Utilize the electrically powered hand control method of eye electricity and brain electric information
Technical field
The invention belongs to information and control technology field; Relate to a kind of useful information that utilizes in the electro-ocular signal to be comprised; Strengthen the Imaginary EEG signal characteristic; Improving under the motion imagination pattern technology based on the limb action recognition effect of EEG signals, specifically is a kind of control information source that utilizes eye electricity and EEG signals as electrically powered hand, through the EEG signals that contain an electrical information are extracted, analyze; Identification obtains a plurality of patterns of action of doing evil through another person, and then realizes doing evil through another person multivariant real-time control.
Background technology
(electro-oculogram EOG) is a kind of bioelectrical signals of following ocular movement to produce to electro-ocular signal.Eyeball is an ambipolar spheroid, and the cornea district presents positive polarity, and retinal field presents negative polarity, and potential difference between the two forms an electric field in the front portion of head.When eyeball rotated, this electric field space orientation changed.Near the electrode that electrical variation can be placed the eyes comprises that the scalp electrode for encephalograms detects.To the electrode detection of eye electricity to voltage signal be exactly electro-ocular signal.Eyeball all can be by corresponding electro-ocular signal record in the motion of vertical direction or horizontal direction.Action nictation can cause the variation of enclosing current potential near the eyes, thereby also can produce corresponding electro-ocular signal.
(electroencephalogram is the potential change that is caused by cerebral cortex neural cell group synapse transmission signal EEG) to EEG signals, can reflect the conscious activity that brain is autonomous or bring out, and is closely related with the action behavior of reality.At present; Adopting EEG signals is brain-machine interaction (braincomputer interface as the control information source of artificial limb; BCI) field hot research problem; Promptly carry out analyzing and processing when carrying out the limb motion imagination, identify the limb motion pattern that the people with disability will realize, produce the corresponding control signal that drives the artificial limb action in view of the above through the EEG signals that the people with disability is sent.
The collection of EEG signals is had two kinds of intrusive mood (invasive) and non-intrusion types (non-invasive), and the intrusive mood eeg signal acquisition uses implanted electrode, and non-intrusion type then adopts scalp electrode.Intrusive mood eeg signal acquisition method is through microsurgery microelectrode to be implanted a kind of method of the measure cerebral signal of telecommunication in the cranial cavity, and polarization is good, and signal to noise ratio is high, but has a series of technical difficulty and bigger clinical risk.At present existing achievement in research proof adopts the feasibility of scalp EEG signals as artificial limb control information source; But because such signal is not in brain neuron, directly to extract; But extract from scalp, weak output signal, and noise is big; Signal to noise ratio is very low, uses it and carries out very difficulty of limb motion imagination pattern recognition.
In scalp eeg signal acquisition process, by the electro-ocular signal that eye movement causes, a part can be propagated along skull, produces with EEG signals and merges, and the EEG signals characteristic is changed.In traditional signal processing, electro-ocular signal is used as the in addition filtering of main interfering signal usually, so be known as " the electric artefact of eye ".But the human most information that from surrounding, obtained come from vision, and retina receives external information, passes to nerve centre through pathways for vision, and outside stimulus causes the thinking activities of brain.It should be noted that especially people in the process of carrying out hand exercise, often need the cooperation of brain, eye, hands, can naturally and understandably follow some eye motions.When for example people wanted to grasp a certain object, eyes also can turn to this object naturally.The electro-ocular signal that eye movement this moment causes has comprised the movable information of hands, and natural fusion takes place at the skull place EEG signals that this electro-ocular signal and same motion imagination process produce.The hand exercise information that electro-ocular signal comprises, the hand exercise information that EEG signals are comprised is enhanced, and signal characteristic is strengthened.
Learn that from above analysis the motion of eyes and the activity of human brain have confidential relation, thereby eye is electric and EEG signals are closely related on physiology.Has very high research value although get rid of the brain electricity analytical of the electric artefact of eye; But in some concrete practical application, the brain-computer interactive system that electric control is done evil through another person like brain there is no need painstakingly to pursue with the filtering of eye electricity artefact; Even can the eye electrical information be used; The limb motion imagination mode that adopts eye, brain to coordinate utilizes electro-ocular signal that the Imaginary EEG signal characteristic is strengthened, in the hope of obtaining the better recognition effect.
