Torque sensor system and drive system for electric bicycle and method of using same

Abstract

The invention relates to a torque sensor system and drive system for an electric bicycle and a method of using the same. The torque sensor comprises a contact sensor and a non-contact sensor. An electric drive system for a bicycle includes a motor having a rotor rotatable about an axis. The output member is coupled to the electric motor and is rotatable about an axis. The input member is rotatable about an axis and concentric with the output member and the rotor. A one-way clutch is disposed between the input member and the output member. The contact sensor is coupled to the output member. The touch sensor is configured to measure a torque applied by the input member to the output member and to provide an input signal. The non-contact sensor is disposed between the output member and the fixed member. The non-contact sensor is configured to provide an output signal proportional to the input signal.

Description

Technical Field

[0001] The present disclosure relates generally to sensors for bicycles, and more particularly to torque sensors, drive systems, and methods of use thereof for electric bicycles. Background Art

[0002] A bicycle with a pedal-assisted electric motor (eg, an e-bike or electric bicycle) may include sensors that monitor parameters at the bicycle. The monitored parameters may include, for example, input torque at the crank arm assembly of the bicycle.

[0003] The sensor monitoring the input torque may be positioned at the rear dropout, where the force applied from the rider to the crankset is transmitted through the chain, flywheel, hub and axle before the sensor receives the force, requiring a series of calculations and compensations, and potential errors in calculating torque. Alternatively, the input shaft may be directly accessible by the control electronics, so the rider torque can be measured directly. However, in a drive system where the motor is concentric with the rider input shaft, there is no direct path between the control electronics and the rider input shaft, making it difficult to measure torque at the rider input interface. Summary of the invention

[0004] In one aspect, an embodiment of a torque sensor system for an electric bicycle includes an output component rotatable about an axis, wherein the output component is configured to be rotated by an electric motor. A contact sensor is coupled to the output component. The contact sensor is configured to measure the torque applied to the output component and provide an input signal. A non-contact sensor is disposed between the output component and a fixed component. The non-contact sensor is configured to provide an output signal proportional to the input signal.

[0005] On the other hand, an embodiment of a torque sensor system for an electric bicycle includes an output component rotatable about an axis, wherein the output component is configured to be rotated by an electric motor. The strain sensor is operably coupled to the output component and rotatable about the axis with the output component. In one embodiment, the internal transformer coil is coupled to the output component and rotatable about the axis with the output component. The non-rotatable external transformer coil is radially spaced from the internal transformer coil and surrounds the internal transformer coil. In another embodiment, a radio transmitter is coupled to the output component and rotatable about the axis with the output component, while a radio receiver communicating with the transmitter is spaced from the transmitter and is not in physical contact with the output component.

[0006] On the other hand, an embodiment of an electric drive system for a bicycle includes a motor having a rotor rotatable about an axis. An output member is coupled to the electric motor and rotatable about the axis. An input member is rotatable about the axis and is concentric with the output member and the rotor. A one-way clutch is disposed between the input member and the output member. When the input member rotates in a first rotational direction, the one-way clutch engages between the input member and the output member, and wherein when the input member rotates in a second rotational direction opposite to the first rotational direction, the one-way clutch disengages between the input member and the output member. A contact sensor is coupled to the output member. The contact sensor is configured to measure a torque applied to the output member by the input member and provide an input signal. A non-contact sensor is disposed between the output member and a fixed member. The non-contact sensor is configured to provide an output signal proportional to the input signal.

[0007] In one embodiment, the torque sensor includes a first sensor component and a second sensor component, wherein the first sensor component is coupled to an output component and is rotatable with the output component about an axis, and the second sensor component is radially spaced apart from the first sensor component and coupled to a stationary component, wherein the first sensor component and the second sensor component are configured to measure a torque applied to the output component.

[0008] In another aspect, one embodiment of a method of measuring torque applied to a bicycle drive train includes: applying torque to an output member using an input member; measuring the torque using a contact sensor coupled to the output member; periodically drawing a load current in a contactless sensor based on the measured torque; supplying a supply current proportional to the load current to the contactless sensor; measuring the supply current supplied to the contactless sensor; and calculating the torque based on the measurement of the supply current.

[0009] Various aspects and embodiments of torque sensors, drive systems and methods provide significant advantages over other torque sensors, drive systems and methods. For example, but not limited to, the torque sensor provides accurate torque measurement and is suitable for drive systems with motor inputs that are concentric with the rider input shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a side view of one example of an electric bicycle including a torque sensor according to the teachings of the present disclosure;

[0012] Figure 2 is a perspective view of one embodiment of a drive system;

[0013] Figure 3 yes Figure 2 A top view of the drive system;

[0014] Figure 4 yes Figure 2 Cross-section of the drive system;

[0015] Figure 5 is a partial cross-section of a drive system including a torque sensor;

[0016] Figure 6 is a partial enlarged cross section of the drive system;

[0017] Figure 7 It is a partial end view of the drive system;

[0018] Figure 8 It is a partial internal stereogram of the drive system;

[0019] Fig. 9 It is a partial external stereogram of the drive system;

[0020] FIG. 10A to FIG. 10C Different contact sensor arrangements are shown;

[0021] Fig.11 is a block diagram illustrating one embodiment of a torque sensor;

[0022] Fig.12 is a schematic diagram of an embodiment of a torque sensor;

[0023] Fig.13 is one embodiment of a graph of current draw versus time for calculating measured torque;

[0024] Fig.14 is another embodiment of a graph of current draw versus time for calculating measured torque.

