c12) United States Patent
`Pasolini et al.
`
`(IO) Patent No.:
`(45) Date of Patent:
`
`US 7 ,698,097 B2
`Apr.13, 2010
`
`(54) METHOD FOR ℃ONTROLLING A
`PEDOMETER BASED ON THE USE OF
`INERTIAL SENSORS AND PEDOMETER
`IMPLEMENTING THE METHOD
`
`5/2005 Blackadar et al. ........... 702/182
`6,898,550 Bl
`7,169,084 B2 * 1/2007 Tsuji ........….................. 482/8
`7,297,088 B2 * 1112007 Tsuji ............................. 482/3
`2001/0031031 Al*
`1 。／2001 Ogawa et al. .............. 377/24.2
`
`(75)
`
`Inventors: Fabio Pasoli时， S Martino Siccomario
`(IT); Ivo Binda, Voghera (IT)
`
`(73) Assignee: STMicroelectronics S.R.L., Agrate
`Brianza (IT)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or a司justed under 35
`U.S.C. 154(b) by 707 days.
`
`(21) Appl. No.: 11/537,986
`
`(22) Filed:
`
`Oct. 2, 2006
`
`(65)
`
`Prior Publication Data
`
`US 2007/0143069 Al
`
`Jun. 21, 2007
`
`(30)
`
`Foreign Application Priority Data
`
`Oct. 3, 2005
`
`(EP)
`
`.................................. 05425684
`
`(51)
`
`Int. Cl.
`(2006.01)
`GOJC 22100
`(2006.01)
`G06F 17140
`(52) U.S. Cl. .........…........... 702/160; 702/176; 702/178;
`377/24.2
`( 58) Field of ℃lassification Search ................ 702/160,
`702/176, 178
`See application 自le for complete search history.
`
`(56)
`
`References ℃ited
`
`U.S. PATENT DOCUMENTS
`6,175,608 Bl*
`1/2001 Pyles et al.
`................ 377/24.2
`
`FOREIGN PATENT DOCU肌1ENTS
`
`GB
`JP
`JP
`
`2 359 890
`63-262784
`04-192095
`
`9/2001
`10/1988
`7 /1992
`
`OTHER PUBLICATIONS
`
`Tasaka, Translation of JP 63262784, published Oct. 31, 1988. *
`Tasaka, Translation ofH04-192095, published Jul. 10, 1992.*
`
`* cited by examiner
`
`Primary Examiner Hal D Wachsman
`(74) Attorney, Agent, or Firm T.isa K. Jorgenson; Robert
`Iannucci; Seed IP Law Group PLLC
`
`(57)
`
`ABSTRA℃ I
`
`A method for controlling a pedometer includes the steps of:
`generating a signal correlated to movements of a user of the
`pedometer; and detecting steps of the user on the basis of the
`signal. The method moreover envisages the steps of checking
`whether s巳quences of detected steps satisfy pre-determined
`conditions of regularity; updating a total number of valid
`steps ifthe conditions of regularity are satis自己d; and prevent(cid:173)
`ing the updating of the total number of valid steps if the
`conditions of regularity are not satis自己d.
`
`26 ℃laims, 3 Drawing Sheets
`
`TO 120
`
`235
`
`2击。
`
`／兀／
`110
`
`TO 120
`
`SAMSUNG EXHIBIT 1006
`
`Page 1 of 10
`
`

`

`U.S. Patent
`
`Apr. 13, 2010
`
`Sheet 1of3
`
`US 7 ,698,097 B2
`
`2
`
`10
`
`1
`
`Fig.1
`
`~ 5
`
`3
`
`NVT
`
`9
`
`Fig.2
`
`INIT.
