WO2019085139A1 - Rehabilitation exercise parameter measurement system and method - Google Patents

Abstract

Provided is a rehabilitation exercise parameter measurement system. The measurement system comprises: a gesture sensor and a controller, wherein the gesture sensor is fixed to a training part for a human body rehabilitation exercise; the gesture sensor is used for acquiring a quaternion of a gesture of the training part and sending same to the controller; and the controller is used for converting the quaternion into Euler angle information of different rotation orders under an inertial navigation coordinate system, and calculating the rehabilitation exercise parameters according to the Euler angle information. In the present invention, on the basis of a gesture quaternion, Euler angles of multiple rotation orders are fused to calculate rehabilitation exercise parameters, thereby avoiding a singular point, so that an exercise angle of a training part of a patient can be accurately represented, which has a special meaning for determining the motion quality and a motion error of the patient and learning about an initial stance habit of the patient.

Description

Measuring system and method for rehabilitation exercise parameters

This application claims priority from Chinese patent application CN201711080208.9 and CN201711079127.7 on November 6, 2017. This application cites the entire text of the above-mentioned Chinese patent application.

Technical field

The invention relates to the field of motion angle measurement, in particular to a measurement system and method for rehabilitation motion parameters.

Background technique

At present, in orthopedic or neurological patients undergo joint rehabilitation exercises after surgery, generally by watching standard movements to follow the rehabilitation exercise or under the guidance of a doctor (healer) to perform the specified rehabilitation actions. In this process, the doctor or patient judges whether the rehabilitation action made by the patient meets the requirements through subjective feelings. This method of subjective judgment cannot accurately determine whether the rehabilitation action meets the expected standard, and will affect the recovery effect and progress of the patient's rehabilitation training. .

In the prior art, the movement of the patient is also analyzed by detecting the angle of movement of the healing action made by the patient. There are generally three methods for calculating the current motion angle: (1) Calculate the attitude angle directly according to the specific value of the acceleration in the inertial coordinate system or the body coordinate system (three directions), and then quantify the motion angle according to the angle difference; however, when When in high-frequency motion, the stability of the attitude angle calculated by this method is very poor. When it is in the singularity position, it can only reflect the angle in two directions. When the motion angle is large, the angle difference calculated from the attitude angle is The value is significantly different from the actual motion angle; (2) directly using the quaternion (ie, the four-dimensional space vector) or the rotation matrix to calculate the spatial angle; however, directly calculating the spatial angle easily introduces the motion angle error in the non-main motion direction; For example, when performing hip frontal motion, if there is a rotation or an internal or external deviation, the spatial angle will include the movement angles of these non-main motion directions, resulting in a large calculated angular error; (3) directly using the elevation angle The roll angle and the heading angle are used for the difference calculation; however, the calculation method also has a singular point and is not suitable for the calculation of the motion angle of an arbitrary posture.

Summary of the invention

The technical problem to be solved by the present invention is to overcome the defect that the calculation method of the joint angle of the joint is large in the prior art, and to provide a defect. Measuring system and method for joint angle.

The invention provides a measurement system for rehabilitation exercise parameters, the measurement system comprising: an attitude sensor and a controller;

The posture sensor is fixed to a training part of a human rehabilitation exercise; the posture sensor is configured to acquire a quaternion of the posture of the training part and send the quaternion to the controller;

The controller is configured to convert the quaternion into Euler angle information of different rotation orders in an inertial coordinate system, and calculate the rehabilitation motion parameter according to the Euler angle information.

Preferably, the rehabilitation motion parameters include: a primary angle and/or an offset angle and/or a rotation angle;

The first attitude sensor is configured to acquire a starting quaternion and a current quaternion of the posture of the training part and send the same to the controller;

The controller is configured to convert the starting quaternion into at least two initial Euler angle information of different rotation orders in an inertial coordinate system, and convert the current quaternion into an inertial coordinate system Calculating the primary angle and/or offset based on the at least two initial Euler angle information and the at least two current Euler angle information Angle and/or angle of rotation;

The main angle is an angle between a projection of the training site on a first plane and a second plane; the first plane is a plane in which a motion path of a standard motion of rehabilitation motion is located, and the second plane is The first plane is vertical;

The offset angle is an angle between a projection of the training portion on the second plane and the first plane;

The rotation angle is an angle change value of the training portion on the Z axis of the inertial coordinate system.

Preferably, the controller includes an Euler angle conversion unit, a first calculation unit, and a first determination unit;

The Euler angle conversion unit converts the starting quaternion and the current quaternion into a first starting Euler angle information and a first current Euler angle of a first rotation sequence in an inertial coordinate system, respectively Information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

When calculating the main angle, the first calculating unit calculates an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

The first determining unit is configured to determine the estimated main angle as a main angle when determining that the estimated main angle is smaller than an angle threshold and the estimated main angle is smaller than the estimated offset angle; otherwise, Calling the first computing unit;

The first calculating unit is further configured to calculate a main angle change value in the second rotation sequence by using the following formula:

Main angle change value = second current nutation angle - second initial nutation angle;

The first calculation unit is further configured to calculate a main angle by the following formula:

Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

Or the first calculating unit is further configured to calculate the main angle by using the following formula when the main angle change value is greater than 90°:

Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

Preferably, the estimated main angle = the first current nutation angle - the first initial nutation angle;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the first calculating unit specifically calculates the estimated offset angle by the following formula:

Estimated offset angle = first current rotation angle - first starting rotation angle;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the first calculation unit Calculate the estimated offset angle by the following formula:

Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

The first initial Euler angle information includes a first initial nutation angle, the first current Euler angle information includes a first current nutation angle, and the second current Euler angle information includes a second current nutation angle And the second current rotation angle, the second starting Euler angle information includes a second initial nutation angle.

Preferably, when calculating the main angle, the controller includes an Euler angle conversion unit, a first calculation unit, and a first determination unit;

The Euler angle conversion unit converts the starting quaternion and the current quaternion into a first starting Euler angle information and a first current Euler angle of a first rotation sequence in an inertial coordinate system, respectively Information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

The first calculating unit calculates an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

The first determining unit is configured to determine the estimated main angle as a main angle when determining that the estimated main angle is smaller than an angle threshold and the estimated main angle is smaller than the estimated offset angle; otherwise, Calling the first computing unit;

The first calculating unit is further configured to calculate a main angle change value in the second rotation sequence by using the following formula:

The main angle change value = the second current nutation angle ± 90 °;

The first calculation unit is further configured to calculate a main angle by the following formula:

Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

Or the first calculating unit is further configured to calculate the main angle by using the following formula when the main angle change value is greater than 90°:

Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

Preferably, the estimated main angle = the first current nutation angle;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the first calculating unit specifically calculates the estimated offset angle by the following formula:

Estimated offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the first calculation unit Calculate the estimated offset angle by the following formula:

Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

The first current Euler angle information includes a first current rotation angle and a first current nutation angle, and the first starting Euler angle information includes a first initial rotation angle and a first initial nutation angle, the second The current Euler angle information includes a second current rotation angle and a second current nutation angle.

Preferably, when calculating the offset angle, the first determining unit is further configured to determine whether the first current nutation angle is smaller than the second current nutation angle;

When the first determining unit determines YES, the first calculating unit calculates the offset angle by the following formula:

Offset angle = first current rotation angle - first starting rotation angle;

Or, the first calculating unit calculates the offset angle by the following formula:

Offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

When the first determining unit determines NO, the first calculating unit calculates the offset angle by the following formula:

Offset angle = second current rotation angle -sign (second starting rotation angle) × 90 °;

The first starting Euler angle information further includes a first starting rotation angle, and the second starting Euler angle information further includes a second starting rotation angle.

Preferably, the rehabilitation exercise parameter comprises: an angle of joint;

The second attitude sensor is configured to acquire a first quaternion of the posture of the training part and send the same to the controller;

The controller is configured to convert the first quaternion to at least two Euler angle information of different rotation orders in an inertial coordinate system;

The third attitude sensor is configured to acquire a second quaternion of the posture of the training part and send the same to the controller;

The controller is further configured to convert the second quaternion to at least two Euler angle information of the different rotation order in an inertial coordinate system;

The controller is further configured to calculate a joint angle of the training portion based on the at least four Euler angle information.

Preferably, the controller comprises an Euler angle conversion unit, a second calculation unit, a third calculation unit and a second determination unit;

When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into the first Euler angle information of the first rotation order in the inertial coordinate system, respectively And second Euler angle information, and third Euler angle information and fourth Euler angle information of the second rotation sequence;

The second determining unit is configured to determine whether an absolute value of the first chapter moving angle is smaller than a first threshold; when the determination is no, the second calculating unit is called; when the determination is yes, the third calculating unit is called ;

The second calculating unit is specifically configured to calculate the joint angle by the following formula when the product of the first chapter moving angle and the second chapter moving angle is greater than 0:

Joint angle = 180 ° - | Chapter 3 Dynamic angle - Chapter 4 dynamic angle |

The second calculating unit is further configured to calculate the joint angle by the following formula when the product of the first chapter moving angle and the second chapter moving angle is less than 0:

Joint angle =|Chapter 3 moving angle + fourth chapter moving angle|;

The third calculating unit is specifically configured to calculate the joint angle by the following formula when the product of the predicted angle and the fourth chapter moving angle is greater than zero:

Joint angle = 180 ° -|Chapter 1 moving angle + sign (third chapter moving angle) × 90 ° - Chapter 4 moving angle |

The third calculating unit is further configured to calculate the joint clip by the following formula when the product of the predicted angle and the fourth chapter moving angle is less than 0. angle:

Joint angle =|Chapter 1 moving angle +sign (third chapter moving angle)×90°+fourth chapter moving angle|;

Among them, the predicted angle = the first chapter moving angle + sign (third chapter moving angle) × 90 °;

The first Euler angle information includes a first nutation angle, the second Euler angle information includes a second nutation angle, and the third Euler angle information includes a third nutation angle, the fourth Europe The pull angle information includes the fourth chapter dynamic angle.

Preferably, the controller comprises an Euler angle conversion unit and a fourth calculation unit;

When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into a third Euler angle information of the second rotation order in the inertial coordinate system, respectively And the fourth Euler angle information;

The fourth calculation unit is configured to calculate an angle of joint by the following formula:

Joint angle = 180° - | third rotation angle - fourth rotation angle |

The third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth rotation angle;

Preferably, the controller further includes a third determining unit;

The fourth calculating unit is further configured to calculate the first temporary angle by the following formula:

First temporary angle=|third rotation angle-fourth rotation angle|;

The third determining unit is further configured to determine whether an absolute value of the first temporary angle is greater than a second threshold, and when the determination is yes, invoke the fourth calculating unit;

The fourth calculating unit is further configured to perform fault tolerance processing on the joint angle by using the following formula to obtain a target joint angle:

Target joint angle = 180° - | first temporary angle - sign (first temporary angle) × 360 ° |.

