Method and system for detecting a manipulation of speed data of an electric bicycle, control device, and electric bicycle
Patent Information
- Application Number
- EP2024701585
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-01-23
- Filing Date
- 2024-01-19
- Publication Date
- 2025-12-03
AI Technical Summary
Existing methods for detecting manipulation of speed data in electric bicycles are inadequate, as they may not accurately differentiate between legitimate and manipulated speed measurements, potentially leading to unsafe operating conditions.
A method and system that utilize a sensor device to detect drive wheel and motor speeds, calculating actual and target driving speeds, and initiating a safety function if a deviation of at least 10% is sustained for a predefined period, which includes reducing or deactivating the electric drive motor to prevent exceeding maximum permissible speeds.
This approach enhances driving safety by reliably detecting speed manipulation and ensuring compliance with specified maximum speeds, reducing the risk of errors and increasing the robustness of the system.
Smart Images
Figure EP2024051210_02082024_PF_FP
Abstract
Description
[0001] ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 Method and system for detecting manipulation of speed data of an electric bicycle, control device, and electric bicycle. The present invention relates to a method and a system for detecting manipulation of speed data of an electric bicycle. Furthermore, the invention also relates to a control device and an electric bicycle. Known electric bicycles are at least partially electrically powered and are also known as e-bikes or pedelecs and have drive motors and a traction drive with which drive power is transmitted to the drive wheel of the electric bicycle, which is preferably designed as the rear wheel. The traction drive can be a chain drive with a derailleur or a belt drive. Systems and methods for detecting manipulation of an e-bike are known from the prior art.which are intended to achieve a higher permissible maximum speed. For example, DE 102021103655 A1 discloses calculating the rotational speed of a wheel of an e-bike in order to subsequently infer the speed of the vehicle from the rotational speed of the wheel, whereby manipulation of the speed measurement can be detected and tuning of the motor's performance by interfering with the speed measurement is prevented. Furthermore, DE 102014212760 A1 discloses a method and a device for checking speed data of an electric bicycle, wherein a comparison is made between the drive wheel speed and the motor speed based on a current gear ratio in order to detect manipulation of the bicycle. The present invention is based on the objectTo provide an alternative method and an alternative system for detecting manipulation of speed data of an electric bicycle. This object is achieved by the respective subject matter of patent claims 1, 8, 13, and 14. Further advantageous embodiments can be found in the dependent claims. ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 According to a first aspect of the invention, in a method for detecting manipulation of speed data of an electric bicycle having at least one drive wheel, a pedal crankshaft, an electric drive motor, a sensor device, and a control device,The sensor device detects a drive wheel speed and a drive motor speed and generates related sensor data. This sensor data is transmitted to the control device, which is communicatively connected to the sensor device. The control device calculates an actual travel speed from the sensor data on the drive wheel speed. The control device calculates a target travel speed from the sensor data on the drive motor speed and data on the drive train configuration. The control device continuously compares the actual travel speed and the target travel speed. The control device initiates a safety function if the actual travel speed and the target travel speed deviate from each other by at least 10% for a predefined period. For example, the cyclist applies a drive speed and a drive torque to the crankshaft via pedals.The pedal crankshaft is connected to a first shaft of a traction drive. The electric motor can be activated by the cyclist to provide assistance. It has a stator fixed to the housing and a rotor connected in a rotationally fixed manner to the rotor shaft. An additional drive power, i.e., an additional drive speed and an additional drive torque, is introduced at least indirectly to the first shaft of the traction drive via the rotor shaft.to support the cyclist's propulsion. The drive power is transmitted between the first shaft and a second shaft via the traction mechanism of the traction drive. For example, the second shaft is rotationally connected to a drive wheel of the electric bicycle designed as a rear wheel. Thus, in addition to the drive power generated by muscle power, the electric bicycle can also be driven by the drive power generated by the drive motor. The electric bicycle can be designed, for example, as an (S-)Pedelec, e-bike, velomobile, or cargo bike. ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 The term "predefined duration" means that the conditions mentioned must be met for a specific period of time before the safety function is initiated. The predefined duration is selected in particular such thatthat normal riding functions or operational changes of the electric bicycle do not trigger or initiate the safety function. In other words, the safety function is not initiated immediately, but only after a predefined period of time during which the actual speed and the target speed differ from each other by at least 10%, in particular such a deviation that the actual speed is higher than the target speed. The safety function is preferably initiated when the actual speed and the target speed differ from each other by at least 10% for a period of at least 20 seconds. This reduces the susceptibility to errors in the case of minor, particularly short-term deviations.while simultaneously increasing driving safety by adhering to specified maximum permissible speeds. This represents a particularly good compromise between a robust and a safe driving system. When we speak of "initiating a safety function," this refers to the beginning of the safety function, during which command signals are generated by the control device and sent to corresponding devices on the electric bicycle that can initiate or execute the safety function. The sensor device can comprise several sensors or sensor assemblies based on various known measuring principles. One or more sensors of the sensor device are designed to measure a rotational speed of the drive wheel, i.e., the drive wheel speed, during operation of the electric bicycle.of the electric bicycle. Preferably, the sensor device has a high-resolution pulse sensor with at least 50 pulses per revolution for detecting the drive wheel speed. Thus, the speed of the drive wheel of the electric bicycle is detected with the high-resolution pulse sensor. Preferably, the rear wheel of the electric bicycle is designed as the drive wheel. In particular, a Hall sensor with a high-resolution encoder disk is suitable as a sensor for detecting the drive wheel speed. ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 ...for example, rotationally fixed, or indirectly via at least one other component. The speed of the drive motor's motor shaft, i.e., the drive motor speed, is detected by the drive motor or sensors integrated therein. The sensor device is communicatively connected to the drive motor in order to record, in particular read, this sensor data. Both the drive motor speed and the drive wheel speed are thus recorded with high resolution and processed by the control device as a sensor signal. "High resolution" means that at least 50 pulses per revolution of the respective component are recorded. This high-resolution position data enables precise and dynamic evaluation of sensor data as well as reliable triggering of the safety function.in particular because the control device can react faster and more precisely to the received sensor data. The measurement data or sensor data from the sensor device can be transmitted individually or in aggregate to the control device, with the control device receiving, storing, and further processing the data, at least to assess whether or not there has been manipulation of speed data. Accordingly, the control device is designed to receive, store, and further process the sensor data from the sensor device. A "communicative connection" provides for the transmission of data and information, such as sensor signals and / or control commands. ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 For example, the safety function provides for reducing and limiting the engine speed in such a way thatthat a permissible maximum speed of the electric bicycle is not exceeded. For example, this impairment initiated by the safety function can persist until the system is restarted while the electric bicycle is stationary. Alternatively, this impairment can be maintained until a service workshop is visited. In addition or alternatively, the safety function can provide for the electric drive motor to be deactivated or decoupled from the drive train of the electric bicycle. Decoupling the drive motor, for example, using a clutch, separates the drive motor from the drive train, so that no drive assistance from the drive motor is possible. In both cases, the electric bicycle can only be operated with the cyclist's muscle power. For example, this impairment initiated by the safety function can persist untiluntil the system is restarted while the electric bicycle is stationary. Alternatively, this impairment can be maintained until a service workshop is visited. In particular, the control device has a data memory. Preferably, the safety function makes an entry regarding the manipulation of speed data in the data memory of the control device. This entry is stored at least until the data memory is read out in the service workshop and documents the detection of the manipulation of the speed data. In particular, design information, in particular data regarding the configuration of the drive train, is also stored in this data memory. Preferably, the safety function provides an event message for the cyclist. The event message can be displayed visually, for example, via a screen arranged on the handlebars of the electric bicycle.haptically via an actuator arranged on the handlebars or pedals, and / or acoustically, for example via loudspeakers, to the cyclist. It is also conceivable that the event message is displayed as a message on a smartphone or the like. The ZF Friedrichshafen AG file 214286 Friedrichshafen 2023-01-23 event message includes at least information on the detected manipulation of the speed data and the initiated safety function. According to a preferred embodiment of the invention, sensor data from a