CN112641447B

CN112641447B - Action assisting device based on surface myoelectricity and action intention identification method

Info

Publication number: CN112641447B
Application number: CN202011394698.1A
Authority: CN
Inventors: 许磊; 汪洋
Original assignee: Shanghai Haimeikang Intelligent Medical Technology Co ltd
Current assignee: Shanghai Haimeikang Intelligent Medical Technology Co ltd
Priority date: 2020-12-02
Filing date: 2020-12-02
Publication date: 2022-07-05
Anticipated expiration: 2040-12-02
Also published as: CN112641447A

Abstract

The invention relates to the technical field of medical rehabilitation instruments, in particular to a surface myoelectric-based action assisting device and an action intention identification method.A control circuit board receives a bioelectric signal transmitted by a sensing unit and extracts the characteristics of the bioelectric signal; the extracted bioelectricity signal characteristics are sent to a classifier for linear discriminant analysis, the classification result is sent to a voter, the final motion intention result is output and an instruction is transmitted to a driver to generate a driving force to control the hand exoskeleton to act by comparing the result of the voter with a threshold value comparison result.

Description

Action assisting device based on surface myoelectricity and action intention identification method

Technical Field

The invention relates to the technical field of medical rehabilitation instruments, in particular to a surface myoelectricity-based action assisting device and an action intention identification method.

Background

The motion auxiliary equipment is mainly used for people with limb movement disorder and is widely applied to the fields of nerve rehabilitation, medical treatment, military and the like. Since the use of hands is very important and frequent in life, the design of the hand motion assisting device is particularly central.

Patients with hand dysfunction can be categorized into two major categories, one due to brain damage and nerve pathway damage and the other due to muscle damage. For patients of the first category, treatment may be by nerve displacement surgery; for patients of the second category, treatment may be by targeted muscle nerve transplantation surgery. However, in both nerve displacement and targeted nerve transplantation, the nerves used are not the corresponding nerves of the original innervating muscles, so the patients usually need rehabilitation training for a period of time after the operation to achieve the purpose of brain remodeling.

Most of the existing motion auxiliary devices are made of rigid materials, heavy in weight, large in size and inconvenient to wear, and can bring extra physical burden to users.

In the aspect of analysis of movement intentions, intention recognition based on mechanical information and intention recognition based on bioelectrical information are mainly available, wherein the intention recognition based on mechanical information mainly utilizes human kinematics and dynamics information, and bioelectrical signals mainly adopt myoelectric signals and electroencephalogram signals. The mechanical information is convenient to collect and stable in signal, but can be obtained only after the user starts to move, so that serious hysteresis exists, and meanwhile, mechanical information cannot be collected due to a small hand action, and meanwhile, the mechanical information cannot directly reflect the movement intention of the user.

The motion intention recognition based on the bioelectric signal can well solve the problem of hysteresis, but the electromyographic signal has interference signals (such as superimposed signals, noise signals and the like) and has low recognition accuracy, so that misleading can be generated on the judgment of the motion intention.

Therefore, it is necessary to design an action assisting device based on surface electromyogram signals and a control method thereof, which can achieve the purposes of light weight, convenient wearing, flexible control and accurate movement intention recognition.

Disclosure of Invention

The invention breaks through the difficult problems in the prior art, and designs the surface myoelectricity-based action auxiliary device and the action intention identification method which can achieve the purposes of light weight, convenient wearing, flexible control and accurate movement intention identification.

In order to achieve the above object, the present invention provides a surface myoelectric-based motion assist device, comprising: the hand exoskeleton robot comprises a sensing unit, a driving line pipe and a hand exoskeleton;

the sensing unit is used for collecting and transmitting surface electromyographic signals of a user and comprises a signal sensor and a signal transmission line, the signal sensor is arranged on the body of the user, the surface electromyographic signals are transmitted to the driving unit through the signal transmission line, the driving unit analyzes and processes the surface electromyographic signals, the generated driving force is transmitted to the hand exoskeleton, and the hand exoskeleton is controlled to act.

The hand exoskeleton is a line-driven hand exoskeleton and comprises flexible exoskeleton gloves or rigid-flexible exoskeleton gloves.

Furthermore, the driving unit comprises a transmission mechanism, a self-locking mechanism, a control circuit board, a power supply and a driver, wherein the power supply is used for supplying power to the driving unit, the control circuit board and the driver are used for receiving the surface electromyographic signals transmitted by the sensing unit, analyzing the signals and transmitting instructions to the driver to enable the driver to generate driving force, and the driving force is transmitted to the hand exoskeleton through the self-locking mechanism and the transmission mechanism to control the hand exoskeleton to act.

Furthermore, the drive spool for the protection combs the drive pencil, including setting up at the reason line ware one of its one end and setting up the drive head at the other end, the drive wire pipe box is established at the drive pencil outsidely, reason line ware one links to each other with the drive pencil that drive unit stretches out, with drive pencil leading-in drive spool back with drive head intercommunication.

Further, the transmission mechanism includes:

the driving shaft is used for providing power required by the transmission mechanism;

the driving shaft is detachably arranged on the side wall of the base, and a one-way bearing is sleeved on the driving shaft;

the driven shaft is detachably arranged on the side wall of the base and is also sleeved with a one-way bearing, and the driven shaft is connected with the driving shaft by a gear pair and rotates along with the driving shaft;

the steering shafts are respectively detachably arranged on the bottom plate of the base and used for changing the direction of the driving wire harness;

the driving wire harness is wound on the one-way bearing of the driving shaft, the one-way bearing of the driven shaft and the steering shaft and then passes through the wire holes in the side wall of the base to be connected with the hand exoskeleton.

Furthermore, the gear pair comprises a driving gear and a driven gear, the driving gear is sleeved on the driving shaft, and the driven gear is sleeved on the driven shaft.

Furthermore, the transmission mechanism further comprises pressing shafts, and the pressing shafts are located on the upper side and the lower side of the driven shaft, so that the wire harness is close to the one-way bearing on the driven shaft, and the wire outlet is reliable.

