A drive system for an electric bicycle equipped with a filter unit, and a method for determining at least one operating parameter.

Abstract

The proposed solution relates to a drive system for an electric bicycle, the drive system comprising: a bottom bracket shaft for applying rider torque at rider pedal rotation speed to generate a driving force for human-powered propulsion of the electric bicycle; at least one drive motor for providing externally powered assist power in addition to the driving force, depending on at least one operating parameter; a rotation speed unit for determining the rider pedal rotation speed; and a torque unit for determining the rider torque. The drive system further comprises an electronic control unit for determining at least one operating parameter based on at least the rider pedal rotation speed and the rider torque. The electronic control unit includes a filter unit configured to perform filtering of one or more values ​​of rider torque based on the rider pedal rotation speed to determine a filtered rider torque; and an evaluation unit configured to determine at least one operating parameter from a predetermined characteristic map that is at least two-dimensional, based on at least the filtered rider torque and the rider pedal rotation speed. The proposed solution further relates to a method for determining at least one operating parameter.

Description

Technical Field

[0001] The proposed solution relates to a drive system for an electric bicycle according to the preamble of claim 1 and a method according to claim 14.

Background Art

[0002] Such a drive system has a drive motor. The drive motor is known to be used to provide assist power for the propulsion of the electric bicycle in addition to the driving force applied by the driver of the electric bicycle. Thereby, the driver of the electric bicycle can achieve faster propulsion of the electric bicycle with less effort.

[0003] Normally, the driver can set the desired assist ratio by selecting an assist level. The assist ratio generally corresponds to the torque ratio at which the drive motor assists the drive system with respect to the rider torque. The torque ratio can be, for example, 200%. Which assist level the driver selects often depends on his preferences and abilities. The selection of the assist level can further be made by the driver according to driving situations such as, for example, starting on a slope, overtaking situations, flat terrain, etc.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In principle, when the driving situation is detected by appropriate means, it can similarly be used as a basis for automatic switching between assist levels. However, in this case, in order to achieve a certain propulsion of the electric bicycle, more or less driving force has to be suddenly applied, so a situation may occur where the driver is surprised by the sudden switching.

Means for Solving the Problems

[0005] Therefore, the objective of the proposed solution is to provide a drive system for electric bicycles that offers an improved user experience for electric bicycle riders.

[0006] Against this backdrop, according to the first aspect, the proposed solution provides a drive system for electric bicycles.

[0007] Such a drive system has a bottom bracket shaft for applying rider torque at rider pedal rotation speed. The bottom bracket shaft is used to transmit the driving force for human-powered propulsion of the electric bicycle. Rider torque can be applied to the bottom bracket shaft, for example, via the crank (and sometimes in combination with the pedals). Rider pedal rotation speed (also called cadence) can be an indicator of the number of rotations of the bottom bracket shaft per unit time.

[0008] The drive system further includes at least one drive motor for providing externally powered assist power in addition to the driving force, depending on at least one operating parameter. The at least one drive motor may include, for example, an electric motor. The driving force and assist power can individually or jointly provide propulsion for the electric bicycle. The at least one operating parameter may, in this case, include a setting for the operation of the at least one drive motor.

[0009] The drive system further includes a rotational speed unit for determining the rider pedal rotation speed. The rotational speed unit may include, for example, at least one magnetic sensor. In addition, the drive system includes a torque unit for determining the rider torque. The torque unit may include at least one torque sensor.

[0010] The drive system further includes an electronic control unit for determining at least one operating parameter based at least on rider pedal rotation speed and rider torque. The control unit includes a filter unit, which is configured to perform filtering of one or more values ​​of rider torque based on rider pedal rotation speed in order to determine filtered rider torque. The filtering in this case may include at least one mathematical operation performed on one or more values ​​of rider torque.

[0011] The electronic control unit further includes an evaluation unit, which is configured to determine at least one operating parameter from a predetermined characteristic map, which is at least two-dimensional, based at least on filtered rider torque and rider pedal rotation speed. The characteristic map can be configured to assign a value for at least one operating parameter to a pair of values ​​for filtered rider torque and rider pedal rotation speed.

[0012] In principle, the drive system can use any measurement variable for filtering and determining at least one operating parameter from a given characteristic map. The measurement variable may be formed by an n-dimensional input vector having at least a partially time-varying component, from which at least one operating parameter is determined as an output value via a given n-dimensional characteristic map. Here, an input vector of any length can be processed continuously over time. In particular, the filter unit can be configured to filter one or more values ​​of a second measurement variable, such as rider torque, based on a first measurement variable, such as rider pedal rotation speed, and to determine the filtered second measurement variable.

