Torque sensor system and drive system for an electric bicycle and methods for using these

Abstract

A torque sensor comprises a contact sensor and a non-contact sensor. An electric drive system for a bicycle includes an electric motor with a rotor that can rotate about an axis. An output component is coupled to the electric motor and can rotate about an axis. An input component can rotate about the axis and is concentric with the output component and the rotor. A one-way coupling is arranged between the input component and the output component. The contact sensor is coupled to the output component. The contact sensor is configured to measure a torque applied to the output component by the input component and to provide an input signal. The non-contact sensor is arranged between the output component and a fixed component. The non-contact sensor is configured to provide an output signal proportional to the input signal.

Description

Background1. FIELD OF DISCLOSUREThe present disclosure generally relates to a sensor for a bicycle, and more particularly to a torque sensor for an electric bicycle, a drive system, and methods of using the same.2. Description of the Prior ArtA bicycle with a pedaling-assist electric motor (e.g., an electric bicycle or an e-bike) may include sensors that monitor parameters on the bicycle. The monitored parameters may include, for example, input torque at a crank arm assembly of the bicycle.Sensors monitoring input torque can be positioned on the rear dropout, wherein the force applied by the driver to the crankset is transmitted through the chain, cassette, hub and wheel shaft before the sensor receives them, which requires a series of calculations and compensation steps and can lead to potential errors in the calculation of the torque. Alternatively, the input axis can be directly accessible via the control electronics, so that the driver's torque can be measured directly. However, in a propulsion system in which the engine is concentric with the driver input axis, there is no direct path between the control electronics and the driver input shaft, making it difficult to measure torque at the driver input interface.SummaryIn one aspect, an embodiment of a torque sensor system for an electric bicycle includes an output component rotatable about an axis, the output component configured to be rotated by an electric motor. A contact sensor is coupled to the output component. The contact sensor is configured to measure a torque applied to the output component and provide an input signal. A contactless sensor is arranged between the output component and a fixed component. The contactless sensor is configured to provide an output signal proportional to the input signal.In another aspect, an embodiment of a torque sensor system for an electric bicycle includes an output component rotatable about an axis, the output component configured to be rotated by an electric motor. A strain sensor is operatively coupled to the output component and is rotatable with the output component about the axis. In one embodiment, an internal transformer coil is coupled to the output component and is rotatable with the output component about the axis. A non-rotatable outer transformer coil is radially spaced from and surrounds an inner transformer coil. In another embodiment, a radio transmitter is coupled to and rotatable with the output component about the axis, while a radio receiver in communication with the transmitter is spaced from the transmitter and does not have physical contact with the output component.In another aspect, an embodiment of an electric drive system for a bicycle includes an electric motor having a rotor rotatable about an axis. An output component is coupled to the electric motor and is rotatable about the axis. An input component is rotatable about the axis and concentric with the output component and the rotor. A one-way clutch is disposed between the input component and the output component. The one-way clutch is disposed between the input component and the output component when the input component is rotated in a first rotational direction, and wherein the one-way clutch is disengaged between the input component and the output component when the input component is rotated in a second rotational direction opposite the first rotational direction. A contact sensor is coupled to the output component. The contact sensor is configured to measure a torque applied to the output component by an input component and provide an input signal. A contactless sensor is arranged between the output component and a fixed component. The contactless sensor is configured to provide an output signal proportional to the input signal.In one embodiment, the torque sensor includes a first sensor component coupled to the output component and rotatable with the output component about the axis and a second sensor component radially spaced from the first sensor component and coupled to a fixed component, the first and second sensor components configured to measure torque applied to the output component.In another aspect, an embodiment of a method for measuring torque applied to a bicycle drive train includes applying torque with an input component to the output component, measuring the torque with a contact sensor coupled to the output component, supplying a contactless sensor with supply current proportional to the load current, measuring the supply current supplied to the contactless sensor, and calculating the torque based on the measurement of the supply current.The various aspects and embodiments of the torque sensor, drive system, and methods provide significant advantages over other torque sensors, drive systems, and methods. In particular, the torque sensor may provide accurate torque measurements, for example, and is suitable for use in a drive system having an engine input concentric with the driver input shaft.Brief Description of the DrawingsObjects, features and advantages of the present invention will become apparent from a reading of the following description taken in conjunction with the figures: FIG. 1 is a side view of an example electric bicycle including a torque sensor in accordance with the teachings of this disclosure; FIG. 2 is a perspective view of an embodiment of a drive system; FIG. 3 is a plan view of the drive system of FIG. 2 ; FIG. 4 is a cross-sectional view of the drive system of FIG. 2 ; FIG. 5 is a partial cross-section of the propulsion system including a torque sensor; FIG. 6 is an enlarged partial cross-sectional view of the drive system; FIG. 7 is a partial end view of the drive system; FIG. 8 is a partial internal perspective view of the drive system; FIG. 9 is a partial exterior perspective view of the drive system; FIGS. 10A-C show various contact sensor assemblies; FIG. 11 is a block diagram showing an embodiment of a torque sensor; FIG. 12 is a schematic illustration of an embodiment of a torque sensor; FIG. 13 is an embodiment of a current draw v. time graph used to calculate the measured torque; FIG. 14 is another embodiment of a current draw v. time graph used to calculate the measured torque;Other aspects and advantages of the embodiments disclosed