DE102018213852A1 - Method and device for operating an auxiliary electric drive and drive device for a vehicle - Google Patents

Abstract

A method for operating an auxiliary electric drive (104) for a bicycle (100) comprises a step of determining an estimated angle of rotation of a shaft (108) of the auxiliary drive (104) using an excitation signal fed into a coil of the auxiliary drive (104) determining a measured direction of rotation of the shaft (108) using a sensor signal representing a signal provided by an inclination sensor (106) coupled to the shaft (108), a step of determining an assumed direction of rotation of the shaft (108) using a request signal indicating a direction of torque requested by the auxiliary drive (104) and acting on the shaft (108), and a step of determining a corrected rotation angle of the shaft (108) using the estimated rotation angle, the measured rotation direction and the assumed rotation direction.

Description

The present invention relates to a method and a device for operating an electrical auxiliary drive and to a drive device for a vehicle, in particular for a bicycle.

To operate an electrical auxiliary drive, for example for a bicycle, knowledge of a current rotational position of the auxiliary drive is advantageous, for example to enable the auxiliary drive to be switched on smoothly.

In the DE 10 2015 100 676 B3 the determination of the rotational position using a rotational position sensor is described.

Against this background, the present invention provides an improved method and an improved device for operating an auxiliary electric drive and an improved drive device for a vehicle, in particular for a bicycle, according to the main claims. Advantageous configurations result from the subclaims and the following description.

The current rotational position of the auxiliary drive can be determined using a sensor, which can advantageously also be arranged outside the auxiliary drive. Knowing the current rotary position of the auxiliary drive is important for the operation of the auxiliary drive. The use of such a sensor, for example in the form of an inclination sensor, makes it possible to implement an electrically assisted bicycle in which the use of position sensors in the auxiliary drive is avoided. This can reduce costs, increase reliability and also save space.

• Bestimmen eines geschätzten Drehwinkels einer Welle des Hilfsantriebs unter Verwendung eines in eine Spule des Hilfsantriebs eingespeisten Anregungssignals;
• Bestimmen einer gemessenen Drehrichtung der Welle unter Verwendung eines Sensorsignals, das ein von einem mit der Welle gekoppelten Sensor, beispielsweise einem Neigungssensor, bereitgestelltes Signal repräsentiert;
• Bestimmen einer angenommen Drehrichtung der Welle unter Verwendung eines Anforderungssignals, das eine Richtung eines von dem Hilfsantrieb angeforderten und auf die Welle wirkenden Drehmoments anzeigt; und
• Ermitteln eines korrigierten Drehwinkels der Welle unter Verwendung des geschätzten Drehwinkels, der gemessenen Drehrichtung und der angenommenen Drehrichtung.

A method for operating an auxiliary electric drive for a vehicle, in particular for a bicycle, comprises the following steps:

• Determining an estimated angle of rotation of a shaft of the auxiliary drive using an excitation signal fed into a coil of the auxiliary drive;
• Determining a measured direction of rotation of the shaft using a sensor signal that represents a signal provided by a sensor coupled to the shaft, for example an inclination sensor;
• Determining an assumed direction of rotation of the shaft using a request signal which indicates a direction of a torque requested by the auxiliary drive and acting on the shaft; and
• Determining a corrected angle of rotation of the shaft using the estimated angle of rotation, the measured direction of rotation and the assumed direction of rotation.

The vehicle can be a manual drive or an internal combustion engine and additionally the vehicle having the electric auxiliary drive. The auxiliary drive can be used for the sole or supportive drive of the vehicle. For example, the vehicle can be an electric bike, a so-called e-bike or pedelec. If the auxiliary drive is active, the auxiliary drive can exert an at least supporting torque on the shaft. The estimated angle of rotation can be determined using known methods in which an excitation signal is fed into the auxiliary drive. For this purpose, for example, a characteristic of the excitation signal during the feed-in or a response signal resulting from the excitation signal can be evaluated. The characteristic can depend on a relative position between a rotor and a stator of the auxiliary drive. The estimated angle of rotation can be inferred using a previously known dependency of the characteristic on the relative position. The excitation signal can be a signal that can be superimposed on a control signal required for operating the auxiliary drive, for example in the form of an operating voltage. The measured direction of rotation can be determined, for example, by evaluating chronologically successive values of the sensor signal. The sensor can be a sensor that is suitable for directly detecting the direction of rotation or that is suitable for providing a signal from which the direction of rotation can be determined. As an alternative to an inclination sensor, an acceleration sensor can be used, for example. The request signal can indicate a direction of the at least supporting torque which acts on the shaft after the auxiliary drive has been activated or when the auxiliary drive is active. The request signal can represent, for example, a signal provided by a drive control of the auxiliary drive. The corrected angle of rotation of the shaft can be understood to mean that angle which, after carrying out the steps of the method mentioned, is assumed to correspond to the current real rotational position. The corrected angle of rotation can be used, for example, to determine the control signal for operating the auxiliary drive. For example, the corrected angle of rotation can be used to take into account a relative position between a rotor and a stator of the auxiliary drive when determining the control signal. This enables the auxiliary drive to be switched on smoothly, for example.

