Upper limb exoskeleton robot skill transfer mirror image control method based on surface electromyogram signals

Abstract

The invention discloses an upper limb exoskeleton robot skill transfer mirror image control method based on surface electromyogram signals, and particularly relates to the field of mirror image training. According to the actual position of the master side wearing mechanism and the actual position of the slave side wearing mechanism, determining a master side expected interaction force; according to the main side interaction force and the main side expected interaction force, the expected position of the main side wearing mechanism is determined, and the main side wearing mechanism is controlled to move according to the expected position of the main side wearing mechanism; according to the master-side electromyographic signals, the slave-side electromyographic signals and the master-side interaction force, the expected interaction force of the slave-side wearing mechanism is determined; according to the slave side interaction force and the slave side expected interaction force, the expected position of the slave side wearing mechanism is determined, and the slave side wearing mechanism is controlled to move according to the expected position of the slave side wearing mechanism. The perceptibility of the trainee to the training process is improved, so that the patient can adjust the training action by himself, that is, the actual position of the main side wearing mechanism is adjusted, the main side expected interaction force meets the requirement of himself, and the training immersion and the training effect can be improved.

Description

Technical Field

[0001] The present application relates to the field of mirror training, and in particular to a mirror control method for skill transfer of an upper limb exoskeleton robot based on surface electromyography signals. Background Art

[0002] In the fields of precision machining, remote operation, rehabilitation training, etc., it is often necessary to use both hands to complete the work. However, people have dominant hands and non-dominant hands. How to efficiently train the non-dominant hand and reduce the overall training cost has always been one of the research focuses of skill training and transfer.

[0003] There are two main mechanisms in the process of transferring motor skills acquired by the dominant hand to the non-dominant hand: one is asymmetric transfer, that is, dominant hand training can significantly improve the motor performance of the non-dominant hand; the other is symmetrical transfer, that is, when both hands are trained at the same time, the motor performance of both hands is improved. In combination with the above mechanisms, the method of mirror training is proposed. Mirror training refers to the use of mirrors or virtual reality technology to make the non-dominant hand imitate the movements of the dominant hand, thereby improving the effect of skill transfer. Through this operation, different areas of the trainee's brain can be stimulated to form new neural connections and reallocate neural resources. Thus, the training of the non-dominant hand can be achieved.

[0004] However, traditional mirror training only involves visual perception and lacks direct force interaction, which limits the immersion and training effects to a certain extent. Summary of the invention

[0005] The main purpose of this application is to provide a mirror control method for skill transfer of an upper limb exoskeleton robot based on surface electromyography signals, aiming to solve the problem of poor training effect of existing mirror training methods.

[0006] To achieve the above-mentioned purpose, the present application provides a mirror control method for skill transfer of an upper limb exoskeleton robot based on surface electromyography signals, which is used to control a mirror training device, wherein the mirror training device includes a master-side wearable mechanism and a slave-side wearable mechanism; the interaction force between the master-side wearable mechanism and the upper limb is obtained as the master-side interaction force; the actual position of the master-side wearable mechanism and the actual position of the slave-side wearable mechanism are obtained, and the master-side expected interaction force is determined according to the actual position of the master-side wearable mechanism and the actual position of the slave-side wearable mechanism; the expected position of the master-side wearable mechanism is determined according to the master-side interaction force and the master-side expected interaction force, and the movement of the master-side wearable mechanism is controlled according to the expected position of the master-side wearable mechanism; the interaction force between the slave-side wearable mechanism and the upper limb is obtained as the slave-side interaction force; the master-side electromyography signals and the slave-side electromyography signals on the human body surface are obtained, and the expected interaction force of the slave-side wearable mechanism is determined according to the master-side electromyography signals, the slave-side electromyography signals and the master-side interaction force; the expected position of the slave-side wearable mechanism is determined according to the slave-side interaction force and the slave-side expected interaction force, and the movement of the slave-side wearable mechanism is controlled according to the expected position of the slave-side wearable mechanism.

[0007] Optionally, after determining the expected position of the slave-side wearing mechanism, the method also includes: acquiring the posture of the master-side wearing mechanism, and determining the expected posture of the side wearing mechanism according to the posture of the master-side wearing mechanism; controlling the movement of the slave-side wearing mechanism according to the expected position of the slave-side wearing mechanism, including: controlling the movement of the slave-side wearing mechanism according to the expected posture of the side wearing mechanism and the expected position of the slave-side wearing mechanism.

