FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"STANDALONE UNIT FOR STATIC BENDING LAMP OPERATION IN A
VEHICLE"
MAHINDRA & MAHINDRA LIMITED
A COMPANY REGISTERED UNDER THE
PROVISIONS OF COMPANIES ACT, 1956
HAVIGN ADDRESS AT
R&D CENTER, AUTOMOTIVE SECTOR,
89, M.I.D.C, SATPUR,
NASHIK - 422 007,
MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES AND ASCERTAINS THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION:-
The present invention relates to automobile headlamps. More particularly the present invention is related to standalone unit for static bending lamps.
BACKGROUND OF THE PRESENT INVENTION:-
It is well experienced that driving at night times can be quite hectic as the ordinary headlamps do not trace the trajectory of the vehicle. This brought the idea of bending lamps; two different approaches have evolved for the same functionality, either to turn the light source or a projector, called dynamic bending and the second approach is to provide a secondary lamp at the corner focusing location for fulfilling the purpose. The present systems rely on the steering wheel sensor and the vehicle speed data for control. This requires the system to have a CAN transceiver module adding to the cost. In this paper, we will be focusing on static bending lamp in which the fixed-focus positioned lamp will be used for lighting the required area, moreover this gives design a more robustness and cost beneficial control system for the static bending lamp. This paper presents a novel idea of a standalone system capable of providing the functionality at a reduced complexity and cost.
STATEMENT OF INVENTION:-
Accordingly the invention provides a standalone unit for static bending lamp operation in a vehicle comprises a pairs of magnetic sensors placed on the steer axle near the end of both the wheels; a magnet fixed on wheel turning brackt such way that turning wheel makes magnet to align with first sensor and then to second sensor thereby activates the said sensors to send the signals a microcontroller consisting of a low pass filter to rceive said signals from the sensors, a debugging unit connected to the said filter output, an ADC unit connected to the out put of said debugging circuit, and a logic unit receive the digital output from thr ADC unit to effect static turning of lights at turning of wheel.

BRIEF DESCRIPTION OF FIGURES:-
Figure 1 shows visibility profile by the headlamps of a vehicle while turning during
night hours.
Figure 2 shows two sensor & microcontroller type Steering angle sensor of the
conventional bend lighting system.
Figure 3 shows Potentiometer type steering angle sensor of the conventional
bend lighting system.
Figure 4 shows mounting position for the sensor in accordance with the present
invention.
Figure 5 shows the Magnet passing-by Switch S1 (turning it OFF) and then
passing by S2 (turning it ON) in accordance with the present invention.
Figure 6 shows schematic arrangement of the sensors in the vehicle in
accordance with the present invention.
Figure 7(a) shows as the magnet is aligned with S1, turns it OFF and Figure 7(b)
shows as the magnet is aligned with S2, turns it ON.
Figure 8 shows working flowchart of the system as per the present invention.
Figure 9 shows the preliminary circuit diagram of the system.
Figure 10 shows the debouncing counter of the present invention.
DESCRIPTION OF THE PRESENT INVENTION:-
Noticing and getting noticed while using road transport are fundamental prerequisites for the safety of all road users. Inadequate visibility is an important factor that increases the risk of a road crashes among all types of road user. In low and middle income countries, the poor visibility of pedestrians and vehicles because of low lighting is a serious problem. The presence of motorized and non-motorized traffic on road, together with poor street lighting, increases the risk for unprotected road users who are not practically in focus of light or are not being noticed. The extent, to which poor visibility increases the count of road traffic crashes, varies between countries and the level of development of roads.

As per the European research, one-third of the casualties with the pedestrians' were because of difficulty in noticing the vehicle passing nearby them, while two-fifth of drivers had difficulty in noticing the pedestrians. A large proportion of pedestrians' and cyclists' collision with on road vehicles in low-income countries occur during the night time and because of poor street lightings. In the developing countries, the rural and sub-urban roads still are not having proper street lights and road turn reflecting indicators, which results in around 2000 deaths annually, a quarter of all deaths due to road accidents. However, thorough research in this area is quite limited.
This invention provides a concept for design engineers and vehicle manufactures to consider a low cost technology to enhance the visibility at turning roads, So that even in the low end vehicles better visibility is delivered. Here more focus is given on standalone sensing unit.
There are different techniques for the operation of static bending lamp, parallely, using speed sensor and steering angle etc as inputs.
Referring to Figure 2, Two sensor & microcontroller type Steering angle sensor used in bend lighting is shown.
• For Left lamp to Turn ON and Right lamp to turn ON, Sensorl & Sensor 2 (Hall Effect, MR) respectively.
• Generated signal is amplified and filtered.
• Analog signal is then converted to digital, using ADC in microcontroller.
• The logic is checked, if Satisfied, the turn ON signal is given to respective side relay to turn on the lamp.
Referring to figure 3 that shows Potentiometer type steering angle sensor of the bend lighting system, is used for giving this safety feature at present.
• Inside the housing, potentiometer is packaged in circular pattern.
• Output is taken from the Connector terminals coming out.
• Microcontroller is for logic matching and filtering
• As per the rotation, the output voltage changes, giving the exact angle positions.

