Method for controlling a drive train of a human-powered vehicle, drive train and human-powered vehicle

Abstract

A method for controlling a drive train (4) of a human-powered vehicle (2) is described, wherein the drive train (4) has a drive motor (12) for providing drive force to assist a driver of the vehicle (2) in driving the vehicle (2). The method comprises determining (S1) a force applied by the driver to drive the vehicle (2). The method further comprises determining (S2) a first time derivative of the determined force. The method further comprises controlling (S3) the drive motor (12), wherein the assistance by the drive motor (12) is switched on or off depending on the determined first time derivative of the force. Furthermore, a drive train (4) for a human-powered vehicle (2) and a human-powered vehicle (2) having such a drive train (4) are described.

Description

[0001] The present invention relates to a method for controlling a drive train of a human-powered vehicle. Furthermore, the present invention relates to a drive train for a human-powered vehicle and to a human-powered vehicle having such a drive train.

[0002] Human-powered vehicles, such as bicycles, e-bikes, pedelecs, or cargo bikes, can also have a drive motor to assist in propelling the vehicle. For example, a pedelec, as a human-powered vehicle, can have an electric motor to assist in propulsion. The assistance provided by the drive motor must be controlled. For safety reasons, for example, assistance may only be provided when a driver of the vehicle is pedaling. To determine whether the driver is pedaling, a driver torque can be measured. The driver torque is the torque that the driver of the vehicle applies to a pedal crankshaft of the vehicle to propel the vehicle using muscle power. Methods and systems that control the drive motor depending on the driver torque are known from the prior art.For example, DE 10 2022 132 256 A1 describes how a driver torque is detected with a sensor, and the drive motor is controlled based on this. Methods and systems are also known from the prior art that control the drive motor based on the first time derivative of the driver torque.

[0003] The object of the invention is to improve the control of the drive motor of a muscle-powered vehicle as a function of the muscle power applied by the driver to drive the vehicle. This object is achieved by the subject matter of the independent claims.

[0004] In a first aspect, the invention relates to a method for controlling a drive train of a human-powered vehicle. The human-powered vehicle can be, for example, a bicycle, e-bike, pedelec, or cargo bike. The method for controlling the drive train can be a method for controlling a drive motor, such as an electric motor of the drive train. Steps of the method can be carried out, for example, using a control device of the vehicle.

[0005] The drivetrain has a drive motor for providing drive power to assist the driver of the vehicle in driving the vehicle. The drive motor can be an electric motor. The drive motor can be used to relieve the driver's workload while driving and, alternatively or additionally, to increase the vehicle's range. The drive motor can be configured to provide drive power to relieve the driver's workload. For example, drive power provided by the driver can be used as muscle power, while drive power provided by the drive motor can be used to drive the vehicle. The drive power provided by the drive motor can relieve the driver's workload.

[0006] The method comprises determining a force applied by the driver to drive the vehicle. This force can correspond to the muscular force applied by the driver to drive the vehicle. The determining can be or comprise a measurement. For example, the force applied by the driver to drive the vehicle as muscular force can be measured using one or more sensors. If the force is measured using multiple sensors, the force can be resolved vectorially, for example. This can be used to determine the magnitude and direction of the force, for example. The force can be determined for one or more points in time. A temporal profile of the force can be determined. The force applied by the driver can be measured periodically. In this way, the force can be determined as a discrete function of time.

[0007] The method comprises determining a first time derivative of the determined force. The first time derivative can be referred to as a gradient. The determination of the first time derivative can be carried out using a numerical method. The determination can be an approximate determination. A numerical method can, for example, determine the first time derivative using a difference quotient. A numerical method can, for example, determine the first time derivative using a differentiating FIRR low-pass filter. For example, the determined force can be derived over time as a discrete function of time with time-equidistant intervals between the measured values ​​of the force. For example, a time profile of the force can be determined, and depending thereon, a time profile of the first time derivative of the force can be determined.

