TWI586574B - Power and resistance coefficient measurement method of bike - Google Patents

Description

Bicycle motion power and drag coefficient measurement method

The invention provides a method for measuring the motion power and the drag coefficient of a bicycle, in particular, a sensing information is used to calculate the air resistance coefficient when riding a bicycle, the rolling friction coefficient of the bicycle tire, and the user applies to the bicycle. The force and its power.

According to the bicycle, it is a short-distance travel tool that is extremely common in daily life, especially in recent years. In order to promote the concept of energy conservation and environmental protection, countries have advocated the widespread use of bicycles as a means of transportation to reduce energy consumption. With modern emphasis on sports, riding a bicycle is also a popular sport today, and is listed as one of the important competitions.

However, the bicycle system relies on the pedal of the user to step on the bicycle to drive the wheel of the bicycle, and the main resistance during the riding of the bicycle includes: the air formed by the projection area of the user and the bicycle in the traveling direction. The resistance, the friction between the bicycle and the ground, and the weight of the bicycle when the bicycle is moving uphill, the gravity is opposite to the direction of travel. The aforementioned resistance will increase the burden on the user to ride the bicycle. Therefore, it is necessary to analyze the resistance one by one. Source, in order to help users overcome or reduce the occurrence of resistance, thereby improving the efficiency of riding bicycles.

Therefore, it is known to provide a device for measuring the total force relative to a moving vehicle and its use method, as described in the Chinese Patent Certificate No. I391281, which measures the speed change, the slope data, and the atmospheric pressure. And air temperature data to estimate air density, relative wind speed, vehicle and rider total weight, aerodynamic drag and area items combined with pneumatic pressure measurement to calculate aerodynamics, bicycle and ground Data such as rubbing force, according to the total force of the bicycle; however, in case No. I391281, it only reveals the measurement of aerodynamic force and friction, and can not accurately measure the air resistance coefficient, and the air resistance coefficient affects the pneumatic The important parameter of resistance is that when the air resistance coefficient cannot be measured, the actual aerodynamic resistance value cannot be calculated by the rapid transmission area, air density and relative wind speed. Therefore, the total number of riding bicycles cannot be quickly obtained. Force and related motion power and other related data.

In view of this, our inventors are concentrating on further research on the measurement of the exercise power and drag coefficient of riding bicycles, and proceeding with research and development and improvement, with a better design to solve the above problems, and after continuous trial and The invention has been made after the modification.

Therefore, the object of the present invention is to solve the problem that the air resistance coefficient when riding a bicycle cannot be reliably measured, and the related data such as the air resistance, the total force of riding the bicycle, and the exercise power consumed cannot be quickly obtained. .

In order to achieve the above object, the inventors provide a method for measuring the exercise power and drag coefficient of a bicycle, the steps comprising: connecting a processing unit of an arithmetic device through a sensor to measure by the sensor or Entering the plurality of sensing information for transmission to the processing unit, the sensing information includes: at least one forward projected area A of a user riding on a bicycle, an air density value ρ , and a traveling speed value V of the bicycle and an acceleration value a, the relative wind speed V _w of a time of travel of the bicycle, the bicycle in a tilt value θ of a road surface, and a total weight of the bicycle with the value m of the user; and a fixed one to the front view Projecting area A , and in a state where the user does not apply force to the bicycle and the bicycle is naturally slid, so that the traveling speed V measured by the sensor changes, assuming that the air resistance coefficient C _d is a constant value, So that the processing unit brings the sensing information into the following formula 1 to obtain the air resistance coefficient C _d and a rolling friction coefficient C _F (V) of the bicycle tire;

Where g is the gravitational acceleration value.

In an embodiment, the front projection area A is obtained by setting a position sensing device included in the sensor by a wearing device, and measuring the position sensed by each of the position sensing devices. The values respectively correspond to the forward-viewing area; and the wearing device is worn by the user to sense the position measurement value by the position sensing device, thereby obtaining the forward-viewing area correspondingly .

