METHOD FOR CONTROLLING A BICYCLE'S GEAR SHIFT

Abstract

The invention relates to a method (50) for controlling a gear shift (105) of a bicycle (100), comprising the steps: determining a reference shift point (1), determining an instantaneous driving situation of the bicycle (100), determining a shift hysteresis (4) based on the determined instantaneous driving situation, and determining a target shift point (31, 32) by adjusting the reference shift point (1) by means of the determined shift hysteresis (4).

Description

State of the art

[0001] The present invention relates to a method for controlling a gear shift of a bicycle, a gear shifting system of a bicycle, and a bicycle.

[0002] Electronically actuated gearshift systems for bicycles are known. This makes it possible to provide automatic gearshifting. Certain shift thresholds, for example, are provided to trigger such an automatically actuated gearshift. Such shift thresholds can be stored in the form of tables in a memory of a control device of the gearshift system. With automatic gearshift systems for bicycles, there is often a conflict of objectives between providing an optimal gear ratio for the greatest possible pedaling comfort for the cyclist and avoiding unnecessarily frequent gearshifts. Disclosure of the invention

[0003] The method according to the invention with the features of claim 1 offers the advantage that an automatic actuation of gear changes in a bicycle's gearshift can be enabled in a simple manner, reliably providing a particularly high level of pedaling comfort for the cyclist. This is achieved according to the invention by a method for controlling a bicycle's gearshift, comprising the steps: Determining a reference switching point, determining a current riding situation of the bicycle, determining a switching hysteresis based on the determined current riding situation, and determining a target switching point by adjusting the reference switching point using the determined switching hysteresis.

[0004] This means that in the method, a characteristic reference switching threshold in the form of the reference switching point is determined, and this is adaptively adjusted by means of a, in particular variable, switching hysteresis in order to determine an actual switching threshold in the form of the target switching point.

[0005] A variety of possible riding situations can be identified and used to adjust the shift hysteresis. For example, the detection of an incline or the detection of a predetermined actuation pattern by a bicycle rider can be identified as a riding situation, and the shift hysteresis can be adjusted accordingly.

[0006] In particular, switching hysteresis is considered to be a specific amount of change by which the reference switching point is shifted toward the target switching point. For example, the switching hysteresis can be considered a cadence value. Alternatively, the switching hysteresis can preferably be defined as another physical quantity, in particular depending on which the reference switching point is defined.

[0007] Preferably, the switching hysteresis can be determined as a specific constant value by which, for example, the reference switching point is shifted toward the target switching point. Alternatively, the switching hysteresis can preferably be determined as a specific percentage deviation from the reference switching point.

[0008] Preferably, in a gearshift with multiple different gear stages, i.e., multiple different gear ratios, a separate reference shift point is determined for each gear stage. Preferably, the reference cadence is identical for all gear stages. Alternatively, a different reference cadence can also be defined for different gear stages.

[0009] The method thus offers the advantage that an optimal shifting strategy can be provided by adjusting an adaptive shift hysteresis depending on the current riding operation of the bicycle. An individual desired cadence of the cyclist can be used as the reference cadence, for example. As a result, the method can, for example, optimally adjust the shifting strategy to a specific cadence, whereby the adaptive adjustment of the shift hysteresis can reduce the number of gear changes. In particular, the adaptive adjustment of the shift hysteresis can achieve the optimum of the most precise adjustment to a predetermined characteristic value and / or the smallest possible number of gear changes. In particular, the method can thus enable particularly efficient and comfortable operation of the bicycle.

[0010] The subclaims contain preferred developments of the invention.

