A hand grasping force evaluation device, a motion-mechanics coupling evaluation system and method

Abstract

The present invention discloses a hand grasping force evaluation device, a motion-mechanics coupling evaluation system and method. Without changing the physical state of hand grasping, the present invention detects the hand grasping force, restoring the real grasping conditions and process; meanwhile, the hand grasping force evaluation device allows the setting of grasping conditions including object shape, roughness and weight on the outer surface of the target object to be grasped, enriching the scope of grasping tests and evaluations; for hand grasping evaluation, feature evaluations under motion-mechanics coupling conditions are proposed, specifically including a hand motion trajectory area-time coupling index and a hand grasping pressure-time coupling index, which can more accurately represent the fluency and smoothness of the target hand motion under the task of hand grasping actions; the present invention can be applied to the task evaluation of hand grasping actions of both natural hands and prosthetic hands, and is particularly applicable to the task evaluation of hand grasping actions of prosthetic hands with tactile feedback.

Description

Technical Field

[0001] The present invention relates to the technology for evaluating hand function grasping, and particularly to a hand grasping force evaluation device, a motion-mechanics coupling evaluation system and an evaluation method thereof. Background Art

[0002] Hand function evaluation is an important way to detect the hand function of natural hands and prosthetic hands, generally including kinematic evaluation and mechanical evaluation. Kinematic evaluation mainly focuses on the degrees of freedom of finger movement, movement range, movement coordination, etc. Mechanical evaluation mainly focuses on finger stiffness, grasping force magnitude, etc., and clinical test methods such as Box and Block Test, Southampton Hand Assessment Procedure, Jebsen-Taylor Test of Hand FunctionTest have been formed.

[0003] The above-mentioned clinical test methods can have a good evaluation of the motor function of natural hands and prosthetic hands. However, with the development of the understanding of the dexterity of human hands, especially the revolutionary technology development of prosthetic hands from having no tactile feedback at the end of the prosthetic hand to having tactile feedback, the mechanical evaluation during the hand grasping process becomes particularly important. Currently, the mechanical evaluation during the hand grasping process often detects and evaluates by attaching a flexible force sensor to the finger tip or the surface of the grasped object. Although this method can obtain some data, the method of attaching a flexible force sensor will bring two main problems. One is that attaching a flexible force sensor directly changes the interface contact state between the finger tip and the grasped object, that is, conditions such as texture and roughness have undergone fundamental changes; the other is that the method of attaching a flexible force sensor determines the uniqueness of the interface contact state, and the tester cannot change the interface contact state between the finger tip and the grasped object.

[0004] In addition, traditional clinical test methods pay more attention to the evaluation of aspects such as the degrees of freedom of hand function, gestures, and the completion degree of grasping tasks, lacking the evaluation of characteristics under the conditions of motion and mechanics coupling during the grasping process, and cannot completely evaluate the smoothness, fluency and other characteristics of the entire hand grasping process. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention proposes a hand grasping force evaluation device, a motion-mechanics coupling evaluation system and an evaluation method thereof, which perform kinematic evaluation and mechanical evaluation on the function of the target evaluation hand. The target evaluation hand is a natural hand or a prosthetic hand, and the fingers participating in the hand grasping task during the evaluation are called evaluation fingers.

[0006] An object of the present invention is to propose a hand grasping force evaluation device.

[0007] The hand grasping force evaluation device of the present invention includes: a target grasping object, an evaluation built-in fixing frame, an evaluation micro lens, and an evaluation built-in processing circuit; wherein, the target grasping object is a hollow and transparent rigid shell-shaped object, and on the outer surface of the target grasping object, there are roughness textures on the premise of not affecting the imaging of the evaluation micro lens; the evaluation built-in fixing frame is fixedly installed on the inner surface of the target grasping object, and a plurality of evaluation micro lenses are distributed and installed on the evaluation built-in fixing frame. The distribution of the plurality of evaluation micro lenses is arranged according to the set grasping actions. Each evaluation micro lens faces the fitting surface of the corresponding evaluation finger and the target grasping object, and the image acquisition area of the evaluation micro lens covers the fitting surface of the front end of the corresponding finger and the outer surface of the target grasping object; the evaluation built-in processing circuit is fixedly installed on the evaluation built-in fixing frame; the evaluation micro lens is connected to the evaluation built-in processing circuit through a data line; during the evaluation process, the front end of the evaluation finger of the target evaluation hand is attached to the outer surface of the target grasping object and applies pressure to the outer surface. Each evaluation micro lens collects the fitting surface graph of the front end of the corresponding evaluation finger and the target grasping object, and transmits the collected fitting surface graph to the evaluation built-in processing circuit; the evaluation built-in processing circuit calculates the pressure value of the hand grasping force of the target evaluation hand through the pressure logical relationship, realizes the acquisition of the mechanical information of the evaluation finger, and further conducts a mechanical evaluation of the hand grasping force.

[0008] The material of the target grasping object is a transparent rigid material, such as glass or plastic; the shape is a hollow shell; the size should be suitable for human hands to grasp; the mass is 50 grams to 20 kilograms; on the premise of not affecting the imaging of the evaluation micro lens, the outer surface of the target grasping object is set with different roughnesses.

[0009] Before the target evaluation hand grasps, when the subject changes or the corresponding evaluation finger changes, it is necessary to calibrate the corresponding finger pressure using the hand grasping force evaluation device calibration system.

