FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
Complete Specification
'VEHICLE SECURITY SYSTEM"


Mahindra & Mahindra Limited An Indian Company, R&D Center, Automotive Sector, 89, M.I.D.C, Satpur, Nashik-422 007, Maharashtra, India.

The following specification particularly describes the invention and the manner



in which it is to be performed

Field of the Invention:
The present invention relates to a vehicle security system. More particularly the present invention relates to an engine security system which prevents an engine from starting unless a valid code is received by the system.
Background and Prior Art Search:
Many devices have been developed to increase vehicle security such as additional locks, steering wheel, gear lever or handbrake clamps, alarms and immobilizers. However, such devices are often employed to deter the opportunist thief and can be removed or bypassed by professional or determined thieves.
United States patent no. US 5615649 discloses an engine security system adapted to receive a sequence of timing pulses which is generated in dependence on the rotation of the engine. The device generates an ignition pulse sequence synchronous with rotation of the engine from the sequence of timing pulses on receipt of an enabling code. The pulses in timing pulse sequence occur at different times from pulses in the ignition pulse sequence. The sequence of timing pulses includes an identity code encoded therein.
This system uses radio frequencies to prevent turning on/off the engine in conjunction with other security systems.
Chinese patent no. CN 101042781, US patent application No. US 20070222293, Japanese patent application no. JP 2007253728 and UK patent no. GB 2436372 describes a vehicle security apparatus equipped with an immobilizer ECU, a remote security ECU, a communication ECU, and the like. The immobilizer ECU controls prohibition and permission of a drive operation of an engine based upon an identification signal transmitted from an electronic key. The immobilizer ECU also controls prohibition and permission of the drive operation of the engine based upon a remote set signal and a
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remote unset signal, which are transmitted form a base station. In a case that the immobilizer ECU permits the drive operation of the engine based upon the identification signal of the key, even when the remote set signal is outputted, the immobilizer ECU maintains to permit the drive operation of the engine.
This is a complex system with dual security; it has a key with transponder plus remote security ECU. The system is used to put engine of a vehicle out of action after the vehicle has been stolen / operated by unauthorized person.
Korean patent application No. KR 20020006102 discusses about a theft prevention system of a vehicle provided to limit the starting of an engine if an ECU (Engine Control Unit) for an immobilizer is replaced with one for a non-immobilizer, by deciding if the current ECU of a vehicle is for an immobilizer or a non-immobilizer. The system consists a starting key having a transponder having specific pre-input code data; a key cylinder accepting the starting key; an ECU for an immobilizer deciding agreement of specific input code data of the transponder with the pre-input input code data; a discrimination unit transmitting/receiving signals with the immobilizer ECU to decide if the current ECU is for an immobilizer; and a starting unit operating a starting system of an engine by control of the immobilizer ECU if the current ECU is for an immobilizer. Even though a vehicle is stolen and an immobilizer ECU is replaced with a non-immobilizer ECU, the ECU does not output specific voltage of 5V to the starting unit by the discrimination unit. Thereby, the engine is not started.
United States patent No. US 7358849 discloses a vehicle anti-theft system which includes a Microcontroller and associated radio frequency receiver/transmitter installed within a vehicle. The Microcontroller is operatively connected to the engine control unit and the existing security system. The vehicle transmitter continuously transmits an interrogating signal within a given transmission field. A remote unit includes a transmitter and a receiver that are in discrete communication with the vehicle receiver and transmitter whenever the remote is within the transmission field. If the remote
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is outside the transmission field and is therefore unresponsive to the interrogating signal, the Microcontroller initiates various security measures such as locking doors, disabling engine and arming the security system. When the remote carrier re-enters the transmission field, the interrogating signal triggers an authorized, encoded response from the remote causing the Microcontroller to reverse each of the security measures to prepare the vehicle for routine operation.
US patent No. 5539260 describes a security system for an automotive vehicle. The system has lock switch operator having a memory device carried thereon with a first security code stored in the memory device. A theft control module having a memory storing a second security code is operatively connected between the switch and the engine running electrical devices. The theft control module operates to first permit the engine running electrical components to enable the starting of the engine and then to compare the first and second security codes. Upon finding the first security code not equal to the second security code, the engine running electrical components are disconnected from the electrical power source which disables the engine..
US patent No. 7034654 describes engine immobilizer security system for ensuring that a motor vehicle is being operated by an authorized operator. The apparatus includes and ECU, an engine immobilizer unit and a shared encryption key. The ECU generates a challenge by combining the output of a pseudo-random number generator and the output of a some what random number generator and cycling the combined number through a linear feedback shift register. The ECU uses the same key to encrypt the challenge and compares the encrypted challenge to the response. If the response matches the encrypted challenge, engine operation is enabled.