[0008] The method further comprises controlling the drive motor, wherein the assistance by the drive motor is switched on and alternatively or additionally switched off depending on the determined first time derivative of the force. For example, a first value of the first time derivative of the force can be determined at a first point in time, and the control of the drive motor can be carried out such that the assistance is switched on depending on this first value. The first value can correspond to a value which indicates that the driver is pedaling. When the assistance is switched on, for example, drive power is provided by the drive motor to drive the vehicle and is transferred, for example, to a driven wheel of the vehicle to drive the vehicle. For example, a second value of the first time derivative of the force can be determined at a second point in time later than the first.This second value may be different from the first value. The second value may correspond to a value which suggests that the rider is not pedaling and, for example, is merely placing their feet on the pedals. For example, the second value may be zero or almost zero, meaning, for example, that there may be no significant change over time in the force applied by the rider to propel the vehicle. The drive motor can be controlled in such a way that the assistance provided by the drive motor is switched off depending on this second value. If the assistance is switched off, for example, no driving force is provided by the drive motor to propel the vehicle.

[0009] Alternatively or additionally, it can be determined whether the rider is pedaling or not based on a specific time profile of the first time derivative of the force. This can be done, for example, by comparing it with at least one predetermined time profile of a first time derivative of the force applied by the rider for propulsion. This predetermined time profile can be stored on the control device executing the method.

[0010] Such a method makes it particularly easy to detect the rider's pedaling and, depending on the rider's pedaling, to switch the drive motor assistance on or off. Switching off the drive motor assistance when the rider is not pedaling may be necessary to increase the safety of human-powered vehicles.

[0011] The torque applied by the rider can be highly dependent on the crank angle of the crank arms on the pedal crankshaft. For example, the rider torque is small when the pedal crankshaft is in a vertical position, but when the crank arms of the pedal crankshaft are in a horizontal position, the rider torque is comparatively large. Accordingly, methods that measure the rider torque and use this measured rider torque to engage or disengage the drive motor are crank angle dependent. Furthermore, methods that use a first time derivative of a rider torque measured in this way to engage or disengage the drive motor are also crank angle dependent. Thus, the time required to detect pedaling may be longer than the method provided here.This can result in a significant time delay when switching the drive motor on or off depending on the specific rider torque in known methods and systems. This can happen, for example, if the rider starts pedaling with the crank arms in an almost vertical position. In this crank position, it can be difficult, for example, to determine rider torque and thus a time derivative of the rider torque, and thus pedaling, using conventional torque sensors. This is uncomfortable for the rider because, for example, there is a significant time delay before the assistance is switched on by the drive motor. Consequently, this disadvantage also affects conventional methods in which the first time derivative of the rider torque is determined and the assistance is switched on or off depending on this. This time delay can be reduced using the method provided.Accordingly, the method represents a possibility to switch the support of the drive motor on or off depending on the pedaling by the driver and at the same time the detection time of the pedaling can be reduced, which can, for example, improve comfort and safety.

[0012] Detection accuracy can also be improved in that there's no need to wait until the crank arms are horizontal, allowing the rider's torque to be accurately determined. Safety can be improved in that the rider can rely on the drive motor's activation or deactivation without significant delay, depending on pedaling and regardless of the crank position. It accurately detects whether the rider is pedaling or not.

[0013] According to a further embodiment, the method can be characterized in that the drive train has pedals. Furthermore, the drive train can have a pedal crankshaft, and crank arms can be connected in a rotationally fixed manner to the pedal crankshaft. For example, two crank arms can be connected in a rotationally fixed manner to the pedal crankshaft, wherein a pedal can be rotatably mounted at one end of each crank arm. The pedal crankshaft can thus also be referred to as a pedal crankshaft. The pedal crankshaft can be rotatably mounted on a frame of the vehicle by means of a bearing of the vehicle. The bearing can be a rolling bearing, for example a ball bearing, a needle bearing, or a roller bearing. The driving force of a driver of the vehicle can be absorbed via the pedals to propel the vehicle.

