TWI695707B - Method for assessing exercise intensity assisted by using accelerometer - Google Patents

Abstract

A method for assessing exercise intensity assisted by using accelerometer includes a measuring step, a pre-processing step, a calculating step and a computing step. The measuring step is to measure three-axis acceleration signals generated when a user is exercising and gather physiological information simultaneously. The pre-processing step is to filter the three-axis acceleration signals in order to remove high frequency noise signals. The calculating step is to calculate an acceleration intensity vector based on the three-axis acceleration signals and then calculate a total acceleration based on the acceleration intensity vector. The computing step is to compute average values of the total acceleration and the physiological information based on a decided time and further compute exercise intensity based on the total acceleration, the physiological information and the average values, thereby detecting the body vibration intensity of the user effectively, calculating the exercise intensity during the excreting period based on the physiological information, and reducing misjudgement greatly to increase the accuracy of assessment effectively.

Description

Using accelerometer to assist in evaluating exercise intensity

The invention relates to an evaluation method, in particular to a method for assisting in evaluating exercise intensity using an accelerometer.

As the social atmosphere evolves, people begin to pay attention to the quality of life and seek to relieve the pressure of life, which leads to the prosperity of various leisure activities. Therefore, more and more people spend their time on it, especially walking, running, etc. Aerobic endurance sports do not require expensive sports equipment or specific sports venues, nor do they require special sports skills, so they can be performed anywhere and at any time. Furthermore, not only can you breathe fresh air during the activity, and Enjoy the outdoor scenery, at the same time you can adjust the speed according to your physical condition during exercise, and use the combination of different speed rhythms to train breathing and endurance, as well as exercise to muscles in different parts of the body, so as to increase muscle mass and consume more calories And so on, so it is loved by all ages.

In order to facilitate the user to grasp the exercise intensity during exercise, it can usually be estimated by parameters such as heart rate, travel speed, slope of the ground, exercise duration, etc., so that the user can understand the body's activity level; The calculation is usually to use an accelerometer to detect the vibration of the body while traveling, according to the collected acceleration changes and the characteristics of the human body's movement pace, and to use the pedometer algorithm to calculate the number of steps and the speed of travel, but the existing The accuracy of the pedometer algorithm has its inherent limitations. Due to different movement laws of different users and different degrees of body vibration, or irregular vibration waveforms, the pedometer algorithm cannot correctly judge Whether it is an effective step is therefore prone to misjudgment, which leads to a decrease in the accuracy of step counting, and further reduces the accuracy of the subsequent evaluation of exercise intensity, which needs to be improved.

Therefore, the purpose of the present invention is to provide a method for assisting the evaluation of exercise intensity using an accelerometer, which can effectively determine the vibration intensity of the body, thereby accurately assessing the exercise intensity during exercise, reducing the probability of misjudgment, and thereby improving the accuracy of the evaluation.

Therefore, the present invention uses an accelerometer to assist in evaluating the exercise intensity, which includes measurement, pre-processing, calculation, and calculation steps; wherein, in this measurement step, the three-axis directions of the user's body movement (ie, side Direction, forward direction and vertical direction) to measure the acceleration generated to obtain the three-axis acceleration signal, at the same time collect the user's physiological information, and prepare a filter in the pre-processing step, using the filter to move Averaging to eliminate high-frequency interference signals in the three-axis acceleration signal, then in the calculation step, an acceleration intensity vector is calculated based on the three-axis acceleration signal, then the total acceleration is calculated from the acceleration intensity vector, and finally the calculation In the step, the average value of the total acceleration and the physiological information are respectively calculated according to a predetermined time, and the total acceleration, the physiological information and the average value are brought into a calculation formula to calculate an exercise intensity; The auxiliary evaluation of the three-axis acceleration is beneficial to effectively detect the vibration intensity of the user's body, and then cooperate with the physiological information to calculate the exercise intensity during the exercise, thereby greatly reducing the misjudgment rate, thereby effectively improving the accuracy of the evaluation.

The foregoing and other technical contents, features and effects of the present invention will be clearly understood in the following detailed description with reference to the preferred embodiments of the drawings.

Referring to FIGS. 1 and 2, a method for assisting in evaluating exercise intensity using an accelerometer of the present invention includes a measurement step, a pre-processing step, a calculation step, and an arithmetic step; first, the measurement step is prepared There is a processor, and the processor measures the acceleration generated in the lateral, forward and vertical directions of the user's body movement. In this embodiment, the lateral direction is the x-axis direction. The forward direction is the y-axis direction, and the vertical direction is the z-axis direction, and then the x-axis acceleration signal, the y-axis acceleration signal, and the z-axis acceleration signal are obtained, and the user's physiological information is collected at the same time, where the physiological information includes There are forward body angle, body temperature and heart rate.

Continuing the foregoing, a filter is prepared in the pre-processing step, and the filter uses moving average processing to eliminate high-frequency interference signals in the x-axis acceleration signal, the y-axis acceleration signal, and the z-axis acceleration signal, The difference equation of the filter is as follows:

、

與

分別是該x、y與z軸加速度訊號，

、

與

則是該濾波器的輸出訊號，M為該濾波器的長度，配合參閱圖4，經過移動平均濾波處理之後的x、y與z軸加速度訊號對比圖3中該x、y與z軸原始加速度訊號明顯更為平滑。 among them,

,

versus

Are the x, y, and z axis acceleration signals,

,

versus

Is the output signal of the filter, M is the length of the filter, with reference to FIG. 4, the x, y, and z axis acceleration signals after moving average filtering are compared. The original accelerations of the x, y, and z axes in FIG. 3 The signal is significantly smoother.

