DE102016210335B4 - Hybrid bicycle and method for controlling a drive motor of a hybrid bicycle - Google Patents

Abstract

Hybrid bicycle powered by muscle power and electrical energy, comprising a generator (2) and pedals (40) connected to the generator (2) for applying a generator torque (G) to the generator (2) by a rider for driving the generator (2), and a drive motor (3) which is connected to a drive wheel (7) of the bicycle for driving the drive wheel (7), and a battery (5) for supplying the drive motor (3), the Generator (2), the drive motor (3) and the battery (5) are electrically connected to each other, as well as a control device (1) which is designed to determine a value of the generator torque (G) and from the determined via a predetermined function Value of the generator torque (G) to determine a target drive torque (A2), the control device (1) being designed to control the drive motor (3) to ensure the target drive torque (A2), characterized in that ss the control device (1) is designed to measure the generator torque (G) over an angular segment that the pedals (40) pass through and to form an average value of the generator torque (G) therefrom and from the average value the value of the generator torque ( G) to be determined.

Description

The invention relates to a hybrid bicycle that is driven by muscle power and electrical energy, according to the preamble of claim 1, and to a method for controlling a drive motor of a hybrid bicycle.

Conventional bicycles have pedals which are mounted on an axle of a bottom bracket and are thus guided over the bottom bracket. The pedals are each connected to the axle of the bottom bracket via a bottom bracket arm. The conventional bicycle is driven in that the pedals are rotated with the bottom bracket arm around the bottom bracket axle and this rotary movement is transmitted directly to a drive wheel, for example via a chain.

By applying muscle power to the pedals, the driver generates a pedal torque due to the connection of the pedals via the bottom bracket arm with the axle of the bottom bracket bracket, which results from the force applied to the pedals and the length of the bottom bracket arm between the pedals and the axle. The torque and the power that a rider applies to the pedals by means of muscle power are thus passed on directly to the drive wheel, so that the drive of the bike that the rider can feel corresponds to the effort he has invested, namely the muscle power he has used. In the case of hybrid bicycles of the generic type which are driven by muscle power and electrical energy, however, the drive wheel is not driven directly by the pedals but at least partially by an electric drive motor. In the case of serial hybrid bicycles, the drive wheel is driven exclusively by an electric drive motor that is supplied with electrical energy by a battery. The pedals, on the other hand, only operate a generator, so that electrical energy is generated by muscle power, which is optionally fed to the battery and / or the drive motor.

Out DE 10 2011 082 082 A1 For example, a serial hybrid bicycle is known in which the pedals operate exclusively a generator, the drive wheel being driven exclusively by a drive motor. In the case of the bicycle, a target pedal speed or a target pedal torque can be entered, the generator opposing the bottom bracket arm and thus the pedals with such a rotational resistance based on a rotation around the axis of the bottom bracket that the target value is achieved by the rider.

Out JP H10-114 293 A It is known to determine irregularities in the pedal torque applied by the driver due to an irregular step by a driver and to control the drive motor in such a way that corresponding irregularities in the drive power applied by the drive motor are as low as possible.

Out DE 10 2014 206 818 A1 It is known to determine the angular position of the pedals based on a rotation around the axis of the bottom bracket and to determine and store the pedal torque applied to each determined angular position, a target drive torque with which the drive motor is to drive the drive wheel is determined from this.

In hybrid bicycles of the generic type, the drive motor must always be controlled intelligently so that the drive power that the drive motor supplies to the drive wheel corresponds to the drive power that the driver wants and that the driver usually - as he is used to from conventional bicycles would like to pretend conscious use of his muscular strength on the pedals.

Usually, the specification of the drive power required for this takes place in that the drive power is determined as a direct function of the generator torque applied by the driver. This can ensure that the drive power with which the drive wheel is driven changes exactly in the ratio in which the force and thus the generator torque changes, which the driver applies to the pedals through his muscle power according to his wishes. However, it goes without saying that a hybrid bike is designed to use the battery to increase muscle strength. This means that the drive power is of course greater than the muscle power applied by the rider, since this is the whole point and purpose of a hybrid bicycle. Usually, a driver can specify the gain factor between driver power and drive power, which reflects the gain factor between the generator torque applied and the drive power determined proportionally therefrom. However, since the generator torque varies with each bicycle as a function of the angular position of the pedals, the hybrid bicycle has uneven driving behavior, since the variation in the generator torque is correspondingly increased by the gain factor. However, this is accepted in the case of hybrid bicycles of the generic type, since the highest possible priority is assigned to the most exact possible correlation between the applied muscle power and the drive power applied to the drive wheel.