[0025] Other aspects and advantages of the embodiments disclosed herein will become apparent by consideration of the following detailed description, in which similar or identical structures are provided with similar reference numerals. DETAILED DESCRIPTION

[0026] A bicycle (e.g., an electric bicycle) having an electric pedal assist motor capable of driving a chain ring independently of a crank is provided. Accurate, robust, and cost-effective torque sensing is provided for controlling an electric bicycle. To proportionally control the electric pedal assist motor, a controller of the bicycle can vary the electric assistance provided by the assist motor based on the amount of input torque generated by the rider at the crank assembly of the bicycle. For example, as the sensed input torque increases, the controller increases the electric assistance provided by the assist motor, and as the sensed input torque decreases, the controller decreases the electric assistance provided by the assist motor.

[0027] For a bicycle transmission / derailleur utilizing electronic shifting, as the cadence (cadence) increases, the controller running the automatic shifting algorithm initiates the shift. However, a bicycle rider may prefer to pedal at a lower cadence when riding at a leisurely pace, and may prefer to pedal at a higher cadence when riding vigorously. Automatic cadence band adjustment may be provided based on sensed riding scenarios. For example, the controller may increase the target cadence for automatic shifting, and therefore increase the target cadence band, when high input torque is sensed, and reduce the target cadence and target cadence band for automatic shifting when low input torque is sensed.

[0028] A torque sensor according to the present disclosure may be incorporated into a radial contact clutch type system, such as a roller bearing or sprag type rotating clutch mechanism of an electric bicycle system. For example, a sprag type rotating clutch mechanism may be disposed between a crank input (e.g., a crank axle) and a chain ring output and / or a motor input of an electric bicycle system. The sprag type rotating 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 chain ring output in a first rotational direction via the sprag type rotating clutch mechanism, but rotates freely in a second rotational direction. The sprag type rotating clutch mechanism slips or overruns when an auxiliary motor of the electric bicycle system drives the chain ring output such that the chain ring output rotates faster than the crank input (e.g., pedaled by a rider of the bicycle).

[0029] For example, a sprag-type rotating clutch mechanism generates high strain in the hoop section of the outer race of the clutch mechanism (e.g., a portion of the chain ring output) that is proportional to the reaction torque. The torque sensor of the present disclosure can measure the strain in the hoop section of the outer race. The measured strain can provide input to the sensor. The torque sensor can be a contact sensor and / or configured to rotate with the hoop section of the outer race to measure the strain or other characteristics of the hoop section that indicate the torque transmitted through the hoop section.

[0030] Various embodiments of the present invention will be described herein with reference to the accompanying drawings. It should be understood that the drawings and descriptions set forth herein are for illustration only and are not limiting of the present invention as defined by the appended claims and any and all equivalents thereof.

[0031] It should be understood that the specific arrangement of the frame, front wheel, rear wheel, drive train, front brake, rear brake, and saddle and the components shown are non-limiting to the disclosed embodiments. For example, while the front and rear brakes are shown as hydraulic disc brakes, hydraulic rim brakes are contemplated and encompassed within the scope of the present disclosure. Additionally, mechanical systems including mechanical rim brakes and mechanical disc brakes, as well as other electronic, hydraulic, pneumatic, and mechanical systems or combinations thereof (such as suspension systems) are contemplated and encompassed within the scope of the present disclosure.

[0032] It should be understood that the term "plurality" as used herein refers to two or more. As used herein, the term "longitudinal" refers to or relates to a length direction or a longitudinal direction. As used herein, the term "lateral" refers to being located in a lateral direction, pointing in a lateral direction, or extending in a lateral direction. The term "coupled" refers to being connected to or joined with... directly or indirectly (e.g., using an intermediate member), and does not require the joining to be fixed or permanent, although it can be fixed or permanent. As used herein, the terms "first", "second", etc. are not meant to be assigned to a specific component so designated, but simply refer to such components in the numerical order mentioned, meaning that a component designated as "first" may later be a "second" such component, depending on the order in which the components are referenced. It should also be understood that the designation of "first" and "second" does not necessarily mean that the two components or values ​​so designated are different, meaning that, for example, the first axis may be the same as the second axis, where each is simply applicable to different components. The terms "upper", "lower", "back", "front", "front", "back", "vertical", "horizontal", "right", "left", "inside", "outside" and variations or derivatives thereof refer to Figure 1 The illustrated exemplary bicycle 50 is oriented from the perspective of a user seated thereon, such that "inboard" components or features are closer to a vertical mid-plane of the bicycle extending in direction A. The term "lateral" means non-parallel. The terms "outboard" and "outwardly" refer to directions or features that point away from a central location, such as the phrases "radially outwardly," "radial directions," and / or their derivatives refer to directions or features that point away from a central location (e.g., Figures 1 to 5 In contrast, the terms "inwardly" and "inwardly" refer to directions toward a center or interior position. The term "subassembly" refers to an assembly of multiple components, wherein the subassembly is capable of being further assembled into other subassemblies and / or a final assembly, such as the bicycle 100.

