Dexterous hand structure driven by sensing function integrated artificial muscle belt and application of dexterous hand structure

Abstract

The invention discloses a dexterous hand structure driven by a sensing function integrated artificial muscle belt and application of the dexterous hand structure. The dexterous hand structure comprises a dexterous hand skeleton and n first driving elements, each first driving element comprises a first artificial muscle belt with a sensing structure, the first artificial muscle belts are attached to the palm sides of the bionic fingers, one end of each first artificial muscle belt is connected with the fingertip part of one bionic finger, and the other end of each first artificial muscle belt is connected with the bionic palm; the sensing structures are arranged on the fingertip portion or the portion, close to the fingertip portion, of the first artificial muscle belt, the first driving element is used for driving the bionic fingers connected with the first driving element to be converted into the bent state from the initial state, and the n sensing structures can measure the shape and size of a grabbed object. The artificial muscle drivers with the sensing function are designed and arranged on the surface of the dexterous hand, flexible movement of each knuckle can be achieved, different gesture actions are made, and the object grabbing and recognizing functions are completed.

Description

TECHNICAL FIELD

[0001] The present application particularly relates to a dexterous hand structure driven by artificial muscle belt and its application, and belongs to the technical field of humanoid robots. BACKGROUND

[0002] Since the birth of humanoid robots, they have been the focus of social attention, and their development represents the continuous breakthroughs of human advanced technology. As an indispensable role in society, humanoid robots have been widely used in various industries, including but not limited to advanced manufacturing, intelligent interaction, and space exploration. Among them, dexterous hands, as an important unit and key component of humanoid robots, their technological progress directly determines the depth of application of humanoid robots in industries, services, medical care, etc., and also becomes the core engine to promote embodied intelligence and robot commercialization.

[0003] Currently, as the core executive component for achieving fine operation in the field of robots, the driving mode of dexterous hands mainly adopts motor direct drive, tendon transmission combined with motor, tendon and screw hybrid drive, etc. However, there are problems such as complex structure, poor flexibility, heavy weight, high energy consumption, high cost, etc. The motor direct drive mode is to integrate the motor directly at the finger joint, and use the rotary motion of the motor to directly drive the joint to rotate. Although this mode can achieve high control accuracy, in order to match the size and movement demand of the finger, it often needs to customize small-sized motors, which not only increases the design difficulty, but also leads to the overall structure of the finger being bloated, the weight being significantly increased, and further affecting the flexible control of the dexterous hand; at the same time, the motor direct drive requires high power transmission efficiency, has high energy consumption during continuous operation, limited gripping force, and the price of customized small-sized hollow cup motors is very expensive. The tendon transmission combined with motor mode is to use the motor as the power source, and transmit the power to the finger joint through the tendon (such as metal wire, high-strength polymer fiber rope, etc.) to realize the flexion and extension movement of the joint. Although this mode arranges the motor at the arm part to a certain extent, it reduces the weight of the dexterous hand, but the tension adjustment of the tendon is difficult, and long-term use may cause relaxation, creep or wear, resulting in a decrease in transmission accuracy and affecting the motion consistency of the dexterous hand; in addition, in order to realize the coordinated movement of multiple joints, multiple motors need to be equipped to cooperate with the tendon, making the overall transmission system structure complex, increasing the assembly and maintenance cost, and the higher the degree of freedom required, the higher the difficulty and cost. The tendon and screw hybrid drive mode combines the flexibility of tendon transmission and the high load capacity of screw transmission, which usually generates linear motion by driving the screw with the motor, and then transmits the force to the joint through the tendon. However, this hybrid structure needs to coordinate the linear displacement of the screw and the tension transmission of the tendon, increasing the complexity of the control system; and the mechanical cooperation of the screw and the tendon requires strict processing precision of the parts, which needs to be customized, further increasing the manufacturing cost, and the additional transmission components also continuously increase the overall weight and energy consumption of the dexterous hand.

[0004] In addition, the current dexterous hand integrated sensing sensor is still mainly rigid sensor. Although such rigid sensor has high sensing accuracy and can accurately capture various physical signals, it also has obvious disadvantages: firstly, it further increases the weight and structural complexity of the dexterous hand, and increases the burden of the driving system; secondly, its hard characteristics make the surface of the dexterous hand show a cold mechanical texture, lack the flexibility and warm touch of human skin, and it is difficult to realize the truly humanized interaction. In contrast, the dexterous hand using flexible sensor has more advantages in weight control, and has relatively small influence on the overall weight, but its application also faces challenges. In order to realize multi-dimensional and high-precision sensing function, it is often necessary to arrange multiple flexible sensing units on the surface of the dexterous hand, which still increases the number of devices and the complexity of wiring, and increases the overall structural complexity of the dexterous hand. Therefore, how to use the integrated device of artificial muscle and artificial electronic skin to make the dexterous hand realize the fusion of driving and sensing functions, and promote its development towards truly humanized direction, is still a technical problem to be solved urgently. SUMMARY

[0005] The main purpose of the present application is to provide a dexterous hand structure with sensing function integrated artificial muscle belt driving and its application, so as to overcome the shortcomings of the prior art.

