Method and control device for determining a mechanical load on a pedal crank unit of a bicycle

Abstract

The method for determining the mechanical load on a bicycle crankset involves determining the rotation angle of a crank arm shaft within at least one predefined range and the torque of the crank arm shaft within at least one predefined torque range. This determination involves determining at least one mechanical load as a function of a pedaling force, where the pedaling force acts simultaneously on the same ends of the crank arms. The pedaling force is determined as a function of at least one acceleration of the bicycle along at least one vertical axis of the bicycle, and as a function of at least one rider mass, or at least one rider mass and at least one rider damping factor.Depending on at least one mechanical stress on the crankset, at least one degree of damage to the crankset is determined and compared with at least one damage limit of the crankset. If at least one damage limit of the crankset is exceeded, at least one notification perceptible to human senses can be generated.

Description

[0001] The present invention relates to a method for determining a mechanical load on a pedal crank unit of a bicycle, a control device, a computer program product, a computer-readable medium and a bicycle.

[0002] Components of a bicycle, such as the drive unit with its electric motor, are subject to various mechanical stresses. When a bicycle's drive unit generates propulsion, it experiences high mechanical loads. These loads arise, for example, from the rider applying torque to the drive unit or from the electric motor providing torque to generate propulsion. The torque applied to or provided by the drive unit is typically measured by a torque sensor on the bicycle. The measured torque values ​​primarily serve as a control parameter for the electric motor.Additionally, mechanical loads on a drive unit are determined based on the measured torques.

[0003] DE 10 2021 213 542 A1 discloses a device and a method for operating an electric bicycle. The device determines the mechanical load caused by the electric motor of the bicycle. If a limit value is exceeded, the torque provided by the drive and the resulting damage due to mechanical loads are limited in order to increase a predefined service life of the drive. This method takes into account mechanical loads resulting from the torque provided by the drive.

[0004] DE 10 2010 027 010 A1 discloses a method and a device for determining an effective torque applied to a bicycle drive mechanism.

[0005] The present invention is based on the objective of taking into account the damaging influence on a pedal crank unit of a bicycle as a result of mechanical loads during certain cycling maneuvers of the bicycle.

[0006] The problem is solved by a method for determining a mechanical load on the crank unit of a bicycle with the features of claim 1, a control device with the features of claim 12, a computer program product with the features of claim 13, a computer-readable medium with the features of claim 14, and a bicycle with the features of claim 15. Further embodiments are included in the dependent claims and are described below.

[0007] The invention claims a method, a control device for use on a bicycle, a computer program product, a computer-readable medium and a bicycle.

[0008] The method for determining the mechanical load on a bicycle crankset is applicable to a bicycle with at least one drive unit, wherein the drive unit comprises at least one crankset with at least one crank axle and at least two crank arms arranged diametrically opposite each other, the crank arms being rotationally fixed to the crank axle. A rotationally fixed connection is a mechanical connection that prevents relative movement of connected elements. A mechanical load on a crankset is understood to mean at least one mechanical load on at least one component of the crankset, or on at least one component mechanically connected to the crankset, or on at least one component of the crankset and on at least one component mechanically connected to the crankset.A component is understood to be any physical object of the bicycle, whereby a component can also be an assembly of components, such as a crankset or a drive unit with a crankset. For example, a component of a crankset is a crank axle, a crank arm, a pedal axle, a pedal, a crankset housing, a chainring, a roller bearing, a plain bearing, or a machine element such as a screw, a nut, a retaining ring, a T-nut, or similar.

[0009] The method according to the invention makes it possible to determine mechanical loads on a crankset with at least one crank axle and at least two diametrically opposed crank arms during certain riding maneuvers, such as a jump, a bunny hop, or a downhill position. During such maneuvers, at least one pedaling force, dependent on the accelerated mass of the cyclist, acts simultaneously on the same ends of the crank arms. Because the pedaling force acts simultaneously on the same ends of the crank arms, no torque is transmitted through the crankset to propel the bicycle. As a result of the simultaneous pedaling force acting on the same ends of the crank arms, mechanical loads arise in the form of two opposing torsional moments, which act primarily on the crank axle and the crank arms.Superimposed on the two opposing torsional moments are two bending moments, which act primarily at both ends of the crank axle and both ends of the crank arms. Parallel to the torsional and bending moments, other forces or moments can also act on the crank assembly, the crank axle, and the crank arms.

[0010] In the method according to the invention, at least one mechanical load on the crank unit is determined at at least one rotation angle of the crank shaft lying within at least one predetermined rotation angle interval and at at least one torque of the crank shaft lying within at least one predetermined torque interval. At least one mechanical load is determined as a function of a pedaling force, wherein the pedaling force acts simultaneously at the same ends of the pedal cranks. The pedaling force is determined as a function of at least one acceleration of the bicycle in the direction of a vertical axis of the bicycle and at least one rider mass of the bicycle, or as a function of at least one acceleration of the bicycle in the direction of a vertical axis of the bicycle and at least one rider mass of the bicycle and at least one rider damping factor of the bicycle.Alternatively or additionally, at least one pedaling force can be determined using at least one force sensor on the bicycle. Depending on at least one mechanical load on the crankset, at least one degree of damage to the crankset is determined and stored in a data memory, and compared with at least one damage threshold for the crankset. If at least one damage threshold of the crankset is exceeded by at least one degree of damage, at least one notification perceptible to human senses can be generated.

[0011] This method allows a cyclist to be warned in good time about an impending component failure of a crank unit, thereby minimizing the risk of an accident or injury to the cyclist.

