Multi-view spinal biomechanics dynamic analysis method and system based on augmented reality

Abstract

The application discloses a kind of based on the multi-view spine biomechanics dynamic analysis method and system of augmented reality, belong to man-machine interaction and biomechanics field.The system of the application includes central client and augmented reality client.Central client includes spine biomechanics analysis module and visual interactive module, respectively for central client user provides the dynamic evaluation of human lumbar and sacral part stress and visual real-time information feedback.Augmented reality client provides gesture interactive mode for augmented reality client user, realizes corresponding interactive action behavior in augmented reality scene, user is based on interactive system, selects model by gesture and downloads selected model to current environment, and interacts with downloaded model by gesture;By building motion capture environment, the real-time collection of human body posture of augmented reality client user is realized, and the real-time motion simulation of virtual human model is realized.The application can optimize working posture and reduce spinal skeletal muscle disease.

Description

TECHNICAL FIELD

[0001] The application relates to a multi-view spine biomechanics dynamic analysis method and system based on augmented reality, and belongs to the field of human-computer interaction and biomechanics. BACKGROUND

[0002] In recent years, in the whole process management of operation personnel, domestic enterprises obviously have the phenomenon of "paying attention to safety and ignoring health", so that the operation personnel are in an uncomfortable working state, and long-term development may lead to the occurrence of diseases such as excessive fatigue of the operation personnel and work-related musculoskeletal disorders (WRMSDs). At present, the evaluation of the operation posture of operation personnel in manufacturing enterprises in China mainly adopts a traditional human factor analysis method, that is, experts observe real experiment personnel operating specified equipment, analyze and evaluate problems existing in human factors engineering in the operation process according to the principle of human factors engineering, but this method seriously depends on the participation of experts, has strong subjectivity, low precision and a long analysis period; meanwhile, the method lacks pertinence and is difficult to quantitatively evaluate the injury risk of the local body of the operation personnel.

[0003] With the implementation of the national intelligent manufacturing project, manufacturing industry needs to respond to the increasing product customization demand and can quickly adapt to the production process, and higher requirements are put forward for the production cycle. Before the product of a manufacturing enterprise is offline, a large amount of simulation verification work for the operation of the operation personnel is needed, and the manufacturing workshop needs to have the ability to quickly arrange and quickly verify the rationality of the man-machine work efficiency of the new production line. The man-machine engineering simulation developed on the basis of virtual simulation technology mainly adjusts the joint angle of the virtual human body in the software according to the actual operation action of the operation personnel to simulate the actual operation action of the personnel, so as to realize the visual simulation and evaluation of the man-machine system, but the low precision and high degree of freedom of the human body model and the complexity of the production line simulation make the simulation process very tedious and very low in efficiency; with the development of virtual reality technology, virtual reality technology is also applied to man-machine work efficiency analysis, but the perception of people in the virtual reality scene is limited, and the modeling workload of the virtual environment is large. SUMMARY

[0004] The application aims to provide a multi-view spine biomechanics dynamic analysis method and system based on augmented reality, which establishes an efficient and accurate human lumbar force evaluation model based on spine biomechanics theory in an augmented reality and motion capture environment, obtains human operation posture data by building a virtual simulation scene, simultaneously analyzes and evaluates the human operation posture data in real time, realizes dynamic feedback of the force condition of the human lumbar region, and enhances the ability of manufacturing enterprises to quickly build a scientific and reasonable safety production mode under the background of intelligent manufacturing.

[0005] The object of the present application is achieved by the following technical solutions:

[0006] The lumbar and sacral stress analysis method based on spine biomechanics disclosed in the present application comprises the following steps:

[0007] Step one, establishing a human body mechanics model. A multi-rigid-body ball stick model of human body segments with hinge joints is used to establish a human body mechanics model. The simplified human body model has 13 main body segments and 12 movement joints. The main body segments include head-neck-spine, left upper arm, right upper arm, left forearm, right forearm, left hand, right hand, left thigh, right thigh, left shank, right shank, left foot, and right foot. The 12 movement joints include symmetrical shoulder joints, elbow joints, wrist joints, hip joints, knee joints, and ankle joints. The body segments are stick-shaped rigid bodies with mass. The human body joints are approximately spherical hinge structures, which are used to connect and drive the body segments of the human body model to rotate. The relative mass (the percentage of the mass of each segment in the weight of the human body), the relative length (the ratio of the length of each segment to the height of the subject), and the relative position of the center of mass (the ratio of the length from the driving joint of the segment to the center of mass of the segment to the total length of the segment) of each segment of the model are obtained from the standard human body proportion model.

