Method for operating a drive unit of an electric bicycle

Abstract

The invention relates to a method for operating a drive unit of an electric bicycle, wherein the drive unit is configured to generate a motor torque intended to drive the electric bicycle in response to an actuation signal, and wherein the actuation signal is modulated with a predetermined modulation signal such that the drive unit generates a predetermined feedback signal perceivable by a rider of the electric bicycle by means of the modulated actuation signal.

Description

State of the art

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

[0002] Electric bicycles are known for their numerous input and output elements. This allows the electric bicycle rider to make manual inputs that can, for example, change the current assistance mode or a navigation system's route guidance. Information can also be provided to the rider, for example visually. Information is often provided via display elements such as screens or LEDs. Such display elements are usually mounted on the handlebars and are not in the rider's direct field of vision. This means that the rider may miss certain information or perceive it only with a delay. Disclosure of the invention

[0003] The method according to the invention with the features of claim 1 is distinguished in that, by means of a particularly simple and cost-effective construction, a reliable and convenient transmission of information to a rider of an electric bicycle can be enabled. In particular, the provision of information can be made possible without additional structural means. This is achieved according to the invention by a method for operating a drive unit of an electric bicycle, wherein the drive unit is configured to generate a motor torque, which is intended at least partially to drive the electric bicycle, in response to an actuation signal generated, for example, by a control unit.In the method, the actuation signal is modulated with a predetermined modulation signal such that the drive unit generates a predetermined feedback signal perceivable by a rider of the electric bicycle by means of the modulated actuation signal.

[0004] In particular, the modulated actuation signal comprises the, in particular original, actuation signal, and additionally the predetermined modulation signal. In other words, the modulation signal is modulated onto the original actuation signal, or in particular, added to it.

[0005] In other words, the method involves actuating the drive unit with a modulated actuation signal which, in addition to generating the engine torque intended for driving, causes the drive unit to operate in such a way that the drive unit generates a predetermined feedback signal perceivable by the driver.

[0006] A feedback signal is considered to be, in particular, a signal that the rider of the electric bicycle can perceive, preferably acoustically and / or haptically. In particular, a feedback signal is considered to be a signal that can transmit predetermined information to the rider.

[0007] The method thus offers the advantage of transmitting information, particularly in the form of a feedback signal, to the rider of the electric bicycle in a particularly simple and cost-effective manner. Because the feedback signal is generated by the drive unit itself and the specific actuation is carried out using the modulated actuation signal, no additional technical means, such as output devices, are required. By using the drive unit, which is already required for propulsion, and its actuation to generate the feedback signal, a particularly simple, cost-effective, and efficient operation of the electric bicycle is enabled.

[0008] The subclaims contain preferred developments of the invention.

[0009] Preferably, an acoustic signal is generated as the feedback signal. This means that the feedback signal comprises a predetermined noise or tone that the rider of the electric bicycle can perceive. For example, the acoustic signals are generated by the drive unit or a part of the drive unit, such as preferably a housing, vibrating. This allows for a particularly simple and clear transmission of a variety of different information to the rider of the electric bicycle.

[0010] Particularly preferably, a haptic signal, preferably a vibration, is generated as the feedback signal. This means that the feedback signal comprises a predetermined movement, such as a vibration, which the driver can feel. This allows specific information to be transmitted to the driver particularly reliably. In particular, the information can be transmitted, for example, with little or no likelihood of distracting the driver from traffic.

[0011] Preferably, the haptic signal is perceptibly generated on at least one pedal of the electric bicycle. This means that a predetermined movement, such as preferably a vibration, is generated on at least one, preferably on both, pedals, in particular on a crank drive of the electric bicycle. For example, the haptic signal can be generated on both pedals together. Alternatively, a separate haptic signal can preferably be generated on each of the two pedals independently of one another. This allows the feedback signal to be transmitted to the rider in a particularly simple manner, for example due to the direct mechanical connection between the drive unit and the pedals, and particularly reliably, in particular since the rider applies manual pedaling force via the pedals.

[0012] Preferably, the haptic signal is generated perceptibly on the saddle of the electric bicycle. This means that the drive unit is actuated in such a way that the haptic signal, preferably in the form of a vibration, is generated on the saddle of the electric bicycle. This can be achieved, for example, by designing and / or knowing a vibration transmission path between the drive unit and the saddle. This allows the electric bicycle rider to directly feel the specially generated feedback signal.

