Method for controlling drive device for vehicle operated by muscle force

Abstract

The invention relates to a method for controlling a drive device for a motor vehicle operated by means of muscle force, said drive device being designed to transmit the muscle force of a rider from a crankshaft (3) to an output wheel (6) via a superposition transmission (4). The transmission ratio at the superposition transmission (4) can be adjusted by adjusting the rotational speed of the first electric machine (8). Making a continuous determination (S0) whether a rotation of the crankshaft (3) for driving the vehicle is present; if it is determined that there is a rotation of the crankshaft (3) for driving the vehicle, the rotational speed of the first electric machine (8) is adjusted (S1.1) in order to produce a predetermined transmission ratio at the superposition transmission (4). If it is determined that there is no longer a rotation of the crankshaft (3) for driving the vehicle, the rotational speed of the first electric machine (8) is adjusted (S2.1) for at most a predetermined time (T1) in order to maintain the transmission ratio at the superposition transmission (4). Adjusting (S3.1) the rotational speed of the first electric motor (8) in order to reduce the transmission ratio, if the absence of the rotation of the crankshaft (3) for driving the vehicle is continuously determined until the predetermined duration has elapsed.

Description

Technical Field

[0001] The invention relates to a method for controlling a drive device for a vehicle operated by muscle power, wherein the muscle power is transmitted via a superposition transmission to drive the vehicle and the transmission ratio at the superposition transmission can be adjusted. The invention also relates to a vehicle configured as a bicycle, which has a controller for implementing the method for controlling the drive device. Background Art

[0002] Methods for controlling a drive for a vehicle operated by muscle power are known from the prior art, in which the transmission ratio of a superposition transmission of the drive can be adjusted by means of an electric motor. Methods are known here by means of which a desired transmission ratio can be adjusted at the superposition transmission. Summary of the invention

[0003] The present invention relates to a method for controlling a drive device for a vehicle operated by muscle power in a first aspect. The vehicle operated by muscle power can be a bicycle, such as an electric power-assisted bicycle. The vehicle can have a controller for implementing the method for controlling the drive device. The drive device is set up to transmit the muscle power of the rider from the crankshaft to the output wheel via a superposition transmission device. The muscle power of the rider of the vehicle can be received via a pedal that can be fastened to the crankshaft by means of a crank arm. The superposition transmission device can, for example, have a planetary transmission device. The output wheel can be connected to the drive wheel of the driven wheel of the vehicle by means of a force transmission device, such as a chain or a belt. A first motor is coupled to the superposition transmission device. Here, torque can be transmitted between the first motor and the superposition transmission device in at least one, for example, two directions. The first motor can have a rotor, which can be connected to a part of the superposition transmission device in a relatively rotation-resistant manner. The first motor can have a stator, which can be connected to the housing of the drive device in a relatively rotation-resistant manner. The first motor can be connected to an energy storage device, such as a battery, of the vehicle, and the first motor can be set up to operate motor-like with the energy stored in the energy storage device. By adjusting the speed of the first electric machine, the transmission ratio between the crankshaft and the output wheel at the superposition gear can be adjusted. The transmission ratio can be adjusted, for example, steplessly between a minimum and a maximum transmission ratio. A controller for controlling the drive according to the method can be configured to adjust the speed in order to adjust the transmission ratio at the superposition gear.

[0004] The method comprises: continuously determining whether there is a rotation of the crankshaft for driving the vehicle. The continuous determination can be performed at regular time intervals and alternatively or additionally in an event-controlled manner. When the rider pedals and receives muscle power for driving and outputs it via the output wheel to drive the vehicle, there may be, for example, a rotation of the crankshaft for driving the vehicle. When the rider rotates the pedal crank arm only with a small movement, wherein the small movement may be less than half a turn of the crankshaft, for example, there may be no rotation of the crankshaft for driving the vehicle. The continuous determination can determine the time curve of the rotation of the crankshaft for driving the vehicle.

[0005] If it is determined that there is a rotation of the crankshaft for driving the vehicle, the speed of the first motor is adjusted. The first motor is adjusted in order to produce a predetermined transmission ratio at the superposition transmission. The adjustment can be performed with a dynamic PID regulator. Information about the predetermined transmission ratio can be stored in a memory of the controller. For example, a table that may contain information about the predetermined transmission ratio can be stored in a memory of the controller for implementing the method. The predetermined transmission ratio can be determined in this case depending on the input variables. According to the desired predetermined transmission ratio, a target speed can be determined, to which the first motor can be adjusted. In the case of continuous determination of the presence of a rotation of the crankshaft for driving the vehicle, the step of adjusting the speed of the first motor can be continuously implemented so as to produce a predetermined transmission ratio at the superposition transmission.

[0006] If it is determined that there is no longer a rotation of the crankshaft for driving the vehicle, the speed of the first motor is adjusted for at most a predetermined duration so that the transmission ratio at the superposition transmission is maintained within the range of the transmission ratio adjusted at the superposition transmission when it is determined that there is no rotation of the crankshaft for driving the vehicle. The determination that there is no longer a rotation of the crankshaft for driving the vehicle can be included in the continuous determination. It can be determined that there is no longer a rotation via the time variation curve of the rotation of the crankshaft. The speed is adjusted to keep the transmission ratio within the range of the transmission ratio, which can be performed with a dynamic PID regulator. The predetermined duration can be, for example, a few seconds, for example, 10 seconds. The range of the transmission ratio can be an absolute range of the transmission ratio or an alternative or additional relative range. The range can be, for example, higher and lower than 10% of the transmission ratio adjusted when there is no longer a rotation of the crankshaft for driving the vehicle. Alternatively, the range can be defined by an absolute value higher or lower than the transmission ratio. After the continuous determination of the presence of the rotation of the crankshaft for driving the vehicle, the transmission ratio can be maintained within the range of the transmission ratio adjusted at the superposition transmission device at the time point when it was first determined that the rotation of the crankshaft for driving the vehicle no longer exists. Maintaining the transmission ratio within the range can be maintaining the transmission ratio at a constant level. Alternatively, maintaining within the range of the transmission ratio can include a linear adaptation of the transmission ratio within the range.

