A glasses hanging rope data correction method for correcting eye posture

Abstract

The present invention provides a method for correcting eye posture using eyeglass lanyard data, comprising the following steps: facing a horizontal calibration plate, obtaining a first left distance value and a first right distance value, and calculating a first distance difference; determining whether the difference exceeds an error threshold; if not, the horizontal calibration is successful; if yes, adjusting the positions of the first sampling end and the second sampling end, and looping step one; and step two, looking horizontally toward a vertical calibration plate, obtaining a second left distance value and a second right distance value, and calculating a second distance difference; determining whether the difference exceeds an error threshold; if no, obtaining several groups of X-axis acceleration data, Y-axis acceleration data, and Z-axis acceleration data and calculating the average to generate a three-axis acceleration value of a reference inclination angle; and vertical calibration is successful; if yes, prompting the user to adjust the head angle, and looping step two. The present invention can accurately calibrate the installation position of the distance sensor and determine the reference inclination parameters of the motion sensor through simple steps, thereby improving detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor calibration, and in particular to a method for correcting glasses hanging rope data for correcting eye posture. Background Art

[0002] Prior art discloses a myopia prevention and control device with a glasses hanging strap structure. The motion sensor and distance sensor in the device are attached to the left and right sides of the glasses frame. The motion sensor is used to collect reading inclination data while the user is reading. However, due to different wearing habits of glasses, the inclination angle of the motion sensor varies when looking straight ahead after wearing glasses, resulting in low accuracy of the reading inclination data.

[0003] Distance sensors on either side of the frame are used to obtain reading distance data from the user's left and right sides. This data is then used to determine whether the user has strabismus, or the severity of the strabismus. However, since the distance sensors are manually installed on the left and right sides of the frame, it is difficult to ensure that the sensors are aligned, which affects the determination of strabismus severity. Summary of the Invention

[0004] In view of this, the problem to be solved by the present invention is to provide a method for correcting glasses strap data for correcting eye posture, which can combine the use of difference factors, accurately calibrate the installation position of the distance sensor through simple steps, and determine the reference inclination parameters of the motion sensor, thereby improving detection accuracy.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for correcting eye posture using a glasses lanyard data includes a first sampling end and a second sampling end fixedly mounted on either side of a glasses frame, wherein the first sampling end includes a first distance sensor that generates a left distance value, and the second sampling end includes a second distance sensor that generates a right distance value. A motion sensor that obtains a tilt angle is included in either the first sampling end or the second sampling end.

[0007] Correction methods based on the above system include:

[0008] Step 1: Look at the first viewpoint on the horizontal calibration plate at an angle, obtain the first left distance value and the first right distance value, and calculate the difference to generate a first distance difference. Determine whether the first difference exceeds the error threshold. If not, provide feedback that the horizontal calibration is successful. If yes, prompt to adjust the positions of the first sampling end and the second sampling end, and repeat step 1.

[0009] Step 2: Look horizontally at the second viewpoint on the vertical calibration board, obtain the second left distance value and the second right distance value and calculate the difference to generate a second distance difference, and determine whether the second distance difference exceeds the error threshold. If not, obtain several groups of X-axis acceleration data, Y-axis acceleration data and Z-axis acceleration data and calculate the average to generate three-axis acceleration value data of the reference inclination angle, and give feedback on successful vertical calibration; if yes, remind to adjust the head angle and repeat step 2.

[0010] Furthermore, the user faces the horizontal calibration plate and the vertical calibration plate, and the first viewpoint and the second viewpoint are both located directly in front of the user.

[0011] Furthermore, the straight-line distance between the first viewpoint, the second viewpoint and the frame is in the range of 30 cm to 100 cm.

[0012] Furthermore, the motion sensor is a six-axis sensor.

[0013] Furthermore, the method for calculating the reading inclination angle by the motion sensor is: obtaining the three-axis acceleration value (x1, y1, z1) of the reference inclination angle, obtaining the three-axis acceleration value (x2, y2, z2) of the current inclination angle through the motion sensor, and using the formula:

[0014]

[0015] Calculate the user's reading inclination angle when reading.

[0016] Furthermore, the first distance sensor and the second distance sensor both implement ranging based on the dToF principle, and the first distance sensor includes a transmitting end and a receiving end;

[0017] The ranging method of the first distance sensor is as follows: within a single frame measurement time, the transmitting end and the receiving end transmit and receive light signals N times, and record the flight time of the light signals N times, make a histogram with time as the horizontal axis and number of times as the vertical axis, obtain the flight time t with the highest frequency, and calculate the first distance value by the formula S=Ct / 2, where: S is the distance; C is the speed of the laser in the air; and t is the time difference between transmitting and receiving the echo.

