DE102021206313A1 - Method for determining a driving speed of a bicycle and sensor arrangement - Google Patents

Abstract

The invention relates to a method for determining a driving speed of a bicycle, in particular a pedelec, e-bike or the like, comprising the steps of - determining a first driving speed of the bicycle based on a first speed signal, - determining a second driving speed of the bicycle based on a second speed signal, the the first and the second speed signal are provided by different sensors, - determining a comparison of the two determined driving speeds, - using the comparison to determine whether there is a fault in one of the sensors, and/or, determining slip for a wheel of the bicycle using the comparison.

Description

State of the art

The invention relates to a method for determining a driving speed of a bicycle, in particular a pedelec, e-bike or the like.

The invention further relates to a sensor arrangement for a bicycle.

The invention further relates to a bicycle.

Although applicable to any bicycles such as motorcycles, eBikes and pedelecs, the present invention is explained with reference to eBikes.

A current speed of a bicycle is determined in a known manner using a magnetic measuring principle. Here, a magnet is located, for example, on a spoke or in the casing of the rear wheel. With a Hall sensor or another magnetic field sensor that can detect the magnetic field of the magnet, the revolutions of the wheel are measured by means of the magnet. A pulse is provided each time the magnet passes the magnetic field sensor. The speed of the eBike can be estimated using the time interval between two consecutive pulses and the known wheel circumference. This estimate should be accurate, as a drive may only support the eBike rider up to a maximum speed. However, external magnetic fields, for example magnetized bridges, the overhead lines of trams, etc., can cause this sensor to malfunction, which means that a reliable estimate of the speed is no longer possible for a short time, so that the driver support must be deactivated at least for a short time.

Disclosure of Invention

• - Ermitteln einer ersten Fahrgeschwindigkeit des Fahrrads basierend auf einem ersten Geschwindigkeitssignal,
• - Ermitteln einer zweiten Fahrgeschwindigkeit des Fahrrads basierend auf einem zweiten Geschwindigkeitssignal, wobei das erste und das zweite Geschwindigkeitssignal von unterschiedlichen Sensoren bereitgestellt werden,
• - Ermitteln eines Vergleichs der beiden ermittelten Fahrgeschwindigkeiten,
• - Ermitteln anhand des Vergleichs, ob eine Störung eines der Sensoren vorliegt, und/oder, Ermitteln eines Schlupfs für ein Rad des Fahrrads anhand des Vergleichs.

In one embodiment, the present invention provides a method for determining a driving speed of a bicycle, in particular a pedelec, e-bike
or the like, comprising the steps

• - determining a first driving speed of the bicycle based on a first speed signal,
• - determining a second driving speed of the bicycle based on a second speed signal, the first and the second speed signal being provided by different sensors,
• - Determine a comparison of the two determined driving speeds,
• - Determining on the basis of the comparison whether there is a fault in one of the sensors, and/or determining slip for a wheel of the bicycle on the basis of the comparison.

In another embodiment, the present invention provides a sensor assembly for a bicycle, comprising
a first sensor for providing a first speed signal for the driving speed of the bicycle,
a second sensor for providing a second speed signal for the driving speed of the bicycle,
a determination device which is designed to determine a first driving speed of the bicycle based on a first speed signal and to determine a second driving speed of the bicycle based on a second speed signal, and
a fault device, designed to determine a comparison of the two determined driving speeds and to determine based on the comparison whether there is a fault in one of the sensors and/or to determine slip for a wheel of the bicycle based on the comparison.

In a further embodiment the present invention provides a bicycle having a sensor arrangement according to any one of claims 12-14.

One of the advantages achieved in this way is that, on the one hand, the driving speed can be determined extremely reliably and, on the other hand, reliable and safe operation of the bicycle is made possible.

The term "fault" is to be understood in the broadest sense and refers in particular in the claims, preferably in the description, to any improper condition, in particular operating condition, assembly position, etc. of a device for providing a signal or the like. A "fault" is in particular any external undesired effect on the sensor that leads to a change in the state, position, signals of the sensor or the like.

Other features, advantages, and other embodiments of the invention are described below or will become apparent thereby.

According to an advantageous development of the invention, in the event of a fault in one of the sensors, the signal from the other of the two sensors is used to determine the driving speed or no signal is used. The advantage of this is that either a reliable signal is used to determine the speed or no signal is used.

