Motion power consumption calculation system and method based on strain gauge and acceleration sensor

Abstract

The invention discloses a motion power consumption calculation system and method based on strain gauges and an acceleration sensor, and relates to the technical field of motion energy monitoring. And calculating respective motion energy consumption and total energy consumption of the left foot and the right foot. According to the design, the specific motion energy consumption is calculated according to the variation of the deformation quantity of the strain gauge, an analog value output after operational amplification and the variation of the value of the acceleration sensor; by increasing or decreasing the reading values of the acceleration sensor in each axial direction, which foot exerts force to do work is judged, the motion energy consumption of each foot or the total motion energy consumption of two feet can be calculated more accurately, and the system has the characteristics of high-precision separation energy consumption, strong anti-interference performance, low-power-consumption operation and real-time feedback. The device can be widely applied to the fields of riding training, rehabilitation monitoring and competitive sports.

Description

Technical Field

[0001] The present invention relates to the technical field of sports energy monitoring, and particularly to a system and method for calculating the motion power consumption based on a strain gauge and an acceleration sensor. The system and method can calculate the motion power consumption of the left and right feet during cycling in real time through the collaborative work of the strain gauge and the acceleration sensor, and are particularly applicable to the energy consumption monitoring of sports equipment such as bicycles and cycling trainers. Background Art

[0002] With the development of society, people pay more and more attention to detailed sports energy consumption and work done, etc. This design is achieved by the cooperation of a strain gauge and an acceleration sensor installed on the chainring of a cycling trainer or a bicycle chainring to accurately calculate the energy consumed or work done during exercise.

[0003] With the improvement of health awareness, the accurate measurement of sports energy consumption has become an important requirement for fitness and competitive training; the existing technologies mainly rely on the following methods:

[0004] Heart rate monitoring method: Estimate energy consumption through heart rate, but it is greatly affected by individual differences and environmental factors, and the error rate exceeds 20%;

[0005] Single sensor method: Only use an accelerometer or a strain gauge, unable to distinguish the contributions of the left and right feet, and is easily affected by torsion interference in the variable speed scenario, resulting in a decrease in accuracy;

[0006] Simple mechanical model: Calculate power based on the product of pedal force and rotational speed, but ignore dynamic factors (such as acceleration changes and multi-axis mechanical responses), and has poor adaptability.

[0007] Defects of the existing technologies:

[0008] It is impossible to accurately separate the energy consumption of the left and right feet and provide data support for optimizing the sports posture;

[0009] When the bicycle is shifted, the torque change generated by the chainring switching will cause the strain gauge signal to be distorted;

[0010] Lack of multi-sensor data fusion algorithm, making it difficult to achieve high-precision dynamic calculation.

[0011] The present invention eliminates torque interference through the arrangement of double-sided strain gauges, combines multi-axis data analysis of the acceleration sensor to judge the foot exerting force, and proposes a dynamic integration algorithm, significantly improving the accuracy and reliability of the motion power consumption calculation. Summary of the Invention[[ID=,38]]

[0012] The present invention provides a motion power consumption calculation system and method based on strain gauges and acceleration sensors. In this application, the deformation amounts of several groups of strain gauges are read, and the values after operational amplification, as well as the acceleration change values of each axis of the acceleration sensor, are used to calculate the motion energy consumption of each of the left and right feet and the total energy consumption. This design calculates the specific motion energy consumption through the change magnitudes of the deformation amounts of the strain gauges in several directions, and the analog values output after operational amplification, as well as the change amounts of the acceleration sensor values. By increasing or decreasing the values read from each axis of the acceleration sensor, it is determined which foot is exerting force to do work. The motion energy consumption of each foot or the total of both feet can be calculated more precisely. Additionally, since there are large, medium, and small chainring disks, and the torque will be affected when switching between disks, to reduce the torque influence, two groups of strain gauges are required, with one group attached to the driving surface and the other to the non-driving surface. After the two groups of strain gauges are bridged, they are connected in parallel and used as the input quantity together to eliminate the influence caused by the torque due to different disks, so as to solve the problems in the background technology.

[0013] To achieve the above object, the present invention provides the following technical solution: A motion power consumption calculation system based on strain gauges and acceleration sensors, double-sided strain gauges: At least one group of strain gauges is arranged on each of the driving surface and the non-driving surface of the bicycle chainring. The strain gauges on the driving surface and the non-driving surface are connected in parallel through a bridge circuit to form a differential signal input to eliminate the torque interference generated by the switching of the chainring disks.

