阅读说明：本技术 主动拨链器系统和方法 (Active derailleur system and method ) 是由 M.朱哈斯 于 2020-10-09 设计创作，主要内容包括：提供了用于主动控制拨链器的系统和方法。拨链器系统包括：盒,其包括多个链轮；驱动单元,其驱动盒；以及链条,其将驱动单元与盒连接。拨链器构造成围绕盒引导链条,拨链器包括可在枢轴组件处旋转以保持链条上的张力的摆臂。锁选择性地锁定摆臂使之不旋转。(Systems and methods for actively controlling a derailleur are provided. The derailleur system includes: a cassette comprising a plurality of sprockets; a driving unit which drives the cartridge; and a chain connecting the driving unit with the cartridge. The derailleur is configured to guide a chain around the cassette, and the derailleur includes a swing arm that is rotatable at a pivot assembly to maintain tension on the chain. The lock selectively locks the swing arm against rotation.)

1. A derailleur system for a bicycle, the system comprising:

a cassette comprising a plurality of sprockets;

a driving unit configured to drive the cartridge;

a chain connecting the driving unit with the cartridge;

a derailleur configured to guide a chain around the cassette, the derailleur including a swing arm rotatable at a pivot assembly to maintain tension on the chain; and

a lock configured to selectively lock the swing arm against rotation.

2. The system of claim 1, wherein the cassette is configured to drive the drive unit through the chain when the lock is in a locked position.

3. The system of claim 1, comprising:

a frame of a bicycle, wherein the derailleur is coupled to the frame,

wherein the pivot assembly comprises a non-rotatable body fixed to the frame and a rotatable body fixed to the swing arm,

wherein the lock comprises a lock actuator disposed between a non-rotatable body and a rotatable body.

4. The system of claim 1, comprising a controller configured to:

determining whether a shift condition is satisfied, wherein the shift condition includes a requirement for initiating a shift between the plurality of sprockets;

unlocking the lock when a shift condition is satisfied; and

the lock is locked when the gear shift is completed.

5. The system of claim 1, comprising a controller configured to:

unlocking the lock to perform a shift between the plurality of sprockets;

locking the lock when the gear shift is completed; and

the pedal torque model is processed to match the timing of the shift to the shift window, where the torque on the chain is below a threshold.

6. The system of claim 1, comprising a controller configured to:

unlocking the lock to perform a shift between the plurality of sprockets;

locking the lock when the gear shift is completed; and

the model is processed to match the timing of the shift to an ideal shift point, where the chain is located at a selected point relative to the box.

7. The system of claim 1, comprising:

a frame of a bicycle, wherein the derailleur is coupled with the frame, wherein the pivot assembly includes a non-rotatable body fixed to the frame and a rotatable body fixed to the swing arm, wherein the lock includes a lock actuator disposed between the non-rotatable body and the rotatable body;

an actuator configured to engage and disengage the lock actuator; and

a controller configured to:

determining whether a shift condition is satisfied, wherein the shift condition includes a requirement for initiating a shift between the plurality of sprockets;

disengaging a lock actuator by an actuator to unlock the lock when a shift condition is satisfied; and

when the shift is complete, the lock is locked by the actuator engaging the lock actuator.

8. A method of operating a derailleur of a bicycle, the method comprising:

connecting a cassette including a plurality of sprockets by a chain with a driving unit configured to drive the cassette;

guiding a chain around the cassette by a derailleur;

maintaining tension on the chain through a swing arm of the derailleur;

unlocking, by the controller, a lock at a pivot assembly of the derailleur to control tension on the chain during the gear shift; and

when the gear shift is completed, the lock is locked by the controller.

9. The method of claim 8, comprising:

determining whether a shift condition is satisfied prior to unlocking the lock, wherein the shift condition includes a requirement for initiating a gear shift.

10. The method of claim 9, wherein determining whether a shift condition is satisfied comprises:

determining whether the braking signal is valid;

determining whether a wheel speed of the bicycle is below a first threshold, wherein the wheel speed is too low to initiate a gear shift; and

it is determined whether the torque is above a second threshold, where the torque is too high to initiate a gear shift.

Technical Field

The present disclosure relates generally to systems and methods for operating a drive system including a derailleur, and more particularly to active control of a derailleur for shifting, tension control, and reverse drive.

Background

Bicycles provide an economical method of transportation and are widely used. They are propelled by manual pedaling, electric power, or a combination of both. Bicycles are constructed in various wheel configurations. Typically, the gear ratio at one or more rear wheels of the bicycle is changed by operation of a gear shifting mechanism. One such mechanism is a derailleur, which guides a drive chain between differently sized sprockets at the rear wheel to change the gear ratio. For shifting gears, the derailleur is typically moved in a direction parallel to the axle of the rear wheel in response to a control input. In addition, a portion of the derailleur is generally free to pivot with a pretension in the direction of the chain path to maintain chain tension and enable movement between sprockets of different sizes.

The limited level of control available to the derailleur limits the ability to provide additional functionality. For example, derailleur responsiveness is typically limited to moving the chain between the sprockets. Conventional derailleurs are not compatible with regenerative braking and reverse driving. In addition, the free-pivoting nature of typical derailleurs can cause the chain to undesirably slacken when operating the bicycle on rough roads or uneven surfaces.

