CN101870109B - Fish swimming imitating robot movement control device and method - Google Patents

Abstract

The invention relates to a fish swimming imitating robot movement control device and a method; a tail joint CPG unit and a pectoral fin CPG unit are coupled into a CPG model; the model comprises ten nonlinear oscillators; and the excitation threshold of the oscillators is not necessarily the same. A saturation function adjusts the frequency and amplitude of all the oscillators so as to coordinate the input excitation signals of the CPG model, change the output behaviors of a CPG network and control the robot to realize different movement modes. The control method is finally integrated in an embedded microprocessor, and can realize the underwater movement control of the fish swimming imitating robot.

Description

A kind of fish swimming imitating robot movement control device and method

Technical field

The invention belongs to the electromechanical integration field, relate to the sub aqua sport control method of multi-joint fish swimming imitating robot, belong to the electromechanical integration field.

Background technology

Common robot motion's control method mainly contains three kinds, a kind of method that is based on model: adopt the thinking of accurate modeling-optimum movement locus planning-feedback mechanism control, make robot motion's convergence ideal trajectory as far as possible; A kind of method that is based on behavior: adopt the control thinking of perception-reflection, with the synthetic meaningful biological behavior of some planless activities, motion is simple, flexible; Also have a kind of be based on biological control method, the modal rhythmic movement of animal in simulating nature circle.Based on the control method more complicated of model, the most direct based on the method mapping of behavior, what of " basic capacity " its level of intelligence depend on, but " basic capacity " generally can not be revised; And biological control method can be coordinated a plurality of freedoms of motion, according to the instruction accurate response that receives, and has the complex environment adaptation mechanism that the experience nature tests.Along with the development of engineering, in the biological control method (Central Pattern generator CPG) more and more receives researcher's concern based on central pattern generator (cpg).CPG is applied to having in the robot control both at home and abroad: the quadruped robot walking on the ground that Matsuoka that EMUs for Kyushu of Japan polytechnical university adopts and Kimura model are applied to have 12 frees degree.Shenyang automation research institute of the Chinese Academy of Sciences has proposed to adopt circulation to suppress the CPG model that connected mode constitutes, and is applied on the snake-shaped robot; The CNN model that L.O.Chua and Yang propose is used for setting up extensive analog signal processing system; People such as Ijspeert have proposed the coupling nonlinear oscillator model of being made up of body CPG and limb CPG at the salamandrine bimodulus motion of creeping and swim.Prior art is based on specific bionical object more, CPG prototype network structure and bionical object are closely related, and it is less to the bionical control research of multi-joint fish swimming imitating robot, the present invention has proposed a kind of new CPG prototype network structure on this basis, is used for realizing the bionic movement control of multi-joint fish swimming imitating robot.

Summary of the invention

The purpose of this invention is to provide a kind of multi-joint fish swimming imitating robot sub aqua sport control device and method, to solve a kind of underwater motion control of fish swimming imitating robot that constitutes by pectoral fin and afterbody based on the CPG model.This method makes full use of robot afterbody and pectoral fin and coordinates the characteristics that advance, has proposed the CPG network model that is made of afterbody CPG and pectoral fin CPG, comprises the coupled relation between structure of models framework and nonlinear oscillator.Utilize this CPG model, can realize the sub aqua sport control of fish swimming imitating robot.

For achieving the above object, a kind of fish swimming imitating robot movement control device of the present invention, technical solution is: comprise the left pectoral fin of fish swimming imitating robot, right pectoral fin and a plurality of tail swings joint, left pectoral fin, right pectoral fin are positioned at the head left and right sides, also have:

A plurality of CPG unit comprises: left pectoral fin CPG unit, right pectoral fin CPG unit and CPG unit, a plurality of joint;

The joint J that the imitative fish of a plurality of modularizations advances _NConstitute the afterbody of robot;

One saturation function unit receives the control signal that the online computing of outside input signal generates each CPG unit;

Described left pectoral fin CPG unit and described right pectoral fin CPG unit are fixedly arranged on respectively on left pectoral fin, the right pectoral fin, described left pectoral fin CPG unit is connected with the saturation function unit with right pectoral fin CPG unit, in control bottom left pectoral fin CPG unit and the right pectoral fin CPG unit controls left side pectoral fin and the motion of right pectoral fin of control signal;

Described a plurality of joint J _NAccording to the y direction of fish swimming imitating robot and an end of head a plurality of joints are set in proper order; And a plurality of joint J _NBetween be dynamically connected mutually, on each joint, be provided with CPG unit, a pair of joint, all CPG unit, joint move under the effect of control signal, realize moving about of imitative fish robot;

CPG unit, described a plurality of joint is connected respectively with between left pectoral fin CPG unit and the right pectoral fin CPG unit, and CPG unit, a plurality of joint provides coupling weights and phase difference to pectoral fin CPG unit, realizes the bionical control in this joint.

Preferably, described a plurality of joint J _NQuantity, be the quantity of adjusting the joint according to fish swimming imitating robot body structure feature.

Preferably, described each CPG unit, joint is provided with a pair of joint oscillator, and the phase difference between the oscillator of described a pair of joint is set at π; Every pair of joint oscillator corresponds respectively to the musculus flexor and the extensor of these joint motions, and every pair of joint oscillator suppresses mutually according to coupling weights and phase difference between them, realizes the bionical control in this joint.The oscillator Mathematical Modeling that each joint oscillator is adopted is as follows:

$\left\{\begin{array}{c}{\stackrel{\·}{\mathrm{\θ}}}_i=2\mathrm{\π}{f}_i+\underset{j}{\mathrm{\Σ}}{a}_j{w}_{\mathrm{ij}}\sin ({\mathrm{\θ}}_j-{\mathrm{\θ}}_i-{\mathrm{\φ}}_{\mathrm{ij}})\\ {\stackrel{\·\·}{a}}_i={\mathrm{\τ}}_i\{\frac{{\mathrm{\τ}}_i}{4}(A_i-a_i)-{\stackrel{\·}{a}}_i\}\\ x_i=a_i\{1+\cos \left({\mathrm{\θ}}_i\right)\}\end{array}\right.$

In the formula, θ _iAnd a _iBe the oscillator state variable, represent phase place and the amplitude of oscillator i respectively,

With

Be its first derivative, Be second dervative; f _iAnd A _iInherent frequency and the amplitude of decision oscillator i; τ _iBe time constant, decision a _iConverge to A _iSpeed; Coupled relation between oscillator i and oscillator j is by the coupling weight w _IjAnd phase difference _IjDetermine x _iOutput for oscillator i.

Preferably, described left pectoral fin CPG unit and right pectoral fin CPG unit are respectively equipped with a left pectoral fin oscillator and a right pectoral fin oscillator, adopt with the identical oscillator Mathematical Modeling of joint oscillator.

