Method for controlling a drive unit of a vehicle that is at least sometimes drivable by human power, control device, drive unit and vehicle

Abstract

A method for controlling a drive unit of a vehicle that is at least sometimes drivable by human power is presented. A first electric motor (70) is operable with energy from an energy store for assisting a mechanical drive with adjustable power. A first rotor (71) of the first electric motor (70) and an input element (4) of the mechanical drive are mechanically action-connected via a superposition transmission to drive an output element (5) for driving the vehicle. At least one sensor is configured to determine a vehicle speed of the vehicle. The method comprises determining (I) the vehicle speed by means of the at least one sensor. The method comprises operating (II) the first electric motor (70) in a standstill operation when a standstill condition is present. The standstill condition is reached at least when the vehicle speed of the vehicle reaches or falls below a speed limit value. The method comprises determining (III) an actual rotor rotation angle of the first rotor (71) when the standstill condition is present. The method comprises setting (IV) the actual rotor rotation angle in consideration of a target rotor rotation angle of the first rotor (71).

Description

Technical Field

[0001] The present invention relates to a method for controlling a drive unit of a vehicle that can at least sometimes be driven by human power, a control device for implementing the method, a drive unit for a vehicle, and a vehicle. Background Technology

[0002] Methods for controlling the drive unit of an electric bicycle are known. The electric bicycle can have both an electric drive and a mechanical drive. The auxiliary power of the electric drive, used to assist the mechanical drive, can be adjusted according to a certain proportion of the rider's pedaling force. This dependence of the auxiliary power on pedaling force may be uncomfortable. Summary of the Invention

[0003] The object of this invention is to provide a method for controlling a drive unit of a vehicle, which can be at least sometimes driven by human power, thereby achieving a high degree of comfort during the operation of the drive unit. This object is achieved by the subject matter having the features of the independent claim. Advantageous further improvements are the subject matter of the dependent claims.

[0004] In a first aspect, a method is proposed for controlling a drive unit of a vehicle that can at least sometimes be driven by human power. A first electric motor can operate using energy from an energy storage device used to assist a mechanical drive with adjustable power. This adjustable power (e.g., auxiliary power) can be adjusted, for example, according to one of the driver's pedaling frequency and pedaling torque. The first electric motor can be formed by a synchronous motor (e.g., a permanent magnet synchronous motor) or an asynchronous motor. The energy storage device can have a battery. A first rotor of the first electric motor and an input element of the mechanical drive are mechanically connected to an output element via a superimposed transmission to drive the vehicle. This enables the drive unit to provide an eCVT system. The input element can be formed by a foot crankshaft. The input element can have a pedal. The input element can be configured to input mechanical driving force. This mechanical driving force can be formed by the driver's pedaling force. The output element can be formed by a sprocket, pulley, and gear. At least one of the input and output elements can be non-rotatably connected to a gear set element of the superimposed transmission. The input element can be non-rotatably connected to the gear set element of the superimposed transmission in the direction of drive rotation via a first freewheel. The driving rotation direction of the input element can be the rotation direction in which the vehicle can move forward along the driving direction.

[0005] If two components are mechanically connected, they are directly or indirectly coupled to each other, such that movement of one component causes a reaction in the other. For example, a mechanical connection can be provided through a form-fit connection or a friction-fit connection. The mechanical connection can correspond to the meshing of corresponding teeth between two components. Other elements, such as one or more spur gear stages, can also be provided between these components. A permanent, non-rotatable connection between two components means that the two components are always rigidly coupled to each other in all specified states of the transmission. In this case, these components can be independent parts that are non-rotatably connected to each other, or they can be integrally formed. A switching element, such as a clutch or brake, can selectively establish or disengage the non-rotatable connection between two components. Similar to a freewheel, the switching element can also be designed to establish a non-rotatable connection only in one direction of rotation.

[0006] At least one sensor is configured to determine the vehicle speed. This sensor may be formed by a GPS module. The sensor may also be formed by a rotational speed sensor. This rotational speed sensor may be configured to detect the wheel rotational speed nRad of a wheel (e.g., a rear wheel or a front wheel). This wheel may be a drive wheel. Thus, the method can be configured to directly determine the vehicle speed by the detected rotational speed. Alternatively, the sensor may be configured to detect rotational motion, such as rotational speed and rotational angle, at least one of an input element, an output element, and a first rotor. Thus, the method can be configured to indirectly determine the vehicle speed by the detected rotational speed, such as the output rotational speed n2 of the output element.

