Bicycle computer with wind and posture sensing
A bicycle computer with a graphical user interface making use of atmospheric pressure sensor for gauging encroaching wind speeds for display to a cyclist through a wind speed gauge and a cyclist face features camera for detection of the cyclist upright and aerodynamic postures for accurate cycling power estimation through proper identification of the cyclist wind resistance and thereof presentation on the graphical user interface of the bicycle computer thereby alleviating the need for mechanical force and torque sensing devices typically necessary for accurate cycling power measurements. Estimation of the cyclist aerodynamic resistance coefficients for upright and aerodynamic postures are derived through aerodynamic calibration routines and the cyclist riding posture recorded by the camera for subsequent comparison to assumed position in real time for identification and application of the proper cyclist aerodynamic resistance coefficient in the power estimation algorithm.
1 . A wind speed computer for a bicycle, comprising:
a) a structural bicycle mount for mechanical anchor of a mobile computing platform to a bicycle steering structure in an open atmospheric area with longitudinal axis of said mobile computing platform thereof disposed at a pre-specified angle of attack to a forward travel vector of said bicycle;
b) a mobile computing platform secured within said structural bicycle mount, said mobile computing platform comprising:
1) A hardware micro-electro-mechanical system (MEMS) atmospheric pressure sensor disposed at an internal sensor port of said mobile computing platform;
2) A global positioning sensor (GPS) receiver;
3) A temperature sensor;
4) A graphical touchscreen user interface;
5) A hardware processor; and
6) A non-transitory computer-readable memory;
c) an aerodynamic software application stored in said non-transitory computer-readable memory for execution thereof by said hardware processor, said aerodynamic software application comprising specialized algorithmic instructions including:
i) a base pressure storage module for identification of a zero-velocity condition of said bicycle via said global positioning sensor GPS receiver, and for sequentially storing a bicycle zero-velocity barometric reference value (P_0) from said MEMS atmospheric pressure sensor in said non-transitory computer-readable memory;
ii) a pressure differential tracking module for determination of a pressure differential (Delta P) for said bicycle via a mathematical subtraction of said stored bicycle zero-velocity barometric reference value P_0 from an active, real-time barometric measurement (P_live) from said MEMS atmospheric pressure sensor;
iii) a temperature-uncompensated air speed-computation module for derivation of an instantaneous temperature-uncompensated impending air speed component (U_air) through a mathematical iteration predominantly based on a mathematical square root of said pressure differential Delta P;
iv) an air speed temperature-compensation module for conversion of said temperature-uncompensated impending air speed component U_air into a temperature-compensated air speed component (V_air) through a relation based on input of said temperature sensor; and
v) a graphical rendering subsystem for driving an enumerated visualization routine with a graphical speed indicator for display of said temperature-compensated air speed component V_air on said graphical touchscreen user interface.
2 . The wind speed computer for a bicycle of claim 1 , wherein said graphical touchscreen user interface further includes a first toggle for activation of additional specialized algorithmic instructions for estimation of said aerodynamic resistance coefficient (C_dA) for a bicycle rider through measurement of a rate of linear deceleration of said bicycle on a level road, under no-wind conditions and with no-power input to pedals of said bicycle by said bicycle rider; wherein said specialized algorithmic instructions for estimation of said aerodynamic resistance coefficient further comprise a first routine for estimation of a first aerodynamic resistance coefficient (C_dAu) corresponding to an upright posture of said bicycle rider, and a second routine for estimation of a second aerodynamic resistance coefficient (C_dAa) corresponding to an aerodynamic posture of said bicycle rider.