In the determining step, the estimated angle of rotation can be determined as the corrected angle of rotation if the assumed direction of rotation corresponds to the measured direction of rotation. The assumed direction of rotation can be used to determine very easily whether a correction of the estimated angle of rotation is necessary.

Furthermore, in the step of determining, the corrected angle of rotation can be determined as the estimated angle of rotation corrected by π rad when the assumed direction of rotation is opposite to the measured direction of rotation. In this case, it can be seen from the assumed direction of rotation that a correction of the estimated angle of rotation is necessary. The use of the unit radiant as an angle measure for the angle values to be processed in the method is common practice, but can be replaced by other units without changing the approach described here. The correction can ensure a 180 ° position inaccuracy of the rotor position of the rotor of the auxiliary drive.

The method can include a step of feeding the excitation signal in the form of a high-frequency signal. For example, a high-frequency signal can be selected with a signal shape that triggers no or only a negligible drive effect on the auxiliary drive.

The step of determining the corrected angle of rotation can be carried out during startup of the auxiliary drive. Knowledge of the corrected angle of rotation is helpful in order to make a transition between a purely manual drive and a drive supported by the auxiliary drive as fluid as possible.

In one embodiment, the method may include a step of determining an observed angle of rotation of the shaft using a system model of the auxiliary drive. All suitable model-based methods can be used to determine the observed angle of rotation, by means of which the observed angle of rotation can be reconstructed as a non-measurable state using at least one manipulated variable or measured variable. In a step of determining, a further corrected angle of rotation of the shaft can be determined using the estimated angle of rotation and the observed angle of rotation. The further corrected angle of rotation can be used, for example, to check the corrected angle of rotation or can be used instead of the corrected angle of rotation, for example if the shaft has a speed of rotation which is above a speed threshold.

For example, the further corrected angle of rotation can be determined as a function of a deviation between the estimated angle of rotation and the observed angle of rotation either as the estimated angle of rotation or the angle of rotation observed, or else as the observed angle of rotation corrected by π rad. In this way, a simple correction is again possible.

The step of determining the further corrected angle of rotation can be carried out during startup of the auxiliary drive at a speed of rotation of the shaft which is above a speed threshold. This can be advantageous if the observed angle of rotation of the shaft can be determined very precisely using the system model at high rotational speeds of the shaft.

The method can include a step of providing a control signal for actuating the auxiliary drive using the corrected rotation angle and additionally or alternatively using the further corrected rotation angle. The control signal can be suitable for driving the auxiliary drive in such a way that the auxiliary drive provides a torque for sole or assisted driving of the shaft. The control signal can represent, for example, an AC voltage or a switching signal for switching an inverter used to operate the auxiliary drive.

The described approach can be implemented using a device for operating an auxiliary electric drive for a vehicle, in particular for a bicycle. Such a device is set up to carry out and / or to control the steps of the mentioned method in corresponding units.

A device can be an electrical device that processes electrical signals, for example sensor signals, and outputs control signals as a function thereof. The device can have one or more suitable interfaces, which can be designed in terms of hardware and / or software. In the case of a hardware configuration, the interfaces can be part of an integrated circuit, for example, in which functions of the device are implemented. The interfaces can also be separate integrated circuits or at least partially consist of discrete components. In the case of software training, the interfaces can be software modules that are present, for example, on a microcontroller in addition to other software modules.

• einen elektrischen Hilfsantrieb;
• einen Neigungssensor, der mit einer Welle des Hilfsantriebs gekoppelt und ausgebildet ist, um ein eine Neigung des Neigungssensors repräsentierendes Sensorsignal bereitzustellen; und
• einer genannte Vorrichtung zum Betreiben des Hilfsantriebs.