Accordingly, it is desirable to provide a system and method for actively controlling a derailleur to maintain chain tension and provide a wider range of functionality. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and description.

Disclosure of Invention

Systems and methods for actively controlling a derailleur are provided. In various embodiments, a derailleur system comprises: a cassette comprising a plurality of sprockets; a driving unit which drives the cartridge; and a chain connecting the driving unit with the cartridge. The derailleur is configured to guide a chain onto a sprocket assembled in the cassette. The derailleur includes a swing arm that is rotatable at a pivot assembly to maintain tension on the chain. The lock selectively locks the swing arm against rotation.

In a further embodiment, the cartridge is configured to drive the drive unit via the chain when the lock is in the locked position.

In another embodiment, the bicycle includes a frame and the derailleur is coupled to the frame. The pivot assembly includes a non-rotatable body fixed to the frame and a rotatable body fixed to the swing arm. The lock includes a lock actuator disposed between the non-rotatable body and the rotatable body.

In further embodiments, the lock actuator comprises a clutch.

In further embodiments, the lock actuator includes a first tooth on the non-rotatable body that is selectively engageable with a second tooth on the rotatable body.

In further embodiments, the controller is configured to: determining whether a shift condition is satisfied, wherein the shift condition includes a requirement for initiating a shift between a plurality of sprockets; unlocking the lock when the gear shifting condition is met; and locking the lock when the gear shift is completed.

In further embodiments, the controller is configured to: unlocking a lock to perform a shift between the plurality of sprockets; locking the lock when the gear shift is completed; and processing the pedal torque model to match a timing of the shift to a shift window, wherein the torque on the chain is below a threshold.

In further embodiments, the controller is configured to: unlocking a lock to perform a shift between the plurality of sprockets; locking the lock when the gear shift is completed; and processing the model to match the timing of the shift to the ideal shift point, wherein the chain is located at a select point relative to the cassette.

In another embodiment, the bicycle includes a frame and the derailleur is coupled to the frame. The pivot assembly includes a non-rotatable body fixed to the frame and a rotatable body fixed to the swing arm. The lock includes a lock actuator disposed between the non-rotatable body and the rotatable body. The actuator is configured to engage and disengage the lock actuator. The controller is configured to: determining whether a shift condition is satisfied, wherein the shift condition includes a requirement for initiating a shift between a plurality of sprockets; disengaging the lock actuator by the actuator to unlock the lock when the shift condition is satisfied; and locking the lock by engaging the lock actuator with the actuator when the gear shift is completed.

In various embodiments, a method of operating a derailleur of a bicycle includes coupling a cassette including a plurality of sprockets with a drive unit configured to drive the cassette. The chain is guided around the cassette by the derailleur. Tension on the chain is maintained by the swing arm of the derailleur. The controller unlocks a lock at a pivot assembly of the derailleur to control tension on the chain during gear shifting. When the gear shift is complete, the controller locks the lock.

In a further embodiment, the cartridge drives the drive unit via a chain generating power to charge the battery when the lock is locked.

In a further embodiment, prior to unlocking the lock, the controller determines whether a shift condition is satisfied, wherein the shift condition includes a requirement for initiating a shift between the plurality of sprockets.

In another embodiment, the derailleur shifts the chain between the plurality of sprockets when the lock is unlocked. The pedal torque model is processed to match the timing of the gear shift to a shift window, where the torque on the chain is below a threshold.

In further embodiments, the shift synchronization model is processed to match the timing of gear shifts to ideal shift points, where the chain is located at a select point relative to the box.

In a further embodiment, the processor determines whether a shift condition is satisfied prior to unlocking the lock, wherein the shift condition includes a requirement for initiating a gear shift.

In further embodiments, determining whether the shift condition is satisfied includes: determining whether the braking signal is valid; determining whether a wheel speed of the bicycle is below a first threshold, wherein the wheel speed is too low to initiate a gear shift; and determining if the torque is above a second threshold, wherein the torque is too high to initiate the gear shift.

In further embodiments, determining whether the shift condition is satisfied includes determining whether regenerative braking is active. When regenerative braking is active, the motor torque is reduced.

In a further embodiment, the gear shift is delayed when the drive unit generates a torque above a threshold value.

In a further embodiment, gear shifting is delayed when the cartridge is positioned before a shift point, where the shift point is a location on the cartridge that facilitates shifting.

In various other embodiments, the derailleur system includes a case having a plurality of sprockets. The driving unit is configured to drive the cartridge. A chain connects the drive unit with the cassette. The derailleur is configured to guide a chain around the cassette and includes a swing arm that is rotatable at a pivot assembly to maintain tension on the chain. The lock is configured to selectively lock the swing arm against rotation. The bicycle includes a frame and a derailleur coupled to the frame. The lock includes a lock actuator disposed between the frame and the swing arm. The actuator engages and disengages the lock actuator. The controller is configured to: determining whether a shift condition is satisfied, wherein the shift condition includes a requirement for initiating a shift between a plurality of sprockets; disengaging the lock actuator by the actuator to unlock the lock when the shift condition is satisfied; and locking the lock by engaging the lock actuator with the actuator when the gear shift is completed.