(Independent Component Analysis ICA) as a kind of information source decomposition technique of rising in recent years, has obtained using comparatively widely in fields such as EEG signals place, speech recognition, communication, Flame Image Process in the independent component analysis.The basic ideas of ICA algorithm are under hybrid matrix and source signal condition of unknown; Utilize independent this hypothesis of statistics between source signal; Seek a matrix of a linear transformation through optimized Algorithm observation signal is carried out linear transformation; Obtain output vector, make it to approach as much as possible source signal, become a estimation source signal.The independent component parser is a lot; But most methods need isolating independent component number identical with detected mixed signal number; Be that signal composition or the various interfering signal composition that needs all will be extracted in the mixed signal, and the signal composition put in order uncertain.Extract required signal composition, also need a large amount of postposition to handle.So traditional independent component analytical method contains in this type of electrical information EEG signals higher-dimension application in extraction, will comprise a large amount of redundant computation, expend ample resources, reduced the quality that signal recovers, far can not satisfy the real-time treatment requirement of electrically powered hand.
Existing scholar proposes the priori of required extraction signal is used for the independent component parser, to improve the accuracy of algorithm, realizes this algorithm more applications.But such algorithm only utilizes reference signal and minimum this type second order of estimated signal mean square deviation criterion to confirm to optimize the weight matrix component at present; And adopt non-protruding, non-linear objective functions such as algorithm optimization negentropy based on gradient, mutual information, sheath degree.In the higher-dimension optimization problem of reality, it is accurate to confirm to optimize the weight matrix short weight based on the second order criterion; Gradient descent algorithm makes Optimization result be very easy to converge to a local optimum point, causes this type of algorithm only can obtain some locally optimal solutions, and the signal element that needs to extract possibly be left in the basket.
(particle swarm optimization is a kind of parallel, global optimization approach at random PSO) to particle swarm optimization algorithm, is a kind of general utility tool that solves optimization problem.This method utilizes probabilistic search to replace exhaustive search; Utilize a plurality of particle parallel computations to reduce computation time; The information that utilization feeds back is constantly revised the direction and the amplitude of next step search of particle, approaches global optimum's point gradually, thereby reaches the target of global optimization.Character such as this algorithm does not require that optimised function has can be little, can lead, continuous, fast convergence rate, the simple programming easily of algorithm realizes.The application of in computer science and engineering problem, having succeeded of PSO algorithm; From traditional problems such as the optimization of initial complicated multimodal nonlinear function, multiple-objection optimizations, to image segmentation, pattern recognition, neural network weight training, robot path ruleization or the like in real time.Particularly there is document to show that (magnetoencephalography, the MEG) application of succeeding in the data analysis shows the application prospect of PSO algorithm in the EEG Processing field to the PSO algorithm in magneticencephalogram in the recent period.
Can know by above analysis; Carry out the signal extraction problem that independent component is analyzed if can will utilize the priori that needs to extract signal; Be converted into the optimization problem that suitable PSO algorithm is found the solution, and then carry out optimizing with the PSO algorithm and calculate, what can solve such ICA algorithm existence at present only can obtain some locally optimal solutions; The uncared-for problem of signal element possibility that causes needs to extract is guaranteed the high efficiency of algorithm and accuracy.
Summary of the invention
The object of the invention is exactly the deficiency to prior art; A kind of 3-degree-of-freedom electrical prosthetic hand control method that adopts eye electricity, EEG signals as the control information source is provided, makes its completion open, close up, wrist is stretched, wrist is bent, wrist outward turning, these six kinds actions of doing evil through another person of wrist inward turning.This kind the bionical paralysis personage who is particularly suitable for nerve, muscle serious degradation that does evil through another person use.
