System for speed-based power calculation

• US 9,341,526 B2
• Filed: 03/27/2014
• Issued: 05/17/2016
• Est. Priority Date: 04/01/2013
• Status: Active Grant

• Current Assignee: SRAM LLC (SRAM International Corp.)
• Original Assignee: Saris Cycling Group Incorporated
• Inventors: Bass, Benjamin R., Watson, Edward M., Bartholomew, Jesse, Iverson, Jeffery T.
• Primary Examiner(s): YEN, JASON TAHAI
• Application Number:
  US14/227,128
• Publication Number:
  US 20140297009A1
• Time in Patent Office: 782 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B62J 45/20 Cycle computers as cycle accessories
• CPC Class Codes: B62J 45/412 Speed sensors
• CPC Class Codes: B62J 45/414 Acceleration sensors
• CPC Class Codes: B62J 45/42 characterised by mounting
• CPC Class Codes: G01L 3/242 by measuring and simultaneously multiplying torque and velocity

Abstract

A system for determining power expended by a bicyclist while riding a bicycle based on speed measurements or sensed-speed values. The system includes a sensing device arranged for detecting a speed-related value of the bicycle and a processor that communicates with the sensing device. The processor is configured to determine a change in the speed-related value and to determine a power value based on the change in the speed-related value.

Claims

1. A system for determining power of a bicyclist while riding a bicycle, comprising:

a bicycle that includes a frame and a rotating component rotatably coupled to the frame;

a sensing device arranged for detecting a speed-related value of the bicycle;

a processor that communicates with the sensing device and is configured to determine a change in the speed-related value and to determine a power value based on the change in the speed-related value;

wherein the sensing device is arranged for sensing a rotational speed of the rotating component and the speed-related value corresponds to the sensed rotational speed of the rotating component, and wherein the change in the speed-related value corresponds to a change in the rotational speed of the rotating component;

wherein the sensing device is an angular accelerometer for measuring at least one of an angular accelerometer of the rotating component and a deceleration of the rotating component; and

wherein the processor determines the change in the speed-related value corresponding to an occurrence of a dead spot in a pedal stroke in which a minimum power is applied by a bicyclist to the bicycle during the pedal stroke.

2. The system of claim 1, wherein the processor determines an energy-lost value and evaluates the change in the speed-related value with respect to the energy-lost value to determine the power value.

3. The system of claim 2, wherein the energy-lost value corresponds to a deceleration during the dead spot in the pedal stroke.

4. The system of claim 2, wherein the energy-lost value is determined based at least in part on an inertia value of the system.

5. The system of claim 4, wherein the inertia value is a sum inertia value define by summing multiple inertia component values of the system.

6. The system of claim 5, wherein the inertia component values of the system include at least one of an inertia value of the bicycle, an inertia value of the bicyclist, and respective inertia values of multiple rotating components of the system.

7. A system for determining power of a bicyclist while riding a bicycle, comprising:

a bicycle that includes a frame and a rotating component rotatably coupled to the frame;

a sensing device arranged for detecting a speed-related value of the bicycle; and

a processor that communicates with the sensing device and is configured to determine a change in the speed-related value and to determine a power value based on the change in the speed-related value; and

wherein the sensing device is arranged at least one of a front wheel, a rear wheel, forks, and a crank assembly of the bicycle for determining the change in the speed-related value of the at least one of the front wheel, the rear wheel, the forks, and the crank assembly of the bicycle.

8. A system for determining power of a bicyclist while riding a bicycle, comprising:

a bicycle that includes a frame and a rotating component rotatably coupled to the frame;

a sensing device arranged for detecting a speed-related value of the bicycle;

a processor that communicates with the sensing device and is configured to determine a change in the speed-related value and to determine a power value based on the change in the speed-related value;

wherein the sensing device is a linear accelerometer for measuring an acceleration and/or deceleration of the bicycle and wherein the speed-related value corresponds to acceleration and/or deceleration of the bicycle; and

further comprising a speed sensor arranged for sensing the speed of the bicycle and wherein the processor communicates with the linear accelerometer and the speed sensor and determines a maximum deceleration value that corresponds to a dead spot of a pedal stroke in which a minimum power is applied by a bicyclist to the bicycle during the pedal stroke and determines the power value based on the speed and deceleration values at the dead spot.

9. A method for determining power of a bicyclist while riding a bicycle, comprising:

determining with a processor communicating with a sensing device a change in a speed-relay value corresponding to a chance in at least one of a linear speed of a bicycle, a rotational speed of a rotating component of the bicycle, and a rotational speed a rotating component of a resistance unit for resisting pedaling effort of a bicyclist pedaling the bicycle;

determining a power value based at least in part on the determined chance in the speed-related value; and

further comprising determining with the processor a dead spot occurrence in which a minimum power is applied by the bicyclist to the bicycle during a pedal stroke and determining the change in the speed-related value for the dead spot occurrence and wherein the power value is determined at least in part by evaluating the change in speed-related value for the dead spot occurrence and an inertia value of the bicycle.