A cpg control system of a hexapod robot and a gait generation method thereof

Abstract

The present application relates to a kind of CPG control system of hexapod robot and its gait generation method, the system includes the periodic rhythm generator with fixed phase difference and the mode combiner of multiple gaits, periodic rhythm generator, mode combiner and hexapod robot body are sequentially connected to constitute closed loop control system, periodic rhythm generator is used to realize multiple different fixed phase difference while generating periodic rhythm;Mode combiner is used to regulate and control the swing sequence of multiple different gait modes of the same phase difference, and act on hexapod robot, realize multiple gait modes of hexapod robot and its mutual switching;Hexapod robot is used to output feedback control signal to periodic rhythm generator.Compared with prior art, the present application uses the regulation of coupled time delay to realize the regulation of multiple fixed phase difference, and parameter setting is simple, parameter regulation is easy, can simply and reliably realize multiple different gait modes of hexapod robot, effectively improve the parameter adjustability and robustness of system.

Description

Technical Field

[0001] This invention relates to the field of biomimetic robot technology, and in particular to a CPG control system for a hexapod robot and its gait generation method. Background Technology

[0002] As a type of parallel robot, hexapod robots have good environmental adaptability due to their flexible and varied movement patterns and strong stability, and have become the mainstream product among biomimetic robots.

[0003] However, the large number of legs in hexapods increases the difficulty of controlling them. The emergence of the Central Pattern Generator (CPG) has provided a new approach to the control of hexapods. CPGs can spontaneously generate stable rhythmic movements in the absence of high-level control signals and external feedback, without the need for environmental or self-modeling, thus reducing the workload of the control system and saving time. However, current CPG controllers have limited gait modes, while hexapods can generate various gait modes based on phase differences and the order of hexapod swings. This makes it impossible for existing CPG controllers to reliably generate multiple gait modes for hexapods. Due to the fully connected network topology, the CPG structural unit is a periodic rhythmic oscillator, which must be a two-dimensional or higher oscillator model. This results in a high-dimensional CPG controller with complex parameter tuning: on the one hand, the generation of periodic rhythms and phase differences requires different parameters to be adjusted. Even when using a periodic rhythmic oscillator as the CPG control unit, the phase difference tuning still requires the participation of multiple parameters. On the other hand, a unified parameter tuning method cannot be provided, and the correspondence between the tuning parameters and the motion mode is unclear. Only one or more sets of fixed parameter values ​​can be obtained based on different gait motion modes using a trial-and-error method, which makes it impossible to guarantee the parameter adjustability and robustness of the system. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a CPG control system for a hexapod robot and its gait generation method, which can simply and reliably realize multiple different gait modes of the hexapod robot and effectively improve the parameter adjustability and robustness of the system.

[0005] The objective of this invention can be achieved through the following technical solution: a CPG control system for a hexapod robot, comprising a periodic rhythm generator with a fixed phase difference and a pattern combiner for multiple gait states, wherein the periodic rhythm generator is connected to the pattern combiner, the pattern combiner is connected to the hexapod robot body, and the hexapod robot body is connected to the rhythm generator to form a closed-loop control system, wherein the periodic rhythm generator is used to generate periodic rhythms while realizing multiple different fixed phase differences.

[0006] The mode combiner is used to control the swaying sequence of six-legged robots with multiple different gait modes under the same phase difference, and acts on the six-legged robot to realize multiple gait modes of the six-legged robot and their switching between each other;

[0007] The hexapod robot is used to output feedback control signals to the periodic rhythm generator.

[0008] Furthermore, the periodic rhythm generator includes six oscillator units for corresponding control of the joints of the hexapod robot. The six oscillator units are connected in sequence to form a unidirectional ring network structure. The connection between the six oscillator units is time-delay coupling. Under the adjustment of the coupling time delay parameter, the generation of periodic rhythm and the generation of different types of fixed phase differences can be controlled.

[0009] Furthermore, the different types of fixed phase differences include periods of 0, 1 / 6, 1 / 4, 1 / 3, and 1 / 2.

[0010] Furthermore, the hexapod swing sequence specifically refers to the swing sequence between the left front (LF), left middle (LM), left rear (LH), and right front (RF), right middle (RM), and right rear (RH) legs of the hexapod robot.

[0011] Furthermore, the hexapod robot has multiple gait modes, including hexapod jumping gait, wave gait, out-of-phase triangular gait, rotating triangular gait, caterpillar gait, star-shaped gait, triangular gait, pacing gait, and quadrupedal gait.

