CN113869180A - Finger gesture sensing device and method based on wireless coupling resonance - Google Patents

Abstract

The invention discloses a finger attitude sensing device and method based on wireless coupling resonance. The device includes a wireless coupling coil assembly worn on the finger, a signal excitation and signal receiving coil installed on the back of the hand, a high-frequency signal generation and reflection signal measurement module fixed on the arm; the signal excitation and signal receiving coils are connected to the high-frequency Signal generation and reflection signal measurement module, the high-frequency signal generation part outputs high-frequency AC signals, and the signal excitation and signal receiving coils are wirelessly coupled with multiple wireless coupling coils on the finger; the high-frequency reflection signal measurement part measures the signal excitation and signal The frequency and amplitude of the reflected signal received by the receiving coil are obtained, and the instantaneous posture of the finger at the installation site of the coil is obtained from the characteristics of the reflected signal. The invention has little influence on the movement of the finger, does not need to install additional active sensors on the finger or perform complex wiring, and has the characteristics of simple system deployment, low cost and high flexibility.

Description

A finger gesture sensing device and method based on wireless coupling resonance

technical field

The invention belongs to the technical field of radio frequency sensing, and in particular relates to a finger gesture sensing device and method based on wireless coupling resonance.

Background technique

Hand motion tracking and gesture recognition are indispensable for evaluating human hand function, and they are widely used in fields such as medicine, sign language communication, and mechanical manipulation. A type of gesture tracking method uses visible light, infrared light, electromagnetic waves, etc., to non-contact irradiate human hands and take pictures, and extract human gestures through image processing algorithms. Since no additional sensors are added to the hand or fingers, the non-contact method has few limitations on flexion and extension of the fingers. However, the range of motion of the hand is often limited to the illumination range of light sources, radars, etc., and the overlap between obstacles and tracked targets in the illumination direction will greatly increase the uncertainty of such measurement results.

Another type of approach is tactile, where various types of sensors are placed on the finger, palm or arm to monitor each finger or finger joint individually. Contact gesture tracking technology is not constrained by the source of illumination, and the user can move freely. In addition, if high-precision sensors are used, the tracking accuracy of gestures can also be improved accordingly. However, the existing contact gesture tracking technology often requires wearing gloves, embedding the sensor circuit board in the glove and fixing it with the fingers, and connecting it to the controller and power supply through cables, and each finger needs to receive signals individually. This makes contact gesture tracking systems cumbersome, bloated and complicated, limiting normal finger movement and dexterity.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the background technology, the present invention proposes a finger gesture sensing device and method based on wireless coupling resonance, including a wireless coupling coil assembly worn on the finger, a signal excitation and signal receiving coil installed on the back of the hand , and the high-frequency signal generation and reflection signal measurement module fixed on the arm, which has little impact on the activity of the finger, does not require additional active sensors or complicated wiring on the finger, and has the advantages of simple system deployment, low cost, and flexibility. high sex characteristics.

The concrete technical scheme adopted in the present invention is as follows:

1. A Finger Gesture Sensing Device Based on Wireless Coupling Resonance

It includes multiple wireless coupling coil assemblies worn on the knuckles of fingers, signal excitation and signal receiving coils installed on the back of the hand, and high-frequency signal generation and reflected signal measurement modules fixed on the arm;

The high-frequency signal generation and reflection signal measurement module is connected with the signal excitation and signal receiving coil; the high-frequency signal generation and reflection signal measurement module includes a high-frequency signal generation part and a high-frequency reflection measurement part. The signal receiving coil transmits high-frequency AC signals in the MHz-GHz frequency band, and the high-frequency reflection measurement part measures the frequency and amplitude of the signal excitation and the reflected signal received by the signal receiving coil in the MHz to GHz working frequency band;

Multiple wireless coupling coil assemblies are wirelessly coupled with signal excitation and signal receiving coils, and multiple wireless coupling coils are mutually resonantly coupled; each wireless coupling coil assembly is mainly composed of a wireless coupling coil and a fixed belt, and the wireless coupling coil is fixed by the fixed belt. on each knuckle of the tracked finger.