[0010] The calibration system for the hand grasping force evaluation device includes: a calibration fixing table, a calibration grasping object, a pressure sensor, a calibration micro lens, a calibration built-in fixing frame, and a calibration built-in processing circuit; among them, the calibration fixing table is in a flat plate shape, and two pressure sensors are fixedly installed on the left and right sides of the upper surface of the calibration fixing table, and the horizontal heights of the upper surfaces of the two pressure sensors are the same; the calibration grasping object is a part of the target grasping object intercepted along the hollow axis of the target grasping object, and the upper surface of the calibration grasping object and the outer surface of the target grasping object, as well as the lower surface of the calibration grasping object and the inner surface of the target grasping object, respectively have exactly the same surface structure and characteristics; the lower surface of the calibration grasping object is placed on the upper surfaces of the two pressure sensors; the calibration built-in fixing frame is fixedly installed on the upper surface of the calibration fixing table and is located between the two pressure sensors, and the calibration micro lens and the calibration built-in processing circuit are fixedly installed on the calibration built-in fixing frame and are located below the lower surface of the calibration grasping object, the calibration micro lens is located in the center position between the two pressure sensors, and the distance between the calibration micro lens and the upper surface of the calibration grasping object is the same as the distance between the evaluation micro lens in the hand grasping force evaluation device and the outer surface of the target grasping object corresponding to the fitting surface of the corresponding evaluation finger; the calibration micro lens is connected to the calibration built-in processing circuit through a data line; each evaluation finger participating in the hand grasping task is calibrated one by one, and during calibration, the evaluation finger being calibrated is called the calibration finger; the calibration finger presses the upper surface of the calibration grasping object corresponding to the calibration micro lens. Since the calibration grasping object and the two pressure sensors form a double-support model, and the slight deformation of the pressure sensor due to pressure is ignored, the actual pressure of the calibration finger is twice the value displayed by a single pressure sensor; when the calibration finger presses the upper surface of the calibration grasping object, since the fitting area and fitting texture on the front of the finger tip change with the change of the pressure value, the fitting surface graphics corresponding to different pressure values are collected through the calibration micro lens; through calculation by the calibration built-in processing circuit, the logical relationship between the pressure value of the calibration finger and the fitting surface graphics is obtained, so as to establish the pressure logic relationship of each evaluation finger, input the calibrated pressure logic relationship into the hand grasping force evaluation device, and then through the hand grasping force evaluation device, the mechanical information of each evaluation finger of the target evaluation hand's hand grasping force is collected, and then the mechanical evaluation of the hand grasping force is carried out.

[0011] The distance between the two pressure sensors is 5 cm to 10 cm.

[0012] In addition, the front of the finger tip of a natural human hand contains relatively clear texture features, while the front of the finger tip of a prosthetic hand generally does not have texture features. The corresponding solution is to spray artificial texture on the front of the finger tip of the prosthetic hand.

[0013] Another object of the present invention is to propose a motion-mechanics coupling evaluation system.

[0014] The motion-mechanics coupling evaluation system of the present invention includes: a fixed frame, motion capture cameras, optical targets, initial position markers, intermediate position markers, target position markers, and a hand grasping force evaluation device; wherein, a plurality of motion capture cameras are fixedly installed on the top of the fixed frame, and by adjusting the field of view and perspective, it is ensured that the corresponding actions can be captured when the target evaluation hand moves within the fixed frame; a plurality of optical targets are attached to the surface of the target evaluation hand, and the attachment positions at least include the back of the ends of five fingers, the back of one palm, and the back of one wrist joint; the initial position marker, the intermediate position marker, and the target position marker are placed at the bottom of the fixed frame, the initial position square is located directly in front of the evaluation object and close to the body of the evaluation object, and according to the set hand grasping task, the intermediate position marker and the target position marker are set and away from the body of the evaluation object;

[0015] Under the initial conditions, the target evaluation hand of the evaluation object is naturally placed at the center of the upper surface of the initial position marker, and the hand grasping force evaluation device is vertically placed at the center of the upper surface of the intermediate position marker; set the process of the evaluation hand grasping task: after the evaluation starts, the target evaluation hand moves from the initial position marker to the intermediate position marker, and after grasping the hand grasping force evaluation device at the intermediate position marker, it moves it to the center of the upper surface of the target position marker, and then the target evaluation hand returns to the center of the upper surface of the initial position marker, that is, one evaluation operation is completed; during the evaluation process, the target evaluation hand starts from the initial position marker, passes through the intermediate position marker and the target position marker, and finally returns to the initial position marker; during the whole evaluation process, the motion capture cameras collect the motion trajectories and speeds of the optical targets, and obtain the moment motion information through the motion trajectories and speeds of the optical targets; each evaluation micro lens collects the fitting surface graph of the front of the finger end of the corresponding evaluation finger and the target grasping object, and transmits the collected fitting surface graph to the evaluation built-in processing circuit; the evaluation built-in processing circuit calculates the pressure value of the hand grasping force of the target evaluation hand through the pressure logic relationship; through the moment motion information and the pressure value, calculate the hand motion trajectory area-time coupling index to represent the overall fluency and smoothness of the target evaluation hand, and the hand grasping pressure-time coupling index to represent the grasping fluency and smoothness of the target evaluation hand, so as to realize the kinematic evaluation and mechanical evaluation of the hand grasping task.

[0016] Another object of the present invention is to propose an evaluation method for a motion-mechanics coupling evaluation system.

[0017] The evaluation method of the motion-mechanics coupling evaluation system of the present invention includes the following steps:

[0018] 1) Calibrate the pressure logic relationship:

[0019] a) Build a calibration system for the hand grasping force evaluation device:

[0020] On the upper surface of a flat calibration fixing table, two pressure sensors are fixedly installed on the left and right sides. The upper surfaces of the two pressure sensors are at the same horizontal height. The calibration gripper is a part of the target gripper intercepted along the hollow axis of the target gripper. The upper surface of the calibration gripper and the outer surface of the target gripper, as well as the lower surface of the calibration gripper and the inner surface of the target gripper, have exactly the same surface structure and characteristics respectively. The lower surface of the calibration gripper is placed on the upper surfaces of the two pressure sensors. The calibration built-in fixing frame is fixedly installed on the upper surface of the calibration fixing table and is located between the two pressure sensors. The calibration micro lens and the calibration built-in processing circuit are fixedly installed on the calibration built-in fixing frame and are located below the lower surface of the calibration gripper. The calibration micro lens is located at the center position between the two pressure sensors. The calibration micro lens is connected to the calibration built-in processing circuit through a data cable;

[0021] b) The fingers participating in the hand grasping task during evaluation are called evaluation fingers. Each evaluation finger participating in the hand grasping task is calibrated one by one. During calibration, the evaluation finger being calibrated is called the calibration finger:

[0022] i. The distance between the calibration micro lens and the upper surface of the calibration gripper is equal to the distance between the evaluation micro lens in the hand grasping force evaluation device and the outer surface of the target gripper to which the contact surface of the corresponding evaluation finger belongs;

[0023] ii. The calibration finger presses the upper surface of the calibration gripper corresponding to the calibration micro lens. Since the calibration gripper and the two pressure sensors form a double-support model, and the slight deformation of the pressure sensor due to pressure is ignored, the actual pressure of the calibration finger is twice the value shown by a single pressure sensor;

[0024] iii. When the calibration finger presses the upper surface of the calibration gripper, since the contact area and contact texture on the front of the finger tip change with the magnitude of the pressure value, the contact surface graphics corresponding to different pressure values are collected by the calibration micro lens;

[0025] iv. Through calculation by the calibration built-in processing circuit, the logical relationship between the pressure value of the calibration finger and the contact surface graphics is obtained, thereby establishing the pressure logic relationship of the evaluation finger;