[0013] The saddle preferably has two different vibration elements, which are arranged, for example, within the saddle. The haptic signal is generated by exciting vibrations from precisely one of the two different vibration elements. The two vibration elements can be arranged on opposite sides of the saddle with respect to the direction of travel, so that the haptic signal can be generated, for example, on the left or right side with respect to the direction of travel. In this way, signals that can be easily distinguished by the rider can be transmitted to the rider. For example, directional information can also be transmitted. Navigation information, for example for an upcoming left or right turn, can thus preferably be transmitted to the rider.Alternatively or additionally, this can preferably be used to signal, for example, approaching hazards in a specific direction, such as vehicles on a collision course. The two vibration elements preferably have different natural frequencies. This makes it particularly easy to specifically excite only one of the two vibration elements in order to generate the haptic signal. For example, the vibration elements can be spring elements provided for cushioning the saddle. Alternatively, the vibration elements can preferably be other components designed to excite vibrations. The two different vibration elements preferably have identical mechanical properties, in particular with regard to seating comfort.

[0014] Further preferably, various predetermined feedback signals are generated to transmit different information to the driver. The various feedback signals are generated in a distinguishable manner using one or more of the following parameters: amplitude, frequency of the feedback signal, frequency of feedback signal generation, and number of feedback signals generated. This means that a distinguishable transmission of information can be provided using simple means.

[0015] The modulation signal preferably comprises a sine wave, a sawtooth wave, a square wave, and / or noise. This enables the generation of the modulation signal and thus the implementation of the method in a particularly simple and cost-effective manner.

[0016] Preferably, the method further comprises the step of recognizing a predetermined riding situation of the electric bicycle. The feedback signal is generated in response to the recognition of the predetermined riding situation. A variety of riding situations can be recognized as a riding situation during a ride of the electric bicycle. The recognition of the riding situation can be based on sensor data from one or more sensors of the electric bicycle. Thus, the feedback signal can provide the rider with information about the riding operation of the electric bicycle, allowing the rider, for example, to proactively adapt their riding style.

[0017] The driving situation preferably comprises an accident and / or a current vehicle state and / or a driving situation and / or a current environmental state and / or an impending collision of the electric bicycle. This means, for example, that an accident and / or an impending accident can be detected, in response to which the feedback signal is generated. Particularly preferably, the detection can be carried out using an environmental sensor system of the electric bicycle. For example, the feedback signal can be generated when it is detected that another road user, such as a motor vehicle, is approaching from the front or from behind, in particular when a collision is imminent. This can be done, for example, based on monitoring a current distance of the other road user from the electric bicycle.Particularly preferably, the feedback signal can be generated as a function of the approaching speed of the other road user and / or as a function of a type of road user, for example, a car or pedestrian. Alternatively or additionally, a current vehicle state, such as a remaining range, can be determined and reported back to the rider via the feedback signal. Further alternatively or additionally, an ambient state of an environment in which the electric bicycle is moving, such as a changing air pressure, can be detected, and information about it can be communicated to the rider. This enables a particularly flexible implementation of the method.

[0018] Preferably, the intensity of the feedback signal is adjusted depending on the detected, predetermined driving situation. Particularly preferably, the intensity increases the higher the determined probability of an impending collision. The intensity is preferably considered to be a vibration characteristic that is perceived to varying degrees by the rider of the electric bicycle. Particularly preferably, the amplitude of the feedback signal is adjusted as the intensity. Alternatively or additionally, the frequency of the feedback signal can be adjusted.

[0019] The feedback signal is preferably generated in such a way that it represents a warning message and / or a notice message and / or an error message and / or navigation information and / or route information and / or training information. An error message can, for example, inform about an error condition in the electric bicycle's system, such as a low battery level, a battery defect, overheating of the drive, or the like. In addition, the feedback signal can indicate that maintenance of the electric bicycle is required. Alternatively or additionally, information can be generated as training information, for example, which can give the rider advice on an optimized riding style. For example, the rider can be shown optimal braking times and / or advice for cornering. This can enable particularly comfortable and efficient operation of the electric bicycle.