[0007] The method includes determining the vehicle speed using at least one sensor. The method includes operating a first electric motor in a stationary state when a stationary condition exists. The stationary state condition may be related to the stationary state of the vehicle. The stationary state condition is reached at least when the determined vehicle speed reaches or falls below a speed limit. The method includes determining an actual rotor rotation angle of a first rotor when the stationary state condition exists. The method includes setting the actual rotor rotation angle, taking into account a target rotor rotation angle of the first rotor. The method may include determining a target rotor rotation angle. The target rotor rotation angle may be formed from the actual rotor rotation angle determined shortly before the vehicle reaches the stationary state condition. The method may be designed to operate the first electric motor in a stationary state when the stationary state condition is reached. During stationary state operation, the actual rotor rotation angle of the first rotor can be adjusted. The first electric motor can operate in a position control mode during stationary state operation, wherein the actual rotor rotation angle is set to or approximately equal to the target rotor rotation angle. To set the target rotor rotation angle, a target rotor torque of the first electric motor can be set. This method can be designed to operate the first motor during travel when the stationary state is not reached; during travel, the auxiliary power can be adjusted by at least one of the rotor speed and rotor torque of the first motor. The auxiliary power can be adjusted in relation to at least one of the pedaling frequency and pedaling torque. During travel, the first motor can operate in a speed-controlled mode, wherein the auxiliary power can be adjusted by the rotor speed.

[0008] When the vehicle is detected to be stationary, the actual rotor rotation angle previously measured in the first rotor's running or speed control mode can be used as the target rotor rotation angle for the position control mode, thereby preventing the first rotor from rotating or significantly rotating in subsequent processes. The target rotor rotation angle is set to the previously measured actual rotor rotation angle only when transitioning from the speed control mode to the position control mode. When maintaining the position control mode, even if the actual rotor rotation angle deviates due to control deviations, the set target rotor rotation angle can be maintained.

[0009] The superimposed transmission unit may have a first planetary gear set. An input element (e.g., a pedal) may be non-rotatably connected to the first planet carrier of the first planetary gear set. A first rotor may be non-rotatably connected to the first sun gear of the first planetary gear set. An output element may be non-rotatably connected to the first ring gear of the first planetary gear set. When the vehicle is stationary, the first ring gear may be stationary. If the target rotor rotation angle is maintained during stationary operation (e.g., via a position controller), a fixed transmission ratio from the input element (e.g., the pedal) to the output element or the first ring gear can be specified. If the vehicle makes minimal movement in the direction of travel (e.g., assuming the method still recognizes the vehicle as stationary), the input element (e.g., the pedal) may move in a habitual manner according to the vehicle's movement, as in the case of a fixed mechanical transmission ratio.

[0010] For position control in position control mode, a P controller with a proportional element P can be used, for example. When the driver applies pedal force while stationary, the pedal may sink slightly due to the control deviation of the actual rotor rotation angle of the first rotor, but not further. This can provide an advantage, for example, compared to P speed control with a target speed of 0. If the driver then releases the pedal force, the pedal may rebound slightly. This gives the driver a feeling of lack of elasticity, which does not cause any disturbance.

[0011] The actual rotor rotation angle can be adjusted by the operating parameters of the first motor (e.g., voltage or current intensity). These operating parameters can be used to adjust the rotor torque of the first motor. The rotor torque can, for example, be oriented opposite to the direction of drive rotation. The rotor torque can, for example, be oriented opposite to the driver's pedal force.

[0012] The rotor torque of the first electric motor can be limited, either in position control mode or speed control mode. This can be achieved, for example, by limiting the rotor torque to a single value, ensuring that the rotor torque is used to assist the driver's pedaling force. The rotor torque can act on the input element in the opposite direction of the drive rotation. This prevents the first electric motor from causing the input element (e.g., the pedal) to rotate in the drive rotation direction (i.e., the direction of pedal movement). This can also be achieved via a first freewheel, through which the input element can be non-rotatably connected to the gear set elements of the first planetary gear set in the drive rotation direction.

[0013] A stationary state condition is achieved when the detected travel speed is below the speed limit. This allows for the identification of a stationary state even with minimal vehicle movement. Two speed limits can be used to create a hysteresis effect. A stationary state condition is achieved when the detected travel speed is below the lower speed limit (e.g., 0.8 km / h). The method can be designed such that, given the stationary state condition, the stationary state condition is only released and the first motor is activated during travel when the detected travel speed exceeds the upper speed limit (e.g., 1.5 km / h). This makes the identification of whether the stationary state condition has been achieved more stable and avoids unintended reactions to measurement errors.

