Method for operating a drive unit of an electric bicycle

Abstract

The present invention relates to a method for operating a drive unit of an electric bicycle, comprising the steps of: determining an assistance situation based on at least one assistance signal, detecting a manual input signal of a user of the electric bicycle after determining the assistance situation, and operating the drive unit in a first assistance mode or in a second assistance mode depending on the determined assistance situation and in response to the detected input signal.

Description

State of the art

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

[0002] Electric bicycles with a push-assist function are known. In this case, for example, in response to a button being pressed by the electric bicycle rider, a motor torque is generated by the electric bicycle's drive unit to assist the rider while pushing. Typically, such a motor torque is generated to propel the electric bicycle at a predetermined target push speed. Furthermore, alternative operating modes of electric bicycles are known that can assist the electric bicycle rider with motor torque. Disclosure of the invention

[0003] The method according to the invention with the features of claim 1 is characterized in that an optimized mode of operation of the drive unit of an electric bicycle can be provided, which can provide a particularly high level of user comfort for the rider of the electric bicycle in a variety of possible situations. In particular, optimal pushing or starting assistance can be provided in a particularly simple and convenient manner. This is achieved according to the invention by a method for operating a drive unit of an electric bicycle, which comprises the steps: - Determining an assistance situation based on at least one assistance signal, - Detecting a manual input signal from a user of the electric bicycle after determining the assistance situation, and - Operating the drive unit in a first support mode or in a second support mode depending on the determined support situation and in response to the detected input signal.

[0004] In particular, the drive unit is operated in such a way as to generate a motor torque that can propel the electric bicycle forward in order to assist the user in moving the electric bicycle forward.

[0005] An assistance situation is defined, in particular, as a state of the system consisting of the electric bicycle and the user in which additional motor torque generated by the drive unit is required to support the user's propulsion of the electric bicycle. Preferably, the assistance situation is defined independently, i.e., outside of normal operation of the electric bicycle.

[0006] Particularly preferably, the assistance situation is determined, in particular exclusively, when the electric bicycle is stationary.

[0007] A manual input signal is considered to be a signal that can be generated manually by the user at any time, in particular by means of an input unit such as a button or key.

[0008] In particular, the first assistance mode and the second assistance mode differ in the way the drive unit's motor torque is generated. For example, different parameters are used to control the motor torque in the two assistance modes.

[0009] The method thus offers the advantage of automatically detecting the current assistance situation and selecting the optimal assistance mode based on that. This eliminates the need for the user to explicitly select the specific assistance mode. Furthermore, the user interface and hardware can be simplified, as a single input element, for example, is sufficient.

[0010] A particularly advantageous feature is that the method reliably executes the appropriate assistance mode whenever the appropriate assistance situation occurs and the manual input signal is simultaneously present. This ensures optimal user comfort for the electric bicycle user at all times.

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

[0012] The assistance signal preferably comprises a rider torque signal. This means that the assistance situation is determined based on a detected rider torque. In particular, a pushing situation can be detected as an assistance situation if the rider torque signal has a value of zero. Preferably, a hill start situation can be detected as an assistance situation, for example, if the rider torque signal has a value greater than zero, preferably if a cadence of zero is also present. This means that in this case, a rider can be stationary, for example, on a hill, and operate the pedals, meaning that a hill start may be imminent.

[0013] Particularly preferably, the first assistance mode includes a push assist. A push assist is considered, in particular, an operating mode in which a motor torque is specifically generated without the user of the electric bicycle pedaling. This means that the electric bicycle is propelled exclusively by the motor torque of the drive unit generated by the push assist. This enables particularly comfortable operation of the electric bicycle by providing the user with motor support when pushing the electric bicycle.

[0014] The second assistance mode preferably includes hill start assist. Hill start assist is considered, in particular, an operating mode in which, preferably starting from a standstill of the electric bicycle, a targeted motor torque is generated while the electric bicycle user pedals with a rider torque. Hill start assist is preferably activated when the rider torque corresponds to at least a predetermined torque threshold. This enables the electric bicycle to start particularly comfortably on an incline, thus providing a particularly high level of user comfort.

[0015] Further preferably, the drive unit is operated in the first assistance mode or in the second assistance mode only as long as the manual input signal is detected. In other words, the drive unit is operated in one of the two operating modes exclusively while the manual input signal is being generated, i.e., for example, as long as the user specifically expresses a request for assistance using the input signal. This allows the method to be carried out in a particularly simple manner and with simple technology.