[0012] The method enables the detection of misuse of the bicycle based on at least one stored damage level. Furthermore, the method can be combined with predictive maintenance models, allowing, for example, the estimation of when maintenance will be required.

[0013] Furthermore, this method can increase the accuracy of damage assessment for a drive unit or crankset. This more precise damage assessment can, in turn, be used for optimization and cost reduction of the crankset or drive unit.

[0014] The term "bicycle" encompasses all vehicles with at least two wheels, or at least one wheel and at least one sliding element such as a sled runner, located in a plane or on an axle. Examples of bicycle types include e-bikes, pedelecs, S-pedelecs, e-mountain bikes (eMTBs), cargo bikes, tricycles, quadricycles, velomobiles, and e-snowbikes.

[0015] The bicycle has at least one drive system with at least one drive unit. The drive unit has at least one crank unit, which has at least one crank axle and at least two crank arms arranged diametrically opposite each other. Additionally, the crank unit has at least two pedal axles and at least two pedals. Both crank arms are fixed to the crank axle or can be fixed to it. The crank arm is fixed to the pedal axle or can be fixed to it. The pedal axle is rotatably connected to the pedal or can be rotatably connected to it. A fixed connection is a mechanical connection that prevents relative movement of connected elements. A rotatable connection allows rotational movement, where rotational movement is a rotational movement about an axis of rotation.

[0016] At least one drive power from the cyclist can be fed into the drive system via the crankset. The cyclist's drive power is proportional to the rotational movement of the crank axle generated by the cyclist. This rotational movement of the crank axle depends on at least one torque from the cyclist. A rotational movement can be characterized by at least one torque and at least one angle of rotation. The cyclist's torque is proportional to at least one pedaling force, whereby the pedaling force acts at most at one end of at most one crank arm of the crankset at any given time. The pedaling force is transmitted from a pedal to the crank arm and then to the crank axle.

[0017] Furthermore, the drive unit includes at least one electric drive motor. An electric drive motor in this context refers to any drive that can convert electrical power into mechanical power or vice versa, such as DC motors, AC motors, three-phase motors, or similar devices.

[0018] In addition to at least one torque provided by the cyclist, the electric drive motor can generate at least one variable torque, allowing the cyclist's power to be partially or completely replaced by the mechanical power of the electric drive motor. Consequently, the bicycle can be powered either by pure muscle power, purely electrically, or in hybrid mode by both muscle power and electricity.

[0019] Furthermore, the drive unit can have at least one automatic transmission with at least one discrete gear ratio. During a shift operation of the automatic transmission, a change in gear ratio occurs without intervention from the bicycle rider, by means of at least one actuator of the automatic transmission, for example, depending on at least one torque of at least one crankshaft, or at least one angle of rotation of at least one crankshaft, or at least one torque of at least one crankshaft and at least one angle of rotation of at least one crankshaft, or similar. Depending on a gear ratio, the automatic transmission can convert a rotation with high speed and low torque into a rotation with low speed and high torque, and vice versa.

[0020] Increasing the gear ratio, for example, allows a rotation of a pedal crank shaft with a high speed and low torque to be converted into a rotation of the pedal crank shaft with a low speed and high torque.

[0021] For example, reducing a gear ratio allows a rotation of a pedal crank shaft at a low speed and high torque to be converted into a rotation of the pedal crank shaft at a high speed and low torque.

[0022] Furthermore, the drive system has at least one energy storage device such as batteries, accumulators such as lithium-ion batteries, capacitors such as supercapacitors or at least one energy converter such as a fuel cell such as a polymer electrolyte fuel cell with a chemical energy storage device consisting of a fuel such as hydrogen or methanol and an oxidizing agent such as air or oxygen.

[0023] Furthermore, the bicycle can have at least one steering system, for example in the form of at least one movable axle, which is mechanically connectable or connected to at least one wheel or sliding element of the bicycle, as well as to the bicycle frame. The movable axle can, for example, be mechanically connected to at least one handlebar. Additionally, the movable axle can be rotatably connected to at least one electric motor. This allows the electric motor to assist the rider's steering movements.

[0024] Additionally or alternatively, the movable axle can have at least one centering spring or a steering damper. The centering spring or steering damper is adjustable depending on at least one torque of at least one crank arm, or at least one rotation angle of at least one crank arm, or at least one torque of at least one crank arm and at least one rotation angle of at least one crank arm, or similar. To stabilize the bicycle, it is possible to increase the restoring force of the centering spring or the damping level of the steering damper. To increase agility, it is possible to reduce the restoring force of the centering spring or the damping level of the steering damper.

[0025] Furthermore, the bicycle must have at least one brake. The brake can be a disc brake, a rim brake, or a drum brake. Additionally, at least one brake can be combined with at least one anti-lock braking system (ABS). Alternatively or additionally, the bicycle can have at least one brake-by-wire braking system with at least one electric actuator.

[0026] Furthermore, the bicycle can have at least one spring-damper system. This spring-damper system can include at least one coil spring, at least one shock absorber, and at least one displacement sensor for determining at least one spring travel of the coil spring. When the bicycle is in motion, one spring travel correlates with at least one acceleration of the bicycle along its vertical axis.

[0027] Alternatively, the spring-damper system can include at least one gas spring with at least one integrated damping mechanism and at least one pressure sensor for determining at least one gas pressure of the gas spring. When the bicycle is in motion, this gas pressure correlates with at least one acceleration of the bicycle along its vertical axis.

[0028] Additionally, the spring-damper system can have at least one actuator for at least one setting of at least one damping level. For example, at least one damping level is adjustable depending on at least one torque of at least one crank axle, or at least one rotation angle of at least one crank axle, or at least one torque of at least one crank axle and at least one rotation angle of at least one crank axle, or similar.