According to a further advantageous development of the invention, the slip is only determined if there is no fault. This saves computing resources and the slip is only determined if it can be reliably determined at all. It is also possible in a further embodiment that the slip is always determined, but the results are discarded and/or are imprecise in the event of a fault.

According to a further advantageous development of the invention, one of the two sensors, in particular the first sensor, provides a speed signal based on a rotating element of the bicycle, with a rotation of the rotating element correlating at least indirectly with the driving speed, in particular with the rotating element in the form of a Wheel of the bicycle is provided. The driving speed can thus be determined in a direct and reliable manner using a rotating element which correlates with the speed, in particular using a wheel which is in frictional contact with the ground.

According to a further advantageous development of the invention, the first sensor is provided in the form of a reed sensor. The advantage of this is the provision of an inexpensive, accurate and reliable speed signal transmitter.

According to a further advantageous development of the invention, drive slip or brake slip is determined when slip is determined. The advantage of this is an exact determination of the slip.

According to a further advantageous development of the invention, if drive slip is determined, an existing driver drive support for the bicycle is at least lowered or switched off and/or if brake slip is determined, an exerted braking effect is lowered. In this way, safety when operating the bicycle can be improved.

According to a further advantageous development of the invention, the second sensor provides the second speed signal based on a detection of at least one non-bicycle object, in particular the second sensor being designed as a sensor sensing the surroundings, preferably as a radar, lidar and/or ultrasonic sensor. The advantage of this is a separate and therefore independent detection of the driving speed, without having to use other components that correspond to the driving speed of the bicycle. The radar, in particular designed with multiple channels, or lidar can resolve angles in at least one dimension, preferably in two dimensions, such as azimuth and elevation, which ultimately enables the vehicle speed to be determined or improves the accuracy of the vehicle speed determination. According to a further advantageous development of the invention, the second sensor can sense in a direction rotated by at least 90 degrees to the direction of movement of the bicycle, in particular by 180 degrees. The advantage of this is that it senses perpendicularly or against the direction of travel of the bicycle, which improves the determination of the driving speed. In principle, any other defined angle other than 90 degrees or 180 degrees is also conceivable as the sensing direction for the second sensor.

• - Ermitteln einer Häufigkeitsverteilung von ermittelten, zweiten Fahrgeschwindigkeiten, und
• - Auswählen derjenigen zweiten Fahrgeschwindigkeit mit der größten Häufigkeit in der Häufigkeitsverteilung.

According to a further advantageous development of the invention, the following steps are carried out when determining the second driving speed:

• - Determining a frequency distribution of determined, second driving speeds, and
• - Selecting that second driving speed with the greatest frequency in the frequency distribution.

In other words, hypotheses for the speed of the bicycle that are derived in particular from the environment are set up in detail, and that hypothesis which occurs most frequently is selected as the second driving speed. The advantage of this is a reliable determination of the driving speed of the bicycle.

According to a further advantageous development of the invention, the determined frequency distribution is smoothed, in particular by means of a moving average. The advantage of this is that a more robust detection of the driving speed is made possible.

According to a further advantageous development, when selecting, a mean value, in particular the geometric mean, of determined second driving speeds is formed in a definable interval around the driving speed with the greatest frequency and this is defined as the selected second driving speed. The advantage of this is a more robust detection of the driving speed and an increase in the accuracy when determining the driving speed of the bicycle. In other words, a definable interval around the found maximum in the frequency distribution is considered here, for example, and this interval, in particular, the geometric mean of the driving speeds determined in the interval is formed. The mean value determined in this way, in particular the geometric mean, now corresponds to the interpolated speed in this interval, which can improve the overall accuracy of the determination of the driving speed.

According to a further advantageous development of the invention, misalignment of at least one speed signal generator, comprising one of the two sensors, is detected on the basis of the comparison. The reliability in the detection or determination of the driving speed and in the operation of the bicycle can thus be further improved. The term "misalignment" is to be understood, in particular in the claims, preferably in the description, as any intentional or unintentional deviation in the configuration of a speed signal transmitter, comprising a signal transmitter, for example a rotating element such as a wheel and a sensor, in particular the alignment, position , connections, etc.

According to a further advantageous development of the sensor arrangement, the first sensor comprises a reed sensor and/or the second sensor comprises a sensor that senses the surroundings, preferably a radar, lidar and/or ultrasonic sensor. The advantage of this is a simple, inexpensive, separate and therefore independent detection of the driving speed.

