WO2016009536A1 - Dispositif de détection d'angle de rotation - Google Patents

Dispositif de détection d'angle de rotation Download PDF

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Publication number
WO2016009536A1
WO2016009536A1 PCT/JP2014/069080 JP2014069080W WO2016009536A1 WO 2016009536 A1 WO2016009536 A1 WO 2016009536A1 JP 2014069080 W JP2014069080 W JP 2014069080W WO 2016009536 A1 WO2016009536 A1 WO 2016009536A1
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WIPO (PCT)
Prior art keywords
acceleration sensor
crank
rotation angle
acceleration
unit
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Application number
PCT/JP2014/069080
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English (en)
Japanese (ja)
Inventor
恭一 寺尾
章雄 福島
悠史 居鶴
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パイオニア株式会社
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Application filed by パイオニア株式会社 filed Critical パイオニア株式会社
Priority to PCT/JP2014/069080 priority Critical patent/WO2016009536A1/fr
Publication of WO2016009536A1 publication Critical patent/WO2016009536A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
    • B62M3/00—Construction of cranks operated by hand or foot
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
    • G01B21/22—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring angles or tapers; for testing the alignment of axes

Definitions

  • the present invention relates to a rotation angle detection device that detects a rotation angle of a crank that rotates about a rotation axis.
  • a device that is mounted on a human-powered machine such as a bicycle and calculates and displays information related to the traveling of the bicycle and information related to the movement of the driver.
  • This type of device calculates and displays predetermined information by receiving data from a sensor provided on the bicycle.
  • the information to be displayed includes a force (torque or the like) applied to the pedal by the driver.
  • this type of device may display the force applied to the pedal at predetermined angular intervals. For this purpose, it is necessary to detect the angle of the crank relative to the reference position.
  • a magnet group 21 in which a plurality of magnets are arranged at intervals of 30 ° around the center C of the frame-shaped member 20 on the surface of an annular frame-shaped member 20 fixed to the side surface of a bicycle frame.
  • a magnetic sensor 22 that is fixed to the chain ring and rotates together with the crank, and describes that the magnetic sensor 22 detects the position of each magnet in the magnet group 21 to detect the angle. Yes.
  • Patent Document 2 describes that the rotation angle of the crank is detected by the angular velocity sensor 10 and the acceleration sensors 11 and 12.
  • the pedaling state measuring device described in Patent Document 2 uses an angular velocity sensor, and thus has a problem of increasing power consumption. It is known that an angular velocity sensor generally consumes more power than an acceleration sensor. Since a device attached to a bicycle or the like is driven by a battery or the like as a power source, low power consumption is desired.
  • an object of the present invention is to provide a rotation angle detection device capable of reducing cost and improving durability and reducing power consumption.
  • the invention described in claim 1 is arranged on a crank attached to a rotating shaft or a member that rotates in conjunction with the crank, and accelerates in a direction parallel to the longitudinal direction of the crank.
  • a first acceleration sensor and a second acceleration sensor to be detected; an acquisition unit that acquires an output value of the first acceleration sensor and an output value of the second acceleration sensor at predetermined time intervals; and an output value of the first acceleration sensor;
  • a rotation angle detection device comprising: an output unit that outputs information on the rotation angle of the crank based on the output value of the second acceleration sensor and the predetermined time interval.
  • an output of a first acceleration sensor that is arranged on a crank attached to a rotating shaft or a member that rotates in conjunction with the crank and detects an acceleration in a direction parallel to a longitudinal direction of the crank.
  • Value and the output value of the second acceleration sensor at predetermined time intervals, the output value of the first acceleration sensor, the output value of the second acceleration sensor, and the predetermined time interval, An output step of outputting information on the rotation angle of the crank.
  • the invention described in claim 11 is a rotation angle detection program that causes a computer to execute the rotation angle detection method according to claim 10.
  • the invention described in claim 12 is a computer-readable recording medium in which the rotation angle detection program according to claim 11 is stored.
  • FIG. 2 is a block configuration diagram of a cycle computer and a measurement module shown in FIG. 1. It is explanatory drawing of arrangement
  • FIG. 4 is a circuit diagram of a measurement module strain detection circuit shown in FIG. 3. It is explanatory drawing of the force added to a right side crank, and a deformation
  • the first acceleration sensor and the second acceleration sensor are arranged on a crank attached to a rotation shaft or a member that rotates in conjunction with the crank, and the longitudinal direction of the crank
  • the acceleration in the parallel direction is detected, and the acquisition unit acquires the output value of the first acceleration sensor and the output value of the second acceleration sensor at predetermined time intervals.
  • an output part outputs the information regarding the rotation angle of a crank based on the output value of a 1st acceleration sensor, the output value of a 2nd acceleration sensor, and a predetermined time interval.
  • the acceleration component of the centrifugal force in the longitudinal direction (detection axis direction) of the crank of the acceleration sensor can be calculated.
  • the crank rotation angle can be detected by calculating information on the crank rotation angle based on the acceleration component of the centrifugal force. Therefore, since no magnet is used, the cost can be reduced, and since it is not affected by dust or iron sand, durability can be improved. Further, since the angular velocity sensor is not used, the power consumption can be reduced.
  • first acceleration sensor and the second acceleration sensor may be arranged at different distances from the rotation axis.
  • the 1st acceleration sensor and the 2nd acceleration sensor can be arranged in the crank of one side, and the information about the rotation angle of a crank can be outputted.
  • the output unit may calculate and output information on the rotation angle of the crank based on the square root of the difference between the output value of the first acceleration sensor and the output value of the second acceleration sensor. By doing so, it is possible to calculate the acceleration component of the centrifugal force in the longitudinal direction (detection axis direction) of the crank by canceling the gravitational acceleration applied to the acceleration sensor based on the two accelerations.
  • a reference position setting unit for setting a reference position of the crank rotation angle may be provided, and the output unit may output information on the crank rotation angle based on the reference position set by the reference position setting unit. By doing in this way, the information regarding the angle based on a reference position can be output. Therefore, the position of the crank can be specified.
  • the reference position setting unit may include a detected unit that is fixedly disposed at a position corresponding to a specific rotation angle of the crank, and a detection unit that is disposed on the crank and detects the detected unit. Good. In this way, for example, by providing a magnetic sensor on the crank and providing a magnet on the bicycle frame, the position of the frame can be set as the reference position.
  • a third acceleration sensor for detecting acceleration in a direction parallel to the short direction of the crank; a notification unit for notifying that the detection unit has detected the detected unit; and the first acceleration sensor or the second acceleration sensor.
  • a timing instruction unit that instructs the acquisition unit to acquire the output value of the first acceleration sensor or the second acceleration sensor and the output value of the third acceleration sensor. Then, the timing instruction unit causes the acquisition unit to acquire the output value of the first acceleration sensor or the second acceleration sensor and the output value of the third acceleration sensor based on the notification that the notification unit has detected the detected portion, and the reference position
  • the setting unit may set the reference position based on the output value of the first acceleration sensor or the second acceleration sensor acquired by the acquisition unit and the output value of the third acceleration sensor.
  • the angle with respect to the perpendicular direction of the position where the to-be-detected part was provided can be calculated based on the gravitational acceleration applied to the crank from which the to-be-detected part was detected. Therefore, it is not necessary to investigate the angle in the vertical direction of the bicycle frame or to measure it with a protractor.
  • the reference position setting unit may set the reference position based on the maximum value or the minimum value of either one of the first acceleration sensor and the second acceleration sensor. In this way, it is possible to detect when the acceleration detected by one acceleration sensor is in the gravity direction or the opposite direction, that is, in the vertical direction. Further, since the output value of the acceleration sensor for detecting the rotation angle of the crank can be used, there is no need to add another sensor or the like.
  • the reference position setting unit multiplies the distance from the rotation axis to the second acceleration sensor and the output value of the first acceleration sensor, the distance from the rotation axis to the first acceleration sensor, and the output value of the second acceleration sensor.
  • the reference position may be set based on a difference from a value obtained by multiplying. By doing so, a value obtained by multiplying the distance from the rotation axis to the second acceleration sensor by the output value of the first acceleration sensor, the distance from the rotation axis to the first acceleration sensor, and the output value of the second acceleration sensor.