[0011] Preferably, the reference shifting point is determined such that, when changing gears at the reference shifting point, a cadence jump caused by the gear change is symmetrical to a reference cadence. This means that a characteristic shifting threshold in the form of the reference shifting point is determined. If a shifting operation, i.e. a gear change, in particular into an immediately adjacent gear, is carried out precisely at this reference shifting point, this gear change causes a specific cadence jump. Preferably based on the previously known mechanical properties of the gearshift, and preferably additionally of the bicycle's drive, the reference shifting point is automatically determined such that the corresponding cadence jump at this reference shifting point is symmetrical to a reference cadence.A cadence jump is defined as the difference in cadence before and after a gear change. In particular, a cadence jump is defined as a theoretical change in cadence that occurs when the pedals are operated before, during, and after a gear change, particularly when the bicycle's drive system is under tension. Such a cadence jump is precisely defined, for example, based on the mechanical interrelationships of the gear system and the bicycle's entire drive train. In other words, the reference shifting point is defined such that, for example, when shifting up to a higher gear ratio, the cadence immediately before the gear change is a predetermined amount higher than the reference cadence. At the same time, the cadence immediately after the gear change is the same predetermined amount lower than the reference cadence.For example, when shifting down to a lower gear ratio, the change in cadence is exactly the opposite.

[0012] The reference cadence is preferably a predefined constant value. Alternatively, the reference cadence is preferably a constant value that can be specified by a user. Further alternatively, the reference cadence is preferably variable and can be set in particular as a function of one or more of the following parameters: current gear position, riding parameters of the bicycle, environmental parameters. In particular, these parameters can be detected using sensors and / or entered using an input device. As riding parameters, for example, a speed and / or an incline and / or an acceleration of the bicycle can be used. For example, as environmental parameters, a current incline on which the bicycle is located and / or route parameters, such as curves to be taken, of a route to be traveled can be used.This allows for a particularly flexible and precise adaptation of the gear shifting strategy to the bicycle's riding conditions and / or to individual user preferences.

[0013] Particularly preferably, in a first riding situation, the shift hysteresis is reduced in order to reduce, in particular to minimize, a deviation of an actual cadence from the reference cadence. The actual cadence is considered to be, in particular, an actual momentary cadence with which the cyclist operates the pedals. In other words, in the first riding situation, a small hysteresis is used to achieve the most precise possible adjustment to the reference cadence. Alternatively or additionally, preferably, in a second riding situation, the shift hysteresis is increased in order to reduce, in particular to minimize, a number of gear changes, in particular during the duration of the second riding situation. In other words, in the second riding situation, a large hysteresis is used to ensure that fewer gear changes are carried out.

[0014] Preferably, for each reference shift point, a target upshift point and a target downshift point are determined using the shift hysteresis. In particular, for this purpose, the reference shift point is shifted in opposite directions using the shift hysteresis. Preferably, the target upshift point is considered to be a shift point at which a shift is made to a higher gear, i.e., a higher transmission ratio. Further preferably, the target downshift point is considered to be a shift point at which a shift is made to a lower gear, i.e., a lower transmission ratio. This makes it possible to provide a particularly reliable and efficient automatic shifting method that can avoid undesirable, frequent gear changes.

[0015] Preferably, the target downshift point is defined at lower speeds, in particular with regard to riding the bicycle, in comparison to the reference shift point. Alternatively or additionally, the target upshift point is defined at higher speeds, in particular with regard to riding the bicycle, in comparison to the reference shift point. For example, this means that when the speed and the associated reduction in cadence are reduced, the gearshift does not occur immediately upon reaching the reference cadence, but only after a further reduction until the target downshift point is reached. Preferably, the upshift occurs in a similar manner when the speed increases. This makes it possible to provide a high level of riding comfort when operating the bicycle with optimal efficiency.

[0016] Further preferably, the switching hysteresis per reference switching point is the same for the respective target downshift point and target upshift point. In other words, by using the same switching hysteresis, the target downshift point and the target upshift point are arranged symmetrically to the reference switching point. Alternatively, the switching hysteresis per reference switching point is preferably different for the respective target downshift point and target upshift point. In other words, by using different switching hystereses, the target downshift point and the target upshift point are arranged asymmetrically to the reference switching point.

