Anti-theft system with remote controlled verification of arming

A remote controlled anti-theft system for transportation vehicles allows the user to easily determine at will if a faulty door position sensor or an open door will inhibit proper operation of the anti-theft system by pressing the lock button on the remote transmitter in a predetermined sequence. A first lock code from the remote transmitter initiates a locking and arming sequence of the anti-theft system. A second lock code received within a predetermined time of the first lock code causes an audible verification to be produced identifying whether the anti-theft system is successfully arming or whether a door ajar or faulty door sensor is preventing the anti-theft system from arming.

BACKGROUND OF THE INVENTION 
The present invention relates in general to remote controlled anti-theft 
systems for vehicles, and more specifically to providing audible horn 
chirps or beeps (and/or visible flashes of exterior lights) identifying 
successful or unsuccessful remote controlled operation of the anti-theft 
system. 
Remote entry systems are known for cars, trucks, and other transportation 
vehicles which operate locks, anti-theft systems and vehicle personality 
features such as seat and mirror position. A remote entry radio receiver 
is mounted in the vehicle which responds to a radio transmitter carried by 
the user of the vehicle. In one common type of system, the user depresses 
a control button on the remote transmitter causing a coded signal to be 
transmitted to the receiver identifying a command desired by the user, 
e.g. lock or unlock doors, unlock trunk, or arm, disarm or trigger an 
anti-theft system. Unique portions of the codes identify the individual 
transmitter to insure that only an authorized user gains access to the 
vehicle or the remote entry functions. 
Anti-theft systems provide perimeter protection by sensing unauthorized 
entry into a vehicle and then initiating a siren or other action to deter 
entry. When in its armed or active state, the anti-theft system monitors 
sensors, such as door position sensors, to detect entry. Other types of 
sensors include vibration sensors, glass breakage sensors, hood position 
switches, and trunk tamper switches, for example. The authorized user 
causes the anti-theft system to enter its armed state when leaving the 
vehicle and disarms the anti-theft system upon returning and prior to 
entering the vehicle. 
When arming the anti-theft system, the user may desire verification of 
proper arming to ensure that the anti-theft system will be effective 
during his absence. Such verification typically takes the form of audible 
beeps or horn chirps that signify successful arming. Verification may also 
take the form of flashing the vehicle exterior lights with or without the 
use of audible chirps. Any combination of the headlamps and parking lights 
can be flashed. 
These verification actions from the vehicle to signify successful arming of 
the anti-theft system may be undesirable in certain situations. Horn 
chirps and headlight flashes may be especially disturbing in a quiet 
residential neighborhood late at night. 
Prior art anti-theft systems have thus been given the ability to optionally 
either provide or not provide verification of arming. This selection is 
made by a setting switch on the anti-theft module in the vehicle for the 
desired mode of operation, i.e., verification mode or non-verification 
mode. Once a system is preset, however, the single chosen mode of 
operation is utilized at each arming, independent of the time of day or 
situation. Thus, the user does not have the option of obtaining 
verification of system arming with horn chirps at loud places during the 
day and then not obtaining verification in quiet settings late at night. 
SUMMARY OF THE INVENTION 
The present invention provides the advantage that the anti-theft system 
user can obtain on-demand verification as desired. 