According to a further advantageous development of the sensor arrangement, a switching device is arranged which, in the event of a fault in one of the two speed signals, in particular in the event of a fault in one of the sensors, switches over to the undisturbed speed signal for further processing of the driving speed signal. The advantage of this is a reliable provision of speed signals for determining the driving speed.

Further important features and advantages of the invention result from the dependent claims, from the drawings and from the associated description of the figures based on the drawings.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

Preferred designs and embodiments of the invention are shown in the drawings and are explained in more detail in the following description, with the same reference symbols referring to identical or similar or functionally identical components or elements.

• 1 Schritte eines Verfahrens gemäß einer Ausführungsform der vorliegenden Erfindung;
• 2 ein Fahrrad gemäß einer Ausführungsform der vorliegenden Erfindung;
• 3 ein Geschwindigkeitshistogramm, ermittelt mit einem Verfahren gemäß einer Ausführungsform der vorliegenden Erfindung;
• 4 ein Puls-Folgen-Signal über die Zeit mit einer Störung eines Reed-Sensors; und
• 5 eine Skizze einer Projektion der gemessenen radialen Geschwindigkeiten auf eine Geschwindigkeit parallel zur Fahrtrichtung gemäß einer Ausführungsform der vorliegenden Erfindung.

while showing

• 1 steps of a method according to an embodiment of the present invention;
• 2 a bicycle according to an embodiment of the present invention;
• 3 a speed histogram determined with a method according to an embodiment of the present invention;
• 4 a pulse train signal over time with a disturbance of a reed sensor; and
• 5 a sketch of a projection of the measured radial speeds on a speed parallel to the direction of travel according to an embodiment of the present invention.

1 shows steps of a method according to an embodiment of the present invention.

In 1 steps of a method for determining a driving speed of a bicycle, in particular a pedelec, e-bike or the like are shown in schematic form.

• - Ermitteln S1 einer ersten Fahrgeschwindigkeit des Fahrrads basierend auf einem ersten Geschwindigkeitssignal,
• - Ermitteln S2 einer zweiten Fahrgeschwindigkeit des Fahrrads basierend auf einem zweiten Geschwindigkeitssignal, wobei das erste und das zweite Geschwindigkeitssignal von unterschiedlichen Sensoren bereitgestellt werden,
• - Ermitteln S3 eines Vergleichs der beiden ermittelten Fahrgeschwindigkeiten,
• - Ermitteln S4 anhand des Vergleichs ob eine Störung eines der Sensoren vorliegt und/oder, Ermitteln S4b eines Schlupfs für ein Rad des Fahrrads anhand des Vergleichs.

The procedure includes the following steps

• - determining S1 a first driving speed of the bicycle based on a first speed signal,
• - determining S2 a second driving speed of the bicycle based on a second speed signal, the first and the second speed signal being provided by different sensors,
• - Determining S3 a comparison of the two determined driving speeds,
• - Determine S4 on the basis of the comparison whether there is a fault in one of the sensors and/or determine S4b a slip for a wheel of the bicycle on the basis of the comparison.

2 shows in schematic form a bicycle according to an embodiment of the present invention and 5 a sketch of a projection of the measured radial speeds on a speed parallel to the direction of travel according to an embodiment of the present invention.
In 2 a bicycle 1 is shown. The bicycle 1 includes a front wheel 2a and a rear wheel 2b. The rear wheel 2b is connected to a motor via a chain 3 with a drive device 4 and can be driven by means of the drive device 4 . A reed sensor 9 is arranged on the frame of the bicycle, together with a magnet in the rear wheel 2b acts to measure the number of revolutions of the rear wheel 2b. On the frame of the bicycle 1, above the rear wheel 2b, there is also a luggage rack 5, at the rear end of which a radar sensor 6 is arranged, which is oriented to the rear. The main radiation direction of the radar therefore points backwards, parallel to the longitudinal axis of the bicycle. The radar measures the vehicle speed based on the assumption that the vast majority of reflections in the radar image are caused by static targets. With the help of the elevation and azimuth angle estimation, the measured radial speeds v_rad of the detected radar targets can be projected onto a speed v_rel parallel to the direction of travel of the eBike, which is described in more detail below. The radar is preferably a multi-channel radar that can preferably resolve angles in azimuth and elevation. Accordingly, the radar provides at least the following measured values for all reflections in the radar image recorded: distance r, radial speed v_rad, angle in azimuth θ, angle in elevation φ. With a rearward orientation parallel to the longitudinal axis of the bicycle, only the measured speeds under 0° azimuth angle and 0° elevation angle correspond to the actual relative speeds v_rel. The measured velocities of the targets v_rad at other angles are projected onto v_rel by projection and the following formula (see 5 ). $$v_{\mathrm{right}el}=\frac{{\upsilon }_{\mathrm{right}a\mathrm{i.e}}}{\text{cos}\left(\theta \right)}$$

