DE102019214616B4 - Device and method for driving a drive wheel of a bicycle - Google Patents

Abstract

Device (12) for driving a stationary wheel (68) of a bicycle (30), comprising:a first input interface (14) for receiving sensor data from a wheel sensor (20) for detecting the movement of a wheel (68) of the bicycle (30); a second input interface (16) for receiving sensor data from a motion sensor (22) for detecting the movement of the bicycle (30), the motion sensor (22) being an optical sensor or a position determination sensor; a processing unit (19) for evaluating the sensor data of the wheel sensor (20) and the motion sensor (22) and detecting the standstill of the wheel (68) despite movement of the bicycle (30) and for generating a control signal for an actuator (24) to enable the wheel (68) to move; an output interface (18) for outputting the control signal to the actuator (24) to move the wheel (68).

Description

The present invention relates to a device and a system for driving a stationary wheel of a bicycle, a bicycle and a method.

In the area of road traffic, safety, especially for cyclists, is playing an increasing role. The number of road users and especially cyclists is constantly increasing, resulting in a high density of road users on the existing traffic routes. The high traffic density leads to critical driving situations that require the bike to slow down significantly. For example, it may be necessary to react and suddenly brake sharply to a pedestrian suddenly stepping onto the road or to a turning vehicle whose driver has overlooked a cyclist moving in the blind spot.

Modern bicycles, especially electric bicycles, e-bikes and pedelecs, have safety components to make riding safer in general and in road traffic in particular. A safety component includes the anti-lock braking system (ABS), which high-quality bicycles are often equipped with. The ABS system prevents a wheel from locking, so that the bike can be steered even under heavy braking. This is particularly true on unpaved surfaces, such as a gravel path or a forest path, or on slippery surfaces, such as icy surfaces.

Despite the use of ABS systems, critical situations still arise because the bike reacts differently than expected when braking. The braked wheel blocks and stands still. Especially on slippery or icy surfaces and at low temperatures, the wheel can come to a standstill despite the ABS system, resulting in slipping and unstable situations.

EP 3 219 598 A1 shows a driving support system for an electric bicycle that can be driven with muscle power and/or motor power and has at least one wheel and a controllable electric generator-motor unit. The generator-motor unit can be mounted on or in the area of a hub of the wheel and can be coupled to the wheel in such a way that the rotation of the wheel can be influenced by braking and / or acceleration.

It is therefore the object of the present invention, based on the prior art, to create a bicycle in which stable driving behavior can be achieved even on very slippery surfaces and prolonged locking of the wheel can be prevented. This task is solved by means of the objects with the features of the independent patent claims. Advantageous further training and refinements can be found in the subclaims.

• einer ersten Eingangsschnittstelle zum Empfangen von Sensordaten eines Radsensors zum Erkennen der Bewegung eines Rads des Fahrrads;
• einer zweiten Eingangsschnittstelle zum Empfangen von Sensordaten eines Bewegungssensors zum Erkennen der Bewegung des Fahrrads, wobei der Bewegungssensor ein optischer Sensor oder ein Positionsbestimmungssensor ist;
• einer Verarbeitungseinheit zum Auswerten der Sensordaten des Radsensors und des Bewegungssensors und Erkennen des Stillstands des Rads trotz Bewegung des Fahrrads und zum Erzeugen eines Ansteuersignals für einen Aktor, um ein Bewegen des Rads zu ermöglichen;
• einer Ausgangsschnittstelle zum Ausgeben des Ansteuersignals an den Aktor, um ein Bewegen des Rads auszuführen.

The present invention relates, in a first aspect, to a device for driving a stationary wheel of a bicycle, with:

• a first input interface for receiving sensor data from a wheel sensor for detecting movement of a wheel of the bicycle;
• a second input interface for receiving sensor data from a motion sensor for detecting motion of the bicycle, the motion sensor being an optical sensor or a positioning sensor;
• a processing unit for evaluating the sensor data of the wheel sensor and the motion sensor and detecting the standstill of the wheel despite movement of the bicycle and for generating a control signal for an actuator in order to enable the wheel to move;
• an output interface for outputting the control signal to the actuator to move the wheel.