[0017] Particularly preferably, the shift hysteresis is variably adjusted depending on one or more of the following parameters: current gear position, riding parameters of the bicycle, environmental parameters, user-specific input. In particular, these parameters can be detected using sensors and / or entered using an input device. Riding parameters can include, for example, a speed and / or an incline and / or an acceleration of the bicycle. For example, environmental parameters can include a current gradient on which the bicycle is located and / or route parameters, such as curves to be negotiated, of a route to be traveled. This allows for a particularly precise adaptation of the shifting strategy to the riding operation of the bicycle.

[0018] Particularly preferably, the method comprises the steps of: determining constant travel as the current driving situation, and reducing the switching hysteresis in response to determining the constant travel. Constant travel preferably corresponds to the first driving situation. Constant travel is preferably regarded as traveling the bicycle at a substantially constant speed over at least a predetermined period of time. For example, constant travel is regarded as traveling the bicycle if, over a period of, for example, at least 10 seconds, in particular at least 30 seconds, a maximum fluctuation in the speed of the bicycle is 15%, preferably 10%, in particular 5%. Preferably, the switching hysteresis is determined in response to determining the constant travel such that the switching hysteresis is a percentage deviation with respect to the reference switching point of a maximum of 10%, preferably a maximum of 7%, in particular a maximum of 5%.This makes it possible to set the rider's desired cadence as accurately as possible during a stationary ride with a substantially constant speed over a longer period of time, which may, for example, correspond to the reference cadence.

[0019] The method further preferably comprises the steps of: determining a pedaling interruption as the current driving situation, and increasing the shift hysteresis in response to determining the pedaling interruption. Preferably, the pedaling interruption corresponds to the second driving situation. Particularly preferably, the increasing of the shift hysteresis in response to determining the pedaling interruption can occur exclusively for the target downshift point, wherein the shift hysteresis for the target upshift point is preferably retained. A pedaling interruption is preferably considered to be a stopping of the pedal actuation by the driver for at least a predetermined period of time, for example, at least 2 seconds, preferably a maximum of 10 seconds.Alternatively, a pedal interruption can generally be regarded as a state in which the cyclist does not exert any pedaling torque on the bicycle's drive train, wherein, for example, further tension-free rotation of the pedals without power transmission to the drive train is also possible. Preferably, the shifting hysteresis is determined in response to the detection of the pedal interruption such that the shifting hysteresis amounts to a percentage deviation from the reference shift point of at least 10%, preferably at least 13%, in particular at least 15%. Such a pedal interruption can occur, for example, when cornering. The, for example, brief, increase in the shifting hysteresis has the effect that a downshift to a lower gear is not immediately triggered when pedaling is interrupted.This can, for example, prevent the driver from having to immediately reverse the previous gear change after resuming pedal operation. This prevents unwanted back-and-forth shifting.

[0020] The method further preferably comprises the steps of: determining uphill riding as the current riding situation, and increasing the shift hysteresis in response to determining the uphill riding. Preferably, the uphill riding corresponds to the second riding situation. Uphill riding is preferably considered to be riding the bicycle uphill on an incline, wherein the incline preferably corresponds to a gradient of at least 5% with respect to a horizontal line. Preferably, the shift hysteresis is determined in response to determining the uphill riding such that the shift hysteresis amounts to a percentage deviation from the reference shift point of at least 10%, preferably at least 13%, in particular at least 15%. Such an increase in the shift hysteresis during uphill riding is particularly advantageous for an electric bicycle. If, for example, the driving speed of the electric bicycle decreases due to low motor power, the bicycle shifts to a lower gear.Especially on an electric bike with a motor located near the crankshaft, gear shifting causes the motor speed to increase again in the lower gear, which can, for example, make more motor power available, allowing the electric bike to accelerate and, for example, shift back into a higher gear. Increasing the shift hysteresis thus effectively prevents unwanted frequent back-and-forth shifting.