Preferably, the controller comprises an Euler angle conversion unit and a fifth calculation unit;

When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into a third Euler angle information of the second rotation order in the inertial coordinate system, respectively And the fourth Euler angle information;

The fifth calculation unit is for calculating an angle of joint by the following formula:

Joint angle = 180° - | third precession angle - fourth precession angle |

The third Euler angle information includes a third precession angle, and the fourth Euler angle information includes a fourth precession angle;

Preferably, the controller further includes a fourth determining unit;

The fifth calculating unit is further configured to calculate the second temporary angle by the following formula:

Second temporary angle =|third precession angle - fourth precession angle|;

The fourth determining unit is further configured to determine whether an absolute value of the second temporary angle is greater than a second threshold;

When the fourth determining unit determines YES, the fifth calculating unit is further configured to perform fault tolerance processing on the joint angle by using the following formula to obtain a target joint angle:

Target joint angle = 180° - | second temporary angle - sign (second temporary angle) × 360 ° |.

Preferably, the controller comprises an Euler angle conversion unit, a fifth determination unit and a sixth calculation unit;

When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into the first Euler angle information of the first rotation order in the inertial coordinate system, respectively And second Euler angle information, and third Euler angle information and fourth Euler angle information of the second rotation sequence;

The fifth determining unit is further configured to determine whether an absolute value of the second chapter moving angle is smaller than a first threshold;

When the fifth determining unit determines NO, the sixth calculating unit calculates the joint angle by the following formula:

Joint angle = 180° - | third rotation angle - (compensation angle + fourth chapter dynamic angle) |;

When the fifth determining unit determines YES, the sixth calculating unit is further configured to calculate the joint angle by the following formula:

Joint angle = 180° - | third rotation angle - (compensation angle + second chapter movement angle ± 90 °) |

The second Euler angle information includes a second chapter angle, the third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth chapter movement angle.

The present invention also provides a method for measuring a rehabilitation exercise parameter, the measurement method being implemented using the above-described measurement system, the measurement method comprising the following steps:

Quaternion S _1, the sensor acquires the posture of the posture of the training site and sent to the controller;

S ₂ , the controller converts the quaternion into Euler angle information of different rotation orders in an inertial coordinate system;

S ₃ , the controller calculates the rehabilitation motion parameter according to the Euler angle information.

Preferably, the rehabilitation motion parameters include: an offset angle and/or an offset angle and/or a rotation angle;

Step S ₁ comprises:

The first attitude sensor acquires a starting quaternion and a current quaternion of the posture of the training part and sends the same to the controller;

Step S ₂ comprises:

The controller converts the initial quaternion into at least two initial Euler angle information of different rotation orders in an inertial coordinate system, and converts the current quaternion into an inertial coordinate system At least two current Euler angle information of the different rotation order;

Step S ₃ comprises:

The controller calculates the primary angle and/or the offset angle and/or the rotation angle according to the at least two initial Euler angle information and the at least two current Euler angle information;

The main angle is an angle between a projection of the training site on a first plane and a second plane; the first plane is a plane in which a motion path of a standard motion of rehabilitation motion is located, and the second plane is The first plane is vertical;

The offset angle is an angle between a projection of the training portion on the second plane and the first plane;

The rotation angle is an angle change value of the training portion on the Z axis of the inertial coordinate system.

Preferably, the step S _2, the initial and the current quaternion quaternion rotation are converted into a first sequence in a first coordinate system INS start information and the first current Euler angles Euler angles Information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

Step S ₃ in accordance with the Euler angles of the at least two initial information and the current step of the at least two primary Euler angles of the angle information calculating comprises:

S _31-1 , calculating an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

_S32-1 , determining whether the estimated main angle is smaller than an angle threshold and whether the estimated main angle is smaller than the estimated offset angle; when the determination is yes, performing step _S33-1 ; When performing step S _33-1 ';

S _33-1 , determining the estimated main angle as a main angle;

S _33-1 ', calculate the main angle change value in the second rotation sequence by the following formula:

Main angle change value = second current nutation angle - second initial nutation angle;

S _34-1 ', calculate the main angle by the following formula:

Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

Or, when the main angle change value is greater than 90°, the main angle is calculated by the following formula:

Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

Preferably, the estimated main angle is calculated in the step S _31-1 by the following formula:

Estimated main angle = first current nutation angle - first initial nutation angle;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the estimated offset angle is calculated by the following formula:

Estimated offset angle = first current rotation angle - first starting rotation angle;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the specific formula is calculated by the following formula Estimate the offset angle:

Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

The first initial Euler angle information includes a first initial nutation angle, the first current Euler angle information includes a first current nutation angle, and the second current Euler angle information includes a second current nutation angle And the second current rotation angle, the second starting Euler angle information includes a second initial nutation angle.

Preferably, the step S _2, the initial and the current quaternion quaternion rotation are converted into a first sequence in a first coordinate system INS start information and the first current Euler angles Euler angles Information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

Step S ₃ in accordance with the Euler angles of the at least two initial information and the current step of the at least two primary Euler angles of the angle information calculating comprises:

S _31-2 , calculating an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

_S32-2 , determining whether the estimated main angle is smaller than an angle threshold and whether the estimated main angle is smaller than the estimated offset angle; when the determination is yes, performing step _S23-3 ; When performing step _S33-2 ';

S _33-2 , determining the estimated main angle as a main angle;

S _33-2 ', calculate the main angle change value in the second rotation order by the following formula:

The main angle change value = the second current nutation angle ± 90 °;

S _34-2 ', calculate the main angle by the following formula:

Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

Or, when the main angle change value is greater than 90°, the main angle is calculated by the following formula:

Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

Preferably, the estimated main angle is calculated in step S _31-2 by the following formula:

Estimated main angle = first current nutation angle;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the estimated offset angle is calculated by the following formula:

Estimated offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the specific formula is calculated by the following formula Estimate the offset angle:

Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

The first current Euler angle information includes a first current rotation angle and a first current nutation angle, and the first starting Euler angle information includes a first initial rotation angle and a first initial nutation angle, the second The current Euler angle information includes a second current rotation angle and a second current nutation angle.

Preferably, the step S ₃ in accordance with the Euler angles of the at least two initial information and the current step of the at least two information calculating Euler angles of the offset angle comprises:

S _31-3 , determining whether the first current nutation angle is smaller than the second current nutation angle; when the determination is yes, executing step _S32-3 ; when the determination is no, executing step _S32-3 ';

S _32-3 , calculate the offset angle by the following formula:

Offset angle = first current rotation angle - first starting rotation angle;

Or, the offset angle = the first current rotation angle -sign (first starting rotation angle) × 90 °;

S _32-4 ', calculate the offset angle by the following formula:

Offset angle = second current rotation angle -sign (second starting rotation angle) × 90 °;

The first starting Euler angle information further includes a first starting rotation angle, and the second starting Euler angle information further includes a second starting rotation angle.

Preferably, the rehabilitation exercise parameter comprises: an angle of joint;

Step S ₁ comprises:

The first attitude sensor acquires a first quaternion of the posture of the training part, and the second attitude sensor acquires a second quaternion of the posture of the training part;

Step S ₂ comprises:

The controller converts the first quaternion into at least two Euler angle information of different rotation orders in an inertial coordinate system, and converts the second quaternion into the inertial coordinate system At least two Euler angle information for different rotation orders;

Step S ₃ comprises:

The controller calculates an angle of joint of the training site based on at least four Euler angle information.

Preferably, the step S _2, the controller sets the first and the second quaternion quaternion rotation are converted into a first sequence in a first INS coordinates information and the Euler angles Two Euler angle information, and third Euler angle information and fourth Euler angle information of the second rotation sequence;

The step of calculating the joint angle of the training portion according to the at least four Euler angle information specifically includes:

S _3-1a , determining whether the absolute value of the first chapter moving angle is smaller than the first threshold; when the determination is no, step S _{3-2a is performed} ; when the determination is YES, executing step S _3-3a ;

S _3-2a , calculating the joint angle according to the third Euler angle information and the fourth Euler angle information;

S _3-3a , calculating the joint angle according to the first Euler angle information, the third Euler angle information, and the fourth Euler angle information;

Preferably, step S _3-2a specifically includes:

When the product of the first chapter of the dynamic angle and the second chapter of the dynamic angle is greater than 0, the joint angle is calculated by the following formula:

Joint angle = 180 ° - | Chapter 3 Dynamic angle - Chapter 4 dynamic angle |

When the product of the first chapter of the dynamic angle and the second chapter of the dynamic angle is less than 0, the joint angle is calculated by the following formula:

Joint angle =|Chapter 3 moving angle + fourth chapter moving angle|;

Preferably, step S _3-3a specifically includes:

When the product of the predicted angle and the fourth chapter of the dynamic angle is greater than 0, the joint angle is calculated by the following formula:

Joint angle = 180 ° -|Chapter 1 moving angle + sign (third chapter moving angle) × 90 ° - Chapter 4 moving angle |

When the product of the predicted angle and the fourth chapter of the dynamic angle is less than 0, the joint angle is calculated by the following formula:

Joint angle =|Chapter 1 moving angle +sign (third chapter moving angle)×90°+fourth chapter moving angle|;

Among them, the predicted angle = the first chapter moving angle + sign (third chapter moving angle) × 90 °;

The first Euler angle information includes a first nutation angle, the second Euler angle information includes a second nutation angle, and the third Euler angle information includes a third nutation angle, the fourth Europe The pull angle information includes the fourth chapter dynamic angle.

Preferably, the step S _2, the first and the second quaternion quaternion Euler angles are converted into the third information and the fourth information of the second Euler angle rotation sequence of the INS coordinates ;

The step of calculating the joint angle of the training portion according to the at least four Euler angle information specifically includes:

S _3-1b , calculate the joint angle by the following formula:

Joint angle = 180° - | third rotation angle - fourth rotation angle |

The third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth rotation angle;

Preferably, after step _S3-1b , the method further includes:

S _3-2b , calculate the first temporary angle by the following formula:

First temporary angle=|third rotation angle-fourth rotation angle|;

S _3-3b , determining whether the absolute value of the first temporary angle is greater than a second threshold, and when the determination is yes, performing step S _3-4b ;

S _3-4b , the fault angle of the joint angle is calculated by the following formula to obtain the target joint angle:

Target joint angle = 180° - | first temporary angle - sign (first temporary angle) × 360 ° |.

Preferably, the step S _2, the first and the second quaternion quaternion Euler angles are converted into the third information and the fourth information of the second Euler angle rotation sequence of the INS coordinates ;

Step S ₃ comprises:

S _3-1c , calculate the joint angle by the following formula:

Joint angle = 180° - | third precession angle - fourth precession angle |

The third Euler angle information includes a third precession angle, and the fourth Euler angle information includes a fourth precession angle;

Preferably, after step _S3-1c , the method further includes:

S _3-2c , calculate the second temporary angle by the following formula:

Second temporary angle =|third precession angle - fourth precession angle|;

S _3-3c , determining whether the absolute value of the second temporary angle is greater than a second threshold; when the determination is yes, performing step S _3-4c ;

S _3-4c , the joint angle is fault-tolerant by the following formula to obtain the target joint angle:

Target joint angle = 180° - | second temporary angle - sign (second temporary angle) × 360 ° |.

