JPH05139249A - Method and device for detecting vehicle burglary - Google Patents

Abstract

PURPOSE:To discriminate burglary from other causes by forming such structure as to detect the average inclination displacement and oscillation of a vehicle and to output the detection of burglary when the average inclination displacement of the fixed angle or more continues for a fixed period or more as well as in the oscillation continued state. CONSTITUTION:A pulse corresponding to the vibration and inclination change of a vehicle is outputted from a magnetic encoder part 10, and the average inclination displacement theta is detected from the abovementioned pulse in an average inclination detecting part 14. When the vehicle is lifted due to burglary the average inclination displacement theta exceeds the reference inclination thetac for a long time, so that an Hlevel is outputted for a long time from the timer circuit l5a of a first judging part 15, and the H-level is outputted from a timer circuit l5c. In the case of burglary, oscillation continues for a long time, so that the output voltage of an oscillation integrating circuit 16 exceeds the reference value, and the H-level is outputted for a long time from a second judging part 17. When the H-level is thus outputted from the timer circuit l5c and the second judging part 17, a burglary detection signal is outputted to a security controller 19 from an circuit 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle theft detection method and a vehicle theft detection apparatus, and more particularly to a vehicle theft detection method and a vehicle theft suitable for preventing a vehicle from being pulled up and carried away by a tow truck or the like. Regarding a detection device.

[0002]

2. Description of the Related Art Various thefts targeting vehicles have been increasing, but sometimes the vehicle itself is pulled up by a tow truck,
It may be carried away. Therefore, it is necessary to equip the vehicle with a car security system so that when the vehicle is about to be carried away, it is detected and an alarm is issued to prevent the vehicle from being stolen.

In a conventional car security system, a vehicle is provided with a motion sensor using a pendulum so as to detect a sway or inclination change of the vehicle that occurs when the vehicle is pulled up and carried away, and an alarm is issued. There is.

[0004]

By the way, various vibrations are intermittently generated in a parked vehicle due to vibrations and winds transmitted on the road surface, an external force accidentally applied by a vehicle or a person passing nearby. .. When the pendulum of the motion sensor swings due to this sway, the motion sensor outputs a detection indicating that the sway has occurred, but since it cannot be distinguished from the removal of the vehicle by a bandit, an erroneous alarm is issued. There was a problem.

Further, the vehicle is shaken due to factors other than bandits,
When the pendulum of the motion sensor swings, it may not return to its original state due to hysteresis due to shaft friction etc. even after the swaying has subsided. There is a problem that an erroneous alarm is issued because it is indistinguishable from the fact that the vehicle has been carried away.

In view of the above, an object of the present invention is to provide a vehicle theft detection method and a vehicle theft detection apparatus capable of reliably detecting the removal of a vehicle by a bandit.

[0007]

SUMMARY OF THE INVENTION In the present invention, the above-mentioned problem is solved by an average inclination displacement detecting means for detecting an average inclination displacement of a vehicle, a sway detecting means for detecting a sway of the vehicle, and an output of the average inclination displacement detecting means. Based on the output of the shake detecting means, the first judging means for judging whether the average tilt displacement of a predetermined angle or more continues for a predetermined time or more from the predetermined initial state, and the presence or absence of continuous shake occurrence is determined. The second discriminating means for discriminating and the second discriminating means discriminate that the continuous shaking is occurring, and the first discriminating means continues the average inclination displacement of a predetermined angle or more from the predetermined initial state for a predetermined time or more. This is achieved by providing a theft detection output means for performing vehicle theft detection output when it is determined that the vehicle is being stolen.

[0008]

According to the present invention, the average inclination displacement of the vehicle and the average inclination displacement of the vehicle which is detected by detecting the sway of the vehicle and continues to sway the vehicle and which is equal to or more than a predetermined angle from a predetermined initial state are obtained. When is continued for a certain time or longer, vehicle theft detection output is performed. As a result, when the vehicle tries to be carried away by a bandit in a state of being pulled up by a tow truck, etc., the vehicle continues to shake, and at the same time, the average inclination displacement of the vehicle at a certain angle or more from the initial state during parking is constant time Since the above continues, it is possible to detect theft, but if various shakings occur in the vehicle due to factors other than bandits and the vehicle shakes, the shaking duration is short, or even if the shaking duration is long, The average tilt displacement of the vehicle rarely exceeds a certain angle from the initial state, and after the shaking has subsided, the tilt displacement from the initial state remains due to hysteresis, and even if the tilt displacement continues for a certain time or more, It is rare that a tilt displacement over a certain angle remains, and even if a tilt displacement over a certain angle remains from the initial state, no continuous shaking is detected at the same time. , Theft detection is not made,
As a result, it is possible to reliably detect the theft caused by the removal of the vehicle and perform the theft detection output.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a vehicle theft detection device according to the present invention.