[0013] In one embodiment, at least one operating parameter is a motor current, motor torque, motor output, or assist rate, and based on these, the assist power can be determined from the driving force. Thus, at least one operating parameter can be configured such that at least one physical quantity that can directly control the operation of at least one drive motor can be derived from that operating parameter. Such a physical quantity may be, for example, the motor current. The motor current may be the current supplied to the drive motor to generate the assist power. By the assist rate, the assist power can be expressed as a multiple (or fraction) of the driver's driving force. In particular, the motor current can be calculated from the current ridor torque and assist rate by a motor current calculation unit. At least one operating parameter can therefore be used for a time interval or rotation interval until the next at least one operating parameter is provided by the evaluation unit.

[0014] Generally, filtering can be based on a predetermined value for lidar torque. This predetermined value can be determined by a filtering unit. For example, a first mathematical calculation can reduce the variability of the lidar torque value per unit time. The predetermined value can be predetermined, for example, to represent one or more values ​​of the lidar torque, particularly over time.

[0015] In one embodiment, the filtering process includes averaging multiple values ​​of the lidar torque (for example, as a first mathematical operation). This could be, for example, an arithmetic mean or a geometric mean. In that case, the average value can be used as a predetermined value.

[0016] In one embodiment, the filter unit is configured to determine a time interval and / or rotational interval of the bottom bracket axis from the rider pedal rotations and to perform filtering based on at least one value of rider torque contained within that time interval and / or rotational interval. Averaging may be performed over multiple values ​​of the time interval or rotational interval. For example, rider torque applied by the rider may be averaged over rotational intervals in the form of half a rotation or a full rotation of the bottom bracket axis. The rotational interval can in this case be defined in particular by a predetermined crank angle, which can be derived from the rider pedal rotations if necessary.

[0017] One advantage of filtering over time intervals is that, in some situations, the drive system can respond more quickly to increases in rider torque. This is true, for example, when the rider is exerting force for an extended period of time only to cause a (slight) movement of the bottom bracket axle. In such cases, it may be desirable for the drive system to provide assist power before the rider rotates the bottom bracket axle through the rotation interval (through effort).

[0018] A second mathematical operation can be performed as a substitute for, or in addition to, the first mathematical operation, to generate a filtered lidar torque that is closer to a predetermined value than the previously filtered lidar torque. For example, the second mathematical operation may include an incremental increase / decrease of the previously filtered lidar torque. In this case, the increment can be predetermined or based on the difference between the previously filtered lidar torque and a predetermined value of the lidar torque. The second mathematical operation can be performed depending on whether the difference exceeds a predetermined difference threshold. Otherwise, in principle, the previously filtered lidar torque can be used as the filtered lidar torque.

[0019] In one embodiment, the filter unit is configured to filter a predetermined number of Rider torque values. This number of values ​​may be predetermined, for example, by the driver. By specifying this value, the delay time of the drive system to the provision of assist power can be set. If the filtered Rider torque is based on a smaller number of values, the drive system becomes more dynamic because small changes in Rider torque can cause rapid and large changes in at least one operating parameter. In contrast, if a larger number of values ​​are input, the drive system becomes slower because assist power can be provided continuously without small changes having an excessive effect on at least one operating parameter. Alternatively, the delay time of the drive system to the provision of assist power can be adjusted by adjusting the amount of change in a stepwise increase or decrease of the previously filtered Rider torque. In this case, a larger amount of change may mean a shorter delay time (because the predetermined Rider torque is reached more quickly), and a smaller amount of change may mean a longer delay time (because the predetermined Rider torque is reached more slowly). This stepwise increase or decrease is preferably performed at a fixed rate, i.e., a (second) sampling rate.

[0020] In one embodiment, a given characteristic map includes a number of combinations of input values, each of which is assigned an output value for at least one operating parameter. The given characteristic map can therefore provide a mapping rule from the values ​​of rider torque and rider pedal rotations to at least one operating parameter. The given characteristic map can be understood as an array having n columns corresponding to the values ​​of rider torque and m rows corresponding to the values ​​of rider pedal rotations. Each field defined by the row and column values ​​can be input with an output value (for at least one operating parameter).

[0021] A characteristic map can assign multiple input values ​​to a single output value. Therefore, a given characteristic map can be multidimensional. The higher the dimension of a given characteristic map, the more precisely the assist power can be adjusted according to driving conditions.

[0022] In one embodiment, the evaluation unit is configured to determine an output value from at least one output value closest to a particular combination of input values ​​if no output value is directly assigned to that combination. For this purpose, the evaluation unit may further be configured to first determine at least one combination of input values ​​closest to a particular combination of input values. The output value of at least one closest combination of input values ​​can be used as the closest output value. In principle, an output value can be determined using multiple output values ​​closest to a combination. For this purpose, the evaluation unit can perform interpolation or extrapolation of at least one output value closest to a combination. A given characteristic map can therefore provide a continuous set of output values.