According to the bicycle power and resistance coefficient measurement method described above, the wearing device is a bicycle helmet.

In another embodiment, the sensor further includes an image capturing device disposed at a front end of the bicycle to capture the front view image of the user and the bicycle, and the processing is performed by the processing The unit operation obtains the forward projected area.

According to the method for measuring the exercise power and the drag coefficient of the bicycle, the step further includes: in a state in which the user applies a force to the bicycle, the processing unit obtains the user for the bicycle by the following formula 2 Shi Zhili f _a ;

According to the method for measuring the exercise power and the drag coefficient of the bicycle, the step further includes: the processing unit is obtained by using a product of a force f _a applied by the user to the bicycle and the traveling speed value V. The power of the person.

According to the method for measuring the motion power and the resistance coefficient of the bicycle, the method further comprises: the method for measuring the motion power and the resistance coefficient of the bicycle according to the above, wherein the sensor further comprises a temperature measuring unit and a Pressure measurement unit to measure or input the sensed resources separately The signal includes an air temperature value and an air pressure value, and the processing unit calculates the air density value by calculating the air temperature value and the air pressure value.

According to the bicycle power and resistance coefficient measurement method, the sensor further includes a speed sensor, an anemometer and a level; the speed sensor measures the traveling speed value and the The acceleration value, the anemometer measures the relative wind speed value, and the level gauge measures the inclination value.

According to the bicycle power and resistance coefficient measurement method described above, the sensor is transmitted through Bluetooth, BLE (Bluetooth Low Energy), GSM (Global System for Mobile Communications,) Wi-Fi (Wireless Fidelity) or ANT+ wireless communication to connect to the computing device.

According to the method for measuring the power and the resistance coefficient of the bicycle, the computing device further includes a display unit and a storage unit, the display unit and the storage unit are coupled to the processing unit; The sensing information sensed by the sensor and the operation result of the processing unit are presented; and the storage unit is configured to store the sensing information sensed by the sensor and the operation result of the processing unit at each time point.

It is apparent from the above description and arrangement that the present invention has the following several advantages and functions, which are described in detail as follows: 1. The present invention is capable of measuring or inputting sensing information and is not applied by the user. The bicycle is naturally gliding, and the traveling speed V measured by the sensor is changed, and assuming that the air resistance coefficient C _d is a constant value, the air resistance coefficient C _{d is} quickly obtained. The rolling friction coefficient C _F (V) of the bicycle tire can be used to calculate the force f _a applied by the user to the bicycle and the motion power of the user, so that the user can know the sensing information and the processing unit. As a result of the calculation, the riding posture can be adjusted to reduce the resistance as much as possible, thereby improving the efficiency of riding the bicycle.

1‧‧‧ sensor

11‧‧‧Speed sensor

12‧‧‧ level

13‧‧‧Temperature measurement unit

14‧‧‧Pressure measuring unit

15‧‧‧Anemometer

16‧‧‧Image capture device

17‧‧‧ position sensing device

2‧‧‧ arithmetic device

21‧‧‧Processing unit

22‧‧‧Display unit

23‧‧‧ storage unit

3‧‧‧Bicycle

31‧‧‧ tires

4‧‧‧ pavement

5‧‧‧ wearing device

S001-S003‧‧‧Steps

Figure 1 is a schematic flow diagram of the present invention.

Figure 2 is a schematic view of the structure of the present invention.

Fig. 3 is a schematic view showing the state of use of the present invention installed in a bicycle.

Fig. 4 is a schematic view showing the state of use of the arithmetic unit of the present invention installed at the front end of the bicycle.

The invention will be described in detail below with reference to the drawings.