[0021] The method preferably comprises the steps of determining an acceleration ride as the current riding situation, and reducing the shift hysteresis for the target upshift point, in particular to the value zero. The shift hysteresis for the target downshift point is preferably kept constant, or alternatively, preferably increased. The acceleration ride preferably corresponds, in particular at least partially, to the first riding situation. An acceleration ride is preferably considered to be a ride of the bicycle with positive acceleration, i.e., with a significantly increasing speed. In particular, if several gear changes occur in succession during the acceleration ride, this can provide an optimal cadence to enable particularly efficient acceleration of the bicycle.For example, the small shift hysteresis, preferably zero, for the target upshift point can enable an immediate, targeted upshift, which can, for example, prevent the pedaling from being faster than optimal during the acceleration process.

[0022] Preferably, the method further comprises the step of determining a shifting speed at the target shifting point based on a gear ratio of the bicycle. In particular, the shifting speed is considered to be the speed at which the bicycle moves, for example theoretically, at the target shifting point. This shifting speed is predetermined in particular by the mechanical relationship between, in particular, the theoretical cadence at the target shifting point and the gear ratio of the bicycle, in particular as a function of the corresponding gear. In this case, an overall gear ratio of the bicycle is considered, for example, between the cranks and a rear wheel. This allows for a particularly simple determination of the advantageous shifting points.

[0023] Preferably, the shifting speed can be determined at any time, for example, even when stationary and / or before the bicycle is first used. The shifting speed can be stored, for example, as a characteristic value for the shifting system.

[0024] The method further preferably comprises the steps of detecting a speed, in particular a current speed of the bicycle, and initiating a gear change when the detected speed reaches the shifting speed. This means that the initiation of the gear shifting processes takes place in the method depending on the detected speed at which the bicycle is moving. This not only makes it particularly simple and cost-effective to carry out the method, but also makes it possible to provide a particularly advantageous gear shifting strategy, since this can be independent, for example, of the current actual cadence at which the rider is operating the bicycle pedals. For example, when riding downhill and no pedaling is taking place, the optimal shifting point can be determined depending on the speed, so that, for example, the optimal gear can be engaged when pedaling is resumed.

[0025] The method preferably comprises the steps of determining a shifting cadence at the target shifting point, detecting a cadence, in particular a current cadence, and initiating a gear change when the detected cadence reaches the shifting cadence. This means that the initiation of the shifting processes occurs depending on the detected cadence at which the rider operates the bicycle pedals. This allows for particularly precise control of the shifting processes for optimal adjustment of a favorable cadence.

[0026] Particularly preferably, the bicycle's gearshift system has several different gears. A separate reference shift point is determined for each gear change between different gears. This means that the shift points are determined individually for each gear. This allows the shifting strategy to be adjusted with particular precision to provide optimal riding comfort for the bicycle rider.

[0027] Furthermore, the invention leads to a gearshift system of a bicycle, preferably an electric bicycle, comprising a gearshift and a control unit. The control unit is configured to actuate the gearshift and carry out the described method. The gearshift preferably comprises a derailleur, which is configured to move a bicycle chain between pinions of different sizes in order to thereby change a transmission ratio. Alternatively or additionally, the gearshift can preferably comprise a transmission. Particularly preferably, the gearshift has an electronic actuating device, wherein in particular the control unit is configured to actuate the electronic actuating device of the gearshift.

