CN108852360A - A kind of human body lower limbs hip and knee angle detection system and method - Google Patents

Abstract

Translated fromChinese

本发明涉及一种人体下肢髋膝关节角度检测系统及方法，该检测系统包括：4个微型航姿模块单元、4个无线单元、1个控制器单元和1台PC机。微型航姿模块单元用于检测人体右大腿、右小腿、左大腿及左小腿的姿态信息并传输至无线单元主模块，无线单元从模块通过zigbee通信方式接收无线单元主模块的数据并传输至控制器单元，控制器单元对大腿、小腿的姿态信息进行传输控制并通过USB线传输至PC机，PC机通过算法完成对人体下肢髋膝关节角度的计算，并将角度信息实时地显示于检测系统软件界面上。该检测系统具有下肢穿戴方便、检测数据准确、实时显示角度变化的特点，适用于人体下肢外骨骼助力机构、康复机构以及生物医学工程。

The invention relates to a system and method for detecting the angle of hip and knee joints of human lower limbs. The detection system comprises four miniature attitude module units, four wireless units, one controller unit and one PC. The micro attitude module unit is used to detect the posture information of the right thigh, right calf, left thigh and left calf of the human body and transmit it to the main module of the wireless unit. The slave module of the wireless unit receives the data of the main module of the wireless unit through zigbee communication and transmits it to the control The controller unit transmits and controls the posture information of the thigh and calf and transmits it to the PC through the USB cable. The PC completes the calculation of the angle of the hip and knee joints of the lower limbs of the human body through an algorithm, and displays the angle information on the detection system in real time. on the software interface. The detection system has the characteristics of easy wearing of lower limbs, accurate detection data, and real-time display of angle changes. It is suitable for human lower limb exoskeleton assisting institutions, rehabilitation institutions, and biomedical engineering.

Description

Translated fromChinese

一种人体下肢髋膝关节角度检测系统及方法A system and method for detecting the angle of hip and knee joints of human lower limbs

技术领域technical field

本发明涉及检测技术领域，具体说，是一种人体下肢髋膝关节角度检测系统及方法。The invention relates to the technical field of detection, in particular to a system and method for detecting the angle of the hip and knee joints of human lower limbs.

背景技术Background technique

髋关节和膝关节的运动构成了人体下肢运动的主要部分，通过检测技术获得准确的髋膝关节运动信息能够为人体下肢助力机构、下肢外骨骼康复机构或者生物医学等工程提供有效的数据信息来源。The movement of the hip joint and knee joint constitutes the main part of the movement of the lower limbs of the human body. Obtaining accurate hip and knee joint movement information through detection technology can provide an effective source of data information for human lower limb power assist institutions, lower extremity exoskeleton rehabilitation institutions, or biomedical engineering .

经查阅国内外文献发现目前检测髋膝关节角度的系统及方法存在以下特点：①使用的传感器有微型加速度计、陀螺仪、光纤角度传感器等，其中单独使用加速度计或者单独使用陀螺仪来测量角度信息都会在角度计算的过程中产生一定的误差，处理该误差的方法一般为通过大量的实验发现误差的波动范围然后在相应的角度上作出补偿，但会增加数据处理的时间，降低测量的实效性。②检测系统数据传输的方式主要有有线和无线两种，有线传输会给实验造成极大的不便，并且增加人体穿戴的不适感。③模型的建立和角度计算方法不尽相同。After reviewing domestic and foreign literature, it is found that the current systems and methods for detecting hip and knee joint angles have the following characteristics: ① The sensors used include micro-accelerometers, gyroscopes, and fiber optic angle sensors, among which the accelerometer or gyroscope is used alone to measure the angle Information will generate certain errors in the process of angle calculation. The method of dealing with this error is generally to find the fluctuation range of the error through a large number of experiments and then make compensation on the corresponding angle, but it will increase the time of data processing and reduce the actual effect of measurement. sex. ② There are two main methods of data transmission in the detection system: wired and wireless. Wired transmission will cause great inconvenience to the experiment and increase the discomfort of wearing it. ③The establishment of the model and the calculation method of the angle are not the same.