[0014] Stationary operation can be achieved by a slow and extremely small sinusoidal superposition of the target rotor rotation angle. Thus, an extremely small rotational motion of the first rotor can be defined. This extremely small rotational motion can alternate between the drive rotation direction and the reverse drive rotation direction. Due to the high transmission ratio between the first rotor and the input element (e.g., the pedal), this extremely small rotational motion can be designed to be almost imperceptible to the driver. This avoids the first rotor operating at the same rotor angular position for extended periods. This reduces the load on the first motor, and if necessary, also reduces the load on the inverter of the first motor. For example, the load can be distributed to the three phases of the first motor, which can be formed, for example, by three electrical conductors (such as stator coils or rotor coils).

[0015] This method can be designed such that, when switching from driving operation to stationary operation, the rotor torque of the first rotor continuously (e.g., smoothly or uniformly) transitions from the rotor torque previously used in driving operation to a new value (e.g., the target rotor torque in stationary operation). This will reduce unpleasant torque abrupt changes.

[0016] This method can be configured such that, upon detecting a travel speed, the first electric motor transitions from stationary operation to driving operation. Furthermore, the method can be configured such that, when switching from stationary operation to driving operation, the rotor torque of the first electric motor continuously (e.g., smoothly or uniformly) transitions from the target rotor torque previously used in stationary operation to a new value (e.g., the rotor torque for driving operation). This reduces unpleasant torque abrupt changes.

[0017] This method can be configured to switch from running operation to stationary operation only when the actual rotor speed of the first rotor is less than or reaches the rotor speed limit. The rotor speed limit can be formed by the value 0.

[0018] The advantage of this is that the first motor will only operate in a stationary state (i.e., prevent the first rotor from continuing to rotate) when the strategy function during the first motor's operation is also required. This avoids the first motor operating in a stationary state prematurely.

[0019] In the position control mode of the first motor, the vehicle starting process can be realized because a certain mechanically predetermined transmission ratio exists between the input and output elements by maintaining (i.e. setting) the actual rotor rotation angle of the first rotor.

[0020] The drive unit may have a second motor, EMo. The second rotor of the second motor may be mechanically connected to the output element, for example, via a transmission mechanism. Thus, the output speed n2 can be determined using the rotational speed nEMo of the second rotor. The transmission mechanism may have a planetary gear set. The transmission mechanism may have an intermediate drive, such as a belt drive or a chain drive. The transmission mechanism may have a pre-transmission ratio iVo from the second rotor to the output element. In this case, a fixed speed ratio of nEMo to n2 can exist through the transmission mechanism, where nEMo = iVo. n2.

[0021] The superimposed transmission unit may include a planetary transmission unit. The planetary transmission unit may have at least one planetary gear set, such as a first planetary gear set. The planetary gear set may be configured as a positive planetary gear set or a negative planetary gear set. The planetary gear set may have at least one planetary gear. The planetary gear may be configured as a stepped planetary gear.

[0022] The vehicle may have a control device. The control device may have an input interface and an output interface. The input interface may be configured to input signals into the control device. The input interface may be configured to input signals from at least one sensor. The control device may have a computing unit, a data memory, and a working memory. The control device may be configured to process signals from the input interface. The control device may be configured to generate signals for the output interface. The output interface may be configured to output signals from the control device. For example, the output interface may be configured to control a first electric motor. For example, the output interface may be configured to output at least one of a voltage value and a current value, for example, for controlling the operating parameters of the first electric motor.

[0023] The vehicle may have drive wheels. The drive wheels may be mechanically connected to an output element. The drive wheels may be mechanically connected to the output element via an output transmission (e.g., a chain drive or belt drive). The drive wheels may have hubs. For example, the drive wheels may be mounted on a fixed component via the hub. The drive wheels may be connected to the output element of the output transmission non-rotatably, at least in the direction of rotation (e.g., against the direction of drive rotation), via the hub and a second free wheel.

[0024] In one embodiment of the method, another sensor is configured to detect braking action of the vehicle. The method may include identifying braking action of the vehicle. Thus, at least when braking action is present, a stationary state condition can be achieved.

[0025] This other sensor can be, for example, a pressure sensor or a contact sensor. This sensor can be mounted on the braking unit, such as on the brake lever. The sensor can be configured to detect braking action when the driver operates the brake lever. The method can be designed such that a stationary state condition exists when braking action is detected and the vehicle speed reaches or falls below a speed limit.

[0026] This method can be designed to switch to the position control mode of the first electric motor only when the driver operates the braking unit (e.g., the brake lever) in addition to the detected vehicle being stationary. For example, the position control mode of the first electric motor can only be used when it is practically useful, such as when the driver has one foot on the pedal while waiting at a red light. In this way, the driver can control whether the pedal can be slowly lowered (e.g., in speed control mode) or whether he wants to maintain the pedal position (e.g., in position control mode) through braking operations. This avoids providing auxiliary power unintentionally and uncomfortably. The speed control mode of the first electric motor can be for normal vehicle operation, such as with an eCVT system. The position control mode can represent a special case, such as for a stationary vehicle.