[0033] Turning now to the accompanying drawings, Figure 1A bicycle 50 is generally shown with which one or more system control devices can be used to implement a bicycle control system using the torque sensors described herein. In this example, the bicycle 50 can be a mountain bike. In some cases, the bicycle 50 can be an electric bicycle. The bicycle 50 has a frame 52, a handlebar 54 near the front end of the frame 52, and a seat or saddle 56 for supporting a rider on top of the frame 52. The bicycle 50 also has a first wheel or front wheel 58 carried by a front fork 60 of the frame 52 and supporting the front end of the frame 52. The bicycle 50 also has a second wheel or rear wheel 62 supporting the rear end of the frame 52. The rear end of the frame 52 can be connected to a rear suspension component 61. The bicycle 50 also has a drive train 64 having a crank assembly 66, which is operably coupled to a rear flywheel 70 located near the axis of rotation of the rear wheel 62 via a chain ring 65, a chain 68, and a rear derailleur 37. The crank assembly 66 includes two cranks 75 on opposite sides of the frame 52 of the bicycle 50 and two pedals 76 respectively connected to the two cranks 75. In the example shown, the rear derailleur 37 includes a power source (e.g., a battery) and a motor, and receives instructions (e.g., wirelessly) from a controller 126 (e.g., a shifter or a central controller) mounted, for example, to the handlebar 54 or the frame 52 to shift gears on the rear flywheel 70.

[0034] A battery 130 for the electric bicycle control system 128 is also supported by the frame 52 of the bicycle 50. For example, the battery 130 for the electric bicycle control system 128 is supported by the bottom tube 53 of the frame 52 of the bicycle 50. One or more components of the bicycle 50 (e.g., the controller 126) can be connected to the power supply 130 of the electric bicycle control system 128 via other wires.

[0035] The battery 130, for example, powers a drive unit 138 (e.g., including an electric bicycle motor 200) that is operably coupled to the crank assembly 66. In one embodiment, the drive unit 138 can also be powered by a separate battery to provide access to electric bicycle controls when the battery 130 of the electric bicycle control system 128 is not attached to the bicycle 100. Figure 4 In one embodiment shown, the motor 200 includes a rotor 250 that rotates relative to a stator 252. The rotationally fixed stator 252 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 coupled to the output member 204 and drives the output member 204. A transmission 260 or speed reducer may be coupled between the rotor 250 and the output member 204.

[0036] 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 through a threaded opening in the frame 52 of the bicycle 50 and one or more bolts. The drive unit 138 can be attached to the frame 52 in other ways. A crank axle 202 (e.g., a crank spindle) extends through the opening of the drive unit 138 and connects the two cranks 75 of the crank assembly 66. During operation, the rider rotates the two cranks 75 via the two pedals 76, thereby rotating the crank axle 202. The crank axle 202, which defines an input member, drives the output member 204 (e.g., a chain ring axle) of the drive unit 138 in a forward driving direction rather than in a rearward pedaling direction by utilizing, for example, a one-way clutch 206 (e.g., a sprag-type rotating clutch mechanism) located between the crank axle 202 and the output member 204.

[0037] The measured torque applied to the crankshaft 202 or input member may be used to control the electric drive motor 200 (e.g., an auxiliary motor) of the drive unit 138. The motor 200 may drive the rotation of the output member 204, either directly or through the use of gears in the transmission 260. Thus, the output member 204 provides an output power to the drivetrain 64 that is a combination of the rider input power from the crankshaft 202 and the output power of the auxiliary motor 200.

[0038] Although Figure 1 The bicycle 50 depicted in the figure is a mountain bike and may include suspension components, such as a suspension fork, but the specific embodiments and examples disclosed herein and alternative embodiments and examples may be implemented on other types of bicycles. For example, the disclosed torque sensor may be used on road bicycles and bicycles with mechanical (e.g., cable, hydraulic, pneumatic, etc.) and non-mechanical (e.g., wired, wireless) drive systems.

[0039] The front and / or forward orientation of the bicycle 50 is determined by Figure 1 In this way, the forward movement direction of the bicycle 50 is indicated by the direction of the arrow "A".

[0040] The drive unit 138 may include internal electronics to control the operation of the auxiliary motor 200, measure shaft inputs, measure the inclination of the bicycle 50, measure the acceleration of the bicycle 50, measure the temperature of the bicycle 50, and / or reduce the voltage of the battery 130 of the electric bicycle control system 128 to accommodate and power external devices when a lower voltage is required. For example, the internal electronics of the drive unit 138 may include one or more torque sensors 220. Additional, fewer, and / or different internal electronics may be provided within the drive unit 138.

[0041] The controller of the drive unit 138 (e.g., an electric bicycle central control system or controller; system control device) can be disposed on the housing of the drive unit 138 and wired to the internal electronics of the drive unit 138. Alternatively or additionally (e.g., as part of the same housing), the electric bicycle controller can be supported by the same housing as the power source 130. The electric bicycle controller can be made of a material through which wireless control signals can pass. In one embodiment, the electric bicycle controller is wired to the electric bicycle control system 128.

[0042] The electric bicycle controller can control power from the power source 130 to components on the bicycle 50 (e.g., the electric drive motor 200 of the drive unit 138). The electric bicycle controller can control power to other and / or different components on the bicycle 50. The electric bicycle controller can send signals (e.g., commands) to and / or receive data (e.g., commands and / or sensor data) from components on the bicycle 50 (e.g., the rear derailleur 37, the suspension system, and / or the seat post assembly) to actuate and / or control components of the bicycle 50.