herein will become apparent upon reading the following detailed description, in which like or identical structures have like reference numerals.DETAILED DESCRIPTION OF THE DISCLOSUREA bicycle is provided with an electric pedaling assist motor that can drive a ring of chains independent of cranks (e.g., an e-bike). To control the e-bike, an accurate, robust and cost effective torque detection is to be provided. To proportionally control the electric pedaling assist motor, a controller of the bicycle may change the electric assist provided by the assist motor based on the input torque generated by a rider on a crank assembly of the bicycle. For example, as the sensed input torque increases, the controller amplifies the electric assist by the assist motor and decreases the sensed input torque, the controller reduces the electric assist by the assist motor.In electronic shift bicycle transmissions, a control device executing an automatic shifting algorithm initiates a shifting operation with an increasing treading frequency. However, a cyclist may be driving at a lower pedaling frequency at a moderate tempo and at a higher pedaling frequency at an aggressive driving mode. The automatic adaptation of the footfall frequency band can take place on the basis of a detected driving scenario. For example, the controller may increase a target input frequency and thus a target input frequency band for automatic shifting when a high input torque is detected, and decrease the target input frequency and the target input frequency band for automatic shifting when a low input torque is detected.A torque sensor according to the disclosure may be incorporated in a radial contact clutch-type system such as a rolling bearing or clamping body rotary clutch mechanism of an E-Bike system. For example, a jam link rotary clutch mechanism may be disposed between a crank input (e.g., a crank axis) and a chain ring output and / or an engine input of the E-Bike system. The clamp body rotary clutch mechanism transmits torque in a first rotational direction, but rotates freely in a second rotational direction opposite to the first rotational direction. For example, the crank input drives the ring gear output in the first rotational direction via the jam body rotational clutch mechanism, but rotates freely in the second rotational direction. When an auxiliary motor of the e-bike system drives the ring gear output such that the ring gear output rotates faster than the crank input (e.g., by the cyclist stepping into the pedals), slippage occurs in the clamp body rotary clutch mechanism or free wheeling occurs.For example, the clamp body rotary clutch mechanism generates a strong strain in a ring portion of an outer race (e.g., a portion of the ring output) of the clutch mechanism that is proportional to the reaction torque. The torque sensor according to the disclosure can measure the strain in the ring section of the outer raceway. The measured strain can be taken into account in a sensor. The torque sensor may be a contact sensor and / or configured to rotate with the ring portion of the outer race to measure the strain or other characteristics of the ring portion indicative of torque transmission therethrough.Various embodiments of the invention are described herein with reference to the drawings. It is to be understood that the drawings and description herein are for illustrative purposes only and do not limit the invention as defined in the appended claims and all their equivalents.Of course, the specific arrangement and illustrated components of the frame, front wheel, rear wheel, powertrain, front brake, rear brake, and seat do not place a limitation on the disclosed embodiments. For example, while the front brake and the rear brake are illustrated as hydraulic disc brakes, hydraulic rim brakes are also conceivable and fall within the scope of the disclosure. Moreover, mechanical systems including mechanical rim brakes and mechanical disc brakes, as well as other electronic, hydraulic, pneumatic, and mechanical systems, or combinations thereof, e.g., suspension systems, are conceivable and fall within the scope of the present disclosure.The term "plurality" as used herein means two or more. As used herein, the term "longitudinal" means from or relative to a length or length direction. As used herein, the term "lateral" means located in, directed to, or extending in a lateral direction. The term "coupled" means directly or indirectly connected or engaged with, for example, an intermediate member, where the engagement need not be fixed or permanent, but may be fixed or permanent. As used herein, the terms "first," "second," etc., are not associated with a particular component so-designated, but refer only to those components in the numerical order given, meaning that a component designated as "first" may later be a "second" such component, depending on the order given. Further, the term "first" and "second" does not necessarily mean that the two components or values so designated are different, i.e., a first axis may be the same as a second axis, for example, each being easily applicable to different components. The terms "upper", "lower", "rear", "front", "front", "rear", "vertical", "horizontal", "right", "left", "inner", "outer", and variations or derivatives thereof refer to the orientation of an exemplary bicycle 50 illustrated in FIG. 1 from the perspective of a user seated thereon, for example, with an "inner" component or feature being closer to a vertical mid-plane of the bicycle extending in a direction A. The term "transverse" means non-parallel. The terms "outward" and "outward" refer to a direction or feature that faces away from a central location, e.g., the terms "radially outward", "radial direction", and / or derivatives thereof refer to a feature that faces away from a central location, e.g., a rotational axis of the ring chain assembly, as shown in FIGS. 1-5. Conversely, the terms "inner" and "inward" refer to a direction facing the central or inner position. The term "subassembly" refers to an assembly of a plurality of components, wherein the subassemblies can be further assembled into other subassemblies and / or an end assembly, e.g., the bicycle 100.Referring now to the drawings, FIG. 1 illustrates a bicycle 50 that may employ one or more system control devices to implement a bicycle control system using the torque sensor described herein. In this example, the bicycle 50 may be a mountain bike. In some cases, the bicycle 50 may be an E-bike. The bicycle 50 includes a frame 52, a handlebar 54 proximate a front end of the frame 52, and a seat or seat 56 that supports a rider over the frame 52. The bicycle 50 further includes a first or front wheel 58 supported by a front fork 60 of the frame 52 and supporting the front end of the frame 52. The bicycle 50 further includes a second or rear wheel 62 that supports a rear end of the frame 52. The rear end of the frame 52 may be connected to a rear suspension component 61. The bicycle 50 further includes a drive train 64 having a crank assembly 66 coupled via a chain ring 65, a chain 68, and a rear derailleur 37 to a rear cassette 70 proximate an axis of