[0014] Furthermore, determining the force applied by the driver can comprise determining a force applied by the driver to the pedals. This force can be referred to as pedal force. Determining the pedal force can be or comprise a measurement. For example, the force applied by the driver to the pedals can be measured using one or more sensors. The pedal force can be determined in terms of magnitude. The pedal force can be determined for each pedal using at least one sensor per pedal. The total force applied by the driver to the pedals can be a sum of the individual forces applied per pedal.

[0015] Determining the first time derivative may include determining a first time derivative of the force applied by the driver to the pedals. For example, a time profile of the pedal force can be measured and thus determined, and a time profile of the first time derivative of the pedal force can be determined based thereon. Furthermore, the drive motor can be controlled based on the determined first time derivative of the force applied to the pedals.

[0016] This makes it particularly easy to determine whether the rider is pedaling by determining the first time derivative of the force applied by the rider to the pedals. Compared to conventional methods, in which the rider torque applied to the pedal crankshaft by the rider is measured and determined using a torque sensor, this method makes it particularly easy to detect whether the rider is pedaling. Also compared to conventional methods, in which a first time derivative of the rider torque is determined, this method makes it particularly easy to detect whether the rider is pedaling. This is done by determining the force applied by the rider to the pedals and determining the first time derivative of the force.Determining rider torque with a dedicated torque sensor is usually more complex than determining pedal force and determining the first time derivative of pedal force due to rotating parts on the crankshaft.

[0017] According to a further embodiment, the method can be characterized in that the drive train has a pedal crankshaft. Crank arms can be connected to the pedal crankshaft in a rotationally fixed manner. For example, two crank arms can be connected to the pedal crankshaft in a rotationally fixed manner, wherein a pedal can be rotatably mounted at one end of each crank arm. The pedal crankshaft can therefore also be referred to as a pedal crankshaft. The pedal crankshaft can be rotatably mounted on a frame of the vehicle by means of a bearing of the vehicle. The bearing can be a rolling bearing, for example a ball bearing, a needle bearing, or a roller bearing. The driving force of a driver of the vehicle can be absorbed via the pedal crankshaft to propel the vehicle.

[0018] Determining the force applied by the rider can involve determining a force acting from the pedal crankshaft onto the bearing. The rider can apply driving force as muscle power to the pedals and thus onto the pedal crankshaft. The force acting from the pedal crankshaft onto the bearing can be referred to as bearing force. Determining can be or involve measuring. For example, the force acting from the pedal crankshaft onto the bearing can be measured using one or more sensors. If the force is measured using multiple sensors, the force can be resolved vectorially, for example. This can be used to determine the magnitude and direction of the force, for example.

[0019] Furthermore, determining the first time derivative may include determining the first time derivative of the force acting from the pedal crankshaft on the bearing. For example, a time profile of the bearing force can be measured and thus determined, and based on this, a time profile of the first time derivative of the bearing force can be determined. Furthermore, controlling the drive motor can be carried out depending on the determined first time derivative of the force acting from the pedal crankshaft on the bearing.

[0020] This makes it particularly easy to determine whether the rider is pedaling by determining the first time derivative of the force acting from the pedal crankshaft on the bearing. Compared to conventional methods, in which the rider torque applied by the rider is measured and determined using a torque sensor, this method makes it particularly easy to detect whether the rider is pedaling. Also compared to conventional methods, in which a first time derivative of the rider torque is determined, this method makes it particularly easy to detect whether the rider is pedaling. This is done by determining the force acting from the pedal crankshaft on the bearing and determining the first time derivative of the force.Determining the rider torque with a dedicated torque sensor is usually more complex than determining the bearing force and determining the first time derivative of the bearing force due to rotating parts on the crankshaft.