This projection can preferably also be calculated in elevation. In the absence of an elevation estimate, only targets at a greater distance r are used for estimating the airspeed, since in this case the elevation estimate only plays a negligible role in the projection and thus only causes a very small systematic error. A narrow radiation characteristic of the radar antennas in elevation supports the estimation, since the targets are suppressed more strongly at a larger elevation angle. By creating a histogram for all measured speeds and selecting the most frequently occurring, discrete speed, the eBike's own speed can also be determined using the radar. This is in the following 3 shown. The bicycle 1 includes a determination device 7, which is designed with the two sensors 6, 9 for determining a first and a second driving speed of the bicycle based on the speed signals provided by the two sensors 6, 9. In addition, a fault device 8 is arranged, which compares the two travel speeds determined and, based on the comparison, determines whether there is a fault in one of the sensors 6, 9 and/or determines whether a wheel 2a, 2b of the bicycle 1 is slipping.

3 shows a speed histogram determined with a method according to an embodiment of the present invention.

1. 1. Glättung des Histogramms (siehe 3 unten). Damit steht eine robustere Basis für die Ermittlung des Geschwindigkeitswerts mit der höchsten Anzahl an Ergebnissen, das heißt der gemessenen, diskreten Geschwindigkeiten, bereit.
2. 2. Mittelwertbildung. Hierbei wird zunächst das Maximum im Histogramm ermittelt, Nachbar-Bins in einem vorgebbaren Intervall miteinbezogen, die Geschwindigkeiten der jeweiligen Bins ermittelt und dann das geometrische Mittel der zugrundeliegenden Geschwindigkeiten gebildet. Damit ist eine Extrapolation einer Geschwindigkeit zwischen den diskreten Geschwindigkeits-Bins möglich, was wiederum eine erhöhte Genauigkeit bei der Ermittlung der Geschwindigkeit ermöglicht.

In 3 a histogram of the determined speeds is shown. The speed associated with the bin that accumulates the most radar blips is taken as the bike's current speed. The speed estimation can be further improved by the following approaches:

1. 1. Smoothing of the histogram (see 3 below). This provides a more robust basis for determining the speed value with the highest number of results, i.e. the measured, discrete speeds.
2. 2. Averaging. In this case, the maximum in the histogram is first determined, neighboring bins are included in a predeterminable interval, the speeds of the respective bins are determined and then the geometric mean of the speeds on which they are based is formed. This allows a speed to be extrapolated between the discrete speed bins, which in turn enables increased accuracy when determining the speed.

This means that the bike's own speed can be determined independently of the usual, for example, magnetic field-based speed measurement in the eBike.

In addition to the radar-based determination of the speed, the current speed of the bicycle can be determined using the well-known Hall sensor method using a magnetic measuring principle. A magnet is located, for example, on a spoke or in the casing of the rear wheel. The revolutions of the wheel and thus of the magnet are measured with a Hall sensor or another sensor that detects the magnetic field. A pulse is generated every time the magnet passes the sensor. The speed of the eBike can be estimated from the time between two consecutive pulses and the known wheel circumference.

If there is a fault in the magnetic field sensor, a lot of power can be seen in the measuring signal of this sensor for a short time. In this way, a fault in the magnetic field sensor can be eliminated in a simple manner to be determined. In this case, the detection of the pulses would not give a reasonable estimate of the speed. An exemplary noisy pulse train signal - strength of the detected magnetic field 101 over time 100 - is shown below 4 shown.

4 shows a pulse train signal over time with a disturbance of a reed sensor.