The high-frequency signal generation and reflected signal measurement module includes a ring coupler, a power amplifier, an up-conversion mixer, a down-conversion mixer, an analog-to-digital converter, a digital-to-analog converter, a control unit, a data output unit, a battery, Local oscillator and RF switch;

In the high-frequency signal generation part, the control unit outputs a low-frequency signal, and the low-frequency signal from the digital-to-analog converter and the high-frequency signal generated by the local oscillator are mixed by an up-conversion mixer to generate a high-frequency AC signal; After the first power amplifier is amplified, it is then output to the signal excitation and signal receiving coil through the ring coupler and the radio frequency switch; the high-frequency signal generating part is coupled with the wireless coupling coil through the high-frequency AC signal emitted by the signal excitation and signal receiving coil. A part is reflected at each wireless coupling coil;

In the high-frequency reflection measurement part, the reflected signal received by the signal excitation and signal receiving coil is input to the second power amplifier after passing through the RF switch and the ring coupler. After being amplified by the second power amplifier, it is down-converted to The low-frequency signal is then input to the control unit through the analog-to-digital converter, and finally the data for attitude analysis is output to the computer through the data output unit.

The ring coupler is used for isolation between the high frequency output signal and the high frequency reflected signal; the battery provides power for each part of the circuit.

One or two wireless coupling coil assemblies are worn on each knuckle; the fixing belt is sleeved on the knuckle of the finger, and the material of the fixing belt is non-metal; the wireless coupling coil is fixed on the fixing belt, and the axial direction is parallel or vertical on the knuckles.

The resonant frequency ω _i of each of the wireless coupling coils needs to be within the frequency range of the high-frequency AC signal MHz-GHz;

The resonant frequency ω _i of each wireless coupling coil is obtained by the following calculation:

且

根据两个无线耦合线圈之间的位置关系，通过诺依曼公式(Neumann’s formula)计算任意两个无线耦合线圈之间的互感

由两个线圈i₁，i₂之间的位置即两个线圈i₁，i₂之间的距离和轴向的相对倾斜角决定；The signal excitation and signal receiving coils are numbered 0, and the wireless coupling coils are numbered i from the base of the finger to the fingertip, i=1, 2, ..., N, N is the number of wireless coupling coils on the tracking finger; The mutual inductance between the two wireless coupling coils is

and

According to the positional relationship between the two wireless coupling coils, the mutual inductance between any two wireless coupling coils is calculated by Neumann's formula

It is determined by the position between the two coils i ₁ , i ₂ , that is, the distance between the two coils i ₁ , i ₂ and the relative inclination angle of the axial direction;

The impedance matrix of the signal excitation and signal receiving coil and the wireless coupling coil on the finger is:

Among them, U ₀ is the output voltage of the high _- frequency signal generation and reflected signal measurement module _{; I 0} , . The impedance value of the coupling coil, Z ₁ =r ₁ +jωL ₁ +1/(jωC ₁ ), L ₁ is the equivalent inductance value of the wireless coupling coil, C ₁ is the parasitic capacitance value of the wireless coupling coil, ω is the frequency of the AC signal , j is the complex impedance; M _0i represents the mutual inductance between the signal excitation and signal receiving coil and the i-th wireless coupling coil, i=1, 2,...,N;

According to the impedance matrix, the resonant frequency ω _i of the i-th wireless coupling coil is:

If the resonance frequency ω _i of the wireless coupling coil is not in the frequency range of the high-frequency AC signal, the resonance frequency ω _i is adjusted by adjusting the number of turns of the wireless coupling coil or the like.

2. A method of finger gesture sensing based on wireless coupling resonance using the above device

Include the following steps:

1) Wear a wireless coupling coil assembly on the tracked finger knuckles, and the high-frequency signal generating part outputs a high-frequency signal, which is transmitted to the wireless coupling coil on the tracking finger in a coupled manner through the signal excitation and signal receiving coil;

2) The high-frequency reflection measurement part measures the frequency and amplitude of the signal excitation and the reflected signal received by the signal receiving coil, denoted as G(ω, A), where ω is the reflected signal frequency, and A is the corresponding reflected signal amplitude;

3) Obtain the frequencies and amplitudes of all maximal points from the curve corresponding to the reflected signal G(ω, A), form the frequency characteristic equation y=f(ω, A), and obtain the closest value of the current reflected signal by solving the optimization problem. Frequency feature, the position between each coil is obtained according to the closest frequency feature, so as to complete the acquisition of finger posture.

The position between the coils includes the distance between the coils and the relative inclination angle, the distance between the coils is the distance between the centers of two adjacent coils, and the relative inclination angle between the coils is the central axis of the two adjacent coils. the angle between.

