BICYCLE TORQUE MEASURING SYSTEM

• US 20090120210A1
• Filed: 11/08/2007
• Published: 05/14/2009
• Est. Priority Date: 11/08/2007
• Status: Active Grant

• Current Assignee: Magnum Engineering, LLC
• Original Assignee: Grand Valley State University
• Inventors: Phillips, Robert Ryan, Lindell, Coty W., Miller, Adam L.
• Granted Patent: US 7,806,006 B2
• Time in Patent Office: Days
• US Class Current: 73/862.338
• CPC Class Codes: B62J 45/411 Torque sensors
• CPC Class Codes: B62J 45/421 at the pedal crank
• CPC Class Codes: B62M 3/00 Construction of cranks operated by hand or foot
• CPC Class Codes: G01L 3/1457 involving resistance strain gauges
• CPC Class Codes: G01L 3/242 by measuring and simultaneously multiplying torque and velocity

Abstract

Strain gauges are mounted on each crank arm of the bicycle and provide a measure of the torque applied to each crank arm. In a preferred embodiment, strain gauges are mounted on opposite edges of each crank arm, which includes a self-contained power, electrical circuitry, and a wireless transmitter for transmitting the strain measurement information to a main controller. The main controller includes a wireless transceiver for transmitting and receiving data from both the left and right crank arms and external devices. Memory is also included for storing such data for subsequent analysis to determine the individual leg performance of a cyclist during a race or training session.

Claims

1. A torque measurement system for a bicycle comprising:

a first crank arm extending between a drive axle and pedal of a bicycle, said first crank arm including at least one strain gauge; and

an electrical circuit including an RF transmitter coupled to said strain gauge for the RF transmission of strain measurement information in a binary format to a remote location, which information is representative of the strain and, therefore, the torque exerted on the axle by the pedal.

2. The system as defined in claim 1 wherein said first crank arm has a longitudinal axis and opposing sides extending parallel to the longitudinal axis and wherein said first crank arm includes a pair of strain gauges, with one strain gauge being positioned on one side of said first crank arm and a second strain gauge being mounted on the opposite side of said first crank arm.

5. The system as defined in claim 1 including first and second crank arms mounted to a bicycle and coupled to the drive axle and wherein each of said first and second crank arms includes a pair of strain gauges mounted on opposite sides of said first and second crank arms and coupled to said electrical circuit.

6. The system as defined in claim 5 and further including a main controller mounted to a bicycle and including a receiver for receiving information from said transmitters of said crank arms.

3. A torque measurement system for a bicycle comprising:

a first crank arm extending between a drive axle and pedal of a bicycle, said first crank arm including at least one strain gauge; and

an electrical circuit coupled to said strain gauge for transmitting strain measurement information to a remote location representative of the strain and, therefore, the torque exerted on the axle by the pedal, wherein said first crank arm has a longitudinal axis and opposing sides extending parallel to the longitudinal axis, and wherein said first crank arm includes a pair of strain gauges, with one strain gauge being positioned on one side of said first crank arm and a second strain gauge being mounted on the opposite side of said first crank arm; and

wherein said first crank arm includes a pocket formed therein and wherein said strain gauges are mounted on the inside walls of said pocket which are parallel to said sides of said first crank arm.

4. The system as defined in claim 3 wherein said circuit for transmitting strain information to said remote location is mounted within said pocket.

7. A torque measurement system for a bicycle comprising:

a first crank arm and a second crank arm extending between a drive axle and pedals of a bicycle, wherein each of said first and second crank arms includes at least one stain gauge;

an electrical circuit on each crank arm coupled to said strain gauges and including a transmitter for transmitting strain measurement information to a remote location representative of the strain and, therefore, the torque exerted on the axle by the pedals; and

a main controller mounted to a bicycle and including a receiver for receiving information from said transmitters of said first and second crank arms and further including a first sensor for detecting the position of a bicycle drive sprocket as it rotates through a cycle of operation and supplying information to said main controller relative to the detected position of said sprocket.

8. The system as defined in claim 7 and further including an index position sensor for supplying information as to a reference location of the crank arm with respect to a cycle of operation.

9. The system as defined in claim 8 wherein said first sensor is an optical sensor and wherein teeth of the sprocket interrupt the light beam of the optical sensor to provide timing signals representative of the position of the sprocket as it rotates through a cycle of operation.

10. The system as defined in claim 9 wherein said second sensor is a Hall effect sensor positioned on the frame of the bicycle and wherein one of said first and second crank arms includes a magnet for providing a signal from said Hall effect sensor when said one crank arm passes a predetermined location during a cycle of operation.

11. The system as defined in claim 10 wherein the main controller includes a microcontroller and memory for storing data over a time period of several cycles of operation.