Drawings

Exemplary embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:

FIG. 1 illustrates a bicycle having a derailleur system in accordance with various embodiments;

FIG. 2 is a schematic view taken from a front perspective view of a portion of a derailleur system in accordance with various embodiments;

FIG. 3 is a schematic diagram taken from a side perspective view of a portion of a derailleur system in accordance with various embodiments;

FIG. 4 is a partially cross-sectional illustration of a clutched locking system of the derailleur system of FIG. 1, in accordance with various embodiments;

FIG. 5 is a partial illustration of a radial-type locking system of the derailleur system of FIG. 1 with a cover removed in accordance with various embodiments;

FIG. 6 is a partial diagrammatic view of an axial-type locking system of the derailleur system of FIG. 1 in accordance with various embodiments;

FIG. 7 is a data flow diagram illustrating an active derailleur control system in accordance with various embodiments;

8A-8B are flow charts of methods for controlling an active derailleur system in accordance with various embodiments;

9A-9B are flowcharts of a method for determining whether a shift condition is satisfied in controlling an active derailleur system in accordance with various embodiments; and

FIG. 10 is a schematic illustration of a drive train of the bicycle of FIG. 1, in accordance with various embodiments.

Detailed Description

The following detailed description is merely exemplary in nature and is not intended to limit the application or uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, brief summary or the following detailed description. As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, alone or in any combination, including but not limited to: application specific integrated circuits, electronic circuits, processors (shared, dedicated, or group) and memory that execute one or more software or firmware programs, combinational logic circuits, and/or other suitable components that provide the described functionality.

Embodiments of the disclosure may be described herein in terms of functional and/or logical block components and various processing steps. It should be appreciated that such block components may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, embodiments of the present disclosure may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments of the present disclosure can be practiced in conjunction with any number of systems, and that the systems described herein are merely exemplary embodiments of the disclosure.

For the sake of brevity, conventional techniques related to signal processing, data transmission, signaling, control, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent example functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the disclosure.

As disclosed herein, improvements are provided to enable regenerative braking in an electric bicycle as well as in managing pedal torque and driveline synchronization to smooth gear shifts and extend durability in any type of bicycle. Derailleurs typically include a lock to enable back driving from the rear wheels to the propulsion system for regenerative battery charging. The timing of the shift control of the derailleur should be synchronized with the unlocking of the derailleur, the low torque window associated with the pedal position and with the ideal shift point of the rear box.

FIG. 1 illustrates a bicycle 10 in accordance with an exemplary embodiment. In various embodiments, the bicycle 10 can be a manually powered bicycle, a manually powered bicycle with power assist, or an engine/motor powered bicycle of various wheel configurations. The bicycle 10 is configured to normally operate in the forward direction 21. The reverse direction 23 is directed opposite to the forward direction 21. Bicycle 10 is configured with a positive derailleur 57 that increases the level of control over chain slack and enables additional functions, as explained in detail below. For example, in various embodiments, the bicycle 10 is also configured with regenerative braking and/or reverse drive operation.

Generally, the bicycle 10 includes a frame 12, and the frame 12 can include a top tube 20 connected to a seat tube 22. The seat assembly 25 is connected to the seat tube 22. A diverter tube 28 may extend from the top tube 20. The down tube 38 may extend between the seat tube 22 and the steerer tube 28. The steerer tube 28 is operatively connected to the front fork 34, with the front fork 34 attached to the front wheel 32 by a front axle assembly 48. The handlebar 30 is attached to the front fork 34 and is used to control the direction of the front wheel 32. The handlebar 30 and the front fork 34 are connected to the frame 12 at the steerer tube 28. The control lever 36 may be disposed on the handlebar 30 or elsewhere and is configured and arranged to be coupled to one or more controlled devices, such as a brake 39. The chain stay 40 and the seat stay 42 extend rearward from the seat tube 22 and support the rear wheel 44 on the rear axle 46.

The bicycle 10 includes a propulsion system 16. In various embodiments, propulsion system 16 includes a crank assembly 14 including a crankshaft 18 connectable with a pair of pedal assemblies 50, 52. Chain 54 is operatively connected between propulsion system 16 and a box 56 of rear wheel 44. Chain 54 passes through derailleur 57, which effects gear changes between the various sprockets of cage 56 at rear wheel 44 in response to control inputs. Derailleur 57 includes a pivot assembly 88 as further described below. In various embodiments, propulsion system 16 includes a drive unit 58 powered by an electric machine 60, with electric machine 60 drawing power from a battery pack 62 and may function as a motor/generator. The drive unit 58 may provide propulsion assistance to the crank assembly 14. In some embodiments, the drive unit 58 can be the sole source of power for propelling the bicycle 10.