The own speed determined by means of a radar sensor can be used for the disturbed area 102 in order to nevertheless make a statement about the own speed. The disrupted measurement period 102 can thus be bridged. Alternatively, the comparison of the two estimated speeds - via the reed sensor on the one hand and the radar sensor on the other - is used to conclude that the radar sensor has been misadjusted in the event of a discrepancy, which would severely impair its other functionality and must therefore be reliably detected in a timely manner. Recognizing the misalignment avoids incorrect speeds being estimated. A possible maladjustment can then be checked as long as the magnetic signal is not disturbed.

If both types of speed measurement - using a reed sensor on the one hand and radar sensor on the other hand - work properly, the two speeds are within a defined tolerance range of each other. Accordingly, if, for example, a fault monitoring device that monitors the eBike's internal speed measurement does not report a fault, the radar's speed estimate must be within the tolerance range of the magnetic field-based speed estimate.

As soon as the speed estimate or determination leaves the tolerance range of the magnet-based speed estimate in this error-free operating mode, it is assumed that the radar sensor is misaligned. The projection of the radial speeds v_rad onto v_rel then supplies incorrect values for v_rel and the fault monitoring device can transmit a corresponding signal to the output unit of the eBike and indicate the misalignment of the radar sensor.

In cases in which the comparison suggests either a fault or slip, a control unit, the fault device or another device using suitable software, in particular algorithms and/or using suitable additional sensors, can make a case decision between either the existence of slip or the existence of a "fault".

To determine the slip, the speed determined by radar is converted into a setpoint speed ω ₀ using the known wheel circumference. The magnetic field sensor supplies the actual speed ω.

From this, the functional unit can determine the slip using the following formula: $$S=\frac{\omega -{\mathrm{<figure-callout\; id="0"\; label="\omega "\; filenames="DE102021206313A1\_0004.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_0}{{\mathrm{<figure-callout\; id="0"\; label="\omega "\; filenames="DE102021206313A1\_0004.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_0}$$

In the case of braking slip, the sign of the slip S is negative, in the case of acceleration slip it is positive.

If drive slip is now detected, the fault device 8 or another computing device can provide a corresponding signal, for example.

If drive slip is present, a check is first made, for example using a power detector, to determine whether or not the speed threshold defined for normal operation of the wheel speed Hall sensor has been exceeded. If this is not the case - no fault - a functional unit calculates the theoretical wheel speed that should be available based on the radar's own speed estimate and quantifies the slip based on the theoretical wheel speed and the wheel speed actually measured with the wheel speed Hall sensor.

In the event of acceleration slip, the speed determined by the wheel speed Hall sensor preferably leaves the tolerance interval upwards, that is to say the acceleration slip exceeds a limit value. The functional unit then reports the detected slip to downstream systems such as output and warning peripherals or to downstream functional units, preferably to an ESP system, which can reduce the motor support based on the information. Furthermore, the detected slip in connection with the yaw and roll rate information from an IMU (inertial measurement unit) can be forwarded by a downstream functional unit for predicting falls, for detecting or preventing a fall.

If brake slip is present, a check is first made, for example by a power detector, to determine whether or not the speed threshold defined for normal operation of the wheel speed Hall sensor has been exceeded. If this is not the case - no error case - calculates a radio tion unit calculates the theoretical wheel speed that should be available based on the radar's own speed estimate and quantifies the slip based on the theoretical wheel speed and the wheel speed actually measured with the wheel speed Hall sensor. The wheel speed measured by the wheel speed Hall sensor leaves a certain tolerance range around the target speed calculated by the radar.

In the event of brake slip, the speed determined by the wheel speed Hall sensor preferably leaves the tolerance interval downwards, that is to say the brake slip falls below a predetermined speed limit value. The speed actually measured by the radar sensor is transmitted to the overall operating system of the bike in order to display the actual speed and not the speed falsified by brake slip even during braking phases. The quantified slip can be passed on to an ABS system, for example, which releases the brakes briefly when a certain brake slip is exceeded in order to achieve maximum braking effect.

• - Bei einer Verwendung des Radars ausschließlich für die Schlupferkennung, zum Beispiel ausgeführt als Speed-over-Ground-Sensor, können Parametrisierungen implementiert werden, die die Messzeit deutlich verkürzen und damit die Update-Rate der Geschwindigkeitsmessung erhöht.
• - Zwei-Wege Bestimmung der Geschwindigkeit.
• - Zuverlässigere Geschwindigkeitsermittlung des Fahrrads.
• - Verbesserte Nutzererfahrung.
• - Erkennung einer Dejustage von Sensoren..