综上所述，本发明具有以下优点：①所使用的微型航姿模块是包括3轴加速度计、3轴陀螺仪及3轴磁场计的传感器，能够将各种传感器所检测的信息融合滤波，特别适合运用于下肢髋膝关节角度测量并能提供准确的角度信息。②数据传输方式为无线传输方式，大大地减少了人体穿戴的不适感，为在各种情况下进行实验提供了可行性，无线技术具体指的是遵循zigbee协议的通信技术，是一种组建无线传感器网络的核心技术。③通过建立连杆模型，模拟人体下肢髋膝关节完成的运动并完成关节角度的计算。④系统实时性能好，数据接收和显示稳定。In summary, the present invention has the following advantages: 1. the used miniature attitude module is a sensor including a 3-axis accelerometer, a 3-axis gyroscope and a 3-axis magnetometer, which can fuse and filter the information detected by various sensors, It is especially suitable for measuring the angle of hip and knee joints of lower limbs and can provide accurate angle information. ②The data transmission method is wireless transmission, which greatly reduces the discomfort of wearing the human body, and provides feasibility for experiments in various situations. Wireless technology specifically refers to the communication technology that follows the zigbee protocol, which is a wireless The core technology of sensor network. ③Through the establishment of the connecting rod model, the movement of the hip and knee joints of the lower limbs of the human body is simulated and the calculation of the joint angle is completed. ④ The real-time performance of the system is good, and the data reception and display are stable.

发明内容Contents of the invention

本发明的目的在于提供一种人体下肢髋膝关节角度检测系统及方法，能够保证所检测角度的准确性，并采用无线通信的方式传输数据，使人体穿戴更加方便，为在各种情况下进行实验提供了可行性。The object of the present invention is to provide a system and method for detecting the angle of the hip and knee joints of human lower limbs, which can ensure the accuracy of the detected angle, and transmit data by means of wireless communication, so that the human body is more convenient to wear, and it can be used in various situations. Experiments provide feasibility.

一种人体下肢髋膝关节角度检测系统及方法，其特征在于该检测系统包括：4个微型航姿模块单元、4个无线单元、1个控制器单元和1台PC机。A detection system and method for hip and knee joint angles of human lower limbs, characterized in that the detection system includes: 4 miniature attitude module units, 4 wireless units, 1 controller unit and 1 PC.

进一步，微型航姿模块单元由微型航姿模块、无线单元主模块、电池充电接口、工作开关、电池连接接口、电池组成，微型航姿模块用于提供9轴的检测信息，包括3轴加速度计信息、3轴陀螺仪信息及3轴磁场计信息，同时实时提供经卡曼滤波优化的姿态信息，无线单元主模块用于接收微型航姿模块检测到的信息，电池为微型航姿模块和无线单元主模块提供能源，在电池电量耗尽后，电池充电接口通过USB线与电脑连接为电池充电，工作开关用于调整微型航姿模块单元的工作状态。Further, the miniature attitude module unit is composed of a miniature attitude module, a wireless unit main module, a battery charging interface, a working switch, a battery connection interface, and a battery. The miniature attitude module is used to provide 9-axis detection information, including a 3-axis accelerometer Information, 3-axis gyroscope information and 3-axis magnetometer information, while providing real-time attitude information optimized by Kaman filtering. The main module of the wireless unit is used to receive the information detected by the miniature attitude module. The main module of the unit provides energy. After the battery is exhausted, the battery charging interface is connected to the computer through a USB cable to charge the battery. The working switch is used to adjust the working state of the micro attitude module unit.

进一步，无线单元由无线单元主模块和无线单元从模块组成，无线单元主、从模块的通信方式遵循的协议为zigbee协议，数据传输前将主、从模块调整至同一频道和相同的波特率，以完成配对，无线单元主模块与微型航姿模块单元其它组成部分焊接在一块电路板上，无线单元从模块与控制器焊接在另一块电路板上。Further, the wireless unit is composed of a wireless unit master module and a wireless unit slave module. The protocol followed by the communication mode of the wireless unit master and slave modules is the zigbee protocol. Before data transmission, the master and slave modules are adjusted to the same channel and the same baud rate , to complete the pairing, the main module of the wireless unit and other components of the miniature attitude module unit are welded on one circuit board, and the slave module of the wireless unit and the controller are welded on another circuit board.

进一步，控制器单元由无线单元从模块和控制器组成，无线单元从模块将接收到的数据传输至控制器，控制器完成大、小腿姿态信息的传输控制并通过USB传输线将数据传输至PC机。Further, the controller unit is composed of a wireless unit slave module and a controller. The wireless unit transmits the received data from the module to the controller. The controller completes the transmission control of the posture information of the big and small legs and transmits the data to the PC through the USB transmission line. .