A drive device for a vehicle, in particular for a bicycle, has the following features:

• an auxiliary electric drive;
• a tilt sensor coupled to a shaft of the auxiliary drive and configured to provide a sensor signal representative of a tilt of the tilt sensor; and
• a named device for operating the auxiliary drive.

The auxiliary drive can be a suitable electrical machine, for example in the form of a direct current, alternating or three-phase motor. It can be an auxiliary drive of the type already used for e-bikes or pedelecs, for example. The inclination sensor can be a known sensor that can monitor an inclination angle. For example, the inclination sensor can be implemented as a microelectromechanical sensor with a spring mass system. A rotation position of the shaft can be assigned to the inclination of the inclination sensor. The inclination sensor can be arranged directly on the shaft or on a part of the shaft coupled to the shaft. The device can have an interface for receiving the sensor signal. The sensor signal can indicate an inclination or a rotational speed of the shaft.

For example, the inclination sensor can be arranged outside the auxiliary drive. In this way, the inclination sensor is easily accessible.

The drive device can have a pedal coupled to the shaft. The tilt sensor can be arranged on the pedal. The pedal offers enough space for a protected arrangement of the inclination sensor.

As an alternative to an inclination sensor, another type of sensor can be used, which enables a direction of rotation of the shaft to be determined. Advantageously, a pi-uncertainty in sensorless control for low speeds can be solved by a position sensor of the pedals, which can refer to the auxiliary drive without sensors. By solving the pi uncertainty in this way, torque jumps are avoided since no current jumps have to be applied in the q axis. Furthermore, no hardware changes to the auxiliary drive are required.

Also advantageous is a computer program product with program code, which can be stored on a machine-readable medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the method according to one of the above-described embodiments when the program is on a computer or a device is performed.

• 1 eine schematische Darstellung eines Fahrrads mit einer Vorrichtung zum Betreiben eines elektrischen Hilfsantriebs gemäß einem Ausführungsbeispiel;
• 2 eine schematische Darstellung einer Vorrichtung zum Betreiben eines elektrischen Hilfsantriebs gemäß einem Ausführungsbeispiel;
• 3 ein Blockdiagramm zum Ermitteln eines korrigierten Drehwinkels gemäß einem Ausführungsbeispiel;
• 4 ein Blockdiagramm zum Ermitteln eines weiteren korrigierten Drehwinkels gemäß einem Ausführungsbeispiel; und
• 5 ein Ablaufdiagramm eines Verfahrens zum Betreiben eines elektrischen Hilfsantriebs gemäß einem Ausführungsbeispiel.

The invention is explained in more detail by way of example with reference to the accompanying drawings. Show it:

• 1 a schematic representation of a bicycle with a device for operating an electric auxiliary drive according to an embodiment;
• 2 a schematic representation of a device for operating an electrical auxiliary drive according to an embodiment;
• 3 a block diagram for determining a corrected rotation angle according to an embodiment;
• 4 a block diagram for determining a further corrected rotation angle according to an embodiment; and
• 5 a flowchart of a method for operating an electrical auxiliary drive according to an embodiment.

In the following description of preferred exemplary embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and acting in a similar manner, and a repeated description of these elements is omitted.

1 shows a schematic representation of a bicycle 100 with one device 102 for operating an electric auxiliary drive 104 of the bike 100 according to an embodiment. Here is the bike 100 exemplary for one with the auxiliary drive 104 shown at least supportively drivable vehicle.

The auxiliary drive 104 is part of a drive device of the bicycle 100 , According to one exemplary embodiment, the drive device has in addition to the auxiliary drive 104 and the device 102 an inclination sensor, for example 106 on that with a wave 108 of the auxiliary drive is coupled. The inclination sensor is an example 106 outside a housing of the auxiliary drive 104 on one with the shaft 108 rigidly coupled pedal 110 of the bike 100 arranged. Instead of the tilt sensor 106 another suitable sensor can also be used.

In the operation of the auxiliary drive 104 is the auxiliary drive 104 trained to according to known electric bicycles by a rider of the bicycle 100 Required torque to turn the shaft 108 and thus to at least support the drive of the bicycle 100 provide. If the auxiliary drive 104 is not in operation, or when the rider of the bike 100 the auxiliary drive 104 want to support, so the driver can wave 108 additionally or alternatively via the pedal 110 drive.