In the present invention, Firstly, in conventional systems the steering angle sensor will be giving continuous input to the body control system for the operation of the lamps. The calibrated angle for the steering angle will be taken as input for the operation of the static bending lamp. For the low end vehicles the cost of the steering angle and the body control module will be too much to accommodate.
The system since being a part of automotive safety should be fail proof and work flawlessly along the varied conditions that could occur while driving. Thus the system should be stable, robust and immune to noise and other errors in the environment. This can be achieved by filtering out the errors and providing a robust control algorithm. Our proposed system consists of magnetic reed switch placed on the steer axle near the end of both the wheels. The sensing is done through two reed switches which sense the direction of the wheel, the sensors are placed as shown. These are actuated by a magnet which moves along with the turning of the wheel. When the magnet passes by, the reed switch is closed and a voltage is received by the controller. And this in turn controls the static bending lamps on the sides.
The logic programmed into the system is, S1 turns the lamp off and S2 turns it on. When the vehicles is in straight condition and then is turned and magnet reaches S2, which is responsible for turning the lamp ON and when it reaches till S1 the lamp is turned OFF. When the vehicle is steering back thus the wheels are returned back, the magnet travels the return path. And when it reaches S1 lamp is turned off. The two sensor arrangement provides redundancy as well as prevents the system from going into unwanted states. This arrangement also prevents the lamps from being turned on unnecessarily in case of small changes like in lane. The position of sensor S1 & S2 to be calibrated in vehicle for the best performance.
A normal operation of the system, when vehicle takes a right turn, is explained in figures 7 (a & b). When the vehicle is taking back the turn, thus the magnet is aligned with S1, turning it off.

The implementation of the system would include a dedicated microcontroller for the system. This also helps to enhance the changes in the signal making it easier to process. The second module is a low pass filter whose purpose is to filter out high frequency noise from the signals. This prevents the system from erratic behaviour, at this level the module only takes care of high frequency signals and not the signals of frequency range similar to the input. This is done in the next module called debouncing module. That will come in the error detection system.
Since it is a dynamic system, changes happen very often thus noise and random signals also should not go to the system. To prevent this, a two stage approach of error detection is designed. This will filter out the error and prevent erratic behaviour of the system. This is of no consequence in ordinary systems. But when a microcontroller working at 8 MHz or more comes in the system. Each bounce will be treated as an individual input, giving unpredictable results.
The debouncing unit, considered in the system is a software debounce, programmed inside the microcontroller. This works with time debounce principle i.e. the input signal from the sensor is not taken as such. It is passed through a debounce system which does not pass it to the next level unless the signal persists for a certain defined debounce period. In this time debouncing an up down strategy is used, i.e. even with the time delay a debounce counter determines the passage of the signal to the next level.
It will be initialized with zero and starts' counting up till a signal is received, and once the counter reaches a threshold value (the debounce limit) the input is passed to the next stage of the system. And if the signal goes in, before reaching the threshold, the counter starts to count down and eventually reaches zero, if not activated again by an input signal. This prevents the system from taking-in the random values which are damaged due to noise.
The second stage is the signal range check. The basic idea of this module is to restrict the specific range of signal from coming, i.e. for 0 to 5V system, the signal range will be limited to 0.5 to 4.5, thus short circuit to ground producing 0 V as input can be identified. This simple and effective system prevents as detecting

short circuit to ground as well as short circuit to battery conditions. This is implemented by adding circuitry to the reed switch to make the two states as 0.5 V and 4.5 V, corresponding to ON and OFF conditions. These signals are connected to the ADC (analogue to digital converter), after the debounce stage they get changed to digital values, but before being fed into the logic system, it is checked for bounds. If it lies within bounds, the signal is allowed to go to next module, unless it discards the measurement.
The third stage is the logic stage, after passing through the error checks the signals from two sensors are taken in to the logic stage where the process happens. The system is designed to implement the logic of a SR flip-flop. i.e. one sensor sets the light, i.e. turns the lamp on while the other sensor resets, i.e. turns off the lamp. In the current paper set is used synonyms to turning on and reset to turning off. While turning, the magnet which actuates moves from inner to outer. The magnet first passes over sensor one, which resets the lamp, and on further turning, it reaches the second sensor which sets the lamp. Thus unless it is turned to a minimum threshold degree, the lamp is not turned on. And on the return path the other sensor will turn the light off. The two sensor arrangement works well in all conditions and irrespective of the situation turns the lamp on and off as required.

WE CLAIM:-
1. A standalone unit for static bending lamp operation in a vehicle comprises a pairs of magnetic sensors placed on the steer axle near the end of both the wheels; a magnet fixed on wheel turning brackt such way that turning wheel makes magnet to align with first sensor and then to second sensor thereby activates the said sensors to send the signals to a microcontroller consisting of a low pass filter to rceive said signals from the sensors , a debugging unit connected to the said filter output, an ADC unit connected to the out put of said debugging circuit, and a logic unit receive the digital output from thr ADC unit to effect static turning of lights at turning of wheel. . .
2. The stand alone unit as claime in claim 1 wherein the said logic unit consists a SR flip flop circuit to effect one sensor sets the light and other sensor resets light.
3. The stand alone unit as claime in claims 1 and 2 wherein the said debugging cuircuit is a software programmed to detect signal through counter from initial value to threshhold value inside the said microcotroller in such way that the signal does not pass through to the next level unless the signal persists for a certain defined debounce period.
4. The stand alone unit as claime in claims 1 to 3 the said low noise filter restricted incoming signal pass through a range 0.5v to 4.5 v.
5. The stand alone unit as claime in claims 1 to 4 wherein the said sensors are reed relays.