[0007] If it is continuously determined that there is no rotation of the crankshaft for driving the vehicle until a predetermined period of time has passed, the rotation speed of the first motor is adjusted after the predetermined period of time has passed so as to reduce the transmission ratio at the superposition transmission device based on a predetermined time variation curve. The regulator for adjusting the rotation speed after the predetermined period of time has passed can be a dynamic PID regulator. The transmission ratio at the superposition transmission device can be reduced to a minimum transmission ratio. The transmission ratio can be reduced from the value adjusted at the superposition transmission device when there is no rotation of the crankshaft for driving the vehicle for the first time. When adjusting the rotation speed to reduce the transmission ratio, the rotation speed of the first motor can be reduced. The minimum transmission ratio that can be adjusted can achieve a transmission ratio for the vehicle to run during slow driving speeds, while a larger transmission ratio enables the vehicle to run at higher driving speeds.

[0008] The control of the drive device is shown by this method, wherein, during a predetermined duration, the transmission ratio can be kept within the range of the transmission ratio that can be adjusted when there is a rotation of the crankshaft for driving the vehicle, that is, in order to be commensurate with the pedaling of the rider. Therefore, the transmission ratio in the first two steps of the adjustment may be the same, for example. The rider may, for example, be unable to distinguish which step of the first two steps of the adjustment the control is in, because the transmission ratio in the two steps of the adjustment may be similar. The transmission ratio can be reduced in the last step of the adjustment, so the rider can distinguish the last step from the first two steps, because this last step can have a reduced transmission ratio at the superposition transmission device. Therefore, the transmission ratio at the superposition transmission device can be generated by means of the third step of the adjustment, which may not be optimal for driving by means of muscle power. At the same time, the speed of the first motor can also be reduced and lowered due to the reduction of the transmission ratio. This can save the energy required for running the first motor. Therefore, in the first two steps of the adjustment, more energy is required per unit time to adjust the first motor than in the third step of the adjustment when the transmission ratio is reduced. In other words, the power consumption of the first motor may be different in different steps of the regulation, wherein the power consumption may be almost the same in the first two steps of the regulation because, after there is a rotation for driving the vehicle, the transmission ratio is maintained within the range of the transmission ratio that was adjusted when there is no longer a rotation of the crankshaft for driving the vehicle for the first time.

[0009] According to another embodiment, the first motor can be adjusted so that a predetermined transmission ratio is generated at the superposition transmission. This step can be performed if the presence of a rotation of the crankshaft for driving the vehicle is determined after a predetermined period of time has passed, during which the absence of a rotation of the crankshaft for driving the vehicle has been continuously determined. After the absence of a rotation of the crankshaft for driving the vehicle for at least a predetermined period of time, when the rotation of the crankshaft for driving the vehicle is present again, an adjustment for generating a predetermined transmission ratio can be performed. The transition from the reduced transmission ratio to the predetermined transmission ratio can be performed linearly, for example, in such a way that the transmission ratio is linearly increased from the reduced transmission ratio to the predetermined transmission ratio over a period of time.

[0010] According to the method, a response to the detection and determination of a rider's renewed pedaling via the rotation of the crankshaft for driving the vehicle can be made, and the transmission ratio in the superposition transmission can be changed by adjusting the rotation speed of the first motor in order to produce a predetermined transmission ratio at the superposition transmission. The method can thus provide a transition from a reduced transmission ratio when the vehicle is coasting, for example without drive, to a predetermined transmission ratio when the vehicle is driven, for example, by the rider's muscle power.

[0011] According to another embodiment, the method may also include: detecting the rotational speed of the wheel of the vehicle. The wheel may be, for example, a driven wheel, such as a driven rear wheel of the vehicle. The rotational speed of the driven wheel, such as the rear wheel, may be detected. According to this embodiment, the first motor may be adjusted depending on the rotational speed of the detected wheel so as to keep the transmission ratio within a range. Alternatively or additionally, further steps of adjusting the first motor may be performed depending on the rotational speed of the detected wheel. When the rotational speed of the detected wheel is low, a smaller transmission ratio may be generated. And when the rotational speed of the detected wheel is high, a larger transmission ratio may be generated. If the rotational speed of the wheel of the vehicle does not change during the adjustment to keep the transmission ratio within a range, the transmission ratio may remain constant. If the rotational speed of the wheel of the vehicle changes, for example due to friction and thus a loss of speed of the vehicle, the adjustment may include slightly reducing the rotational speed of the first motor to reduce the transmission ratio.

[0012] In this way, it is possible to react to changes in the vehicle's speed during the step of adjusting to keep the transmission ratio within the range. Thus, during this adjustment, in the phase when the vehicle is coasting without being driven by the rider, the transmission ratio can be adapted to the changing rotational speed of the wheels and thus to the changing speed of the vehicle. If the rider pedals during this adjustment step, a matching transmission ratio can be present, so that a transmission ratio is present that is comfortable for the rider when pedaling.

[0013] According to a further embodiment, the predetermined time profile for regulating the first electric machine to reduce the transmission ratio comprises a linear time profile of the rotational speed of the first electric machine. This linear profile can be ramp-shaped. Alternatively, other functional profiles of the rotational speed, for example parabolic profiles, are also possible. The linear time profile can be determined as a function of the time period during which the transmission ratio should be reduced to the minimum transmission ratio. Furthermore, the linear time profile can be dependent on the value of the minimum transmission ratio and, alternatively or additionally, on the initial value of the transmission ratio present at the start of the regulation for reducing the transmission ratio.

[0014] This method allows the transmission ratio to be reduced continuously, wherein the reduction can be determined using a simple temporal relationship. The longer the waiting time for the rider to pedal again is in the step of adjusting the transmission ratio, the smaller the transmission ratio will be when the rider starts pedaling again. This in turn can also lead to a longer time until the predetermined transmission ratio is established again at the superposition transmission. This can represent a trade-off between energy saving and the optimal transmission ratio for pedaling and the time it takes until the predetermined transmission ratio is set again at the superposition transmission.