The device 102 is designed to rotate the shaft 108 using one of the tilt sensor 106 provided signal to determine. The device is optional 102 further configured to provide a control signal for controlling the auxiliary drive 106 to provide using the determined angle of rotation. The control signal can be the auxiliary drive 106 Control so that the requested torque from the auxiliary drive 106 provided.

2 shows a schematic representation of a device 102 for operating an electric auxiliary drive 106 according to an embodiment. This can be a device 102 and an auxiliary drive 106 act as they are based on 1 are described.

The device 102 has a determination device according to an embodiment 220 to determine an estimated rotation angle 222 the shaft of the auxiliary drive 104 on. The destination facility 220 is designed to the estimated angle of rotation 222 to be determined without sensors. This is the determination facility 220 trained to the estimated angle of rotation 222 using one in a coil of the auxiliary drive 104 fed excitation signal 224 to determine. For example, the determination device 220 trained to the excitation signal 224 to an interface to the auxiliary drive 104 provide and the estimated rotation angle 222 using one from the excitation signal 224 to determine the resulting response signal. For example, to determine the estimated angle of rotation 222 a phase shift between the excitation signal 224 and the response signal can be evaluated. The destination facility 220 is formed, for example, by an estimated angle of rotation 222 provide representative value in the form of an electrical signal. According to one embodiment, the excitation signal 224 represents a radio frequency signal.

For feeding the excitation signal 224 All suitable injection schemes, for example alternating, rotating or arbitrary, can be used, which make it possible to obtain information about the angle of rotation, which is used to determine the estimated angle of rotation 222 can be used.

The device 102 according to an embodiment has a further determination device 230 on, which is designed to a measured direction of rotation 232 the shaft using a sensor signal 234 to determine. The further determination device 230 is designed to the sensor signal 234 via an interface to the inclination sensor 106 to recieve. According to a different embodiment, the sensor signal shows 234 an inclination of the shaft or a rotational speed of the shaft. The further determination device 230 is designed, for example, around the measured direction of rotation 232 provide representative value in the form of an electrical signal.

The device 102 has an additional determination device according to an embodiment 240 on, which is designed to assume an assumed direction of rotation 242 the wave using a request signal 244 to determine. The request signal 244 shows a direction of one of the auxiliary drive 104 requested torque acting on the shaft. For example, the request signal 244 from a control device 250 provided, which is configured to a control signal 252 to the auxiliary drive 104 to provide to the auxiliary drive 104 to be controlled so that the auxiliary drive provides the requested torque. The additional determination device 240 is designed, for example, around the assumed direction of rotation 242 provide representative value in the form of an electrical signal.

The device 102 has a determination device according to an exemplary embodiment 260 on, which is designed to a corrected angle of rotation 262 to determine the wave. The investigative facility 260 is designed to correct the angle of rotation 262 using the estimated rotation angle 222 , the measured direction of rotation 232 and the assumed direction of rotation 242 to investigate. The investigative facility 260 is designed, for example, by a corrected angle of rotation 262 provide representative value in the form of an electrical signal.

The investigative facility 260 is designed according to an embodiment to the estimated angle of rotation 222 than the corrected angle of rotation 262 to take over if the assumed direction of rotation 242 and the measured direction of rotation 232 to match. If the assumed direction of rotation 242 and the measured direction of rotation 232 mismatch is the investigative facility 260 trained to the estimated angle of rotation 222 to correct π rad, for example the estimated angle of rotation 222 to increase or decrease the value π and the resulting value as a corrected angle of rotation 262 to use.

For example, the control device 250 trained to the control signal 252 using the corrected rotation angle 262 provide.

According to one embodiment, the determination device is 220 trained to use a system model of the auxiliary drive 104 an observed angle of rotation 264 to determine the wave. The investigative facility 260 in this case is designed to use the estimated rotation angle 222 and the observed angle of rotation 264 another corrected rotation angle 266 to determine the wave.

To determine the observed angle of rotation 264 suitable known observers can be used. For example, suitable model-based techniques can be used. For example, a regulated adaptation with a parallel comparison model (MRAS), a Luenberger observer or an alpha-beta observer is mentioned.

Here is the investigative facility 260 formed according to an embodiment to a deviation between the estimated angle of rotation 222 and the observed angle of rotation 264 to determine and the further corrected angle of rotation 266 to be determined depending on the deviation.