`NVT=O
`NVC=O
`NINV=O
`
`140-
`
`I COUNT
`
`110
`
`Fig.3
`
`130
`
`Page 2 of 10
`
`

`

`U.S. Patent
`
`Apr. 13, 2010
`
`Sheet 2 of 3
`
`US 7,698,097 B2
`
`TO
`
`才 20
`
`235
`
`265
`
`255
`
`Nvc = Nvc刊
`
`TO 120
`
`Nvc = Nvc + 1
`
`400
`
`140
`
`Nvc = Nvc+1 俨 410
`
`I Nvc = Nvc+1
`
`l-420
`
`Nvc = Nvc+1
`
`卡／＂＇ 430
`
`440
`
`TO 120
`
`/l/"' I NVT = Nvr + Nη
`
`:>""'
`
`Nvc=O
`NINV =O
`FsT=C
`
`110
`
`Fig.4
`
`Fig. 8
`
`Page 3 of 10
`
`

`

`U.S. Patent
`
`Apr. 13, 2010
`
`Sheet 3 of 3
`
`US 7 ,698,097 B2
`
`TO
`
`110
`
`340
`
`NN
`CN
`vwmw
`-
`-
`-
`
`唱吨－
`
`户F
`
`TO 110
`
`Fig.7
`
`Az
`
`Azp
`
`AzN
`
`350
`
`Nvc = min(O, Nvc - 2)
`NVT= NVT+1
`
`Fig.5
`
`盯K-1 「去
`
`2
`
`...
`
`I K-2
`
`I K-1
`
`IK
`
`T R(1)
`
`T R(2) •
`
`T R(K-2)
`
`TR(K-1)
`
`TR(K)
`
`Fig.6
`
`TA
`
`TB
`
`TV
`
`Page 4 of 10
`
`

`

`US 7,698,097 B2
`
`1
`METHOD FOR ℃ONTROLLING A
`PEDOMETER BASED ON THE USE OF
`INERTIAL SENSORS AND PEDOMETER
`IMPLEMENTING THE METHOD
`
`BACKGROUND OF THE INVENTION
`
`2
`regularity are satisfied; and preventing updating of the total
`number of valid steps if the conditions of regularity are not
`satis自己d.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRAWINGS
`
`For a better understanding of the invention, an 巳mbodiment
`thereof is now described, purely by way of non-limiting
`1. Field of the Invention
`The present invention relates to controlling a pedometer 10 example and with reference to the attached plate of drawings,
`wherein:
`based on the use of inertial sensors.
`2. Description of the Related Art
`FIG.1 shows a simpli自己d and partially sectioned perspec-
`tive view of a portable electronic device incorporating a
`As is known, a pedometer is a device that can be carried by
`pedometer according to the present invention;
`a user and has the function of counting the number of steps 15
`FIG. 2 is a simplified block diagram of the pedometer of
`FIG. l:
`during various walking or running activities for estimating
`FIG. 3 shows a flowchart correspondi吨 to a control
`accordi吨ly the distance traveled. The indications supplied
`are useful for quantifying the motor activity performed by a
`method according to the present invention executed by the
`person in the course of a giv叫出od』rinstance』rcli叫ω pedometer of FIGS. 1and2;
`purposes, for assessing the athletic performance, or even Just 20
`FIG. 4 is a more detailed flowchart corresponding to a first
`step of the method of FIG. 3;
`for simple personal interest.
`The reliability of a pedometer obviously depends on the
`FIG. 5 is a graph that represents first quantities used in the
`precision in estimating the step length of the user at the
`method according to the present invention;
`various rates of locomotion, but also on the selectivity in
`FIG. 6 is a graph that represents second quantities used in
`recognizing and ignoring events not correlated to the gait, 25 the method according to the present invention;
`FIG. 7 is a more detailed flowchart corresponding to a
`which, however, cause perturbations resembling those pro-
`duced by a step. For example, many p巳：dometers are based on
`second step of the method of FIG. 3; and
`the use of inertial sensors, which detect accelerations along a
`FIG. 8 is a more detailed flowchart corresponding to a third
`substantially vertical axis, and recognize that a step has been 30 step of the method of FIG. 3.