The present invention has for its object to provide a hybrid bicycle that the at least partially eliminates the problems and disadvantages of conventional hybrid bicycles described above. Furthermore, the present invention is based on the object of providing a method for controlling the drive motor of a hybrid bicycle which at least partially eliminates the problems and disadvantages described.

As a solution to at least one of the objects mentioned, the invention proposes a hybrid bicycle with the features of claim 1. The hybrid bicycle according to the invention is driven by muscle power and electrical energy and is designed, in particular, as a hybrid bicycle driven in series. A hybrid bicycle driven in series is characterized in that the drive wheel is driven exclusively by the drive motor of the hybrid bicycle and not directly by the pedals, which instead exclusively drive a generator. The hybrid bicycle according to the invention comprises a generator and pedals which are connected to the generator for applying a generator torque to the generator by a driver for driving the generator. The hybrid bicycle according to the invention further comprises a drive motor which is connected to a drive wheel of the bicycle for driving the drive wheel. The hybrid bicycle according to the invention also includes a battery for supplying the drive motor. The battery is an energy store for electrical energy and can be designed, for example, as a conventional nickel metal hydride or lithium-ion accumulator. The generator, the drive motor and the battery are electrically connected to one another in such a way that the battery can feed the drive motor with electrical energy and the generator can feed the battery with electrical energy. In one embodiment, the generator and drive motor are also connected to one another in such a way that the generator can supply the drive motor directly with electrical energy. The hybrid bicycle according to the invention further comprises a control device which is designed to determine a value of the generator torque and to use a predetermined function to determine a target drive torque from the determined value of the generator torque, the control device being designed to ensure the drive motor of the target drive torque. The control device is of course also electrically connected to the generator and the drive motor so that it can determine the generator torque and control the drive motor. In one embodiment, the control device is also electrically connected to the battery and controls the distribution of the electrical energy generated by the generator between the drive motor and the battery. According to the invention, the control device is designed to continuously measure the generator torque over an angular segment that the pedals traverse and to form an average value of the generator torque therefrom and to determine the value of the generator torque from the average value. In the hybrid bicycle according to the invention, a current value of the generator torque, which corresponds to a current angular position of the pedals on the bottom bracket, is not always used as the basis for determining the specified target drive torque of the drive motor, but the generator torque is used at different angular positions of the pedals on the Pedal bearing, namely over an angular section, is determined and then a mean value of the generator torque, which the generator torque has on average over the entire angular section, is determined and this mean value is then taken as the basis for specifying the target drive torque. The measurements in the angular section can be made at discrete angular positions in the angular section. The measurement can also be carried out continuously. For example, the measurement of the generator torque by the control unit can already be ensured in that the control unit controls the generator to a specific torque that has to be applied to drive the generator through the pedals, so that the control unit knows the generator torque per se. Thanks to the invention, unsteady driving behavior can thus be effectively avoided, because irregularities in the generator torque, which are caused by a driver applying the generator torque irregularly depending on the angular position via the pedals, are not to the same extent, at least not directly in corresponding irregularities of the Target drive torque converted. At this point it should be noted that the "angular position of the pedals" is of course always the angular position of the pedals in relation to a rotation around the axis of the bottom bracket, since this rotation is used to drive the driver.