[0027] In one embodiment of the method, another sensor may be configured to determine the actual rotor torque of the first electric motor. The method may include determining the actual rotor torque. The method may also include operating the first electric motor in a stationary state while taking the actual rotor torque into account.

[0028] This other sensor can be, for example, a torque sensor, a pressure sensor, or one or more strain gauges. This other sensor can be configured to detect the actual rotor torque. The drive unit can have a first sensor and a second sensor. The first sensor can be configured to determine the vehicle speed. The second sensor can be configured to determine the actual rotor torque of the first electric motor.

[0029] The rotor torque of the first electric motor (which controls the rotor rotation angle in position control mode) can be limited to a maximum permissible rotor torque limit. This rotor torque limit can be set by the maximum operating torque set by the motor manufacturer for the first electric motor. The rotor torque limit is adjustable. This prevents the motor or the power electronics used to drive the first motor from overheating. Furthermore, it limits the power required from the battery.

[0030] The method can be designed such that when the rotor torque of the first motor reaches or exceeds a rotor torque limit (e.g., when the driver applies a large pedal torque), the first rotor begins to rotate, and, for example, the pedal begins to descend. During descent or rotation, the first rotor can rotate in the drive rotation direction, thereby generating a new actual rotor rotation angle different from the target rotor rotation angle used for the position control mode. The method can be designed such that, in the case of descent or rotation, the new actual rotor rotation angle forms a new target rotor rotation angle for the position control mode. Alternatively, the method can be designed such that the difference between the new actual rotor rotation angle and the target rotor rotation angle is added to the target rotor rotation angle, thereby forming a new target rotor rotation angle for the position control mode. Thus, for example, when the driver removes the large pedal torque, the input element (e.g., the pedal) can remain substantially stationary, for example, at the new target rotor rotation angle, without returning to, for example, its initial position at the target rotor rotation angle. Thus, after applying a large pedal torque, the pedal can also remain in its new position without rebounding a considerable distance.

[0031] In one embodiment of the method, the second rotor of the second motor can be mechanically connected to the output element via a superimposed transmission section to drive the vehicle. The method may include shutting off the second motor when stationary conditions exist.

[0032] For example, when the stationary condition is not met, the second motor can operate in auxiliary mode. The method can be designed to shut off the second motor during stationary operation, for example, by no longer operating in auxiliary mode. The position control mode can be designed, for example, to not transmit adjustment torque to the second motor. If the stationary condition is met, such as when the driver stops at a red light and the vehicle is stationary, the vehicle is no longer driven by the second motor, and therefore no current is required.

[0033] This can be particularly combined with implementations of the method that include recognizing braking operation. For example, this allows the driver to control whether he desires the auxiliary power provided by the second electric motor, such as the starting torque when starting the vehicle from a standstill.

[0034] During operation, the method may include detecting the actual rotor torque of the first electric motor. This can be achieved, for example, by measuring the phase current on the first electric motor. Alternatively, in a simpler embodiment, it may be assumed that the actual rotor torque is approximately equal to, for example, the rotor torque generated by the operation of the first electric motor based on the driver's pedaling frequency. In this case, the actual rotor torque may have a value within a permissible range, for example, specified by the electric motor manufacturer. For example, if the torque ratio or transmission ratio of the first planetary gear set between the first sun gear and the first planetary carrier is constant, the actual pedaling torque at the input element can be determined based on the actual rotor torque of the first electric motor. During operation, an auxiliary torque for the second rotor can be determined and provided to assist the mechanical drive based on the actual pedaling torque thus determined.

[0035] In one embodiment of the method, the method may include determining the actual pedaling torque of the input element. The method may also include operating the second motor in an auxiliary mode when a stationary condition exists and the actual pedaling torque reaches or exceeds a pedaling torque limit.

[0036] If the actual pedal torque exceeds the pedal torque limit in the position control mode of the first electric motor (i.e., when the stationary condition is met), the second electric motor can operate in auxiliary mode. The second electric motor can, for example, be restarted. If the stationary condition is met, for example when the driver stops at a red light and the vehicle is stationary, and the driver adjusts the pedal to an angle conducive to starting (e.g., by rotating it backward, which can be achieved based on the first freewheel) and places his foot on the pedal, then essentially only the weight of his leg acts on the pedal. The pedal torque limit can be formed by a value of this order of magnitude. Up to the pedal torque limit, the first electric motor can operate in position control mode. The second electric motor can then be turned off. If the driver increases the pedal torque (in the way that he, for example, actively presses the pedal because he, for example, wants to start), the actual pedal torque may exceed the pedal limit, and the second electric motor can operate in auxiliary mode from that point without delay, i.e., before the vehicle speed is detected. Thus, the vehicle can be comfortably started from a stationary state with the assistance of the second electric motor, which is particularly advantageous, for example, on a slope. If the vehicle speed is subsequently detected, the first electric motor can operate in speed control mode.