[0008] Optionally, the desired posture of the side wearing mechanism is determined based on the posture of the main side wearing mechanism, the normal vector of the mirror plane, and the first preset relationship.

[0009] Optionally, the expected interaction force on the master side is determined according to the actual position of the master-side wearing mechanism and the actual position of the slave-side wearing mechanism, and a second preset relationship.

[0010] Optionally, the expected position of the main-side wearing mechanism is determined based on the main-side interaction force, the main-side expected interaction force, the preset expected position of the main-side wearing mechanism, the inertia coefficient, the damping coefficient and the stiffness coefficient, and a third preset relationship.

[0011] Optionally, the third preset relationship is:

[0012] In the formula, is the main side inertia coefficient, is the main side damping coefficient, is the main side stiffness coefficient, The preset desired position of the main side wearing mechanism, is the first-order derivative of the preset desired position of the main-side wearing mechanism, is the second-order derivative of the preset desired position of the main-side wearing mechanism, is the desired position of the main-side wearing mechanism, is the first derivative of the desired position of the main-side wearing mechanism, is the second derivative of the desired position of the main-side wearing mechanism, is the main side interaction force, The expected interaction force on the main side.

[0013] Optionally, the expected position of the slave side wearing mechanism is determined based on the slave side interaction force, the expected slave side interaction force, the preset expected position of the slave side wearing mechanism, the slave side inertia coefficient, the slave side damping coefficient and the slave side stiffness coefficient, and a fifth preset relationship.

[0014] Optionally, the fifth preset relationship is:

[0015] In the formula, is the inertia coefficient from the side, is the damping coefficient from the side, is the lateral stiffness coefficient, The preset desired position of the wearing mechanism from the side, The preset desired position of the wearing mechanism from the side, The desired position for wearing the mechanism from the side, is the lateral interaction force, is the expected interaction force from the side.

[0016] Optionally, the preset expected position of the slave-side wearing mechanism is obtained by mirroring the actual position of the master-side wearing mechanism; the expected interaction force of the slave-side wearing mechanism is determined based on the master-side electromyographic signal, the slave-side electromyographic signal and the master-side interaction force, and a fourth preset relationship; the slave-side stiffness coefficient is determined based on the master-side electromyographic signal, the slave-side electromyographic signal, the slave-side stiffness coefficient at the initial moment, and a sixth preset relationship.

[0017] Optionally, the master-side wearing mechanism and the slave-side wearing mechanism have the same structure; the master-side wearing mechanism includes: an interaction mechanism, used for force interaction with the upper limbs of the human body; a force sensor, connected to the interaction mechanism, used to measure the interaction force; a mechanical arm, connected to the force sensor; a drive motor, connected to the mechanical arm, used to drive the mechanical arm to move; an encoder is provided on the drive motor, and the encoder is used to measure the position of the master-side wearing mechanism; an electromyography sensor, used to obtain the master-side electromyography signals and the slave-side electromyography signals on the surface of the human body.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals of the present invention determines the expected interaction force on the master side based on the difference between the actual position of the master-side wearable mechanism and the actual position of the slave-side wearable mechanism, realizes the master-side force rendering, and improves the trainee's perception of the training process, so that the patient can adjust the training movements by himself, that is, adjust the actual position of the master-side wearable mechanism, so that the expected interaction force on the master side meets his own requirements, which can improve the training immersion and training effect; by obtaining the master / slave side surface electromyography signals of the trainees, according to the changes of the master / slave side surface electromyography signals, the slave-side force guidance and control strategy are adjusted in real time, thereby improving the skill transfer training efficiency; by the healthy side (master side) driving the affected side (slave side) to synchronize movement and real-time adjustment of the interaction force, different areas of the patient's brain are stimulated to produce movement, sensation and pain awareness, thereby promoting the reconstruction of hemiplegic limb motor function and brain function remodeling in stroke patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a process for a mirror control method of upper limb exoskeleton robot skill transfer based on surface electromyography signals in this application; Figure 2 This is a schematic diagram of the structure of the main-side wearing mechanism in a mirror control method for skill transfer of an upper limb exoskeleton robot based on surface electromyography signals in this application; The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] The first embodiment of the present invention provides a mirror control method for skill transfer of an upper limb exoskeleton robot based on surface electromyography signals, which is used to control a mirror training device, wherein the mirror training device includes a master-side wearing mechanism and a slave-side wearing mechanism, wherein the master-side wearing mechanism can be worn on the healthy upper limb of a human body, and the slave-side wearing mechanism can be worn on the healthy upper limb of a human body, such as Figure 1 As shown, the specific steps include: Step S1, obtaining the interaction force between the main-side wearing mechanism and the upper limb as the main-side interaction force; Step S2, obtaining the actual position of the master-side wearing mechanism and the actual position of the slave-side wearing mechanism, and determining the master-side expected interaction force according to the actual position of the master-side wearing mechanism and the actual position of the slave-side wearing mechanism; Specifically, the master-side expected interaction force is determined according to the actual position of the master-side wearing mechanism and the actual position of the slave-side wearing mechanism, and a second preset relationship; wherein the second preset relationship is:

[0022] In the formula, For the scaling factor, set , is the actual position of the main side wearing mechanism, It is the actual position of the wearing mechanism from the side.

[0023] Step S3, determining an expected position of the main-side wearing mechanism according to the main-side interaction force and the main-side expected interaction force, and controlling the movement of the main-side wearing mechanism according to the expected position of the main-side wearing mechanism; Specifically, the expected position of the main-side wearing mechanism is determined according to the main-side interaction force, the main-side expected interaction force, the preset expected position of the main-side wearing mechanism, the inertia coefficient, the damping coefficient and the stiffness coefficient, and the third preset relationship; wherein the third preset relationship is:

[0024] In the formula, is the main side inertia coefficient, , is the main side damping coefficient, , is the main side stiffness coefficient, , The preset desired position of the main side wearing mechanism, , is the first-order derivative of the preset desired position of the main-side wearing mechanism, , is the second-order derivative of the preset desired position of the main-side wearing mechanism, , is the desired position of the main-side wearing mechanism, is the first derivative of the desired position of the main-side wearing mechanism, is the second derivative of the desired position of the main-side wearing mechanism, is the main side interaction force, The expected interaction force on the main side.

[0025] Step S4, obtaining the interaction force between the slave-side wearing mechanism and the upper limb as the slave-side interaction force; Step S5, acquiring a master-side electromyographic signal and a slave-side electromyographic signal on the human body surface, and determining an expected interaction force of the slave-side wearing mechanism according to the master-side electromyographic signal, the slave-side electromyographic signal and the master-side interaction force; Specifically, the expected interaction force of the slave-side wearing mechanism is determined according to the master-side electromyographic signal, the slave-side electromyographic signal, the master-side interaction force, and a fourth preset relationship; wherein the fourth preset relationship is:

[0026]

[0027] In the formula, is the surface electromyographic signal of the dominant arm at time t, is the surface electromyographic signal from the side arm at time t, is the difference between the master-side EMG signal and the slave-side EMG signal at the initial moment, i.e., t=0, is the difference between the master-side EMG signal and the slave-side EMG signal at the current moment, Main side interaction force.

[0028] Step S6: determining an expected position of the slave-side wearing mechanism according to the slave-side interaction force and the slave-side expected interaction force, and controlling the movement of the slave-side wearing mechanism according to the expected position of the slave-side wearing mechanism.

[0029] Specifically, the expected position of the slave-side wearing mechanism is determined according to the slave-side interaction force, the expected slave-side interaction force, the preset expected position of the slave-side wearing mechanism, the slave-side inertia coefficient, the slave-side damping coefficient and the slave-side stiffness coefficient, and a fifth preset relationship; wherein the fifth preset relationship is:

[0030] In the formula, is the inertia coefficient from the side, , is the damping coefficient from the side, , is the lateral stiffness coefficient, The preset desired position of the wearing mechanism from the side, The preset desired position of the wearing mechanism from the side, is the first-order derivative of the preset desired position of the side-wearing mechanism, is the second-order derivative of the preset desired position of the side wearing mechanism, The desired position for wearing the mechanism from the side, is the first derivative of the desired position of the wear mechanism from the side, is the second derivative of the desired position of the wear mechanism from the side, is the lateral interaction force, is the expected interaction force from the side.

[0031] The preset expected position of the slave-side wearing mechanism is obtained by mirroring the actual position of the master-side wearing mechanism, and the calculation formula is:

[0032] The slave side stiffness coefficient is determined according to the master side electromyographic signal, the slave side electromyographic signal, the slave side stiffness coefficient at the initial moment, and a sixth preset relationship; further, the sixth preset relationship is:

[0033] In the formula, is the difference between the master-side EMG signal and the slave-side EMG signal at the initial moment, is the difference between the master-side EMG signal and the slave-side EMG signal at the current moment, is the initial lateral stiffness coefficient, which can be selected .