Preferably, the step S _2, the first and the second quaternion quaternion Euler angles are converted into the first information and the second information of the first Euler angle rotation sequence of the INS coordinates And third Euler angle information and fourth Euler angle information of the second rotation sequence;

Step S ₃ comprises:

S _3-1d , determining whether the absolute value of the second chapter moving angle is smaller than the first threshold; when the determination is no, step S _{3-2d is performed} ; when the determination is YES, executing step S _3-3d ;

S _3-2d , calculate the joint angle by the following formula:

Joint angle = 180° - | third rotation angle - (compensation angle + fourth chapter dynamic angle) |;

S _3-3d , calculate the joint angle by the following formula:

Joint angle = 180° - | third rotation angle - (compensation angle + second chapter movement angle ± 90 °) |

The second Euler angle information includes a second chapter angle, the third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth chapter movement angle.

The positive progress of the present invention is that the present invention combines the Euler angles in the multi-rotation order to calculate the main angle on the basis of the attitude quaternion, avoids the singular points, and can accurately represent the movement angle of the training part of the patient. It has special significance for judging the quality of the action made by the patient, the error of the movement, and understanding the initial position of the patient.

DRAWINGS

1 is a schematic structural view of a measurement system for a rehabilitation exercise parameter according to Embodiment 1 of the present invention.

2 is a first schematic structural view of a controller in a measurement system for a rehabilitation exercise parameter according to Embodiment 1 of the present invention.

3 is a second schematic structural view of a controller in a measurement system for a rehabilitation exercise parameter according to Embodiment 1 of the present invention.

4 is a schematic structural view of a controller in a measurement system for a rehabilitation exercise parameter according to Embodiment 3 of the present invention.

FIG. 5 is a schematic structural diagram of a controller in a measurement system for a rehabilitation exercise parameter according to Embodiment 4 of the present invention.

6 is a schematic structural view of a controller in a measurement system for rehabilitation exercise parameters according to Embodiment 5 of the present invention.

Fig. 7 is a flow chart showing a method of measuring a rehabilitation exercise parameter according to a sixth embodiment of the present invention.

FIG. 8a is a first flowchart of calculating a main angle in step 130 of the method for measuring rehabilitation exercise parameters according to Embodiment 6 of the present invention.

Figure 8b is a second flow chart for calculating the main angle in the step 130 of the method for measuring the rehabilitation exercise parameters according to the sixth embodiment of the present invention.

Fig. 9 is a flow chart showing the calculation of the offset angle in the step 130 of the method for measuring the rehabilitation motion parameters according to the sixth embodiment of the present invention.

Fig. 10 is a flow chart showing the calculation of the joint angle in the step 130 of the method for measuring the rehabilitation exercise parameters according to the sixth embodiment of the present invention.

Figure 11 is a flow chart for calculating the joint angle in the step 130 of the method for measuring the rehabilitation exercise parameters according to the eighth embodiment of the present invention.

Figure 12 is a flow chart for calculating the joint angle in the step 130 of the method for measuring the rehabilitation exercise parameters according to the ninth embodiment of the present invention.

Fig. 13 is a flow chart showing the calculation of the joint angle in the step 130 of the method for measuring the rehabilitation exercise parameters according to the tenth embodiment of the present invention.

Detailed ways

Example 1

The measurement system of the present embodiment is for measuring a human rehabilitation exercise parameter, and the rehabilitation exercise parameter includes at least one of the following parameters: a main angle, an offset angle, a rotation angle, and a joint angle. The main angle is the angle between the projection of the training part (four limbs or the trunk) on the first plane and the second plane; the first plane is the plane of the motion path of the standard motion of the rehabilitation motion, the second plane and the first plane vertical. The offset angle is the angle between the projection of the training part on the second plane and the first plane. Taking the hip joint front movement as an example, the offset angle is the angle of the abduction direction inside the thigh. The rotation angle is the angle change value of the training part on the Z axis of the inertial coordinate system. Taking the hip joint front motion as an example, the rotation angle is the difference angle between the training position and the initial position due to the rotation of the training part.

It should be noted that the main angle or the angle of the joint is the main parameter for measuring the quality of the movement. Only when the main angle reaches the standard angle of the standard movement as much as possible, the quality of the rehabilitation training will be higher and the training effect is better. Of course, two or three or four motion parameters can also be used to evaluate whether the action made by the patient is up to standard.

As shown in FIG. 1, the measurement system of the present embodiment includes an attitude sensor 1, a controller 2, and an alarm 3. It should be noted that when calculating the main angle, the offset angle and the rotation angle, an attitude sensor is theoretically required to implement the calculation. If a plurality of attitude sensors are provided, the results obtained by the plurality of attitude sensors can be averaged or fitted. . At least two attitude sensors are required to calculate the angle of the joint. For convenience of explanation, in the present embodiment, the attitude sensor that calculates the main angle, the offset angle, and the rotation angle is referred to as a first attitude sensor, and the attitude sensor that calculates the angle of the joint is referred to as a second attitude sensor and a third attitude sensor. In this embodiment, the attitude sensor may specifically be a 6-axis or a 9-axis sensor.

First, the following describes the specific calculation process of the main angle, the offset angle and the rotation angle.

In the case of rehabilitation training, the posture sensor is fixed to the training part of the human body rehabilitation exercise, and the posture sensor is fixed on the training thigh by taking the standing hip joint forward motion as an example. For convenience of description, it is assumed that the posture sensor is worn on the outer side of the thigh, and when in the standard standing position, the Y-axis of the body coordinate system of the attitude sensor coincides with the Z-axis of the inertial coordinate system (that is, the northeast sky coordinate system). When the patient is in the standing posture, the posture sensor obtains the starting quaternion of the posture of the training part (the quaternion of the posture of the patient before the rehabilitation action), and the initial quaternion coordinate is Pos1 (Q0, Q1, Q2, Q3). ). When the patient makes hip joint motion, the attitude sensor obtains the current quaternion of the posture of the training part in real time (the quaternion of the posture of the patient after hip joint motion), and the current quaternion coordinate is Pos2 (Q0', Q1' , Q2', Q3'). The attitude sensor is also used to send the starting quaternion and the current quaternion to the controller.

As shown in FIG. 2, the controller specifically includes an Euler angle conversion unit 21, a first calculation unit 221, and a first determination unit 231. The controller converts the starting quaternion obtained by the attitude sensor into at least two initial Euler angle information of different rotation orders in the INS coordinate system, and converts the current quaternion into the difference in the INS coordinate system Rotating at least two current Euler angle information in sequence, and calculating a primary angle and/or an offset angle and/or a rotation angle based on the at least two starting Euler angle information and the two current Euler angle information. For the convenience of description, the two rotation sequences of ZYX and ZXY are used for the algorithm description.

The formula for the angle conversion of the Euler angle conversion unit is as follows:

AngleX _zyx = Atan2 (2 × (Q0 × Q1 + Q2 × Q3), 1-2 × (Q1 × Q1 + Q2 × Q2));

AngleY _zyx =Asin(2×(Q0×Q2-Q3×Q1));

AngleZ _zyx = Atan2 (2 × (Q0 × Q3 + Q1 × Q2), 1-2 × (Q2 × Q2 + Q3 × Q3));

AngleX _zxy = Asin (2 × (Q0 × Q1 + Q3 × Q2));

AngleY _zxy = Atan2 (2 × (Q0 × Q2 - Q1 × Q3), 1-2 × (Q1 × Q1 + Q2 × Q2));

AngleZ _zxy = Atan2 (2 × (Q0 × Q3 - Q1 × Q2), 1-2 × (Q1 × Q1 + Q3 × Q3));

Among them, AngleX _zyx (first initial rotation angle), AngleY _zyx (first initial nutation angle) and AngleZ _zyx (first initial precession angle) are the first of the first rotation order (ZYX) in the inertial coordinate system. Information contained in the initial Euler angle information; AngleX _zxy (second initial nutation angle), AngleY _zxy (second initial rotation angle), and AngleZ _zxy (second initial precession angle) are the second in the inertial coordinate system The information contained in the second starting Euler angle information of the rotation order (ZXY).

Similarly, the Euler angle conversion unit calculates the first current Euler angle information of the first rotation order (ZYX) in the inertial coordinate system according to Pos2 (Q0', Q1', Q2', Q3'), the first current Euler angle The angular information includes AngleX' _zyx (first current rotation angle), AngleY' _zyx (first current nutation angle), and AngleZ' _zyx (first current precession angle), and the second rotation order in the inertial coordinate system (ZXY) Second current Euler angle information, the second current Euler angle information includes AngleX' _zxy (second current nutation angle), AngleY' _zxy (second current rotation angle), and AngleZ' _zxy (second current precession) angle).

(1) Calculation of the main angle.

The main angle is mainly calculated by AngleY _zyx , AngleY' _zyx , AngleX _zxy , AngleY' _zxy, and AngleX' _zxy .

When the main angle is less than 90°, it is reflected in the Euler angle in the first rotation order (ZYX). When crossing 90°, AngleY′ _zyx appears to increase to 90 first because of the singularity limit of its own Euler angle. ° Further decrease, and in the second rotation sequence (ZXY), when the main angle is greater than 90°, AngleX' _zxy can well reflect the angle change, and is less affected by the deflection angle. The specific calculation method is:

The first calculating unit first calculates the estimated main angle PrMainAngle and the estimated offset angle PrSideAngle according to the first starting Euler angle information and the first current Euler angle information, and the calculation formula is as follows:

PrMainAngle=AngleY' _zyx -AngleY _zyx ;

When AngleY' _zyx <AngleX' _zxy and the training part is not near the singular point (ie |AngleX' _zxy | ≥ 5), PrSideAngle = AngleX' _{zyx -} AngleX _zyx ;

When AngleY' _zyx <AngleX' _zxy and the training part is just at the singular point position of (ZYX) (ie |AngleX' _zxy |<5), or AngleY' _zyx ≥AngleX' _zxy , PrSideAngle=AngleY' _zxy -sign( AngleY' _zyx ) × 90.

Secondly, the first determining unit determines whether the estimated main angle is smaller than the angle threshold. The angle threshold is typically 90°.

When the judging unit judges PrMainAngle<90° and PrMainAngle<PrSideAngle, the estimated main angle PrMainAngle is determined as the main angle, that is, the main angle MainAngle=PrMainAngle.

Otherwise, when the first determining unit determines PrMainAngle≥90° and/or PrMainAngle≥PrSideAngle, the first calculating unit is called to calculate the main angle, specifically:

The first calculating unit calculates a main angle change value AngleZXY in the second rotation order according to the second start Euler angle information and the second current Euler angle information;

AngleZXY=AngleX' _zxy -AngleX _zxy ;

The first calculating unit specifically calculates the main angle MainAngle by the following formula:

MainAngle=sign(PrMainAngle)×max(|AngleZXY|,|PrMainAngle|);

When AngleZXY>90°, the first calculation unit can also calculate the main angle MainAngle by the following formula:

MainAngle=sign(PrMainAngle)×(2×standard angle-AngleY _zyx -AngleY′ _zyx );

Among them, the standard angle is selected according to actual needs, for example, it can be 90° or -90°.