The inventors have recognized that it is advantageous to provide an angle of 0 ° to 180 °, in particular between 60 ° and 180 °, as the angle section. The inventors have recognized that, because of the provision of two pedals on a hybrid bicycle according to the invention, it is particularly advantageous to set the angular segment at 180 °, since this means that all the fluctuations in the pedal torque that occur during a full revolution can be taken into account thanks to two pedals. Accordingly, an average value of the generator torque can thereby be formed, which can correspond particularly well to the actual driving request of the driver. It must be taken into account that the driver himself is usually not aware that he generates a different generator torque in the course of one revolution of the pedals, but rather that the driver usually distributes his power over an entire pedal revolution in such a way that it corresponds to a desired driving behavior. By setting the angular section to an angle of 180 °, a specification of the drive power of the drive motor for driving the drive wheel can be provided because of the two pedals, which corresponds particularly well to the driver's request. In other embodiments, however, the angle section can also be set to smaller angles. This can be advantageous for ensuring a compromise between uniform driving behavior and adapting the setpoint drive torque to the driver's request as quickly as possible. Because it goes without saying that by specifying a smaller angle for an angular section, the mean value of the generator torque can be determined at shorter intervals, so that a changing driver's request for a different driving behavior or a different drive power can be met more quickly if smaller angles can be chosen for the angle segment. Establishing the angle section at an angle of 60 ° to 120 °, in particular 90 °, has proven to be a particularly good compromise. In one embodiment, the hybrid bicycle has a default switch, via which the rider can enter the amount of the angle of the angular segment. In this embodiment, the driver himself can choose between driving behavior that is as uniform as possible or the possibility of specifying the drive power as quickly as possible, depending on his applied muscle power.

) dem entsprechenden Integral über das momentan aufgebrachte Generatordrehmoment G (d.h.: ${\displaystyle \underset{0}{\overset{360°}{\int }}{\displaystyle \underset{0}{\overset{T}{\int }}\omega }}\left(t,\phi \right)\ast G\left(t,\phi \right)dtd\phi$

) identisch entspricht. In einer Ausführungsform kann das Hybrid-Fahrrad einen Gewichtungsschalter aufweisen, über den durch den Fahrer die Gewichtung vorgebbar ist. Dieser Gewichtungsschalter kann beispielsweise mit dem Vorgabeschalter eine Einheit bilden. In einer Ausführungsform erfasst die Steuereinrichtung die Winkellage der Pedale und ordnet einem Winkelabschnitt, über den der Mittelwert des Generatordrehmoments ermittelt wurde, eine mittlere Winkellage zu, wobei die Steuereinrichtung den Wert des Generatordrehmoments in Abhängigkeit von der mittleren Winkellage und dem gebildeten Mittelwert des Generatordrehmoments festlegt.In one embodiment, the control device is designed to equate the value of the generator torque with the mean value formed in order to determine the setpoint drive torque. This can bring about a particularly uniform drive behavior. In one embodiment, the control device is designed to determine the target drive torque to form the value of the generator torque by summing the mean value and a current measured generator torque with a predetermined weighting of mean value and currently measured generator torque. This ensures that the drive behavior is on the one hand uniform and on the other hand can be adapted as directly as possible to changing specifications by the driver. The weighting can be used to specify whether the drive behavior should be adapted as uniformly as possible or as directly as possible to the currently applied generator torque. In particular, the weighting and summation of the mean value and the currently measured generator torque can preferably always be specified in such a way that the integral of the product of the angular velocity ω with the value of the generator _{torque G Σ} obtained from the summation over the angle dφ and the time dt over a full pedal revolution with 360 ° rotation and rotation time T
(this means: ${\displaystyle \underset{0}{\overset{360°}{\int }}{\displaystyle \underset{0}{\overset{T}{\int }}\omega }}\left(t,\phi \right)\ast G_{\mathrm{\Sigma }}\left(t,\phi \right)dtd\phi$

) the corresponding integral over the currently applied generator torque G (ie: ${\displaystyle \underset{0}{\overset{360°}{\int }}{\displaystyle \underset{0}{\overset{T}{\int }}\omega }}\left(t,\phi \right)\ast G\left(t,\phi \right)dtd\phi$

) is identical. In one embodiment, the hybrid bicycle can have a weighting switch, via which the weighting can be specified by the rider. This weighting switch can form a unit with the default switch, for example. In one embodiment, the control device detects the angular position of the pedals and assigns a mean angular position to an angular segment over which the mean value of the generator torque was determined, the control device determining the value of the generator torque as a function of the mean angular position and the mean value of the generator torque formed.

