CN106910314B - A kind of personalized fall detection method based on the bodily form - Google Patents

A kind of personalized fall detection method based on the bodily form Download PDF

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CN106910314B
CN106910314B CN201710063265.XA CN201710063265A CN106910314B CN 106910314 B CN106910314 B CN 106910314B CN 201710063265 A CN201710063265 A CN 201710063265A CN 106910314 B CN106910314 B CN 106910314B
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蒋昌俊
闫春钢
王成
傅晓玲
谭正
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Tongji University
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    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/02Alarms for ensuring the safety of persons
    • G08B21/04Alarms for ensuring the safety of persons responsive to non-activity, e.g. of elderly persons
    • G08B21/0407Alarms for ensuring the safety of persons responsive to non-activity, e.g. of elderly persons based on behaviour analysis
    • G08B21/043Alarms for ensuring the safety of persons responsive to non-activity, e.g. of elderly persons based on behaviour analysis detecting an emergency event, e.g. a fall
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/02Alarms for ensuring the safety of persons
    • G08B21/04Alarms for ensuring the safety of persons responsive to non-activity, e.g. of elderly persons
    • G08B21/0438Sensor means for detecting
    • G08B21/0446Sensor means for detecting worn on the body to detect changes of posture, e.g. a fall, inclination, acceleration, gait

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Abstract

The purpose of the present invention is to overcome the deficiency in the prior art, and design personalized and really practical high-precision fall detection method propose use the feature selection approach based on the bodily form thus.A kind of personalized fall detection method based on the bodily form, it is divided into four-stage, the number of first stage record experiment user, the essential informations such as height and weight, and the acceleration transducer and gyroscope embedded using smart phone records its X under required movement, Y, the acceleration and angular speed information in three directions of Z axis calculate 13 common time domain features according to these data informations after carrying out data prediction.Second stage is gathered user for 3-5 class using k means clustering method according to height and body-mass index (body-mass index, that is, weight kilogram counts square divided by height rice number) information of user.Deng.

Description

A kind of personalized fall detection method based on the bodily form
Technical field
The present invention relates to human body fall detection technical fields.
Background technique
With the acceleration evolution of social senilization, the physically and mentally healthy problem of the elderly obtains people and more pays close attention to.It falls It is one of the key factor for causing the elderly's disability even dead, much because dead caused by falling and indirect because of falling this Body, but because caused by not given treatment to timely after falling.Therefore fall detection system is protected as the safety of the elderly Barrier, higher detection accuracy are the emphasis that we study.
Different fall detection technologies is had proposed and had studied at present, but is not widely used.Main cause is These fall detectors of all users use unified disaggregated model, do not account for the movement difference between user, cause to examine It is lower to survey precision.Therefore, in order to solve this problem, the relevant technologies propose personalized fall detection system- Chameleon.By combining the threshold strategies based on group with individual adjusting thresholds strategy, the threshold value based on weight is established Model is extracted, solves low precision problem caused by fixed threshold.However, the system only considers gender and the age of user, and It does not account for realizing more accurate fall detector using the body profile parameter of different users.In addition, adaptive technique is only fitted For early stage.It does not account for after user determined threshold value, some variations occur for the behavior of user, and threshold value cannot be again The case where change.Thus while the algorithm based on threshold value is relatively easy, but it can not fully achieve the tumble of property one by one Detection system.The method based on threshold value is removed in fall detection technology, there are also the methods of pattern-recognition, it is relative to threshold test Method is more accurate.Although having the personalized fall detection method based on pattern-recognition at present, however, what this technology used It is video mode, it limits the freedom of user, is very easy to leakage privacy of user, and cannot use in the dark.Therefore, Given this disadvantage, wearable fall detection mode are more big well-established.The technology on wearable device by being embedded in acceleration Degree meter, the sensors such as gyroscope realize the real time monitoring to monitoring individual.In the pattern-recognition fall detection based on smart phone In technology, it will usually select optimal characteristic of division using feature selection approach to improve characteristic of division.But it is only capable of into The tumble event of function identification about 90%.
Based on this, the present invention is filtered out during different body parameter groups fall using feature selecting algorithm and is changed significantly Character subset, using this feature trained group disaggregated model, realize based on bodily form feature selecting personalized falls Detection method.