`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
`With reference to FIGS. 1 and 2, a pedometer 1 is inte(cid:173)
`acceleration p四k (i.已， a peak directed upwards) having an
`amplitude greater than a first threshold, followed, at a dis- 35 grated within a portable electronic device, such as a cell
`phone 2. The pedometer 1 comprises an inertial sensor 3, a
`tance of some tenths of second, by a negative acceleration
`peak (directed downwards) having an amplitude greater than
`control unit 5, equipped with a nonvolatile-memory module
`(not illustrated herein), a display 6, and a communication
`a second threshold. However, there are many random events
`that can interfere with correct recognition of the step. Impact
`interface 8, all housed on a card 9, which is, in tum, fixed
`or other external vibrations and given movem巳nts of the user 40 within a casing 10 of the cell phone 2. In the embodiment
`can, in fact, give rise to so-called “ false positives”, i.e., to
`described herein, the control unit 5 performs control func-
`events that are recogr世zed as steps even though in actual fact
`tions of the pedometer 1 and, moreover, presides over bi-
`directional communication and over handling of the func-
`they are not, because the morphological characteristics pro-
`tions envisaged for the cell phone 2. Likewise, the display 6,
`duced are compatible. Events of this type are very frequent
`45 which is obviously arranged so as to be visible from the
`also in periods of rest, when the user, albeit not walking, in
`outside of the casing lO, can be used for displaying both
`any case performs movements that can be detected by the
`information regarding the pedometer 1 and, more in general,
`pedometer. In the majority of cases, also “isolat巳d” steps or
`information regarding the operation of the cell phone 2.
`very brief sequences of steps are far from significant and
`The inertial sensor 3 is a linear accelerometer of a MEMS
`should preferably be ignored because they are, in effi巳ct, irrel- 50 (micro-electromechanical systems) type and is mounted on
`the card 9 so as to have a detection axis z substantially parallel
`evant in regard to assessment of the motor activity for which
`thep巳：dometer is being used.
`to a longitudinal axis L of the casing 10 of the cell phone 2. In
`Of course, in all these situations, the count of the steps may
`practice, the detection axis Zand the longitudinal axis Lare
`prove to be completely erroneous.
`substantially horizontal, when the cell phone 2 is resting on a
`55 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 A2,
`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 A2 as explained in detail hereinafter for identifying and
`counting a total number of valid steps N vr made by a user
`One embodiment is a method for controlling a p巳dometer.
`wearing or carrying the pedometer 1, for example, on his belt
`The method includes: generating a signal correlated to move-
`ments of a user of the pedometer; detecting steps of the user
`or on his shoulder. In addition, the control unit 5 is preferably
`based on the signal; checking whether s巳quences of the 65 configur巳d for generating an estimate of the distance traveled
`by the user and other data, such 邸， for example, estimates of
`detected steps satisfy pre-determined conditions of regular-
`ity; updating a total number of valid steps if the conditions of
`the average speed during movement and energy consumption.
`
`One embodiment of the present invention is a method for
`controlling a pedometer and a pedometer which overcome the
`described above limitations.
`
`60
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`BRIEF SUMMARY OF THE INVENTION
`
`Page 5 of 10
`
`

`

`US 7,698,097 B2
`
`3
`4
`after the test on the state flag F ST of block 120 of FIG. 3, the
`The total number of valid steps N VT and the other data possi-
`surveying procedure is executed, block 140). Otherwise (out-
`bly produced are sent to the display 6.
