DE102022107155A1 - Processor and method, in particular computer-implemented method, for controlling a gear hub of a bicycle with an auxiliary motor and a hub gear with such a processor - Google Patents

Abstract

The invention relates to a processor (30) and a computer-implemented method for controlling a hub gear (18, 20) of a bicycle (1) with an auxiliary motor (2). The hub gearbox (18, 20) has an input shaft (68) and an actuator (48), the actuator (48) serving to drive the gear change of the hub gearbox (18, 20). The aim is to enable the user to change gears comfortably, even under load. This is achieved in that the processor (30) is designed to receive a gear change signal (92) which is representative of a gear change initiated by the user of the bicycle (1). Furthermore, the processor (30) is designed to receive a drive parameter signal (96) that is representative of a torque (82) applied to the input shaft. Finally, the processor (30) is designed to generate and output the switching signal (106) depending on the drive parameter signal (96) after receiving the gear change signal (92). The computer-implemented method is designed accordingly. By outputting the switching signal (106) as a function of the drive parameter signal (96), it is possible to make the switching process dependent on the torque on the input shaft (68). The friction in the hub gearbox (18, 20) depends on this torque.

Description

The invention relates to a processor and a method, in particular a computer-implemented method for controlling a hub gearbox of a bicycle with an auxiliary motor, which is provided with an input shaft and an actuator for changing gears depending on a switching signal. The invention further relates to a transmission switching system for a bicycle with an auxiliary motor with such a processor and with a hub gearbox.

On bicycles with an auxiliary motor, so-called pedelecs, gear shifts ensure that a user can pedal at different speeds with an approximately constant cadence. Derailleur gears that have several sprockets on the rear wheel hub and one or more chainrings on the bottom bracket shaft are currently the most widespread. By placing the chain on the different chainrings and sprockets, the different gears or gear steps can be engaged. Although derailleur gears are light, they are also very maintenance-intensive and wear out quickly. The rapid wear of derailleur gears is primarily due to the fact that they are exposed to the environment without protection.

In order to avoid these disadvantages, hub gears are often used on bicycles with an auxiliary motor, in which a hub gear is arranged in a sealed housing around the rear wheel hub. Due to the arrangement in the housing, the hub gear is encapsulated from the environment, so that there is less wear and tear. Hub gears can be used with a timing belt instead of a chain. The timing belt is largely maintenance-free and, with smoother running, has a longer service life than a chain. The disadvantage of a timing belt, however, is that it requires a special bicycle frame that has to be opened in the area of the rear frame triangle when the timing belt is changed.

The advantage of a hub gear compared to a bottom bracket gear, for example, is that there is more space in the bottom bracket area for the auxiliary motor, which supports the user's pedaling performance with its assistance.

However, one problem with hub gears is that they are difficult or impossible to shift under load. Shortly before switching between different gears on the hub gear, the user must take power from the pedal in order to switch. If this does not happen, the desired gear may not be able to be engaged. This disrupts the flow of the vehicle and impairs the driving experience. Changing gears may become impossible, especially when driving uphill.

In view of this, the invention is based on the object of providing hub gears that can be switched better under load.

This task is solved for the processor mentioned at the beginning in that the processor is designed to receive a gear change signal that is representative of a gear change triggered by a user of the bicycle and a drive parameter signal that is representative of at least a torque applied to the input shaft , wherein the processor is further designed to output the switching signal depending on the drive parameter signal after receiving the gear change signal.

The object is further achieved by a method for switching between the gears of a multi-speed hub gearbox of a bicycle with an auxiliary motor, which is actuated by an actuator, the actuator being activated automatically in response to a gear change signal generated by a user, in particular only when a gear change signal is activated The torque applied to the input shaft of the hub gearbox is less than a predetermined limit value.

Accordingly, a gear change signal is first received, which the user generates, for example, via a shift lever or a shift button on the bicycle handlebar. With the gear change signal, the user gives the command to change the gear of the hub gearbox. The actual gear change is carried out by outputting the switching signal to the actuator or receiving the switching signal by the actuator. However, this only occurs after receiving the gear change signal and depending on the drive parameter signal, i.e. depending on the torque applied to the input shaft, which is represented by the drive parameter signal.

The torque applied to the input shaft is crucial for the friction generated in the hub gearbox. If this torque is high, a high frictional force is created, and the parts that move relative to one another, for example the teeth or pawls of clutches, can only be moved with great effort.

However, the actuator, for example a magnetic or electric drive with possibly a gear that drives the switching movement, can only use a limited switching force. By generating and outputting the switching signal As a function of the drive parameter signal, the switching process can now take place when the torque applied to the input shaft has a value that is large enough for the actuator to be able to overcome the friction present in the transmission.

The term "received" includes both active retrieval of the signal, for example by polling a memory location, and passive reception, for example by an input interface of the processor or by writing from outside to a memory location of the processor. The term "output" generally includes providing a signal for access from outside the signal, for example by providing a storage location for reading from outside the processor or by applying a signal to an output interface.

The invention can be improved by the following optional further features, each of which is advantageous and can be combined with one another in any way. The features specified below can be used indiscriminately for both a device and a method, regardless of whether they are described in connection with a device or with a method.

For example, the switching signal can be an incremental signal or an absolute signal. If the shift signal is an incremental signal, the shift signal represents shifting up or down by one gear or a predetermined number of gears starting from the gear currently engaged. The switching signal can be a switching pulse or a sequence of switching pulses, with each switching pulse or its duration representing an upshift or downshift by a predetermined number of gears or triggering it in conjunction with the actuator.

If the switching signal is an absolute signal, it can represent a specific gear that is to be engaged by the actuator. In this case, the switching signal indicates which gear the actuator should engage, regardless of the gear engaged. This gear is referred to below as the target gear. The gear currently engaged is referred to as the actual gear.

The drive parameter signal does not necessarily have to directly represent the torque applied to the input shaft, as would be provided, for example, by a torque sensor that is arranged on the input shaft and directly detects the torque applied there. The drive parameter signal can also be a combination of several individual signals, which together allow the torque applied to the input shaft to be calculated or estimated. In this case, the processor is preferably designed to determine the torque applied to the input shaft from the individual signals of the drive parameter signal. For example, the drive parameter signal includes at least one individual signal that is representative of a characteristic value from the group of angular position, torque, speed, power and/or acceleration. The individual signal can represent the characteristic value of a point from the group containing a motor shaft of the auxiliary motor, the bottom bracket shaft, at least one pedal crank, the input shaft of the hub gear and an output shaft of the hub gear, for example because the sensor generating the respective individual signal is attached to this point or . measures. When we talk about drive parameter signals, this means any individual signal that is contained in the drive parameter signal and is required to determine the torque applied to the input shaft.

The drive parameter signal may be representative of the torque currently applied to the input shaft, or may be representative of a moving time average of the torque at the input shaft over a time window ending at the current time. Such a time window can be, for example, one second, three seconds or ten seconds.

The processor can further be designed to receive, store and/or process a time profile of the drive parameter signal. For example, the processor can be designed to determine an average value representative of the torque applied to the input shaft from a time profile of the drive parameter signal. This allows short-term fluctuations that play no role in the switching process to be filtered out.

As already mentioned, the drive parameter signal does not necessarily have to be determined directly on the input shaft of the hub gearbox. For example, the drive parameter signal can also be determined on the bottom bracket shaft, for example by one or more sensors arranged there. The torque determined or measured there can represent a first approximation of the torque applied to the input shaft if friction losses on the way to the input shaft are neglected. The processor can be designed to take these losses into account, for example by the processor being designed to calculate a predetermined correction of the drive parameter signal, for example by calculating a predetermined one Correction factor, a predetermined correction function or a lookup table with predetermined correction factors or correction functions applies to the drive parameter signal. This correction in the form of a mathematical loss compensation can take friction losses into account and, for example, be dependent on speed, torque and/or power. A correction is preferably only necessary if the drive parameter signal is not detected directly on the input shaft.

The processor is preferably designed to output the switching signal in particular only if the drive parameter signal or, equivalently, the torque represented by the drive parameter signal is smaller than a predetermined value. The predetermined value represents a torque on the input shaft at which the actuator can still switch safely. If the torque represented by the drive parameter signal or the drive parameter signal itself is greater than the predetermined value, no switching signal is output in this embodiment. In this case, the actuator would not be able to carry out the switching process safely. The greatest torque applied to the input shaft at which the actuator can still switch safely is referred to below as the load-shifting maximum.