[0037] In a second aspect, a control device is proposed, configured to perform the method according to any of the foregoing embodiments. The control device includes at least: an input interface for inputting signals into the control device; and an output interface for outputting signals for controlling the drive unit.

[0038] The control device may have a user interface for inputting information, such as limit values, to determine shutdown conditions. The control device may have an input interface and an output interface. The input interface may be configured to input signals into the control device. The input interface may be configured to input signals from at least one sensor. The control device may have a computing unit, data memory, and working memory. The control device may be configured to process signals from the input interface. The control device may be configured to generate signals for the output interface. The output interface may be configured to output signals from the control device. For example, the output interface may be configured to control at least one of a first motor and a second motor. The output interface may, for example, be configured to output at least one operating parameter, such as a voltage value or a current value, from at least one of the first motor and the second motor.

[0039] In a third aspect, a drive unit for a vehicle that can at least sometimes be driven by human power is proposed. A first electric motor operates using energy from an energy storage device, which is used to provide adjustable power assistance to the mechanical drive via a control device according to any embodiment of the second aspect. A first rotor of the first electric motor and the input element of the mechanical drive are mechanically connected to the output element via a superimposed transmission section to drive the vehicle. At least one sensor is configured to determine the vehicle speed.

[0040] The sensor can be formed by at least one of a GPS module or a speed sensor, for example, to detect the rotational speed of a vehicle's wheels (such as drive wheels).

[0041] In one embodiment of the drive unit, the superimposed transmission section may have a first planetary gear set, which includes a first gear set element, a second gear set element, and a third gear set element. An input element may be mechanically connected to the second gear set element to input driving force into the first planetary gear set. A first rotor may be mechanically connected to the first gear set element to input driving force into the first planetary gear set. An output element may be mechanically connected to the third gear set element to output driving force from the first planetary gear set.

[0042] The first motor can be configured to set the rotational speed of the input element, such as the user's pedaling frequency. This allows the drive unit to provide an electrically continuously switchable transmission, such as an eCVT system. The first motor can be configured to set the gear ratio of an iCVT. The first rotor can be arranged coaxially with the input element.

[0043] The first planetary gear set may include a first sun gear, a first planet carrier, a first planetary pin, a first planetary gear, and a first ring gear. The first sun gear may be arranged coaxially with the input element. The first sun gear may be arranged coaxially with the first rotor. The first sun gear may mesh with the first planetary gear. The first planetary gear may mesh with the first ring gear. The first planetary gear is rotatably mounted on the first planetary pin, for example, via a sliding bearing, needle roller bearing, or roller bearing. The first planetary gear may be formed of a stepped planetary gear. The first planetary pin may be fixed to the first planet carrier.

[0044] The first planetary gear set can be formed by either a positive planetary gear set or a negative planetary gear set. The first gear set element can be formed by a first sun gear. The second gear set element can be formed by a first planet carrier. The third gear set element can be formed by a first ring gear.

[0045] The input element can be non-rotatably connected to the second gear set element. The input element can be non-rotatably connected to the second gear set element in one direction via a first free wheel. The first free wheel can be designed to connect the input element non-rotatably to the second gear set element in the direction of drive rotation, and to be rotatably connected relative to the second gear set element in the opposite direction of drive rotation.

[0046] The first rotor can be mechanically connected to the first gear set elements via a pre-stage transmission unit. The pre-stage transmission unit may have a second planetary gear set. The second planetary gear set may be formed by a positive planetary gear set or a negative planetary gear set. The second planetary gear set may have a second sun gear, a second planet carrier, a second planetary pin, a second planetary gear, and a second ring gear. The first rotor can be non-rotatably connected to the second sun gear. The second sun gear can mesh with the second planetary gear. The second planetary gear can mesh with the second ring gear. The second planetary gear can be rotatably mounted on the second planetary pin via a bearing (e.g., a needle roller bearing, a sliding bearing, or a ball bearing). The second planetary gear may be formed by a step-type planetary gear. The second planetary pin can be connected to the second planet carrier.

[0047] The first rotor, the first planetary gear set, the second planetary gear set, the input element, and the output element can be arranged coaxially. The first planetary gear set and the second planetary gear set can be arranged axially between the first motor and the output element. The input element can be oriented axially. The input element can extend axially through at least one of the first rotor, the first planetary gear set, the second planetary gear set, and the output element.