[0026] v. Repeat steps i) to iv) to obtain the pressure logic relationship of each evaluation finger in the hand grasping task;

[0027] c) Input the calibrated pressure logic relationship into the hand grasping force evaluation device;

[0028] 2) Under the initial conditions, the target evaluation hand of the evaluation object is naturally placed at the center of the upper surface of the initial position mark, and the hand grasping force evaluation device is vertically placed at the center of the upper surface of the middle position mark;

[0029] 3) Set the process for evaluating the hand grasping task:

[0030] a) One evaluation operation: The target evaluation hand moves from the initial position marker to the intermediate position marker. After completing the grasping of the hand grasping force evaluation device at the intermediate position marker, it moves to the center of the upper surface of the target position marker, and then the target evaluation hand returns to the center of the upper surface of the initial position marker, thus completing one evaluation operation;

[0031] b) Time setting:

[0032] Taking the optical target attached to the back of the hand of the target evaluation hand as the main tracking target, its movement speed changes with the evaluation hand grasping task: The moment when the target evaluation hand leaves the initial position marker and moves towards the intermediate position marker is marked as the zero-th moment t0. At the zero-th moment t0, the evaluation is started, and the absolute value of the speed of the tracking target starts to increase from zero; when approaching the intermediate position marker, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target evaluation hand reaches the intermediate position marker. The moment when the absolute value of the speed of the target evaluation hand first decreases to zero is marked as the first moment t1, that is, at the first moment t1, the target evaluation hand reaches the intermediate position marker; after reaching the intermediate position marker, the target evaluation hand needs to successfully grasp the hand grasping force evaluation device and leave the intermediate position marker with the hand grasping force evaluation device. The moment when the target evaluation hand leaves the intermediate position with the hand grasping force evaluation device is marked as the second moment t2. At the second moment t2, the absolute value of the speed of the tracking target starts to increase from zero. When approaching the target position marker, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target position marker is reached. The moment when the absolute value of the speed of the target evaluation hand secondarily decreases to zero is marked as the third moment t3, that is, at the third moment t3, the target evaluation hand reaches the target position marker; after reaching the target position marker, the target evaluation hand needs to release the hand grasping force evaluation device. After successful release, it leaves the target position marker. The moment when the target evaluation hand leaves the target position marker is marked as the fourth moment t4; at the fourth moment t4, the absolute value of the speed of the tracking target starts to increase from zero. When approaching the initial position marker, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target evaluation hand finally returns to the initial position marker. The moment when the absolute value of the speed of the target evaluation hand thirdly decreases to zero is marked as the fifth moment t5, that is, at the fifth moment t5, the target evaluation hand returns to the initial position marker;

[0033] After the target evaluation hand reaches the intermediate position marker at the first moment t1, the moment when the target evaluation hand starts to fit the outer surface of the target object to be grasped is denoted as the grasping moment t 12 At the grasping moment t 12The target evaluation hand starts to grasp the hand grasping force evaluation device, and the pressure value of the evaluation finger detected during the grasping process gradually increases; after successful grasping, the target evaluation hand transports the hand grasping force evaluation device to the target position mark at the second moment t2 and reaches the target position mark at the third moment t3. During this transportation process, the pressure value of the evaluation finger is relatively stable; after reaching the target position mark, the target evaluation hand needs to release the hand grasping force evaluation device. The moment when the target evaluation hand is completely separated from the outer surface of the target object to be grasped is recorded as the release moment t 34 , at the release moment t 34 The target evaluation hand successfully releases the hand grasping force evaluation device. During the separation process, the pressure value of the evaluation finger gradually decreases to zero; after successfully releasing the hand grasping force evaluation device, the target evaluation hand leaves the target position mark at the fourth moment t4;

[0034] 4) Evaluation process:

[0035] During the evaluation process, the target evaluation hand starts from the initial position mark, passes through the intermediate position mark and the target position mark, and finally returns to the initial position mark; during the entire evaluation process, the motion capture camera collects the motion trajectory and speed of the optical target point, obtains the moment motion information through the motion trajectory and speed of the optical target point, and the evaluation micro lens of the hand grasping force evaluation device collects the fitting surface graph of the front end of the evaluation finger and the target object to be grasped, and obtains the pressure value through the pressure logic relationship;

[0036] 5) Hand grasping task evaluation:

[0037] a) Hand motion trajectory area-time coupling index η1:

[0038] During the evaluation process, the target evaluation hand starts from the initial position mark, passes through the intermediate position mark and the target position mark, and finally returns to the initial position mark. During this process, the tracking target point forms a closed actual motion trajectory in space and a closed projection trajectory at the bottom of the fixed frame; in the vertical direction, the area size enclosed between the actual motion trajectory and the projection trajectory is marked as S1, and the product index of this area size and the time taken by the actual motion trajectory is the hand motion trajectory area-time coupling index η1. The hand motion trajectory area-time coupling index η1 can represent the overall fluency and smoothness of the target evaluation hand:

[0039] η1 = S1·(t5 - t0)

[0040] The motion physical characteristics of the human hand follow the principle of minimum energy consumption and highest efficiency. The smaller the enclosed area S1, the lower the energy consumption of the target evaluation hand; the smaller the time taken (t5 - t0), the higher the time efficiency of the target evaluation hand; therefore, the smaller η1, the better the motion fluency and smoothness of the target evaluation hand in the hand grasping task;

[0041] b) Hand grasping pressure-time coupling index η2:

[0042] During the evaluation process, the evaluation finger of the target evaluation hand and the outer surface of the target grasping object have experienced three processes: grasping, transporting, and releasing. The recorded value of the pressure of the evaluation finger starts from the grasping moment t 12 The evaluation finger starts to contact the target grasping object and ends at the release moment t 34 The evaluation finger is completely separated from the target grasping object. During this process, the absolute value of the enclosed area formed by the recorded pressure value of the evaluation finger and the time axis is marked as S2. The product of the area size and the time taken for the contact process between the evaluation finger and the target grasping object and the ratio to the pure movement time is the hand grasping pressure-time coupling index η2. The hand grasping pressure-time coupling index η2 can further represent the grasping fluency and smoothness of the target evaluation hand:

[0043]

[0044] When the area S2 is smaller, it indicates that the target evaluation hand can complete the hand grasping task with a smaller hand grasping force, that is, complete the hand grasping task with less energy consumption. At the same time, the smaller the ratio of the contact time between the evaluation finger and the target grasping object to the pure movement time, the higher the grasping efficiency. Therefore, the smaller η2 is, the better the completion of the hand grasping task, and further indicates that the movement fluency and smoothness of the target evaluation hand under the hand grasping task are better;

[0045] The hand movement trajectory area-time coupling index η1 and the hand grasping pressure-time coupling index η2 perform kinematic and mechanical evaluations on the hand grasping task.