In some hub gear transmissions, the powershift maximum can have a different value for downshifting than for upshifting. The processor can therefore be designed to receive a switching direction signal that is representative of a switching direction in the direction of a higher or lower gear, that is, representative of an upshift or downshift. The processor is preferably designed to output the switching signal depending on the switching direction signal and drive parameter signal. This configuration is advantageous because in a hub gearbox the powershift maximum can be dependent on the shifting direction. For example, downshifting may require a lower gear change force than upshifting. By generating or outputting the switching signal (also) depending on the switching direction signal, the switching direction dependence of the load switching maximum can be taken into account when carrying out the switching process. In this embodiment, the processor can be designed to determine the load switching maximum depending on the switching direction or to assign a load switching maximum to a switching direction.

In one embodiment, the shift direction signal can be part of the gear change signal. If the gear change signal is, for example, an incremental signal, then the shift direction signal is included in the gear change signal. If the gear change signal is an absolute signal, then it is advantageous if the processor is designed to calculate the shift direction signal from the shift signal. This can be done, for example, by calculating the difference between the gear represented in the switching signal, the target gear, and the actual gear currently engaged from a switching signal generated as an absolute signal. To determine the actual gear, the processor can be designed to receive a gear signal representative of the gear currently engaged.

The actuator is preferably operated when a predetermined crank position is reached by the pedal cranks of the bicycle. For this purpose, it can be provided that the processor is designed to receive a crank position signal that is representative of the angular position of one or both pedal cranks of the bicycle. In other words, the crank position signal is representative of the crank position of the bicycle. The processor is in particular designed to output the switching signal (also) depending on the crank position signal or on the angular position of the pedal cranks. The crank position signal can be an incremental signal that merely represents a change in the angular position of the pedal cranks. Alternatively, the crank position signal can be an absolute signal that represents an angular value of the angular position of the pedal cranks between, for example, 0° and 360°. The crank position signal can be included in the drive parameter signal or be a separate signal.

The output of the switching signal depending on the crank position signal makes it possible to carry out a switching process when the user notices it least due to the pedaling movement and/or when he is exerting the least force on the cranks. For example, the pedaling force generated by the user is lowest when the pedal cranks are at the dead centers, i.e. are aligned vertically or around the vertical. The vertical alignment of the cranks is referred to below as the dead center position. In a further development, the processor can be designed to output the switching signal when the angular position of the pedal crank represented by the crank position signal corresponds to a predetermined limit angle in front of the vertical or vertical pedal position. Such a critical angle can be, for example, approximately 25° to 10° before the dead center position.

In a further embodiment, the processor can be designed to calculate, depending on the drive parameter signal and the crank position signal, the angular position at which the pedaling force generated by the user or the torque generated by the user is minimum and to determine this value as the dead center position. This can be done, for example, by designing the processor is to receive a time course of the crank position signal and a time course of the drive parameter signal, and to assign the drive parameter to at least some angular positions represented in the crank position signal and to average them over several pedal revolutions for the individual angular positions. Using a curve fit, an estimate of the future course can be calculated.

The processor can further be designed to receive a power signal that is representative of a pedaling power of the user and/or a support power of the auxiliary motor, in particular on the input shaft of the hub gearbox. The processor is preferably designed to determine the three services pedal power, support power and total power depending on the power signal. Furthermore, the processor can be designed to determine, depending on the drive parameter signal and the power signal, the portion generated by the user and/or the portion generated by the auxiliary motor of the torque applied to the input shaft.

Receiving the power signal and determining the pedaling power is advantageous in that it enables the processor to control the auxiliary motor more precisely. In particular, the power signal enables the auxiliary motor or its support power to be controlled by the processor as a function of the gear change signal. This is discussed in more detail below.

According to a further advantageous embodiment, the processor can be designed to generate and output an engine control signal that is representative of an assistance power to be delivered by the auxiliary engine, wherein the processor is designed to generate the engine control signal depending on the gear change signal and the drive parameter signal. With this configuration, it is possible to adapt the assistance power generated by the auxiliary motor, which increases the pedaling power generated by the user, so that a gear change is possible.

It is also preferred if the support power of the auxiliary motor is reduced, in particular temporarily, during operation of the actuator. In particular, the assistance power can be reduced during operation of the actuator to a value at which the torque on the input shaft of the hub gearbox is smaller than the powershift maximum. For example, the processor can be designed to determine the user's pedaling power depending on the drive parameter signal and/or the power signal and to generate the motor control signal depending on the determined pedaling power.

The processor can in particular be designed to set or control the assistance power of the auxiliary motor depending on the drive parameter signal and the gear change signal. In addition, the processor can be designed to set or control the support power depending on the power signal or the pedaling power. It is advantageous if the processor is designed to set the assist torque of the auxiliary motor so that the torque at the input shaft is smaller than the powershift maximum when the pedal power generates a torque at the input shaft that is smaller than the powershift maximum. So if the torque applied to the input shaft of the hub gearbox is greater than the powershift maximum because the support power of the auxiliary motor is added to the pedaling power, then in this embodiment the support power is reduced so that the sum of the pedaling power resulting from the pedaling power is at the input shaft of the hub gearbox Torque and the torque resulting from the support power is smaller than the powershift maximum.

During operation, it can happen that the user generates several switching commands and thus gear change signals in a shorter sequence than the hub gearbox can shift. This can be the case in particular if the powershift maximum is only undershot at certain crank positions and/or switching only takes place at certain crank positions, because then the conditions necessary for switching are only met at certain times. Furthermore, it can happen that individual switching commands in such a sequence cancel each other out, for example because the user triggers a gear increase twice and a gear reduction once in quick succession. Consequently, in an advantageous embodiment, the processor should be able to store the gear change signals that have not yet been processed. Furthermore, it is advantageous if the processor is designed to combine the not yet processed, successive gear change signals and to output the switching signal depending on the summary. For example, if two commands to shift up by one gear each and one command to shift down by one gear each are given in quick succession, a switching signal is output as a result of the combination, which only shifts up one gear. According to another example, if three commands are given to shift down by one gear and one command to shift up by one gear, the processor combines the gear change signals based thereon so that the shift signal represents downshifting by two gears. In one In other cases, a one-time upshift and an immediate downshift or, conversely, no gear change at all.

For a precise switching process, it is advantageous if the processor is designed to receive a gear signal that is representative of the gear currently engaged on the hub gearbox. The processor can be designed to generate the switching signal depending on the gear signal. In this embodiment, it is possible for the processor not to output a shift signal if the gear change signal and/or the shift direction signal represents a downshift when the lowest gear is engaged or the gear change signal and/or the shift direction signal represents an upshift when the highest gear is engaged.

The gear signal does not necessarily have to be brought to the processor from outside. It can also be determined in the processor itself by adding up the successive gear change signals continuously or starting from a reference gear if they are incremental signals, or by the last gear change signal representing the gear signal in the case of an absolute signal. However, this solution is disadvantageous compared to determining the gear signal directly on the transmission because no control of the gear position can be implemented.

In a further embodiment, the gear signal can be determined from the drive parameter signal if, for example, the drive parameter signal or the gear signal contains two individual signals that are representative of the speed of the input shaft and the speed of the output shaft of the hub gearbox. In this way, the actual gear can be determined using the ratio of these two speeds and, for example, a lookup table stored in the processor that represents the gear ratios of the gear stages of the hub gearbox. The processor can therefore be designed to determine the gear currently engaged based on the drive parameter signal. Furthermore, the processor can be designed to determine a target gear, i.e. the gear to be engaged, depending on at least one received gear change signal, and an actual gear, i.e. the gear currently engaged, depending on the gear signal. The processor is preferably designed to output the switching signal until an actual gear corresponding to the target gear is represented in the gear signal.

The processor can further be designed to determine the switching direction signal from the gear change signal and the gear signal. This is particularly advantageous if the gear change signal is an absolute signal, i.e. represents the target gear and not, like an incremental signal, a number of gears to be shifted.

In one embodiment, the gear signal can be composed of individual signals, with each individual signal of the gear signal representing the switching state of a clutch of the hub gearbox. The processor can be designed to assign the switching states represented by the individual signals to an actual gear.

The processor can further be designed to receive a partial transmission speed signal that is representative of a speed between two partial transmissions of the hub gearbox. The partial transmission speed signal can be part of the drive parameter signal. The processor can be designed to determine the actual gear depending on the drive parameter signal and the transmission speed signal. According to a further embodiment, the processor can use the speed between two partial transmissions to determine the gear ratio and from this the gear currently engaged. The partial transmission speed signal can also be a rotation angle signal. In this case, the processor should be designed to determine the speed by deriving the rotation angle signal over time.

The shifting force required to change gears can depend not only on the shifting direction, but also on the gear currently engaged, i.e. the actual gear. In order to take this dependency into account, the processor can be designed to calculate the load shift maximum depending on the gear signal or to calculate the switching signal depending on the gear signal. For example, the processor can be designed to determine the powershift maximum using a lookup table depending on the gear signal. In the lookup table, different powershift maximums can be assigned to different gears.