[0048] The drive unit may have a fixed component, such as a bicycle frame. The second ring gear may be fixed to this fixed component. The second planetary carrier may be non-rotatably connected to the first gear element of the first planetary gear set.

[0049] In one embodiment of the drive unit, the second rotor of the second motor can be mechanically connected to the third gear set element to input driving force into the superimposed transmission unit.

[0050] The second motor can be configured to provide the required torque, auxiliary power, or differential power for the mechanical drive. The second motor can be arranged axially parallel to the input element.

[0051] The second rotor can be mechanically connected to a second or third gear set element via a transmission mechanism. This transmission mechanism may include a third planetary gear set. The third planetary gear set may include a third sun gear, a third planet carrier, a third planetary pin, a third planetary gear, and a third ring gear. The second rotor can be non-rotatably connected to the third sun gear. The third sun gear can mesh with the third planetary gear. The third planetary gear can mesh with the third ring gear. The third planetary gear can be rotatably mounted on the third planetary pin via a bearing (e.g., a sliding bearing, needle roller bearing, or ball bearing). The third planetary gear can be formed of a stepped planetary gear. The third planetary pin can be fixed to the third planet carrier. The third planet carrier can be mechanically connected, for example, via another transmission mechanism, to a third gear set element (e.g., a first ring gear) or a second gear set element (e.g., a first planet carrier) of the first planetary gear set. The third ring gear of the third planetary gear set can be fixed to a stationary component.

[0052] In a fourth aspect, a vehicle is proposed that has at least drive wheels and a drive unit according to any embodiment of the third aspect. The vehicle may sometimes be manually driven. The vehicle may be a bicycle, electric bicycle, or electric scooter. The drive wheels are mechanically connected to the drive unit, thereby enabling the drive unit to move the vehicle forward.

[0053] The drive wheel can be mechanically connected to the output element. The drive wheel can be mechanically connected to the output element via an output drive (e.g., a chain drive or belt drive). The drive wheel can have a hub. For example, the drive wheel can be mounted on a fixed component via the hub. The output element of the output drive can be non-rotatably connected to the drive wheel via the hub and a second free wheel in at least one rotational direction (e.g., the driving rotation direction). Attached Figure Description

[0054] Figure 1 A flowchart is shown as one embodiment of a method for controlling the drive unit of a vehicle that can at least sometimes be driven by human power.

[0055] Figure 2 A flowchart of one embodiment of the method for controlling the drive unit is shown.

[0056] Figure 3A schematic cross-sectional view of the drive unit is shown. Detailed Implementation

[0057] Figure 1 A flowchart illustrating one embodiment of a method for controlling a drive unit of a vehicle (currently an electric bicycle) that is at least sometimes manually driven. The drive unit includes an input element 4 (currently a foot crankshaft with a mechanical actuator and pedals), an output element 5 (currently a sprocket), a first electric motor 70 with a first rotor 71 and a first stator 72, an energy storage device (currently a battery), a superimposed transmission, and at least one sensor for determining the vehicle's speed. The drive unit and its components will be described with reference to... Figure 3 Provide a detailed description.

[0058] The first electric motor 70 can operate using energy from an energy storage device, which is used to assist the mechanical drive with adjustable power. The first rotor 71 of the first electric motor 70 and the input element 4 of the mechanical drive are mechanically connected to the output element 5 via a superimposed transmission section to drive the vehicle.

[0059] The method includes, in a first step, determining the vehicle speed. The method includes, in a second step, operating the first electric motor 70 in a stationary state, provided that a stationary condition exists. The stationary condition is met at least when the vehicle speed reaches or falls below a speed limit. The method includes, in a third step, determining the actual rotor rotation angle of the first rotor 71, provided that the stationary condition exists. The method includes, in a fourth step, adjusting the actual rotor rotation angle, taking into account a target rotor rotation angle of the first rotor 71. The method then restarts from the first step. This prevents the crankshaft pedal from sinking when the driver, while the vehicle is stationary, rests their foot on the pedal and unintentionally drives the vehicle.

[0060] The following will describe the method and other details of the driving unit.

[0061] In another embodiment, the method includes, in a fifth step, identifying braking operation of the vehicle. A stationary state condition is met at least when braking operation is present. This ensures that the first electric motor 70 can operate in a stationary state when the driver requests braking. Currently, the fifth step is performed after the first step. After the fifth step, the method continues with the second step according to the first embodiment.

[0062] In another embodiment, the method includes, in a sixth step, determining the actual rotor torque of the first motor 70. The operation of the first motor 70 in a stationary state is performed taking into account the actual rotor torque. In this case, the actual rotor torque is limited to a maximum permissible value and does not exceed that value. This prevents the first motor 70 from overheating. Currently, the sixth step is performed after the first step. After the sixth step, the method continues with the second step according to the first embodiment.