Summary of the invention
The purpose of the present invention is to overcome the deficiency in the prior art, design personalized and really practical high-precision fall detection Method proposes use the feature selection approach based on the bodily form thus.This is because we have found for different users he Optimal detection feature be different.But the computation complexity of individualized feature is selected but to make this for each specific user Method is difficult to realize.
For this purpose, the technical solution provided are as follows:
A kind of personalized fall detection method based on the bodily form, which is characterized in that it is divided into four-stage,
First stage records the number of experiment user, the essential informations such as height and weight, and embedded using smart phone Acceleration transducer and gyroscope record its X under required movement, Y, the acceleration and angular speed information in three directions of Z axis, It carries out data prediction and calculates 13 common time domain features according to these data informations later.
(body-mass index, that is, weight kilogram number is divided by height according to the height and body-mass index of user for second stage Square of rice number) information, user is gathered for 3-5 class using k means clustering method.
Phase III combines the 13 most common time domain features for each user being calculated in the first stage Cluster situation with the user in second stage, using packaged type feature selecting algorithm calculate the optimal motion characteristic of every class user to Amount.First three above-mentioned stage is the data prediction of experiment user, predominantly obtains the optimal motion characteristic vector of every class user.
Fourth stage is the scene of practical application.The user according to obtained in second stage classifies situation and in the phase III The optimal motion characteristic vector of obtained every class user, using the method for support vector machines combine body inclination angle based on threshold value and The duration judgement of improper body posture carries out fall detection again, continues to optimize classification finally by on-line learning algorithm Parameter realizes high-precision personalized fall detection algorithm.
The first stage specific implementation step:
The number of user 1-1) is recorded, the essential informations such as height and weight will be equipped with acceleration transducer and top later The smart phone of the data acquisition program of spiral shell instrument is placed in the waist pocket of user, and direction is random.Pass through 6 normal behaviours (walking is jogged, and jump goes upstairs, goes downstairs, sits down) (forward direction is fallen, backward to fall, laterally for the tumble behavior different with 3 kinds Fall) carry out data acquisition.Because human motion frequency is generally below 20Hz, therefore according to Nyquist Sampling Theorem, data are acquired Frequency is 50Hz.The number information of user is wherein indicated using N, H indicates the height data of user, and W indicates the weight letter of user Breath, ax, ay, azIndicate the X of collected acceleration transducer, the acceleration information of tri- axis of Y, Z, px, py, pzExpression collects Gyroscope X, the angular velocity data of tri- axis of Y, Z.
1-2) using Kalman filtering algorithm to 1-1) in ax, ay, azAnd px, py, pzSix groups of data are pre-processed, and are disappeared Influence except noise to acceleration transducer and gyroscope measured value, to improve the accuracy of data.
1-3) based on the acceleration and angular velocity data after 1-2) filtering processing, the resultant acceleration of every user is calculated ValueWith close angle velocity amplitudeAnd extract 13 correlated characteristic F ={ f1,f2,…,fi,…fn(n=13), specific features are described as follows:
f1: aveVSA, i.e. the mean value of VSA.
f2: aveVSP, i.e. the mean value of VSP.
f3: Δ VSA, i.e. VSA maximin absolute value of the difference.
f4: Δ VSP, i.e. VSP maximin absolute value of the difference.
f5: Δ tVSA, i.e. time difference corresponding to VSA maximin.
f6: Δ tVSP, i.e. time difference corresponding to VSP maximin.
f7: stdVSA, i.e. the standard deviation of VSA.
f8: stdVSP, i.e. the standard deviation of VSP.
f9: EVSA, i.e., movable energy value, wherein
f10: S, i.e. slope, wherein
f11: Δ φ, i.e. body minimax inclination angle difference, wherein φ (t) indicates t moment body and ground angle,
f12: Δ pitch, the minimax difference of pitch angle, wherein
f13: Δ roll, the minimax difference of roll angle, wherein
The second stage specific implementation step:
2-1) as 1-1) obtained in user's height data H and weight data W calculate user's body performance figure BMI=H/ W2, and the physiological characteristic vector of user is expressed as FB=(H, BMI).
2-2) based on the user's physiological characteristic vector F being calculated in 2-1)B, user is gathered using K mean cluster algorithm For 3~5 classes.
The phase III specific implementation step:
3-1) to 1-3) in motion characteristic set F={ f1,f2,…,fi,…fn(n=13), owned by traversal Motion characteristic proper subclass set G={ F1,F2,…,Fj,…Fm(m=8191).