Described step 3) is specifically:

3.1) Obtain the frequencies and amplitudes of all maximum points from the curve corresponding to the reflected signal G(ω, A) to form a frequency characteristic equation y=f(ω, A); the frequency of each maximum point is the frequency of each wireless the resonant frequency ω _i of the coupled coil;

Based on the frequency characteristic equation, solve the optimization problem of the following formula, and obtain the closest frequency characteristic F _p (ω, A):

为互感频率特征字典中所有频率特征的集合；in,

is the set of all frequency features in the mutual inductance frequency feature dictionary;

3.2) Build a dictionary of mutual inductance frequency characteristics;

3.3) In the mutual inductance frequency feature dictionary, obtain the positional relationship Sp ( _{d 1} ,...,d _N , θ ₁ , θ 1 , of each wireless coupling coil under the current reflected signal according to the closest frequency feature F _p (ω, A), ..., θ _N ), where d _i , θ _i are the distance and relative inclination angle between the ith and (i-1)th coils, respectively, i=1, ..., N;

Since the position of each coil on the finger after wearing is fixed, the finger posture can be obtained according to the position Sp ( _{d 1} , . . . , d _N , θ ₁ , . . . , θ _N ) of each wireless coupling coil. .

The step 3.2) is specifically:

According to the accuracy requirements of finger gesture recognition, from curling to fully straightening, P different finger gestures are defined, and the positional relationship of each wireless coupling coil corresponding to each finger gesture is recorded as:

Sp ( _{d 1} , . . . , d _N , θ ₁ , . . . , θ _N ), p=1, 2, . . . , P;

根据手指姿态及对应的频率特征，获得互感频率特征字典，具体为：After wearing the sensor device, perform system calibration, measure the reflected signals of P attitudes, extract the frequency and amplitude of the maximum point, and form a set of each group of frequency characteristic equations F(ω, A) corresponding to all attitudes

According to the finger posture and the corresponding frequency features, the mutual inductance frequency feature dictionary is obtained, specifically:

When tracking multiple fingers, all tracked fingers need to wear wireless coupling coil components, and install signal excitation and signal receiving coils corresponding to each tracking finger on the back of the hand, and each finger corresponds to a signal excitation and signal receiving coil;

Each signal excitation and signal receiving coil is connected to the ring coupler through a radio frequency switch, and then enters the subsequent circuit of the high-frequency signal generation and reflected signal measurement module; the radio frequency switch switches between each signal excitation and signal receiving coil, and the same Only one signal excitation and signal receiving coil is turned on at any time; after recognizing the instantaneous posture of each finger, the postures of all tracked fingers are combined to complete gesture recognition.

The beneficial effects that the present invention has are:

1) The present invention uses the principle of wireless coupling between coils, fixes the wireless coupling coil on the finger, and obtains the resonance state of the wireless coupling coil by measuring the frequency amplitude characteristics of the working frequency band of the reflected signal, so as to reverse the relative position and inclination between the coils. , so as to obtain the instantaneous gesture of the finger. Gesture recognition can be achieved if multiple fingers are tracked at the same time and the instantaneous gestures of the fingers are combined.

2) The system of the present invention does not need to install additional active sensors on the finger or perform complicated wiring, and will not affect the normal movement of the finger or reduce the function of the finger, and the system is simple to deploy and has high flexibility.

Description of drawings

FIG. 1 is a schematic structural diagram of the system of the present invention tracking a single finger.

FIG. 2 is a schematic diagram of the working principle of the high-frequency signal generation and reflected signal measurement module of the present invention.

3 is a schematic diagram of the relative positions of the wireless coupling coils in the system of the present invention under two different finger gestures.

FIG. 4 is a schematic structural diagram of the system of the present invention tracking multiple fingers.

In the figure: wireless coupling coil assembly 1, wireless coupling coil 101, fixed belt 102, signal excitation and signal receiving coil 2, high-frequency signal generation and reflected signal measurement module 3, ring coupler 301, power amplifier 302, up-conversion frequency mixing 303 , down-conversion mixer 304 , analog-to-digital converter 305 , digital-to-analog converter 306 , control unit 307 , data output unit 308 , battery 309 , local oscillator 310 and radio frequency switch 311 .

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 , the present invention includes a wireless coupling coil assembly 1 worn on the finger, a signal excitation and signal receiving coil 2 installed on the back of the hand, and a high-frequency signal generation and reflection signal measurement module 3 fixed on the arm. The signal excitation and signal receiving coil 2 is connected to the high frequency signal generating and reflected signal measuring module 3 . The high-frequency signal generating part of the high-frequency signal generating and reflected signal measuring module 3 generates a high-frequency AC signal of a certain frequency band (100MHz-5GHz), and outputs it to the signal excitation and signal receiving coil 2 . The signal excitation and signal receiving coils 2 are coupled with the wireless coupling coils 101 worn on the knuckles of the fingers, and the wireless coupling coils 101 are mutually resonantly coupled. The high-frequency reflection measurement part of the high-frequency signal generation and reflected signal measurement module 3 measures the frequency and amplitude of the reflected signal at the working frequency band of the signal excitation and signal receiving coil 2, and infers the instantaneous gesture of the finger from the characteristics of the reflected signal.

