CN104793766A - Wireless mouse implementation method based on radio frequency tag - Google Patents

Abstract

The invention discloses a wireless mouse implementation method based on a radio frequency tag. The wireless mouse implementation method includes the steps that A, the tag is pasted to the specific position of a small ball; B, phase position values are collected through an antenna array; C, the original state of the small ball is calculated; D, the moving small ball is tracked; E, transition of changes of the state of the small ball is carried out; F, the changes of the state of the small ball are converted into user interaction behaviors. By means of the wireless mouse implementation method, influences of white noise and diversity in radio frequency identification positioning can be effectively eliminated; through overall modeling on the small ball, the phase position of the radio frequency tag serves as the observation amount, high precision real-time tracking on the state of the small ball is carried out, the user interaction behaviors are accordingly speculated, and a wireless mouse based on the radio frequency tag is obtained.

Description

A kind of wireless mouse implementation method based on radio-frequency (RF) tag

Technical field

The present invention relates to technical field of three-dimensional interaction, particularly relate to a kind of wireless mouse implementation method based on radio-frequency (RF) tag.

Background technology

Mouse has obtained applying the most widely since being invented by American scientist Douglas Engelbart from 1963 in human-computer interaction device.Mouse carrys out work by detecting its two dimensional motion in operation plane, and it plays a part great in two-dimentional man-machine interaction.But along with the development of three-dimensional technology for revealing, in computing machine use procedure, user needs to process three-dimensional scenic, and traditional mouse can not well be applied in three-dimensional scenic.So Three-Dimensional Interaction Technology arises at the historic moment.

Existing Three-Dimensional Interaction Technology is mainly divided three classes: based on the method for computer vision, sensor-based method and apparatus independently method.Method based on computer vision utilizes the correlation technique of image procossing to catch user action by camera and infrared ray, and the Kinect of such as Microsoft can identify the joint motions of user, and LeapMotion can the finger of track user.But the method for view-based access control model must guarantee that user directly can be caught on camera head and catch, and is difficult to the problem processing user's overlap.Sensor-based method utilizes a large amount of sensors to carry out perception to user behavior, such as data glove.But the cost of these class methods is high, be difficult to popularize.Equipment independently method utilizes human body on the impact of electromagnetic wave or Acoustic Wave Propagation to judge user behavior, and its accuracy is limited.

Radio-frequency (RF) identification (Radio Frequency Identification, RFID) technology obtains increasing application in daily life.Because RFID label tag and radio-frequency (RF) tag are disposed conveniently, deployment that can be a large amount of at a lower cost.A label is made up of a microchip and antenna.Reader can collect the identity recognition number (ID) of label under the prerequisite of not contact chip.The original intention of RFID design is automatic recognition object, but in recent years, its potential application obtains to be studied widely.Utilize RFID to carry out man-machine interaction and can overcome above-mentioned three class methods Problems existing, but the current technology for single radio frequency label also exists that phase measurement is inaccurate, Doppler shift, precision are not enough, affect the problems such as large by staff.

Summary of the invention

The object of the invention is to, by a kind of wireless mouse implementation method based on radio-frequency (RF) tag, solve the problem that above background technology part is mentioned.

For reaching this object, the present invention by the following technical solutions:

Based on a wireless mouse implementation method for radio-frequency (RF) tag, it comprises:

A, label is attached to bead assigned address;

B, by aerial array, acquisition phase value;

The original state of C, calculating bead;

D, to motion in bead follow the trail of;

E, to bead state change smoothing;

F, by bead state change be converted to user interactions behavior.

Especially, described steps A specifically comprises:

According to certain rule, divide sphere place area of space;

Radio-frequency (RF) tag to be attached to equably on sphere or other positions in spheroid, to guarantee that the relative position of label and spheroid does not change;

Set up spheroidal coordinate system, calculate the coordinate figure of each label under spheroidal coordinate system.

Especially, described step B specifically comprises:

Control antenna array acquisition also records the phase value of label;

For the label that antenna does not read, record its phase value for empty.