Furthermore, the self-locking mechanism is a rotary bidirectional self-locking mechanism and comprises an output shaft and an input shaft, one end of the output shaft is connected with the transmission mechanism, one end of the input shaft is connected with the driver, the other end of the output shaft is fixed with the locking part, the locking part is provided with a mounting hole and an assembly groove, an elastic part is mounted in the mounting hole, two ends of the elastic part extend out of the locking part and abut against the limiting column, the side wall of the limiting column is in contact with the end part of the elastic part and the outer side surface of the assembly groove, and two ends of the limiting column respectively abut against the locking part and the limiting part tightly;

the limiting part is fixed at the other end of the input shaft, and the inner wall of the limiting part is provided with assembling teeth matched with the assembling grooves, so that the limiting part and the locking part can be installed and matched, and the elastic part and the limiting column are fixed in the limiting part and the locking part to form a locking assembly;

the locking assembly is sleeved with a sleeve, and the inner wall of the sleeve is also contacted with the side wall of the limiting column.

Furthermore, the hand exoskeleton comprises a glove body, a line collecting device and a second line arranging device arranged between the line collecting device and the glove, wherein the glove body comprises a finger sleeve part, a hand back part and a palm part, the finger sleeve part, the hand back part and the palm part are connected through driving lines, and the driving lines enter the line collecting device after being arranged through the second line arranging device and are connected with the driving lines.

Furthermore, the wire collecting device comprises a shell and a rotatable wheel axle arranged in the shell, a wire through groove is formed in the rear part of the shell, a wire inlet hole is formed in one side face of the shell, a wire outlet hole is formed in the upper part of the wire inlet hole, a wire collecting hole is formed in the lower part of the wire inlet, the ends, located in the shell, of the wire inlet hole and the wire outlet hole are close to the wheel axle, and the end, located in the shell, of the wire collecting hole penetrates through the lower part of the wheel axle and is communicated with the wire through groove; the wire passing groove is detachably connected with the driving head, so that the driving wire harness is communicated with the driving wire penetrating into the wire collecting device, and the driving unit can control the hand exoskeleton to move through the driving wire tube.

The invention further designs an action intention identification method of the action auxiliary device based on the surface myoelectricity, which is characterized by comprising the following steps: the method comprises the following steps:

s1, collecting and preprocessing surface electromyographic signals;

s2, setting a system storage threshold value, and receiving and storing the processed surface electromyogram signal;

s3, when the stored surface electromyogram signal reaches a storage threshold value, extracting the surface electromyogram signal characteristic;

s4, sending the extracted surface electromyogram signal characteristics to a classifier, and performing linear discriminant analysis to obtain a classification result;

s5, sending the classification result to a voter to obtain a voting result;

s6, comparing the surface myoelectric signal characteristic threshold;

and S7, comparing the result of the voter with the result of the threshold, if the result of the voter is consistent with the result of the threshold, outputting a final movement intention result, and if the result of the voter is inconsistent with the result of the threshold, outputting a resting state result.

Further, the specific method of the pretreatment in S1 is: the collected surface electromyogram signals are input into an instrument amplifier for amplification and then sent into a band-pass filter for filtering interference sound, then the electrical signals are sent into a filtering and sampling circuit, adaptive amplification is carried out through a program adjustable amplifier, and then the electrical signals are sent into an ADC through a low-pass filter to finish pretreatment.

Further, the electrical signal characteristics in S3 are an absolute average MAV of the surface electromyogram signal and a zero crossing number ZC, where the calculation formula of the absolute average MAV of the surface electromyogram signal is:

the calculation formula of the zero crossing number ZC is as follows:

wherein N represents the number of data points of the surface electromyographic signals collected within a set time, x_iAnd the surface electromyogram signal of the ith channel is represented, and i belongs to N.

Further, the specific method for comparing the surface electromyogram signal characteristic threshold in S6 is as follows:

s61 sets thresholds TH1 and TH 2;

s62 comparing MAV with TH1, TH 2;

here, TH1 represents a stretching threshold, TH2 represents a bending threshold, and it is determined that the action intention is stretching when MAV > TH1 and bending when MAV > TH 2.

Compared with the prior art, the invention has the following advantages:

(1) the novel transmission mechanism is designed, so that the forward power and the reverse power of the motor are separated, and the stretching and bending actions of the hand are controlled respectively, so that the stretching and bending actions are realized by one motor, the utilization rate of the motor is improved, the quality of the hand action auxiliary device is reduced, a brand-new winding mode is adopted, different fingers can have different bending angles under the condition of single power input, objects in different shapes can be further gripped, the flexibility is improved, the daily wearing and the use are facilitated, the primary control on winding and unwinding of the wire harness is realized by utilizing the gear pair, and the final confirmation on the wire unwinding speed can be realized by utilizing the speed ratio between the wire winding harness and the wire unwinding harness;

(2) the rotary bidirectional self-locking mechanism is designed, large parts such as a planet wheel and a differentiator are omitted, a special locking part and a limiting part are utilized, only a corresponding structure needs to be milled by a milling cutter, the processing flow and the processing cost are simplified, and the elastic part is utilized for positioning, so that the limiting column is always in contact with the side surface of the inner wall of the sleeve and the cambered surface of the assembling groove tooth, the self-locking return clearance is eliminated, and the safety and the reliability of the self-locking mechanism are greatly improved; the stage that the motor needs to output for a long time is eliminated, so that the efficiency is improved to a greater extent, the endurance time is prolonged, meanwhile, the light weight of the battery is facilitated, and the weight of the device is further reduced;

(3) the wearing requirements of the patient can be met by selective use of the flexible exoskeleton gloves and the rigid-flexible exoskeleton gloves; the rigid-flexible exoskeleton glove is made of flexible materials, is comfortable to wear and light to use, provides rigidity required by training, facilitates shaping to adapt to different patients, and overcomes the defects of heavy weight, inconvenience in carrying and poor comfort of the conventional rehabilitation assisting exoskeleton glove;

(4) aiming at the aspect of maintenance and replacement, the invention specially designs the wire collecting device with the wire passing groove, and by utilizing the characteristic of detachable connection, the driving mechanisms of different models and the exoskeleton devices of different models can be freely assembled and paired, so that the convenience and the practicability of glove maintenance are greatly improved;

(5) the electric signal is preprocessed, low-frequency interference generated by displacement of an electrode plate and high-frequency noise coupled in by the environment are filtered, meanwhile, a classifier, a voting device and a threshold value are combined, the difficulty that the movement intention of the electric signal is identified inaccurately is overcome, the control delay of the whole system is reduced, and the movement intention of a user can be directly reflected.