[0012] Furthermore, the oscillator unit is represented by a differential equation with one variable, or it can be represented by a differential equation with multiple variables. In practical applications, for simplicity, a differential equation with a single variable is considered.

[0013] A gait generation method for a CPG control system of a hexapod robot includes the following steps:

[0014] S1. Tune the coupling delay of the periodic rhythm generator to determine the parameter values ​​corresponding to the coupling delay;

[0015] S2. Based on the adjustment effect of the coupling time delay parameter, a fixed phase difference rhythm signal is generated and transmitted to the mode combiner.

[0016] S3. Based on the fixed phase difference rhythm signal, the mode combiner obtains the six-leg swing sequence of the hexapod robot's gait motion through different combinations of rhythm sequences, and applies it to the hexapod robot to realize multiple asynchronous state modes. At the same time, the hexapod robot outputs feedback control signals to the periodic rhythm generator.

[0017] Furthermore, step S1 is specifically based on the Hopf bifurcation theory of time-delay nonlinear systems, using the eigenvalues ​​and eigenvectors of the linearized nonlinear system to tune the coupled time-delay parameters of the periodic rhythm generator.

[0018] Furthermore, step S1 specifically includes the following:

[0019] S11. Linearize the time-delay coupled nonlinear system near the equilibrium point to obtain the corresponding linear system and its characteristic equation.

[0020] S12. Separate the real and imaginary parts of the characteristic equation of the linear system, and combine them with trigonometric function relationships to obtain the frequency equation used to generate periodic rhythms;

[0021] S13. The frequency equation is solved using numerical methods to obtain the coupling time delay critical value. The coupling time delay critical value is the boundary line between different parameter regions. The periodic rhythms within each parameter region have the same phase difference, while the phase differences between different parameter regions are different.

[0022] Furthermore, the frequency equation has two non-repeating positive roots.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] I. This invention addresses the problem of numerous gait movement modes in hexapod robots and the complexity of generating and controlling these different modes. It proposes a CPG control system for hexapod robots, comprising a periodic rhythm generator with a fixed phase difference and a pattern combiner for various gait modes. The fixed-phase-difference periodic rhythm generator includes six oscillator units controlling the joints of the hexapod robot. Each oscillator unit is coupled with a time delay, and the network topology is a unidirectional ring connection. By adjusting the coupling time delay parameter, a fixed phase difference of the periodic rhythm can be achieved. These periodic rhythms, under the action of the pattern combiner, regulate the swing sequence between different legs of the hexapod robot, realizing multiple gait modes and their switching. Furthermore, the hexapod robot outputs feedback control signals to the periodic rhythm generator, forming a closed-loop control system. Therefore, to address the phase difference relationship of hexapod robot gait patterns, a periodic rhythm generator with a fixed phase difference and a pattern combiner for multiple gait patterns are adopted. This can generate a greater variety of different hexapod robot gait patterns. A unidirectional ring network topology is used, and the structural unit can be described by a differential equation with a single variable. Under the action of coupling time delay, a periodic rhythm with a fixed phase difference is generated. The periodic rhythm and phase difference are completed simultaneously. It has few control parameters and is easy to implement in engineering.

[0025] Second, this invention also proposes a gait generation method for a CPG control system of a hexapod robot. Periodic rhythm and phase difference are simultaneously achieved under the same parameter control. Utilizing the Hopf bifurcation theory of time-delay nonlinear dynamic systems, a periodic rhythm with a fixed phase difference is generated. This method features simple parameter tuning, a variety of gait patterns, easy parameter control, and the ability to achieve multiple fixed phase difference controls through the adjustment of coupling time delay. Based on theoretical analysis, the method provides parameter regions corresponding to different phase difference factors, clarifying the correspondence between control parameters and gait patterns. Within a specific parameter region, the phase difference does not change with parameter variations; that is, changes in control parameters within the region do not affect the phase difference. Furthermore, parameter changes between parameter regions enable rapid switching between different phase differences, resulting in better system robustness and parameter adjustability. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the method flow of the present invention;

[0028] Figure 3 This is a flowchart illustrating the gait generation and control process of the CPG controller for the hexapod robot in this embodiment.

[0029] Figure 4 This is a schematic diagram of a unidirectional ring network structure consisting of six oscillator units in a periodic rhythm generator.