[0021] According to a further embodiment, the method can be characterized in that, during control, the assistance can be switched on by the drive motor when the determined first time derivative of the force exceeds a first threshold. Switching on the assistance can involve providing drive force by the drive motor. The first threshold can be defined, for example, such that the value of the first time derivative of the force becomes greater than the first threshold when the rider begins pedaling. For example, the rider can begin pedaling, and thus the value of the first time derivative of the force can exceed the first threshold.

[0022] Thus, depending on the first threshold value, which can be stored, for example, as a hard-coded value on the vehicle's control device, a limit value for activating assistance by the drive motor can be objectively defined. This allows the time at which pedaling begins to be detected. Thus, the method can implement event detection regarding the start of pedaling by determining the first time derivative of the force. This allows pedaling to be detected particularly quickly, since only a change in state with regard to pedaling is detected.

[0023] According to a further embodiment, the method can be characterized in that, during control, the assistance provided by the drive motor can be switched off if the determined first time derivative of the force falls below a second threshold. Switching off the assistance can be a termination of the provision of the drive force by the drive motor. The first and second thresholds can be different. For example, the first and second thresholds can have different signs. The magnitude of the first threshold can be the same as or different from the magnitude of the second threshold.

[0024] This allows the point in time at which pedaling ceases to occur to be detected. The method can thus implement event detection regarding the cessation of pedaling by determining the first time derivative of the force. This allows pedaling to be detected particularly quickly, since only a change in state regarding pedaling is detected.

[0025] For example, a first time derivative of the force applied by the driver to propel the vehicle can be positive at a first point in time and exceed the first threshold value, which can be positive. This can be used to determine that the driver is pedaling and applying muscle power to propel the vehicle at the first point in time. In such a case, the force applied by the driver can increase over time. At a later, second point in time, the first time derivative of the force applied by the driver to propel the vehicle can be negative and fall below the second threshold value, which can be negative. In such a case, the force applied by the driver can decrease over time. This can be used to determine, for example, that the driver is no longer applying muscle power to propel the vehicle.

[0026] For example, a hysteresis effect can be provided by the method if the values ​​of the first and second threshold values ​​are different. For example, the value of the first threshold value can be greater than the value of the second threshold value. If, for example, the value of the first threshold value is greater than the value of the second threshold value, the assistance can only be switched on when the first time derivative of the force is larger, whereas the assistance can be switched off when the first time derivative is smaller. This can ensure, for example, that the activation only occurs when a time gradient of the force applied by the driver to drive the vehicle exceeds a certain minimum value.At the same time, the smaller value of the second threshold ensures that the rider has to stop applying power more quickly than they started. The assistance can then be switched off. This allows the drive motor to switch off the assistance in a defined manner via the second threshold.

[0027] According to a further embodiment, the method can be characterized in that a further measured variable can be determined on the drive train. As a further measured variable, for example, the crank angle of the crank arms of the pedal crankshaft, the crank angular velocity or a rotational speed of a wheel, for example a driven wheel of the vehicle, can be determined. For example, the measured variable can be measured, for example with at least one sensor. Alternatively or additionally, the measured variable can be determined approximately, for example with an approximation method depending on a further measured variable. The control of the drive motor can be carried out depending on the determined further measured variable. In this case, the control of the drive motor can be carried out depending on the determined further measured variable and additionally depending on the determined first time derivative of the force.Thus, the activation or deactivation of the support by the drive motor can be carried out both depending on the determined first time derivative of the force and depending on the determined further measured variable.

[0028] This can, for example, further improve accuracy. Alternatively or additionally, it can make the process more fail-safe, as redundancy can be implemented.

[0029] According to a further embodiment, the drive train can have a pedal crankshaft, and when determining the further measured variable, a torque on the pedal crankshaft can be determined. The torque can be determined, for example, using a sensor, such as a torque sensor, and alternatively or additionally using other means, for example, using an approximation method depending on further measured variables. The drive motor can be controlled depending on the determined torque. In this case, the drive motor can be controlled and thus, for example, the activation or deactivation of the assistance by the drive motor can be carried out both depending on the determined first time derivative of the force and depending on the determined torque on the pedal crankshaft.