rotation of the rear wheel 62. The crank assembly 66 includes two cranks 75 and two pedals 76 that are respectively connected to the two cranks 75 on opposite sides of the frame 52 of the bicycle 50. In the illustrated example, the rear derailleur 37 includes a power source (e.g., a battery) and a motor and receives commands (e.g., wirelessly) from a controller 126 (e.g., a shift lever or a central controller) mounted, e.g., to the handlebar 54 or the frame 52 to shift gears on the rear cassette 70.The battery 130 for the e-bike control system 128 is also supported by the frame 52 of the bicycle 50. For example, the battery 130 of the e-bike control system 128 is supported by a down tube 53 of the frame 52 of the bicycle 50. One or more components (e.g., the controller 126) of the bicycle 50 may each be coupled to the power source 130 of the e-bike control system 128 via other cables.The battery 130, for example, powers a propulsion unit 138 (e.g., an e-bike motor 200) operatively coupled to the crank assembly 66. In one embodiment, the drive unit 138 may also be powered by a separate battery to allow access to the e-bike controls when the battery 130 of the e-bike control system 128 is not mounted to the bicycle 100. In an embodiment shown in FIG. 4, the motor 200 includes a rotor 250 that rotates relative to a stator 252. The stator 252, which is fixed rotationally fixed, receives current from the battery 130 and generates a magnetic field that drives or rotates the rotor 250. The rotor 250 is directly or indirectly connected to and drives an output component 204. A gear box 260 or reduction gear box may be coupled between the rotor 250 and the output component 204.The drive unit 138 is mounted to the frame 52 of the bicycle 50. For example, the drive unit 138 is mounted to the frame 52 of the bicycle 50 with one or more bolts and threaded apertures in the frame 52 of the bicycle 50. The drive unit 138 may also be mounted to the frame 52 in another manner. A crank axle 202 (e.g., a crankshaft) passes through an opening in the drive unit 138 and connects the two cranks 75 of the crank assembly 66. during operation, the driver rotates the two cranks 75 via the two pedals 76, thereby rotating the crank axle 202. The crank axle 202, which defines an input component, drives the output component 204 (e.g., a chain ring shaft) of the drive unit 138 in a forward travel direction, but not in a rearward pedaling direction, for example, through the use of a one-way clutch 206 (e.g., a dog ring rotary clutch mechanism) between the crank axle 202 and the output component 204.The measured torque applied to the crank axle 202 or the input component may be used to control the electric propulsion motor 200 (e.g., an assist motor) of the propulsion unit 138. The motor 200 may drive rotation of the output component 204 directly or through the use of gears in the transmission 260. The output component 204 thus provides an output power to the powertrain 64 that combines the driver input power of the crank axle 202 and an output power of the assist motor 200.While the bicycle 50 illustrated in FIG. 1 is a mountain bike and may include suspension components such as a shock absorbing front fork, the specific embodiments and examples disclosed herein, as well as alternative embodiments and examples, may also be used on other types of bicycles. For example, the disclosed torque sensors may be used on racing bicycles as well as bicycles with mechanical (e.g., cable, hydraulic, pneumatic, etc.) and non-mechanical (e.g., wired, wireless) drive systems.The front and / or front orientation of the bicycle 50 is indicated by the direction of arrow "A" in FIG. 1. Thus, a forward direction of the movement of the bicycle 50 is indicated by the direction of the arrow A.The drive unit 138 may include internal electronics to control operation of the assist motor 200, measure axle inputs, measure a slope of the bicycle 50, measure an acceleration of the bicycle 50, measure a temperature of the bicycle 50, and / or reduce a voltage of the battery 130 of the e-bike control system 128 to take into account and power external devices when lower voltages are required. For example, the internal electronics of the drive unit 138 may include one or more torque sensors 220. Additional, fewer, and / or other internal electronics may be provided in the drive unit 138.A control unit of the drive unit 138 (e.g. a central e-bike control system or a control unit; a system control device) may be arranged on a housing of the drive unit 138 and may be wired to the internal electronics of the drive unit 138. Alternatively or additionally (e.g., as part of the same housing), the e-bike controller may be supported by the same housing as the power source 130. The e-bike controller may be made of a material through which control signals may be wirelessly transmitted. In one embodiment, the e-bike controller is wired to the e-bike control system 128.The e-bike controller may control the power supply from the power source 130 to the components of the bicycle 50, e.g., to the electric drive motor 200 of the drive unit 138. The e-bike controller may control the power supply to other and / or other components of the bicycle 50. The e-bike controller may send signals (e.g., commands) to components of the bicycle 50 and / or receive data (e.g., commands and / or sensor data) from components of the bicycle 50, e.g., the rear derailleur 37, a suspension system, and / or a seat post assembly to actuate and / or control components of the bicycle 50.In other embodiments, the e-bike controller may be located at other locations (e.g., on the handlebar 54) of the bicycle 50 or alternatively distributed among various components of the bicycle 50, with the required signal and current paths routed via a communication link. For example, a control unit 126 (e.g., as an e-bike controller; a system controller) may be mounted on the handlebar 54 to drive a motor of the rear derailleur 37 and actuate the rear derailleur 37 to perform gear changes and gear selections. However, the control unit 126 and / or the e-bike controller may be located at any location of the bicycle 50 or alternatively distributed among various components of the bicycle 50, wherein the required signal and current paths are routed via a communication link. The control unit and / or the e-bike controller may also be mounted at a location other than the bicycle 50, such as at the rider's wrist or in a tricot bag. The communication link may be wired, wireless, or a combination thereof. The controller and / or e-bike controller may include a processor, a communication device (e.g., a wireless communication device), a memory, and one or more communication interfaces.Data from the drive unit 138 (e.g., sensors 220) and / or the crank assembly 66 may be transmitted to the e-bike controller. The data may be transmitted over one or more wired connections and / or wirelessly. For example, a torque sensor 220 generates data representing the input torque and / or the power applied to the crank axle 202 and transmits the data to the e-bike controller.All communication between the one or more system controllers of the