[0034] In this embodiment, the master-side electromyographic signal and the slave-side electromyographic signal are acquired in real time, and the expected interaction force of the slave-side wearable mechanism is determined according to the change values ​​of the master-side electromyographic signal and the slave-side electromyographic signal, and the master-side interaction force, so as to adjust the expected position (i.e., the motion trajectory) of the slave-side wearable mechanism, thereby achieving the purpose of real-time adjustment of the mirror control strategy according to the trainee's training situation.

[0035] In order to more accurately train the slave-side wearing mechanism so that it imitates the master-side wearing mechanism, after determining the expected position of the slave-side wearing mechanism, the expected posture of the slave-side wearing mechanism is determined, and the movement of the slave-side wearing mechanism is controlled by the expected position and the expected posture. The specific method for determining the expected posture is as follows.

[0036] The posture of the main side wearing mechanism is obtained, and the expected posture of the side wearing mechanism is determined according to the posture of the main side wearing mechanism. Specifically, the expected posture of the side wearing mechanism is determined according to the posture of the main side wearing mechanism, the normal vector of the mirror plane, and the first preset relationship; wherein the posture of the main side wearing mechanism Expressed in quaternion form, , the first preset relationship is:

[0037]

[0038]

[0039] In the formula, is the mirror plane normal vector, The desired posture for wearing the mechanism from the side.

[0040] The structures of the master-side wearing mechanism and the slave-side wearing mechanism are the same, and the master-side wearing mechanism is taken as an example for introduction below.

[0041] like Figure 2As shown, the main-side wearable mechanism includes an interactive mechanism 1, a force sensor 2, a mechanical arm 3, a drive motor 4, and an electromyographic sensor 5, wherein the interactive mechanism 1 is used to perform force interaction with the upper limbs of the human body; the force sensor 2 is connected to the interactive mechanism 1 for measuring the interactive force; the mechanical arm 3 is connected to the force sensor 2; the drive motor 4 is transmission-connected to the mechanical arm 3 for driving the mechanical arm 3 to move; an encoder is provided on the drive motor 4, and the encoder is used to measure the position of the motor (of the main-side wearable mechanism); the electromyographic sensor 5 is worn on the forearm of the human body and is used to obtain the main-side electromyographic signals and the slave-side electromyographic signals on the surface of the human body.

[0042] Exemplarily, the interactive mechanism 1 can be a handle, the force sensor 2 can be a six-dimensional force sensor 2, the robotic arm 3 can be a seven-degree-of-freedom robotic arm 3, the seven-degree-of-freedom robotic arm 3 is installed on a base, and the mirror plane can be parallel to the base surface of the dual seven-degree-of-freedom robotic arm 3, located at the midpoint of the common perpendicular line of the two base surfaces.

[0043] When in use, the trainee grasps the handles with both hands, and the driving motor 4 drives the mechanical arm 3 to move along a preset trajectory (i.e., a preset desired position). During the movement, the six-dimensional force sensor 2 collects the interaction forces between the master and slave side wearable mechanisms and the upper limbs. , i.e. the master-side interaction force and the slave-side interaction force, the position of the drive motor 4 is collected through the encoder, i.e. the actual position of the master-side and slave-side wearing mechanisms, and at the same time, the myoelectric sensor 5 is Record 8 channels of EMG signals at a frequency of .

[0044] In this embodiment, compared with the mirror training method that directly uses a mirror or virtual reality, the robotic arm 3 is connected to the handle through the force sensor 2, so that force guidance and force feedback can be achieved, and the immersion and training effect are greatly improved.

[0045] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A mirror control method for skill transfer of an upper limb exoskeleton robot based on surface electromyography signals, characterized in that: Used to control the mirror training device, the mirror training device comprising a master-side wearing mechanism and a slave-side wearing mechanism; Obtaining the interaction force between the main-side wearing mechanism and the upper limb as the main-side interaction force; Acquire the actual position of the master-side wearing mechanism and the actual position of the slave-side wearing mechanism, and determine the master-side expected interaction force according to the actual position of the master-side wearing mechanism and the actual position of the slave-side wearing mechanism; Determining an expected position of a main-side wearing mechanism according to the main-side interaction force and the main-side expected interaction force, and controlling the movement of the main-side wearing mechanism according to the expected position of the main-side wearing mechanism; Obtaining the interaction force between the slave-side wearing mechanism and the upper limb as the slave-side interaction force; Acquire a master-side electromyographic signal and a slave-side electromyographic signal on a human body surface, and determine an expected interaction force of the slave-side wearing mechanism according to the master-side electromyographic signal, the slave-side electromyographic signal and the master-side interaction force; According to the slave-side interaction force and the slave-side expected interaction force, an expected position of the slave-side wearing mechanism is determined, and the movement of the slave-side wearing mechanism is controlled according to the expected position of the slave-side wearing mechanism.

