HTC v. Uniloc Luxembourg
`
`Page 1 of 10
`
`HTC Ex. 1006
`
`Page 1 of 10
`
`SAMSUNG EXHIBIT 1006
`
`

`

`US. Patent
`
`Apr. 13, 2010
`
`Sheet 1 of3
`
`US 7,698,097 B2
`
`
`
`
`
`
`Fig.2
`
`
`
`COUNT ||
`
`120
`
`140
`
`Fig.3
`
`130
`
`HTC V. Uniloc Luxembourg
`
`Page 2 of 10
`
`HTC Ex. 1006
`
`Page 2 of 10
`
`HTC v. Uniloc Luxembourg
`
`Page 2 of 10
`
`HTC Ex. 1006
`
`Page 2 of 10
`
`

`

`US. Patent
`
`Apr. 13, 2010
`
`Sheet 2 of3
`
`US 7,698,097 B2
`
`
`120
`
`
`140
`
`T0
`
`HTC V. Uniloc Luxembourg
`
`Page 3 of 10
`
`HTC EX. 1006
`
`Page 3 of 10
`
`HTC v. Uniloc Luxembourg
`
`Page 3 of 10
`
`HTC Ex. 1006
`
`Page 3 of 10
`
`

`

`US. Patent
`
`Apr. 13, 2010
`
`Sheet 3 of3
`
`US 7,698,097 B2
`
`NW: Nw+1
`
`ch = min(0. ch - 2)
`
`ATK
`
`
`
`TR“ )
`
`TR(2)
`
`‘ ' '
`
`TR( K'Z)
`
`TR(K'1)
`
`
`
`
`Fig.6
`
`HTC V. Uniloc Luxembourg
`
`Page 4 of 10
`
`HTC Ex. 1006
`
`Page 4 of 10
`
`HTC v. Uniloc Luxembourg
`
`Page 4 of 10
`
`HTC Ex. 1006
`
`Page 4 of 10
`
`