Can specifically be expressed as: in eeg signal acquisition and processing procedure, regard electro-ocular signal as a kind of available signal source; The corresponding eye motion that when doing hand motion, is aided with naturally with reference to people in the daily life; Adopt the eye brain coordination mode imagination of moving; The useful information that utilizes in the electro-ocular signal to be comprised strengthens same sports consciousness and produces the EEG signals characteristic; (determination component analysis based on particle swarm optimization algorithm DCA-PSO) contains an electrical information EEG signals extraction and the pattern recognition of the hand exercise imagination to utilize the definite analysis of components algorithm based on particle group optimizing that is proposed; And then the control signal that obtains doing evil through another person is exported to drive circuit, the control that drive motors drive electrically powered hand is done evil through another person to Three Degree Of Freedom by people with disability's motion wish realization.
Concrete control method of the present invention is that the scalp power-collecting electrode that the brain electricity picks up in the electric transducer is placed on the brain frons F that international electroencephalography meeting standard 10-20 lead system is confirmed
P1Or F
P2Position, reference electrode are placed on the auricle position.Pick up the primary signal that electric transducer picks up by the brain electricity and convert data acquisition (sophisticated signal processing technology in the eeg signal acquisition is adopted in elementary amplification, after-treatment, A/D conversion) through elementary amplification, after-treatment, A/D; Get into microprocessor; Application contains based on definite analysis of components method of particle group optimizing that an electrical information EEG signals extracts and the motor pattern classification, identify open, close up, wrist is stretched, wrist is bent, wrist outward turning, these six kinds of hand exercise patterns of wrist inward turning and hand attonity pattern.When recognition result was certain hand exercise pattern, the output corresponding control signal was given drive circuit, and drive motors drives the sports consciousness action of electrically powered hand by the people with disability.When recognition result is hand attonity pattern, output zero setting, the expression people with disability does not have hand exercise consciousness, does evil through another person and is failure to actuate, and is in relaxation state.Microprocessor output corresponding control signal is given drive circuit, and drive motors drives electrically powered hand action employing existing mature technology.
Traditional independent component analytical method makes up a separation matrix W=(w through the gradient descent algorithm optimizing
Ij)
N * n,, isolate and the same number of independent component of detected mixed signal according to u=Wx (wherein x picks up the detection signal of electric transducer for the brain electricity).But extract required signal composition, also want a large amount of postposition to handle; And owing to adopt gradient descent algorithm to make Optimization result be very easy to converge to a local optimum point, the signal element that causes needs to extract possibly be left in the basket.Can only extract the required definite signal relevant and use the definite analysis of components method that is proposed with reference signal based on particle group optimizing; Promptly replace optimizing estimation entire n * n separation matrix W; Only need to use particle group optimizing method and find certain w of delegation among the W; Thereby obtain expecting the signal composition that extracts by output signal u=wx, this can effectively improve efficiency of algorithm and accuracy.
Application comprises that based on definite analysis of components method of particle group optimizing structure reference signal, extraction contain an electrical information EEG signals and motor pattern classification.
Use this method and at first make up reference signal (comprising signal extraction reference signal and Classification and Identification reference signal).Specifically: at standard compliant EEG signals laboratory; Collection is held in hand and is got, hands opens, turn on the wrist, turn under the wrist, wrist inward turning, six kinds of corresponding original detection signals of true hand motion of wrist outward turning; Adopt existing maturation method that it is carried out off-line analysis and handle, obtain corresponding with six kinds of hand exercise patterns containing an electrical information EEG signals as sample signal.
This sample signal as the Classification and Identification reference signal, is carried out motor pattern identification according to a Classification and Identification reference signal and a dependency of electrical information EEG signals that contains that is extracted.
(Projection Pursuit, PP) method makes up the signal extraction reference signal to adopt projection pursuit.Contain an electrical information EEG signals sample according to six types and all have the characteristics of unimodal pulse, select for use unimodal pulse signal to make up the initial model of signal extraction reference signal as need; Select six kinds to contain a kind of in the electrical information EEG signals sample again; According to Hall projection index; With the sample signal data projection on the one-dimensional space; Find out with initial model and differ maximum projection, the structure that does not reflect in the initial model that this projection is comprised merges on the initial model new model that is improved.From then on new model sets out again, from six kinds of sample signals, reselects a kind ofly, repeats above step, and model is revised once more, contains an electrical information EEG signals sample until six kinds and all selects to dispose by above-mentioned steps.The correction model of this moment is comprising six types and containing a signal extraction reference signal of electrical information EEG signals sample prior information of required structure.
