FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
{SEE SECTION 10; RULE 13)
"ADAPTIVE VOLUME CONTROL AND ONLINE COMPENSATION SYSTEM IN AUTOMOTIVE VEHICLE"
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 PATICULARLY DESCRIBES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION
The present invention relates to entertainment system in automotive vehicles. More particularly the invention relates to the intervention and modification of the music signal to the audio system so as to selectively reduce the effect of noise in the environment without obstructing the user's interaction with the same environment.
BACKGROUND OF THE PRESENT INVENTION
Automotive vehicles work in the environment which is generally surrounded with ambient noise comprising the road noise, wind noise, engine noise, other radios, audible out- put and talking. In such environment if the audio system of the vehicle is tuned ON, the user/occupant of the vehicle has to adjust its volume very often to overcome the ambient noise level. As the ambient noise level keeps on changing with the driving conditions, the user will have to frequently adjust the volume of the audio system. In order to overcome this burden, there exist some systems which will increase the gain of the music along with the increase of noise component. But these systems will try to suppress all the signals which are not identified as the music produced by the audio system. This can cause certain degree of discomfort to the user as the sounds which are required will also get masked. In case of automobiles the certain audio feedback from the driving environment is necessary to ensure safety. The sound of horn/siren should be audible for the driver in order to take the necessary action if required. Also in cases when any of the users gets a phone call, the music volume will have to be turned low before being able to attend the call.
Along with the feed back from the traffic, some critical audible feedback from the vehicle, which might indicate malfunctions, are also cut out from the user when the music is on. Thus there is a requirement of intelligent action of the audio system by identifying which all sounds are required and which all needs to be suppressed along with identifying cases when volume of music should be turned down.

Currently there are many auto-manufactures providing noise compensation along with their music systems so the quality of the music is not hampered by the engine noise or traffic. These systems reduce the effect of noise by boosting certain frequency bands of the music to over come the effect of noise. Though the quality of the music gets improved with system, the driver will have a very less feedback from his driving environment. In instances when there is an ambulance approaching or a vehicle horning, these sounds are not easily recognised by the driver (especially when the volume is high).
The drawback of not able to identify the horn sound of the other incoming vehicle can be over come when there is a special algorithm to recognise horn/siren and take the corrective action of reproducing the same siren sound through Audio signal, i.e. When ever there is some siren sounding near the vehicle, it will be reproduced by the system through the audio system of the car aptly.
OBJECTS OF THE PRESENT INVENTION
The main objective of the present invention is to provide intelligent adaptive volume control and online compensation system for automotive vehicles.
Another objective of the present invention is to provide intelligent adaptive volume control and online compensation system which is configured to adaptively control the gain of music signal by identifying the noise level within the environment/cabin and adjusting the music signal adaptively to maintain the signal to noise ratio within the defined band.
Another objective of the present invention is to overcome the drawback reduced audibility of the sounds which are required by the user.
Still another objective of the present invention is to provide intelligent adaptive volume control and online compensation system wherein the sound of a

horn/siren, mobile phone ring-tone etc. are not suppressed by the system, instead they are reproduced by the system aptly through the audio system.
Still further objective of the present invention is to overcome the technical drawbacks of the prior art systems.
STATEMENT OF INVENTION
Accordingly the invention provides An adaptive volume control and online compensation system in automotive vehicle comprising a controller unit having digital signal processing unit provided with an external signal sensor means fitted at out side the vehicle to sense outside sound signal and an internal signal sensor means fixed inside the vehicle to sense internal sound signals; a loud speaker through an amplifier connected to the out put of the said digital processor; an artificial neural network implemented in the control unit to enable recognise set signals accordingly to reproduce or to suppress or to lower the out put level if signals of (earning technique detected; an embedded software loaded in the said control unit as per the algorithm as ■herein described with reference figures of drawings such that the sound signals received through the said external and internal signal sensors are classified and fed to the said Artificial neural network and after identifying send vehicle noise to DIS for warning, recognise external noise such as horn/sirens to reproduce and suppress if cabin noise such as mobile ring.
DESCRIPTION OF THE FIGURES
Figure 1 shows adaptive volume control and online compensation system on the vehicle.
Figure 2 shows schematic of adaptive volume control and online compensation system in accordance with the present invention.
Figure 3 shows the working of outside microphone distinguishing the source of the sound (from vehicle or external sources).