transmission configured to set different gear ratios for a driver's cadence are used to verify the plausibility of the sensor data on the drive wheel speed and the sensor data on the drive motor speed.used. In other words, the determined drive wheel speed and drive motor speed can be checked for plausibility based on the gear ratio and the rider's cadence. According to a second aspect of the invention, a system for detecting manipulation of speed data of an electric bicycle with at least one drive wheel comprises a pedal crankshaft for applying a drive power generated by muscle power, an electric drive motor connected to the drive wheel via a fixed gear ratio for drive assistance, a sensor device configured to detect a drive wheel speed and a drive motor speed and to generate related sensor data, a control device communicatively connected to the sensor device and configured to receive sensor data on the drive wheel speed and to calculate an actual travel speed,To receive sensor data on the drive motor speed and calculate a target travel speed, to continuously compare the actual travel speed and the target travel speed, and to initiate a safety function if the actual travel speed and the target travel speed deviate from each other by at least 10% for a predefined period. During normal operation of the electric bicycle as a pedelec, i.e., when no manipulation of speed data has been detected, the cyclist's drive power is transmitted via pedals to the crankshaft and transferred to the drive wheel via a traction drive. The drive motor has a fixed gear ratio to the drive wheel due to the design configuration of the drive train and supports the cyclist's drive power. To do this, the motor shaft rotates at a drive motor speed that matches the drive wheel speed.and thus leads to a reduction in the cyclist's workload. ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 According to a preferred embodiment, a transmission can be provided for setting different gear ratios for a rider's cadence. The transmission is arranged in the power flow between the pedals and the pedal crankshaft and thus only sets a gear ratio for the cyclist, but not for the drive motor. A control device according to the invention is designed to carry out the method according to the invention. Thus, the control device monitors the sensor data and initiates the safety function if necessary. The above definitions as well as explanations regarding technical effects, advantages, and advantageous embodiments of the method according to the invention also apply mutatis mutandis to the control device according to the invention. An electric bicycle according to the invention comprises a system according to the invention and at least two wheels,wherein at least one of the wheels is designed as a drive wheel and is drivingly connected to the electric drive motor and the pedal crankshaft. The electric bicycle according to the invention comprises the usual components of a muscle-powered electric bicycle and additionally the system according to the invention. The electric drive can reduce the cyclist's load during locomotion or increase their range, depending on the capacity of an associated energy storage device. The above definitions as well as explanations of technical effects, advantages, and advantageous embodiments of the system according to the invention also apply mutatis mutandis to the electric bicycle according to the invention. A preferred embodiment of the invention is explained in more detail below with reference to the single figure.wherein like elements are provided with the same reference numerals. The single figure shows a schematic side view of an electric bicycle according to the invention with a highly simplified system for detecting manipulation of speed data according to a preferred embodiment. ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 According to the single figure, the electric bicycle 1 is designed as a pedelec and can thus be driven partly by the muscle power of a cyclist (not shown) and partly electromechanically by means of a drive train 8. Whenever an electric bicycle 1 is mentioned below, this refers to a pedelec. The electric bicycle 1 comprises a first wheel, which is designed as a front wheel 2, and a second wheel,which is designed as a rear drive wheel 3. Furthermore, in addition to the drive train 8, the electric bicycle 1 comprises a system for detecting manipulation of speed data. The drive train 8 comprises an electric drive motor 7, the traction drive 10, and a transmission 16. For reasons of clarity, the figure omits a detailed illustration of the typical drive train 8, in particular the transmission 16, a shifting device in the transmission 16 with shifting elements for shifting the gear stages, and the corresponding connection of the drive motor 7 and the pedal crankshaft 4 to the traction drive 10. The traction drive 10 is designed as a chain drive and comprises an input component in the form of a pinion 12, an output component on the drive wheel 3 in the form of a driven gear 13, and a traction means 9 arranged therebetween and designed as a chain.which connects the pinion 12 to the output gear 13 in a driving manner. The output gear 13 serves as the output element of the traction drive 10 and the drive train 8 during traction operation and is connected in a rotationally fixed manner to the drive wheel 3. In the present case, the transmission 16 has several gear stages and is designed to set different gear ratios