It can happen that the load shift maximum on the input shaft of the manual transmission is exceeded during the switching process, even though it had not yet been exceeded when the switching process was initiated or the switching signal was output. In this case, there is a risk that the actuator or the switching element will remain in a position that lies between two gears. To avoid this, the processor can be designed to compare the actual gear with the target gear after a switching process has ended and, if the actual gear does not correspond to the target gear, to equate the target gear to the actual gear and set one To issue a switching command that represents a switching process to the target gear. As a result, the actuator or the switching element is moved back to the position that was last fully inserted th gear corresponds to how it is represented in the gear signal.

A transmission switching system for a bicycle with an auxiliary motor, which has a processor in one of the above embodiments, is preferably provided with the hub gearbox having the input shaft, the actuator and with a sensor device which is designed to generate the drive parameter signal.

The sensor arrangement can have one or more drive parameter sensors, whereby in the case of several drive parameter sensors, each sensor can generate an individual signal of the drive parameter signal.

For example, a drive parameter sensor of the sensor arrangement can be arranged directly on the input shaft of the hub gearbox. The drive parameter sensor on the input shaft can be a torque sensor, so that the drive parameter signal generated by it directly represents the torque applied to the input shaft. However, in a further embodiment, the drive parameter sensor on the input shaft can also have a speed sensor and/or rotation angle sensor and/or be a power sensor.

Such a drive parameter sensor or a further drive parameter sensor can alternatively or additionally be arranged at a location other than the input shaft of the hub gear, for example on the bottom bracket shaft and/or the rear wheel hub. As described above, the drive parameter signal generated by a drive parameter sensor placed in this way can be used with or without correction as a signal representing the torque on the input shaft of the hub gear, since it reproduces the torque applied to the input shaft with sufficient accuracy.

In a further advantageous embodiment, the sensor arrangement can have a crank position sensor which is designed to output the crank position signal. The crank position sensor can be arranged on the bottom bracket shaft or a crank.

Furthermore, the sensor arrangement can have a gear sensor that is designed to generate the gear signal. The gear sensor can be integrated in the hub gearbox or arranged within a housing of the hub gearbox. The gear sensor can have one or more speed sensors and / or rotation angle sensors, which are arranged, for example, on the input shaft of the hub gear, the output shaft of the hub gear and / or an output shaft or gear shaft (if present) of the actuator. The gear sensors on the input shaft and/or the output shaft of the transmission can simultaneously serve as drive parameter sensors. Furthermore, the gear sensor can have a position sensor, for example a rotation angle sensor or a position sensor on a switching element driven by the actuator, for example a switching drum, of the transmission. The gear sensor can also have one or more rotation angle sensors and/or rotation position sensors between sub-gears of the hub gearbox. Finally, the gear sensor can have one or more position sensors that are designed to detect the position of clutch elements of the hub gear and output it as a gear signal, as already explained above.

The sensor arrangement can also have a power sensor which is designed to determine at least two services from the group containing pedaling power, support power and total power and to output them as a power signal. The power sensor can include one or more individual sensors, for example the power at an output of the auxiliary motor, on the bottom bracket shaft, on the output shaft of the transmission and/or on the input shaft of the transmission, and/or the motor current, the motor voltage and/or the current Record the electrical power consumed by the auxiliary motor.

According to a further embodiment, the transmission switching system can have a gear switch designed to be manually operable and designed to generate the gear change signal when actuated. The gear switch can be integrated into the handlebars, frame, brake handle of the bicycle and/or another component that is ergonomically accessible to the user.

The transmission shifting system may further include the auxiliary motor, which is designed to generate assistance power depending on the engine control signal.

The actuator of the transmission switching system is preferably an electric motor or a magnetic drive. The actuator is preferably an electric motor with a reduction gear in order to generate the highest possible switching force or switching torque.

The actuator is designed to drive a switching process depending on the switching signal. The actuator moves one or more switching elements, through the movement of which clutches of the hub gearbox are engaged and disengaged in a predetermined sequence and thus engage and disengage the gear stages assigned to the clutches. The ones from Actuator driven movement can be a rotational or translational movement or a combination of a translational or rotational movement. For example, the switching element can be a switching drum or switching shaft, the angular position of which determines the switching state of the clutches and thus the gear selected. The clutches can have tooth clutches or pawls that can be engaged and disengaged. The hub gearbox is preferably designed to be able to be shifted even when stationary.

The gear change signal, the drive parameter signal, the shift signal, the power signal, the shift direction signal, the crank position signal and/or the gear signal are preferably electrical signals. These can be analog or digital electrical signals. The individual signals can be sent independently of each other via wire or wirelessly.

The processor is preferably an electronic component, for example an ASIC or a correspondingly programmed control unit of the auxiliary motor. The processor can also be a smartphone running an application with the functionality described above.

The processor may have an input interface designed to receive the above-mentioned signals. The input interface can be designed for wired and/or wireless reception of these signals. For example, the input interface can have a Bluetooth, ANT and/or WLAN receiver. Furthermore, the processor can have a wired and/or wireless output interface at which the switching signal and/or the motor control signal can be called up, is sent and/or is present from outside the processor. The output interface can in particular have a Bluetooth, ANT and/or WLAN transmitter. Of course, the Bluetooth, ANT and/or WLAN transmitter and Bluetooth, ANT and/or WLAN receiver can be integrated in an electronic component.

The invention is explained below using an exemplary embodiment with reference to the accompanying drawings. In accordance with the above description, features whose technical effect is not important for a specific application can be omitted from the exemplary embodiment described. Conversely, features described above that are not present in the exemplary embodiment described can be added if the technical effect associated with these features is important in a particular application.

In the description below, features that correspond to one another in terms of function and/or structure are given the same reference numerals.

• 1 eine schematische Darstellung eines Fahrrads mit Hilfsmotor, Prozessor und Getriebeschaltsystem;
• 2 eine schematische Perspektivdarstellung einer Ansicht eines Getriebeschaltsystems mit einem Aktor von außen;
• 3 eine schematische Darstellung des Aufbaus eines Getriebeschaltsystems;
• 4 eine schematische Darstellung des Verlaufs eines von einem Benutzer erzeugten Tretmoments;
• 5 eine schematische Darstellung eines Verfahrens zur Verarbeitung eines Gangwechselsignals;
• 6 eine schematische Darstellung eines Verfahrens zur Ermittlung eines Drehmoments an einer Eingangswelle eines Nabenschaltgetriebes;
• 7 eine schematische Darstellung eines Verfahrens zur Ermittlung des gerade eingelegten Ganges;
• 8 eine schematische Darstellung eines Verfahrens zur Ermittlung einer Kurbelstellung; und
• 9 eine schematische Darstellung eines Verfahrens zum Schalten unter Last.

Show it:

• 1 a schematic representation of a bicycle with an auxiliary motor, processor and transmission switching system;
• 2 a schematic perspective representation of a view of a transmission shifting system with an actuator from the outside;
• 3 a schematic representation of the structure of a transmission switching system;
• 4 a schematic representation of the course of a pedaling torque generated by a user;
• 5 a schematic representation of a method for processing a gear change signal;
• 6 a schematic representation of a method for determining a torque on an input shaft of a hub gearbox;
• 7 a schematic representation of a method for determining the gear currently engaged;
• 8th a schematic representation of a method for determining a crank position; and
• 9 a schematic representation of a method for switching under load.

1 shows an example of a bicycle 1 with an auxiliary motor 2, particularly in the form of an electric motor. The auxiliary motor 2 is arranged here in the area of a bottom bracket 4. The auxiliary motor 2 serves to support a pedaling movement exerted by a user (not shown), for which the bicycle is provided with pedals 6 which are arranged at the end of pedal cranks 8.

The bicycle 1 also has an accumulator 10, which serves as an energy source for the auxiliary motor 2.

The auxiliary motor 2 adds assistance power to the pedaling power generated by the user. A traction drive 12, for example a belt drive or a chain drive, serves to transmit the drive power, which is made up of the pedal power and the support power, to the rear wheel 14. A hub gear 18 in the form of a hub gear 20 is located on the rear wheel hub 16. The auxiliary motor 2 can be used as an alternative to the one in 1 illustrated embodiment also arranged on the rear wheel hub 16 be. In this case, the hub gear 18 and the auxiliary motor 2 can be structurally united.