`

`US 7,698,097 B2
`
`1
`METHOD FOR CONTROLLINGA
`PEDOMETER BASED ON THE USE OF
`INERTIAL SENSORS AND PEDOMETER
`IMPLEMENTING THE METHOD
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates to controlling a pedometer
`based on the use of inertial sensors.
`
`2. Description of the Related Art
`As is known, a pedometer is a device that can be carried by
`a user and has the function of counting the number of steps
`during various walking or running activities for estimating
`accordingly the distance traveled. The indications supplied
`are useful for quantifying the motor activity performed by a
`person in the course ofa given period, for instance, for clinical
`purposes, for assessing the athletic performance, or even just
`for simple personal interest.
`The reliability of a pedometer obviously depends on the
`precision in estimating the step length of the user at the
`various rates of locomotion, but also on the selectivity in
`recognizing and ignoring events not correlated to the gait,
`which, however, cause perturbations resembling those pro-
`duced by a step. For example. many pedometers are based on
`the use of inertial sensors, which detect accelerations along a
`substantially vertical axis, and recognize that a step has been
`being made by a user when the time plot of the acceleration
`signal shows given morphological characteristics. Basically,
`a step is recognized when the pedometer detects a positive
`acceleration peak (i.e., a peak directed upwards) having an
`amplitude greater than a first threshold, followed, at a dis-
`tance of some tenths of second, by a negative acceleration
`peak (directed downwards) having an amplitude greater than
`a second threshold. However, there are many random events
`that can interfere with correct recognition of the step. Impact
`or other external vibrations and given movements of the user
`can, in fact, give rise to so-called “false positives”, i.e., to
`events that are recognized as steps even though in actual fact
`they are not, because the morphological characteristics pro-
`duced are compatible. Events of this type are very frequent
`also in periods of rest, when the user, albeit not walking, in
`any case performs movements that can be detected by the
`pedometer. In the majority of cases, also “isolated” steps or
`very brief sequences of steps are far from significant and
`should preferably be ignored because they are, in effect, irrel-
`evant in regard to assessment of the motor activity for which
`the pedometer is being used.
`Of course, in all these situations, the count ofthe steps may
`prove to be completely erroneous.
`
`BRIEF SUMMARY OF THE INVENTION
`
`One embodiment of the present invention is a method for
`controlling a pedometer and a pedometer which overcome the
`described above limitations.
`
`One embodiment is a method for controlling a pedometer.
`The method includes: generating a signal correlated to move—
`ments of a user of the pedometer; detecting steps of the user
`based on the signal; checking whether sequences of the
`detected steps satisfy pre-determined conditions of regular-
`ity; updating a total number of valid steps if the conditions of
`
`10
`
`15
`
`20
`
`25
`
`30
`
`'55
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`regularity are satisfied; and preventing updating of the total
`number of valid steps if the conditions of regularity are not
`satisfied.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`
`
`VIEWS OF THE DRAWINGS
`
`For a better understanding ofthe invention, an embodiment
`thereof is now described, purely by way of non—limiting
`example and with reference to the attachedplate ofdrawings,
`wherein:
`FIG. 1 shows a simplified and partially sectioned perspec-
`tive View of a portable electronic device incorporating a
`pedometer according to the present invention;
`FIG. 2 is a simplified block diagram of the pedometer of
`FIG. 1;
`FIG. 3 shows a flowchart corresponding to a control
`method according to the present invention executed by the
`pedometer of FIGS. 1 and 2;
`FIG. 4 is a more detailed flowchart corresponding to a first
`step of the method of FIG. 3;
`FIG. 5 is a graph that represents first quantities used in the
`method according to the present invention;
`FIG. 6 is a graph that represents second quantities used in
`the method according to the present invention;
`FIG. 7 is a more detailed flowchart corresponding to a
`second step of the method of FIG. 3; and
`FIG. 8 is a more detailed flowchart corresponding to a third
`step ofthe method of FIG. 3.
`
`
`
`DETAII 4D D *SCRIPTION OF THE INVENTION
`
`
`
`With reference 0 FIGS. 1 and 2, a pedometer 1 is inte-
`grated within a portable electronic device, such as a cell
`phone 2. The pedometer 1 comprises an inertial sensor 3, a
`control unit 5, equipped with a nonvolatile-memory module
`(not illustrated herein), a display 6. and a communication
`interface 8, all housed on a card 9, which is, in turn, fixed
`within a casing 10 of the cell phone 2. In the embodiment
`described herein, the control unit 5 performs control func—
`tions of the pedometer 1 and, moreover, presides over bi-
`directional communication and over handling of the func—
`tions envisaged for the cell phone 2. Likewise, the display 6,
`which is obviously arranged so as to be visible from the
`outside of the casing 10, can be used for displaying both
`information regarding the pedometer 1 and, more in general,
`information regarding the operation of the cell phone 2.
`The inertial sensor 3 is a linear accelerometer of a MEMS
`(micro—electromechanical systems) type and is mounted on
`the card 9 so as to have a detection axis Z substantially parallel
`to a longitudinal axis L ofthe casing 10 ofthe cell phone 2. In
`practice, the detection axis Z and the longitudinal axis L are
`substantially horizontal, when the cell phone 2 is resting on a
`surface, and substantially vertical or slightly inclined with
`respect to the vertical when the cell phone 2 is handled. The
`inertial sensor 3 supplies at output an acceleration signal AZ,
`which is correlated to the accelerations undergone by the
`inertial sensor 3 itself along the detection axis Z.
`The control unit 5 receives and processes the acceleration
`signal AZ as explained in detail hereinafter for identifying and
`counting a total number of valid steps NVT made by a user
`wearing or carrying the pedometer 1, for example, on his belt
`or on his shoulder. In addition, the control unit 5 is preferably
`configured for generating an estimate of the distance traveled
`by the user and other data, such as, for example, estimates of
`the average speed during movement and energy consumption.
`
`HTC v. Uniloc Luxembourg
`
`Page 5 of 10
`
`HTC Ex. 1006
`
`Page 5 of 10
`
`HTC v. Uniloc Luxembourg
`
`Page 5 of 10
`
`HTC Ex. 1006
`
`Page 5 of 10
`
`