进一步，PC机配备1个USB分线器来扩展PC机的USB口，并且配备4个USB转串口模块，以接收来自控制器单元传输的数据，完成对髋膝关节角度的计算并实时地显示在应用程序界面上。Furthermore, the PC is equipped with a USB splitter to expand the USB port of the PC, and is equipped with 4 USB-to-serial modules to receive the data transmitted from the controller unit, complete the calculation of the hip and knee joint angle and display it in real time on the application interface.

进一步，髋膝关节角度的计算方法是通过将人体双肢简化为8自由度的连杆模型，一侧拥有4个自由度，以右腿为例，其髋关节利用一个球副来等效代替，其膝关节利用一个转动副来等效代替，结合D-H方法建立坐标系，通过姿态变换求解关节变量进而得出髋膝关节角度。Furthermore, the calculation method of the hip and knee joint angle is to simplify the human limbs into a connecting rod model with 8 degrees of freedom, and one side has 4 degrees of freedom. Taking the right leg as an example, the hip joint is equivalently replaced by a ball pair , the knee joint is equivalently replaced by a rotating pair, and the coordinate system is established by combining the D-H method, and the joint variables are solved by attitude transformation to obtain the hip and knee joint angle.

附图说明Description of drawings

图1是检测系统及方法实现的流程框图；Fig. 1 is the flowchart block diagram that detection system and method realize;

图2是微型航姿模块单元的正视与后视图；Fig. 2 is the front view and rear view of the miniature attitude module unit;

图3是检测系统的连接示意图；Fig. 3 is the connection schematic diagram of detection system;

图4是人体标定及穿戴微型航姿模块单元示意图；Fig. 4 is a schematic diagram of the human body calibration and wearing miniature attitude module unit;

图5是人体行走过程示意图；Fig. 5 is a schematic diagram of the walking process of a human body;

图6是人体下肢连杆模型示意图；Fig. 6 is a schematic diagram of a human lower limb connecting rod model;

图7是坐标系示意图；Fig. 7 is a schematic diagram of a coordinate system;

图8是检测系统PC机应用程序界面显示图。Fig. 8 is a display diagram of the PC application program interface of the detection system.

具体实施方式Detailed ways

以下结合附图对本发明的实施方式进行具体说明。Embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings.

图1是检测系统及方法实现的流程框图，图2是微型航姿模块单元的正视与后视图，图3是检测系统的连接示意图，图4是人体标定及穿戴微型航姿模块单元示意图，图5是人体行走过程示意图，图6是人体下肢连杆模型示意图，图7是坐标系示意图，图8是检测系统PC机应用程序界面显示图。Fig. 1 is a flow diagram of the detection system and method realization, Fig. 2 is a front view and a rear view of the micro-attitude attitude module unit, Fig. 3 is a schematic diagram of the connection of the detection system, and Fig. 4 is a schematic diagram of the human body calibration and wearing micro-attitude attitude module unit, Fig. 5 is a schematic diagram of the walking process of a human body, FIG. 6 is a schematic diagram of a human lower limb connecting rod model, FIG. 7 is a schematic diagram of a coordinate system, and FIG. 8 is a display diagram of a PC application program interface of the detection system.