`The communication interface 8 in this case is based on the
`put NO from block 205), the duration of the time interval Tc
`is compared with a second time threshold T s2, shorter than the
`transceiver system (known and not shown) of the cell phone 2
`first time threshold T si and equal, for example, to 3 s (block
`ar时， preferably, also comprises a port (also known and not 5
`215). If the second time threshold Ts2 has been exceeded
`shown) for communication with a computer. The communi-
`cation interface 8 can thus be used both for downloading the
`(output YES from block 215), the number of valid control
`steps N vc and the number of invalid steps N INV are set to zero
`data produced by the pedometer 1 (amongst which at least the
`total number of valid steps N vT) and for uploading operating
`(block 220); then a step-recognition test is carried out (block
`10 225). Otherwise (output NO from block 215), the control unit
`parameters for the pedometer 1 into the control unit 5.
`5 directly executes the step-recognition test.
`The control unit 5 is configured for executing a control
`In the step-recognition test of block 225, the control unit 5
`procedure, as illustrated with reference to FIGS. 3-8.
`verifies whether the time plot of the acceleration signal A2
`Upon switching-on of the p巳：dometer 1, an initialization
`(i.e., the sequence of the samples acquired) has pre-deter-
`step is executed (block 100, FIG. 3), in which a first counter
`of the total number of valid steps N盯； a second counter, 15 mined characteristics. In particular (FIG. 剑， a step is recog-
`hereina武er referred to as number of valid control steps N vc;
`nized if the acceleration signal A2 shows a positive peak,
`and a third counter, hereinafter referred to as number of
`higher than a positive acceleration thresholdAZP, followed by
`invalid steps NINn are set to zero.
`a negative peak, smaller than a negative acceleration thresh-
`old AZN, and if the negative peak falls within a time window
`The control unit 5 then executes a first counting procedure
`(block 110), based upon the sampling of the acceleration 20 TW of pre-determined amplitude and, moreover, located at a
`signal A2 at a pre-determined fr巳quency, for example 25 Hz.
`pre-determined distance after the positive peak.
`If the control unit 5 does not recognize an event corre-
`In this step, the user is considered at rest and the control unit
`5 is considered as waiting to recognize, on the basis of the
`sponding to a step (output NO from block 225), an巳w sample
`of the acceleration signal A2 is read (block 200). If, instead,
`acceleration signal A2, sequences of events corresponding to
`a sequence of steps that are close to one another, which satisfy 25 the step-recognition test is passed (output YES from block
`pre-deterr丑ined conditions of regularity described in detail
`225), the control unit 5 executes a first validation test, corre-
`hereina武er. When a sequence of steps corresponding to a
`sponding to the r巳gularity of the individual step (block 230).
`regular gait of the user is recognized, the first counting pro-
`With reference also to FIG. 6, the validation occurs when the
`duration li. T K of a current step K is substantially homoge-
`cedure is interrupted. Alternatively, the first counting proce-
`dure terminates when a time interval Tc that has elapsed from 30 n巳:ous with respect to the duration li. T K 1 of an immediately
`pr，巳ceding step K-1 (the duration of a generic step is deter-
`the last step recognized is longer than a first time threshold
`Tsu for example 10 s. On exit from the first calculation
`mined by the time that has elapsed between an instant of
`procedure, the control unit 5 sets a state flag F sT to a first value
`recognition of the step of which the duration is evaluated and
`C, if a sequence of steps that satisfies the conditions of r，巳gu-
`an instant of recognition of the step that immediately pre-
`larity has been recognized, and to a second value PD, if the 35 cedes it). More precisely, the last step r巳：cognized is validated
`if the instant of recognition of the current step T R(K) falls
`first time threshold T si has been exceeded.
`At the end of the first counting procedure, the control unit
`within a validation interval TV, defined with respect to the
`5 checks whether the state flag F sT has been set at the first
`instant of recognition of the immediately preceding step
`value C (block 120), i.已， whether a sequence of steps has been
`T R(K-1 ), in the following way:
`recognized. If so (output YES from block 120), a second 40
`counting procedure is executed (block 130). The user is con-
`where TA and TB are complementary portions of the valida-
`sidered to be moving, and a first counter, hereinafter referred
`tion interval TV. In the embodiment of the invention
`to as total number of valid steps Nvr, is incremented when-
`ever an event corresponding to a step is recognized. Further-
`described herein, the complementary portions TA, TB are
`more, the control unit 5 checks the regularity of the sequences 45 defined as follows, for the generic current step K:
`of steps, as explained hereinafter, and, when an interruption in
`the locomotion is detected, the second counting procedure is
`terminated, and execution of the first counting procedure
`resumes (block 110).