`

`US 7,698,097 B2
`
`
`
`3
`The total number of valid steps NVT and the other data possi-
`bly produced are sent to the display 6.
`The communication interface 8 in this case is based on the
`transceiver system (knoan and not shown) ofthe cell phone 2
`and, preferably, also comprises a port (also known and not
`shown) for communication with a computer. The communi-
`cation interface 8 can thus be used both for downloading the
`data produced by the pedometer 1 (amongst which at least the
`total number of valid steps NW) and for uploading operating
`parameters for the pedometer 1 into the control unit 5.
`The control unit 5 is configured for executing a control
`procedure, as illustrated with reference to FIGS. 3-8.
`Upon switching-on of the pedometer 1, an initialization
`step is executed (block 100, FIG. 3), in which a first counter
`of the total number of valid steps NW; a second counter,
`hereinafter referred to as number of valid control steps NVC;
`and a third counter, hereinafter referred to as number of
`invalid steps NINW are set to zero.
`The control unit 5 then executes a first counting procedure
`(block 110), based upon the sampling of the acceleration
`signal AZ at a pre-determined frequency, for example 25 Hz.
`n this step, the user is considered at rest and the control unit
`5 is considered as waiting to recognize, on the basis of the
`acceleration signal AZ, sequences of events corresponding to
`a sequence ofsteps that are close to one another, which satisfy
`ore-detemiined conditions of regularity described in detail
`icrcinaftcr. When a sequence of steps corresponding to a
`regular gait of the user is recognized, the first counting pro-
`cedure is interrupted. Alternatively, the first counting proce—
`dure terminates when a time interval 'I'C that has elapsed from
`he last step recognized is longer than a first time threshold
`T51, for example 10 5. On exit from the first calculation
`arocedure, the control unit 5 sets a state flag FSTto a first value
`C, if a sequence of steps that satisfies the conditions of regu—
`arity has been recognized, and to a second value PI ), ifthe
`first time threshold TSi has been exceeded.
`At the end of the first counting procedure, the control unit
`5 checks whether the state flag FST has been set at the first
`value C (block 120), i.e., whether a sequence ofsteps has been
`recogni7ed. If so (output YES from block 120), a second
`counting procedure is executed (block 130). The user is con-
`sidered to be moving, and a first counter, hereinafter referred
`o as total number of valid steps NW, is incremented when-
`ever an event corresponding to a step is recognized. Further—
`more, the control unit 5 checks the regularity ofthe sequences
`of steps, as explained hereinafter, and, when an interruption in
`he locomotion is detected, the second counting procedure is
`erminated, and execution of the first counting procedure
`resumes (block 110).
`If, instead, the state flag FST has the second value PD, the
`oedometer 1 is set in a low-consumption wait state (“power
`down” state), and the control unit 5 executes a surveying
`3rocedure (block 140). The surveying procedure terminates
`when a variation of the dc. component of the acceleration
`signal AZ is detected, i.e., when the cell phone 2 that includes
`he pedometer 1 is moved. The control unit 5 then returns to
`execution of the first calculation procedure (block 110).
`The first counting procedure is illustrated in greater detail
`in FIG. 4.
`Initially, the control unit 5 reads a sample of the accelera-
`tion signalAZ (block 200) and then evaluates whether the time
`interval TC that has elapsed from the last step recognized is
`higher than the first time threshold Tm , i.e., whether the step
`recognition fails for a period longer than the first time thresh—
`old TS1 (block 205). If so (output YES from block 205), the
`state flag FSTis set at the second value PD (block 210) and the
`first counting procedure is terminated (in this eventuality,