bicycle 50 (e.g., e-bike control system 128) and each component is through wired or wireless communication. There may be discrete control with single wires from the respective system controller to each component to be controlled by the respective system controller, or at least one of the system controllers may use a controller area network (CAN) bus configured to enable communication of microcontrollers and devices in applications.The data transmitted to the system controller may be used to determine the amount of assistance to be provided to the drive unit 138 via the electric drive motor 200. Alternatively or additionally, the data transmitted to the system control device can be used for automatic shifting.The data transmitted to the system controller may include torque data from one or more sensors 220 (e.g., from the drive unit 138 and / or the crank assembly 66). The torque data may correspond to the torque input by a rider at the cranks 75 and may be used by the system controller to control, for example, an amount of assistance provided by the electric drive motor 200 (e.g., to proportionally control the electric drive motor 200) and / or as input to control an automatic shifting mode of the bicycle 50.FIGS. 5-10C show a first example of a torque sensor that can generate such torque data 220 for use by the system controller. Referring to FIGS. 4-7, the crank axle 202 or input component drives the output component 204 formed as an output ring 230 (e.g., track ring output and motor input) of the drive unit 138 in a forward drive direction, but not in a rearward drive direction, for example, through the use of a jam rotating clutch mechanism 206 (e.g., a clutch mechanism) between the crank axle 202 and the output ring 204. The crank axle 202 acts as an inner race of the clutch mechanism 206 and the output ring 230 acts as an outer race of the clutch mechanism 206.The crank axis 202 and the output ring 230 are cylindrical. For example, the crank axis 202 is a solid cylinder and the output ring 230 is a hollow cylinder. In one embodiment, the crank axle 202 is also a hollow cylinder. The crank axle 202 can be made of any number of materials, e.g., steel or an aluminum alloy.Referring to FIGS. 4-7, the clutch mechanism 206 includes members 232 disposed between the crank axle 202 and the output ring 230. The elements 232 are, for example, clamp body elements (e.g., cam-shaped wedges). Referring to FIG. 6, the clutch mechanism 206 may include any number of clamp body members 232 disposed in a volume between the crank axle 202 and the output ring 230. For example, as shown in FIG. 7, the clutch mechanism 206 may include eighteen clamp body members 232 disposed about the crank axis 202. In other embodiments, the clutch mechanism 206 includes more or fewer clamp body members 232. The clamp body members 232 may be equally spaced relative to each other about the crank axis 202.Each of the clamp body members 232 is angled relative to a radius of the crank axis 202 by a center of gravity of the respective clamp body member 232. In one embodiment, each clamp body member 232 is inclined at an equal angle. This orientation of the clamp body members 232 relative to the crank axis 202 and the output ring 230 causes the crank axis 202 and the output ring 230 to rotate together (e.g., lock like a fixed shaft) when the crank axis 202 is rotated in a first rotational direction D 1. If the crank axle 202 is rotated in a second rotational direction D 2 opposite the first rotational direction D 1 or if the output ring 230 is rotated faster than the crank axle 202 (e.g. via the electric drive motor 200), slip or free-wheeling occurs in the clamping body elements 232 such that the crank axle 202 can rotate relative to the output ring 230 or vice versa.The clutch mechanism 206 generates a strong strain in a ring portion 240 of the outer race of the clutch mechanism 206 (e.g., the output ring 230), as shown in FIGS. 5-10C, for example. The elongation in the ring portion 240 is proportional to the reaction torque. For example, by measuring the strain in the ring portion 240 of the output ring 230 (i.e., the output component), the input torque at the crank axis 202 (i.e., the input component) can be determined.The drive unit 138 and / or the frame 52 of the bicycle 50 may hold the torque sensor 220, shifts that drive the torque sensor 220, and shifts that process signals measured by the torque sensor 220.Referring to FIGS. 2-4, the drive unit 138 may be attached to the frame 52 of the bicycle via a support structure 300. The support structure 300 may include first and second brackets 302 that support the drive unit 138 on opposite sides of the drive unit 138, respectively. The first and second brackets 302 may be mounted to the frame 52 of the bicycle with the drive unit 138 being supported in the support structure 300 and the support structure 300 being mounted to the bicycle. In one embodiment, the bicycle frame 52 may include a hollow cylindrical portion (e.g., a bottom bracket housing) through which the drive unit 138 extends, and the first and second brackets 302 are mounted on opposite sides of the hollow cylindrical portion of the bicycle frame. The support structure 300 may be attached to the bicycle frame in any manner, e.g., with bolts and openings in the support structure 300 and the bicycle frame. As can be seen, the motor 200, including the rotor 250, the transmission 260, the output component 204, and the input component, both rotate about the same axis 272 and are therefore concentric.Referring to FIGS. 4-12, a torque sensor system 270 includes the output component 204 rotatable about a rotational axis 272 and the torque sensor 220. The output component 204 is rotated by the electric motor 200, for example, by the rotor 250 that is rotatable about the axis 272 and concentric with the output component 204. The torque sensor 220 includes a contact sensor 242 coupled to the output component 204, for example, the surface of the ring portion 240. The term "contact sensor" refers to a sensor that is in physical contact with the component from which the sensor acquires the information that is being captured. For example, the contact sensor 242 may be in contact with the output component 204 and is rotatable with the output component 204 about the axis 272 to measure torque applied to the output component 204 and provide an input signal. In one embodiment, the contact sensor 242 may be a strain sensor 246, such as a strain gauge, coupled to the output component 204, and more specifically to the outer circumferential surface angle 244 of a cylindrical portion of the ring portion 240 that experiences ring loading. For example, the contact sensor 242, e.g., the strain gauge, may be coupled to the output component, such as by attaching the strain gauge to the output component outer circumferential surface angle 244, wherein the contact sensor 242 is rotatable with the output component 204, and more specifically with the ring portion 240, in one embodiment.The contact sensor 242 may maintain contact with the component through the use of any technique. Gluing and / or another type of physical attachment may be used, for