If the deviation is in a first range, the determining device is 260 trained to the estimated angle of rotation 222 than the further corrected rotation angle 266 to use. Alternatively, the determination device 260 trained to the observed angle of rotation 264 than the further corrected rotation angle 266 to be used if the deviation is in the first range

If the deviation is in a second range, the determining device is 260 formed, the observed angle of rotation corrected by the value π 264 than the further corrected rotation angle 266 to use. Here is the investigative facility 260 formed according to an embodiment by the observed angle of rotation corrected by the value π 264 than the further corrected rotation angle 266 to use when the deviation between the estimated rotation angle 222 and the observed angle of rotation 264 amount corresponds approximately to the value π.

The control device 250 is designed according to an embodiment to the control signal 252 optionally using the corrected angle of rotation 262 or the further corrected angle of rotation 266 provide. For example, the control device 250 trained to correct the angle of rotation 262 to be used if the current rotational speed of the shaft is below a speed threshold and the further corrected rotational angle 266 to be used if the current rotational speed of the shaft is above the speed threshold.

The functionalities of the facilities shown 220 . 230 . 230 . 250 . 260 can also be implemented in other facilities. For example, functionalities can be summarized or on devices other than those shown 220 . 230 . 230 . 250 . 260 be distributed. For example, the functionality of the further determination device 230 into the investigation facility 260 be integrated, as it is based on 3 is described. The functionality of the determination device can also 220 be divided into two facilities, hereinafter based on 4 is described.

According to one embodiment, at least some of the functionalities of the devices 220 . 230 . 230 . 250 . 260 implemented in an integrated circuit.

3 shows a block diagram for determining a corrected rotation angle 262 according to an embodiment. This can be a corrected angle of rotation as it is based on 2 is described.

The inclination sensor is shown 106 , which is designed according to this exemplary embodiment as a sensor of a pedal. The tilt sensor 106 is designed to the sensor signal 234 To provide, which indicates a rotational speed ω _pedal according to this embodiment. The tilt sensor 106 is chosen only as an example. Alternatively, an acceleration sensor can also be used, for example.

Furthermore, the determination device 220 shown, which is designed according to this embodiment as a unit for self-sensing at a low speed. The destination facility 220 is designed to the estimated angle of rotation 222 provide here in the form of the value θ̂.

An investigative facility 360 , here in the form of a unit for performing a commissioning procedure, is designed to correct the angle of rotation 262 , here in the form of the value θ̂ _corr , using the sensor signal 234 and the estimated rotation angle 222 to determine and provide.

According to one exemplary embodiment, the approach described enables sensor-free starting with the impressing of RF signals with replacement of the π-wheel uncertainty by an inclination sensor-controlled pedal positioning. In this sense, sensorless can mean that no sensor installed within the auxiliary motor is required. About the imprint of the RF signals, which can be interpreted as excitation signals, the estimated angle of rotation 222 be determined.

Advantageously, the auxiliary drive can be controlled in the form of an electrical machine in e-bikes or pedelec applications without the use of position sensors. Here, an electrically assisted bicycle or another electrically assisted vehicle with an additional feature for pedal positioning at zero speed with an inclination sensor 106 will be realized. According to one exemplary embodiment, the underlying algorithm uses the information of the measured pedal position to solve the inherent π uncertainty in self-monitoring methods at low speed.

With the described approach to sensorless control at low speed, an uncertainty of π radians can be eliminated in the first angle estimation. This approach can be used in place of or in addition to the injection of q-direction voltage pulses that cause the motor to generate acoustic noise. The approach described here advantageously works for all common types of machines, since special construction properties of the machines are not disruptive in the approach described here. Thus, regardless of the type of auxiliary drive, reliable results for the corrected rotation angle can be obtained 262 can be achieved.

According to one embodiment, the inclination sensor 106 used as an example of a pedal position sensor to identify an angular orientation to find out whether the angle of rotation is estimated 222 designated calculated angle is a north or a south pole. In this way, the corrected angle of rotation 262 an exact position of the rotor of the auxiliary drive can be determined.

Based on the in 3 The block diagram shown below is the underlying scheme for determining the corrected angle of rotation 262 described in more detail according to an embodiment.

oder $${\theta }_{corr}=\widehat{\theta }+\pi$$

The value θ _{corr of} the corrected rotation angle 262 can take two possible values: $${\theta }_{cOrr}=\widehat{\theta }$$

or $${\theta }_{cOrr}=\widehat{\theta }+\pi$$

The choice between these two options is made based on the sign of the instructed engine torque, the expected sign for the speed of rotation ω _pedal and its actual value. The speed of rotation can correspond to the pedal speed. If the sign of ω _pedal corresponds to its expected value, then equation (1) is chosen. If the sign of ω _pedal is opposite to the expected value, then equation (2) is chosen.

