Bicycle torque measuring system

• US 7,806,006 B2
• Filed: 11/08/2007
• Issued: 10/05/2010
• Est. Priority Date: 11/08/2007
• Status: Expired due to Fees

• Current Assignee: Magnum Engineering, LLC
• Original Assignee: Grand Valley State University
• Inventors: Phillips, Robert Ryan, Lindell, Coty W., Miller, Adam L.
• Primary Examiner(s): Caputo; Lisa M
• Assistant Examiner(s): ROY, PUNAM P
• Application Number:
  US11/936,847
• Publication Number:
  US 20090120210A1
• Time in Patent Office: 1,062 Days
• Field of Search: 738/623.38, 733/790.1, 482/8, 280/200, 280/209, 280/259, 280/260, 280/261
• 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 and a second crank arm extending between a drive axle and pedals of the 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 main controller representative of the strain and, therefore, the torque exerted on the axle by the pedals;

a main controller mounted to the 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, 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; and

an index position sensor for supplying information as to a reference location of the crank arm with respect to a cycle of operation, wherein said index position 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.

2. The system as defined in claim 1 wherein the main controller includes a microcontroller and memory for storing data over a time period of several cycles of operation.

3. The system as defined in claim 2 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.

4. A torque measurement system for a bicycle having a frame, said system comprising:

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

an electrical circuit for storing all of 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 and further including a first sensor mounted to the bicycle frame 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;

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; and

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.

5. A torque measurement system for a bicycle having a frame, said system comprising:

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

an electrical circuit for storing all of 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 and further including a first sensor mounted to the bicycle frame 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;

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; and

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, 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.

6. A torque measurement system for a bicycle comprising:

crank arms extending between a drive axle and the pedals of the 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 each of said pockets and coupled to a strain gauge on an associated crank arm 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 main controller;

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

a first sensor for detecting the position of the 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, 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; and

an index position sensor for supplying information as to a reference location of at least one of the crank arms with respect to a cycle of operation, 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.

7. The system as defined in claim 6 wherein said main controller includes a microcontroller and memory for storing data over a time period of several cycles of operation.

8. The system as defined in claim 7 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.

9. A torque measurement system for a bicycle having a pair of crank arms coupled to a drive sprocket coupled to a drive axle, said system comprising:

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

an electrical circuit coupled to each of said crank arms for providing information in a binary format representative of the torque exerted on the axle which information is associated with an address identifying each crank arm;

a first sensor for detecting the teeth of the bicycle sprocket as it rotates through a cycle of operation;

a second sensor for detecting a reference position of at least one of said crank arms;

a microprocessor coupled to said electrical circuit and to said first and second sensors for storing instantaneous torque information for each crank arm through 360°

of rotation of said sprocket as detected by said first and second sensors; and

a computer for coupling to said microprocessor and programmed for analyzing information stored by said microprocessor and outputting signals which provide polar diagrams of the torque applied to each crank arm through at least one cycle of operation.