Drawings

Fig. 1 is a wearing schematic diagram of a surface myoelectricity-based motion assisting device in an embodiment.

Fig. 2 is a schematic structural diagram of a driving unit in the surface myoelectricity-based motion assisting device in an embodiment.

Fig. 3 is a top view of a transmission mechanism in the surface myoelectricity-based motion assisting device in a bending state of the exoskeleton glove in a specific embodiment.

Fig. 4 is a front view of a transmission mechanism in the surface myoelectricity-based motion assisting device in a bending state of the exoskeleton glove in a specific embodiment.

Fig. 5 is a top view of the transmission mechanism of the surface myoelectricity-based motion assist device in an embodiment in a stretched state of the exoskeleton glove.

Fig. 6 is a front view of the transmission mechanism of the surface myoelectricity-based locomotion assisting device in a stretched state of the exoskeleton glove in one embodiment.

Fig. 7 is an exploded view of a rotary bidirectional self-locking mechanism in the surface myoelectricity-based motion assisting device according to an embodiment.

Fig. 8 is a top view of a locking part of a rotary bidirectional self-locking mechanism in the surface myoelectric-based motion assisting device according to an embodiment.

Fig. 9 is a side view of a line concentration device in the surface myoelectricity-based motion assistance apparatus according to an embodiment.

Fig. 10 is a sectional view of a line concentration device in the surface myoelectric-based motion assist device in an embodiment.

Fig. 11 is a front view of a concentrator of the surface myoelectricity-based motion assist device in accordance with an embodiment.

Fig. 12 is a flowchart illustrating a method for recognizing an action intention of a surface myoelectricity-based action assisting device according to an embodiment of the present invention.

Fig. 13 is a schematic diagram illustrating the processing of extracting the bio-electrical signal features in the method for recognizing the action intention of the surface myoelectric-based action assisting device according to an embodiment of the invention.

Fig. 14 is a schematic diagram illustrating a pre-processing flow of a bio-electrical signal in a method for recognizing an action intention of a surface myoelectric-based action assisting device according to an embodiment of the invention.

Detailed Description

The invention is further described with reference to the accompanying drawings, but is not to be construed as being limited thereto.

In a specific embodiment, the electrode plates are arranged on the body of a user, the surface electromyogram signals of the user are collected to be used as bioelectricity signals, 3 electrode plates are designed, wherein the No. 1 electrode plate and the No. 3 electrode plate collect the surface electromyogram signals of the user, and the No. 2 electrode plate is used as a reference motor, so that the absolute voltage of the electromyogram signals is prevented from exceeding the working range of an instrument amplifier.

Referring to fig. 1, in a specific embodiment, a hand motion assisting device based on line driving is designed, which is characterized in that: the method comprises the following steps: the hand exoskeleton device comprises a sensing unit 2, a driving unit 1, a driving line tube 3 and a hand exoskeleton 4;

referring to fig. 2, the driving unit 1 comprises a transmission mechanism 1-1, a self-locking mechanism 1-2, a control circuit board 1-3, a power supply 1-4 and a driver 1-5, the power supply 1-4 is used for providing power for the driving unit 1, the control circuit board 1-3 and the driver are used for receiving the bioelectric signals transmitted by the sensing unit 2, analyzing and transmitting instructions to the driver 1-5 to enable the driver to generate driving force, the driving force is transmitted to the hand exoskeleton 4 through the self-locking mechanism 1-2 and the transmission mechanism 1-1 to control the hand exoskeleton 4 to act, when the hand exoskeleton 4 maintains a certain position and does not move any more, the control circuit board 1-3 disconnects the power supply of the driver 1-5, and the bent shape of the hand exoskeleton 4 is locked by the self-locking mechanism 1-2, thereby achieving the effect of saving electricity;

the sensing unit 2 is used for collecting and transmitting a bioelectrical signal of a user, and comprises a signal sensor 2-1 and a signal transmission line 2-2, wherein the signal sensor 2-1 is arranged on the body of the user, and the bioelectrical signal is transmitted to the driving unit 1 by utilizing the signal transmission line 2-2;

the driving wire tube 3 is used for protecting and combing a driving wire harness and comprises a first wire arranging device arranged at one end of the driving wire harness and a driving head arranged at the other end of the driving wire harness, the driving wire harness 3 is sleeved outside the driving wire harness, the first wire arranging device is connected with the driving wire harness extending out of the driving unit 1, and the driving wire harness is led into the driving wire tube 3 and then communicated with the driving head;

the hand exoskeleton 4 is a flexible exoskeleton glove 41 or a rigid-flexible exoskeleton glove 42 and comprises a glove body, a line collecting device 4-1 and a second line arranging device arranged between the line collecting device 4-1 and the glove, wherein the glove body comprises a finger sleeve part, a hand back part and a palm part, the finger sleeve part, the hand back part and the palm part are connected through a driving line, and the driving line enters the line collecting device 4-1 and is connected with a driving line tube 3 after being arranged through the second line arranging device.