The present invention provides a remote controlled anti-theft system for a 
transportation vehicle providing on-demand audible verification of 
anti-theft system operation comprising a portable transmitter which 
transmits a lock code in response to a manual activation. Door lock 
actuators will lock the doors of the transportation vehicle in response to 
a lock command signal that may be generated following reception of a lock 
code if it is received with a valid user code. Door position sensors 
associated with the doors each generate a respective door-closed signal 
when its respective one of the doors is closed. A sound transducer, such 
as a car horn, produces an audible sound output in response to an 
energizing signal. A vehicle-mounted control module responds to a first 
occurrence of the lock code to (1) generate the lock command signal which 
is sent to the door lock actuators, and (2) enter an armed state if each 
of the door position sensors produces a door closed signal. The control 
module is further responsive to a second occurrence of the lock code 
received within a predetermined time of the first occurrence of the lock 
code to generate a first energizing signal to produce a first audible 
sound output if the lock command has been sent and each of the door 
position sensors produces a door-closed signal, or to generate a second 
energizing signal to produce a second audible sound output if at least one 
of the door position sensors fails to produce a door-closed signal. The 
control module does not produce any energizing signal absent the second 
occurrence of the lock code.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to FIG. 1, a vehicle-mounted remote anti-theft module 10 contains 
electronics for performing remote entry and anti-theft functions as are 
well known in the art. A speaker or car horn 11 is connected to module 10 
to receive an energizing signal for producing beeps or horn chirps as are 
described below. Likewise, exterior lamps 18 are coupled to module 10 for 
producing visible flashes under control of module 10. Module 10 is 
connected to an antenna 12 for communicating with a remote transmitter 13 
having its own internal antenna 14. Module 10 is further connected to a 
door module 15 and provides lock and unlock command signals to door module 
15. In turn, door module 15 actually locks or unlocks an appropriate 
vehicle door via a respective lock actuator 16. 
Remote transmitter 13 includes a plurality of push buttons including a lock 
push button 17. When lock push button 17 is manually activated, a coded 
signal is sent from remote transmitter 13 through a radio frequency signal 
to module 10, which recognizes the coded signal and locks vehicle doors 
via a lock command signal to door module 15. Preferably, upon locking of 
the vehicle doors, module 10 enters an anti-theft mode and attempts to arm 
the anti-theft system. 
The RF signal transmitted from remote transmitter 13 includes at least two 
data segments, namely a user code that will identify whether the 
transmitter is authorized for vehicle entry and a function code (e.g., the 
lock code) identifying which push button was pressed. 
Perimeter protection is provided by a plurality of door position sensors 
comprised of door switches 20-23, each associated with a respective 
vehicle door. When authorized remote transmitter 13 transmits a lock code 
in response to depressing lock button 17, remote anti-theft module 10 
locks the vehicle doors and then enters a pre-arm state in which a 
ready-to-arm indicator light on the vehicle instrument panel is 
illuminated and the opened/closed status of the vehicle doors are checked. 
Thus, door position sensors 20-23 are checked to determine whether all the 
doors are closed, and if not all doors are closed then module 10 waits in 
the pre-armed state until they are all closed. Once all doors are closed, 
a predetermined exit delay, e.g., 30 seconds, is begun. The exit delay is 
necessary since the door lock command may have been initiated from within 
the vehicle and time may be needed to allow the occupants to leave the 
vehicle. After this exit delay, the system becomes fully armed and any 
change in condition of a door position sensor from a door-closed signal to 
a door-opened signal results in a siren signal from horn 11. 
The present invention provides on-demand audible and/or visual verification 
of anti-theft system operation as follows. Such audible or visible 
verification is initiated using a unique button sequence on remote 
transmitter 13, but no audible or visible verification is provided without 
such a specific request by the user. In a preferred embodiment, the unique 
button sequence is comprised of a second occurrence of a transmission of 
the lock code from the portable transmitter within a predetermined time of 
the first transmission of the lock code which initiated locking of the 
vehicle doors. The predetermined time may be about five seconds. Thus, if 
a second lock code is received within five seconds of the initial lock 
code, an audible verification is made to identify the state of the 
anti-theft system, i.e., whether the anti-theft system is successfully 
entering an armed state. The ability to enter an armed state depends upon 
the closing of all perimeter doors as indicated by door position sensors 
20-23. One distinctive audible sound indicates that all doors are closed 
and that arming of the anti-theft system is successful, and a second 
audible sound, different from the first, indicates an open door and 
unsuccessful arming of the anti-theft system. In a preferred embodiment, a 
single horn chirp indicates that the anti-theft system is arming while a 
double horn chirp indicates an inability to arm. Anti-theft module 10 
provides an energizing signal to transducer 11 to produce the chirps. A 
chirp preferably is obtained by sounding transducer 11 for about 1/20th of 
a second at the normal operating frequency of the horn. The double chirp 
comprises two successive 1/20th of a second horn chirps separated by about 
1/3rd of a second. Thus, a first energizing signal from module 10 for 
producing the first audible sound is comprised of an alternating voltage 
signal with a duration of 1/20th of a second. The second energizing signal 
is comprised to two successive alternating voltage signals, each with a 
duration of 1/20th of a second. If visible flashes are given for 
verification, then similar times are used for flash duration and 
separation. 