example, as part of the contact sensor to locate the contact sensor in contact with the output component 204. For example, as with the embodiments of the strain sensor described herein, foil-type strain gauges 246 may be coupled to the output component 204 using an adhesive between the strain gauge 246 and the output component 204. The strain gauge 246 therefore remains in contact with the output component 204 such that the strain of the output component, and particularly the ring portion 240, may be sensed by the strain sensor 246 through and / or with the adhesive, in one embodiment. Such a configuration provides a contact sensor 242. In further embodiments, a measurement device of a contact sensor 242 may be coupled to the output component 204 such that the strain of the output component 204 may be measured without the adhesive. For example, a clip, strap, or other suitable technique / attachment device may be used to couple the measurement device, i.e., contact sensor 242, to the output component 204 so that the contact sensor 242 is in physical contact with the component.As shown in FIGS. 10A-C, the contact sensor 242 may include a plurality of strain sensors 246, 248. In one embodiment, a pair of strain gauges 246, 248 are disposed along the race of the output component 204 and in radial alignment with the clamp body rotary clutch mechanism 206 as shown in FIGS. 5 and 6. During driving, the rotary clutch 206 generates a large strain in the ring portion 240 of the outer race or output component 204 in proportion to the reaction torque. The strain gauges 246, 248 may measure the strain in the ring portion 240 of the output component 204. The contact sensor 242 may be applied to other components or to other areas of the output component. In one embodiment, a primary strain gauge 246 is aligned along the race circumference of the output component 204 or orthogonally to the axis 272 in a region radially aligned with the clutch 206 to be sensitive to ring loading, while a reference strain gauge 248 is aligned orthogonally to the race circumference or parallel to the axis 272 to be sensitive to ring loading. The orientation of the primary and reference strain gauges 246, 248 are non-parallel and are orthogonal in one embodiment. By measuring the strain with a pair of strain gauges 246, 248 having different orientations, a signal resulting from thermal expansion can be removed from the output of the strain gauge 246. While the contact sensor 242 may also detect torque of the motor 200 applied to the output component, the ring load of the clamp clutch 206 and the user input is substantially greater and the magnitude of the resistance is greater (e.g., 100 x) than the strain applied to the output component 204 by the motor 200.In an alternative embodiment shown in FIG. 10C, the series of strain gauges 246, 248 may be slightly skew, for example, at an angle α, to automatically balance the motor torque signal. In various embodiments, the angle α may be between 3-5 degrees relative to a circumferential race 247 or a line 249 along the surface parallel to the axis 272.In another embodiment, shown in FIG. 10B, an additional pair of strain gauges 251, 253 may be applied to the output component 204 and directed to sense the torque applied to the output component by the motor 200. For example, the pair of strain gauges 251, 253 shown in FIG. 10B may be applied to the output component in addition to the strain gauges 246, 248 shown in FIG. 10A. A microprocessor receives input from both strain gauge sets 246, 258, 251, 253 and applies a balance of the configuration shown in FIG. 10A to the strain gauge set 246, 248 to subtract the input signal of the sensed motor torque from the strain gauge set 251, 253 of FIG. 10C.Referring to FIGS. 4-6, 11 and 12, a contactless sensor 400 is disposed between the output component 204 and a fixed component 402, such as a housing or a bicycle frame. The term "contactless sensor" refers to a sensor or device that includes a component or portion that is not in physical contact with the component, from which the sensor obtains the information that is detected or communicated even when another portion of the sensor is in physical contact with the component. As shown, the contactless sensor 400 is configured to provide an output signal that is proportional to an input signal of the contact sensor 242. The input signal is received by microprocessor 408. In one embodiment, the contactless sensor 400 is configured as a transformer and includes an inner transformer coil 404 and an outer transformer coil 406 spaced from and surrounding the inner transformer coil 404. The inner transformer coil 404 is coupled to the output component 204 and is rotatable with the output component 204 about the axis 272. As shown in FIG. 8, the inner transformer coil 404 may be axially or longitudinally spaced from the contact sensor 242. The outer transformer coil 406 is coupled to the fixed component 402, which is non-rotatable, and partially defines the "contactless sensor" because the outer transformer coil 406 is not in physical contact with the output component 204 or the inner transformer coil 404 but is radially spaced from both. Thus, the transformer defines a contactless sensor through the outer transformer coil 406 regardless of the inner transformer coil 404 being in physical contact with the output component 204. A microprocessor 408 is coupled to the output component 204 and is rotatable with the output component 204 about the axis 272. The microprocessor 408 is operatively coupled to the contact sensor 242. A bridge amplifier 416 may be disposed between the contact sensor 242 and the microprocessor 408 that is in communication with the rotating coil 404. The microprocessor 408 is configured to receive the input signal from the contact sensor 242 and control a duration or frequency of a load current drawn by the contactless sensor 400. A second microprocessor 410 may be operatively connected to the contactless sensor 400, the second microprocessor 410 configured to receive an output signal and calculate the torque applied to the output component. In one embodiment, microprocessor 410 is operatively coupled to outer transformer coil 406. A current shunt amplifier 419 may be disposed between the microprocessor 410 and the fixed coil 406.A printed circuit board (PCB) 412 may be coupled to the output component 204 and is rotatable with the output component 204 about the axis 272. In an embodiment shown in FIG. 8, the circuit board 412 is located between the contact sensor 242 and the inner transformer coil 404 and is coupled to the output component 204. The circuit board may include the microprocessor 408 operatively coupled to the contact sensor 242, e.g., the strain sensors 246, 248. In one embodiment, the circuit board 412 is formed as an annular ring having an inner circumferential surface 414 that surrounds and is coupled to the outer circumferential surface 244 of the output component 204 and the cylindrical portion of the output component 204, particularly in one embodiment, by, for example, friction fit and / or adhesive bonding.In operation, and as shown in FIGS. 11 and 12, the rotating