[0063] In another embodiment, the drive unit has a second motor 80 with a second rotor 81 for inputting driving force into the superimposed transmission unit. The second rotor 81 is mechanically connected to the output element 5 via the transmission unit and the superimposed transmission unit. In this embodiment, the method includes, in a seventh step, turning off the second motor 80 when a stationary condition exists. This results in energy-efficient operation of the drive unit when the vehicle is stationary.

[0064] The method includes, in an eighth step, determining the actual pedal torque of the input element 4. The method also includes, in a ninth step, operating the second motor 80 in assist mode when a stationary condition exists and the actual pedal torque reaches or exceeds a pedal torque limit. This allows the driver's starting request to be assisted even before the vehicle speed is identified. Currently, the seventh step is performed after the first step. After the ninth step, the method continues with the second step according to the first embodiment.

[0065] Figure 2 A flowchart of at least one of the aforementioned embodiments of a method for controlling a drive unit is shown. As previously described, the method begins with a first step, namely, determining the vehicle speed. Subsequently, at least by means of the vehicle speed, it is checked whether the vehicle is stationary. If the vehicle is stationary, the first motor 70 operates in stationary operation. Otherwise, the first motor 70 operates in driving operation, in which the first motor 70 provides auxiliary power.

[0066] Figure 3 A schematic cross-sectional view of the drive unit is shown. The drive unit can be controlled by a method according to any of the foregoing embodiments. The drive unit has all the features of at least one of the foregoing embodiments. The superimposed transmission section is formed by a first planetary gear set 10. The drive unit also has a front-stage transmission section formed by a second planetary gear set 20, a rear wheel as the drive wheel, and a fixed member 9 (currently formed by a bicycle frame). The rear wheel is operatively connected to the output element 5 via an output transmission section (currently a chain drive) to drive the vehicle.

[0067] The first rotor 71, the first planetary gear set 10, the second planetary gear set 20, the input element 4, and the output element 5 are arranged coaxially. The first planetary gear set 10 and the second planetary gear set 20 are arranged axially between the first motor 70 and the output element 5. The input element 4 extends axially through the first rotor 71, the first planetary gear set 10, the second planetary gear set 20, and the output element 5.

[0068] The first planetary gear set 10 has a first sun gear, a first planet carrier, a plurality of first planet bolts, a plurality of first planet gears, and a first ring gear. The first sun gear meshes with the first planet gears. Each first planet gear is rotatably mounted on one of the first planet bolts. The first planet bolts are fixed to the first planet carrier. The first planet gears mesh with the first ring gear. The second planetary gear set 20 has a second sun gear, a second planet carrier, a plurality of second planet bolts, a plurality of second planet gears, and a second ring gear. The second sun gear meshes with the second planet gears. Each second planet gear is rotatably mounted on one of the second planet bolts. The second planet bolts are fixed to the second planet carrier. The second planet gears mesh with the second ring gear.

[0069] Input element 4 is non-rotatably connected to the first planetary carrier. The first ring gear is non-rotatably connected to the output element 5. This mechanically connects input element 4 and output element 5 to drive the vehicle. In one embodiment, input element 4 is non-rotatably connected to the first planetary carrier via a first freewheel 41 in the direction of drive rotation. Thus, input element 4 can rotate relative to the first planetary carrier in the opposite direction of drive rotation via the first freewheel 41.

[0070] The first stator 72 is fixed to the fixed component 9. The first rotor 71 is non-rotatably connected to the second sun gear. The second ring gear is fixed to the fixed component 9. The second planetary carrier is non-rotatably connected to the first sun gear. Therefore, the first rotor 71 is mechanically connected to the output element 5 to drive the vehicle.

[0071] The output element of the output transmission unit (currently an output sprocket) is non-rotatably connected to the drive wheel in the direction of drive rotation via a second free wheel 42. The drive wheel is rotatably mounted on the fixed component 9 via a bearing unit. This configures the drive wheel for driving the vehicle.

[0072] The drive unit has a second motor 80, which has a second rotor 81 and a second stator 82. The second stator 82 is fixed to the fixing member 9. The second rotor 81 is arranged axially parallel to the first rotor 71. The second rotor 81 is arranged in the same plane as the first rotor 71 in the axial direction. The second rotor 81 is mechanically connected to the first gear ring through a transmission drive.

[0073] The transmission unit has a third planetary gear set, which includes a third sun gear, a third planet carrier, several third planetary pins, several third planetary gears, and a third ring gear. The third sun gear meshes with the third planetary gears. Each third planetary gear is rotatably mounted on one of the third planetary pins. The third planetary pins are fixed to the third planet carrier. The transmission unit also has an intermediate transmission unit (e.g., a belt drive unit) with input and output elements.

