FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION A Method of Characterization of Signals and a System thereof
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Ravindra A Rode, Vishwas M Vaidya, Shekhar R Pardeshi
All Indian Nationals
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following complete specification particularly describes the invention and the
manner in which it is to be performed.

FIELD OF INVENTION
The present invention relates in general to electronic unit which uses the signal sensors to acquire the signal data and characterizes it based on the gradient of change in the signal value.
BACKGROUND OF INVENTION
US Patent number 4147143 discusses the engine acceleration detection apparatus which uses the diaphragm unit for detection of the acceleration and further uses this information for control of adjustment of engine operating conditions to work with the Exhaust Gas Re-circulation (EGR) technology.
US Patent number 4670852 discusses the wheel speed and acceleration detection technology, which uses the wheel speed pulse signal as input. The difference between the successive values of the wheel speed is compared with predetermined thresholds to conclude over the average wheel acceleration. The invention is used in the design of antiskid control systems.
Both the above patents show the importance of "rate of change of the signal" information and its uses in different automotive systems like EGR Control systems, antiskid control systems, etc.
OBJECTS OF INVENTION
The main object of the invention is to provide an electronic unit that characterizes the input sensor signal, like a pulse train from alternator, based on the gradient of change of the signal value and generate five output signals that represent the rate of change of the input signal.
2

Another object of this invention is to provide an electronic unit that characterizes the input sensor signal and can be easily configured based on requirements.
Yet another object of this invention is to provide an electronic unit that characterizes the input sensor signal with data logging feature and online calibration features.
Yet another object of this invention is to develop a model that can generate a signal, algorithm for characterizing the generated signal and display the output signal information and said model can be embedded into the electronic unit.
STATEMENT OF INVENTION
The said electronic unit comprises of the analog input channels for acquiring analog input signals like throttle position input, frequency input channels for acquiring pulse train signals like engine rpm signal. The said electronic unit is designed to characterize the input signal and provide five digital outputs that are the end results of the characterization. For the purpose of developing and demonstrating the said electronic system the engine rpm input signal, which a frequency pulse signal, is characterized based on the gradient of change of the signal value.
A method of characterization of signal(s) comprising the steps of Acquiring the signal; Filtering the acquired signal; Deriving incremental values of the filtered signal and storing the consecutive values; Deriving hard acceleration and hard deceleration using said incremental values; Deriving acceleration trend and deceleration trend using said incremental values; Deriving slow acceleration, slow deceleration and steady state using the said acceleration trend, deceleration
3

trend and hard deceleration; Giving precedence to said hard acceleration and hard deceleration over said soft acceleration, soft deceleration and steady state; Finalizing on the five outputs of the electronic unit.
Another objective of the present invention to provide a system for characterization of signals comprising
an electronic control unit embeds a module for acquiring the signals; a module for filtering the signals; a module for deriving incremental values of the filtered signals; a module for storing said incremental values; a module for deriving hard acceleration and hard deceleration; a module for deriving acceleration trend and deceleration trend; a module for deriving slow acceleration, slow deceleration and steady state, a module for giving precedence to said hard acceleration and said hard deceleration over said slow acceleration and slow deceleration and steady state, and a module for output said signals.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 shows the hardware block diagram of the electronic unit used for
characterization.
Fig. 2 shows RPM characterization model
Fig. 3 shows flow diagram for filter design.
Fig. 4 shows flow diagram for hard acceleration deceleration box.
Fig. 4a shows flow diagram for Min - Max - Sum Box
Fig. 4b shows flow diagram for hard decision box.
Fig. 5 shows flow diagram soft acceleration deceleration box
Fig. 5a shows flow diagram for soft decision accumulator
Fig. 5b shows flow diagram for soft decision subtraction box
Fig. 5c shows flow diagram for soft acceleration deceleration decision box.
Fig. 6 shows flow diagram for hard decision precedence box
4