Please refer to FIG. 1 first, the present invention is a method for measuring the power and drag coefficient of a bicycle, and the steps thereof include:

S001: connected to the processing unit 21 of the computing device 2 through a sensor 1, as shown in FIG. 2, to measure or input complex sensing information by the sensor 1 for transmission to the processing unit 21, Wherein, as shown in FIG. 3 and FIG. 4, the sensor 1 can be disposed at an appropriate position of a bicycle 3 according to the value to be measured, and the computing device 2 can be mounted on any of the bicycles 3, In this embodiment, the computing device 2 is mounted on the front end of the bicycle 3, and the sensing information includes: at least one forward projected area A of a user riding on a bicycle 3, an air density value ρ , and a bicycle. a travel speed value V and an acceleration value a , a relative wind speed value V _w when the bicycle 3 travels, an inclination value θ of the bicycle 3 on a road surface 4, and a total weight value of the bicycle 3 and the user m ; since the invention is based on Newton's second law of motion, thereby defining a motion equation for a bicycle 3, as shown in Fig. 3, the total force F _{T of the} user riding the bicycle 3 includes the user's 3 bicycles. applied force f _a, 3 of the bicycle wheel with a friction surface of f _b, 3 during travel of the bicycle in the air resistance generated by f _c, and user 3 bicycle component 3 in the traveling direction of the gravity of the bicycle f _d, where, f _a, f _b, f _c, and positive and negative values of f _d, Department According to the defined direction, the total force F _T can be expressed by the following mathematical formula 1: [Math 1] F _T =f _a +f _b +f _c +f _d =ma

The total weight value m of the bicycle 3 and the user can be directly input into the processing unit 21 of the computing device 2 by the user; and the acceleration value a can be obtained by the speed sensor 11 of the sensor 1 The traveling speed value V is measured and is obtained by calculating the amount of change of the traveling speed value V per unit time, wherein the speed sensor 11 can be mounted on the tire 31 of the bicycle 3, such as as shown in FIG. 3, to speed conversion operations by the tire 31 to obtain the value of the traveling speed V, but not as defined; and in another embodiment, an accelerometer can be measured by an acceleration value a ; bicycle on the ground in terms of friction and 3 f _b, may be expressed as the following mathematical 2: [equation 2] f _b = C _F mgcosθ

Wherein C _F is the rolling friction coefficient of the bicycle 3 tire 31, g is the gravitational acceleration, and θ is the inclination value of the bicycle 3 on the road surface 4, which can be measured by one level 12 in the sensor 1 In an embodiment, the level 12 can be integrated into the computing device 2; in the case where the state of the road surface 4 and the tire 31 are not changed, the rolling friction coefficient C _F can be a function of the traveling speed V of the bicycle 3, so rolling The friction coefficient C _F can be expressed as C _F (V) , and the rolling friction coefficient C _{F is} actually affected by the traveling speed V , and also by the tire pressure P _t of the tire 31 and the contact area A between the tire 31 and the road surface 4. _f and road surface conditions (dry road, wet road, pavement material) R _f , so the rolling friction coefficient C _F can also be expressed as C _F (V, P _t , A _f , R _f ) , and according to user habits The riding mode and route, the tire pressure P _t , the contact area A _f and the road surface condition R _f can be fixed values, so that the rolling friction coefficient C _F can also be simplified to be expressed as C _F (V) , and gravity The value of the acceleration g can be directly written into the processing unit 21 without measurement.

Continuing with the air resistance f _c generated during the travel of the bicycle 3, the air resistance f _c can be expressed as shown in the following Mathematical Formula 3:

Where ρ is the air density value, V _w is the relative wind speed value when the bicycle 3 travels, A is the front projected area of the user riding on a bicycle 3, C _d is the air resistance coefficient; for determining the air density value ρ , The user can input the processing unit 21 directly by the user. In this embodiment, one of the temperature measuring unit 13 and the pressure measuring unit 14 included in the sensor 1 can be separately measured or input. The sensing information includes an air temperature value and an air pressure value, so that the processing unit 21 can pass the gas equation (eg, the ideal gas equation) to obtain the air density value ρ . In an embodiment, the temperature measurement The unit 13 and the pressure measuring unit 14 can be directly integrated into the computing device 2; and the relative wind speed value V _w can be measured by an anemometer 15 included in the sensor 1 , and the anemometer 15 is In one embodiment, it may be arranged to be similar to a windmill to be mounted on the front end of the bicycle 3. In the present embodiment, the anemometer 15 may also be integrated into the computing device 2; and for the user to ride on a bicycle 3 A view of the projected area before In an embodiment, the sensor 1 further includes an image capturing device 16 that can be mounted on the front end of the bicycle 3 to capture the front view image of the user and the bicycle 3 and borrow The position of the front view projection area is obtained by the processing unit 21; in the embodiment, the position sensing device 17 included in the sensor 1 is disposed in a wearing device 5, wherein The wearing device 5 can be a bicycle 3 helmet worn by the user when riding the bicycle 3, and the relative position of the wearing device 5 relative to the bicycle 3 is different depending on the riding posture of the user. By taking the position measurement value sensed by each of the position sensing devices 17 in advance, the user can ride the bicycle 3 to view the photo by the corresponding self or by the assistance of another person, so as to correspond to the riding by computer operation. The position of the projected area is previously viewed, whereby the position measurement value can be sensed by the position sensing device 17 to quickly obtain the forward projected area A.

The bicycle 3 and the user's gravity in the direction of travel of the bicycle 3, f _d , can be expressed as shown in the following Mathematical Formula 4: [Math 4] f _d = mgsin θ

S002: By the above, the total force F _{T of the} mathematical formula 1 can be rewritten to the following mathematical formula 5:

Wherein, the force f _a applied by the user to the bicycle 3, the air resistance coefficient C _d and the rolling friction coefficient C _F (V) of the bicycle 3 tire 31 are still unknown, so by fixing one of the front projections The area A causes the bicycle 3 to slide naturally, and the user does not apply force to the bicycle 3. Since the force f _a applied by the user to the bicycle 3 is 0 in this state, the mathematical formula 5 can be described as The following mathematical formula 6 shows:

The traveling speed V of the bicycle 3 series which is naturally gliding will only be directly affected by the frictional force f _b and the air resistance f _c, and the traveling speed V will change, so that the traveling speed V measured by the sensor 1 changes. In the state, assuming that the air resistance coefficient C _d is a fixed value, and the sensing information is brought into the mathematical formula 6, the mathematical equation 6 can be obtained through the different traveling speed V , and the processing unit 21 is The air resistance coefficient C _d and the rolling friction coefficient C _F (V) of the bicycle 3 tire 31 can be obtained;

S003: With the above, the processing unit 21 to the air drag coefficient C _d and the rolling friction coefficient C _F (V) into the equation 5 to obtain the user of the bicycle by the force applied to the 3 f _a The motion power applied by the user to the bicycle 3 can be defined as the product of f _a and the traveling speed value V , f _a V .

In a preferred embodiment, as shown in FIG. 2 and FIG. 4, the computing device 2 further includes a display unit 22 and a storage unit 23, and the display unit 22 and the storage unit 23 are coupled to each other. The processing unit 21; the display unit 22 corresponds to the sensing information sensed by the sensor 1 and the operation result of the processing unit 21, and as described above, the operation result of the processing unit 21 will include the aforementioned air resistance coefficient C. _d , the rolling friction coefficient C _F (V) , the force f _a and the moving power f _a V applied by the user to the bicycle 3, so that the user can know the riding condition, and then adjust the riding posture to reduce the air resistance. f _c, the lift riding efficiency, and the display unit 22 of the information presented to facilitate a user to view, so are preferred, computing device 2 may be a smart phone, and the calculation means 2 may be disposed in line 3 of the bicycle The storage unit 23 can store the sensing information sensed by the sensor 1 and the operation result of the processing unit 21 at each time point, so that the user can later access the bicycle at a certain point in time. Multiply the situation.

In a preferred embodiment, the sensor 1 is transmitted through Bluetooth, BLE (Bluetooth Low Energy), GSM (Global System for Mobile Communications), and Wi-Fi (Wireless Fidelity). The wireless fidelity or ANT+ wireless communication is connected to the computing device 2, so that the sensor 1 can be distributed to the bicycle 3 to measure the sensing information.