[0030] Furthermore, the first time derivative of the torque at the pedal crankshaft can be determined, for example, using the control device. The drive motor can be controlled depending on the determined first time derivative of the torque. Controlling the drive motor and thus, for example, switching the assistance provided by the drive motor on or off can be performed both depending on the determined first time derivative of the force and depending on the determined first time derivative of the torque at the pedal crankshaft.

[0031] This method allows redundancy to be implemented when controlling the drive motor and when providing assistance by the drive motor by switching it on or off. This can be advantageous for safety-critical functions, such as switching the assistance of the drive motor on or off. Such a method can also reduce the time delay that is present in conventional methods, which only have a torque sensor for determining the driver torque and switch the assistance of the drive motor on or off depending on this. With the method presented here, for example, the switching on or off can initially be carried out solely depending on the determined first time derivative of the force.Within a specific time window, this control of the assistance and the control of the drive motor can then be checked as a function of the specific torque, and alternatively or additionally as a function of the specific first time derivative of the torque. This allows the specific driver torque to be used to control the drive motor to engage or disengage the assistance of the drive motor, whereby the time delay can be reduced by means of the specific first time derivative of the force. For example, with such a method, the driver torque can also be determined uniaxially, for example, only with respect to one crank arm.This may be sufficient for the method described here, since the determined driver torque is used, for example, only to check the control of the drive motor for assistance by the drive motor depending on the determined first time derivative of the force.

[0032] A second aspect of the present invention relates to a drive train for a human-powered vehicle. The human-powered vehicle can be a bicycle, e-bike, pedelec, or cargo bike. The drive train can have pedals. The drive train can have a pedal crankshaft. Crank arms can be connected to the pedal crankshaft in a rotationally fixed manner. For example, two crank arms can be connected to the pedal crankshaft in a rotationally fixed manner, with a pedal being rotatably mounted at one end of each crank arm. The pedal crankshaft can therefore also be referred to as a pedal crankshaft. The pedal crankshaft can be rotatably mounted on a frame of the vehicle by means of a bearing of the vehicle. The bearing can be a rolling bearing, for example a ball bearing, a needle bearing, or a roller bearing. Driving force from a driver of the vehicle to propel the vehicle can be absorbed via the pedals and further via the pedal crankshaft.

[0033] Furthermore, the drive train can include a drive motor, such as an electric motor, for providing drive power to assist a driver of the vehicle in driving the vehicle. The drive motor can be configured to reduce the driver's workload while driving and to increase the range. Furthermore, the drive motor can be configured to provide drive power to reduce the driver's workload.

[0034] The drivetrain may include a means for determining a force applied by the driver to propel the vehicle. The means for determining the force may include one or more sensors for measuring the force. For example, the drivetrain may include at least one sensor per pedal for measuring a force applied to the pedals by the driver of the vehicle, for example, a pedal force. Alternatively or additionally, the drivetrain may include at least one sensor for measuring a force acting from the pedal crankshaft on the bearing, for example, a bearing force.

[0035] The at least one sensor per pedal for measuring pedal force can, for example, be arranged in the pedal, for example, below a surface of the pedal on which the rider places their foot when pedaling. The pedal itself can be rotatably mounted on a crank arm, but the sensor for measuring the force can be arranged stationary in the surface of the pedal. This makes it particularly easy to measure force, for example, because the sensor is arranged stationary in the surface of the pedal and does not rotate relative to the surface of the pedal and thus relative to the pedal.

[0036] The at least one sensor for measuring the bearing force can be a sensor on an outer ring of the bearing for measuring the force. The outer ring can be a bearing shell of the bearing. The sensor can be arranged, for example, on a non-rotating outer ring of the bearing. This makes it particularly easy to measure the force on a non-rotating part, such as the non-rotating outer ring of the bearing.