for the rider's cadence and is thus arranged in the power flow between the pedals 11 and the pedal crankshaft 4. This eliminates the need for a derailleur. Thus, in the present case, the electric drive motor 7 is connected to the drive wheel 3 via a fixed gear ratio. Design-specific information regarding this fixed gear ratio is stored in the system in the form of data for configuring the drive train 8. The pedal crankshaft 4 is connected to the pedals 11 of the electric bicycle 1 via the transmission 16 and is designed toto transmit a drive power generated by the cyclist's muscle power, depending on the ratio of a transmission 16, via a traction drive 10 to the drive wheel 3. The drive motor 7 is arranged in the region of a pedal crankshaft 4 as a central drive and is configured to transmit an electromechanically generated drive power to assist the cyclist via the traction drive 10 to the drive wheel 3. The system for detecting manipulation of speed data comprises a sensor device 5 configured to detect a drive wheel speed and a drive motor speed and to generate related sensor data, as well as a control device 6.which is communicatively connected to the sensor device 5. For simplification, the sensor device 5 is shown as a dashed rectangle and comprises a high-resolution pulse sensor 5.1 with at least 50 pulses per revolution, which continuously records the drive wheel speed. Furthermore, the sensor device 5 is communicatively connected to the drive motor 7 for detecting the drive motor speed. Optionally, sensor data from the transmission 16, which is configured to set different gear ratios for a driver cadence, can be used to verify the plausibility of the sensor data for the drive wheel speed and the sensor data for the drive motor speed. The control device 6 is configured toto carry out the inventive method described below for detecting manipulation of speed data of the electric bicycle 1. The sensor device 5 continuously records the drive wheel speed and the drive motor speed, and generates related sensor data. This sensor data is transmitted to the control device 6. The control device 6 continuously calculates an actual driving speed from the sensor data on the drive wheel speed and a target driving speed from the sensor data on the drive motor speed and from the data on the configuration of the drive train 8. This is made possible by the fact that the drive motor is connected to the drive wheel via a fixed, i.e., non-changeable, gear ratio, and is thus independent of the shifting state of the transmission 16.which is configured to set different gear ratios for the rider's cadence. Furthermore, the control device 6 continuously compares the actual driving speed and the target driving speed. If, for a predefined period of, for example, 20 seconds, the actual driving speed and the target driving speed differ from each other by at least 10%, the control device 6 initiates a safety function. Such a deviation over such a period of time can lead to a reduction in road safety. In particular, such deviations are attributable to tuning measures intended to make the electric bicycle 1 travel faster. In this case, the safety function reduces and limits the motor speed in such a way thatthat a permissible maximum speed of the electric bicycle 1 can no longer be exceeded. In other words, the maximum motor power is throttled. Furthermore, the safety function can deactivate the electric drive motor 7 or decouple it from the drive train 8 of the electric bicycle 1, for example via a clutch. Furthermore, the safety function makes an entry for the manipulation of speed data in a data memory 17 of the control device 6. In particular, the safety function can provide a visual and / or acoustic event message for the cyclist. In the present case, the system comprises a screen 14,which is arranged on the handlebar 15 of the electric bicycle 1 and is within the cyclist's field of vision. The screen 14 is communicatively connected to the control device 6. The screen 14 visually informs the cyclist about the triggered safety function. For this purpose, the screen receives information from the control device 6. In addition to the visual event message, acoustic signals can be emitted via a loudspeaker integrated in the screen 14 to direct the cyclist's gaze to the screen 14. The event message on the screen 14 also prompts the cyclist to visit a service workshop to correct the manipulation of speed data detected by the system. For example, by restarting the system, i.e., turning the system off and on again while the electric bicycle 1 is stationary, the regular operation of the drive motor 7 can be resumed.until the safety function is triggered again. However, each triggering of the safety function, along with other driving data of the electric bicycle 1 (ZF Friedrichshafen AG File 214286 Friedrichshafen, 2023-01-23), is stored in the data memory 17 of the control device 6 and made available for reading from the data memory 17 in the service workshop. The invention is not limited to the exemplary embodiment described here. It is also conceivable for the drive motor 7 to be arranged on the drive wheel 3 in the form of a wheel hub drive. Accordingly, a drive power generated by muscle power is then transmitted to the drive wheel 3 via the transmission 16, the pedal crankshaft 4, and the traction drive 10, with an electromechanically generated drive power of the drive motor 7 being transmitted directly to the drive wheel 3 to assist the cyclist.