[0008] Step two, establishing a human body skeletal hierarchy. There is no relative displacement between the human body bones, so it is equivalent to a complete rigid body. The human skeleton is composed of multiple such "rigid bodies". The movable part of the bone is called a joint, which connects different parts of the "rigid skeleton". The movement of the parts around the joint is equivalent to the spatial rotation of the rigid body around the node. Based on the analysis of interosseous movement, the whole body movement is described as the rotational movement of the skeletal rigid body around the joint. The movement of each part of the human body is interlinked and interdependent. The movement of the upper joint directly affects the position of the lower bone, i.e. the movement of the upper arm directly affects the position of the forearm. The expression form of human movement is the rotational change between child and parent bones. In order to analyze the human movement and the relationship between parent and child bones, a human body skeletal hierarchy is established.

[0009] The upper limbs of the human body are divided into three parts: upper arm, forearm, and hand, corresponding to the driving joints of the shoulder, elbow, and wrist joints. The lower limbs of the human body are divided into three parts: thigh, shank, and foot, corresponding to the driving joints of the hip, knee, and ankle joints. Since the movement of the palms and soles of the hands and feet does not need to be analyzed, they are not subdivided. The skeletal hierarchy of the head and torso also does not need to be subdivided.

[0010] Step three, analysis of the lumbar and sacral stress. With the human anatomy axis as a reference to establish the following coordinate system: x-axis is the human sagittal axis, the direction is the human front facing; y-axis is the human vertical axis, the direction is vertical upward; z-axis is the human coronal axis, its direction and the x-axis and y-axis direction meet the right-hand Cartesian coordinate system.

[0011] According to the static equilibrium principle, the force and moment borne by a joint of the human body are generated by the body weight and external load gravity, then under the condition of static at each time, the force and moment acting on the human sagittal plane satisfy:

[0012] ∑F X = 0, ∑F Y = 0, ∑M Z = 0 (1)

[0013] Wherein, F X is the force on the sagittal plane along the x-axis direction; F Y is the force on the sagittal plane along the y-axis direction; M Z is the moment on the sagittal plane pointing to the z-axis direction.

[0014] For the task of two-hand operation, the force analysis of each link in the human sagittal plane is carried out:

[0015] According to the static equilibrium theorem, the local force analysis of each segment is carried out:

[0016] Left forearm:

[0017]

[0018] Right forearm:

[0019]

[0020] Wherein: is the load force borne by the left arm;

[0021] is the load force borne by the right arm;

[0022] is the action force exerted by the left elbow joint on the left forearm;

[0023] is the action force exerted by the right elbow joint on the right forearm;

[0024] is the moment exerted by the left elbow joint on the left forearm;

[0025] is the moment exerted by the right elbow joint on the right forearm;

[0026] F LAthe forearm's own weight;

[0027] L1 is the horizontal distance between the line of action of the left arm load force vector and the line of action of the left forearm's own weight;

[0028] R1 is the horizontal distance between the line of action of the right arm load force vector and the line of action of the right forearm's own weight;

[0029] L2 is the horizontal distance between the line of action of the left forearm's own weight and the line of action of the force exerted by the left elbow joint on the left forearm;

[0030] R2 is the horizontal distance between the line of action of the right forearm's own weight and the line of action of the force exerted by the right elbow joint on the right forearm.