  • the acceleration component of the centrifugal force of the value detected by each acceleration sensor can be canceled by the difference from the value multiplied by, and only the gravitational acceleration component can be obtained.
  • the crank is determined to be 180 °, and when the gravitational acceleration is ⁇ 1 [G], it is determined to be directly above the crank, 0 °, etc. be able to. Further, since the output value of the acceleration sensor for detecting the rotation angle of the crank can be used, there is no need to add another sensor or the like.
  • a filter unit that performs a filter process on the output values of the first acceleration sensor and the output value of the second acceleration, and a delay angle correction unit that performs an angle correction process after the filter process is performed may be included.
  • acceleration components other than gravitational acceleration and centrifugal force acceleration applied to the crank due to vibration or the like can be removed, and the accuracy of information related to the rotation angle of the crank can be improved.
  • the delay generated by the filter process can be corrected by the delay angle correction unit.
  • the rotation angle detection method includes a first acceleration sensor and a second acceleration sensor arranged on a crank attached to a rotation shaft or a member that rotates in conjunction with the crank in the acquisition step.
  • the acceleration in the direction parallel to the longitudinal direction of the crank is acquired at predetermined time intervals.
  • information on the rotation angle of the crank is output based on the output value of the first acceleration sensor, the output value of the second acceleration sensor, and the predetermined time interval.
  • the crank rotation angle can be detected by calculating information on the crank rotation angle based on the acceleration component of the centrifugal force. Therefore, since no magnet is used, the cost can be reduced, and since it is not affected by dust or iron sand, durability can be improved. Further, since the angular velocity sensor is not used, the power consumption can be reduced.
  • a rotation angle detection program that causes a computer to execute the rotation angle detection method described above may be used.
  • the acceleration component of the centrifugal force in the longitudinal direction (detection axis direction) of the crank of the acceleration sensor can be calculated using a computer.
  • the crank rotation angle can be detected by calculating information on the crank rotation angle based on the acceleration component of the centrifugal force. Therefore, since no magnet is used, the cost can be reduced, and since it is not affected by dust or iron sand, durability can be improved. Further, since the angular velocity sensor is not used, the power consumption can be reduced.
  • the rotation angle detection program described above may be stored in a computer-readable recording medium. In this way, the program can be distributed as a single unit in addition to being incorporated in the device, and version upgrades can be easily performed.
  • a bicycle 1 including a cycle computer 201 having a rotation angle detection device according to a first embodiment of the present invention will be described with reference to FIGS.
  • the bicycle 1 includes a frame 3, a front wheel 5, a rear wheel 7, a handle 9, a saddle 11, a front fork 13, and a drive mechanism 101.
  • Frame 3 is composed of two truss structures.
  • the frame 3 is rotatably connected to the rear wheel 7 at the rear end portion.
  • a front fork 13 is rotatably connected in front of the frame 3.
  • the front fork 13 is connected to the handle 9.
  • the front fork 13 and the front wheel 5 are rotatably connected at the front end position of the front fork 13 in the downward direction.
  • the front wheel 5 has a hub part, a spoke part, and a tire part.
  • the hub portion is rotatably connected to the front fork 13. And this hub part and the tire part are connected by the spoke part.
  • the rear wheel 7 has a hub part, a spoke part, and a tire part.
  • the hub portion is rotatably connected to the frame 3. And this hub part and the tire part are connected by the spoke part.
  • the hub portion of the rear wheel 7 is connected to a sprocket 113 described later.
  • the bicycle 1 has a drive mechanism 101 that converts a stepping force (stepping force) by a user (driver) foot into a driving force of the bicycle 1.
  • the drive mechanism 101 includes a pedal 103, a crank mechanism 104, a chain ring 109, a chain 111, and a sprocket 113.
  • the pedal 103 is a part in contact with a foot for the user to step on.
  • the pedal 103 is supported so as to be rotatable by a pedal crankshaft 115 of the crank mechanism 104.
  • the crank mechanism 104 includes a crank 105, a crankshaft 107, and a pedal crankshaft 115 (see FIGS. 2, 4, and 9).
  • the crankshaft 107 passes through the frame 3 in the left-right direction (from one side of the bicycle side to the other).
  • the crankshaft 107 is rotatably supported by the frame 3. That is, it becomes the rotating shaft of the crank 105.
  • the crank 105 is provided at a right angle to the crankshaft 107.
  • the crank 105 is connected to the crankshaft 107 at one end.
  • the pedal crankshaft 115 is provided at a right angle to the crank 105.
  • the axial direction of the pedal crankshaft 115 is the same as that of the crankshaft 107.
  • the pedal crankshaft 115 is connected to the crank 105 at the other end of the crank 105.
  • the crank mechanism 104 has such a structure on the side opposite to the side surface of the bicycle 1. That is, the crank mechanism 104 has two cranks 105 and two pedal crankshafts 115. Therefore, the pedal 103 is also provided on each side of the bicycle 1.
  • the right crank 105R and the left crank 105L are connected so as to extend in opposite directions around the crankshaft 107.
  • the right pedal crankshaft 115R, the crankshaft 107, and the left pedal crankshaft 115L are formed in parallel and on the same plane.
  • the right crank 105R and the left crank 105L are formed in parallel and on the same plane.
  • the chain ring 109 is connected to the crankshaft 107.
  • the chain ring 109 is preferably constituted by a variable gear capable of changing the gear ratio.
  • a chain 111 is engaged with the chain ring 109.
  • the chain 111 is engaged with the chain ring 109 and the sprocket 113.
  • the sprocket 113 is connected to the rear wheel 7.
  • the sprocket 113 is preferably composed of a variable gear.
  • the bicycle 1 converts the stepping force of the user into the rotational force of the rear wheel by such a drive mechanism 101.
  • the bicycle 1 has a cycle computer 201 and a measurement module 301 (see also FIG. 2).
  • the cycle computer 201 is disposed on the handle 9. As shown in FIG. 2, the cycle computer 201 includes a cycle computer display unit 203 that displays various types of information and a cycle computer operation unit 205 that receives user operations.
  • the various types of information displayed on the cycle computer display unit 203 include the speed of the bicycle 1, position information, the distance to the destination, the estimated arrival time to the destination, the travel distance since the departure, and the elapsed time since the departure. These are time, propulsive force, loss power, efficiency, etc. for each angle of the crank 105.
  • the propulsive force is the magnitude of the force applied in the rotation direction of the crank 105.
  • the loss force is a magnitude of a force applied in a direction different from the rotation direction of the crank 105.
  • the force applied in a direction different from the rotational direction is a useless force that does not contribute to the driving of the bicycle 1. Therefore, the user can drive the bicycle 1 more efficiently by increasing the propulsive force as much as possible and decreasing the loss force as much as possible. That is, these forces are loads applied to the crank 105 when the crank 105 rotates.
  • the cycle computer operation unit 205 is shown as a push button in FIG. 2, but is not limited thereto, and various input means such as a touch panel or a plurality of input means can be used in combination.
  • the cycle computer 201 has a cycle computer wireless reception unit 209.
  • the cycle computer wireless reception unit 209 is connected to the main body portion of the cycle computer 201 through wiring.
  • the cycle computer wireless reception unit 209 does not need to have a reception-only function. For example, you may have a function as a transmission part.
  • an apparatus described as a transmission unit or a reception unit may also have both a reception function and a transmission function.
  • the measurement module 301 is provided on the inner surface of the crank 105, for example, and uses a strain gauge 369 (see FIGS. 3 and 9) composed of a plurality of strain gauge elements. Is detected. Specifically, a propulsive force that is the rotational force of the crank 105 and serves as the driving force of the bicycle 1 and a loss force that is a force applied in a direction different from the rotational direction are calculated. The measurement module 301 also detects the rotation angle of the crank 105 using an acceleration sensor 371 described later.
  • the measurement module 301 has a magnetic sensor 373 that detects the approach of the magnet 503 provided on the frame 3 of the bicycle 1 (see FIG. 3).
  • the magnetic sensor 373 detects the position of the magnet 503 by being turned on by the approaching magnet 503. That is, when the magnetic sensor 373 is turned on, the crank 105 is also present at the position where the magnet 503 is present. Therefore, the cycle computer 201 can obtain cadence [rpm] from the output of the magnetic sensor 373. That is, the measurement module 301 also has a cadence sensor function.