3-2) randomly select sample for every group of user 80 percent passes through 3-1 respectively) in motion characteristic proper subclass Feature in set G uses support vector machines train classification models, is tested using remaining 20 percent sample.Make The method verified with right-angled intersection, seeks each feature vector FjThe disaggregated model trained is attainable for every group of user institute Precision.Finally choose the optimal motion characteristic vector F that can make to reach the highest feature vector of precision as the groupA.If in case of Dry feature vector reaches precision highest simultaneously, then feature quantity is least as optimal characteristics vector F in selected characteristic vectorA
The fourth stage specific implementation step:
4-1) in practice, affiliated group is matched according to specific user's physiological characteristic, affiliated group pair is extracted to it The optimal characteristics vector answered, and disaggregated model is constructed using support vector machines, carry out first fall detection judgement.
4-2) in order to further improve the performance of fall detection system, will add two features here: most lifelong Then the duration at body inclination angle and improper body posture judge again using thresholding algorithm to reduce False Rate.Choosing The reason of selecting the two features is that the value size of their threshold values is unrelated with the body parameter of user.Only when this improper appearance The tilt angle of gesture and duration are just finally judged as falling when being more than the threshold value of our settings.
By on-line study machine after characteristic of division building fall detection model 4-3) selected according to user's group The daily behavior of system study specific user and judge that data constantly adjusts and Optimum Classification parameter, really realization personalization with Adaptive fall detection.
The daily behavior of on-line study mechanism study specific user and judge that data constantly adjust and Optimum Classification Parameter really realizes personalized and adaptive fall detection, and algorithm is as follows:
Input: user's height H and weight W
Output: tumble behavior occurs for user
(1) the specific body parameter inputted according to user, including height H and weight W, the body quality for calculating user refer to Number BMI, and the affiliated group of the user is matched with BMI according to H, it executes step (2).
(2) X, the Y of user, the acceleration information and angular velocity data of Z axis are acquired in real time, and extracting according to acquisition data should The optimal motion characteristic vector value of group corresponding to user executes step (3).
(3) fall detection detection judgement is carried out using the method for support vector machines (SVM), if judging result is normal behaviour It thens follow the steps (5), it is no to then follow the steps (4).
(4) judging result is further detected for the case where improper behavior, passes through and extracts the most lifelong of user The duration at body inclination angle and improper body posture judge again using thresholding algorithm to reduce False Rate.Judge non- Whether the tilt angle of normal posture and duration are more than threshold value that we are arranged, if so then execute step (5), and export use Tumble behavior occurs for family, no to then follow the steps (5).
(5) learn daily behavior and the tumble behavior of specific user, continuous adjustment and optimization by on-line study mechanism Sorting parameter executes step (2).
The present invention is grouped according to the similitude of the optimal characteristics of all experiment users first, and calculates each group most Excellent feature vector.Experiment shows that the detection accuracy of this method significantly improves.In addition, we experimentally found that based on user's The similitude classification of the bodily form (i.e. height and body-mass index) can produce and be based on personal optimal characteristics similitude classification side The almost the same result of method.Therefore, we indicated that the feature selecting based on the bodily form can effectively improve detection accuracy.In reality In, by according to user's bodily form extract it belonging to the corresponding optimal characteristics vector of grouping, use support vector machines and threshold value Judge that the mode combined carries out fall detection judgement, further improves detection accuracy in this way.It is learned secondly by online Habit mode constantly adjusts and Optimum Classification parameter, really realizes personalized and adaptive fall detection.
Detailed description of the invention
A kind of personalized fall detection method module map based on the bodily form of Fig. 1
1 flow chart of Fig. 2 algorithm
Specific embodiment
(case)
Entire scheme is divided into four-stage, as shown in Figure 1: the number of first stage record experiment user, height and weight Etc. essential informations, and using smart phone embed acceleration transducer and gyroscope record its X, Y, Z axis under required movement The acceleration and angular speed information in three directions calculates 13 often according to these data informations after carrying out data prediction With time domain characteristic of division.Second stage is according to height and the body-mass index (body-mass index, that is, weight kilogram number of user Divided by square of height rice number) information, user is gathered for 3-5 class using k means clustering method.Phase III combines the first stage In user in the 13 most common time domain features and second stage of each user that are calculated cluster situation, make The optimal motion characteristic vector of every class user is calculated with packaged type feature selecting algorithm.First three stage is that the data of experiment user are pre- Processing, predominantly obtains the optimal motion characteristic vector of every class user, and fourth stage is the scene of practical application.According to second-order User obtained in section classifies the optimal motion characteristic vector of every class user obtained in situation and phase III, using support to The method of amount machine combines the duration judgement at body inclination angle and improper body posture based on threshold value to carry out inspection of falling again It surveys, continues to optimize sorting parameter finally by on-line learning algorithm and realize high-precision personalized fall detection algorithm.