[0031] left upper arm:

[0032]

[0033] right upper arm:

[0034]

[0035] wherein: is the reaction force of the left forearm on the left elbow joint;

[0036] is the reaction force of the right forearm on the right elbow joint;

[0037] is the reaction torque of the left forearm on the left elbow joint;

[0038] is the reaction torque of the right forearm on the right elbow joint;

[0039] F UA is the forearm's own weight;

[0040] is the force exerted by the left shoulder joint on the left upper arm;

[0041] is the force exerted by the right shoulder joint on the right upper arm;

[0042] L3 is the horizontal distance between the line of action of the reaction force of the left forearm on the left elbow joint and the line of action of the left upper arm's own weight;

[0043] R3 is the horizontal distance between the line of action of the reaction force of the right forearm on the right elbow joint and the line of action of the right upper arm's own weight;

[0044] L4 is the horizontal distance between the line of action of the left upper arm's own weight and the line of action of the force exerted by the left shoulder joint on the left upper arm;

[0045] R4 is the horizontal distance between the line of action of the weight of the right upper arm and the line of action of the force exerted by the right shoulder joint on the right upper arm.

[0046] spine:

[0047]

[0048]

[0049] wherein: is the reaction force of the left upper arm on the left shoulder joint;

[0050] is the reaction force of the right upper arm on the right shoulder joint;

[0051] is the reaction torque of the left upper arm on the left shoulder joint;

[0052] is the reaction torque of the right upper arm on the right shoulder joint;

[0053] F T is the weight of the trunk;

[0054] F' L5 / S1 is the reaction force of the L5 / S1 intervertebral disc on the L5 vertebra;

[0055] M' L5 / S1 is the reaction torque of the L5 / S1 intervertebral disc on the L5 vertebra;

[0056] T5 is the horizontal distance between the line of action of the shoulder joint and the line of action of the weight of the trunk;

[0057] T6 is the horizontal distance between the line of action of the weight of the trunk and the line of action of the reaction force of the L5 / S1 intervertebral disc on the L5 vertebra.

[0058] According to formula (2), formula (3), formula (4), formula (5), formula (6), formula (7), the calculation expression of the L5 / S1 intervertebral disc force F L5 / S1 and torque M L5 / S1 when the operator is performing a two-handed operation is:

[0059]

[0060]

[0061] Referring to the force mode in the sagittal plane of the lumbosacral region, the force F m of the back muscle tension on the axis is x cm, and a is the angle between the axis of the spine and the horizontal plane. According to the static biomechanical balance principle, the following force analysis is performed on the L5 / S1 intervertebral disc:

[0062] F Muscle = M L5 / S1 / 0.01x (10)

[0063] F Compression = F Muscle + F L5 / S1 *cos a (11)

[0064] F Shear = F L5 / S1 *sin a (12)

[0065] In the formula: F Muscle is the back muscle tension; F Compression is the axial compression force of L5 / S1 intervertebral disc; F Shear is the transverse shear force of L5 / S1 intervertebral disc.

[0066] By means of the spinal biomechanics method and the real-time collected human posture data of the motion capture device, the force conditions of the lumbar-sacral part (i.e. L5 / S1 intervertebral disc) in the sagittal plane of the human body in different postures are analyzed, and then the evaluation and optimization of the working posture are realized, so that the purpose of reducing the spinal skeletal muscle disease is achieved.

[0067] The application further discloses an interactive system of multi-view spinal biomechanics dynamic analysis based on augmented reality, which comprises a central client and an augmented reality client.

[0068] The central client comprises a spinal biomechanics analysis module and a visual interactive module, which respectively provide the dynamic evaluation of the force of the human lumbar-sacral part and the visual real-time information feedback for the central client user.

[0069] The augmented reality client provides a gesture interactive mode for the augmented reality client user, realizes the corresponding interactive action behavior in the augmented reality scene, and the user selects a model by gestures based on the interactive system and downloads the selected model to the current environment, and further interacts with the downloaded model by gestures; the real-time collection of the working posture of the human body of the augmented reality client user is completed by building a motion capture environment, and the real-time motion simulation of the virtual human model is realized.