With the signal extraction reference signal with output signal correction as the required fitness function of constraints constitution optimization algorithm, specifically:
Adopt negentropy maximization object function, the negentropy J (u) of output signal u does
J(u)=H(u
g)-H(u) (1)
U in the formula
gBe and the identical Gaussian random vector of output signal u variance; The negentropy of H (.) expression signal; To be it remain unchanged to any linear transformation of u the characteristics of negentropy, and total right and wrong are minus, and having only when u is Gauss distribution just is zero.Based on this point, negentropy is a good object function.Make system that the maximization of output composition negentropy can cause the separation of signal.
A. people such as
has proved J in the article of being delivered " New approximations of differential entropy for independent component analysis and projection pursuit "; (u) value can through type; (2) carry out reliable approximate evaluation.
J(u)≈c[E{G(u)}-E{G(v)}]
2 (2)
G is any non-quadratic function in the formula, and c is positive constant, and v is a gaussian variable with zero-mean, unit variance.
To estimate to be correlated with as constraints between output u and the corresponding reference signal r, combine, be used to optimize solution procedure with the negentropy maximal criterion.Relevant through type (3) expression between output u and the corresponding reference signal r.
f(u)=ε(u,r)=Cov(u,r)=E{u,r}-{E(u)E(r)
T}>0 (3)
Formula (3) as constraints, is added object function, disposable accurate extraction is contained the optimization problem that a problem of electrical information EEG signals is converted into the inequality constraints of a band.
Maximize J
G(u)
subject?to f(u)=ε(u,r)>0(4)
Be to guarantee the signal composition of independent component for needing that extracted, promptly institute's composition that extracts reaches some suitable degree with the dependency of reference signal, also is the simplification optimized Algorithm simultaneously, and introducing vector z converts inequality constraints into equality constraint, makes
h(u)=f(u)-z
2=0 (5)
Then problem further is converted into the optimization problem of band equality constraint, shown in (6).
Maximize J
G(u)
subject?to h(u)=ε(u,r)-z
2=0(6)
The means of Lagrange multiplier method obtains corresponding Augmented Lagrangian Functions formula, with the fitness function of this functional expression as particle swarm optimization algorithm, shown in (7).
F(w,μ,z)=J
G(u)+μh(u) (7)
μ is that positive Lagrangian number is taken advantage of vector in the formula; U=wx, x are a primary electrical information EEG signals that contain.
Utilize particle swarm optimization algorithm to carry out optimizing and calculate, obtain the vectorial w of row of required separation matrix W, thereby obtain expecting the signal composition that extracts by output signal u=wx.Particle swarm optimization algorithm is a kind of sophisticated parallel, global optimization approach at random, is a kind of general utility tool that solves optimization problem.In the DCA-PSO algorithm, each of optimization problem is separated and is called a particle, and i particle is expressed as κ
i=(w
i, μ
i, z
i), each particle has its direction and speed separately in the search volume, and the experience of foundation oneself and the experience of other particle are sought optimal location in problem search space flight.The behavior of each particle is assessed by defined fitness function.Finish the algorithm operation through setting maximum iteration time.
The flow process of carrying out optimizing calculating is following:
I) if optimize first, then determine individual number of initial population and relevant parameter, as far as the i individuals, it has given at random position and speed.
Ii), calculate each individual fitness function of optimizing according to formula (7).
Fitness function of iii) each individuality being tried to achieve and the individual optimal solution in its record compare, if current separate before optimal result better (the fitness function value is bigger), then with the individual optimal solution of replacement.In addition, if separating of trying to achieve at present is superior to colony's optimal solution, then colony's optimal solution is reset to present result.
The parameter value w that iv) colony's optimal solution is tried to achieve, μ, z, the value before replacing.