In the figure, reference numeral 10 is a magnetic echo unit, which generates a number of positive or negative pulses depending on the direction and magnitude when the vehicle vibrates or changes in inclination.
Reference numeral 11 denotes a magnetic encoder, which has a pendulum, a magnetic drum that rotates according to the movement of the pendulum, and a magnetoresistive element (MR element) arranged so as to oppose the magnetic drum. When vibration or inclination change occurs in a certain vehicle, two signals of A phase and B phase having phases different from each other by 90 ° are generated.

2A and 2B are structural views of such a magnetic encoder. FIG. 2A is a side view and FIG. 2B is a front view. Reference numeral 11a is a side L-shaped attachment member, and 11b is a magnetic sensor. The magnetic sensor 11b is composed of a magnetoresistive element body of a permalloy thin film pattern formed on glass, and an electric circuit for generating two signals of A phase and B phase which are 90 ° out of phase with each other. Reference numeral 11c is a screw for attaching the magnetic sensor 11b, 11d is a magnetic drum magnetized on the peripheral side surface at a predetermined pitch, and faces the magnetic sensor 11b with a minute gap. 11e is a pendulum, 1
1f has a pendulum 11e fixed to the tip and a magnetic drum 11d fixed to the other end, and is a suspender for rotating the magnetic drum 11d in the same manner by rotating integrally with the pendulum 11e, and 11g is a magnetic drum 11d and a suspender 11f. Is a support portion that rotatably supports.

When the vehicle to which the magnetic encoder 11 is attached vibrates or tilts, the pendulum 11e vibrates vertically so as to stabilize, or tilts, and the magnetic drum 11d rotates accordingly. , Magnetic sensor 11
A two-phase signal is output from b.

FIGS. 3 and 4 are explanatory diagrams of the operating principle of the magnetic sensor 11b. The magnetoresistive element has a characteristic that when an electric current is passed in the longitudinal direction of the pattern, the electric resistance value R of the magnetoresistive element decreases when a magnetic field perpendicular to the electric resistance value R is present. Therefore, when the patterns of the magnetoresistive elements MRa and MRb are arranged so as to correspond to the magnetization pattern of the magnetic drum 11d as shown in FIG. 3A, in other words, the magnetoresistive elements MRa and MRb are 3λ from each other. / 4 (λ indicates the pitch of the magnetization pattern) is arranged with a phase shift,
The resistance values of the magnetoresistive elements MRa and MRb alternately decrease with the movement of the magnetization pattern. In the state of FIG. 3A, the resistance value of the magnetoresistive element MRa becomes small and the resistance value of the magnetoresistive element MRb becomes large. Becomes As a result, the output terminal O
An AC signal output can be obtained from the UT (see FIG. 3B) according to the rotation of the magnetic drum 11d, that is, the movement of the magnetization pattern.

The magnetic sensor 11a is actually shown in FIG.
As shown in (a) and (b), the magnetoresistive element a _i (i =
1 to 4) and b _j (j = 1 to 4) are combined to form a bridge structure, thereby increasing the output voltage and improving the temperature characteristic, and also from the magnetic resistance element a _i to the magnetic drum 11d.
By arranging another magnetoresistive element b _i at a position shifted by 1/4 wavelength with respect to the magnetization pattern pitch of A, the A required for the increment encoder is output from the output terminal OUT1.
A phase signal output can be obtained, and a B phase signal output can be obtained from the output terminal OUT2.

The magnetic encoder 1 thus constructed
1 is when the vehicle vibrates or changes in inclination in the front-back direction,
It is mounted on the vehicle to output a signal.