The sequence of operation of the present invention is shown in greater 
detail in the flow chart of FIG. 2. The flow chart illustrates a preferred 
subroutine to be implemented in a microprocessor contained within 
anti-theft module 10 and begins at a start block 20. In step 21, a first 
lock code is received from the remote transmitter after manual activation 
by the user of a lock push button. The doors are locked and a timer is 
initiated to distinguish a second lock code transmitted within a 
predetermined time of the first lock code. After the lock commands are 
sent to the door modules, the remote anti-theft module illuminates a 
ready-to-arm indicator light in step 22 to inform the vehicle operator 
that the anti-theft system is attempting to arm (i.e., it enters a pre-arm 
state). 
A check is made in step 23 to determine whether the door position sensors 
indicate that all doors are closed, which would allow perimeter protection 
to be initiated. If door-closed signals are received from all door 
position sensors, then a check is made in step 24 to determine whether a 
second lock code was transmitted within the predetermined period of time. 
If the second lock code was received within five seconds, then the vehicle 
horn is chirped once (and/or the lights are flashed once) in step 25, 
otherwise step 26 is executed. If the second lock command was not received 
within five seconds, then the horn chirp (and/or light flash) of step 25 
is bypassed. 
In step 26, an exit delay of a predetermined time, such as thirty seconds, 
is established to allow opening and closing of a door without triggering 
an alarm siren. Thus, the exit delay in step 26 allows time for a person 
to leave the vehicle or to retrieve an item after having exited the 
vehicle without disturbing the anti-theft system. After the exit delay, 
the anti-theft system becomes fully armed in step 27 and the method is 
completed and exited in step 28. 
If a door is not closed after the doors have been locked from the remote 
fob ("fob" refers to a keychain transmitter), either because a door is 
ajar or a door position sensor is faulty, then perimeter protection is not 
possible. Thus, in step 23, if it is determined that door-closed signals 
have not been received from all door position sensors, a check is made in 
step 30 to determine whether a second lock code was received within five 
seconds. If it was, then a double horn chirp (and/or a double light flash) 
is produced in step 31 by appropriate energizing signals from the 
anti-theft module to the horn to inform the vehicle operator that arming 
of the anti-theft system is not possible. If the second lock code was not 
received within five seconds, the double horn chirp (and/or double light 
flash) is bypassed. 
In step 32, a check is made to determine if all the doors have become 
closed since the last check of the door position sensors. If they are not 
closed, then a check is made in step 33 to determine whether a 
predetermined time, such as thirty minutes, has elapsed since the 
reception of the lock code from the remote fob. If not, then the door 
position sensors are again checked in step 32. If it is determined in step 
33 that all doors have now been closed, then the exit delay is initiated 
in step 26 followed by fully arming the anti-theft system in step 27. If 
30 minutes elapses without the closing of all the doors, then the 
pre-armed state is cancelled (i.e., the ready-to-arm light is 
extinguished) in step 34 and the method is exited in step 35. 
In summary, the present invention has provided for on-demand remote 
controlled verification of the operation of an anti-theft system. 
Different audible sound outputs, such as horn chirps, or different light 
flashes, identify the state of the anti-theft system. In particular, one 
chirp sequence or light flash sequence identifies a locked and arming 
vehicle while another chirp sequence or light flash sequence indicates the 
inability to arm the anti-theft system. The user is provided with a 
convenient method for indicating whether confirmation is desired at the 
time of initiating the arming sequence, thereby allowing the user to 
obtain the verification in a proper environment but avoiding the 
verification in environments where the disturbance inherent in the 
verification is not desired. If verification is desired more than five 
seconds after having issued the first lock code, the user is able to 
transmit a new pair of lock codes within five seconds of each other, so 
that the lock, arming, and verification sequence of FIG. 2 will be 
repeated.