[0037] Alternatively or additionally, the sensor for measuring the bearing force can be a strain gauge on an outer ring of the bearing for determining deformation in the outer ring of the bearing. The outer ring can be a bearing shell of the bearing. For example, the strain gauge can be arranged on a non-rotating outer ring of the bearing. The sensor can have one or more strain gauges for determining the deformation. This makes it particularly easy to determine the deformation in the outer ring of the bearing, and the force acting on the bearing from the crankshaft can then be determined based on this.

[0038] Furthermore, the drive train can have a control device for determining a first time derivative of the determined force and for controlling the drive motor. The assistance provided by the drive motor can be activated and alternatively or additionally deactivated depending on the determined first time derivative of the force.

[0039] Thus, the drive train can be configured to engage or disengage the relief or assistance provided by the drive motor depending on the first time derivative of the pedal force and, alternatively or additionally, depending on the first time derivative of the bearing force on the pedal crankshaft. Further features, embodiments, and advantages can be found in the descriptions of the first aspect. Conversely, features, embodiments, and advantages of the second aspect also represent features, embodiments, and advantages of the first aspect.

[0040] According to a further embodiment, the drive train can be characterized in that the control device can be configured to carry out steps of a method according to an embodiment of the first aspect of the present invention. The drive train can be configured to carry out all steps of the method according to an embodiment of the first aspect. For example, the means for determining the force and the control device can be jointly configured to carry out all steps of the method according to an embodiment of the first aspect. For example, the drive train can further comprise a torque sensor for determining the torque on the pedal crankshaft.

[0041] A third aspect of the present invention relates to a human-powered vehicle with a drive train according to an embodiment of the second aspect of the present invention. The human-powered vehicle can be a bicycle, e-bike, pedelec, or cargo bike. Further features, embodiments, and advantages can be found in the descriptions of the first aspect and the second aspect, respectively. Conversely, features, embodiments, and advantages of the third aspect also represent features, embodiments, and advantages of the first and second aspects, respectively. Fig. 1 schematically shows steps of a method for controlling a drive train of a human-powered vehicle. Fig. Figure 2 shows schematically a muscle-powered vehicle with a drive train and a control device for carrying out the functions schematically shown in Fig. 1 depicted steps of the method for controlling the drive train.

[0042] Fig. 1 schematically shows steps of a method for controlling a drive train 4 of a muscle-powered vehicle 2. Fig. 2 schematically shows such a muscle-powered vehicle 2 with such a drive train 4. The drive train 4 has a pedal crankshaft 6. The pedal crankshaft 6 is rotatably mounted on a frame 10 of the vehicle 2 by means of a bearing 8 of the vehicle 2. The pedal crankshaft 6 also has pedals 5, which are rotatably arranged on crank arms (not shown) of the pedal crankshaft 6. The bearing 8 is a rolling bearing. Furthermore, the drive train 4 has a drive motor 12 for providing drive power to assist a driver of the vehicle 2 in driving the vehicle 2.

[0043] Furthermore, the drive train 4 has a means for determining S1 a force applied by the driver to propel the vehicle 2. In one embodiment, the means has a sensor 13 per pedal 5, and determining S1 of the force applied by the driver comprises determining S1.1 a force applied by the driver on the pedals 5. Such a force is referred to as pedal force. In one embodiment, the means has a sensor 14 on a non-rotating outer ring of the bearing 8, and determining S1 of the force applied by the driver comprises determining S1.2 a force acting from the pedal crankshaft 6 on the bearing 8. Such a force is referred to as bearing force. In one embodiment, the drive train 4 has both a sensor 13 for determining S1.1 the pedal force and a sensor 14 for determining S1.2 the bearing force. In an alternative embodiment, the drive train 4 has either a sensor 13 for determining S1.1 of the pedal force or a sensor 14 for determining S1.2 of the bearing force.