Returning to FIG. 1, 12a and 12b are shaping amplifier circuits for shaping and amplifying the waveforms of the two-phase signals generated from the magnetic encoder 11 to generate two-phase signals A and B that are rectangular waves, and 13 is a shaping amplifier circuit. This is a direction discriminating and quadrupling circuit that generates a positive pulse train PP or a negative pulse train NP according to the vibration direction or the inclination direction at each rising and falling portion of the A-phase and B-phase signals.

FIG. 5 is a diagram for explaining the operation of the direction discriminating and quadrupling circuit 13 and shows the case where the vehicle vibrates or leans in the positive direction (the direction in which the front side becomes lower when viewed from the rear side of the vehicle). .. In the figure, A and B are A-phase signals and B-phase signals that are 90 ° out of phase with each other, ΔA is a signal delayed from the A-phase signal by a predetermined time, ΔB is a signal delayed from the B-phase signal by a predetermined time, * Δ.
A and * ΔB are negation signals of signals ΔA and ΔB (* means negation), P1 is a positive pulse generated by AND operation of A · * ΔA, and P2 is generated by AND operation of B · * ΔB. Positive pulse, P3 is a positive pulse generated by AND operation of * A · ΔA, P4 is a positive pulse generated by AND operation of * B · ΔB, PP is a positive pulse train, and is one of A phase or B phase signal. It has four positive pulses P1 to P4 per cycle.

Reference numeral 14 denotes an average inclination displacement detecting section for detecting the average inclination displacement of the vehicle, which detects the average inclination displacement of the vehicle from the output pulse of the magnetic encoder section 10 and outputs it as an analog amount. Reference numeral 14a denotes an up / down counter, which counts up each time a positive pulse PP is input to the up clock terminal UP and counts down each time a negative pulse NP is input to the down clock terminal DW. The up / down counter 14a is reset based on a reset signal described later, and the count value is reset to zero. When the vehicle vibrates or tilts in the positive direction, the count value increases, and when the vehicle vibrates or tilts in the negative direction (the direction in which the front side becomes higher when viewed from the rear side of the vehicle), the count value decreases. Therefore, the count value after initialization by resetting is a value indicating the instantaneous tilt displacement from the initial state.

Reference numeral 14b is a D / A converter for D / A converting the count value (digital value) of the up / down counter 14a to convert it into an analog voltage value. When the count value is zero, it is 0V and is positive. When is negative, a positive voltage proportional to the count value is output, and when negative, a negative voltage proportional to the count value is output. Reference numeral 14c is an LPF for outputting the average inclination displacement (θ) obtained by removing a high frequency component from the output voltage of the D / A converter 14b and removing a fine vibration component in an analog amount.

Reference numeral 15 is a first discriminating section, which is the average inclination displacement θ.
It is determined whether or not the state in which the angle becomes equal to or more than the certain angle from the predetermined initial state continues for more than the certain time. Reference numeral 15a is a comparison circuit, which compares the output of the LPF 14c with the positive reference inclination angle (+ θc) and the negative reference inclination angle (−θc), and when θ ≧ + θc or θ ≦ −θc, averages from the initial state. An H-level comparison signal indicating that the tilt displacement is equal to or greater than a certain angle is output. Conversely, when + θc>θ> −θc, an L-level comparison indicating that the average tilt displacement from the initial state is equal to or less than the certain angle is output. Output a signal. The positive side reference inclination angle and the negative side reference inclination angle have the same absolute value, so that it can be detected that the vehicle is inclined to the positive direction or the negative direction to some extent.
After the vehicle is shaken due to factors other than bandits, such as wind,
When the pendulum 11e is in a state where it does not return to its original position due to hysteresis due to shaft friction or the like, and the average tilt displacement from the initial state deviates from zero, an H level comparison signal is not output within the predetermined range. Is set to.

However, if the vibration is great while the vehicle is shaking due to a factor other than the bandits, the comparison circuit 1 is sometimes used.
A comparison signal of H level may be output from 5a.
Therefore, in the present invention, the timer circuit 15b monitors the duration T of the H level of the comparison signal, and when the time T becomes longer than the predetermined set time Tc, the average inclination displacement from the predetermined initial state is A first determination signal of H level indicating that the state of a certain angle or more is longer than the set time Tc is output, and if the duration T is shorter than the set time Tc even if the comparison signal becomes the H level, the bandage The first discrimination signal at the H level is not output as an influence of wind or the like.