Preferably, the input signal that described a plurality of CPG unit receives is by being provided with different threshold values to each swinging joint, participate in the swing along with input signal increases each joint gradually by from back to front order, realize the length control of joint swing, utilize wobble length to realize the motion control of multi-joint fish swimming imitating robot.

For achieving the above object, the control method of a kind of fish swimming imitating robot motion of the present invention, technical solution is: at first utilize the input signal drive of saturation function unit reception from the outside, output has the control signal of a frequency of oscillation f and an amplitude signal A after processing is regulated in the saturation function unit; The control signal that has oscillation frequency signal f and amplitude signal A is then controlled the swing of left pectoral fin oscillator and right pectoral fin oscillator and each joint oscillator of afterbody; Coupled relation between oscillator i and oscillator j is by the coupling weight w in the Mathematical Modeling of oscillator _IjAnd phase difference _IjDecision;

According to the coupled relation between each oscillator frequency of oscillation f and amplitude signal A are adjusted again, generate a plurality of joint J of control left pectoral fin, right pectoral fin and afterbody _NThe oscillator signal of vibration is used to make fish swimming imitating robot to produce the capable ripple of propagating from front to back and advances, and realizes fish swimming imitating.

Preferably, the coupled relation between caudal articular process CPG unit and the pectoral fin CPG unit is by weight w _IjAnd phase difference _IjDetermining, is to adjust according to an effective excitation value, and when input signal was lower than effective excitation value, pectoral fin CPG unit and caudal articular process CPG unit did not have coupling, and its weights are 0; Otherwise, when input signal reaches effective excitation value, pectoral fin CPG unit will " be forced to " hunting of frequency with caudal articular process CPG unit, pectoral fin CPG unit and caudal articular process CPG unit suitable swing, unidirectional inhibition pectoral fin CPG unit, caudal articular process CPG unit, its weights are 30.

Preferably, each CPG unit, joint of described left pectoral fin CPG unit and right pectoral fin CPG unit and afterbody is provided with oscillator, finally on embedded microprocessor, adopt the C Programming with Pascal Language to realize to described each oscillator control parameter in line computation according to Euler method, obtain the frequency and the amplitude of each oscillator in real time, the physical condition that is implemented in existing steering wheel driving force, embedded microprocessor processing speed limits the most continuous Position Control down.

Preferably, the fish swimming imitating travel robot sub aqua sport of this pectoral fin CPG unit, left side and right pectoral fin CPG unit and each CPG unit, joint of afterbody is controlled on the embedded microprocessor and is achieved; By regulating the input signal of this motion control device, craspedodrome, turning, the come-up dive motor pattern of robot will be produced; Identical and greater than excitation during threshold value, robot keeps straight on when left and right sides input signal; Different and during greater than the input signal threshold value, robot turns when left and right sides input signal, wherein, when left input signal during greater than right input signal, robot turns right, otherwise turns left; In addition, when craspedodrome is moved about, keep level when left and right sides pectoral fin is initial, the initial deflection angle is 0, and the identical control method of moving about that adopts and keep straight on when adding an initial deflection angle that makes progress simultaneously for left and right sides pectoral fin, realizes the dive campaign of fish swimming imitating robot; When giving the additional simultaneously downward initial deflection angle of left and right sides pectoral fin, realize the come-up motion of fish swimming imitating robot.

Beneficial effect of the present invention: the CPG network model is proposed, finally integrated on the robot platform of our development in conjunction with concrete control device, carried out the Physical Experiment of multi-joint fish swimming imitating.Experimental result has shown the validity of the CPG model that is proposed, and has imitated truly moving about of biological fish well, has certain reference value.

Description of drawings

Fig. 1 is a multi-joint fish swimming imitating robot body structure schematic diagram;

Figure 21 is a multi-joint fish swimming imitating robot CPG network model;

Figure 22 encourages the threshold value schematic diagram;

Fig. 3 is a control device hardware configuration schematic diagram;

Fig. 4 is the flow chart of control method;

Fig. 5 is that input signal is 1 o'clock comparison of wave shape result schematic diagram of moving about of keeping straight on;

Fig. 6 is that input signal is 1.5 o'clock comparison of wave shape result schematic diagrams of moving about of keeping straight on;

Fig. 7 is that input signal is 2 o'clock comparison of wave shape result schematic diagrams of moving about of keeping straight on;

Fig. 8 is that input signal is 2.5 o'clock comparison of wave shape result schematic diagrams of moving about of keeping straight on;

Fig. 9 is the input signal and the length velocity relation schematic diagram that moves about of moving about of keeping straight on;

Figure 10 is the schematic diagram that concerns of left and right sides input signal difference and radius of turn.

The specific embodiment

Below in conjunction with accompanying drawing the multi-joint fish swimming imitating robot sub aqua sport control method based on central pattern generator (cpg) (CPG) model is explained.

One, fish swimming imitating robot CPG network structure

Neural oscillator is the basic composition unit of CPG model, the oscillator Mathematical Modeling that is adopted as shown in Equation (1):

$\left\{\begin{array}{c}{\stackrel{\·}{\mathrm{\θ}}}_i=2\mathrm{\π}{f}_i+\underset{j}{\mathrm{\Σ}}{a}_j{w}_{\mathrm{ij}}\sin ({\mathrm{\θ}}_j-{\mathrm{\θ}}_i-{\mathrm{\φ}}_{\mathrm{ij}})\\ {\stackrel{\·\·}{a}}_i={\mathrm{\τ}}_i\{\frac{{\mathrm{\τ}}_i}{4}(A_i-a_i)-{\stackrel{\·}{a}}_i\}\\ x_i=a_i\{1+\cos \left({\mathrm{\θ}}_i\right)\}\end{array}\right.---\left(1\right)$

In the formula, θ _iAnd a _iBe the oscillator state variable, represent phase place and the amplitude of oscillator i respectively,

With

Be its first derivative,

Be second dervative; f _iAnd A _iInherent frequency and the amplitude of decision oscillator i; τ _iBe time constant, decision a _iConverge to A _iSpeed; Coupled relation between oscillator i and oscillator j is by weight w _IjAnd phase difference _IjDetermine x _iOutput for oscillator i.

For the performance of moving about that makes the multi-joint fish swimming imitating robot approaches true fish more, need a kind of control method that more meets biological prototype to realize the coordination control of pectoral fin and afterbody, thereby obtain the performance of moving about rapidly and efficiently.

Fig. 1 has provided the multi-joint fish swimming imitating robot body structure schematic diagram that the inventive method is used, comprise a pair of pectoral fin propulsive mechanism, pectoral fin as shown in Figure 1 comprises left pectoral fin 2, right pectoral fin 3, left side pectoral fin 2, right pectoral fin 3 are positioned at head 1 left and right sides, and its reciprocally swinging can the driven machine people advance under water; Joint J by the imitative fish propelling of a plurality of modularizations _NConstitute afterbody 4, be disposed in order at head 1 rear according to y direction, be dynamically connected mutually, its suitable swing is realized fish swimming imitating, and robot is that the capable ripple that the suitable swing generation of dependence head 1, left pectoral fin 2, right pectoral fin 3 and afterbody 4 is propagated from front to back advances.Wherein, joint J _NQuantity is unfixing, adjusts joint J according to application demand _NQuantity.Therefore, at multi-joint fish swimming imitating robot body structure feature, obtain the basic structure of multi-joint fish swimming imitating robot CPG network.