The wireless coupling coil assembly 1 is composed of a wireless coupling coil 101 and a fixing belt 102 . The material of the fixing belt 102 is non-metal. The wireless coupling coil 101 is fixed on the knuckles of the tracked finger by a fixing strap, and each knuckle wears one or two wireless coupling coil assemblies. The axial direction of the wireless coupling coil shown in Figure 1 is parallel to the phalanx of the finger. The axial direction of the wireless coupling coil can be parallel to the knuckle where it is located, or it can be perpendicular to the knuckle.

As shown in FIG. 2, the high-frequency signal generation and reflected signal measurement module 3 includes a ring coupler 301, a power amplifier 302, an up-conversion mixer 303, a down-conversion mixer 304, an analog-to-digital converter 305, and a digital-to-analog converter 306 , a control unit 307 , a data output unit 308 , a battery 309 , a local oscillator 310 and a radio frequency switch 311 . The radio frequency switch 311 forms two branches through the ring coupler 301, the branch of the high-frequency signal generation part and the branch of the high-frequency reflection measurement part; frequency converter 303 and digital-to-analog converter 306, the local oscillator 310 connected to the control unit 307 is connected to the up-conversion mixer 303; the branch of the high-frequency reflection measurement part includes the second power amplifier 302, the down-conversion mixer connected in sequence 304 , the analog-to-digital converter 305 , the digital-to-analog converter 306 , and the analog-to-digital converter 305 are connected to the data output unit 308 via the control unit 307 .

In the high-frequency signal generation part, the control unit 307 outputs a low-frequency signal, which is mixed with the high-frequency signal generated by the local oscillator 310 through the digital-to-analog converter 306 through the up-conversion mixer 303 to generate a high-frequency AC signal, which is passed through the power amplifier 302. Amplify, output to signal excitation and signal receiving coil 2, and transmit it to the outside. A part of the high-frequency AC signal is coupled with the wireless coupling coil 101 , and a part is reflected, and the reflected signal is measured by the high-frequency reflection measurement circuit of the high-frequency signal generation and reflected signal measurement module 3 . In the high-frequency reflection measurement part, after the reflected signal is amplified by the power amplifier 302, it is down-converted to a low-frequency signal through the down-conversion mixer 304, sent to the control unit 307 through the analog-to-digital converter 305, and finally output the reflected signal through the data output unit 308. for subsequent data processing. The control unit 307 performs control and function scheduling for each part of the circuit. The ring coupler 301 is used for isolation between the high frequency output signal and the high frequency reflected signal. A battery 309 provides power to various parts of the circuit.

且

由两个线圈i₁，i₂之间的距离和轴向的相对倾斜角决定；根据两个无线耦合线圈之间的位置关系，通过诺依曼公式(Neumann's formula)计算任意两个无线耦合线圈之间的互感

由两个线圈i₁，i₂之间的位置即两个线圈i₁，i₂之间的距离和轴向的相对倾斜角决定；1 and 3 , under the excitation of a high-frequency AC signal, the signal excitation and signal receiving coil 2 is coupled with the wireless coupling coil 101 on the finger, and the wireless coupling coils 101 are mutually resonantly coupled. The impedance value of the signal excitation and signal receiving coil is Z ₀ , the impedance value of the wireless coupling coil 101 fixed on the finger is Z ₁ , Z ₁ =r ₁ +jωL ₁ +1/(jωC ₁ ), where r ₁ is the wireless The resistance value of the coupling coil 101, L ₁ is the equivalent inductance value, C ₁ is the parasitic capacitance value, ω is the frequency of the AC signal, and j is the complex impedance. The signal excitation and signal receiving coils 2 are numbered as 0, and the wireless coupling coils 101 are numbered as i from the base of the finger to the fingertip, i=1, 2, . . Then the mutual inductance between any two wireless coupling coils is

and

It is determined by the distance between the two coils i ₁ , i ₂ and the relative inclination angle of the axial direction; according to the positional relationship between the two wireless coupling coils, any two wireless coupling coils are calculated by Neumann's formula mutual inductance

