Left and right wheels 11... Assist transmission mechanism 12... Electric power steering motor (EPS motor) 20...Motor drive unit 22 ... Torque sensor 24 ... Vehicle speed sensor 26... Ignition switch 50 ... Steering control device 51…Alarm device I1: First motor drive current I2: Second motor drive current I3: Third motor drive current M: Vehicle (own vehicle)

Claims

1. a driver verification means for verifying whether driver information acquired from the driver matches pre-registered registration information; a steering torque detection means for detecting a steering torque input to a steering system by the driver; an actuator that generates a driving torque to be applied to the steering system; a steering control means for controlling the drive torque generated by the actuator based on the steering torque; An anti-theft device for a vehicle, comprising: The steering control means When the driver verification means determines that the driver information does not match the registered information, the driver is permitted to steer until the host vehicle travels a set distance, and then the actuator generates the drive torque that prohibits the driver from steering; and generating a first assist torque by the actuator as the driving torque when it is determined that the driver information matches the registered information; The vehicle theft prevention device further comprises the actuator generating a second assist torque smaller than the first assist torque as the driving torque from the time it is determined that the driver information does not match the registration information until the vehicle travels the set distance.

2. 2. The vehicle theft prevention device according to claim 1, wherein the steering control means generates an interference torque in the opposite direction to the steering torque as the driving torque by the actuator after the vehicle has traveled the set distance since it was determined that the driver information does not match the registered information.

3. 3. The vehicle theft prevention device according to claim 1, wherein the driver verification means acquires facial recognition information of the driver as the driver information.

4. 4. The vehicle theft prevention device according to claim 1, wherein the steering control means issues a warning to the driver before generating the driving torque that prohibits the driver from steering.

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