Referring to fig. 3 to 6, preferably, the transmission mechanism 1-1 includes:

the driving shaft 1-1-1 is used for providing power required by the transmission mechanism 1-1;

the driving shaft 1-1-1 is detachably arranged on the side wall of the base 1-1-2, and a one-way bearing is sleeved on the driving shaft;

the driven shaft 1-1-3 is detachably arranged on the side wall of the base 1-1-2 and is also sleeved with a one-way bearing, and the driven shaft 1-1-3 is connected with the driving shaft 1-1-1 by a gear pair and rotates along with the driving shaft 1-1-1;

the steering shafts are respectively detachably arranged on the bottom plates of the bases 1-1-2 and used for changing the direction of the driving wire harness;

the driving wire harness is wound on the one-way bearing of the driving shaft 1-1-1, the one-way bearing of the driven shaft 1-1-3 and the steering shaft, and then passes through the wire hole on the side wall of the base 1-1-2 to be connected with the hand exoskeleton 4.

As the hand exoskeleton 4 is controlled to perform two motion states of bending and stretching, the one-way bearing on the driving shaft 1-1-1 is divided into a first one-way bearing 1-1-4 and a second one-way bearing 1-1-5 in the specific embodiment; the one-way bearing on the driven shaft 1-1-3 is divided into a third one-way bearing 1-1-6 and a fourth one-way bearing 1-1-7; the steering shaft is divided into a first steering shaft 1-1-8 and a second steering shaft 1-1-9; the driving wire harness is divided into a first wire harness 1-1-10 and a second wire harness 1-1-11, and the surrounding modes of the first wire harness and the second wire harness in the transmission mechanism 1-1 are respectively as follows:

the first wire harness is wound on a first one-way bearing 1-1-4 of the driving shaft 1-1-1, a third one-way bearing 1-1-6 of the driven shaft 1-1-3 and a first steering shaft 1-1-8 and then passes through a first wire hole in the side wall of the base 1-1-2 to be connected with the hand exoskeleton 4;

the second wire harness is wound on a second one-way bearing 1-1-5 of the driving shaft 1-1-1, a fourth one-way bearing 1-1-7 of the driven shaft 1-1-3 and a second steering shaft 1-1-9 and then passes through a second wire hole in the side wall of the base 1-1-2 to be connected with the hand exoskeleton 4.

The gear pair comprises a driving gear 1-1-12 and a driven gear 1-1-13, wherein the driving gear 1-1-12 is sleeved on the driving shaft 1-1-1, and the driven gear 1-1-13 is sleeved on the driven shaft 1-1-3.

In the specific embodiment, the transmission mechanism further comprises pressing shafts 1-1-14, wherein the pressing shafts 1-1-14 are positioned on the upper side and the lower side of the driven shaft 1-1-3, so that the wiring harness is close to a one-way bearing on the driven shaft 1-1-3, and the outgoing line is reliable.

When the device is installed, the driving shaft 1-1-1 is detachably installed on the side wall of the base 1-1-2, one end of the driving shaft penetrates through the side wall of one side of the base 1-1-2 to be connected with an external power source, and the other end of the driving shaft is sleeved with a driving gear 1-1-12 of a gear pair.

The driven shaft 1-1-3 is also detachably arranged on the side wall of the base 1-1-2 and is positioned beside the driving shaft 1-1-1, the driven shaft 1-1-3 is provided with a driven gear 1-1-13 of a gear pair, and the driven gear 1-1-13 is meshed with the driving gear 1-1-12, so that the driven shaft 1-1-3 is driven to rotate along with the driving shaft 1-1-1.

Preferably, the steering shafts are detachably mounted on the bottom plates of the bases 1-1-2, respectively, that is, the bottom ends of the steering shafts are fixed with the bottom plates of the bases.

The driving shafts of the two strands of wire harnesses for controlling bending and stretching of the hand exoskeleton 4 are controlled by a single motor, the clutch effect of the one-way bearing is utilized to realize time-sharing independent control of the revolving and winding-up of the two strands of wire harnesses, and when one strand of wire harness acts, the revolving and winding-up of the other strand of wire harness is not influenced; and the rotation of the driving shaft and the driven shaft can be simultaneously driven by a single motor through the matching of the gear pair.

Changing the direction of the driving wire harness by using a steering shaft according to the direction requirement of the hand exoskeleton on the driving wire harness; according to the design schemes of the hand exoskeleton for the ratio of the winding and unwinding speeds of the two wire harnesses, the requirements of wearing personnel are different, the power source drives the driving shaft 1-1-1 to rotate actively, the driven shaft 1-1-3 moves along with the driving shaft to drive the wire harnesses to perform winding and unwinding movements, and the speed is controlled by the hand exoskeleton 4 but not higher than a certain value.

The winding and the paying-off of the wire harness corresponding to the bending and the stretching of the two different actions of the hand exoskeleton 4 are completely opposite, and the speed ratio is kept consistent.

Referring to fig. 3 and 4, an embodiment of a small range adaptive take-up and pay-off line ratio transmission mechanism in a curved state of the hand exoskeleton is shown.

The bending of the hand exoskeleton requires the first strand 1-1-10 to be fed around the drive shaft 1-1-1 at a rate of A1, and the second strand 1-1-11 to be fed around the drive shaft 1-1-1 at a rate of A2, A2 is not more than A1.

The method specifically comprises the following steps: the motor rotates to ensure that the first wiring harness 1-1-10 is fed at the speed of A1, and the retraction and release rate of the second wiring harness 1-1-11 are not influenced due to the existence of the first one-way bearing 1-1-4 and the second one-way bearing 1-1-5 on the driving shaft 1-1-1; the motor rotates, and the fixed speed reverse rotation of the driven shaft 1-1-3 relative to the driving shaft 1-1-1 is realized through the transmission of a gear pair between the driving shaft 1-1-1 and the driven shaft 1-1-3; due to the existence of the third one-way bearing 1-1-6 and the fourth one-way bearing 1-1-7 on the driven shaft 1-1-3, the incoming line of the first wiring harness 1-1-10 is not influenced by the rotation of the driven shaft 1-1-3; a first wire harness 1-1-10 is transmitted out of the transmission mechanism through a first steering shaft 1-1-8 to be connected with the hand exoskeleton and control the hand exoskeleton to bend at a fixed speed.

The bending of the hand exoskeleton drives the second wire harness 11 to be led out at a speed A2, the driven shaft 3 and the driving shaft 1 are forced to be led out at a speed A2 through the second steering shaft 9, and the pressing shaft 14 ensures the reliability of the led-out.