It is determined by the position between the two coils i ₁ , i ₂ , that is, the distance between the two coils i ₁ , i ₂ and the relative inclination angle of the axial direction;

Under high-frequency signal excitation, the impedance matrix of the signal excitation and signal receiving coil 2 and the wireless coupling coil 101 on the finger is:

Wherein, U ₀ is the output voltage of the high _- frequency signal generation and reflected signal measurement module 3 , and I ₀ , . . . , IN are the currents of the respective coils. Z ₀ is the impedance value of the signal excitation and signal receiving coil 2; Z ₁ is the impedance value of the wireless coupling coil (101), Z ₁ =r ₁ +jωL ₁ +1/(jωC ₁ ), L ₁ is the wireless coupling coil Equivalent inductance value, C ₁ is the parasitic capacitance value of the wireless coupling coil, M _0i is the mutual inductance between the signal excitation and signal receiving coil and the ith wireless coupling coil, i=1, 2,...,N;

According to the impedance matrix, the resonant frequency ω _i of the ith (i=1, 2, . . . , N) wireless coupling coil 101 is:

Measure the reflected signal G(ω, A), extract the frequency and amplitude of the extreme point from it, and form the frequency characteristic equation y=f(ω, A). The excitation coil corresponding to the current attitude and the mutual inductance between each wireless coupling coil can be obtained through the following optimization problem:

为互感频率特征字典中的频率特征。in,

is the frequency feature in the mutual inductance frequency feature dictionary.

Formula (1) judges the currently measured reflected signal by calculating the minimum value of norm 2 between f(ω, A) obtained from the measurement result and each frequency feature F(ω, A) calibrated in the mutual inductance frequency feature dictionary Which frequency feature F is closest to. Obtain the positional relationship Sp _{( d 1} , . . . , _{d N} , θ ₁ , . After wearing, the position of each coil on the finger is fixed, and the finger posture can be obtained from the positional relationship.

The mutual inductance frequency feature dictionary is established by the first system calibration after wearing the device. According to the accuracy requirements of finger gesture recognition, from curling to fully straightening, P different finger gestures are defined, and the positional relationship of each wireless coupling coil corresponding to each finger gesture is recorded as: S _p (d ₁ ,...,d _N , θ ₁ , ..., θ _N ), p=1, 2, ..., P;

根据手指姿态及对应的频率特征，获得互感频率特征字典，具体为：After wearing the sensor device, perform system calibration, measure the reflected signals of P attitudes, extract the frequency and amplitude of the maximum point, and form a set of each group of frequency characteristic equations F(ω, A) corresponding to all attitudes

According to the finger posture and the corresponding frequency features, the mutual inductance frequency feature dictionary is obtained, specifically:

Since the position of each coil on the finger is fixed after wearing, the finger posture can be obtained from the positional relationship S(d ₁ , . . . , d _N , θ ₁ , . . . , θ _N ).

In the case of tracking multiple fingers, all the fingers to be tracked need to wear wireless coupling coil components, and the signal excitation and signal receiving coils corresponding to the fingers are installed on the back of the hand, and the fingers are combined after recognizing the instantaneous posture of each finger. Gesture recognition can be done.

Each finger corresponds to a signal excitation and signal receiving coil, and the signal excitation and signal receiving coil are connected to the ring coupler through the radio frequency switch, and then enter the subsequent circuit of the high-frequency signal generation and reflected signal measurement module. The RF switch switches between each signal excitation and signal receiving coil, and only one signal excitation and signal receiving coil is turned on at the same time, that is, only the gesture of one finger is recognized at the same time.

The specific implementation work of the present invention is as follows:

As shown in FIG. 1 , the high-frequency signal generation and reflection signal measurement module 3 fixed on the arm generates a high-frequency AC signal of a certain frequency band, and is transmitted through the signal excitation and signal receiving coil 2 . The signal excitation and signal receiving coil 2 is coupled with the wireless coupling coil 101 worn on the finger, and the wireless coupling coils 101 are mutually resonantly coupled. The impedance value of the signal excitation and signal receiving coil 2 is set to Z ₀ , the impedance value of the wireless coupling coil 101 is Z ₁ , Z ₁ =r ₁ +jωL ₁ +1/(jωC ₁ ), where r ₁ is the wireless coupling coil 101 The resistance value, L ₁ is the equivalent inductance value, C ₁ is the parasitic capacitance value, and ω is the frequency of the AC signal.