1, first stage specific implementation step:
The number of user 1-1) is recorded, the essential informations such as height and weight will be equipped with acceleration transducer and top later The smart phone of the data acquisition program of spiral shell instrument is placed in the waist pocket of user, and direction is random.Pass through 6 normal behaviours (walking is jogged, and jump goes upstairs, goes downstairs, sits down) (forward direction is fallen, backward to fall, laterally for the tumble behavior different with 3 kinds Fall) carry out data acquisition.Because human motion frequency is generally below 20Hz, therefore according to Nyquist Sampling Theorem, data are acquired Frequency is 50Hz.The number information of user is wherein indicated using N, H indicates the height data of user, and W indicates the weight letter of user Breath, ax, ay, azIndicate the X of collected acceleration transducer, the acceleration information of tri- axis of Y, Z, px, py, pzExpression collects Gyroscope X, the angular velocity data of tri- axis of Y, Z.
1-2) using Kalman filtering algorithm to 1-1) in ax, ay, azAnd px, py, pzSix groups of data are pre-processed, and are disappeared Influence except noise to acceleration transducer and gyroscope measured value, to improve the accuracy of data.
1-3) based on the acceleration and angular velocity data after 1-2) filtering processing, the resultant acceleration of every user is calculated ValueWith close angle velocity amplitudeAnd extract 13 correlated characteristic F ={ f1,f2,…,fi,…fn(n=13), specific features are described as follows:
f1: aveVSA, i.e. the mean value of VSA.
f2: aveVSP, i.e. the mean value of VSP.
f3: Δ VSA, i.e. VSA maximin absolute value of the difference.
f4: Δ VSP, i.e. VSP maximin absolute value of the difference.
f5: Δ tVSA, i.e. time difference corresponding to VSA maximin.
f6: Δ tVSP, i.e. time difference corresponding to VSP maximin.
f7: stdVSA, i.e. the standard deviation of VSA.
f8: stdVSP, i.e. the standard deviation of VSP.
f9: EVSA, i.e., movable energy value, wherein
f10: S, i.e. slope, wherein
f11: Δ φ, i.e. body minimax inclination angle difference, wherein φ (t) indicates t moment body and ground angle,
f12: Δ pitch, the minimax difference of pitch angle, wherein
f13: Δ roll, the minimax difference of roll angle, wherein
2, second stage specific implementation step:
2-1) as 1-1) obtained in user's height data H and weight data W calculate user's body performance figure BMI=H/ W2, and the physiological characteristic vector of user is expressed as FB=(H, BMI).
2-2) based on the user's physiological characteristic vector F being calculated in 2-1)B, user is gathered using K mean cluster algorithm For 3~5 classes.
2-3) in 2-2) in use FBIt is described as follows as the reason of cluster foundation: the current research in relation to fall detection In, influence of the different motion characteristics for final accuracy rate does not obtain abundant consideration, we have chosen quotes in recent years 13 class motion characteristic used in relatively high research is measured, based on the data acquired in 1-1), is calculated for every user Arrived 1-3) shown in motion characteristic, and be found through experiments that for every user all there is one group of specific accuracy rate most High motion characteristic, this group of motion characteristic is defined as the optimal motion characteristic vector F of user by weA.Our experiment is simultaneously It demonstrates in fall monitoring system, if we can calculate an optimal motion characteristic vector to every user, Detection accuracy is available to be obviously improved.But in practical applications, for every user train an optimal motion characteristic to A series of problems, such as amount is faced with cold start-up, data acquisition and computing resource is limited, therefore, if certain generic features can be passed through Classify to user, and calculate its distinctive optimal motion characteristic vector for every a kind of user, is to solve actual application problem An approach.In order to find this generic features, we are firstly the need of providing the classification being of practical significance for fall detection. So on the basis of previous experiments, it is believed that the similarity of the optimal characteristics vector between two users is higher, they are just More it is possible that in one kind, experiment user is divided into 3-5 class, each group of optimal motion characteristic vector eventually by the similarity gFAEqually obtained via experimental calculation.It is demonstrated experimentally that by the rule classification, final accuracy in detection be every user Calculate FAObtained accuracy no significant difference.But this classifying rules is not suitable for practical application.By to every class The observation of user's various features (including gender, age, height, weight etc.), it has been found that height H and body in each group group Performance figure BMI difference is smaller, and group difference is larger.Our physiological characteristic vectors based on user as a result, use K mean value User is equally polymerized to n class by cluster, it is found that the cluster result coincide substantially with the result according to the grouping of optimal motion characteristic vector, Therefore in practical applications, we can be according to physiological characteristic vector FBClassify to user, and the optimal movement for calculating every class is special Vector is levied, when a new user arrives, only need to can correspond to its optimal movement according to the physiological characteristic vector of its own Feature vector.
