Real-time motion control method for crawler robots based on phase domain synthesis

Abstract

The present invention proposes a real-time motion control method for a reptile robot based on phase domain synthesis. First, the corresponding relationship between the local phase representing the segment extension and contraction rhythm of the reptile robot and time is established, and the relationship between the reference joint position and phase of the reptile robot in different motion modes is calculated. Fast Fourier transform is performed, and compression and feature extraction are performed in the frequency domain to obtain the characteristics of different motion modes. After obtaining the operation instruction, the instruction phase and motion mode characteristics are generated. The characteristics corresponding to the operation instruction are used to align and superimpose with the linear motion mode characteristics in the phase domain to synthesize a new motion mode. By establishing a local phase, the present invention transfers the motion mode synthesis work from the time domain to the phase domain, effectively reducing the characteristic dimension of the motion mode and achieving efficient synthesis of motion modes of different time scales with constant time consumption. This allows users to correct the motion path in real time according to the terrain and motion conditions, thereby improving the maneuverability of the reptile robot in complex terrain.

Description

Technical Field

[0001] The present invention relates to the field of crawler robot motion control, and in particular to a real-time motion control method for a multi-segment serial-parallel hybrid crawler robot based on phase domain synthesis. Background Art

[0002] Chinese patent CN115352545B proposes a highly maneuverable crawler robot that is easy to miniaturize. The robot adopts a serial-parallel hybrid structure with a high degree of freedom. It can realize multiple motion modes such as extension, deflection, and pitch, and is suitable for performing tasks in confined spaces. Because this type of crawler robot uses its feet to grip the ground to provide adhesion and changes its attachment position by periodically deforming its body to achieve movement, its body shape should conform to the terrain as much as possible during movement to ensure good foot adhesion and improve movement stability. This requires the design of motion control methods and control systems for the joints of this type of robot that are adapted to spatial motion tasks, and the generation of corresponding robot reference joint positions in real time based on the operating instructions of the human operator. However, existing control methods and control systems are difficult to meet task requirements in terms of the richness of motion skills and time expenditure. Summary of the Invention

[0003] In order to overcome the problems existing in the prior art, the present invention proposes a real-time motion control method for a crawler robot based on phase domain synthesis. For a crawler robot adopting a serial-parallel hybrid structure, the phase domain features of the robot's basic motion mode, preset path, and operation instructions are extracted, and a synthesis strategy of the three is provided to generate a reference joint position that can adapt to complex ground environments.

[0004] The technical solution of the present invention is:

[0005] A real-time motion control method for a crawler robot based on phase domain synthesis includes the following steps:

[0006] Step 1: Establish the correspondence between the local phase and time of the segment extension and contraction rhythm of the crawler robot:

[0007]

[0008] Where, Indicates the Segments in The phase of the moment, Indicates phase exist The speed of change at a moment; using vector Represent the local phase of all segments: , is the number of segments of the crawler robot;

[0009] Step 2: Calculate the relationship between the reference joint position and phase of the reptile robot under different motion modes based on the reptile robot's spine kinematic model and dynamic model ,in In a certain motion mode, the local phase is When , the vector consisting of the positions of all joints, represents all allowed joint positions, Indicates the number of joints; the motion modes include linear motion mode, spatial motion mode and preset terrain mode;

[0010] Step 3: Perform a fast Fourier transform on the relationship between the reference joint position and phase obtained in step 2, and perform compression and feature extraction in the frequency domain to obtain the characteristics of different motion patterns: ,in, Indicates FFT operation, represents the initial joint position, represents the frequency component of the feature, Represents frequency components The corresponding value;

[0011] Step 4: Get the operation instruction, where Operation instructions corresponding to the time , thereby generating a set of command phases and motion pattern characteristics ;

[0012] Step 5: Use the features corresponding to the operation instructions obtained in step 4 , and the linear motion mode characteristics , in the phase domain, according to the current local phase and command phase Align and superimpose to synthesize a new motion pattern and obtain the relationship between the reference joint position and phase of the new motion pattern:

[0013]

[0014] Then, based on the relationship between the local phase and time established in step 1, the corresponding relationship between the reference joint position and time in the future period is obtained. ;in, Indicates the number of operation instructions. Indicates instruction characteristics All the corresponding frequency components, Represents linear motion characteristics All corresponding frequency components;

[0015] Step 6: For Enter new operation instructions at any time and repeat steps 4 and 5 to re-synthesize a new exercise pattern until the exercise is completed.