Especially, described step C specifically comprises:

The state space possible to bead divides;

Travel through coccoid state space, suppose that the subregion state of each division is dbjective state;

Calculate by the notional phase value on hypothesis state ball between each label and each antenna;

Relatively notional phase value and measurement phase value, assessing each hypothesis state is target-like probability of state.

Especially, described step D specifically comprises:

The state change of prediction bead;

The theoretical value that distance after obtaining state change on ball between each label and each antenna changes;

According to the difference size of the distance changing value of described theoretical value and actual computation, the state estimation of bead is revised;

Wherein, the state change of described prediction bead specifically comprises: the state vector obtaining laststate bead; Utilization state vector, according to state transition equation, obtains the state vector of bead at current time;

The described theoretical value obtaining the distance on the rear ball of state change between each label and each antenna and change; According to the difference size of the distance changing value of described theoretical value and actual computation, the state estimation of bead is revised, specifically comprises: calculate the weight factor between the transfer of bead state with observed reading; Weight factor is acted in the deviation of observed reading and theoretical value, revise the bead state vector of prediction, obtain bead state estimation.

Especially, described step e specifically comprises:

Choose that current time arrives for the previous period as level and smooth time window;

According to bead state estimation all in time window and the ball label phase value recorded, smoothing process is shifted to the state of bead.

Especially, described step F specifically comprises:

According to the state of bead in each moment, estimate the movement tendency of bead;

By the judgement to bead movement tendency, the interbehavior of estimating user.

Especially, in described steps A, set up spheroidal coordinate system, calculate the coordinate figure of each label under spheroidal coordinate system, specifically comprise:

Determine spheroidal coordinate system initial point;

Selected axis, sets up right hand rectangular coordinate system;

Record the coordinate figure of each tag hub on spheroid.

Especially, control antenna array acquisition in described step B also records the phase value of label, specifically comprises:

Reader is used to gather the phase value of label with preset rules scheduling antenna;

Record phase value and phase value acquisition time;

To calculate on ball each label compared with a upper moment with the changing value of the distance of each antenna.

Especially, state space possible to bead in described step C divides, and specifically comprises:

For the rotation status of bead, choose the characteristic quantity that can determine bead rotation status, calculate the span of each characteristic quantity, carry out decile according to default granularity;

For the translation state of bead, choose the characteristic quantity that can determine little ball position, calculate the span of each characteristic quantity, carry out decile according to default granularity;

The rotation peace shifting state amount of comprehensive bead, obtains the state space of the bead after dividing.

The wireless mouse implementation method based on radio-frequency (RF) tag that the present invention proposes effectively can eliminate white noise and multifarious impact in radio-frequency (RF) identification location, and pass through bead Holistic modeling, radio-frequency (RF) tag phase place is used as observed quantity, high precision real-time tracing is carried out to bead state, infer the interbehavior of user with this, realize the wireless mouse based on radio-frequency (RF) tag.

Accompanying drawing explanation

The wireless mouse implementation method process flow diagram based on radio-frequency (RF) tag that Fig. 1 provides for the embodiment of the present invention;

The label that Fig. 2 provides for the embodiment of the present invention and the graph of a relation between antenna distance and phase place;

The rotation angle schematic diagram that Fig. 3 provides for the embodiment of the present invention.

Embodiment

Below in conjunction with drawings and Examples, the invention will be further described.Be understandable that, specific embodiment described herein is only for explaining the present invention, but not limitation of the invention.It also should be noted that, for convenience of description, illustrate only part related to the present invention in accompanying drawing but not full content, unless otherwise defined, all technology used herein and scientific terminology are identical with belonging to the implication that those skilled in the art of the present invention understand usually.Term used herein, just in order to describe specific embodiment, is not intended to be restriction the present invention.

Please refer to shown in Fig. 1, the wireless mouse implementation method process flow diagram based on radio-frequency (RF) tag that Fig. 1 provides for the embodiment of the present invention.

Wireless mouse implementation method based on radio-frequency (RF) tag in the present embodiment specifically comprises:

S101, label is attached to bead assigned address.

According to certain rule, divide sphere place area of space.

Radio-frequency (RF) tag to be attached to equably on sphere or other positions in spheroid, to guarantee that the relative position of label and spheroid does not change.