inner coils 404 receive additional load current added by QLoad+RLoad, where QLoadis a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) to switch the additional load current. Another example is a BJT (bipolar transistor) or any other switching device. The microprocessor 408 on the rotating circuit board 412 controls how long the addition of the load current takes to generate a regular, supplemental current in the rotating inner coils 404. In the transformer coils, a voltage is induced in the fixed outer coils 406 by the regular supplemental current of the rotating inner coils 404. An alternating current is measured across the fixed outer coils 406 by applying a Rshunt (shunt resistor) with an inverter. Thus, the current supplied by the fixed coils 406 in the fixed assembly is proportional to the current consumed by the rotating inner coils 404 in the rotating assembly. A measured torque of the strain gauge 246, 248 can therefore be determined from the rotating assembly to the fixed assembly with the contactless sensor or transformer by regularly drawing additional current added by QLoad+RLoad.The duration that the additional current is drawn is proportional to the measured torque of the contact sensor 242. The first microprocessor 408 is configured to receive the input signal from the contact sensor 242 and control a duration or frequency of a load current drawn by the inner transformer coil 404. The duration in which the additional current is drawn is proportional to the measured torque.For example, according to the "transformer electric current versus time" graph shown in FIG. 13, a measured torque of 1 Nm may be derived as corresponding to a current pulse of 1 ms; a measured torque of 3 Nm may be derived as corresponding to a current pulse of 3 ms. The communication pulse would repeat with new measurement data at a useful rate or update period, such as every 50 ms. The pulse may have a minimum duration such that a torque of zero does not result in a signal such that communication errors may be detected. In another embodiment shown in FIG. 14, the pulse duration may be fixed (e.g., 1 ms), the time interval between the pulses representing the torque value (frequency coding).Referring to FIGS. 11 and 12, the torque sensor includes a fixed assembly 502 and a rotating assembly 500. In addition to the contact sensor 242, microprocessor 408, and inner transformer coil 404, the rotating assembly may include, for example, an antenna 504 and a voltage regulator 506 on the circuit board 412 and provide signal conditioning. The fixed arrangement may include, for example, an antenna 516, the microprocessor 410, inverter 514, and amplifier 419, and the external transformer coil 406 on a printed circuit board. The rotating assembly may be driven with some current conditioning / regulation after the rectifier stage by the transformer (coils 404, 406).In another embodiment, and as shown in FIG. 12, a radio transmitter 521 is in communication therewith and may transmit a signal from the microprocessor 408 on the rotating assembly (e.g., including the output component 204) via an antenna to a radio receiver 523 on the fixed assembly, for example, coupled to the radio transmitter 521 and receiver 523 on the microprocessor 410, thereby defining a contactless sensor in which the receiver 523 is spaced apart from and not in contact with the transmitter 521 or the output component 204. The radio transmitter 521 and the microprocessor 408 may be powered from a local power source (e.g., a battery) coupled to the output component 204 on the printed circuit board 412, for example, or may be powered by the transformer (coils 404, 406) or by an inductive power source. The output signal of the radio transmitter 521 received by the receiver 523 is proportional to the input signal of the contact sensor 242 or the torque measured thereby.The torque sensor may be configured to include a first sensor component, for example, the contact sensor 242, the inner transformer coil 404, and / or the radio transmitter 521 coupled to the output component 204 and rotatable with the output component 204 about the axis 272, and a second sensor component, for example, the outer transformer coil 406 and / or the radio receiver 523 radially spaced from the first sensor component and coupled to a fixed component 402, wherein the first and second sensor components are configured to measure a torque applied to the output component 204. The system requires a first sensor component rotatable with the output component and a second sensor component non-rotatable with the output component, wherein the first and second sensor components are configured to measure a torque applied to the output component 204.In one embodiment, the driver applies torque to the input component, such as the crank axle 202. The input component, in turn, applies torque to the output component via a one-way clutch 206, e.g., a clamping clutch. The method also includes measuring the torque with the contact sensor 242 coupled to the output component, regularly drawing a load current into the contactless sensor 400 based on the measured torque, supplying a contactless sensor 400 with supply current proportional to the load current, measuring the supply current supplied to the contactless sensor 400, and calculating the torque based on the measurement of the supply current. In an embodiment, regularly pulling the load current comprises generating the load current in the rotating inner transformer coil 404 and supplying the supply current comprises supplying the outer transformer coil 406 with supply current. Operation may also include receiving an input signal corresponding to torque from the contact sensor 242 with the microprocessor 408, and where regularly drawing the load current includes controlling the duration or frequency of drawing the load current with the microprocessor 408. In addition, the calculation of the supply current supplied to the contactless sensor 400 includes receiving a second input signal corresponding to the supply current from the contactless sensor with the microprocessor 410 and calculating the torque with the microprocessor 410 based on the second input signal.Alternatively, the method includes measuring torque with the contact sensor 242 coupled to the output component and transmitting an output signal from the transmitter 521 to the receiver 523. The microprocessor 410 may calculate the torque based on the output signal received from the receiver and provide a signal to control the input of the motor 200 to the output component 204.Herein, wireless communication between components is described. Although the present description describes components and functions that may be implemented in certain embodiments of wireless communication with reference to certain standards and protocols, the invention is not limited to such standards and protocols. For example, standards for transmission over the Internet and other packet switched networks (e.g., TCP / IP, UDP / IP, HTML, HTTP, HTTPS) are examples of the prior art. These standards are periodically replaced by faster or more efficient equivalents having substantially the same functions. Accordingly, replacement