[0016] Furthermore, in step 2, the spatial motion mode includes a pitch motion mode and a yaw motion mode.

[0017] Furthermore, in step 4, when , corresponds to the preset terrain mode.

[0018] On this basis, the present invention proposes a real-time motion control system for a crawler robot based on phase domain synthesis, which includes a user operation terminal, a motion mode controller and a joint servo controller;

[0019] The user operation terminal can be used to input operation instructions;

[0020] The motion pattern controller includes an internal clock module, a motion pattern feature storage module, a motion pattern synthesis module, a client communication module and a reference angle output module;

[0021] The internal clock module is used for timing and provides an alignment reference between operation instructions;

[0022] The motion pattern feature storage module is used to store the features of different motion patterns obtained in step 3;

[0023] The motion pattern synthesis module is used to execute steps 4 to 6, generate a motion pattern controlled by the user in real time, output reference joint angles for a period of time in the future, and realize real-time motion control of the crawler robot;

[0024] The client communication module is used for communication between the motion mode controller and the user operation terminal, receiving user operation instructions, and uploading current joint position information to the user operation terminal;

[0025] The reference angle output module is used to output the reference joint angle to the joint servo controller;

[0026] The joint servo controller is used to control the joint movement so that the actual position of the robot joint tracks the reference joint position output by the motion mode controller.

[0027] Furthermore, the user operation terminal can also be used to monitor the current joint positions of the crawler robot.

[0028] Furthermore, the motion mode controller runs on an embedded microcontroller carried by the crawler robot, or runs on a remote terminal.

[0029] Furthermore, the joint servo controller is implemented using an embedded microcontroller and integrated into the robot body.

[0030] Furthermore, the form of the user operation terminal includes but is not limited to a handle, an application running on a mobile phone or a laptop computer; the user can output the user-set operation instructions through a handle joystick, keyboard keys or clicking screen buttons.

[0031] Beneficial effects

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] 1. The present invention proposes a real-time motion control method for a reptile robot based on phase domain synthesis. This method is based on a preset terrain and a few basic motion modes, and can generate new motion modes, thereby improving the richness of the reptile robot's motion modes, thereby improving the reptile robot's motion ability in complex terrain, and also reducing the workload of the robot's motion mode design.

[0034] 2. The real-time motion control method for a reptile robot based on phase domain synthesis described in the present invention transfers the motion pattern synthesis work from the time domain to the phase domain by establishing a local phase, which can effectively reduce the characteristic dimension of the motion pattern and realize the efficient synthesis of motion patterns of different time scales under constant time consumption, so that the user can correct the motion path in real time according to the terrain and motion conditions, thereby improving the maneuverability of the reptile robot in complex terrain.

[0035] 3. This invention proposes a real-time motion control system for a crawler robot based on phase-domain synthesis. This system establishes a flexible motion control system framework for implementing the control method described herein, enabling users to control the three-dimensional motion of the crawler robot in real time via wired or wireless communication via a variety of operating terminals. Crawler robots based on this method and system can be applied in tasks such as nuclear facility inspection, in-situ engine testing, space station maintenance, and disaster relief.

[0036] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0038] Figure 1 :Flowchart of real-time motion control method for crawler robot based on phase domain synthesis;

[0039] Figure 2 : Structure diagram of a 4-segment serial-parallel hybrid crawler robot;

[0040] Figure 3:Architecture diagram of real-time motion control system for crawler robot based on phase space synthesis. DETAILED DESCRIPTION

[0041] The following describes in detail embodiments of the present invention. The embodiments are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.