Multi-joint fish swimming imitating robot CPG network structure as shown in figure 21, wherein: correspondence is provided with a left pectoral fin CPG unit and right pectoral fin CPG unit on left pectoral fin 2 and right pectoral fin 3, is provided with an oscillator in left pectoral fin CPG unit and the right pectoral fin CPG unit; Described oscillator is a nonlinear oscillator; Afterbody 4 comprises the joint J that the imitative fish of a plurality of modularizations advances _N: adopt N joint J _N, N is a natural number, for example when embodiment selects N=4 joint for use, and described joint J _NBe the first joint J ₁, second joint J ₂, the 3rd joint J ₃With the 4th joint J ₄, implement joint J _NThe selection of quantity is given unnecessary details no longer in detail; Implement described joint J _NThe time, each joint J _NTo a CPG unit should be arranged, CPG unit, described four joints comprises: CPG unit, first joint 41, second joint CPG unit 42, CPG unit, the 3rd joint 43 and CPG unit, the 4th joint 44.Each CPG unit, joint respectively contains a left joint oscillator and a right joint oscillator, and wherein: CPG unit, described first joint 41 contains joint oscillator 411 and joint oscillator 412; Described second joint CPG unit 42 contains joint oscillator 421 and joint oscillator 422; CPG unit, described the 3rd joint 43 contains joint oscillator 431 and joint oscillator 432; CPG unit, described the 4th joint 44 contains joint oscillator 441 and joint oscillator 442.

Know that by above-mentioned pectoral fin and afterbody two parts have ten oscillators, described ten oscillator structures are identical.

The input quantity of CPG network is input signal (drive) among Figure 21, and input signal is divided into left and right sides two parts: left input signal d _LeftWith right input signal d _Right, with left input signal d _LeftWith right input signal d _RightAfter regulating processing, the saturation function unit obtains the oscillation frequency signal f and the amplitude signal A of each oscillator.Wherein, left input signal d _LeftDriven machine head part 1 the left pectoral fin 2 and the left side health of afterbody 4, right input signal d _RightDriven machine head part 1 the right pectoral fin 3 and the right side health of afterbody 4.Input signal only just adopts d when turning motion _LeftAnd d _RightThe difference of representing health left and right sides input signal respectively, otherwise unify to represent with drive, below repeat no more.The arc lines are represented between each oscillator and are had annexation among Figure 21, and arrow is a closure.

The left pectoral fin CPG unit of about 1 two symmetries of robot head, right pectoral fin CPG unit constitute pectoral fin CPG, described pectoral fin has single-degree-of-freedom, can do reciprocally swinging, forms of motion is fairly simple, and the swing of actual fish pectoral fin also only limits to the local muscle activity of fin base.Simple in structure in view of pectoral fin, the CPG unit, joint of afterbody 4 and the coupled relation between pectoral fin CPG unit are represented left pectoral fin CPG unit, right pectoral fin CPG unit respectively, in practice as Figure 21 with a nonlinear oscillator for convenience of description; During the biology fish swimming, its left pectoral fin 2, right pectoral fin 3 are generally same phase swinging, and therefore the phase difference with two oscillators is set at 0, is same phase relation between them.In addition, the output of each oscillator is as the output of CPG unit, its place.

Bionics Study shows that the musculus flexor of animal movement effector organ and extensor control neuron are represented by the mutual inhibition of described a pair of nonlinear oscillator.In the CPG of the joint of afterbody 4, each joint J _NThe non-linear joint oscillator of the left and right sides corresponds respectively to the musculus flexor and the extensor of these joint motions, passes through the coupling weight w between them _IjAnd phase difference _IjSuppress mutually, realize the bionical control in this joint.The joint oscillator and the pectoral fin oscillator structure of afterbody 4 are basic identical, each joint oscillator coordinates to produce the rhythmic movement of the wavy swing of afterbody mutually, their annexation is defined as three kinds, is respectively from bottom to top, connects from top to bottom and laterally, shown in arc lines among Figure 21.Here, annexation comprises and suppresses weights and based on the phase difference of the fish bulk wave direction of propagation.Wherein, be anti-phase relation between two joint oscillators that connect laterally, the difference of its joint oscillator output is as the output of CPG unit, this joint, as being horizontally connected with joint oscillator 411 and joint oscillator 412 among Figure 21, joint oscillator 421 and joint oscillator 422, joint oscillator 431 and joint oscillator 432, joint oscillator 441 and joint oscillator 442, the difference of the output of two oscillators that it laterally connects is as the output of its CPG unit, joint of living in, and the output of left pectoral fin oscillator and right pectoral fin oscillator is respectively as the output of left pectoral fin CPG unit and right pectoral fin CPG unit.

When fish swimming imitating robot moves under water, rely on the suitable swing of left pectoral fin 2, right pectoral fin 3 and afterbody 4 to advance, have certain coupled relation between the CPG unit, joint of afterbody and left pectoral fin CPG unit, the right pectoral fin CPG unit.When advancing at utmost speed, the fluctuation of left pectoral fin, right pectoral fin and whole afterbody 4 is consistent, and promotes the fish body; When low-speed forward, then by the separately fluctuation or coordinate to advance of left and right pectoral fin with the small fluctuation of afterbody 4.As seen, in both annexations, the CPG unit, joint of afterbody 4 plays inhibitory action to left pectoral fin CPG unit, right pectoral fin CPG unit, therefore, make the left pectoral fin CPG of the unidirectional inhibition in CPG unit, joint unit, the right pectoral fin CPG unit of afterbody 4, as the arc lines arrow points of unidirectional inhibition oscillator is shown, contain joint oscillator 411, joint oscillator 421, joint oscillator 431, the left pectoral fin 2 of joint oscillator 441 unidirectional sensings among Figure 21, joint oscillator 412, joint oscillator 422, joint oscillator 432, the right pectoral fin 3 of joint oscillator 442 unidirectional sensings.

Two, the excitation threshold value of CPG model vibrator

At nature, most of fish adopt hunting frequency and the method that wobble amplitude is coordinated mutually to come realization speed to regulate.When slowly moving about, have only the part of afterbody 4 or pectoral fin to produce propulsive force in small amplitude wobble; When its acceleration was moved about or move about at a high speed, the swing part of health all participated in fluctuation at a high speed.