FIG. 6 is a circuit diagram showing a specific structure of the timer circuit 15b, and FIG. 7 is a waveform diagram for explaining the operation of the timer circuit 15b. When the vehicle is inclined from the initial state by a certain angle or more and a comparison signal of H level is output from the comparison circuit 15a,
The transistor Tr is turned on, the capacitor C that has been charged up to that point starts discharging through the route of C → R2 → Tr1 (time constant is C · R2, R2 = 2.2 MΩ), and the capacitor terminal voltage Vc is as shown in FIG. It attenuates as shown in (a). In this case, when the H level period of the comparison signal is sufficiently long, the capacitor C is sufficiently discharged, and the capacitor terminal voltage Vc becomes equal to or lower than the threshold level V _TH (the input of the inverter INV is L level) after the set time Tc. , Inverter I
The H level is output from NV. After that, the comparison signal is L
When returning to the level, the transistor Tr is turned off and the capacitor C is rapidly charged in the route of R1 → diode D → capacitor C (time constant is C · R1, R1 = 10k
Ω), the capacitor terminal voltage Vc rises rapidly and exceeds the threshold level V _TH (input of the inverter INV is H level), and the output of the inverter INV drops to L level.

Unlike this, when the vehicle leans due to factors other than bandits, such that the duration of the comparison signal becomes H level, which is shorter than the set time Tc (see FIG. 7B), The capacitor C is not fully discharged, in other words, the capacitor terminal voltage Vc is the threshold level V
_It does not _fall below _TH , and the inverter INV does not output H level.

By the way, the vehicle is shaken by a factor other than bandits, and after this shake is subsided, the pendulum 11e is not returned to its original position due to hysteresis due to shaft friction and the like, and the average inclination displacement is from zero. If the deviation exceeds the predetermined range, the comparison circuit 15a may continuously output the H-level comparison signal for the set time Tc or longer, and the presence or absence of the theft may be determined only by the output of the timer circuit 15b. Then, there is a risk of making a wrong decision. Therefore, in the present invention, the continuous state of the vehicle sway is also monitored, and the vehicle is continuously swayed to a certain extent while the inclination change of the vehicle at a certain angle or more continues for a certain time or more. Only then is it determined that a theft has occurred.

Reference numeral 16 is a swing integration for detecting the continuous state of the vehicle sway by integrating the positive pulse PP and the negative pulse NP output from the magnetic encoder unit 10 as a sway detection signal and integrating the positive pulse PP and the negative pulse NP. Circuit. 16
a is O for performing a logical sum operation of the positive pulse PP and the negative pulse NP
R circuit, 16b is an up / down counter, OR
The output pulse of the circuit 16a is input to the up clock terminal UP to perform a count up operation (charging operation), and the clock CLK having a constant cycle input from the outside is input to the down clock terminal DW to perform a count down operation (discharging operation). Thus, the integration operation of the positive pulse PP and the negative pulse NP is equivalently performed. However, the up / down counter 16b is designed so that the count value does not fall below zero, and 0 ≦
Counting is performed within the range of count values.

When the vehicle continues to swing in the positive direction or the negative direction, the positive pulse PP or the negative pulse NP is continuously output from the magnetic encoder unit 10, so that the count value of the up / down counter 16b increases. I will do it. When the shaking of the vehicle stops, the count value decreases in accordance with the time constant determined by the cycle of the clock CLK. As a result, the magnitude of the count value of the up / down counter 16b indicates the duration of the sway of the vehicle.

Reference numeral 16c is a D / A converter, which D / A converts the count value of the up / down counter 16b to convert it into an analog voltage. When the count value is zero, 0V is output, and when the count value is positive, a positive voltage proportional to the count value is output.

Reference numeral 17 denotes a second discriminator composed of a comparison circuit, which compares the output of the D / A converter 16c of the shake integration circuit 16 with a predetermined reference value Ec and, if it is equal to or larger than the reference value Ec, shakes. The H-level comparison signal indicating that the shaking continues for a certain amount is output, and if it is below the reference value Ec, the L-level second determination signal indicating that the shaking does not continue is output.