[0043] In other embodiments, the electric bicycle controller can be located at other locations on the bicycle 50 (e.g., mounted on the handlebars 54), or alternatively, can be distributed between various components of the bicycle 50, where communication links are arranged to accommodate the necessary signal and power paths. For example, the control unit 126 (e.g., used as an electric bicycle controller; system control device) can be mounted to the handlebars 54 for actuating the motor of the rear derailleur 37 and operating the rear derailleur 37 to perform shifting and gear selection. However, the control unit 126 and / or the electric bicycle controller can be located at any location on the bicycle 50, or alternatively, can be distributed between various components of the bicycle 50, where communication links are arranged to accommodate the necessary signal and power paths. The control unit and / or the electric bicycle controller can also be located at other locations besides the bicycle 50, for example, on the rider's wrist or in a jersey pocket. The communication link can include wireless, can be wireless, or can be a combination of wired and wireless. The control unit and / or the electric bicycle controller can include a processor, a communication device (e.g., a wireless communication device), a memory, and one or more communication interfaces.

[0044] Data from the drive unit 138 (e.g., sensor 220) and / or the crank assembly 66 can be transmitted to the electric bicycle controller. The data can be transmitted via one or more wired connections and / or wirelessly. For example, the torque sensor 220 generates data representing the input torque and / or power applied to the crankshaft 202 and transmits the data to the electric bicycle controller.

[0045] All communications between one or more system control devices (e.g., the electric bicycle control system 128) of the bicycle 50 and each component are accomplished via wired or wireless communications. Discrete control may be accomplished using individual lines from the respective system control device to each component to be controlled by the respective system control device, or at least one of the system control devices may use a controller area network ("CAN") bus configured to allow microcontrollers and devices to communicate with each other in an application.

[0046] The data transmitted to the system control may be used to determine the amount of assistance provided via electric drive motor 200 of drive unit 138. Alternatively or additionally, the data transmitted to the system control may be used for automatic gear shifting.

[0047] The data transmitted to the system control device may include torque data from one or more sensors 220 (e.g., of drive unit 138 and / or crank assembly 66). For example, the torque data may correspond to the torque input by the rider at crank 75 and may be used by the system control device to control the amount of assistance provided by electric drive motor 200 (e.g., for proportional control of electric drive motor 200) and / or as an input for controlling an automatic shifting mode of bicycle 50, for example.

[0048] Figures 5 to 10C A first example of a torque sensor 220 that can generate such torque data for use by system control is shown. Figures 4 to 7 The crankshaft 202 or input member drives the output member 204 (the output member 204 is configured as an output ring 230) of the drive unit 138 in a forward driving direction but not in a rearward pedaling direction by utilizing, for example, a sprag-type rotating clutch mechanism 206 (e.g., a clutch mechanism) located between the crankshaft 202 and the output member 204 (e.g., a chain ring output and a motor input). The crankshaft 202 serves as an inner race of the clutch mechanism 206, and the output ring 230 serves as an outer race of the clutch mechanism 206.

[0049] The crankshaft 202 and the output ring 230 are cylindrical. For example, the crankshaft 202 is a solid cylinder and the output ring 230 is a hollow cylinder. In one embodiment, the crankshaft 202 is also a hollow cylinder. The crankshaft 202 can be made of any number of materials, including, for example, steel or aluminum alloys.

[0050] Reference Figures 4 to 7 , the clutch mechanism 206 includes an element 232 disposed between the crankshaft 202 and the output ring 230. The element 232 is, for example, a wedge element (eg, a cam-shaped wedge). Figure 6 , the clutch mechanism 206 may include any number of sprag elements 232 disposed within the volume between the crankshaft 202 and the output ring 230. For example, Figure 7 As shown, the clutch mechanism 206 can include eighteen sprag elements 232 disposed about the crank axle 202. In other embodiments, the clutch mechanism 206 includes more or fewer sprag elements 232. The sprag elements 232 can be equally spaced relative to each other about the crank axle 202.

[0051] Each wedge element 232 is angled or tilted relative to a radius of the crankshaft 202 passing through the centroid of the corresponding wedge element 232. In one embodiment, each wedge element 232 is angled or tilted at the same angle. When the crankshaft 202 rotates in the first rotational direction D1, this orientation of the wedge elements 232 relative to the crankshaft 202 and the output ring 230 provides that the crankshaft 202 and the output ring 230 rotate together (e.g., locked like a solid shaft). When the crankshaft 202 rotates in a second rotational direction D2 opposite to the first rotational direction D1 or the output ring 230 rotates faster than the crankshaft 202 (e.g., via the electric drive motor 200), the wedge elements 232 slip or overtake, thereby allowing the crankshaft 202 to rotate relative to the output ring 230, and vice versa.

[0052] The clutch mechanism 206 generates high strain in the hoop section 240 of the outer race (eg, output ring 230) of the clutch mechanism 206, such as Figures 5 to 10C The strain in the hoop section 240 is proportional to the reaction torque. Therefore, by measuring the strain in the hoop section 240 of the output ring 230 (ie, the output component), for example, the input torque at the crankshaft 202 (ie, the input component) can be determined.

[0053] The drive unit 138 and / or the frame 52 of the bicycle 50 may support the torque sensor 220 , circuitry that drives the torque sensor 220 , and circuitry that processes signals measured by the torque sensor 220 .

[0054] refer to Figures 2 to 4, the drive unit 138 can be mounted to the frame 52 of the bicycle via the support structure 300. The support structure 300 can include a first support and a second support 302 that support the drive unit 138 on opposite sides of the drive unit 138, respectively. The first support and the second support 302 can be attached to the frame 52 of the bicycle, wherein the drive unit 138 is captured within the support structure 300, and the support structure 300 is attached to the bicycle. In one embodiment, the frame 52 of the bicycle can include a hollow cylindrical portion (e.g., a bottom bracket shell), the drive unit 138 extends through the hollow cylindrical portion, and the first support and the second support 302 are attached to opposite sides of the hollow cylindrical portion of the frame of the bicycle. The support structure 300 can be attached to the frame of the bicycle in any number of ways, including, for example, with openings and bolts located in the support structure 300 and the frame of the bicycle. As can be appreciated, the motor 200 including the rotor 250, the transmission 260, the output member 204, and the input member all rotate about the same axis 272, and are therefore concentric.