[0070] The application further discloses a working method of the interactive system of multi-view spinal biomechanics dynamic analysis based on augmented reality, which comprises the following steps:

[0071] Step 1, construction and sharing of a digital scene model resource library.

[0072] Before the evaluation starts, according to the digital scene model required by the evaluation, the augmented reality client user constructs a digital scene model resource library in the resource management module of the augmented reality client, and packs and uploads the constructed digital scene model resource library to a cloud disk.

[0073] Step 2, setting up of the motion capture environment and motion calibration.

[0074] The augmented reality client user wears the motion capture device and performs motion calibration on the motion capture device.

[0075] Step 3, perspective sharing of multiple augmented reality clients.

[0076] The augmented reality client user wears the augmented reality device, opens and enters the augmented reality client, connects to the central server through the network connection module, performs position calibration and evaluation of the augmented reality device, and realizes perspective sharing between multiple augmented reality client users.

[0077] Step 4, augmented reality client scene model loading.

[0078] The augmented reality client obtains the shared digital scene model resource library from the cloud disk, the augmented reality client user opens the shared digital scene model resource library in the resource management module, and selects the scene model. The selected scene model will be downloaded to the current augmented reality scene, and the augmented reality client user will interact with the model based on the interaction system through gestures, place the scene model in the appropriate position, and realize augmented reality client scene model loading.

[0079] Step 5, the augmented reality client user performs corresponding operations according to the scene.

[0080] Step 6, dynamic biomechanical analysis.

[0081] The user obtains the real-time lumbar force analysis result of the augmented reality client user under the loaded scene model through the spine biomechanical analysis module. The specific analysis result includes: real-time analysis result and visual chart of spine biomechanical indicators (shear force, compression force, moment of lumbar region).

[0082] Step 7: based on the real-time analysis result and visual chart of the spine biomechanical indicators obtained in step 6, realize dynamic feedback of human lumbar force, and enhance the ability of manufacturing enterprises to quickly build scientific and reasonable safety production mode under the background of intelligent manufacturing.

[0083] Beneficial effects:

[0084] 1. The lumbar-sacral stress analysis method based on spinal biomechanics disclosed in the application, which establishes a human lumbar-sacral stress evaluation model based on the theory of spinal biomechanics, constructs a human biomechanics model, and according to the static spinal biomechanics theory, analyzes and evaluates the stress on the sagittal plane of the lumbar-sacral part (i.e. L5 / S1 intervertebral disc) of the human body in different postures, realizes dynamic feedback of the stress on the lumbar-sacral part of the human body, and provides important evaluation data basis for realizing the evaluation and optimization of working posture and reducing spinal skeletal muscle disorders.

[0085] 2. The multi-view spinal biomechanics dynamic analysis interactive system based on augmented reality disclosed in the application, which builds a virtual simulation scene and obtains human working posture data through an augmented reality device and a motion capture device, simultaneously analyzes and evaluates the human working posture data in real time, significantly improves the accuracy of working posture evaluation, further shortens the working simulation cycle, and has important practical significance for manufacturing enterprises to quickly build a scientific and reasonable safety production mode and protect the occupational health of employees under the background of intelligent manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0086] Figure 1 The flowchart of the multi-view spinal biomechanics dynamic analysis method based on augmented reality of the application;

[0087] Figure 2 The schematic diagram of the multi-view spinal biomechanics dynamic analysis system based on augmented reality of the application;

[0088] Figure 3 The augmented reality client model resource library interface schematic diagram in the multi-view spinal biomechanics dynamic analysis method based on augmented reality of the application;

[0089] Figure 4 The augmented reality client user carries the car seat model to the car body model schematic diagram in the multi-view spinal biomechanics dynamic analysis method based on augmented reality of the application;

[0090] Figure 5 The central server interface schematic diagram in the multi-view spinal biomechanics dynamic analysis method based on augmented reality of the embodiment of the application. DETAILED DESCRIPTION

[0091] In order to better illustrate the purpose and advantages of the application, the content of the application is further described below in combination with the drawings and examples.