`Consequently, the validation interval is asymmetrical with
`I卫 instead, the state flag F sr has the second value PD, the 50
`pedometer 1 is set in a low-consumption wait state (“power
`respect to the instant TR(K-l)+li.T K-l and has an 缸叩litude
`equal to 3li.TK /2. The validation interval TV could, how-
`down" state), and the control unit 5 executes a surveying
`ever, be symmetrical and have a different amplitude. In prac-
`procedure (block 140). The sur飞呵ing procedure terminates
`tice, it is verified that the last step recognized is compatible
`when a variation of the d.c. component of the acceleration
`signalA2is detected, i.e., when the cell phone 2 that includes 55 with the frequency of the last steps made previously.
`If the verification yields a negative result (output NO from
`the pedometer 1 is moved. The control unit 5 then returns to
`execution of the first calculation procedure (block 110).
`block 230), the number of invalid steps NINv is incremented
`by one (block 235) before being compared with a first pro-
`The first counting procedure is illustrated in greater detail
`in FIG. 4.
`grammablethresholdnumberNn,forexarnple3 (block240).
`Initially, the control unit 5 reads a sample of the accelera- 60 If the number of invalid steps NINv has reached the first
`threshold number N n (output YES from block 240), both the
`ti on signalA2 (block 200) and then evaluates whether the time
`interval Tc that has elapsed from the last step recognized is
`number of invalid steps NINn and the number of valid control
`higher than the first time threshold Ts1, i.e., whether the step
`steps N vc are set to zero (block 245), and the first counting
`recognition fails for a period longer than the first time thresh-
`procedure is resumed, with reading of a new sample of the
`old Ts1 (block 205). If so (output YES from block 205), the 65 acceleration signal A2 (block 200). If, instead, the number of
`state flag F sTis set atthe second value PD (block 210) and the
`invalid steps NINvis smaller than the first threshold number
`N n (output NO from block 240), the number of valid control
`first counting procedure is terminated (in this eventuality,
`
`TV二fTR(K 1 )+/'1T K 1 日， TR(K 1)+1'1TK i+TB}
`
`TA 二1'1TK /2
`
`TB~!'1TK i
`
`Page 6 of 10
`
`

`

`US 7,698,097 B2
`
`5
`6
`and 4, respectively) when he remains for a long time in a
`steps N vc is decrement巳d (block 250). In the embodiment
`described herein, the decrement is equal to two. If the result of
`closed environment, for example an office or a room, where it
`the decrement operation is negative, the number of valid
`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-
`control steps N vc is set to zero (in practice, the updat巳d value
`of the number of valid control steps N vc is equal to the 5 dated and counted. Instead, during a more constant and
`smaller between zero and the previous value of the number of
`intense activity, such as runnir鬼， the gait remains constant for
`valid control steps N町，由creased by two). Then, the control
`a long time, and hence the first threshold number N n and the
`unit 5 reads a new sample of the acceleration signal A2 (block
`second threshold number N n can be progranrmed with
`200).
`higher values (for example, 4 and 12, respectively). Step
`If the first validation test of block 230 is passed, the number 10 sequences that are shorter and not very significant in relation
`of valid control steps N vc is incremented by one (block 255),
`to the activity performed can be ignored.
`and then the control unit 5 executes a first test on regularity of
`FIG. 7 illustrates in detail the second counting procedure
`the sequence of steps r巳:cognized (block 260). The first regu-
`(executed in block 130 of FIG. 3).