[0016] Preferably, the input signal comprises only the on and off states. This means that, for example, a variable sensor signal is not considered an input signal, but rather only a signal with the on and off states. This allows the method to be implemented in a particularly simple manner. Furthermore, particularly simple and cost-effective hardware can be used to carry out the method.

[0017] The first assistance mode preferably comprises speed-controlled operation of the drive unit, in particular based on a detected speed of the drive unit. This means that the motor torque is provided by the drive unit during the first assistance mode, preferably exclusively, based on the current speed of the drive unit. This allows pushing assistance to be provided in a particularly simple and reliable manner, providing optimal support to the user when pushing.

[0018] Further preferably, the second assistance mode comprises torque-controlled operation of the drive unit, in particular based on a detected instantaneous motor torque of the drive unit and / or a detected instantaneous driver torque of a pedal actuation. Preferably, the drive unit is additionally operated in the second assistance mode based on an assistance factor, which can be set by the user, for example. This means that in the second assistance mode, the assisting motor torque is provided depending on the instantaneous load of the drive unit. This allows for particularly effective and comfortable starting assistance, especially on inclines.

[0019] Particularly preferred is a push situation, which is used when no rider torque is detected and the electric bicycle is also preferably stationary. This means that if no pedaling by the rider is detected, a push situation is assumed. This allows for a particularly simple way to provide push assistance.

[0020] Preferably, a hill start situation is determined as the assistance situation when at least one predetermined gradient and / or at least one predetermined rider torque is detected, preferably when the electric bicycle is also stationary. This means that, depending on a currently detected gradient and / or a currently detected rider torque, it can be determined that a hill start situation exists in order to provide starting assistance.

[0021] Particularly preferably, the drive unit is operated in each of the two support modes exclusively when the electric bicycle is stationary. This means that each of the two support modes is provided exclusively when the electric bicycle is stationary.

[0022] Furthermore, the invention leads to an electric bicycle comprising a drive unit and a control unit. The control unit is configured to operate the drive unit in a controlled manner. Furthermore, the control unit is configured to carry out the described method for operating the drive unit of the electric bicycle. Short description of the drawings

[0023] Embodiments of the invention are 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 according to a preferred embodiment of the invention is carried out, and Fig. 2 a simplified schematic of a sequence of implementation of the method according to the preferred embodiment. Embodiments of the invention

[0024] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0025] Fig. Figure 1 shows a simplified schematic view of an electric bicycle 100 having a drive unit 1. The drive unit 1 is arranged in the region of a bottom bracket of the electric bicycle 100 and 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.

[0026] By means of a drive torque generated by the drive unit 1, a pedal force generated by muscle power of a rider of the electric bicycle 100 can be motor-assisted.

[0027] The electric bicycle 100 also comprises a control unit 50 which is configured to operate the drive unit 1. Preferably, the control unit 50, as shown in the Fig. 1, can be integrated into the drive unit 1. The control unit 50 is also designed to carry out a method 10 for operating a pushing aid of the electric bicycle 100 according to a preferred embodiment of the invention.

[0028] The method 10 is described in detail below, with reference to the Fig. 2 is referred to. Fig. 2 shows a simplified schematic view of a sequence of the method 10.

[0029] Method 10 is carried out exclusively while the electric bicycle 100 is stationary. This means that the steps described below, in particular steps 11 and 12, are carried out exclusively while the electric bicycle 100 is stationary.

[0030] In the method 10, a support situation 11 is first determined based on at least one support signal.

[0031] A rider torque signal is detected as the assistance signal, which represents the instantaneous pedaling torque manually generated by the user of the electric bicycle 100. For example, the rider torque signal can be detected using a torque sensor.

[0032] Preferably, additional alternative assistance signals can be detected and used to determine the assistance situation 11. For example, a current rider position can also be detected as an assistance signal. Preferably, it is determined whether the rider is sitting on a saddle 107 of the electric bicycle 100 or, for example, whether the rider is standing next to the electric bicycle 100. Further preferably, a current incline on which the electric bicycle 100 is located can be detected as an assistance signal, for example.

[0033] Based on the support signals, the support situation is determined as a pushing situation or a hill start situation.

[0034] In particular, the pushing situation is determined when no rider torque is detected, i.e., when the pedaling torque is zero. Alternatively or additionally, the pushing situation can be determined when, for example, based on additional sensors, it is detected that the rider is pushing the electric bicycle 100.