• einer Vorrichtung für ein Fahrrad nach einem der vorhergehenden Ansprüche;
• einem Radsensor für ein Rad;
• einem Bewegungssensor zum Erkennen der Bewegung des Fahrrads, wobei der Bewegungssensor ein optischer Sensor oder ein Positionsbestimmungssensor ist; und einem Aktor zum Antreiben des Rads.

In a further aspect, the present invention relates to a system for driving a stationary wheel of a bicycle, comprising:

• a device for a bicycle according to one of the preceding claims;
• a wheel sensor for a wheel;
• a motion sensor for detecting movement of the bicycle, the motion sensor being an optical sensor or a positioning sensor; and an actuator to drive the wheel.

In a further aspect, the present invention relates to a bicycle with a system having the above-mentioned features.

Further aspects of the invention relate to a corresponding method. Additionally, a computer program product having program code for performing the steps of the method, when the program code is executed on a computer, can carry out the method. A storage medium on which a computer program is stored can, when executed on a computer, effect execution of the method described herein.

Preferred embodiments of the invention are described in the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or alone, without departing from the scope of the present invention. In particular, the method and the computer program product can be designed in accordance with the configurations described for the device and the method in the dependent claims.

According to the invention it is provided that the movement of a wheel of the bicycle is detected by means of a wheel sensor. The measured sensor data is received by a first interface of the device according to the invention. In particular, it is recognized that the wheel of the bicycle is stationary. The movement of the bicycle is detected using a motion sensor, with the sensor data from the motion sensor being received by the device via a second interface. In a processing unit, the standstill of the wheel is detected despite the bike moving. This can happen, for example, after releasing the brake on the bicycle if the bearing forces of the wheel are greater than the coefficient of friction that the wheel or tire brings to the road or surface. In this case, a stationary wheel will not start rotating again. So the bike slides overall. Simply releasing the brake is not enough to initiate further rolling of the wheel. Therefore, according to the invention, when the standstill of the wheel is detected despite the movement of the bicycle, a control signal is generated for an actuator that enables the wheel to move. This control signal is transferred to the actuator via an output interface in order to drive the wheel electrically or mechanically. This means that the wheel can be prevented from slipping and thus the wheel breaking away or slipping away, especially when braking with an ABS system.

The actuator for driving the wheel to enable the wheel to start rolling again is preferably arranged directly on the wheel. For example, in a preferred embodiment, the actuator can be a motor. This can be a small engine that needs to produce very little power. In an electric bicycle, this motor can be provided in addition to the drive motor.

In a particularly preferred embodiment, in an electric bicycle, the actuator is the drive motor of the bicycle, which receives a control command from the device according to the invention in order to drive the drive wheel again if it is stationary or blocked even though the bicycle is moving. This can be done directly by the motor if it is installed directly on the wheel (rear wheel or front wheel) of the bicycle. With a mid-engine in the bottom bracket of the bicycle, the drive takes place via the bicycle chain or the bicycle timing belt.

In order to initiate the actuator to drive the stationary wheel, a movement of the bicycle must also be detected in addition to detecting that the wheel is stationary. In a special embodiment, the motion sensor is an optical sensor. This can be, for example, a camera, a radar sensor, a lidar sensor or an ultrasonic sensor. It is also possible to use a positioning sensor, for example a GPS sensor. A change in the position of the bicycle is detected by the sensor, which is interpreted as a movement.

For example, it is conceivable to use the camera in a cell phone when it is mounted on a bicycle. The camera data could then be transmitted to the device according to the invention, for example wirelessly. The same applies to using the GPS sensor in a cell phone.

In a preferred embodiment, the motion sensor can be a wheel sensor that is arranged on the second wheel of the bicycle. For example, the speed of the bicycle can be measured via the wheel rotation. In this case, the motion sensor can be, for example, a Hall sensor, a magnetic sensor or a simple light barrier. This embodiment is significantly cheaper than using a camera.

In a likewise preferred embodiment, the motion sensor can be an accelerometer that is installed on the bicycle. Alternatively, the motion sensor can be a (classic) speed sensor mounted redundantly on the bicycle, which could be arranged on the front wheel or on the rear wheel.