[0046] Advantages of the present invention:

[0047] (1) The hand grasping force evaluation device proposed by the present invention can detect the hand grasping force without changing the physical state of the hand grasping, restoring the real grasping conditions and processes. At the same time, the hand grasping force evaluation device allows the setting of grasping conditions including object shape, roughness, and weight on the outer surface of the target grasping object, enriching the scope of grasping tests and evaluations;

[0048] (2) For hand grasping evaluation, the present invention proposes a feature evaluation under the condition of motion-mechanics coupling, specifically including the hand movement trajectory area-time coupling index and the hand grasping pressure-time coupling index, which can more accurately represent the fluency and smoothness of the target hand movement under the hand grasping task;

[0049] (3) The system and method proposed by the present invention can be applied to the evaluation of hand grasping tasks of both natural hands and prosthetic hands, especially suitable for the evaluation of hand grasping tasks of prosthetic hands with tactile feedback. Description of the Drawings

[0050] Figure 1 Schematic diagram of an embodiment of the hand grasping force evaluation device of the present invention;

[0051] Figure 2 Schematic diagram of the use of an embodiment of the hand grasping force evaluation device of the present invention;

[0052] Figure 3 Schematic diagram of an embodiment of the calibration system of the hand grasping force evaluation device of the present invention;

[0053] Figure 4 Side view of an embodiment of the calibration system of the hand grasping force evaluation device of the present invention;

[0054] Figure 5 Schematic diagram of an embodiment of the motion-mechanics coupling evaluation system of the present invention;

[0055] Figure 6 Schematic diagram of the motion-mechanics coupling evaluation method of the present invention, wherein (a) is a schematic diagram of the motion trajectory of the target evaluation hand, (b) is a schematic diagram of the change curve of the motion speed of the target evaluation hand, and (c) is a schematic diagram of the change curve of the evaluation finger during the grasping process. Detailed implementation manners

[0056] The present invention will be further described below in conjunction with the accompanying drawings through specific embodiments.

[0057] As Figure 1 and 2 shown, the hand grasping force evaluation device of this embodiment includes: a target grasping object 801, an evaluation built-in fixing frame 802, an evaluation micro lens 803, and an evaluation built-in processing circuit 804; wherein, the target grasping object 801 is a hollow and transparent rigid shell-shaped object, and on the outer surface of the target grasping object 801, there are roughness textures on the premise of not affecting the imaging of the evaluation micro lens 803; an evaluation built-in fixing frame 802 is fixedly installed on the inner surface of the target grasping object 801, and a plurality of evaluation micro lenses 803 are distributed and installed on the evaluation built-in fixing frame 802. The distribution of the plurality of evaluation micro lenses 803 is arranged according to the set grasping action. Each evaluation micro lens 803 faces the fitting surface of the corresponding evaluation finger and the target grasping object 801, and the image acquisition area of the evaluation micro lens 803 covers the fitting surface of the front end of the corresponding finger and the outer surface of the target grasping object 801; an evaluation built-in processing circuit 804 is fixedly installed on the evaluation built-in fixing frame 802; the evaluation micro lens 803 is connected to the evaluation built-in processing circuit 804 through a data line.

[0058] As Figure 3 and 4As shown in the figure, the calibration system of the hand grasping force evaluation device includes: a calibration fixing table 901, a calibration grasping object 902, a pressure sensor 903, a calibration micro lens 904, a calibration built-in fixing frame 905, and a calibration built-in processing circuit 906. Among them, the calibration fixing table 901 is in the shape of a flat plate. Two pressure sensors 903 are fixedly installed on the left and right sides of the upper surface of the calibration fixing table 901, and the upper surface horizontal heights of the two pressure sensors 903 are the same. The calibration grasping object 902 is a part of the target grasping object 801 intercepted along the hollow axis of the target grasping object 801. The upper surface of the calibration grasping object 902 and the outer surface of the target grasping object 801, and the lower surface of the calibration grasping object 902 and the inner surface of the target grasping object 801 respectively have exactly the same surface structure and characteristics. The lower surface of the calibration grasping object 902 is placed on the upper surfaces of the two pressure sensors 903. The calibration built-in fixing frame 905 is fixedly installed on the upper surface of the calibration fixing table 901 and is located between the two pressure sensors 903. The calibration micro lens 904 and the calibration built-in processing circuit 906 are fixedly installed on the calibration built-in fixing frame 905 and are located below the lower surface of the calibration grasping object 902. The calibration micro lens 904 is located at the center position between the two pressure sensors 903, and the distance between the calibration micro lens 904 and the upper surface of the calibration grasping object 902 is the same as the distance between the evaluation micro lens 803 in the hand grasping force evaluation device and the outer surface of the target grasping object 801 where the fitting surface of the corresponding evaluation finger is located. Figure 4 The arrow in the figure indicates the pressure direction of the calibration finger.

[0059] In this embodiment, the material of the target grasping object 801 is made of transparent rigid glass or the like; the shape is a rectangular parallelepiped hollow shell; on the basis of not affecting the imaging of the evaluation micro lens 803, the outer surface of the target grasping object 801 is set to have different roughnesses; artificial textures are spray-painted on the front of the finger ends of the prosthetic hand; the distance between the two pressure sensors 903 is 8 cm.

[0060] As Figure 5As shown in the figure, the motion-mechanics coupling evaluation system of this embodiment includes: a fixed frame 1, motion capture cameras 2, optical targets 4, initial position markers 5, intermediate position markers 6, target position markers 7, and a hand grasping force evaluation device 8. Among them, multiple motion capture cameras 2 are fixedly installed on the top of the fixed frame 1. By adjusting the field of view and perspective, it is ensured that corresponding actions can be captured when the target evaluation hand 3 moves within the fixed frame 1. A plurality of optical targets 4 are attached to the surface of the target evaluation hand, and the attachment positions at least include the backs of the ends of five fingers, the back of a palm, and the back of a wrist joint. The initial position marker 5, the intermediate position marker 6, and the target position marker 7 are placed at the bottom of the fixed frame 1. The initial position marker 5, the intermediate position marker 6, and the target position marker 7 are all rectangular blocks of the same size. The initial position block is located directly in front of the evaluation object and close to the body of the evaluation object. And according to the set hand grasping task, the intermediate position marker 6 and the target position marker 7 are set and are far from the body of the evaluation object.