Set up spheroidal coordinate system, calculate the coordinate figure of each label under spheroidal coordinate system, in the present embodiment, detailed process is as follows: determine spheroidal coordinate system initial point, usually elect the centre of sphere as, but be not limited to this; Selected axis, sets up right hand rectangular coordinate system; Record the coordinate figure of each tag hub on spheroid, be denoted as wherein, n is label sequence number, and b denotation coordination value obtains in spheroidal coordinate system.

S102, by aerial array, acquisition phase value.

Control antenna array acquisition also records the phase value of label, and in the present embodiment, detailed process is as follows: use reader to gather the phase value of label with preset rules scheduling antenna.Suppose currently have M root antenna, be expressed as A={A ₁, A ₂..., A _m, the position of every root antenna is known, and is connected to same reader, is scheduled successively and carries out digital independent.

Record phase value and phase value acquisition time.

For the label that antenna does not read, record its phase value for empty.

Any label recorded current slot t, for the phase value of any antenna, compares with the measured value of a upper time period t-1, to calculate on ball each label compared with a upper moment with the changing value of the distance of each antenna.Label and the relation between antenna distance and phase place are as shown in Figure 2, in figure, Tag is radio-frequency (RF) tag, Reader Antenna is reader antenna, d is the distance of radio-frequency (RF) tag and reader antenna, λ is electromagnetic wavelength, Backscatter wave is back scattering wave, and Orientation is the anglec of rotation of label, θ _t, θ _r, θ _tAGbe respectively the phase gain of emitting antenna, receiving antenna, label, θ is the phase value that reader parses:

$\mathrm{\θ}=(\frac{2\mathrm{\π}}{\mathrm{\λ}}\×2d+{\mathrm{\θ}}_T+{\mathrm{\θ}}_R+{\mathrm{\θ}}_{\mathrm{TAG}})\mathrm{mod}2\mathrm{\π}$

The phase differential of two time periods is denoted as Δ θ, and distance changing value is denoted as Δ d, then wherein, λ is electromagnetic wavelength, and k is-1,0, the integer in 1.Thus, distance change can be released by phase differential:

$\mathrm{\&Delta;d}=\left\{\begin{array}{c}\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}}\mathrm{\&Delta;\&theta;},\left|\mathrm{\&Delta;\&theta;}\right|\&le;\mathrm{\&pi;},k=0\\ \frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}}(\mathrm{\&Delta;\&theta;}+2\mathrm{\&pi;}),\mathrm{\&Delta;\&theta;}>\mathrm{\&pi;},k=-1\\ \frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}}(\mathrm{\&Delta;}-2\mathrm{\&pi;}),\mathrm{\&Delta;\&theta;}<-\mathrm{\&pi;},k=1\end{array}\right.$

Suppose to share N number of label, use Δ d _{m, n}distance during (t) expression time period t between reader antenna m and radio-frequency (RF) tag n and the changing value of a upper time period.

The original state of S103, calculating bead.

The state space possible to bead divides, and in the present embodiment, detailed process is as follows: for the rotation status of bead, chooses the characteristic quantity that can determine bead rotation status, calculates the span of each characteristic quantity, carries out decile according to the granularity preset.As shown in Figure 3, XYZ coordinate axle is the rigid body coordinate axis rotated, and xyz coordinate axis is actionless laboratory reference axle, N is xy-plane is the line of nodes with the crossing of XY-plane, α is the angle of x-axle and the line of nodes, and β is the angle of z-axle and Z-axle, and γ is the angle of the line of nodes and X-axle; The state of bead can be expressed as: S=[O Φ] ^t, wherein, O represents the position of the bead centre of sphere at world coordinate system, and Φ represents the rotation angle of label.

The present invention utilizes rotation angle as the quantity of state characterizing bead rotation, Φ=[φ _xφ _yφ _z], wherein, φ _x, φ _zscope be [0,2 π), φ _yscope be [0, π), granularity of division is π/180.

For the translation state of bead, choose the characteristic quantity that can determine little ball position, calculate the span of each characteristic quantity, carry out decile according to certain granularity.The present invention utilizes the coordinate O=[x of the bead centre of sphere in world coordinate system ₀y ₀z ₀] as the quantity of state characterizing bead translation, span is determined by bead range of movement, and granularity is 1cm.