  • FIG. 3 is a block diagram of the cycle computer 201 and the measurement module 301.
  • the measurement module 301 includes a measurement module wireless transmission unit 309, a measurement module control unit 351, a measurement module storage unit 353, a power sensor 368, an acceleration sensor 371, and a magnetic sensor 373.
  • the measurement module wireless transmission unit 309 is based on the propulsive force and loss force calculated from the strain information by the measurement module control unit 351, the rotation angle of the crank 105 calculated from the output information of the acceleration sensor 371, and the output of the magnetic sensor 373.
  • the calculated cadence or the like is transmitted to the cycle computer radio reception unit 209.
  • the measurement module control unit 351 comprehensively controls the measurement module 301.
  • the measurement module control unit 351 includes a propulsive force calculation unit 351a, a rotation angle estimation unit 351b, a reference angle detection unit 351c, a transmission data creation unit 351d, and a cadence calculation unit 351e.
  • the propulsive force calculation unit 351a calculates the propulsive force and the loss force from the strain information output from the power sensor 368. A method for calculating the propulsive force and the loss force will be described later.
  • the rotation angle estimation unit 351b calculates (estimates) the rotation angle of the crank 105 calculated from the output information of the acceleration sensor 371 acquired at predetermined time intervals, and controls the timing at which strain information is acquired. A method for calculating the rotation angle of the crank 105 will be described later.
  • the reference angle detector 351c detects whether or not the position of the crank 105 is at the reference position.
  • the reference position is detected by receiving an output of an information signal indicating that the magnetic sensor 373 is turned on.
  • the cadence calculation unit 351e refers to the value of the counter that it has. Then, cadence is calculated from the counter value. Specifically, the time (cycle) [second] at which the magnetic sensor 373 is turned on is calculated by multiplying the count number (C) of the counter by one count interval (T). Then, cadence [rpm] is calculated by dividing 60 by this period.
  • the counter may be externally provided as a timer or the like.
  • the transmission data creation unit 351d generates transmission data from the propulsive force and loss force calculated by the propulsive force calculation unit 351a, the rotation angle of the crank 105 calculated by the rotation angle estimation unit 351b, and the cadence calculated by the cadence calculation unit 351e. Created and output to the measurement module wireless transmission unit 309.
  • the measurement module storage unit 353 stores various types of information.
  • the various types of information are, for example, a control program for the measurement module control unit 351 and temporary information required when the measurement module control unit 351 performs control.
  • the measurement module storage unit 353 stores a reference angle storage unit 355 and a constant storage unit 357 in addition to the information described above.
  • the reference angle storage unit 355 is configured by a non-volatile memory such as a flash memory, for example, and stores an angle with respect to the vertical direction of the frame 3 on which the magnet 503 is provided.
  • a value or the like actually measured using a protractor or the like is stored in advance by referring to a design drawing or specifications of the frame 3 in advance.
  • the constant storage unit 357 is composed of, for example, a ROM (Read Only Memory), and stores a correspondence table between a rotation angle and a rotation angle obtained by multiplying a constant K described later.
  • the magnetic sensor 373 is switched ON / OFF when the magnet 503 approaches. When the magnetic sensor 373 is turned on, the magnetic sensor 373 outputs an information signal indicating that to the measurement module control unit 351.
  • the acceleration sensor 371 is bonded to the crank 105 and integrated.
  • the acceleration sensor 371 may be appropriately selected from known methods such as a capacitance type and a piezoresistive type.
  • the acceleration sensor 371 includes a first acceleration sensor 371a and a second acceleration sensor 371b.
  • FIG. 4 shows an example of the arrangement of the acceleration sensor 371 in the present embodiment on the crank 105.
  • the acceleration sensor 371 is bonded to the inner surface 119 of the crank 105.
  • the inner surface of the crank 105 is a surface on which the crankshaft 107 is protruded (connected), and is a surface (side surface) parallel to a plane including a circle defined by the rotational motion of the crank 105.
  • the outer surface 120 of the crank 105 is a surface on which the pedal crankshaft 115 is protruded (connected) so as to face the inner surface 119. That is, it is a surface on which the pedal 103 is rotatably provided.
  • the upper surface 117 of the crank 105 is one of the surfaces extending in the longitudinal direction in the same direction as the inner surface 119 and the outer surface 120 and orthogonal to the inner surface 119 and the outer surface 120.
  • a lower surface 118 of the crank 105 is a surface facing the upper surface 117.
  • the acceleration sensor 371 is described as being bonded to the inner surface 119 of the crank 105. However, the acceleration sensor 371 may be bonded to the outer surface 120, the upper surface 117, or the lower surface 118, or provided inside the crank 105. May be.
  • the first acceleration sensor 371a and the second acceleration sensor 371b have a detection direction parallel to the longitudinal direction of the crank 105, that is, parallel to the central axis C1 of the inner surface 119 and provided at different distances from the center of the crank shaft 107. It has been. In the example of FIG. 4, the first acceleration sensor 371a is provided at a position closer to the center of the crankshaft 107 than the second acceleration sensor 371b. The first acceleration sensor 371a and the second acceleration sensor 371b have a detection direction that is parallel to the longitudinal direction of the crank 105. Further, the first acceleration sensor 371a and the second acceleration sensor 371b may not be provided on a straight line as shown in FIG.
  • the detection result (output) of the acceleration sensor 371 is output to the measurement module control unit 351.
  • analog information may be converted into digital information by an A / D converter (not shown).
  • FIG. 5 is an explanatory diagram for the acceleration detected by the acceleration sensor 371 when the crank 105 is stationary.
  • the longitudinal direction in FIG. 5 is the longitudinal direction of the crank 105, and the direction toward the tip of the arrow indicates the direction from the crankshaft 107 toward the pedal crankshaft 115.
  • it is in the state which has stopped at the position shifted
  • the crank 105 rotates, it becomes as shown in FIG.
  • the first acceleration sensor 371a is provided at a distance r1 from the center of the crankshaft 107
  • the second acceleration sensor 371b is provided at a distance r2 from the center of the crankshaft 107. Further, r1 ⁇ r2.
  • centrifugal force is generated in the longitudinal direction of the crank 105 (direction from the crankshaft 107 to the pedal crankshaft 115, that is, the normal direction of rotation of the crank 105) together with the gravitational acceleration. Join.
  • the acceleration of the centrifugal force increases as the distance from the rotation center (center of the crankshaft 107) increases. Further, the acceleration (instantaneous acceleration) obtained by adding the gravitational acceleration and the acceleration of centrifugal force is added to the first acceleration sensor 371a, and the acceleration (acceleration of the gravity acceleration and the acceleration of centrifugal force) is added to the second acceleration sensor 371b.
  • Instantaneous acceleration As described above, since the detection direction of the acceleration sensor 371 is parallel to the longitudinal direction of the crank 105, the longitudinal component of the instantaneous acceleration is actually detected.
  • the instantaneous acceleration of the first acceleration sensor 371a is expressed by the following equation (4)
  • the instantaneous acceleration of the second acceleration sensor 371b is expressed by the following equation (5).
  • the detection value (output value) of the first acceleration sensor 371a is expressed by the following equation (6)
  • the detection value (output value) of the second acceleration sensor 371b is expressed by the following equation (7).
  • the value obtained by integrating ⁇ 1 to ⁇ 7 calculated at the sampling frequency fs that is a predetermined time interval is the rotation angle ⁇ from the reference position.
  • the equation (12) can be expressed as the equation (14). That is, the square root of the difference between the output value of the second acceleration sensor 371b and the output value of the first acceleration sensor 371a may be obtained and integrated.
  • a2 t and a1 t indicate the t- th output values of the output value a1 of the first acceleration sensor 371a and the output value a2 of the second acceleration sensor 371b, respectively.
  • the value (K ⁇ 30 °) of the equation (14) at every predetermined angle such as every 30 ° is previously stored in the measurement module storage unit 353 as the constant storage unit 357, and is calculated by the equation (14).
  • the predetermined angle is detected by comparing with the result. That is, in this embodiment, the rotation angle estimation unit 351b functions as an acquisition unit and an output unit, and uses the square root of the difference between the output value of the first acceleration sensor and the output value of the second acceleration sensor acquired at predetermined time intervals. Based on this, an angle is output as information on the rotation angle of the crank. In addition, as information regarding the rotation angle of the crank, not the angle but the calculated K ⁇ ⁇ may be output as it is and converted into the angle ( ⁇ ) at the output destination.