2-4) in 2-3) in user gathered be described as follows for the reason of 3 to 5 class: according to above-mentioned analysis it is found that based on user In the classification of optimal motion characteristic vector, granularity of classification is thinner, then every group of accessible precision reality that is higher, but passing through us It issues after examination and approval now, if granularity of classification is too thin, the diversity factor of the physiological characteristic vector in every class and between all kinds of is not obvious enough, it is difficult to use Physiological characteristic vector alternative acts feature vector is classified.We are tested by multiple groups and are found, 3 to 5 classes are most suitably adapted for reality The classification of border application.
3, phase III specific implementation step:
3-1) to 1-3) in motion characteristic set F={ f1,f2,…,fi,…fn(n=13), owned by traversal Motion characteristic proper subclass set G={ F1,F2,…,Fj,…Fm(m=8191).
3-2) randomly select sample for every group of user 80 percent passes through 3-1 respectively) in motion characteristic proper subclass Feature in set G uses support vector machines train classification models, is tested using remaining 20 percent sample.Make The method verified with right-angled intersection, seeks each feature vector FjThe disaggregated model trained is attainable for every group of user institute Precision.Finally choose the optimal motion characteristic vector F that can make to reach the highest feature vector of precision as the groupA.If in case of Dry feature vector reaches precision highest simultaneously, then feature quantity is least as optimal characteristics vector F in selected characteristic vectorA
4, fourth stage specific implementation step:
4-1) in practice, affiliated group is matched according to specific user's physiological characteristic, affiliated group pair is extracted to it The optimal characteristics vector answered, and disaggregated model is constructed using support vector machines, carry out first fall detection judgement.
4-2) in order to further improve the performance of fall detection system, will add two features here: most lifelong Then the duration at body inclination angle and improper body posture judge again using thresholding algorithm to reduce False Rate.Choosing The reason of selecting the two features is that the value size of their threshold values is unrelated with the body parameter of user.Only when this improper appearance The tilt angle of gesture and duration are just finally judged as falling when being more than the threshold value of our settings.
By on-line study machine after characteristic of division building fall detection model 4-3) selected according to user's group The daily behavior of system study specific user and judge that data constantly adjusts and Optimum Classification parameter, really realization personalization with Adaptive fall detection (being specifically shown in algorithm 1).
Personalized fall detection algorithm of the algorithm 1 based on the bodily form (detailed process is shown in Fig. 2)
Input: user's height H and weight W
Output: tumble behavior occurs for user
(1) the specific body parameter inputted according to user, including height H and weight W, the body quality for calculating user refer to Number BMI, and the affiliated group of the user is matched with BMI according to H, it executes step (2).
(2) X, the Y of user, the acceleration information and angular velocity data of Z axis are acquired in real time, and extracting according to acquisition data should The optimal motion characteristic vector value of group corresponding to user executes step (3).
(3) fall detection detection judgement is carried out using the method for support vector machines (SVM), if judging result is normal behaviour It thens follow the steps (5), it is no to then follow the steps (4).
(4) judging result is further detected for the case where improper behavior, passes through and extracts the most lifelong of user The duration at body inclination angle and improper body posture judge again using thresholding algorithm to reduce False Rate.Judge non- Whether the tilt angle of normal posture and duration are more than threshold value that we are arranged, if so then execute step (5), and export use Tumble behavior occurs for family, no to then follow the steps (5).
(5) learn daily behavior and the tumble behavior of specific user, continuous adjustment and optimization by on-line study mechanism Sorting parameter executes step (2).