Consider this mechanism of moving about of bionical object, and in order to save the robot energy when low speed moves about, fish swimming imitating robot adopts the control of swing part length.As shown in figure 22, drive increases gradually when input signal, but less than the minimum threshold d of input signal _Low(with the 4th joint J ₄Threshold value d _{Low, 4}Equate, and the threshold value of each and arranged on left and right sides joint, joint oscillator is identical, below repeats no more) time, all the not starting of oscillations of oscillator among Figure 21, it is static that robot keeps; When input signal drive reaches the 4th joint J ₄Threshold ones d _{Low, 4}The time, joint oscillator 441 among Figure 21 and joint oscillator 442 and left pectoral fin oscillator and right pectoral fin oscillator starting oscillation (left pectoral fin oscillator threshold value, right pectoral fin oscillator threshold value and the 4th joint J ₄Threshold value is identical, also is threshold value d _{Low, 4}), tail fin is the 4th joint J ₄With left pectoral fin 2,3 swings of right pectoral fin, robot slowly moves about; Input signal drive increases to threshold value d _{Low, 3}The time, frequency of oscillation increases, and caudal peduncle is the 3rd joint J ₃Participate in the swing, joint oscillator 431 and joint oscillator 432 be starting oscillation also; Input signal drive continues to increase to threshold value d _{Low, 2}The time, second joint J ₂Joint, left and right sides oscillator 421 and joint oscillator 422 also participate in the swing; When increasing, input signal drive is threshold value d _{Low, 1}The time, all the oscillator starting of oscillations among Figure 21, robot left side pectoral fin 2, right pectoral fin 3 and afterbody 4 are all as swing part, and driven machine people moves about.Therefore, by giving pectoral fin and each joint J of afterbody ₁, J ₂, J ₃And J ₄Different excitation threshold value d is set respectively _{Low, 1}, d _{Low, 2}, d _{Low, 3}And d _{Low, 4}, realize utilizing swing part length to obtain the imitative fish movement control of robot under water.

Three, the saturation function of CPG model

When fish moved about under water, the hunting frequency of its health each several part was generally different with amplitude.Its pectoral fin is mainly used in the balance health and grasps the direction of motion, and relies on 1/3rd places, afterbody rear to produce the required power that moves about.Therefore, each oscillator of fish swimming imitating robot has different hunting frequencies and amplitude under identical input stimulus, and tail fin joint J ₄The wobble amplitude maximum.In the CPG model, we are by definition a kind of saturation function unit, and its parameter is set realizes above-mentioned functions, specifically implement as follows:

Input signal drive is from threshold value d _{Low, 4}In the process that beginning increases gradually, the frequency f of each oscillator and amplitude A also increase gradually, show as the increase of each joint hunting frequency and amplitude.In order to imitate truly moving about of fish, the amplitude of each swing part participation swing is inequality, shows as tail fin joint J ₄The wobble amplitude maximum.As the limit value d of wealthy family that reaches excitation _HighThe time, frequency of oscillation and amplitude all reach maximum, and robot moves about fastest.As left and right input signal d _Left, d _RightGreater than the limit value d of wealthy family _HighThe time, oscillator does not stop, but vibrates with the frequency and the amplitude of wealthy family's limit value correspondence, is:

if?d _left，right≥d _high d _left，right＝d _high

Therefore, at each joint J _NParticipate in the difference of the amplitude of swing, the saturation function shown in Figure 21 produces different wobble amplitude to each CPG unit, joint of afterbody respectively with left and right pectoral fin CPG unit under identical input signal drive.For simplicity, all oscillator amplitudes all adopt identical linear function form

$A=\left\{\begin{array}{cc}{k}_A\mathrm{drive}+b_A& \mathrm{if\; drive}\≥d_{\mathrm{low}}\\ A_{\mathrm{sat}}& \mathrm{otherwise}\end{array}\right.$

But to its parameter of each oscillator k _A, b _ADrive is not quite similar with input signal, will state it in detail below.

The motion of the pectoral fins of fish does not have absolute symmetry, and left pectoral fin 2, right pectoral fin 3 be respectively single nonlinear oscillator, therefore makes left and right pectoral fin CPG that the unit is separate, and left pectoral fin oscillator and right pectoral fin oscillator are respectively with frequency f separately _{Pec, left}, f _{Pec, right}Vibration adopt identical linear function form, and its parameter is identical, and slope is k _{F, pec}, intercept is b _{F, pec}, its function is formula (2):

$\begin{array}{c}{f}_{\mathrm{pec},\mathrm{left}}=\left\{\begin{array}{cc}{k}_{f,\mathrm{pec}}{d}_{\mathrm{left}}+b_{f,\mathrm{pec}}& \mathrm{if}\min (d_{\mathrm{left}},d_{\mathrm{right}})\≥d_{\mathrm{low}}\\ f_{\mathrm{sat}}& \mathrm{otherwise}\end{array}\right.\\ f_{\mathrm{pec},\mathrm{right}}=\left\{\begin{array}{cc}{k}_{f,\mathrm{pec}}{d}_{\mathrm{right}}+b_{f,\mathrm{pec}}& \mathrm{if}\min (d_{\mathrm{left}},d_{\mathrm{right}})\≥d_{\mathrm{low}}\\ f_{\mathrm{sat}}& \mathrm{otherwise}\end{array}\right.\end{array}---\left(2\right)$

Wherein, f _{Pec, left}, f _{Pec, right}Be respectively the frequency of oscillation of left pectoral fin, right pectoral fin, d _Left, d _RightBe respectively left and right input signal, k _{F, pce}, b _{F, pec}Be the parameter of linear function (2), f _SatBe saturation frequency.When robot turns, the input signal difference of left and right sides pectoral fin, d _Left≠ d _Right, then by following formula (2), the hunting frequency difference of left and right pectoral fin helps to realize the turning of robot.

If the joint oscillator of each CPG unit, joint and arranged on left and right sides of afterbody vibrates according to different frequency, both have output the waveform of different cycles, obtain one and two left and right joint oscillator wave cycles brand-new waveform all inequality after subtracting each other, from biological angle, the relation of and arranged on left and right sides joint oscillator " excitement-inhibition " is upset, and has destroyed the left joint oscillator of CPG unit, joint, the coupled relation between the oscillator of right joint.Therefore, for simplicity, get left and right input signal d _Left, d _RightAverage as input, and make all joint oscillators in the CPG unit, joint of afterbody with same hunting of frequency, its function is formula (3):

$f_{J1-\mathrm{<figure-callout\; id="4"\; label="J"\; filenames="H2009100820832E00011.png,H2009100820832E00012.png"\; state="\{\{state\}\}">J</figure-callout>}4}=\left\{\begin{array}{cc}{k}_{f,\mathrm{tail}}\frac{d_{\mathrm{left}}+d_{\mathrm{right}}}{2}+b_{f,\mathrm{tail}}& \mathrm{if}\min (d_{\mathrm{left}},d_{\mathrm{right}})\&GreaterEqual;d_{\mathrm{low}}\\ f_{\mathrm{sat}}& \mathrm{otherwise}\end{array}\right.---\left(3\right)$

Obvious when left and right sides input signal is identical, d _Left=d _Right, following formula also can satisfy.