In this case, the movement of the pedal can be accepted because the movement is inherent in the function of the positioning of the pedal. If this function is not available, pedal movement can still be accepted if it is kept to a minimum. This is only necessary to recognize the sign of the pedal speed.

According to one exemplary embodiment, this starting process is carried out each time the engine is switched on.

4 shows a block diagram for determining a further corrected rotation angle 266 according to an embodiment.

The determination device is shown 220 which, according to this exemplary embodiment, is designed as a unit for self-sensing at a low speed. The destination facility 220 is designed to the estimated angle of rotation 222 provide here in the form of the value θ̂ _LS . The low speed can be below the speed threshold already mentioned.

Furthermore, a determination device 420 shown, which is designed according to this embodiment as a unit for self-sensing at a high speed. The destination facility 420 is formed around the observed angle of rotation 264 provide here in the form of the value θ̂ _HS .

An investigative facility 460 , here in the form of a unit for mixing, is designed to correct the further angle of rotation 266 , here in the form of the value θ̂ _Hyb , using the observed angle of rotation 264 and the estimated rotation angle 222 to determine and provide.

According to one embodiment, the further corrected angle of rotation 266 determined as a safety function to track the correct angular alignment.

Self-monitoring procedures can be carried out for the entire speed range Mixing two different types of observers can be implemented. An observer based on low speed signal injection and a model based strategy for higher speeds can be used. In 4 An embodiment of a corresponding strategy is shown.

About the orientation of the angle θ̂ _LS , here the estimated angle of rotation 222 To check, track the alignment and even allow the system to start at higher speeds, the angle θ̂ _LS becomes the angle θ̂ _HS , here in the form of the observed angle of rotation 264 , compared. If the difference between these two values is π ± ∈, where ∈ is a predefined tolerance, then: $${\widehat{\theta }}_{H{S}_{cOrr}}={\widehat{\theta }}_{HS}+\pi$$

The approach described on the basis of the previous figures can be used with all possible injection schemes (alternating, rotating, arbitrary, etc.) and all model-based techniques (MRAS, Luenberger Observer, Alpha-Beta observer, etc.).

The functionalities based on the 3 and 4 Block diagrams can be described using the 1 and 2 shown devices are executed or by performing method steps of the using 5 described procedure are implemented.

5 shows a flowchart of a method for operating an electrical auxiliary drive according to an embodiment. The method can be used, for example, in connection with an auxiliary application for a bicycle.

In one step 501 an estimated angle of rotation of a shaft of the auxiliary drive is determined using an excitation signal fed into a coil of the auxiliary drive. At the same time or with a slight offset in one step 503 determines a measured direction of rotation of the shaft using a sensor signal. The sensor signal is in an optional step 505 using a sensor, for example a tilt sensor. In one step 507 an assumed direction of rotation of the shaft is determined using a request signal which indicates a direction of a torque requested by the auxiliary drive and acting on the shaft. In one step 509 a corrected angle of rotation of the shaft is determined using the estimated angle of rotation, the measured direction of rotation and the assumed direction of rotation.

In an optional step 511 the excitation signal is fed into the auxiliary motor. Optional is in the step 511 also receive a response signal caused by the excitation signal. In this case, the step 501 the estimated angle of rotation can be determined using the excitation signal and additionally or alternatively using the response signal.

The steps 501 . 503 . 505 . 507 . 509 . 511 are carried out, for example, during commissioning of the auxiliary drive.

According to one exemplary embodiment, the method also has a step 513 determining an observed angle of rotation of the shaft using a system model of the auxiliary drive. In one step 515 Another corrected rotation angle of the shaft is determined using the estimated rotation angle and the observed rotation angle.

In one step 517 a control signal is optionally provided for controlling the auxiliary drive using the corrected rotation angle and / or the further corrected rotation angle.

If an exemplary embodiment comprises a “and / or” link between a first feature and a second feature, this can be read in such a way that the embodiment according to one embodiment has both the first feature and the second feature and according to a further embodiment either only the first Feature or only the second feature.

