Method for operating a drive arrangement of an electric bicycle

Abstract

The present invention relates to a method for operating a drive arrangement of an electric bicycle, comprising the steps of: determining a deceleration of the electric bicycle, detecting an active braking process based on the determined deceleration, and checking the plausibility of a braking signal based on the determined deceleration and the detection of the braking process.

Description

State of the art

[0001] The present invention relates to a method for operating a drive arrangement of an electric bicycle, as well as an electric bicycle.

[0002] Electric bicycles are known to have drive arrangements that include a drive unit for generating motor torque to provide motor assistance for a rider's manual pedaling power, and a braking system for decelerating the electric bicycle. Electric bicycles are also known to have a brake-applied mechanism that prevents the drive unit from generating drive torque, for example, due to legal requirements. A brake signal, generated, for example, by a brake switch, is often used for this purpose. However, in the event of defects such as cable breaks, reliable detection of brake application cannot always be guaranteed. Disclosure of the invention

[0003] The method according to the invention with the features of claim 1 is distinguished by the fact that a check of the brake signal on an electric bicycle can be carried out in a particularly simple and reliable manner. In particular, the method can be carried out using simple means. This is achieved according to the invention by a method for operating a drive arrangement of an electric bicycle, comprising the steps: - Determining a deceleration of the electric bicycle, - Detection of an active braking process based on the determined deceleration, and - Plausibility check of a braking signal based on the determined deceleration and the detection of the braking process.

[0004] Deceleration is defined as a reduction in the speed of the electric bicycle, i.e., a slowdown. Deceleration is defined as a measure of the reduction in speed.

[0005] Preferably, an active braking process is considered to be a braking process directly initiated by the electric bicycle rider. This means that the active braking process is triggered by a targeted, particularly manual, brake application by the electric bicycle rider.

[0006] A brake signal is considered, in particular, a signal representing the braking process. For example, the brake signal can comprise an electrical signal representing the active braking process. In particular, the brake signal can be generated by means of a signaling device and / or a sensor and / or a brake actuation device.

[0007] The brake signal can preferably be used for other functions of the electric bicycle, such as a signaling device, in particular in the form of a brake light. Particularly preferably, the brake signal can be used to deactivate a drive unit of the electric bicycle. This means that, in response to the generated brake signal, operation of the drive unit can be actively prevented.

[0008] Plausibility testing is considered, in particular, a check of the brake signal for its plausibility. This means that the plausibility check preferably verifies the correct functioning of the brake signal, and in particular of the components involved, such as a brake switch. In particular, the plausibility check can be used to check whether a brake signal is generated simultaneously when a braking operation is detected. Particularly preferably, it can also be used to check whether a brake signal is generated simultaneously when an active braking operation is detected.

[0009] In other words, the method, for example, uses sensors to monitor the deceleration of the electric bicycle, and detects an active braking action, i.e., one induced by a targeted braking maneuver using a braking device on the electric bicycle. Detection of such an active braking action is used to verify the plausibility of the generation of a corresponding braking signal representing the braking action.

[0010] The method thus offers the advantage of being able to verify the correct function of the brake signal generation in a particularly simple and reliable manner. By explicitly detecting an active braking process and, among other things, checking the plausibility of a brake signal based on this, the function of the braking system can be verified particularly reliably. In particular, a defect in the brake signal generation can be easily and reliably detected. This allows additional functions based on the brake signal, such as deactivating motor assistance, to be implemented or deactivated particularly reliably.

[0011] The subclaims show preferred developments of the invention.

[0012] Preferably, the deceleration is determined by directly detecting the acceleration of the electric bicycle, preferably using an acceleration sensor. In particular, a negative acceleration relative to a direction of travel is detected as the deceleration. This means that a corresponding acceleration that occurs during a braking operation is directly determined as the deceleration. Particularly preferably, a characteristic negative acceleration, for example, with a specific temporal progression, can be recognized as an active braking operation. This allows an active braking operation to be detected easily and particularly clearly.

[0013] Particularly preferably, the deceleration is determined by detecting a change in speed of the electric bicycle. The change in speed is preferably detected by means of a speed sensor, which may, for example, comprise a wheel speed sensor. Preferably, a value of the speed and a change in the speed over time can be detected. Alternatively, the change in speed can also be detected in a different way, for example based on other sensor signals. Preferably, the change in speed can alternatively be determined based on a signal from a generator or dynamo. For example, a deceleration can be detected based on a reduction in the voltage frequency of the generated current. This allows the deceleration and the active braking process to be determined in a particularly simple and cost-effective manner.

[0014] Preferably, an active braking operation is detected if the amount of the determined deceleration is greater than or equal to a predetermined deceleration threshold. The predetermined deceleration threshold is preferably at least 2 m / s. 2 , in particular at least 4 m / s 2 This means that the detection of the active braking process is based, in particular, on determining a deceleration of such a magnitude that can only be achieved through active braking using a braking system, and not, for example, through coasting on an incline. This allows the active braking process to be detected particularly reliably and easily.