[0055] refer to Figures 4 to 12 , the torque sensor system 270 includes an output member 204 rotatable about a rotation axis 272 and a torque sensor 220. The output member 204 is rotated by the electric motor 200, for example, by the rotor 250, which is rotatable about the axis 272 and is concentric with the output member 204. The torque sensor 220 includes a contact sensor 242 coupled to the output member 204 (e.g., the surface of the hoop section 240). The phrase "contact sensor" refers to a sensor that is in physical contact with a component from which the sensor obtains sensed information. For example, the contact sensor 242 can be in contact with the output member 204 and can rotate with the output member 204 about the axis 272 to measure the torque applied to the output member 204 and provide an input signal. In one embodiment, the contact sensor 242 can be a strain sensor 246 (e.g., a strain gauge) coupled to the output member 204, and specifically coupled to the outer circumferential surface 244 of the cylindrical portion of the hoop section 240 that is subjected to hoop stress or hoop stress. In one embodiment, a contact sensor 242 (eg, a strain gauge) may be coupled to the output member, such as by adhering the strain gauge to an outer circumferential surface 244 of the output member, wherein the contact sensor 242 may rotate with the output member 204 and particularly the hoop segment 240 .

[0056] The contact sensor 242 can be maintained in contact with the component using any technique. For example, adhesion and / or other physical attachment can be used as part of the contact sensor to place the contact sensor in contact with the output component 204. In one embodiment, for example, as with the strain sensor embodiments described herein, the foil strain gauge 246 can be coupled to the output component 204 using an adhesive between the strain gauge 246 and the output component 204. In this way, the strain gauge 246 will be maintained in contact with the output component 204 in a manner such that the strain of the output component (in one embodiment, particularly the hoop section 240) can be sensed by the strain sensor 246 through the adhesive and / or using the adhesive. This configuration results in the contact sensor 242. In other embodiments, the measurement device of the contact sensor 242 can be coupled to the output component 204 so that the strain of the output component 204 can be measured in the absence of an adhesive. For example, a clamp, a band or other suitable technique / attachment device can be used to couple the measurement device (i.e., the contact sensor 242) to the output component 204 so that the contact sensor 242 is in physical contact with the component.

[0057] like FIG. 10A to FIG. 10C As shown, 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 member 204 and radially aligned with the sprag type rotating clutch 206, as shown in FIG. Figure 5 and Figure 6 As shown. During riding, the rotating clutch 206 generates high strain in the hoop section 240 of the outer race or output member 204 that is proportional to the reaction torque. The strain gauges 246, 248 can measure the strain in the hoop section 240 of the output member 204. The contact sensor 242 can be applied to other components or other areas of the output member. In one embodiment, the main strain gauge 246 is aligned / consistent with the seat circumference of the output member 204 along the seat circumference of the output member 204 in an area radially aligned with the clutch 206 or oriented orthogonally to the axis 272 so as to be sensitive to hoop stress, while the reference strain gauge 248 is oriented orthogonal to the seat circumference or parallel to the axis 272 so as to be insensitive to hoop stress. The orientations of the main strain gauge 246 and the reference strain gauge 248 are non-parallel and, in one embodiment, are orthogonal. By measuring strain with a pair of strain gauges 246, 248 having different orientations, signals due to thermal expansion can be removed from the output of the strain gauge 246. While the contact sensor 242 may also sense torque applied to the output member from the motor 200 , the hoop stress from the sprag clutch 206 and user input is significantly greater than the strain introduced to the output member 204 by the motor 200 , by several orders of magnitude (eg, 100x).

[0058] exist Fig. 10C In the illustrated alternative embodiment, the set of strain gauges 246, 248 may be slightly tilted, for example, at an angle α to automatically compensate for the motor torque signal. In various embodiments, the angle α may be between 3 and 5 degrees, including 3 and 5 degrees, relative to the circumferential race 247 or relative to a line 249 along a surface parallel to the axis 272.

[0059] In another embodiment, Fig. 10B As shown, an additional set of strain gauges 251, 253 may be applied to the output member 204 and oriented to detect the torque applied to the output member by the motor 200. For example, in addition to Fig. 10A In addition to the strain gauges 246 and 248 shown in FIG. Fig. 10B A set of strain gauges 251, 253 shown in FIG. 2 can be applied to the output component. The microprocessor receives inputs from the two sets of strain gauges 246, 258, 251, 253 and responds to the Fig. 10A The strain gauge groups 246, 248 in the configuration shown apply compensation to subtract the Fig. 10C The strain gauge groups 251 and 253 detect the input signal of the motor torque.