LIST OF REFERENCE NUMBERS

100

bicycle

102

contraption

104

auxiliary drive

106

tilt sensor

108

wave

110

pedal

220

determiner

222

estimated rotation angle

224

excitation signal

230

further determination device

232

measured direction of rotation

234

sensor signal

240

additional determination device

242

assumed direction of rotation

244

request signal

250

control device

252

control signal

260

determining device

262

corrected rotation angle

264

observed angle of rotation

266

further corrected angle of rotation

360

determining device

420

determiner

460

determining device

501

Step of determining an estimated angle of rotation

503

Step of determining a measured direction of rotation

505

Step of providing a sensor signal

507

Step of determining an assumed direction of rotation

509

Step of determining a corrected angle of rotation

511

Step of feeding

513

Step of determining an observed angle of rotation

515

Step of determining a further corrected angle of rotation

517

Step of providing a control signal

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102015100676 B3 [0003]

Claims (13)

Method for operating an electrical auxiliary drive (104) for a vehicle, in particular for a bicycle (100), characterized in that the method comprises the following steps: determining (501) an estimated angle of rotation (222) of a shaft (108) of the auxiliary drive ( 104) using an excitation signal (224) fed into a coil of the auxiliary drive (104); Determining (503) a measured direction of rotation (232) of the shaft (108) using a sensor signal (234) representing a signal provided by a sensor coupled to the shaft (108), in particular an inclination sensor (106); Determining (507) an assumed direction of rotation (242) of the shaft (108) using a request signal (244) indicating a direction of a torque requested by the auxiliary drive (104) and acting on the shaft (108); and determining (509) a corrected angle of rotation (262) of the shaft (108) using the estimated angle of rotation (222), the measured direction of rotation (232) and the assumed direction of rotation (242). Procedure according to Claim 1 , characterized in that in step (509) of determining the estimated angle of rotation (222) is determined as the corrected angle of rotation (262) if the assumed direction of rotation (242) corresponds to the measured direction of rotation (232). Method according to one of the preceding claims, characterized in that in the step (509) of determining the corrected angle of rotation (262) is determined as the estimated angle of rotation (222) corrected by π rad when the assumed direction of rotation (242) of the measured direction of rotation (232 ) is opposite. Method according to one of the preceding claims, characterized in that the method comprises a step (511) of feeding the excitation signal (224) in the form of a high-frequency signal. Method according to one of the preceding claims, characterized in that the step (509) of determining the corrected angle of rotation (262) is carried out during startup of the auxiliary drive (104). Method according to one of the preceding claims, characterized in that the method comprises a step (513) of determining an observed angle of rotation (264) of the shaft (108) using a system model of the auxiliary drive (104) and a step (515) of determining one further corrected rotation angle (266) of the shaft (108) using the estimated rotation angle (222) and the observed rotation angle (264). Procedure according to Claim 8 , characterized in that in step (515) of determining the further corrected rotation angle (266) depending on a deviation between the estimated rotation angle (222) and the observed rotation angle (264) either as the estimated rotation angle (222) or the observed rotation angle ( 264), or as the observed rotation angle (264) corrected by π rad. Method according to one of claims 6 or 7, characterized in that the step (515) of determining the further corrected rotational angle (266) is carried out during startup of the auxiliary drive (104) at a rotational speed of the shaft (108) which is above a speed threshold. Method according to one of the preceding claims, characterized in that the method comprises a step (517) of providing a control signal (252) for actuating the auxiliary drive (104) using the corrected rotation angle (262) and / or the further corrected rotation angle (266) includes. Device (102) for operating an electrical auxiliary drive (104) for a vehicle, in particular for a bicycle (100), characterized in that the device (102) is set up to carry out the steps of the method according to one of the preceding claims in corresponding units and / or to control. Drive device for a vehicle, in particular for a bicycle (100), characterized in that the drive device has the following features: an electrical auxiliary drive (104); a tilt sensor (106) coupled to a shaft (108) of the auxiliary drive (104) and configured to provide a sensor signal (234) representative of a tilt of the tilt sensor (106); and a device (102) according to Claim 10 to operate the auxiliary drive (104). Drive device according to Claim 11 , characterized in that the inclination sensor (106) is arranged outside the auxiliary drive (104). Drive device according to Claim 11 or 12 , characterized in that the drive device is a pedal coupled to the shaft (108) (110), wherein the inclination sensor (106) is arranged on the pedal (110).

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