[0006] In order to achieve the above-mentioned purpose of the application, the technical scheme adopted by the present application comprises: The first aspect of the embodiment of the present application provides a dexterous hand structure with sensing function integrated artificial muscle belt driving, which comprises a dexterous hand skeleton and a first driving mechanism, the dexterous hand skeleton comprises a bionic palm and m bionic fingers which are movably connected with the bionic palm and have multiple bending degrees of freedom, the first driving mechanism comprises n first driving elements, the first driving element comprises a first artificial muscle belt with a sensing structure, the first artificial muscle belt is attached to the palm side of the bionic finger, one end of each first artificial muscle belt is connected with the fingertip part of the bionic finger, and the other end is connected with the bionic palm, the sensing structure is arranged on the part of the first artificial muscle belt located at or close to the fingertip part, the first driving element is used to drive the bionic finger connected therewith to transform from an initial state to a bending state, n sensing structures can measure the shape and size of the grasped object, and n≥m≥1.

[0007] Further, the first artificial muscle belt is conductive, each first artificial muscle belt is connected in series in a first conductive circuit, and the first artificial muscle belt can occur expansion and deformation under Joule heat stimulation.

[0008] Further, the n first conductive circuits are independently operated.

[0009] Further, the bionic finger has x joints, the bionic finger can bend around the joints, the first artificial muscle band is close to the joints, or the first artificial muscle band is connected with the joints, x≥1.

[0010] Further, the first artificial muscle band is bound on the bionic finger by a binding piece, and the binding piece is arranged at the joints.

[0011] Further, the binding piece includes a rubber ring, cotton thread or metal wire.

[0012] Further, the sensing structure includes a low-modulus flexible film-shaped pressure sensor or a more sensitive micro-column array-based pressure sensor arranged on the first artificial muscle band.

[0013] In a more specific embodiment, the first driving mechanism further includes n second driving elements, the second driving elements are arranged on the back of the bionic finger, one end of each second driving element is connected with a fingertip of the bionic finger, and the other end is connected with the bionic palm, and the second driving element is used to drive the bionic finger connected therewith to recover from the bent state to the initial state.

[0014] Further, each second driving element is also connected with a first driving element to form an antagonistic driving structure.

[0015] Further, the second driving element is an elastic mechanical element or a second artificial muscle band.

[0016] Further, the second artificial muscle band is conductive, each second artificial muscle band is connected in series in a second conductive circuit, and the second artificial muscle band can be deformed in extension and contraction under the stimulation of Joule heat.

[0017] Further, the n second conductive circuits are independently operated.

[0018] Further, the elastic mechanical element includes a flexible elastic element or a rigid elastic element.

[0019] Further, the flexible elastic element includes an elastic band, and the rigid elastic element includes a spring.

[0020] The second aspect of the embodiment of the present application provides an upper limb of a humanoid robot, including a bionic arm and a bionic hand, and the bionic hand adopts a dexterous hand structure driven by an artificial muscle band with sensing functions.

[0021] Further, the bionic arm comprises a large arm, a small arm and a second driving mechanism, the large arm is movably connected with the small arm, and the second driving mechanism is connected with the large arm and the small arm respectively and used for driving the small arm to make flexion and extension movement relative to the large arm.

[0022] Further, the second driving mechanism comprises a spindle-shaped artificial muscle or an artificial muscle bundle.

[0023] Further, the spindle-shaped artificial muscle or the artificial muscle bundle is conductive, the spindle-shaped artificial muscle or the artificial muscle bundle is connected in series into a third conductive circuit, and the spindle-shaped artificial muscle or the artificial muscle bundle can be deformed in extension and contraction under Joule heat stimulation.

[0024] Further, the spindle-shaped artificial muscle comprises a support frame and a plurality of third artificial muscle belts, the radial section area of the two end portions of the support frame is smaller than the radial section area of the middle portion, the plurality of third artificial muscle belts are attached to the surface of the support frame, the two ends of each third artificial muscle belt are fixedly connected with the two end portions of the support frame respectively, and the whole third artificial muscle belt presents a spindle-shaped structure.