3 . The wind speed computer for a bicycle of claim 2 , wherein said mobile computing platform further includes an inertial measurement unit (IMU) and an inclination gyroscope, and wherein said graphical touchscreen user interface further includes a second toggle for activation of additional specialized algorithmic instructions for estimation of a real-time mechanical power output value for said bicycle rider through a closed-form physics computation predominantly based on speed updates by said global positioning sensor GPS receiver of said bicycle compounded by summation of following forces:
a) inertial acceleration force predominantly based on output of said inertial measurement unit IMU resolved in a forward direction of said bicycle against a total user-specified system mass value stored in said non-transitory computer-readable memory;
b) gravitational climbing force predominantly based on inclination measurements of said inclination gyroscope over a running distance interval against said total user-specified system mass value; and
c) instantaneous aerodynamic resistance force predominantly based on an active selection between said first aerodynamic resistance coefficient C_dAu, corresponding to said upright posture of said bicycle rider and said second aerodynamic resistance coefficient C_dAa, corresponding to said aerodynamic posture of said bicycle rider, applied against said temperature-compensated air speed component V_air.
4 . The wind speed computer for a bicycle of claim 3 , wherein said mobile computing platform further comprises a rider-features optical camera sensor; and wherein said aerodynamic software application comprises further algorithmic instructions including:
a) a rider-features capture routine for capture of a first calibration image via said rider-features optical camera sensor for an upright posture of said bicycle rider, and a second calibration image via said rider-features optical camera sensor for an aerodynamic posture of said bicycle rider;
b) a features area mapping routine for real-time computation of a percent occupation of facial features of said bicycle rider within a field of view of said rider-features optical camera sensor, and a mapping of said real-time computation to either of said first calibration image corresponding to said upright posture of said bicycle rider or said second calibration image corresponding to said aerodynamic posture of said bicycle rider;
c) a dynamic parameter memory-mapping routine for real-time update of said specialized algorithmic instructions for estimation of a real-time mechanical power output value for said bicycle rider with said first aerodynamic resistance coefficient C_dAu, corresponding to said upright posture of said bicycle rider, and said second aerodynamic resistance coefficient C_dAa, corresponding to said aerodynamic posture of said bicycle rider; and
d) a graphical rendering subsystem for driving an enumerated visualization routine for real-time display of said first aerodynamic resistance coefficient C_dAu, corresponding to said upright posture of said bicycle rider, and said second aerodynamic resistance coefficient C_dAa, corresponding to said aerodynamic posture of said bicycle rider.
5 . A computer-vision driven rider posture parsing apparatus for a bicycle, comprising:
a) a structural bicycle mount for mechanical anchor of a mobile computing platform to a bicycle steering structure in an open atmospheric area and oriented to face a bicycle rider;
b) a mobile computing platform secured within said structural bicycle mount, said mobile computing platform further comprising:
1) A rider-features optical camera sensor;
2) A hardware processor;
3) A graphical touchscreen user interface; and
4) A non-transitory computer-readable memory;
c) a posture profiling application stored in said non-transitory computer-readable memory for execution thereof by said hardware processor, said posture profiling application comprising specialized algorithmic instructions including:
i) a rider-features capture routine for capture of a first calibration image via said rider-features optical camera sensor for an upright posture of said bicycle rider, and a second calibration image via said rider-features optical camera sensor for an aerodynamic posture of said bicycle rider;
ii) a features area mapping routine for real-time computation of a percent occupation of facial features of said bicycle rider within a field of view of said rider-features optical camera sensor, and a mapping of said real-time computation to either of said first calibration image corresponding to said upright posture of said bicycle rider or said second calibration image corresponding to said aerodynamic posture of said bicycle rider; and
iii) a dynamic real-time parameter update module for real-time structural data switch of an aerodynamic resistance coefficient (C_dA) between a first pre-recorded numerical value (C_dAu) corresponding to said upright posture for said bicycle rider and a second pre-recorded numerical value (C_dAa) corresponding to said aerodynamic riding posture for said bicycle rider.