[0002] ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 Reference symbol 1 Electric bicycle 2 Front wheel 3 Drive wheel 4 Crankshaft 5 Sensor device 5.1 High-resolution pulse sensor 6 Control device 7 Drive motor 8 Drive train 9 Traction mechanism 10 Traction mechanism drive 11 Pedal 12 Pinion 13 Output gear 14 Display 15 Handlebar 16 Gearbox 17 Data memory
Claims
ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 Patent claims 1. Method for detecting manipulation of speed data of an electric bicycle (1) having at least one drive wheel (3), a pedal crankshaft (4), an electric drive motor (7), a sensor device (5), and a control device (6), - wherein a drive wheel speed and a drive motor speed are detected by means of the sensor device (5), and related sensor data are generated, - wherein these sensor data are transmitted to the control device (6) communicatively connected to the sensor device (5), - wherein the control device (6) calculates an actual driving speed from the sensor data relating to the drive wheel speed, - wherein the control device (6) calculates a target driving speed from the sensor data relating to the drive motor speed and data relating to the configuration of the drive train,- wherein the control device (6) continuously compares the actual driving speed and the target driving speed, - wherein the control device (6) initiates a safety function if the actual driving speed and the target driving speed deviate from each other by at least 10% for a predefined period.
2. The method according to claim 1, wherein the safety function reduces and limits the motor speed such that a permissible maximum speed of the electric bicycle (1) is not exceeded.
3. The method according to one of the preceding claims, wherein the safety function deactivates the electric drive motor (7) or decouples it from the drive train (8) of the electric bicycle (1).
4. The method according to one of the preceding claims, wherein the safety function makes an entry for manipulating speed data in a data memory (17) of the control device (6). ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 5. The method according to one of the preceding claims, wherein the safety function provides an event message for the cyclist.
6. The method according to one of the preceding claims, wherein the safety function is initiated if the actual driving speed and the target driving speed deviate from each other by at least 10% for a period of at least 20 seconds.
7. The method according to one of the preceding claims, wherein sensor data from a transmission (16) configured to set different gear ratios for a rider's cadence are used to check the plausibility of the sensor data for the drive wheel speed and the sensor data for the drive motor speed.
8. A system for detecting manipulation of speed data of an electric bicycle (1) having at least one drive wheel (3),comprising - a pedal crankshaft (4) for applying a drive power generated by muscle power, - an electric drive motor (7) which is connected to the drive wheel (3) via a fixed gear ratio for drive assistance, - a sensor device (5) which is configured to detect a drive wheel speed and a drive motor speed and to generate related sensor data, - a control device (6) which is communicatively connected to the sensor device (5) and is configured to receive sensor data on the drive wheel speed and calculate an actual travel speed, receive sensor data on the drive motor speed and calculate a target travel speed, continuously compare the actual travel speed and the target travel speed, and initiate a safety function,if the actual driving speed and the target driving speed differ from each other by at least 10% for a predefined period. ZF Friedrichshafen AG File 214286 Friedrichshafen 2023-01-23 9. The system according to claim 8, wherein the sensor device (5) has a high-resolution pulse sensor (5.1) with at least 50 pulses per revolution for detecting the drive wheel speed.
10. The system according to claim 8 or 9, wherein the sensor device (5) for detecting the drive motor speed is communicatively connected to the drive motor (7).
11. The system according to one of claims 8 to 10, wherein the control device (6) has a data memory (17).
12. The system according to one of claims 8 to 11, further comprising a transmission (16) for setting different gear ratios for a driver cadence.
13. A control device (6) designed to carry out a method according to one of claims 1 to 7. 14.Electric bicycle (1), comprising a system according to one of claims 8 to 12 and at least two wheels, wherein at least one of the wheels is designed as a drive wheel (3) and is drivingly connected to the electric drive motor (7) and the pedal crankshaft (4).