In one embodiment, the predetermined function is defined as a linear function A = b * G, where A is the target drive torque, G is the generator torque and b is a gain factor, the hybrid bicycle having a selector switch for the driver to specify the gain factor, which is connected to the control device for transmitting the gain factor to the control device. The predetermined function can be stored in the control device, for example. In the exemplary embodiment described, the predefined function thus defines that the setpoint drive torque is directly proportional to the value of the generator torque. A driver can use the selector switch to specify how much he would like his muscle strength to be increased by the drive motor. Correspondingly, a driver can influence the driving behavior of the hybrid bicycle via the selector switch.

In one embodiment, the control device is designed to determine an expected generator torque from the mean value of the generator torque for each angular position of the pedals, the control device for determining the angular position of the pedals and for comparing the generator torque determined for a specific angular position with the angular position determined for this expected generator torque is formed, wherein the control device is designed in particular to perform the predetermined function as a function of the deviation of the generator torque determined at the specific angular position from the generator torque expected at the specific angular position adjust. In this embodiment, the target drive torque can thus be adapted almost instantaneously to a change in the force that the driver applies to the pedals, without having to wait for a new mean value of the generator torque to be determined. This can be particularly advantageous during braking maneuvers when the driver suddenly reduces the force. In such braking maneuvers it is particularly advantageous if the drive torque drops to 0 as instantaneously as possible. Since the control device assigns an expected generator torque to each angular position of the pedals as a function of the determined mean value of the generator torque and monitors the deviation of the actual current generator torque determined at a specific angular position from the generator torque expected at this specific angular position, the control device can determine the target drive torque that it specifies for the drive motor, immediately change it if it detects a corresponding deviation. By setting the predefined function as a function of the deviation, a particularly continuous adaptation of the setpoint drive torque to the wishes of the driver predefined by muscle power can also be made possible.

In one exemplary embodiment, the control device is designed to use the generator torque determined at the specific angular position to fall below the expected generator torque at a specific angular position by more than a predetermined percentage of the expected generator torque, in particular by more than 50%, the currently determined generator torque as a value of the generator torque. In this embodiment, in the event of an abrupt change, the control device can switch over to defining the currently applied generator torque as the value of the generator torque instead of the value of the generator torque based on the mean value of the generator torque, whereby changes in the driver's wishes can be taken into account particularly quickly. For example, the control device can be designed in such a way that it only forms the value of the generator torque from the mean value of the generator torque again when the currently determined generator torque deviates from the mean value by less than the specified percentage. Correspondingly, the control device can be designed to switch between the described states, so that it meets the driver's wishes as quickly as possible when the generator torque varies widely and enables the hybrid bike to ride as smoothly as possible when the generator torque fluctuates less.

The invention further comprises a method for controlling a drive motor of a hybrid bicycle that is driven by muscle power and electrical energy, a value of a generator torque being determined and a setpoint drive torque being determined from the determined value of the generator torque via a predetermined function, wherein the drive motor is controlled to ensure the drive torque. According to the invention, the generator torque is measured continuously over an angular segment that the pedals pass through and a mean value of the generator torque is formed therefrom, the value of the generator torque being determined from the mean value formed. The method according to the invention brings the advantages described above in connection with the hybrid bicycle according to the invention. The method according to the invention can have further advantageous features that have been described above in connection with the hybrid bicycle according to the invention.

• 1: ein Schema eines Ausschnitts eines erfindungsgemäßen Hybrid-Fahrrads;
• 2: Schemata zum Illustrieren der Entstehung und des Verlaufs des Generatordrehmoments in Abhängigkeit von der Winkellage der Pedale;
• 3: in Schema zur Illustrierung des Verlaufs von Soll-Antriebsdrehmoment und Generatordrehmoment in Abhängigkeit von der Winkellage.

The invention is explained in more detail below with reference to three figures. Show it:

• 1 : a diagram of a section of a hybrid bicycle according to the invention;
• 2 : Schemes to illustrate the development and the course of the generator torque as a function of the angular position of the pedals;
• 3 : in a scheme to illustrate the course of the target drive torque and generator torque as a function of the angular position.