In a preferred embodiment of the invention, the device has a third sensor in order to detect that the wheel monitored by the wheel sensor is not being braked intentionally. For example, the third sensor can be a status sensor of a brake, which allows a statement to be made as to whether braking is taking place. The monitored wheel will only be driven again if the brake is not applied. Alternatively and also preferably, the third sensor can be an ABS sensor of an ABS system (anti-lock braking system). The ABS sensor provides information about whether the bicycle is being braked by the ABS system. Only when the brake is released and no braking intervention occurs is the control signal generated and/or transmitted to the actuator.

Monitoring the movement of the wheel using the wheel sensor and receiving the sensor data usually takes place cyclically. The query cycle is a few milliseconds, preferably less than 100 ms. The cycle time of the query cycle is particularly preferred in the range from 10 ms to 50 ms. The motion sensor and the third sensor can be queried with similar or the same cycle times as the wheel sensor. This makes it possible to intervene quickly, so that even when the wheel being monitored comes to a standstill, the system reacts quickly, preventing the wheel from slipping or breaking away.

In a preferred embodiment of the invention, the control signal for the actuator is time-limited. The control signal is preferably present at the actuator for a time between 50 ms and 500 ms. A time of 100 ms to 250 ms is particularly preferred. The time in which a force acts on the actuator is particularly preferably between 100 ms and 150 ms.

In a preferred embodiment of the invention, the level of the control signal is increased if the wheel cannot be restarted and rolled again by a first control signal. For example, the signal level can be increased as time progresses. Particularly preferably, the control signal is a ramp-shaped signal, with the heights of the individual ramps very preferably having the same value, particularly preferably also the same length. In a likewise preferred variant, the signal level of the control signal can asymptotically approach a predetermined maximum value. This maximum value usually corresponds to a fraction of the maximum possible control level for the motor, especially if the motor is the drive motor of an electric bicycle.

In a preferred embodiment, the drive motor is controlled in such a way that the transmitted force, at least when the motor is activated for the first time, is less than 20% of the maximum force of the motor, preferably at most 10% of the total force.

In practice, values that achieve a force of 0.1 Nm to 10 Nm have proven to be sufficient and positive. In particular, the lower values of this range are initially started, since the control signal is only intended to cause the wheel to start again, but acceleration of the bicycle is to be avoided. It has also proven in practice that the force is not so great that the bike has a noticeable thrust. A non-noticeable restart of the stationary wheel is perceived as very comfortable. In addition to driving comfort, safety is also increased, as a noticeable or noticeable acceleration of the bicycle could frighten the cyclist.

• 1 eine schematische Darstellung eines Systems gemäß einem Aspekt der vorliegenden Erfindung;
• 2 eine schematische Darstellung eines Elektrofahrrads gemäß einem weiteren Aspekt der vorliegenden Erfindung;
• 3 eine schematische Darstellung eines Elektrofahrrads gemäß einem anderen Aspekt der vorliegenden Erfindung; und
• 4 eine schematische Darstellung eines Elektrofahrrads gemäß einem anderen Aspekt der vorliegenden Erfindung.

The invention is described and explained in more detail below using a few selected exemplary embodiments in connection with the accompanying drawings. Show it:

• 1 a schematic representation of a system according to an aspect of the present invention;
• 2 a schematic representation of an electric bicycle according to a further aspect of the present invention;
• 3 a schematic representation of an electric bicycle according to another aspect of the present invention; and
• 4 a schematic representation of an electric bicycle according to another aspect of the present invention.

1 shows a schematic representation of a system 10 for driving a stationary wheel of a bicycle with a device 12 which has a first input interface 14, a second input interface 16, an output interface 18 and a processing unit 19 for receiving data received via the first and second input interfaces 14, 16 Process sensor data. The system 10 further includes a wheel sensor 20 connected to the first input interface 14 and a motion sensor 22 connected to the second input interface 16. The two sensors 20, 22 transmit sensor data to the system 10, the wheel sensor 20 being used to monitor a wheel of a bicycle and in particular being able to detect when the wheel is at a standstill. The motion sensor 22 is used to detect the movement of the bicycle. The sensor data is preferably transmitted wirelessly to the input interfaces.