`
`
`
`4
`after the test on the state flag F57 ofblock 120 ofFIG. 3, the
`surveying procedure is executed, block 140). Otherwise (out—
`put NO from block 205), the duration of the time interval TC
`is compared with a second time threshold T52, shorter than the
`first time threshold TSl and equal, for example, to 3 s (block
`215). If the second time threshold T,52 has been exceeded
`(output YES from block 215), the number of valid control
`steps NVC and the number of invalid steps NINV are set to zero
`(block 220); then a step—recognition test is carried out (block
`225). ()therwise (output N() from block 215), the control unit
`5 directly executes the step-recognition test.
`In the step-recognition test of block 225, the control unit 5
`verifies whether the time plot of the acceleration signal AZ
`(i.e., the sequence of the samples acquired) has pre—deter—
`mined characteristics. In particular (FIG. 5), a step is recog-
`nized if the acceleration signal AZ shows a positive peak,
`higher than a positive acceleration thresholdAZP, followed by
`a negative peak, smaller than a negative acceleration thresh-
`old AZN, and if the negative peak falls within a time window
`TW of pre-determined amplitude and, moreover, located at a
`pre-determined distance after the positive peak.
`If the control unit 5 does not recognize an event corre-
`sponding to a step (output NO from block 225), a new sample
`of the acceleration signal AZ is read (block 200). If, instead,
`the step-recognition test is passed (output YES from block
`225), the control unit 5 executes a first validation test, corre-
`sponding to the regularity of the individual step (block 230).
`With reference also to FIG. 6, the validation occurs when the
`duration ATK of a current step K is substantially homoge—
`neous with respect to the duration ATM1 of an immediately
`preceding step K—l (the duration of a generic step is deter-
`mined by the timc that has elapsed between an instant of
`recognition of the step of which the duration is evaluated and
`an instant of recognition of the step that immediately pre—
`cedes it). More precisely, the last step recognized is validated
`if the instant of recognition of the current step TR(K) falls
`within a validation interval TV, defined with respect to the
`instant of recognition of the immediately preceding step
`TR(K—1), in the following way:
`TV:[TR(K— 1)+MK,1— TA, TR(K— 11+ATK, l+TB]
`
`where TA and TB are complementary portions of the valida-
`tion interval TV.
`In the embodiment of the invention
`described herein, the complementary portions TA, TB are
`defined as follows, for the generic current step K:
`TA:ATK,1/2
`
`TBATK,l
`
`Consequently, the validation interval is asymmetrical with
`respect to the instant TR(K—1)+ATK_, and has an amplitude
`equal to 3ATK71/2. The validation interval TV could, how—
`ever, be symmetrical and have a different amplitude, In prac-
`tice. it is verified that the last step recognized is compatible
`with the frequency of the last steps made previously.
`If the verification yields a negative result (output NO from
`block 230), the number of invalid steps NINV is incremented
`by one (block 235) before being compared with a first pro-
`grammablethresholdnumber N“, for example 3 (block240).
`If the number of invalid steps N[NV has reached the first
`threshold number N1.1 (outputYES from block 240), both the
`number ofinvalid steps NINV, and the number ofvalid control
`steps NVC are set to zero (block 245), and the first counting
`procedure is resumed, with reading of a new sample of the
`acceleration signal AZ (block 200), If, instead, the number of
`invalid steps NINV is smaller than the first threshold number
`NT1 (output NO from block 240), the number ofvalid control
`
`10
`
`15
`
`20
`
`25
`
`30
`
`'55
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`HTC v. Uniloc Luxembourg
`
`Page 6 0f10
`
`HTC Ex. 1006
`
`Page 6 of 10
`
`HTC v. Uniloc Luxembourg
`
`Page 6 of 10
`
`HTC Ex. 1006
`
`Page 6 of 10
`
`