Deficiencies of Prior Art:
• Most of the prior art concept uses wireless communication in the system and the code entry is through keypad.
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• The prior art systems have transponder in the key which may permit the thief to operate the vehicle provided he procures a key of the vehicle.
• Prior art system uses radio frequencies for its operation.
• The vehicle security systems available in the public domain are vulnerable to theft or come into play after the vehicle has been stolen.
• Most of the prior art vehicle security system uses two track key and none of the prior art systems have code logging lever embedded in combination switch.
Objects of the Present Invention:
The main object of the invention is to provide full proof engine security system to guard vehicles against the theft such that engine cannot be started unless and until the security code is logged and it matches with the reference code registered with the Microcontroller the system.
Another object of the invention is to provide an extra level of security by allowing the vehicle engine to crank only through a personalised password.
Still another object of the invention is to provide simple mechanism built inside the third stalk of the combination switch to log the security code.
Yet another object of the invention to provide personalized and low cost engine security system for automotive vehicles and like. Accordingly the present invention provides a vehicle security system comprising microcontroller circuit to receive a first input from a the ignition switch to sense the vehicle start and stop; a code logging combination switch connected to a reference voltage source having three voltage levels for
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selecting any one of said voltage levels and switching on the said selected voltage level as a second input to the said microcontroller through a signal conditioner and anlog -digital converter; an engine management system communicating to said microcontroller to receive and check a variable bit key generated by an algorithm in the said microcontroller to activate or deactivate an immobiliser module for operation of fuel pump; a relay unit for switching on/off battery supply to the starter motor is connected microcontroller; and a display console connected to the microcontroller to view instruction during logging code
Detailed Description of the Present Invention:
For better understanding of the description of the present invention, drawings are enclosed wherein a practical embodiment of the engine security system is shown.
Description of figures accompanying drawings are as follows:
Figure 1A shows schematic block diagram of an embodiment of vehicle
security system according to the present invention,
Figure 1B a circuit diagram showing various components inter connection as
per the present invention
Figures 2A&2B show a lever embedded with a code logging switch with its
operable positions.
Figure 3 & 4 are the flow charts explaining the operation of an engine security
system in accordance with the present invention described herein.
Referring to figure 1A the block diagram showing various component which
are as follows.
The positive Battery terminal
This terminal is used for power input as well as to sense the battery terminal.
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If the battery terminal is cut off, the security system is activated. The microcontroller does the following operations if the battery terminal is cut off or not sensed:
1. Starter motor relay cut off
2. Deactivation of fuel pump by EMS
3. Activation of the GPS unit
4. Activation of the communication system
This terminal is used for power input as well as to sense the battery terminal. If the battery terminal is cut off, the security system is activated. The microcontroller does the following operations if the battery terminal is cut off or not sensed:
5. Starter motor relay cut off
6. Deactivation of fuel pump by EMS
7. Activation of the GPS unit
8. Activation of the communication system
Sensor Module:
The reference voltage used herein is 5 V. This device uses three voltage levels currently 0,2.5,5V for detecting three positions of the third leyer of the combination switch. The lever has a code logging switch to enter the code into the security system.
The code logging switch used here is for three different function as per the state of the system. The three different states of the system are described as follows:
1. The lever is used for entering the through code logging switch normally while entering the code after turning the Ignition ON.
2. The lever is used for activating the system after it is turned OFF. This activation of the security system is done by keeping the lever in top position & pressing the code logging switch for more than 3 seconds.
3. The lever is used for changing system configuration settings after the engine is turned ON by the security system. This is done by keeping the lever in top position & pressing the code logging switch for more
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than 3 seconds thus allowing the driver to change the security system code or turning the security system OFF.
In future applications the reference voltage used here can be increased up to 12 Volts or decreased as per the application. Also the number of positions of the combination switch can be increased as per the requirement.
Ignition Switch:
The ignition switch will send a signal to the microcontroller when the ignition is
turned ON & turned OFF.
Steering wheel lock solenoid:
The steering wheel is locked through a solenoid. This solenoid is actuated by
the microcontroller when there is a mismatch in the code entered.
Alarm:
The alarm is activated whenever the security system is activated due to mismatch in the code entered.
EMS:
The Engine Management System (EMS) communicates to the security system microcontroller over CAN. The microcontroller generates a variable bit key generated by an algorithm which is present in both the security system microcontroller & the EMS. This key is sent by security system microcontroller to EMS over controller area network(CAN). This key is verified by the EMS for activating the fuel pump.