DETAILED DESCRIPTION OF INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.
A signal affected by noise is taken and then it is characterized into various categories depending upon the trend followed by that signal. To reduce the effect of the noise, the signal is first filtered. Then the filtered signal is characterized into fast acceleration, i.e. steep increase in signal value, slow acceleration, i.e. gradual increase in the signal value, steady state, i.e. signal value maintained almost constant over a period of time, slow deceleration, i.e. gradual decrease in the signal value and fast deceleration, i.e. steep decrease in the signal value. The decision for slow acceleration, steady state and slow deceleration is based on the trend followed by that signal. One such signal is RPM pulse signal received from the alternator. The different categories of the signal will determine the state of the vehicle engine, whether it is accelerating, decelerating or moving with the constant steady speed. These flags can be further used for EGR control so that EGR can be turned OFF irrespective of the value of the RPM signal.
Fig. 1 shows the hardware block diagram of the electronic unit used for characterization of the signals. The block "EU" is the said electronic unit used for characterizing the signals. "A" is the RPM pulse signal used for development of the concept. The said electronic controller can be used to characterize any of the analog inputs or pulse inputs or any input that can be given to the micro-controller based unit which can be represented by a finite number in the software developed for the said electronic unit. These all signal are collectively represented by "B". "a" represents the Hard Acceleration output generated by the electronic unit in the digital form. Similarly, "b" demonstrates Soft Acceleration output, "c"
5

demonstrates Steady State output, "d" demonstrates Soft Deceleration and "e" demonstrates Hard Deceleration.
Fig. 2 shows RPM characterization model which is designed for developing the algorithm for characterizing the signal using the said electronic unit. It contains six important blocks, namely rpm signal generator (Bl), filter box (B2), hard acceleration deceleration box (B3), soft acceleration deceleration box (B4), hard decision precedence box (B5) and display box (B6). Out of these mentioned blocks, filter box (B2), hard acceleration deceleration box (B3), soft acceleration deceleration box (B4) and hard decision precedence box (B5) are embedded in the said electronic unit. The electronic unit is designed to acquire the signals and the signal acquisition replaces the rpm signal generator block in the said electronic unit. In the model, rpm signal generator block is designed to produce samples of the signal "Ml" at regular time intervals.
Fig. 3 shows flow diagram for filter box (B2) which is a first order recursive filter designed using a discrete integrator and an adder. The basic functionality of this is to filter out the frequency component due to sampling process and noise frequency in the signal due to jerks. Inputs to this are the current signal value "Ml" and signal value "M2" during electronic unit power up. The outputs generated by the filter box are the filtered signal value "M9", incremental change "M6" in the signal value during the current time interval, incremental change "M7" in the signal value during the one time interval before and incremental change "M8" in the signal value during the two time intervals before.
Fig. 4 shows flow diagram for hard acceleration deceleration box (B3), which decides over the hard acceleration "M10" and hard deceleration "M9" states of the signal. This block uses the incremental changes in the signal "M6", "M2" and "M8", as generated by the Filter box, to decide the hard acceleration "M10" and
6

hard deceleration "M9" conditions. This block also concludes over the acceleration trend "Mil" or the deceleration trend "Ml2" followed by the signal. Hard acceleration deceleration box (B3) is made up of two blocks, namely Min-Max-Sum Box (B7) and hard decision box (B8).
Fig. 4a shows flow diagram for Min - Max - Sum Box (B7), which generates the sum "M41" of the incremental signal values and the scales this value using the constant. Further, it also finds the minimum "M40" of the three incremental values and the maximum "M42" of the three incremental values.
Fig. 4b shows flow diagram for hard decision box (B8), which uses the scaled sum "M41" of the incremental changes in the signal value, minimum "M40" of the incremental values and maximum "M42" of the incremental value to generate hard acceleration "M10", hard deceleration "M9", acceleration trend "Mil" and deceleration trend "Ml2" outputs. Said acceleration trend is a digital output which is set if the scaled sum of the incremental changes in the signal value during the current time interval is greater than that during the previous time interval. Similarly said deceleration trend is a digital output which is set if the scaled of the incremental changes in the signal value during the current time interval is smaller than that during the previous time interval.
Fig. 5 shows soft acceleration deceleration box (B4) which consists of soft decision accumulator (B9), soft decision subtractor box (BIO) and soft decision box (Bll). This block uses acceleration trend "Mil", deceleration trend "M12" and hard deceleration "M9" to generate soft acceleration "Ml3", soft deceleration "Ml4" and the steady "Ml5" outputs. These outputs are further processed by the hard decision precedence box (B5).
7