  • the magnetic sensor 373 and the magnet 503 used for cadence measurement are used. Since the magnet 503 is provided on the frame 3 as described above, the angle ⁇ 0 with respect to the vertical direction of the frame 3 on which the magnet 503 is provided is used as a reference position as shown in FIG.
  • the angle ⁇ 0 of the reference position is stored in the reference angle storage unit 355 in advance by, for example, referring to the design drawing or specification of the frame 3 or measuring in advance with a protractor or the like.
  • the rotation angle estimation unit 351b notifies the rotation angle estimation unit 351b that the reference position is detected, and the rotation angle estimation unit 351b notifies the rotation angle estimation unit 351c.
  • the value calculated by the equation (14) is reset.
  • the magnet 503 functions as a detected unit
  • the magnetic sensor 373 functions as a detection unit
  • the reference angle detection unit 351c, the rotation angle estimation unit 351b, and the reference angle storage unit 355 function as a reference position setting unit.
  • the angle calculated by the equation (14) is an angle from the angle ⁇ 0 of the reference position and is not an angle based on the vertical direction. Therefore, in order to obtain an angle of 0 ° when the tip of the crank 105 faces directly upward, the angle ⁇ 0 of the reference position may be added to the angle calculated by the equation (14) as described above. . If the addition results in 360 ° or more, 360 may be subtracted.
  • the measurement module control unit 351 (rotation angle estimation unit 351b, reference angle detection unit 351c, transmission data creation unit 351d), and measurement module storage unit 353 (reference angle storage unit 355, constant storage unit). 357), the acceleration sensor 371 (the first acceleration sensor 371a and the second acceleration sensor 371b), the magnetic sensor 373, and the magnet 503 constitute the rotation angle detection device 310 according to the present embodiment.
  • the magnetic sensor 373 and the magnet 503 are used as the detecting unit and the detected unit.
  • the present invention is not limited to this, and can be installed on the crank 105 and the frame 3 such as an optical sensor or a mechanical sensor. Any sensor capable of detecting one rotation may be used.
  • the power sensor 368 has a strain gauge 369 and a measurement module strain detection circuit 365.
  • the strain gauge 369 is bonded to the crank 105 and integrated.
  • the strain gauge 369 includes a first strain gauge 369a, a second strain gauge 369b, a third strain gauge 369c, and a fourth strain gauge 369d (see FIG. 9 and the like). Each terminal of the strain gauge 369 is connected to the measurement module strain detection circuit 365.
  • FIG. 9 shows an example of the arrangement of the strain gauge 369 on the crank 105 in this embodiment.
  • the strain gauge 369 is bonded to the inner surface 119 of the crank 105.
  • the first strain gauge 369a and the second strain gauge 369b have a detection direction parallel to the longitudinal direction of the crank 105, that is, parallel to the central axis C1 of the inner surface 119 and symmetrical to the central axis C1 of the inner surface 119. It is provided to become.
  • the third strain gauge 369c is provided on the central axis C1, and the detection direction is parallel to the central axis C1, and is provided between the first strain gauge 369a and the second strain gauge 369b.
  • the fourth strain gauge 369d is provided on the central axis C1 in the detection direction perpendicular to the longitudinal direction of the crank 105, that is, perpendicular to the central axis C1 of the inner surface 119.
  • the direction parallel to the central axis C1 (the vertical direction in FIG. 9) that is the axis extending in the longitudinal direction of the crank 105, that is, the direction parallel to the longitudinal direction of the crank 105 is the first strain gauge 369a
  • the detection direction of the strain gauge 369b and the third strain gauge 369c is the detection direction of the fourth strain gauge 369d in the direction perpendicular to the central axis C1 (the lateral direction in FIG. 9), that is, the direction perpendicular to the longitudinal direction of the crank 105. It becomes. Accordingly, the detection directions of the first strain gauge 369a to the third strain gauge 369c and the fourth strain gauge 369d are orthogonal to each other.
  • or the 4th strain gauge 369d is not restricted to FIG. In other words, other arrangements may be used as long as a parallel or vertical relationship with the central axis C1 is maintained.
  • the first strain gauge 369a and the second strain gauge 369b are arranged symmetrically across the central axis C1
  • the third strain gauge 369c and the fourth strain gauge 369d are arranged on the central axis C1, as will be described later. This is preferable because each deformation can be detected with high accuracy.
  • crank 105 is described as a simple rectangular parallelepiped, but the corners may be rounded or a part of the surface may be formed of a curved surface depending on the design or the like. Even in such a case, each deformation described later can be detected by arranging the strain gauge 369 so as to maintain the above-described arrangement as much as possible. However, the detection accuracy decreases as the relationship (parallel or vertical) with the center axis C1 is shifted.
  • the measurement module strain detection circuit 365 is connected to the first strain gauge 369a, the second strain gauge 369b, the third strain gauge 369c, and the fourth strain gauge 369d, and outputs the strain amount of the strain gauge 369 as a voltage.
  • the output of the measurement module strain detection circuit 365 is converted from analog information to strain information signals that are digital information by an A / D converter (not shown). Then, the strain information signal is output to the propulsive force calculation unit 351a of the measurement module control unit 351.
  • the measurement module strain detection circuit 365 includes a first detection circuit 373a and a second detection circuit 373b that are two bridge circuits.
  • the first strain gauge 369a and the second strain gauge 369b are connected in this order from the power source Vcc. That is, the first strain gauge 369a and the second strain gauge 369b are connected in series with the power supply Vcc.
  • the fixed resistor R and the fixed resistor R are connected in this order from the power source Vcc.
  • the third strain gauge 369c and the fourth strain gauge 369d are connected in this order from the power source Vcc. That is, the third strain gauge 369c and the fourth strain gauge 369d are connected in series with the power supply Vcc.
  • the fixed resistor R and the fixed resistor R are connected in this order from the power source Vcc.
  • the two fixed resistors R are shared by the first detection circuit 373a and the second detection circuit 373b.
  • the two fixed resistors R have the same resistance value.
  • the two fixed resistors R have the same resistance value as that before the compression or expansion of the strain gauge 369 occurs.
  • the first strain gauge 369a to the fourth strain gauge 369d have the same resistance value.
  • the detection direction of the strain gauge 369 is the direction in which the wiring extends, and as described above, the first strain gauge 369a, the second strain gauge 369b, and the third strain gauge 369c are parallel to the central axis C1,
  • the fourth strain gauge 369d is in a direction perpendicular to the central axis C1.
  • the resistance value of the first strain gauge 369a decreases and the resistance value of the second strain gauge 369b increases. It becomes higher and the potential Vr does not change. That is, a potential difference is generated between the potential Vab and the potential Vr.
  • the resistance value of the first strain gauge 369a increases and the resistance value of the second strain gauge 369b decreases. The potential Vr does not change. That is, a potential difference is generated between the potential Vab and the potential Vr.
  • both the first strain gauge 369a and the second strain gauge 369b When both the first strain gauge 369a and the second strain gauge 369b are compressed, the resistance value of both the first strain gauge 369a and the second strain gauge 369b decreases, so the potential difference between the potential Vab and the potential Vr is almost zero. It becomes.
  • both the first strain gauge 369a and the second strain gauge 369b are extended, the resistance value of both the first strain gauge 369a and the second strain gauge 369b increases, so that the potential difference between the potential Vab and the potential Vr is almost zero. It becomes.
  • the second detection circuit 373b operates similarly to the first detection circuit 373a. That is, when the third strain gauge 369c is compressed and the fourth strain gauge 369d is expanded, the potential Vcd is increased, the potential Vr is decreased, and a potential difference is generated between the potential Vcd and the potential Vr. When the third strain gauge 369c is expanded and the fourth strain gauge 369d is compressed, the potential Vcd is decreased, the potential Vr is increased, and a potential difference is generated between the potential Vcd and the potential Vr. When both the third strain gauge 369c and the fourth strain gauge 369d are compressed and when both the third strain gauge 369c and the fourth strain gauge 369d are expanded, the potential difference between the potential Vcd and the potential Vr becomes almost zero. .