[0015] Preferably, determining the deceleration comprises determining a temporal change in the deceleration, wherein the plausibility check is additionally carried out based on the determined temporal change in the deceleration. This means that a gradient of the deceleration, in particular a gradient of the negative acceleration, is additionally determined, and preferably the detection of the active braking process and the plausibility check of the braking signal are carried out based on this gradient. In particular, an active braking process can be detected based on the fact that the determined temporal change in the deceleration is greater than a predetermined threshold value. This allows each active braking process to be detected particularly reliably, and the braking signal to be checked for plausibility based on this.

[0016] Particularly preferably, the brake signal is a signal from a brake switch. A brake switch is considered to be, in particular, a switch, for example, an electrical and / or mechanical switch, that generates the brake signal in response to a brake application of the electric bicycle. For example, the brake switch can be actuated by means of a brake lever.

[0017] For example, the brake signal can be used as a condition for the operation of the drive unit of the electric bicycle and / or for signal generation by means of a brake signal light.

[0018] Preferably, a defect in the brake switch is detected by means of the plausibility check. In particular, the defect is detected when, upon detection of an active braking process, no brake signal is detected. Preferably, in response to the detected defect in the brake switch, a notification can be issued to the rider of the electric bicycle. Alternatively or additionally, one or more functions of the drive arrangement, such as the torque generation capability, can be deactivated in response to the detected defect. Thus, the method can be used to determine defects in the brake switch in a particularly simple and efficient manner.

[0019] Further preferably, the brake switch is configured to deactivate a drive unit of the drive assembly of the electric bicycle. In particular, the brake switch can prevent the drive unit from generating motor torque, preferably while a brake signal is being generated, preferably by means of the brake signal itself. In other words, the brake switch can actively prevent motor assistance when the brake is applied.

[0020] Preferably, the plausibility check of the brake signal additionally comprises: detecting a brake application in response to a predetermined actuation situation, and determining whether the brake signal was generated during the brake application. A predetermined actuation situation is considered to be, in particular, a situation in which a brake application can be assumed. Preferably, during the actuation situation, a notification is issued to the rider of the electric bicycle, instructing the rider to apply the brake, preferably while the electric bicycle is stationary. This means that the rider is prompted by the system to manually apply the brake, so that the system can check the function of the brake signal generation during this time by checking the plausibility. This allows the correct generation of the brake signal to be checked in a particularly simple manner.

[0021] Particularly preferably, the method further comprises the step of determining a number of braking operations per predetermined driving cycle, wherein the plausibility check is additionally carried out based on the determined number of braking operations per driving cycle. A driving cycle can in particular be regarded as a journey of the electric bicycle for a predetermined period of time and / or over a predetermined distance. The plausibility check can preferably be carried out by comparing the number of determined braking operations per driving cycle with a number of determined brake signals during this driving cycle. In response to a determined deviation, a defect in the brake switch, for example, can be detected. This allows an additional, particularly reliable check of the brake signal generation to be carried out.

[0022] More preferably, the deceleration is determined using an anti-lock braking system of the electric bicycle. In particular, an active braking process can be determined based on signals from the anti-lock braking system. This allows, for example, the sensors and operating mode of the anti-lock braking system to be used to reliably detect the active braking process and to verify the plausibility of the braking signal.

[0023] Furthermore, the invention leads to an electric bicycle comprising a drive assembly and a control unit. The drive assembly preferably comprises a drive unit configured for the controlled generation of motor torque and a braking system, preferably comprising a brake switch. The control unit is configured to carry out the described method. Short description of the drawings

[0024] An embodiment of the invention will be described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 a simplified schematic view of an electric bicycle in which a method for operating a drive arrangement of the electric bicycle is carried out according to a preferred embodiment of the invention, and Fig. 2 a highly simplified schematic view of the method according to the invention. Embodiments of the invention

[0025] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0026] Fig. 1 shows a simplified schematic view of an electric bicycle 100 in which a method 20 for operating a drive arrangement 10 of the electric bicycle 100 is carried out according to a preferred embodiment of the invention.

[0027] The drive assembly 10 comprises a drive unit that includes a motor, which is in particular an electric motor. The motor can be supplied with electrical energy by means of an electrical energy storage device 109 of the electric bicycle 100.

[0028] The drive unit is arranged in the area of ​​a bottom bracket of the electric bicycle 100. The motor torque generated by the motor can provide motor assistance to the pedaling force generated by the muscular power of a rider of the electric bicycle 100. The rider's muscular power can be applied via a crank drive.

[0029] The drive assembly 10 further comprises a control unit 50 configured to actuate the drive unit in a controlled manner. For example, the control unit 50 can control an electrical actuation current for actuating the motor of the drive unit.

[0030] In addition, the drive assembly 10 includes a braking system 30, which includes brakes 32 and a brake lever 31. Using the brake lever 31, a rider of the electric bicycle 100 can manually actuate the brakes 32 to brake, i.e., decelerate, the electric bicycle 100.

[0031] In addition, the braking system 30 comprises a brake switch 34 on the brake lever 31, which is configured to generate a braking signal in the event of manual actuation of the brake lever 31.

