METHOD OF MEASURING MOTION POWER AND RESISTANCE COEFFICIENT OF BICYCLE
20170138807 ยท 2017-05-18
Inventors
- JIUN-JIH MIAU (TAINAN CITY, TW)
- Shau-Shiun Jan (Tainan City, TW)
- SYH-TSANG JENG (TAINAN CITY, TW)
- CHIH-CHUNG HU (TAINAN CITY, TW)
- HSI WONG (TAINAN CITY, TW)
Cpc classification
International classification
Abstract
A method of measuring motion power and resistance coefficient of a bicycle measures sensed data including at least one front projecting area of a bicycle ridden by a user, an air temperature value, an air pressure value, a traveling speed value, an acceleration value, a relative wind speed value, an inclination value and a total weight value to calculate an air resistance coefficient, a rolling friction coefficient of a bicycle tire, a force and a motion power applied to the bicycle by the user, so that the user may learn a better riding posture for different riding conditions and reduce the air resistance effectively by adjusting the riding posture, so as to reduce the consumed motion power. Through the installation of a display unit, the user may know about the data sensed by the sensor and the computation result of the processing unit anytime.
Claims
1. A method of measuring a motion power and a resistance coefficient of a bicycle, comprising the steps of: connecting a sensor to a processing unit of a computing means, and the sensor measuring or inputting a plurality of sensed data to be transmitted to the processing unit, and the sensed data including: at least one front projecting area A of a bicycle ridden by a user, an air density value , a traveling speed value V and an acceleration value a of the bicycle, a relative wind speed value V.sub.w while the bicycle is traveling, an inclination value of a road surface where the bicycle is ridden, and a total weight value m of the bicycle and the user; and fixing one of the front projecting areas A, and calculating the air resistance coefficient C.sub.d and a rolling friction coefficient C.sub.F(V) of the bicycle tire by substituting the sensed data into Equation 1 through the processing unit, provided that the user has not applied a force to the bicycle and the bicycle slides naturally, such that a change of the traveling speed value V measured by the sensor occurs and assumed that an air resistance coefficient C.sub.d is as constant, wherein Equation 1 is expressed as
2. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 1, further comprising the step of calculating a force f.sub.a applied to the bicycle by the user through the processing unit by Equation 2, provided that the user has applied the force to the bicycle, wherein Equation 2 is expressed as
3. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 2, further comprising the step of calculating a user's motion power by the product of the force f.sub.a applied to the bicycle by the user and the traveling speed value V through the processing unit.
4. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 1, further comprising the steps of: installing a position sensing means included in the sensor through a wearing means, wherein a position measuring value sensed by each position sensing means is corresponsive to the respective front projecting area; and obtaining the front projecting area by the position measuring value sensed by the position sensing means provided that the user is wearing the wearing means.
5. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 4, wherein the wearing means is a bicycle helmet.
6. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 1, wherein the sensor further comprises an image capturing means installed at a front end of the bicycle for capturing a front-viewing image of the user and the bicycle, and the processing unit calculates the front projecting area.
7. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 1, wherein the sensor further comprises a temperature measuring unit and a pressure measuring unit for measuring or inputting the sensed data including an air temperature value and an air pressure value, and the processing unit calculates the air density value by the air temperature value and the air pressure value.
8. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 1, wherein the sensor further comprises a speed sensor, an anemometer and a level meter, and the speed sensor is provided for measuring the traveling speed value and the acceleration value, and the anemometer is provided for measuring the relative wind speed value, and the level meter is provided for measuring the inclination value.
9. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 1, wherein the sensor is connected to the computing means through Bluetooth, Bluetooth Low Energy (BLE), Global System for Mobile Communications (GSM), Wireless Fidelity (WiFi) or ANT+ wireless communication.
10. The method of measuring a motion power and a resistance coefficient of a bicycle as claimed in claim 1, wherein the computing means further comprises a display unit and a storage unit, both coupled to the processing unit, and the display unit is provided for displaying the data sensed by the sensor and the computation result of the processing unit, and the storage unit is provided for storing the data sensed by the sensor and the computation result of the processing unit at each time point.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
[0021]
[0022]
[0023]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The present invention will become clearer in light of the following detailed description of an illustrative embodiment of this invention described in connection with the drawings. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive.
[0025] With reference to
[0026] S001: Connect a sensor 1 to a processing unit 21 of a computing means 2 as shown in
F.sub.T=f.sub.a+f.sub.b+f.sub.cf.sub.d=ma(Mathematical Equation 1)
[0027] Where, the total weight value m of the bicycle 3 and the user may be inputted into the processing unit 21 of the computing means 2 by the user directly, and the acceleration value a is obtained by measuring a traveling speed value V by a speed sensor 11 installed in the sensor 1 and computing a change of the traveling speed value V per unit time. Wherein, the speed sensor 11 may be installed at a tire 31 of the bicycle 3 as shown in
[0028] The friction force f.sub.b of the bicycle 3 with respect to the ground is calculated by the Mathematical Equation 2 below:
f.sub.b=C.sub.Fmg cos (Mathematical Equation 2)
[0029] Where, C.sub.F is the rolling friction coefficient of the tire 31 of the bicycle 3, g is the gravitational acceleration, is the inclination value of the road surface 4 where the bicycle 3 is ridden and which is measured by a level meter 12 installed in the sensor 1. In a preferred embodiment, the level meter 12 may be integrated into the computing means 2. The rolling friction coefficient C.sub.F may be a function of the traveling speed value V of the bicycle 3 provided that the conditions of the road surface 4 and the tire 31 remain unchanged, so that the rolling friction coefficient C.sub.F may be expressed as C.sub.F(V), and the rolling friction coefficient C.sub.F is actually affected by the traveling speed value V as well as a tire pressure P.sub.t of the tire 31, a contact area A.sub.f between the tire 31 and the road surface 4, and the road surface condition (such as a dry road surface, a wet road surface, and the material of the road surface) R.sub.f, so that the rolling friction coefficient C.sub.F may also be expressed as C.sub.F(V, P.sub.t, A.sub.f, R.sub.f). Provided that the user's riding habit and route, the tire pressure P.sub.t, the contact area A.sub.f and the road surface condition R.sub.f are constants, the rolling friction coefficient C.sub.F may be simplified and expressed as C.sub.F(V), and the numerical value of the gravitational acceleration g may be written into the processing unit 21 without the need of taking the measurement.