`larity test is based upon a first condition of regularity and
`The control unit 5 initially reads a sample of the accelera-
`em也ages comparing the number of valid control steps N vc 15 ti on signal A2 (block 300), and then evaluates whether the
`with a second progranrmable threshold number N n greater
`time interval Tc that has elapsed from the last step r巳：cognized
`than the first threshold number N n (for example, 8). In prac-
`is higherthan the first second time threshold Ts2 (block 305).
`If so (output YES from block 205), the numberofinvalid steps
`tice, the first condition of regularity is satis自己d when there is
`a significant prevalence of steps spaced in a substantially
`NINV and the number of valid control steps N vc are zeroized
`uniform way, at the most interrupted sporadically by a num- 20 (block 310), and the second counting procedure is terminated.
`ber of irregular steps smaller than the first threshold nm丑ber
`Otherwise (output NO from block 305), a step-recognition
`Nn. If the number of valid control steps N vc is smaller than
`test is carried out (block 315), identical to the step-recogni-
`the second threshold number N n (output NO 企om block
`tion test of block 225 of FIG. 3. Also in this case, then, step
`260), the first condition of regularity is not satisfied, and the
`recognition is based upon the detection of a positive peak of
`first regularity test indicates that there has not yet been iden- 25 the acceleration signal A2 followed by a negative peak that
`tifi巳d a sequence of steps corresponding to a sufficiently
`falls in the time window TW (see FIG. 5).
`If the control unit 5 does not recognize an event corre-
`regular gait, and hence the control unit 5 acquires once again
`a new sample of the acceleration signalA2(block 200), with-
`sponding to a step (output NO from block 315), an巳w sample
`of the acceleration signal A2 is read (block 300). If, instead,
`out the total number of valid steps N vr being incremented.
`Otherwise (output YES from block 260), a sequence of steps 30 the step-recognition test is passed (output YES from block
`is recognized that satisfies the first condition ofregularity, and
`315), a second validation test is made, corresponding to the
`the first regularity test is passed. The number of invalid steps
`regularity of the individual step (block 320). The second
`NINvand the number of valid control steps N vc are set to zero,
`validation test is altogether similar to the first validation test
`whereas the total number of valid steps N vr is updated and
`carried out in block 230 of FIG. 3. Also in this case, then, the
`incremented by a value equal to the second threshold number 35 last step recognized is validated if the instant of r，巳cognition of
`N n (block 265). Furthermore, the state flag F sr is set at the
`the current step Tc(K) falls within the validation interval TV
`count value, and the first counting procedure is terminat巳d. In
`defin巳d above. In practice, it is verified that the last step
`this case, a武erthe test on the state flag ofblock 120 of FIG. 3,
`recognized is compatible with the frequency of the last steps
`the second counting procedure is executed (block 130).
`made previously.
`If the check yields a positive result (output YES from block
`In practice, the first counting procedure enables the pedom- 40
`eter 1 to remain waiting for a sequence of events correspond-
`320), the control unit 5 updates the total number of valid steps
`ing to a sequence of steps that satisfies the first condition of
`N vrand the number of valid control steps N vo incrementing
`regularity. The regularity of the gait is considered sufficient
`them by one (block 325). The number of valid control steps
`when the number of valid control steps N vc reaches the sec-
`N vc is then compared with a third programmable threshold
`ond threshold number N n. The events considered im巳gular or 45 number N n (block 330), which, in the embodiment described
`herein, is equal to the second threshold number N n· If the
`a waiting time that is too long between two successive steps
`cause the decrement (block 250) or the zeroing (blocks 220
`number of valid control steps N vc is smaller than the second
`and 245) of the number of valid control steps N vo so thatthe
`threshold number Nn (output NO from block 330), the con-
`trol unit 5 once again dir，巳ctly acquires a new sample of the
`first counting procedure resumes from the start. As long as the
`pedometer 1 is in the waiting condition, the total number of 50 acceleration signal A2 (block 300), whereas otherwise (out-
`put YES from block 330), the number of invalid steps NINv
`valid steps N vr is not incremented because the user is still
`considered as at rest. However, when the first regularity test
`and the number of valid control steps N vc are set to zero
`(block 260) is pas时， the total number of valid steps N vr is
`(block 335) prior to acquisition of a new sample A2.