[0028] Furthermore, the invention relates to a bicycle, preferably an electric bicycle, which comprises the described gear system. Short description of the drawings

[0029] The invention is described below using exemplary embodiments in conjunction with the figures. In the figures, functionally identical components are identified by the same reference numerals. Here: Figure 1 shows a simplified schematic view of a bicycle in which a method for controlling a gear shift of the bicycle is carried out according to a first embodiment of the invention. Figure 2 shows a highly simplified schematic view of steps of the method of the first embodiment. Figure 3 shows a simplified schematic view of shifting operations when carrying out the method of the first embodiment. Figure 4 shows a simplified schematic view of shifting operations when carrying out a method according to a second embodiment of the invention. Figure 5 shows a highly simplified schematic view of steps of a method according to a third embodiment of the invention. Figure 6 shows a simplified schematic view of shifting operations when carrying out the method of the third embodiment.and Figure 7 shows a simplified schematic view of switching operations when carrying out a method according to a fourth embodiment of the invention. , Preferred embodiments of the invention

[0030] Figure 1 shows a simplified schematic view of a bicycle 100 with a gear system 107, which includes a gearshift 105 and a control unit 106. The gearshift 105 is a derailleur system, which includes a front derailleur and several differently sized pinions on at least one rear wheel hub of the bicycle 100.

[0031] The gearshift 105 has an electronic actuation device that, in response to receiving electronic actuation signals, effects a gear change, i.e., a change in a gear ratio in the drivetrain of the bicycle 100. The electronic actuation signals can be generated by the control unit 106. In particular, an automatic gear shift of the bicycle 100 can be provided.

[0032] The bicycle 100 is an electric bicycle comprising a drive unit 101, in particular with an electric motor. The control unit 106 is preferably integrated into the drive unit 101. The drive unit 101 can be supplied with electrical energy by means of an electrical energy storage device 109 of the bicycle 100. The drive unit 101 can thereby support the pedaling force generated by the muscular power of a rider of the bicycle 100 with a motor torque generated by an electric motor.

[0033] The control unit 6 is configured to carry out a method 50 for, in particular, automatically controlling the gearshift 105 of the bicycle 100. The method steps of the method 50 are shown schematically in a highly simplified manner in the Figure 2 Details of the switching processes will be described in detail later. First, a general, highly simplified description of process 50 is given.

[0034] In the method 50, in step 51, a reference shift point 1 is determined and, based thereon, a target upshift point 31 and a target downshift point 32 are determined.

[0035] At the target upshift point 31, the next higher gear is shifted up, preferably as the speed 22 of the bicycle 100 increases. At the target downshift point 32, the next lower gear is shifted down, preferably as the speed 22 of the bicycle 100 decreases.

[0036] Likewise, in step 51, for each target upshift point 31 and target downshift point 32, a shift speed 30 can be determined at which the corresponding shift point is located.

[0037] In step 52, in the method 50, a current speed 22 of the bicycle 100 is detected. In step 53, a gear change is triggered when the detected current speed 22 reaches one of the shift speeds 30.

[0038] A more detailed description of the switching points follows below. The first embodiment of the method 50 according to the Figures 1 to 3 shows a particularly simple embodiment of the method 50. The method 50 according to the second to fourth embodiments shows further modifications.

[0039] The shift points and gear changes described below are described using a gear change between the two highest gears, i.e., between the two largest gear ratios, as an example. Preferably, the description applies analogously to all other gears of gearshift 105.

[0040] In the Figure 3 a simplified schematic view of switching operations when carrying out the method 50 of the first embodiment is shown. Figure 3shows a so-called development diagram 20 of the drive system of the bicycle 100. The development diagram 20 shows a relationship between a cadence 21 and a speed 22 for each of the gear steps of the gearshift 105. The straight lines 23 represent the different gear steps of the gearshift 105. These straight lines 23 are firmly defined by the respective mechanical properties of the drive system of the bicycle 100, in particular a mechanical transmission path between the pedals 104 and the rear wheel 111 of the bicycle 100. In particular, the respective gradients of the straight lines 23 depend on the respective gear ratio of each gear step.

[0041] The straight lines 23 with a lower gradient, i.e. in the direction of the bottom right in the development diagram 20, represent higher gears with larger gear ratios.

