Power meter, power measurement method, program and storage medium

A power meter includes a first measurement unit 7 that measures a force applied to a first pedal B322 and calculates predetermined first information (power and/or torque) on the first pedal B322, and a second measurement unit 6 that measures a force applied to a second pedal B321 and calculates second information (power and/or torque) on the second pedal B321, which is the same kind of the first information. The first measurement unit 7 transmits first information data indicating the first information to the second measurement unit 6, and the second measurement unit 6 adds the first information to the second measurement information and transmits an added value data indicating an added value obtained by adding the first information to the second information.

TECHNICAL FIELD

The present invention relates to a power meter that measures the power of the pedals of a vehicle when the cranks connected to the pedals are rotated, and also relates to a power measurement method, a program and a storage medium.

BACKGROUND ART

Conventionally, a device called “cycle computer” mounted on a bicycle has been known, which calculates information on the running of the bicycle and information on the exercise of the cyclist, and displays these pieces of information. Such a cycle computer calculates predetermined information, based on detection signals transmitted from various sensors provided on the bicycle.

For example, there is a cycle computer that calculates the total power and torque of the pedaling, based on detection signals (measured data) transmitted from strain sensors provided on the right and left pedals, and displays the result. For another example, there is a cycle computer that calculates the total power and torque of the pedaling, based on a detection signal transmitted from a sensor provided on a sprocket, and displays the result.

SUMMARY OF INVENTION

Technical Problem

As described above, there are cycle computers as power meters having different configurations and standards, which calculate the power and torque. Therefore, calculation methods and sensors used for the detection vary with the types of the cycle computers. That is, sensors applicable to a cycle computer as a power meter are predetermined. Therefore, if a cycle computer does not support the sensors provided on the bicycle, it is not possible to measure power and so forth.

In view of the background set forth in the preceding paragraphs, it is therefore an object of the present invention to provide a power meter that can solve the above-described problem.

Solution to Problem

To solve the above-described problem, a power meter for use with a vehicle that individually measures a force applied to each of pedals of the vehicle, when cranks connected to the pedals are rotated, the power meter comprising: a first measurement unit configured to measure a force applied to a first pedal and calculate predetermined first information on the first pedal based on a measured value; and a second measurement unit configured to measure a force applied to a second pedal and calculate predetermined second information on the second pedal based on a measured value, the second information being a same kind of the first information, wherein: the first measurement unit transmits first information data to the second measurement unit, the first information data indicating the first information calculated by the first measurement unit; and the second measurement unit adds the first information indicated by the first information data transmitted from the first measurement unit, to the second information calculated by the second measurement unit, and transmits to a predetermined controller added value data indicating an added value obtained by adding the first information to the second information.

To solve the above-described problem, a method of measuring power of pedals of a vehicle, when cranks connected to the pedals are rotated, the method comprising: a first transmission step including: measuring a force applied to a first pedal by using a first measurement part; calculating predetermined first information on the first pedal based on a measured value; and transmitting first information data indicating the first information to a second measurement part, an addition step including: measuring a force applied to a second pedal by using the second measurement part; calculating predetermined second information on the second pedal based on a measured value, the second information being a same kind of the first information; and adding to the second information the first information indicated by the first information data transmitted from the first measurement part, and a second transmission step of transmitting to a predetermined controller added value data indicating an added value obtained by adding the first information to the second information.

To solve the above-described problem, a program stored in a power peter that measures power of pedals of a vehicle when cranks connected to the pedals are rotated, the program causing the power meter to function as: a first transmission part configured to measure a force applied to a first pedal by using a first measurement part, to calculate predetermined first information on the first pedal based on a measured value, and to transmit first information data indicating the first information to the second measurement part; an adding part configured to measure a force applied to a second pedal by using the second measurement part, to calculate predetermined second information on the second pedal that is a same kind as the first information based on a measured value, and to add to the second information the first information indicated by the first information data transmitted from the first measurement part; and a second transmission part configured to transmit to a predetermined controller added value data indicating an added value obtained by adding the first information to the second information.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the embodiments of the present invention will be described with reference to the drawings.FIG. 1Ais a side view showing a bicycle B with a pedaling monitor100that calculates pedal effort of each of the right and left pedaling every predetermined crank rotation angle and displays the result.FIG. 1Bis a front view showing the bicycle B with the pedaling monitor100. The bicycle B includes: a flame B1of the bicycle body; two wheels B2pivotally supported with the frame B1on the front and back of the bicycle B (front wheel B21and rear wheel B22) to movably support the frame B1; a drive mechanism B3that transmits driving force to drive the bicycle B forward, to the rear wheel B22; a handle B4operated by the cyclist; and a saddle B5on which the cyclist sits.

The drive mechanism B3includes: a crank B31having an axis of rotation (crank axle) at its first end that is pivotably mounted with respect to the frame B1; a pedal B32which is pivotably mounted at the second end of the crank B31and is applied with a force from the cyclist; a chain ring B34connected to the crank B31to rotate together with the crank B31with respect to the same axis of rotation, which is the crank axle at the first end of the crank B31; a chain B33connected to a rear sprocket (not shown) provided to rotate together with the rear wheel B22with respect to the same axis of rotation, which is the axis of rotation of the rear wheel22, so as to transmit the force applied to the pedal B32(hereinafter referred to as “pedal effort”), to the rear wheel B22via the crank B31.

The crank B31includes a right crankshaft B311provided in the right side of the direction of forward movement of the bicycle B and a left crankshaft B312provided in the left side of the direction of the forward movement of the bicycle B. These right and left crankshafts B311and B312are fixed at the positions symmetrically with respect to the crank axle. Meanwhile, the pedal B32includes: a right pedal B321rotatably supported by a right pedal shaft (not shown) mounted to the front end of the right crankshaft B311and a left pedal B322rotatably supported by a left pedal shaft (not shown) mounted to the front end of the left crankshaft B312. Here, the right crankshaft B311and the left crankshaft B312have the same shape and structure. Likewise, the right pedal B321and the left pedal B322have the same shape and structure.

The pedaling monitor100includes: a crank rotation angle detection sensor2that detects the rotation angle of the crank B31; a rotational component detection sensor3that detects the magnitude of the pedal effort in the rotating direction of the crank B31(hereinafter “pedal effort rotational component”); a radial component detection sensor4that detects the magnitude of the pedal effort in the radial direction with respect to the crank axle or in the direction of the radius of gyration of crank B31(hereinafter “pedal effort radial component”); a cadence detection sensor5that detects the rotating speed of the crank B31; a right leg unit6and a left leg unit7that each calculate the pedal effort at a predetermined crank rotation angle, based on detection signals (measured data) transmitted from the crank rotation angle sensor2, the rotational component detection sensor3and the radial component detection sensor4, and transmit the result of the calculation to a cycle computer1; and the cycle computer1that displays the pedal effort at the predetermined crank rotation angle.

Here, with the present embodiment, the rotation angle of the crank is represented with respect to the right crankshaft B311. That is, when the right crankshaft B311is positioned at twelve o'clock (the front end is turned up), the rotation angle of the crank is “0 degrees.” When the right crankshaft B311is positioned at three o'clock (the front end faces forward), the crank angle detection sensor2indicates that the rotation angle of the crank is “90 degrees.” Moreover, when the right crankshaft B311is positioned at nine o'clock (the front end faces backward), the crank angle detection sensor2indicates that the rotation angle of the crank is “270 degrees.” Here, the range of the rotation angle (θ) of the crank, which is detected by the crank angle detection sensor2, is equal to or more than 0 degrees and less than 360 degrees (0≦θ<360 degrees). The direction in which the right crankshaft B311rotates from twelve o'clock in clockwise direction is defined as “+ direction.”

Here, the sensors2to5and the units6to7are connected to each other by wires. Meanwhile, the cycle computer1, the right leg unit6and the left leg unit7have transmitters (not shown) and are connected to each other without wires.