[0018] Furthermore, the transmitting end transmits an optical signal, the receiving end receives the optical signal, the reftof value corresponds to the intensity of the optical signal, and in order to improve the receiving efficiency of the optical signal, the step 1 includes temperature calibration;

[0019] The temperature calibration includes: obtaining a current reftof value at a current temperature based on the flight time t of the first distance sensor or the second distance sensor, wherein the distance sensor includes a factory reftof value, and comparing the current reftof value with the factory reftof value to adjust the optical power of the transmitting end and the power-off voltage position of the receiving end to improve the performance of the distance sensor.

[0020] The advantages and positive effects of the present invention are:

[0021] By setting the horizontal and vertical calibration to adjust the sensor's baseline values ​​before the user uses the glasses, the distance sensor and motion sensor can be calibrated simply and accurately based on the user's wearing habits, thereby improving the accuracy of the reading distance and reading inclination detection when the user is reading. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 This is an overall flow chart of a method for correcting eye posture and glasses hanging rope data according to the present invention;

[0024] Figure 2 It is a right triangle diagram formed by the first motion data, the second motion data and the constant temperature vertical calibration plate in the glasses hanging rope data correction method for correcting eye posture of the present invention;

[0025] Figure 3 This is a dToF principle diagram of a glasses strap data correction method for correcting eye posture according to the present invention;

[0026] Figure 4 The present invention is a histogram of a method for correcting data of glasses hanging ropes for correcting eye posture. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] The present invention provides a method for correcting eye posture using a glasses strap. The glasses strap structure includes a first sampling end and a second sampling end attached to the left and right sides of the glasses frame. A first distance sensor is fixedly mounted within the first sampling end, and a second distance sensor is fixedly mounted within the second sampling end. When a user reads, the first and second distance sensors simultaneously acquire the linear distance to the book or tablet to generate reading distance data. This reading distance data is then used to determine whether the reading posture is normal or whether there is strabismus.

[0030] A motion sensor is fixedly mounted in the first sampling end or the second sampling end. In one embodiment of the present application, the motion sensor may be a six-axis sensor, fixedly mounted in the first sampling end. The sensor can obtain three-axis inclination and three-axis acceleration values ​​while the user is reading, and the inclination and movement path of the user while reading can be determined based on the three-axis inclination.

[0031] Glasses need to be worn every day, and long-term use of the distance sensor will affect the accuracy of the device. Or the performance of different devices of the same model may not be exactly the same, which will cause the errors of the two distance sensors to be different.

[0032] like Figure 2 To improve reading distance accuracy, a distance calibration strategy is included. Taking the calibration process for a single distance sensor as an example, the following steps are performed: The user puts on their glasses and faces a vertical plane (vertical calibration plate), which can be a wall. The motion sensor adjusts the frame position to a horizontal position, notifies the user that the frame is in a first position, and acquires first distance data and first motion data. The user is then prompted to adjust the vertical angle of the frame and manually confirms that the frame has reached a second position, acquiring second distance data and second motion data.

[0033] The coordinates of the first position are defined as the origin coordinates. The motion sensor determines the movement path to obtain the coordinates of the second position, which are defined as the destination coordinates. The rotation angle of the frame is determined based on the first and second motion data. The first and second distance data are then completed based on the rotation angle, the origin coordinates, and the destination coordinates. A right triangle is formed between the first and second distance data and the vertical plane.

[0034] Because the rotation angle θ obtained by the motion sensor is accurate, the error value X between the first and second distance data obtained by the same distance sensor is the same. The cosine theorem can be used to calculate the measurement error of the first distance sensor. Since the movement paths of the first and second distance sensors are identical, the two distance sensors should be calibrated synchronously.

[0035] The specific embodiment is as follows: obtaining the completed first distance data L1, the second distance data L2 and the rotation angle θ, wherein: the accuracy interval of the first distance sensor is [a1.a2], the interval of the rotation angle θ is [0.90], and the cosine calculation formula is:

[0036]

[0037] When there are multiple solutions for X in the above formula, the solution closest to the accuracy interval [a1.a2] is used as the final solution. Calibrate the first distance sensor error based on the accuracy interval. This is a simple and quick operation, allowing users to calibrate themselves and improve the accuracy of the distance sensor. The distance sensor can be calibrated every few months. Before calibration, the motion sensor's reference must be reset so that the frame can be adjusted based on the motion sensor data and placed horizontally.

[0038] Due to varying eyewear habits, the tilt of the frame varies when the user is looking straight ahead, affecting the accuracy of the reading angle data. Because the first and second sampling terminals on the left and right sides of the frame are manually installed, the positions of the first and second distance sensors are not aligned, affecting the consistency between the two sets of reading distance data. To avoid affecting the judgment of the user's reading posture, the first and second distance sensors and the motion sensor must be calibrated.