[0029] Furthermore, the bicycle has at least one human-machine interface, such as a light signal transmitter, a sound signal transmitter, a screen, or a wearable device (a computer system that can be worn on the human body). The human-machine interface can be located on at least one handlebar of the bicycle.

[0030] Furthermore, the human-machine interface is capable of generating at least one notification perceptible to human senses. The notification can be visual, auditory, or haptic. For example, at least one notification can be generated visually using at least one screen or at least one light signal generator of the human-machine interface. Alternatively or additionally, at least one notification can be generated audibly using at least one loudspeaker of the human-machine interface. Alternatively or additionally, at least one notification can be generated haptically using at least one vibration motor.

[0031] Furthermore, the bicycle has at least one rotation angle sensor for determining at least one rotation angle of the bicycle. Preferably, at least one rotation angle of the crank axle, or at least one crank arm, or at least one rotatable component of the bicycle can be determined, wherein a rotational movement of the crank axle correlates with a rotational movement of the rotatable component. Alternatively or additionally, it is also possible to determine at least one rider cadence using the rotation angle sensor.

[0032] Additionally, the bicycle has at least one torque sensor for determining at least one torque. Preferably, at least one torque of the crank axle, or at least one crank arm, or at least one rotatable component of the bicycle can be determined, wherein the torque of the crank axle correlates with the torque of the rotatable component. Alternatively or additionally, it is possible to determine at least one torque of the rider of the bicycle using the torque sensor.

[0033] Additionally, the bicycle has at least one accelerometer for measuring at least one acceleration along at least one vertical axis. For example, the accelerometer can be a micro-electro-mechanical system accelerometer or a piezoelectric accelerometer. The accelerometer can be installed, for example, on the bicycle frame, in the bicycle's control unit, or in a human-machine interface.

[0034] Additionally, the bicycle may have at least one force sensor for measuring at least one pedaling force applied by the rider. The force sensor can be designed as a load cell or a strain gauge. The force sensor can be positioned, for example, at one end of a crank arm or within a pedal of the crank arm. A rider's pedaling force can act on the crank axle, on at least one crank arm of the crank arm, or on the crank axle and at least one crank arm of the crank arm. Alternatively or additionally, a rider's pedaling force can act on at least one pedal of the crank arm, on at least one pedal axle of the crank arm, or on at least one pedal axle of the crank arm.

[0035] Furthermore, the bicycle may be equipped with at least one speed sensor for determining the rotational speed of at least one of the bicycle's rotating wheels. The speed sensor can be mounted on the bicycle frame.

[0036] The method for determining a mechanical load on a crank unit of a bicycle is applicable to a bicycle with at least one drive unit, wherein the drive unit has at least one crank unit with at least one crank shaft and at least two cranks arranged diametrically opposite each other, wherein the cranks are connected to the crank shaft in a rotationally fixed manner.

[0037] The method according to the invention makes it possible to determine mechanical loads during certain riding maneuvers, such as a jump, a bunny hop, or a downhill position. During such maneuvers, at least one pedaling force, dependent on the accelerated mass of the cyclist, acts simultaneously at the same ends of the crank arms. Since the pedaling force acts simultaneously at the same ends of the crank arms, no torque is transmitted via the crank arm assembly for propulsion of the bicycle. As a result of the pedaling force acting simultaneously at the same ends of the crank arms, mechanical loads arise in the form of two opposing torsional moments, which act primarily on the crank axle and the crank arms. Superimposed on these two opposing torsional moments are two bending moments, which act primarily on both ends of the crank axle and both ends of the crank arms.In addition to torsional moments and bending moments, other forces or moments can act on the crank unit and crank axle, as well as on the crank arms.

[0038] Furthermore, it is possible that at any given time a first pedaling force acts at most at one end of a pedal crank and a second pedaling force acts at most at one end of another pedal crank, whereby the first pedaling force and the second pedaling force fluctuate around the same mean value over time.

[0039] The method according to the invention can be carried out while a bicycle is being used by a rider. Use of the bicycle can be detected by means of at least one sensor on the bicycle. For example, use of the bicycle can be detected when a predetermined acceleration threshold is exceeded by a previously determined acceleration of the bicycle. In this case, at least one acceleration of the bicycle can be determined by means of at least one acceleration sensor on the bicycle. Alternatively or additionally, use of the bicycle can be detected when a predetermined rotational speed of at least one rotatable wheel of the bicycle is exceeded. In this case, at least one rotational speed of the rotatable wheel of the bicycle can be determined by means of at least one rotational speed sensor.

[0040] At the beginning of the method according to the invention, in a first step, at least one rotation angle of at least one crank arm of a bicycle crank unit is determined by means of at least one rotation angle sensor of the bicycle. A determined rotation angle corresponds to a relative change in rotation angle resulting from at least one rotational movement of the crank arm about at least one rotationally symmetric axis of the crank arm. In addition, at least one torque of the crank arm is determined by means of at least one torque sensor of the bicycle. A determined torque correlates with at least one pedaling force of a rider of the bicycle, wherein the pedaling force acts at most at one end of at most one crank arm of the crank unit at any given time.

[0041] In a second step of the method according to the invention, at least one rotation angle interval is retrieved from at least one data storage device and at least one torque interval is retrieved from at least one data storage device. The rotation angle interval can, for example, cover values ​​of [0°, 10°] or [-10°, +10°] or [0°, +20°] or [-20°, +20°] or similar values. The torque interval can, for example, cover values ​​of [0 Nm, 3 Nm] or [0 Nm, 5 Nm], [0 Nm, 10 Nm] or similar values.