[0074] The second rotor 81 is non-rotatably connected to the third sun gear. The third ring gear is fixed to the fixed component 9. The third planetary carrier is non-rotatably connected to the input element of the intermediate transmission unit. The output element of the intermediate transmission unit is non-rotatably connected to the first ring gear.

[0075] List of reference numerals 4 input elements 5 output components 9 Fixed components 10 First Planetary Gear Set 20 Second Planetary Gear Set 41 First Freewheel 42 Second Freewheel 70 First Electric Motor 71 First Rotor 72 First Stator 80 Second Electric Motor 81 Second Rotor 82 Second Stator I determine the vehicle's speed. II. This causes the first motor to operate while in a stationary state. III. Determine the actual rotor rotation angle of the first rotor. IV. Set the actual rotor rotation angle while taking into account the target rotor rotation angle. V identifies the vehicle's braking operation. VI. Determine the actual rotor torque of the first electric motor. VII. Turn off the second motor VIII determines the actual pedaling torque of the input element. IX enables the second motor to operate in auxiliary mode.

Claims

1. A method for controlling a drive unit of a vehicle that is at least sometimes manually driven, wherein, - The first electric motor (70) can operate using energy from an energy storage device, which is used to assist the mechanical drive with adjustable power. - The first rotor (71) of the first electric motor (70) and the input element (4) of the mechanical drive are mechanically connected to the output element (5) via a superimposed transmission section to drive the vehicle. - At least one sensor is configured to determine the vehicle speed; The method includes: - Determine the vehicle speed (I) using the at least one sensor; - When a stationary condition exists, the first motor (70) is operated in a stationary state (II) at least when the determined vehicle speed of the vehicle reaches or falls below the speed limit. - When the aforementioned static state condition exists, determine (III) the actual rotor rotation angle of the first rotor (71); and - The actual rotor rotation angle (IV) is set taking into account the target rotor rotation angle of the first rotor (71).

2. The method according to claim 1, characterized in that, Configure another sensor to detect the vehicle's braking operation. The method includes: - Identify (V) the braking operation of the vehicle, wherein the stationary state condition is reached at least when the braking operation is present.

3. The method according to any one of the preceding claims, characterized in that, Another sensor is configured to determine the actual rotor torque of the first motor (70). The method includes: - Determine the actual rotor torque as described in (VI); and - The first motor (70) is operated in the stationary state, taking into account the actual rotor torque (II).

4. The method according to any one of the preceding claims, characterized in that, The second rotor (81) of the second electric motor (80) is mechanically connected to the output element (5) via the superimposed transmission section to drive the vehicle, and The method includes: - When the static state condition is present, turn off (VII) the second motor (80).

5. The method according to claim 4, characterized in that, The method includes: - Determine the actual pedaling torque of the input element (4) described in (VIII); and - When the static state condition exists and the actual pedaling torque reaches or exceeds the pedaling torque limit, the second motor (80) is operated in auxiliary mode (IX).

6. A control device configured to perform the method according to any one of the preceding claims, wherein, The control device has at least: an input interface for inputting signals into the control device; And an output interface for outputting signals to control the drive unit.

7. A drive unit for a vehicle that is at least sometimes manually driven, wherein, - The first electric motor (70) can operate using energy from an energy storage device, which is used to assist the mechanical drive with adjustable power via the control device according to claim 6. - The first rotor (71) of the first electric motor (70) and the input element (4) of the mechanical drive are mechanically connected to the output element (5) via a superimposed transmission section to drive the vehicle, and - At least one sensor is configured to determine the vehicle speed.

8. The driving unit according to claim 7, characterized in that, - The superimposed transmission unit has a first planetary gear set (10), which includes a first gear set element, a second gear set element, and a third gear set element. - The input element (4) is mechanically connected to the second gear set element to input driving force into the first planetary gear set (10). - The first rotor (71) is mechanically operatively connected to the first gear set element for inputting driving force into the first planetary gear set (10), and - The output element (5) is mechanically connected to the third gear set element for outputting driving force from the first planetary gear set (10).

9. The driving unit according to claim 7 or 8, characterized in that, The second rotor (81) of the second electric motor (80) is mechanically connected to the third gear set element to input driving force into the superimposed transmission unit.

10. A vehicle, said vehicle having at least drive wheels and a drive unit according to any one of claims 7 to 9, wherein, The vehicle may sometimes be driven by human power, and wherein the drive wheels are mechanically connected to the drive unit so that the drive unit enables the vehicle to move forward.

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