[0015] According to another embodiment, the drive device can also be set up to transmit the driving force of the second motor to the output wheel via the superposition transmission. The second motor can be connected to the energy storage device of the vehicle and can be supplied with electric energy by this energy storage device to operate as an electric motor. The second motor can be coupled to the superposition transmission device. The rotor of the second motor can be coupled or connected to a part of the superposition transmission device in a relatively rotation-resistant manner, for example. The stator of the second motor can be connected to the housing of the drive device in a relatively rotation-resistant manner. The second motor can be an electric drive machine for driving the vehicle. The controller for implementing the method can control the second motor. If it is determined that there is no longer a rotation of the crankshaft for driving the vehicle, the second motor can be adjusted to a predetermined time length at most continuously to resist friction. The friction of the driving force for driving the vehicle can be resisted as follows, that is, the drive device is non-driven and resists friction at least to a specific value. When no driving force is transmitted to the driven wheels of the vehicle, the drive device can be non-driven. The specific value can be the minimum value of the force for resisting the friction of the driving force for driving the vehicle. This value can be an absolute value of the force, alternatively a relative value, such as 90% to 100% of the friction against the driving force for driving the vehicle. The friction against the driving force for driving the vehicle can, for example, include: friction in the bearing of the drive device, or friction of the chain or belt between the drive device and the driven wheel. The adjustment for a predetermined duration can be completed with a hysteresis PID regulator. When adjusting the second motor for a predetermined duration at most, for example, the torque can be adjusted. Alternatively, the speed can be adjusted, wherein the swing of the regulator for adjusting the speed of the first motor can be avoided by means of a hysteresis regulator, and the first motor is coupled to the second motor by means of a superposition transmission. If it is still continuously determined that there is no rotation of the crankshaft for driving the vehicle until the predetermined duration has passed, then the second motor can be adjusted so as to resist the friction up to a specific value. For example, the friction can be resisted to a maximum of 90%. In the step of adjusting to resist the friction up to a specific value, it can include: reducing the speed of the second motor to save energy used to run the second motor. The resistance friction can be adjusted up to a certain value based on a predetermined time profile and the speed of the second electric machine can be reduced according to a linear time profile. Thus, the speed of the second electric machine can be reduced in a ramp-like manner. Other time profiles of the speed of the second electric machine are also conceivable, such as a parabolic profile.

[0016] If there is no rotation of the crankshaft for driving the vehicle, this method can ensure that no propulsion occurs via the second electric machine. At the same time, friction losses in the drive device and in the components between the drive device and the driven wheels can be avoided for a predetermined period of time by reducing the friction to a certain value. After the predetermined period of time, the second electric machine can be regulated in such a way that the rotational speed of the second electric machine is reduced and energy can be saved.

[0017] According to another embodiment, the second motor can be adjusted so that the driving force is transmitted from the second motor to the output wheel via the superposition transmission device to drive the vehicle. This step is performed if it is determined that there is a rotation of the crankshaft for driving the vehicle. If there is a rotation of the crankshaft for driving the vehicle again after there is no rotation of the crankshaft for driving the vehicle, then the adjustment can be performed. If there is a rotation of the crankshaft for driving the vehicle after a predetermined time period (during which the absence of the rotation of the crankshaft for driving the vehicle is continuously determined), then the adjustment can be performed. Here, the rotation speed of the second motor can be increased in a ramp shape to the maximum rotation speed, so as to achieve the driving of the vehicle with a predetermined driving force.

[0018] The method can therefore be transferred and applied to a vehicle having a drive device and an auxiliary motor, wherein, if the rider starts pedaling again, the auxiliary motor, ie the second electric machine, applies the driving force for driving the vehicle to the output wheel via the superposition gear.

[0019] According to another embodiment, the driving force for driving the vehicle can be transmitted from the output wheel to the driven wheel via the one-way clutch. The one-way clutch can be a rear wheel one-way clutch, wherein the driven wheel can be a driven rear wheel. By adjusting the second motor to resist friction at least to a specific value, the one-way clutch can be kept synchronized. Therefore, the second motor can provide just enough driving force to resist the friction against the driving force for driving the vehicle so that the friction is just eliminated. Conversely, in the step of adjusting the second motor to resist friction up to a specific value, the one-way clutch can be lifted.

[0020] In this way, the driving characteristics can be improved by keeping the freewheeling clutch synchronized by the control and thus no time is lost until the freewheeling clutch becomes effective again when the rider resumes pedaling.

[0021] According to another embodiment, adjusting the second motor to resist friction to at least a specific value may be to adjust the speed of the second motor. Adjusting the second motor to resist friction to a specific value may be to adjust the speed of the second motor. Adjusting the second motor to transfer the driving force from the second motor to the output wheel to drive the vehicle may be to adjust the torque of the second motor. Adjusting the second motor may be performed depending on the speed of the detected wheel so as to resist friction not only to at least a specific value but also to a specific value. These adjustment steps may be performed depending on the speed of the detected driven wheel. Therefore, for each step of adjusting the speed of the second motor, the target speed may be determined via the mutual relationship between the second motor and the wheel according to the transmission ratio and depending on the speed of the detected wheel.

[0022] Thus, the method can be used to react to a reduced driving speed of the vehicle and to adjust the speed of the second electric machine in a manner adapted thereto. It can thus be ensured that the freewheeling clutch, for example, remains synchronized or slightly lifted, wherein a small speed difference can exist. Thus, both the step of adjusting the friction to at least a certain value and the step of adjusting the friction to a certain value can be carried out in a manner adapted to the driving speed.

[0023] According to a further embodiment, the first motor can be adjusted up to a first maximum torque in order to implement the safety function of the first motor. By adjusting to the first maximum torque, it is possible, for example, to prevent a maximum value of the driving force, which is transmitted to the driven wheel, for example via a chain, from being exceeded. For this purpose, the first maximum torque can be a value that can be parameterized so that the desired maximum driving force can be generated. It can thus be avoided, for example, that the first motor could transmit too much torque to the superposition transmission. The safety function of the first motor can thus, for example, prevent foreign bodies from being caught in a chain with a driving force strength exceeding the maximum. Accident protection can thus be implemented and at the same time outer parts, such as trousers, can be protected, so that the adjustment is only carried out up to the first maximum torque.

[0024] According to a further embodiment, the second motor can be adjusted up to a second maximum torque in order to implement the safety function of the second motor. This function can be performed similarly to the safety function of the first motor. The first and second maximum torques can be different or the same. The second motor can thus also generate a driving force only up to a maximum value and apply it to the chain to drive the driven wheel.