[0044] Furthermore, the drive train 4 has a torque sensor 15. This torque sensor 15 is arranged between the pedal crankshaft 6 and the bearing 8. The torque sensor 15 is configured to determine S4 a further measured variable on the drive train 4. When determining S4 the further measured variable, a determination S4.1 of a torque on the pedal crankshaft 6 is performed using the torque sensor 15.

[0045] The drive train 4 further comprises a control device 16 for determining S2 a first time derivative of the determined force and for controlling S3 the drive motor 12. The control device 16 is communicatively connected to the torque sensor 15, the means for determining S1 the force applied by the driver to drive the vehicle 2, and to the drive motor 12.

[0046] The determination S2 of the first time derivative of the determined force is carried out using a numerical method. According to one embodiment, the determination S2 of the first time derivative of the determined force comprises determining S2.1 a first time derivative of the force applied by the rider to the pedals 5. According to one embodiment, the determination S2 of the first time derivative of the determined force comprises determining S2.2 a first time derivative of the force acting from the pedal crankshaft 6 on the bearing 8. In one embodiment, the determination S2 comprises both determining S2.1 the first time derivative of the pedal force and determining S2.2 the first time derivative of the bearing force. In an alternative embodiment, the method comprises either determining S2.1 the first time derivative of the pedal force or determining S2.2 the first time derivative of the bearing force.

[0047] The assistance provided by the drive motor 12 is switched on or off depending on the determined first time derivative of the force. Once the determination S2.1 of the first time derivative of the pedal force has been performed, the control S3 of the drive motor 12 is performed depending on the determined first time derivative of the force applied to the pedals 5. Once the determination S2.2 of the first time derivative of the bearing force has been performed, the control S3 of the drive motor 12 is performed depending on the determined first time derivative of the force acting from the pedal crankshaft 6 on the bearing 8.

[0048] The control device 16, the means and the torque sensor 15 are configured to carry out steps of the schematically shown Fig. 1 shown procedure.

[0049] During control S3, the assistance by the drive motor 12 is switched on S3.1 if the determined first time derivative of the force exceeds a first threshold value. Furthermore, during control S3, the assistance by the drive motor 12 is switched off S3.2 if the determined first time derivative of the force falls below a second threshold value. The first and second threshold values ​​have different signs. In the embodiment shown, an absolute value of the first threshold value is greater than an absolute value of the second threshold value. This achieves a hysteresis effect, according to which the assistance is switched on S3.1 at a different absolute value of the first time derivative of the force than the assistance is switched off S3.2. This ensures that the assistance is switched on for a longer period of time. In an alternative embodiment, the absolute values ​​of the first and second threshold values ​​are identical.

[0050] Furthermore, control S3 of the drive motor 12 is performed as a function of the determined further measured variable. Control S3 of the drive motor 12 is performed as a function of the determined torque, which was determined using the torque sensor 15. This implements redundancy through the method. Control S3 of the drive motor 12 as a function of the first time derivative of the force, which is determined using the control device 16, is checked using the determined torque.

[0051] Such a method and such a drive train 4 enable the precise and rapid detection and determination of pedaling by the driver of the vehicle 2. To determine whether the driver is pedaling or not, the crank arms of the pedal crankshaft 6 do not necessarily have to be in a horizontal position. Thus, the method and the drive train 4 are configured to detect and determine pedaling more accurately and quickly than known methods and drive trains that detect pedaling based solely on determining the driver torque at the pedal crankshaft 6 or based on a time derivative of the driver torque. This increases safety when using the vehicle 2 with such a drive train 4 controlled by such a method.The activation or deactivation of the assistance by the drive motor 12 is thus carried out more quickly compared to known methods and drive trains which activate or deactivate the assistance based solely on the measured driver torque and alternatively or additionally based on the time derivative of the driver torque. Reference symbol 2 vehicles 4 Drivetrain 5 pedals 6 Crankshaft 8 camps 10 frames 12 Drive motor 13 Sensor for measuring the force applied by the driver to the pedals 14 Sensor for measuring a force acting from the crankshaft on the bearing 15 Torque sensor 16 Control device S1 Determine the force applied by the driver to drive the vehicle S1.1 Determine the force applied by the driver to the pedals S1.2 Determine the force acting from the crankshaft on the bearing S2 Determining a first time derivative of the determined force S2.1 Determining a first time derivative of the force applied by the driver to the pedals S2.2 Determine a first time derivative of the force acting from the crankshaft on the bearing S3 Control of the drive motor S3.1 Activation of support by the drive motor S3.2 Switching off the support by the drive motor S4 Determining another measured variable on the drive train S4.1 Determining a torque of a pedal crankshaft QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 132 256 A1