2. The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals according to claim 1 is characterized in that: After determining the desired position of the side wearing mechanism, the method further includes: Acquire the posture of the main-side wearing mechanism, and determine the expected posture of the side wearing mechanism according to the posture of the main-side wearing mechanism; The controlling the movement of the slave-side wearing mechanism according to the desired position of the slave-side wearing mechanism comprises: The movement of the slave-side wearing mechanism is controlled according to the desired posture of the side wearing mechanism and the desired position of the slave-side wearing mechanism.

3. The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals according to claim 2 is characterized in that: The expected posture of the side wearing mechanism is determined according to the posture of the main side wearing mechanism, the normal vector of the mirror plane, and the first preset relationship.

4. The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals according to claim 1 is characterized in that: The master-side expected interaction force is determined according to the actual position of the master-side wearing mechanism and the actual position of the slave-side wearing mechanism, and a second preset relationship.

5. The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals according to claim 1 is characterized in that: The expected position of the main-side wearing mechanism is determined according to the main-side interaction force, the main-side expected interaction force, the preset expected position of the main-side wearing mechanism, the inertia coefficient, the damping coefficient and the stiffness coefficient, and the third preset relationship.

6. The method for upper limb exoskeleton robot skill transfer mirror control based on surface electromyography signals according to claim 5 is characterized in that: The third preset relationship is: In the formula, is the main side inertia coefficient, is the main side damping coefficient, is the main side stiffness coefficient, The preset desired position of the main side wearing mechanism, is the first-order derivative of the preset desired position of the main-side wearing mechanism, is the second-order derivative of the preset desired position of the main-side wearing mechanism, is the desired position of the main-side wearing mechanism, is the first derivative of the desired position of the main-side wearing mechanism, is the second derivative of the desired position of the main-side wearing mechanism, is the main side interaction force, The expected interaction force on the main side.

7. The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals according to claim 1 is characterized in that: The expected position of the slave-side wearing mechanism is determined based on the slave-side interaction force, the expected slave-side interaction force, the preset expected position of the slave-side wearing mechanism, the slave-side inertia coefficient, the slave-side damping coefficient and the slave-side stiffness coefficient, and a fifth preset relationship.

8. The method for upper limb exoskeleton robot skill transfer mirror control based on surface electromyography signals according to claim 7 is characterized in that: The fifth preset relationship is: In the formula, is the inertia coefficient from the side, is the damping coefficient from the side, is the lateral stiffness coefficient, The preset desired position of the wearing mechanism from the side, The preset desired position of the wearing mechanism from the side, The desired position for wearing the mechanism from the side, is the lateral interaction force, is the expected interaction force from the side.

9. The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals according to claim 7 is characterized in that: The preset expected position of the slave-side wearing mechanism is obtained by mirroring the actual position of the master-side wearing mechanism; The expected interaction force of the slave-side wearing mechanism is determined according to the master-side electromyographic signal, the slave-side electromyographic signal and the master-side interaction force, and a fourth preset relationship; The slave side stiffness coefficient is determined according to the master side electromyographic signal, the slave side electromyographic signal, the slave side stiffness coefficient at an initial moment, and a sixth preset relationship.

10. The upper limb exoskeleton robot skill transfer mirror control method based on surface electromyography signals according to claim 1, characterized in that: The master-side wearing mechanism and the slave-side wearing mechanism have the same structure; The main-side wearing mechanism comprises: An interactive mechanism, used for force interaction with the upper limbs of a human body; A force sensor connected to the interaction mechanism and used to measure the interaction force; a mechanical arm connected to the force sensor; A driving motor, which is connected to the mechanical arm and is used to drive the mechanical arm to move; an encoder is provided on the driving motor, and the encoder is used to measure the position of the main side wearing mechanism; The electromyographic sensor is used to obtain the master-side electromyographic signal and the slave-side electromyographic signal on the surface of the human body.

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