In addition, when robot turns, need each joint J _NWaveform table to reveal the left and right sides asymmetric, and under the identical prerequisite of frequency of oscillation, can only show this asymmetrical relationship by the amplitude difference of the non-linear joint of the and arranged on left and right sides of afterbody 4 oscillator, therefore, the amplitude of the joint oscillator of all afterbodys 4 adopts identical functional form, for simplicity, also adopt linear function.The difference of left side pectoral fin oscillator, right pectoral fin oscillator wobble amplitude also helps robot and realizes turning, and therefore adopts the oscillation amplitude form identical with the joint oscillator of afterbody 4.Under identical oscillation amplitude function, different parameter combinations will obtain different wobble amplitude.In addition, even same kind of parameter group closed, the difference of left and right sides input signal also can cause the difference of wobble amplitude.Therefore, the different parameter combinations of each CPG unit, joint employing of afterbody 4 realizes the difference of each joint wobble amplitude, but same joint J _NThe joint oscillator parameter combination of both sides is identical, by left and right input signal d _Left, d _RightDifference realize the difference of and arranged on left and right sides wobble amplitude.The parameter combinations of pectoral fin CPG unit, a left side, right pectoral fin CPG unit is identical, also by left and right input signal d _Left, d _RightDifference realize the difference of wobble amplitude.The wobble amplitude function of each oscillator is formula (4) among Figure 21:

$A=\left\{\begin{array}{cc}{k}_A\mathrm{drive}+b_A& \mathrm{ifdrive}\&GreaterEqual;d_{\mathrm{low}}\\ A_{\mathrm{sat}}& \mathrm{otherwise}\end{array}\right.---\left(4\right)$

Joint J wherein ₁-J ₄Parameter combinations k _AAnd b _ADifference, but same joint J _NThe parameter combinations k of the joint oscillator of and arranged on left and right sides _AAnd b _AIdentical.The parameter combinations k of left side pectoral fin, right pectoral fin _A, b _AIdentical, but with each joint J of afterbody _NDifferent.The excitation drive of and arranged on left and right sides oscillator gets left input signal d respectively in the formula (4) _LeftWith right input signal d _Right, joint oscillator 411, joint oscillator 421, joint oscillator 431, joint oscillator 441 and left pectoral fin oscillator are got left input signal d _Left, joint oscillator 412, joint oscillator 422, joint oscillator 432, joint oscillator 442 and right pectoral fin oscillator are got right input signal d _Right, the wobble amplitude difference of and arranged on left and right sides oscillator realizes the underwater effective turning of robot.

In fish swimming imitating robot CPG network, in conjunction with the characteristic of truly moving about of fish, the frequency parameter k of each oscillator saturation function _f, b _fWith amplitude parameter k _A, b _A, excitation threshold value d _{Low, 1}-d _{Low, 4}, parameters such as saturation frequency, saturated amplitude are gathered by the Computer Simulation examination and are obtained, shown in table 1CPG network saturation function parameter.

Table 1CPG network saturation function parameter

Four, the coupled relation between the CPG model vibrator

From biology, the CPG unit among Figure 21 is made of " musculus flexor-extensor " oscillator of a pair of mutual inhibition.For left pectoral fin 2, right pectoral fin 3, its left pectoral fin CPG unit, right pectoral fin CPG unit are respectively by separately an oscillator reduced representation, therefore its coupled relation might not require to suppressing relation, and, during the biology fish swimming, its left pectoral fin 2, right pectoral fin 3 are generally same phase swinging, and therefore the phase difference with two oscillators is set at 0.The joint CPG of afterbody 4 is that strict " musculus flexor-extensor " suppresses structure, so laterally be connected to anti-phase relation between the oscillator of joint, its phase difference is defined as π; Based on the characteristics that fish fish bulk wave is propagated from front to back, the top-down phase difference of joint oscillator of afterbody 4 should be on the occasion of, be defined as π/4, corresponding therewith, phase difference from bottom to top is-π/4.The forms of motion of fish in water is generally the synthetic of various motion motor patterns, wherein just comprises the coordinated movement of various economic factors of afterbody 4 imitative Scad sections shape fluctuation and left pectoral fin 2, right pectoral fin 3, has certain annexation between this explanation caudal articular process CPG and the pectoral fin CPG.For correct phase difference between the joint oscillator of each CPG unit, joint of keeping afterbody 4, guarantee the oscillator in-phase oscillation of left pectoral fin 2, right pectoral fin 3 simultaneously, making the phase difference of the joint oscillator 441 of the oscillator of left pectoral fin 2 and afterbody 4 is 0, with the phase place of left pectoral fin 2 is 0 for referencial use, and obtains the phase place of joint oscillator 411, joint oscillator 421, joint oscillator 431, joint oscillator 441, joint oscillator 412, joint oscillator 422, joint oscillator 432 and the joint oscillator 442 of afterbody 4 and arranged on left and right sides in view of the above respectively.

Some fish has flourishing pectoral fin, but is mainly used in the balance health and grasps the direction of motion, and when advancing at utmost speed, the fluctuation of pectoral fin and whole afterbody 4 is consistent, and promotes the fish body; When low-speed forward, then by separately fluctuation or coordinate to advance of pectoral fin with the small fluctuation of afterbody 4.As seen, in both annexations, left pectoral fin CPG unit is tackled in the CPG unit, joint of afterbody 4, right pectoral fin CPG unit plays inhibitory action, therefore, make the left pectoral fin CPG of the unidirectional inhibition in CPG unit, joint unit, the right pectoral fin CPG unit of afterbody 4, the arrow closure in is the left pectoral fin CPG of the unidirectional sensing of each the joint oscillator unit, CPG unit, joint of afterbody 4, the oscillator of right pectoral fin CPG unit as shown in figure 21.The oscillator of the joint oscillator 411 of afterbody 4, joint oscillator 421, joint oscillator 431, the left pectoral fin 2 of joint oscillator 441 unidirectional sensings, the oscillator of the joint oscillator 412 of afterbody 4, joint oscillator 422, joint oscillator 432, the right pectoral fin 3 of joint oscillator 442 unidirectional sensings.Each joint oscillator of CPG unit, joint of afterbody 4 is all identical to the unidirectional inhibition weights of the oscillator of the CPG unit of left and right pectoral fin, has 0 and 30 two kind.When robot moves about at a slow speed, be input signal drive hour, the CPG unit, joint of definition afterbody 4 to left pectoral fin CPG unit, the inhibition weights of right pectoral fin CPG unit are 0, pectoral fin and afterbody 4 are swung with different frequency, the pectoral fin hunting frequency is greater than the hunting frequency of afterbody 4, and pectoral fin is bigger to the contribution that advances; When input signal drive increases, when robot need advance at a high speed, make unidirectional inhibition weights increase to 30, the oscillator of the oscillator of left pectoral fin 2, right pectoral fin 3 will " be forced to " hunting of frequency with the joint oscillator of afterbody 4, both suitable swings.With effective pumping signal d _EffectDefine the critical point of unidirectional inhibition weights, d _Effect=(d _Left+ d _Right)/2.Work as d _Effect＜3 o'clock, weights were 0, work as d _Effect〉=3 o'clock, weights were 30.Coupled relation occurrence between each oscillator of fish swimming imitating robot CPG sees Table 2.