[0042] This embodiment takes a 4-segment serial-parallel hybrid crawler robot as an example, that is, Each segment of the robot is driven by 3 motors, with a total of There are four user operation instructions: turn left, turn right, climb, and descend, corresponding to the horizontal deflection and vertical pitch motion. Although only four operation instructions are given in this embodiment, the operation instructions can also be expanded according to the actual needs of those skilled in the art. In this embodiment, the method for real-time motion control of the crawler robot includes the following steps:

[0043] Step 1: Establish the correspondence between the local phase and time of the segment extension and contraction rhythm of the crawler robot:

[0044]

[0045] Where, Indicates the Segments in The phase of the moment, Indicates phase exist The speed of change at each moment is determined by the linear motion gait cycle , swing time and delay time Joint decision. , ,if ,So ;otherwise, ; Use vector Represent the local phase of all segments: .

[0046] Step 2: Calculate the relationship between the reference joint position and phase of the reptile robot in the linear motion mode, the preset terrain mode, and the spatial motion mode based on the spine kinematic model and dynamic model of the reptile robot. , where the spatial motion pattern corresponds to the above-mentioned horizontal deflection and vertical pitch motion. In a certain motion mode, the local phase is When , the vector consisting of the positions of all joints, Represents all allowed joint positions. In this embodiment, any driven joint angle satisfies .

[0047] Step 3: Perform a fast Fourier transform (FFT) on the relationship between the reference joint position and phase obtained in step 2, and perform compression and feature extraction in the frequency domain to obtain the characteristics of different motion patterns: ,in, Indicates FFT operation, represents the initial joint position, represents the frequency component of the feature, Represents frequency components The corresponding value.

[0048] Step 4: Get the operation instruction, where Operation instructions corresponding to the time , thereby generating a set of command phases and motion pattern characteristics ; In particular, indicates a preset terrain.

[0049] Step 5: Use the features corresponding to the operation instructions obtained in step 4 , and the linear motion mode characteristics , in the phase domain, according to the current local phase and command phase Align and superimpose to synthesize a new motion pattern and obtain the relationship between the reference joint position and phase of the new motion pattern:

[0050]

[0051] Among them, the frequency characteristics and are all complex numbers and can be expressed as Then, based on the relationship between the local phase and time established in step 1, the corresponding relationship between the reference joint position and time in the future period is obtained. ;in, Indicates the number of operation instructions. Indicates instruction characteristics All the corresponding frequency components, Represents linear motion characteristics All corresponding frequency components.

[0052] Step 6: For Enter new operation instructions at any time and repeat steps 4 and 5 to re-synthesize a new exercise pattern until the exercise is completed.

[0053] On this basis, this embodiment proposes a real-time motion control system for a crawler robot based on phase domain synthesis, including a user operation terminal, a motion mode controller and a joint servo controller;

[0054] The user operation terminal can be used to input operation instructions; specifically, the user operation terminal includes but is not limited to a handle, an application running on a mobile phone or a laptop computer; the user can output the user-set operation instructions through the handle joystick, keyboard keys or clicking on the screen button. In this embodiment, the user operation terminal is in the form of an application that runs on the user's laptop computer. During the movement of the robot, the user can click on the "turn left", "turn right", "uphill", "downhill", "straight line motion" and other buttons on the user operation interface at any time to send the corresponding operation instructions to the robot. At the same time, the current driving joint angle of the robot is displayed on the interface of the user operation terminal.

[0055] The motion mode controller includes an internal clock module, a motion mode feature storage module, a motion mode synthesis module, a client communication module and a reference angle output module; the motion mode controller runs on an embedded microcontroller carried by the crawler robot, or runs on a remote terminal; in this embodiment, the motion mode controller runs on the user's laptop computer.

[0056] The internal clock module is used for timing and provides an alignment reference between operation instructions.

[0057] The motion pattern feature storage module is used to store the features of different motion patterns obtained in step 3.

[0058] The motion pattern synthesis module is used to execute steps 4 to 6, generate a motion pattern controlled by the user in real time, output reference joint angles within a period of time in the future, and realize real-time motion control of the crawler robot.

[0059] The client communication module is used for Socket communication between the motion mode controller and the user operation terminal, receives user operation instructions, and uploads current joint position information to the user operation terminal.

[0060] The reference angle output module is used to output the reference joint angle to the joint servo controller.

[0061] The joint servo controller is used to control joint motion, using a PID controller to ensure that the actual joint position of the robot tracks the reference joint position output by the motion pattern controller. The joint servo controller runs on an embedded microcontroller integrated into the robot body and communicates with the motion pattern controller via Wi-Fi.