As shown inFIG. 2A, the crank rotation angle detection sensor2is constituted by an annular frame member20, a group of a plurality of magnets (magnets21ato21l) which are fixed on the surface of the frame member20at a predetermined interval, and a magnetic sensor22. The frame member20on which the magnet group21is fixed is formed of a circular ring and has an outer diameter of 54 mm and an inner diameter of 44 mm. The frame member20is fixed to the side face of the frame B1such that the magnet group21faces the crank B31while the center C of the frame member20corresponds to the crank axle. Meanwhile, the magnetic sensor22is fixed to the chain ring B34and rotates together with the crank B31.

The magnet group21is constituted by twelve magnets21ato21lthat are arranged every 30 degrees with respect to the center C of the annular frame member20. The magnets21ato21lare neodymium magnets that have very strong magnetic forces and coercive forces. To be more specific, each of the magnets21aand21lis constituted by two first neodymium magnets (each 3 mm×3 mm×3 mm) in series. The north poles of the respective first neodymium magnets are arranged on the same line to face the same direction. Meanwhile, each of the other magnets21bto21kis constituted by two second neodymium magnets (each 2 mm×2 mm×3 mm) in series. The magnetic force of the second neodymium magnet is smaller than of the first neodymium magnet. That is, the magnet group21is constituted by two kinds of magnets having different magnetic forces.

In addition, each of the magnets21ato21lis arranged such that its center axis corresponds to the radial direction of the frame member20. The magnets having the north poles facing the outside and the magnets having the north poles facing the inside (center) are alternately arranged. To be more specific, the north poles of the magnets21a,21c,21e,21g,21iand21kface the outside in the radial direction of the frame member20. Meanwhile, the north poles of the magnets21b,21d,21f,21h,21jand21lface the inside (center) in the radial direction of the frame member20. Moreover, the magnets21ato21lhave the same distance L4 between the outer ends of the respective magnets21ato21lin the radial direction and the center C of the frame member20.

The magnetic sensor22includes a first element22a, a second element22band a third element which are accommodated in a case22d. The first element22aand the second element22bdetect the line of magnetic force (magnetic field) in a predetermined direction (facing to the left in the horizontal direction inFIG. 2A). The first elements22aand the second element22boutput “Hi” when detecting the line of magnetic force opposite to their detection direction, that is, when detecting a magnet with the north pole facing the first elements22aand the second element22b. On the other hand, the first elements22aand the second element22boutput “Lo” when detecting the line of magnetic force in the same direction as their detection direction, that is, when detecting a magnet with the south pole facing the first elements22aand the second element22b. Here, when the first element22aand the second element22bdo not detect any line of magnetic force with a predetermined strength, they maintain the output state.

When the crank rotation angle detection sensor2is used (where the frame member20and the magnetic sensor22are appropriately fixed to the bicycle B), the first element22aand the second element22bare arranged outside the frame member20in the radial direction, that is, arranged with the distance from the center C of the frame member20that is longer than the distance between the magnets21ato21land the center C of the frame member20, viewed from the side of the bicycle B. In addition, the elements22aand22bhave the same detection direction, and the center C of the frame member20is located on the detection direction. The distance between the first element22aand the center C of the frame member20is shorter than the distance between the second element22band the center C, so that the first element22ais closer to the outer end of each of the magnetics21ato21lpassing on the detection direction. To be more specific, the first element22ais provided at a position 9.0 mm away from the outer end of the closest magnet (that is, away from closer one of the cross points of the movement path of the magnets and the detection direction). Meanwhile, the second element22bis provided at a position 13.5 mm away from the outer end of the closest magnet. It is because, as described later, the first element22ais used to detect all the magnets21ato21l, and the second element is used to detect only the magnet21aindicating the crank rotation angle=0 degrees. Here, the frame member20and the magnetic sensor22are fixed to the bicycle B such that when the crank rotation angle (θ) is 0 degrees (when the right crankshaft B311points to twelve o'clock), the second element22bdetects the magnet21a.

The magnetic sensor22also includes the third element22cwith lower power consumption than of the first element22aand the second element22b. The third element22cis provided in the vicinity of the first element22a, and, upon detecting any of the magnets21ato21l, activates the system of the unit6.

Next, a method of detecting the crank rotation angle by the crank rotation angle detection sensor2will be described with reference toFIG. 3. As described above, the magnets21ato21lare arranged on the annular frame member20every 30 degrees with respect to the center C. The magnet21ahaving the strongest magnetic force is located to be detected by the second element22bwhen the crank rotation angle (θ) is 0 degrees (hereinafter, the magnet21amay be referred to as “reference magnet21a”). In addition, the directions of the north poles of the magnets21ato21lare alternated. Therefore, when the magnetic sensor22fixed to the chain ring B34rotates around the crank axle with the rotation of the crank B31, the first element22aof the magnetic sensor22switches output between Hi and Lo every time passing in front of each of the magnets21ato21l. Likewise, the second element22bof the magnetic sensor22switches output between Hi and Lo every time passing in front of the magnets21aand21l. “Hi” or “Lo” is outputted from the first element22a, so that it is possible to detect that the crank B31has rotated 30 degrees (hereinafter referred to as “angular interval detection signal”). Meanwhile, “Hi” is outputted from the second element22b, so that it is possible to detect that the crank rotation angle (θ) is 0 degrees (hereinafter referred to as “reference angle detection signal”).

As described above, by using the angular interval detection signal and the reference angle detection signal, it is possible to detect the crank rotation angle (θ) at intervals from 0 to 30 degrees. Here, the Hi outputted from the second element22bbecomes Lo (that is, is reset) after passing in front of the magnet21lwhich has the same magnetic force and has the north pole facing the opposite direction. Therefore, it is possible to continuously detect the crank rotation angle. Hereinafter, “Lo” outputted from the second element22bwill be referred to as “reset signal.”

Here, it is preferred that distance L2 between the outer ends of the magnets21ato21land the first element22a, distance L3 between the outer ends of the magnets21ato21land the second element22b, and distance L4 between the center C of the frame member20and the outer ends of the magnets21ato21lsatisfy the following relationship. The reason is to prevent the first element22afrom detecting the reference magnet21awhen the distance between the reference magnet21aand the first element22bis maximized. Here, with the present embodiment, since L2 is 9.0 mm, L3 is 13.5 mm and L4 is within a range between 47 mm and 54 mm, L2, L3 and L4 satisfy the following equation.
(2L4+L2)>L3  Equation 1

In addition, in order to prevent the first element22afrom detecting the reference magnet21awhen the distance between the first element22aand the reference magnet21ais maximized, it is preferred that: the second element22bcan detect the reference magnet21awhen the distance between the reference magnet21aand the second element22bis minimized on the detection direction of the second element22b(hereinafter referred to as “second detection direction”); the first element22acan detect the magnets21cto21lhaving the smallest magnetic force when the distance between the first element22aand the magnets21cto21lis minimized on the detection direction of the first element22a(hereinafter referred to as “first detection direction”); and the first element21acannot detect the reference magnet21awhen the distance between the reference magnet21aand the first element22ais maximized on the first detection direction.

Here, with the present embodiment, the center C is located on the central axis of each of the magnets21ato21l, and the directions of the north poles are alternated in the circumferential direction. By this means, it is possible to prevent the adjacent magnets from repelling each other, and therefore to prevent the coercive forces of the magnets21ato21lfrom decreasing.

In addition, with the present embodiment, the magnets21ato21lare arranged at a predetermined interval, and, when the distance between each of the magnets21ato21land each of the elements21aand22bis minimized, the central axis of each of the magnets21ato21lcorresponds to the detection direction of each of the elements22aand22b. By this means, it is possible to improve the accuracy of the crank rotation angle detection sensor2to detect the crank rotation angle. It is because the magnitude of the magnetic field is increased relative to each of the elements22aand22b.