[0025] Further, the support frame comprises a support rod, a first support disc and two second support discs, the two second support discs are fixedly arranged on the two sides of the first support disc along the axial direction of the support rod, the diameter of the second support disc is smaller than that of the first support disc, and the plurality of third artificial muscle belts are sequentially arranged along the circumferential direction of the first support disc or the second support disc, and each third artificial muscle belt is fixedly connected with the two end portions of the support rod.

[0026] Further, the first support disc and the two second support discs are arranged at equal intervals.

[0027] The third aspect of the embodiment of the present application provides a humanoid robot, and the humanoid robot has the perception function set artificial muscle belt driven dexterous hand structure or upper limbs of the humanoid robot.

[0028] Compared with the prior art, the present application has the following advantages: The present application provides a dexterous hand structure completely assembled by flexible perception-driving integrated devices by arranging artificial muscle drivers with perception function on the surface of the dexterous hand, which can realize flexible movement of each finger joint, make different gesture actions, complete object grasping and recognition functions, and the dexterous hand has the flexibility and soft touch of human skin, and no longer presents the cold mechanical texture.

[0029] The full-flexible driving unit driven humanoid robot dexterous hand provided by the embodiment of the present application has simple structure, high dexterity, light weight and low price; and the full-flexible driving unit driven humanoid robot dexterous hand provided by the embodiment of the present application can realize the functions of object grabbing and identification at the same time, preliminarily realize the flexibility and soft touch of human skin, develop towards the direction of humanization interaction, and the perception function and the driving unit are integrally arranged, thereby reducing the structural complexity of the humanoid robot.

[0030] The structure design and large driving output force function of the linear contraction spindle-shaped artificial muscle with muscle function and shape provided by the embodiment of the present application are expected to develop towards the direction of humanization of the artificial muscle driver. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a working process schematic diagram of a humanoid robot dexterous hand and forearm provided in a typical embodiment of the present application; Figure 2 is a size comparison between an adult hand and an artificial muscle driven dexterous hand provided in a typical embodiment of the present application; Figure 3 is a schematic diagram and a physical diagram of the bending movement of each finger of a dexterous hand and different gesture movements provided in a typical embodiment of the present application; Figure 4a is a structure schematic diagram of a spindle-shaped artificial muscle provided in a typical embodiment of the present application; Figure 4b is a physical structure of a spindle-shaped artificial muscle provided in a typical embodiment of the present application; Figure 4c is a working mechanism of a spindle-shaped artificial muscle provided in a typical embodiment of the present application; Figure 5 is a lifting weight capacity demonstration diagram of a spindle-shaped artificial muscle provided in a typical embodiment of the present application; Figure 6a 、 Figure 6b is a process demonstration diagram of a spindle-shaped artificial muscle driving a humanoid robot arm provided in a typical embodiment of the present application; Figure 7 is a process diagram of an artificial muscle driven dexterous hand realizing object grabbing and releasing provided in a typical embodiment of the present application; Figure 8 is a demonstration diagram of an artificial muscle driven dexterous hand realizing the classic action of imitating "Salt Brother" to sprinkle salt provided in a typical embodiment of the present application; Figure 9ais a typical embodiment of the present application, which provides a kind of artificial muscle belt driven dexterous hand with integrated sensing function to realize the object grasping and identification function display figure; Figure 9b Different surface microstructures of the grasped object are shown. Figure 9c Identification curves for the grasped object with different surface microstructures are shown. Figure 9d The accuracy of machine learning is shown. DETAILED DESCRIPTION

[0032] In view of the deficiencies in the prior art, the present application has been proposed after long-term research and a large number of practices. The technical solution, its implementation process and principles will be further explained in combination with the drawings and specific embodiments.