Figure 4 shows the working of System training module in accordance with the present invention.
Figure 5 shows the operational flow chart of adaptive volume control and online compensation system
DETAILED DESCRIPTION OF THE PRESENT INVENTION
Referring to figure 1 the vehicle is provided with internal and external micro phones for sensing internal and external sound signals. The said microphones are connected to the digital signal processing unit of controller unit as indicated in figure 2. An adaptive volume control and online compensation system comprises of external microphone, internal microphone and digital signal processing unit. External microphone picks up the noise signals generated outside the vehicle, internal microphone captures all the audible sounds in the passenger compartment. Digital signal processing unit processes all the inputs and takes the required actions to effectively deliver the output.
In figure 2 digital processing unit is loaded with embedded software base noise classification algorithms as per the flow diagram of figures 3.and 5 and Artificial Neural Networks (ANN) programmed as per the flow diagram of figure 4 the out is classified and out of the said digital process is (a) vehicle noise is fed to DIS if inconsistent with expected data send error to DIS as warning to driver to check vehicle functioning, (b) external noise sent to loud speaker through the comparator recognise horn/siren to reproduce them and (c) cabin noise suppression by the set program of the said software. This is clearly illustrated in figure 5.
The microphone in the vehicle will in the vehicle will capture all the noises/sounds within the passenger compartment. Referring to Fig. 3, the microphone place outside will help in distinguishing the source of the sound (from vehicle or external sources). The signals captured by the microphones

are compared with the output of the audio system which will help to recognise the unwanted signals. The effect of these unwanted audio signals will be masked by the audio system output to generate better quality of music. This is done by increasing the relative loudness of certain freq. bands of the music so that the effect of the noise is reduced.
There are two modes of operation for the system, which are (a) System Training and (b) System Running. In System training mode we will train the neural network to recognise the horn/siren signals and mobile phone ring tones. Once the patterns for these signals are obtained, the system will be able to distinguish sirens, horns and ring tones form the ambient noise present in the microphone input. System running mode is the regular operating mode of the system. This mode will work effective only after the system training is done. The output of this mode of operation will depend on the system training. Thus system training may be carried out if change is system running is desired.
Special algorithms for identifying these signals will be implemented in Artificial Neural Networks (ANN). The pattern of the required signals will be fed to the system by the learning techniques of ANN. If the noise signal matches to the learnt ring tones then the audio signal is automatically lowered there by allowing the user to speak without any intervention to the audio system or when ever there is some siren sounding near the vehicle it will be audibly reproduced for the driver. Another objective of the invention is an external MIC fixed out side of the vehicle. This will be used to extract the horn or siren sound present in the environment.
.The vehicle internal noise which is coming inside the passenger compartment is being masked using audio system by increasing the audio signal gain to maintain the SNR within the desired range. This will reduce the effect of all the unpleasant noises for the passengers when the audio system is on. When there is horn/siren from external vehicle then the audio signal strength is lowered and the horn/siren sound is reproduced through the same audio

system. This will improve the distinguish ability of these sounds for the driver which in turn improves safety.
When the mobile of driver/passengers is ringing then the audio signal is lowered until the driver acknowledges the system to operate in normal mode. The incoming call is identified by detecting the ring tone of the mobile phone. When there is continuous abnormal noise from vehicle the audio system will give indication to driver by a warning message in Driver information system. This will help in easy identification of any malfunction within the vehicle.
When there is horn/siren from external vehicle then the audio signal strength is lowered and the horn/siren sound is amplified through the same audio system. When the mobile of driver/passengers is ringing then the audio signal is lowered until the driver acknowledges it by pressing a button in the audio signal. The vehicle internal noise which is coming inside the passenger compartment is being masked using audio system. When there is continuous abnormal noise from engine compartment the audio system will give indication to driver by momentary some unique sound will be given by audio system and warning message in DIS (driver information system).

WE CLAIM:-
1. An adaptive volume control and online compensation system in automotive vehicle comprising a controller unit having digital signal processing unit provided with an external signal sensor means fitted at out side the vehicle to sense outside sound signal and an internal signal sensor means fixed inside the vehicle to sense internal sound signals; a loud speaker through an amplifier connected to the out put of the said digital processor; an artificial neural network implemented in the control unit to enable recognise set signals accordingly to reproduce or to suppress or to lower the out put level if signals of learning technique detected; an embedded software loaded in the said control unit as per the algorithm as herein described with reference figures of drawings such that the sound signals received through the said external and internal signal sensors are classified and fed to the said Artificial neural network and after identifying send vehicle noise to DIS for warning, recognise external noise such as horn/sirens to reproduce and suppress if cabin noise such as mobile ring.
2. An adaptive volume control and online compensation system as claimed in claim 1 where in said external and internal signal sensors are microphones.
3. An adaptive volume control and online compensation system as claimed in claims 1 and 2 wherein the said artificial neural network implementation techniques achieved an algorithms as herein described with reference to flow diagram such way that the pattern of the required signals will be fed to the system by the learning techniques of ANN and If the noise signal matches to the learnt ring tones then the audio signal is automatically lowered there by allowing the user to speak without any intervention to the audio system or when ever there is some siren sounding near the vehicle it will be audibly reproduced for the driver.