[0042] Subsequently, at least one comparison is made between at least one determined rotation angle and at least one retrieved rotation angle interval, as well as at least one comparison between at least one determined torque and at least one retrieved torque interval. If at least one rotation angle and at least one torque fall within at least one rotation angle interval, the process continues in a third step. Otherwise, the process is terminated prematurely.

[0043] In the third step of the method according to the invention, at least one acceleration of the bicycle in the direction of at least one vertical axis of the bicycle is determined by means of at least one acceleration sensor of the bicycle. In addition, at least one rider mass of the bicycle is determined by means of at least one suitable sensor of the bicycle.

[0044] For example, it is possible to determine at least one rider mass of a bicycle using at least one acceleration sensor or at least one torque sensor on the bicycle. Furthermore, it is possible to determine at least one rider mass of a bicycle using at least one displacement sensor or at least one pressure sensor on the bicycle's suspension system. It is also possible to determine at least one rider mass of a bicycle using at least one force sensor on the bicycle.

[0045] Alternatively, at least one rider mass is retrieved from at least one data storage device. At least one rider mass can be stored in at least one data storage device via at least one human-machine interface. For example, a cyclist can store at least one rider mass in at least one data storage device using at least one human-machine interface on the bicycle.

[0046] In addition, at least one rider damping level of a cyclist is determined using at least one suitable sensor on the bicycle.

[0047] For example, it is possible to determine at least one rider damping level of a rider of the bicycle by means of at least one acceleration sensor of the bicycle or by means of at least one displacement sensor of a spring-damper system of the bicycle or at least one pressure sensor of a spring-damper system of the bicycle.

[0048] Alternatively, at least one driver damping level is retrieved from at least one data storage device. At least one driver damping level can be stored in at least one data storage device via at least one human-machine interface. For example, a cyclist can store at least one driver damping level in at least one data storage device using at least one human-machine interface on the bicycle.

[0049] A rider damping rating quantifies the ability of a bicycle rider and the rider's footwear to absorb vibrations and shocks during a bicycle ride.

[0050] In a fourth step of the method according to the invention, at least one pedaling force is determined, wherein the pedaling force acts simultaneously at the same ends of the pedal cranks. For this purpose, at least one pedaling force is determined as a function of at least one acceleration of the bicycle in the direction of at least one vertical axis of the bicycle and at least one rider mass of the bicycle. Alternatively, at least one pedaling force is determined as a function of at least one acceleration of the bicycle in the direction of at least one vertical axis of the bicycle and at least one rider mass of the bicycle and at least one rider damping factor of the bicycle. Alternatively or additionally, at least one pedaling force can be determined by means of at least one force sensor of the bicycle.

[0051] In a fifth step of the method according to the invention, at least one mechanical load on the crank assembly is determined as a function of at least one pedaling force, wherein the pedaling force acts simultaneously on the same ends of the crank arms. A mechanical load on a crank assembly is understood to mean at least one mechanical load on at least one component of the crank assembly, or on at least one component mechanically connected to the crank assembly, or on at least one component of the crank assembly and on at least one component mechanically connected to the crank assembly. Preferably, at least one mechanical load is determined in the form of at least two opposing torsional moments and two bending moments on the crank axle and on both crank arms.

[0052] In a sixth step of the method according to the invention, at least one degree of damage to the crank assembly is determined as a function of at least one mechanical load on the crank assembly. A degree of damage to the crank assembly is understood to mean at least one degree of damage to at least one component of the crank assembly, or at least one component mechanically connected to the crank assembly, or at least one component of the crank assembly and at least one component mechanically connected to the crank assembly. Preferably, at least one degree of damage to the crank axle and at least one degree of damage to at least one crank arm are determined.

[0053] The degree of damage can be determined, for example, by means of a linear damage accumulation as a function of at least one mechanical load. For this purpose, at least one mechanical load is converted into at least one load spectrum using standard counting methods from materials science, where each load spectrum describes at least one frequency of at least one occurring mechanical load. The load spectrum is then compared with at least one S-N curve, and at least one degree of damage is determined.

[0054] A determined damage level is stored in at least one data storage device. A determined damage level can be retrieved from at least one data storage device. Alternatively or additionally, it is possible to transmit at least one determined damage level via mobile communication from a human-machine interface, such as a smartphone, to another data storage device, such as a server, for product improvement purposes.

[0055] Furthermore, it is possible to include at least one mechanical load for an existing accumulation of damage in order to determine at least one degree of damage to a component of the bicycle, such as a crank unit, more accurately.

[0056] In a seventh step of the method according to the invention, at least one damage limit of the crank unit is retrieved from at least one data storage device and compared with at least one determined degree of damage of the crank unit. A damage limit of the crank unit is understood to be at least one damage limit of at least one component of the crank unit, or at least one component mechanically connected to the crank unit, or at least one component of the crank unit and at least one component mechanically connected to the crank unit. Preferably, at least one damage limit of the crank axle is compared with at least one determined degree of damage of the crank axle, and at least one damage limit of a crank arm is compared with at least one determined degree of damage of a crank arm.

[0057] If at least one damage limit of the crank unit is reached or exceeded by at least one degree of damage to the crank unit, the procedure continues in an eighth step. Otherwise, the procedure is terminated.

[0058] In the eighth step of the method according to the invention, at least one notification perceptible to human senses can be generated by means of at least one human-machine interface of the bicycle. For example, a cyclist can be informed of an impending component failure or upcoming component maintenance by means of at least one notification from the human-machine interface. The method is then terminated.