In addition, in order to improve the accuracy of the detection of the crank rotation angle by increasing the magnetic forces of the magnets21ato21l, the proportion of the length of each of the magnets21ato21lmay be increased in the central axis direction. Moreover, bobbins may be mounted to the magnets21ato21l.

Moreover, it is preferred that the magnets21ato21lare arranged on the frame member20such that the central axes of the magnets21ato21lare parallel, to the surface of the frame member20. By this means, it is possible to reduce the thickness of the frame member20with respect to the magnets having the same length in the direction of the central axes (or the same intensity of the magnetic forces), and therefore reduce the cost.

The rotational component detection sensor3includes a unit3aconstituted by two strain sensors (hereinafter referred to as “rotational strain sensor unit3a”). As shown inFIG. 1andFIG. 4, the rotational component detection sensor3is attached to the front face of the crank B31, which faces the traveling direction when the crankshafts B311and B312point to six o'clock. The rotational component detection sensor3is constituted by a right rotational component detection sensor31attached to the right crankshaft B311and a left rotational component detection sensor32attached to the left crankshaft B312. Moreover, the rotational component detection sensor3also includes a rotational strain detection circuit (not shown) connected to the terminals of the strain sensors constituting the rotational strain sensor unit3a, and a rotational component controller that totally control the sensor3.

As shown inFIG. 5A, the strain sensors of the rotational strain sensor unit31aare attached to the front face of the crankshaft B311such that the strain sensors are orthogonal to one another. The same applies to the crankshaft B312. The rotational strain detection circuit amplifies and adjusts the output from each of the strain sensors, and transmits information indicating the total amount of strain (hereinafter referred to as “rotational strain information” to the rotational component controller. The rotational component controller of each of the sensors31and32calculates rotational component Fx(N) of the crank effort according to the following Equation 2, based on the rotational strain information transmitted from the rotational strain detection circuit, and transmits a rotational component detection signal corresponding to the rotational component Fz of the crank effort, to each of the units6and7.
Fx=mg(X−Xz)/(Xc−Xz)  Equation 2

Here, “m” represents mass; “g” represents acceleration of gravity; “X” represents the amount of strain detected by the rotational strain detection circuit; “Xc” represents the amount of strain in the front face of the crank B31when vertical force (N) is applied to the pedal B32while the crank B31is kept horizontal; and “Xz” represents the amount of strain in the front face of the crank B31when no load is applied to the crank B31. Here, Xc and Xz are acquired by calibrating the sensor unit3aattached to the front face of the crank B31before use of the sensor3.

The radial component detection sensor4includes a sensor unit4aconstituted by two strain sensors (hereinafter referred to as “radial direction strain sensor unit4a). As shown inFIG. 1andFIG. 4, the radial component detection sensor4is attached to the outside face of the crank B31. The radial component detection sensor4is constituted by a right radial component detection sensor41attached to the right crankshaft B311and a left radial component detection sensor42attached to the left crankshaft B312. In addition, the radial component detection sensor4includes a radial strain detection circuit (not shown) connected to the terminals of the strain sensors constituting the radial strain sensor unit4a, and a radial component controller that totally controls the sensor4.

As shown inFIG. 5B, the strain sensors of the radial strain sensor unit41aare attached to the lateral surface of the crankshaft B311such that the strain sensors are orthogonal to one another. The same applies to the crankshaft B312. The rotational strain detection circuit amplifies and adjusts the output of each strain sensor and transmits information indicating a total amount of strain (hereinafter referred to as “rotational strain information”) detected by the sensor unit4ato the rotational component controller. The radial component controller of each of the sensors41and42calculates a radial component Fy of the crank effort, according to the following equation 3, based on the radial strain information transmitted from each of the radial strain detection circuits, and transmits to each measurement units6and7a radial component detection signal according to the radial component Fy of the pedal effort.
Fy=mg(Y−Yz)/(Yu−Yz)  Equation 3

Here, “m” represents mass; “g” represents acceleration of gravity, “Y” represents the amount of strain detected by the radial strain detection circuit: “Yu” represents the amount of strain in the lateral surface of the crank B31when vertical force (N) is applied to the pedal B32while the pedal B32is located at the bottom dead center; and “Yz” represents the amount of strain in the lateral surface of the crank B31when no load is applied to the crank B31. Here, Yu and Yz are acquired by calibrating the sensor unit4aattached to the lateral surface of the crank B31before use of the sensor4.

The cadence detection sensor5is constituted by a magnet fixed to, for example, the left crankshaft B312and a magnet detector mounted on the frame B1at a predetermined position. The cadence detection sensor5detects the number of the rotation of the crank B31per unit of time (one minute) by detecting the number of times n (rpm) the magnet passes through the front face of the magnet detector. This sensor5transmits a cadence detection signal according to the number of the rotation of the crank B31per unit of time, to each of the units6and7.

Next, the configuration of the pedaling monitor100will be described with reference toFIG. 7. The pedaling monitor100includes: a right leg unit6that calculates torque and power (consumption energy) of the right leg, based on a right rotational component detection signal transmitted from the right rotational component detection sensor31and a right radial component detection signal transmitted from the right radial component detection sensor41; a left leg unit7that calculates torque and power of the left leg, based on a left rotational component detection signal transmitted from the left rotational component detection sensor32and a left radial component detection signal transmitted from the left radial component detection sensor42; and the cycle computer1that provides comprehensive or composite visualization of the result of calculation, based on the result of the calculation by both the units6and7.

As shown inFIG. 6, the cycle computer1is mounted to the bicycle B via a predetermined attaching member8that is removably attached to the handle B4of the bicycle B. The cycle computer1includes: an input part11used to input predetermined information; a display part12used to display predetermined information; a controller13(seeFIG. 7) having an operating circuit that performs predetermined processing for pedaling; and a housing14that accommodates these input part11, display part12and controller13.

The input part11includes: three operation parts11a,11band11cthat are arranged side by side and protrude from the upper surface of the housing14to allow the cyclist to operate these parts; and a power switch11dthat can be slid to switch between on and off of the power supply.

As shown inFIG. 6, the input part11has an input control circuit11ethat relays input signals inputted by the operation of the operation parts11ato11cand the power switch11d, to the controller13, as control information. Each of the controllers11aand11cis formed of a button, and the operation part11bis formed as a numerical keypad. When each of the operation parts11ato11cis operated, the input control circuit11econverts the input signal into control information corresponding to the operation, and transmits the information to the controller13. By this means, it is possible to realize a plurality of kinds of input operations whose number is equal to or greater than the kinds of the operation parts11ato11c, by combining the operations of these buttons. Therefore, the cyclist can perform input operations including input of unique information on the cyclist and the bicycle, input to start/stop of measurement and so forth.

The display part12includes: a liquid crystal panel12aused to display torque, power and so forth for each of a predetermined crank rotation angle for each of the legs; and a display control circuit12ethat controls the display of the liquid crystal panel12adepending on the information to be displayed. Here, another configuration is possible where the liquid crystal panel12amay be a touch panel, and the input part11and the display part12are integrally formed.

The controller13of the cycle computer1is constituted by a CPU13a, a ROM13b, a RAM13c, an oscillating circuit13d, a recording medium I/F13e, a communication I/F13f, a sensor I/F13g, a right leg unit transmitting I/F13h, a right leg unit receiving I/F13i, a left leg unit transmitting I/F13jand a left leg unit receiving I/F13k. These are connected to each other via a bus13l.

The CPU13acontrols the basic actions of the cycle computer1, which includes the display of predetermined parameters for pedaling, based on a program stored in the ROM13bin advance. The ROM13bpreviously stores program codes to perform the basic processing of the cycle computer1, which is performed by the CPU13a. The RAM13cfunctions as a working area for data and so forth in arithmetic processing that is performed when the CPU13aperforms the basic processing of the cycle computer1.