The rotation peace shifting state amount of comprehensive bead, obtains the state space of the bead after dividing.In order to reduce calculated amount, system requirements user when initialization by bead towards assigned direction, suppose that user has the deviation of 10 ° three anglecs of rotation, bead moves in the region of 1m × 1m × 1m, and state space size is 10 × 10 × 10 × 100 × 100 × 100.

Travel through coccoid state space, suppose that the subregion state of each division is dbjective state, calculate by the notional phase value on hypothesis state ball between each label and each antenna.Suppose that bead is in a certain state, utilize the rotation angle Φ of bead, rotation matrix R can be released.So the coordinate of each label in world coordinate system on bead can be released

$T_n^w=R{T}_n^b+O$

Notional phase value can be drawn thus

$\mathrm{\&theta;}(A_m^w,T_n^w)=\frac{4\mathrm{\&pi;}}{\mathrm{\&lambda;}}|A_m^w,T_n^w|\mathrm{mod}2\mathrm{\&pi;}$

The theoretical value of all labels is Θ={ θ _1,1..., θ _m,N, suppose that measured value is relatively notional phase value and measurement phase value, assessing each hypothesis state is target-like probability of state.The present invention utilizes the principle of " enhancing hologram " to assess each shape probability of state, and the related function of theoretical value and measured value is

$\mathrm{Cov}(\widetilde{\mathrm{\&Theta;}},\mathrm{\&Theta;})=\left|{\mathrm{\&Sigma;}}_{m=1}^M{\mathrm{\&Sigma;}}_{n=1}^{N}2F\left(\right|\widetilde{{\mathrm{\&theta;}}_{m,n}}-{\mathrm{\&theta;}}_{m,n}|;\mathrm{0.0.1})e^{J(\widetilde{{\mathrm{\&theta;}}_{m,n}}-{\mathrm{\&theta;}}_{m,n})}\right|$

Wherein, $F(x;\mathrm{\&mu;},\mathrm{\&sigma;})=\frac{1}{\mathrm{\&sigma;}\sqrt{2\mathrm{\&pi;}}}\underset{x}{\overset{\&infin;}{\&Integral;}}\exp (-\frac{{(t-\mathrm{\&mu;})}^2}{{2\mathrm{\&sigma;}}^2})\mathrm{dtF}(x;\mathrm{\&mu;},\mathrm{\&sigma;})$

The original state of bead is the state making the value of related function maximum.

S104, to motion in bead follow the trail of.

The present invention utilizes EKF to follow the tracks of bead.The flow process of Kalman filtering is:

Status predication:

wherein, for t is to the estimated value of t and t+1 moment motion state, f is state transition equation.

Observed value is predicted:

$\hat{Z}(t+1|t)=h\left(\hat{X}(t+1|t)\right),$ Obtain observed deviation $\hat{V}(t+1)=Z(t+1)-\hat{Z}(t+1|t)$

State updating:

$\hat{X}(t+1|t+1)=\hat{X}(t+1|t)+G\left(t\right)\hat{V}(t+1),$ Wherein G (t) is kalman gain.

In order to obtain kalman gain, Kalman filtering is safeguarded by the covariance matrix of iteration to state and observation, and flow process is:

State defences difference prediction jointly:

P (t+1|t)=F (t) P (t|t) F (t) ^t+ Q (t), wherein, F (t) is state-transition matrix, q be state transfer noise defence difference jointly.

Observed reading prediction covariance upgrades:

S (t+1)=H (t+1) P (t+1|t) H (t+1) ^t+ R (t+1), wherein R be observation noise defence difference jointly.