`immediately updated so as to take into account the valid steps
`I卫 instead, the second validation test of block 320 is nega-
`(equal to N n) that make up the sequence considered as being 55 tive, the number of invalid steps NINv is incremented by one
`(block 340) before being compared with a fourth program-
`regular. Isolated events and sequence of steps that are in any
`mable threshold number N r4 (block 345), which, in the
`case too short are thus advantageously ignored, whereas
`counting of the steps promptly resumes also in the case of
`present embodiment, is equal to the first threshold number
`N n. If the number of invalid steps Nmv is smaller than the
`isolated irregularities (for example, due to a non-homoge-
`neous acceleration or to a loss of balance at the start of 60 fourth threshold number N r4 (output NO from block 345), the
`number of valid control steps N vc is decremented (block
`locomotion).
`The possibility of programming the value of the first
`350), here by two. Also in this case, if the result of the
`threshold number N n and of the second threshold number
`d巳：crement operation is negative, the number of valid control
`Nn enables modification of the sensitivity of the pedometer
`steps N vc is set to zero (the updated value of the number of
`in recognizing an initial sequence of steps. For example, the 65 valid control steps N vc is equal to the smaller between zero
`and the previous value of the number of valid control steps
`user can program lower values of the first threshold number
`Nn and of the second threshold number Nn (for example 2
`N町， decreased by two). Then, the control unit 5 reads a new
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`Page 7 of 10
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`US 7,698,097 B2
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`8
`7
`sample of the acceleration signal A2 (block 300). If the num-
`the active functions, which can thus access the resources
`themselves in a more efficient way.
`ber of invalid steps N INV has reached the fourth threshold
`number Nr4 (output YES from block 345), the number of
`Finally, it is evident that modifications and variations can
`be made to the device described herein, without thereby
`invalid steps NINvand the nur丑ber of valid control steps N vc
`are set to zero (block 355), and the second counting procedure s departing from the scope of the present invention, as defined
`is terminated.
`in the annexed claims.
`In practice, the second counting procedure is based on a
`In particular, the control procedure described can be used
`second condition of regularity, which is satisfied as long as
`to advantage in a stand-alone pedometer or in any case one
`sporadic irregular steps occur within s叫uences of steps
`integrated in a 且rrther portable device, but with stand-alone
`spaced in a substantially homogeneous way. More precisely, 10 and non-shared resources.
`Furthermore, the conditions of regularity used to enable or
`the second condition of regularity is satisfied as long as the
`number ofinvalid steps N INvis smaller than the fourth thresh-
`prevent counting of the steps r巳cognized can be different from
`old number N r4· Consequently, the second counting proce-
`the ones described. For example, a sequence of steps can be
`dure continues to update and increment the total number of
`considered regular when possible steps recognized and not
`valid steps N vr as long as the gait of the user is kept regular. 15 validat巳d are separated by at least one pre-determined number
`of consecutive validated steps. Again, a sequence of a pre-
`Possible isolated im巳gularities are ignored and do not inter-
`rupt or suspend updating of the count, which is, instead,
`determined number of validated or non-validated steps (se-
`interrupted when prolonged pauses occur or in the presence
`quence of fixed length) can be considered regular when the
`of significant discontinuities in locomotion. However, if the
`validated steps are at least a given percentage of the steps of
`gait becomes regular again, even with a different rhythm, also 20 the sequence.
`the count promptly resumes, because the first counting pro-
`Finally, the inertial sensor can be of the type with two or
`cedure is once again executed. This prevents a significant
`three axes of detection. In this case, step recognition can
`number of steps from being neglected.