[0033] The present application provides a dexterous hand completely assembled by flexible sensing and driving integrated devices by designing and arranging artificial muscle drivers on the surface of the dexterous hand, which can realize flexible movement of each finger joint and make different gestures. The present application also provides a spindle-shaped artificial muscle, which has similar functions and forms to mammalian muscles. With the large driving force of the spindle-shaped artificial muscle, the forearm of the humanoid robot can be driven by the spindle-shaped artificial muscle, and the dexterous hand driven by the fully flexible device can realize object grasping and identification functions. The present application adheres artificial muscles to the surface of the artificial muscle belt without affecting the driving performance and effect, realizes the integration of skin and muscle, provides a flexible and simple design scheme for the design of the dexterous hand of the humanoid robot, and is more likely to make the future humanoid robot realize the flexibility and soft touch of human skin, no longer present the cold mechanical texture, and finally promote its development and recognition in the companion and service industry. The artificial skin can be a low-modulus flexible film-shaped pressure sensor (lignin / electrospun nanofiber film impregnated with MXene / carbon nanotube and other carbon-based conductive materials) or a micro-pillar array-based pressure sensor, which is adhered to the surface of the artificial muscle belt to form a "skin-muscle" structure through an adhesive, or a micro-pillar array structure is added between the flexible film-shaped pressure sensor and the artificial muscle belt to improve the sensing sensitivity. The low-modulus flexible film-shaped pressure sensor and the micro-pillar array structure do not limit the deformation of the artificial muscle belt and can perceive external pressure through slight deformation. It should be noted that the low-modulus flexible film-shaped pressure sensor and the micro-pillar array-based pressure sensor can be obtained by market purchase, and the specific product model is not limited here.

[0034] Please refer to Figure 1The upper limb of the humanoid robot comprises a bionic arm and a bionic hand, the bionic arm comprises a large arm, a small arm and a second driving mechanism, the large arm is movably connected with the small arm, the second driving mechanism is connected with the large arm and the small arm respectively and is used for driving the small arm to make flexion and extension movement relative to the large arm, and the bionic hand is installed on the small arm.

[0035] In a more specific embodiment, the bionic hand is a dexterous hand structure with a sensing function set by artificial muscle belts, comprising a dexterous hand skeleton and a first driving mechanism, the dexterous hand skeleton comprises a bionic palm and m bionic fingers movably connected with the bionic palm and having multiple bending degrees of freedom, the first driving mechanism comprises n first driving elements, the first driving element comprises a first artificial muscle belt with a sensing structure, the first artificial muscle belt is attached to the palm side of the bionic finger, one end of each first artificial muscle belt is connected with the fingertip part of the bionic finger, and the other end is connected with the bionic palm, the sensing structure is arranged on the part of the first artificial muscle belt located at or close to the fingertip part, the first driving element is used for driving the bionic finger connected therewith to transform from an initial state to a bending state, n sensing structures can measure the shape and size of the grasped object, the sensing structure comprises a low-modulus flexible film-shaped pressure sensor or a more sensitive micro-column array-based pressure sensor and the like integrally arranged on the first artificial muscle belt, and n≥m≥1.

[0036] It should be noted that the dexterous hand skeleton is a bionic hand skeleton known in the art, as a preferred scheme, m=n=5, that is, the dexterous hand skeleton comprises the same bionic structure as the human hand, that is, has five fingers, as shown in Figure 2 , and the size of the dexterous hand skeleton is preferably the same as or close to the size of an adult's hand, the bionic finger has x joints, the bionic finger can bend around the joints, and it can be understood that the number of joints of the n bionic fingers is not exactly the same. The structure and material of the dexterous hand skeleton can be selected according to specific needs, and here is not limited, Figure 2 , the size of the adult hand and the dexterous hand provided by the present application is compared, and it can be seen from Figure 2 that the dexterous hand provided by the present application realizes the design of 1:1 size with the adult hand, and can even be designed to be larger in size according to the needs, which has important significance for the practical application of the dexterous hand.

[0037] Specifically, the first artificial muscle band is conductive, each of the first artificial muscle bands is connected in series into a first conductive circuit, the first artificial muscle band can be deformed in extension and contraction under the stimulation of Joule heat, the n first conductive circuits are independently operated, that is, each conductive circuit can be independently controlled to be turned on or turned off, and each first conductive circuit has a switch, the n switches of the n first conductive circuits are connected with a controller and can be independently adjusted in working state. It should be noted that the first conductive circuit structure and the controller herein can be known in the art and can be obtained by purchase, and are not limited specifically herein.

[0038] Specifically, the first artificial muscle band is tightly attached to the joint, or the first artificial muscle band is connected with the joint, x≥1, and more specifically, the first artificial muscle band is bound to the bionic finger by a binding member, and the binding member is correspondingly arranged at the joint. The binding member includes a rubber ring, cotton thread or metal wire, etc.