[0014] Acceleration sensor: Installed at the chainring or the pedal, it collects three-axis acceleration data in real time and judges the force application states of the left and right feet through the change direction of the acceleration on the Y axis.

[0015] Operational amplifier: Used to amplify the weak differential voltage signal output by the strain gauges.

[0016] MCU: Used to receive and process the differential voltage signal output by the strain gauges and the acceleration sensor data.

[0017] Further, after the output signal of the strain gauges is amplified by the operational amplifier, an ADC value proportional to the deformation amount is generated.

[0018] The MCU judges the magnitude of the motion work done according to the change of the ADC value, and judges the force application states of the left and right feet through the change of the data on the Y axis of the acceleration sensor.

[0019] Further, the bridge circuit is a full-bridge circuit. The strain gauges on the driving surface and the non-driving surface respectively form two arms of the bridge, and the superimposed signal is output through parallel connection to eliminate the symmetric torque interference.

[0020] The operational amplifier is an instrumentation amplifier, and the amplification factor of the operational amplifier is adjustable to adapt to the output ranges of different strain gauges.

[0021] Further, the MCU calculates the motion energy consumption through the following steps:

[0022] Calculate the deformation amount of each group of strain gauges according to the ADC value;

[0023] Combined with the axial data of the acceleration sensor, judge the force application states of the left and right feet;

[0024] Calculate the individual energy consumption of the left and right feet through the deformation amount and the force application states;

[0025] Add the energy consumption of the left and right feet to obtain the total energy consumption.

[0026] Further, the change of the Y-axis data of the acceleration sensor is used to judge the force application states of the left and right feet:

[0027] When the Y-axis data increases, it is judged that the right foot is applying force;

[0028] When the Y-axis data decreases, it is judged that the left foot is applying force.

[0029] Further, the double-sided strain gauge includes a temperature compensation circuit, which monitors the ambient temperature in real time through an integrated temperature sensor and corrects the zero drift of the strain gauge caused by temperature changes;

[0030] The MCU has a built-in static calibration program to establish a linear relationship model between the deformation amount ADC value and the actual acting force by applying a known load.

[0031] Further, the strain gauges on the driving surface and the non-driving surface adopt a symmetric patch layout. Each group of strain gauges includes at least two strain gauge units, which are arranged circumferentially and radially along the chainring to detect multi-dimensional deformations;

[0032] The MCU improves the anti-interference ability and accuracy of force value calculation by weighted fusion of multi-group strain gauge data.

[0033] Further, the system supports a wireless communication module to transmit the calculated energy consumption data of the left and right feet and the total energy consumption data to an external terminal device in real time;

[0034] The external terminal device provides a visualization interface to display the real-time power curve, energy consumption distribution and motion efficiency analysis results.

[0035] A motion power consumption calculation method, implemented based on the motion power consumption calculation system based on strain gauges and acceleration sensors, includes the following steps:

[0036] Detect the deformation amount through two groups of strain gauges installed on the chainring and output a differential voltage signal;

[0037] Amplify the differential voltage signal through an operational amplifier;

[0038] Detect the acceleration changes in each axis through an acceleration sensor;

[0039] Collect the amplified voltage signal (ADC value) and acceleration sensor data through an MCU;

[0040] Calculate the individual energy consumption of the left and right feet and the total energy consumption based on the ADC value and the acceleration sensor data.

[0041] Furthermore, the method further includes:

[0042] When the speed change disc is switched, eliminate the torque influence through a double-sided patch design;

[0043] Automatically stop data collection when the movement stops.

[0044] Compared with the prior art, the present invention provides a motion power consumption calculation system based on strain gauges and acceleration sensors, having the following beneficial effects:

[0045] For the motion power consumption calculation system and method based on strain gauges and acceleration sensors, the present invention calculates the respective motion energy consumption and total energy consumption of the left and right feet through the deformation amounts of two groups of strain gauges and the acceleration change values in each axis of the acceleration sensor. At the same time, in order to prevent the torque influence caused by the size change of the cycling speed change disc, several groups of strain gauges are patch-mounted on both the driving surface and the non-driving surface to eliminate the torque influence and improve the calculation accuracy of the energy consumption for doing work. This system has the characteristics of high-precision energy consumption separation, strong anti-interference ability, low-power operation, and real-time feedback, and can be widely applied to the fields of cycling training, rehabilitation monitoring, and competitive sports. Brief Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 It is a schematic diagram of the overall system of the present invention;

[0048] Figure 2 It is a schematic circuit diagram of the present invention;

[0049] Figure 3 It is a sampling calculation work flow chart of the present invention;

[0050] Figure 4 It is a schematic diagram of a single-group strain bridge of the present invention;

[0051] Figure 5Schematic diagram of the output of a single group of strain gauges for the present invention. Detailed implementation manners

[0052] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe in detail the specific implementation manners of the present invention with reference to the accompanying drawings of the specification.