[0025] According to another embodiment, if there is a rotation of the crankshaft for driving the vehicle, for example, when this rotation is present again, the first motor is adjusted so as to produce a predetermined transmission ratio. Therefore, if it is determined that there is a rotation for driving the vehicle again after determining that there is no rotation of the crankshaft for driving the vehicle for at most a predetermined time period, then this adjustment can be performed. Then the second motor can also be adjusted so that the driving force is transferred from the second motor to the output wheel to drive the vehicle. Therefore, if at most a predetermined time period has passed since the pedaling was stopped, then these steps of adjustment can be performed when the rotation speed of the first and second motors is reduced when pedaling is resumed.

[0026] Thus, a method can be provided, wherein the method enables the rider of the vehicle to achieve a driving characteristic that does not differ from the driving characteristic that exists when the rider is pedaling for a predetermined period of time. Thus, for example, the rider can interrupt pedaling for at most a predetermined period of time and then immediately experience the predetermined transmission ratio and the drive of the vehicle by means of the driving force of the second electric machine again when pedaling again.

[0027] According to another embodiment, the first motor and the second motor are regulated only when the detected rotational speed of the wheel is greater than a minimum rotational speed of the wheel. In particular, these steps can be performed only when the detected rotational speed of the wheel, for example the driven rear wheel, is greater than a minimum rotational speed when there is no pedaling, that is, when there is no rotation of the crankshaft for driving the vehicle.

[0028] The method can therefore be limited to scenarios in which the vehicle has a minimum speed. At lower speeds, the first electric machine can be adjusted, for example, in such a way that the minimum transmission ratio is immediately generated when it is determined that there is no longer any rotation of the crankshaft for driving the vehicle. In the case of a very low vehicle speed, the difference between the predetermined transmission ratio and the minimum transmission ratio during pedaling may be very small, and therefore the difference for the rider during pedaling in both situations may be very small. This can increase the energy saving effect and avoid reducing the speed according to the time curve.

[0029] According to a further embodiment, the method further comprises: detecting a user input and determining a predetermined duration as a function of the detected user input. The user input may be made with respect to a driving mode of the vehicle. The driving mode may, for example, comprise an economy mode, a sports mode or another mode. In the economy mode, the duration may, for example, be determined to be shorter than in the sports mode. In the case of a shorter duration, in order to reduce the rotational speed of the first motor and, alternatively or additionally, the second motor, the ramp may be steeper than in the case of a longer predetermined duration.

[0030] Thus, the method can be influenced towards more energy efficiency or towards more optimal driving characteristics depending on whether the user input performed by the user is influenced towards more energy efficiency or towards more optimal driving characteristics.

[0031] According to another embodiment, the first motor and the second motor can be supplied with electrical energy from an energy store. The energy store can be a battery of the vehicle. The first motor and the second motor can only be controlled when the energy store has at least a certain charge state, for example 20% of the maximum charge capacity.

[0032] According to the method, the first and second electric machines can be adjusted only when there is sufficient energy stored in the energy storage device to ensure the complete implementation of the method. It can thus be ensured that there is at least enough energy for the adjustment for a predetermined period of time and for the adjustment to reduce the transmission ratio and the rotational speed of the second electric machine in order to be able to implement these steps.

[0033] According to another embodiment, the drive device can have a one-way clutch. The one-way clutch can be, for example, a ratchet one-way clutch. The one-way clutch can be specified by the drive device to prevent the transmission of force in at least one rotational direction in the direction of the crankshaft. For example, the force from the first motor cannot be transmitted to the crankshaft along the first rotational direction, but the force can be transmitted in the second rotational direction opposite to the first rotational direction. Alternatively or additionally, in at least one rotational direction, no force can be transmitted from the second motor to the crankshaft. Alternatively or additionally, in at least one rotational direction, no force can be transmitted from the output wheel to the crankshaft. Here, adjusting the first motor and adjusting the second motor can be performed depending on the relative position of the one-way clutch in the superposition transmission. The different steps of adjustment can include: matching the rotational speed of the first motor and alternatively or additionally matching the rotational speed of the second motor. Here, depending on the relative position of the one-way clutch, it may be necessary to control different speed jumps at different times.

[0034] A second aspect of the present invention relates to a controller, which is configured to implement a method according to an embodiment of the first aspect of the present invention. The controller can be configured to control a drive device. The controller can have an input interface for receiving data and an output interface for sending data. For example, information about the rotation of a crankshaft can be received, wherein information about adjusting the rotation speed of a first motor and a second motor can be sent.

[0035] A third aspect of the invention relates to a bicycle having at least two wheels, a drive device and a controller according to the second aspect of the invention. The bicycle may be an electric power-assisted bicycle having an energy storage device. The energy storage device may be a battery, such as a lithium-ion battery. The bicycle may have a user interface, such as a display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1a A schematic illustration of a drive device for a vehicle operated by muscle power according to a first embodiment is shown, with a bicycle as the vehicle;

[0037] Figure 1b Shown according to Figure 1a time profiles of the rotational speeds of the various components of the drive device;

[0038] Figure 2a A schematic view of a drive device for a vehicle operated by muscle power according to a second embodiment is shown, showing a bicycle as the vehicle;

[0039] Figure 2b Shown according to Figure 2a time profiles of the rotational speeds of the various components of the drive device;

[0040] Figure 3 A schematic view of a drive device for a vehicle operated by muscle power according to a third embodiment is shown, which is a bicycle as the vehicle;

[0041] Figure 4a A schematic view of a drive device for a vehicle operated by muscle power according to a fourth embodiment is shown, which is a bicycle as the vehicle;

[0042] Figure 4b Shown according to Figure 4a time profiles of the rotational speeds of the various components of the drive device;

[0043] Figure 5 The steps of a method for controlling a drive of a vehicle operated by muscle power according to a first specific embodiment are schematically shown. DETAILED DESCRIPTION

[0044] Figure 1aIn a schematic view, a drive device for a vehicle operated by muscle power according to a first embodiment is shown, wherein the vehicle is a bicycle. The drive device has a superposition transmission 4, a first motor 8, a second motor 46, an output wheel 6 and a crankshaft 3. A crank arm is mounted on the crankshaft 3, and the crank arm has pedals for the rider of the vehicle to pedal. The crankshaft can be coupled to the superposition transmission 4 via a one-way clutch 11. The superposition transmission 4 has a first planetary group 9, a second planetary group 18 and a third planetary group 20. The first motor 8 is coupled to the first planetary group 9 via the second planetary group 18 and also via the third planetary group 20. Here, the rotor of the first motor 8 is coupled to the sun gear 19 of the second planetary group 18. The stator of the first motor 8 is connected to the housing 10 of the drive device in a rotationally fixed manner. The third planetary group 20 is coupled to the sun gear 12 of the first planetary group 9. The crankshaft 3 can be coupled to the planet carrier 17 of the first planetary group 9 via the one-way clutch 11. The ring gear 16 of the first planetary gear set 9 is coupled to the driven gear 6. Some parts of the drive device are connected to the housing 10 in a rotationally fixed manner.