[0061] The evaluation method of the motion-mechanics coupling evaluation system of this embodiment includes the following steps:

[0062] 1) Calibrate the pressure logical relationship:

[0063] a) Build a calibration system for the hand grasping force evaluation device:

[0064] b) The fingers participating in the hand grasping task during evaluation are called evaluation fingers. Each evaluation finger participating in the hand grasping task is calibrated one by one. During calibration, the evaluation finger being calibrated is called the calibration finger:

[0065] i. The distance between the calibration micro lens 904 and the upper surface of the calibration grasping object 902 is equal to the distance between the evaluation micro lens 803 in the hand grasping force evaluation device 8 and the outer surface of the target grasping object 801 to which the fitting surface of the corresponding evaluation finger belongs.

[0066] ii. The calibration finger presses the upper surface of the calibration grasping object 902 corresponding to the calibration micro lens 904. Since the calibration grasping object 902 and the two pressure sensors 903 form a double-support model, and the slight deformation of the pressure sensor 903 due to pressure is ignored, the actual pressure of the calibration finger is twice the value displayed by a single pressure sensor 903.

[0067] iii. When the calibration finger presses the upper surface of the calibration grasping object 902, since the fitting area and fitting texture on the front of the finger end change with the magnitude of the pressure value, the fitting surface graphics corresponding to different pressure values are collected through the calibration micro lens 904.

[0068] iv. Calculate the logical relationship between the calibrated finger pressure value and the fitting surface pattern through the built-in processing circuit 906 for calibration, so as to establish the pressure logic relationship for evaluating the finger.

[0069] v. Repeat steps i) to iv) to obtain the pressure logic relationship of each evaluated finger for the hand grasping task.

[0070] c) Input the calibrated pressure logic relationship into the hand grasping force evaluation device 8.

[0071] 2) Under the initial conditions, the target evaluated hand of the evaluation object is naturally placed at the center of the upper surface of the initial position marker 5, and the hand grasping force evaluation device 8 is vertically placed at the center of the upper surface of the middle position marker 6.

[0072] 3) Set the process of the evaluated hand grasping task:

[0073] a) One evaluation operation: The target evaluated hand moves from the initial position marker 5, after grasping the hand grasping force evaluation device 8 at the middle position marker 6, moves it to the center of the upper surface of the target position marker 7, and then the target evaluated hand returns to the center of the upper surface of the initial position marker 5, that is, one evaluation operation is completed.

[0074] b) Time setting:

[0075] Taking the optical target 4 attached to the back of the hand of the target evaluation hand as the main tracking target, its movement speed changes with the grasping task of the evaluation hand: The moment when the target evaluation hand leaves the initial position mark 5 and moves towards the middle position mark 6 is marked as the zero moment t0. At the zero moment t0, the evaluation is started, and the absolute value of the speed of the tracking target starts to increase from zero; when approaching the middle position mark 6, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target evaluation hand reaches the middle position mark 6. The moment when the absolute value of the speed of the target evaluation hand decreases to zero for the first time is marked as the first moment t1, that is, at the first moment t1, the target evaluation hand reaches the middle position mark 6; after reaching the middle position mark 6, the target evaluation hand needs to successfully grasp the hand grasping force evaluation device 8 and leave the middle position mark 6 with the hand grasping force evaluation device 8. The moment when the target evaluation hand leaves the middle position with the hand grasping force evaluation device 8 is marked as the second moment t2. At the second moment t2, the absolute value of the speed of the tracking target starts to increase from zero. When approaching the target position mark 7, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target position mark 7 is reached. The moment when the absolute value of the speed of the target evaluation hand decreases to zero for the second time is marked as the third moment t3, that is, at the third moment t3, the target evaluation hand reaches the target position mark 7; after reaching the target position mark 7, the target evaluation hand needs to release the hand grasping force evaluation device 8. The moment when the target evaluation hand leaves the target position mark 7 after successful release is marked as the fourth moment t4; at the fourth moment t4, the absolute value of the speed of the tracking target starts to increase from zero. When approaching the initial position mark 5, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target evaluation hand finally returns to the initial position mark 5. The moment when the absolute value of the speed of the target evaluation hand decreases to zero for the third time is marked as the fifth moment t5, that is, at the fifth moment t5, the target evaluation hand returns to the initial position mark 5;

[0076] After the target evaluation hand reaches the middle position mark 6 at the first moment t1, the moment when the target evaluation hand starts to fit with the outer surface of the target object 801 is recorded as the grasping moment t 12 , at the grasping moment t 12 the target evaluation hand starts to grasp the hand grasping force evaluation device 8, and the pressure value of the evaluation finger detected during the grasping process gradually increases; after successful grasping, the target evaluation hand transports the hand grasping force evaluation device 8 towards the target position mark 7 at the second moment t2 and reaches the target position mark 7 at the third moment t3. During this transportation process, the pressure value of the evaluation finger is relatively stable; after reaching the target position mark 7, the target evaluation hand needs to release the hand grasping force evaluation device 8. The moment when the target evaluation hand is completely separated from the outer surface of the target object 801 is recorded as the release moment t 34 , at the release moment t 34The target evaluation hand successfully releases the hand grasping force evaluation device 8. During the separation process, the pressure value of the evaluation finger gradually decreases to zero. After successfully releasing the hand grasping force evaluation device 8, the target evaluation hand leaves the target position marker 7 at the fourth moment t4.

[0077] 4) Evaluation process:

[0078] During the evaluation process, the target evaluation hand starts from the initial position marker 5, passes through the intermediate position marker 6 and the target position marker 7, and finally returns to the initial position marker 5. During the entire evaluation process, the motion capture camera 2 collects the motion trajectory and speed of the optical target point 4, obtains the moment motion information through the motion trajectory and speed of the optical target point 4, and the evaluation micro lens 803 of the hand grasping force evaluation device 8 collects the fitting surface graphics of the evaluation finger, and obtains the pressure value through the pressure logical relationship.