V) revise each individual position and speed in the population according to formula (8), formula (9).
is called the speed of particle i in the formula, is characterized in the change of particle position in the j time iteration.
is characterized in the current location of particle i in the j time iteration.
is characterized in the correction position of particle i in the j time iteration.
is characterized in the j time iteration, the desired positions that particle is previous.
is characterized in the j time iteration, the optimal location that current all particles have reached.
is the positive acceleration coefficient; γ is called inertia power;
is the uniform random number between [0,1].
Obtain containing the EEG signals of an electrical information according to u=wx.
According to Classification and Identification reference signal and the method for being extracted that a dependency of electrical information EEG signals carries out motor pattern identification that contains be:
Foundation
Calculate respectively and extract signal and six kinds of Classification and Identification reference signal r
iBetween the size of correlation coefficient, u is by being extracted signal, r in the formula
iBe in six kinds of Classification and Identification reference signals.Select maximum one group of correlation coefficient and make comparisons with preset threshold, if greater than the threshold value Δ, with the pairing hand exercise pattern of Classification and Identification reference signal of the maximum group of correlation coefficient as recognition result; Export the motion control instruction of doing evil through another person accordingly,, explain that this moment, the people with disability did not have hand motion consciousness if maximum correlation coefficient is less than or equal to the threshold value Δ; Differentiate and be hand attonity pattern; Controller is exported zero setting, do evil through another person and be failure to actuate, 0.5≤Δ≤1.
The inventive method adopts eye, brain coordination mode to express the hand exercise wish, and the useful information that utilizes electro-ocular signal to comprise strengthens the characteristic of EEG signals that same sports consciousness produces; Use the definite analysis of components algorithm (DCA-PSO) that is proposed and extract, analyze, handle, realize the identification of hand multi-locomotion mode containing an electrical information EEG signals based on particle group optimizing.Because the DCA-PSO method is in the signal extraction process; To comprise needs to extract the reference signal of signal priori and exports signal correction as constraints; Make up the optimization problem model of belt restraining condition, and use have parallel, at random, the particle swarm optimization algorithm of global optimization characteristic carries out optimizing and calculates, thereby guarantee the disposable desired signal composition that from original detection signal, extracts; And can overcome in the present independent component analytical method owing to adopt optimized Algorithm based on gradient; Make when solving actual higher-dimension optimization problem, converge to a local optimum point easily, rather than converge to the problem of global optimum's point.Since as bionical electrically powered hand signal source to contain an electrical information EEG signals characteristic obvious; Thereby the accuracy of hand exercise pattern recognition is high; The action control of doing evil through another person is reliable; Realized under the highly reliable discrimination Three Degree Of Freedom real-time control of six actions of doing evil through another person, and the paralysis personage who is specially adapted to nerve, muscle serious degradation uses.
Description of drawings
Fig. 1 among the present invention based on the sketch map of definite analysis of components method of particle group optimizing;
Fig. 2 is a mode identification method sketch map among Fig. 1.
The specific embodiment
The present invention selects the brain electricity to pick up the EEG signals that the electric transducer collection comprises an electrical information.Each brain electricity picks up that electric transducer comprises the scalp power-collecting electrode and as for the reference electrode of ear; Reach the elementary amplifying circuit that is connected with reference electrode with power-collecting electrode; The outfan of elementary amplifying circuit connects with corresponding after-treatment circuit input end respectively, and the after-treatment circuit comprises trap circuit, back level amplifying circuit, the compensating circuit (being used to eliminate common-mode signal) of 50Hz.The after-treatment circuit output end is connected with the input of A/D change-over circuit.Three motors that 3-degree-of-freedom electrical is done evil through another person connect with corresponding drive circuit respectively.Microprocessor is connected with the outfan of A/D change-over circuit, the input end signal of drive circuit respectively.
The drive circuit of the elementary amplifying circuit in this device, after-treatment circuit (containing back level amplifying circuit, filter circuit etc.), A/D change-over circuit, microprocessor, motor all adopts bionical corresponding circuit and the device of doing evil through another person of existing single-degree-of-freedom.