[0045] The one-way clutch 11 ensures that force is transmitted from the crankshaft 3 to the planet carrier 17 when the crankshaft 3 rotates in a first direction, and that no force is transmitted from the crankshaft 3 to the planet carrier 17 when the crankshaft 3 rotates in the opposite direction.

[0046] Figure 1a The energy storage device and the controller are not shown. The controller is designed to control the speed and direction of rotation of the electric motor 8 so that a corresponding rotation can be introduced into the superposition gear 4. The controller is also designed to carry out the steps of the method for controlling the drive device as described below. The electric motor 8 is operated with the electrical energy stored in the energy storage device.

[0047] The second motor 46 of the drive device can be driven via the control device and using the electrical energy of the energy storage device. The driving force of the second motor 46 can be applied to the output wheel 6. Therefore, the muscle force applied by the rider of the bicycle via the crankshaft 3 can be supplemented by the driving force of the second motor 46. Therefore, the drive device represents an electrically supported drive such as used in an electric power-assisted bicycle or an electric bicycle. The superposition transmission device 4 and the motor 8 are arranged to adjust a variable transmission ratio at the superposition transmission device 4 between the crankshaft 3 and the output wheel 6.

[0048] The second electric machine 46 is coupled to the superposition gear 4 via a fourth planetary gear set 52 and via a spur gear set 54. The spur gear set 54 is coupled to the spur gear stage 24. The spur gear stage 24 is coupled to the driven gear 6 and the ring gear 16 of the first planetary gear set 9.

[0049] Figure 5The steps of a method for controlling a drive device of a vehicle operated by muscle power according to an embodiment are schematically shown. First, a continuous determination S0 is performed to determine whether there is a rotation of the crankshaft 3 for driving the vehicle. The continuous determination S0 is performed in dependence on the information detected by the sensor at the crankshaft 3 and the determination is implemented by the controller. The information is sent to the controller, which is configured to implement the method for controlling the drive device. The controller is also configured to implement the following steps of adjusting the first motor 8 and the second motor 46. Therefore, in the step of adjusting S1.1, the rotation speed n of the first motor 8 is adjusted to generate a predetermined transmission ratio at the superposition transmission device 4. This step is performed if it is determined that there is a rotation of the crankshaft 3 for driving the vehicle. The transmission ratio is generated at the superposition transmission device 4 by adjusting the rotation speed n of the first motor 8 in the following manner, that is, a specific rotation speed n of the first motor 8 adjusts a specific transmission ratio at the superposition transmission device 4. Thus, when the rotational speed n of the sun gear 19 of the second planetary set 18 coupled to the output element of the first electric machine 8 is higher, a greater transmission ratio is present at the superposition gear 4 between the crankshaft 3 and the output wheel 6. The predetermined transmission ratio is predetermined here via a relationship stored in a memory of the controller. The transmission ratio is thus dependent on the user input and the current driving speed. Thus, for example, the predetermined transmission ratio at the superposition gear 4 is adjusted in such a way that the rider can pedal at a cadence of between 60 and 90 revolutions per minute in accordance with the driving speed in order to drive the vehicle.

[0050] A one-way clutch 11 is provided to ensure that no disruptive torque reaction occurs from the superposition gear 4 to the crankshaft 3 when the rider stops pedaling. In addition, a further one-way clutch, not shown, is provided between the output wheel 6 of the vehicle and the driven wheel, which prevents force transmission in at least one direction. This one-way clutch, not shown (hereinafter also referred to as the rear wheel one-way clutch at the driven rear wheel of the vehicle), ensures that when the driven rear wheel rotates faster than the element driving the driven rear wheel, such as a pinion (driven by a chain via the output wheel 6), the rear wheel one-way clutch is lifted and therefore no force is reacted on the output wheel 6 of the drive device.

[0051] Figure 1b An exemplary speed profile of the speed n of various components of the drive device is shown over time t. Figure 1b The exemplary speed curve shown in FIG. 1 is related to a rotational speed curve having Figure 1aA first embodiment of a bicycle with a drive device. The pedaling is performed by the rider until time t1. At time t1, it is determined S0 that there is no longer any rotation of the crankshaft for driving the vehicle. Then, the rotation speed of the first motor 8 is adjusted S2.1 for at most a predetermined duration T1, so as to keep the transmission ratio within the range of the transmission ratio adjusted at the superposition transmission 4 when it is determined S0 that there is no longer any rotation of the crankshaft 3 for driving the vehicle. During the predetermined duration T1, the rotation speed n1 of the output wheel 6 will not change and remain constant, assuming that the friction losses are negligible. This is achieved by adjusting S2.2 the second motor 46, so as to resist the friction that opposes the driving force for driving the vehicle in such a way that the rear wheel one-way clutch remains synchronized. This is presented in the following way, that is, under the assumption of continued movement without losses, the rotation speed n1 of the output wheel 6 remains constant.

[0052] The speed n3 of the sun gear 12 of the first planetary set 9 remains constant between the time t1 and the time t2 after the predetermined time period T1 has elapsed. This is achieved by maintaining the speed of the sun gear 19 of the second planetary set 18 at a constant value by regulating the first electric motor 8 S2.1. Since the speed n3 is maintained at a constant level, the transmission ratio at the superposition transmission 4 between the crankshaft 3 and the output wheel 6 remains within the range of the transmission ratio adjusted at the superposition transmission 4 when there is no longer any rotation of the crankshaft 3 for driving the vehicle. In the presence of friction losses, the speed n3 is adapted so that the transmission ratio matches the reduced driving speed of the vehicle. This is Figure 1b It can be seen that the speed n3 decreases with a small slope between t1 and t2. It should be noted that the speed n3 is negative due to the transmission ratio of the superposition transmission 4. If a matching positive transmission ratio is used, the previous and following descriptions are also valid for the positive curve of the speed n3 of the sun gear 19 of the second planetary group 18.