[0030] Figure 5 The parameter region for the fixed phase difference periodic rhythm generated by the CPG controller of the hexapod robot in the embodiment;

[0031] Figure 6 This is a schematic diagram of the 0-phase-difference periodic rhythm signal output of the CPG controller of the hexapod robot in the embodiment;

[0032] Figure 7 This is a schematic diagram of the phase difference periodic rhythm signal output of the CPG controller T / 6 of the hexapod robot in the embodiment;

[0033] Figure 8 This is a schematic diagram of the phase difference periodic rhythm signal output of the CPG controller T / 3 of the hexapod robot in the embodiment;

[0034] Figure 9 This is a schematic diagram of the phase difference periodic rhythm signal output of the CPG controller T / 2 of the hexapod robot in the embodiment;

[0035] Figure 10 This is a schematic diagram of the T / 4 phase difference periodic rhythm signal output when the coupling time delay between the six-legged robot CPG controllers ⑥① and ③④ is 0 in the embodiment;

[0036] The markings in the diagram are as follows: A, Periodic Rhythm Generator; B, Pattern Combiner; C, Hexapod Robot. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0038] Example

[0039] like Figure 1 As shown, a CPG control system for a hexapod robot includes a periodic rhythm generator A with a fixed phase difference and a pattern combiner B for various gait patterns. The periodic rhythm generator A is connected to the pattern combiner B, the pattern combiner B is connected to the hexapod robot body C, and the hexapod robot body C is connected to the rhythm generator A to form a closed-loop control system. The periodic rhythm generator A is used to generate periodic rhythms while realizing various different fixed phase differences. The periodic rhythm generator A includes six oscillator units for corresponding control of the joints of the hexapod robot. The six oscillator units are connected in sequence to form a unidirectional ring network structure. The connection between the six oscillator units is time-delay coupling. Under the adjustment of the coupling time delay parameter, the generation of periodic rhythms and the generation of different types of fixed phase differences are controlled. The different types of fixed phase differences include periods of 0, 1 / 6, 1 / 4, 1 / 3, and 1 / 2. The oscillator units can be represented by differential equations described by one or more variables. For simplicity, this embodiment uses differential equations described by a single variable.

[0040] The mode combiner B is used to regulate the swing sequence of six legs under the same phase difference and to act on the six-legged robot to realize the multiple gait modes of the six-legged robot C and their switching between each other. The swing sequence of the six legs is specifically the swing sequence between the left front (LF), left middle (LM), left rear (LH) and right front (RF), right middle (RM), and right rear (RH) legs of the six-legged robot C. The multiple gait modes of the six-legged robot C include six-legged jumping gait, wave gait, out-of-phase triangle gait, rotation triangle gait, caterpillar gait, star-shaped gait, triangle gait, pacing gait, and quadruped gait.

[0041] In addition, the hexapod robot C is used to output feedback control signals to the periodic rhythm generator A.

[0042] Using the above system, a gait generation method for a CPG control system of a hexapod robot is implemented, such as... Figure 2 As shown, it includes the following steps:

[0043] S1. Parameter tuning of the coupling delay of the periodic rhythm generator is performed to determine the parameter values ​​corresponding to the coupling delay. Specifically, this is based on the Hopf bifurcation theory of time-delay nonlinear systems, utilizing the eigenvalues ​​and eigenvectors of the linearized nonlinear system to tune the coupling delay parameters of the periodic rhythm generator.

[0044] First, the time-delay coupled nonlinear system is linearized near the equilibrium point to obtain the corresponding linear system and its characteristic equation.

[0045] Then, by separating the real and imaginary parts of the characteristic equation of the linear system and combining them with trigonometric function relationships, a frequency equation for generating periodic rhythms is obtained, which has two non-repeating positive roots.

[0046] The frequency equation is then solved using numerical methods to obtain the coupling time delay critical value. The coupling time delay critical value is the boundary line between different parameter regions. The periodic rhythms within each parameter region have the same phase difference, while the phase differences between different parameter regions are different.

[0047] S2. Based on the adjustment effect of the coupling time delay parameter, a fixed phase difference rhythm signal is generated and transmitted to the mode combiner.

[0048] S3. Based on the fixed phase difference rhythm signal, the mode combiner obtains the six-leg swing sequence of the hexapod robot's gait motion through different combinations of rhythm sequences, and applies it to the hexapod robot to realize multiple asynchronous state modes. At the same time, the hexapod robot outputs feedback control signals to the periodic rhythm generator.