Referring to fig. 5 and 6, an embodiment of a small-range adaptive take-up and pay-off line ratio transmission mechanism in a hand exoskeleton extended state is shown.

The stretching of the hand exoskeleton requires that the second wire harness 1-1-11 is fed in around the driving shaft 1-1-1 at the speed of B1, the first wire harness 1-1-10 is then fed out around the driving shaft 1-1-1 at the speed of B2, and B1 is more than or equal to B2.

The method specifically comprises the following steps: the motor rotates to ensure that the second wiring harness 1-1-11 is fed at a speed B1, and the retraction and release speed of the first wiring harness 1-1-10 are not influenced due to the existence of the one-way bearing on the driving shaft 1-1-1; the driven shaft 1-1-3 rotates reversely relative to the driving shaft 1-1-1 at a fixed speed; due to the existence of the one-way bearing on the driven shaft 1-1-3, the incoming line of the second wiring harness 1-1-11 is not influenced by the rotation of the driven shaft; and a second wiring harness 1-1-11 is connected with the hand exoskeleton through a second steering shaft 1-1-9 and the transmission mechanism to control the hand exoskeleton to stretch at a fixed speed.

The stretching of the hand exoskeleton drives the first wiring harness 1-1-10 to output at a speed B2, the driven shaft 1-1-3 and the driving shaft 1-1-1 are forced to output at a speed B2 through the first steering shaft 1-1-8, and the reliability of the output is ensured by pressing the shaft 1-1-14.

In conclusion, the transmission mechanism 1-1 of the invention only uses one power source, and the unidirectional bearing is arranged and installed, when the wire harness moves around the unidirectional bearing, the self-adaptive control of the speed ratio between the wire take-up beam and the wire release beam required by the hand exoskeleton is realized, and the transmission mechanism 1-1 is flexible control, and the adopted wire harness is also a flexible component, thereby reducing the volume of the transmission mechanism, and being easy to carry and wear.

Referring to fig. 7, preferably, the self-locking mechanism 1-2 of the present invention is a rotary bidirectional self-locking mechanism, one end of the output shaft 1-2-1 is a shaft hole, wherein a thread is turned on the shaft hole for connecting with the transmission mechanism 1-1, the other end of the output shaft 1-2-1 is milled to form a locking component 1-2-3 by a milling cutter for matching with the input shaft, meanwhile, the locking component 1-2-3 is provided with a mounting hole 1-2-3-1 and an assembly groove 1-2-3-2, an elastic component 1-2-4 is mounted in the mounting hole 1-2-3-1, and has a contact self-locking function, two ends of the elastic component 1-2-4 extend out of the locking component 1-2-3 and then abut against the limiting column 1-2-5, the side wall of the limiting column 1-2-5 is in contact with the end part of the elastic component 1-2-4 and the outer side surface of the assembling groove 1-2-3-2, the two ends of the limiting column 1-2-5 are respectively and tightly abutted against the locking component 1-2-3 and the limiting component 1-2-6, so that the locking effect is achieved, and meanwhile, when the transmission mechanism 1-1 has the tendency of reversely driving the output shaft, the locking effect can be immediately achieved.

One end of the input shaft 1-2-2 is also provided with a shaft hole, the shaft hole is also threaded and is used for connecting with a driver such as a motor and the like, the other end of the input shaft 1-2-2 is also milled with a milling cutter to form a limiting part 1-2-6, the inner wall of the limiting part 1-2-6 is provided with assembling teeth 1-2-6-1 matched with the assembling grooves 1-2-3-2, so that the limiting part 1-2-6 and the locking part 1-2-3 can be installed and matched, namely the assembling teeth 1-2-6-1 and the assembling grooves 1-2-3-2 are installed in a matched manner, and the connecting shaft 1-2-6-2 and the connecting shaft hole 1-2-3-5 are installed in a matched manner, thereby fixing the elastic part 1-2-4 and the limiting column 1-2-5 inside the two to form a locking assembly.

The sleeve 1-2-7 is sleeved outside the locking assembly, and the inner wall of the sleeve 1-2-7 is also contacted with the side wall of the limiting column 1-2-5.

The self-locking mechanism can finally realize the function that one side of the input shaft 1-2-2 can actively and freely rotate forwards and backwards, and once one side of the output shaft 1-2-1 and the input shaft 1-2-2 have a reverse rotation trend, the output shaft can be locked and cannot rotate.

Referring to fig. 8, preferably, the locking member 1-2-3 is an integral part with the output shaft 1-2-1, preventing the locking member 1-2-3 from being disengaged from the output shaft 1-2-1 during rotation, resulting in ineffective locking. The locking component 1-2-3 is provided with an assembly groove tooth 1-2-3-3, one side surface of the assembly groove tooth 1-2-3-3 is a plane, the other side surface is an arc surface, and the planes of the two assembly groove teeth 1-2-3-3 are oppositely arranged to form the assembly groove 1-2-3-2.

Preferably, the locking part 1-2-3 is further provided with an installation wing 1-2-3-4, the installation wing 1-2-3-4 is located on the outer side of the cambered surface of the assembly tooth 1-2-6-1, the installation wing 1-2-3-4 and the assembly tooth are integrally designed, and the installation wing 1-2-3-4 is provided with a longitudinal through hole, namely the installation hole 1-2-3-1.

Referring to fig. 7, in the specific embodiment, 2 assembling grooves, 2 assembling wings, 2 assembling teeth are designed, 2 springs are used as elastic components, and 4 limiting columns are used to form the rotary bidirectional self-locking mechanism designed by the invention.

Of course, in the specific implementation, according to different required conditions, different numbers of the assembling grooves 1-2-3-2, the assembling teeth 1-2-6-1 and the mounting wings 1-2-3-4 can be used, but it should be noted that the numbers of the three parts must be the same, otherwise, the purpose of corresponding matching self-locking cannot be achieved, and at the same time, the numbers of the three parts are at least 2, and if the numbers of the three parts are less than 2, the self-locking effect is extremely poor, and the mechanical requirement cannot be met.