[0053] At time t1, the rotation speed n2 of the crankshaft 3 decreases because the rider stops pedaling. Between time t1 and t2, the rotation speed n6 of the planet carrier 17 of the first planetary group 9 remains constant. The one-way clutch 11 is released.

[0054] At a point in time t2 after a predetermined duration T1 and after it has been determined that there is still no rotation of the crankshaft 3 for driving the vehicle, the speed of the first electric machine 8 is adjusted S3.1 in order to reduce the transmission ratio at the superposition gear 4 based on a time profile. In this case, the speed n3 of the sun gear 12 of the first planetary set 9 is reduced. The reduction is carried out via a linear profile between the point in time t2 and the point in time t3 during the duration T2 for reducing the transmission ratio at the superposition gear 4. Figure 1bThe speed n3 shown in is the speed that is set without friction losses. In the case of losses, for example, friction losses, which cause the vehicle to lose speed during the time t, this linear reduction can take place with a larger gradient. The friction that opposes the driving force for driving the vehicle is resisted by adjusting S3.2 up to a certain value. In this case, the rear wheel freewheel clutch is lifted. The speed n1 of the output wheel 6 is reduced. The reduction in the speed of the second electric machine 46 is achieved here via the fixed transmission ratio of the fourth planetary set 52 and the spur gear set 54 between the second electric machine 46 and the superposition gear 4.

[0055] The rider starts pedaling again just before the time point t3, thereby continuously confirming S0 that the rotation of the crankshaft 3 for driving the vehicle is re-existing. The speed n2 of the crankshaft 3 increases. The speed n3 of the sun gear 12 of the first planetary set 9 is increased by adjusting S1.1, so that the predetermined transmission ratio is generated again at the superposition transmission 4. The second motor 46 is adjusted S1.2 so that the driving force of the second motor 46 is transmitted to the output wheel 6 via the superposition transmission 4 to drive the vehicle. Therefore, the speed n1 of the output wheel 6 increases between the time points t3 and t4. At the time point t3, the one-way clutch 11 is synchronized again and the speed n2 of the crankshaft 3 and the speed n6 of the planet carrier 17 are the same. Between the time points t3 and t4, the speeds n1, n2, n3 and n6 all increase. From the time point t4, pedaling is performed again with the predetermined transmission ratio as before the time point t1.

[0056] The method further comprises a step S4 of detecting the rotational speed of the wheels of the vehicle, wherein the rotational speed of the driven rear wheels is detected. In this case, the first electric machine 8 is adjusted S2.1 in dependence on the rotational speed of the detected wheels in order to maintain the transmission ratio. If the rotational speed of the wheels decreases, for example, due to friction losses, the transmission ratio is also adapted. Therefore, in the step of adjustment 2.1, if there are friction losses, the rotational speed n3 of the sun gear 12 of the first planetary set 9 is reduced in a slightly ramp-like manner. Depending on the rotational speed of the detected wheels, the second electric machine 46 is also adjusted S2.2 in order to synchronize the rear wheel one-way clutch. If the rotational speed of the wheels decreases, for example, due to friction losses, the rotational speed of the second electric machine 46 is also adapted so that the rear wheel one-way clutch is synchronized and at the same time no force for driving the vehicle is transmitted from the second electric machine 46 via the superposition gear 4 to the output wheel 6 and the driven wheel.

[0057] The method further comprises the step of detecting S5 a user input. The user input can be done, for example, via a switch at the handlebar of the vehicle. The user can predetermine via the user input how the method for controlling the drive device should be carried out. Thus, the rider can predetermine, for example, that he wants to drive in a particularly sporty manner. Alternatively, the rider can predetermine that the vehicle should be driven as energy-efficiently as possible. In the step of determining S6, a predetermined duration T1 is determined depending on the detected user input. When driving in a sporty manner, the predetermined duration T1 is selected to be longer than when driving in a resource-saving manner. In the case of a longer duration T1, the transmission ratio at the superposition transmission 4 will be maintained for a longer period of time. Therefore, the rider has more time to start pedaling again and experience the same transmission ratio at the superposition transmission 4 as at the time when he stopped pedaling. On the contrary, if the rider wants to drive in a resource-saving manner, the predetermined duration T1 is selected to be shorter. As a result, the transmission ratio is reduced more quickly by reducing the rotation speed n of the first motor 8 and reducing the rotation speed n of the second motor 46, so that the rear wheel one-way clutch is lifted. Energy is thereby saved in a particularly resource-saving manner, since only the rotational speed n of the first and second electric machine 8 , 46 has to be reduced.

[0058] The predetermined time duration T1 is several seconds. Therefore, by adjusting S2.1 and S2.2, the first and second motors 8, 46 maintain the predetermined transmission ratio at the superposition transmission 4 and keep the rear wheel freewheel clutch synchronized, so that the rider does not feel the disturbing delayed reaction of the drive device due to the re-pedaling.

[0059] Figure 2a A further drive device for a bicycle is shown according to a second specific embodiment. Figure 2b Here, a corresponding variation of the rotational speed n over time t is shown. In the following, only the differences from the first embodiment are discussed. Figure 1a The drive device of the vehicle according to the first embodiment shown in FIG. 1 is different in that the one-way clutch 11 is arranged between the ring gear 16 of the first planetary set 9 and the output wheel 6. Therefore, the force transmission in at least one rotational direction between the ring gear 16 and the output wheel 6 is prevented. The spur gear stage 24 is arranged on the driven side of the one-way clutch 11, so that the force transmission in two directions occurs between the second motor 46 and the output wheel 6. The one-way clutch 11 is also as Figure 1a The freewheel 11 shown is used to prevent disruptive torque reactions on the crankshaft 3 due to the inertial mass of the drive, for example the electric motor 8 , 46 , in the event of a sudden interruption of pedaling by the rider.