[0053] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0054] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is separate or selectively exclusive of other embodiments.

[0055] Please refer to Figures 1-5 , the present invention discloses a motion power consumption calculation system based on strain gauges and acceleration sensors, including:

[0056] Double-sided strain gauges: At least one group of strain gauges is arranged on each of the driving surface and the non-driving surface of the bicycle chainring. The strain gauges on the driving surface and the non-driving surface are connected in parallel through a bridge circuit to form a differential signal input to eliminate the torque interference caused by the switching of the transmission disk.

[0057] Acceleration sensor: Installed at the chainring or the pedal, it collects three-axis acceleration data in real time and judges the left and right foot force states through the change direction of the Y-axis acceleration.

[0058] Operational amplifier: Used to amplify the weak differential voltage signal output by the strain gauge.

[0059] MCU (Micro Control Unit): Used to receive and process the differential voltage signal output by the strain gauge and the acceleration sensor data, and calculate the motion power consumption through the following steps:

[0060] The weak differential voltage signal output by the strain gauge is amplified by the operational amplifier and then input into the ADC module to obtain the ADC value corresponding to the deformation amount.

[0061] According to the increasing or decreasing trend of the Y-axis data of the acceleration sensor, determine whether the current force-applying foot is the left foot or the right foot; based on the ADC value of the deformation amount and the acceleration integral speed, calculate the instantaneous power:

[0062] P = F × v; where F is calibrated by the deformation amount of the strain gauge, and v is obtained by integrating the acceleration data.

[0063] Accumulate the product of the instantaneous power of the left and right feet and the time interval to obtain the independent energy consumption of the left and right feet and the total energy consumption respectively.

[0064] The MCU collects ADC values and acceleration sensor data at a preset frequency (such as 50Hz - 200Hz) to ensure the real-time and accuracy of the data.

[0065] As Figure 1 、 Figure 2 and Figure 3 shown, at the start of the movement, step on the bicycle pedal, the data of each axis of the acceleration sensor changes, generating an interruption, and the MCU wakes up to start collecting data. The left and right feet alternately step on the pedal forcefully. The several strain gauges on the driving surface and the non-driving surface undergo different amounts of deformation, outputting different weak differential voltage values. After the differential voltage values are amplified by the operational amplifier, larger-amplitude ADC values are generated. The ADC values are input into the MCU. The more the ADC value rises, the greater the force applied and the more work done; when the ADC value returns to zero and there is no numerical change in each axis of the acceleration sensor, it indicates that the movement has stopped. The MCU calculates the movement energy consumption based on the collected ADC values. At the same time, the MCU reads the numerical change of the Y axis of the acceleration sensor. When the Y-axis data increases, it indicates that the pedal of the right foot of the bicycle is descending, that is, the right foot is exerting force; when the Y-axis data decreases, it indicates that the pedal of the left foot of the bicycle is descending, that is, the left foot is exerting force, so as to calculate the independent movement energy consumption on the left and right sides. The strain gauge patches on the chainring are double-sided patches, with one group on the driving surface and one group on the non-driving surface, which can improve the torque influence caused by the switching of the large, medium, and small chainring discs, and prevent the deviation of the movement power consumption calculation.

[0066] As Figure 5 shown, the output of a single group of strain gauges is as follows:

[0067]

[0068] Design to calculate the respective movement energy consumption and total energy consumption of the left and right feet through the amount of deformation of two groups of strain gauges and the acceleration change values of each axis of the acceleration sensor. At the same time, in order to prevent the torque influence caused by the switching of the chainring disc sizes during cycling, several groups of strain gauges are double-sided patches on the driving surface and the non-driving surface to eliminate the torque influence and improve the calculation accuracy of the work energy consumption.

[0069] Specifically, the output signal of the strain gauge is amplified by the operational amplifier to generate an ADC value proportional to the amount of deformation; the MCU judges the magnitude of the movement work according to the change of the ADC value, and judges the force application state of the left and right feet through the change of the Y-axis data of the acceleration sensor.