`

`US 7,698,097 B2
`
`
`
`5
`steps NW. is decremented (block 250). In the embodiment
`described herein, the decrement is equal to two. Ifthe result of
`the decrement operation is negative, the number of valid
`control steps NVC is set to zero (in practice. the updated value
`of the number of valid control steps NVC is equal to the
`smaller between zero and the previous value ofthe number of
`valid control steps NVC, decreased by two). Then. the control
`unit 5 reads a new sample of the acceleration signal AZ (block
`200).
`[fthe first validation test ofblock 230 is passed, the number
`of valid control steps NVC is incremented by one (block 255),
`and then the control unit 5 executes a first test on regularity of
`he sequence of steps recognized (block 260). The first regu-
`arity test is based upon a first condition of regularity and
`envisages comparing the number of valid control steps NVC
`with a second programmable threshold number NT, greater
`Iran the first threshold number NT1 (for example, 8). In prac-
`ice, the first condition of regularity is satisfied when there is
`a significant prevalence of steps spaced in a substantially
`uniform way, at the most interrupted sporadically by a num-
`3er of irregular steps smaller than the first threshold number
`\In. If the number of valid control steps NVC is smaller than
`he second threshold number N12 (output NO from block
`260), the first condition of regularity is not satisfied. and the
`irst regularity test indicates that there has not yet been iden-
`ified a sequence of steps corresponding to a sufficiently
`regular gait, and hence the control unit 5 acquires once again
`a new sample of the acceleration signal AZ (block 200), with-
`out the total number of valid steps NVT being incremented.
`Otherwise (outputYl {S from block 260), a sequence of steps
`is recognized that satisfies the first condition ofregularity, and
`the first regularity test is passed. The number of invalid steps
`NINVand the number ofvalid control steps NVC are set to zero,
`whereas the total number of valid steps NVT is updated and
`incremented by a value equal to the second threshold number
`NT2 (block 265). Furthermore, the state flag FISTis set at the
`count value, and the first counting procedure is terminated. In
`this case, after the test on the state flag ofblock 120 of FIG. 3,
`the second counting procedure is executed (block 130).
`In practice, the first counting procedure enables the pedom-
`eter 1 to remain waiting for a sequence of events correspond-
`ing to a sequence of steps that satisfies the first condition of
`regularity. The regularity of the gait is considered suflicient
`when the number of valid control steps NVC reaches the sec—
`ondthreshold number ND. The events considered irregular or
`a waiting time that is too long between two successive steps
`cause the decrement (block 250) or the zeroing (blocks 220
`and 245) of the number of valid control steps NVC, so that the
`first counting procedure resumes from the start. As long as the
`pedometer 1 is in the waiting condition, the total number of
`valid steps N” is not incremented because the user is still
`considered as at rest. However, when the first regularity test
`(block 260) is passed, the total number of valid steps NW is
`immediately updated so as to take into account the valid steps
`(equal to N12) that make up the sequence considered as being
`regular. Isolated events and sequence of steps that are in any
`case too short are thus advantageously ignored, whereas
`counting of the steps promptly resumes also in the case of
`isolated irregularities (for example, due to a non—homoge—
`neous acceleration or to a loss of balance at the start of
`locomotion).
`The possibility of programming the value of the first
`threshold number NT] and of the second threshold ntunber
`NH enables modification of the sensitivity of the pedometer
`in recognizing an initial sequence of steps. For example, the
`user can program lower values of the first threshold number
`NT1 and of the second threshold number N72 (for example 2
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`6