The hub gear 20 provides a plurality of gears. In the exemplary embodiment described here, the hub gear 20 is switched electrically by the user triggering a gear change by operating a gear switch 22, which can be attached to a handlebar 24 or to a brake (not shown) attached to the handlebar. The bicycle 1 also has a control unit 26 with which the auxiliary motor 2 and, if necessary, other functions of the bicycle 1 can be controlled and which provides the user with various information such as speed, cadence, kilometers traveled or navigation functions by means of a display 28. Gear switch 22 and control unit 26 can be two separate devices or structurally united.

A processor 30 is used to control the hub gear, in particular to control the switching process of the hub gear 20. The processor 30 can be part of the gear switch 22, the control unit 26 or represent a separate part that is located somewhere on the bicycle, for example in or in the Proximity of the auxiliary motor 2 or the hub gear 20. The processor 30 can be implemented as hardware and/or software. For example, the processor 30 can be formed by an application that runs on one or more electronic components. An example of such an electronic component is an ASIC. The processor 30, if it is not integrated into these devices, can be connected to the gearshift 22 and/or the control unit 26 via a bidirectional data connection, which can be wired or wireless.

The control unit 26 can, for example, be provided by the manufacturer of the auxiliary motor 2 or be a smartphone on which an application for controlling the auxiliary motor 2 is running.

2 shows a detail of the area around the rear wheel hub 16 of a bicycle 1, of whose frame 32 only the chain stays 34 and the seat stays 36 are shown. The hub gear 20 here in the form of a hub gear 18 extends around the rear wheel hub 16. On a housing 38 serving as the output shaft of the hub gear 18, the spoke holes 40 are usually the spokes of the rear wheel 14 ( 1 ), which are, however, omitted here for the sake of clarity. There can also be a brake disc 42 on the rear wheel hub 16 if the bicycle has disc brakes. A brake caliper attached to a caliper mount 44 is in 2 also omitted. From the traction drive 12 ( 1 ), is in 2 a toothed belt pulley 46 can be seen, via which a drive torque is fed into the hub gear 20.

An actuator 48, for example an electric motor or a magnetic drive, is housed in a housing 50. The actuator 48 drives the switching processes in the hub gearbox 20. For energy supply and/or control, a line 52 can be provided, which connects the actuator 48 to the gearshift 22, the control unit 26 and/or the accumulator 10.

In 3 the structure of a transmission switching system 52 is shown schematically. The hub gearbox 20, the actuator 48 and the auxiliary motor 2 are part of the gearshift system 52 in this illustration.

During operation, the user steps on the pedals 6 with a pedaling force 54. As a result, a pedaling torque 58 acts on a bottom bracket shaft 56. The pedaling torque 58 leads to a pedaling power generated by the user, which corresponds to the product of the pedaling torque 58 and the speed of the bottom bracket shaft 56.

The auxiliary motor 2 supports the user's pedaling performance by adding assist power. The drive power with which the bicycle 1 ( 1 ) is driven, corresponds to the total power resulting from the sum of pedal power and drive power.

The auxiliary motor 2 is connected via a motor gear 60, a hollow shaft 61 and optionally a freewheel 62 to the bottom bracket shaft 56 in a torque-transmitting manner in at least one direction of rotation. The support power provided by the auxiliary motor 2 generates a support torque 64 on the hollow shaft 61, which acts on the bottom bracket shaft 56 in addition to the pedaling torque 58. At the bottom bracket shaft 56, the pedaling power and the support power are added to the total power, which is transmitted in the direction of the rear wheel hub via a blade 66 attached to the bottom bracket shaft 56, for example a chainring or a pulley as part of the traction drive 12. On the rear wheel hub there is the toothed belt pulley 46, or, when using a chain drive, a pinion, which introduces the total power into the hub gear 20 via an input shaft 68 of the hub gear 20.

If the auxiliary motor 2 is a hub motor, then the assistance power is only added to the pedal power at the rear wheel hub 16.

The hub gear 20 has one or more gear stages 69, for example one first gear stage 69a, a second gear stage 69b and a third gear stage 69c. The number of gear stages essentially determines the number of gears provided by the hub gearbox 20. Each gear stage 69 can, as in 3 shown only as an example, have a planetary gear 70. Instead of a planetary gear 70, however, a spur gear with an intermediate shaft can also be present as a gear stage.

Each gear stage 69 has at least one clutch 72 that can be engaged and disengaged to shift a gear. A freewheel can be integrated into the clutch 72.

The respective combination of the engaged and disengaged clutches 72 of all gear stages 69 determines the power or torque flow through the hub gearbox 20 and thus which gear is currently engaged in the hub gearbox 20. The gear currently engaged is referred to as the actual gear.

The clutches 72 can contain, for example, switchable tooth clutches or movable pawls. The clutches of the hub gearbox 20 are synchronized or moved together by at least one movable switching element 74, for example a rotating switching drum, which engages and disengages the clutches 72 via link controls 76. Instead of a switching drum, another way can of course be provided to engage and disengage the clutches 72. For example, a camshaft can be used to switch the clutches 72 instead of the switching drum 74. Furthermore, instead of a rotary movement, a translational movement along a hub axis 78 can also be used, so that the switching element 74 is moved in the manner of a plunger or drawing wedge. Each position of the switching element 74, in the case of a rotating switching element, each angular position of the switching element 74, is assigned a different gear. For this purpose, the switching element 74 can assume discrete positions in which it can be locked or inhibited.

The switching element 74, which causes the switching process in the hub gearbox 20, is driven by the actuator 48. Between the actuator 48 and the switching element 74 there can be an actuator gear 80, which is particularly useful if a small, high-speed electric motor 48 is used as the actuator 48, the high speed of which must be reduced to a low speed on the switching element 74. The actuator gear 80 can also contain a speed superposition gear, not shown here, if the switching element 74 rotates and the actuator 50 is fixedly arranged on the housing. For example, control via such a speed superposition gear is not possible EP000001982913A1 known.

The torque applied to the input shaft 68 of the hub gearbox will be conducted via the torque-transmitting components of the hub gearbox 20. The currently engaged clutches 72 represent a portion of these torque transmitting components. When changing gear under load, some or all of the engaged clutches 72 must be disengaged and some or all of the disengaged clutches 72 must be engaged while torque is being transferred.

If the clutches 72 have teeth for torque transmission, the teeth of the engaged clutches 72, which are pressed against one another by the torque, are released from one another. The higher the torque 82 on the input shaft 68, the more force is required to separate the toothings from each other, because with the torque the surface pressure increases and thus the friction between the meshing teeth that are to be disengaged.

Friction that increases with the torque 82 can also occur on guides 86, for example splines, which guide the parts of the clutches that move during switching.

The greater the torque 82, the more force is required for the switching process.

The drive power of the actuator 48 is limited, so that the switching element 74 can be moved accordingly with only a certain maximum force. If this force is not sufficient to release a torque-transmitting clutch 72, a gear change cannot take place. The actuator 48 can therefore only reliably switch the hub gearbox 20 up to a certain maximum torque 82 on the input shaft 68. This maximum torque is referred to as the powershift maximum.

As long as the torque 82 is below the powershift maximum, switching between the gears of the hub gearbox 20 is unproblematic.

A gear change is triggered by the user by actuating the gear switch 22, for example by pressing a button 88 to shift up a gear or a button 90 to shift down a gear. If the torque 82 on the input shaft 68 is below the powershift maximum at the time the gear switch 22 is actuated, the gear can be changed immediately become. However, if the torque 82 exceeds the powershift maximum at the time the gear switch 22 is actuated, the actuator 48 cannot bring about a gear change, at least momentarily.

The following describes how a shifting process is made possible by the transmission shifting system 52 under load.

Actuation of the gear switch 22 generates a gear change signal 92 which is received by the processor 30. The gear change signal 92 is representative of a user-initiated gear change.

The gear change signal 92 may be an incremental signal or an absolute signal. As an incremental signal, it simply represents shifting up or down one or another number of gears. As an absolute signal, the gear change signal represents the gear to be engaged.

The transmission shifting system 52 has a sensor assembly that includes one or more sensors included in 3 are labeled S.

One or more of these sensors S form a drive parameter sensor 94, which generates a drive parameter signal 96 that is representative of at least the torque 82 on the input shaft 68 and is received by the processor 30.

For example, a torque sensor 98 can be arranged on the input shaft 68, which directly measures the torque 82 and outputs it in the form of the drive parameter signal 96.

The torque sensor 98 can be part of a power sensor 100 on the input shaft 68, which, in addition to the torque, also detects the speed of the input shaft 68 and outputs it as part of the drive parameter signal 96.

The drive parameter signal 96 itself does not have to contain the torque 82 directly in coded form. The torque 82 only needs to be able to be determined using the drive parameter signal 96.