  • the first detection circuit includes a connection point between the first strain gauge 369a and the second strain gauge 369b where the potential Vab of the first detection circuit 373a can be measured, and a connection point between the two fixed resistors R capable of measuring the potential Vr.
  • the output of 373a (hereinafter referred to as A output).
  • the connection point between the third strain gauge 369c and the fourth strain gauge 369d that can measure the potential Vcd of the second detection circuit 373b, and the connection point of the two fixed resistors R that can measure the potential Vr are represented by the second detection circuit 373b.
  • Output (hereinafter referred to as B output).
  • the A output and B output become strain information.
  • FIG. 11 shows a deformed state of the right crank 105R when a force (stepping force) is applied by the user.
  • (A) is a plan view seen from the upper surface 117 of the right crank 105R
  • (b) is a plan view seen from the inner surface 119 of the right crank 105R
  • (c) is seen from the end of the right crank 105R on the crankshaft 107 side. It is a top view.
  • the right crank 105R will be described, but the same applies to the left crank 105L.
  • the bending deformation x is a deformation in which the right crank 105R is bent so as to bend from the upper surface 117 toward the lower surface 118 or from the lower surface 118 toward the upper surface 117. Is a deformation caused by That is, distortion due to deformation generated in the rotation direction of the crank 105 (distortion generated in the rotation direction of the crank 105) is detected, and rotation direction distortion generated in the crank 105 can be detected by detecting the bending deformation x.
  • the bending deformation y is a deformation in which the right crank 105R bends from the outer surface 120 toward the inner surface 119 or from the inner surface 119 toward the outer surface 120, and the loss force Fr.
  • the tensile deformation z is a deformation caused by the right force 105R being stretched or compressed in the longitudinal direction and caused by the loss force Fr. That is, the strain due to the deformation generated in the direction in which the crank 105 is pulled or pushed in the longitudinal direction (strain generated in the direction parallel to the longitudinal direction) is detected. The strain in the tensile direction can be detected.
  • the torsional deformation rz is that the right crank 105R is deformed so as to be twisted, and is generated by the propulsive force Ft. That is, distortion due to deformation generated in the direction in which the crank 105 is twisted is detected, and distortion in the torsion direction generated in the crank 105 can be detected by detecting the torsional deformation rz.
  • each deformation may occur in the direction opposite to the arrow. .
  • the measurement module strain detection circuit 365 is arranged as shown in FIG. 9 and connected to the first strain gauge 369a, the second strain gauge 369b, the third strain gauge 369c, and the fourth strain gauge 369d as shown in FIG.
  • a method for detecting (measuring) the bending deformation x, the bending deformation y, the tensile deformation z, and the torsional deformation rz will be described.
  • the output A of the first detection circuit 373a is a positive output (the potential Vab is high and the potential Vr is low).
  • the output A of the first detection circuit 373a is a negative output (the potential Vab is low and the potential Vr is high).
  • Bending deformation y causes the right crank 105R to deform from the outer surface 120 toward the inner surface 119 or in the opposite direction.
  • the resistance value of both decreases. Therefore, the output A of the first detection circuit 373a is zero (there is no potential difference between the potential Vab and the potential Vr).
  • both the first strain gauge 369a and the second strain gauge 369b are stretched, so that the resistance value of both increases. For this reason, the output A of the first detection circuit 373a is zero.
  • the tensile deformation z deforms so that the right crank 105R is stretched or compressed in the longitudinal direction.
  • both the first strain gauge 369a and the second strain gauge 369b are extended, so that the resistance value of both increases. For this reason, the output A of the first detection circuit 373a is zero.
  • both the first strain gauge 369a and the second strain gauge 369b are compressed, so that the resistance value of both decreases. For this reason, the output A of the first detection circuit 373a is zero.
  • the twist deformation rz deforms so that the right crank 105R is twisted.
  • both the first strain gauge 369a and the second strain gauge 369b are stretched, so that the resistance value of both increases. For this reason, the output A of the first detection circuit 373a is zero.
  • both the first strain gauge 369a and the second strain gauge 369b are extended, so that the resistance value of both increases. For this reason, the output A of the first detection circuit 373a is zero.
  • the first detection circuit 373a is connected to the first strain gauge 369a and the second strain gauge 369b, and detects the rotational strain generated in the crank 105.
  • the B output of the second detection circuit 373b is zero.
  • Bending deformation y causes the right crank 105R to deform from the outer surface 120 toward the inner surface 119 or in the opposite direction.
  • the third strain gauge 369c is compressed and thus the resistance value is decreased, and the fourth strain gauge 369d is expanded and the resistance value is increased. Therefore, the B output of the second detection circuit 373b is a positive output (the potential Vcd is high and the potential Vr is low).
  • the third strain gauge 369c is expanded and thus the resistance value is increased, and the fourth strain gauge 369d is compressed and the resistance value is decreased. Therefore, the output B of the second detection circuit 373b is a negative output (the potential Vcd is low and the potential Vr is high).
  • the tensile deformation z deforms so that the right crank 105R is stretched or compressed in the longitudinal direction.
  • the third strain gauge 369c is extended and the resistance value is increased, and the fourth strain gauge 369d is compressed and the resistance value is decreased. Therefore, the B output of the second detection circuit 373b is a negative output.
  • the third strain gauge 369c is compressed and thus the resistance value is decreased, and the fourth strain gauge 369d is expanded and the resistance value is increased. Therefore, the B output of the second detection circuit 373b is a positive output.
  • the twist deformation rz deforms so that the right crank 105R is twisted.
  • the resistance value increases because the third strain gauge 369c is expanded, and the resistance value does not change because the fourth strain gauge 369d does not deform in the detection direction. . Therefore, the B output of the second detection circuit 373b is a negative output.
  • the B output of the second detection circuit 373b is a negative output.
  • the second detection circuit 373b is connected to the third strain gauge 369c and the fourth strain gauge 369d, and detects the inward / outward strain or tensile strain generated in the crank 105.
  • the propulsive force calculation unit 351a determines that the propulsive force Ft is the following equation (15) and the loss force Fr is the following (16).
  • Each is calculated by an equation.
  • the tensile deformation z is very small compared to the bending deformation y and can be ignored. That is, the values calculated by the equations (15) and (16) are values relating to the load applied to the crank 105 when the crank 105 rotates.
  • A is the A output value at the time of calculating the propulsive force Ft (or loss force Fr)
  • A0 is the A output value at no load
  • B is B at the time of calculating the propulsive force Ft (or loss force Fr).
  • the output value, B0 is the B output value when there is no load
  • p, q, s, u are coefficients, which are values calculated by simultaneous equations consisting of the following equations (17) to (20).
  • Am is an A output value when m [kg] is placed on the pedal 103 with the angle of the crank 105 facing forward in the horizontal direction (a state in which the crank 105 extends horizontally and in the direction of the front wheel 5).
  • Be is the B output value when the angle of the crank 105 is horizontally forward and m [kg] is placed on the pedal 103.
  • Ae is an A output value when m [kg] is placed on the pedal 103 with the angle of the crank 105 being vertically downward (a state in which the crank 105 extends vertically and toward the ground).
  • Bm is the B output value when the angle of the crank 105 is vertically downward and m [kg] is placed on the pedal 103.
  • the thrust Ft can be calculated by substituting A and B into the equation (15).
  • the A output is corrected using the B output.
  • strain gauges 369 and the configuration of the bridge circuit are not limited to the configurations shown in FIGS.
  • the number of strain gauges 369 is not limited to four, and the number of bridge circuits is not limited to one.
  • any configuration that can calculate the propulsive force Ft and the loss force Fr may be used.
  • the cycle computer 201 includes a cycle computer display unit 203, a cycle computer operation unit 205, a cycle computer wireless reception unit 209, a cycle computer storage unit 253, and a cycle computer control unit 251.
  • the cycle computer display unit 203 displays various types of information based on user instructions and the like.
  • the propulsive force Ft and the loss force Fr are visualized and displayed.
  • the visualization method may be any method, but based on the rotation angle of the crank 105 transmitted from the measurement module 301, for example, the propulsive force Ft and the loss when the rotation angle of the crank 105 is 30 °.
  • the force Fr can be displayed as a vector.