[0092] Example 1:

[0093] The embodiment applies a multi-view dynamic biomechanical analysis method based on augmented reality to evaluate the working posture of the automobile manufacturing enterprise during the carrying operation. The operator carries the automobile seat model to the automobile body model by using two different types of working postures in turn, and the dynamic biomechanical analysis is carried out during the process.

[0094] As shown in Figure 1 , the embodiment discloses a multi-view dynamic biomechanical analysis system based on augmented reality, which comprises a center server and an augmented reality device.

[0095] The center server and the augmented reality client are connected through a network connection module using a local wireless network.

[0096] The center server is deployed on a notebook computer and comprises a spine biomechanical analysis module and a motion capture system.

[0097] In the embodiment, the motion capture system adopts the Perception Neuron 3 motion capture system of NUI LAB, which provides real-time human kinematics data for the spine biomechanical analysis module to carry out dynamic biomechanical analysis.

[0098] The spine biomechanical analysis module comprises a group of spine biomechanical indexes, including the real-time analysis results and visualized charts of the tangential force, compression force and moment of action on the lumbosacral part.

[0099] The augmented reality device adopts the Microsoft HoloLens 2, which is deployed with an augmented reality client.

[0100] The augmented reality client comprises a network connection module, a resource management module and an interaction system.

[0101] The network connection module realizes the asynchronous receiving and data transmission between the center server and the augmented reality client by constructing a high-performance input / output completion port model.

[0102] The resource management module comprises a digital scene model resource library and a cloud disk, and the digital scene model resource library contains all current digital assets.

[0103] The digital assets include models and materials in the entire augmented reality scene, and all digital assets are stored in the cloud disk.

[0104] The interaction system provides a gesture interaction mode for the augmented reality client user to perform corresponding interactive actions in the augmented reality scene.

[0105] Based on the interaction system, the augmented reality client user selects a model by gesture and presses a download button to download the selected model to the current environment, and interacts with the downloaded model by gesture.

[0106] Further, as shown in Figure 2 The embodiment discloses a multi-view dynamic biomechanics analysis system based on augmented reality, which performs dynamic biomechanics analysis on the process of moving the seat model to the vehicle body model, and comprises the following steps:

[0107] Step one, construction and sharing of digital scene model resource library:

[0108] Before evaluation starts, according to the digital scene model of the vehicle body required by the vehicle seat assembly scene, as shown in Figure 3 The augmented reality client user constructs the digital scene model resource library containing the vehicle body and the seat in the resource management module of the Microsoft HoloLens 2, and packs and uploads the digital scene model resource library containing the vehicle body and the seat to the cloud disk;

[0109] Step two, construction and action calibration of the motion capture system:

[0110] The Microsoft HoloLens 2 user wears the Nuitrack Perception Neuron 3 motion capture system, and calibrates the Nuitrack Perception Neuron 3 motion capture system:

[0111] Step three, perspective sharing of multiple augmented reality clients:

[0112] The augmented reality client user wears the Microsoft HoloLens 2, opens and enters the augmented reality client, connects to the central server through the network connection module, calibrates and solves the position of the Microsoft HoloLens 2, and realizes perspective sharing between multiple Microsoft HoloLens 2 users;

[0113] Step four, augmented reality client scene model loading:

[0114] The Microsoft HoloLens 2 obtains the shared digital scene model resource library containing the vehicle body and the seat from the cloud disk, the augmented reality client user opens the shared digital scene model resource library containing the vehicle body and the seat in the Microsoft HoloLens 2 resource management module as shown in Figure 3 , and selects the vehicle body model and the seat model, the selected vehicle body model and the seat model will be downloaded to the current augmented reality scene, the augmented reality client user interacts with the model through gestures based on the interaction system, places the vehicle body and the seat model in the appropriate position, and realizes augmented reality client scene model loading;

[0115] Step five, the AR client user according to the car seat assembly scene, in turn, using the following two different types of work posture to carry the car seat model to the car body model:

[0116] (1) Work posture type one: using a half squatting posture, knee bending about 120°, trunk bending about 45°, both arms vertically downward to lift the heavy object. In the end of lifting stage, the operator's legs stand straight, the upper limbs and trunk slightly forward, the upper arm slightly forward, the elbow flexion, the heavy object relatively far away from the trunk;

[0117] (2) Work posture type two: using a full squatting posture, knee joint fully bent, the angle between the trunk and the horizontal plane about 45°, the upper arm and forearm keep relaxed state to lift the heavy object. The operator's legs stand straight, the upper limbs and trunk keep straight, the upper arm in neutral position, the elbow slightly flexion, the heavy object relatively close to the trunk.