[0059] In the method according to the invention, it is possible to retrieve all data necessary for the method from at least one sensor and from at least one data storage device at the beginning of the method.

[0060] Furthermore, at least one mechanical load on at least one component of the bicycle can be determined in relation to at least one mechanical load on the crankset. For example, a mechanical load on the bicycle frame can be determined.

[0061] The control unit comprises means for carrying out the method according to the invention. The control unit can, for example, be implemented as a control device (electronic control unit or electronic control module).

[0062] When the control unit is used in a bicycle or outside of a bicycle, the control unit is connected to at least one sensor and at least one data storage device or to at least one sensor, at least one data storage device and at least one human-machine interface in a signal-effective manner.

[0063] The sensor can be configured as a rotary angle sensor, torque sensor, acceleration sensor, force sensor, speed sensor, displacement sensor, or pressure sensor. The data storage device can be configured as a non-volatile data storage device, such as a read-only memory (ROM) in the form of an electrically erasable, programmable read-only memory (EEPROM) or a flash memory in the form of a NAND flash memory.

[0064] A signal-effective connection is one that enables data and signal exchange between the connected devices. For this purpose, each device has a corresponding interface. Data exchange, signal exchange, or both can occur via wired or wireless connections. The control unit, sensor, data storage device, and human-machine interface therefore have interfaces that facilitate such a connection.

[0065] The control unit can be integrated into a housing or into a housing containing the drive unit. The housing can be mechanically connected to or attached to a vehicle frame.

[0066] A computer program product comprises instructions which, when the program is executed by the control device already described, cause it to execute the procedure already described.

[0067] A computer-readable medium comprises instructions that, when executed by the control device described above, cause it to perform the procedure already described. The computer-readable medium can be, for example, a data carrier or a downloadable data stream.

[0068] The bicycle includes at least one control device for carrying out the method according to the invention.

[0069] Exemplary embodiments of the invention are shown in the figures. Specifically, they show: Fig. 1 a schematic representation of a bicycle according to an exemplary embodiment and a schematic representation of a drive unit of the bicycle Fig. 2 a schematic representation of various bicycle maneuvers Fig. 1 Fig. 3 A schematic representation of two different mechanical loads on a pedal crank unit according to an exemplary embodiment Fig. 4 a schematic representation of the time course of a rotation angle and a torque of a pedal crank shaft of the pedal crank unit of the bicycle Fig. 1 and a time course of an acceleration of bicycle 1 from Fig. 1 in the direction of the bicycle's vertical axis 1 out Fig. 1 Fig. 5 a representation of the process for determining a mechanical load on the pedal crank unit TKE of bicycle 1 from Fig. 1 Fig. 6 a representation of an alternative sequence of the procedure for determining a mechanical load on the pedal crank unit TKE of bicycle 1 from Fig. 1

[0070] Fig. Figure 1 shows a schematic representation of a bicycle according to an exemplary embodiment as well as a schematic representation of a drive unit of the bicycle.

[0071] In Fig. 1a The bicycle 1 is exemplified as an e-bike, pedelec, S-pedelec, or, in particular, as an e-mountain bike (eMTB). Alternatively, the bicycle 1 can be configured as a cargo bike, tricycle, quadricycle, velomobile, or e-snowbike. The bicycle 1 has at least one bicycle frame 14 and at least one drive system 2.

[0072] The drive system 2 comprises at least one drive unit 3 with at least one electric drive motor EM and at least one crank unit TKE. The drive unit 3 can be arranged in the area between a down tube of the bicycle frame 14 and a chainstay of the bicycle frame 14. At least one rotary movement can be generated at a rear wheel 12 of the bicycle 1 via the drive unit 3. The drive unit 3 is described in detail in Fig. Figure 1b shows the pedal crank unit TKE, which comprises at least one pedal crank axle 4, at least two pedal cranks 5 arranged diametrically opposite each other, at least two pedals 6, and at least two pedal axles 7. The pedal cranks 5 are non-rotatably connected to the pedal crank axle 4. The pedal cranks 5 are non-rotatably connected to the pedal axles 7. The pedal axles 7 are rotatably connected to the pedals 6.

[0073] The pedal crank unit (TKE) allows the rider of bicycle 1 to input power into the drive unit 3 and thus into the drive system 2. The rider's power output is proportional to the rotational movement (DB) of the pedal crank shaft 4 generated by the rider. This rotational movement (DB) of the pedal crank shaft 4 results from the rotational movement of the pedal cranks 5. Fig. 1b is a position of the crank arms 5, the pedals 6 and the pedal shafts 7 after a rotational movement DB of the crank arms 5, the pedals 6 and the pedal shafts 7 shown with dashed lines.

[0074] The rotational movement DB of the crank arm 4 depends on at least one torque DM. The torque DM correlates with at least one pedaling force TF, which acts at most at one end of at most one crank arm 5 at any given time. The drive unit 3 has at least one torque sensor SenM and at least one angle sensor SenW. At least one torque DM can be determined at the crank arm 4 using the torque sensor SenM. Furthermore, an angle DW of the crank arm 4 can be determined using the angle sensor SenW.

[0075] Furthermore, the drive system 2 includes an energy storage device 13, which is electrically connected to the electric drive motor EM via a line 17 and is also connected in a signal-effective manner. Additionally, the energy storage device 13 can supply the electric drive motor EM with energy (motor operation) or can be supplied with electrical energy by the electric drive motor EM (generator operation).

[0076] In addition to the torque generated by the cyclist, the electric drive motor (EM) can also generate variable torque, allowing the cyclist's power to be partially or completely replaced by the mechanical power of the electric drive motor. Consequently, the bicycle can be powered either purely by muscle power, purely electrically, or in hybrid mode by both muscle power and electricity.