  • any method such as graph display, color-coded display, symbol display, and three-dimensional display may be used. Also, a combination thereof may be used.
  • the cycle computer operation unit 205 receives a user instruction (input). For example, the cycle computer operation unit 205 receives a display content instruction from the user on the cycle computer display unit 203.
  • the cycle computer wireless reception unit 209 receives transmission data (propulsion force Ft, loss force Fr, rotation angle and cadence of the crank 105) transmitted from the measurement module 301.
  • the cycle computer storage unit 253 has a RAM and a ROM.
  • the ROM stores a control program and various parameters, constants, and the like for converting the propulsive force Ft and the loss force Fr into data that is visually displayed on the cycle computer display unit 203.
  • the cycle computer control unit 251 comprehensively controls the cycle computer 201. Further, the measurement module 301 may be comprehensively controlled. The cycle computer control unit 251 converts the propulsive force Ft and the loss force Fr into data that is visually displayed on the cycle computer display unit 203.
  • step ST11 the processing of the measurement module 301 is shown in FIG.
  • step ST11 values detected by the first acceleration sensor 371a and the second acceleration sensor 371b are acquired.
  • K ⁇ ⁇ (t) is calculated by the above-described equation (14). That is, step ST11 functions as an acquisition process and an output process.
  • step ST13 it is determined whether or not the rotation angle detected in step ST11 is an angle of every 30 °. If it is an angle of every 30 ° (in the case of YES), the process proceeds to step ST15. Returns to step ST11. Whether or not the rotation angle is an angle of every 30 ° can be determined by comparing the calculated value of K ⁇ ⁇ with the value of the constant storage unit 357 as described above. In this step, the value calculated in step ST11 is converted into an angle with respect to the vertical direction based on the angle ⁇ 0 of the reference position stored in the reference angle storage unit 355.
  • step ST11 until K ⁇ ⁇ is calculated, unless it is determined that the angle is every 30 ° in this step, it is not converted into a rotation angle. That is, in this embodiment, step ST13 is also an output process. In this embodiment, every 30 ° is used, but of course, every other angle such as every 45 ° may be used.
  • step ST15 the measurement module strain detection circuit 365 is driven. That is, a power source voltage is applied to the bridge circuit as shown in FIG.
  • step ST17 the propulsive force Ft and the loss force Fr are calculated based on the outputs (A output and B output) from the measurement module strain detection circuit 365.
  • the transmission data creation unit 351d transmits the calculated propulsive force Ft, loss force Fr, rotation angle, and cadence as transmission data via the measurement module wireless transmission unit 309.
  • the transmitted propulsive force Ft and loss force Fr, rotation angle, and cadence are received by the cycle computer radio reception unit 209 of the cycle computer 201.
  • the cadence need not be transmitted every time and may be transmitted once per rotation, so in the present embodiment, it may be transmitted once every 12 times.
  • step ST71 when the cycle computer control unit 251 receives the propulsive force Ft, the loss force Fr, the rotation angle, or the cadence, an interruption is performed. That is, when the cycle computer control unit 251 detects that the cycle computer wireless reception unit 209 has received the propulsive force Ft, the loss force Fr, the rotation angle, or the cadence, the cycle computer control unit 251 interrupts the processing up to that point ( Interrupt) to start the processing from step ST73.
  • step ST73 the cycle computer control unit 251 causes the cycle computer display unit 203 to display the propulsive force Ft, the loss force Fr, and the cadence for each rotation angle.
  • the cycle computer display unit 203 displays the propulsive force Ft and the loss force Fr as a vector for each rotation angle of the crank 105, or displays a cadence value as a numerical value.
  • the propulsive force Ft and the loss force Fr are displayed with arrows or the like at every predetermined rotation angle (30 °) of the crank 105.
  • step ST75 the cycle computer control unit 251 stores the propulsive force Ft, the loss force Fr, and the cadence in the cycle computer storage unit 253 of the cycle computer storage unit 253. Thereafter, the cycle computer control unit 251 performs other processes until the interrupt of step ST51 is performed again.
  • the first acceleration sensor 371a and the second acceleration sensor 371b are arranged on the crank 105 attached to the crankshaft 107, detect accelerations a1 and a2 in a direction parallel to the longitudinal direction of the crank 105,
  • the rotation angle estimation unit 351b acquires the acceleration a1 that is an output value of the first acceleration sensor 371a and the acceleration a2 that is an output value of the second acceleration sensor 371b at a predetermined time interval ⁇ t. Then, the value calculated based on the acceleration a1 and the acceleration a2 (the square root of a2-a1) is integrated to output the rotation angle ⁇ of the crank 105.
  • the acceleration component of the centrifugal force in the longitudinal direction (detection axis direction) of the crank of the acceleration sensor 371 can be calculated.
  • the rotation angle of the crank 105 can be calculated and detected based on the acceleration component of the centrifugal force. Therefore, since no magnet is used for the angle detection itself, the cost can be reduced and it is not affected by dust or iron sand, so that the durability can be improved. Further, since the angular velocity sensor is not used, the power consumption can be reduced.
  • an angular velocity sensor since an angular velocity sensor is not used, it is possible to reduce power consumption.
  • An angular velocity sensor such as a gyro sensor, generally consumes more power than an acceleration sensor because a vibrator or the like must be constantly vibrated. Therefore, as in this embodiment, by detecting the rotation angle only with the acceleration sensor 371, the power consumption can be reduced and the driving time of the battery or the like can be extended.
  • the power sensor 368 is operated when the detected rotation angle is an angle of every 30 °, the operation period of the power sensor 368 can be limited, and the power consumption can be further reduced.
  • the measurement module control unit 351 outputs information on the rotation angle of the crank based on the square root of the calculated value of a2-a1, the gravitational acceleration applied to the acceleration sensor from the two accelerations a1 and a2 is canceled.
  • the acceleration component of the centrifugal force in the longitudinal direction (detection axis direction) of the crank 105 can be calculated.
  • the K ⁇ 30 ° value is stored in the constant storage unit 357 in advance, and the measurement module control unit 351 (rotation angle estimation unit 351b) outputs the rotation angle of the crank 105 based on the constant storage unit 357. Therefore, it is not necessary to perform an operation with a constant, and the processing of the operation can be reduced.
  • the reference position setting unit that sets the reference position of the rotation angle of the crank 105 includes a magnet 503 that is fixedly disposed on the frame 3 and a magnetic sensor 373 that is disposed on the crank 105 and detects the magnet 503. Configured. In this way, the position of the frame 3 can be set as the reference position (reference angle). Moreover, since it can serve as a cadence sensor, a dedicated sensor or the like is not required.
  • the first acceleration sensor 371a and the second acceleration sensor 371b are disposed on one crank 105, but one acceleration sensor is provided for each of the cranks 105 on both sides, that is, the crank 105R and the crank 105L. May be arranged.
  • the absolute value of the distance from the crankshaft 107 of each acceleration sensor may be the same.
  • the distance from the crankshaft 107 may be expressed as a positive number for one crank and a negative number for the other crank.
  • the measured value a (a1 or a2) of the acceleration sensor on the side where the distance is expressed by a negative number may be expressed by multiplying by a negative number ( ⁇ 1).
  • the predetermined time interval is a time based on the sampling frequency fs, that is, a constant time interval, but is not limited to a constant time interval.
  • the sampling frequency fs becomes a variable, and the square root of the difference between the output value of the second acceleration sensor 371b and the output value of the first acceleration sensor 371a is multiplied by the time interval and integrated. That's fine.
  • the angle of the frame 3 provided with the magnet 503 with respect to the vertical direction needs to be measured in advance using a protractor or the like by referring to the design drawing and specifications of the frame in advance. Then, the point which measures the angle with respect to the perpendicular direction of the flame
  • frame 3 is different, without requiring them.
  • FIG. 13 shows the configuration of this example.
  • a third acceleration sensor 371c, an LED 374, and a setting unit 375 are added to FIG.
  • the third acceleration sensor 371c differs from the first acceleration sensor 371a and the second acceleration sensor 371b in that the direction parallel to the short direction of the crank 105 (tangential direction of rotation of the crank 105) is the detection direction. Further, the third acceleration sensor 371c is not an individual sensor, and one of the first acceleration sensor 371a and the second acceleration sensor 371b may be a biaxial acceleration sensor.