[0049] This embodiment applies the above technical solution, and its system and control flow are as follows: Figure 3As shown, a unidirectional ring network structure containing six oscillator units is first constructed, as follows: Figure 4 As shown, the structural unit model of the hexapod robot CPG controller is a VDP oscillator that can be expressed by a single variable. The coupled topology is a unidirectional ring network 1→2→3→4→5→6→1. The hexapod robot CPG controller is constructed as follows:

[0050]

[0051] Wherein, parameters α>0 and β>0 are used to adjust the frequency and amplitude of the periodic rhythm signal, ε>0 is the nonlinear damping coefficient in the VDP system, used to control the shape of the periodic rhythm, τ>0 is the coupling delay between the VDP oscillators, k is the coupling connection weight, and x... i For the output signal of the i-th VDP oscillator, These are the corresponding velocity and acceleration signals, respectively. Variable substitution is used. The equivalent control system model is obtained as follows:

[0052]

[0053] For the CPG gait mode controller of a hexapod robot, the first step is to find the parameter region where the system generates periodic rhythms through parameter tuning. Within each different region, the phase difference of the periodic rhythm remains constant. This process is the Hopf bifurcation theory analysis of time-delay nonlinear systems. To this end, we first use the linearization method for nonlinear systems near the equilibrium point to obtain the characteristic equation of the corresponding linear system:

[0054] Q(λ,τ)=(β+(k-εα)λ+λ 2 ) 6 -(kλe -λτ ) 6 =0

[0055] Under the influence of coupling delay τ>0, the aforementioned CPG controller can generate a stable periodic rhythm. Let the characteristic value be λ=iω, where ω is the frequency of the periodic rhythm. Separating the real and imaginary parts of the characteristic equation, we obtain...

[0056]

[0057] in

[0058] q1(ω)=(β+(k-εα-ω)ω)·(β-ω(k-εα+ω))·

[0059] (β 2 +2β(2k-2εα-ω)ω+ω 2 ((k-εα) 2 -4(k-εα)ω+ω2 ))·

[0060] (β 2 -2βω(2k-2εα+ω)+ω 2 ((k-εα) 2 +4(k-εα)ω+ω 2 ))

[0061] q2(ω)=ω(2(k-εα)(β-ω 2 (-β) 2 +(2β+3(k-εα) 2 )ω 2 -ω 4 )·

[0062] (-3β 2 +(6β+(k-εα) 2 )ω 2 -3ω 4 )

[0063] Using cos 2 (6ωτ)+sin 2 (6ωτ)=1, resulting in the following algebraic equation:

[0064]

[0065] The frequency equation for the periodic rhythm generated by the CPG controller is obtained numerically, and the roots of the algebraic equation are found. It is important to note that in order for the periodic solution to have multiple fixed phase differences, the frequency equation must have two non-repeating positive roots, assumed here to be ω1 > 0 and ω2 > 0. Therefore, the critical condition that the coupling delay of the system's periodic control parameters should satisfy is as follows:

[0066]

[0067] Based on the eigenvectors corresponding to the eigenvalues, the eigenvalues ​​described above have the following eigenvectors:

[0068]

[0069] The vector η1 = (1, iω1) corresponds to the critical time delay. The vector η2=(1,iω2) corresponds to j = 0, 1, ..., n, that is, the periodic rhythm caused by the time delay satisfies the above phase difference, forming a phase correspondence relationship of gait patterns, and generating a periodic rhythm with a fixed phase difference relationship in different regions.

[0070] To further illustrate that the theoretical analysis method based on the above parameter tuning can yield different parameter regions, and that the periodic rhythm of the CPG controller within each region has the same phase difference, while the phase differences differ across regions, this embodiment provides a numerical example. With the CPG controller system parameters fixed at α = 1, β = 1, and ε = 0.03, based on the above theoretical analysis steps, the parameter region of the periodic rhythm in the (τ,k) plane is given, as follows: Figure 5 As shown, the boundary line of each region is the theoretically calculated critical time delay value τ. j i .

[0071] exist Figure 5 In this diagram, Region I represents a periodic rhythm with a fixed phase difference of 0. At this time, the six oscillator units of the hexapod robot's CPG controller output signals are perfectly synchronized periodic rhythms. Each oscillator drives the joint movements of the hexapod robot, thus achieving the hexapod robot's hopping gait (Pronk) mode. Its control signal output is as follows: Figure 6 As shown.