[0079] 5) Hand grasping task evaluation:

[0080] a) Hand motion trajectory area-time coupling index η1:

[0081] During the evaluation process, the target evaluation hand starts from the initial position marker 5, passes through the intermediate position marker 6 and the target position marker 7, and finally returns to the initial position marker 5. During this process, the tracking target point forms a closed actual motion trajectory in space and a closed projection trajectory at the bottom of the fixed frame 1. In the vertical direction, the area size enclosed between the actual motion trajectory and the projection trajectory is marked as S1, and the product index of this area size and the time consumed by the actual motion trajectory is the hand motion trajectory area-time coupling index η1. The hand motion trajectory area-time coupling index η1 can represent the overall fluency and smoothness of the target evaluation hand:

[0082] η1 = S1·(t5 - t0)

[0083] The motion physical characteristics of the human hand follow the principle of minimum energy consumption and highest efficiency. The smaller the enclosed area S1, the lower the energy consumption of the target evaluation hand; the smaller the time consumption (t5 - t0), the higher the time efficiency of the target evaluation hand. Therefore, the smaller η1 is, the better the motion fluency and smoothness of the target evaluation hand in the hand grasping task.

[0084] b) Hand grasping pressure-time coupling index η2:

[0085] During the evaluation process, the evaluation finger of the target evaluation hand experiences three processes of grasping, transporting, and releasing with the outer surface of the target grasping object 801. The recorded value of the pressure value of the evaluation finger starts at the grasping moment t 12 The evaluation finger starts to contact the target grasping object 801 and ends at the release moment t 34It is evaluated that the evaluation finger is completely separated from the target object to be grasped 801. During this process, the absolute value of the enclosed area formed by the pressure value of the evaluation finger recorded and the time axis is marked as S2. The product of the size of this area and the time taken for the evaluation finger to contact the target object to be grasped 801 and the ratio to the pure movement time is the hand grasping pressure-time coupling index η2. The hand grasping pressure-time coupling index η2 can further represent the grasping fluency and smoothness of the target evaluation hand:

[0086]

[0087] When the area S2 is smaller, it indicates that the target evaluation hand can complete the hand grasping task with a smaller hand grasping force, that is, complete the hand grasping task with less energy consumption. At the same time, the smaller the ratio of the contact time between the evaluation finger and the target object to be grasped 801 to the pure movement time, the higher the grasping efficiency can also be indicated. Therefore, the smaller η2 is, the better the completion degree of the hand grasping task is, and further indicates that the movement fluency and smoothness of the target evaluation hand in the hand grasping task are better;

[0088] The hand movement trajectory area-time coupling index η1 and the hand grasping pressure-time coupling index η2 are used to evaluate the hand grasping task.

[0089] Finally, it should be noted that the purpose of disclosing the embodiments is to help further understand the present invention. However, those skilled in the art can understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the scope of protection required by the present invention is defined by the scope of the claims.

Claims

1. A hand grasping force evaluation device, where the target hand for evaluation is a natural hand or a prosthetic hand, and the fingers participating in the hand grasping task during evaluation are called evaluation fingers. It is characterized in that, The hand grasping force evaluation device includes: a target grasping object, an evaluation built-in fixing frame, an evaluation micro lens, and an evaluation built-in processing circuit; wherein, the target grasping object is a hollow and transparent rigid shell-shaped object, and on the outer surface of the target grasping object, there are roughness textures without affecting the imaging of the evaluation micro lens; the evaluation built-in fixing frame is fixedly installed on the inner surface of the target grasping object, and a plurality of evaluation micro lenses are distributed and installed on the evaluation built-in fixing frame. The distribution of the plurality of evaluation micro lenses is arranged according to a set grasping action. Each evaluation micro lens faces the fitting surface of the corresponding evaluation finger and the target grasping object, and the image acquisition area of the evaluation micro lens covers the fitting surface of the front end of the corresponding finger and the outer surface of the target grasping object; the evaluation built-in processing circuit is fixedly installed on the evaluation built-in fixing frame; the evaluation micro lens is connected to the evaluation built-in processing circuit through a data line; during the evaluation process, the front end of the evaluation finger of the target evaluation hand is attached to the outer surface of the target grasping object and applies pressure to the outer surface. Each evaluation micro lens collects the fitting surface pattern of the front end of the corresponding evaluation finger and the target grasping object, and transmits the collected fitting surface pattern to the evaluation built-in processing circuit; the evaluation built-in processing circuit calculates the pressure value of the hand grasping force of the target evaluation hand through the pressure logic relationship, realizes the acquisition of the mechanical information of the evaluation finger, and further conducts a mechanical evaluation of the hand grasping force.

2. The hand grasping force evaluation device according to claim 1, characterized in that, The material of the target grasping object is a transparent rigid material.

3. The hand grasping force evaluation device according to claim 1, characterized in that, It further includes a calibration system for the hand grasping force evaluation device, and the calibration system for the hand grasping force evaluation device includes: a calibration fixing table, a calibration grasping object, a pressure sensor, a calibration micro lens, a calibration built-in fixing frame, and a calibration built-in processing circuit; wherein, the calibration fixing table is in a flat plate shape, and two pressure sensors are fixedly installed on the left and right sides of the upper surface of the calibration fixing table, and the horizontal heights of the upper surfaces of the two pressure sensors are the same; the calibration grasping object is a part of the target grasping object intercepted along the hollow axis of the target grasping object, and the upper surface of the calibration grasping object and the outer surface of the target grasping object, as well as the lower surface of the calibration grasping object and the inner surface of the target grasping object, respectively have exactly the same surface structure and characteristics; the lower surface of the calibration grasping object is placed on the upper surfaces of the two pressure sensors; the calibration built-in fixing frame is fixedly installed on the upper surface of the calibration fixing table and is located between the two pressure sensors, and the calibration micro lens and the calibration built-in processing circuit are fixedly installed on the calibration built-in fixing frame and are located below the lower surface of the calibration grasping object, the calibration micro lens is located at the center position between the two pressure sensors, and the distance between the calibration micro lens and the upper surface of the calibration grasping object is the same as the distance between the evaluation micro lens in the hand grasping force evaluation device and the outer surface of the target grasping object where the fitting surface of the corresponding evaluation finger is located; the calibration micro lens is connected to the calibration built-in processing circuit through a data line; each evaluation finger participating in the hand grasping task is calibrated one by one, and during calibration, the evaluation finger being calibrated is called the calibration finger; the calibration finger presses the upper surface of the calibration grasping object corresponding to the calibration micro lens. Since the calibration grasping object and the two pressure sensors form a double-support model, and the slight deformation of the pressure sensor due to pressure is ignored, the actual pressure of the calibration finger is twice the value displayed by a single pressure sensor; when the calibration finger presses the upper surface of the calibration grasping object, since the fitting area and fitting texture on the front surface of the finger tip change with the magnitude of the pressure value, the fitting surface graphics corresponding to different pressure values are collected through the calibration micro lens; the logical relationship between the pressure value of the calibration finger and the fitting surface graphics is calculated through the calibration built-in processing circuit, so as to establish the pressure logical relationship of each evaluation finger, input the calibrated pressure logical relationship into the hand grasping force evaluation device, and then the hand grasping force evaluation device collects the mechanical information of each evaluation finger of the target evaluation hand, and further conducts a mechanical evaluation of the hand grasping force.