Correspondingly, the number of the limiting columns 1-2-5 is 2 times of that of the elastic parts 1-2-4, and the limiting columns 1-2-5 are designed at two ends of each elastic part to prevent the elastic parts 1-2-4 from falling out of the mounting holes 1-2-3-1.

In the process of layout, in order to meet the requirements of mechanical aesthetics and load balance, the number of the assembly grooves 1-2-3-2, the assembly teeth 1-2-6-1 and the mounting wings 1-2-3-4 are rotationally symmetrical, and the symmetrical center is the central point of corresponding parts, namely the locking mechanism and the limiting mechanism.

Likewise, the skilled person can choose to use the appropriate elastic members 1-2-4 according to the needs of the real situation.

In the specific implementation, a rotary bidirectional self-locking mechanism as shown in fig. 7 is adopted, and for convenience of expression, the 4 limiting posts are respectively numbered A, B, C, D.

When the input shaft 1-2-2 rotates clockwise for a certain angle, the limiting surface on the limiting part 1-2-6 pushes the limiting column A and the limiting column C to move relative to the output shaft 1-2-1, so that the limiting column A and the limiting column C are separated from the inner wall of the sleeve 1-2-7, namely the limiting column A and the limiting column C are not in contact with the inner wall of the sleeve 1-2-7, then the side surface of the assembling tooth 1-2-6-1 on the limiting part 1-2-6 is in contact with the side surface of the assembling groove 1-2-3-2 of the locking part 1-2-3, and the output shaft 1-2-1 starts to be pushed to rotate clockwise.

When the input shaft 1-2-2 stops rotating clockwise and no longer provides torque, the output shaft 1-2-1 has a tendency of counterclockwise rotation, namely a rebound tendency, due to the action of load force, at the moment, the limit column B is in a space formed by the cambered surface of the assembly groove teeth 1-2-3-3 and the inner wall of the sleeve 1-2-7, the pressure angle is about 5-10 degrees and smaller than a friction angle, so that the limit column B can only roll in the space but can not slide, and due to the fact that the limit column B rolls, the cambered surface of the assembly groove teeth 1-2-3-3 and the inner wall of the sleeve 1-2-7 can relatively move, and the distance between the limit column B and a tangent point between the limit column B is reduced due to the movement, the limit column B is pressed, so that the limit column B can not roll, therefore, the arc surfaces of the assembling groove teeth 1-2-3-3 and the inner walls of the sleeves 1-2-7 are prevented from moving relatively, in the same way, the limiting column D can also prevent the arc surfaces of the assembling groove teeth 1-2-3-3 and the inner walls of the sleeves 1-2-7 from moving relatively, and because the sleeves 1-2-7 are fixed, the output shaft 1-2-1 where the arc surfaces of the assembling groove teeth 1-2-3-3 are located cannot move, so that a self-locking effect is generated.

Similarly, when the input shaft 1-2-2 rotates anticlockwise, the limiting column B and the limiting column D are pushed away to be unlocked, and then the output shaft 1-2-1 is driven to rotate anticlockwise.

When the input shaft 1-2-2 stops rotating anticlockwise and no torque is supplied any more, the output shaft 1-2-1 has a tendency of rotating clockwise, and the limiting columns A and C are located in a space formed by the arc surface of the assembling groove teeth 1-2-3-3 and the inner wall of the sleeve 1-2-7, and the locking effect is achieved through the same principle and process.

According to the self-locking mechanism, one side of the input shaft can actively and freely rotate forwards and backwards, one side of the output shaft can be locked and cannot rotate once the input shaft and the output shaft have a reverse rotation trend, a real-time self-locking function is kept, meanwhile, the limiting column can be always kept in contact with the sleeve due to the spring, a self-locking return clearance is eliminated, the real-time self-locking function of the mechanism is obviously improved, the self-locking mechanism is more stable and reliable, the self-locking mechanism is simple in structure, low in cost and suitable for large-scale popularization of products, small in size and beneficial to miniaturization of the mechanism, and particularly has a wide application field in the aspect of small and miniature products.

Referring to fig. 9 to 11, preferably, the wire collecting device 4-1 includes a housing 4-1-1 and a rotatable wheel axle 4-1-2 arranged inside the housing 4-1-1, a wire passing groove 4-1-3 is formed at the rear portion of the housing 4-1-1, a wire inlet 4-1-4 is formed at one side surface of the housing 4-1-1, a wire outlet 4-1-5 is formed at the upper portion of the wire inlet 4-1-4, a wire collecting hole 4-1-6 is formed at the lower portion of the wire inlet, the wire inlet 4-1-4 and the wire outlet 4-1-5 are both close to the wheel axle 4-1-2 at one end inside the housing 4-1-1, and the wire collecting hole 4-1-6 is located at one end inside the housing 4-1-1 The lower part of the wheel shaft 4-1-2 is communicated with the through wire groove 4-1-3; the wire passing grooves 4-1-3 are detachably connected with the driving head, so that the driving wire harness is communicated with the driving wires penetrating into the wire collecting device 4-1, and the driving unit 1 can control the hand exoskeleton 4 to move through the driving wire tube 3.

In a specific embodiment, the invention further designs an action intention identification method of the action assisting device based on the surface myoelectricity, and the specific flow is shown in fig. 12.

Referring to fig. 14, after the surface electromyogram signals are collected, the surface electromyogram signals are input into an instrument amplifier, the surface electromyogram signals are amplified by 500 times and then sent into a band-pass filter of 10-500 Hz, so that low-frequency interference generated by displacement of electrode plates and high-frequency noise coupled by the environment are filtered, and then the electric signals are sent into a filtering and sampling circuit. The circuit is an analog-digital mixed circuit, wherein interference sources such as a crystal oscillator, an MCU (microprogrammed control unit), an electrode driver and the like can be integrated, in addition, the universality of the electromyographic sensor is reduced due to the difference of the strength of the electromyographic signals of users, so a program adjustable amplifier is added, the program can automatically adjust the circuit to a proper amplification factor for different users, and then the circuit is sent to an ADC (analog-to-digital converter) through a low-pass filter to complete the pretreatment.