[0039] like Figure 1 As shown in the figure, the calibration process is:

[0040] Step 1: Tilt and look toward the first viewpoint on the horizontal calibration plate, obtain the first left distance value and the first right distance value, and calculate the difference to generate a first distance difference. Determine whether the first difference exceeds the error threshold. If not, give feedback that the horizontal calibration is successful. If yes, remind to adjust the positions of the first sampling end and the second sampling end, and repeat step 1.

[0041] During horizontal calibration, the user faces forward and looks at the horizontal calibration board. Pause for several seconds. The first and second distance sensors acquire the first left and right distance values. The viewing position is called the viewpoint. The straight-line distance between the viewpoint and the user is not fixed; it only needs to be directly in front of the user.

[0042] The difference between the first left distance value and the first right distance value is calculated and a first distance difference is generated. A determination is made as to whether the first distance difference is less than an error threshold. If so, the left and right distance sensors are aligned, and a horizontal calibration completion reminder is displayed. The eyeglass lanyard structure can vibrate to alert the user that the calibration is successful. The eyeglass lanyard structure includes a Bluetooth module that is wirelessly connected to the sports terminal (mobile phone) and can also provide radial text reminders on the mobile terminal.

[0043] If no, the user is reminded to adjust the positions of the first distance sensor and the second distance sensor through different vibration frequencies, and the first left distance value and the first right distance value are obtained again, and judgment is made until the horizontal calibration is successful.

[0044] Step 2: Look horizontally at the second viewpoint on the vertical calibration board, obtain the second left distance value and the second right distance value and calculate the difference to generate a second distance difference, and determine whether the second distance difference exceeds the error threshold. If not, obtain several sets of X-axis acceleration data, Y-axis acceleration data and Z-axis acceleration data and calculate the average to generate a three-axis acceleration value of the reference inclination angle, and give feedback on successful vertical calibration; if yes, remind to adjust the head angle and repeat step 2.

[0045] After successful horizontal calibration, the two distance sensors are aligned. Ensure your head does not swing left or right, raise your head and look straight at the vertical calibration board. Pause for a few seconds and obtain the second left distance value and the second right distance value.

[0046] The difference between the second left distance value and the second right distance value is calculated to generate a second distance difference value. A determination is made as to whether the second distance difference value exceeds an error threshold. If not, this indicates that there is no left-right offset in the frame. Several sets of X-axis acceleration data, Y-axis acceleration data, and Z-axis acceleration data are obtained and averaged to generate three-axis acceleration data for a reference inclination angle. The mobile terminal provides a text reminder indicating that vertical calibration is complete, or the glasses strap structure vibrates to remind the user that vertical calibration is complete.

[0047] The three-axis acceleration data for the baseline tilt angle represents the three-axis acceleration data of the motion sensor when the user is wearing glasses normally and looking straight ahead. This data is defined as the baseline data. Based on the user's wearing habits, the motion sensor baseline data is adjusted to improve the accuracy of the reading tilt angle data. For example, different nose bridge heights will result in different frame tilt angles.

[0048] If yes, it means that the user's head has shifted left or right, and the vertical calibration has failed. The user is reminded to adjust the synchronization angle position and then re-obtain the second left distance value and the second right distance value and make a judgment.

[0049] The reading inclination calculation method based on the three-axis acceleration value data of the reference inclination angle is as follows: obtain the three-axis acceleration value (x1, y1, z1) of the reference inclination angle, obtain the three-axis acceleration value (x2, y2, z2) of the current inclination angle through the motion sensor, and use the formula:

[0050]

[0051] Calculate the user's reading angle. Reading angles above 180 degrees require additional calculation for rotation. Since wearable devices cannot rotate more than 180 degrees while being worn, only applications with reading angles between 0 and 180 degrees are considered for simplicity.

[0052] Before calibrating the sensor, you need to determine the horizontal calibration plate and the vertical calibration plate. The horizontal calibration plate can be a desktop, and the vertical calibration plate can be against a wall. In one embodiment of the present application, the vertical calibration plate can be a flat wall or a computer screen.

[0053] like Figure 3 and Figure 4 As shown, both the first distance sensor and the second distance sensor implement ranging based on the dToF principle. The first distance sensor includes a transmitter and a receiver. Taking the ranging process of the first distance sensor as an example: the transmitter emits a light signal, and the receiver receives the light signal. Within a single frame measurement time, the light signal is continuously emitted and received N times, and the time of light signal emission and reception is obtained to calculate the flight time t of the N light signals. Based on the flight time t and the number of times N of the light signal, a histogram is constructed with the flight time t as the horizontal axis and the number of times as the vertical axis. Based on the histogram, the flight time t with the highest frequency is obtained, and the first distance value is calculated using the formula S = Ct / 2, where: S is the distance; C is the speed of the laser in air; and t is the time difference between the emission and reception of the echo.