The oscillating circuit13dhas a crystal oscillator as a clock oscillator and outputs a pulse signal to the CPU13aat a predetermined period by counting generated clock pulses. The recording medium I/F13eis an interface for recording predetermined information on a recording medium such as a memory card and so forth. The communication I/F13fis an interface to transmit and receive data to/from an external processing device, for example, a mobile terminal such as a cellular phone or a PC installed at home. The sensor I/F13gis an interface to capture various kinds of detection signals transmitted from predetermined sensors. The right leg unit transmitting I/F13his an interface to transmit a mode conversion signal to the right leg unit6. The right leg receiving I/F13iis an interface to receive data from the right leg unit6. The left leg unit transmitting I/F13jis an interface to transmit a mode conversion signal to the left leg unit7. The left leg unit receiving I/F13kis an interface to receive data from the left leg unit7. Here, the input part11, the display part12and the controller13are connected to each other via the bus13lto transmit and receive necessary information.

As shown inFIG. 1, the right leg unit6is mounted to the right crankshaft B311of the bicycle B. The right unit6includes a controller61having an operating circuit that performs predetermined processing for the calculation of torque and power of the pedaling with the right leg, and a case62that accommodates the controller61. Likewise, the left leg unit7is mounted on the left crankshaft B312of the bicycle B, and includes a controller71having an operating circuit that performs predetermined processing for the calculation of torque and power of the pedaling with the left leg, and a case72that accommodates the controller71.

As shown inFIG. 8B, the controller71of the left leg unit7is constituted by a CPU71a, a ROM71b, a RAM71c, an oscillating circuit71d, a sensor I/F71e, a cycle computer receiving I/F71f, a cycle computer transmitting I/F71gand a right leg unit transmitting I/F71h. These components are connected to each other via a bus71j.

The CPU71acontrols the basic actions of the left leg unit7, which includes the calculation of torque and power of the pedaling with the left leg, based on the program stored in the ROM13bin advance. The ROM71bpreviously stores program codes to perform the basic processing of the cycle computer1, which is performed by the CPU71a. The RAM71cfunctions as a working area for data and so forth in arithmetic processing that is performed when the CPU71aperforms the basic processing of the left leg unit7.

The oscillating circuit71dhas a crystal oscillator as a clock oscillator and outputs a pulse signal to the CPU71aat a predetermined period by counting clock pulses generated according to a functional mode (pedaling monitor mode/power meter mode) set at power on. The oscillating circuit71doutputs a pulse signal at 6.05 Hz in the pedaling monitor mode, and outputs a pulse signal at 4.10 Hz in the power meter mode. The sensor I/F71eis an interface to capture various kinds of detection signals transmitted from the above-described crank rotation angle detection sensor2, the left rotational component detection sensor32, the left radial component detection sensor42and the cadence detection sensor5. The cycle computer receiving I/F71fis an interface to receive a mode switching signal transmitted from the cycle computer1. The cycle computer transmitting I/F71gis an interface to transmit various calculated value data to the cycle computer1in the pedaling monitor mode. The right leg unit transmitting I/F71his an interface to transmit various calculated value data to the cycle computer1in the power meter mode.

As shown inFIG. 8A, the controller61of the right leg unit6is constituted by a CPU61a, a ROM61b, a RAM61c, an oscillating circuit61d, a sensor I/F61e, a cycle computer receiving I/F61f, a cycle computer transmitting I/F61gand a left leg unit receiving I/F61h. These components are connected to each other via a bus71j.

The CPU61acontrols the basic actions of the right leg unit6, which includes the calculation of torque and power of the pedaling with the right leg, the total torque and power of the pedaling with both legs, the accumulated torque, the accumulated power, and the contribution of the right leg, based on the program stored in the ROM61bin advance. The ROM61bpreviously stores program codes to perform the basic processing of the right leg unit6, which is performed by the CPU61a. The RAM61cfunctions as a working area for data and so forth in arithmetic processing that is performed when the CPU61aperforms the basic processing of the right leg unit6.

The oscillating circuit61dhas a crystal oscillator as a clock oscillator and outputs a pulse signal to the CPU61aat a predetermined period by counting clock pulses generated according to the functional mode (pedaling monitor mode/power meter mode) set at power on. The oscillating circuit61doutputs a pulse signal at 6.00 Hz in the pedaling monitor mode, and outputs a pulse signal at 4.00 Hz in the power meter mode. The cycle computer receiving I/F61eis an interface to receive a mode switching signal transmitted from the cycle computer1. The sensor I/F61fis an interface to capture various kinds of detection signals transmitted from the above-described crank rotation angle detection sensor2, the right rotational component detection sensor31, the right radial component detection sensor41and the cadence detection sensor5. The cycle computer transmitting I/F61fis an interface to transmit various calculated value data to the cycle computer1. The left leg unit receiving I/F61gis an interface to receive various calculated value data transmitted from the left leg unit7in the power meter mode.

FIG. 9is a control (functional) block diagram showing the configuration of the pedaling monitor100according to the present embodiment of the invention. The left leg unit7of the pedaling monitor100includes a measured data receiving part7A, a mode switching signal receiving part7B, a mode switch7C, a frequency switching part7D, a frequency generating part7E, a calculation part7F and a left leg data transmitting part7G.

The measured data receiving part7A receives a crank rotation angle detection signal outputted from the crank rotation angle detection sensor2, a left rotational component detection signal, outputted from the left rotational component detection sensor32, a left radial component detection signal outputted from the left radial component detection sensor42and a cadence detection signal outputted from the cadence detection sensor5, and has a function to store those signals in storage areas of the RAM71C.

The mode switching signal receiving part7B receives a mode switching signal outputted from the cycle computer1. At the time the mode switching signal receiving part7B receives the mode switching signal, the mode switch7C turns on a pedaling monitor mode flag in a cycle mode flag storage area of the RAM71c, and switches the mode from the power meter mode as default to the pedaling monitor mode. At the time the mode switch7C switches the mode to the pedaling monitor mode, the frequency switching part7D switches the frequency of a pulse signal outputted from the frequency generating part7E (oscillating circuit71d) to the CPU71a, from 4.10 Hz as default to 6.05 Hz.

The frequency generating part7E has a crystal oscillator as a clock oscillator and outputs a pulse signal to the CPU71aat a predetermined period by counting clock pulses generated according to the mode (pedaling monitor mode/power meter mode) set at power on.

The calculation part7F calculates torque and power (consumption energy) for the pedaling with the left leg, based on the crank rotation angle (θ), the rotational component (N) of the pedal effort for the left leg, and the radial component (N) of the pedal effort for the left leg which are stored in the RAM71c, and stores the result of the calculation in a left torque storage area and a left power storage area of the RAM71c.

The left data transmitting part7G transmits the left torque data and the left power data, based on the functional mode (power meter mode/pedaling monitor mode). When the mode is the power meter mode, the left data transmitting part7G transmits the left torque data and the left power data to the right leg unit6. On the other hand, when the mode is the pedaling monitor mode, the left data transmitting part7G transmits the data to the cycle computer1.

Meanwhile, the right unit6of the pedaling monitor100includes a measured data receiving part6A, a mode switching signal receiving part6B, a mode switch6C, a frequency generating part6E, a calculation part6F, a left leg data receiving part6G and a right leg data transmitting part6H.

The measured data receiving part6A receives a crank rotation angle detection signal outputted from the crank rotation angle detection sensor2, a rotational component detection signal outputted from the right rotational component detection sensor31, a radial component detection signal outputted from the right radial component detection sensor41and a cadence detection signal, outputted from the cadence detection sensor5, and has a function to store those signals in storage areas of the RAM61c.