[0060] refer to Figures 4 to 6 , Fig.11 and Fig.12 , the non-contact sensor 400 is disposed between the output component 204 and a fixed component 402 (such as a housing or a bicycle frame). The phrase "non-contact 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 sensed or transmitted information), even if another portion of the sensor may be in physical contact with the component. As shown, the non-contact sensor 400 is configured to provide an output signal proportional to an input signal from the contact sensor 242. The input signal is received by a microprocessor 408. In one embodiment, the non-contact sensor 400 is configured as a transformer and includes an internal transformer coil 404 and an external transformer coil 406 spaced apart from and surrounding the internal transformer coil 404. The internal transformer coil 404 is coupled to the output component 204 and is rotatable about the axis 272 with the output component 204. The internal transformer coil 404 may be axially or longitudinally spaced apart from the contact sensor 242, such as Figure 8As shown. The outer transformer coil 406 is coupled to the fixed component 402 (the fixed component 402 is non-rotatable) and partially defines a "non-contact 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. In this way, the transformer defines a non-contact sensor through the outer transformer coil 406, although the inner transformer coil 404 is in physical contact with the output component 204. The microprocessor 408 is coupled to the output component 204 and can rotate with the output component about the axis 272. The microprocessor 408 is operably coupled to the contact sensor 242. A bridge amplifier 416 can be provided between the contact sensor 242 and the microprocessor 408, which communicates with the rotating coil 404. The microprocessor 408 is configured to receive an input signal from the contact sensor 242 and control the duration or frequency of the load current drawn by the non-contact sensor 400. The second microprocessor 410 can be operably coupled to the non-contact sensor 400, wherein the second microprocessor 410 is configured to receive the output signal and calculate the torque applied to the output component. In one embodiment, the microprocessor 410 is operably coupled to the external transformer coil 406. A current shunt amplifier 419 can be disposed between the microprocessor 410 and the stationary coil 406.

[0061] A printed circuit board (PCB) 412 can be coupled to the output member 204 and can rotate with the output member 204 about the axis 272. Figure 8 As shown, the PCB 412 is positioned between the contact sensor 242 and the internal transformer coil 404 and coupled to the output component 204. The PCB may include a microprocessor 408 operably coupled to the contact sensor 242 (e.g., the strain sensors 246, 248). In one embodiment, the PCB 412 is configured as an annular ring having an inner circumferential surface 414 that surrounds and couples to the outer circumferential surface 244 of the output component 204, and in particular, in one embodiment, surrounds and couples to the cylindrical portion of the output component 204, such as by friction fit and / or bonding with an adhesive.

[0062] In operation, and with reference to Fig.11 and Fig.12 , the rotating internal coil 404 receives the Q Load +R Load The additional load current added, where Q Loadis a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) for switching the additional load current. Another example would be a BJT (Bipolar Junction Transistor) or any other switching device. The microprocessor 408 on the rotating PCB 412 controls the duration of the added load current to generate a periodic additional current to the rotating inner coil 404. Within the transformer coil, the periodic additional current through the rotating inner coil 404 induces a voltage in the fixed outer coil 406. By applying R shunt (shunt resistor) and inverter to measure the AC from the stationary external coil 406. In this way, the current supplied by the stationary external coil 406 in the stationary assembly is proportional to the current consumed by the rotating internal coil 404 in the rotating assembly. Load +R Load The additional current added may determine the measured torque from the strain gauges 246, 248 from the rotating component to the stationary component using a non-contact sensor or transformer.

[0063] In simple terms, the duration of the additional current draw is proportional to the measured torque of the contact sensor 242. The first microprocessor 408 is configured to receive an input signal from the contact sensor 242 and control the duration or frequency of the load current drawn by the internal transformer coil 404. The duration of the additional current draw is proportional to the measured torque.

[0064] References Fig.13 The transformer current versus time graph shown in , can obtain a measured torque of 1Nm corresponding to a current pulse of 1ms; can obtain a measured torque of 3Nm corresponding to a current pulse of 3ms. The communication pulse will be repeated with new measurement data at a useful rate or update period (for example, every 50ms). The pulse can have a minimum duration so that zero torque does not result in no signal, so that communication errors can be detected. In another embodiment, as Fig.14 As shown, the pulse duration may be fixed (eg 1 ms), with the period between pulses representing the torque value (frequency encoding).

[0065] Reference Fig.11 and Fig.12 , the torque sensor includes a fixed component 502 and a rotating component 500. In addition to the contact sensor 242, the microprocessor 408 and the internal transformer coil 404, the rotating component may include an antenna 504 and a voltage regulator 506, for example, on a PCB 412, and provide signal conditioning. The fixed component may include an antenna 516, a microprocessor 410, an inverter 514 and an amplifier 419, and the external transformer coil 406, for example, on a PCB. The rotating component may be powered by the transformer (coils 404, 406) with some power conditioning / regulation after the rectifier stage.

[0066] In another embodiment, and with reference to Fig.12 , the radio transmitter 521 communicates with the microprocessor 408 on the rotating component (e.g., including the output component 204) and can transmit signals from the microprocessor 408 on the rotating component to the radio receiver 523 (which is, for example, coupled to the microprocessor 410) on the fixed component via an antenna, wherein the radio transmitter 521 and the receiver 523 thereby define a non-contact sensor because the receiver 523 is spaced apart from and not in physical contact with the transmitter 521 or the output component 204. The radio transmitter 521 and the microprocessor 408 can be powered by a local power source (e.g., a battery) coupled to the output component 204, for example, on the PCB 412, or can be powered by a transformer (coils 404, 406) or an inductive power source. The output signal from the radio transmitter 521 received by the receiver 523 is proportional to the input signal from the contact sensor 242 or the torque measured by the contact sensor 242.

[0067] The torque sensor may be configured to include a first sensor component (e.g., contact sensor 242, inner transformer coil 404, and / or radio transmitter 521) coupled to output component 204 and rotatable with output component 204 about axis 272, and a second sensor component (e.g., outer transformer coil 406 and / or radio receiver 523) radially spaced from the first sensor component and coupled to stationary component 402, wherein the first sensor component and the second sensor component are configured to measure torque applied to output component 204. It should be appreciated that the system requires a first sensor component that is rotatable with the output component and a second sensor component that is non-rotatable with the output component, wherein the first sensor component and the second sensor component are configured to measure torque applied to output component 204.