And the ADC receives the preprocessed electromyographic signals uninterruptedly and sends the electromyographic signals into the electric signal storage module.

Setting the storage threshold value of the electric signal storage module to be 128, and after the storage of 128 electromyographic signals, carrying out feature extraction, namely extracting the absolute average value MAV and the number ZC of zero-crossing points of the surface electromyographic signals, wherein the formula is

In order to ensure real-time performance and recognition rate, the data processing window length in the system is 256 data points, and the sliding window length is 128 data points. At a 1860Hz sampling rate, the delay time for processing is 68.8ms, which is less than the acceptable delay time of 300 ms. Since two myoelectric channels, namely the No. 1 electrode slice and the No. 3 electrode slice, are designed in this embodiment, when 128 data points are obtained in each channel, the data are merged with the previous 128 data points, and features are extracted, that is, the window length is 256 data points, and the sliding window length is 128 data points. The specific processing procedure can be seen in fig. 13.

And then sending the extracted MAV and ZC into an LDA classifier to perform linear discriminant analysis, sending the analysis result into a voter to vote, inputting the result with the most votes into a motion intention judgment module, and simultaneously directly sending the extracted MAV into a threshold comparison unit of the motion intention judgment module to perform threshold comparison.

The specific method for comparing the threshold value comprises the following steps: firstly, setting thresholds TH1 and TH2 in a movement intention judging module, wherein TH1 represents an extension threshold, TH2 represents a bending threshold, and secondly, comparing the absolute average value of the calculated surface electromyogram signal with TH1 and TH 2; the action intention is judged to be a stretching motion when MAV > TH1, and judged to be a bending motion when MAV > TH 2.

And finally, two results are obtained in a judging unit of the motion intention judging module, wherein one result is a voting result of the voter, the other result is a threshold value comparison result, the two results are compared, if the two results are the same, an identification result is output, and if the two results are different, a resting state result is output.

It will be understood by those skilled in the art that all or part of the processes of the methods of the above embodiments may be implemented by hardware related to computer program instructions, and the program may be stored in a computer readable storage medium, for example, in the storage medium of a computer system, and executed by at least one processor in the computer system, so as to implement the processes of the embodiments including the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description is specific and detailed, but it should not be understood as the limitation of the scope of the present invention, it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the concept of the present invention, and these all fall into the protection scope of the present invention.

Claims

1. Action auxiliary device based on surface flesh electricity, its characterized in that: comprises a sensing unit (2), a driving unit (1), a driving line pipe (3) and a hand exoskeleton (4);

the sensing unit (2) is used for collecting and transmitting surface electromyogram signals of a user and comprises a signal sensor (2-1) and a signal transmission line (2-2), the signal sensor (2-1) is arranged on the body of the user, the surface electromyogram signals are transmitted to the driving unit (1) through the signal transmission line (2-2), the driving unit (1) analyzes and processes the surface electromyogram signals, generated driving force is transmitted to the hand exoskeleton (4), and the hand exoskeleton (4) is controlled to act;

the hand exoskeleton (4) is a line-driven hand exoskeleton and comprises flexible exoskeleton gloves (41) or rigid-flexible exoskeleton gloves (42); the driving unit (1) comprises a transmission mechanism (1-1), a self-locking mechanism (1-2), a control circuit board (1-3), a power supply (1-4) and a driver (1-5), wherein the self-locking mechanism (1-2) is a rotary bidirectional self-locking mechanism, the power supply (1-4) is used for supplying power to the driving unit (1), the control circuit board (1-3) is used for receiving surface myoelectric signals transmitted by the sensing unit (2), analyzing and transmitting instructions to the driver (1-5) to enable the driver to generate driving force, and the driving force is transmitted to the hand exoskeleton (4) through the self-locking mechanism (1-2) and the transmission mechanism (1-1) to control the hand exoskeleton (4) to act;

the self-locking mechanism (1-2) comprises an output shaft (1-2-1) and an input shaft (1-2-2), one end of the output shaft (1-2-1) is connected with the transmission mechanism (1-1), one end of the input shaft (1-2-2) is connected with the driver (1-5), the other end of the output shaft (1-2-1) is fixed with the locking component (1-2-3), the locking component (1-2-3) is provided with a mounting hole (1-2-3-1) and an assembling groove (1-2-3-2), an elastic component (1-2-4) is mounted in the mounting hole (1-2-3-1), and two ends of the elastic component (1-2-4) extend out of the locking component (1-2-3) The side wall of the limiting column (1-2-5) is contacted with the end part of the elastic component (1-2-4) and the outer side surface of the assembling groove (1-2-3-2), and the two ends of the limiting column (1-2-5) are respectively tightly contacted with the locking component (1-2-3) and the limiting component (1-2-6);

the limiting component (1-2-6) is fixed at the other end of the input shaft (1-2-2), the inner wall of the limiting component (1-2-6) is provided with an assembling tooth (1-2-6-1) matched with the assembling groove (1-2-3-2), so that the limiting component (1-2-6) and the locking component (1-2-3) can be installed and matched, and the elastic component (1-2-4) and the limiting column (1-2-5) are fixed in the limiting component (1-2-4) and the locking column (1-2-5) to form a locking assembly;

the locking assembly is sleeved with a sleeve (1-2-7), and the inner wall of the sleeve (1-2-7) is also contacted with the side wall of the limiting column (1-2-5).

2. A surface myoelectricity-based action assisting device according to claim 1 characterised in that: drive spool (3) for the protection combs the drive pencil, including setting up at the reason line ware one of its one end and setting up the drive head at the other end, drive spool (3) cover is established at the drive pencil outside, reason line ware one links to each other with the drive pencil that drive unit (1) stretches out, with drive pencil leading-in drive spool (3) back and drive head intercommunication.