In summary, at least one of the following features and/or at least one of the following advantages can be provided by at least one embodiment:

• - When using the radar exclusively for slip detection, for example designed as a speed-over-ground sensor, parameterizations can be implemented that significantly reduce the measurement time and thus increase the update rate of the speed measurement.
• - Two-way speed determination.
• - More reliable bike speed detection.
• - Improved user experience.
• - Detection of misalignment of sensors..

Although the present invention has been described on the basis of preferred exemplary embodiments, it is not limited thereto but can be modified in many different ways.

Claims (15)

Method for determining a driving speed of a bicycle (1), in particular a pedelec, e-bike or the like, comprising the steps - Determining (S1) a first driving speed of the bicycle (1) based on a first speed signal, - determining (S2) a second driving speed of the bicycle (1) based on a second speed signal, the first and the second speed signal being provided by different sensors (6, 9), - Determining (S3) a comparison of the two determined driving speeds, - Determine (S4) based on the comparison whether there is a fault in one of the sensors (6, 9). and or Determining (S4b) a slip for a wheel (2a, 2b) of the bicycle (1) based on the comparison. procedure according to claim 1 In the event of a fault in one of the sensors (6, 9), the signal from the other of the two sensors (6, 9) is used to determine the driving speed, or no signal is used. Method according to one of Claims 1 - 2 , whereby the slip is only determined if there is no fault. Method according to one of Claims 1 - 3 , wherein one of the two sensors, in particular the first sensor (9), provides a speed signal based on a rotating element of the bicycle (1), wherein a rotation of the rotating element correlates at least indirectly with the driving speed, in particular wherein the rotating element is in the form of a Wheel (2a, 2b) of the bicycle (1) is formed. procedure according to claim 4 , wherein the first sensor (9) is designed in the form of a reed sensor. Method according to one of Claims 1 - 5 , wherein when determining (S4b) the slip, a drive slip or brake slip is determined. procedure according to claim 6 , wherein, if drive slip is determined, an existing driver drive support (4) for the bicycle (1) is at least lowered or switched off and/or, if brake slip is determined, an applied braking effect is lowered. Method according to one of Claims 1 - 7 , wherein the second (6) of the at least two sensors (6, 9) provides the second speed signal based on the detection of at least one non-bicycle object, in particular wherein the second sensor (6) is designed as a sensor that senses the surroundings, preferably as a radar , lidar and/or ultrasonic sensor. Method according to one of Claims 1 - 8th , wherein the following steps are carried out when determining the second driving speed: - determining a frequency distribution of determine th, second driving speeds, and - selecting that second driving speed with the greatest frequency in the frequency distribution. procedure according to claim 9 , wherein the determined frequency distribution is smoothed, in particular by means of moving average formation and/or wherein, when selecting, a mean value, in particular the geometric mean, of determined, second driving speeds is formed in a definable interval around the driving speed with the greatest frequency and this as the selected second driving speed is determined. Method according to one of Claims 1 - 10 , wherein a misalignment of at least one speed signal transmitter, comprising one of the two sensors (6, 9), is detected on the basis of the comparison. Sensor arrangement for a bicycle (1), comprising a first sensor (9) for providing a first speed signal for the driving speed of the bicycle (1), a second sensor (6) for providing a second speed signal for the driving speed of the bicycle (1), a determination device (7) which is designed to determine a first driving speed of the bicycle based on a first speed signal and to determine a second driving speed of the bicycle (1) based on a second speed signal, and a fault device (8) designed to determine a comparison of the two determined driving speeds and to determine based on the comparison whether there is a fault in one of the sensors (6, 9) and/or to determine slip for a wheel of the bicycle based on the comparison. Sensor arrangement according to claim 12 , wherein the first sensor (9) comprises a reed sensor and/or the second sensor (6) comprises a sensor that senses the surroundings, preferably a radar, lidar and/or ultrasonic sensor. Sensor arrangement according to one of Claims 12 - 13 , wherein a switching device is arranged, which switches over to the undisturbed speed signal for further processing of the driving speed signal in the event of a fault in one of the two speed signals, in particular in the event of a fault in one of the sensors (6, 9). Bicycle (1) with a sensor arrangement according to one of Claims 12 - 14 .

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