The mode switching signal receiving part6B receives a mode switching signal outputted from the cycle computer1. At the time the mode switching signal receiving part6B receives the mode switching signal, the mode switch6C turns on a pedaling monitor mode flag in a cycle mode flag storage area of the RAM61c, and switches the mode from the power meter mode as default to the pedaling monitor mode. At the time the mode switch6C switches the mode to the pedaling monitor mode, the frequency switching part6D switches the frequency of a pulse signal outputted from the frequency generating part6E (oscillating circuit61d) to the CPU61a, from 4.00 Hz as default to 6.00 Hz.

The frequency generating part6E has a crystal oscillator as a clock oscillator and outputs a pulse signal to the CPU61aat a predetermined period by counting clock pulses generated irrespective of the mode (pedaling monitor mode/power meter mode) set at power on.

The calculation part6F calculates torque and power for the pedaling with the right leg, based on the crank rotation angle (θ), the rotational component (N) of the pedal effort for the right leg, and the radial component (N) of the pedal effort for the right leg which are stored in the RAM61c, and stores the result of the calculation in a right torque storage area and a right power storage area of the RAM63c.

The left leg data receiving part6G receives left torque data and left power data transmitted from the left leg unit7in the power meter mode, and stores the data in the left torque data storage area and the left power data storage area of the RAM61c. The right leg data transmitting part6H transmits predetermined calculated value data to the cycle computer1irrespective of the kind of the mode.

Next, process and method of transmitting predetermined calculated value data (left torque data and left power data) by the left leg unit7will be described with reference toFIGS. 10 to 12.

<Main Processing for the Left Leg>

When the left leg unit7is supplied with power, system reset occurs in the CPU71a, and then, the CPU71astarts a main process shown inFIG. 10. First, in step S100, the CPU71aperforms an initialization process. In this process, the CPU71areads an activation program from the ROM71band performs a process for the initialization of a predetermined storage area in the RAM71c.

Next, in step S1002, the CPU71asets the functional mode to the power meter mode. That is, the functional mode is set to the power meter mode as default. To be more specific, a power meter flag (e.g. “00H”) is turned on in the functional mode flag storage area of the RAM71c. Then, the CPU71adetermines whether or not the cycle computer1outputs a mode switching signal in step S1003. When determining that a mode switching signal has not been outputted, the CPU71amoves the step to step S1005. On the other hand, when determining that the mode switching signal has been outputted, the CPU71aturns on a pedaling monitor mode flag (e.g. “01H”) in the mode flag storage area of the RAM71cin step S1004, so that the functional mode is set to the pedaling monitor mode.

In the step S1005, the CPU71adetermines whether or not the crank B31rotates 360 degrees. That is, the CPU71adetermines whether or not a reference angle detection signal indicating the crank rotation angle (θ)=0 degrees has been received from the crank rotation angle detection sensor2. Here, when determining that a reference angle detection signal has not been received, the CPU71areturns the step to the step S1003. On the other hand, when determining that the reference angle detection signal has been received, the CPU71amoves the step to step S1006.

In the step S1006, the CPU71acalculates the average torque value and the average power value of the left leg for one turn of the crank B31, and stores left torque data indicating the average torque value and left power data indicating the average power value in the left torque data storage area and the left power data storage area, respectively, in the RAM71c. In step S1007, a torque update flag and a power update flag are turned on in a torque update flag storage area and a power update flag storage area, respectively, in the PAM71c. The steps S1003to S1007are repeatedly performed until predetermined interrupt processing is performed.

Here, the method of calculating the average torque value and the average power value for the left leg is not limited. As described above, the left leg unit7receives measured data (detection signals) transmitted from the left rotational component detection sensor32, the left radial component detection sensor42and the cadence detection sensor5at a predetermined time interval, and stores the data in a predetermined area in the RAM71c. Then, the CPU71acalculates the average torque value and the average power value for the left leg, by using the data. Note that necessary data other than the measured data, such as crank length L1, is acquired by appropriate processing, for example, input processing by the input part11of the cycle computer1.

<Interrupt Processing with a Crank Rotation Angle Detection Signal for the Left Leg>

Next, interrupt processing with a crank rotation angle detection signal for the left leg will be described with reference toFIG. 11. The crank rotation angle detection sensor2outputs to the left leg unit7a crank rotation angle detection signal including a reference angle detection signal or an angular interval detection signal. As a result, the following interrupt processing is performed.

In step S2001, the CPU71adetermines whether or not the signal is a reference angle detection signal. When determining that the signal is the reference angle detection signal, the CPU71aresets a rotation angle determination counter provided in the RAM71c, that is, the counter value is set to “0” in step S2002. In step S2003, the CPU71aclears a pedal effect data storage area in the RAM71c, and terminates the interrupt processing.

When determining that the signal is not a reference angle detection signal but an angular interval detection signal, the CPU71aadds “1” to the counter value of the rotation angle determination counter to update the counter in step S2004. In step S2005, the CPU71adetermines the current crank rotation angle by using a rotation angle determination table stored in the ROM71b. As shown inFIG. 18A, the counter values are associated with the crank rotation angles in the left leg rotation angle determination table. With the present embodiment, the crank rotation angle detection sensor2transmits an angular interval detection signal to the left leg unit7every time the crank B31rotates 30 degrees (because one turn of the crank B31is divided into twelve parts). Therefore, the counter values range from “1” to “12”, and the crank rotation angle is increased by 30 degrees every time the counter value increments by one. Here, when the reference angle detection signal is outputted, the right crankshaft B311points to twelve o'clock, but the left crankshaft points to six o'clock. That is, there is a phase difference of 0.180 degrees between the right crankshaft B311and the left crankshaft B312. Therefore, when the counter value is “7”, the crank rotation angle (θ) of the left crankshaft B312is 0 degrees.

In step S2006, the CPU71acalculates the current pedal effort F (e.g. F=((Fx)^+(Fy)^2)^(½)). In step S2007, the CPU71astores pedal effort data indicating the pedal effort associated with the crank rotation angle in the pedal effort data storage area of the RAM71c, and terminates the interrupt processing.

Here, with the present embodiment, the rotational component Fx and the radial component Fy for the left leg are detected, and therefore, by using the crank rotation angle (θ), the direction of the pedal effort F (for example, angle α to the surface of the ground) is calculated, so that it is possible to store pedal effort data indicating the crank rotation angle (θ), the pedal effort; (F) and the direction of the pedal effort (α). In addition, as described later, at the time the crank B31rotates 360 degrees, the pedal effort data for one turn of the crank B31is collectively transmitted. Therefore, note that the pedal effort data storage area in the RAM71chas an area to store data for at least one turn of the crank B31(for example, at least twelve pedal effort data can be stored).

<Timer Interrupt Processing for the Left Leg in the Power Meter Mode>

Next, timer interrupt processing for the left leg in the power meter mode will be described with reference toFIG. 12A. When the oscillating circuit71dprovided in the left leg unit7generates a clock pulse at a predetermined period, the following timer interrupt processing is performed. When receiving a pulse signal from the oscillating circuit71d, the CPU71achecks the functional mode flag storage area. Here, when the power meter mode flag is turned on, the CPU71aperforms steps S3001to S3003, and meanwhile, when the pedaling monitor mode flag is turned on, the CPU71aperforms steps S3501to S3504. As described above, a pulse signal is outputted to the CPU71aat 4.10 Hz in the power meter mode. Therefore, in the power meter mode, the timer interrupt processing for the left leg is performed at 4.10 Hz.

In step S3001, the CPU71adetermines whether or not an update flag is turned on in the update flag storage area in the RAM71c. When determining that the update flag is turned on, the CPU71atransmits the left torque data and the left power data stored in the RAM71cto the right leg unit6in step the S3002. In the step S3003, the CPU71aturns off the update flag, and terminates the timer interrupt processing for the left leg. On the other hand, when determining that the update flag is not turned on, the CPU71asimply terminates the timer interrupt processing for the left leg.