The electrically powered hand control method of utilizing eye electricity and brain electric information is that the scalp power-collecting electrode that the brain electricity picks up in the electric transducer is placed on the brain frons F that international electroencephalography meeting standard 10-20 lead system is confirmed
P1Or F
P2Position, reference electrode are placed on the auricle position; Adopt eye, the brain coordination mode of nature to carry out the hand exercise imagination when wearing the people with disability that 3-degree-of-freedom electrical does evil through another person; During the expressive movement will; Pick up the primary signal that electric transducer picks up by the brain electricity and convert data acquisition through elementary amplification, after-treatment, A/D; Get into microprocessor, the definite analysis of components method based on particle group optimizing used contains that an electrical information EEG signals extracts and the motor pattern classification, identify open, close up, wrist is stretched, wrist is bent, wrist outward turning, these six kinds of hand exercise patterns of wrist inward turning and hand attonity pattern; Hand exercise pattern output corresponding control signal according to identification is given drive circuit, drives three motors of doing evil through another person through drive circuit, accomplishes certain action that 3-degree-of-freedom electrical is done evil through another person; When recognition result was hand attonity pattern, output zero setting was done evil through another person and is failure to actuate.
As shown in Figure 1, comprise based on definite analysis of components method of particle group optimizing making up reference signal, extracting and contain an electrical information EEG signals and motor pattern classification.
(1) reference signal comprises signal extraction reference signal and Classification and Identification reference signal, and the concrete grammar that makes up reference signal is:
1. at standard compliant EEG signals laboratory; Collection is held in hand and is got, hands opens, turn on the wrist, turn under the wrist, wrist inward turning, six kinds of corresponding original detection signals of true hand motion of wrist outward turning; Carry out off-line analysis and handle, obtain corresponding with six kinds of hand exercise patterns containing an electrical information EEG signals as sample signal.
2. with this sample signal directly as the Classification and Identification reference signal.
3. adopt projection Pursuit Method to make up the signal extraction reference signal, specifically: contain a unimodal pulse signal that electrical information EEG signals sample all comprises as the initial model that makes up the signal extraction reference signal according to six types; Select six kinds to contain a kind of in the electrical information EEG signals sample again; According to Hall projection index; With the sample signal data projection on the one-dimensional space; Find out with initial model and differ maximum projection, the structure that does not reflect in the initial model that this projection is comprised merges on the initial model new model that is improved; Again from new model, from six kinds of sample signals, reselect a kind ofly, repeat above step, model is revised once more, contain an electrical information EEG signals sample until six kinds and all select to dispose by above-mentioned steps; Final correction model is the signal extraction reference signal.
(2) extract and to contain a concrete grammar of electrical information EEG signals and be:
A. at first that signal extraction reference signal r is relevant as the required fitness function of constraints constitution optimization algorithm, specifically with output signal u:
Adopt negentropy maximization object function, the negentropy J (u) of output signal u does
J(u)=H(u
g)-H(u) (1)
U in the formula
gBe the Gaussian random vector identical, the negentropy of H (.) expression signal with output signal u variance; Formula (1) is reduced to
J(u)≈c[E{G(u)}-E{G(v)}]
2 (2)
G is any non-quadratic function in the formula, and c is positive constant, and v is a gaussian variable with zero-mean, unit variance.
To export between signal u and the signal extraction reference signal r and be correlated with, be expressed as as constraints
ε(u,r)=Cov(u,r)=E{u,r}-{E(u)E(r)
T}>0 (3)
Formula (3) as constraints, is added negentropy maximization object function, introduce vector z simultaneously, extraction is contained the Optimization Model that a problem of electrical information EEG signals is converted into the band equality constraint, be expressed as
Maximize J
G(u)
subject?to h(u)=ε(u,r)-z
2=0 ?(4)
The means of Lagrange multiplier method obtains corresponding Augmented Lagrangian Functions formula, with the fitness function of this functional expression as particle swarm optimization algorithm, is expressed as
F(w,μ,z)=J
G(u)+μh(u) (5)
μ is that positive Lagrangian number is taken advantage of vector in the formula; U=wx, x are that original detection signal, w are the row vector of separation matrix W.