[0077] The drive system 2, the electric drive motor EM and the energy storage device 13 are connected to a control unit EC of the bicycle 1 by means of a line 17 in a signal-effective manner.

[0078] Furthermore, the bicycle 1 has a steering system consisting of a movable axle 8 and a handlebar 9. The movable axle 8 is connected to the frame 14 of the bicycle 1, as well as to the handlebar 9 and a front wheel 11 of the bicycle 1. The movable axle 8 can be rotated about its rotationally symmetrical axis by means of the handlebar 9, thereby enabling a steering movement of the front wheel 11.

[0079] The handlebar 9 has at least one human-machine interface (HMI). The human-machine interface (HMI) is connected to the control unit (EC) of the bicycle 1 via a signal.

[0080] Furthermore, bicycle 1 has at least one accelerometer SenB. The accelerometer SenB can be positioned, for example, near the movable axis 8. The accelerometer SenB allows the acceleration of the bicycle in the direction of a vertical axis Z of bicycle 1 to be determined. Additionally, at least one acceleration of the bicycle in the direction of a longitudinal axis X and in the direction of a transverse axis Y can be determined. The accelerometer SenB is connected to the control unit EC of bicycle 1 via a signal-effective connection 17.

[0081] Furthermore, the bicycle 1 has at least one brake 10 on the rear wheel 12. The brake 10 can be, for example, a disc brake, a rim brake, or a drum brake. Additionally, it is possible to combine the brake 10 with at least one anti-lock braking system (ABS). Actuating the brake 10 reduces or prevents the rotation of the rear wheel 12. The brake 10 is connected to the control unit EC via a signal.

[0082] Furthermore, the bicycle 1 has a spring damper system 15 with a pressure sensor SenP and another spring damper system 16 with a displacement sensor SenL.

[0083] Furthermore, the bicycle 1 has at least one speed sensor SenN on the rear wheel 12. The speed sensor SenN is connected to the control unit EC via a line 17. When the rear wheel 12 rotates, at least one rotational speed of the rear wheel can be determined by means of the speed sensor SenN.

[0084] Fig. Figure 2 shows a schematic representation of various riding maneuvers of bicycle 1. Fig. 1.

[0085] In Fig. Figure 2a illustrates the downhill riding maneuver. The bicycle descends a slope with an uneven surface, as can be seen at time t1 and time t2. To increase stability, the rider braces their feet against the pedals. Due to the uneven surface, both the bicycle and the rider experience acceleration along the bicycle's vertical axis. This results in a pedaling force acting simultaneously at the same ends of the crank arms, dependent on the rider's mass and the bicycle's vertical acceleration. At time t1, the rider is seated on the saddle, while at time t2, the rider is standing on the pedals.The simultaneous pedaling force at the same ends of the pedal cranks is less in magnitude at time t1 than at time t2, because at time t1 only part of the rider's mass rests on the pedals, whereas at time t2 the entire rider's mass rests on the pedals.

[0086] In Fig. Figure 2b illustrates the bunny hop maneuver. The maneuver is performed from a slope. At an initial time t1, the cyclist pulls the handlebars upwards, causing the front wheel to lift off the ground. To achieve this, the cyclist shifts their center of mass and applies their full weight to the pedals. This generates a pedaling force, dependent on the cyclist's mass, and an acceleration along the bicycle's vertical axis, acting simultaneously at the same ends of the crank arms. The cyclist then generates momentum by shifting their center of mass. This momentum causes the bicycle to accelerate along its vertical axis. This acceleration lifts the bicycle off the ground, resulting in a jump.At a subsequent third time point, t3, the bicycle lands back on the road surface. Upon landing, the bicycle experiences an acceleration along its vertical axis, dependent on the height from which it fell. At landing, the rider's feet are on the pedals, resulting in a pedaling force acting simultaneously at the same ends of the crank arms. This force is dependent on the acceleration along the bicycle's vertical axis and the rider's total mass. The magnitude of the acceleration along the vertical axis is lower at time t1 than at time t3.

[0087] Fig. Figure 3 shows a schematic representation of two different mechanical loads on a crankset according to an exemplary embodiment. The crankset TKE has at least one crank axle 4 and at least two crank arms 5 arranged diametrically opposite each other. Additionally, the crankset TKE has at least two pedal axles 7 and at least two pedals 6. Both crank arms 5 are non-rotatably connected to the crank axle 4. The crank arms 5 are non-rotatably connected to the pedal axles 7. The pedal axles 7 are rotatably connected to the pedals 6. Both crank arms 5 have the same length.

[0088] In Fig. 3a. A pedaling force TF acts at most on one end of a crank arm 5 of the pedal crank unit TKE at any given time. Depending on the length of the crank arm 5 of the pedal crank unit TKE, the pedaling force TF generates a torque DM on the pedal crank axle 4, causing the pedal crank axle 4 to rotate about a rotationally symmetric axis of rotation by an angle DW. The same applies to the crank arms 5, pedal axles 7, and pedals 6. The torque DM is proportional to the pedaling force and can be determined using a torque sensor SenM.

[0089] A mechanical load on the crank unit TKE, as in Fig. As shown in 3b, this arises due to certain driving maneuvers, as in Fig. 2a and Fig. 2b shown. Fig. 3b A pedaling force TF acts simultaneously at both ends of the pedal cranks 5. Depending on the length of a pedal crank 5, the pedaling force TF generates two opposing torsional moments TM, which act on the pedal crank axle 4. Superimposed on the torsional moments TM are two bending moments BM, which act on the ends of the pedal crank axle 4. The torsional moments TM and the bending moments BM cannot be determined using the torque sensor SenM.