<Timer Interrupt Processing for the Left Leg in the Pedaling Monitor Mode>

Next, timer interrupt processing for the left leg in the pedaling monitor mode will be described with reference toFIG. 12B. A pulse signal is outputted to the CPU71aat 6.05 Hz in the pedaling monitor mode. Therefore, in the pedaling monitor mode, the timer interrupt processing for the left leg is performed at 6.05 Hz.

In step the S3501, the CPU71adetermines whether or not the update flag is turned on in the update flag storage area in the RAM71c. When determining that the update flag is turned on, the CPU71atransmits the left torque data and the left power data stored in the RAM71cto the cycle computer1in the step S3502. In the step S3503, the CPU71aturns off the update flag.

Next, in the step S3504, the CPU71atransmits to the cycle computer1a plurality of pedal effort data (for one turn of the crank B31), which are associated with predetermined crank rotation angles stored in the pedal effort data storage area of the RAM71c, and terminates the timer interrupt processing for the left leg. When determining that the update flag is not turned on in the step S3501, the CPU71asimply terminates the timer interrupt processing for the left leg.

Next, process and method of transmitting predetermined calculated value data (right torque data and right power data) by the right leg unit6will be described with reference toFIGS. 13 to 17.

<Main Processing for the Right Leg>

When the right leg unit6is supplied with power, system reset occurs in the CPU61a, and then, the CPU61astarts a main process shown inFIG. 13. First, in step S4001, the CPU61aperforms an initialization process. In this process, the CPU61areads an activation program from the ROM61band performs a process for the initialization of a predetermined storage area in the RAM61c.

Next, in step S4002, the CPU61asets the functional mode to the power meter mode. That is, the functional mode is set to the power meter mode as default. To be more specific, the power meter flag (e.g. “00H”) is turned on in the functional mode flag storage area of the RAM61c. Then, the CPU61adetermines whether or not the cycle computer1outputs a mode switching signal in step S4003. When determining that a mode switching signal has not been outputted, the CPU61amoves the step to step S4005. On the other hand, when determining that the mode switching signal has been outputted, the CPU61aturns on the pedaling monitor mode flag (e.g. “01H”) in the mode flag storage area of the PAM61cin step S4004, so that the functional mode is set to the pedaling monitor mode.

In the step S4005, the CPU61adetermines whether or not the crank B31rotates 360 degrees. That is, the CPU61adetermines whether or not a reference angle detection signal indicating the crank rotation angle (θ)=0 degrees has been received from the crank rotation angle detection sensor2. Here, when determining that a reference angle detection signal indicating the crank rotation angle (θ)=0 degrees has not been received, the CPU61areturns the step to the step S4003. On the other hand, when determining that the reference angle detection signal indicating the crank rotation angle (θ)=0 degrees has been received, the CPU61amoves the step to step S4006.

In the step S4006, the CPU61acalculates the average torque value and the average power value of the right leg for one turn of the crank B31, and stores right torque data indicating the average torque value and right power data indicating the average power value in the right torque data storage area and the right power data storage area, respectively, in the RAM61c. In step S4007, a torque update flag and a power update flag are turned on in a torque update flag storage area and a power update flag storage area, respectively, in the PAM61c. The steps S4003to S4007are repeatedly performed until predetermined interrupt processing is performed.

Here, the method of calculating the average torque value and the average power value for the right leg is not limited. As described above, the right leg unit6receives measured data (detection signals) transmitted from the right rotational component detection sensor31, the right radial component detection sensor41and the cadence detection sensor5at a predetermined time interval, and stores the data in a predetermined area in the RAM61c. Then, the CPU61acalculates the average torque value and the average power value for the right leg, by using the data. Note that necessary data other than the measured data, such as the crank length L1, is acquired by appropriate processing, for example, input processing by the input part11of the cycle computer1.

<Interrupt Processing with a Crank Rotation Angle Detection Signal for the Right Leg>

Next, interrupt processing with a crank rotation angle detection signal for the right leg will be described with reference toFIG. 14. The crank rotation angle detection sensor2outputs to the right leg unit6a crank rotation angle detection signal including a reference angle detection signal or an angular interval detection signal. As a result, the following interrupt processing is performed.

In step S5001, the CPU61adetermines whether or not the signal is a reference angle detection signal. When determining that the signal is the reference angle detection signal, the CPU61aresets a rotation angle determination counter provided in the RAM61c, that is, the counter value is set to “0” in step S5002. In step S5003, the CPU61aclears a pedal effect data storage area in the RAM61c, and terminates the interrupt processing.

When determining that the signal is not a reference angle detection signal but an angular interval detection signal, the CPU61aadds “1” to the counter value of the rotation angle determination counter to update the counter in step S5004. In step S5005, the CPU61adetermines the current crank rotation angle by using a rotation angle determination table stored in the ROM61b. As shown inFIG. 18B, the counter values are associated with the crank rotation angles in the right leg rotation angle determination table. With the present embodiment, the crank rotation angle detection sensor2transmits an angular interval detection signal to the right leg unit6every time the crank B31rotates 30 degrees. Therefore, the counter values range from “1” to “12”, and the crank rotation angle is increased by 30 degrees every time the counter value increments by one. When the counter value is “1”, the crank rotation angle (θ) is 0 degrees.

In step S5006, the CPU61acalculates the current pedal effort F (F=((Fx)^+(Fy)^2)^(½)). In step S5007, the CPU61astores pedal effort data indicating the pedal effort associated with the crank rotation angle in the pedal effort data storage area of the RAM61c, and terminates the interrupt processing.

Here, with the present embodiment, the rotational component Fx and the radial component Fy for the right leg is detected, and therefore, by using the crank rotation angle (θ), the direction of the pedal effort F (for example, angle α to the surface of the ground) is calculated, so that it is possible to store pedal effort data indicating the crank rotation angle (θ), the pedal effort (F) and the direction of the pedal effort (α). In addition, as described later, at the time the crank B31rotates 360 degrees, the pedal effort data for one turn of the crank B31is collectively transmitted. Therefore, note that the pedal effort data storage area in the RAM61chas an area to store data for at least one turn of the crank B31(for example, at least twelve pedal effort data can be stored).

<Interrupt Processing on Receiving Left Leg Data>

Next, interrupt processing on receiving left leg data in the pedaling monitor mode will be described with reference toFIG. 15. Upon receiving the left torque data and the left power data from the left leg unit7, the CPU61astores the received data in the left torque data storage area and the left power data storage area, respectively, in the RAM61cin step S6001, and terminates this interrupt processing.

<Timer Interrupt Processing for the Right Leg in the Power Meter Mode>

Next, timer interrupt processing for the right leg in the power meter mode will be described with reference toFIG. 16A. When the oscillating circuit61dprovided in the right leg unit6generates a clock pulse per predetermined period, the following timer interrupt processing is performed. When receiving a pulse signal from the oscillating circuit61d, the CPU61achecks the functional mode flag storage area. Here, when the power mode flag is turned on, the CPU61aperforms steps S7001to S7016, and meanwhile, when the pedaling monitor mode flag is turned on, the CPU61aperforms steps S7501to S7504. As described above, a pulse signal is outputted to the CPU61aat 4.00 Hz in the power meter mode. Therefore, in the power meter mode, the timer interrupt processing for the right leg is performed at 4.00 Hz.

In the step S7001, the CPU61adds “1” to the counter value of a processing determination counter provided in the RAM61c. In step S7002, the CPU61adetermines whether or not the processing determination counter is “4”. When determining that the processing determination counter is “4”, the CPU61amoves the step to the step S7008. On the other hand, when determining that the processing determination counter is not “4”, the CPU61amoves the step to the step S7003.

In the step S7003, the CPU61adetermines whether or not the torque update flag is turned on in the torque update flag storage area of the RAM61c. When determining that the torque update flag is not turned on, the CPU61amoves the step to the step S7007. On the other hand, when determining that the torque update flag is turned on, the CPU61amoves the step to the step S7004.