Coupled relation between table 2CPG network oscillation device

Variable	Variable symbol	Afterbody CPG	Pectoral fin CPG
				Coupled relation (between the afterbody oscillator)	(downwards) [w ij，φ ij] (making progress) [w ij，φ ij] (laterally) [w ij，φ ij]	[10，π/4] [10，-π/4] [10，π]
Coupled relation (the afterbody oscillator is to the pectoral fin oscillator)	[w 411，2，φ 411,2] [W 421，2，φ 421，2] [W 431，2，φ 431，2] [W 441，2，φ 441，2] [W 412，3，φ 412，3] [W 422，3，φ 422，3] [W 432，3，φ 432，3] [W 442，3，φ 442，3]	[0/30，3π/4] [0/30，2π/4] [0/30，π/4] [0/30，0] [0/30，-π/4] [0/30，-2π/4] [0/30，-3π/4] [0/30，-π]
				Coupled relation (between the pectoral fin oscillator)	[w 2，3，φ 2，3]		[10，0]

(wherein, w _Ij,

Coupling weights and phase difference between expression oscillator i and the oscillator j)

Five, the online generation of CPG control parameter

Each joint J of the left pectoral fin 2 of fish swimming imitating robot, right pectoral fin 3 and afterbody 4 ₁-J _NSwing realize that by the width of pulse signal (PWM) of control steering wheel be embodied in, its wobble amplitude A realizes by the turned position of control steering wheel, and the velocity of rotation of hunting frequency f by the control steering wheel realizes.In the former realization, the turned position of steering wheel in a fish bulk wave cycle is computer artificial result, it is the discrete point of fixing, its velocity of rotation is regulated mainly to lean against and is inserted time-delay between two steering wheel control cycles (being two continuous turned positions), it is big more to delay time, and velocity of rotation is more little, and it is more little to delay time, velocity of rotation is fast more, does not have time-delay velocity of rotation maximum.In a fish bulk wave cycle because discrete point is limited, when hunting frequency hour, will there be certain stagnation in steering wheel between two discrete turned positions, cause the swing in left pectoral fin 2, right pectoral fin 3 and afterbody 4 each joint stiff, unsmooth easily, influence movement effects.And because discrete turned position is fixed, robot can not be according to the variation adjustment fluctuation parameter of external environment condition or internal state.In order to realize better movement effects, we utilize the online generation of CPG model to control parameter in real time, are the hunting frequency f of each oscillator among Figure 21 _iWith amplitude A _iWe have write the online Accounting Legend Code in CPG unit that c program is realized, and move on the AT91RM9200 based on the ARM kernel, and its processor frequencies is 180MHz.When adopting Euler method, its on-line operation time is 13-14ms, less than the 20ms control cycle of robot used driving steering wheel pwm pulse, has satisfied the requirement that real-time online calculates.

Six, the AT91RM9200 of CPG motion control realizes

AT91RM9200 is that a processing speed is fast, the embedded microprocessor of super low-power consumption, has stronger data storage expanded function and interrupts handling property, and support real time operating system such as uC/OS-II.UC/OS-II is as a kind of real-time multi-task operating system, and source code is open, and the code overwhelming majority all is to be write by ANSI C, and the transplanting code relevant with platform cut out as required, and is portable good, has very high stability and reliability.Therefore, uC/OS-II is implanted among the AT91RM9200, can satisfy the real-time requirement of robot motion's control, make control system can fast, stably respond the variation of control parameter and environment, can realize the scheduling and the switching of multiple motion control task simultaneously under water.

The hardware configuration of control device as shown in Figure 3, upper strata controller 10 sends control command by wireless module 9 to robot, left and right input signal d is provided for the CPG model _Left, d _Right, the AT91RM9200 control panel 8 that is installed on robot head receives left and right input signal d _Left, d _Right, left and right input signal d is arranged between wireless module 9 and the AT91RM9200 control panel 8 _Left, d _RightProcessing through calculating of online CPG unit and saturation function unit, obtain left pectoral fin CPG unit, the control parameter of each joint oscillator of CPG unit, joint of right pectoral fin CPG unit and afterbody 4, be hunting frequency f and amplitude A, and and then be converted into the pulse signal PWM of the respective width of adjusting the steering wheel turned position, be left pectoral fin CPG unit and left pectoral fin steering wheel 5, right pectoral fin CPG unit and right pectoral fin steering wheel 6, between the CPG unit, each joint of afterbody 4 and the corresponding joint steering wheel pulse signal PWM is arranged, remove to drive left pectoral fin steering wheel 5, right pectoral fin steering wheel 6, four joint steering wheels 7 make left pectoral fin 2, right pectoral fin 3 and each joint J _NSteering wheel swing to corresponding position, the continuous real-time online by the CPG model calculates, and obtains the existing physical condition restriction that drives the most continuous steering wheel position control signal down gradually, promotes robot and realizes underwater fish swimming imitating.Sensor 11 and power supply 12 provide information perception and energy to robot system.

The flow process of control method as shown in Figure 4.The control of fish swimming imitating robot is realized by the underwater exercise control task, by transplanting the uC/OS-II system management in ARM9200.Wherein, underwater exercise control is to realize by the CPG network model, will carry out the left input signal d that wireless telecommunications receive with wireless module _LeftWith right pumping signal d _RightAfter the interruption processing and saturation function adjustment through the uC/OS-II system, the pulse signal of each oscillator hunting frequency and amplitude correspondence drives steering wheel, to realize the suitable swing in left and right pectoral fin and each joint of afterbody among acquisition Figure 21.Wherein, sensor is used for accepting the feedback of external sense signal, induction robot motion's environmental information.