`and 4, respectively) when he remains for a long time in a
`closed environment, for example an office or a room, where it
`would not in any case be possible to maintain a regular gait for
`a long time. In this way, shorter sequences of steps are vali—
`dated and counted.
`Instead, during a more constant and
`intense activity, such as rulming, the gait remains constant for
`a long time. and hence the first threshold number NT1 and the
`second threshold number N12 can be programmed with
`higher values (for example, 4 and 12, respectively). Step
`sequences that are shorter and not very significant in relation
`to the activity performed can be ignored.
`FIG. 7 illustrates in detail the second counting procedure
`(executed in block 130 of FIG. 3).
`The control unit 5 initially reads a sample of the accelera—
`tion signal AZ (block 300), and then evaluates whether the
`time interval TC that has elapsed from the last step recognized
`is higher than the first second time threshold TS2 (block 305).
`If so (outputYES from block 205), the number ofinvalid steps
`N[NV and the number of valid control steps NVC are zeroized
`(block 31 0), and the second counting procedure is terminated.
`Otherwise (output NO from block 305), a step-recognition
`test is carried out (block 315). identical to the step-recogni-
`tion test ofblock 225 of FIG. 3. Also in this case, then, step
`recognition is based upon the detection of a positive peak of
`the acceleration signal A2 followed by a negative peak that
`falls in the time window TW (see FIG. 5).
`If the control unit 5 does not recognize an event corre-
`sponding to a step (output NO from block 315), a new sample
`of the acceleration signal AZ is read (block 300). If, instead,
`the step-recognition test is passed (output YI‘IS from block
`315), a second validation test is made, corresponding to the
`regularity of the individual step (block 320). The second
`validation test is altogether similar to the first validation test
`carried out in block 230 ofFIG. 3. Also in this case, then, the
`last step recognizedis validatedifthe instant ofrecognition of
`the current step T600 falls within the validation interval TV
`defined above. In practice, it is verified that the last step
`recognized is compatible with the frequency of the last steps
`made previously.
`Ifthe check yields a positive result (outputYFS from block
`320), the control unit 5 updates the total number ofvalid steps
`NVT and the number ofvalid control steps NVC, incrementing
`them by one (block 325). The number of valid control steps
`NVC is then compared with a third programmable threshold
`number N13 (block 330), which, in the embodiment described
`herein, is equal to the second threshold number N12. If the
`number of valid control steps NVC is smaller than the second
`threshold number N12 (output NO from block 330), the con-
`trol unit 5 once again directly acquires a new sample of the
`acceleration signal A2 (block 300), whereas otherwise (out-
`put YES from block 330), the number of invalid steps NINV
`and the number of valid control steps NVC are set to zero
`(block 335) prior to acquisition of a new sample Az-
`If, instead, the second validation test of block 320 is nega—
`tive, the number of invalid steps N[NV is incremented by one
`(block 340) before being compared with a fourth program-
`mable threshold number NT4 (block 345), which,
`in the
`present embodiment, is equal to the first threshold number
`N“. If the number of invalid steps NINV is smaller than the
`fourth threshold number NT4 (output NO from block 345), the
`number of valid control steps N W is decremented (block
`350), here by two. Also in this case, if the result of the
`decrement operation is negative, the number of valid control
`steps NVC is set to zero (the updated value of the number of
`valid control steps NVC is equal to the smaller between zero
`and the previous value of the number of valid control steps
`NVC, decreased by two). Then, the control unit 5 reads a new
`
`HTC v. Uniloc Luxembourg
`
`Page 7 of 10
`
`HTC Ex. 1006
`
`Page 7 of 10
`
`HTC v. Uniloc Luxembourg
`
`Page 7 of 10
`
`HTC Ex. 1006
`
`Page 7 of 10
`
`