[0042] In method 50, a reference cadence 3 is defined, which is, for example, a predetermined constant value. For example, reference cadence 3 can be specified by the rider of bicycle 100.

[0043] During operation of the bicycle 100, in particular, each operating point of the switching system 107 lies on an operating line 26, as in Figure 3 The operating line 26 is always located on one of the straight lines 23, whereby when changing gears, the adjacent straight line 23 is switched on by means of a Figure 3 vertically displayed jump is changed.

[0044] In the first embodiment, a reference shift point 1 is determined such that, when a gear change is performed at the reference shift point 1, a cadence jump 2 caused by this gear change is symmetrical to the reference cadence 3. In the development diagram 20, the cadence jump 2 corresponds to an amount of a cadence difference, i.e., a vertical distance, between the current straight line 23 and the adjacent straight line 23, into which a jump is made by means of the gear change.

[0045] In other words, the reference switching point 1 is selected such that exactly at the reference switching point 1 a partial amount 29a between the reference cadence 3 and the cadence 21 in the gear stage before or after the gear change is the same.

[0046] In the first embodiment, the reference shift point 1 determined in this way corresponds simultaneously to a target upshift point 31 and a target downshift point 32 at which the upshift or downshift is actually initiated.

[0047] By means of the correspondingly defined reference switching points 1, and since these also correspond to the actual target switching points in the first embodiment, a speed range 27 for each gear step can be read from the development diagram 20 with the correspondingly defined operating line 26 as the range between two adjacent vertical cadence jumps, as in the Figure 3 marked as an example for the eighth gear.

[0048] Furthermore, in the method 50, a shifting speed 30 is determined for each target shifting point 31, 32 and, for example, stored. During operation of the method 50, the gear changes are controlled, preferably exclusively, depending on the speed. This means that if the current speed of the bicycle 100 increases and reaches the shifting speed 30 for one of the gears, a gear change to the next higher gear is controlled. Analogously, if the current speed of the bicycle 100 decreases and reaches the shifting speed 30 for one of the gears, a gear change to the next lower gear is controlled.

[0049] Preferably, the determination of all shift points 1, 31, 32 can be carried out once, for example, before the bicycle 100 is put into operation, using the control unit 106. Preferably, the respective shift speeds 30 can be stored for all shift points 1, 31, 32.

[0050] It is particularly advantageous if, during operation of the bicycle 100, all gear changes are controlled, in particular exclusively, based on the current gear position and the shift speeds 30. This enables a particularly simple and reliably precise selection of the gear positions in every riding situation, in order to enable efficient and comfortable operation of the bicycle 100.

[0051] In an alternative embodiment, the control of the gear changes can be based on a determined shifting cadence 39 at the target shifting point 31, 32 and a detection of the current cadence of the bicycle 100.

[0052] Figure 4 shows a simplified schematic view of switching operations when carrying out a method 50 according to a second embodiment of the invention. The second embodiment essentially corresponds to the first embodiment of the Figures 1 to 3 , with the difference that a switching hysteresis 4 is additionally provided to determine the actual target switching points 31, 32.

[0053] In detail, in the second embodiment, the Figure 4For each reference switching point 1, a separate target upshift point 31 and a separate target downshift point 32 are defined. The target upshift point 31 is defined in that the reference switching point 1 is shifted by the switching hysteresis 4 towards higher speeds 22. The target downshift point 32 is defined in that the reference switching point 1 is shifted by the switching hysteresis 4 towards higher speeds 22. Thus, with increasing speed 22, upshifting only occurs later at higher speeds 22, and with decreasing speed 22, downshifting analogously only occurs later at lower speeds, in each case compared to the reference switching point 1. This also results in an upshift speed 41 for the target upshift point 31, which is different from a downshift speed 42 of the target downshift point 32.

[0054] This means, for example, that gear changes are initiated significantly less frequently during frequent speed changes close to reference shift point 1. In particular, this prevents frequent, unwanted back-and-forth shifting.