[0090] Furthermore, it is possible that a first pedaling force acts at one end of a crank arm 5 and a second pedaling force acts at one end of another crank arm 5, with both pedaling forces fluctuating around an identical mean value over time. In this case, the crank arm shaft 4, both crank arms 5, both pedal shafts 7, and both pedals 6 oscillate back and forth by a rotational angle DW.

[0091] Fig. Figure 4 shows a schematic representation of the time course of a rotation angle and a torque of a pedal crank shaft of the pedal crank unit of the bicycle. Fig. 1 and a time course of an acceleration of bicycle 1 from Fig. 1 in the direction of the bicycle's vertical axis 1 out Fig. 1.

[0092] In the first time period ZA1, the temporal progressions during a bicycle ride on a level road surface are depicted. A mechanical load acts upon it, as in Fig. Figure 3a shows the effect on the bicycle's crank unit as a result of a pedaling force acting at most at one end of at most one crank arm. In a second time period, ZA2, the time profiles during a riding maneuver, such as a downhill position, a bunny hop, or a jump, on an uneven road surface are depicted. A mechanical load acts on this, as shown in Figure 3a. Fig. Figure 3b shows the effect on the bicycle's crank unit due to at least one pedaling force acting at the same ends of the crank arms. In the first time interval ZA1, the rotation angle DW and the torque DM are greater in magnitude than in time interval ZA2, whereas the acceleration AZ of the bicycle in the direction of its vertical axis is less in magnitude than in time interval ZA2.

[0093] Determining a mechanical load, as in Fig. 3b, at the crank unit, occurs as soon as the rotation angle DW is within a rotation angle interval DWI and the torque DM is within a torque interval DMI.

[0094] Fig. Figure 5 shows a representation of the procedure for determining a mechanical load on the crank unit TKE of bicycle 1. Fig. 1. At the beginning of the procedure 100, in a first step 101 at least one rotation angle DW of the pedal crank shaft of the pedal crank unit is determined by means of the rotation angle sensor SenW of the bicycle and at least one torque DM of the pedal crank shaft of the pedal crank unit is determined by means of the torque sensor SenM of the bicycle.

[0095] In a second step 102 of the procedure 100, at least one rotation angle interval DWI and at least one torque interval DMI are retrieved from at least one data storage STO. Subsequently, at least one comparison is made between at least one determined rotation angle DW and a retrieved rotation angle interval DWI, as well as at least one comparison between at least one determined torque DM and at least one retrieved torque interval DMI. If at least one determined rotation angle DW exceeds the rotation angle interval DWI, or if at least one determined torque DM exceeds the torque interval DMI, the procedure 100 continues in a third step 103. Otherwise, the procedure 100 is terminated prematurely.

[0096] In the third step 103 of procedure 100, at least one acceleration AZ of the bicycle in the direction of the bicycle's vertical axis is determined using the bicycle's acceleration sensor SenB. Additionally, at least one rider mass GW and at least one rider damping coefficient DG are retrieved from at least one data storage device STO.

[0097] In a fourth step 104 of procedure 100, at least one pedaling force TF is determined, whereby the pedaling force TF acts simultaneously at the same ends of the pedal cranks of the pedal crank unit. For this purpose, at least one pedaling force TF is determined as a function of at least one acceleration AZ of the bicycle in the direction of the vertical axis of the bicycle and the applied rider mass GW as well as the applied rider damping coefficient DG.

[0098] In a fifth step 105 of the procedure 100, at least one mechanical load MBL on the crank unit is determined as a function of at least one pedaling force TF, whereby the pedaling force TF acts simultaneously on the same ends of the cranks of the crank unit.

[0099] In a sixth step 106 of the procedure 100, at least one degree of damage SG of the pedal crank unit is determined depending on at least one mechanical load MBL on the pedal crank unit.

[0100] In a seventh step 107 of the procedure 100, at least one damage limit SGZ of the crank unit is retrieved from at least one data storage device STO and compared with at least one determined damage degree SG of the crank unit. If at least one damage limit SGZ of the crank unit is reached or at least one damage degree SG of the crank unit is exceeded, the procedure continues in an eighth step 108. Otherwise, the procedure is terminated.

[0101] In step 108 of procedure 100, at least one notification perceptible to human senses (MSG) is generated by means of at least one human-machine interface (HMI) of the bicycle. Procedure 100 is then terminated.

[0102] Fig. Figure 6 shows a representation of an alternative sequence of the procedure for determining a mechanical load on the pedal crank unit TKE of bicycle 1. Fig. 1. Steps 101, 102, 104, 106, 107 are linked to the corresponding steps from Fig. 5 identical. Only the differences between the process from Fig. 5 for the alternative procedure from Fig. 6 explained.