[0062] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A real-time motion control method for a crawler robot based on phase domain synthesis, characterized by: The following steps are involved: Step 1: Establish the correspondence between the local phase and time of the segment extension and contraction rhythm of the crawler robot: Where, represents the phase of the i-th segment at time t, Indicates the phase φ (i) exist The speed of change at each moment; the local phase of all segments is represented by vector φ: n s is the number of segments of the crawler robot; Step 2: Calculate the relationship between the reference joint position and phase of the reptile robot under different motion modes based on the reptile robot's spine kinematic model and dynamic model in In a certain motion mode, when the local phase is φ, the vector composed of the positions of all joints, Θ represents all allowed joint positions, n a Indicates the number of joints; the motion modes include linear motion mode, spatial motion mode and preset terrain mode; Step 3: Perform a fast Fourier transform on the relationship between the reference joint position and phase obtained in step 2, and perform compression and feature extraction in the frequency domain to obtain the characteristics of different motion patterns: in, represents the FFT operation, θ e represents the initial joint position, ω represents the frequency component of the feature, and Γ(ω) represents the value corresponding to the frequency component ω; Step 4: Get the operation instruction, where the kth operation instruction corresponds to time t k , thereby generating a set of command phases and motion pattern characteristics Step 5: Use the feature Γ corresponding to the operation instruction obtained in step 4 k (ω), and the linear motion mode characteristic Γ r (ω), in the phase domain, according to the current local phase φ and the command phase φ r,k Align and superimpose to synthesize a new motion pattern and obtain the relationship between the reference joint position and phase of the new motion pattern: Then, based on the relationship between the local phase and time established in step 1, the corresponding relationship between the reference joint position and time in the future period is obtained. Among them, n c Indicates the number of operation instructions, Ω k Represents instruction feature Γ k (ω) corresponds to all frequency components, Ω r Represents the linear motion characteristic Γ r (ω) all frequency components corresponding to; Step 6: For t k+1 For every new operation command input, repeat steps 4 to 5 to synthesize a new motion pattern until the motion is completed.

2. The real-time motion control method for a crawler robot based on phase domain synthesis according to claim 1, characterized in that: In step 2, the spatial motion mode includes a pitch motion mode and a yaw motion mode.

3. The real-time motion control method for a crawler robot based on phase domain synthesis according to claim 1, characterized in that: When k=0 in step 4, it corresponds to the preset terrain mode.

4. A real-time motion control system for a crawler robot that implements the method according to any one of claims 1 to 3, characterized in that: It includes a user operation terminal, a motion mode controller and a joint servo controller; The user operation terminal can be used to input operation instructions; The motion pattern controller includes an internal clock module, a motion pattern feature storage module, a motion pattern synthesis module, a client communication module and a reference angle output module; The internal clock module is used for timing and provides an alignment reference between operation instructions; The motion pattern feature storage module is used to store the features of different motion patterns obtained in step 3; The motion pattern synthesis module is used to execute steps 4 to 6, generate a motion pattern controlled by the user in real time, output reference joint angles for a period of time in the future, and realize real-time motion control of the crawler robot; The client communication module is used for communication between the motion mode controller and the user operation terminal, receiving user operation instructions, and uploading current joint position information to the user operation terminal; The reference angle output module is used to output the reference joint angle to the joint servo controller; The joint servo controller is used to control the joint movement so that the actual position of the robot joint tracks the reference joint position output by the motion mode controller.

5. The real-time motion control system for a crawler robot according to claim 4, characterized in that: The user operation terminal can also be used to monitor the current joint positions of the crawler robot.

6. The real-time motion control system for a crawler robot according to claim 4, characterized in that: The motion mode controller runs on an embedded microcontroller carried by the crawler robot, or runs on a remote terminal.

7. The real-time motion control system for a crawler robot according to claim 4, characterized in that: The joint servo controller is implemented using an embedded microcontroller and integrated on the robot body.

8. The real-time motion control system for a crawler robot according to claim 4, characterized in that: The user operation terminal includes but is not limited to a handle, an application running on a mobile phone or a laptop computer; the user can output the user-set operation instructions through a handle joystick, keyboard keys or clicking screen buttons.

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