[0060] The speed n2 decreases from time t1 due to the rider's cessation of pedaling. The speed n3 is maintained during a predetermined duration T1 in order to maintain the transmission ratio at the superposition transmission 4. The speed n1 of the output wheel 6 is maintained by adjusting the second motor 46 S2.2. The rear wheel one-way clutch remains synchronized. The speed n7 of the ring gear 16 of the first planetary set 9 decreases with the speed n2 of the crankshaft 3 and the planet carrier 17. The one-way clutch 11 is lifted. From time t2, the speeds n3 and n1 are reduced by reducing the speeds of the first and second motors 8, 46 in order to save energy. At the same time, the speed n7 of the ring gear 16 of the first planetary set 9 is reduced via the transmission ratio at the superposition transmission 4. Just before time t3, the rider starts pedaling again. From the continuous determination S0, it is concluded that there is a rotation of the crankshaft 3 for driving the vehicle. The speeds n2 and n7 increase and the one-way clutch 11 is activated again. From time t3 onwards, the speeds n3 and n1 increase in order to increase the transmission ratio at the superposition gear 4 back to the predetermined transmission ratio and provide a driving force for driving the vehicle. From time t4 onwards, a situation similar to that before time t1 exists.

[0061] Figure 3 A driving device for a bicycle according to a third embodiment is schematically shown. Figure 1a In the first embodiment shown, the second electric machine 46 is similarly arranged between the crankshaft 3 and the planet carrier 17. In the following, only the differences from the first embodiment are discussed. In contrast to the first embodiment, the second electric machine 46 is coupled to the planet carrier 17 via a spur gear set 54. Figure 1b The qualitative speed variation curve shown for the first embodiment is also qualitatively Figure 3 The third embodiment is effective. Here, Figure 1b The speed n6 multiplied by the fixed transmission ratio is equivalent to the speed of the second motor 46. In other respects, the speed change curve is similar in nature to Figure 1b The speed curve of the first embodiment shown in FIG. 1 is similar.

[0062] exist Figure 4a A driving device of a bicycle according to a fourth embodiment is shown in FIG. Figure 4b The curve of the speed n over time t is shown as an example for the fourth embodiment. Only the differences from the first embodiment are discussed below. The one-way clutch 11 is arranged between the sun gear 12 of the first planetary gear set 9 and the planet carrier 21 of the third planetary gear set 20. The one-way clutch 11 performs a similar function as in the previous embodiment, that is, if the rider stops pedaling, the torque reaction on the crankshaft 3 is prevented.

[0063] At time t1, the speed n2 of the planet carrier 17 connected to the crankshaft 3 in a rotationally fixed manner decreases. The speed n1 of the output gear 6 is initially kept constant during a predetermined time period T1, as the speed at the second electric machine 46 is maintained. The speed n3 of the sun gear 12 of the first planetary set is therefore increased. Here, the increase in speed n3 again involves an absolute value, ignoring the direction of rotation. The speed n5 of the planet carrier 21 of the third planetary set 20 remains constant for a predetermined time period T1. The one-way clutch 11 is thus released. At time t2, the speed n5 of the planet carrier 21 of the third planetary set 20 is reduced by reducing the speed of the output element of the first electric machine 8. The speed n of the second electric machine 46 is also reduced from t2. As a result, the speed n1 of the output gear 6 decreases. As a result, the speed n3 of the sun gear 12 of the first planetary set 9 also decreases. Shortly before time t3, the rider starts pedaling again, and the speed n2 increases. As a result, the speed n3 of the sun gear 12 of the first planetary set 9 decreases. The freewheel 11 acts and adjusts S1.1 the first electric machine 8 in order to produce the predetermined transmission ratio in the superposition gear 4 again. Here, between t3 and t4, the rotational speed n5 of the planet carrier 21 of the third planetary set 20 and thus the rotational speed n3 of the sun gear 12 of the first planetary set 9 increases, wherein the freewheel 11 is synchronized between these times t3 and t4. The rotational speed n1 of the output gear 6 is increased by increasing the rotational speed of the second electric machine 46. The transmission of driving force from the second electric machine 46 to the output gear 6 occurs. From the time t4 onwards, a situation similar to that before the time t1 exists.

[0064] Reference numerals list

[0065] 3 Crankshaft

[0066] 4 Superposition transmission

[0067] 6 output wheel

[0068] 8 First Motor

[0069] 9 (First) Planet Group

[0070] 10 Shell

[0071] 11One-way clutch

[0072] 12Sun gear of the first planetary group

[0073] 16 Ring gear of the first planetary set

[0074] 17Planet carrier for the first planetary group

[0075] 18 (Second) Planet Group

[0076] 19 Sun gear of the second planetary group

[0077] 20 (Third) Planet Group

[0078] 21 Planet carrier of the third planetary group

[0079] 24 cylindrical gear stages

[0080] 46 Second Motor

[0081] 52 (Fourth) Planet Group

[0082] 54 cylindrical gear set

[0083] S0 (step) continuously determines whether there is rotation of the crankshaft for driving the vehicle

[0084] S1.1 (step) adjustment to produce a predetermined transmission ratio

[0085] S1.2 (step) regulation to transmit driving force

[0086] S2.1 (step) adjustment to maintain the transmission ratio

[0087] S2.2 (Step) Adjustment so that the resistance to friction is at least a certain value

[0088] S3.1 (step) adjustment to reduce the transmission ratio

[0089] S3.2 (Step) Adjustment so that the resistance to friction is up to a specific value

[0090] S4 (step) detecting the rotation speed of the wheels of the vehicle

[0091] S5 (step) detect user input

[0092] S6 (step) determining the predetermined duration

[0093] Speed

[0094] n1 Output wheel speed

[0095] n2 Crankshaft speed

[0096] n3 Speed ​​of the sun gear of the first planetary group

[0097] n5 Speed ​​of the planet carrier of the third planetary group

[0098] n6 Speed ​​of the planet carrier of the first planetary group

[0099] n7 Speed ​​of the ring gear of the first planetary group

[0100] t time

[0101] t1 (time point) ends the rotation of the crankshaft for driving

[0102] t2 (time point) The crankshaft has not rotated for the drive for a predetermined period of time

[0103] t3 (time point) the crankshaft rotates again to drive

[0104] t4 (time point) the crankshaft rotates at a predetermined gear ratio to drive