In summary, the technical means disclosed by the present invention can effectively solve the problems of the prior knowledge, achieve the intended purpose and efficacy, and are not found in the publication before publication, have not been publicly used, and have long-term progress, The invention referred to in the Patent Law is correct, and the application is filed according to law, and the company is invited to give a detailed examination and grant a patent for invention.

The above is only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equivalent changes and modifications made by the scope of the invention and the contents of the invention are all It should remain within the scope of this invention.

S001-S003‧‧‧Steps

Claims (10)

A method for measuring a motion power and a drag coefficient of a bicycle, the method comprising: connecting, by a sensor, a processing unit of an arithmetic device to measure or input complex sensing information by the sensor for transmission to the processing unit The sensing information includes: at least one forward projected area of a user riding on a bicycle Air density value , the speed of the bicycle And acceleration value Relative wind speed value when the bicycle is traveling The inclination angle of the bicycle on a road surface And the total weight of the bicycle and the user And fixing one of the forward projected areas And the user does not apply force to the bicycle and the bicycle is naturally slid, so that the speed measured by the sensor Under the state of change, assume an air resistance coefficient a set value for causing the processing unit to bring the sensing information into the following formula 1 to obtain the air resistance coefficient And a rolling friction coefficient of the bicycle tire ; (Formula 1) where It is the value of gravity acceleration. The method for measuring the exercise power and the drag coefficient of the bicycle according to the first aspect of the patent application, the method further includes: in a state in which the user applies a force to the bicycle, the processing unit obtains the use by using the following formula 2 The force exerted on the bicycle ; (Formula 2). The method for measuring the exercise power and the drag coefficient of the bicycle according to claim 2, the step further comprising: the processing unit applying a force to the bicycle by the user And the speed of travel The product of the product to obtain the motion power of a user. The method for measuring the motion power and the drag coefficient of the bicycle according to any one of claims 1 to 3, wherein the step further comprises: providing a position sensing device included in the sensor by a wearing device And the position measurement value sensed by each of the position sensing devices respectively corresponds to the front view projection area; and the wearing device is worn by the user to sense by the position sensing device The position measurement value is used to obtain the forward projected area correspondingly. The method for measuring the exercise power and the drag coefficient of a bicycle according to claim 4, wherein the wearing device is a bicycle helmet. The method for measuring the motion power and the resistance coefficient of a bicycle according to any one of the preceding claims, wherein the sensor further comprises an image capturing device, the image capturing device being disposed on the bicycle At the front end, the front view projection area is obtained by taking the user and the bicycle front view image and calculating by the processing unit. The method for measuring the motion power and the drag coefficient of a bicycle according to any one of the preceding claims, wherein the sensor further comprises a temperature measuring unit and a pressure measuring unit for respectively measuring Or the input sensing information includes an air temperature value and an air pressure value, and the processing unit calculates the air density value by calculating the air temperature value and the air pressure value. The method for measuring the motion power and drag coefficient of a bicycle according to any one of the preceding claims, wherein the sensor further comprises a speed sensor, an anemometer and a level; the sense of speed The detector measures the travel speed value and the acceleration value, the anemometer measures the relative wind speed value, and the level gauge measures the tilt angle value. The method for measuring the motion power and the drag coefficient of a bicycle according to any one of claims 1 to 3, wherein the sensor transmits Bluetooth, BLE (Bluetooth Low Energy) ), GSM (Global System for Mobile Communications), Wi-Fi (Wireless Fidelity), or ANT+ wireless communication to connect to the computing device. The method for measuring the motion power and the resistance coefficient of the bicycle according to any one of the preceding claims, wherein the computing device further comprises a display unit and a storage unit, the display unit and the storage unit coupled Connected to the processing unit; the display unit corresponds to the sensing information sensed by the sensor and the operation result of the processing unit; and the storage unit corresponds to the sensing information sensed by the sensor at each time point. And the result of the operation of the processing unit.