Seven, the sub aqua sport of fish swimming imitating robot control:

CPG network model recited above is applied on the fish swimming imitating robot, adopts the control parameter shown in table 1,2, carry out the sub aqua sport experiment, by regulating left and right input signal d _Left, d _RightRealize craspedodrome, turning, come-up and dive campaign, its specific embodiment is as follows:

1. keep straight on and move about

(left and right sides is identical, is d to apply varying strength to robot respectively _Left=d _Right, with drive reduced representation) input signal drive, make left pectoral fin 2, right pectoral fin 3 and each joint J _NParticipate in gradually in the wavy swing, promote the robot craspedodrome and move about.Actual waveform and the simulation waveform of moving about of contrast robot, the result is shown in Fig. 5-8, and wherein, each lines is represented joint J respectively ₁-J ₄The robot picture is the sectional drawing that moves about in real time, and the sectional drawing lower waveform is corresponding simulation result with it, and the contrast duration is an one-period.When input signal drive is 1, as shown in Figure 5, owing to have only left pectoral fin 2, right pectoral fin 3 and the 4th joint J this moment ₄Satisfy the excitation threshold value, the oscillator of left pectoral fin 2, right pectoral fin 3 and the 4th joint J ₄Two joint oscillators 441,442 starting of oscillations simultaneously, the joint not starting of oscillation of oscillator of all the other joint J1-J3, the joint remains on the centre position; In like manner, the experimental result when Fig. 6 is input signal drive=1.5, pectoral fin and the 3rd, the 4th joint J ₃-J ₄Participate in advancing; Among Fig. 7, input signal drive is 2, second joint J ₂About also starting oscillation of two joint oscillators 421,422, and pectoral fin and joint J ₃-J ₄The corresponding increase of hunting frequency and amplitude; When input signal drive=2.5, the result as shown in Figure 8, all oscillators all are activated.

In addition, known by the comparing result among the figure that robot swing in real time and simulation waveform are consistent substantially, the rule of moving about is under water followed the restriction on the parameters of CPG network model structure and saturation function, has verified the theoretical correctness of putting forward.

According to coupled relation between described CPG network model of Figure 21 and oscillator, tested speed and input signal (the left and right input signal d of moving about that keep straight in the robot water _Left, d _RightIdentical, be designated as drive) relation, as shown in Figure 9, wherein input signal drive is by the 0-5 linear change.By finding out among the figure, when input signal drive reaches threshold value d _LowThe time, robot is by the static motion state that enters, left pectoral fin 2, right pectoral fin 3 and joint J ₄Participate in swing, the robot speed of moving about is very little, similarly is at water float.When input signal drive by threshold value d _{Low, 4}Increase to threshold value d _{Low, 1}The time, rate curve shape and exponential curve are similar, and it is big that acceleration constantly becomes, and movement velocity sharply increases; When input signal drive greater than threshold value d _{Low, 1}The time, speed continues to increase, but acceleration obviously reduces; Input signal drive reaches threshold value d _HighThe time, it is maximum that movement velocity reaches.As can be seen, the move about relation of speed and input signal of robot obviously presents two kinds of curve shapes, and with threshold value d _{Low, 1}Be the boundary, this is because input signal drive is by threshold value d _{Low, 4}Increase to threshold value d _{Low, 1}Process in, except joint hunting frequency and amplitude constantly increased, the body length that participates in swing also constantly increased, so velocity variations is big; When input signal drive by threshold value d _{Low, 1}Increase to threshold value d _HighThe time, because all joints have participated in the propelling, can only improve movement velocity by the increase of hunting frequency and amplitude, so its speed increment rule generation significant change.Rate curve explanation swing part length has bigger influence to the speed of moving about of robot.

2. turn and move about

When fish swimming imitating robot moves under water, as left and right input signal d _Left, d _RightOccur not simultaneously, the hunting frequency and the amplitude of left pectoral fin 2 and right pectoral fin 3 are all inequality with causing, and the asymmetric output of its left and right pectoral fin will make robot turn.In addition, left and right input signal d _Left, d _RightDifference non-linear joint, afterbody 4 left and right sides oscillator wave amplitude is changed, be the feature of center line symmetry thereby the output of its difference was no longer kept with the zero point, robot also will turn.In order to find out left and right input signal d _Left, d _RightThe difference size is to the influence of radius of turn, and we have measured respectively as left and right input signal average (d _Left+ d _Right)/2 are constant, and left and right input signal d _Left, d _RightThe robot radius of turn of (a side input signal increases, and opposite side equivalent reduces, and mean value remains unchanged) when being the symmetry variation, different left and right sides input signal d as shown in table 3 _Left, d _RightCorresponding radius of turn:

The radius of turn of the different input signal correspondences of table 3

Figure 10 is seen in diagrammatic representation, and vertical line is the mean value of left and right input signal, and special representation point in both sides is respectively left and right input signal d _Left, d _RightAs can be seen, the difference of left and right input signal has decisive influence to radius of turn, and difference is big more, and radius is more little, and radius of turn and input signal difference are linear approximate relationship.Among Figure 10 (1)-10 (3), as left input signal d _LeftBe reduced to less left input signal value d gradually by bigger value _Left, joint oscillator 431,431-421, the 431-411 failure of oscillations are arranged, joint J respectively at=1 o'clock ₃, J ₃-J ₂, J ₃-J ₁Swing be limited in the left side of longitudinal midline, realize turning left, obtained less radius of turn.And swing part is long more, and radius of turn is more little.And in Figure 10 (4), be reduced to d owing to work as left input signal _Left=2 o'clock, have only joint oscillator 411 failure of oscillations, the oscillator negligible amounts of failure of oscillation, radius of turn and preceding 3 kinds of situations are more relatively large, but have obtained pace faster.

In addition, keep straight on when moving about, keep level when left and right pectoral fin is initial, the initial deflection angle is 0, the employing and the identical control method of moving about of keeping straight on when adding an initial deflection angle that makes progress simultaneously for left and right pectoral fin, realize the dive campaign of fish swimming imitating robot; When giving the additional simultaneously downward initial deflection angle of left and right pectoral fin, realize the come-up motion of fish swimming imitating robot.Except that the initial deflection angle of left and right pectoral fin and craspedodrome move about different, other parameter and control mode directly adopt and the craspedodrome identical mode of moving about.

Through top experimental verification this CPG model feasible and respond well aspect the sub aqua sport control of multi-joint fish swimming imitating robot.

As mentioned above, the sub aqua sport control method based on the CPG model proposed by the invention has favorable applicability to the multi-joint fish swimming imitating robot with pectoral fin and tail structure, realizes the propelling rapidly and efficiently of fish swimming imitating under water.

Although principle of the present invention is showed in conjunction with the embodiments and is described, it will be understood to those of skill in the art that under the situation that does not depart from principle of the present invention and essence, change these embodiments, as caudal articular process J _NStructure, the form of saturation function and the adjustment of parameter etc. of quantity, pectoral fin and afterbody, its scope also falls in claim of the present invention and the equivalent institute restricted portion thereof.