[0023] In one embodiment, the evaluation unit has a set of characteristic maps configured for different driving conditions and that can be specified for determining at least one operating parameter. Alternatively, the evaluation unit may also have a set of modifications for the characteristic maps configured for different driving conditions and that can be applied to the characteristic maps. The set and / or modifications of the characteristic maps may allow the driver to adapt the provision of assisted power according to his preferences. It is also conceivable and possible to specify the characteristic maps according to at least one physiological characteristic of the driver (e.g., athletic ability or body weight).

[0024] Similarly, the electronic control unit can be configured and provided to replace or modify a predetermined characteristic map depending on the driving conditions. Therefore, changes to the characteristic map can be made dynamically. For example, the evaluation unit may have a starting characteristic map provided for starting an electric bicycle using assisted power.

[0025] Alternative driving situations can likewise be specified by a fitness program selected by the driver (for example, characteristic maps for training intervals and characteristic maps for relaxation intervals), or, for example, based on an analysis of the navigation data of a GPS unit (for example, characteristic maps for roads and characteristic maps for rocky terrain). Further driving situations can be defined by detected dangerous situations. For example, a brake characteristic map can be used when the brakes of the electric bicycle are applied. The brake characteristic map can, in this case, provide reduced assist power.

[0026] In principle, the characteristic map can be provided in accordance with the temporal profile of the input values. For example, the control unit can be set to determine the temporal profile of the rider torque (for example, in the form of a decrease in the values of the rider torque over a plurality of rotation intervals). Based on the determined temporal profile of the rider torque, the characteristic map can be specified.

[0027] The evaluation unit can have an interface that enables it to update a set of characteristic maps and / or a set of changes to a predetermined characteristic map. This enables the manufacturer of the drive system to define new characteristic maps and add them to existing drive systems, or to update existing characteristic maps.

[0028] With regard to the set of changes, the evaluation unit can enable not only permanent changes to a predetermined characteristic map, but also reversible changes during the operation of the drive system.

[0029] In one embodiment, the evaluation unit is configured to further determine at least one operating parameter based on one or more of the road gradient, navigation information, charge level of the electronic energy storage device, service life of the electronic energy storage device, at least one biometric parameter of the electric bicycle driver, and / or at least one set parameter. These parameters can be included as input values in the determination of the output value via a predetermined characteristic map. In this regard, additional dimensions of the predetermined characteristic map can be defined.

[0030] When the gradient is large, for example, high assist power can be provided even with low rider torque. The same applies in the case of a headwind. Therefore, the drive system can have an inclination sensor and / or a wind sensor.

[0031] The navigation information can include, for example, the total route length. When the total route is short, for example, higher assist power can be provided because there is no need to worry about the consumption of the electronic energy storage device (e.g., a bicycle battery). Alternatively, the navigation information regarding the remaining route can be used to adapt the assist power so that the electronic energy storage device can provide electrical energy until the end of the route. The navigation information can further include imminent user actions derivable from the route course. Such user actions can include, for example, approaching an intersection where the route course indicates a turn, so that the electric bicycle has to decelerate or at least does not need to continue accelerating (with assist power). In such a situation, it may be advantageous to reduce the assist power early in order to assist the braking operation and save electrical energy. In this way, the drive system can provide an assist power that is economical and optimized for the range.

[0032] By setting a characteristic map to reduce assist power when the charge level is low or when a long service life is desired, the charge level and / or service life of the electronic energy storage device can be reflected in the determination of at least one operating parameter. In this case, the electronic energy storage device may have at least one battery and / or at least one rechargeable battery.

[0033] At least one of the driver's bioparameters could be, for example, heart rate. A given characteristic map can be configured such that higher assist power is provided when at least one bioparameter is outside the target range, particularly above the target range.

[0034] At least one configuration parameter can be specified, for example, by user settings on the drive system's input system. Alternatively, at least one configuration parameter can be specified via the user's mobile phone interface. A further possibility for specifying at least one configuration parameter is a setting by the drive system manufacturer in the drive system's storage device.

[0035] In one embodiment, the electronic control unit is configured to continuously determine at least one operating parameter. The continuous determination may include using each value of rider torque determined by the torque unit (during operation) to determine at least one operating parameter. Alternatively, the continuous determination may include determinations for each rotational interval and / or time interval determined by the filter unit from the rider pedal rotation speed. The assist power can therefore be provided continuously and at an appropriate level at all times, thereby enabling an improved user experience for the electric bicycle rider.