In the embodiment of fig. 1, the bicycle 10 includes a controller 68. Generally, the controller 68 receives information from various sources, processes the information, and provides control commands based thereon to effect results such as operation of the vehicle propulsion system 16 and other systems, including the active derailleur control system 64. In the illustrated embodiment, the controller 68 includes a processor 70, a memory device 72, and is coupled with a storage device 74. The controller 68 can receive signals from the sensor system 67 of the bicycle 10. The sensor system 67 includes one or more sensing devices that sense an observable condition of the bicycle 10. In this embodiment, the sensing devices include, but are not limited to, a cartridge position sensor 69 that senses the rotational angle of the cartridge 56, a gear position sensor 71 on a sprocket of the cartridge 56 to which the chain 54 is engaged, a pedal position sensor 73 that senses the angular position of the pedals 50, 52, a pedal torque sensor 75 that senses the torque applied by the pedals 50, 52, a drive torque sensor 77 that senses the total torque on the drive train 89, a rotational speed sensor 79 that senses the pedal frequency, a speed sensor 81 that senses the angular speed of the wheels 44, and a brake sensor 83 that senses the actuation of the brakes 39. The controller 68 may also receive shift commands from the shift system 85, including shift commands from an operator interface 87, which operator interface 87 may be a manual actuation device such as a lever. In some embodiments, the shift command may originate from the processor 70. Processor 70 performs the computing and control functions of controller 68 and may include any type of processor or processors, a single integrated circuit such as a microprocessor, or any suitable number of integrated circuit devices and/or circuit boards working in cooperation to perform the functions of a processing unit. During operation, processor 70 executes one or more programs 76, which may be loaded into memory device 74, thus generally controlling the overall operation of controller 68 when executing lock and shift control system 90, and performs processes described herein, such as processes 300 and 400 described further below in connection with fig. 8 and 9.

The memory device 72 may be any type of suitable memory. For example, the memory device 72 may include volatile and non-volatile storage in, for example, Read Only Memory (ROM), Random Access Memory (RAM), and Keep Alive Memory (KAM). The KAM is a persistent or non-volatile memory that may be used to store various operating variables when the processor 70 is powered down. The memory device 72 may be implemented using any of a number of known memory devices such as PROMs (programmable read Only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or any other electrical, magnetic, optical, or combination memory device capable of storing data used by the controller 68, some of which represent executable instructions. In some examples, the memory device 72 is located and/or co-located on the same computer chip as the processor 70.

In the illustrated embodiment, the storage device 74 stores the above-described programs 76, as well as other information. For example, the memory device 74 stores data for automatically controlling the system of the bicycle 10. The storage device 74 may be any suitable type of storage device, including direct access storage devices, such as hard disk drives, flash memory systems, floppy disk drives, and optical disk drives. In an exemplary embodiment, the storage device 74 includes a source from which the memory device 72 receives a program 76 that performs one or more embodiments of one or more processes of the present disclosure, such as the steps of the processes 300, 400 (and any sub-processes thereof) described further below in connection with fig. 8 and 9. In another exemplary embodiment, the programs 76 may be stored directly in the memory device 72 and/or otherwise accessed by the memory device 72. The routine 76 represents executable instructions used by the electronic controller 68 to process information and control the bicycle 10 (including the active derailleur control system 64). The instructions may comprise one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. The instructions, when executed by the processor 70, support the reception and processing of signals, such as from the sensor system 67, executing logic, calculations, methods and/or algorithms to automatically control the components and systems of the bicycle 10. Processor 70 may generate control signals, such as for drive unit 58 and/or derailleur 57, based on logic, calculations, methods and/or algorithms.

In fig. 2 and 3, mechanical aspects of derailleur 57 are schematically illustrated. The cassette 56 is arranged to rotate with the rear wheel 44 and engage the chain 54. In general, derailleur 57 includes a portion that moves in a direction parallel to rotational axis 55 of rear wheel 44 in a gear changing motion 80. Derailleur 57 also includes a portion that moves in rotational direction 82 to take up slack and apply tension to chain 54, and to adjust as chain 54 moves between the sprockets of cassette 56. More specifically, derailleur 57 includes a shift link 86 that is coupled to frame 12 at plate 78 thereof and suspends the riding wheel in wheel assembly 84 for movement parallel to rear axle 46 in gear changing movement 80 to shift between the sprockets of case 56. When moving in the gear change motion 80, the shift link 86 pushes the chain 54 up and down along the box 56 while remaining parallel to the various sprockets. Wheel assembly 84 includes a guide wheel 90, an idler wheel 92, and a swing arm 94 that generates tension on chain 54. A spring (not shown) may be engaged with the swing arm 94 to apply tension. Guide pulley 90 keeps chain 54 in line as chain 54 moves between sprockets during shifting. The idler pulley 92 tensions the chain 54 through various gear selections. Swing arm 94 holds the chain in line between guide pulley 90 and idler pulley 92. Generally, the swing arm 94 and the wheel assembly 84 rotate about the shift link 86 at the pivot assembly 88.

An embodiment of the pivot assembly 88 is shown in the referenced figures 3-5. The pivot assembly 88 generally includes a lock 100, the lock 100 being a mechanism that prevents the swing arm 94 from swinging in the direction of rotation 82 and may be configured in various embodiments. Locking the swing arm 94 means that the swing arm 94/wheel assembly 84 cannot be tension adjusted and therefore does not support gear changes between different sized sprockets of the cassette 56. However, since the tension remains constant, rear wheel 44 may be used to drive cassette 56 and through it to drive chain 54, with kinetic energy transferred to propulsion system 16. For example, the chain 54 may be used to provide regenerative braking, wherein the propulsion system 16 decelerates the bicycle 10 and generates electricity through the motor 10 to charge the battery pack 62. In addition, operation of the bicycle 10 in the reverse direction 23 enables driving via the derailleur 57. In many embodiments, cartridge 56 does not include a flywheel feature, or may include an override of the flywheel, such as a clutch (not shown), to enable rear wheels 44 to drive propulsion system 16.