[0020] Further preferably, the feedback signal is generated in such a way that, at least within a predetermined period of time within which the feedback signal is preferably generated, no resulting change in the motor torque occurs. Preferably, the feedback signal is additionally generated in such a way that the total motor torque generated by the drive unit is always greater than or equal to zero. This means that the feedback signal is generated in such a way that the additional modulation signal does not affect the resulting motor torque, in particular in such a way that it is not noticeable to the rider. As a result, the feedback signal can be generated unnoticed by the rider with regard to the operation of the electric bicycle to move forward, thereby providing a particularly high level of riding comfort.

[0021] The feedback signal is particularly preferably generated by operating the drive unit in the radial direction and / or in the tangential direction. Operating in the radial direction is considered in particular to mean that the drive unit is supplied with power in such a way that a force is generated in the radial direction in its motor between the stator and rotor. This is preferably made possible by supplying the motor with a current in the so-called d-direction. This allows the feedback signal to be generated in a simple and reliable manner without this generating additional torque. Operating in the tangential direction is considered in particular to mean that the drive unit is supplied with power in such a way that a force is generated in the tangential direction in its motor between the stator and rotor. This is preferably made possible by supplying the motor with a current in the so-called q-direction.

[0022] This makes it particularly easy, for example, to modulate the actuation signal.

[0023] Furthermore, the invention leads to a drive arrangement for an electric bicycle, comprising a drive unit and a control unit. The control unit is configured to actuate the drive unit with an actuation signal. Furthermore, the control unit is configured to carry out the described method. This makes it possible to provide a drive arrangement which, in addition to generating the motor torque for propelling the electric bicycle, enables the generation of feedback signals to inform the rider. In particular, this makes it possible to ensure that no additional components and / or structural changes to the drive arrangement are required to generate the feedback signals.

[0024] Furthermore, the invention relates to an electric bicycle which comprises the described drive arrangement. Short description of the drawings

[0025] The invention is described below using an exemplary embodiment in conjunction with the figures. In the figures, functionally identical components are identified by the same reference numerals. Here: 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, Fig. 2 a simplified schematic detailed view of the electric bicycle of the Fig. 1, Fig. 3 a simplified view of a detail of the electric bicycle of the Fig. 1 according to a first preferred further training, and Fig. 4 a simplified view of a detail of the electric bicycle of the Fig. 1 according to a second preferred further training. Preferred embodiments of the invention

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

[0027] The electric bicycle 100 has a crank drive with two cranks 104 located opposite one another with respect to a pedal axis 30. Pedals 102 are arranged on the cranks 104, via which a rider can generate a pedaling torque using muscle power.

[0028] The crank mechanism also includes a pedal shaft 108, which is non-rotatably connected to the cranks 104. The pedal shaft 108 is rotatably mounted in a drive unit 1 of the electric bicycle 100 via bottom brackets.

[0029] The drive unit 1 is part of a drive arrangement 110, which additionally comprises a control unit 105. The drive arrangement 110 is shown schematically in a highly simplified manner in the Fig. 2 shown.

[0030] To support the pedaling torque with an additional motor torque, the electric bicycle 100 comprises the drive unit 1, which is configured to generate the motor torque, preferably by means of an electric motor, which is supplied with electrical energy in particular by an electrical energy storage device 109.

[0031] The drive unit 1 is designed to provide the motor torque preferably via a gear on the pedal shaft 108.

[0032] Actuation of the drive unit 1 is effected by means of the control unit 105, in that the control unit 105 controls the supply of an electric current to the electric motor of the drive unit 1. This supply of the electric current is hereinafter referred to as an actuation signal.

[0033] The actuation signal is preferably provided as a function of a manual actuation of the crank mechanism by the rider of the electric bicycle 100, in such a way as to generate a specific motor torque depending on the level of pedaling torque. The electric bicycle 100 is driven by the motor torque and additionally by the pedaling torque generated by the rider.

[0034] When implementing the method, the control unit 105 additionally generates a specific modulation signal, by means of which the actuation signal is modulated. The modulated actuation signal is transmitted to the drive unit 1 to actuate it.

[0035] The modulation signal is generated such that the resulting modulated actuation signal, in addition to generating the intended motor torque, causes an actuation of the drive unit 1 such that the drive unit 1 generates a predetermined feedback signal perceivable by the rider of the electric bicycle 100.