As shown in FIG. 2 , the control unit 307 of the high-frequency signal generation and reflected signal measurement module 3 outputs a low-frequency signal, which is mixed with the high-frequency signal generated by the local oscillator 310 through the digital-to-analog converter 306 through the up-conversion mixer 303 , A high-frequency AC signal of 100MHz-5GHz is generated, and the high-frequency AC signal is amplified by the power amplifier 302 and output to the signal excitation and signal receiving coil 2 . A part of the high-frequency AC signal is coupled with the wireless coupling coil 101, and a part is reflected. After the reflected signal is amplified by the power amplifier 302, it is down-converted to a low-frequency signal through the down-conversion mixer 304, and sent to the control unit 307 through the analog-to-digital converter 305. Finally, it is output through the data output unit 308 for subsequent data processing. The control unit 307 performs control and function scheduling for each part of the circuit, and the ring coupler 301 is used for isolation between the high-frequency output signal and the high-frequency reflected signal. A battery 309 provides power to various parts of the circuit.

且

由两个线圈i₁，i₂之间的距离和轴向的相对倾斜角决定；The signal excitation and signal receiving coils 2 are numbered 0, and each wireless coupling coil 101 is numbered i from the base of the finger to the fingertip, i=1, 2, . . . , N, and N is the number of wireless coupling coils 101 on the finger. number. One or two wirelessly coupled coil assemblies can be worn per knuckle. As shown in FIG. 3 , one wireless coupling coil assembly 1 is worn on the first and third phalanx of the finger, and two wireless coupling coil assemblies are worn on the second phalanx, so N=4. The mutual inductance between any two coils is

and

It is determined by the distance between the two coils i ₁ , i ₂ and the relative inclination angle of the axial direction;

Under the excitation of the high frequency signal, the impedance matrix of the signal excitation and signal receiving coil 2 and the wireless coupling coil 101 on the finger is:

Wherein, U ₀ is the output voltage of the high-frequency signal generation and reflected signal measurement module 3 , and I ₀ , . . . , I ₄ are the currents of the respective coils.

The resonant frequency ω _i of the i-th (i=1, 2, 3, 4) wireless coupling coil 101 is:

As shown in Fig. 3, the finger posture 1 and the finger posture 2, when the posture of the finger changes, the relative positions of the wireless coupling coils 101 change, and the resonant frequency of the wireless coupling coils 101 also changes. According to the required finger posture recognition accuracy, the postures of the fingers from curling to fully straightening are roughly divided into 7 types. After wearing the device, the system is first calibrated. The positional relationship of each wireless coupling coil corresponding to each finger posture is marked as :

Sp ( _{d 1} ,..., d ₄ , θ ₁ ,..., θ ₄ ), p=1, 2,..., 7;

The reflected signals of the seven attitudes are measured and the frequency and amplitude of the extreme points are extracted to form the frequency characteristic equation F(ω, A). The establishment of the mutual inductance frequency feature dictionary is as follows:

Measure the reflected signal G(ω, A) and obtain the frequencies and amplitudes of all extreme points in the corresponding curve to form a frequency characteristic equation y=f(ω, A). Solve the optimization problem to get the closest frequency feature F _p (ω, A):

为互感频率特征字典中的频率特征。in,

is the frequency feature in the mutual inductance frequency feature dictionary.

In the mutual inductance frequency feature dictionary, the position relationship S( _{d 1} , . . . , _{d 4} , θ ₁ , . where d _i , θ _i , i=1, . . . , 4 are the distance between the i-th coil and the (i-1)-th coil and the angle between the central axes of the coils, respectively. Since the position of each coil on the finger is fixed after wearing, the finger posture can be obtained from the positional relationship S(d ₁ , . . . , d ₄ , θ ₁ , . . . , θ ₄ ).

As shown in Figure 4, in the case of tracking multiple fingers, the wireless coupling coil assembly 1 needs to be worn on the fingers to be tracked, and corresponding to each finger, a signal excitation and signal receiving coil 2 needs to be installed on the back of the hand . The signal excitation and signal receiving coil 2 is connected to the ring coupler 301 through the radio frequency switch 311 , and then enters the subsequent circuit of the high frequency signal generation and reflected signal measurement module 3 . The radio frequency switch 311 switches between each signal excitation and signal receiving coil 2 at a speed of 100 times per second, and only one signal excitation and signal receiving coil 2 is turned on at the same time. That is, the gesture of only one finger is recognized at the same time. Since the switching speed of the radio frequency switch 311 is 10ms, the user gesture obtained by sequentially recognizing the instantaneous gestures of each finger and combining them can meet the gesture recognition requirements.