In the embodiment of fig. 4, the lock 100 includes a non-rotatable body 102 configured as a ring-shaped element secured to the frame 12, and includes a rotatable body 104 secured to the swing arm 94 and configured as a cylinder disposed inside the non-rotatable body 102. A tensioning spring 107 is provided to rotationally bias the rotatable body 104 to apply tension on the chain 54, and a clutch 106 is provided as a lock actuator 107 to alternately lock and unlock the swing arm 94 relative to the non-rotatable body 102. The clutch 106 may be actuated in a variety of ways, and in the present embodiment includes an electrical actuator 108. When the actuator 108 is de-energized, the clutch 106 closes and locks the rotatable body 104 against rotation relative to the non-rotatable body 102 and the frame 12. When the actuator 108 is energized, the clutch 106 opens and the rotatable body 104 unlocks from the non-rotatable body 102 to rotate freely under the bias of the tension spring 107.

As shown in FIG. 5, another embodiment of the lock 100 includes a non-rotatable body 112 configured as a lever and disposed on a pivot 114. When the non-rotatable body 112 pivots, it does not rotate with the swing arm 94, but is fixed to the frame 12 by a pivot 114. The lock 100 also includes a rotatable body 116 configured as a toothed wheel that is fixed for rotation with the swing arm 94 by a bolt 118. The non-rotatable body 112 includes teeth 120 that engage with teeth 126 of the rotatable body 116, which is a lock actuator 119, to lock the swing arm 94 against rotation. The spring 122 biases the teeth 120, 126 into engagement such that the rotatable body 116 is normally locked from rotation. An actuator 124 is coupled with the non-rotatable body 112 and, when energized, pivots the non-rotatable body 112 to compress the spring 122 and release the teeth 120 from the teeth 126 of the rotatable body 116. The rotatable body 116 is then free to rotate.

Fig. 6 shows another embodiment of the lock 100, the lock 100 comprising a non-rotatable body 132 configured as an annular toothed wall 133. The wall 133 is disposed on the shift link 86 that is fixed to the frame 12 (fig. 3). As a result, the non-rotatable body 132 does not rotate with the swing arm 94, but is fixed to the frame 12. The lock 100 further includes a rotatable body 136 configured with a toothed wheel 135 fixed for rotation with the swing arm 94. The non-rotatable body 132 includes teeth 140, the teeth 140 engaging with teeth 142 of the rotatable body 136 as a lock actuator 143 that locks the swing arm 94 against rotation. The spring 146 biases the teeth 142 into engagement with the teeth 140 so that the rotatable body 136 is normally locked against rotation. An actuator 144, such as a solenoid, is coupled to rotatable body 136 and, when energized, pulls rotatable body 136 to compress spring 122 and release tooth 142 from tooth 140. The rotatable body 136 is then free to rotate, as is the swing arm 94.

Thus, the lock 100 comprises lock actuators 107, 119, 143 which in each case alternately lock and unlock the swing arm 94 so as not to rotate or swivel. The actuators 108, 124, 144 may be controlled to unlock the lock actuators 107, 119, 143, allowing the swing arm 94 to move in the rotational direction 82, and may be controlled to lock the lock actuators 107, 119, 143 to prevent the swing arm 94 from moving in the rotational direction 82. When unlocked, a gear change can be made and derailleur 57 regulates the movement of chain 54 between the sprockets of cassette 56 while maintaining tension. When locked, gear change is inhibited, but regenerative braking, reverse operation, and chain slack prevention are enabled.

Referring to FIG. 7, a dataflow diagram illustrates various embodiments of an active derailleur control system 64, at least a portion of which can be embedded within a controller 68 and executed by a processor 70. In general, active derailleur control system 64 receives inputs from sensor system 67 and memory device 74 and, via processor 70, controls various aspects of bicycle 10 including shifting system 85 and derailleur 57. For example, active derailleur control system 64 controls when gear shifting is enabled and controls unlocking derailleur 57. Generally speaking, the active derailleur control system 64 includes a shift condition module 202, a derailleur lock and shift control module 204, an error management module 206, a driveline synchronization module 208, a pedal position module 210, and a data store 212, which may contain data from the memory device 74.

The shift condition module 202 processes a shift condition algorithm (described below) that can be accessed from the data store 212 to determine whether a shift will be enabled. The shift condition module 202 receives a gear shift request signal 220, for example, from the shift system 85, a pedal torque signal 222, for example, from the pedal torque sensor 75, a motor torque signal 224, which may be derived, for example, from the driveline torque sensor 77 and the pedal torque sensor 75 or from the propulsion system 16, a brake signal 226, for example, from the brake sensor 83, a wheel speed signal 228, for example, from the rotational speed sensor 79, and a regenerative active signal 230, for example, from the propulsion system 16. The shift condition module 202 processes the signals through a shift condition algorithm and determines whether the conditions are appropriate for a gear shift. When the shift condition is met, the shift condition module 202 sends a signal 232 to the derailleur lock and shift control module 204. If an error occurs in the determination, an error message 205 may be passed to the error management module 206.

Derailleur lock and shift control module 204 processes a derailleur lock and shift control algorithm (described below) that can be accessed from data store 212 to determine whether unlocking of lock 100 of derailleur 57 can be performed and whether a gear shift is initiated by operation of derailleur 57. The derailleur lock and shift control module 204 receives a derailleur lock status signal 234, such as from the lock 100, a gear status signal 233, such as from the gear position sensor 71, and a shift condition satisfaction signal 232 from the shift condition module 202. The derailleur lock and shift control module 204 can unlock the lock 100 via an unlock signal 236 and can transmit a gear shift confirmation signal 238. In some embodiments, the gear shift confirmation signal 238 is processed by the driveline synchronization module 208 to synchronize the gear shift with the position of the cartridge 56 and by the pedal position module to time the gear shift with the position of the pedals 50, 52 to avoid high torque shifts. In other embodiments, the gear shift confirmation signal 238 may be used to initiate a shift.