4. The hand grasping force evaluation device according to claim 1, characterized in that, The distance between the two pressure sensors is 5 cm to 10 cm.

5. The hand grasping force evaluation device according to claim 1, characterized in that, Spray artificial texture on the front surface of the finger tip of the prosthetic hand.

6. A motion-mechanics coupling evaluation system, characterized in that, The motion-mechanics coupling evaluation system includes: a fixed frame, motion capture cameras, optical targets, initial position markers, intermediate position markers, target position markers, and a hand grasping force evaluation device; among them, multiple motion capture cameras are fixedly installed on the top of the fixed frame, and by adjusting the field of view and perspective, it is ensured that the corresponding actions can be captured when the target evaluation hand moves within the fixed frame; a plurality of optical targets are attached to the surface of the target evaluation hand, and the attachment positions include at least the back of the tips of five fingers, the back of one palm, and the back of one wrist joint; the initial position marker, intermediate position marker, and target position marker are placed at the bottom of the fixed frame, the initial position square is located directly in front of the evaluation object and close to the body of the evaluation object, and according to the set hand grasping task, the intermediate position marker and target position marker are set and far from the body of the evaluation object; The hand grasping force evaluation device includes: a target grasping object, an evaluation built-in fixing frame, an evaluation micro lens, and an evaluation built-in processing circuit; among them, the target grasping object is a hollow transparent rigid shell-like object, and on the outer surface of the target grasping object, there is a rough texture on the premise of not affecting the imaging of the evaluation micro lens; the evaluation built-in fixing frame is fixedly installed on the inner surface of the target grasping object, and a plurality of evaluation micro lenses are distributed and installed on the evaluation built-in fixing frame. The distribution of the plurality of evaluation micro lenses is arranged according to the set grasping action, and each evaluation micro lens faces the corresponding fitting surface of the evaluation finger and the target grasping object, and the image acquisition area of the evaluation micro lens covers the corresponding fitting surface of the front of the finger tip and the outer surface of the target grasping object; the evaluation built-in processing circuit is fixedly installed on the evaluation built-in fixing frame; the evaluation micro lens is connected to the evaluation built-in processing circuit through a data line; Under the initial conditions, the target evaluation hand of the evaluation object is naturally placed at the center of the upper surface of the initial position marker, and the hand grasping force evaluation device is vertically placed at the center of the upper surface of the intermediate position marker; set the process of the evaluation hand grasping task: after the evaluation starts, the target evaluation hand moves from the initial position marker to the intermediate position marker, and after grasping the hand grasping force evaluation device at the intermediate position marker, it moves it to the center of the upper surface of the target position marker, and then the target evaluation hand returns to the center of the upper surface of the initial position marker, that is, one evaluation operation is completed; during the evaluation process, the target evaluation hand starts from the initial position marker, passes through the intermediate position marker and the target position marker, and finally returns to the initial position marker; during the whole evaluation process, the motion capture camera collects the motion trajectory and speed of the optical target point, and obtains the moment motion information through the motion trajectory and speed of the optical target point; each evaluation micro lens collects the fitting surface graph of the front end of the corresponding evaluation finger and the target grasping object, and transmits the collected fitting surface graph to the evaluation built-in processing circuit; the evaluation built-in processing circuit calculates the pressure value of the hand grasping force of the target evaluation hand through the pressure logical relationship; through the moment motion information and the pressure value, calculate the hand motion trajectory area-time coupling index to represent the overall fluency and smoothness of the target evaluation hand, and the hand grasping pressure-time coupling index to represent the grasping fluency and smoothness of the target evaluation hand, so as to realize the kinematic evaluation and mechanical evaluation of the hand grasping task.

7. An evaluation method for the motion-mechanics coupling evaluation system according to claim 6, characterized in that, The evaluation method includes the following steps: 1) Calibrate the pressure logical relationship; 2) Under the initial conditions, the target evaluation hand of the evaluation object is naturally placed at the center of the upper surface of the initial position marker, and the hand grasping force evaluation device is vertically placed at the center of the upper surface of the intermediate position marker; 3) Set the process of the evaluation hand grasping task: a) One evaluation operation: The target evaluation hand moves from the initial position marker to the intermediate position marker, and after grasping the hand grasping force evaluation device at the intermediate position marker, it moves it to the center of the upper surface of the target position marker, and then the target evaluation hand returns to the center of the upper surface of the initial position marker, that is, one evaluation operation is completed; b) Moment setting: Taking the optical target attached to the back of the hand of the target evaluation hand as the main tracking target, its speed changes with the grasping task of the evaluation hand: When the target evaluation hand leaves the initial position marker and moves towards the middle position marker, the moment is marked as the zero moment t0, and the evaluation is started at the zero moment t0. The absolute value of the speed of the tracking target starts to increase from zero; when approaching the middle position marker, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target evaluation hand reaches the middle position marker. The moment when the absolute value of the speed of the target evaluation hand first decreases to zero is marked as the first moment t1, that is, at the first moment t1, the target evaluation hand reaches the middle position marker; after reaching the middle position marker, the target evaluation hand needs to successfully grasp the hand grasping force evaluation device and leave the middle position marker while holding the hand grasping force evaluation device. The moment when the target evaluation hand leaves the middle position while holding the hand grasping force evaluation device is marked as the second moment t2. At the second moment t2, the absolute value of the speed of the tracking target starts to increase from zero. When approaching the target position marker, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target position marker is reached. The moment when the absolute value of the speed of the target evaluation hand second decreases to zero is marked as the third moment t3, that is, at the third moment t3, the target evaluation hand reaches the target position marker; after reaching the target position marker, the target evaluation hand needs to release the hand grasping force evaluation device and leave the target position marker after successful release. The moment when the target evaluation hand leaves the target position marker is marked as the fourth moment t4; at the fourth moment t4, the absolute value of the speed of the tracking target starts to increase from zero. When approaching the initial position marker, the absolute value of the speed starts to decrease. When the absolute value of the speed decreases to zero, it indicates that the target evaluation hand finally returns to the initial position marker. The moment when the absolute value of the speed of the target evaluation hand third decreases to zero is marked as the fifth moment t5, that is, at the fifth moment t5, the target evaluation hand returns to the initial position marker; After the target evaluation hand reaches the middle position mark at the first moment t1, the moment when the outer surface of the target evaluation hand starts to fit with the outer surface of the target object to be grasped is recorded as the grasping moment t 12 , at the grasping moment t 12 The target evaluation hand starts to grasp the hand grasping force evaluation device, and the pressure value of the evaluation finger detected during the grasping process gradually increases; after successful grasping, the target evaluation hand transports the hand grasping force evaluation device to the target position mark at the second moment t2 and reaches the target position mark at the third moment t3. During this transportation process, the pressure value of the evaluation finger is relatively stable; after reaching the target position mark, the target evaluation hand needs to release the hand grasping force evaluation device, and the moment when the outer surface of the target evaluation hand is completely separated from the outer surface of the target object to be grasped is recorded as the release moment t 34 , at the release moment t 34 The target evaluation hand successfully releases the hand grasping force evaluation device. During the separation process, the pressure value of the evaluation finger gradually decreases to zero; after successfully releasing the hand grasping force evaluation device, the target evaluation hand leaves the target position mark at the fourth moment t4; 4) Evaluation process: During the evaluation process, the target evaluation hand starts from the initial position marker, passes through the middle position marker and the target position marker, and finally returns to the initial position marker; during the entire evaluation process, the motion capture camera collects the motion trajectory and speed of the optical target, obtains the moment motion information through the motion trajectory and speed of the optical target, and the evaluation micro lens of the hand grasping force evaluation device collects the fitting surface graph of the front of the finger tip of the evaluation finger and the target object to be grasped, and obtains the pressure value through the pressure logical relationship; 5) Hand grasping task evaluation: The hand movement trajectory area-time coupling index η1 and the hand grasping pressure-time coupling index η2 are used to evaluate the hand grasping task.