Innovative point of the present invention
1. this project find and demonstrate user optimal detection feature it is related to its bodily form feature (height and weight) Property.
2. this project proposes the personalized fall detection method based on the bodily form, filtered out using feature selecting algorithm The character subset that different body parameter groups are changed significantly during falling, using this feature trained group disaggregated model, Realize the personalized fall detection method based on bodily form feature selecting.
Annotation: the present invention in related term and following data can be found in for previous major technique.
[1]Ren L,Shi W.Chameleon:personalised and adaptive fall detection of elderly people in home-based environments[J].International Journal of Sensor Networks,2016,20(3):163-176.
[2]Yu M,Yu Y,Rhuma A,et al.An online one class support vector machine-based person-specific fall detection system for monitoring an elderly individual in a room environment[J].IEEE journal of biomedical and health informatics,2013,17(6):1002-1014.
[3]Baek W S,Kim D M,Bashir F,et al.Real life applicable fall detection system based on wireless body area network[C]//2013 IEEE 10th Consumer Communications and Networking Conference(CCNC).IEEE,2013:62-67.
[4]Pierleoni P,Belli A,Palma L,et al.A high reliability wearable device for elderly fall detection[J].IEEE Sensors Journal,2015,15(8):4544- 4553.
[5]Shan S,Yuan T.A wearable pre-impact fall detector using feature selection and support vector machine[C]//IEEE 10th INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING PROCEEDINGS.IEEE,2010:1686-1689.
[6]Liang S,Ning Y,Li H,et al.Feature selection and predictors of falls with foot force sensors using KNN-based algorithms[J].Sensors,2015,15 (11):29393-29407.
[7]Kansiz A O,Guvensan M A,Turkmen H I.Selection of time-domain features for fall detection based on supervised learning[C]//Proceedings of the World Congress on Engineering and Computer Science,San Francisco,CA, USA.2013:23-25.

Claims (5)

1. a kind of personalized fall detection method based on the bodily form, which is characterized in that it is divided into four-stage,
First stage records number, height and the weight essential information of experiment user, and the acceleration embedded using smart phone Sensor and gyroscope record its X under required movement, Y, and the acceleration and angular speed information in three directions of Z axis is being counted 13 common time domain features are calculated according to these data informations after Data preprocess;
For second stage according to the height and body-mass index information of user, being gathered user using k means clustering method is 3~5 Class;
Phase III combines the 13 most common time domain features of each user being calculated in the first stage and the User in two-stage clusters situation, and the optimal motion characteristic vector of every class user is calculated using packaged type feature selecting algorithm;
First three above-mentioned stage is the data prediction of experiment user, predominantly obtains the optimal motion characteristic vector of every class user;
Fourth stage is the scene of practical application: the user according to obtained in second stage classifies situation and to be obtained in the phase III Every class user optimal motion characteristic vector, using the method for support vector machines combine body inclination angle based on threshold value and it is non-just The duration judgement of normal body posture carries out fall detection again, continues to optimize sorting parameter finally by on-line learning algorithm Realize high-precision personalized fall detection algorithm;
The first stage specific implementation step:
Number, height and the weight essential information of user 1-1) are recorded, acceleration transducer and gyroscope will be installed later The smart phone of data acquisition program is placed in the waist pocket of user, and direction is random;Not by 6 normal behaviours and 3 kinds Same tumble behavior carries out data acquisition, and 6 normal behaviours are walking, jog, jump, going upstairs, going downstairs, sitting down, Described 3 kinds different tumble behaviors are to falling, falling backward, laterally tumble for before, and acquisition data frequency is 50Hz, wherein using N indicates the number information of user, and H indicates the height data of user, and W indicates the weight information of user, ax, ay, azExpression collects Acceleration transducer X, the acceleration information of tri- axis of Y, Z, px, py, pzIndicate the X of collected gyroscope, Y, Z tri- The angular velocity data of axis;
1-2) using Kalman filtering algorithm to 1-1) in ax, ay, azAnd px, py, pzSix groups of data are pre-processed, and elimination is made an uproar Influence of the sound to acceleration transducer and gyroscope measured value, to improve the accuracy of data;
1-3) be based on 1-2) filtering processing after acceleration and angular velocity data, be calculated every user resultant acceleration value and Close angle velocity amplitude, resultant acceleration valueClose angle velocity amplitudeAnd extract ten Three correlated characteristic F={ f1,f2,…,fi,…fn, n=13 is 13 common time domain features, specific features explanation It is as follows:
f1: aveVSA, i.e. the mean value of VSA;
f2: aveVSP, i.e. the mean value of VSP;
f3: Δ VSA, i.e. VSA maximin absolute value of the difference;
f4: Δ VSP, i.e. VSP maximin absolute value of the difference;
f5: Δ tVSA, i.e. time difference corresponding to VSA maximin;
f6: Δ tVSP, i.e. time difference corresponding to VSP maximin;
f7: stdVSA, i.e. the standard deviation of VSA;
f8: stdVSP, i.e. the standard deviation of VSP;
f9: EVSA, i.e., movable energy value, wherein
f10: S, i.e. slope, wherein
f11: Δ φ, i.e. body minimax inclination angle difference, wherein φ (t) indicates t moment body and ground angle,
f12: Δ pitch, the minimax difference of pitch angle, wherein
f13: Δ roll, the minimax difference of roll angle, wherein
2. the method as described in claim 1, which is characterized in that the second stage specific implementation step:
2-1) as 1-1) obtained in user's height data H and weight data W calculate user's body performance figure BMI=H/W2, and The physiological characteristic vector of user is expressed as FB=(H, BMI);
2-2) based on the user's physiological characteristic vector F being calculated in 2-1)B, being gathered user using K mean cluster algorithm is 3~5 Class.
3. the method as described in claim 1, which is characterized in that the phase III specific implementation step:
3-1) to 1-3) in motion characteristic set F={ f1,f2,…,fi,…fn, n=13 obtains all movements by traversal Feature proper subclass set G={ F1,F2,…,Fj,…Fm, m=8191;
3-2) randomly select sample for every group of user 80 percent passes through 3-1 respectively) in motion characteristic proper subclass set G In feature use support vector machines train classification models, tested using remaining 20 percent sample;Use ten The method of word cross validation seeks each feature vector FjThe disaggregated model trained is for every group of attainable essence of user institute Degree;Finally choose the optimal motion characteristic vector F that can make to reach the highest feature vector of precision as the groupA;In case of several Feature vector reaches precision highest simultaneously, then feature quantity is least as optimal characteristics vector F in selected characteristic vectorA
4. the method as described in claim 1, which is characterized in that the fourth stage specific implementation step:
4-1) in practice, affiliated group is matched according to specific user's physiological characteristic, it is corresponding that affiliated group is extracted to it Optimal characteristics vector, and disaggregated model is constructed using support vector machines, carry out first fall detection judgement;
4-2) in order to further improve the performance of fall detection system, two features are added: final body inclination angle and improper Then the duration of body posture judge again using thresholding algorithm to reduce False Rate;Select the two features The reason is that the value size of their threshold values is unrelated with the body parameter of user;Only when the tilt angle of this improper posture and Duration is just finally judged as falling when being more than the threshold value of setting;
By on-line study mechanism after characteristic of division building fall detection model 4-3) selected according to user's group It practises the daily behavior of specific user and judges that data constantly adjust and Optimum Classification parameter, real realization are personalized and adaptive The fall detection answered.
5. method as claimed in claim 4, which is characterized in that the daily behavior of the on-line study mechanism study specific user It is constantly adjusted and Optimum Classification parameter with data are judged, really realizes personalized and adaptive fall detection, algorithm is such as Under:
Input: user's height H and weight W
Output: tumble behavior occurs for user
(1) the specific body parameter inputted according to user, including height H and weight W, calculate the body-mass index of user BMI, and the affiliated group of the user is matched with BMI according to H, it executes step (2);
(2) X, the Y of user, the acceleration information and angular velocity data of Z axis are acquired in real time, and extract the user according to acquisition data The optimal motion characteristic vector value of corresponding group executes step (3);
(3) fall detection detection judgement is carried out using the method for support vector machines, executes step if judging result is normal behaviour Suddenly (5), it is no to then follow the steps (4);
(4) judging result is further detected for the case where improper behavior, the final body by extracting user inclines The duration at angle and improper body posture judge again using thresholding algorithm to reduce False Rate;Judge improper Whether the tilt angle of posture and duration are more than threshold value that we are arranged, if so then execute step (5), and export user's hair Raw tumble behavior, it is no to then follow the steps (5);
(5) learn daily behavior and the tumble behavior of specific user, continuous adjustment and Optimum Classification by on-line study mechanism Parameter executes step (2).
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