[0072] Region II parameters enable the CPG controller to generate a periodic rhythmic signal with a fixed phase difference of T / 6, and its output signal is as follows: Figure 7 As shown, denoted as ①→②→③→④→⑤→⑥→①, the arrow → indicates an increasing phase difference between signals. Under the action of the mode combiner, three different gait modes of the hexapod robot can be generated: Wave gait, Metachronal tripod, and Rolling tripod. Specifically, to generate Wave gait, the correspondence between the oscillator unit and the robot's leg joints is ①—LF, ②—RF, ③—LM, ④—RM, ⑤—LH, ⑥—RH, as shown in Table 1. Similarly, the corresponding connections for Metachronal and Rolling tripods are ①—LF, ②—RH, ③—RM, ④—RF, ⑤—LH, ⑥—LM and ①—LF, ②—RH, ③—LM, ④—RF, ⑤—LH, ⑥—RM, respectively.

[0073] The parameters within Region III allow the CPG controller to generate a periodic rhythmic signal with a phase difference of T / 3, and its output signal is as follows: Figure 8As shown, denoted as {①④}→{②⑤}→{③⑥}, where "{}" represents ①④, ②⑤, and ③⑥. The oscillators have the same output signal, forming a synchronous periodic rhythm mode. The arrow → indicates an increasing phase difference, with an increment of T / 3. Under the action of the mode combiner, two gaits for the hexapod robot can be generated: the caterpillar gait and the rice gait. The caterpillar gait is combined as follows: {①④}—{LF,RF}, {②⑤}—{LH,RH}, {③⑥}—{LM,RM}. That is, the LF and RF leg joints can be driven by any output signal of unit ①④, and so on. The rice gait is combined as follows: {①④}—{LF,RH}, {②⑤}—{LH,RF}, {③⑥}—{LM,RM}, as shown in Table 1.

[0074] Table 1. Parameter range and gait type of the CPG controller for the hexapod robot.

[0075]

[0076] The parameters within Region IV enable the CPG controller to generate a periodic rhythmic signal with a fixed phase difference of T / 2, and its output signal is as follows: Figure 9 As shown, the output signals of oscillator units ①③⑤ and ②④⑥ are in complete synchronization mode, denoted as: {①③⑤}→{②④⑥}, with the arrow → indicating an increasing phase difference of T / 2. At this time, under the action of the mode combiner, two asynchronous states of the hexapod robot can be generated: tripod gait and pacing gait. The tripod gait can be combined as follows: {①③⑤}—{LF,LH,RM}, {②④⑥}—{LM,RF,RH} and {①③⑤}—{LF,LM,LH}, {②④⑥}—{RF,RM,RH}.

[0077] To achieve the classic tetrapod gait of a hexapod robot, simply set the coupling delay between oscillator units ⑥① and ③④ to 0, and the coupling delay between other units to the values ​​of Region II. The output signal of the CPG controller will then be as follows: Figure 10 As shown in the figure, oscillator units ①⑥ and ③④ are in fully synchronized mode, while other units have an increasing phase difference of T / 4, denoted as: {⑥①}→②→{③④}→⑤. Under the action of the mode combiner, {⑥①}—{LF,RH}, ②—RM, {③④}—{RF,LH}, and ⑤—LM are used to realize the quadrupedal gait of the hexapod robot.

[0078] In summary, this technical solution addresses the phase difference relationship of hexapod robot gait patterns by employing a fixed-phase-difference periodic rhythm generator and a pattern combiner for multiple gait modes. This allows for the generation of a wider variety of different hexapod robot gait patterns. A unidirectional ring network topology is used, where each structural unit can be a differential equation described by a single variable. Under the influence of coupling time delay, a periodic rhythm with a fixed phase difference is generated. The periodic rhythm and phase difference are generated simultaneously, requiring fewer control parameters and facilitating engineering implementation.

[0079] Furthermore, this technical solution is based on the Hopf bifurcation theory of time-delay nonlinear dynamics. The periodic rhythm and phase difference are determined by the eigenvalues ​​and eigenvectors of the linearized nonlinear system to achieve parameter tuning of the CPG controller. Based on theoretical analysis, the parameter regions corresponding to different phase difference factors are given, and the correspondence between the control parameters and the gait mode is clarified. Within the parameter region, the change of control parameters will not affect the phase difference, while the parameter switching between parameter regions realizes the change of different phase differences, so that the designed CPG controller has good parameter adjustability and system robustness.