For example, the processor 30 can be designed to calculate the torque 82 using the drive parameter signal 96. For example, the drive parameter signal 96 may contain a speed and a power as individual signals, so that the processor can calculate the torque from these two individual signals, for example by dividing the power contained in the drive parameter signal by the speed contained in the drive parameter signal. Torque, speed and/or power do not have to be measured at the same location or on the input shaft 68.

Alternatively or additionally, a torque sensor 102 can also be arranged on the bottom bracket shaft 56 as a drive parameter sensor 94. The torque sensor 102 detects the pedaling torque 58 acting on the bottom bracket shaft 56 by the user. In this exemplary embodiment, the supporting torque 64 is passed on to the pinion 66 through a hollow shaft together with the pedaling torque 58. The total torque in the hollow shaft can be considered representative of the torque 82 on the input shaft 68 of the hub gear 20 if one assumes, as a first approximation, that the losses in the chain drive 12 are negligible or independent of speed and torque and the translation of the traction drive 12 is known .

The processor 30 can also be designed to correct the torque detected by the torque sensor 102, for example by applying a correction factor, a correction function or a lookup table to the torque detected by the torque sensor 102 in order to take into account the losses in the traction drive 12 and its translation . Through the correction, the total torque is mapped onto the torque 82, as it were. The correction can therefore represent a transfer function from the torque on the bottom bracket shaft to the torque on the input shaft.

The torque sensor 102 can be part of a power sensor 104 on the bottom bracket shaft 56, which, in addition to the torque acting on the bottom bracket shaft 56, also detects the speed of the bottom bracket shaft 56.

The drive parameter signal 96 may be representative of the torque currently applied to the input shaft or representative of a time average of the torque applied to the input shaft. In particular, however, the processor 30 can be designed to calculate a time average of the torque 82 applied to the input shaft 68 as the value representing the torque 82 from a time profile of the drive parameter signal. The generation of the switching signal 106 by the processor 30 can be dependent on a current value or an average value of the drive parameter signal or the torque 82 represented by it.

The processor 30 is designed to generate and output a switching signal 106 depending on the drive parameter signal 96 and the gear change signal 92.

The actuator 48 is actuated by the switching signal 106. If the actuator 48 receives the switching signal, it carries out a drive movement that is predetermined or determined by the switching signal 106. The output of the switching signal 106 by the processor 30 can be wired or wireless. Wireless output can be done using Bluetooth or ANT, for example. An output can also take place through a remote query or reading out of a memory location by another electronic component or another functional unit.

The switching signal 106 can be an incremental signal, in response to which the actuator 48 moves over a predetermined distance or a distance that is dependent on the switching signal 106 in a direction that is dependent on the switching signal 106. This distance is dimensioned such that the switching element 74 advances exactly a predetermined number of gears which is dependent on the switching signal 106.

Alternatively, the switching signal 106 can also be an absolute signal, in response to which the actuator 48 moves to a specific location, i.e. is moved to the gear represented in the switching signal 106.

By generating or outputting the switching signal 106 as a function of the drive parameter signal 96, which represents at least the torque 82, and after receiving the gear change signal 92, the processor 30 is put in the position of having a switching process carried out by the actuator 48 only when on the input shaft 68 the load switching maximum is undershot.

The load switching maximum or, synonymously, a representative value can be stored in the processor 30. The processor can, for example, be designed to compare the stored load switching maximum with the drive parameter signal 96 and to output the switching signal 106 depending on this comparison.

The pedaling force 54 applied by the user and its direction and thus also the pedaling torque 58 change at least approximately cyclically during a complete rotation of a crank 8.

This is explained below with reference to 4 explained, which schematically represents the course of the pedaling torque 58 on the bottom bracket shaft 56 depending on the crank position 8 during a complete revolution of one of the two cranks 8. The angular position 0° refers to the crank 8 pointing vertically upwards, while at the angular positions 90° and 270° the crank is aligned horizontally in the opposite direction. It can be seen that the pedaling torque 58 becomes maximum at certain angular positions 108 of the pedal cranks 8 and becomes minimum at certain other angular positions. The pedaling torque 58 is always maximum when the pedal cranks are at least approximately horizontal. In the at least approximately vertical position of the pedal cranks 8 there are dead center positions 110 at which the pedaling torque 58 is minimal.

The sum of the pedaling torque 58 and the supporting torque 62, possibly minus any losses, is present at the input shaft 68.

If the support torque 62 is always in a certain relationship to the pedaling torque 58 or if the support torque is constant over time, the course of the torque 82 on the input shaft 68 follows the course of the pedaling torque 58. In such a case, the course of the torque 82 is also cyclical; the course of the torque 82 has a minimum at the dead center positions 110. It may therefore be the case that, although the powershift maximum at the input shaft is exceeded at the time at which the gear change signal 92 is received, the powershift maximum is exceeded at one point during a crank revolution. The switching process can therefore be carried out with a short delay as soon as the load switching maximum is undershot. Since the processor 30 can determine the current value of the torque 82 based on the drive parameter signal 96, the switching signal 10 is only output or the switching process is only carried out if the torque 82 is only temporarily below the load switching maximum.

The transmission switching system 52 may have a crank position sensor 112, which outputs a crank position signal 114 representative of the angular position of one or both pedal cranks 8. The processor 30 is designed to detect the crank position signal 114 and to output the switching signal 106 as a function of the crank position signal 114.

For example, the switching signal 106 is only output if the angular position 108 of a pedal crank 8 is in a predetermined range 116 ( 4 ) is located. The area 116 preferably extends around the dead center position 110. The area 116 can begin 10° or 20° before the dead center position 110, i.e. at a crank position of approximately 160° or approximately 170°. The area 116 can also extend up to approximately 10° or approximately 20° behind the dead center position 110, i.e. up to approximately 190° or up to approximately 200°. The area 116 does not have to be determined by the angular position 108 of a pedal crank 8, but can alternatively or cumulatively be determined by the power shift maximum 117, for example in that in the area 116 the torque 58 is below the power shift maximum 117.

Shifting at the bottom dead center position 110 or in the area 116 also makes sense if the torque 82 is always or over a larger range of a crank revolution below the power shift maximum, because when shifting in the area 116, the user's natural pedaling movement is influenced by the The switching process is at least disturbed.

In one embodiment, the processor 30 can be designed to generate or output the switching signal 106 independently of the drive parameter signal 96 when the crank position or angular position of the crank 8 represented by the crank position signal 114 is in the area 116.

In an alternative embodiment, the crank position sensor 112 can be dispensed with. The processor 30 can thus be designed to determine the dead center position 110 based on the drive parameter signal 96. In this case, the drive parameter signal 96 also represents the crank position.

The processor can thus be designed to adapt a sine function to the course of the drive parameter signal 96, i.e. to the course of the torque 82 or the pedal torque 58. From such an adjustment, the dead center position results from the minimum of the adjusted sine function. The term sine function means not only a trigonometric function, but also an essentially sinusoidal function that is calculated in another way, for example using polynomials or a spline curve. This calculation offers the advantage that the future course of the torque 82 or the crank position 108 can be estimated and the switching signal 106 can be output before the range 116 is reached or the torque 82 has fallen below the power shift maximum 117 in order to ensure reaction times that are the inertia of the actuator 48 and the mechanics of the hub gear 20 result must be taken into account.

Such a curve fit can of course also be carried out if a crank position signal 114 is present.

It may happen that the torque 82 on the input shaft 68 of the hub gearbox 20 does not fall below the powershift maximum 117 during one or more pedal revolutions. This can have two causes.

Firstly, the user's pedaling power itself can be below the powershift maximum, so that the torque 82 on the input shaft 68 does not fall below the powershift maximum only because the support power of the auxiliary motor 2 is added to the pedaling power. Secondly, the user's pedaling power can already lead to a torque 82 that is greater than the powershift maximum.

In the former case, it makes sense if the processor 30 is designed to determine the proportion of the pedal power to the torque 82 and/or the proportion of the assistance power to the torque 82. Furthermore, the processor 30 should be designed to reduce the assistance power generated by the auxiliary motor 2 in the area 116 and/or at another angular position 108 of the pedal crank 8 so that the torque 82 drops below the powershift maximum 117. This is described in detail below.

In the second case, a switching process cannot be carried out because the switching force required by the actuator 48 is not sufficient to move the switching element 64 against the internal friction. In this case, it makes sense that the processor 30 is designed to output an alarm signal 118, which can be output, for example, in the form of a visual warning signal 120 and/or an acoustic warning signal 122 on the gear switch 22 or the control unit 26.

The processor 30 can have a memory 124 in which gear change signals 92 that have not yet been processed are stored. For example, if a gear change is not possible at the time the gear change signal 92 is received because the torque 82 does not fall below the power shift maximum 117 during a full crank revolution, the gear change signal 96 can be stored in the memory 124 in order to be processed immediately when the torque 82 drops below the load switching maximum 117.