本实施例提供了一种人体下肢髋膝关节角度检测系统及方法，检测过程及角度实现方法参图1流程框图所示，参图4、图5下肢穿戴微型航姿模块单元，进行人体标定并开始行走实验，4个微型航姿模块单元分别为Ⅰ级微型航姿模块单元1、Ⅱ级微型航姿模块单元2、Ⅲ级微型航姿模块单元3及Ⅳ级微型航姿模块单元4，它们具有相同的结构，下肢穿戴时4个微型航姿模块单元正面保持与人体矢状面平行，人体静止站立时保持微型航姿模块传感器坐标系中X轴垂直于地面且方向向下，微型航姿模块单元粘贴于布带上，之后利用布带21，通过绑缚的方式将Ⅰ级微型航姿模块单元1和Ⅱ级微型航姿模块单元2分别与人体右大腿17和右小腿18保持紧致连接，Ⅲ级微型航姿模块单元3和Ⅳ级微型航姿模块单元4分别与人体左大腿19和右小腿20保持紧致连接，之后对无线单元的主、从模块进行调频配对接收大腿和小腿姿态信息，姿态信息传输给控制器，控制器对大、小腿姿态信息进行传输控制并通过USB线将信息传输至PC机，PC机完成对髋、膝角度的计算，并将角度信息实时地显示于应用程序界面上。This embodiment provides a system and method for detecting the angle of the hip and knee joints of the lower limbs of the human body. The detection process and the angle realization method are shown in the flow chart of FIG. Start the walking experiment, and the four miniature attitude module units are Class I miniature attitude module unit 1, Level II miniature attitude module unit 2, Level III miniature attitude module unit 3 and Level IV miniature attitude module unit 4. With the same structure, when the lower limbs are worn, the fronts of the four miniature attitude module units are kept parallel to the sagittal plane of the human body. The module unit is pasted on the cloth tape, and then the cloth tape 21 is used to keep the first-level micro-attitude attitude module unit 1 and the second-level micro-attitude attitude module unit 2 tightly to the right thigh 17 and right calf 18 of the human body by binding Connection, level III micro attitude module unit 3 and level IV micro attitude module unit 4 are tightly connected to the left thigh 19 and right calf 20 of the human body respectively, and then the master and slave modules of the wireless unit are FM paired to receive the thigh and calf Attitude information, the attitude information is transmitted to the controller, the controller transmits and controls the attitude information of the big and lower legs and transmits the information to the PC through the USB cable, and the PC completes the calculation of the hip and knee angles, and displays the angle information in real time on the application interface.

在本实例中，4个微型航姿模块单元具有相同的结构，参图2所示，以Ⅰ级微型航姿模块单元1为例，Ⅰ级微型航姿模块单元1由微型航姿模块5、无线单元主模块6、电池充电接口7、工作开关8、电池连接接口9、电池10组成。工作开关8调整Ⅰ级微型航姿模块单元1的工作状态，当使微型航姿模块单元1进行工作时，微型航姿模块5用于提供姿态信息，无线单元主模块6与微型航姿模块5连接，以接收检测到的信息，电池10通过电池连接接口9与Ⅰ级微型航姿模块单元1连接，为微型航姿模块5和无线单元主模块6提供能源，工作开关8调整Ⅰ级微型航姿模块单元1的工作状态，当Ⅰ级微型航姿模块单元1进行充电时，电池充电接口7通过USB线与电脑连接为电池充电。In this example, the four miniature attitude module units have the same structure, as shown in Figure 2, taking the first-level miniature attitude module unit 1 as an example, the first-level miniature attitude module unit 1 is composed of the miniature attitude module 5, The wireless unit main module 6, the battery charging interface 7, the working switch 8, the battery connection interface 9, and the battery 10 are composed. The working switch 8 adjusts the working state of the Class I miniature attitude module unit 1. When the miniature attitude module unit 1 is working, the miniature attitude module 5 is used to provide attitude information, and the wireless unit main module 6 and the miniature attitude module 5 connected to receive the detected information, the battery 10 is connected to the Class I miniature attitude module unit 1 through the battery connection interface 9, and provides energy for the miniature attitude module 5 and the wireless unit main module 6, and the working switch 8 adjusts the level I miniature attitude module unit 1. In the working state of the attitude module unit 1, when the Class I miniature attitude module unit 1 is being charged, the battery charging interface 7 is connected to the computer via a USB cable to charge the battery.

在本实例中，检测系统的连接方式参图3所示，控制器单元12包括无线单元从模块11和控制器芯片13，PC机16通过USB分线器14将其USB口扩展成4个，控制器单元12通过USB转串口模块15与PC机16完成数据传输。In this example, the connection mode of the detection system is shown in Figure 3, the controller unit 12 includes a wireless unit slave module 11 and a controller chip 13, and the PC 16 expands its USB port to 4 through the USB splitter 14, The controller unit 12 completes data transmission with the PC 16 through the USB-to-serial port module 15 .

在本实例中，参图6和图7所示，髋膝关节的角度实现通过将人体双肢简化为8自由度的连杆模型，一侧拥有4个自由度，以右腿为例，其髋关节利用一个球副等效代替，其膝关节利用一个转动副等效代替。In this example, as shown in Figure 6 and Figure 7, the angle of the hip and knee joints is realized by simplifying the human limbs into a connecting rod model with 8 degrees of freedom, and one side has 4 degrees of freedom. Taking the right leg as an example, its The hip joint is equivalently replaced by a spherical joint, and the knee joint is equivalently replaced by a rotational joint.