[0055] In the second embodiment, switching hysteresis 4 is defined as a predefined constant percentage deviation from reference switching point 1. Specifically, switching hysteresis 4 corresponds to 5% of the speed value of reference switching point 1.

[0056] As in the Figure 4 As can be seen, the switching hysteresis 4 results in a wider speed range 27 for the individual gear steps, whereby these speed ranges 27 partially overlap due to the switching hysteresis 4 (not shown).

[0057] In the Figure 4In the embodiment shown, the switching hysteresis 4 is designed symmetrically with respect to the reference switching point 1. In an alternative embodiment, an asymmetric switching hysteresis 4 can also be provided. This means that for each reference switching point 1, a different switching hysteresis 4 is used to determine the corresponding target upshift point 31 than for determining the corresponding target downshift point 32.

[0058] Figure 5 shows a highly simplified schematic view of steps of a method 50 according to a third embodiment of the invention. The third embodiment essentially corresponds to the second embodiment of the Figure 4 , with the difference that the switching hysteresis 4 is designed to be adaptive to the current driving operation of the bicycle 100.

[0059] For this purpose, the method 50 comprises the additional steps 56 to 58 after step 51 of determining the reference shifting point 1 and before step 52. In step 56, the current driving situation of the bicycle 100 is determined. Preferably, the current driving situation is detected and recognized using a sensor system 110 of the bicycle 100. Based on the driving situation thus determined, the current shifting hysteresis 4 is then adaptively adjusted in step 57. In step 58, the target upshift point 31 and the target downshift points 32 are determined based on the adjusted shifting hysteresis 4.

[0060] The adaptive adjustment of the shift hysteresis 4 can be carried out based on a wide variety of characteristic riding situations. Preferably, based on the detected riding situation, it can be determined whether either an optimal adjustment to the reference cadence 3 or, alternatively, a minimization of the number of shift changes should be prioritized. For the first case, namely a preferred minimization of a deviation of an actual cadence from the reference cadence 3, a low shift hysteresis 4, for example, a maximum of 10%, is set. This corresponds, for example, to the development diagram 20 of the Figure 4 . For the second case, namely a preferred minimization of the number of gear changes, a high switching hysteresis 4, for example more than 10%, is set.

[0061] In the method 20, predefined driving situations can be detected and predefined switching hystereses 4 can be set in response thereto. For example, with the method 50 according to Figure 5 , as already mentioned that unfolding diagram 20 of the Figure 4 This can be achieved by adaptively adjusting the switching hysteresis 4 when constant travel is determined as the current driving situation. Constant travel can be detected, for example, when a substantially constant speed 22 is detected. In this case, the switching hysteresis 4 is reduced to the comparatively low value of 5% in order to enable precise adjustment to the reference cadence 3.

[0062] In addition, the procedure can be 50 Figure 5a determination of a pedal interruption as the current driving situation and / or a determination of a hill climb as the current driving situation can be carried out and in response to this, the switching hysteresis 4 can be increased to, for example, at least 15%. A corresponding development diagram 20 is shown in the Figure 6 As shown in the Figure 6 As can be seen, this results in an even wider speed range 27 for a single gear, and thus, for example, a significantly greater overlap between the individual gears. This allows the total number of gear changes when riding the bicycle 100 to be reduced, which has a beneficial effect on the rider's riding comfort in these riding situations.

[0063] Figure 7shows a simplified schematic view of switching operations when carrying out a method 50 according to a fourth embodiment of the invention. The fourth embodiment essentially corresponds to the third embodiment of the Figures 5 and 6 , and can be regarded in particular as a further development of the method 50 of the third embodiment by a further additional driving situation. In the fourth embodiment of the Figure 7 an asymmetrical adjustment of the switching hysteresis 4 takes place in response to the detection of an acceleration ride as the current driving situation of the bicycle 100.