[0036] The feedback signal can preferably be generated in two different ways. In a first variant, the feedback signal is generated as an acoustic signal. The feedback signal is generated in such a way that, by actuating the drive unit 1 by means of the modulated actuation signal, the operation of the electric motor of the drive unit 1 leads to vibration of parts of the drive unit 1 and / or parts of the electric bicycle 100 connected thereto, which causes a noise perceptible to the rider. Preferably, a housing 17 of the drive unit 1 is set into vibration in order to generate the noise (cf. Fig. 2). Alternatively, a bicycle frame of the electric bicycle 100 can be set into vibration to generate the noise.

[0037] Alternatively or additionally, in a second variant, the feedback signal can be generated as a haptic signal, preferably in the form of a vibration. The drive unit 1 is actuated by the modulated actuation signal in such a way as to generate a predetermined vibration pattern that the driver can perceive.

[0038] In detail, the feedback signal in the second variant is generated in such a way that a noticeable vibration occurs at the pedals 114. This is achieved by actuating the electric motor of the drive unit 1 in such a way as to generate a mechanical vibration excitation depending on a mechanical transmission path between the electric motor and the pedals 114 in such a way as to generate the vibration at the pedals 114.

[0039] In this method, various predetermined feedback signals can be generated to convey different information to the driver. The various feedback signals can differ in terms of vibration parameters and / or a temporal sequence of feedback signal generation. For example, the amplitude and / or frequency of the feedback signal can be adjusted to convey different information to the driver.

[0040] Furthermore, a frequency of generation of the feedback signal and / or a number of generated feedback signals, in particular for a specific event, can be specifically adjusted in order to transmit different information.

[0041] The modulation signal is preferably generated in the form of a sine wave. Alternatively, a sawtooth wave, a square wave, or noise can be generated as the modulation signal to enable simple implementation of the method.

[0042] The feedback signal is generated during the implementation of the method depending on various driving situations of the electric bicycle 100. These driving situations can be detected by means of a sensor system of the electric bicycle 100, such as an environmental sensor system and / or an inertial measuring unit and / or speed sensors, and recognized by the control unit 105.

[0043] For example, an accident and / or a current traffic situation can be identified as driving situations, and a warning message and / or a note can be issued as a feedback signal.

[0044] Further preferably, operating states of the electric bicycle 100 can be communicated to the rider by means of the feedback signal, such as an indication of a low battery level or the like.

[0045] For example, a state of a gearshift system of the electric bicycle 100 can also be considered an operating state. For example, the feedback signal can provide the rider with an indication of optimal shifting times. In particular, a signal for an upshift to be performed can be signaled by an increasing amplitude of the feedback signal. More preferably, a signal for a downshift to be performed can be signaled by a decreasing amplitude of the feedback signal.

[0046] Furthermore, navigation information and / or route information can be transmitted to the rider of the electric bicycle 100 by means of the feedback signals.

[0047] In detail, navigation instructions can be transmitted easily using the feedback signals, for example, without distracting the rider from the route and / or traffic. For example, a directional instruction can be generated by the haptic signal on the pedal 114 of the respective side of the electric bicycle 100. This means that, for example, when a right turn is approaching, the right pedal 114 in the direction of travel A can vibrate, while, for example, when a left turn is approaching, the left pedal 114 in the direction of travel A can vibrate.

[0048] The feedback signal can also be generated depending on the current pedal position, for example, if a direction instruction is signaled to the corresponding pedal 140 when the corresponding pedal 114 is essentially at bottom dead center or forward. This makes it easy to ensure that the feedback signal is clearly transmitted to the driver by increasing manual pedal pressure in this range.

[0049] Preferably, the angular range, in particular with respect to a pedal revolution, can also be adjusted, preferably depending on the distance to the upcoming change of direction. For example, the angular range in which the feedback signal is generated can be increased the closer the electric bicycle 100 is to the change of direction.

[0050] Furthermore, the feedback signal can be generated more frequently or less frequently, for example, at specific intervals relative to entire pedal revolutions. For example, if a change in direction is imminent, the feedback signal can be generated with every pedal revolution, whereas at greater intervals, the feedback signal can be generated only every other pedal revolution, or less frequently.

[0051] Further preferably, a riding experience for the rider of the electric bicycle 100 can be enhanced by targeted generation of a feedback signal, for example to convey a feeling of dynamism and sportiness, for example by specifically generating vibrations during acceleration processes.