standards and protocols having the same or similar functions as disclosed herein are considered equivalents.In one embodiment, the bicycle components described herein communicate with each other. In the case of wireless communication, the components are first coupled to enable secure communication between the bicycle components without interference from devices not associated with the system. Subsequently, one or more components may be coupled to a separate device such as a computer, tablet, or telephone. This paired device may represent the user interface through which the user may communicate with the bicycle components, e.g., the system control device. Examples of communication include firmware update, variable setting, and diagnostic tools and analysis execution.According to the various embodiments of the present disclosure, the methods described herein may be implemented with software programs executable by a computer system such as the system controller. Moreover, in an exemplary, non-limiting embodiment, the implementations may include distributed processing, component / object distributed processing, and parallel processing. Alternatively, virtual computer system processing may be constructed to implement one or more of the methods or functions described herein.The methods and techniques described herein may be implemented using the hardware configurations described herein and one or more computer programs that provide instructions to the hardware. A computer program (also referred to as a program, software, software application, script, or code) may be written in any programming language, including compiled or interpreted languages, and may be provided in any form, including as a stand-alone program or as a module, component, subroutine, or other device suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a portion of a file that also contains other programs or data (e.g., one or more scripts stored in a markup language document), a single file dedicated to the program in question, or multiple coordinated files (e.g., files that store one or more modules, subroutines, or portions of code). A computer program may be provided for execution on one computer or on multiple computers located at one site or distributed across multiple sites and interconnected via a communication network.The processes and logic flows described in this specification may be executed by one or more programmable processors executing one or more computer programs to perform functions by responding to input data and generating output. The processes and logic flows may also be performed by dedicated logic circuits (e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit)), and the device may also be implemented as such.As used herein, the term "circuit" or "circuit" refers to all of the following elements: (a) hardware-only circuit implementations (e.g., implementations in only analog and / or digital circuits), and (b) combinations of circuits and software (and / or firmware) such as (if applicable): (i) a combination of processor(s), or (ii) portions of processor / processors / software (including digital signal processor(s)), software and memory(s) that cooperate to cause a device such as a mobile phone or server to perform various functions), and (c) circuits such as microprocessor(s) or a portion of microprocessor / microprocessors, requiring software or firmware for operation even if the software or firmware is not physically present.This definition of "circuitry" applies to all uses of this term in this application, including all claims. As another example, the term "circuitry" as used in this application would also include an implementation of only one processor (or more processors) or a portion of a processor and its (or its) accompanying software and / or firmware. The term "circuit" would also include, for example and if applicable to the respective claim element, baseband integrated circuit or application processor integrated circuit for a mobile computing device or similar integrated circuit in a server, a cellular device or other network device.Processors suitable for executing a computer program include, for example, both general and special purpose microprocessors, and one or more processors of all types of digital computers. Generally, a processor receives instructions and data from a read-only memory or a random-access memory, or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer also includes or is operatively coupled to receive data from or transmit data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical, or optical disks. However, a computer does not need to have such devices. Moreover, a computer may be embedded in another device, such as a mobile phone, a personal digital assistant ("PDA"), a mobile audio player, a global positioning system (GPS) receiver, or a system controller 150, just to name a few. Computer readable media suitable for storing computer program instructions and data include any form of non-transitory memory, media and storage devices, e.g., semiconductor memories such as EPROM, EEPROM, and flash memory, magnetic disks, e.g., internal hard or removable disks, magneto-optical disks, and CD-ROMs and DVD-ROMs. The processor and the memory may be supplemented by or integrated into special logic circuits. In one embodiment, a system controller is integrated with a mobile phone, a PDA, a mobile audio player, and a GPS receiver and wirelessly communicates with the bicycle components to enable automatic control.The figures of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The figures are not a full description of all elements and features of devices and systems that utilize the structures or methods described herein. Many other embodiments will be apparent to those skilled in the art upon review of the disclosure. Other embodiments may be utilized and derived from the disclosure such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Moreover, the figures are merely representative and may not be drawn to scale. Certain proportions in the figures may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and figures are to be regarded as illustrative rather than restrictive.While this specification contains many details, these should not be construed as limitations on the scope of the invention or the claimed subject matter, but as descriptions of features specific to particular embodiments of the invention. Certain features described in this specification in connection with individual embodiments may also be realized in combination in a single embodiment. Conversely, various features described in connection with a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features are described above as acting in certain combinations and even originally claimed as such, one or more features from a claimed combination may in some cases be taken out of the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.Although operations and / or steps are illustrated and described in a particular order in the drawings, it is not to be understood that these operations must be performed in the illustrated order or in sequential order, or that all illustrated operations must