6 . The computer-vision driven posture parsing apparatus for a bicycle of claim 5 , further comprising:
a) a hardware micro-electro-mechanical system (MEMS) atmospheric pressure sensor positioned at an internal sensor port of said mobile computing platform;
b) a global positioning sensor (GPS) receiver integrated within said mobile computing platform;
c) a temperature sensor integrated within said mobile computing platform; and
d) further specialized algorithmic instructions within said posture profiling application including:
i) a base pressure storage module for identification of a zero-velocity condition of said bicycle via said GPS receiver, and for sequentially storing a bicycle zero-velocity barometric reference value (P_0) from said MEMS atmospheric pressure sensor in said non-transitory computer-readable memory;
ii) a pressure differential tracking module for determination of a pressure differential (Delta P) for said bicycle via a mathematical subtraction of said stored bicycle zero-velocity barometric reference value P_0 from an active, real-time barometric measurement (P_live) from said MEMS atmospheric pressure sensor;
iii) a temperature-uncompensated air speed computation module for derivation of an instantaneous temperature-uncompensated impending air speed component (U_air) through a mathematical iteration predominantly based on a mathematical square root of said pressure differential Delta P;
iv) an air speed temperature-compensation module for conversion of said temperature-uncompensated impending air speed component U_air into a temperature-compensated air speed component (V_air) through a relation based on input of said temperature sensor; and
v) a graphical rendering subsystem for driving an enumerated visualization routine with a graphical speed indicator for display of said temperature-compensated air speed component V_air on said graphical touchscreen user interface.
7 . The computer-vision driven posture parsing apparatus for a bicycle of claim 6 , wherein said graphical touchscreen user interface further includes a first toggle for activation of additional specialized algorithmic instructions for estimation of said aerodynamic resistance coefficient C_dA for a bicycle rider through measurement of a rate of linear deceleration of said bicycle on a level road, under no-wind conditions and with no-power input to pedals of said bicycle by said bicycle rider; wherein said specialized algorithmic instructions for estimation of said aerodynamic resistance coefficient further comprise a first routine for estimation of said first aerodynamic resistance coefficient C_dAu corresponding to said upright posture of said bicycle rider, and a second routine for estimation of said second aerodynamic resistance coefficient C_dAa corresponding to said aerodynamic posture of said bicycle rider.
8 . The computer-vision driven posture parsing apparatus for a bicycle of claim 7 , wherein said mobile computing platform further includes an inertial measurement unit (IMU) and an inclination gyroscope, and wherein said graphical touchscreen user interface further includes a second toggle for activation of additional specialized algorithmic instructions for estimation of a real-time mechanical power output value for said bicycle rider through a closed-form physics computation predominantly based on speed updates by said global positioning sensor GPS receiver of said bicycle compounded by summation of following forces:
a) inertial acceleration force predominantly based on output of said inertial measurement unit IMU resolved in a forward direction of said bicycle against a total user-specified system mass value stored in said non-transitory computer-readable memory;
b) gravitational climbing force predominantly based on inclination measurements of said inclination gyroscope over a running distance interval against said total user-specified system mass value; and
c) instantaneous aerodynamic resistance force predominantly based on an active selection between said first aerodynamic resistance coefficient C_dAu, corresponding to said upright posture of said bicycle rider, and said second aerodynamic resistance coefficient C_dAa, corresponding to said aerodynamic posture of said bicycle rider, applied against said temperature-compensated air speed component V_air.