[0002]

Claims

[1] Method for controlling a drive train (4) of a muscle-powered vehicle (2), wherein the drive train (4) has a drive motor (12) for providing drive force to assist a driver of the vehicle (2) in driving the vehicle (2), the method comprising the steps of: determining (S1) a force applied by the driver to drive the vehicle (2); determining (S2) a first time derivative of the determined force; and controlling (S3) the drive motor (12), wherein the assistance by the drive motor (12) is switched on or off depending on the determined first time derivative of the force. [2] Method according to claim 1, characterized bythat the drive train (4) has pedals (5), that the determination (S1) of the force applied by the driver comprises determining (S1.1) a force applied by the driver to the pedals (5), that the determination (S2) of the first time derivative comprises determining (S2.1) a first time derivative of the force applied by the driver to the pedals (5), and that the control (S3) of the drive motor (12) is carried out as a function of the determined first time derivative of the force applied to the pedals (5). [3] Method according to one of the preceding claims, characterized bythat the drive train (4) has a pedal crankshaft (6), wherein the pedal crankshaft (6) is rotatably mounted on a frame (10) of the vehicle (2) by means of a bearing (8) of the vehicle (2), that the determination (S1) of the force applied by the rider comprises a determination (S1.2) of a force acting from the pedal crankshaft (6) on the bearing (8), that the determination (S2) of the first time derivative comprises a determination (S2.2) of a first time derivative of the force acting from the pedal crankshaft (6) on the bearing (8), and that the control (S3) of the drive motor (12) is carried out as a function of the determined first time derivative of the force acting from the pedal crankshaft (6) on the bearing (8). [4] Method according to one of the preceding claims, characterized bythat during control (S3) a switching on (S3.1) of the support by the drive motor (12) is carried out if the determined first time derivative of the force exceeds a first threshold value. [5] Method according to one of the preceding claims, characterized by that during control (S3) a switching off (S3.2) of the support by the drive motor (12) is carried out if the determined first time derivative of the force falls below a second threshold value. [6] Method according to one of the preceding claims, characterized by that a determination (S4) of a further measured variable is carried out on the drive train (4), and that the control (S3) of the drive motor (12) is carried out as a function of the determined further measured variable. [7] Method according to claim 6, characterized bythat the drive train (4) has a pedal crankshaft (6), that when determining (S4) the further measured variable a determination (S4.1) of a torque on the pedal crankshaft (6) is carried out, and that the control (S3) of the drive motor (12) is carried out as a function of the determined torque. [8] Drive train (4) for a muscle-powered vehicle (2), wherein the drive train (4) has a drive motor (12) for providing drive force to assist a driver of the vehicle (2) in driving the vehicle (2), wherein the drive train (4) has a means for determining (S1) a force applied by the driver to drive the vehicle (2), and wherein the drive train (4) has a control device (16) for determining (S2) a first time derivative of the determined force and for controlling (S3) the drive motor (12), wherein the assistance by the drive motor (12) is switched on or off depending on the determined first time derivative of the force. [9] Drive train (4) according to claim 8, characterized by that the control device (16) is arranged to carry out steps of a method according to one of claims 1 to 7. [10] Muscle-powered vehicle (2) with a drive train (4) according to claim 9.

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