Reference numeral 18 is an AND circuit, which is a timer circuit 15
The AND operation of b and the output of the second discriminating unit 17 is performed, and only when both are at the H level, the H level theft detection signal is output. Reference numeral 19 denotes a security controller, which gives a reset signal to the up / down counter 14a to initialize the count value to zero when the driver puts the vehicle in the arm state after parking the vehicle. When a level theft detection signal is input, a predetermined warning operation is performed by sounding a siren or blinking a headlight.

8 to 10 are waveform diagrams for explaining the operation of the above-mentioned vehicle theft detection device, which will be described below with reference to FIG.

When the vehicle is parked and brought into an arm state by the driver, the security controller 19 gives a reset signal to the up / down counter 14a to make the count value zero and initialize it.

When the vehicle vibrates or leans after the initial state, the magnetic encoder unit 1 is operated in the positive direction (the direction in which the front side becomes lower when viewed from the rear side of the vehicle).
The positive pulse PP is output from 0, and the negative pulse NP is output from the magnetic encoder unit 10 in the negative direction (the direction in which the front side becomes higher when viewed from the rear side of the vehicle). By the positive pulse PP and the negative pulse NP, the average inclination displacement detection unit 1
The up / down counter 14a of 4 performs an up-counting operation or a down-counting operation to determine the instantaneous inclination displacement of the vehicle from the initial state during parking as a digital amount. The count value of the up / down counter 14a is D /
After being converted into an analog quantity by the A converter 14b, the LPF
In step 14c, the fine vibration component is removed to obtain the average tilt displacement θ. Then, the comparison circuit 15a of the first determination unit 15
Is compared with the positive side reference inclination angle + θc and the negative side reference inclination angle −θc, and it is determined whether the average inclination displacement from the initial state is equal to or more than a certain angle.

On the other hand, when the positive pulse PP or the negative pulse NP is output from the magnetic encoder unit 10, it is added by the up / down counter 16b of the swing integration circuit 16, but at the same time, it is subtracted according to the clock CLK and the swing continues. A count value according to time is obtained, and the D / A converter 16c
Is converted into an analog quantity. Then, the second discriminating unit 17 compares it with the reference value Ec and discriminates whether or not the duration of the shaking is long to some extent.

Here, when the vehicle is shaken by the influence of wind other than the bandits and vibrates or tilts, it is assumed that the shake continuously occurs and the count value of the up / down counter 16b is equal to the reference value Ec. Exceeds the value corresponding to
Even if the level is output, the average inclination displacement θ rarely becomes large, the H level is rarely output from the comparison circuit 15a, and even if the H level is output,
Its duration T is relatively short. Comparison circuit 15a
If the H level is not output from or if the duration T is short even if it is output, the H level is not output from the timer circuit 15b and the theft detection signal is not output from the AND circuit 18 (see FIG. 8). ).

Pendulum 11e, even after the upset has subsided
When the average inclination displacement θ remains large due to hysteresis due to shaft friction of No. 3, the comparison circuit 15a continues to output the H level, and the timer circuit 15b outputs the H level with a delay of the set time Tc. .. However, since the count value of the up / down counter 16b decreases toward zero when the fluctuation is stopped, the output of the second discriminating unit 17 becomes L when the output of the D / A converter 16c falls below the reference value Ec. Fall to the level. Therefore, if the set time Tc in the timer circuit 15b is properly determined, the second determination unit 1
Since the output of the timer circuit 15b becomes H level after the output of 7 drops to L level, the theft detection signal is not output from the AND circuit 18 again (see FIG. 9).

As described above, even if the vehicle is shaken due to factors such as wind other than the bandits, the theft detection signal will not be erroneously output.

In contrast to this, because a bandit steals the vehicle, when the rear side of the vehicle is pulled up by a wrecker or the like and is attempted to be carried away, the vehicle is greatly tilted in the forward direction and continuously shakes. In this case, the average tilt displacement detection unit 14
The average tilt displacement θ detected at is the positive reference tilt angle + θc
Is exceeded for a long time, and the H level is output from the comparison circuit 15a for a long period, so that the H level is output from the timer circuit 15b. Further, since the vibration of the vehicle continues, the output voltage of the vibration integration circuit 16 exceeds the reference value Ec and becomes large, and the second discriminating unit 17 outputs the H level for a relatively long period. H level is output from the timer circuit 15b,
When the H level is output from the second discriminating unit 17, A
A high level theft detection signal is output from the ND circuit 18 to the security controller 19. When the vehicle is being carried away by bandits when the average tilt displacement of a certain angle or more from the initial state during parking continues for a certain period of time and the swaying also continues for some time. As you can think, the security controller 19
When an H-level theft detection signal is input from the circuit 18, the siren is sounded or the headlamp is flashed to perform a predetermined alarm operation to prevent the vehicle from being carried away.