Claims (9)

1. a fish swimming imitating robot movement control device comprises the left pectoral fin of fish swimming imitating robot, right pectoral fin and a plurality of tail swings joint, and left pectoral fin, right pectoral fin are positioned at the head left and right sides, it is characterized in that:

Have a plurality of CPG unit, comprising: left pectoral fin CPG unit, right pectoral fin CPG unit and CPG unit, a plurality of joint; CPG is a central pattern generator (cpg);

Has the joint J that the imitative fish of a plurality of modularizations advances _NConstitute the afterbody of robot;

Have a saturation function unit and receive the control signal that the online computing of outside input signal generates each CPG unit;

Described left pectoral fin CPG unit and described right pectoral fin CPG unit are fixedly arranged on respectively on left pectoral fin, the right pectoral fin, described left pectoral fin CPG unit is connected with the saturation function unit with right pectoral fin CPG unit, in control bottom left pectoral fin CPG unit and the right pectoral fin CPG unit controls left side pectoral fin and the motion of right pectoral fin of control signal;

Described a plurality of joint J _NAccording to the y direction of fish swimming imitating robot and an end of head a plurality of joints are set in proper order; And a plurality of joint J _NBetween be dynamically connected mutually, on each joint, be provided with CPG unit, a joint, all CPG unit, joint produce the fish bulk wave that robot advances under the effect of control signal, realize moving about of imitative fish robot, wherein _NNatural number;

CPG unit, described a plurality of joint is connected respectively with between left pectoral fin CPG unit and the right pectoral fin CPG unit, CPG unit, a plurality of joint provides coupling weights and phase difference to the pectoral fin CPG unit that comprises left pectoral fin CPG unit and right pectoral fin CPG unit, realizes the bionical control in this joint.

2. fish swimming imitating robot movement control device according to claim 1 is characterized in that, described a plurality of joint J _NQuantity, be the quantity of adjusting the joint according to fish swimming imitating robot body structure feature.

3. fish swimming imitating robot movement control device according to claim 1 is characterized in that, described each CPG unit, joint is provided with a pair of joint oscillator, and the phase difference between the oscillator of described a pair of joint is set at π; Every pair of joint oscillator corresponds respectively to the musculus flexor and the extensor of these joint motions, and every pair of joint oscillator suppresses mutually according to coupling weights and phase difference between them, realizes the bionical control in this joint; The oscillator Mathematical Modeling that each joint oscillator is adopted is as follows:

$\left\{\begin{array}{c}{\stackrel{.}{\mathrm{\&theta;}}}_i={2\mathrm{\&pi;f}}_i+\underset{j}{\mathrm{\&Sigma;}}{a}_j{w}_{\mathrm{ij}}\sin ({\mathrm{\&theta;}}_j-{\mathrm{\&theta;}}_i-{\mathrm{\&phi;}}_{\mathrm{ij}})\\ {\stackrel{..}{a}}_i={\mathrm{\&tau;}}_i\{\frac{{\mathrm{\&tau;}}_i}{4}(A_i-a_i)-{\stackrel{.}{a}}_i\}\\ x_i=a_i\{1+\cos \left({\mathrm{\&theta;}}_i\right)\}\end{array}\right.$

In the formula, θ _iAnd a _iBe oscillator i state variable, represent phase place and the amplitude of oscillator i respectively, θ _jAnd a _jBe oscillator j state variable, represent phase place and the amplitude of oscillator j respectively, With

Be its first derivative,

Be second dervative; f _iAnd A _iInherent frequency and the amplitude of decision oscillator i; τ _iBe time constant, decision a _iConverge to A _iSpeed; Coupled relation between oscillator i and oscillator j is by the coupling weight w _IjAnd phase difference _IjDetermine x _iOutput for oscillator i.

4. fish swimming imitating robot movement control device according to claim 3, it is characterized in that, described left pectoral fin CPG unit and right pectoral fin CPG unit are respectively equipped with a left pectoral fin oscillator and a right pectoral fin oscillator, adopt with the identical oscillator Mathematical Modeling of joint oscillator.

5. fish swimming imitating robot movement control device according to claim 1, it is characterized in that, the input signal that described a plurality of CPG unit receives is by being provided with different threshold values to each swinging joint, participate in the swing along with input signal increases each joint gradually by from back to front order, realize the length control of joint swing, utilize wobble length to realize the motion control of multi-joint fish swimming imitating robot.

6. a control method of using the described fish swimming imitating robot movement control device of claim 3 is characterized in that,

At first utilize the input signal drive of saturation function unit reception from the outside, output has the control signal of a frequency of oscillation f and an amplitude signal A after processing is regulated in the saturation function unit;

The control signal that has frequency of oscillation f and amplitude signal A is then controlled the swing of left pectoral fin oscillator and right pectoral fin oscillator and each joint oscillator of afterbody;

Coupled relation between oscillator i and oscillator j is by the coupling weight w in the Mathematical Modeling of oscillator _IjAnd phase difference _IjDecision;

According to the coupled relation between each oscillator frequency of oscillation f and amplitude signal A are adjusted again, generate a plurality of joint J of control left pectoral fin, right pectoral fin and afterbody _NThe oscillator signal of vibration is used to make fish swimming imitating robot to produce the capable ripple of propagating from front to back and advances, and realizes fish swimming imitating.

7. according to the control method of claim 6, it is characterized in that the coupled relation between caudal articular process CPG unit and the pectoral fin CPG unit is by weight w _IjAnd phase difference _IjDetermining, is to adjust according to an effective excitation value, and when input signal was lower than effective excitation value, pectoral fin CPG unit and caudal articular process CPG unit did not have coupling, and its weights are 0; Otherwise, when input signal reaches effective excitation value, pectoral fin CPG unit will " be forced to " hunting of frequency with caudal articular process CPG unit, pectoral fin CPG unit and caudal articular process CPG unit suitable swing, unidirectional inhibition pectoral fin CPG unit, caudal articular process CPG unit, its weights are 30.

8. according to the control method of claim 6, it is characterized in that, each CPG unit, joint of described left pectoral fin CPG unit and right pectoral fin CPG unit and afterbody is provided with oscillator, finally on embedded microprocessor, adopt the C Programming with Pascal Language to realize to described each oscillator control parameter in line computation according to Euler method, obtain the frequency and the amplitude of each oscillator in real time, the physical condition that is implemented in steering wheel driving force, embedded microprocessor processing speed limits the most continuous Position Control down.

9. control method according to Claim 8 is characterized in that, the sub aqua sport control of fish swimming imitating robot has been realized in each CPG unit, joint of this pectoral fin CPG unit, left side and right pectoral fin CPG unit and afterbody by embedded microprocessor; By regulating the input signal of this motion control device, craspedodrome, turning, come-up and the dive motor pattern of robot will be produced; Identical and greater than excitation during threshold value, robot keeps straight on when left and right sides input signal; Different and during greater than the input signal threshold value, robot turns when left and right sides input signal, wherein, when left input signal during greater than right input signal, robot turns right, otherwise turns left; In addition, keep straight on when moving about, keep level when left and right sides pectoral fin is initial, the initial deflection angle is 0; The employing and the identical control method of moving about of keeping straight on when adding an initial deflection angle that makes progress simultaneously for left and right sides pectoral fin, realize the dive campaign of fish swimming imitating robot; When giving the additional simultaneously downward initial deflection angle of left and right sides pectoral fin, realize the come-up motion of fish swimming imitating robot.

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