`

`US 7,698,097 B2
`
`7
`sample ofthe acceleration signal AZ (block 300). If the num-
`ber of invalid steps NINV has reached the fourth threshold
`number NT4 (output YES from block 345), the number of
`invalid steps NINV and the number of valid control steps NVC
`are set to zero (block 355), andthe second counting procedure
`is terminated.
`
`In practice, the second counting procedure is based on a
`second condition of regularity, which is satisfied as long as
`sporadic irregular steps occur within sequences of steps
`spaced in a substantially homogeneous way. More precisely,
`the second condition of regularity is satisfied as long as the
`number of invalid steps NINVis smaller thanthe fourth thresh-
`old number NT4. Consequently, the second counting proce—
`dure continues to update and increment the total number of
`valid steps NW as long as the gait of the user is kept regular.
`Possible isolated irregularities are ignored and do not inter—
`rupt or suspend updating of the count, which is,
`instead,
`interrupted when prolonged pauses occur or in the presence
`of significant discontinuities in locomotion. However, if the
`gait becomes regular again, even with a different rhythm, also
`the count promptly resumes, because the first counting pro—
`cedure is once again executed, This prevents a significant
`number of steps from being neglected.
`The surveying procedure executed in block 140 of FIG. 3
`will now be described in greater detail, with reference to FIG.
`8.
`
`When the surveying procedure is started, a current mean
`value AZM of the acceleration signal AZ is stored in the non-
`volatile—memory module (not illustrated) ofthe control unit 5
`(block 400). The current mean value AZM represents an esti-
`mate of the DC component of the acceleration signal AZ,
`which, when the cell phone 2 containing the pedometer 1 is
`stationary, is determined substantially by the contribution of
`the acceleration of gravity along the detection axis Z. In
`practice, then, the current mean value AZM provides an esti-
`mate of the position of the cell phone 2 and of the pedometer
`1.
`
`After storage ofthe current mean value AZM, the pedometer
`l is set in a low-consumption operating condition (power-
`down condition), in which at least the inertial sensor 3 is
`inactive (block 410).
`Awaiting cycle is then carried out (block 420), for example
`of the duration of 10 s, after which all the functions of the
`oedometer 1 are re-activated (“power on”, block 430).
`The control unit 5 acquires from the inertial sensor 3 a
`number of samples ofthe acceleration signal AZ sufficient for
`estimating an updated mean value AZM' (block 440), which is
`hen compared with the current mean value AZM previously
`stored (block 450).
`If the updated mean value AZM departs from the current
`mean value AZM (output NO from block 450), the surveying
`orocedure is interrupted, and the first counting procedure
`indicated in block 110 of FIG. 3 is executed. If, instead, the
`updated mean value AZM'
`is substantially unvaried with
`respect to the current mean value r ZM (output YES from
`alock 450), the surveying procedure proceeds and the pedom-
`eter l is set again in the low—consumption operating condition
`(block 410).
`Clearly, the use ofthe surveying procedure enables a dras-
`ic reduction in the power consumption when the pedometer
`1 is not used and, hence increases the autonomy thereof. If, as
`in the embodiment described, the pedometer 1 is integrated in
`a portable device with which it shares the use ofresources, for
`example the control unit 5, the surveying procedure entails
`further advantages. In fact, the de-activation of the functions
`linked to the pedometer 1 frees the shared resources for use by
`
`
`
`to
`
`5
`
`20
`
`25
`
`30
`
`'55
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`8
`the active functions, which can thus access the resources
`themselves in a more efficient way.
`Finally, it is evident that modifications and variations can
`be made to the device described herein. without thereby
`departing from the scope of the present invention, as defined
`in the annexed claims.
`In particular, the control procedure described can be used
`to advantage in a stand-alone pedometer or in any case one
`integrated in a further portable device, but with stand—alone
`and non-shared resources.
`Furthermore, the conditions of regularity used to enable or
`prevent counting ofthe steps recognized canbe different from
`the ones described. For example, a sequence of steps can be
`considered regular when possible steps recognized and not
`validated are separated by at least one pre—determined number
`of consecutive validated steps. Again, a sequence of a pre-
`determined number of validated or non-validated steps (se-
`quence of fixed length) can be considered regular when the
`validated steps are at least a given percentage of the steps of
`the sequence.
`Finally, the inertial sensor can be of the type with two or
`three axes of detection. In this case, step recognition can
`advantageously be performed by selecting the acceleration
`signal corresponding to the detection axis nearest to the ver—
`tical. The nearer the detection axis used is to the vertical, in
`fact, the greater the amplitude of the signal useful for step
`recognition. The detection axis is selected on the basis of the
`value of the DC component of the respective acceleration
`signal, which is correlated to the contribution ofthe accelera—
`tion of gravity. The detection axis nearest to the vertical is the
`axis along which the contribution of the acceleration of grav-
`ity is greater. The pedometer can then be used independently
`of how it is oriented.
`The invention claimed is:
`l . A method for controlling a pedometer, the method com-
`prising:
`generating a signal correlated to movements ofa user ofthe
`pedometer;
`detecting steps of the user based on said signal;
`checking whether sequences of the detected steps indicate
`whether the sequences of the detected steps correspond
`to a regular gait of the user;
`updating a total number of valid steps if said sequences
`correspond to the regular gait of the user;
`preventing updating of said total number of valid steps if
`said sequences do not correspond to the regular gait of
`the user; and
`partially deactivating the pedometer if said detecting steps
`of the user based on said signal fails for a period longer
`than a time threshold.
`2. The method according to claim 1 , wherein said checking
`comprises:
`in a first operating condition, checking whether a first
`condition of regularity is satisfied; and
`in a second operating condition, checking whether a sec-
`ond condition of regularity is satisfied.
`3. The method according to claim 2, wherein, during said
`checking whether said first condition ofregularity is satisfied,
`the updating of said total number of valid steps is prevented.
`4, The method according to claim 2, wherein, during said
`checking whether said second condition of regularity is sat-
`isfied, the updating of said total number of valid steps is
`allowed.
`5. A method for controlling a pedometer, the method com—
`prising:
`generating a signal correlated to movements ofa user ofthe
`pedometer;
`
`HTC v. Uniloc Luxembourg
`
`Page 8 of 10
`
`HTC Ex. 1006
`
`Page 8 of 10
`
`HTC v. Uniloc Luxembourg
`
`Page 8 of 10
`
`HTC Ex. 1006
`
`Page 8 of 10
`
`