[0070] Specifically, the bridge circuit is a full-bridge circuit. The strain gauges on the driving surface and the non-driving surface respectively form two arms of the bridge, and the superposition signal is output through parallel connection to eliminate the symmetric torsion interference;

[0071] The operational amplifier is an instrumentation amplifier with an amplification factor of 100 - 1000 times. The amplification factor of the operational amplifier is adjustable to adapt to the output ranges of different strain gauges.

[0072] Specifically, the MCU calculates the exercise energy consumption through the following steps:

[0073] Calculate the deformation amount of each group of strain gauges based on the ADC value;

[0074] Combined with the axial data of the acceleration sensor, judge the force application states of the left and right feet;

[0075] Calculate the individual energy consumptions of the left and right feet through the deformation amount and the force application states;

[0076] Add the energy consumptions of the left and right feet to obtain the total energy consumption.

[0077] The MCU calculates the instantaneous power in real time and distributes it to the left and right feet according to the Y-axis acceleration trend;

[0078] Total energy consumption formula: E = ∑(P 左 +P 右 )×Δt.

[0079] Specifically, the Y-axis of the acceleration sensor module is aligned with the vertical movement direction of the bicycle pedal. When the Y-axis value increases, it is determined that the right foot is doing work by pressing down, and when the value decreases, it is determined that the left foot is doing work by pressing down; the MCU works through an interrupt wake-up mechanism: the acceleration sensor continuously monitors, and when an acceleration mutation is detected, it triggers the MCU to wake up from the low-power mode and start data acquisition and calculation.

[0080] The Y-axis data change of the acceleration sensor is used to judge the force application states of the left and right feet:

[0081] When the Y-axis data increases, it is judged that the right foot is applying force;

[0082] When the Y-axis data decreases, it is judged that the left foot is applying force.

[0083] Specifically, the double-sided strain gauge includes a temperature compensation circuit, which continuously monitors the ambient temperature through an integrated temperature sensor and corrects the zero drift of the strain gauge caused by temperature changes;

[0084] The MCU has a built-in static calibration program to establish a linear relationship model between the deformation amount ADC value and the actual acting force by applying a known load.

[0085] Specifically, the strain gauges on the driving surface and the non-driving surface adopt a symmetric patch layout. Each group of strain gauges includes at least two strain gauge units, which are arranged circumferentially and radially along the chainring to detect multi-dimensional deformation.

[0086] The MCU improves the anti-interference ability and accuracy of force value calculation by weighted fusion of multi-group strain gauge data.

[0087] The MCU is also used to: automatically stop data acquisition when the movement stops (the ADC value returns to zero and the acceleration sensor does not change); transmit the energy consumption data to an external device through a wireless communication module (such as Bluetooth or Wi-Fi).

[0088] The MCU adopts a dynamic sampling strategy and adaptively adjusts the ADC sampling frequency according to the acceleration change rate:

[0089] When the acceleration change rate exceeds the threshold, increase the sampling frequency to more than 1 kHz;

[0090] When the acceleration change rate is lower than the threshold, reduce the sampling frequency to less than 100 Hz to reduce the system power consumption.

[0091] The device also includes a calibration module for calibrating the zero points of the strain gauges and the acceleration sensor in the initial state.

[0092] Specifically, the system supports a wireless communication module to transmit the calculated energy consumption data of the left and right feet and the total energy consumption data to an external terminal device in real time;

[0093] The external terminal device provides a visual interface to display the real-time power curve, energy consumption distribution, and motion efficiency analysis results.

[0094] A method for calculating motion power consumption includes the following steps:

[0095] Detect the deformation amount through two groups of strain gauges installed on the chainring and output a differential voltage signal;

[0096] Amplify the differential voltage signal through an operational amplifier;

[0097] Detect the acceleration changes in each axial direction through an acceleration sensor;

[0098] Collect the amplified voltage signal (ADC value) and acceleration sensor data through the MCU;

[0099] Calculate the individual energy consumption and total energy consumption of the left and right feet according to the ADC value and acceleration sensor data.

[0100] The method also includes:

[0101] When switching the variable-speed chainring, eliminate the torque influence through a double-sided patch design;

[0102] Automatically stop data collection when the movement stops.