8. The evaluation method according to claim 7, characterized in that, In step 1), the calibration of the pressure logical relationship includes the following steps: a) Construction of the calibration system for the hand grasping force evaluation device: On the upper surface of a flat calibration fixing table, two pressure sensors are fixedly installed on the left and right sides. The upper surface horizontal heights of the two pressure sensors are the same. The calibration gripper is a part of the target gripper intercepted along the hollow axis of the target gripper. The upper surface of the calibration gripper and the outer surface of the target gripper, as well as the lower surface of the calibration gripper and the inner surface of the target gripper, respectively have exactly the same surface structure and characteristics. The lower surface of the calibration gripper is placed on the upper surfaces of the two pressure sensors. The calibration internal fixing frame is fixedly installed on the upper surface of the calibration fixing table and is located between the two pressure sensors. The calibration micro lens and the calibration internal processing circuit are fixedly installed on the calibration internal fixing frame and are located below the lower surface of the calibration gripper. The calibration micro lens is located at the center position between the two pressure sensors. The calibration micro lens is connected to the calibration internal processing circuit through a data cable. b) The fingers participating in the hand grasping task during evaluation are called evaluation fingers. Each evaluation finger participating in the hand grasping task is calibrated one by one. During calibration, the evaluation finger being calibrated is called the calibration finger: i. The distance between the calibration micro lens and the upper surface of the calibration gripper is equal to the distance between the evaluation micro lens in the hand grasping force evaluation device and the outer surface of the target gripper to which the fitting surface of the corresponding evaluation finger belongs. ii. The calibration finger presses the upper surface of the calibration gripper corresponding to the calibration micro lens. Since the calibration gripper and the two pressure sensors form a double-support model, and the slight deformation of the pressure sensor due to pressure is ignored, the actual pressure of the calibration finger is twice the value displayed by a single pressure sensor. iii. When the calibration finger presses the upper surface of the calibration gripper, since the fitting area and fitting texture on the front of the finger tip change with the magnitude of the pressure value, the fitting surface graphics corresponding to different pressure values are collected by the calibration micro lens. iv. Through calculation by the calibration internal processing circuit, the logical relationship between the pressure value of the calibration finger and the fitting surface graphics is obtained, thereby establishing the pressure logic relationship of the evaluation finger. v. Repeat steps i) to iv) to obtain the pressure logic relationship of each evaluation finger in the hand grasping task. c) Input the calibrated pressure logic relationship into the hand grasping force evaluation device.

9. The evaluation method according to claim 7, characterized in that, Hand movement trajectory area-time coupling index η1: During the evaluation process, the target evaluation hand starts from the initial position mark, passes through the intermediate position mark and the target position mark, and finally returns to the initial position mark. During this process, the tracking target forms a closed actual movement trajectory in space and a closed projection trajectory at the bottom of the fixed frame. In the vertical direction, the area size enclosed between the actual movement trajectory and the projection trajectory is marked as S1. The product index of this area size and the time taken for the actual movement trajectory is the hand movement trajectory area-time coupling index η1. The hand movement trajectory area-time coupling index η1 represents the overall fluency and smoothness of the target evaluation hand: η1 = S1·(t5 - t0) The movement physical characteristics of the human hand follow the principle of minimum energy consumption and maximum efficiency. The smaller the enclosed area S1, the lower the energy consumption of the target evaluation hand; the smaller the time taken (t5 - t0), the higher the time efficiency of the target evaluation hand. Therefore, the smaller η1 is, the better the movement fluency and smoothness of the target evaluation hand in the hand grasping task.

10. The evaluation method according to claim 7, characterized in that, Hand grasping pressure-time coupling index η2: During the evaluation process, the evaluation finger of the target evaluator experiences three processes of grasping, transferring, and releasing with the outer surface of the target object to be grasped. The recorded value of the pressure of the evaluation finger starts at the grasping moment t 12 The evaluation finger starts to contact the target object to be grasped and ends at the release moment t 34 The evaluation finger is completely separated from the target object to be grasped. During this process, the absolute value of the enclosed area formed by the recorded pressure value of the evaluation finger and the time axis is marked as S2. The product of the size of this area and the time taken for the contact process between the evaluation finger and the target object to be grasped and the ratio to the time taken for pure movement is the hand grasping pressure-time coupling index η2. The hand grasping pressure-time coupling index η2 further represents the grasping fluency and smoothness of the target evaluator When the area S2 is smaller, it indicates that the target evaluation hand can complete the hand grasping task with a smaller hand grasping force, that is, complete the hand grasping task with less energy consumption. At the same time, the smaller the ratio of the contact time between the evaluation finger and the target object to the pure movement time, the higher the grasping efficiency can also be indicated. Therefore, the smaller η2 is, the better the completion degree of the hand grasping task, and further indicates that the movement fluency and smoothness of the target evaluation hand in the hand grasping task are better.

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