，而前述該算式如下列： Continuing with the foregoing, in this calculation step, the x, y, and z axis acceleration signals filtered by the filter are brought into a formula through the processor to further calculate the x, y, and z axis acceleration signals. Acceleration intensity vector

, And the aforementioned formula is as follows:

予以帶入下述算式中，藉以計算出總加速度

， Then the acceleration intensity vector

Take it into the following formula to calculate the total acceleration

,

與該生理資訊的平均值，當前述該預訂時間較短時，所計算出的運動強度可以反應出使用者於較短時間內的運動強度，反之，當該預訂時間較長時，該運動強度可以反應出使用者於較長時間內的運動強度，接著將該總加速度

、該生理資訊與前述平均值予以帶入一算式中，而前述該算式如下列： Where N represents the length of time, and finally in the calculation step, the total acceleration is calculated by the processor according to a predetermined time

With the average value of the physiological information, when the aforementioned booking time is shorter, the calculated exercise intensity can reflect the user's exercise intensity in a shorter time, and conversely, when the booking time is longer, the exercise intensity Can reflect the user's exercise intensity for a long time, and then the total acceleration

The physiological information and the aforementioned average value are brought into a calculation formula, and the aforementioned calculation formula is as follows:

Exercise intensity = (average total acceleration / maximum total acceleration) x total acceleration ratio (%) + (average body forward angle / maximum forward angle) x forward angle ratio (%) + (average body temperature / maximum body temperature) x body temperature ratio (%) + (average heart rate / maximum heart rate) x heart rate ratio (%);

The total acceleration ratio, the forward tilt angle ratio, the body temperature ratio and the heart rate ratio are 100%.

Continuing the above, the exercise intensity during exercise can be calculated in this way, so the auxiliary evaluation of the lateral, forward and vertical accelerations (ie, x, y, and z axis accelerations) can be used to effectively determine the vibration intensity of the body , In conjunction with the physiological information, and then calculate the exercise intensity during exercise, not only greatly reduce the misjudgment rate, but also effectively improve the accuracy of the assessment.

In summary, the present invention uses an accelerometer to assist in evaluating the exercise intensity, which includes steps such as measurement, pre-processing, calculation, and calculation; wherein, in the measurement step, the processor measures three movements of the user's body The axis acceleration signal is collected at the same time as the user's physiological information. Then, in the pre-processing step, the filter is used to remove the high-frequency interference signal in the tri-axis acceleration signal by the moving average process. The calculation step is further based on the three The axis acceleration signal calculates the acceleration intensity vector, and then calculates the total acceleration from the acceleration intensity vector, and finally calculates the average value of the total acceleration and the physiological information according to the predetermined time in the calculation step, and by the total acceleration, The physiological information and the aforementioned average value calculate the exercise intensity, so that the vibration intensity of the user's body can be effectively detected, and the exercise intensity during the exercise can be calculated in conjunction with the physiological information, thereby greatly reducing the misjudgment rate, thereby effectively improving the evaluation accuracy.

However, the above are only for explaining the preferred embodiments of the present invention, but the scope of the implementation of the present invention cannot be limited by this, that is, simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the description of the invention , Should still fall within the scope of this invention patent.

(Invention) None

FIG. 1 is a schematic flowchart of a preferred embodiment of the present invention. FIG. 2 is another schematic block diagram of the preferred embodiment. Figure 3 is a schematic diagram of the three-axis acceleration signal before filtering. Fig. 4 is a schematic diagram of the three-axis acceleration signal after filtering.

Claims (1)

An accelerometer-assisted method for evaluating exercise intensity includes the following steps: In a measurement step, it is equipped with a processor which measures the acceleration generated in the lateral, forward and vertical directions of the user's body movement to obtain the lateral acceleration signal, the forward acceleration signal and the vertical acceleration signal, At the same time, the user's physiological information is collected, wherein the physiological information includes the body forward angle, body temperature and heart rate; A pre-processing step, which is equipped with a filter, and the filter uses a moving average process to eliminate high-frequency interference signals in the lateral acceleration signal, the forward acceleration signal, and the vertical acceleration signal; A calculation step, which further calculates the acceleration of the lateral acceleration signal, the forward acceleration signal and the vertical acceleration signal through the processor according to the lateral acceleration signal, the forward acceleration signal and the vertical acceleration signal filtered by the filter Intensity vector, and then calculate the total acceleration from the acceleration intensity vector; and An operation step, which calculates the average value of the total acceleration and the physiological information respectively according to a predetermined time through the processor, and brings the total acceleration, the physiological information and the average value into a formula to calculate An exercise intensity, where the formula is: Exercise intensity = (average total acceleration/maximum total acceleration) x total acceleration ratio (%) + (Average body forward angle/Max forward angle) x Proportion of forward angle (%)+ (Average body temperature/maximum body temperature) x body temperature ratio (%)+ (Average heart rate/maximum heart rate) x heart rate ratio (%); and the sum of the total acceleration ratio, the anteversion angle ratio, the body temperature ratio and the heart rate ratio is 100%.

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