[0035] In addition, a hill start situation is preferably detected when at least a predetermined rider torque is detected, i.e., when the rider deliberately operates the pedals of the electric bicycle 100. Alternatively or additionally, the hill start situation can be determined when at least one predetermined gradient on which the electric bicycle 100 is currently located is detected.

[0036] Subsequently, the method 10 detects whether a manual input signal 12 from the user of the electric bicycle 100 is present.

[0037] The manual input signal can be generated by the user by means of an input device 105, which, for example, comprises a button on the handlebar of the electric bicycle 100.

[0038] The manual input signal only includes the on and off states. This means that the manual input signal can only be used to select whether or not support should be provided; in particular, it cannot be used to adjust the level of support or anything similar.

[0039] Depending on the determined support situation and while the manual input signal is generated, the drive unit 1 is then operated in a first support mode 13 or in a second support mode 14. In particular, the selection of whether the drive unit 1 is operated in the first support mode 13 or in the second support mode 14 is made based on the determined support situation.

[0040] The first assistance mode includes a push assist. The first assistance mode is selected when a push situation is detected.

[0041] The operation of the drive unit 1 in the first assistance mode 13 is carried out in such a way that a speed-controlled operation of the drive unit 1 is carried out. This means that in the first assistance mode, a predetermined speed-dependent actuation of the drive unit 1 takes place. As a result, in the first assistance mode, a torque is generated in a simple manner by means of the drive unit 1 in order to specifically assist the rider when pushing the electric bicycle 100.

[0042] The second assistance mode includes hill start assist. The second assistance mode is selected when a hill start situation is detected.

[0043] The drive unit 1 is operated in the second assistance mode 14 in such a way that a torque-controlled operation of the drive unit 1 is carried out. This means that a current motor torque of the drive unit 1 and / or the current driver torque is preferably detected by a pedal actuation of the driver, and based on this, the desired motor torque of the drive unit 1 is controlled, by means of which the driver is assisted when starting off. Preferably, an assistance factor, which can be set automatically or manually by the user, for example, can also be taken into account when controlling the motor torque.

[0044] Method 10 thus comprises an initial differentiation of the currently existing assistance situation of the system consisting of electric bicycle 100 and user, specifically between a pushing situation and a starting situation. Depending on the determined assistance situation, the corresponding assistance mode is executed when the user of electric bicycle 100 requests targeted assistance via the manual input signal.

[0045] This allows the appropriate assistance mode to be provided automatically, reliably, and specifically, whenever assistance is manually requested, thus providing optimal support for the user. In particular, there is no need for the user to explicitly select the assistance mode. This means, for example, that only a simple button press is required, allowing the user to receive optimal support from drive unit 1 both when pushing and when starting, for example, on a hill.

Claims

[1] Method for operating a drive unit (1) of an electric bicycle (100), comprising the steps: - determining a support situation (11) based on at least one support signal, - detecting a manual input signal (12) of a user of the electric bicycle (100) after determining the assistance situation (11), and - Operating the drive unit (1) in a first support mode (13) or in a second support mode (14) depending on the determined support situation and in response to the detected input signal. [2] The method of claim 1, wherein the assistance signal comprises a driver torque signal. [3] Method according to one of the preceding claims, wherein the first assistance mode comprises a pushing aid. [4] Method according to one of the preceding claims, wherein the second assistance mode comprises a hill start assist. [5] Method according to one of the preceding claims, wherein the operation of the drive unit (1) in the first support mode (13) or in the second support mode (14) only takes place as long as the manual input signal is detected. [6] Method according to one of the preceding claims, wherein the input signal comprises exclusively the states on and off. [7] Method according to one of the preceding claims, wherein the first support mode comprises a speed-controlled operation of the drive unit (1). [8] Method according to one of the preceding claims, wherein the second assistance mode comprises a torque-controlled operation, preferably additionally based on an assistance factor, of the drive unit (1). [9] Method according to one of the preceding claims, wherein a pushing situation is determined as the assistance situation if no driver torque is detected. [10] Method according to one of the preceding claims, wherein a hill start situation is determined as the assistance situation if at least one predetermined gradient and / or at least one predetermined driver torque is detected. [11] Method according to one of the preceding claims, wherein the operation of the drive unit (1) in the first support mode (13) or in the second support mode (14) is carried out exclusively from a standstill of the electric bicycle (100). [12] Electric bicycle, comprising: - a drive unit (1), and - a control unit (50) which is configured to carry out the method according to one of the preceding claims.

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