In the event of code mismatch or tampering of the battery cable the security system microcontroller does not send this key thus preventing the fuel pump from getting activated thus preventing engine from starting.
GPS (Global Positioning System) Unit:
The GPS unit is activated by the security system upon the mismatch in the code entered or tampering of the battery signal.
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The GPS unit when activated will start sending a signal to the main station through a satellite. The GPS unit will send the vehicle location to the main station where the location of the vehicle can be found out. Communication System:
The communication system when activated starts a voice call to the owner to alert the owner of the intrusion inside the vehicle. This voice call can be sent to the vehicle owner, owner's relative as per the phone numbers entered into the system.
Referring to Figure 1B, the vehicle security system (1) comprises of a lever (2) with a code logging switch (3) embedded in it, connected to input of signal conditioning unit (4), which is connected to input of Analog-Digital converter (5), for sending digital output to Microcontroller or ECU (Engine control unit) (6). An ignition module (7) connected to the said microcontroller to make enable/disenable the start of engine. EMS (Engine Management System) (8) and immobilizer unit (9) is connected to activate/deactivate fuel pump. The said code logging switch is spring biased, normally open, push type operation. The said lever (2) is operable in three positions namely top position (2a), middle position (2b) and bottom position (2c) to select three voltage levels as shown in Figure 2, in the third stalk of the combination switch generally used in automotive vehicles. A code logging switch (3) on lever (2) is responsible to enter the code into the system (1). Signal conditioning unit (4) acts as an intermediate stage between the signal to be processed and the A/D converter (5). It involves the amplification and attenuation of a signal to "prepare" it for the next stage of processing. The different positions of the lever (2) are differentiated through different voltage levels. These Voltage levels are given to signal conditioning unit (4) before feeding to A/D converter (5). The Analog to Digital Converter (5) converts the input analog voltage to digital voltage to be fed to the Microcontroller (6).
The Microcontroller (6) has two main inputs. One is from ignition battery switch for sensing engine on/off condition and other is write signal from the code logging switch. A display console is connected to the said
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microcontroller for display of instruction during logging code. The
Microcontroller (6), which is the ECU of the security system, executes the
following actions. (Fig.3&4)
Step 1: Checks the Write Signal from Code Logging Switch. If it is high, then
it executes step 2. else "Do Nothing".
Step 2: Get the Digital voltage from the A/D Converter (inbuilt into the
microcontroller).
Step 3: Find the Voltage level by comparing this data with the Look Up Table.
Step 4: Set the appropriate bits in the buffers.
Step 5: Repeat Steps 1 to 4 for three times.
Step 6: If the password matches with the password stored earlier, then send
a key to EMS ECU & ignition module to Start the Engine. Enable the starter
motor.
Step 7: If the password does not match then don't send key to EMS ECU
and Start the Alarm, Activate the GPS unit & communication system, Activate
the steering lock, deactivate the ignition module.
The system senses the input through the lever (2) of the third stalk of the combination switch. The lever position and code logging switch (3) is used to know whether the system has a valid input or not. The driver of the vehicle has to move the lever (2) manually by his hand and press the code logging switch to enter the correct password.
If the lever is in any of the three positions and a code logging switch is pressed, one bit of the password will get registered into the Microcontroller (6) of the security system (1). When the lever is in TOP position (2a) and the code logging switch is pressed, Code 3 gets registered. Likewise, when the lever is in MIDDLE position (2b) and the code logging switch is pressed, Code 2 gets registered and when the lever is in BOTTOM position (2c) and the code logging switch is pressed, Code 1 gets registered in the Microcontroller (6) of the system.
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This system has been currently designed to allow a password up to A digits.
This password can be entered by following the process described herein.
Keep the lever in any of the three positions and press the Code logging
Switch, the corresponding lever code will get registered. Repeat the process
three times by keeping the lever in any of the three positions.
Example: If a password '1231' has to be Entered:
Step 1: Put the lever in BOTTOM position and press the code logging switch.
The digit 1 gets registered with the Microcontroller.
Step 2: Put the lever in MIDDLE position and press the code logging switch.
The digit 2 gets registered.
Step 3: Put the lever in TOP position and press the code logging switch. The
digit 3 gets registered.
Step 4: Put the lever in BOTTOM position and press the code logging switch.
The digit 1 gets registered.
The length of the password can be increased depending on the level of security needed by the driver or the length of the password that the Driver is comfortable with. The three positions top (2a), middle (2b), bottom (2c) of the lever correspond to 5V, 2.5V and OV respectively.