Claims (10)

1. a finger gesture sensor device based on wireless coupling resonance, is characterized in that: comprising a plurality of wireless coupling coil assemblies (1) worn on finger knuckles, signal excitation and signal receiving coils (2) installed on the back of the hand ) and a high-frequency signal generation and reflection signal measurement module (3) fixed on the arm; The high-frequency signal generation and reflection signal measurement module (3) is connected with the signal excitation and signal receiving coil (2); the high-frequency signal generation and reflection signal measurement module (3) includes a high-frequency signal generation part and a high-frequency reflection measurement part, The high-frequency signal generating part transmits high-frequency AC signals in the MHz-GHz frequency band through the signal excitation and signal receiving coil (2), and the high-frequency reflection measuring part measures the signal excitation and signal receiving coil (2) in the MHz to GHz working frequency band to receive The frequency and amplitude of the reflected signal received; A plurality of wireless coupling coil assemblies (1) are wirelessly coupled with the signal excitation and signal receiving coils (2), and the plurality of wireless coupling coils (101) are mutually resonantly coupled; each wireless coupling coil assembly (1) is mainly composed of a wireless coupling coil (101) is composed of a fixing belt (102), and the wireless coupling coil (101) is fixed on each phalanx of the tracked finger through the fixing belt (102). 2. A finger gesture sensing device based on wireless coupling resonance according to claim 1, characterized in that: the high-frequency signal generation and reflected signal measurement module (3) comprises a ring coupler (301), a power amplifier (302), up-conversion mixer (303), down-conversion mixer (304), analog-to-digital converter (305), digital-to-analog converter (306), control unit (307), data output unit (308) , a battery (309), a local oscillator (310) and a radio frequency switch (311); In the high-frequency signal generation part, the control unit (307) outputs a low-frequency signal, and the low-frequency signal passed through the digital-to-analog converter (306) and the high-frequency signal generated by the local oscillator (310) are mixed by an up-conversion mixer (303). , generate a high-frequency AC signal; the high-frequency AC signal is amplified by the first power amplifier (302), and then output to the signal excitation and signal receiving coil (2) through the ring coupler (301) and the radio frequency switch (311); A part of the high-frequency AC signal emitted by the signal excitation and signal receiving coil (2) is coupled with the wireless coupling coil (101) by the frequency signal generating part, and a part is reflected at each wireless coupling coil; In the high-frequency reflection measurement part, the reflected signal received by the signal excitation and signal receiving coil (2) is input to the second power amplifier (302) through the radio frequency switch (311) and the ring coupler (301), and the second power amplifier is passed through the second power amplifier. (302) After amplification, down-converted to a low-frequency signal through a down-conversion mixer (304), then input to a control unit (307) through an analog-to-digital converter (305), and finally output through a data output unit (308) for attitude analysis data to the computer. 3. A kind of finger gesture sensing device based on wireless coupling resonance according to claim 2, is characterized in that: described ring coupler (301) is used for isolation between high frequency output signal and high frequency reflection signal; The battery (309) provides power to various parts of the circuit. 4. A finger gesture sensing device based on wireless coupling resonance according to claim 1, characterized in that: one or two wireless coupling coil assemblies (1) are worn on each knuckle; the fixing belt (102) ) is fitted on the knuckles of the fingers, the material of the fixing band (102) is non-metal; the wireless coupling coil (101) is fixed on the fixing band (102), and the axial direction is parallel or perpendicular to the knuckles. 5. a kind of finger attitude sensing device based on wireless coupling resonance according to claim 1, is characterized in that: the resonance frequency ω _i of each described wireless coupling coil needs to be in the frequency of high frequency alternating current signal MHz-GHz within the range; The resonant frequency ω _i of each wireless coupling coil is obtained by the following calculation: The signal excitation and signal receiving coils (2) are numbered as 0, and the wireless coupling coils (101) are numbered i from the base of the finger to the fingertip. (101); the mutual inductance between any two wireless coupling coils is

and

According to the positional relationship between the two wireless coupling coils, the mutual inductance between any two wireless coupling coils is calculated by the Neumann formula

The impedance matrix of the signal excitation and signal receiving coil (2) and the wireless coupling coil (101) on the finger is:

Wherein, U ₀ is the output voltage of the high _- frequency signal generation and reflected signal measurement module (3) _; I ₀ , . Z ₁ is the impedance value of the wireless coupling coil (101), Z ₁ =r ₁ +jωL ₁ +1/(jωC ₁ ), L ₁ is the equivalent inductance value of the wireless coupling coil, and C ₁ is the Parasitic capacitance value, ω is the frequency of the AC signal, j is the complex impedance; M _0i represents the mutual inductance between the signal excitation and signal receiving coil and the i-th wireless coupling coil, i=1, 2,...,N; According to the impedance matrix, the resonant frequency ω _i of the i-th wireless coupling coil is:

If the resonance frequency ω _i of the wireless coupling coil is not within the frequency range of the high-frequency AC signal, the resonance frequency ω _i is adjusted by adjusting the number of turns of the wireless coupling coil. 6. A wireless coupling resonance-based finger gesture sensing method using any one of the devices of claims 1 to 5, wherein the method comprises the following steps: 1) Wear the wireless coupling coil assembly (1) on the finger knuckles to be tracked, the high-frequency signal generating part outputs a high-frequency signal, and the signal excitation and the signal receiving coil (2) are coupled to transmit the wireless coupling on the tracking finger. a coupling coil (101); 2) The high-frequency reflection measurement part measures the frequency and amplitude of the signal excitation and the reflected signal received by the signal receiving coil (2), denoted as G(ω, A), where ω is the reflected signal frequency, and A is the corresponding reflected signal amplitude; 3) Obtain the frequencies and amplitudes of all maximal points from the curve corresponding to the reflected signal G(ω, A), form the frequency characteristic equation y=f(ω, A), and obtain the closest value of the current reflected signal by solving the optimization problem. Frequency feature, the position between each coil is obtained according to the closest frequency feature, so as to complete the acquisition of finger posture. 7 . The method for sensing finger gestures based on wireless coupling resonance according to claim 6 , wherein the positions between the coils include a distance and a relative inclination angle between the coils, and the The distance is the distance between the centers of two adjacent coils, and the relative inclination angle between the coils is the included angle between the central axes of the two adjacent coils. 8. a kind of finger gesture sensing method based on wireless coupling resonance according to claim 6, is characterized in that, described step 3) is specifically: 3.1) Obtain the frequencies and amplitudes of all maximum points from the curve corresponding to the reflected signal G(ω, A) to form a frequency characteristic equation y=f(ω, A); the frequency of each maximum point is the frequency of each wireless the resonant frequency ω _i of the coupled coil; Based on the frequency characteristic equation, solve the optimization problem of the following formula, and obtain the closest frequency characteristic F _p (ω, A):

in,

is the set of all frequency features in the mutual inductance frequency feature dictionary; 3.2) Build a dictionary of mutual inductance frequency characteristics; 3.3) In the mutual inductance frequency feature dictionary, obtain the positional relationship Sp ( _{d 1} ,..., _{d N} , θ ₁ , .. ., θ _N ), where d _i , θ _i are the distance and relative inclination angle between the ith and (i-1)th coils, respectively, i=1,...,N; Since the position of each coil on the finger after wearing is fixed, the finger posture can be obtained according to the position Sp ( _{d 1} , . . . , d _N , θ ₁ , . . . , θ _N ) of each wireless coupling coil. . 9. a kind of finger gesture sensing method based on wireless coupling resonance according to claim 8, is characterized in that, described step 3.2) is specifically: According to the accuracy requirements of finger gesture recognition, from curling to fully straightening, P different finger gestures are defined, and the positional relationship of each wireless coupling coil corresponding to each finger gesture is recorded as: Sp ( _{d 1} , . . . , d _N , θ ₁ , . . . , θ _N ), p=1, 2, . . . , P; After wearing the sensor device, perform system calibration, measure the reflected signals of P attitudes, extract the frequency and amplitude of the maximum point, and form a set of each group of frequency characteristic equations F(ω, A) corresponding to all attitudes

According to the finger posture and the corresponding frequency features, the mutual inductance frequency feature dictionary is obtained, specifically:

10. A kind of finger gesture sensing method based on wireless coupling resonance according to claim 7, it is characterized in that, when tracking multiple fingers, all the tracking fingers need to wear wireless coupling coil assembly (1), and A signal excitation and signal receiving coil (2) corresponding to each tracking finger is installed on the back of the hand; Each signal excitation and signal receiving coil (2) is connected to the ring coupler (301) through a radio frequency switch (311); the radio frequency switch (311) switches between each signal excitation and signal receiving coil (2), the same Only one signal excitation and signal receiving coil (2) is turned on at a time; after recognizing the instantaneous posture of each finger, the postures of all tracked fingers are combined to complete gesture recognition.

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