In the above-mentioned embodiment, when the continuous state of the swing is monitored, the magnitude of the swing does not matter, but it is inputted to the down clock terminal of the up / down counter which constitutes the swing integration circuit. If the cycle of the clock is shortened, when a relatively small sway occurs due to factors such as wind other than the removal of the vehicle, the count value of the up / down counter does not increase to the reference value Ec even if the sway continues for a long time. Even if the vehicle is carried away by a bandit, a relatively large sway of a certain amount or more occurs, and the count value of the up / down counter can increase beyond the reference value Ec when the swaying continues for a certain amount of time or more. Good.

[0039]

As described above, according to the present invention, the average tilt displacement of the vehicle and the sway of the vehicle are detected, the sway of the vehicle is maintained, and the vehicle is at a certain angle or more from the predetermined initial state. When the average tilt displacement continues for a certain period of time or more, it is configured to output the theft detection of the vehicle.Therefore, when the vehicle tries to be carried away by a bandit with a tow truck etc., if the vehicle shakes continuously At the same time, since the average tilt displacement of the vehicle at a certain angle or more continues for a certain time or more from the initial state during parking, it is possible to detect theft, while various fluctuations occur in the vehicle due to factors other than bandits and the vehicle shakes. In this case, even if the sway duration is short or the sway duration is long, the average tilt displacement of the vehicle rarely exceeds a certain angle from the initial state. Even if the tilt displacement from the initial state remains and the tilt displacement continues for a certain period of time or more, it is rare that the tilt displacement of a certain angle or more remains from the initial state, and if the tilt displacement of a certain angle or more remains from the initial state. However, since the continuous shaking is not detected at the same time, the theft detection output is not performed, and as a result, the theft detection output can be surely made by distinguishing the theft caused by the removal of the vehicle.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle theft detection device that embodies a vehicle theft detection method according to the present invention.

FIG. 2 is a structural diagram of a magnetic encoder.

FIG. 3 is a first explanatory diagram showing the operating principle of the magnetic sensor.

FIG. 4 is a second explanatory diagram showing the operating principle of the magnetic sensor.

FIG. 5 is a waveform diagram for explaining the operation of the direction determination / quadrupling circuit.

FIG. 6 is a circuit diagram showing a specific configuration of a timer circuit.

FIG. 7 is a waveform diagram illustrating the operation of the timer circuit.

FIG. 8 is a waveform diagram showing the operation of the vehicle theft detection device.

FIG. 9 is a waveform diagram showing the operation of the vehicle theft detection device.

FIG. 10 is a waveform diagram showing the operation of the vehicle theft detection device.

[Explanation of symbols]

 11 magnetic encoder 14 average inclination displacement detector 15 first discriminator 16 shake integration circuit 17 second discriminator 18 AND circuit

Claims (2)

[Claims] 1. An average tilt displacement of a vehicle and a vehicle sway are detected, and while the vehicle sway continues, the average tilt displacement of the vehicle at a certain angle or more from a predetermined initial state is at least a certain time. The vehicle theft detection method is characterized in that when the operation is continued, the vehicle theft detection output is performed. 2. An average inclination displacement detecting means for detecting an average inclination displacement of a vehicle, a sway detecting means for detecting a sway of the vehicle, and an output of the average inclination displacement detecting means from a predetermined initial state to a predetermined angle or more. A first discriminating means for discriminating whether or not the average tilt displacement of No. 1 has continued for a certain period of time or more, a second discriminating means for discriminating whether or not a continuous shake has occurred based on the output of the shake detecting means, and a second discriminating means. The vehicle is stolen when it is determined that a continuous sway is occurring in the vehicle, and when the first determination means determines that the average inclination displacement of a predetermined angle or more has continued for a predetermined time or more from the predetermined initial state. A vehicle theft detection device comprising: a theft detection output means for performing a detection output.