Through the above formula calculation, the main angle of the rehabilitation exercise made by the patient can be accurately obtained, so that whether the rehabilitation movement made by the patient is up to standard can be determined by judging whether the main angle reaches the standard angle.

(2) Calculation of offset angle

The offset angle is mainly calculated by AngleX _zyx , AngleX' _zyx , AngleY _zxy, and AngleY' _zxy .

When the main angle spans 90°, AngleX′ _zyx and AngleY′ _zxy will have a 180° compensation change. When the main angle is less than 90°, the difference is directly made. When the main angle is greater than 90°, the angle compensation is needed after the difference; When the main angle is a small angle (below 45°), AngleX' _zyx can reflect the change of the offset angle very well. When the main angle is a large angle (greater than 45°), AngleX' _{zyx is} affected by the main angle. Large, while AngleY' _zxy can reflect the current deflection angle very well. specific:

When calculating the offset angle, the first determining unit first determines whether the first current nutation angle is smaller than the second current nutation angle.

In AngleY' _zyx <AngleX' _zxy , the first calculation unit calculates the offset angle SideAngle by the following formula:

SideAngle=AngleX' _zyx -AngleX _zyx ;

When AngleY zyx _≥ AngleX' _zxy , the first calculation unit calculates the offset angle SideAngle by the following formula:

SideAngle=AngleY' _zxy -sign(AngleY _zxy )×90;

The offset angle is mainly used to measure the degree of left and right deviation of the rehabilitation motion and the standard motion made by the patient. In this embodiment, the rehabilitation motion of the patient can also be evaluated by means of the offset angle, and the absolute value of the deflection angle is larger. The greater the difference between the action and the standard action, the lower the action quality.

In this embodiment, the first calculating unit may also validate the offset angle and limit it to (-180, 180) to implement the judgment and filtering of the wrong action.

|SideAngle|-180>0 or SideAngle=-180, implemented by the following formula:

SideAngle'=SideAngle-sign(SideAngle)×360;

Otherwise, it is implemented by the following formula:

SideAngle'=SideAngle;

Among them, SideAngle' is the final offset angle after being effectively processed.

(3) Calculation of rotation angle

Mainly in AngleZ, directly make a difference, and then the angle is effectively converted to ensure that the angle falls within (-180, 180). The specific rotation angle RotationAngle is calculated as follows:

RotationAngle=AngleZ' _zyx -AngleZ _zyx ;

Among them, AngleZ' _zyx characterizes the current angle of the training part on the Z axis of the inertial coordinate system, and AngleZ _zyx characterizes the starting angle of the training part on the Z axis of the inertial coordinate system.

The rotation angle is used to measure the rotational deviation of the position of the individual's habits and the standard position during the movement. The angle is only used as a reference.

Second, the following describes the specific calculation process of the joint angle.

At the time of rehabilitation training, at least two posture sensors are fixed to the training site of the human rehabilitation exercise. Taking the angle of the knee joint as an example, the attitude sensor is fixed to the side of the training thigh and calf. When in the standard standing position, the posture sensor body sits. The Y-axis of the singularity coincides with the Z-axis of the INS coordinate system (ie, the Northeast celestial coordinate system).

The working principle of the measuring system is explained below by means of two attitude sensors. For convenience of explanation, the two attitude sensors are referred to as a second attitude sensor A and a third attitude sensor B, respectively. When the patient makes hip joint motion, the second attitude sensor A acquires the first quaternion of the posture of the training part in real time and sends it to the controller, and the first quaternion coordinate is Pos1 (Q0, Q1, Q2, Q3). The third attitude sensor B acquires the second quaternion of the posture of the training part in real time and sends it to the controller, and the second quaternion coordinate is Pos2 (Q0', Q1', Q2', Q3').

It should be noted that the number of attitude sensors can be set according to the data requirements. Of course, the more the number, the more accurate the measurement results will be. When more than three attitude sensors are provided, the joint angle can be calculated by any two attitude sensors, and then the calculated multiple joint angles are averaged.

As shown in FIG. 3, the controller includes a Euler angle conversion unit 21, a second calculation unit 222, a third calculation unit 223, and a second determination unit 232. The controller converts the first quaternion into at least two Euler angle information of different rotation orders in the inertial coordinate system, and converts the second quaternion into at least two of the different rotation orders in the inertial coordinate system The Euler angle information and the joint angle of the training site is calculated based on at least four Euler angle information.

In the present embodiment, for convenience of explanation, an algorithm description is performed using two rotation sequences of ZXY (first rotation order) and ZYX (second rotation order). The formula conversion process of the Euler angle conversion unit is basically the same as the calculation of the main angle, the offset angle and the rotation angle, and will not be described here.

After conversion, AngleXA _zxy (first chapter moving angle), AngleYA _zxy (first rotation angle) and AngleZA _zxy (first precession angle) are the first European order of the first rotation order (ZXY) in the inertial coordinate system. The information contained in the pull angle information; AngleXA _zyx (third rotation angle), AngleYA _zyx (third chapter dynamic angle) and AngleZA _zyx (third precession angle) are the second rotation order (ZYX) in the inertial coordinate system The information contained in the third Euler angle information. AngleXB _zxy (Chapter 2 dynamic angle), AngleYB _zxy (second rotation angle) and AngleZB _zxy (second precession angle) are the second Euler angle information of the first rotation order (ZXY) in the inertial coordinate system. Contained information; AngleXB _zyx (fourth rotation angle), AngleYB _zyx (fourth movement angle) and AngleZB _zyx (fourth precession angle) are the fourth rotation of the second rotation order (ZYX) in the inertial coordinate system The information contained in the pull angle information.

In this embodiment, since both attitude sensors are disposed on the sides of the thigh and the lower leg, the Z-axis of the body coordinate system of the attitude sensor is The size of the legs is vertical, and the direction is parallel to the left and right direction of the human body, so that when the patient performs training exercises such as standing position, sitting position, and supine position, the angle change of the knee joint angle is expressed on the Y axis.

During the training process, when the patient is following the movement, the training position will be deflected due to the irregular movement, and the deflection angle will affect the calculation result, especially in the vicinity of the singularity of the rotation order. In order to improve the accuracy of the measurement, the criticality is required. The value is filtered to some extent, that is, the measurement drift of the attitude sensor is subjected to certain fault tolerance processing, so different calculation methods are adopted in the vicinity of the singularity. Specifically, the controller calculates the angle of the joint by:

The second determining unit determines whether there is a sensor in the vicinity of the singularity position, taking the attitude sensor A in the vicinity of the singularity point of (ZYX) as an example, and the second determining unit determines whether the absolute value of the AngleXA _zxy is smaller than the first threshold, wherein the first threshold Usually 5°. When |AngleXA _zxy | ≥ 5, indicating that it is a normal angle, the second calculating unit is called to calculate the joint angle based on the third Euler angle information and the fourth Euler angle information. When |AngleXA _zxy |<5, indicating that the attitude sensor A is at the singularity point, the third calculation unit is called to calculate the joint angle based on the first Euler angle information, the third Euler angle information, and the fourth Euler angle information. .

Further, before the second calculating unit calculates the angle of the joint, first determine the sign of _{AngleXA zxy} and AngleXB _zxy .

When AngleXA _zxy >0 and AngleXB _zxy >0 (or AngleXA _zxy <0 and AngleXB _zxy <0), the second calculation unit calculates the joint angle TwoSensorAngle by the following formula:

TwoSensorAngle=180°-|AngleYA _zyx -AngleYB _zyx |

When AngleXA _zxy >0 and AngleXB _zxy <0 (or AngleXA _zxy <0 and AngleXB _zxy <0), the second calculation unit calculates the joint angle by the following formula:

TwoSensorAngle=|AngleYA _zyx +AngleYB _zyx |.

The third calculation unit first calculates the product of the estimated angle PrAngle and AngleYB _zyx before calculating the joint angle. Among them, PrAngle=AngleXA _zxy +sign(AngleYA _zyx )×90°.

When PrAngle×AngleYA _zxy >0, the third calculation unit calculates the joint angle by the following formula:

TwoSensorAngle=180°-|AngleXA _zxy +sign(AngleYA _zyx )×90°-AngleYB _zyx |.

Otherwise, the third calculation unit calculates the joint angle by the following formula:

TwoSensorAngle=|AngleXA _zxy +sign(AngleYA _zyx )×90°+AngleYB _zyx |.

In this embodiment, the alarm module 3 is configured to determine whether the main angle and/or the offset angle and/or the rotation angle and/or the joint angle are within respective threshold ranges, and issue a prompt message when the judgment is no, to remind The patient's movements are not up to standard and the direction or magnitude of the movement needs to be changed. The prompt information may be outputted in the form of voice, or may be outputted in the form of text, and the prompt information may include information such as direction information and magnitude of the patient's deviation.

It should be noted that, in this embodiment, the calculation process of the three angles of the present invention is only described by the two rotation sequences of ZYX and ZXY. The user can, but is not limited to, ZYX and ZXY as the selection rotation order, and the number is not limited to two. It can be three or more, and generally has the following rotation order: ZYX', 'ZYZ', 'ZXY', 'ZXZ', 'YXZ', 'YXY', 'YZX', 'YZY', 'XYZ' , 'XYX', 'XZY' and 'XZX'. However, when the rotation order is selected, the two rotation orders with the same singular point cannot be selected.

In this embodiment, on the basis of the full-status quaternion, the Euler angles in the multi-rotation sequence are fused to calculate the main angle, the offset angle, and the rotation angle of the joint angle, thereby avoiding the singular points and accurately characterizing the patient. The joint angle of the training site has special significance for judging the quality of the action made by the patient, the motion error, and understanding the patient's initial standing habit.

Example 2

Embodiment 2 is basically the same as Embodiment 1, except that in this embodiment, a standard position is defined for each rehabilitation exercise (when the main angle, the offset angle, and the rotation angle are both 0°), that is, the standard is Bit as the start bit. Thus, in the calculation of the main angle, the first calculation unit calculates the estimated main angle and the estimated offset angle according to the following formula:

PrMainAngle=AngleY'_zyx;

PrSideAngle=AngleX' _zyx ±90°;

Specifically, when AngleY' _zyx <AngleX' _zxy and the training part is not near the singular point (ie |AngleX' _zxy | ≥ 5), PrSideAngle = AngleX' _zyx -sign(AngleX _zyx ) × 90°; when AngleY' _zyx <AngleX' _zxy and the training part is just at the singular point position of (ZYX) (ie |AngleX' _zxy |<5), or AngleY' _zyx ≥AngleX' _zxy , PrSideAngle=AngleY' _zxy -sign(AngleY' _zyx )× 90°.