[0103] In summary, for the motion power consumption calculation system based on strain gauges and acceleration sensors, this invention calculates the respective motion energy consumption and total energy consumption of the left and right feet through the deformation amounts of two groups of strain gauges and the acceleration change values of each axis of the acceleration sensor. At the same time, in order to prevent the torque influence caused by the size switching of the cycling speed change disc, several strain gauges are pasted on both the driving surface and the non-driving surface to eliminate the torque influence and improve the calculation accuracy of the energy consumption for doing work. This system has the characteristics of high-precision energy consumption separation, strong anti-interference ability, low-power operation, and real-time feedback, and can be widely applied to the fields of cycling training, rehabilitation monitoring, and competitive sports.

[0104] It should be understood that each part of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits with logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits with appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0105] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A motion power consumption calculation system based on strain gauges and acceleration sensors, characterized in that Including: Dual-sided strain gauges: At least one set of strain gauges is arranged on the driving surface and the non-driving surface of the bicycle chainring. The strain gauges on the driving surface and the non-driving surface are connected in parallel through a bridge circuit to form a differential signal input, so as to eliminate the torque interference caused by the switching of the transmission discs; Acceleration sensor: Installed at the chainring or the pedal, it collects three-axis acceleration data in real time and judges the force application states of the left and right feet according to the change direction of the acceleration in the Y-axis; Operational amplifier: Used to amplify the weak differential voltage signal output by the strain gauge; MCU: Used to receive and process the differential voltage signal output by the strain gauge and the data of the acceleration sensor.

2. The motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, wherein: After the output signal of the strain gauge is amplified by the operational amplifier, a value ADC proportional to the deformation amount is generated; The MCU judges the magnitude of the work done during exercise according to the change of the ADC value, and judges the force application states of the left and right feet according to the change of the Y-axis data of the acceleration sensor.

3. The motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, wherein: The bridge circuit is a full-bridge circuit. The strain gauges on the driving surface and the non-driving surface respectively form two arms of the bridge, and the superimposed signal is output through parallel connection to eliminate the symmetric torque interference; The operational amplifier is an instrumentation amplifier, and the amplification factor of the operational amplifier is adjustable to adapt to the output ranges of different strain gauges.

4. The motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, characterized in that: The MCU calculates the energy consumption during exercise through the following steps: Calculate the deformation amount of each group of strain gauges according to the ADC value; Combined with the axial data of the acceleration sensor, judge the force application states of the left and right feet; Calculate the individual energy consumption of the left and right feet through the deformation amount and the force application state; Add the energy consumption of the left and right feet to obtain the total energy consumption.

5. The motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, wherein: The change of the Y-axis data of the acceleration sensor is used to judge the force application states of the left and right feet: When the Y-axis data increases, it is judged that the right foot is applying force; When the Y-axis data decreases, it is judged that the left foot is applying force.

6. The motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, wherein: The dual-sided strain gauge includes a temperature compensation circuit, which monitors the ambient temperature in real time through an integrated temperature sensor and corrects the zero drift of the strain gauge caused by temperature changes; The MCU has a built-in static calibration program, and a linear relationship model between the deformation amount ADC value and the actual acting force is established by applying a known load.

7. A motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, characterized in that: The strain gauges on the driving surface and the non-driving surface adopt a symmetric patch layout. Each group of strain gauges includes at least two strain gauge units, which are arranged along the circumferential and radial directions of the chainring respectively to detect multi-dimensional deformations; The MCU improves the anti-interference ability and accuracy of the force value calculation by weighted fusion of multiple groups of strain gauge data.

8. A motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, characterized in that: The system supports a wireless communication module, and transmits the calculated energy consumption data of the left and right feet and the total energy consumption data to an external terminal device in real time; The external terminal device provides a visualization interface to display the real-time power curve, energy consumption distribution and the analysis results of the exercise efficiency.

9. A method for calculating exercise power consumption, implemented based on the exercise power consumption calculation system according to any one of claims 1-7, characterized in that, Including the following steps: Detect the deformation amount through two groups of strain gauges installed on the chainring and output a differential voltage signal; Amplify the differential voltage signal through an operational amplifier; Detect the acceleration changes of each axis through an acceleration sensor; Collect the amplified voltage signal (ADC value) and the data of the acceleration sensor through the MCU; Calculate the individual energy consumption of the left and right feet and the total energy consumption according to the ADC value and the data of the acceleration sensor.

10. The motion power consumption calculation system based on a strain gauge and an acceleration sensor according to claim 1, wherein: The method further includes: When switching the transmission discs, eliminate the torque influence through the double-sided patch design; Automatically stop data collection when the movement stops.

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