[0064] In this case, the switching hysteresis 4 for the target upshift point 31 is set to the value zero, so that the target upshift point 31 corresponds to the reference switching point 1.

[0065] At the same time, the shift hysteresis 4 for the target downshift point 32 is maintained or, alternatively, increased, for example, to 15%. This allows an optimal cadence, particularly close to the reference cadence 3, to be consistently adjusted when accelerating the bicycle 100 across multiple gears by always shifting gears close to it. Thus, optimized riding comfort can be provided for the rider of the bicycle 100 even in this riding situation.

[0066] It should be noted that the described embodiments can be combined with one another in any desired manner. For example, each of the described embodiments can be provided for specific time periods and / or specific operating modes of the bicycle 100.

Claims

1. Method for controlling a gear shift (105) of a bicycle (100), comprising the steps of: - determining a reference shift point (1), - determining a current riding situation of the bicycle (100), - determining a shift hysteresis (4) based on the determined current riding situation, and - determining a target shift point (31, 32) by adjusting the reference shift point (1) by means of the determined shift hysteresis (4).

2. Method according to claim 2, wherein the reference shifting point (1) is determined such that, when a gear change occurs at the reference shifting point (1), a cadence jump (2) caused by the gear change is symmetrical to a reference cadence (3).

3. Method according to claim 2, - wherein in a first driving situation the shift hysteresis (4) is reduced in order to reduce a deviation of an actual cadence from the reference cadence (3), and / or - wherein in a second driving situation the shift hysteresis (4) is increased in order to reduce a number of gear changes.

4. Method according to one of the preceding claims, wherein for each reference switching point (1) a desired upshift point (31) and a desired downshift point (32) are determined by adapting the reference switching point (1) by means of the switching hysteresis (4).

5. The method according to claim 4, wherein the desired downshift point (32) is at lower speeds (22) compared to the reference shift point (1), and / or wherein the desired upshift point (31) is at higher speeds (22) compared to the reference shift point (1).

6. Method according to claim 4 or 5, wherein the switching hysteresis (4) per reference switching point (1) is determined to be the same or different for the respective target downshift point (32) and target upshift point (31).

7. Method according to one of the preceding claims, comprising the steps of: - determining a constant speed as the current driving situation, and - reducing the switching hysteresis (4) in response to the determination of the constant speed.

8. Method according to one of the preceding claims, comprising the steps of: - determining a pedaling interruption as a current driving situation, and - increasing the switching hysteresis (4) in response to the determination of the pedaling interruption.

9. Method according to one of the preceding claims, comprising the steps of: - determining an uphill drive as the current driving situation, and - increasing the switching hysteresis (4) in response to the determination of the uphill drive.

10. Method according to one of claims 4 to 9, comprising the steps of: - determining an acceleration run as the current driving situation, and - reducing the switching hysteresis (4) for the desired upshift point (31), in particular to the value zero.

11. Method according to one of the preceding claims, wherein the determination of the current driving situation of the bicycle (100) is carried out by means of sensor data from a sensor system (110) of the bicycle (100), in particular which comprises one or more of the following sensor data: inclination, acceleration, speed, pedaling torque, cadence.

12. Method according to one of the preceding claims, comprising the steps of: - determining a shifting speed (30) at the target shifting point (31, 32) based on a gear ratio of the bicycle (100), - detecting a speed (22), and - initiating a gear change when the detected speed (22) reaches the shifting speed (30).

13. Method according to one of the preceding claims, wherein the gearshift (105) of the bicycle (100) has a plurality of gear stages, and wherein a separate target shift point (31, 32) is determined for each gear change between all gear stages.

14. A gearshift system of a bicycle (100), comprising a gearshift (105), and a control unit (106) configured to actuate the gearshift (105), wherein the control unit (106) is configured to carry out the method (50) according to any one of the preceding claims.

15. Bicycle, in particular electric bicycle, comprising a switching system (107) according to claim 14.