3. The surface myoelectricity-based motion assist device according to claim 1, characterized in that: the transmission mechanism (1-1) comprises:

the driving shaft (1-1-1) is used for providing power required by the transmission mechanism (1-1);

the driving shaft (1-1-1) is detachably arranged on the side wall of the base (1-1-2), and a one-way bearing is sleeved on the driving shaft and is divided into a first one-way bearing 1-1-4 and a second one-way bearing 1-1-5;

the driven shaft (1-1-3) is detachably mounted on the side wall of the base (1-1-2), a one-way bearing is sleeved on the driven shaft, the one-way bearing is divided into a third one-way bearing (1-1-6) and a fourth one-way bearing (1-1-7), and the driven shaft (1-1-3) is connected with the driving shaft (1-1-1) through a gear pair and rotates along with the driving shaft (1-1-1);

the steering shaft is divided into a first steering shaft (1-1-8) and a second steering shaft (1-1-9), which are respectively and detachably arranged on the bottom plate of the base (1-1-2) and used for changing the direction of the driving wire harness;

the driving wire harness is divided into a first wire harness (1-1-10) and a second wire harness (1-1-11) in a winding way;

the first wire harness is wound on the first one-way bearing (1-1-4) of the driving shaft (1-1-1), the third one-way bearing (1-1-6) of the driven shaft (1-1-3) and the first steering shaft (1-1-8), and then passes through a first wire hole in the side wall of the base (1-1-2) to be connected with the hand exoskeleton (4); the second wire harness is wound on the second one-way bearing (1-1-5) of the driving shaft (1-1-1), the fourth one-way bearing (1-1-7) of the driven shaft (1-1-3) and the second steering shaft (1-1-9), and then penetrates through a second wire hole in the side wall of the base (1-1-2) to be connected with the hand exoskeleton (4).

4. The surface myoelectricity-based motion assist device according to claim 3, characterized in that: the gear pair comprises a driving gear (1-1-12) and a driven gear (1-1-13), the driving gear (1-1-12) is sleeved on the driving shaft (1-1-1), and the driven gear (1-1-13) is sleeved on the driven shaft (1-1-3).

5. The surface myoelectricity-based motion assist device according to claim 3, characterized in that: the transmission mechanism further comprises pressing shafts (1-1-14), wherein the pressing shafts (1-1-14) are located on the upper side and the lower side of the driven shaft (1-1-3), so that the wire harness is close to the one-way bearing on the driven shaft (1-1-3), and the wire outlet is reliable.

6. The surface myoelectricity-based motion assist device according to claim 1, characterized in that: the hand exoskeleton (4) comprises a glove body, a line collecting device (4-1) and a line arranging device II arranged between the line collecting device (4-1) and the glove, wherein the glove body comprises a finger sleeve part, a hand back part and a palm part, the finger sleeve part, the hand back part and the palm part are connected through a driving line, and the driving line enters the line collecting device (4-1) and is connected with a driving line pipe (3) after being arranged through the line arranging device II.

7. The surface myoelectricity-based motion assist device according to claim 6, characterized in that: the wire collecting device (4-1) comprises a shell (4-1-1) and a rotatable wheel axle (4-1-2) arranged in the shell (4-1-1), a wire passing groove (4-1-3) is formed in the rear portion of the shell (4-1-1), a wire inlet hole (4-1-4) is formed in one side face of the shell (4-1-1), a wire outlet hole (4-1-5) is formed in the upper portion of the wire inlet hole (4-1-4), a wire collecting hole (4-1-6) is formed in the lower portion of the wire inlet hole, one end, located in the shell (4-1-1), of each wire inlet hole (4-1-4) and each wire outlet hole (4-1-5) is close to the wheel axle (4-1-2), one end of the line collecting hole (4-1-6) positioned in the shell (4-1-1) penetrates through the lower part of the wheel shaft (4-1-2) and is communicated with the line passing groove (4-1-3); the wire passing groove (4-1-3) is detachably connected with the driving head, so that the driving wire harness is communicated with the driving wire penetrating into the wire collecting device (4-1), and the driving unit (1) can control the hand exoskeleton (4) to move through the driving wire pipe (3).

8. The method for recognizing the action intention of the surface myoelectricity-based action assisting device according to claim 1, wherein: the method comprises the following steps:

s1, collecting and preprocessing surface electromyographic signals;

s5, sending the classification result to a voter to obtain a voting result;

s6, comparing the surface myoelectric signal characteristic threshold;

and S7, comparing the result of the voter with the threshold value comparison result, if the result of the voter is consistent with the threshold value comparison result, outputting the final movement intention result, and if the result of the voter is inconsistent with the threshold value comparison result, outputting the rest state result.

9. The method for recognizing the action intention of the surface myoelectricity-based action assisting device according to claim 8, wherein: the specific method of the pretreatment described in S1 is: the collected surface electromyogram signals are input into an instrument amplifier for amplification and then sent into a band-pass filter for filtering interference signals, then the electrical signals are sent into a filtering and sampling circuit, adaptive amplification is carried out through a program adjustable amplifier, and then the electrical signals are sent into an ADC through a low-pass filter to complete pretreatment.

10. The method for recognizing the action intention of the surface myoelectricity-based action assisting device according to claim 8, wherein: the electrical signal characteristics in S3 are the absolute average MAV of the surface electromyogram signal and the number ZC of zero-crossing points, where the calculation formula of the absolute average MAV of the surface electromyogram signal is:

the calculation formula of the zero crossing number ZC is as follows:

wherein, N represents the data point number of the surface electromyogram signal collected in the set time, xi represents the surface electromyogram signal of the ith channel, and i belongs to N.

11. The method for recognizing the action intention of the surface myoelectricity-based action assisting device according to claim 8, wherein: the specific method for comparing the surface electromyogram signal characteristic threshold in S6 is as follows:

s61 sets thresholds TH1 and TH 2;

s62 comparing MAV with TH1, TH 2;

here, TH1 represents a stretching threshold, TH2 represents a bending threshold, and when MAV > TH1, it is determined that the action intention is stretching, and when MAV > TH2, it is determined that the action intention is bending.