[0118] The actual operation process is shown in Figure 4 ;

[0119] Step six, dynamic biomechanical analysis and evaluation of work posture:

[0120] As shown in Figure 5As shown, the test subject with a height of 1.85 meters and a weight of 80 kilograms is in a lumbar-sacral stress situation when assembling a car seat with a weight of 22.5 kilograms. According to the actual weight of the car seat, the load of the spinal biomechanics analysis module is configured as 22.5 kilograms (each hand load is 11.25 kilograms); the central server user obtains the real-time lumbar-sacral stress analysis result of the augmented reality client user in the car seat assembly scene through the spinal biomechanics analysis module, and draws the following conclusions: in the process of simulating the operation of the car seat in the automobile manufacturing enterprise, the lumbar-sacral stress of the L5 / S1 intervertebral disc is analyzed in real time. Among the two types of carrying postures, the first type of operation posture uses a half-squatting posture to carry heavy objects, and the lumbar-sacral load is obviously larger. The maximum transverse shear force of the L5 / S1 intervertebral disc is 644.55N, and the maximum axial compression force is 3622.26N, both of which exceed the safety risk threshold of the lumbar-sacral part (the shear force safety threshold is 500N, and the compression force safety threshold is 3400N), so there is a high risk of injury to the lumbar-sacral part of the operator; the second type of operation posture uses a full squatting posture to carry out the carrying operation, and the lumbar-sacral stress is obviously reduced. Therefore, through the lumbar-sacral stress analysis data of the two types of operation postures, it can be concluded that the first type of operation posture needs to be improved. When the operator carries out the carrying operation, the normal curvature of the spine should be maintained as much as possible and the horizontal distance between the center of gravity of the heavy object and the lumbar-sacral part of the human body should be reduced, so as to reduce the load on the spine caused by the human and the heavy object. Through the full squatting operation posture, the counterforce of the double legs can be used to realize the lifting of the heavy object, instead of relying on the excessive load of the spinal joints, so as to realize the evaluation and optimization of the operation posture, and reduce the spinal skeletal muscle diseases.