[0054] The transmitter emits a light signal, and the receiver collects it. Due to the varying operating temperatures of the distance sensor, the receiver's power-off voltage detection is inaccurate, affecting the collection of the light signal. The reftof value corresponds to the intensity of the light signal received by the receiver. To improve the efficiency of light signal reception, a temperature calibration is set in step 1.

[0055] Temperature calibration includes: obtaining the current reftof value at the current temperature based on the flight time t of the first distance sensor or the second distance sensor, including the factory reftof value tested during the factory test in the distance sensor, comparing the current reftof value with the factory reftof value, and adjusting the optical power of the transmitting end and the power-off voltage position of the receiving end based on the ratio to improve the performance of the distance sensor.

[0056] During calibration, the user faces the horizontal and vertical calibration plates. Visually verify that the straight-line distance between the camera frame and the plates is between 30cm and 100cm. Avoid short distances, which can result in a short time-of-flight (t) and affect the calibration of the first and second distance sensors.

[0057] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent.

Claims

1. A method for correcting eyeglass strap data for correcting eye posture, characterized in that: The system comprises a first sampling end and a second sampling end fixedly mounted on both sides of the frame, wherein the first sampling end comprises a first distance sensor for generating a left distance value, and the second sampling end comprises a second distance sensor for generating a right distance value, and the first sampling end and the second sampling end comprise motion sensors for acquiring acceleration data; Correction methods include: Step 1: Calibrate the installation positions of the first sampling end and the second sampling end, look at the first viewpoint on the horizontal calibration plate at an angle, obtain the first left distance value and the first right distance value, and calculate the difference to generate a first distance difference. Determine whether the first difference exceeds the error threshold. If not, provide feedback that the horizontal calibration is successful. If yes, prompt to adjust the positions of the first sampling end and the second sampling end, and repeat step 1. Step 2: Calibrate the horizontal reference value of the motion sensor. Look horizontally at the second viewpoint on the vertical calibration plate, obtain the second left distance value and the second right distance value, and calculate the difference to generate a second distance difference. Determine whether the second distance difference exceeds the error threshold. If not, obtain several sets of X-axis acceleration data, Y-axis acceleration data, and Z-axis acceleration data and calculate the average to generate a three-axis acceleration value of the reference inclination angle, and provide feedback on successful vertical calibration. If yes, remind the user to adjust the head angle and repeat step 2. The first distance sensor and the second distance sensor both implement ranging based on the dToF principle, and the first distance sensor includes a transmitting end and a receiving end; The first distance sensor has a ranging method as follows: within a single frame measurement time, the transmitting end and the receiving end transmit and receive light signals N times, and record the flight time of the light signals N times. A histogram is drawn with time as the horizontal axis and the number of times as the vertical axis, and the flight time t with the highest frequency is obtained. The first distance value is calculated using the formula S=Ct / 2, where: S is the distance; C is the speed of the laser in the air; and t is the time difference between the emission and reception of the echo. The transmitting end transmits an optical signal, the receiving end receives the optical signal, the reftof value corresponds to the intensity of the optical signal, and in order to improve the receiving efficiency of the optical signal, the step 1 includes temperature calibration; The temperature calibration includes: obtaining a current reftof value at a current temperature based on the flight time t of the first distance sensor or the second distance sensor, wherein the distance sensor includes a factory reftof value, and comparing the current reftof value with the factory reftof value to adjust the optical power of the transmitting end and the power-off voltage position of the receiving end to improve the performance of the distance sensor.

2. The method for correcting eye posture using eyeglasses strap data according to claim 1, characterized in that: The user faces the horizontal calibration plate and the vertical calibration plate, the first viewpoint is located directly in front of the user, and the second viewpoint is located directly in front of the user's face.

3. The method for correcting eyeglass strap data for correcting eye posture according to claim 2, characterized in that: The straight-line distance between the first viewpoint, the second viewpoint and the mirror frame ranges from 30cm to 100cm.

4. The method for correcting eye posture using glasses strap data according to claim 1, characterized in that: The motion sensor is a six-axis sensor.

5. The method for correcting eye posture using eyeglasses strap data according to claim 1, characterized in that: The calculation method for reading the inclination data is as follows: obtain the three-axis acceleration value (x1, y1, z1) of the reference inclination, obtain the three-axis acceleration value (x2, y2, z2) of the current inclination through the motion sensor, and use the formula: Calculate the user's reading inclination angle when reading.

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