Claims

1. A CPG control system for a hexapod robot, characterized in that, The system includes a periodic rhythm generator with a fixed phase difference and a pattern combiner for multiple gait patterns. The periodic rhythm generator is connected to the pattern combiner, the pattern combiner is connected to the hexapod robot body, and the hexapod robot body is connected to the rhythm generator to form a closed-loop control system. The periodic rhythm generator is used to generate periodic rhythms while achieving multiple different fixed phase differences. The mode combiner is used to regulate the swinging sequence of six legs in multiple different time state modes under the same phase difference, and acts on the six-legged robot to realize multiple gait modes of the six-legged robot and their switching between each other. The multiple gait modes of the six-legged robot include six-legged jumping gait, wave gait, out-of-phase triangular gait, rotating triangular gait, caterpillar gait, star-shaped gait, triangular gait, pacing gait, and quadruped gait. The hexapod robot is used to output feedback control signals to the periodic rhythm generator; The periodic rhythm generator includes six oscillator units for corresponding control of the joints of the hexapod robot. The six oscillator units are connected in sequence to form a unidirectional ring network structure. The connection between the six oscillator units is time-delay coupling. Under the adjustment of the coupling time delay parameter, the generation of periodic rhythm and the generation of different types of fixed phase differences are controlled. The different types of fixed phase differences include 0, 1 / 6, 1 / 4, 1 / 3 and 1 / 2 periods. When the fixed phase difference is 0, the six-legged jumping gait of the six-legged robot is realized under the action of the mode combiner. When the fixed phase difference is 1 / 6, the waveform gait, out-of-phase triangular gait, and rotational triangular gait of the hexapod robot are realized under the action of the mode combiner. When the fixed phase difference is 1 / 4, the quadruped gait of the hexapod robot is realized under the action of the mode combiner. When the fixed phase difference is 1 / 3, the caterpillar gait and the star-shaped gait of the hexapod robot are realized under the action of the mode combiner. When the fixed phase difference is 1 / 2, the triangular gait and pacing gait of the hexapod robot are realized under the action of the mode combiner.

2. The CPG control system for a hexapod robot according to claim 1, characterized in that, The specific swing sequence of the six legs refers to the swing sequence between the left front, left middle, and left rear legs, as well as the right front, right middle, and right rear legs of the six-legged robot.

3. The CPG control system for a hexapod robot according to claim 1, characterized in that, The oscillator unit is represented by a differential equation with one variable or multiple variables.

4. A gait generation method for a CPG control system of a hexapod robot, characterized in that, Includes the following steps: S1. Tune the coupling delay of the periodic rhythm generator to determine the parameter values ​​corresponding to the coupling delay; S2. Based on the adjustment effect of the coupling time delay parameter, a fixed phase difference rhythm signal is generated and transmitted to the mode combiner. S3. Based on the fixed phase difference rhythm signal, the mode combiner obtains the six-leg swing sequence of the hexapod robot's gait motion through different combinations of rhythm sequences, and applies it to the hexapod robot to realize multiple asynchronous state modes. At the same time, the hexapod robot outputs feedback control signals to the periodic rhythm generator.

5. The gait generation method for a CPG control system of a hexapod robot according to claim 4, characterized in that, Step S1 is specifically based on the Hopf bifurcation theory of time-delay nonlinear systems, using the eigenvalues ​​and eigenvectors of the linearized nonlinear system to tune the coupled time-delay parameters of the periodic rhythm generator.

6. The gait generation method for a CPG control system of a hexapod robot according to claim 5, characterized in that, Step S1 specifically includes the following: S11. Linearize the time-delay coupled nonlinear system near the equilibrium point to obtain the corresponding linear system and its characteristic equation. S12. Separate the real and imaginary parts of the characteristic equation of the linear system, and combine them with trigonometric function relationships to obtain the frequency equation used to generate periodic rhythms; S13. The frequency equation is solved using numerical methods to obtain the coupling time delay critical value. The coupling time delay critical value is the boundary line between different parameter regions. The periodic rhythms within each parameter region have the same phase difference, while the phase differences between different parameter regions are different.

7. The gait generation method for a CPG control system of a hexapod robot according to claim 6, characterized in that, The frequency equation has two non-repeating positive roots.

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