Method for controlling a switching process

Abstract

Method for controlling a switching operation of an electrical circuit (306) of a bicycle (301), wherein the method comprises the steps: - Receiving (S1) a switching request signal; - Determining (S2) a pedal crank torque of a pedal crank of the bicycle (301); - Actuating (S4) the shifting depending on the specified pedaling torque based on a pedal cadence, a pedal acceleration and / or a pre-known shifting time of the shifting; wherein the actuation step (S4) depending on the specified pedaling torque occurs when the pedal cadence is above a first threshold and / or below a second threshold, the second threshold being greater than the first threshold, and otherwise a direct actuation of the shifting occurs.

Description

Technical field

[0001] The present invention relates to a method for controlling a switching process, wherein the load on the switching components is reduced. The present invention further relates to an associated bicycle with an associated control device. State of the art

[0002] In the current state of the art, bicycles, including electric bicycles, are known to have derailleur gears, hub gears, and bottom bracket gears. These can be actuated manually or electrically, for example, by radio or cable, meaning the shifting process can be triggered.

[0003] With known, state-of-the-art circuits, the problem arises that shifting under load places increased stress on the circuit components and can also produce unpleasant noises for the user. Shifting under load, in this context, refers to shifting while the cyclist is applying increased force to the pedals, and thus to the bottom bracket and the associated or integrated circuitry.

[0004] This problem occurs with both manual and electrically actuated shifting systems. Electrically actuated shifting systems can be triggered either by a user input via a control unit on the bicycle, or automatically by a mechanism that controls the gear change.

[0005] For example, an automatic system can be designed in such a way that a predetermined cadence is maintained, and corresponding switching operations are triggered if there is a deviation from this cadence.

[0006] DE 10 2014 208 479 A1 discloses a gearshift for a bicycle with an electric auxiliary drive, comprising a stepped transmission and an electromechanical actuator for triggering a gear change of the transmission. DE 10 2017 128 147 A1 discloses a method for generating a shift command for a gearshift of a vehicle with a pedal drive. Description of the invention

[0007] It is therefore an object of the present invention to provide a control method for controlling a shifting process of a bicycle which has a reduced load on the components.

[0008] A corresponding method for controlling a switching process of an electrical circuit of a bicycle according to the present invention will be described below.

[0009] An electrical circuit, in this context, refers to a circuit in which the actuation and thus the triggering of the shifting mechanism is at least partially electrical. Accordingly, the actuation occurs through electrical impulses. This is used, for example, to operate a derailleur or a front derailleur. The actuation can be automatic, based on an automatic gear shifting system, or based on a user request via an input device, such as a lever. The bicycle in question can be either a purely muscle-powered bicycle or a bicycle with at least partial electrical assistance, such as a pedelec or e-bike. The latter has a motor or electric machine that is powered by a battery. This battery can also supply power to the electrical circuit. The term "battery" here also includes accumulators.

[0010] In the first step of the aforementioned process, a shift request signal is received. This signal can be received, for example, by a user who expresses their shift request via a user input device, such as a gearshift lever. Alternatively, the signal can be received by an automatic transmission that controls the shifting automatically, for example, based on the cadence. "Receiving" here refers both to receiving an electrical signal and to reading a corresponding indicator from a memory.

[0011] Next, the torque at the bicycle's crank arm is determined. This determination can be based on receiving a signal from a suitable sensor, such as a crank arm sensor. Thus, a torque at the crank arm is determined.

[0012] In the third step of the process, the gear shift is then activated depending on the specific pedaling torque. This can be achieved by sending a control signal to the bicycle's electronic shifting system. Accordingly, the activation, based on the received shift request and the pedaling torque, occurs with a certain delay, unlike direct activation upon receiving a shift request signal.

[0013] By taking the pedaling torque into account, it is possible to shift gears to a point in time that is optimal for the specific drivetrain being used. This can, for example, reduce stress on the drivetrain components or minimize noise.

[0014] For example, the actuation can be carried out in such a way that the shifting process takes place at a time when the force exerted on the pedals by the rider is minimal, i.e. when the pedals are in a vertical position and thus at a dead point, and therefore the pedaling torque is minimal.

[0015] In one embodiment, the actuation can occur depending on the difference between a specific crank torque and a predetermined minimum crank torque. On the one hand, a difference of zero can be targeted, meaning the crank torque is already minimal and the crank position is already at dead center, i.e., at the point of minimum pedal torque. On the other hand, the actuation can also be staggered, meaning the difference is predefined, but not zero. This is advantageous, for example, if a switching time—that is, a time between an actuation and the execution of the shifting process or a specific part of the shifting process—is known, and the shifting process or a specific part of the shifting process is to be scheduled at the point of minimum pedal torque in order to further reduce the load on the shifting system.The predetermined minimum pedal crank torque mentioned here can be derived, for example, from the pedal crank torque curve during previous pedal crank revolutions or from a prior pedal crank torque curve. Accordingly, the method can also include a step of determining the minimum pedal crank torque, for example, from prior sensor readings.