[0039] In order to facilitate the recovery of the finger after bending, the first driving mechanism further comprises n second driving elements, the second driving elements are arranged on the back side of the bionic finger, one end of each of the second driving elements is connected with the fingertip of the bionic finger, and the other end is connected with the bionic palm, and the second driving element is used to drive the bionic finger connected therewith to recover from the bent state to the initial state. Specifically, each of the second driving elements can also be connected with a first driving element to form an antagonistic driving structure, so as to accelerate the speed of the bionic finger recovering to the initial state. More specifically, the second driving element is an elastic mechanical element or a second artificial muscle band. As a typical embodiment, the second artificial muscle band is conductive, each of the second artificial muscle bands is connected in series into a second conductive circuit, the second artificial muscle band can be deformed in extension and contraction under the stimulation of Joule heat, and the n second conductive circuits are independently operated, that is, each conductive circuit can be independently controlled to be turned on or turned off, and each second conductive circuit has a switch, the n switches of the n second conductive circuits are connected with a controller and can be independently adjusted in working state. It should be noted that the conductive circuit structure and the controller herein can be known in the art and can be obtained by purchase, and are not limited specifically herein. As another typical embodiment, the elastic mechanical element includes a flexible elastic element or a rigid elastic element, and the flexible elastic element includes an elastic band, etc.

[0040] Figure 3is a schematic diagram and a physical diagram of the bending motion of each finger of the dexterous hand in the embodiment of the present application and the motion of different gestures. Each finger of the dexterous hand can flex like a human finger, and can perform basic gestures such as "yeah", "6", "OK" and "fist", which shows its potential in the field of communication applications, including sign language and gesture-based human-computer interaction.

[0041] Specifically, the second driving mechanism includes a spindle-shaped artificial muscle or an artificial muscle bundle, and the structure of the spindle-shaped artificial muscle is as shown in Figure 4a 、 Figure 4b 、 Figure 4c , wherein the spindle-shaped artificial muscle or the artificial muscle bundle is conductive, the spindle-shaped artificial muscle or the artificial muscle bundle is connected in series into a third conductive circuit, and the spindle-shaped artificial muscle or the artificial muscle bundle can be deformed in length under the stimulation of Joule heat. It should be noted that the circuit structure of the third conductive circuit and the controller and the like can be known in the art, which can be obtained by purchase, and are not limited here.

[0042] Specifically, the spindle-shaped artificial muscle includes a support frame and a plurality of third artificial muscle belts, the radial cross-sectional area of the end portions of the support frame is smaller than the radial cross-sectional area of the middle portion, the plurality of third artificial muscle belts are attached to the surface of the support frame, and the two ends of each third artificial muscle belt are fixedly connected to the two end portions of the support frame, and the whole presents a spindle-shaped structure. More specifically, the support frame includes a support rod, a first support disc (or a support ring, the same below), and two second support discs (or support rings, the same below), the two second support discs are fixedly arranged on the two sides of the first support disc along the axial direction of the support rod, the diameter of the second support disc is smaller than the diameter of the first support disc, and a plurality of third artificial muscle belts are sequentially arranged along the circumferential direction of the first support disc or the second support disc, and each third artificial muscle belt is fixedly connected to the two end portions of the support rod.

[0043] For example, the effective driving length of the spindle-shaped artificial muscle is 10.5 cm, which is composed of 11 third artificial muscle belts, the ends of the third artificial muscle belts are fixed on a polytetrafluoroethylene support rod which can be regarded as a tendon, the center is supported by a polytetrafluoroethylene disc (i.e. a first support disc) with a diameter of 3.9 cm, and a quarter is supported by two polytetrafluoroethylene discs (i.e. second support discs) with a diameter of 2.1 cm, thereby forming a spindle-shaped structure. Figure 5 The spindle-shaped artificial muscle is shown to lift a heavy object, and the spindle-shaped artificial muscle driven by a heat gun can generate a huge force, which can drive a 5 N load and achieve a contraction stroke of 22%.

[0044] Figure 6a 、 Figure 6bThe process of driving the humanoid robot arm by the spindle-shaped artificial muscle is described, and the humanoid robot arm of adult size is driven by the spindle-shaped artificial muscle to achieve a rotation range of 36°.

[0045] It should be noted that the skeleton of the bionic arm in the embodiment of the present application can adopt a structure known in the art, which is not specifically limited here.

[0046] Specifically, the first artificial muscle belt, the second artificial muscle belt and the third artificial muscle belt in the present application can be the same in structure except that the first artificial muscle belt is integrated with a sensing structure. Specifically, the artificial muscle belt is formed by arranging or weaving artificial muscle fibers, and the artificial muscle fibers include at least one of carbon nanotube fibers, graphene fibers and carbon fibers, or the artificial muscle fibers include composite fibers formed by at least one of carbon nanotube fibers, graphene fibers and carbon fibers and at least one of nylon fibers, aramid fibers, polyimide fibers, spandex fibers, silica gel fibers, rubber fibers and liquid crystal elastomer fibers. Specifically, the liquid crystal elastomer fibers in the third artificial muscle belt forming the spindle-shaped artificial muscle can also be replaced by polydimethylsiloxane, nylon and the like.