[0068] In one embodiment, the rider applies torque to an input member, such as a crankshaft 202. The input member in turn applies torque to an output member through a one-way clutch 206 (e.g., a sprag clutch). The method also includes measuring torque using a contact sensor 242 coupled to the output member, periodically drawing a load current in a non-contact sensor 400 based on the measured torque, supplying a supply current proportional to the load current to the non-contact sensor 400, measuring the supply current supplied to the non-contact sensor 400, and calculating torque based on the measurement of the supply current. In one embodiment, periodically drawing the load current includes generating the load current in a rotating internal transformer coil 404, and supplying the supply current includes supplying the supply current to an external transformer coil 406. Operations may also include receiving an input signal corresponding to the torque from the contact sensor 242 using a microprocessor 408, and wherein periodically drawing the load current includes controlling the duration or frequency of drawing the load current using the microprocessor 408. In addition, calculating the supply current supplied to the non-contact sensor 400 includes receiving a second input signal corresponding to the supply current from the non-contact sensor using the microprocessor 410 , and calculating the torque using the microprocessor 410 based on the second input signal.

[0069] Alternatively, the method includes measuring torque using a contact sensor 242 coupled to the output member and sending an output signal from a transmitter 521 to a receiver 523. The microprocessor 410 can calculate the torque based on the output signal received by the receiver and provide a signal to control the input from the motor 200 to the output member 204.

[0070] Wireless communication between components is described herein. Although this specification describes components and functions that can be implemented in specific wireless communication embodiments with reference to specific standards and protocols, the present invention is not limited to such standards and protocols. For example, standards for Internet and other packet-switched network transmissions (e.g., TCP / IP, UDP / IP, HTML, HTTP, HTTPS) represent examples of prior art. Such standards are periodically replaced by faster or more efficient equivalents having substantially the same functions. Therefore, replacement standards and protocols having functions identical or similar to those disclosed herein are considered to be their equivalents.

[0071] In one embodiment, the components of the bicycle described herein will communicate with each other. In the case of wireless communication, the components will initially be paired to allow secure communication between the components on the bicycle without interfering with devices not associated with the system. Next, one or more of the components can be paired with a separate device such as a computer, tablet, or phone. The pairing device can provide a user interface to allow a user to communicate with the components on the bicycle (e.g., system control device). Examples of communication are updating firmware, setting variables, and running diagnostic tools and analysis.

[0072] According to various embodiments of the present disclosure, the methods described herein may be implemented with a software program executable by a computer system (such as a system control device). In addition, in an exemplary non-limiting embodiment, implementation may include distributed processing, component / object distributed processing, and parallel processing. Alternatively, a virtual computer system process may be constructed to implement one or more of the methods or functions described herein.

[0073] The methods and techniques described herein can 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) can be written in any form of programming language (including compiled or interpreted languages), and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that stores other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordination files (e.g., files storing one or more modules, subroutines, or code portions). A computer program can be deployed to execute on one computer or on multiple computers located at one site or distributed on multiple sites and interconnected by a communication network.

[0074] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by special purpose logic circuits (e.g., field programmable gate arrays (FPGAs) or application specific integrated circuits (ASICs)), and the devices can also be implemented as special purpose logic circuits.

[0075] As used in this application, the terms "circuitry" or "circuit" refer to all of the following: (a) hardware-only circuit implementations (such as implementations in the form of analog and / or digital circuitry only) and (b) combinations of circuits and software (and / or firmware), such as (where applicable): (i) a combination of a processor or (ii) portions of a processor / software (including a digital signal processor), software, and memory that work together to enable a device such as a mobile phone or server to perform various functions) and (c) circuits that require software or firmware to operate, such as a microprocessor or portion of a microprocessor, even if the software or firmware is not physically present.

[0076] This definition of "circuitry" applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term "circuitry" would also cover an implementation of only a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and / or firmware. The term "circuitry" would also cover (for example and if applicable to a particular claim element) a baseband integrated circuit or an application processor integrated circuit for a mobile computing device or a similar integrated circuit in a server, cellular network device, or other network device.

[0077] For example, processors suitable for executing computer programs include general and special purpose microprocessors and any one or more processors of any type of digital computer. Typically, the processor receives instructions and data from a read-only memory or a random access memory or both. The basic elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, the computer also includes one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data or is operably connected to one or more mass storage devices for storing data to receive data from it or to transmit data to it or both. However, the computer does not need to have such a device. In addition, the computer can 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 control device 150 (to name a few). Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CDROM and DVD-ROM disks. The processor and memory may be supplemented by, or incorporated in, special purpose logic circuitry.In an embodiment, the system control is integrated with a mobile phone, PDA, mobile audio player, GPS receiver, and communicates wirelessly with bicycle components to provide automatic mode control.

[0078] The illustrations of the embodiments described herein are intended to provide a general understanding of the structures of the various embodiments. The illustrations are not intended to be used as a complete description of all elements and features of the devices and systems utilizing the structures or methods described herein. By reading this disclosure, many other embodiments may be apparent to those skilled in the art. Other embodiments may be utilized and derived from this disclosure, so that structural and logical replacements and changes may be made without departing from the scope of this disclosure. In addition, the illustrations are merely representative and may not be drawn to scale. Certain proportions in the illustrations may be exaggerated, while other proportions may be minimized. Therefore, this disclosure and the accompanying drawings should be considered illustrative rather than restrictive.