The driveline synchronization module 208 accesses a driveline synchronization model (described below), e.g., from the data store 212, for determining shift timing. The pedal position module 210 accesses a pedal torque model (described below), e.g., from the data store 212, that is also used to determine shift timing. After any timing modifications from the driveline synchronization module 208 and the pedal position module 210, a shift gear signal 242 is transmitted to the derailleur 57. If an error occurs in unlocking lock 100 or shifting gears, an error message 240 may be communicated to error management module 206 for use as described below. Error message 244 is sent to data store 212 for storage and retrieval. In the event that either the shift condition module 202 or the derailleur lock and shift control module identifies an error requiring service, then a service signal 246 is transmitted.

Process 300 for controlling derailleur 57 is illustrated in flowchart form in FIG. 8. The process 300 starts 302 and a determination 304 is made, for example by the processor 70, as to whether a gear shift signal 220 is received. When the determination 304 is negative, the process 300 returns to the start 302. When the determination 304 is affirmative, the process 300 continues with a determination 306 of whether a shift condition is satisfied, such as by the shift condition module 202. The shift conditions may evaluate factors such as torque speed and braking status, as described further below, and generally include a requirement for initiating a shift between the plurality of sprockets on the cartridge 56. When the determination 306 is negative and the shift condition is not satisfied, the process 300 proceeds to determine 308 whether the load condition has changed within a short time window (e.g., a fraction of a second). For example, when the rider applies high torque via the pedals 50, 52, the load conditions may initially be too high for shifting, so immediate shifting is not preferred. However, the rider may select a gear change via the operator interface 87, and the rider may then release the pedal, reducing the driveline torque sufficient to satisfy the determination 306 via the shift condition. When such a condition occurs, it is reevaluated at decision step 306 whether the shift condition is satisfied. Specifically, when the determination 308 is affirmative, the process 300 loops back and proceeds again to the determination 306.

When determination 306 results in a positive result and the shift condition is satisfied, process 300 proceeds to initiate 310 operation of derailleur 57, such as by the shift condition satisfying signal 232. Derailleur 57 is unlocked 312, such as via unlock signal 236. For example, the lock 100 is operated by the derailleur lock and shift control module 204 to unlock the pivot assembly 88 to enable the swing arm 94 to swing in the rotational direction 82 to adjust the chain 54 to a different size sprocket of the cassette 56. A determination 314 is made as to whether derailleur 57 has been successfully unlocked. For example, a position sensor (not shown) in the pivot assembly 88 may indicate that the lock 100 has moved to the unlocked position.

When determination 314 is affirmative, process 300 proceeds to shift gear 316 by operation of derailleur 57, e.g., in response to issuance of shift gear signal 242. The shift range signal 242 may be issued directly by the derailleur lock and shift control module 204, or the shift confirmation signal 238 may be issued and further processed as described below before issuing the shift signal 242. It should be appreciated that in many embodiments, derailleur 57 can have an electrical actuator (not shown) that is responsive to controller 68 to move shift link 86. In other embodiments, movement of the shift link 86 may be inhibited by an electromechanical stop (not shown) responsive to the controller 68 and moving to allow shifting. In other embodiments, derailleur 57 may be mechanically actuated and may include a mechanism (not shown) that remains actuated prior to shifting gear signal 242. The process 300 proceeds to determine 318 whether the gear shift has been successful. For example, the gear position sensor 71 may be used to indicate the current gear. When the determination is negative, process 300 proceeds to shift back 320 to the starting gear and again attempts to shift gear 316.

When determination 318 is affirmative and the gear is successfully shifted, process 300 proceeds to lock 322 derailleur 57. For example, the lock 100 returns to its normally locked state, such as by discontinuing power to the actuators 108, 124, 144. A determination 324 is made as to whether derailleur 57 was successfully locked. When the determination 324 is negative, the process 300 proceeds to disable 326 regenerative braking. For example, error management module 206 may communicate disable signal 246 to propulsion system 16. The process retries to lock 322 derailleur 57. When determination 324 is affirmative, process 300 completes 328 the gear shift routine and derailleur 57 is locked, e.g., to enable reverse flow of energy from rear wheels 44 to propulsion system 16 for regenerative braking. When the gear shift is complete 328, the status is reported for logging 332.