12. The system as defined in claim 11 wherein said main controller includes a transceiver for receiving information from each of said crank arm transmitters and for transmitting signal information to a remote computer for analysis.

13. A torque measurement system for a bicycle comprising:

first and second crank arms extending between a drive axle and pedals of a bicycle, said crank arms each including strain gauges mounted on opposing longitudinal sides of said crank arms;

an electrical circuit for storing said strain gauge measurement information and, therefore, the individual torque exerted on the axle by each crank arm on the drive axle; and

a first sensor coupled to said electrical circuit for detecting the position of a bicycle drive sprocket as it rotates through a cycle of operation and supplying information relative to the detected position of said sprocket.

14. A torque measurement system for a bicycle comprising:

first and second crank arms extending between a drive axle and pedals of a bicycle, said crank arms each including strain gauges mounted on opposing longitudinal sides of said crank arms; and

an electrical circuit for storing said strain gauge measurement information and, therefore, the individual torque exerted on the axle by each crank arm on the drive axle, wherein each crank arm includes a pocket formed therein and wherein said strain gauges are mounted on the inside walls of said pocket which are parallel to sides of said crank arm.

15. The system as defined in claim 14 and further including a first sensor for detecting the position of a bicycle drive sprocket as it rotates through a cycle of operation and supplying information relative to the detected position of said sprocket.

16. The system as defined in claim 15 and further including an index position sensor for supplying information as to a reference location of at least one crank arm with respect to a cycle of operation.

17. The system as defined in claim 16 wherein said first sensor is an optical sensor and wherein teeth of the sprocket interrupt the light beam of the optical sensor to provide timing signals representative of the position of the sprocket as it rotates through a cycle of operation.

18. The system as defined in claim 17 wherein said index position sensor is a Hall effect sensor positioned on the frame of the bicycle and wherein one of said crank arms includes a magnet for providing a signal from said Hall effect sensor when the crank arm passes a predetermined location during a cycle of operation.

19. A torque measurement system for a bicycle comprising:

crank arms extending between a drive axle and the pedals of a bicycle, said crank arms each having a longitudinal axis and a strain gauge positioned on opposite sides of each of said crank arms in alignment with said longitudinal axis;

a pocket formed in each crank arm; and

an electrical circuit mounted in said pocket and coupled to said strain gauges for obtaining information representative of the strain and, therefore, the torque exerted on the axle by each crank arm.

20. The system as defined in claim 19 wherein said circuit includes a transmitter and power supply for transmitting strain information to a remote location.

21. The system as defined in claim 20 and further including a main controller mounted to a bicycle and including a receiver for receiving information from said transmitters of said crank arms.

22. A torque measurement system for a bicycle comprising:

crank arms extending between a drive axle and the pedals of a bicycle, said crank arms each having a longitudinal axis and at least one strain gauge positioned on each of said crank arms in alignment with said longitudinal axis;

a pocket formed in each crank arm;

an electrical circuit mounted in said pocket and coupled to said strain gauge for obtaining information representative of the strain and, therefore, the torque exerted on the axle by each crank arm, wherein said circuit includes a transmitter and power supply for transmitting strain information to a remote location;

a main controller mounted to a bicycle and including a receiver for a receiving information from said transmitters of said crank arms; and

a first sensor for detecting the position of a bicycle drive sprocket as it rotates through a cycle of operation and supplying information to said main controller relative to the detected position of said sprocket.

23. The system as defined in claim 22 and further including an index position sensor for supplying information as to a reference location of at least one crank arm with respect to a cycle of operation.

24. The system as defined in claim 23 wherein said first sensor is an optical sensor and wherein teeth of the sprocket interrupt the light beam of the optical sensor to provide timing signals representative of the position of the sprocket as it rotates through a cycle of operation.

25. The system as defined in claim 24 wherein said index position sensor is a Hall effect sensor positioned on the frame of the bicycle and wherein one of said crank arms includes a magnet for providing a signal from said Hall effect sensor when the crank arm passes a predetermined location during a cycle of operation.

26. The system as defined in claim 25 wherein said main controller includes a microcontroller and memory for storing data over a time period of several cycles of operation.

27. The system as defined in claim 26 wherein said main controller includes a transceiver for receiving information from each of said crank arm transmitters and for transmitting signal information to a remote computer for analysis.

28. A torque measurement system for a bicycle having a pair of crank arms and a sprocket, said system comprising:

crank arms extending between a drive axle and the pedals of a bicycle, said crank arms each having a longitudinal axis;

an electrical circuit coupled to said crank arms for obtaining information representative of the torque exerted on the axle individually by each crank arm; and

a sensor coupled to said electrical circuit for detecting the position of the bicycle sprocket as it rotates through a cycle of operation and supplying information as to the position of said sprocket.