The alarm signal 118 may alternatively or cumulatively be representative of one or more unprocessed gear change signals 92 being contained in the memory 124. The gear switch 22 and/or the control unit 96 can display an information signal 126 in the display 28 depending on the alarm signal 118 or gear change signals 92 stored in the memory 124. In 1 For example, a “plus” sign is displayed in the display 28 as an indication that a gear change signal 92 representative of an upshift is still stored, i.e. the gear change initiated by the user is still pending.

The processor 30 can also be designed to combine gear change signals 92 that have not yet been processed in order to avoid unnecessary switching operations. For example, if the user presses the downshift button 90 in the previously illustrated situation in which the gear shift has not yet shifted up, this would cancel the previously issued upshift command. Such a combination can be carried out in the processor 30 by simply adding the gear change signals 92 or the gear changes represented by them if they are incremental signals. If the gear change signal 92 is an absolute signal, the processor should be designed to calculate and add up the resulting gear jumps from the absolute signals located in the memory 124.

The processor 30 can be designed to delete a gear change signal 92 stored in the memory 124 if a gear change was not possible for a predetermined time or number of crank revolutions.

In order to enable the processor 30 to determine the proportion of power or assistance power to the torque 82, the transmission shifting system may have one or more power sensors 119. For example, a power sensor 119, which is designed to detect the assistance power of the auxiliary motor 2, can be arranged on a motor shaft of the auxiliary motor or at another location between the auxiliary motor and the freewheel 62. Alternatively or additionally, a power sensor 119 can be arranged, for example, on the pedals 6 or on at least one pedal crank 8 in order to detect the pedal force 54 applied by the user and a speed of the cranks 8. A power sensor 119 can be designed to determine the motor current and/or the motor voltage of the auxiliary motor 2 and/or the electrical power consumed by the auxiliary motor 2 and to output it as a power signal.

In the cases mentioned, the power sensor 119 is designed to generate a power signal 130. In the case of the power sensor on the pedals 6, the power signal 130 represents the pedaling power of the user, in the other case the support power of the auxiliary motor 2. The power signal 130 can be an angular position signal, a speed signal, a torque signal and/or a force signal, for example, as individual signals represents the pedals.

Together with the drive parameter signal 96, which is generated, for example, by the power sensor 104 attached to the bottom bracket shaft 58, the processor 30 is enabled with the power signal 130 to determine the proportion of the pedal power and/or the assistance power in the torque 82 at the input shaft 68 calculate. Here again, as a first approximation, the torque on the bottom bracket shaft 56 can be viewed as representative of the corresponding torque on the input shaft 68. In particular, it can be assumed that the proportion of the pedal power and/or the assistance power in the respective total torque remains unchanged along the torque flow.

If it turns out that the portion of the torque 82 based solely on the user's pedaling power is below the powershift maximum, the assistance power of the auxiliary motor 2 can be reduced to such an extent that the torque 82 actually drops below the powershift maximum. In principle, the support power can be reduced at any point in the crank position 108. However, the support power in area 116 is preferably reduced.

For this purpose, the processor 30 is designed to generate a motor control signal 132 depending at least on the drive parameter signal 96, but preferably also on the crank position signal 114 and/or the power signal 130. The engine control signal 132 is output to the auxiliary engine 2 or its controller (not shown), and can be representative of a setpoint of the assistance power. The support power is then regulated to this setpoint. The engine control signal 132 can be generated by the processor 30 at regular intervals or permanently, for example if the support power of the auxiliary engine 2 is basically regulated by the processor 30. The motor control signal 132 may be a digital or analog signal. With an analog motor control signal 132, for example, a current strength and/or voltage of the motor control signal 132 can be proportional to the support power.

Immediately after the pedal cranks 8 have passed the area 116 or the switching process has ended, the assistance power is increased again to the previous value.

A gear sensor 134 of the transmission switching system 52 generates a gear signal 136 that is representative of the gear currently engaged on the hub transmission 20. Using the gear signal 136, the end of the shifting process can be determined by the processor 30.

The gear sensor 134 can be constructed in different ways and can also have different individual sensors. For example, the gear sensor 134 can detect a position, for example angular position, of an actuator output shaft 138. Alternatively, the gear sensor 134 can detect the position, for example angular position, of the switching element 74. Both the position of the actuator output shaft 138 and the position of the switching element 74 are representative of the gear currently engaged.

Alternatively, the gear sensor 134 can comprise two individual sensors, each of which outputs a value representative of the speed of the input shaft 68 and the speed of the output shaft 38 of the hub gear 20. The speed of the input shaft 68 can already be contained in the drive parameter signal 96. The ratio of the speeds of the input shaft 68 and the output shaft 38 of the hub gearbox 20 is representative of the gear currently engaged. A transfer function can be stored in the memory 124 of the processor 30, for example in the form of an analytical function or a lookup table, which assigns the gear corresponding to this ratio to different ratios of the speeds of the input shaft 68 and the output shaft 38. A transfer function can also be used in the processor 30 to assign a value representative of the gear currently engaged to the positions of the actuator output shaft 138 or the switching element 74.

Alternatively or additionally, the gear sensor 134 can also monitor the position of the clutches 72, for example by arranging a position sensor 134 on each clutch 72, which outputs a signal representative of the position of the clutch 72. In 3 For the sake of clarity, only two sensors 134 are shown on the two clutches of the right partial transmission. The individual signals from the sensors 134 determining the respective position of the clutches 72 reflect the switching state of the hub gearbox 20 and thus also represent the gear currently engaged. Here too, the processor 30 is preferably designed to use a transfer function to assign a currently engaged gear to a combination of clutch positions represented in the gear signal.

Instead of monitoring the clutch positions, the speeds of the partial transmissions can also be monitored.

The processor 30 is designed to output the switching signal 106 depending on the gear signal 136. For example, the processor 30 does not output a switching signal 106 to the actuator 48 if it is determined based on the gear signal 136 that the lowest gear is already engaged and the user still wants to downshift. The same applies if the actual gear determined by the processor 30 is the highest gear of the hub gearbox 20 and the user wants to shift up. In such a case, the processor 30 may be configured to clear the gear change signal.

The processor 30 can also be designed to determine the target gear resulting from the gear change signals 92 that have not yet been processed and to compare it with the actual gear. If the comparison shows that the target gear does not yet correspond to the actual gear, the switching signal 136 can be output - again depending on at least the drive parameter signal 96.

In the gear switch 22 or the control unit 26, a gear display 140 can be provided, for example in the display 28, which shows the actual gear. The actual gear can be included in the alarm signal 118.

Depending on the structure of the hub gearbox 20, the switching force to be applied by the actuator 48 to shift between two gears can also depend on the gear currently engaged. For example, fewer clutches 72 have to be moved during certain gear changes than during other gear changes, or due to the gear ratios of the partial transmissions, the friction-generating torque in certain gears on the clutches to be moved is smaller than in other gears. The load-shifting maximum can therefore be gear-dependent. In order to take this dependency into account, the processor can be designed to output the switching signal 136 depending on the gear signal 136. The processor 30 can have a conversion function in the memory 124 that assigns a load shift maximum to an actual gear. In this case, the switching signal 136 is only sent out when the torque 82 drops below this gear-dependent powershift maximum.

Furthermore, the processor 30 can be designed to output the engine control signal 132 depending on the gear signal 136. For example, when switching between some gears, the assistance power is reduced more than when switching between other gears in order to reduce the torque 82 on the input shaft 68 below the powershift maximum.

With reference to the 5 until 9 Examples of methods for switching under load are described below. The methods are particularly intended for use on a processor, for example the processor 30 of the 3 to be executed.

In 5 is shown that a user triggers a gear change signal 92 in a step 200, i.e. generates a shift command. The gear change signal 92 is stored in a memory, for example the memory 124, in a step 202. In step 204, the gear change signal 92 stored in the memory is updated and/or successive and stored gear change signals 92 are combined so that mutually canceling gear change signals are deleted.

In addition, in step 204, the gear change signal in the memory can be corrected if the gear change signal wants to shift a gear beyond the lowest or beyond the highest gear. In this case, the gear change signal in the memory can be set to a value that represents the smallest or largest gear.

In step 204, the switching state can also be taken into account, which results after a gear change that has been completely carried out, only partially carried out or not carried out at all after the switching signal has been output. The result of the switching process is provided by step 206. If, for example, all gear change signals have been processed by successfully executing a switching process - the actual gear corresponds to the target gear - then the gear change signal can be deleted, unless the user has switched again in step 200 in the meantime Gear change signal generated. If, on the other hand, the shifting process could only be carried out incompletely, then in step 206, for example, the actual gear engaged is transmitted and the gear change signal in the memory is updated accordingly in step 204: There are still gears that need to be shifted. The gear change could not be carried out at all, as shown below 9 is carried out, then the gear change signal remains unchanged.