In this embodiment, the first calculating unit calculates the main angle change value AngleZXY in the second rotation sequence according to the following formula:

AngleZXY=AngleX' _zxy ±90°;

Among them, the sign is selected according to the angle corresponding to the initial position.

The first calculating unit specifically calculates the main angle MainAngle by the following formula:

MainAngle=sign(PrMainAngle)×max(|AngleZXY|,|PrMainAngle|)

When AngleZXY>90°, the first calculation unit can also calculate the main angle MainAngle by the following formula:

MainAngle=sign(PrMainAngle)×(2×standard angle-AngleY _zyx -AngleY′ _zyx ).

Among them, the standard angle is selected according to actual needs, for example, it can be 90° or -90°.

It should be noted that the two angle calculation methods (the angle calculation method in Embodiment 1 and the angle calculation method in Embodiment 2) can be stored in the controller at the same time, so that the rehabilitation engineer or the user can select and use according to actual needs. The angle calculation method of the initial position is still the angle calculation method using the standard position.

Example 3

This embodiment provides another possible implementation manner for calculating the angle of the joint. The structure of the measurement system is basically the same as that of the embodiment 1, as shown in FIG. 4, except that the controller in this embodiment specifically includes Euler. An angle conversion unit 21, a fourth calculation unit 224, and a third determination unit 233.

In this embodiment, the knee joint angle is taken as an example. During the training, the attitude sensor A and the attitude sensor B are both fixed on the front or the back of the trained thigh and calf. When in the standard standing position, the posture sensor body The Y-axis of the coordinate system coincides with the Z-axis of the INS coordinate system (that is, the northeast celestial coordinate system), and the Z-axis is perpendicular to the large and small legs, and the direction is perpendicular to the left-right direction of the human body, so that when the patient makes a standing position, a sitting position, and a supine position When the training is performed, the angle of the knee joint is expressed on the X-axis or the Y-axis.

In this embodiment, it is theoretically necessary to convert the first quaternion number and the second quaternion number into Euler angle information of a rotation order in the inertial coordinate system, respectively, to calculate the joint angle. Taking ZYX (second rotation order) as an example, that is, the Euler angle conversion unit converts the first quaternion number and the second quaternion number into the third Euler angle information and the fourth Euler angle information of ZYX, respectively. The formula conversion process of the Euler angle conversion unit is basically the same as that in Embodiment 1, and details are not described herein again.

In this embodiment, the fourth calculating unit calculates TwoSensorAngle by the following formula:

TwoSensorAngle=180°-|AngleXA _zyx -AngleXB _zyx |.

In this embodiment, in order to avoid that the posture sensor has a position near ±180°, the first temporary angle TempAngle1 is obviously not in the effective range, and the value needs to be effectively processed. Specifically:

The fourth calculation unit calculates the first temporary angle TempAngle1 by the following formula:

TempAngle1=AngleXA _zyx -AngleXB _zyx .

The third determining unit determines whether |TempAngle1| is greater than a second threshold, wherein the second threshold is generally 180°.

That is, when |TempAngle1|-180°>0, the fourth calculation unit is called to perform fault tolerance processing on the joint angle by the following formula to obtain the target joint angle TwoSensorAngle':

TwoSensorAngle'=180°-|TempAngle1-sign(TempAngle1)×360°|.

In this embodiment, the alarm module is further configured to determine whether the target joint angle is within the target angle threshold, and issue a prompt message when the determination is negative.

Example 4

The measuring system of the embodiment is suitable for measuring the angle of the joint of the patient to perform the lateral position action, and the posture sensor can be disposed at the front or the back of the training part (the Z axis of the body coordinate system of the posture sensor is perpendicular to the size leg, and the direction Vertically to the left and right direction of the human body, they may also be disposed on the side of the training site (the Z axis of the body coordinate system of the attitude sensor is perpendicular to the size leg and the direction is parallel to the left and right direction of the human body).

The structure of the measurement system is substantially the same as any of the above embodiments, as shown in FIG. 5, except that the controller of the present embodiment includes a Euler angle conversion unit 21, a fifth calculation unit 225, and a fourth determination unit 234.

In this embodiment, it is theoretically necessary to convert the first quaternion number and the second quaternion number into Euler angle information of a rotation order in the inertial coordinate system, respectively, to calculate the joint angle. Taking ZYX (second rotation order) as an example, that is, the Euler angle conversion unit converts the first quaternion number and the second quaternion number into the third Euler angle information and the fourth Euler angle information of ZYX, respectively. The formula conversion process of the Euler angle conversion unit is basically the same as any of the above embodiments, and details are not described herein again.

In this implementation, the fifth computing unit calculates TwoSensorAngle by:

TwoSensorAngle=180°-|AngleZA _zyx -AngleZB _zyx |.

In this embodiment, in order to avoid that the posture sensor has a position near ±180°, the second temporary angle TempAngle2 is obviously not in the effective range, and the value needs to be effectively processed. Specifically:

The fifth calculating unit calculates the second temporary angle TempAngle2 by the following formula:

TempAngle2=AngleZA _zyx -AngleZB _zyx .

The fourth determining unit determines whether |TempAngle2| is greater than a second threshold, wherein the second threshold is generally 180°.

That is, when |TempAngle2|-180°>0, the fifth calculation unit performs fault tolerance processing on the joint angle by the following formula to obtain the target joint angle TwoSensorAngle':

TwoSensorAngle'=180°-|TempAngle2-sign(TempAngle2)×360°|.

Example 5

The measuring system of the embodiment is suitable for the case where the initial posture is different by 90° on the Z axis (the angular changes of the attitude sensor are not on the Z axis), and the structure of the measuring system is basically the same as any of the above embodiments, as shown in FIG. The difference is that, in this embodiment, the controller includes the Euler angle conversion unit 21, the sixth calculation unit 226, and the fifth determination unit 235.

Similarly, in this embodiment, it is theoretically necessary to convert the first quaternion number and the second quaternion number into Euler angle information of a rotation order in the inertial coordinate system, respectively, to calculate the joint angle. Taking ZYX (second rotation order) as an example, that is, the Euler angle conversion unit converts the first quaternion number and the second quaternion number into the third Euler angle information and the fourth Euler angle information of ZYX, respectively. The formula conversion process of the Euler angle conversion unit is basically the same as any of the above embodiments, and details are not described herein again.

Taking the angle between the lumbar joint and the thigh as an example, the posture sensor A is worn on the chest and the posture sensor B is worn on the lateral side of the thigh according to the actual movement and wearing condition, and the angle between the joints, that is, the angle between the two sensors is calculated. angle AngleXA _zyx desired performance on the attitude sensor A, in the performance of the posture sensor AngleYB _zyx B.

The following describes the process by which the controller calculates the angle of the joint:

The fifth determining unit determines whether there is a sensor in the vicinity of the singularity position, taking the attitude sensor B in the vicinity of the singular point of (ZYX) as an example, and the fifth determining unit determines whether |AngleXB _zxy | is smaller than the first threshold, wherein the first threshold is generally 5°.

When |AngleXB _zxy | ≥ 5, the description is normal angle, and the sixth calculation unit calculates the joint angle TwoSensorAngle by the following formula:

TwoSensorAngle=180°-|AngleXA _zyx - (compensation angle + AngleYB _zyx )|.

Among them, the compensation angle can be determined according to the actual situation, generally 90 °.

When |AngleXB _zxy |<5, it indicates that the attitude sensor A is at the singularity point, and the sixth calculation unit calculates the joint angle by the following formula: TwoSensorAngle:

TwoSensorAngle=180°-|AngleXA _zy' - (compensation angle + AngleXB _zxy ±90°)|.

Among them, the angle of AngleXB _zxy ±90° is chosen _{according to} the sign of AngleYB _zyx of the singularity attachment.

If the compensation angle is 90°, the above formula can be simplified as:

TwoSensorAngle=180°-|AngleXB _zxy -AngleXA _zyx |.

Example 6

FIG. 7 shows a measurement method of a rehabilitation exercise parameter, which is implemented by the measurement system of Embodiment 1, as shown in FIG. 7, the measurement method includes the following steps:

Step 110: The posture sensor acquires the quaternion of the posture of the training part and sends it to the controller.

Step 120: The controller converts the starting quaternion into Euler angle information of different rotation orders in the INS coordinate system.

Step 130: The controller calculates a primary angle and/or an offset angle and/or a rotation angle and/or a joint angle according to the Euler angle information.

Wherein, the main angle is an angle between the projection of the training part on the first plane and the second plane; the first plane is a plane in which the motion path of the standard motion of the rehabilitation motion is located, and the second plane is perpendicular to the first plane. The offset angle is the angle between the projection of the training part on the second plane and the first plane. Taking the hip joint front movement as an example, the offset angle is the angle of the abduction direction inside the thigh. The rotation angle is the angle change value of the training part on the Z axis of the inertial coordinate system. Taking the hip joint front motion as an example, the rotation angle is the difference angle between the training position and the initial position due to the rotation of the training part.

Step 140: Determine whether the main angle and/or the offset angle and/or the rotation angle and/or the joint angle are within respective preset ranges, and issue a prompt message when the judgment is no.

The prompt message can remind the patient to change the direction or magnitude of the motion when the patient's motion is not up to standard. The prompt information may be outputted in the form of voice, or may be outputted in the form of text, and the prompt information may include information such as direction information and magnitude of the patient's deviation. Thereby, the patient is reminded when the patient's motion is not up to standard, and the direction or magnitude of the action needs to be changed. The prompt information may be outputted in the form of voice, or may be outputted in the form of text, and the prompt information may include information such as direction information and magnitude of the patient's deviation.

It should be noted that the main angle is the main parameter for measuring the quality of the movement. Only when the main angle reaches the standard angle of the standard movement as much as possible, the quality of the rehabilitation training will be higher and the training effect will be better. Of course, you can also use two or three or four angle parameters to evaluate Whether the price of the patient's action is up to standard.

In this embodiment, when calculating the offset angle and/or the offset angle and/or the rotation angle, step 110 specifically includes:

The attitude sensor acquires the starting quaternion of the posture of the training part and the current quaternion and sends it to the controller;

Step 120 specifically includes:

The controller converts the starting quaternion into at least two starting Euler angle information of different rotation orders in the INS coordinate system, and converting the current Quaternion into at least two different rotation orders in the INS coordinate system Two current Euler angle information.

Step 130 specifically includes:

The controller calculates a primary angle and/or an offset angle and/or a rotation angle based on the at least two initial Euler angle information and the at least two current Euler angle information.

In this embodiment, when calculating the main angle and/or the offset angle and/or the rotation angle, in step 120, the starting quaternion and the current quaternion are respectively converted into the first rotation order in the inertial coordinate system. a starting Euler angle information and first current Euler angle information, and a second starting Euler angle information and a second current Euler angle information of the second rotation sequence.