be performed to achieve the desired results. Under certain circumstances, multi-tasking and parallel processing may be advantageous. Moreover, the separation of various system components in the above-described embodiments is not to be understood as requiring such separation in all embodiments, and it is understood that all described program components and systems may generally be integrated into a single software product or packaged into multiple software products.One or more embodiments of the disclosure may be referred to herein, individually and / or collectively, by the term "invention," without the intention of limiting the scope of this application to a particular invention or inventive concept. Although certain embodiments are illustrated and described herein, any arrangement that performs the same or similar purpose may replace the illustrated embodiments. This disclosure is intended to cover any later adaptations or variations of the various embodiments. Combinations of the above embodiments and other embodiments not specifically described herein will be apparent to those skilled in the art upon review of the specification.The Abstract of the Disclosure is provided in accordance with 37 C.F.R. §1.72(b) and is submitted with the proviso that it is not used to interpret or limit the scope or meaning of the claims. Moreover, in the foregoing detailed description, various features may be summarized or described in a single embodiment to simplify the disclosure. This disclosure is not to be understood as requiring more features than are expressly recited in the individual claims. Rather, as the following claims reflect, the subject matter of the invention may be directed to less than all features of any of the disclosed embodiments. Therefore, the following claims are incorporated into the Detailed Description, with each claim standing on its own and defining the claimed subject matter separately.The foregoing detailed description is to be regarded as illustrative rather than restrictive, and the following claims, including all equivalents, are intended to define the scope of the invention. The claims are not to be understood as limited to the described order or elements unless noted. Therefore, all embodiments which fall within the scope of the following claims and their equivalents and are within the scope thereof are claimed as the invention.

Claims

A torque sensor system for an electric bicycle, comprising: an output component rotatable about an axis, the output component configured to be rotated by an electric motor; a contact sensor coupled to the output component, the contact sensor configured to measure a torque applied to the output component and provide an input signal; and a contactless sensor disposed between the output component and a fixed component, the contactless sensor configured to provide an output signal proportional to the input signal.The torque sensor system of claim 1, wherein the contact sensor comprises a strain gauge coupled to the output component.The torque sensor system of claim 1 or 2, wherein the contactless sensor comprises an inner transformer coil and an outer transformer coil spaced from and surrounding the inner transformer coil, wherein the inner transformer coil is coupled to the output component and is rotatable about the axis with the output component, and wherein the outer transformer coil is coupled to the fixed component.The torque sensor system of any preceding claim, further comprising a first microprocessor coupled to the output component and rotatable with the output component about the axis, the first microprocessor operatively coupled to the contact sensor, the first microprocessor configured to receive the input signal and a duration of a load current drawn by a contactless sensor.The torque sensor system of claim 4, further comprising a second microprocessor operatively connected to the contactless sensor, the second microprocessor configured to receive an output signal and calculate the torque applied to the output component.The torque sensor system of any preceding claim, further comprising an input component rotatable about the axis and concentric with the output component and a one-way clutch disposed between the input component and the output component, wherein the one-way clutch is engaged between the input component and the output component when the input component is rotated in a first rotational direction and wherein the one-way clutch is disengaged between the input component and the output component when the input component is rotated in a second rotational direction opposite the first rotational direction.The torque sensor of any preceding claim, wherein the output component comprises a cylindrical portion, the contact sensor being applied to the cylindrical portion.The torque sensor of any preceding claim, wherein the contactless sensor comprises a radio transmitter coupled to the output component and a radio receiver coupled to the fixed component.A torque sensor system for an electric bicycle, comprising: an output component rotatable about an axis, the output component configured to be rotated by an electric motor; a strain sensor coupled to the output component and rotatable with the output component about the axis.The torque sensor of claim 9, further comprising: an inner transformer coil coupled to the output component and rotatable with the output component about the axis; and a non-rotatable outer transformer coil radially spaced from and surrounding an inner transformer coil.The torque sensor of claim 10, further comprising a printed circuit board (PCB) coupled to the output component and rotatable with the output component about the axis.The torque sensor of claim 11, wherein the circuit board is formed as an annular ring.The torque sensor of claim 11 or 12, further comprising a second microprocessor operatively coupled to the outer transformer coil.The torque sensor of any of claims 9 to 13, further comprising an input component rotatable about the axis and concentric with the output component and a one-way clutch disposed between the input component and the output component, wherein the one-way clutch is engaged between the input component and the output component when the input component is rotated in a first rotational direction, and wherein the one-way clutch is disengaged between the input component and the output component when the input component is rotated in a second rotational direction opposite the first rotational direction.The torque sensor of any of claims 9 to 14, wherein the output component comprises a cylindrical portion, the strain sensor being applied to the cylindrical portion.The torque sensor of claim 15, wherein the strain sensor comprises a first strain gauge having a first orientation and a second strain gauge having a second orientation that is non-parallel to the first orientation.The torque sensor of any of claims 9 to 16, further comprising: a radio transmitter coupled to the output component and rotatable with the output component about the axis; and a radio receiver spaced from and in communication with the radio transmitter.

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