[0079] Although this specification contains many details, these details should not be interpreted as limitations on the scope of the present invention or the content that can be claimed, but as descriptions of features specific to a particular embodiment of the present invention. Certain features described in the context of a separate embodiment in this specification may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination. In addition, although features may be described above as acting in certain combinations and even initially claimed as such, in some cases, one or more features from the claimed combination may be removed from the combination, and the claimed combination may involve a sub-combination or a variation of the sub-combination.

[0080] Similarly, although operations and / or actions are depicted in the accompanying drawings and described herein in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in a sequential order, or that all of the operations shown be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of the various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that any described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0081] One or more embodiments of the present disclosure may be referred to herein individually and / or collectively by the term "invention", which is merely for convenience and is not intended to actively limit the scope of the present application to any particular invention or inventive concept. In addition, although specific embodiments have been shown and described herein, it should be understood that any subsequent arrangements designed to achieve the same or similar purposes may replace the specific embodiments shown. The present disclosure is intended to cover any and all subsequent modifications or variations of the various embodiments. By reading the specification, the combination of the above-mentioned embodiments and other embodiments not specifically described herein will be apparent to those skilled in the art.

[0082] The Abstract of the present disclosure is provided to comply with 37 CFR §1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of simplifying the disclosure. This disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than those expressly recited in each claim. On the contrary, as reflected in the following claims, the inventive subject matter may involve features that are less than all the features of any disclosed embodiment. Therefore, the following claims are incorporated into the Detailed Description, with each claim independently defining a separately claimed subject matter.

[0083] It is intended that the foregoing detailed description be regarded as illustrative rather than restrictive, and it should be understood that the appended claims, including all equivalents, are intended to define the scope of the invention. The claims should not be understood to be limited to the described order or elements unless otherwise stated. Therefore, all embodiments falling within the scope and spirit of the appended claims and their equivalents are claimed to be protected as inventions.

Claims

1. A torque sensor system for an electric bicycle, the torque sensor system comprising: an output member rotatable about an axis, wherein the output member is configured to be rotated by an electric motor; a contact sensor coupled to the output member, wherein the contact sensor is configured to measure torque applied to the output member and provide an input signal; and A non-contact sensor is disposed between the output component and the fixed component, wherein the non-contact sensor is configured to provide an output signal proportional to the input signal.

2. The torque sensor system according to claim 1, wherein: The contact sensor includes a strain gauge coupled to the output member.

3. The torque sensor system according to claim 1, wherein: The contactless sensor includes an inner transformer coil and an outer transformer coil spaced apart from and surrounding the inner transformer coil, wherein the inner transformer coil is coupled to the output component and rotatable about the axis with the output component, and wherein the outer transformer coil is coupled to the fixed component.

4. The torque sensor system of claim 1 further comprising a first microprocessor coupled to the output member and rotatable with the output member about the axis, wherein: The first microprocessor is operably coupled to the contact sensor, wherein the first microprocessor is configured to receive the input signal and control a duration of a load current drawn by the contactless sensor.

5. The torque sensor system of claim 4, further comprising a second microprocessor operably coupled to the non-contact sensor, wherein: The second microprocessor is configured to receive the output signal and calculate a torque applied to the output member.

6. The torque sensor system according to claim 1, further comprising: an input member rotatable about the axis and concentric with the output member; and a one-way clutch disposed between the input member and the output member, wherein the one-way clutch is engaged between the input member and the output member when the input member rotates in a first rotational direction, and wherein the one-way clutch is disengaged between the input member and the output member when the input member rotates in a second rotational direction opposite to the first rotational direction.

7. The torque sensor system according to claim 1, wherein: The output member includes a cylindrical portion, wherein the contact sensor is applied to the cylindrical portion.

8. The torque sensor system according to claim 1, wherein: The non-contact sensor includes a radio transmitter coupled to the output component and a radio receiver coupled to the fixed component.

9. A torque sensor system for an electric bicycle, the torque sensor system comprising: an output member rotatable about an axis, wherein the output member is configured to be rotated by an electric motor; A strain sensor is coupled to the output member and is rotatable with the output member about the axis.

10. The torque sensor system according to claim 9, further comprising: an internal transformer coil coupled to the output member and rotatable about the axis with the output member; as well as An outer transformer coil is non-rotatable and radially spaced from and surrounding the inner transformer coil. 11 . The torque sensor system of claim 10 , further comprising a printed circuit board coupled to the output member and rotatable about the axis with the output member.

12. The torque sensor system according to claim 11, wherein: The printed circuit board is configured as an annular ring.

13. The torque sensor system of claim 11 further comprising a second microprocessor operably coupled to the external transformer coil.

14. The torque sensor system according to claim 9, further comprising: an input member rotatable about the axis and concentric with the output member; and a one-way clutch disposed between the input member and the output member, wherein the one-way clutch is engaged between the input member and the output member when the input member rotates in a first rotational direction, and wherein the one-way clutch is disengaged between the input member and the output member when the input member rotates in a second rotational direction opposite to the first rotational direction.

15. The torque sensor system according to claim 9, wherein: The output component includes a cylindrical portion, wherein the strain sensor is applied to the cylindrical portion.

16. The torque sensor system according to claim 15, wherein: The strain sensor includes 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.

17. The torque sensor system according to claim 9, further comprising: a radio transmitter coupled to the output member and rotatable with the output member about the axis; as well as A radio receiver is spaced apart from and in communication with the radio transmitter.

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