Fig. 5a shows flow diagram for soft decision accumulator (B9), which uses a combination of a truth table based logic and delay units to realize accumulator functionality. Fig. 5b shows flow diagram for soft decision subtraction box (BIO) which generates the differences "M52" and "M53" in the accumulated signal trends "M49" and "M47" at the current time interval and the accumulated signal trend value 80 time intervals before the current time interval respectively. Fig. 5c shows flow diagram for soft acceleration deceleration decision box (Bl 1) wherein a truth table is implemented that decides over soft acceleration "Ml3", soft deceleration "M14" and steady "M15" outputs. These outputs are further processed by the hard decision precedence box (B5).
Fig. 6 shows flow diagram for hard decision precedence box (B5) which processes the decision outputs namely hard acceleration "M10", soft acceleration "Ml3", steady state "Ml5", soft deceleration "M14" and hard deceleration "M9" so as to give precedence to the hard acceleration "M10" and hard deceleration "M9" over soft acceleration "Ml3", soft deceleration "Ml4" and steady "Ml5" state. Thus the final soft outputs, namely soft acceleration final "Ml6", steady final "Ml8" and soft deceleration final "Ml 7", are generated at this stage.
The algorithm for characterizing the signal as discussed above can be fine tuned and applied to different signals having different signature of variation. Further, this "rate of change of signal" information can be used in different systems in various technological domains.
8

WE CLAIM
1. A method of characterization of signal(s) comprising the steps of
Acquiring the signal;
Filtering the acquired signal;
Deriving incremental values of the filtered signal and storing the
consecutive values;
Deriving hard acceleration and hard deceleration using said incremental
values;
Deriving acceleration trend and deceleration trend using said incremental
values;
Deriving slow acceleration, slow deceleration and steady state using the
said acceleration trend, deceleration trend and hard deceleration;
Giving precedence to said hard acceleration and hard deceleration over said
soft acceleration, soft deceleration and steady state;
Finalizing on the five outputs.
2. The method as claimed in claim 1 wherein said signal is an rpm pulse, continuous or discrete input.
3. The method as claimed in claim 1 wherein said three incremental values stored in a refreshing window.
4. The method as claimed in any one of the previous claims wherein said hard acceleration and deceleration derived using said refreshing window.
5. The method as claimed in any one of the previous claims wherein said acceleration trend and deceleration trend derived using said refreshing window.
9

6. The method as claimed in any one of the preceding claims 1 to 5, wherein said soft acceleration, soft deceleration, steady state derived using the hard deceleration, accumulated acceleration trend and deceleration trend.
7. The method as claimed in any one of the preceding claims 1 to 5, wherein said soft acceleration, soft deceleration, steady state derived using the accumulated acceleration trend and deceleration trend.
8. A system for characterization of signals comprising
an electronic control unit embeds modules for characterizing signal(s) includes acquiring the signals; filtering; deriving incremental values of the filtered signals; storing said incremental values; deriving hard acceleration and hard deceleration; deriving acceleration trend and deceleration trend; deriving slow acceleration, slow deceleration and steady state, applying precedence to said hard acceleration and said hard deceleration over said slow acceleration and slow deceleration and steady state, and output said signals.
9. A method of characterization of signals substantially as herein described with reference to accompanying drawings.
10. A system for characterization of signals substantially as herein described with reference to accompanying drawings.
Dated this 10th day of October 2007

10

ABSTRACT
A Method of Characterization of Signals and a System thereof
An electronic unit comprises of the analog input channels for acquiring analog input signals like throttle position input, frequency input channels for acquiring pulse train signals like engine rpm signal. The said electronic unit is designed to characterize the input signal and provide five digital outputs that are the end results of the characterization. For the purpose of developing and demonstrating the said electronic system the engine rpm input signal, which a frequency pulse signal, is characterized based on the gradient of change of the signal value.
Fig 1.