[0047] In a more specific embodiment, a method for manufacturing an upper limb of a humanoid robot, the artificial muscle belt with sensing function and the designed spindle-shaped artificial muscle are respectively installed on the dexterous hand and the arm skeleton to achieve object grasping and recognition, and the specific steps are as follows: The upper limb skeleton is formed by 3D printing or the like, and the upper limb skeleton includes a dexterous hand skeleton and an arm skeleton. The dexterous hand skeleton and the arm skeleton are connected, and the structure of the dexterous hand skeleton and the arm skeleton is similar to the overall structure and function of the skeleton of the human hand and arm, i.e., the dexterous hand skeleton includes five fingers with bending freedom. The specific structure of the upper limb skeleton is not specifically limited here.

[0048] 1) The first driving element with sensing function is fixed to the inner side of each finger (i.e., the palm side or the palm side, the same below), one end is connected to the fingertip, and the other end is fixed to the palm. The first driving element is used to drive the bionic finger connected thereto to change from the initial state to the bending state.

[0049] In addition, a binding member is wound around the second and third joints of each finger, which not only maintains the attachment of the artificial muscle belt to the finger, but also does not hinder the free contraction of the artificial muscle belt along the length direction. Therefore, each joint of each finger can achieve free bending. Exemplarily, the binding member includes a rubber ring, cotton thread or metal wire, etc.

[0050] As a preferred mode, in order to facilitate the recovery of the finger after bending, the dorsal side of the finger (opposite to the inner side of the finger, i.e. the dorsal side of the palm or the dorsal side of the hand) is provided with a second driving element connected thereto, one end of each of the second driving elements is connected to the fingertip of the bionic finger, and the other end is connected to the bionic palm, and the second driving element is used to drive the bionic finger connected thereto to recover from the bent state to the initial state. Specifically, each of the second driving elements can also be connected to one of the first driving elements to form an antagonistic driving structure, so as to accelerate the speed of the bionic finger recovering to the initial state. More specifically, the second driving element is an elastic mechanical element or a second artificial muscle belt.

[0051] 2) A second driving mechanism is installed on the arm to drive the adult-sized arm to assist the dexterous hand in grasping and lifting objects, and specifically, the second driving mechanism is connected to the large arm and the small arm respectively and is used to drive the small arm to make flexion and extension movements relative to the large arm.

[0052] Specifically, the second driving mechanism includes a spindle-shaped artificial muscle or an artificial muscle bundle, and the structure of the spindle-shaped artificial muscle is as shown in Figure 4a 、 Figure 4b wherein the spindle-shaped artificial muscle or the artificial muscle bundle is conductive, the spindle-shaped artificial muscle or the artificial muscle bundle is connected in series into a third conductive circuit, and the spindle-shaped artificial muscle or the artificial muscle bundle can be deformed in extension and contraction under the stimulation of Joule heat.

[0053] 3) The object grasping data is trained by using a decision tree model.

[0054] The specific steps are as follows: first, 500 repeated tests are performed on each grasping action, and resistance signals are collected, and then the data is automatically segmented by an automatic waveform recognition algorithm. Next, all the data is randomly shuffled, 30% of which is used as a test set and 70% of which is used as a training set. Finally, a training model is constructed by using a decision tree model and an confusion matrix is output. By analyzing the significant features (such as slope, peak value and standard deviation) of the pressure sensing signals generated when the dexterous hand grasps different objects, accurate identification and judgment of the shape of the object can be realized.

[0055] The dexterous hand driven by the first driving element with sensing function can realize grasping and identification of different surface microstructure objects under the assistance of machine learning, and the objects can be cylinders, cubes, spheres, pyramids, prisms and polyhedrons, and the surface structures can be planes, hemispheres, triangular prisms, pentagonal prisms and arc gear teeth, and the machine learning model can be a decision tree model or a neural network model. It should be noted that the training model and the training process adopted by the present application are known in the art, and will not be limited here.

[0056] Figure 1is a schematic diagram of the working process of a humanoid robot dexterous hand and arm in a typical embodiment of the present application. The fingers of the dexterous hand are directly driven to bend by flexible and linearly contractible artificial muscle belts through Joule heat stimulation. The forearm of the humanoid robot is driven by a spindle-shaped artificial muscle, which converts the linear contraction of the spindle-shaped artificial muscle into the rotational bending of the forearm. The micro-column array-based sensor integrated in the fingertip part of the artificial muscle belt can sense the shape and size of the object grasped by the dexterous hand.