In 1 a section of an embodiment of a hybrid bicycle according to the invention is shown in a scheme. The hybrid bike includes a bottom bracket 4th with pedals 40 . The pedals 40 are with a generator 2 connected to drive the generator 2 , with a gear between the pedals and the generator, in the described embodiment a reduction gear 400 , is switched. The generator 2 is with a battery 5 and a drive motor 3 connected for feeding battery 5 and drive motor 3 with electrical energy. The illustrated hybrid bicycle also includes a control device 1 that came with the generator 2 and the drive motor 3 connected is. battery 5 and generator 2 are present via the control device 1 electronically with the drive motor 3 connected. The control device 1 on the one hand controls the drive motor 3 and indicates that from the drive motor 3 to the drive wheel 7th target drive torque to be output A ₂ in front. On the other hand, the control device controls 1 the distribution of the generated by the generator 2 generated electrical Energy between battery 5 and drive motor 3 . The control device 1 is also equipped with a selector switch 8th connected, with which a driver can influence the specified function. In the present case, the specified function is set so that the target drive torque A ₂ about a factor b directly proportional to the generator torque G is set, the driver adjusting the gain b via the selector switch 8th can pretend. Out 1 it can also be seen that the drive motor 3 via a transmission 6th with the drive wheel 7th is connected and thus via the transmission 6th its drive power to the drive wheel 7th gives.

In 2 comprehensive the 2a , 2 B and 2c is the origin of the generator torque G and the course of the generator torque G shown as a function of the angular position. In 2a is schematically a bottom bracket 4th with pedals 40 shown with the pedals 40 are shown in different angular positions. In 2a is the direction of rotation R. the pedals 40 specified as well as the force F ' that a driver usually puts on a pedal 40 Depending on their angular position. Out 2a can clearly be seen that the force F ' both in their direction and in their amount from the angular position of the pedals 40 depends. This dependence on force F ' indicates the generator torque G of course identical, since the generator torque G the sum of the pedal torques G' of the two pedals 40 corresponds to, where the pedal torque G' the product of the force F ' with the bottom bracket arm length, that is, the distance between the bottom bracket 4th and pedal 40 , corresponds. In 2 B is the curve of the pedal torque G' of a pedal 40 shown as a function of the angular position. The 2 B thus represents the course of the pedal torque G' that is made up of 2a results. In 2c is the course of the generator torque G shown as a function of the angular position. The generator torque G corresponds to the sum of the two pedal torques G' , the two pedal torques G' are shifted in their dependence on the angular position by an angle of 180 °, from which the course according to 2c results. Out 2c is thus particularly vivid and clear the irregularity of the driver on the generator 2 applied generator torque G evident.

In 3 is the course of the generator torque G according to 2c as well as the mean value G̅ determined over a full revolution by averaging over an angular segment of 180 °. In addition, is the target drive torque A ₁ , which in a conventional hybrid bicycle by the control device 1 is determined, as well as the target drive torque A ₂ , to which the control device 1 in a hybrid bicycle according to the invention, the drive motor 3 controls, shown. The control device is in both the conventional hybrid bicycle and the hybrid bicycle according to the invention 1 designed for the target drive torque A ₁ , A ₂ on the basis of a linear predefined function from determined values of the generator torque G to be determined (according to A = b * G), where b is set to the value 2.3. In the case of a conventional hybrid bicycle, the current amount of the generator torque is used directly to calculate the target drive torque A ₁ used. Out 3 it can be clearly seen that by the gain factor b the variation in the generator torque on a conventional hybrid bike G as a function of the angular position is amplified uncomfortably for a driver, so that this results in an uncomfortably jerky driving behavior of the hybrid bicycle. The course curve of the setpoint drive torque shows accordingly A ₁ very high and sharp maxima. In contrast, this is the setpoint drive torque specified for a hybrid bicycle according to the invention A ₂ independent of the angular position over the entire rotation of 360 ° constant, since the mean value of the generator torque G̅ in the two angular segments of 180 ° each is the same. The hybrid bicycle according to the invention thus enables the drive wheel to be driven comfortably and continuously 7th , not only increasing the variation in the generator torque G is avoided depending on the angular position, but the variation of the generator torque G is even completely compensated depending on the angular position in the present embodiment. Out 3 the right-hand scaling also shows the drive power curve, which is directly proportional to the target drive torque.