  • the LED 374 is a light emitting diode that emits light in response to an information signal indicating that the magnetic sensor 373 is turned on. That is, the LED 374 functions as a notification unit that notifies that the magnetic sensor 373 (detection unit) has detected the magnet 503 (detected unit). Note that the notification unit is not limited to notification by display such as the LED 374 but may be notification by a buzzer or the like.
  • the setting unit 375 is configured by a push button, for example, and can be operated by the user in accordance with the lighting of the LED 374.
  • the setting unit 375 is a timing instruction unit that instructs the rotation angle estimation unit 351b (acquisition unit) to acquire the output value of the first acceleration sensor 371a or the second acceleration sensor 371b and the output value of the third acceleration sensor 371c. Function.
  • the acceleration sensor 371 When the acceleration sensor 371 is arranged as in the present embodiment, the first acceleration sensor 371a and the second acceleration sensor 371b detect the longitudinal acceleration of the crank 105, and the third acceleration sensor 371c The acceleration in the short direction is detected.
  • FIG. 14 shows an example in the case of gravitational acceleration G. As shown in FIG. 13, the acceleration component in the longitudinal direction can be detected by the first acceleration sensor 371a or the second acceleration sensor 371b, and the acceleration component in the short direction can be detected by the third acceleration sensor 371c.
  • the relationship between the output values of these accelerations and the rotation angle of the crank 105 is as shown in the graph in FIG. From this graph, the acceleration in the short-side direction has a positive value when 0 ° ⁇ ⁇ ⁇ 180 °, and a negative value when 180 ° ⁇ ⁇ ⁇ 360 °. Therefore, the angle of the frame 3 can be detected by referring to both the acceleration in the longitudinal direction and the acceleration in the short direction.
  • the crank 105 when the crank 105 is rotationally moved to a position parallel to the frame 3, the magnetic sensor 373 detects the magnet 503. Then, an information signal indicating that the magnetic sensor 373 is turned on is output, and the LED 374 emits light. Therefore, the crank 105 is stopped at that position, and the setting unit 375 is operated.
  • the rotation angle estimation unit 351b obtains the gravitational acceleration when the setting unit 375 is operated, obtains the crank angle, that is, the angle of the frame 3, and stores the obtained angle of the frame 3 in the reference angle storage unit 355.
  • the setting unit 375 outputs the output value of the first acceleration sensor 371a or the second acceleration sensor 371b and the output value of the third acceleration sensor 371c based on the notification that the LED 374 (notification unit) detects the magnet 503 (detected unit). Are acquired by the rotation angle estimation unit 351b (acquisition unit). Then, the rotation angle estimation unit 351b (reference position setting unit) sets the reference position based on the acquired output value of the first acceleration sensor 371a or the second acceleration sensor 371b and the output value of the third acceleration sensor 371c. is doing.
  • the third acceleration sensor 371c that detects acceleration in a direction parallel to the short direction of the crank 105, the LED 374 that notifies that the magnetic sensor 373 has detected the magnet 503, and the first acceleration sensor 371a.
  • a setting unit 375 that instructs the timing for acquiring the output value of the second acceleration sensor 371b and the output value of the third acceleration sensor 371c is provided. Then, the setting unit 375 instructs acquisition of the output value of the first acceleration sensor 371a or the second acceleration sensor 371b and the output value of the third acceleration sensor 371c based on the notification that the LED 374 detects the magnet 503, and the rotation angle.
  • the estimation unit 351b sets the reference position based on the output value of the first acceleration sensor 371a or the second acceleration sensor 371b and the output value of the third acceleration sensor 371c. By doing in this way, the angle with respect to the vertical direction of the said position is computable based on the gravitational acceleration added to the crank 105 by which the magnet 503 was detected. Therefore, it is not necessary to investigate the angle in the vertical direction of the frame 3 of the bicycle 1 or to measure it with a protractor or the like.
  • the notification unit and the timing instruction unit are provided in the measurement module 301, but may be provided separately.
  • the cycle computer display unit 203 and the cycle computer operation unit 205 of the cycle computer 201 may also function.
  • FIGS. a rotation angle detection apparatus according to a third embodiment of the present invention will be described with reference to FIGS.
  • the same parts as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
  • FIG. 17 is a graph of output values of the first acceleration sensor 371a or the second acceleration sensor 371b.
  • FIG. 17A is a graph when the crank 105 is stationary, and
  • FIG. 17B is a graph when the crank 105 is rotating. Since the centrifugal force is applied when the crank 105 rotates, an offset is applied to the curve.
  • the angle of the crank 105 is 180 ° (the direction of gravity, that is, the tip of the crank 105 faces directly below). Therefore, by detecting this, 180 ° can be set as the reference position.
  • the rotation angle estimation unit 351b (reference position setting unit) sets the reference position based on the maximum value of the output value of either the first acceleration sensor 371a or the second acceleration sensor 371b.
  • the case where the output value of one of the first acceleration sensor 371a and the second acceleration sensor 371b is the maximum value is set as the reference position. In this way, it is possible to detect when the acceleration detected by one acceleration sensor is in the direction of gravity, that is, when it is in the vertical direction. Further, since the output value of the acceleration sensor 371 for detecting the rotation angle of the crank 105 can be used, there is no need to add another sensor or the like.
  • the minimum value may be used instead of the maximum value.
  • the detected reference position is 0 ° (in the opposite direction to gravity, that is, the tip of the crank 105 faces directly above).
  • the configuration is the same as in FIG. 16, but the reference position is obtained from the output values of the first acceleration sensor 371a and the second acceleration sensor 371b.
  • the output value of the first acceleration sensor 371a and the output value of the second acceleration sensor 371b are expressed as in the expressions (6) and (7).
  • the acceleration of the centrifugal force is proportional to the distance from the center of the crankshaft 107, the acceleration component of the centrifugal force can be canceled when r2 ⁇ a1 ⁇ r1 ⁇ a2. That is, the following equation (21) is derived from the equations (1) and (4) to (7).
  • the rotation angle estimator 351b (reference position setting unit) multiplies the distance from the crankshaft 107 (rotary axis) to the second acceleration sensor 371b by the output value of the first acceleration sensor 371a and the crankshaft 107 ( The reference position is set based on the difference between the distance from the rotation axis) to the first acceleration sensor 371a and the value obtained by multiplying the output value of the second acceleration sensor 371b.
  • a threshold value may be provided for the calculated value of the gravitational acceleration in the longitudinal direction as in the third embodiment.
  • the reference position is set based on r2 ⁇ a1-r1 ⁇ a2.
  • the acceleration component of the centrifugal force detected by each acceleration sensor can be canceled, and only the gravitational acceleration component can be obtained. Therefore, when the gravitational acceleration is 1 [G], it is assumed that the crank 105 is directed downward 180 °, and when the gravitational acceleration is ⁇ 1 [G], it is assumed that the crank 105 is directed directly above 0 °. Can be determined.
  • the gravitational acceleration in the longitudinal direction is not limited to 1 [G] or ⁇ 1 [G], and the reference position may be 0 [G].
  • [0] is determined to be 90 [deg.]
  • the past longitudinal acceleration of gravity such as the previous calculated value
  • the past longitudinal direction If the gravitational acceleration is positive, it can be determined as 270 °. That is, when the negative value is “0”, it is determined as 90 °, and when the positive value is “0”, it is determined as 270 °.
  • FIGS. a rotation angle detection apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS.
  • the same parts as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
  • the output of the acceleration sensor 371 is subjected to a low-pass filter (LPF) process, and the rotation angle estimation unit 351b2 corrects the amount delayed by the low-pass filter process. That is, the LPF 372 functions as a filter unit.
  • LPF low-pass filter
  • the acceleration sensor 371 Since a vehicle equipped with a rotation angle detection device such as a bicycle is subjected to various vibrations from the outside, the acceleration sensor 371 often includes an acceleration component other than the acceleration component of gravity acceleration or centrifugal force in its output value. Accordingly, the output of the acceleration sensor 371 is subjected to low-pass filter processing using a digital filter such as an FIR (finite impulse response) filter or an IIR (infinite impulse response) filter with the LPF 372, thereby causing vibrations included in the output of the acceleration sensor 371. Remove noise components.