Finally, in step 204, the switching direction resulting from the gear change signal and, if necessary, by comparing the gear change signal and the gear signal can be determined and also saved in step 202.

This in 5 The method shown can be carried out in a fixed cycle. Alternatively or additionally, this can be done in 4 For example, the methods shown are carried out under interrupt control whenever the user generates a gear change signal 92 or a switching process is completed.

With the in 6 In the method shown, the torque 82 on the input shaft 68 can be recorded and continuously updated. In addition, the proportion of the pedal power or the support power to the torque 82 can be continuously determined. Furthermore, using the method of 6 the load switching maximum can be determined.

This in 6 The method presented can be carried out in parallel or alternately with that in 5 procedures shown can be carried out.

In step 300, a signal representative of the torque 82 is detected, for example the drive parameter signal 96. In addition, a signal representative of the pedaling power and/or the support power at the input shaft 68, for example the power signal 130, which can also be part of the drive parameter signal 96, recorded. In step 302 this value is saved and in step 304 it is updated and corrected if necessary, as above 3 is described.

In step 304, the respective load-shifting maximum can also be calculated and also saved depending on the shifting direction and/or the actual gear engaged. This is in 6 represented by the schematically illustrated reading of the gear change signal updated in step 202. Alternatively, the power shift torque can be calculated in step 204 depending on the shifting direction and/or the actual gear engaged and updated in step 202 together with the gear change signal. In step 304, for example, a predetermined power shift maximum can be assigned to an actual gear and/or a shifting direction using a lookup table.

The procedure according to 6 can be carried out by the processor at a fixed, preferably as short a time interval as possible, so that the values updated in step 302 reflect the current state as accurately as possible.

In 7 Another method is shown, for example by the processor 3 , in parallel or alternating with the procedures of 5 and 6 can be carried out. In a step 400, a gear signal representative of the gear currently engaged, the actual gear, is received and stored in step 402.

8th shows another method that works in parallel or sequentially to the methods of 5 until 7 can be carried out. In step 500, a value representative of the crank position of the cranks 8 is received, for example the crank position signal 114. In step 502, this value is stored, for example in memory 124. In optional step 504, the value received in step 500 can be processed, for example by im Step 502 not only the current, but the time course of the crank position is saved and a curve adjustment to the time course is calculated. The curve fitting can be carried out, for example, by means of a spline fit or an adaptation of a sinusoidal curve, for example a sine function or a polynomial. For example, the calculation step 504 can also be used to calculate the time that will elapse until the area 116 is reached at the current cadence.

In 9 The sequence of a process is shown as an example with which the hub is under load manual transmission 20 can be switched. This in 9 The method presented can be carried out in parallel or sequentially to those in 5 until 8th procedures shown can be carried out. It can be carried out at predetermined time intervals or under interrupt control, for example when a gear change signal 92 is received. The procedures of the 5 until 8th can also be part of the procedure 9 be.

In step 600, the value representative of the current torque 82 on the input shaft 68 is read out, which is after step 302 6 is continually updated.

In addition, in step 600 the load switching maximum 117 can also be read out, which is continuously updated in step 302. Alternatively, the load shift maximum 117 may also be a value stored in memory 124 as a constant value.

In step 602, the torque at the input shaft is compared with the power shift maximum 117. If the torque 82 is smaller than the powershift maximum, this means that the actuator 48 is able to change gears. In this case, the switching process can be carried out immediately and the process continues with step 604.

In step 604, the desired gear to be engaged is first read out, for example in step 202 according to the method of 5 continuously updated.

In step 606, the target gear is compared with the actual gear that was saved in step 402.

If this comparison shows that the target gear cannot be engaged because, for example, the lowest gear is already engaged when shifting down or the highest gear is already engaged when shifting up, the gear changing process ends without changing gears in step 206. The gear changing signal can be deleted beforehand become.

If it is determined based on the comparison in step 606 that the target gear can be engaged, the switching process is carried out in step 608. This means, for example, in 3 illustrated embodiment, that the switching signal 106 is output to the actuator 48 and the actuator 48 actuates the switching element 74. In step 608, a waiting loop may be implemented that suspends execution of the next step for a predetermined period of time. This period of time is preferably greater than a predetermined period of time, which corresponds, for example, to the length of the period of time for changing gears.

Step 606 can also be omitted if the target gear is in the process 5 is continuously updated and the comparison made in step 606 and the resetting of the gear shift signal in step 612 are already taking place in step 204.

After the switching process 608, the actual gear now engaged is compared in step 610 with the target gear read in in step 604.

If the comparison between the actual and target gear in step 610 shows that the gear to be engaged is actually engaged, i.e. the target gear corresponds to the actual gear, then the gear changing process is ended in step 206. The gear change signal is then generated according to the method of 5 updated automatically or can be reset or deleted at this point.

If, on the other hand, it turns out in step 610 that the requested gear change could not be carried out completely, i.e. the actual gear does not correspond to the target gear, then in step 612 the target gear is set to the actual gear and a gear change 608 is carried out again before the gear changing process is ended in step 206. This situation can occur, for example, if the load switching maximum is exceeded while step 608 is being carried out, so that the actuator 48 or the switching element 74 cannot complete the switching movement. In this case, setting the target gear to the current actual gear in step 612 and then carrying out the switching process in step 608 causes the actuator 48 or the switching element 74 to return to the position corresponding to the actual gear. Such a return is possible at any time due to the freewheeling functions in the clutches 72.

If it is determined in step 602 that the torque on the input shaft of the hub gearbox is greater than the powershift maximum, then in step 618 the current crank position can be determined, for example according to the method of 8th updated. As long as the crank position is not in the area 116, i.e. in a predetermined angular range around the dead center position 110, the next method step is not carried out.

In step 620, the portion of the torque 82 that is due to the pedaling power is compared with the powershift maximum. The proportion of torque 82 attributable to the pedaling power is determined using the method of 6 continuously updated and saved in step 302.

If the proportion of the pedal power to the torque at the input shaft is above the powershift maximum, this means that even if the support power of the auxiliary motor 2 is reduced, the actuator 48 will not be able to activate a switching process. After comparison 620, the method is therefore ended in step 206 without carrying out a switching process.

Alternatively, step 620 can be omitted and simply continued with step 604 instead. This is possible in particular if steps 610, 612 and 608 are used to check again whether the gear could be fully engaged and it is ensured that the actuator 48 or the switching element is moved to a position corresponding to the actual gear .

If it is determined in step 620 that the portion of the torque 82 due to the pedaling power is smaller than the power shift torque, the process continues with step 604.

In step 604, the current target gear from step 202 is read out and compared with the actual gear in step 606. If the requested switching process is not possible, the switching process is ended in step 206, whereby the gear change signal can be reset beforehand.

If the target gear can be selected based on the actual gear, then in step 622 the assistance power of the auxiliary motor is reduced to such an extent that the torque on the input shaft of the manual transmission is less than or equal to the powershift maximum. For this purpose, the processor 30 can calculate and output the engine control signal accordingly.

The switching process 608 is then carried out and in step 624 the assistance power is increased again to the proportion that it had before the switching process 608. Step 624 can be carried out within a certain time after the switching signal is output or depending on the crank position and/or a change in the actual gear. For example, the support performance can be restored if the actual gear corresponds to the target gear. Otherwise, you can simply wait for the time that the actuator 48 and the hub gear 20 need to shift from the actual gear to the target gear.

The process then continues with step 610 and checks the gear engaged.