The process 300 also includes error handling, for example, by the error management module 206. When the shift condition satisfaction determination 306 identifies an input signal error, a report 330 is sent to be recorded 332, for example, in the data store 212. Additionally, an error is reported to be recorded 332 when the derailleur unlock success determination 314 is negative, when the gear shift success determination is negative, or when the derailleur lock success determination 324 is negative. For example, error messages passing through the error management module 206 may be categorized by severity, may be used for diagnostics, may be used to send messages to riders, and may be used to disable functionality. Typically, the process 300 retries after reporting the failure to perform a function that informs whether the error is the result of a simple glitch or persists, such as due to a hardware problem. For example, if the first attempt fails, then the derailleur unlock, gear shift, and derailleur lock functions are all attempted again. Process 300 proceeds to determine 334 whether the hardware involved is capable of responding. For example, hardware may be damaged or overload or overheating may result, such as due to congestion. If the hardware is unable to respond to a successfully transmitted signal, an error message may be transmitted indicating that maintenance is required to be perceived by the rider. When the determination 334 is affirmative, the process may continue with start 302. When the determination 334 is negative and the hardware involved is unable to respond, the process 300 disables 336 the gear shift, for example, via the disable signal 246, awaiting service. Additionally, a successful gear shift reported from gear shift completion 328 may be used to clear error messages, such as a need for service.

Details of a process 400 for the shift condition satisfaction determination 306 are shown in fig. 9 with additional reference. The process 400 begins 402 and resets 404 the input signal error and continues with the gear shift signal 304 from the process 300. A determination 406 is made as to whether a braking signal is present. For example, the brake signal 226 may be present from the brake sensor 83. When the determination 406 is affirmative and the brake signal 226 is present (meaning that the brakes are active), the process 400 proceeds to determine 408 whether regenerative braking is active. For example, propulsion system 16 may use input from rear wheels 44 to charge battery pack 62 to drive chain 54 and electric machine 60 as a generator, as indicated by regenerative braking signal input 230.

When determination 408 is affirmative and regenerative braking is active, process 400 proceeds to determine 410 whether the pedal torque exceeds a threshold and is at a too high level to shift gears. In making the determination 410, the process 400 may receive a pedal torque value, for example, from the pedal torque sensor 75 via the pedal torque signal 222. When the determination 410 is affirmative, the process 400 proceeds to conclude that the shift condition is not satisfied 426 and proceeds to end 428. When determination 410 is negative, process 400 proceeds to determine 416 if the motor torque is above the threshold and at a too high level to perform the shift. For example, shifting at high torque may not be preferred due to rough shifting and mechanical wear/stress. In making the determination 416, the process 400 may use the motor torque value, for example, from the motor torque signal 224, or it may be derived from inputs from the drive torque sensor 77 and the pedal torque sensor 75. When the determination 416 is affirmative, the process 400 proceeds to reduce 420 the motor torque and again processes the determination 416. When determination 416 is negative, process 400 proceeds to determine 422 whether the wheel speed is below a threshold and at a level that is too low to shift, e.g., based on wheel speed input 228 from wheel speed sensor 81. When the determination 422 is affirmative, the process 400 proceeds to a decision 426 that the shift condition is not satisfied and ends 428. When determination 422 is negative, process 400 proceeds to determine 430 whether deceleration is above a threshold and at a too high level for the shift. In making the determination 430, the process 400 may receive an indication of a wheel deceleration value, such as may be derived from the wheel speed sensor 81 input 228 or from other sources such as an acceleration sensor. When the determination 430 is affirmative, the process 400 proceeds to conclude 426 that the shift condition is not satisfied and ends 428. When determination 430 is negative, process 400 proceeds to process 434 where the powertrain shift synchronization model is executed. In some embodiments, process 434 the powertrain synchronization model may be optional, and process 400 may proceed directly to conclude 436 that the shift condition is satisfied and end 428.

Returning to determining 408 whether regenerative braking is active, when determination 408 is negative, process 400 proceeds to determining 438 whether the pedal torque is at an excessively high level, such as by using the received pedal torque input 222. When the determination 438 is negative, the process 400 proceeds to and begins from the determination 422, as described above. When the determination 438 is affirmative, the process 400 proceeds to a decision 426 that the shift condition is not satisfied and ends 428.

Returning to decision 414, a result may be derived from the wheel speed signal 228 as to whether the wheel speed is at an excessively low level. For example, zero and near zero speeds may be too low to perform a shift. When the determination 414 is negative, the process 400 proceeds to determine 440 whether the optional pedal torque model is to be processed. For example, the controller 68 may be programmed to process the pedal torque model under all or select conditions. In other embodiments, the pedal torque model may not be used, and the process 400 may proceed directly to determine 442 as to whether the pedal torque is at an excessively high level. The determination 442 may be processed, for example, by using the pedal torque input 222. When the determination 442 is affirmative, the process 400 proceeds to decision 426 that the shift condition is not satisfied and ends 428. When the determination 442 is negative, the process 400 proceeds to determine 444 whether the total driveline torque is above a threshold and at a too high level, such as by using the motor torque input 224 and the pedal torque input 222. When the determination 444 is negative, the process 400 proceeds to reduce 446 the motor torque and reprocess the determination 444. When the determination 444 is negative, the process 400 proceeds to process the driveline synchronization model 434 or, alternatively, when the driveline synchronization model is not in use, it is directly determined 436 that the shift condition is satisfied and ends 428.

Returning to the determination 440, when the determination is affirmative and the pedal torque model is used, for example in the pedal position module 208, the pedal torque model is processed 446, as described further below. Process 400 proceeds to process driveline synchronization model 434, also described further below, or alternatively, when the driveline synchronization model is not in use, directly to determine 436 that the shift condition is satisfied and ends 428. Any input signal errors that occur during process 400 are stored 448, for example in data store 212, and may be used in error management module 206.