Upgrade kalman gain:

G(t+1)＝P(t+1|t)H(t+1) ^TS(t+1) ^-1

State covariance upgrades:

P(t+1|t+1)＝P(t+1|t)-G(t+1)S(t+1)G(t+1) ^T

In the present invention, flow process is embody rule:

The state change of prediction bead.Utilize laststate bead state vector, according to state transition equation, obtain the state vector of bead at current time.Suppose that the motion of bead meets continuous white noise acceleration model, have the equation of motion

O(t+1)＝O(t)+ΔO(t)

R(t+1)＝R(t)·ΔR(t)

ΔO(t+1)＝ΔO(t)

ΔR(t+1)＝ΔR(t)

Be used as motion state by the sphere center position of bead, rotation angle, instantaneous translation vector, rotation angle that instantaneous rotation matrix is corresponding, then have

X(t)＝[O(t)Φ(t)ΔO(t)ΔΦ(t)] ^T

The transfer equation of note rotation matrix and rotation angle is R=RPY (Φ (t)), can obtain state transition equation

$f\left(X\left(t\right)\right)=\left\{\begin{array}{c}O(t+1)=O\left(t\right)+\mathrm{\&Delta;O}\left(t\right)\\ \mathrm{\&Phi;}(t+1)={\mathrm{RPY}}^{-1}(\mathrm{RPY}(\mathrm{\&Phi;}\left(t\right)\&CenterDot;\mathrm{RPY}\left(\mathrm{\&Delta;\&Phi;}\left(T\right)\right))\\ \mathrm{\&Delta;O}(t+1)=\mathrm{\&Delta;O}\left(t\right)\\ \mathrm{\&Delta;\&Phi;}(t+1)=\mathrm{\&Delta;\&Phi;}\left(t\right)\end{array}\right.$

Suppose that current time t bead state is then measurable lower a moment state so the theoretical value that the distance after can obtaining state change on ball between each label and each antenna changes.Utilize the rotation angle Φ of bead, rotation matrix R can be released, so the coordinate of each label in world coordinate system on bead can be released

$T_n^w\left(t\right|t)=R\left(t\right|t)T_n^b+O\left(t\right|t)$

$T_n^w(t+1|t)=R(t+1|t)T_n^b+O(t+1|t)$

Can apart from changing value: ${\mathrm{\&Delta;d}}_{m,n}(t+1|t)=|A_m^w,T_n^w(t+1|t)|-|A_m^w,T_n^w\left(t\right|t)|$

Actual range changing value can change and obtain by recording phase place, according to the difference size of the distance changing value of theoretical value and actual computation, revises the state estimation of bead,

$\hat{X}(t+1|t+1)=\hat{X}(t+1|t)+G\left(t\right)\hat{V}(t+1).$

S105, to bead state change smoothing.

The present invention utilizes Rauch-Tung-Striebel smoother smoothing.

Choose that current time arrives for the previous period as level and smooth time window, be denoted as t, t-1 ..., t-w.According to bead state estimation all in time window with the ball label phase value recorded, and covariance matrix smoothing process is shifted to the state of bead.Smoothing method for from t according to iterative equation to return iterative value t-w.Original state ${\hat{X}}^s\left(t\right)=\hat{X},{\hat{P}}^s\left(t\right)=\hat{P}\left(t\right|t),$ Iterative equation is:

$\hat{X}\left(t\right|t-1)=F(t-1)\hat{X}(t-1|t-1)$

$\hat{P}\left(t\right|t-1)=F(t-1)P(t-1)F{(t-1)}^{\mathrm{\&Gamma;}}+Q(t-1)$

G(t-1)＝P(t-1|t-1)F(t-1) ^T[P(t|t-1] ^-1

${\hat{X}}^s(t-1)=\hat{X}(t-1|t-1)+G(t-1)\left[{\hat{X}}^s\left(t\right)\widehat{-X}\left(t\right|t-1)\right]$

${\hat{P}}^s(t-1)=P(t-1)+G(t-1)[{\hat{P}}^s\left(t\right)-P\left(t\right|t-1)]G^T(t-1)$

S106, by bead state change be converted to user interactions behavior.

According to the state of bead in each moment, estimate the movement tendency of bead.According to the motion state of bead, the position of bead can be learnt, towards, translational speed and rotational speed.

By the judgement to bead movement tendency, the interbehavior of estimating user.And then user operation is projected on computer screen.

Technical scheme of the present invention effectively can eliminate white noise and multifarious impact in radio-frequency (RF) identification location, and pass through bead Holistic modeling, radio-frequency (RF) tag phase place is used as observed quantity, high precision real-time tracing is carried out to bead state, infer the interbehavior of user with this, realize the wireless mouse based on radio-frequency (RF) tag.