`advantageously be performed by selecting the acceleration
`The surveying procedure executed in block 140 of FIG. 3
`signal corresponding to the det巳：ction axis nearest to the ver-
`will now be described in greater detail, with reference to FIG. 25 ti cal. The nearer the det巳：ction axis used is to the vertical, in
`s.
`fact, the greater the amplitude of the signal useful for step
`When the surveying procedure is started, a current mean
`recognition. The detection axis is selected on the basis of the
`value AZM of the acceleration signal Az is stored in the non-
`value of the DC component of the respective acceleration
`signal, which is correlated to the contribution of the accelera-
`volatile-memory module (not illustrated) of the control unit 5
`(block 400). The current mean value AZM represents an esti- 30 ti on of gravity. The detection axis nearest to the vertical is the
`mate of the DC component of the acceleration signal Az,
`axis along which the contribution of the acceleration of grav-
`which, when the cell phone 2 containing the pedometer 1 is
`ity is greater. The pedometer can then be us巳d independently
`stationary, is determined substantially by the contribution of
`of how it is oriented.
`the acceleration of grav即 alo吨 the detection axis z. In
`The i盯entio川laimed ~~：
`.1: A method for controllmg a p巳：dometer, the method com-
`practice, then, the current mean value AZM provides an esti- 35
`mate of the position of the cell phone 2 and of the pedometer
`pnsmg:
`1.
`generating a signal correlated to movements ofa user of the
`pedometer;
`After storage of the current mean valueAZM, the pedometer
`detecting steps of the user based on said signal;
`1 is set in a low-consumption operating condition (power-
`checking whether sequences of the detect巳d steps indicate
`down condition), in which at least the inertial sensor 3 is
`whether the sequences of the detected steps correspond
`inactive (block 410).
`to a regular gait of the user;
`A waiting cycle is then carried out (block 420), for example
`updating a total number of valid steps if said sequences
`of the duration of 10 s, after which all the functions of the
`correspond to the regular gait of the user;
`pedometer 1 are re-activated (“power on”, block 430).
`preventing updating of said total number of valid steps if
`said sequences do not correspond to the regular gait of
`The control unit 5 acquires from the inertial sensor 3 a
`the user: and
`number of samples of the acceleration signal A2 sufficient for
`创timating an updated mean value AZM’(block 440), which is
`partially deactivating the pedometer if said detecting 阳ps
`then compared with the current mean value AZM previously
`of the user based on said signal fails for a period longer
`than a time threshold.
`stored (block 450).
`If the updated mean value AZM' departs from the current
`2. The method according to claim 1, wherein said checking
`mean value AZM (output NO from block 450), the surveying
`comprises:
`in a first operating condition, checking whether a first
`procedure is interrupted, and the first counting procedure
`condition of regularity is satisfied; and
`indicated in block 110 of FIG. 3 is executed. I卫 instead, the
`updated mean value AZM' is substantially unvaried with 55
`in a second operating condition, checking whether a sec-
`respect to the current mean value AZM (output YES from
`ond condition ofregularity is satisfied.
`block 450), the surveying procedure proc臼ds and thepedom-
`3. The method according to claim 2, wherein, during said
`checking whether said first condition ofregularity is satisfied,
`eter 1 is set again in the low-consumption operating condition
`the updating of said total number of valid steps is prevented.
`(block 410).
`Clearly, the use of the surveying procedure enables a dras- 60
`4. The method according to claim 2, wherein, during said
`checking whether said second condition of regularity is sat-
`tic reduction in the power consumption when the pedometer
`1 is not used and, hence increases the autonomy thereof. If, as
`isfied, the updating of said total number of valid steps is
`in the embodiment described, the pedometer 1 is integrated in
`allowed.
`a portable device with which it shares the use of resources, for
`5. A method for controlling a p巳：dometer, the method com-
`ex缸丑ple the control unit 5, the survey