FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"AUTOMATIC TURN INDICATION SYSTEM FOR AUTOMOTIVE VEHICLES"
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 DESCRIBES THE NATURE OF THE INVENTION AND MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION:-
The present invention is related to the field of automatic vehicle system. More particularly the present invention relates to an automatic turn indication system for automotive vehicles.
BACKGROUND OF THE PRESENT INVENTION:-
Now a day, automatic systems in automotive vehicles are adding to the comfort, safety and ease of drivers and passengers as well. When the driver of the vehicle want's to take a turn either to the left or right of the road, he has to manually put the turn lamps ON through combination switch. Otherwise, at the turnings, taking a turn without putting turn lamps ON may lead to the accidents / dash by the following vehicle. This situation may result in losing the lives of occupants of following vehicle as well as the leading vehicle. Every time prior to take a turn, switching ON the turn lamps may be bothersome to drivers of the vehicle. Therefore, the manual systems require the expert drivers who can sincerely perform the manual actions prior to each turn. Variety of automatic turn indication systems are available in public domain which has met with varying degree of success.
OBJECTIVES OF THE PRESENT INVENTION:-
The main object of the present invention is to provide automatic turn indication system for automotive vehicles.
Another objective of the present invention is to provide automatic turn indication system for vehicles wherein turn indication is achieved through inputs from steering angle sensor and Navigation system.
Still another objective of the present invention is to provide turn indication system for automotive vehicles wherein driver needs not to use combination switch stalk for left/right turn indication.

Still further object of the present invention is to provide automatic turn indication system wherein the system gets activated at turns without the intervention of driver.
STATEMENT OF THE INVENTION:-
Accordingly the invention provides an automatic turn indication system for automotive vehicles comprises of steering angle sensor (2) and navigation system (3) connected to an electronic control unit (ECU) through Controller Area Network (CAN) network, a controller area network a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other within a vehicle; the turn lamps indictor connected to the out put of said electronic control unit (ECU) through wiring harness; the said electronic control unit loaded with an embedded software programme as herein described and is configured to receive the messages from steering angle sensor and navigation system and process to give output signal to the turn on/off side indicator lamps.
BRIEF DESCRIPTION OF THE FIGURES:-
The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein
Figure 1 shows schematic diagram of the automatic turn indication system in accordance with the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION:-
Referring to figure 1, automatic turn indication system (1) for automotive vehicle comprises of steering angle sensor (2), navigation system (3), electronic control unit (ECU) (4) and turn lamps (5). The steering angle sensor senses the rotational movement of the steering angle. The steering angle sensor and

navigation system are connected to the electronic control unit through CAN network (6). CAN is a controller area network and it is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other within a vehicle. CAN is a message based protocol designed specifically for automotive applications. The electronic control unit is embedded with a particular logic to perform tasks as listed in the following paragraphs and is configured to receive the messages from steering angle sensor and navigation system; process it and then send the output message to the turn lamps. The turn lamps are connected to the electronic control unit through wiring harness (7). The turn indication lamps are mounted outside the vehicle on vehicle body with two lamps on front end corners and two lamps on rear end corners of the vehicle.
The feature automatic turn indication means the left/right turn indication is automatically turned on without driver intervention. The turn indication is shown to the external environment via the turn indicator lamps and side repeater lamps. When the system gets activated automatically at the turns, the turn indication is indicated to the driver of the vehicle also via the instrument cluster turn left/turn right telltales. This feature eliminates the need of driver to use combination switch stalk for left/right turn indication.
The turn indication is achieved through inputs from Steering Angle sensor and Navigation system provided in the vehicle. The Navigation system works by providing the turn left/right instruction to the driver. On setting the Navigation mode ON, the driver has to enter the destination location and from thereon the turn left/right indication is given by the Navigation system. The Automatic turn indication system uses turn left/right signal from Navigation system over Controller Area Network (CAN). The Automatic turn indication ECU receives the turn signal over CAN, processes it and switches ON the turn indicator lamps. The turn indicator lamps include turn lamps in headlamp and tail lamp, side repeater lamps, turns indication in instrument cluster/driver information system and any such indication which provides turn indication to the driver.

The Electronic control unit then waits till the turn is completed by the driver. After the turn is completed the ECU switches the turn indicator lamps OFF. The input for turn signal completion to the ECU is provided by the steering angle sensor. The steering angle sensor measures the rotational movement of the steering wheel and transmits it over CAN. The steering angle information over CAN is used by Automatic turn indication ECU. The steering angle is used to know whether the turn is completed or not. The steering angle is shown for a range from -780 (counter clockwise) to 780 (clockwise) degrees. When the driver goes for a turn in any direction there is a constant increase (either positive or negative) in the steering angle this shows that turn is on its process to the ECU. When the ECU senses a specified decrease in the steering angle it cuts off the turn indicator lamps. The decrease in the steering angle for ECU to cut off turn indication lamps is calibrate able.
Thus the above described system serves the purpose of automatic turn indication achieved through Navigation system and steering angle sensor. At any point of time if the driver does not want to follow the navigation system/turn indication, he can do so by a manual override. The manual override is provided by the combination switch stalk (8). The driver has to move the stalk to left/right turn indication position and get it back to the centre position. The ECU then detects this combination stalk movement to turn off the turn indication lamps.
For the vehicle not having Navigation system, the combination switch is used to turn ON the lamps and steering angle sensor message on CAN is used to turn +OFF the indicator lamps. The advantage over here is to avoid the self cancellation mechanism used in the steering wheel and clock spring.
There is always a possibility of driver not turning ON the turn indicator lamps while negotiating a turn. Also on highways while changing lanes the driver might not turn ON the turn indicator lamps. For such a case the Automatic Turn indicator system uses the steering angle sensor feedback for turning ON the turn lamps. The system uses steering angle to know whether the driver is actually take a turn, or changing lane. The system does it by detecting the change in steering angle & if it is above a certain limit the turn indicator lamps

are switched ON. The turn indicators are switched off when the system reads that steering wheel is returning to original centre position. This unique feature comes into action only when the turn indicator lamps are not switched ON by the driver or navigation system.
An embedded programme , loaded in the said electronic control unit, IS based on the following functional features,
• Receive input signal to electronic controller unit from the steering angle sensor at set angle and process to turn on/off side indicator lamps
• If navigation system present in the vehicle, receive input to electronic controller unit from the navigation mode if driver has set destination location and process to turn on/off side indicator lamp.
• The electronic controller unit to sense the manual over ride signal of combination switch operated by the driver to turn on/off side indicator lamps ;
• for the vehicle not having navigation system the combination switch to turn on side indicator lamps and steering angle sensor to turn off side indicator lamp;

WE CLAIM:-
1. An automatic turn indication system for automotive vehicles comprises of steering angle sensor (2) and navigation system (3) connected to an electronic control unit (ECU) through Controller Area Network (CAN) network, a controller area network a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other within a vehicle; the turn lamps indictor connected to the out put of said electronic control unit (ECU) through wiring harness; the said electronic control unit loaded with an embedded software programme as herein described and is configured to receive the messages from steering angle sensor and navigation system and process to give output signal to the turn on/off side indicator lamps.
2. An automatic turn indication system as claimed in claim 1 wherein the said steering angle is calibrate able to decrease in the steering angle for ECU to cut off turn indication lamps.
3. An automatic turn indication system as claimed in claim 1 wherein the said steering angle is set for a range from -780 (counter clockwise) to 780 (clockwise) degrees.