[0016] Furthermore, in one embodiment, the actuation can be triggered by comparing the current pedaling torque with a predetermined torque curve. Since the pedaling torque generally repeats cyclically, comparing the current torque with a predetermined or preceding torque curve allows the system to determine the current phase of the curve and the estimated time remaining until the minimum torque is reached – i.e., how far the pedals are from a vertical position and thus from the dead center. Here, too, a shift can be triggered, for example, taking a shift time into account, to achieve a gear change close to the minimum torque.

[0017] As explained above, in one embodiment the shift request signal can be determined either based on a control signal for automatic gear shifting or based on a shift request from a user received by an input device. The control signal for automatic gear shifting is, for example, output by an automatic gearshift mechanism and is determined, for instance, depending on a predefined or user-defined cadence. Alternatively, a corresponding input device can be used to input a shift request from a user, which could, for example, be designed as a shift lever on the bicycle's stem.

[0018] The actuation step of the shifting mechanism is further determined based on the pedal cadence, pedal acceleration and / or a predetermined shifting time of the shifting mechanism.

[0019] As explained above, by considering pedal acceleration, pedal cadence, and / or a known shift time, it is possible to determine at what point in time—for example, at what crank torque—a shift must be triggered so that the shifting process, or a specific part of it, occurs with minimal force applied to the pedals. For instance, if it is known that one revolution takes 300 milliseconds at the current pedal cadence, and it is also known that after a shift activation, the portion of the shift that is to be shifted to the dead center takes 250 milliseconds, then it can be determined at what point in time, and thus at what crank torque, an activation must occur.In other words, it is then possible to determine, based on a known or predetermined progression of the pedal crank torque, at which specific pedal crank torque an actuation must occur.

[0020] Therefore, it is advantageous to also include the pedal cadence, pedal acceleration and / or a known shift time of the transmission in the determination.

[0021] It may be desirable to apply such a delay in actuation as described above only when the current pedal cadence, i.e., the rotational speed of the pedal mechanism, is within a specific range. This is because, at very low cadence, direct actuation may be preferable to avoid any delay between the shifting request and the actuation. Similarly, at very high cadence, direct actuation is preferable because the desired reproducibility is more difficult to achieve. Accordingly, it is intended that, depending on the specific crank torque, actuation occurs only if the pedal cadence is above a first threshold and / or below a second threshold, where the second threshold is greater than the first. Otherwise, direct actuation, i.e., actuation without delay, takes place.

[0022] Similarly, in a preferred embodiment, it can be provided that actuation depending on the specific pedaling torque only occurs when a predefined riding mode is selected, and otherwise direct actuation, i.e., actuation without delay, takes place. Accordingly, for example, one riding mode can be provided in which shifting always occurs directly, and another riding mode can be provided in which a delay is acceptable.

[0023] In a further embodiment, the method additionally comprises the steps of determining an actuation point based on the pedal cadence and / or pedal acceleration as well as the shift time. The actuation step is then executed at the determined actuation point.

[0024] For the advantages of including pedal cadence, pedal acceleration and shift time, please refer to the above explanations.

[0025] An activation point can be either a specific time or, for example, a specific crank position or a specific crank torque.

[0026] In one embodiment, it is provided that the step of determining the pedal crank torque is carried out repeatedly in order to determine the current point in the course of the pedal crank torque (e.g. pointing or descending pedal crank torque) and / or to determine the course itself.

[0027] Accordingly, in another embodiment, a predetermined switching phase of the derailleur can be triggered by means of the actuator in the region of minimum pedaling torque, i.e., when the pedals are in a vertical position. If, for example, the shifting process has several phases, one of which should advantageously be placed at the dead center due to the load on the derailleur, then precisely that switching phase can be positioned and placed accordingly to further reduce the load on the derailleur. Such a switching phase could, for example, be the point at which a pawl of a derailleur engages, which can cause a high load on the derailleur and a high noise level.

[0028] In one embodiment, the aforementioned crank arm position with minimal pedal torque can be a vertical position of the crank arm. In other words, this is the aforementioned dead center or a pedal position in which the force exerted by the bicycle user is minimal.

[0029] In a further embodiment, the position of the bicycle's crank arm can also be determined. This can be done using the aforementioned sensor or a separate sensor. The determined crank arm position can then also be used in the activation step. Accordingly, the activation of the gear shift can also be performed based on the determined crank arm position. By additionally using the crank arm position, the timing of the activation can be validated. Changes in the user's pedaling behavior can also be detected, thus preventing shifting at the wrong time.

[0030] The above-mentioned procedural steps are not to be understood as being limited to the sequence shown, but can also be carried out in a different order if technically possible.