[0030] The air resistance f.sub.c produced during the traveling process of the bicycle 3 is expressed in the Mathematical Equation 3 below:
where, is the air density value, V.sub.w is the relative wind speed value while the bicycle 3 is traveling, A is the front projecting area of the bicycle 3 ridden by the user, and C.sub.d is the air resistance coefficient. The air density value may be inputted into the processing unit 21 by the user. In this preferred embodiment, the sensor 1 includes a temperature measuring unit 13 and a pressure measuring unit 14 for measuring or inputting sensed data including an air temperature value and an air pressure value, so that the processing unit 21 may calculate the air density value by a gas equation (such as the ideal gas equation). In a preferred embodiment, the temperature measuring unit 13 and the pressure measuring unit 14 are integrated directly into the computing means 2.
[0031] The relative wind speed value V.sub.w is measured by an anemometer 15 included in the sensor 1. In a preferred embodiment, the anemometer 15 is substantially windmill shaped and installed at a front end of the bicycle 3, and the anemometer 15 is also integrated into the computing means 2.
[0032] As to the calculation of the front projecting area A of a bicycle 3 ridden by a user, the sensor 1 of a preferred embodiment, sensor 1 further comprises an image capturing means 16 installed at a front end of bicycle 3 for capturing a front-viewing image of the user and the bicycle 3, and the processing unit 21 is provided for calculating the front projecting area. In this preferred embodiment, a position sensing means 17 included in the sensor 1 is installed to a wearing means 5, wherein the wearing means 5 may be a helmet of a bicycle 3 ridden by the user. The position of the wearing means 5 with respect to the bicycle varies with the user's riding posture, so that a position measuring value is sensed by each position sensing means 17 in advance and a front-viewing photo of the bicycle 3 ridden by the user is taken by the user or any other person and computed by a computer to obtain the front projecting area of the user's riding posture, so that the position sensing means 17 senses the position measuring value, and the corresponding front projecting area A can be obtained immediately.
[0033] The componential force f.sub.d of the gravitational force of the bicycle 3 and the user in the traveling direction of the bicycle 3 is expressed in Mathematical Equation 4 below:
f.sub.d=mg sin (Mathematical Equation 4)
[0034] S002: The total force F.sub.T of the Mathematical Equation 1 is further expressed in the Mathematical Equation 5 below:
[0035] Where, the force f.sub.a applied to the bicycle 3 by the user, the air resistance coefficient C.sub.d and the rolling friction coefficient C.sub.F(V) of the tire 31 of the bicycle 3 are still unknown, so that one of the front projecting areas A is fixed, so that the force f.sub.a applied to the bicycle 3 by the user is 0 provided that the bicycle 3 slides naturally, and the user has not applied a force to the bicycle 3. In such conditions, the Mathematical Equation 5 may be expressed as the Mathematical Equation 6 below:
[0036] The traveling speed value V of the naturally sliding bicycle 3 is just affected directly by the friction force f.sub.b and the air resistance f.sub.c to produce a change of the traveling speed value V. Provided that there is a change of the traveling speed value V measured by the sensor 1, and assumed that an air resistance coefficient C.sub.d is a constant, the sensed data are substituted into Mathematical Equation 6, and simultaneous equations of the Mathematical Equation 6 are obtained from different traveling speed values V, and the processing unit 21 calculates the air resistance coefficient C.sub.d and a rolling friction coefficient C.sub.F(V) of the tire 31 of the bicycle 3 from the simultaneous equation.
[0037] S003: The processing unit 21 substitutes the air resistance coefficient C.sub.d and the rolling friction coefficient C.sub.F(V) into the Mathematical Equation 5 to obtain the force f.sub.a applied to the bicycle 3 by the user, and the motion power of the force f.sub.a applied to the bicycle 3 by the user is defined by the product f.sub.aV of the force f.sub.a and the traveling speed value V.
[0038] In a preferred embodiment as shown in
[0039] In a preferred embodiment, the sensor 1 is connected to the computing means 2 via a Bluetooth, Bluetooth Low Energy (BLE), Global System for Mobile Communications (GSM), Wireless Fidelity (WiFi) or ANT+ wireless communication, and the sensor 1 may be installed at any appropriate position of the bicycle 3 to facilitate the user to measure the sensed data.
[0040] In summation of the description above, the technical measures disclosed in the present invention overcome the drawbacks of the prior art and achieve the expected objectives and effects. In addition, the present invention has not been published or disclosed publicly prior to filing the patent application, and the invention complies with the patent application requirements, and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights.
[0041] While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.