As shown in FIG. 8a, in step 130, the step of calculating the main angle according to the at least two initial Euler angle information and the at least two current Euler angle information specifically includes:

Step 131-1, calculating an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

Step 132-1, determining whether the estimated main angle is smaller than the angle threshold and estimating whether the main angle is smaller than the estimated offset angle. When the determination is yes, step 133-1 is performed; when the determination is no, step 133-1' is performed;

In step 133-1, the estimated main angle is determined as the main angle.

Step 133-1', the main angle change value is calculated, and then step 135-1a' is performed.

Specifically, the main angle change value in the second rotation order is calculated by the following formula:

Main angle change value = second current nutation angle - second initial nutation angle;

In step 135-1a', the main angle is calculated by the following formula:

Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |).

Figure 8b provides another possible implementation for calculating the main angle. Figure 8b is substantially identical to the step flow of Figure 8a, except that step 134-1' is performed after step 133-1' in Figure 8b.

In step 134-1', it is judged whether or not the main angle change value is equal to or smaller than 90°; when it is judged as YES, step 135-1a' is performed; when the determination is negative, step 135-1b' is executed.

In step 135-1b', the main angle is calculated by the following formula:

Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle).

Among them, the standard angle is selected according to actual needs, for example, it can be 90° or -90°.

The first starting Euler angle information includes a first starting nutation angle, the first current Euler angle information includes a first current nutation angle, the second current Euler angle information includes a second current rotation angle, and the second initial Euler angle The angular information includes a second starting angle of rotation.

In this embodiment, the estimated main angle is calculated by using the following formula in step 131-1:

Estimated main angle = first current nutation angle - first initial nutation angle;

When calculating the estimated offset angle, first determining whether the first current nutation angle is smaller than the second current nutation angle and whether the absolute value of the second current nutation angle is greater than or equal to 5;

When the judgment is YES, the estimated offset angle is calculated by the following formula:

Estimated offset angle = first current rotation angle - first starting rotation angle;

When the judgment is no (that is, when the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle ), calculate the estimated offset angle by the following formula:

Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

At this time, the second current Euler angle information further includes a second current rotation angle.

In this embodiment, as shown in FIG. 9, in step 130, the step of calculating an offset angle according to at least two initial Euler angle information and at least two current Euler angle information specifically includes:

Step 131-2, determining whether the first current nutation angle is smaller than the second current nutation angle; when the determination is yes, step 132-2 is performed; if the determination is no, step 132-2' is performed;

In step 132-2, the offset angle is calculated by the following formula:

Offset angle = first current rotation angle - first starting rotation angle;

In step 132-2', the offset angle is calculated by the following formula:

Offset angle = second current rotation angle -sign (second starting rotation angle) × 90°.

The first current Euler angle information further includes a first current rotation angle, the first starting Euler angle information further includes a first starting rotation angle, and the second starting Euler angle information further includes a second starting rotation angle.

In this embodiment, after calculating the offset angle, the measurement method further includes:

Step 133-2: The offset angle is validated. The formula is as follows:

Target offset angle = offset angle - sign (offset angle - 180 °) × 360 °.

In this embodiment, the calculation formula of the rotation angle is as follows:

Rotation angle = current angle of the training part on the Z axis of the inertial coordinate system - the starting angle of the training part on the Z axis of the inertial coordinate system.

In this embodiment, when calculating the angle of the joint, step 110 specifically includes:

The two attitude sensors respectively acquire the first quaternion and the second quaternion of the posture of the training part.

The measuring method of the embodiment is suitable for measuring the joint angle of the patient in a training position such as standing position, sitting position, supine position, etc., and measuring the angle of the knee joint as an example, fixing the first posture sensor and the second posture sensor to the training. The side of the thigh and the calf, when the patient is in the standard standing position, the Y-axis of the body coordinate system of the attitude sensor coincides with the Z-axis of the inertial coordinate system (ie, the northeast sky coordinate system), and the Z-axis is perpendicular to the size leg, and The direction is parallel to the left and right direction of the human body.

Step 120 specifically includes:

The controller converts the first quaternion to at least two Euler angle information of different rotation orders in the inertial coordinate system, and converts the second quaternion to at least two of different rotation orders in the inertial coordinate system Euler angle information.

Step 130 specifically includes:

The controller calculates the joint angle of the training site based on at least four Euler angle information.

In this embodiment, when calculating the joint angle, in step 120, the first quaternion number and the second quaternion number are respectively converted into the first Euler angle information and the second ou in the first rotation order in the inertial coordinate system. Pull angle information, and third Euler angle information of the second rotation order and fourth Europe Pull angle information;

Specifically, as shown in FIG. 10, step 130 includes:

Step 131-3: Determine whether the absolute value of the first chapter moving angle is smaller than the first threshold.

When the determination is no, step 132-3a is performed; when the determination is yes, step 132-3b is performed;

Step 132-3a calculates the joint angle based on the third Euler angle information and the fourth Euler angle information.

Specifically, step 132-3a includes:

When the product of the first chapter of the dynamic angle and the second chapter of the dynamic angle is greater than 0, the joint angle is calculated by the following formula:

Joint angle = 180 ° - | Chapter 3 Dynamic angle - Chapter 4 dynamic angle |

When the product of the first chapter of the dynamic angle and the second chapter of the dynamic angle is less than 0, the joint angle is calculated by the following formula:

Joint angle =|Chapter 3 moving angle + fourth chapter moving angle|.

Step 132-3b calculates the joint angle based on the first Euler angle information, the third Euler angle information, and the fourth Euler angle information.

Specifically, step 132-3b includes:

When the product of the predicted angle and the fourth chapter of the dynamic angle is greater than 0, the joint angle is calculated by the following formula:

Joint angle = 180 ° -|Chapter 1 moving angle + sign (third chapter moving angle) × 90 ° - Chapter 4 moving angle |

When the product of the predicted angle and the fourth chapter of the dynamic angle is less than 0, the joint angle is calculated by the following formula:

Joint angle =|Chapter 1 moving angle +sign (third chapter moving angle)×90°+fourth chapter moving angle|;

Among them, the predicted angle = the first chapter of the dynamic angle + sign (third chapter dynamic angle) × 90 °.

Example 7

Embodiment 7 is basically the same as Embodiment 6, except that in this embodiment, one standard bit is defined for each rehabilitation exercise, that is, the standard position is used as the start bit, so that the estimation is calculated by the following formula in this embodiment. Main angle and estimated offset angle:

Estimated main angle = first current nutation angle;

When the first current nutation angle is smaller than the second current rotation angle and the absolute value of the second current rotation angle is greater than or equal to 5, the estimated offset angle is calculated by the following formula:

Estimated offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the estimation is calculated by the following formula Offset angle:

Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

The first current Euler angle information further includes a first current rotation angle, the first starting Euler angle information further includes a first starting rotation angle, the second current Euler angle information further includes a second current nutation angle, and a second The current Euler angle information also includes a second current rotation angle.

In this embodiment, the main angle change value in the second rotation sequence is calculated by the following formula:

The main angle change value = the second current nutation angle ± 90 °.

In this embodiment, when calculating the offset angle, when determining that the first current nutation angle is smaller than the second current nutation angle, the offset angle is calculated by the following formula:

Offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

When it is determined that the first current nutation angle is greater than or equal to the second current nutation angle, the offset angle is calculated by the following formula:

Offset angle = second current rotation angle -sign (second starting rotation angle) × 90 °;

The second starting Euler angle information includes a second starting rotation angle.

Example 8

The embodiment 8 is basically the same as the embodiment 6. The same applies to the measurement of the joint angle when the patient performs the training action such as standing position, sitting position, supine position, etc., the difference is that the measurement of the knee joint angle is taken as an example. An attitude sensor and a second attitude sensor are fixed on the front or the back of the thigh and the lower leg. When in the standard standing position, the Y coordinate of the body coordinate system of the attitude sensor and the Z coordinate system (that is, the northeast sky coordinate system) Z The axes coincide, the Z axis is perpendicular to the size of the legs, and the direction is perpendicular to the left and right direction of the human body.

In this implementation, in step 120, the first quaternion number and the second quaternion number are respectively converted into the third Euler angle information and the fourth Euler angle information in the second rotation order in the inertial coordinate system.

As shown in FIG. 11, step 130 specifically includes:

Step 131-4, calculate the joint angle by the following formula:

Joint angle = 180° - | third rotation angle - fourth rotation angle |

Step 132-4, calculating the first temporary angle by the following formula:

First temporary angle=|third rotation angle-fourth rotation angle|;

Step 133-4: Determine whether the absolute value of the first temporary angle is greater than a second threshold.

When the determination is yes, step 134-4 is performed. When the determination is no, step 140 is performed.

In step 134-4, the joint angle is subjected to fault tolerance processing by the following formula to obtain the target joint angle:

Target joint angle = 180° - | first temporary angle - sign (first temporary angle) × 360 ° |.

In step 140, it is determined whether the joint angle or the target joint angle is within a respective preset range, and a prompt message is issued when the judgment is negative.

Example 9

The measuring method of the present embodiment is applicable to the measurement of the angle of the joint when the patient is in the lateral position. The measurement procedure is basically the same as that in the embodiment 8, as shown in FIG. 12, except that the step 130 specifically includes:

Step 131-5, calculate the joint angle by the following formula:

Joint angle = 180° - | third precession angle - fourth precession angle |.

Step 132-5, calculating the second temporary angle by the following formula:

Second temporary angle = | third precession angle - fourth precession angle |.

Step 133-5: Determine whether the absolute value of the second temporary angle is greater than a second threshold. When the determination is yes, step 134-5 is performed; if the determination is no, step 140 is performed.

In step 134-5, the joint angle is subjected to fault tolerance processing by the following formula to obtain the target joint angle:

Target joint angle = 180° - | second temporary angle - sign (second temporary angle) × 360 ° |.

Example 10

The measurement system of the present embodiment is suitable for the case where the initial posture is different by 90° on the Z axis (the angle change of the attitude sensor is not on the Z axis), and the angle between the lumbar joint and the thigh is calculated as an example, and the attitude sensor A is required. Wearing on the chest, the posture sensor B is worn on the lateral side of the thigh. The measurement method of the embodiment is substantially the same as that of the embodiment 6, as shown in FIG. 13 , except that the step of calculating the angle of the joint in step 130 specifically includes:

Step 131-6: Determine whether the absolute value of the second chapter moving angle is smaller than the first threshold.

If the determination is no, step 132-6 is performed; if the determination is yes, step 133-6 is performed.

In step 132-6, the joint angle is calculated by the following formula:

Joint angle = 180° - | third rotation angle - (compensation angle + fourth chapter dynamic angle) |.

Step 133-6, calculating the joint angle by the following formula:

Joint angle = 180 ° - | third rotation angle - (compensation angle + second chapter movement angle ± 90 °) |.

While the invention has been described with respect to the preferred embodiments of the embodiments of the embodiments of the invention modify. Accordingly, the scope of the invention is defined by the appended claims.