  • a digital filter such as an FIR (finite impulse response) filter or an IIR (infinite impulse response) filter with the LPF 372, thereby causing vibrations included in the output of the acceleration sensor 371.
  • an analog filter may be used instead of a digital filter.
  • the rotation angle estimation unit 351b2 corrects the rotation angle by performing a calculation as shown in the equation (24) described later. That is, the rotation angle estimation unit 351b2 functions as a delay angle correction unit.
  • the acceleration a far from the centrifugal force can be calculated by the equation (9) shown in the first embodiment.
  • the rotation acceleration is calculated by measuring the time between the half rotations, and the acceleration of the centrifugal force for correction is obtained from the value. You may do it. Then, during the half rotation, the acceleration of the centrifugal force calculated from the previous half rotation time is used.
  • an LPF 372 that performs filter processing on the first acceleration and the second acceleration
  • a rotation angle estimation unit 351b2 that performs angle correction processing after the filter processing is performed.
  • acceleration components other than gravitational acceleration and acceleration of centrifugal force applied to the crank 105 due to vibration or the like can be removed, and the accuracy of information regarding the rotation angle of the crank 105 can be improved.
  • the rotation angle estimation unit 351b2 can correct the delay generated by the filter processing.
  • FIGS. a rotation angle detection apparatus according to a sixth embodiment of the present invention will be described with reference to FIGS.
  • the same parts as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
  • crank 105 components other than the crank 105 that can detect the rotation angle of the crank 105 by detecting the acceleration in the longitudinal direction of the crank 105 will be described.
  • FIG. 20 is a plan view showing the chain ring 109 and the crank 105A according to the present embodiment
  • FIG. 21 is a plan view showing the crank 105A shown in FIG.
  • the crank 105A is attached to the chain ring 109 via a spider arm 77 described later.
  • the chain ring 109 has two large and small sprockets (an example of a front chain wheel) 109a and 109b.
  • the crank 105A extends radially from the crankshaft side, and has five spider arms 77 that can mount two large and small sprockets 109a and 109b at the tip, and a pedal crankshaft mounting hole 115a that is fixed to the crankshaft 107 and formed at the tip. And a crank arm 78.
  • the crank 105A is an arm member having a plurality of arm portions extending radially from the crankshaft, and corresponds to a member that rotates in conjunction with the crank.
  • a sprocket mounting portion 77a having a through hole 77b through which a fixing bolt passes and two mounting surfaces 77c for mounting the sprockets 109a and 109b is formed.
  • the large-diameter sprocket 109a has an annular gear member.
  • the gear member is made of, for example, an aluminum alloy material.
  • Gear teeth 86a with which the chain 111 is engaged are formed on the outer periphery of the gear member.
  • the small-diameter sprocket 109b has an annular gear member.
  • the gear member is made of, for example, an aluminum alloy material.
  • Gear teeth 72a with which the chain 111 is engaged are formed on the outer periphery of the gear member.
  • the spider arm 77 is formed integrally with the crank arm 78.
  • the present invention is not limited thereto and may be a separate body.
  • the rotation angle of the crank arm 78 can be calculated in the same manner as shown in the first embodiment.
  • One acceleration sensor may be disposed on the spider arm 77, the other may be disposed on the crank arm 78, or both may be disposed on the spider arm 77.
  • the detection axes of the two acceleration sensors are parallel to the longitudinal direction of the crank arm 78 and are provided on the same right or left side, The distance from the crankshaft center of the acceleration sensor needs to be different.
  • any crank or member that rotates in conjunction with the crank and that can detect the acceleration in the longitudinal direction of the crank is applicable.
  • the interlock means that the same rotation shaft as the crank rotates at the same rotation speed as the crank.
  • At least one acceleration sensor is arranged in the spider arm 77, and based on the output value of the acceleration sensor and the output value of the acceleration sensor arranged in the other spider arm 77 or the crank arm 78.
  • information about the rotation angle of the crank arm 78 (K ⁇ ⁇ , etc.) is calculated.
  • the rotational angle of the crank arm 78 can be obtained even if the acceleration sensor is arranged on a part other than the crank arm 78, and the degree of freedom of the arrangement of the acceleration sensor is increased.
  • the propulsive force, the loss force, and the rotation angle measured by the measurement module 301 are displayed in real time on the cycle computer display unit 203 of the cycle computer 201, but are not limited thereto.
  • the information output from the measurement module 301 to a recording medium such as a memory card, and the information recorded on the memory card later is read by a personal computer or the like, and the propulsive force and loss force are displayed in time series for each rotation angle of the crank 105. May be.
  • the human-powered machine in the present invention refers to a machine driven by human power equipped with a crank 105 (crank arm 78) such as a bicycle 1 or a fitness bike.
  • a crank 105 crank arm 78
  • any human-powered machine may be used as long as it is a machine that is driven by a human power equipped with the crank 105 (it is not always necessary to move locally).
  • the measuring device in the present invention may be a part of the cycle computer 201 or another independent device. Further, it may be an aggregate of a plurality of devices physically separated. In some cases, a device other than the strain gauge 369 (measurement module strain detection circuit 365) and the acceleration sensor 371 may be a device in a completely different place through communication.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Abstract

La présente invention concerne un dispositif de détection d'angle de rotation avec lequel une réduction des coûts est possible et pour lequel la durabilité peut être améliorée et avec lequel la consommation d'énergie peut être réduite. Un premier capteur d'accélération (371a) et un second capteur d'accélération (371b) sont fournis à une manivelle (105), qui est fixée à un arbre de manivelle (107) et détectent une accélération a1 et une accélération a2, qui sont dans une direction parallèle à la direction longitudinale de la manivelle (105). Dans un intervalle de temps prescrit Δt, une unité d'estimation d'angle de rotation (351b) acquiert l'accélération a1 qui est la valeur de sortie du premier capteur d'accélération (371a) et l'accélération a2 qui est la valeur de sortie du second capteur d'accélération (371b) et sur la base de l'accélération a1, de l'accélération a2 et de l'intervalle de temps prédéterminé Δt, l'unité d'estimation d'angle de rotation produit un angle de rotation θ de la manivelle (105).
PCT/JP2014/069080 2014-07-17 2014-07-17 Dispositif de détection d'angle de rotation WO2016009536A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2014/069080 WO2016009536A1 (fr) 2014-07-17 2014-07-17 Dispositif de détection d'angle de rotation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2014/069080 WO2016009536A1 (fr) 2014-07-17 2014-07-17 Dispositif de détection d'angle de rotation

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109077749A (zh) * 2018-06-26 2018-12-25 上海联影医疗科技有限公司 扫描床、医疗影像系统及其床高确定方法、装置及介质
US10458868B2 (en) 2015-12-21 2019-10-29 Shimano Inc. Bicycle crank arm assembly
US11029225B1 (en) 2019-12-27 2021-06-08 Shimano Inc. Electronic device, crank assembly with electronic device and drive train including crank assembly with electronic device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012011995A (ja) * 2010-02-16 2012-01-19 Equos Research Co Ltd 車両
WO2012053114A1 (fr) * 2010-10-22 2012-04-26 パイオニア株式会社 Dispositif de mesure et procédé de mesure
JP2014008789A (ja) * 2012-06-27 2014-01-20 Tomoki Kitawaki ペダリング状態計測装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012011995A (ja) * 2010-02-16 2012-01-19 Equos Research Co Ltd 車両
WO2012053114A1 (fr) * 2010-10-22 2012-04-26 パイオニア株式会社 Dispositif de mesure et procédé de mesure
JP2014008789A (ja) * 2012-06-27 2014-01-20 Tomoki Kitawaki ペダリング状態計測装置

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10458868B2 (en) 2015-12-21 2019-10-29 Shimano Inc. Bicycle crank arm assembly
CN109077749A (zh) * 2018-06-26 2018-12-25 上海联影医疗科技有限公司 扫描床、医疗影像系统及其床高确定方法、装置及介质
CN109077749B (zh) * 2018-06-26 2022-08-16 上海联影医疗科技股份有限公司 扫描床、医疗影像系统及其床高确定方法、装置及介质
US11029225B1 (en) 2019-12-27 2021-06-08 Shimano Inc. Electronic device, crank assembly with electronic device and drive train including crank assembly with electronic device

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