Note, above are only preferred embodiment of the present invention and institute's application technology principle.Skilled person in the art will appreciate that and the invention is not restricted to specific embodiment described here, various obvious change can be carried out for a person skilled in the art, readjust and substitute and can not protection scope of the present invention be departed from.Therefore, although be described in further detail invention has been by above embodiment, the present invention is not limited only to above embodiment, when not departing from the present invention's design, can also comprise other Equivalent embodiments more, and scope of the present invention is determined by appended right.

Claims (10)

1., based on a wireless mouse implementation method for radio-frequency (RF) tag, it is characterized in that, comprising:

A, label is attached to bead assigned address;

B, by aerial array, acquisition phase value;

The original state of C, calculating bead;

D, to motion in bead follow the trail of;

E, to bead state change smoothing;

F, by bead state change be converted to user interactions behavior.

2. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 1, it is characterized in that, described steps A specifically comprises:

According to certain rule, divide sphere place area of space;

Radio-frequency (RF) tag to be attached to equably on sphere or other positions in spheroid, to guarantee that the relative position of label and spheroid does not change;

Set up spheroidal coordinate system, calculate the coordinate figure of each label under spheroidal coordinate system.

3. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 1, it is characterized in that, described step B specifically comprises:

Control antenna array acquisition also records the phase value of label;

For the label that antenna does not read, record its phase value for empty.

4. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 1, it is characterized in that, described step C specifically comprises:

The state space possible to bead divides;

Travel through coccoid state space, suppose that the subregion state of each division is dbjective state;

Calculate by the notional phase value on hypothesis state ball between each label and each antenna;

Relatively notional phase value and measurement phase value, assessing each hypothesis state is target-like probability of state.

5. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 1, it is characterized in that, described step D specifically comprises:

The state change of prediction bead;

The theoretical value that distance after obtaining state change on ball between each label and each antenna changes;

According to the difference size of the distance changing value of described theoretical value and actual computation, the state estimation of bead is revised;

Wherein, the state change of described prediction bead specifically comprises: the state vector obtaining laststate bead; Utilization state vector, according to state transition equation, obtains the state vector of bead at current time;

The described theoretical value obtaining the distance on the rear ball of state change between each label and each antenna and change; According to the difference size of the distance changing value of described theoretical value and actual computation, the state estimation of bead is revised, specifically comprises: calculate the weight factor between the transfer of bead state with observed reading; Weight factor is acted in the deviation of observed reading and theoretical value, revise the bead state vector of prediction, obtain bead state estimation.

6. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 1, it is characterized in that, described step e specifically comprises:

Choose that current time arrives for the previous period as level and smooth time window;

According to bead state estimation all in time window and the ball label phase value recorded, smoothing process is shifted to the state of bead.

7. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 1, it is characterized in that, described step F specifically comprises:

According to the state of bead in each moment, estimate the movement tendency of bead;

By the judgement to bead movement tendency, the interbehavior of estimating user.

8. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 2, is characterized in that, set up spheroidal coordinate system in described steps A, calculates the coordinate figure of each label under spheroidal coordinate system, specifically comprises:

Determine spheroidal coordinate system initial point;

Selected axis, sets up right hand rectangular coordinate system;

Record the coordinate figure of each tag hub on spheroid.

9. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 3, is characterized in that, control antenna array acquisition in described step B also records the phase value of label, specifically comprises:

Reader is used to gather the phase value of label with preset rules scheduling antenna;

Record phase value and phase value acquisition time;

To calculate on ball each label compared with a upper moment with the changing value of the distance of each antenna.

10. the wireless mouse implementation method based on radio-frequency (RF) tag according to claim 4, is characterized in that, state space possible to bead in described step C divides, and specifically comprises:

For the rotation status of bead, choose the characteristic quantity that can determine bead rotation status, calculate the span of each characteristic quantity, carry out decile according to default granularity;

For the translation state of bead, choose the characteristic quantity that can determine little ball position, calculate the span of each characteristic quantity, carry out decile according to default granularity;

The rotation peace shifting state amount of comprehensive bead, obtains the state space of the bead after dividing.