The system 10 further includes an actuator 24 which is connected to the output interface 18 of the device 12. The control signals for the actuator 24 determined in the processing unit 19 are transmitted via the output interface 18 to the actuator 24, which is preferably a motor.

The 2 until 4 each show a bicycle 30 in the form of an electric bicycle 32, each of which is equipped with the system 10 according to the invention. Each of the electric bicycles 32 has a rechargeable battery 66 (battery) to supply the respective electric motor of the bicycle 30 with energy. At the same time, the device 12 and an optional ABS control unit 64 are supplied with energy. Optionally, the device 12 according to the invention can have its own power supply, for example via a separate rechargeable battery or a separate battery, which can be integrated into the device 12.

The electric bike 32 in 2 with frame 42, wheels 68, handlebars 48 and saddle has a front wheel motor 34 in its front wheel 36, which drives the front wheel 36. A wheel sensor 20 monitors the movement of the front wheel 36 and detects its standstill. A motion sensor 22 is arranged on the frame 42 of the bicycle 30 near the rear wheel 44. In the embodiment shown here, the motion sensor 22 is also a wheel sensor that detects the rotation of the rear wheel 44. Alternatively, the motion sensor 22 can be an optical sensor, such as a camera 46, which can be arranged on the head tube or on the handlebars 48 of the bicycle 30. Alternatively, the camera of a mobile device arranged on the handlebar 48, for example a cell phone, can be used.

Preferably, the system 10 additionally includes a third sensor 50, which is a status sensor 52 and monitors the status of the brake that brakes the wheel 68 monitored by the wheel sensor 20. The status sensor 52 sends a signal that the brake is released to the device 12, which can be arranged, for example, on the frame 42 between the top tube and the seat tube. The processing unit 19 of the device 12 evaluates the sensor data of the wheel sensor 20, the motion sensor 22 and the status sensor 52 and in this example detects that the front wheel 36 is at a standstill. The status sensor 52 transmits a signal that the brake on the front wheel 36 is released, and the Motion sensor 22 receives a signal that the bicycle is moving, while wheel sensor 20 detects that the front wheel 36 is at a standstill, a control signal is generated in device 12. The control signal is sent to the front wheel motor 34, which takes over the function of the actuator 24. A blockage of the front wheel 36 is therefore solved by generating a torque in the front wheel motor 34. In this way, the front wheel 36 can be set in rotation again if, despite releasing the brake of the front wheel 36, the bearing forces of the front wheel 36 are greater than the coefficient of friction between the front wheel 36 and the ground, which can happen on ice, for example.

The sensors 20, 22, 52 are monitored cyclically with a query cycle of preferably 10 to 50 ms. If the torque applied to the front wheel motor 34 is not sufficient to set the front wheel 36 in motion, either the duration of the control signal or its level can be increased. A cascaded procedure can be implemented in which the signal level of the control signal is increased as time progresses. The control signal is preferably ramp-shaped. It has proven to be advantageous in practice if the control signal is selected such that a force in the range of preferably 0.1 Nm to 5 Nm is initially generated in the front wheel motor 34. If this force is not sufficient, it is increased and preferably generated in the range of 2 Nm to 8 Nm. In a further step, the force generated by the front wheel motor 34 based on the control signal of the device 12 can be increased to a range of preferably 5 Nm to 15 Nm, particularly preferably up to 20 Nm.

3 shows an embodiment of an electric bicycle 32 with a mid-motor 54, in which the rear wheel 44 is driven via a toothed belt 56, which can also be a chain. The rear wheel 44 is braked by means of a disc brake 58. A wheel sensor 20 arranged on the frame 42 checks the movement of the rear wheel 44 and detects a standstill. A motion sensor 22 is positioned on the front wheel 36 to monitor the movement of the bicycle. An integrated in the disc brake 58, in 3 Invisible condition sensor 52 monitors the condition of the brake and detects that the brake is released. From the sensor data of the status sensor 52, the wheel sensor 20 and the motion sensor 22, a blocking of the rear wheel is detected, which can be solved by controlling the mid-motor 54 using the device 12.

Also in the embodiment of the electric bicycle 32 according to 3 The motion sensor 22 may be a camera 46 or another optical sensor that detects the movement of the bicycle 30. The wheel sensor 20 can be a light barrier, a Hall sensor or another optical sensor.