[0057] Figure 7 The process of object grasping and releasing by the artificial muscle belt driven dexterous hand is shown, which simulates the process of human grasping objects and lifting actions. A 4.5 cm long, 2.5 cm wide and 3 cm high wooden block is successfully grasped by the five fingers driven by the artificial muscle belt, and the spindle-shaped artificial muscle drives the forearm connected to the dexterous hand to lift the object. When a certain height is reached, the artificial muscle belt driving the fingers stops power supply, and the bent fingers return to their original position, and the wooden block is released. Finally, the humanoid robot arm and dexterous hand return to the initial state. Figure 8 The artificial muscle belt driven dexterous hand is shown to realize the classic action of imitating "Salt Brother" sprinkling salt. Interestingly, the humanoid robot arm and dexterous hand driven by the artificial muscle belt reproduce the iconic salt sprinkling gesture popularized by "Salt Brother", highlighting the performance potential of this flexible driving system in humanoid robot realistic motion.

[0058] Figure 9a The artificial muscle belt driven dexterous hand with integrated sensing function is shown to realize the object grasping and recognition function, Figure 9b The different surface microstructures of the grasped objects are shown, Figure 9c The recognition curves for the grasped objects with different surface microstructures are shown, Figure 9d The accuracy of machine learning is shown. The dexterous hand driven by the artificial muscle belt with sensing function successfully realizes the grasping and recognition of different surface microstructure cylinders (plane, hemisphere, triangular prism, pentagonal prism and arc gear) with the assistance of machine learning.

[0059] The specific steps of training object grasping data using the decision tree model are as follows: first, 500 repeated tests are performed for each grasping action and the resistance signals are collected, then the data is automatically segmented by automatic waveform recognition algorithm. Next, all the data is randomly shuffled, of which 30% is used as the test set and 70% is used as the training set. Finally, the training model is constructed using the decision tree model and the confusion matrix is output. By analyzing the significant features (such as slope, peak value and standard deviation) of the pressure sensing signals generated by the dexterous hand when grasping different objects, accurate recognition and judgment of the shape of the object can be achieved. For cylinders with different surface microstructures, the average recognition accuracy can reach 94.72%.

[0060] The flexible perception-driving integrated artificial muscle is fully adopted to realize the grasping and recognition functions of the dexterous hand, and the broad application prospect of the artificial muscle in the future humanoid robot field is fully shown.The dexterous hand will open up new opportunities for the fields of industrial production, scientific research, medical rehabilitation, daily life and the like.For example, in daily life, the dexterous hand can play the role of an entertainment partner, and communicate with human beings through diversified interactive forms such as chessboard games and building block assembly.In the field of rehabilitation treatment, it can also assist patients in hand training by simulating real hand movements, and effectively promote the recovery of hand muscles and nerves.

[0061] The present application provides a dexterous hand structure assembled by flexible perception-driving integrated devices by designing and arranging artificial muscle drivers with perception function on the surface of the dexterous hand, which can realize flexible movement of each finger joint, make different gesture actions, complete object grasping and recognition functions, and has the flexibility and warm touch of human skin, and no longer presents the cold mechanical texture.

[0062] The dexterous hand of the humanoid robot driven by the full-flexible driving unit provided by the embodiment of the present application has simple structure, high dexterity, light weight and low price; and the dexterous hand of the humanoid robot driven by the full-flexible driving unit provided by the embodiment of the present application can realize the grasping and recognition functions of objects at the same time, preliminarily realize the flexibility and warm touch of human skin, develop towards the direction of humanization interaction, and in addition, the perception function and the driving unit are integrated and arranged, thereby reducing the structural complexity of the humanoid robot.

[0063] The structural design and large driving output force function of the linear contraction spindle-shaped artificial muscle with muscle-like function and shape provided by the embodiment of the present application are expected to develop towards the direction of humanization of the artificial muscle driver.

[0064] It should be understood that the above embodiments are only for illustrating the technical concept and characteristics of the present application, and its purpose is to enable those skilled in the art to understand the content of the present application and implement it, and it cannot limit the protection scope of the present application.Any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A dexterous hand structure with integrated sensory functions and driven by artificial muscles, comprising a dexterous hand skeleton and a first driving mechanism, wherein the dexterous hand skeleton includes a bionic palm and m bionic fingers movably connected to the bionic palm and having multiple degrees of bending freedom, characterized in that: The first driving mechanism includes n first driving elements. Each first driving element includes a first artificial muscle band with a sensing structure. The first artificial muscle band is attached to the palm side of the bionic finger. One end of each first artificial muscle band is connected to the fingertip of the bionic finger, and the other end is connected to the bionic palm. The sensing structure is disposed on the portion of the first artificial muscle band located at or near the fingertip. The first driving element is used to drive the bionic finger connected thereto to change from an initial state to a bent state. The n sensing structures are capable of measuring the shape and size of the object being grasped, where n ≥ m ≥ 1.