Reference symbols

1

Bicycle

2

Auxiliary engine

4

bottom bracket

6

pedal

8th

Pedal crank

10

accumulator

12

Traction drive

14

rear wheel

16

Rear wheel hub

18

Hub gears

20

Hub gearbox

22

Transfer Switch

24

Handlebars

26

Control unit

28

display

30

processor

32

Frame

34

Chainstay

36

seat stay

38

Housing

40

spoke holes

42

Brake disc

44

Brake caliper mount

46

timing belt pulley

48

Actor

50

Housing

52

Transmission shifting system

54

pedal power

56

bottom bracket shaft

58

pedaling torque

60

Engine / gear

61

hollow shaft

62

Freewheel

64

Support moment

66

Blade, output pinion

68

input shaft

69

Gear stage

69a

first gear stage

69b

second gear stage

69c

third gear stage

70

Planetary gear

72

coupling

74

Switching element

76

Scene control

78

hub axle

80

Actuator gear

82

Torque on the input shaft

84

Coupling teeth

86

guide

88

Button for shifting up a gear

90

Button for downshifting a gear

92

Gear change signal

94

Drive parameter sensor

96

Drive parameter signal

98

Torque sensor on the input shaft

100

Power sensor on the input shaft

102

Torque sensor on the bottom bracket shaft

104

Power sensor on the bottom bracket shaft

106

Switching signal

108

Angle position of a pedal crank

110

Dead center position

112

Crank position sensor

114

Crank position signal

116

Area around dead center position

117

Load switching maximum

118

Alarm signal

119

Power sensor

120

visual warning signal

122

acoustic warning signal

124

Storage

126

Warning signal

128

output shaft

130

Power signal

132

Motor control signal

134

Gear sensor

136

Gear signal

138

Actuator output shaft

140

Gear indicator

200

Triggering a gear change signal

202

Storing the gear change signal

204

Updating the gear change signal

206

Detecting the actual gear to update the gear change signal

300

Detecting a value representative of the torque on the input shaft of the hub gearbox and optionally for the proportion of the pedaling power and/or the assistance power to the torque on the input shaft

302

Saving the value

304

Update and optionally correct and process the value

400

Receiving a gear signal 402 representative of the gear engaged, storing the gear signal

500

Receipt of a value representative of the crank position

502

Saving the value

504

Processing the value

600

Detecting the torque on the output shaft and the power shift maximum

602

Comparison of torque and powershift maximum

604

Detecting the target gear

606

Comparison of the target gear with the actual gear

608

Command for executing the switching process or executing the switching process

610

Comparison of the target gear with the actual gear

612

Resetting the target gear

618

Comparison of the crank position with the dead center position

620

Comparison of the proportion of pedal power to the torque at the input shaft with the power shift torque

622

Reducing support performance

624

Increasing support performance

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 000001982913 A1 [0074]

Claims (30)

Processor (30) for controlling a hub gearbox (18, 20) of a bicycle (1) with an auxiliary motor (2), which is provided with an input shaft (68) and with an actuator (48) for changing gears depending on a switching signal (106). Processor (30) is designed, - to receive a gear change signal (92) which is representative of a switching command triggered by a user of the bicycle (1), and - to receive a drive parameter signal (96) which is representative of at least one torque (82) applied to the input shaft (68), - wherein the processor (30) is further designed to output the switching signal (106) depending on the drive parameter signal (96) after receiving the gear change signal (92). Processor (30) after Claim 1 , wherein the processor (30) is designed to receive a power signal (130) that is representative of a pedaling power of the user and / or an assistance power of the auxiliary motor (2), and wherein the processor (30) is designed to be dependent on the drive parameter signal (94) and from the power signal (130) to determine the proportion of the torque (82) applied to the input shaft (68) generated by the user. Processor (30) after Claim 1 or 2 , wherein the processor (30) is designed to output the switching signal (106) when the torque (82) represented by the drive parameter signal (96) is less than a predetermined value (117). Processor (30) according to one of the Claims 1 until 3 , wherein the processor (30) is designed to determine a switching direction that is representative of a switching direction in the direction of a higher or lower gear, and wherein the processor (30) is designed to output the switching signal (106) depending on the determined switching direction . Processor (30) according to one of the Claims 1 until 4 , wherein the processor (30) is designed to receive a crank position signal (114) which is representative of an angular position of a pedal crank (8) of the bicycle (1) and wherein the processor (30) is designed to depend on the switching signal (106). from the crank position signal (114). Processor (30) after Claim 5 , wherein the processor (30) is designed, depending on a time profile of the crank position signal (114) and the drive parameter signal (96), to determine a dead center position (110) at which the torque (82) on the input shaft (68) is minimal and / or is smaller than a predetermined value (117). Processor (30) according to one of the Claims 1 until 6 , wherein the processor (30) is designed to generate and output an engine control signal (132) which is representative of a support power to be delivered by the auxiliary engine (2), and wherein the processor (30) is designed to generate the engine control signal (132) depending on the To generate gear change signal (92) and drive parameter signal (92). Processor (30) after Claim 7 , wherein the processor (30) is designed to generate the engine control signal (132) depending on the crank position sensor (112). Processor (30) after Claim 7 or 8th and after Claim 2 , wherein the processor (30) is designed to determine the pedaling power of the user of the bicycle (1) depending on the power signal (130). Processor (30) according to one of the Claims 1 until 9 , wherein the processor (30) is designed to combine a plurality of temporally successive gear change signals (92) and output them as a switching signal (106). Processor (30) according to one of the Claims 1 until 10 , wherein the processor (30) is designed to receive a gear signal (136) which is representative of the gear currently engaged on the hub gearbox (18, 20), and wherein the processor (30) is designed to depend on the switching signal (106). from the gear signal (136). Processor (30) after Claim 11 , wherein the processor (30) is designed to determine a target gear to be engaged on the transmission depending on the gear change signal (92) and an actual gear engaged on the hub gearbox (20) depending on the gear signal (136), and wherein the processor (30) is designed to output the switching signal (106) depending on the drive parameter signal (96) until the actual gear corresponds to the target gear. Processor (30) after Claim 11 or 12 , wherein the gear signal (130) contains a speed of the input shaft (68) and a speed of the output shaft (128) of the hub gearbox (18, 20) or the ratio of these two speeds. Processor (30) after Claim 3 and after one of the Claims 11 until 13 , wherein the processor (30) is designed to determine the predetermined value (117) of the torque (82) on the input shaft (68) depending on the gear signal (130). Computer-implemented method for controlling a with an input shaft (68) and with an actuator (48) for changing gears depending on a switching signal (106) of a hub gearbox (18, 20) of a bicycle (1) with an auxiliary motor (2), a gear changing signal (92) being representative of a user of the bicycle (1) triggered switching command, and a drive parameter signal (96) is received, which is representative of a torque (82) applied to the input shaft (68), wherein after receipt of the gear change signal (92), the switching signal (106) depends on the drive parameter signal (96 ) is output. Computer-implemented method Claim 15 , wherein the switching signal (106) is output when the torque (82) on the input shaft (68) represented by the drive parameter signal (96) is less than a predetermined value (117). Computer program product or computer-readable storage medium, comprising instructions that, when the program is executed by a computer, cause it to follow the method Claim 15 or 16 to carry out. Gear shifting system (52) for a bicycle (1) with an auxiliary motor (2), - with a processor (30) according to one of the Claims 1 until 14 , - the hub gearbox (18, 20) having the input shaft (68), - the actuator (48) and - with a drive parameter sensor (94) which is designed to generate the drive parameter signal (96). Transmission switching system (52). Claim 18 , wherein the drive parameter sensor (94) has at least one power sensor (100, 104) which is arranged on the bottom bracket shaft (56) or the input shaft (68). Transmission switching system (52). Claim 18 or 19 , wherein the transmission switching system (52) has a crank position sensor (112) which is designed to output the crank position signal (114). Transmission switching system (52) according to one of the Claims 18 until 20 , wherein the transmission switching system (52) has a gear sensor (134) which is designed to generate the gear signal (136). Transmission switching system (52). Claim 21 , wherein the drive parameter sensor (94) is designed to detect at least two services from the group containing the user's pedaling power, the support power of the auxiliary motor (2) and the total power. Transmission switching system (52) according to one of the Claims 18 until 22 , wherein the transmission switching system (52) has a manually operable gear switch (22) which is designed to generate the gear change signal (92) when actuated. Transmission switching system (52) according to one of the Claims 18 until 23 , wherein the transmission switching system (52) has an auxiliary motor (2). Method for switching between the gears of a multi-speed hub gearbox (18, 20) of a bicycle (1) with an auxiliary motor (2), which is actuated by an actuator (48), in response to a gear change signal (92) generated by a user of the bicycle (1). the actuator (48) is actuated automatically depending on a torque (82) on the input shaft (68). Procedure according to Claim 25 , wherein the actuator (48) is operated when the torque (82) applied to the input shaft (68) of the hub gearbox (18, 20) is less than a predetermined value. Procedure according to Claim 25 or 26 , wherein the actuator (48) is operated automatically when an angular position (108) of a pedal crank (8) of the bicycle (1) is in a predetermined range (116). Procedure according to one of the Claims 25 until 27 , wherein a support power of the auxiliary motor (2) is automatically reduced during operation of the actuator (48). Procedure according to Claim 28 , wherein the assistance power is automatically reduced to a value at which the torque (82) on the input shaft (68) is less than a predetermined limit. Procedure according to one of the Claims 25 until 29 , wherein the predetermined value of the torque (82) during a switch depends on a switching direction.

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