利用D-H方法为右腿连杆模型建立坐标系，将球副以上作为固定端，在第一关节即髋关节处建立基坐标系{0}(简称系{0})，为简化计算，系{0}的建立与微型航姿模块传感器自身的固定坐标系{S}(简称系{S})同向，综合微型航姿模块穿戴方式，选择所有坐标系的Z轴正方向为垂直人体向外，连杆围绕各轴旋转的正负根据旋转矢量方向的右手法则确定；Using the D-H method to establish a coordinate system for the right leg link model, the upper part of the ball pair is used as the fixed end, and the base coordinate system {0} (referred to as the system {0}) is established at the first joint, the hip joint. In order to simplify the calculation, the system { The establishment of 0} is in the same direction as the fixed coordinate system {S} (referred to as system {S}) of the micro-head attitude module sensor itself. Integrating the wearing mode of the micro-head attitude module, the positive direction of the Z-axis of all coordinate systems is selected to be vertical to the outside of the human body. , the positive and negative rotation of the connecting rod around each axis is determined according to the right-hand rule of the direction of the rotation vector;

系{0}由X_O、Y_O、Z_O轴表示，以球副中心O为原点，X_O垂直于地面，向下为其正方向，Y_O轴水平，方向由X_O和Z_O决定。系{1}的X₁轴在连杆1和连杆2的公共法线上，其方向由连杆1指向连杆2，Z₁与Z_O重合，Y₁由X₁和Z₁决定，在大腿穿戴的微型航姿模块单元上建立大腿传感器坐标系，简称系{2}，用X₂、Y₂、Z₂表示，由穿戴方式可知，系{2}的坐标轴方向与系{1}均相同，系{3}的X₃轴在连杆2和末端的公共法线上，方向由连杆2指向末端，以小腿穿戴的微型航姿模块单元作为连杆的末端，并建立小腿传感器坐标系，简称系{4}，由穿戴方式可知，系{4}的坐标轴方向与系{3}均相同。The system {0} is represented by X_O , Y_O , and Z_O axes, with the spherical subcenter O as the origin, X_O is perpendicular to the ground, and its positive direction is downward, and the Y_O axis is horizontal, and the direction is determined by X_O and Z_O . The X₁ axis of system {1} is on the common normal line of connecting rod 1 and connecting rod 2, its direction is from connecting rod 1 to connecting rod 2, Z₁ coincides with Z_O , Y₁ is determined by X₁ and Z₁ , The thigh sensor coordinate system is established on the miniature attitude module unit worn on the thigh, referred to as system {2}, represented by X₂ , Y₂ , Z₂ , it can be known from the wearing method that the coordinate axis direction of system {2} is the same as that of system {1 } are the same, the X₃ axis of the system {3} is on the common normal of the connecting rod 2 and the end, the direction is from the connecting rod 2 to the end, the miniature attitude module unit worn on the lower leg is used as the end of the connecting rod, and the lower leg is established The sensor coordinate system, referred to as system {4}, can be seen from the way of wearing, the coordinate axis direction of system {4} is the same as that of system {3}.

髋关节角度通过将穿戴在大腿的微型航姿模块单元检测到的姿态信息转换到系{0}中计算得到，具体实现方法是：采用欧拉角表示运动姿态，其旋转次序定为先绕Z₂轴旋转α角，再绕Y₂轴旋转β角，最后绕X₂轴旋转γ角，得到的姿态信息表示为：The hip joint angle is calculated by converting the attitude information detected by the miniature attitude module unit worn on the thigh into the system {0}. The specific implementation method is: use the Euler angle to represent the movement attitude, and the rotation order is set to first revolve around Z Rotate the α angle around the₂ axis, then rotate the β angle around the Y₂ axis, and finally rotate the γ angle around the X₂ axis, the attitude information obtained is expressed as:

式中c代表cos，s代表sin。In the formula, c represents cos, and s represents sin.