[0031] The present invention further comprises a bicycle with an electrical circuit, wherein the bicycle further comprises a control device which is configured to carry out a method according to one of the preceding embodiments.

[0032] As previously explained, a bicycle can be either a purely muscle-powered bicycle or an electric bicycle, which includes a motor and a battery to assist propulsion. For the definition of an electrical circuit, please refer to the explanations above.

[0033] A control unit can be, for example, a microprocessor, which is implemented externally or integrated into one of the other components listed here. The control unit can also be a software component within existing software that runs on an existing microprocessor or processing unit. Distributing the functionalities of the control unit across multiple microprocessors is also possible. Brief description of the characters Fig. Figure 1 shows a method according to the invention. Fig. Figure 2 shows a schematic representation of a bicycle according to the present invention. Detailed description of embodiments

[0034] With reference to Fig. 1. An exemplary method of the present invention will first be described. Reference will already be made to the methods described in Section 1. Fig. 2. The schematic representation of the device shown is taken.

[0035] First, in step S1 in Fig. 1 at the control unit 302 in Fig. 2. Receive a shift request signal, which represents a shift request from the user or the automatic transmission / gearbox. This can either be from the in Fig. The input device 303 of the bicycle 301, as shown in Figure 2, is received when activated by a user. This shifting request is then transmitted to the control unit 303 via an electrical signal and received there. Alternatively, such a shifting request can be received by the gearshift mechanism 304 in Fig. 2 transferred and connected to control unit 302 in Fig. 2 will be received.

[0036] Subsequently, based on the data from sensor device 305 in Fig. 2 received sensor data, the pedal crank torque of the bicycle is determined by the control unit 302, step 2 in Fig. 1.

[0037] In the present exemplary embodiment, step S3 then involves determining an actuation point based on the pedal cadence, pedal acceleration, and switching time. The pedal cadence and pedal acceleration can also be determined by the control unit 302 using data received from the sensor unit 305. In this embodiment, the actuation point is selected such that a specific section of the switching process is executed in the region of minimum pedal crank torque, i.e., at the moment the pedal cranks are in a vertical position. Accordingly, a predetermined switching time, known for the electrical circuitry, is taken into account between the triggering or actuation and the execution of the respective section of the switching process.By using the known switching time, a predetermined course of the pedal crank torque (here the course of the preceding pedal crank revolutions), and the determined current pedal crank torque, the exact actuation point can then be determined.

[0038] Then, in step 4, Fig. 1. The actuation of the circuit is carried out at this determined actuation point by activating the electronic circuit 306 of the bicycle 301 in Fig. 2 is controlled by means of an electrical signal.

[0039] The electrical circuit then executes the corresponding switching process, whereby the predetermined switching phase of the circuit is carried out in the area of ​​minimum pedal crank torque by selecting the activation point, thus reducing the load on the bicycle components. Reference sign Step S1 Receiving the switching request Step S2 Determining the pedal crank torque Step S3 Determining the activation point Step S4 Updating the circuit 301 Bicycle 302 Control unit 303 Input device 304 automatic transmission 305 Sensor device 306 electrical circuit

Claims

[1] Method for controlling a switching operation of an electrical circuit (306) of a bicycle (301), wherein the method comprises the steps: - Receiving (S1) a switching request signal; - Determining (S2) a pedal crank torque of a pedal crank of the bicycle (301); - Actuating (S4) the shifting depending on the specified pedaling torque based on a pedal cadence, a pedal acceleration and / or a pre-known shifting time of the shifting; wherein the actuation step (S4) depending on the specified pedaling torque occurs when the pedal cadence is above a first threshold and / or below a second threshold, the second threshold being greater than the first threshold, and otherwise a direct actuation of the shifting occurs. [2] Method according to claim 1, wherein - the activation occurs depending on the difference between the specified pedal crank torque and a predetermined minimum pedal crank torque. [3] Method according to claim 1, wherein - the activation occurs depending on a comparison of the specific pedal crank torque with a predetermined course of the pedal crank torque. [4] Method according to one of the preceding claims, wherein the shift request signal is determined either based on a control signal for automatic gear shifting or based on a shift request from a user received by an input device (303). [5] Method according to any of the preceding claims, further comprising the step: - Determining an actuation point (S3) based on the pedal cadence and / or pedal acceleration as well as the shift time, wherein - the actuation step (S4) is executed at the specified actuation point. [6] Method according to claim 5, wherein the actuation point is a pedal crank position and by means of actuation to the specified actuation point a predetermined switching phase of the shifting takes place in the area of ​​the minimum pedal crank torque. [7] Method according to claim 5, wherein the actuation point is a pedal crank torque and by means of actuation to the determined actuation point a predetermined switching phase of the shifting takes place in the area of ​​the minimum pedal crank torque. [8] Bicycle (301) with an electrical circuit (306), wherein the bicycle (301) further comprises a control device (302) which is configured to carry out a method according to one of the preceding claims.

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