In the step S7004, the CPU61asums the left torque indicated by the left torque data that is transmitted from the left leg unit7and is stored in the left torque data storage area and the right torque indicated by the right torque data that is stored in the right torque data storage area to obtain the total torque (with both legs), and stores the total torque data in a total torque data storage area of the RAM61c.

In the S7005, the CPU61acalculates the accumulated torque. For example, the CPU61acalculates the accumulated torque for a predetermined period, and stores the accumulated torque data indicating the accumulated torque in the accumulated torque storage area of the RAM61c. Here, by adding the current total torque to the previous accumulated torque stored in the accumulated torque storage area, the CPU61amay calculate a new accumulated torque and store the accumulated torque data in the accumulated torque data storage area.

In the step37006, the CPU61aturns off the torque update flag. In the step S7007, the CPU61atransmits to the cycle computer1the total torque data stored in the total torque data storage area and the accumulated torque data stored in the accumulated torque data storage area, and moves the step to the step S7015.

In the step S7008, the CPU61adetermines whether or not the power update flag is turned on in the power update flag storage area of the RAM61c. When determining that the power update flag is not turned on, the CPU61amoves the step to the step S7013. On the other hand, when determining that the power update flag is turned on, the CPU moves the step to the step S7009.

In the step S7009, the CPU61asums the left power indicated by the left power data that is transmitted from the left leg unit7and is stored in the left power data storage area and the right power indicated by the right power data that is stored in the right power data storage area to obtain the total power (with both legs), and stores the total power data indicating the total power in the total power data storage area of the RAM61a.

In the step S7010, the CPU61acalculates the contribution of the right leg. That is, the CPU61acalculates the contribution of the right leg that is the proportion of the right power to the total power calculated in the step S7009, and stores the data of the contribution of the right leg in a right leg contribution data storage area.

In the step S7011, the CPU61acalculates the accumulated power. For example, the CPU61acalculates the accumulated power, and stores accumulated power data indicating the accumulated power in an accumulated power storage area of the RAM61c. Here, by adding the current power to the accumulated power stored in the accumulated power storage area, the CPU61amay calculate new accumulated power and store the accumulated power data in the accumulated power storage area.

In the step S7012, the CPU61aturns off the power update flag. In the step S7013, the CPU61atransmits to the cycle computer1the total power data stored in the total power data storage area, the right leg contribution data stored in the right leg contribution data storage area, and the accumulated power data stored in the accumulated power data storage area, and moves the step to the step S7014.

In the step S7014, the CPU61aresets the processing determination counter (that is, the counter value becomes “0”). As described above, because the processing determination counter is reset when the counter value is “4”, the power, the contribution of the right leg, and the accumulated power must be calculated every four times in the timer interrupt processing during the power meter mode of the right leg unit6.

In the step S7015, the CPU61aacquires cadence data from the cadence detection sensor5. In the step S7016, the CPU61atransmits the cadence data to the cycle computer1, and terminates the timer interrupt processing for the right leg in the power meter mode.

<Timer Interrupt Processing for the Right Leg in the Pedaling Monitor Mode>

Next, timer interrupt processing for the right leg in the pedaling monitor mode will be described with reference toFIG. 17. As described above, a pulse signal is outputted to the CPU61aat 6.00 Hz in the pedaling monitor mode. Therefore, in the pedaling monitor mode, the timer interrupt processing for the right leg is performed at 6.00 Hz.

In the step S7501, the CPU61adetermines whether or not the update flag is turned on in the update flag storage area of the RAM61c. When determining that the update flag is turned on, the CPU61atransmits the right torque data and the right power data stored in the RAM61cto the cycle computer1in step the S7502. In the step S7503, the CPU61aturns off the update flag.

Next, in the step S7504, the CPU61atransmits to the cycle computer1a plurality of pedal effort data (for one turn of the crank B31), which are associated with predetermined crank rotation angles stored in the pedal effort data storage area of the RAM61c, and terminates the timer interrupt processing for the right leg. When determining that the update flag is not turned on in the step S7501, the CPU61asimply terminates the timer interrupt processing for the right leg.

As described above, the pedaling monitor100including the right leg unit6and the left leg unit7can measure the pedal effort of the right leg and the pedal effort of the left leg individually, and analyze the pedal effort at a predetermined crank rotation angle for each leg. Each of the right leg unit6and the left leg unit7has the power meter mode. In this power meter mode, the left torque data and the left power data measured by the left leg unit7is transmitted to the right leg unit6, and the left torque and the left power indicated by the transmitted data is added to the right torque and the right power measured by the right leg unit6. As a result, the total torque and the total power are calculated, and the result of the calculation is transmitted to the cycle computer1at a predetermined frequency (predetermined standard, for example, “ANT”). Therefore, even if the cycle computer1is not designed to measure the pedal effort for both legs individually, for example, even if the cycle computer1only functions as a simple power meter, the right leg unit6and the left leg unit7can be applied to that cycle computer1. By this means, it is possible to improve the versatility of the right leg unit6and the left leg unit7. Here, the left torque and the left power constitute the first information of the present invention, and the right torque and the right power constitute the second information of the present invention.

In addition, in the power meter mode, the data transmission frequency is different between the right leg unit6(4.0 Hz) and the left leg unit7(4.10 Hz). Therefore, even if a data collision occurs, it is possible to prevent an unavailable period from being prolonged. Moreover, the data transmission interval between the left leg unit6and the right leg unit7is shorter than the data transmission interval between the left leg unit7and the cycle computer1, so that it is possible to prevent incomplete data from being transmitted. Here, “incomplete data” means the total torque and the total power consisting of the torque and the power measured by the left leg unit7that transmits data to the cycle computer1.

Moreover, with the present embodiment, the power meter mode is initially set. Therefore, even if the cycle computer1is not designed to measure the pedal effort for both legs individually, it is possible to reliably apply the right leg unit6and the left leg unit7to the cycle computer1.

Next, the crank rotation angle detection sensor2according to Embodiment 2 will be described with reference toFIG. 19. This crank rotation angle detection sensor2has the same configuration as in Embodiment 1 other than the shape of the magnets21ato21l, the fixed positions and the fixed directions of the magnets21ato21lin the frame member20, and the fixed position and the fixed direction of the magnetic sensor22. The same components are given the same names and the same reference numerals, and descriptions thereof are omitted.

With the present embodiment, the frame member20is formed of a circular ring and has an outer diameter of 54 mm and an inner diameter of 47 mm, like Embodiment 1. Cylindrical insertion holes20ato20linto which the magnets21ato21lare inserted are formed in the frame member20in its thickness direction. The centers (central axes) of the cross-sections of the insertion holes20ato20lare arranged every 30 degrees on the circumference of the circle with a radius of 50 mm from the center C. The insertion holes20ato20lcan be classified into two kinds, “insertion holes20aand20l” and “insertion holes20bto20k.” That is, each of the inversion holes20aand20lhas a diameter of 6 mm, while each of the insertion wholes20bto20khas a diameter of 4 mm.

Then, the magnets21ato21lare inserted and fixed in the insertion holes20ato20l. That is, the magnets21ato21lare also formed of cylinders, and the cross-section of each of the magnets21aand21lis formed of a circle with a radius of 6 mm while the cross-section of each of the magnets21bto21kis formed of a circle with a radius of 4 mm. In addition, each of the magnets21aand21bhas the north pole at its one end and also has the south pole at the other end. The central axes of the magnets21ato21linserted into the insertion holes20ato20lare parallel to the crank axle of the crank B31. Moreover, the magnets21ato21lare arranged alternately to face the directions opposite to each other. The north pole of the reference magnet21afaces the crank B31.