`

`US 7,698,097 B2
`
`9
`detecting steps of the user based on said signal;
`checking whether sequences ofthe detected steps indicate
`whether the sequences of the detected steps correspond
`to a regular gait of the user;
`updating a total number of valid steps if said sequences
`correspond to the regular gait of the user; and
`preventing updating of said total number of valid steps if
`said sequences do not correspond to the regular gait of
`the user,
`wherein checking whether sequences of the detected steps
`indicate whether the sequences of the detected steps
`correspond to a regular gait of the user includes:
`executing a first validation test ofa current detected step;
`incrementing a number of valid control steps if based on
`said first validation test said current detected step is
`validated; and
`incrementing a number ofinvalid steps and decrementing
`said number of valid control steps if based on said first
`validation test said current detected step is not validated.
`6. The method according to claim 5, wherein said execut-
`ing said first validation test of said current detected step
`comprises evaluating whether a duration of said current
`detected step is homogeneous with respect to a duration of an
`immediately preceding detected step.
`7. The method according to claim 6, wherein said first
`validation test yields a positive result when an instant of
`recognition of the current detected step TR(K) falls within a
`validation interval, defined with respect to an instant of rec—
`ognition of the irmuediately preceding detected step TR(K—
`l), in the following way:
`TI’:[TR(K—1‘)+ATK,i—TA, TR(K—1)+ATK,1+TB]
`
`where ATK_1 is said duration of the immediately preceding
`detected step, and TA and TB are complementary portions of
`said validation interval.
`8. The method according to claim 5, further comprising
`checking whether a first condition of regularity is satisfied,
`wherein said checking whether said first condition of regu—
`larity is satisfied comprises comparing said number ofinvalid
`steps with a first threshold number and comparing said num-
`ber of valid control steps with a second thresh