2. The dexterous hand structure with integrated sensory function and artificial muscle belt drive according to claim 1, characterized in that: The first artificial muscle band is conductive, and each of the first artificial muscle bands is connected in series in a first conductive circuit. The first artificial muscle band can stretch and deform under Joule heat stimulation. Preferably, each of the n first conductive circuits operates independently.

3. The dexterous hand structure with integrated sensory function and artificial muscle belt drive according to claim 1 or 2, characterized in that: The bionic finger has x joints, and the bionic finger can bend around the joints. The first artificial muscle band is closely attached to the joints, or the first artificial muscle band is connected to the joints, where x ≥ 1. Preferably, the first artificial muscle band is bound to the bionic finger by a strapping device, which is correspondingly disposed at the joint; Preferably, the binding element includes a rubber ring, cotton thread, or metal wire.

4. The dexterous hand structure with integrated sensory function and artificial muscle belt drive according to claim 1, characterized in that: The sensing structure includes a low-modulus flexible membrane pressure sensor or a micropillar array-based pressure sensor integrated on the first artificial muscle band.

5. The dexterous hand structure with integrated sensory function and artificial muscle belt drive according to claim 1, characterized in that: The first driving mechanism further includes n second driving elements, which are disposed on the back side of the bionic finger. One end of each second driving element is connected to the fingertip of the bionic finger, and the other end is connected to the bionic palm. The second driving element is used to drive the bionic finger connected to it to return from a bent state to an initial state. Preferably, each of the second driving elements is further connected to a first driving element to form an antagonistic driving structure; Preferably, the second driving element is an elastic mechanical element or a second artificial muscle band; Preferably, the second artificial muscle band is conductive, and each second artificial muscle band is connected in series in a second conductive circuit. The second artificial muscle band can stretch and deform under Joule heat stimulation. Preferably, the n second conductive circuits operate independently; Preferably, the elastic mechanical element includes a flexible elastic element or a rigid elastic element; Preferably, the flexible elastic element includes a rubber band, and the rigid elastic element includes a spring.

6. An upper limb of a humanoid robot, comprising a bionic arm and a bionic hand, characterized in that: The bionic hand adopts the dexterous hand structure with integrated sensory functions and artificial muscle belts as described in any one of claims 1-5.

7. The upper limb of the humanoid robot according to claim 6, characterized in that: The bionic arm includes an upper arm, a forearm, and a second drive mechanism. The upper arm is movably connected to the forearm, and the second drive mechanism is connected to the upper arm and the forearm respectively, and is used to drive the forearm to perform flexion and extension movements relative to the upper arm.

8. The upper limb of the humanoid robot according to claim 7, characterized in that: The second drive mechanism includes a spindle-shaped artificial muscle or an artificial muscle bundle; Preferably, the spindle-shaped artificial muscle or the artificial muscle bundle is conductive, and the spindle-shaped artificial muscle or the artificial muscle bundle is connected in series in a third conductive circuit. The spindle-shaped artificial muscle or the artificial muscle bundle can stretch and deform under Joule heat stimulation.

9. The upper limb of the humanoid robot according to claim 8, characterized in that: The spindle-shaped artificial muscle includes a support frame and multiple third artificial muscle bands. The radial cross-sectional area of ​​the two ends of the support frame is smaller than that of the middle part. The multiple third artificial muscle bands are attached to the surface of the support frame. The two ends of each third artificial muscle band are fixedly connected to the two ends of the support frame, and the whole presents a spindle-shaped structure. Preferably, the support frame includes a support rod, a first support plate, and two second support plates arranged coaxially. The two second support plates are fixedly spaced on both sides of the first support plate along the axial direction of the support rod. The diameter of the second support plate is smaller than the diameter of the first support plate. Multiple third artificial muscle bands are arranged sequentially along the circumference of the first or second support plates. Each third artificial muscle band is fixedly connected to both ends of the support rod. Preferably, the first support plate and the two second support plates are arranged at equal intervals.

10. A humanoid robot, characterized in that, The humanoid robot has a dexterous hand structure with integrated artificial muscle belts for sensing functions as described in any one of claims 1-5, or an upper limb of the humanoid robot as described in any one of claims 6-9.

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