List of reference symbols

1

Control device

2

generator

3

Drive motor

4th

Bottom bracket

5

battery

6th

transmission

7th

drive wheel

8th

Selector switch

40

Pedals

400

Reduction gear

A ₁

Target drive torque of a conventional hybrid bicycle

A ₂

Target drive torque of the hybrid bicycle according to the invention

b

Gain factor

F '

force

G

Generator torque

G'

Pedal torque

G

Average

R.

Direction of rotation

Claims (10)

Hybrid bicycle powered by muscle power and electrical energy, comprising a generator (2) and pedals (40) connected to the generator (2) for applying a generator torque (G) to the generator (2) by a rider for driving the generator (2), and a drive motor (3) which is connected to a drive wheel (7) of the bicycle for driving the drive wheel (7), and a battery (5) for supplying the drive motor (3), the Generator (2), the drive motor (3) and the battery (5) are electrically connected to one another, as well as a control device (1) which is designed to determine a value of the generator torque (G) and use a predetermined function from the determined Value of the generator torque (G) _{to determine a target drive torque (A 2} ), the control device (1) being designed to control the drive motor (3) to ensure the target drive torque (A ₂ ), characterized that the control device (1) is designed to measure the generator torque (G) over an angular segment that the pedals (40) pass through and to form an average value of the generator torque (G) therefrom and the value of the generator torque from the average value (G) to be determined. Hybrid bike after Claim 1 , characterized in that the angle section corresponds to an angle of 0 ° to 180 °. Hybrid bike after Claim 2 , characterized in that the hybrid bicycle has a default switch via which the rider can enter the amount of the angle of the angular section. Hybrid bicycle according to one of the preceding claims, characterized in that the control device (1) is designed to determine the setpoint drive torque (A ₂ ) the value of the generator torque (G) with the mean value formed ( G ) equate. Hybrid bike according to one of the Claims 1 to 3 , characterized in that the control device (1) is designed to determine the target drive torque (A ₂ ) the value of the generator torque (G) by adding up the mean value formed ( G ) and a currently measured generator torque (G) with a given weighting of mean value ( G ) and the currently measured generator torque (G). Hybrid bike after Claim 5 , characterized in that the hybrid bicycle has a weighting switch, via which the weighting can be specified by the rider. Hybrid bicycle according to one of the preceding claims, characterized in that a linear function A = b * G is defined as the predetermined function, where A is the target drive torque, G is the value of the generator torque and b is a gain factor, the hybrid Bicycle has a selector switch (8) for specifying the amplification factor (b) by the rider, which is connected to the control device (1) for transmitting the amplification factor (b) to the control device (1). Hybrid bicycle according to one of the preceding claims, characterized in that the control device (1) is designed to use the mean value ( G ) of the generator torque (G) to determine an expected generator torque (G) for each angular position of the pedals (40), the control device (1) for determining the angular position of the pedals (40) and for comparing the generator torque (G ) is designed with the generator torque (G) expected at this specific angular position, the control device (1) being designed in particular to perform the predetermined function as a function of the deviation of the generator torque (G) determined for the specific angular position from that for the specific angular position expected generator torque (G). Hybrid bike after Claim 8 , characterized in that the control device (1) is designed to, if the generator torque (G) determined at the specific angular position falls below the expected generator torque (G) at a specific angular position by more than a predetermined percentage of the expected generator torque (G) , in particular by 50%, to set the currently determined generator torque (G) as the value of the generator torque (G). Method for controlling a drive motor (3) of a hybrid bicycle, which is driven by muscle power and electrical energy, whereby a value of a generator torque (G) is determined and a setpoint drive torque is determined from the determined value of the generator torque (G) via a predetermined function (A ₂ ) is determined, the The drive motor (3) is controlled to ensure the target drive torque, characterized in that the generator torque (G) is measured continuously over an angular segment through which the pedals (40) pass and a mean value ( G ) of the generator torque (G) and from the mean value ( G ) the value of the generator torque (G) is determined.

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