The process 446, such as the pedal torque model typically in the pedal position module 210, involves an assessment of the frequency of pedaling, and may time shifts that occur within a low torque shift window, where the torque on the chain 54 is below a selected threshold to ensure smooth shifts and durability of system components. The shift may be delayed by a time delay, such as a fraction of a second, to allow the pedals 50, 52 to move to an angle that coincides with the shift window. Shifting within the shift window is preferred because of the low torque condition. When shifting within the shift window, there is no need to reduce the motor torque. As schematically shown in fig. 10, the pedals 50, 52 rotate about the drive unit 58 during pedaling and exert a relatively high torque on each side via the pedals 50, 52 during downward force. A pair of low torque windows 450, 452 occurs as the pedal approaches and departs from the 12 o 'clock and 6 o' clock positions. When the pedals 50, 52 are outside of the low torque shift windows 450, 452, a shift delay 454 may be set to time the shift to occur during the shift windows 450, 452.

Processing 446 the pedal torque model involves receiving inputs for: such as pedal position from pedal position sensor 73, pedal torque from pedal torque sensor 75, pedal frequency from rotational speed sensor 79, motor torques that can be derived from pedal torque sensor 75 and driveline torque sensor 77, for example, shift torque limits that can be retrieved from data store 212, current gear position from gear position sensor 71, shift input from gear shift system 85, for example, and input signal error data from data store 212, for example.

The logic of the pedal torque model includes: the gear is shifted when the sum of the pedal torque and the motor torque is less than or equal to a threshold value of a shift torque limit of the driveline 89. When the sum of pedal torque and motor torque exceeds a shift torque limit threshold of driveline 89, the time to reach shift windows 450, 452 is calculated prior to the shift. To determine the torque, the pedal torque used is the highest torque registered by the pedal torque sensor during the previous pedal stroke. The highest motor torque value used is the highest torque recorded during the current period in which the bicycle 10 is operating. To calculate the time to shift windows 450, 452, pedal frequency and position are used. The minimum value of shift window angle 455 is the minimum angle required for chain engagement during a shift. The minimum angle 455 may take into account the mechanical delay for the application. The current shift window angle 456 is the maximum angle at which the sum of the pedal torque and the motor torque is less than or equal to the shift torque limit. Calculating shift windows 450, 452 includes defining positive and negative limits for shift window angle 456 and its mirrored shift window angle 458 at 180 degrees. When the current shift window angles 456, 458 are less than the minimum shift window angle 455 plus any added tolerance, the motor torque is reduced such that the sum of the motor torque and the pedal torque is less than the shift torque limit. The shift may continue when the pedal position is within the shift window angle plus any added tolerance. The shift delay 454 is implemented when the pedal position is not within the shift window angle plus any added tolerance, and the shift continues once the delay 454 expires. In some embodiments, instead of calculating current shift window angles 456, 458, a generic shift window may be stored, such as in data store 212, and retrieved for use. When there is a signal error, the shift function may implement a "home" gear to safely return or the shift may be performed without regard to torque.

Also shown in FIG. 10 are ideal shift points 461 & 464 of the cartridge 56, which are specific locations where shifting between the sprockets of the cartridge 56 is made easier due to shift ramps 466 formed in the sprocket teeth of the cartridge 56. The driveline shift synchronization model, as processed by the driveline synchronization module 208, matches the shift points of the derailleur 57 to the optimal rotational position of the cassette 56 to achieve smooth chain engagement with low input torque. The number and location of ideal shift points 461-. Inputs for the powertrain shift synchronization model include, for example, a cartridge position from cartridge position angle sensor 69, a current gear, for example, from gear position sensor 71, shift inputs, for example, from shift system 85, and input signal error data, for example, from data store 212, as well as shift window data, for example, that may be retrieved from data store 212.

When a shift signal is present, the angle that must be traversed to reach the next desired shift point is calculated, for example, by the driveline synchronization module 208. The angle required to reach the ideal shift point 461-. Until the angle at which the shift is reached is equal to the ideal shift point position minus the position of the cartridge. The angle that must pass until the shift is reached may be translated from the cassette 56 to the crankshaft 18 using the physical relationship between the current sprocket of the cassette 56 and the current sprocket of the crank assembly 14. When the translational angle at the drive unit 58 is within the shift windows 450, 452, then after any desired delay to the ideal shift point at the cartridge 56, a gear shift is made. The motor torque may be reduced such that the sum of the motor torque and the pedal torque is less than or equal to the shift torque limit, and the shift is performed. When the calculated angle indicates a delay needed to reach the ideal shift point, the angle that must be passed to reach the shift point is determined and is equal to the ideal shift point minus the box position. When the sum of the motor torque plus the pedal torque is less than or equal to the shift torque limit, a delay is implemented to pass the angle to be shifted and initiate the shift. Otherwise, the motor torque is reduced such that the sum of the motor torque and the pedal torque is less than or equal to the shift torque limit, and a delay is performed to pass the angle to be shifted and initiate the shift. In some embodiments, driveline shift synchronization may be disabled or skipped. In such embodiments, gear changes may be more difficult and chain durability may be reduced.

Accordingly, derailleur design and operation enables regenerative braking at shift timings that take into account pedal torque and driveline synchronization, resulting in smoother shifting and greater durability. Control may be customized for preferential performance or durability in shift timing. Other benefits include reducing chain leaning and chain dropping during rough road travel by employing a derailleur lock to maintain tension. While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.