9 . A hardware-implemented data processing method for estimation of power exerted by a bicycle rider in real-time, comprising:
a) providing a mobile computing platform comprising:
1) A hardware micro-electro-mechanical system (MEMS) atmospheric pressure sensor disposed at an internal sensor port of said mobile computing platform;
2) A global positioning sensor (GPS) receiver;
3) A temperature sensor;
4) An inertial measurement unit (IMU) including a multi-axis hardware accelerometer array;
5) An inclination gyroscope;
6) A rider-features optical camera sensor;
7) A graphical touchscreen user interface;
8) A hardware processor; and
9) A non-transitory computer-readable memory;
b) securing said mobile computing platform within a structural bicycle mount mechanically anchored to a bicycle steering structure in an open atmospheric area with a longitudinal axis of said mobile computing platform disposed at a pre-specified angle of attack to a forward travel vector of said bicycle;
c) providing a rider power estimation software application with pressure-sensing and air-speed computation routines within said non-transitory computer-readable memory, comprising:
1) A base pressure storage routine for identification of a zero-velocity condition of said bicycle via said GPS receiver, and for sequentially storing a bicycle zero-velocity barometric reference value (P_0) from said MEMS atmospheric pressure sensor;
2) A pressure differential tracking routine for determination of a pressure differential (Delta P) for said bicycle via a mathematical subtraction of said stored bicycle zero-velocity barometric reference value P_0 from an active, real-time barometric measurement (P_live) from said MEMS atmospheric pressure sensor;
3) A temperature-uncompensated air speed-computation routine for derivation of an instantaneous temperature-uncompensated impending air speed component (U_air) through a mathematical iteration predominantly based on a mathematical square root of said pressure differential Delta P; and
4) An air speed temperature-compensation routine for conversion of said temperature-uncompensated impending air speed component U_air into a temperature-compensated air speed component (V_air) through a relation based on input of said temperature sensor;
d) providing said rider power estimation software application with rider aerodynamic calibration routines within said non-transitory computer-readable memory, comprising:
1) An interactive user interface selection routine driven by a first toggle on said graphical touchscreen user interface for activation of additional specialized algorithmic instructions for estimation of an aerodynamic resistance coefficient (C_dA) for said bicycle rider through measurement of a rate of linear deceleration of said bicycle on a level road, under no-wind conditions and with no-power input to pedals of said bicycle by said bicycle rider;
2) A first calibration estimation routine for estimation of a first aerodynamic resistance coefficient (C_dAu) corresponding to an upright posture of said bicycle rider; and
3) A second calibration estimation routine for estimation of a second aerodynamic resistance coefficient (C_dAa) corresponding to an aerodynamic posture of said bicycle rider;
e) providing said rider power estimation software application with camera-driven rider posture parsing routines within said non-transitory computer-readable memory, comprising:
1) A rider-features capture routine for capture of a first calibration image via said rider-features optical camera sensor for said upright posture of said bicycle rider, and a second calibration image via said rider-features optical camera sensor for said aerodynamic posture of said bicycle rider;
2) A features area mapping routine for real-time computation of a percent occupation of facial features of said bicycle rider within a field of view of said rider-features optical camera sensor, and a mapping of said real-time computation to either of said first calibration image corresponding to said upright posture of said bicycle rider or said second calibration image corresponding to said aerodynamic posture of said bicycle rider; and
3) A dynamic real-time parameter update routine for real-time structural data switch of said aerodynamic resistance coefficient C_dA between a first pre-recorded numerical value C_dAu, corresponding to said upright posture of said bicycle rider, and a second pre-recorded numerical value C_dAa, corresponding to said aerodynamic posture of said bicycle rider;
f) providing said rider power estimation software application with arithmetic instructions for estimation of a real-time mechanical power output value (P_rider) for said bicycle rider within said non-transitory computer-readable memory, through a closed-form physics computation predominantly based on speed updates by said GPS receiver of said bicycle compounded by summation of the following forces:
1) An inertial acceleration force predominantly based on output of said IMU resolved in a forward direction of said bicycle against a total user-specified system mass value stored in said non-transitory computer-readable memory;
2) A gravitational climbing force predominantly based on inclination measurements of said inclination gyroscope over a running distance interval against said total user-specified system mass value; and
3) An instantaneous aerodynamic resistance force predominantly based on an active selection between said first aerodynamic resistance coefficient C_dAu, corresponding to said upright posture of said bicycle rider, and said second aerodynamic resistance coefficient C_dAa, corresponding to said aerodynamic posture of said bicycle rider, applied against said temperature-compensated air speed component V_air; and
g) providing said rider power estimation software application with graphical touchscreen user interface driving routines within said non-transitory computer-readable memory, comprising:
1) An enumerated visualization routine driven by a graphical rendering subsystem for real-time display of said resolved real-time mechanical power output value P_rider on said graphical touchscreen user interface; and
2) A graphical speed indicator routine driven by said graphical rendering subsystem for real-time display of said temperature-compensated air speed component V_air on said graphical touchscreen user interface.