该旋转次序可由系{S}中相反的旋转次序来解释：先绕X_S轴旋转γ角，再绕Y_S轴旋转β角，最后绕Z_S轴旋转α角，系{0}相对于系{S}不存在旋转变换，该旋转次序在系{0}中解释与系{S}中相同，所以在系{0}中髋关节的旋转角度表示为绕X_O旋转的γ角，收展角度表示为绕Y_O轴的β角，屈伸角度表示为绕Z_O轴的α角。This rotation order can be explained by the opposite rotation order in the system {S}: first rotate γ angle around the X_S axis, then rotate β angle around the Y_S axis, and finally rotate α angle around the Z_S axis, the system {0} is relative to the system There is no rotation transformation in {S}, and the rotation order in system {0} is the same as that in system {S}, so the rotation angle of the hip joint in system {0} is expressed as the γ angle of rotation around X_O , stretching Angles are expressed as β angles around the Y_O axis, and flexion and extension angles are expressed as α angles around the Z_O axis.

膝关节角度通过将穿戴在小腿的微型航姿模块单元检测到的姿态信息转换到系{0}中计算得到，具体实现方法是：穿戴在小腿的微型航姿模块单元作为右腿连杆的末端，膝关节由一个转动副代替，故仅考虑微型航姿模块单元绕Z₄轴的旋转，假设绕Z₄轴旋转θ角，得到的姿态信息表示成齐次变换矩阵为：The knee joint angle is calculated by converting the attitude information detected by the miniature attitude module unit worn on the lower leg into the system {0}. The specific implementation method is: the miniature attitude module unit worn on the lower leg is used as the end of the right leg link , the knee joint is replaced by a revolving pair, so only the rotation of the micro attitude module unit around the Z₄ -axis is considered, assuming that the rotation around the Z₄ -axis is angle θ, the obtained attitude information is expressed as a homogeneous transformation matrix:

即which is

连杆运动方程为设第一关节变量设为θ₁，第二关节变量设为θ₂。The equation of motion of the connecting rod is Let the first joint variable be θ₁ , and the second joint variable be θ₂ .

将(11)、(12)、(13)、(14)、(15)均代入连杆运动方程为Substituting (11), (12), (13), (14), and (15) into the equation of motion of the connecting rod is

由(10)θ₁＝α，由(16)From (10) θ₁ = α, from (16)

由(17)by (17)

θ₂＝θ-α (18)θ₂ = θ - α (18)

由(18)by (18)

膝关节屈伸角度等于θ₂。The knee flexion and extension angle is equal to θ₂ .

在本实例中，人体穿戴微型航姿模块单元进行行走实验和角度信息显示见图5和图8。In this example, the human body wears the miniature attitude module unit to carry out the walking experiment and display the angle information as shown in Fig. 5 and Fig. 8 .

本发明提供一种人体下肢髋膝关节角度检测系统及方法，有如下优点：The invention provides a system and method for detecting the angle of the hip and knee joints of human lower limbs, which has the following advantages:

1)所使用的微型航姿模块是包括3轴加速度计、3轴陀螺仪及3轴磁场计的传感器，能够将各种传感器所检测的信息融合滤波，特别适合运用于下肢髋膝关节角度测量并能提供准确的角度信息。1) The miniature attitude module used is a sensor including a 3-axis accelerometer, a 3-axis gyroscope and a 3-axis magnetometer, which can fuse and filter the information detected by various sensors, and is especially suitable for measuring the angle of the hip and knee joints of the lower limbs And can provide accurate angle information.

2)所采用数据传输方式为无线传输方式，大大地减少了人体穿戴的不适感，为在各种情况下进行实验提供了可行性，无线技术具体指的是遵循zigbee协议的通信技术，是一种组建无线传感器网络的核心技术。2) The data transmission method adopted is wireless transmission, which greatly reduces the discomfort of wearing the human body and provides feasibility for experiments in various situations. Wireless technology specifically refers to the communication technology following the zigbee protocol, which is a A core technology for building wireless sensor networks.

3)通过建立连杆模型，模拟人体下肢髋膝关节完成的运动并完成关节角度计算。3) By establishing a connecting rod model, the movement of the hip and knee joints of the lower limbs of the human body is simulated and the joint angle calculation is completed.

4)系统实时性能好，数据接收和显示稳定。4) The real-time performance of the system is good, and the data reception and display are stable.