The ignition module comprises of battery (10), relay switch (11) and starter motor (12). The purpose of the ignition module (7) is to turn on the engine through the starter motor (12). The Starter Motor (12) is operated by a relay switch (11). This relay (11) wiil be controlled by the ECU (6) of the security system, thereby controlling the starting of the engine. If the logged password matches with the reference password registered with the vehicle, relay switch (11) will be turned ON, otherwise it will be cut off from the starter motor (12).
Engine Management system(EMS) Immobilizer module (9) controls the fuel injection pump (FIP) (13) which controls the supply of fuel to the engine. If the logged password does not match with the reference password, fuel will be cut off from the engine, thereby preventing the engine from starting.
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Working of the system:
Step 1: Put the Key in Ignition and turn it to ON position.
Step 2: Driver will get a message on the Driver Information System Display "is
your Security Code Programmed?" If 'Yes' then proceed to step 3.
Step 3: Move the Combination Switch according to your Code.
Step 4: Microcontroller (6) checks the code whether it is matching with the
programmed code.
If the code matches with the programmed code system will crank the engine. If the logged code does not match with the programmed code, the key is not sent to EMS which prevents the fuel supply to engine. The alarm, GPS unit, communication system, steering wheel lock solenoid is activated. The ignition module is deactivated.
If the Driver wants to Switch ON the security system again after turning it the engine OFF, the driver has to put the third stafk fever of combination switch in top position (2a) and has to press the code logging switch (3) for more than 3 seconds, the engine security system will turn ON.
It is to be understood by the person skilled in the art that the present invention is not limited in its application to the details of the construction and to the arrangements of the components as mentioned in the above description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, the terminologies used herein are for the purpose of description and should not be regarded as limiting.
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Advantages of Present Invention:
• It is a full proof, simple and low cost system for providing security to the engine cranking by an unauthorized user.
• It does not get affected by the loss of the key / RKE (Remote Keyless Entry) Remote.
• No Wireless communications and transponder based keys are required.
• PIN logging mechanism is simple.
• System does not require radio frequencies for its operation.
• Owner of the vehicle can set the password as per his convenience as and when required once he buys the vehicle.
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We claim:-
1. A vehicle security system comprising microcontroller configured to receive a first input from a the ignition switch to sense the vehicle start and stop; a code logging combination switch connected to a reference voltage source having three voltage levels for selecting any one of said voltage levels and switching on the said selected voltage level as a second input to the said microcontroller through a signal conditioner and analog-digital converter; an engine management system communicating to said microcontroller to receive and check a variable bit key generated by an algorithm in the said microcontroller to activate or deactivate an immobiliser module for operation of fuel pump; a relay unit for switching on/off battery supply to the starter motor is connected microcontroller; and a display console connected to the microcontroller to view instruction during logging code.
2. a vehicle security system as claimed in claim 1 wherein the said combination switch comprises a lever operating at three different position to select any of the three voltage levels corresponding to the position of switch and a code logging switch on top of the said lever to switch on the said selected voltage level.
3. A vehicle security system as claimed in claims 1 and 2 where the said lever is movable at three different positions includes top, middle and bottom position.
4. A vehicle security system as claimed in claim 2 wherein the said switch is embedded switch on top of the said lever for switching on the selected voltage level.
5. A vehicle security system as claimed in claim 2 wherein the said different voltage level includes 5v,2.5v and 0 v corresponds to top, middle and bottom position of the said lever.
6. A vehicle security system as claimed in claim 4 where in said embedded switch on lever is spring biased , normally open, push type operation.
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7. A vehicle security system as claimed in claims 1 to 6 wherein the said reference voltage sensor includes a potentiometer connected across a battery of 5 volt to select any of the one voltage level from 5v, 2.5v and Ov by moving the said \e\/er in different position.
8. A vehicle security system as claimed in claims 1 to 7 wherein the said signal conditioning unit comprises an amplifier and attenuator.
9. A vehicle security system as claimed in claims 1 to 8 wherein the said engine management system is communicating to the said microcontroller in the controller network area.
10. A vehicle security system as claimed in claims 1 to 9 wherein the said microcontroller provided with alarm system to safe guard tampering of security.
11. A vehicle security system as claimed in claims 1 to 10 wherein the said microcontroller is having access to communication network to communicate to the any telephone number registered therein if security is tempered.
12.A vehicle security system as claimed in claims 1 to 11 wherein the microcontroller is having access to GPS system for locating vehicle in case theft.
13. A vehicle security system as claimed in claims 1 to 12 wherein said microcontroller is given positive battery supply for power supply and for sensing of battery terminal so as to detect tampering battery terminal and activate security.
14. A vehicle security system as claimed in claims 1 to 13 and as herein described with reference to the drawings of the accompanying specification.
Dated this 25th Day of September 2008

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