B. utilize particle swarm optimization algorithm to carry out optimizing and calculate, obtain the vectorial w of row of required separation matrix W, thereby obtain expecting the signal composition that extracts by output signal u=wx; Finish the algorithm operation through setting maximum iteration time.The flow process of carrying out optimizing calculating is following:
I) if optimize first, then determine individual number of initial population and relevant parameter, as far as the i individuals, it has given at random position and speed, and i particle is expressed as κ
i=(w
i, μ
i, z
i);
Ii), calculate each individual fitness function F (w that optimizes according to formula (5)
i, μ
i, z
i);
Fitness function F (the w that iii) each individuality is tried to achieve
i, μ
i, z
i) with the record in this individual adaptive optimal control degree functional value compare; If current fitness function value is greater than this previous individual adaptive optimal control degree functional value; Then with current fitness function value as the record in adaptive optimal control degree functional value; If current fitness function value is smaller or equal to this previous individual adaptive optimal control degree functional value, then this individual adaptive optimal control degree functional value in the record is constant; If current adaptive optimal control degree functional value that should individuality is greater than the adaptive optimal control degree functional value of colony, then with current adaptive optimal control degree functional value that should individuality as the adaptive optimal control degree functional value of colony; If current adaptive optimal control degree functional value size that should individuality equals the adaptive optimal control degree functional value of colony, then the adaptive optimal control degree functional value of colony is constant;
The parameter value w that iv) colony's optimal solution is tried to achieve, μ, z, the value before replacing;
V) revise each individual position and speed in the population according to formula (6) and formula (7);
is the speed of particle i in the formula, i.e. the change of particle position in the j time iteration;
is the current location of particle i in the j time iteration;
is the correction position of particle i in the j time iteration;
is in the j time iteration, the desired positions that particle is previous;
is in the j time iteration, the optimal location that current all particles have reached;
is the positive acceleration coefficient; γ is an inertia power;
is the uniform random number between [0,1];
C. obtain exporting signal u according to u=wx, promptly contain the EEG signals of an electrical information;
(3) as shown in Figure 2, the motor pattern classification is to carry out motor pattern identification according to a Classification and Identification reference signal and a dependency of electrical information EEG signals that contains that is extracted, and concrete grammar is:
Foundation
Calculate respectively and extract signal and six kinds of Classification and Identification reference signal r
iBetween the size of correlation coefficient, u is by being extracted signal, r in the formula
iBe in six kinds of Classification and Identification reference signals; Select maximum one group of correlation coefficient and make comparisons with preset threshold, if greater than the threshold value Δ, with the pairing hand exercise pattern of Classification and Identification reference signal of the maximum group of correlation coefficient as recognition result; Export the motion control instruction of doing evil through another person accordingly,, explain that this moment, the people with disability did not have hand motion consciousness if maximum correlation coefficient is less than or equal to the threshold value Δ; Differentiate and be hand attonity pattern; Controller is exported zero setting, do evil through another person and be failure to actuate, 0.5≤Δ≤1.
Concrete work process is:
When wearing people with disability that 3-degree-of-freedom electrical does evil through another person when needing the artificial hand controlled action; Brain, eye, the Handball Association of being accustomed to adopting with reference to people transfers in the pattern of capable hand exercise; Adopt eye brain coordination mode to carry out the hand exercise imagination, the electrically powered hand system will be according to an electrical information EEG signals that contain of corresponding hand motion, on analysis, base of recognition; Artificial hand controlled is accomplished corresponding action: turn over motor control consciousness on the wrist, do evil through another person to accomplish synchronously and stretch the wrist action; Turn over motor control consciousness under the wrist, do evil through another person to accomplish synchronously and bend the wrist action; Wrist outward turning motor control consciousness is done evil through another person and is accomplished the wrist outward turning synchronously; Wrist inward turning motor control consciousness is done evil through another person and is accomplished the wrist inward turning synchronously; The five fingers stretching control consciousness, the hand of doing evil through another person opens; The motor control of clenching fist consciousness, the hand of doing evil through another person closes up; Hand loosens consciousness, does evil through another person and does not do any action.Avoid the multiple freedom degrees hand-prosthesis of conventional commercial need be, realized the do evil through another person real-time control of six actions of Three Degree Of Freedom through repeatedly switching the situation just can reach multiple freedom degrees hand-prosthesis control.