[0121] The above specific description further details the purpose, technical solution and beneficial effects of the application. It should be understood that the above description is only a specific embodiment of the application and is not used to limit the protection scope of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. A lumbar-sacral force analysis method based on spinal biomechanics, characterized in that: The method comprises the following steps, Step one, establishing a human body mechanics model; a multi-rigid-body ball stick model of human body segments and hinge joints is used to establish a human body mechanics model, the simplified human body model has 13 main body segments and 12 movement joints, the main body segments include head-neck-spine, left upper arm, right upper arm, left forearm, right forearm, left hand, right hand, left thigh, right thigh, left shank, right shank, left foot, right foot, the 12 movement joints include symmetrical shoulder joints, elbow joints, wrist joints, hip joints, knee joints and ankle joints; the body segments are stick-shaped rigid body structures with mass; the human body joints are approximately spherical hinge structures, which are used to connect and drive the body segments of the human body model to rotate; the relative mass, relative length and relative position of the mass center of each segment of the model are obtained from a standard human body proportion model; Step two, establishing a human body bone hierarchy; there is no relative displacement between the human body bones, so they are equivalent to a complete rigid body, and the human body skeleton is composed of multiple such "rigid bodies"; the movable part of the bone is called a joint, the joint connects different parts of the "rigid skeleton", and the movement of the parts around the joint is equivalent to the spatial rotation of the rigid body around the node; based on the analysis of the interosseous movement, the whole body movement is described as the rotational movement of the bone rigid body around the joint; the movement of each part of the human body is mutually connected and influenced, the movement of the upper joint directly affects the position of the lower bone, i.e. the movement of the upper arm directly affects the position of the forearm; the expression form of human body movement is the rotational change between the child bone and the parent bone, in order to facilitate the analysis of human body movement and the ownership between the parent and child bones, a human body bone hierarchy is established; The upper limbs of the human body are divided into three parts: upper arm, forearm and hand, and the corresponding driving joints are shoulder, elbow and wrist joints; The lower limbs of the human body are divided into three parts: thigh, shank and foot, and the corresponding driving joints are hip joint, knee joint and ankle joint; since the movement of the palms of the hands and the soles of the feet does not need to be analyzed, they are not subdivided; the bone hierarchy of the head and torso also does not need to be subdivided; Step three, analyzing the stress condition of the lumbosacral part; the following coordinate system is established with the human body anatomical axis as the reference: the x-axis is the human body sagittal axis, the direction is the front of the human body; the y-axis is the human body vertical axis, the direction is vertically upward; the z-axis is the human body coronal axis, the direction satisfies the right-hand Cartesian coordinate system with the directions of the x-axis and the y-axis; According to the statics balance principle, the force and torque borne by a joint of the human body are generated by the gravity of the human body and external load gravity, so under the condition of static at each time, the force and torque acting on the human body sagittal plane satisfy: ∑F X = 0, ∑F Y = 0, ∑M Z = 0 (1) where F X is the force in the x-axis direction on the sagittal plane; F Y is the force in the y-axis direction on the sagittal plane; M Z is the moment directed in the z-axis direction on the sagittal plane; For a two-handed operation task, the stress of each link in the human body sagittal plane is analyzed: According to the statics balance theorem, the local stress of each segment is analyzed to obtain: Left forearm: Right forearm: wherein: is the load force borne by the left arm; Load force experienced by the right arm; Fleftel is the force exerted by the left elbow joint on the left forearm; Frcor is the force exerted by the right elbow joint on the right forearm; moment of force exerted by the left elbow joint on the left forearm; Mrightelbow is the moment applied by the right elbow joint on the right forearm; F LA The force of gravity on the forearm itself; L1 is the horizontal distance between the left arm load force vector action line and the left forearm self-gravity action line; R1 is the horizontal distance between the right arm load force vector action line and the right forearm self-gravity action line; L2 is the horizontal distance between the left forearm self-gravity action line and the force action line exerted by the left elbow joint on the left forearm; R2 is the horizontal distance between the line of action of the right forearm's own weight and the line of action of the force exerted by the right elbow joint on the right forearm; Left upper arm: Right upper arm: wherein: is the reaction force of the left forearm on the left elbow joint; Frcor is the reaction force of the right forearm on the right elbow joint; Ml is the moment of the left forearm on the left elbow joint; is the reaction torque of the right elbow joint on the right forearm; F UA The force of gravity on the forearm itself; This refers to the force exerted by the left shoulder joint on the left upper arm. Fright is the force exerted by the right shoulder joint on the right upper arm; L3 is the horizontal distance between the line of action of the left forearm's reaction force on the left elbow joint and the line of action of the left upper arm's own weight; R3 is the horizontal distance between the line of action of the right forearm's reaction force on the right elbow joint and the line of action of the right upper arm's own weight; L4 is the horizontal distance between the line of action of the left upper arm's own weight and the line of action of the force exerted by the left shoulder joint on the left upper arm; R4 is the horizontal distance between the line of action of the right upper arm's own weight and the line of action of the force exerted by the right shoulder joint on the right upper arm; Spine: wherein: is the reaction force of the left upper arm on the left shoulder joint; FUR is the reaction force of the right upper arm on the right shoulder joint; Tl is the reaction torque of the left upper arm on the left shoulder joint; TUR is the reaction torque of the right upper arm to the right shoulder joint; F T For the trunk of the body itself gravity; F′ L5 / S1 F′ is the reaction force of the L5 / S1 disc on the L5 vertebra M' L5 / S1 M' is the reaction moment of the L5 / S1 disc on the L5 vertebra; T5 is the horizontal distance between the line of action of the shoulder joint and the line of action of the trunk's own weight; T6 is the horizontal distance between the line of action of the trunk's own weight and the line of action of the L5 / S1 intervertebral disc's reaction force on the L5 vertebra; According to formula (2), formula (3), formula (4), formula (5), formula (6), formula (7), when the operator performs the two-hand operation, the stress F of the L5 / S1 intervertebral disc L5 / S1 And the moment M L5 / S1 The calculation expression is: Referring to the force mode in the sagittal plane of the lumbosacral region, taking the center of the L5 / S1 intervertebral disc as the axis, the back muscle tension F m The force arm to the axis is x cm, and a is the included angle between the spinal axis and the horizontal plane; according to the static biomechanical balance principle, the following force analysis is carried out on the L5 / S1 intervertebral disc: F Muscle = M L5 / S1 / 0.01 x (10) F Compression = F Muscle + F L5 / S1 * cos a (11) F Shear = F L5 / S1 sina (12) where: F Muscle is the back muscle tension; F Compression is the L5 / S1 disc axial compression force; F Shear is the L5 / S1 disc transverse shear force; Through the method of spine biomechanics and real-time collection of human posture data by motion capture equipment, the stress condition of the human lumbar and sacral region in the sagittal plane under different postures is analyzed, and the evaluation and optimization of the working posture are realized.