[0105] T1 Predetermined duration

[0106] T2 is the time duration for reducing the transmission ratio

Claims

1. A method for controlling a drive device of a vehicle for operation by muscle power, wherein: The drive device is configured to transmit the rider's muscle force from the crankshaft (3) to the output wheel (6) via a superposition transmission device (4) coupled to a first motor (8), and wherein the transmission ratio between the crankshaft (3) and the output wheel (6) at the superposition transmission device (4) is adjusted by adjusting the rotation speed of the first motor (8), wherein the method comprises at least the following steps: continuously determining (S0) whether there is a rotation of the crankshaft (3) for driving the vehicle; if it is determined that there is a rotation of the crankshaft (3) for driving the vehicle, adjusting (S1.1) the rotation speed of the first motor (8) so as to produce a predetermined transmission ratio at the superposition transmission device (4); if it is determined that there is no rotation of the crankshaft (3) for driving the vehicle, adjusting (S1.2) the rotation speed of the first motor (8) so as to produce a predetermined transmission ratio at the superposition transmission device (4); If the crankshaft (3) is rotated for driving the vehicle, the rotation speed of the first motor (8) is adjusted (S2.1) for at most a predetermined time period (T1) in order to keep the transmission ratio at the superposition transmission (4) within the range of the transmission ratio adjusted at the superposition transmission (4) when it is determined (S0) that the crankshaft (3) is not rotating for driving the vehicle; and if the absence of the crankshaft (3) for driving the vehicle is still continuously determined until the predetermined time period has expired, the rotation speed of the first motor (8) is adjusted (S3.1) after the predetermined time period has expired in order to reduce the transmission ratio at the superposition transmission (4) based on a predetermined time variation curve.

2. The method according to claim 1, wherein: If the presence of a rotation of the crankshaft (3) for driving the vehicle is detected after a predetermined period of time has elapsed during which the absence of a rotation of the crankshaft (3) for driving the vehicle has been continuously detected, the first electric machine (8) is adjusted (S1.1) so as to produce a predetermined transmission ratio at the superposition transmission (4).

3. The method according to any one of the preceding claims, further comprising: detecting (S4) a rotational speed of a wheel of the vehicle, wherein: The first electric machine (8) is adjusted (S2.1) according to the detected rotation speed of the wheel so as to keep the transmission ratio within the range.

4. A method according to any one of the preceding claims, wherein: The predetermined time profile for regulating (S3.1) the first electric machine (8) in order to reduce the transmission ratio comprises a linear time profile of the rotational speed of the first electric machine (8).

5. A method according to any one of the preceding claims, wherein: The drive device is also configured to transmit the driving force of the second motor (46) to the output wheel (6) via a superposition transmission device (4) coupled to the second motor (46), and the method further comprises the steps of: if it is determined that the rotation of the crankshaft (3) for driving the vehicle no longer exists, then adjusting (S2.2) the second motor (46) for at most a predetermined time period (T1) to resist friction that opposes the driving force for driving the vehicle, so that the drive device is undriven and the friction is resisted to at least a specific value; and if it is continuously determined that the rotation of the crankshaft (3) for driving the vehicle does not exist until the predetermined time period has passed, adjusting (S3.2) the second motor (46) to resist the friction to a maximum of a specific value.

6. The method according to claim 5, wherein: If, after the predetermined period of time during which it is continuously determined that the crankshaft (3) is not rotating for driving the vehicle, it is determined that the crankshaft (3) is rotating for driving the vehicle, the second motor (46) is adjusted (S1.2) so that the driving force is transmitted from the second motor (46) to the output wheel (6) via the superposition transmission (4) to drive the vehicle.

7. The method according to claim 5 or 6, wherein: The driving force for driving the vehicle can be transmitted from the output wheel (6) to the driven wheel via a one-way clutch, and wherein the one-way clutch is synchronized by adjusting (S2.2) the second motor (46) to resist friction to at least a specific value.

8. The method according to any one of claims 5 to 7, wherein: Adjusting (S2.2) the second motor (46) so as to reduce friction to at least a certain value and adjusting (S3.2) the second motor (46) so as to reduce friction to a certain value is adjusting (S2.2; S3.2) the rotation speed of the second motor (46) and is performed in dependence on the detected rotation speed of the wheel.

9. A method according to any one of the preceding claims, wherein: The first electric machine (8) is adjusted to a first maximum torque in order to implement a safety function of the first electric machine (8).

10. The method according to any one of claims 5 to 9, wherein: The second electric machine (46) is adjusted to a second maximum torque in order to implement a safety function of the second electric machine (46).

11. A method according to any one of the preceding claims, wherein: If it is determined that the crankshaft (3) is rotating for driving the vehicle after it has been determined that the crankshaft (3) is no longer rotating for driving the vehicle for at most a predetermined time period (T1), then the first motor (8) is adjusted (S1.1) to produce a predetermined transmission ratio, and the second motor (46) is adjusted (S1.2) to transmit the driving force from the second motor (46) to the output wheel (6) to drive the vehicle.

12. The method according to any of the preceding claims, wherein the first electric machine (8) is regulated (S1.1; S2.1; S3.1) and the second electric machine (46) is regulated (S1.2; S2.2; S3.2) only when the detected rotational speed of the wheel is greater than a minimum rotational speed of the wheel. 13 . The method according to claim 1 , further comprising: detecting ( S5 ) a user input and determining ( S6 ) the predetermined duration as a function of the detected user input.

14. A method according to any one of the preceding claims, wherein: The first electric machine (8) and the second electric machine (46) are supplied with electrical energy from an energy store, wherein the first electric machine (8) is regulated (S1.1; S2.1; S3.1) and the second electric machine (46) is regulated (S1.2; S2.2; S3.2) only when the energy store has at least a certain charge state.

15. A method according to any one of the preceding claims, wherein: The drive device has a one-way clutch (11) to prevent the transmission of force in at least one rotational direction in the direction of the crankshaft (3), and wherein the adjustment (S1.1; S2.1; S3.1) of the first motor (8) and the adjustment (S1.2; S2.2; S3.2) of the second motor (46) are carried out depending on the relative positioning of the one-way clutch (11) in the superposition transmission (4).

16. A control device configured to carry out the method according to claim 1 for controlling a drive device, wherein: The controller has an input interface for receiving data and an output interface for sending data.

17. A bicycle having at least two wheels, a drive device and a controller according to claim 16.

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