[0052] Fig. 3 shows a simplified detailed view of the electric bicycle of the Fig. 1 according to a preferred first embodiment of the invention. Fig. Figure 3 shows a saddle 120 of the electric bicycle 100. In this preferred embodiment, the saddle 120 is designed such that it has two different vibration elements 121, which have different natural frequencies. The vibration elements 121 are formed by spring elements of the saddle 120, which are provided for damping.

[0053] The oscillation elements 121 are designed such that they experience vibration excitation through the targeted actuation of the drive unit 1 with the modulated actuation signal, thereby generating a haptic signal, preferably in the form of a vibration, as a feedback signal. Due to the different natural frequencies, the oscillation elements 121 can be easily and specifically excited independently of one another, so that only one of the two oscillation elements 121 generates the feedback signal at a time. This allows the driver to be easily and specifically provided with directional information, such as navigation instructions and / or hazard warnings, such as impending collisions, or the like.

[0054] Fig. 4 shows a simplified detailed view of the electric bicycle 100 of the Fig. 1 according to a preferred second embodiment of the invention, wherein Fig. 4 shows an alternative saddle 120 of the electric bicycle 100. The second development of the Fig. 4 essentially corresponds to the first training of the Fig. 3, with the difference of an alternative design of the vibration elements 121. In the second development of the Fig. 4, the saddle 120 can be designed, for example, as a gel saddle, wherein the vibration elements 121 are additionally provided components which are explicitly designed to excite vibration in order to be able to generate the feedback signal.

Claims

[1] Method for operating a drive unit (1) of an electric bicycle (100), - wherein the drive unit (1) is configured to generate a motor torque intended to drive the electric bicycle (100) in response to an actuation signal, and - wherein the actuation signal is modulated with a predetermined modulation signal such that the drive unit (1) generates a predetermined feedback signal perceptible by a rider of the electric bicycle (100) by means of the modulated actuation signal. [2] Method according to claim 1, wherein an acoustic signal is generated as the feedback signal. [3] Method according to claim 1 or 2, wherein a haptic signal, in particular a vibration, is generated as the feedback signal. [4] Method according to claim 3, wherein the haptic signal is perceptibly generated on at least one pedal (114) of the electric bicycle (100). [5] Method according to claim 3 or 4, wherein the haptic signal is perceptibly generated on a saddle (120) of the electric bicycle (100). [6] Method according to claim 5, wherein the haptic signal is generated by vibration excitation of one of two different vibration elements (120) arranged in the saddle (120), in particular wherein the two vibration elements (120) have different natural frequencies. [7] Method according to one of the preceding claims, - wherein various predetermined feedback signals are generated for conveying various information, and - where the different feedback signals differ in one or more of the following parameters: amplitude, frequency of the feedback signal, frequency of generation of the feedback signal, number of feedback signals generated. [8] Method according to one of the preceding claims, wherein the modulation signal comprises a sine wave and / or a sawtooth wave and / or a square wave and / or noise. [9] Method according to one of the preceding claims, further comprising the step: - Detection of a predetermined driving situation of the electric bicycle (100), - wherein the feedback signal is generated in response to the detection of the predetermined driving situation. [10] The method of claim 9, wherein the driving situation comprises: an accident and / or a vehicle condition and / or a driving situation and / or an environmental condition and / or an impending collision. [11] Method according to one of claims 7 or 10, wherein an intensity of the feedback signal is adjusted depending on the detected predetermined driving situation. [12] Method according to one of the preceding claims, wherein the feedback signal represents a warning message and / or a notice message and / or an error message and / or navigation information and / or route information and / or training information. [13] Method according to one of the preceding claims, wherein the feedback signal is generated such that no resulting change in the engine torque occurs at least within a predetermined period of time. [14] Method according to one of the preceding claims, wherein the feedback signal is generated by operating the drive unit (1) in the radial direction and / or in the tangential direction. [15] Drive arrangement of an electric bicycle (100), comprising: - a drive unit (1), and - a control unit (105) which is configured to actuate the drive unit (1) with an actuation signal and which is configured to carry out the method according to one of the preceding claims. [16] An electric bicycle comprising a drive assembly (110) according to claim 15.

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