[0103] In an alternative fourth step 114 of procedure 100, at least one pedaling force TF is determined as a function of a requested rider mass, a requested rider damping degree DG, and an acceleration AZ of the bicycle in the direction of the bicycle's vertical axis. Additionally, at least one pedaling force TF is determined using the bicycle's force sensor SenF. An average pedaling force TF is calculated from both determined pedaling forces TF. Reference sign 1 bicycle 2 Drive system 3 Drive unit 4. Crankshaft 5 Crankset 6 pedal 7 Pedal shaft 8 movable axes 9 handlebars 10 Brake 11 Front wheel 12 rear wheel 13 Energy storage 14 bicycle frames 15 Spring-damper system 16 spring-damper system 17 Management X Longitudinal axis Y transverse axis Z vertical axis TKE crank unit EM electric drive motor EC control unit SenM torque sensor SenW rotary angle sensor SenB accelerometer SenF force sensor SenN speed sensor SenP pressure sensor SenL displacement sensor HMI Human-Machine Interface DB rotary motion DW rotation angle DM torque TF pedal power TM Torsional Moment BM bending moment t time t1 first time point t2 second time point t3 third time point ZA1 first time period ZA2 second time period AZ acceleration in the direction of a vertical axis 100 procedures 101 First Step 102 second step 103 third step 104 fourth step 114 alternative fourth step 105 fifth step 106 sixth step 107 seventh step 108 eighth step Start of procedure End of procedure STO Data Storage DWI Rotation Angle Interval DMI torque interval GW driver mass DG driver damping level MBL mechanical stress SG Degree of damage SGZ damage threshold MSG notification

Claims

[1] Method (100) for determining at least one mechanical load (MBL) on a drive unit (3) of a bicycle (1), characterized by, that the drive unit (3) has at least one crank unit (TKE), wherein the crank unit (TKE) has at least one crank shaft (4) and at least two crank arms (5) arranged diametrically opposite each other, wherein the crank arms (5) are or can be connected to the crank shaft (4) in a rotationally fixed manner, wherein at least one determination of at least one mechanical load (MBL) on the crank unit (TKE) is carried out at at least one rotation angle (DW) of the crank shaft (4) lying within at least one rotation angle interval (DWI) and at at least one torque (DM) of the crank shaft (4) lying within at least one torque interval (DMI), wherein at least one mechanical load (MBL) on the crank unit (TKE) is determined as a function of at least one pedaling force (TF), wherein the pedaling force (TF) acts simultaneously on the same ends of the pedal arms (5). [2] Method (100) according to claim 1, characterized by, that at least one mechanical load (MBL) on at least one component of the bicycle (1) can be determined as a function of at least one mechanical load (MBL) on the crank unit (TKE). [3] Method (100) according to claim 1, characterized by , that at least one rotation angle interval (DWI) is retrieved from at least one data storage (STO) and at least one torque interval (DMI) is retrieved from at least one data storage (STO) or at least one rotation angle interval (DWI) and at least one torque interval (DMI) is retrieved from at least one data storage (STO). [4] Method (100) according to claim 1, characterized by , that at least one rotation angle (DW) of the pedal crank shaft (4) is determined by means of at least one rotation angle sensor (SenW) of the bicycle (1). [5] Method (100) according to claim 1, characterized by, that at least one torque (DM) of the pedal crank shaft (4) is determined by means of at least one torque sensor (SenM) of the bicycle (1). [6] Method (100) according to claim 1, characterized by , that at least one pedaling force (TF) can be determined by means of at least one force sensor (SenF) of the bicycle (1). [7] Method (100) according to claim 1, characterized by , that the pedaling force (TF) is determined as a function of at least one acceleration (AZ) of the bicycle in the direction of at least one vertical axis (Z) of the bicycle (1) and at least one rider mass (GW) of the bicycle (1) or as a function of at least one acceleration (AZ) of the bicycle (1) in the direction of at least one vertical axis (Z) of the bicycle (1) and at least one rider mass (GW) of the bicycle (1) as well as at least one rider damping factor (DG) of the bicycle (1). [8] Method (100) according to claim 7, characterized by, that at least one acceleration (AZ) of the bicycle (1) in the direction of at least one vertical axis (Z) of the bicycle (1) is determined by means of at least one acceleration sensor (SenB) of the bicycle (1). [9] Method (100) according to claim 7, characterized by , that at least one rider mass (GW) is determined by means of at least one suitable sensor of the bicycle (1) or retrieved from at least one data storage device (STO), wherein at least one rider mass (GW) can be stored in at least one data storage device (STO) by means of at least one human-machine interface (HMI) of the bicycle (1). [10] Method (100) according to claim 7, characterized by, that at least one rider damping level (DG) is determined by means of at least one suitable sensor of the bicycle (1) or retrieved from at least one data storage device (STO), wherein at least one rider damping level (DG) can be stored in at least one data storage device (STO) by means of at least one human-machine interface (HMI) of the bicycle (1). [11] Method (100) according to claim 1, characterized by, that at least one degree of damage (SG) of the crank unit (TKE) is determined as a function of at least one mechanical load (MBL) on the crank unit (TKE) and compared with at least one damage limit (SGZ) of the crank unit (TKE), wherein at least one degree of damage (SG) of the crank unit (TKE) is stored in at least one data storage device (STO), wherein at least one damage limit (SGZ) of the crank unit (TKE) is retrieved from a data storage device (STO), wherein, in the event of at least one damage limit (SGZ) of the crank unit (TKE) being reached or at least one being exceeded, at least one notification (MSG) perceptible to human senses can be generated by means of at least one human-machine interface (HMI) of the bicycle (1). [12] Control unit (EC) for a bicycle (1), characterized by, that at least one sensor and at least one data storage device (STO) or at least one sensor, at least one data storage device (STO) and at least one human-machine interface (HMI) can be connected to the control device (EC) in a signal-effective manner, wherein the sensor can be configured as a rotary angle sensor (SenW) or a torque sensor (SenM) or an acceleration sensor (SenB) or a force sensor (SenF) or a speed sensor (SenN) or a displacement sensor (SenL) or a pressure sensor (SenP) and wherein the control device (EC) comprises means for carrying out the method (100) according to one of claims 1 to 11. [13] Bicycle (1) with at least one control unit (EC) according to claim 12.

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