4 shows a further embodiment of an electric bicycle 32 with a rear wheel motor 60 for driving the bicycle 30. The movement of the electric bicycle 32 can be detected by a motion sensor 22 on the front wheel 36, alternatively by a camera 46 or another sensor. The wheel sensor 20 for detecting the standstill or the movement of the rear wheel 44 can be attached to the frame 42. The condition sensor 52 of the brake, which detects whether the brake is released is, is preferably integrated in the rim brake 62 of the rear wheel 44.

Instead of the rim brake 62, a disc brake 58, as additionally shown here, could be provided. The status sensor 52 would then preferably be integrated in the disc brake 58. An optional, additional ABS system includes an ABS control unit 64, which controls the disc brake 58. In this case, the device 12 could also evaluate and take into account the ABS signal from the ABS control unit 64. In particular, the state of the disc brake 58 can be detected in the ABS control unit 64, so that this signal can be used instead of the sensor data of the state sensor 52 to detect a release or actuation of the disc brake 58.
A computer program may be stored/distributed on a non-volatile storage medium, such as optical storage or a solid-state drive (SSD). A computer program may be distributed together with hardware and/or as part of hardware, for example via the Internet or via wired or wireless communication systems.

Reference symbols

10

system

12

contraption

14

first input interface

16

second input interface

18

Output interface

19

Processing unit

20

Wheel sensor

22

Motion sensor

24

Actor

30

Bicycle

32

Electric bike

34

Front wheel motor

36

front wheel

42

Frame

44

rear wheel

46

camera

48

Handlebars

50

third sensor

52

Condition sensor

54

Mid-engine

56

timing belt

58

Disc brake

60

Rear wheel motor

62

Rim brake

64

ABS control unit

66

battery

68

wheel

Claims (8)

Device (12) for driving a stationary wheel (68) of a bicycle (30), with: a first input interface (14) for receiving sensor data from a wheel sensor (20) for detecting the movement of a wheel (68) of the bicycle (30); a second input interface (16) for receiving sensor data from a motion sensor (22) for detecting movement of the bicycle (30), the motion sensor (22) being an optical sensor or a positioning sensor; a processing unit (19) for evaluating the sensor data of the wheel sensor (20) and the motion sensor (22) and detecting the standstill of the wheel (68) despite movement of the bicycle (30) and for generating a control signal for an actuator (24). to allow movement of the wheel (68); an output interface (18) for outputting the control signal to the actuator (24) in order to move the wheel (68). Device (12) after Claim 1 , wherein the actuator (24) is a motor, preferably a drive motor of the bicycle (30). Device (12) according to one of the preceding claims, wherein the device has a third sensor, which is preferably an ABS sensor of an ABS system or a status sensor (52) of a brake. Device (12) according to one of the preceding claims, wherein the wheel (68) is a drive wheel of the bicycle (30). System (10) for driving a stationary wheel (68) of a bicycle (30), with: a device (12) for a bicycle (30) according to one of the preceding claims; a wheel sensor (20) for a wheel (68); a motion sensor (22) for detecting movement of the bicycle (30); and an actuator (24) for driving the wheel (68). Bicycle (30) with a system (10). Claim 5 . Method for driving a stationary wheel (68) of a bicycle (30), comprising the following Steps: receiving sensor data from a wheel sensor (20) to detect the movement of the wheel (68) of the bicycle (30); receiving sensor data from a motion sensor (22) to detect movement of the bicycle (30); Evaluating the sensor data of the wheel sensor (20) and the motion sensor (22), the motion sensor (22) being an optical sensor or a position determination sensor; Detecting the standstill of the wheel (68) despite movement of the bicycle (30); Generating a control signal for an actuator (24) to enable movement of the wheel (68); Outputting the drive signal to the actuator (24) to move the wheel (68), the drive signal being a ramp-shaped signal whose signal level is increased as time progresses. Procedure according to Claim 7 , wherein the control signal for the actuator (24) is time-limited, preferably lasting between 50 ms and 500 ms, particularly preferably between 100 ms and 250 ms, very preferably between 100 ms and 150 ms.

Images