Although the configuration of the magnetic sensor22is the same as in Embodiment 1, the relationship between the magnetic sensor22and the magnets21ato21lfixed to the chain ring B34is different from that in Embodiment 1. To be more specific, in order to allow the first element22aand the second element22bto detect the magnets21ato21lon the frame member20fixed to the frame B1, the magnetic sensor22is provided such that the measurement direction of the first element22aand the second element22bis parallel to the central axes of the magnets21ato21l, that is, orthogonal to the plane of the frame member20and the magnets21aand21bface the movement paths of the first and second elements22aand22b.

In addition, the frame member20and the magnetic sensor are appropriately fixed such that the reference magnet21aon the frame member20faces the second element22bof the fixed magnetic sensor22when the crankshaft B311points to twelve o'clock, that is, the crank rotation angle is 0 degrees. The position in which the magnetic sensor22is fixed is not limited.

With the present embodiment, any magnet cannot exist on the opposite side of the magnet to be detected by the first element22a. Therefore, it is possible to reduce the restriction on the relationship between the distance from the center C to each of the magnets21ato21land the distance L3 from the outer end of each of the magnets21ato21lto the second element22b. By this means, it is possible to reduce the size of the frame member20, and therefore to reduce the cost.

Next, the crank rotation angle detection sensor2according to Embodiment 3 will be described with reference toFIG. 20. This crank rotation angle detection sensor2has the same configuration as in Embodiment 1 other than the kind of the magnets21ato21l, the fixed positions of the magnets21ato21lin the frame member20, and the fixed position of the magnetic sensor22. The same components are given the same names and the same reference numerals, and descriptions thereof are omitted.

With the present embodiment, all the magnets21ato21lare formed by the same kind of magnets (for example, each size is 2 mm×2 mm×3 mm like Embodiment 1). However, the positions in which the magnets21aand the magnet21lare fixed is different from those in Embodiment 1. To be more specific, the distance between the center C of the frame member20and each of the magnets21aand21lis different from that in Embodiment 1. More specifically, the reference magnet21aand the reset magnet21lare fixed to the frame member20such that the outer ends of the reference magnet21aand the reset magnet21lcontact the outer periphery of the frame member20. The other magnets21bto21kare fixed to the frame member20such that the inner ends contact the inner periphery of the frame member20. The magnetic sensor22is fixed to the chain ring B34such that the first element22acan detect all the magnets21ato21lwhile the second element22bcan detect only the reference magnet21aand the reset magnet21l.

In this way, the magnets21ato21lare formed by the same kind of magnets, so that it is possible to reduce the production cost of the crank rotation angle detection sensor2.

Next, the rotation angle detection sensor2according to Embodiment 4 will be described with reference toFIG. 21. This crank rotation angle detection sensor2has the same configuration as in Embodiment 1 other than the magnets21aand21l. The same components are given the same names and the same reference numerals, and descriptions thereof are omitted.

With the present embodiment, all the magnets21ato21lare formed by the same kind of magnets (for example, each size is 2 mm×2 mm×3 mm like Embodiment 1). With the present embodiment, the magnets21ato21lare fixed to the frame member20at the positions with the same distance from the center C of the frame member20. However, the present embodiment is different from Embodiment 1 in that bobbins23are mounted to only the reference magnet21aand the reset magnet21l. Therefore, reference magnet21aand the reset magnet21lwith the bobbins23have stronger magnetic fields than of the other magnets21bto21k. Therefore, it is possible to allow the second element22bto detect only the reference magnet21aand the reset magnet21l. In this way, the magnets21ato21lare formed by the same kind of magnets, so that it is possible to reduce the production cost of the crank rotation angle detection sensor2.

Another Embodiment

With Embodiments 1 to 4, a configuration has been described where the frame member20and the magnet group21are mounted to the frame B1while the magnetic sensor22is mounted to the chain ring B34. However, it is by no means limiting, but another configuration is possible where the frame member20and the magnet group21are mounted to the chain ring B34while the magnetic sensor22is mounted to the frame B1. In addition, although the crank rotation angle detection sensor2is mounted to the bicycle B, part or all thereof may be incorporated in the bicycle B. For example, the frame member20and the magnetic group21may be incorporated into and integrated with the chain ring B34. In this case, only the magnet group21may be incorporated into and integrated with the chain ring B34without the frame member20.

In addition, with Embodiments 1 to 4, a configuration of the crank rotation angle detection sensor2has been described where the magnetic group21is immovable with respect to the frame member20. However, it is by no means limiting, but another configuration is possible where, as shown inFIG. 22, the frame member20is constituted by an annular base20A having an annular groove20B and a rotating member20C engaging with the annular groove B. The magnet group21is fixed to the rotating member20C. The rotating member20C can rotate about the center C and can be fixed to the base20A at a desired position. In this case, the frame member20and the magnetic sensor22are appropriately mounted to the bicycle B, and then the rotating member20C is rotated. By this means, it is possible to make an adjustment of crank rotation angle=0 degrees. This helps make it easy to mount the crank rotation angle detection sensor2.

Moreover, a configuration has been described where the crank rotation angle detection sensor2has the reference magnet21aand its dedicated element (second element)22bin order to detect a specific crank rotation angle (0 degrees). However, it is by no means limiting, but a plurality of reference magnets and their dedicated elements may be provided in order to detect a plurality of specific crank rotation angles. That is, for detecting the first reference point (e.g. 0 degrees), there may be provided a first reference magnet and a first reference element that detects only the first reference magnet, and, for detecting the second reference point (180 degrees), there may be provided a second reference magnet and a second reference element that detects only the first reference magnet and the second reference magnet. In this way, a plurality of reference points are set, so that it is possible to eliminate the effects of inverse rotation or noise, and therefore to detect a predetermined crank rotation angle.

Moreover, with Embodiments 1 to 4, the reset magnet21lis provided to reset the second element22bin Hi. The reason is that Hi is maintained unless the second element22bdetects a magnetic field with a predetermined intensity, with Embodiments 1 to 4. Therefore, the second element22bautomatically becomes “0”, or is reset, the reset magnet21lis not required. However, the second element22boutputs Lo, so that it is possible to detect the second reference point of the crank rotation angle.

Moreover with Embodiments 1 to 4, although the neodymium magnets are used, the other kinds of magnets are applicable. Moreover, the interval at which the crank rotation angle is detected is not limited to, and also the reference crank rotation angle is not limited to the above-described Embodiments 1 to 4. Furthermore, the shape of the frame member20is not limited to Embodiments 1 to 4.

In addition, with Embodiments 1 to 4, a configuration has been described where, in the power meter mode, the calculated value data obtained by the left leg unit7is transmitted to the right leg unit6, the calculated values are summed in the right leg unit6, and the summed value is transmitted to the cycle computer1. However, it is by no means limiting, but another configuration is possible where the calculated value data obtained by the right leg unit6is transmitted to the left leg unit7, the calculated values are summed in the left leg unit7, and the summed value is transmitted to the cycle computer1.

Moreover, with Embodiments 1 to 4, although the strain detection sensor is used to measure the pedal effort, the kind of sensor is not limited to the strain detection sensor. Moreover, with Embodiment 1, torque and power are measured by the right leg unit6and the left leg unit7, however it is by no means limiting. Torque and power may be calculated by the cycle computer by transmitting pedal effort to the cycle computer1.

Moreover, in addition to a bicycle running on the road, the pedaling monitor100is applicable, to a vehicle that has cranks connected to pedals and is driven by rotating the cranks, such as a stationary exercise bike in a gym, and a boat (e.g. swan boat) which can be driven forward by a person who is pedaling.

In addition, with Embodiments 1 to 4, the cycle computer1displays the pedal effort and the average torque value. However, it is by no means limiting, but the pedal, effort and the average torque value may be displayed by application software of a mobile terminal such as a cellular phone. In this case, the mobile terminal may be set on the bicycle B or carried by the cyclist.

REFERENCE SIGNS LIST