Claims (20)

1. A measurement system for rehabilitation exercise parameters, characterized in that the measurement system comprises: an attitude sensor and a controller;

   The posture sensor is fixed to a training part of a human rehabilitation exercise; the posture sensor is configured to acquire a quaternion of the posture of the training part and send the quaternion to the controller;

   The controller is configured to convert the quaternion into Euler angle information of different rotation orders in an inertial coordinate system, and calculate the rehabilitation motion parameter according to the Euler angle information.
2. The measurement system of claim 1 wherein said rehabilitation motion parameters comprise: a primary angle and/or an offset angle and/or a rotation angle;

   The first attitude sensor is configured to acquire a starting quaternion and a current quaternion of the posture of the training part and send the same to the controller;

   The controller is configured to convert the starting quaternion into at least two initial Euler angle information of different rotation orders in an inertial coordinate system, and convert the current quaternion into an inertial coordinate system Calculating the primary angle and/or offset based on the at least two initial Euler angle information and the at least two current Euler angle information Angle and/or angle of rotation;

   The main angle is an angle between a projection of the training site on a first plane and a second plane; the first plane is a plane in which a motion path of a standard motion of rehabilitation motion is located, and the second plane is The first plane is vertical;

   The offset angle is an angle between a projection of the training portion on the second plane and the first plane;

   The rotation angle is an angle change value of the training portion on the Z axis of the inertial coordinate system.
3. The measurement system according to claim 2, wherein said controller comprises an Euler angle conversion unit, a first calculation unit, and a first determination unit;

   The Euler angle conversion unit converts the starting quaternion and the current quaternion into a first starting Euler angle information and a first current Euler angle of a first rotation sequence in an inertial coordinate system, respectively Information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

   When calculating the main angle, the first calculating unit is based on the first starting Euler angle information and the first current Euler angle letter Calculate the estimated main angle and the estimated offset angle separately;

   The first determining unit is configured to determine the estimated main angle as a main angle when determining that the estimated main angle is smaller than an angle threshold and the estimated main angle is smaller than the estimated offset angle; otherwise, Calling the first computing unit;

   The first calculating unit is further configured to calculate a main angle change value in the second rotation sequence by using the following formula:

   Main angle change value = second current nutation angle - second initial nutation angle;

   The first calculation unit is further configured to calculate a main angle by the following formula:

   Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

   Or the first calculating unit is further configured to calculate the main angle by using the following formula when the main angle change value is greater than 90°:

   Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

   Preferably, the estimated main angle = the first current nutation angle - the first initial nutation angle;

   When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the first calculating unit specifically calculates the estimated offset angle by the following formula:

   Estimated offset angle = first current rotation angle - first starting rotation angle;

   When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the first calculation unit Calculate the estimated offset angle by the following formula:

   Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

   The first initial Euler angle information includes a first initial nutation angle, the first current Euler angle information includes a first current nutation angle, and the second current Euler angle information includes a second current nutation angle And the second current rotation angle, the second starting Euler angle information includes a second initial nutation angle.
4. The measurement system according to claim 2, wherein when calculating the main angle, the controller comprises an Euler angle conversion unit, a first calculation unit, and a first determination unit;

   The Euler angle conversion unit converts the starting quaternion and the current quaternion into a first starting Euler angle information and a first current Euler angle of a first rotation sequence in an inertial coordinate system, respectively Information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

   The first calculating unit calculates an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

   The first determining unit is configured to determine the estimated main angle as a main angle when determining that the estimated main angle is smaller than an angle threshold and the estimated main angle is smaller than the estimated offset angle; otherwise, Calling the first computing unit;

   The first calculating unit is further configured to calculate a main angle change value in the second rotation sequence by using the following formula:

   The main angle change value = the second current nutation angle ± 90 °;

   The first calculation unit is further configured to calculate a main angle by the following formula:

   Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

   Or the first calculating unit is further configured to calculate the main angle by using the following formula when the main angle change value is greater than 90°:

   Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

   Preferably, the estimated main angle = the first current nutation angle;

   When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the first calculating unit specifically calculates the estimated offset angle by the following formula:

   Estimated offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

   When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the first calculation unit Calculate the estimated offset angle by the following formula:

   Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

   The first current Euler angle information includes a first current rotation angle and a first current nutation angle, and the first starting Euler angle information includes a first initial rotation angle and a first initial nutation angle, the second The current Euler angle information includes a second current rotation angle and a second current nutation angle.
5. The measurement system according to claim 3 or 4, wherein the first determining unit is further configured to determine whether the first current nutation angle is smaller than the second current nutation angle when calculating the offset angle;

   When the first determining unit determines YES, the first calculating unit calculates the offset angle by the following formula:

   Offset angle = first current rotation angle - first starting rotation angle;

   Or, the first calculating unit calculates the offset angle by the following formula:

   Offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

   When the first determining unit determines NO, the first calculating unit calculates the offset angle by the following formula:

   Offset angle = second current rotation angle -sign (second starting rotation angle) × 90 °;

   The first starting Euler angle information further includes a first starting rotation angle, and the second starting Euler angle information further includes a second starting rotation angle.
6. The measurement system of claim 1 wherein said rehabilitation motion parameters comprise: an angle of joint;

   The second attitude sensor is configured to acquire a first quaternion of the posture of the training part and send the same to the controller;

   The controller is configured to convert the first quaternion to at least two Euler angle information of different rotation orders in an inertial coordinate system;

   The third attitude sensor is configured to acquire a second quaternion of the posture of the training part and send the same to the controller;

   The controller is further configured to convert the second quaternion to at least two Euler angle information of the different rotation order in an inertial coordinate system;

   The controller is further configured to calculate a joint angle of the training portion based on the at least four Euler angle information.
7. The measurement system according to claim 6, wherein said controller comprises an Euler angle conversion unit, a second calculation unit, a third calculation unit, and a second determination unit;

   When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into the first Euler angle information of the first rotation order in the inertial coordinate system, respectively And second Euler angle information, and third Euler angle information and fourth Euler angle information of the second rotation sequence;

   The second determining unit is configured to determine whether an absolute value of the first chapter moving angle is smaller than a first threshold; when the determination is no, the second calculating unit is called; when the determination is yes, the third calculating unit is called ;

   The second calculating unit is specifically configured to calculate the joint angle by the following formula when the product of the first chapter moving angle and the second chapter moving angle is greater than 0:

   Joint angle = 180 ° - | Chapter 3 Dynamic angle - Chapter 4 dynamic angle |

   The second calculating unit is further configured to calculate the joint angle by the following formula when the product of the first chapter moving angle and the second chapter moving angle is less than 0:

   Joint angle =|Chapter 3 moving angle + fourth chapter moving angle|;

   The third calculating unit is specifically configured to calculate the joint angle by the following formula when the product of the predicted angle and the fourth chapter moving angle is greater than zero:

   Joint angle = 180 ° -|Chapter 1 moving angle + sign (third chapter moving angle) × 90 ° - Chapter 4 moving angle |

   The third calculating unit is further configured to calculate the joint angle by the following formula when the product of the predicted angle and the fourth chapter moving angle is less than 0:

   Joint angle =|Chapter 1 moving angle +sign (third chapter moving angle)×90°+fourth chapter moving angle|;

   Among them, the predicted angle = the first chapter moving angle + sign (third chapter moving angle) × 90 °;

   The first Euler angle information includes a first nutation angle, the second Euler angle information includes a second nutation angle, and the third Euler angle information includes a third nutation angle, the fourth Europe The pull angle information includes the fourth chapter dynamic angle.
8. The measurement system of claim 6 wherein said controller comprises an Euler angle conversion unit and a fourth calculation unit;

   When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into a third Euler angle information of the second rotation order in the inertial coordinate system, respectively And the fourth Euler angle information;

   The fourth calculation unit is configured to calculate an angle of joint by the following formula:

   Joint angle = 180° - | third rotation angle - fourth rotation angle |

   The third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth rotation angle;

   Preferably, the controller further includes a third determining unit;

   The fourth calculating unit is further configured to calculate the first temporary angle by the following formula:

   First temporary angle=|third rotation angle-fourth rotation angle|;

   The third determining unit is further configured to determine whether an absolute value of the first temporary angle is greater than a second threshold, and when the determination is yes, invoke the fourth calculating unit;

   The fourth calculating unit is further configured to perform fault tolerance processing on the joint angle by using the following formula to obtain a target joint angle:

   Target joint angle = 180° - | first temporary angle - sign (first temporary angle) × 360 ° |.
9. The measurement system of claim 6 wherein said controller comprises an Euler angle conversion unit and a fifth calculation unit;

   When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into a third Euler angle information of the second rotation order in the inertial coordinate system, respectively And the fourth Euler angle information;

   The fifth calculation unit is for calculating an angle of joint by the following formula:

   Joint angle = 180° - | third precession angle - fourth precession angle |

   The third Euler angle information includes a third precession angle, and the fourth Euler angle information includes a fourth precession angle;

   Preferably, the controller further includes a fourth determining unit;

   The fifth calculating unit is further configured to calculate the second temporary angle by the following formula:

   Second temporary angle =|third precession angle - fourth precession angle|;

   The fourth determining unit is further configured to determine whether an absolute value of the second temporary angle is greater than a second threshold;

   When the fourth determining unit determines YES, the fifth calculating unit is further configured to perform fault tolerance processing on the joint angle by using the following formula to obtain a target joint angle:

   Target joint angle = 180° - | second temporary angle - sign (second temporary angle) × 360 ° |.
10. The measurement system according to claim 6, wherein said controller comprises an Euler angle conversion unit, a fifth determination unit, and a sixth calculation unit;

    When calculating the joint angle, the Euler angle conversion unit converts the first quaternion and the second quaternion into the first Euler angle information of the first rotation order in the inertial coordinate system, respectively And second Euler angle information, and third Euler angle information and fourth Euler angle information of the second rotation sequence;

    The fifth determining unit is further configured to determine whether an absolute value of the second chapter moving angle is smaller than a first threshold;

    When the fifth determining unit determines NO, the sixth calculating unit calculates the joint angle by the following formula:

    Joint angle = 180° - | third rotation angle - (compensation angle + fourth chapter dynamic angle) |;

    When the fifth determining unit determines YES, the sixth calculating unit is further configured to calculate the joint angle by the following formula:

    Joint angle = 180° - | third rotation angle - (compensation angle + second chapter movement angle ± 90 °) |

    The second Euler angle information includes a second chapter angle, the third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth chapter movement angle.
11. A method of measuring a rehabilitation motion parameter, characterized in that the measurement method is implemented by the measurement system according to any one of claims 1 to 10, the measurement method comprising the steps of:

    Quaternion S _1, the sensor acquires the posture of the posture of the training site and sent to the controller;

    S ₂ , the controller converts the quaternion into Euler angle information of different rotation orders in an inertial coordinate system;

    S ₃ , the controller calculates the rehabilitation motion parameter according to the Euler angle information.
12. The measuring method according to claim 11, wherein the rehabilitation motion parameters comprise: an offset angle and/or an offset angle and/or a rotation angle;

    Step S ₁ comprises:

    The first attitude sensor acquires a starting quaternion and a current quaternion of the posture of the training part and sends the same to the controller;

    Step S ₂ comprises:

    The controller converts the initial quaternion into at least two initial Euler angle information of different rotation orders in an inertial coordinate system, and converts the current quaternion into an inertial coordinate system At least two current Euler angle information of the different rotation order;

    Step S ₃ comprises:

    The controller calculates the primary angle and/or the offset angle and/or the rotation angle according to the at least two initial Euler angle information and the at least two current Euler angle information;

    The main angle is an angle between a projection of the training site on a first plane and a second plane; the first plane is a plane in which a motion path of a standard motion of rehabilitation motion is located, and the second plane is The first plane is vertical;

    The offset angle is an angle between a projection of the training portion on the second plane and the first plane;

    The rotation angle is an angle change value of the training portion on the Z axis of the inertial coordinate system.
13. The measuring method as claimed in claim 12, wherein, in the step S _2, the first initial starting rotation of the first sequence and the current quaternion quaternion are converted to the coordinate system INS Euler angle information and first current Euler angle information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

    Step S ₃ in accordance with the Euler angles of the at least two initial information and the current step of the at least two primary Euler angles of the angle information calculating comprises:

    S _31-1 , calculating an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

    _S32-1 , determining whether the estimated main angle is smaller than an angle threshold and whether the estimated main angle is smaller than the estimated offset angle; when the determination is yes, performing step _S33-1 ; When performing step S _33-1 ';

    S _33-1 , determining the estimated main angle as a main angle;

    S _33-1 ', calculate the main angle change value in the second rotation sequence by the following formula:

    Main angle change value = second current nutation angle - second initial nutation angle;

    S _34-1 ', calculate the main angle by the following formula:

    Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

    Or, when the main angle change value is greater than 90°, the main angle is calculated by the following formula:

    Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

    Preferably, the estimated main angle is calculated in the step S _31-1 by the following formula:

    Estimated main angle = first current nutation angle - first initial nutation angle;

    When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the estimated offset angle is calculated by the following formula:

    Estimated offset angle = first current rotation angle - first starting rotation angle;

    When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the specific formula is calculated by the following formula Estimate the offset angle:

    Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

    The first initial Euler angle information includes a first initial nutation angle, the first current Euler angle information includes a first current nutation angle, and the second current Euler angle information includes a second current nutation angle And the second current rotation angle, the second starting Euler angle information includes a second initial nutation angle.
14. The measuring method as claimed in claim 12, wherein, in the step S _2, the first initial starting rotation of the first sequence and the current quaternion quaternion are converted to the coordinate system INS Euler angle information and first current Euler angle information, and second start Euler angle information and second current Euler angle information of the second rotation sequence;

    Step S ₃ in accordance with the Euler angles of the at least two initial information and the current step of the at least two primary Euler angles of the angle information calculating comprises:

    S _31-2 , calculating an estimated main angle and an estimated offset angle according to the first starting Euler angle information and the first current Euler angle information;

    _S32-2 , determining whether the estimated main angle is smaller than an angle threshold and whether the estimated main angle is smaller than the estimated offset angle; when the determination is yes, performing step _S23-3 ; When performing step _S33-2 ';

    S _33-2 , determining the estimated main angle as a main angle;

    S _33-2 ', calculate the main angle change value in the second rotation order by the following formula:

    The main angle change value = the second current nutation angle ± 90 °;

    S _34-2 ', calculate the main angle by the following formula:

    Main angle = sign (estimated main angle) × max (|main angle change value |, | estimated main angle |);

    Or, when the main angle change value is greater than 90°, the main angle is calculated by the following formula:

    Main angle = sign (estimated main angle) × (2 × standard angle - first starting nutation angle - first current nutation angle);

    Preferably, the estimated main angle is calculated in step S _31-2 by the following formula:

    Estimated main angle = first current nutation angle;

    When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is greater than or equal to 5, the estimated offset angle is calculated by the following formula:

    Estimated offset angle = first current rotation angle -sign (first starting rotation angle) × 90 °;

    When the first current nutation angle is smaller than the second current nutation angle and the absolute value of the second current nutation angle is less than 5, or the first current nutation angle is greater than or equal to the second current nutation angle, the specific formula is calculated by the following formula Estimate the offset angle:

    Estimated offset angle = second current rotation angle -sign (first current nutation angle) × 90 °;

    The first current Euler angle information includes a first current rotation angle and a first current nutation angle, and the first starting Euler angle information includes a first initial rotation angle and a first initial nutation angle, the second The current Euler angle information includes a second current rotation angle and a second current nutation angle.
15. The method of claim 13 or measuring as claimed in claim 14, wherein the step S _3, the Euler angles of the at least two current information calculating the offset angle of the at least two initial information and the Euler angles The steps specifically include:

    S _31-3 , determining whether the first current nutation angle is smaller than the second current nutation angle; when the determination is yes, executing step _S32-3 ; when the determination is no, executing step _S32-3 ';

    S _32-3 , calculate the offset angle by the following formula:

    Offset angle = first current rotation angle - first starting rotation angle;

    Or, the offset angle = the first current rotation angle -sign (first starting rotation angle) × 90 °;

    S _32-4 ', calculate the offset angle by the following formula:

    Offset angle = second current rotation angle -sign (second starting rotation angle) × 90 °;

    The first starting Euler angle information further includes a first starting rotation angle, and the second starting Euler angle information further includes a second starting rotation angle.
16. The measuring method according to claim 11, wherein the rehabilitation motion parameter comprises: an angle of joint;

    Step S ₁ comprises:

    The first attitude sensor acquires a first quaternion of the posture of the training part, and the second attitude sensor acquires a second quaternion of the posture of the training part;

    Step S ₂ comprises:

    The controller converts the first quaternion into at least two Euler angle information of different rotation orders in an inertial coordinate system, and converts the second quaternion into the inertial coordinate system At least two Euler angle information for different rotation orders;

    Step S ₃ comprises:

    The controller calculates an angle of joint of the training site based on at least four Euler angle information.
17. The measuring method as claimed in claim 16, wherein, in the step S _2, the first controller sets the first and the second quaternion quaternion are converted to the coordinate system INS a first Euler angle information and a second Euler angle information of the rotation order, and third Euler angle information and fourth Euler angle information of the second rotation sequence;

    The step of calculating the joint angle of the training portion according to the at least four Euler angle information specifically includes:

    S _3-1a , determining whether the absolute value of the first chapter moving angle is smaller than the first threshold; when the determination is no, step S _{3-2a is performed} ; when the determination is YES, executing step S _3-3a ;

    S _3-2a , calculating the joint angle according to the third Euler angle information and the fourth Euler angle information;

    S _3-3a , calculating the joint angle according to the first Euler angle information, the third Euler angle information, and the fourth Euler angle information;

    Preferably, step S _3-2a specifically includes:

    When the product of the first chapter of the dynamic angle and the second chapter of the dynamic angle is greater than 0, the joint angle is calculated by the following formula:

    Joint angle = 180 ° - | Chapter 3 Dynamic angle - Chapter 4 dynamic angle |

    When the product of the first chapter of the dynamic angle and the second chapter of the dynamic angle is less than 0, the joint angle is calculated by the following formula:

    Joint angle =|Chapter 3 moving angle + fourth chapter moving angle|;

    Preferably, step S _3-3a specifically includes:

    When the product of the predicted angle and the fourth chapter of the dynamic angle is greater than 0, the joint angle is calculated by the following formula:

    Joint angle = 180 ° -|Chapter 1 moving angle + sign (third chapter moving angle) × 90 ° - Chapter 4 moving angle |

    When the product of the predicted angle and the fourth chapter of the dynamic angle is less than 0, the joint angle is calculated by the following formula:

    Joint angle =|Chapter 1 moving angle +sign (third chapter moving angle)×90°+fourth chapter moving angle|;

    Among them, the predicted angle = the first chapter moving angle + sign (third chapter moving angle) × 90 °;

    The first Euler angle information includes a first nutation angle, the second Euler angle information includes a second nutation angle, and the third Euler angle information includes a third nutation angle, the fourth Europe The pull angle information includes the fourth chapter dynamic angle.
18. The measuring method as claimed in claim 16, wherein, in the step S _2, the first and the second quaternion quaternion into a third respectively a second rotation sequence under INS coordinates Euler angle information and fourth Euler angle information;

    The step of calculating the joint angle of the training portion according to the at least four Euler angle information specifically includes:

    S _3-1b , calculate the joint angle by the following formula:

    Joint angle = 180° - | third rotation angle - fourth rotation angle |

    The third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth rotation angle;

    Preferably, after step _S3-1b , the method further includes:

    S _3-2b , calculate the first temporary angle by the following formula:

    First temporary angle=|third rotation angle-fourth rotation angle|;

    S _3-3b , determining whether the absolute value of the first temporary angle is greater than a second threshold, and when the determination is yes, performing step S _3-4b ;

    S _3-4b , the fault angle of the joint angle is calculated by the following formula to obtain the target joint angle:

    Target joint angle = 180° - | first temporary angle - sign (first temporary angle) × 360 ° |.
19. The measuring method as claimed in claim 16, wherein, in the step S _2, the first and the second quaternion quaternion into a third respectively a second rotation sequence under INS coordinates Euler angle information and fourth Euler angle information;

    Step S ₃ comprises:

    S _3-1c , calculate the joint angle by the following formula:

    Joint angle = 180° - | third precession angle - fourth precession angle |

    The third Euler angle information includes a third precession angle, and the fourth Euler angle information includes a fourth precession angle;

    Preferably, after step _S3-1c , the method further includes:

    S _3-2c , calculate the second temporary angle by the following formula:

    Second temporary angle =|third precession angle - fourth precession angle|;

    S _3-3c , determining whether the absolute value of the second temporary angle is greater than a second threshold; when the determination is yes, performing step S _3-4c ;

    S _3-4c , the joint angle is fault-tolerant by the following formula to obtain the target joint angle:

    Target joint angle = 180° - | second temporary angle - sign (second temporary angle) × 360 ° |.
20. The measuring method as claimed in claim 16, wherein, in the step S _2, the first and the second quaternion quaternion are converted to a first order in a first rotational INS coordinates Euler angle information and second Euler angle information, and third Euler angle information and fourth Euler angle information of the second rotation sequence;

    Step S ₃ comprises:

    _S3-1d , determining whether the absolute value of the second chapter moving angle is smaller than the first threshold; when the determination is no, step _{S3-2d is performed} ; when the determination is yes, step _{S3-3d is performed} ;

    S _3-2d , calculate the joint angle by the following formula:

    Joint angle = 180° - | third rotation angle - (compensation angle + fourth chapter dynamic angle) |;

    S _3-3d , calculate the joint angle by the following formula:

    Joint angle = 180° - | third rotation angle - (compensation angle + second chapter movement angle ± 90 °) |

    The second Euler angle information includes a second chapter angle, the third Euler angle information includes a third rotation angle, and the fourth Euler angle information includes a fourth chapter movement angle.

Images