上述仅详细地说明了本发明的实施方式和优点，这些实施方式不视为对本发明的限制，但基于本发明的系统结构和方法原理所做的改进，均属于本发明的保护范围之内。The above only describes the embodiments and advantages of the present invention in detail, and these embodiments are not considered to limit the present invention, but improvements made based on the system structure and method principles of the present invention all fall within the scope of protection of the present invention.

Claims (4)

1. a kind of human body lower limbs hip and knee angle detection system, it is characterised in that the detection system includes：4 miniature navigation attitude mouldsModule unit, 4 radio-cells, 1 controller unit and 1 PC machine；

When carrying out the detection of human body lower limbs hip and knee angle, human body only need to be on right thigh, right leg, left thigh and left legMiniature navigation attitude modular unit is simply dressed, the posture information for the large and small leg of human body that miniature navigation attitude modular unit detects passes throughThe mode of wireless communication is transmitted to controller unit, and controller unit carries out transmission control to the posture information of large and small leg and leads toIt crosses USB transmission line and is transmitted to PC machine, PC machine completes storage, calculating and display in relation to data；

The mode that the human body dresses miniature navigation attitude modular unit is that miniature navigation attitude modular unit front is kept and human body sagittal planeIn parallel, kept when human body stands still in miniature navigation attitude module coordinate system X-axis perpendicular to ground and direction it is downward, miniature navigation attitude mouldModule unit is pasted on cloth band, shares 4 miniature navigation attitude modular units, their structures having the same, by way of bondageI grade of miniature navigation attitude modular unit and II grade of miniature navigation attitude modular unit are kept into compact company with human body right thigh and right leg respectivelyIt connects, III grade of miniature navigation attitude modular unit and IV grade of miniature navigation attitude modular unit keep compact with human body left thigh and right leg respectivelyConnection；

The miniature navigation attitude modular unit by miniature navigation attitude module, radio-cell main module, battery charging interface, operating switch,Battery connecting interface, battery composition；

Miniature navigation attitude module is for providing 9 repacking measurement informations, including 3 axis accelerometer information, 3 axis gyroscope information and 3 axis magneticField meter information, while the posture information optimized through Kalman Filtering being provided in real time, radio-cell main module is for receiving miniature navigation attitudeThe information that module detects, battery provides the energy for miniature navigation attitude module and radio-cell main module, after dead battery capabilityBattery charging interface is connected as battery charging by USB line and computer, and operating switch is for adjusting miniature navigation attitude modular unitWorking condition.

2. human body lower limbs hip and knee angle detection system according to claim 1, it is characterised in that：The controller listMember is made of radio-cell from module and controller；

The data received are transmitted to controller from module by radio-cell, and controller completes the biography of thigh, shank posture informationDefeated control simultaneously sends data to PC machine by USB transmission line, and the transmission of the thigh and shank posture information controls realization sideMethod is as follows：

By taking right leg as an example, controller receives the data of thigh, enters interruption using program and carries out storage processing, after the completion of storageFrame head is searched, to obtain specified digit data after frame head, only retains the posture information that miniature navigation attitude module provides, gives up originalInformation includes 3 axis accelerometer information, 3 axis gyroscope information and 3 axis magnetometer information, filters out shank using identical methodPosture information and stored, after the storage of the posture information of one group of thigh and one group of shank is complete, controller is logical by 2This two group information is transmitted to PC machine with asynchronism transceiver, is so recycled, PC machine can be realized to the same of thigh and shank dataWhen receive.

3. human body lower limbs hip and knee angle detection system according to claim 1, it is characterised in that：The radio-cellIt is made of radio-cell main module and radio-cell from module；

The agreement that the communication mode of the master and slave module of radio-cell follows is zigbee agreement, by master and slave module tune before data transmissionIt is whole to same channel and identical baud rate, to complete to match, miniature navigation attitude mould described in radio-cell main module and claim 3The other component parts of module unit are welded on one piece of circuit board, and radio-cell is welded on another block of electricity from module and the controllerOn the plate of road.