[0032] When the brake signal is generated, it can be provided that the control unit 50 stops the actuation of the drive unit, for example, in response to receiving the brake signal. In other words, when the brake signal is generated, the operation of the drive unit is deactivated.

[0033] Furthermore, the braking system 30 may comprise a brake light 33 which, when the braking signal is generated, emits a light signal in order to optically signal an active braking process.

[0034] The method 20 is provided for checking the function of the brake signal generation of the brake system 30, that is to say in particular for checking a function of the brake switch 34. The steps of the method 20 are described below with reference to the Fig. 2 described.

[0035] First, in the method 20, a deceleration of the electric bicycle 100 is determined 21. As a deceleration, a negative acceleration of the electric bicycle 100 is detected directly by means of an acceleration sensor 54. This means that by means of the acceleration sensor 54, a force acting on the electric bicycle 100 against a direction of travel A (compare Fig. 1) effective acceleration is recorded as deceleration.

[0036] In this case, an active braking process is detected 22 based on the determined deceleration. Specifically, the active braking process is detected when the determined acceleration corresponds to a predetermined acceleration. In particular, the deceleration is detected as an active braking process, i.e., a braking process initiated by a targeted brake application, when the determined acceleration is greater than or equal to a predetermined deceleration threshold.

[0037] In addition, a temporal change in the deceleration can be detected using the acceleration sensor 54. This allows, for example, a deceleration of the electric bicycle 100 caused actively by targeted braking to be detected particularly reliably.

[0038] Subsequently, the brake signal is checked for plausibility 23 based on the determined deceleration and the detected braking process. This means, in particular, that a check is carried out to determine whether a signal is generated by the brake switch 34 during a detected braking process.

[0039] By means of the plausibility check 23, a defect in the ignition switch 34 can be detected. In particular, a defect can be detected if no brake signal is present during the detected braking process.

[0040] For example, in response to a detected defect in the brake switch, operation of the drive unit can be automatically deactivated because a brake signal-dependent shutdown of the drive unit can no longer be reliably enabled.

[0041] Alternatively or additionally, the deceleration can be determined 21 by detecting a change in speed of the electric bicycle 100. In this case, the speed of the electric bicycle 100 can preferably be detected by means of a speed sensor 53, which can, for example, comprise a rotational speed sensor on a rear wheel of the electric bicycle 100. Alternatively or additionally, the speed change can preferably be detected, for example, by means of a dynamo and / or an anti-lock braking system of the electric bicycle 100.

[0042] Method 20 offers the advantage that a reliable check of the function of the brake signal, and in particular of the brake switch 34, can be carried out in a particularly simple manner and using simple and cost-effective means. By explicitly detecting an active braking action initiated by the driver and checking the plausibility of a braking signal based on the detected braking action, it is possible to detect particularly reliably whether a corresponding intended braking signal is being generated. This allows, for example, additional functions, such as, in particular, the deactivation of motor assistance, to be implemented particularly reliably.

Claims

[1] Method for operating a drive arrangement (10) of an electric bicycle (100), comprising the steps: - Determining (21) a deceleration of the electric bicycle (100), - detecting (22) an active braking operation based on the determined deceleration, and - Plausibility check (23) of a braking signal based on the determined deceleration and the detection of the braking process. [2] Method according to claim 1, wherein the determination (21) of the deceleration is carried out by directly detecting an acceleration of the electric bicycle (100), in particular by means of an acceleration sensor (54). [3] Method according to one of the preceding claims, wherein the determination (21) of the deceleration is carried out by detecting a change in speed of the electric bicycle (100), in particular by means of a speed sensor (53). [4] Method according to one of the preceding claims, wherein an active braking operation is detected if an amount of the determined deceleration is greater than or equal to a predetermined deceleration threshold value, preferably at least 2 m / s 2 , in particular at least 4 m / s 2 , is. [5] Method according to one of the preceding claims, wherein the determination (21) of the delay comprises determining a temporal change in the delay, and wherein the plausibility check (23) is additionally carried out based on the determined temporal change in the delay. [6] Method according to one of the preceding claims, wherein the brake signal is a signal from a brake switch (34). [7] Method according to claim 6, wherein a defect of the brake switch (34) is detected by means of the plausibility check (23). [8] Method according to one of claims 6 or 7, wherein the brake switch is arranged to deactivate a drive unit of the drive arrangement (10) of the electric bicycle (100). [9] Method according to one of the preceding claims, wherein the plausibility check (23) of the brake signal additionally comprises: detecting a brake actuation in response to a predetermined actuation situation, and determining a generation of the brake signal during the brake actuation. [10] Method according to one of the preceding claims, further comprising the step of: determining a number of braking operations per predetermined driving cycle, wherein the plausibility check (23) is additionally carried out based on the determined number of braking operations per driving cycle. [11] Method according to one of the preceding claims, wherein the determination (21) of the deceleration is carried out by means of an anti-lock braking system (105) of the electric bicycle. [12] Electric bicycle, comprising a drive arrangement (10) and a control unit (50) which is arranged to carry out the method according to one of the preceding claims.

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