2. An interactive system for augmented reality-based multi-view spinal biomechanics dynamic analysis, for implementing a lumbar-sacral force analysis method based on spinal biomechanics as claimed in claim 1, characterized in that: The center client and the augmented reality client are included, The center client includes a spine biomechanics analysis module and a visualization interaction module, which respectively provide real-time information feedback of dynamic evaluation and visualization of human lumbar and sacral stress for the center client user; The augmented reality client provides gesture interaction for the augmented reality client user, realizes corresponding interactive action behavior in the augmented reality scene, and the user selects a model by gesture based on the interaction system and downloads the selected model to the current environment, and further interacts with the downloaded model by gesture; through the construction of the motion capture environment, the real-time collection of the human working posture of the augmented reality client user is completed, and the real-time motion simulation of the virtual human model is realized.

3. The interactive system for augmented reality based multi-view spine biomechanics dynamic analysis of claim 2, wherein: The working method includes the following steps, Step 1, construction and sharing of the digital scene model resource library; Before the evaluation starts, the augmented reality client user constructs a digital scene model resource library in the resource management module of the augmented reality client according to the digital scene model required for the evaluation, and packs and uploads the constructed digital scene model resource library to the cloud disk; Step 2, construction of the motion capture environment and motion calibration; The augmented reality client user wears the motion capture equipment, and calibrates the motion of the motion capture equipment; Step 3, sharing of the perspective of multiple augmented reality clients; The augmented reality client user wears the augmented reality equipment, opens and enters the augmented reality client, connects to the center server through the network connection module, calibrates the position of the augmented reality equipment and evaluates, and realizes the perspective sharing between multiple augmented reality client users; Step 4, loading of the augmented reality client scene model; The augmented reality client obtains the shared digital scene model resource library from the cloud disk, the augmented reality client user opens the shared digital scene model resource library in the resource management module, and selects a scene model, which will be downloaded to the current augmented reality scene, the augmented reality client user interacts with the model by gesture based on the interaction system, places the scene model in the appropriate position, and realizes the loading of the augmented reality client scene model. Step 5, the augmented reality client user performs corresponding operations according to the scene; Step 6, dynamic biomechanical analysis; The user obtains the real-time lumbar-sacral force analysis result of the augmented reality client user under the loaded scene model through the spine biomechanical analysis module; the specific analysis result includes: real-time analysis result and visual chart of the spine biomechanical index (shear force, compression force and moment of the lumbar-sacral part); Step 7: according to the real-time analysis result and visual chart of the spine biomechanical index obtained in step 6, the dynamic feedback optimization of the human lumbar-sacral force condition is realized.

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