4. human body lower limbs hip and knee angle detection system according to claim 1, it is characterised in that：The PC machine is equipped with1 USB deconcentrator extends the USB port of PC machine, and is equipped with 4 USB and turns serial port module, is passed with receiving from controller unitDefeated data are completed the calculating to hip and knee angle and are displayed in real time on Application Program Interface, the human body lower limbs hipIt is as follows that knee joint angle calculates concrete methods of realizing：

The movement of human body lower limbs hip and knee be divided into the rotary motion of hip joint, movement of taking down the exhibits, flexion and extension and it is kneed bendMovement to be stretched, thus the double limbs of human body are reduced to the connecting rod model of 8 freedom degrees, side possesses 4 freedom degrees, by taking right leg as an example,Hip joint is using a ball pair come equivalent replacement, and knee joint is using a revolute pair come equivalent replacement；

It is right leg connecting rod model foundation coordinate system using D-H method, ball is secondary above as fixing end, it is closed in the first joint, that is, hipIt is established at section basis coordinates system { 0 }, is referred to as { 0 }, be the foundation and the fixation of miniature navigation attitude module itself of { 0 } to simplify the calculationIn the same direction, the fixed coordinate system { S } of miniature navigation attitude module itself is referred to as { S } to coordinate system { S }；Comprehensive miniature navigation attitude module wearing sideFormula selects the Z axis positive direction of all coordinate systems outside for vertical human body, and connecting rod is positive and negative according to rotating vector around the rotation of each axisThe right-hand rule in direction determines；

It is { 0 } by X_O、Y_O、Z_OAxis indicates, using ball sub-center O as origin, X_OIt is downwards its positive direction, Y perpendicular to ground_OAxis waterFlat, direction is by X_OAnd Z_OIt determines, is the X of { 1 }₁In the common normal of connecting rod 1 and connecting rod 2, direction is directed toward by connecting rod 1 to be connected axisBar 2, Z₁With Z_OIt is overlapped, Y₁By X₁And Z₁It determines, establishes thigh sensor coordinates on the miniature navigation attitude modular unit of thigh wearingSystem is referred to as { 2 }, uses X₂、Y₂、Z₂Indicate, by wearing mode it is found that be { 2 } change in coordinate axis direction be that { 1 } is all the same, be{ 3 } X₃For axis in the common normal of connecting rod 2 and end, end is directed toward by connecting rod 2 in direction, the miniature navigation attitude mould dressed with shankEnd of the unit as connecting rod, and shank sensor coordinate system is established, it is referred to as { 4 }, by wearing mode it is found that being the seat of { 4 }Parameter direction be that { 3 } are all the same；

Hip Angle is in { 0 } by the way that the posture information that the miniature navigation attitude modular unit for being worn on thigh detects to be transformed intoIt is calculated, concrete methods of realizing is：Indicate that athletic posture, rotation sequence are set to first around Z using Eulerian angles₂Axis rotation alpha angle,Further around Y₂Axis rotation β angle, finally around X₂Axis rotates the angle γ, and obtained posture information is expressed as：

C represents cos, behalf sin in formula；

The rotation sequence is explained by being rotation sequence opposite in { S }：First around X_SAxis rotates the angle γ, further around Y_SAxis rotation β angle,Finally around Z_SAxis rotation alpha angle is { 0 } relative to being { S } there is no rotation transformation, which is being to explain in { 0 } and beIt is identical in { S }, so being that the rotation angle of hip joint in { 0 } is expressed as around X_OThe angle γ of rotation, spreading angle are expressed as around Y_OThe angle β of axis, bends and stretches angle and is expressed as around Z_OThe angle α of axis；

Knee joint bends and stretches angle by the way that the posture information that the miniature navigation attitude modular unit for being worn on shank detects to be transformed into{ 0 } it is calculated in, concrete methods of realizing is：It is worn on end of the miniature navigation attitude modular unit of shank as right leg connecting rod,Knee joint is replaced by a revolute pair, therefore only considers miniature navigation attitude modular unit around Z₄The rotation of axis, it is assumed that around Z₄Axis rotates the angle θ,Obtained posture information is expressed as homogeneous transform matrix：

I.e.

Link motion equation isIf the first joint variable is set as θ₁, second joint variable is set as θ₂；

(2), (3), (4), (5), (6) are substituted into link motion equation is

Angle, θ is bent and stretched by (1) hip joint₁=α, by (7)

C θ=c α c θ₂-sαsθ₂ (8)

S θ=s α c θ₂+cαsθ₂

By (8)

θ₂=θ-α (9)

By (9)

Knee joint bends and stretches angle equal to θ₂；

It is shown on interface in real time after the angle calculation of PC machine completion human body lower limbs hip and knee, and saves angle letterBreath.