[0036] In one embodiment, the drive system has a scaling unit configured to increase or decrease the filtered rider torque by a scaling factor for use by an evaluation unit. This scaling factor is based on one or more of the following: at least one previously filtered rider torque, the current rider torque, and / or rider pedal revolutions per minute. Alternatively, scaling can be applied to the (unfiltered) rider torque. In one embodiment, the scaling factor may be a value configurable via a parameter, which increases or decreases the filtered rider torque for further processing using a predetermined function, such as linear. To provide previously filtered rider torques, the drive system may have a memory unit that stores values ​​of previously filtered rider torques. By taking into account the history of filtered rider torques, the drive system can provide a more consistent user experience for the electric bicycle.

[0037] Furthermore, by individually influencing the filtered rider torque based on the current rider torque, it is possible to take into account adaptation to sudden riding conditions that are not considered (or at least not considered to a sufficient extent) in the filtered rider torque. Another configuration is possible in which, if the current rider torque exceeds or falls below a predetermined change threshold in the threshold unit, the filtered rider torque is influenced (favorably in an increasing form) via a second processing path from the torque unit, bypassing the filter unit. This can enable a quicker response in providing assist power, for example, in the case of a sudden intermediate sprint.

[0038] In a further embodiment, the filter unit is configured to process the filtered lidar torque in such a manner that, in a series of intervals in which the average lidar torque changes in steps, the steps representing an increase in the average lidar torque are reproduced more strongly than those representing a decrease. In this case, the intervals may be formed by time intervals and / or rotational intervals. For example, in a first section of the series of intervals, the filtered lidar torque may have a first value (within the acceptable range). In a second section of the series of intervals, the filtered lidar torque may have a second value (within the acceptable range).

[0039] A decrease may occur if the first value of rider torque is greater than the second value. In this situation, where the assist power is high at the start, it may be desirable to decrease the filtered rider torque more slowly, especially to prevent the assist power from decreasing too quickly during a brief decrease in the driver's driving force. As a result, a reasonably high assist power will still be available for a while when requested again after a brief interruption of rider torque.

[0040] In one embodiment, the electronic control unit is configured to further increase the filtered rider torque when the rider torque exceeds a change threshold. As a result, at least one operating parameter can be increased more rapidly than in the case of pure filtering, if necessary. This avoids the delay in increase that may be caused by the filtering unit and any scaling unit. The increase can be carried out, for example, via an additional processing path that bypasses the filtering unit from the torque unit. In addition, the next filtered rider torque can be determined starting from the preceding increased filtered rider torque. In other words, the increased filtered rider torque can be used as a new operating point for the filtering unit. The possibility of additional increases is advantageous, for example, when starting on an incline where very high rider torque exists at very low pedal revolutions and high assist power is desired. In principle, or when the current rider torque exceeds the change threshold, the time interval and / or rotational interval in which filtering is performed can be shortened. This also ensures a rapid response of the drive system to the rider's demands. In either case, the change threshold can be adjusted according to the rider pedal revolutions.

[0041] In principle, the filter unit can be configured to process rider torque in such a way that changes in rider torque are smoothed over a series of intervals. Smoothing may include amplification or attenuation of the filtered rider torque. As a result, the electric bicycle rider can experience consistent assist power (without surprising abrupt changes). However, if the rider torque exceeds a change threshold, it may be desirable to prioritize an immediate increase in assist power to an appropriate value, or an increase over at least several intervals, before smoothing the changes in the filtered rider torque, so that the rider is better assisted. For this purpose, the filtered rider torque is further increased via a second processing path.

[0042] According to a second embodiment, the objective is achieved by a method for determining at least one operating parameter for at least one drive motor of an electric bicycle.

[0043] This method includes the following steps:

[0044] The generation of driving force for human-powered propulsion of an electric bicycle by applying rider torque to the bottom bracket shaft of at least one drive motor based on the rider's pedal rotation speed. Determination of rider pedal rotation speed and rider torque, Filtering one or more values ​​of rider torque based on rider pedal rotations to determine filtered rider torque, Determination of at least one operating parameter from a predetermined characteristic map, based at least on filtered rider torque and rider pedal rotation speed, and Providing externally powered assist power by at least one drive motor, in addition to the driving force, depending on at least one operating parameter.

[0045] The given characteristic map may be at least two-dimensional, in this case, to assign a value for at least one operating parameter to each combination of filtered rider torque and rider pedal rotation speed values.

[0046] As described above, higher-dimensional characteristic maps can also be conceived and are possible. Furthermore, the features and advantages described in relation to the first embodiment of the proposed solution can also be applied to the second embodiment.

[0047] The proposed solution further includes a computer program product having instructions that cause at least one processor to execute a method according to a second aspect of the proposed solution when executed by at least one processor of an electronic control unit for the drive system of an electric bicycle.

[0048] In addition, the proposed solution includes an electric bicycle equipped with a drive system according to the first embodiment. [Brief explanation of the drawing]

[0049] The attached drawings illustrate possible embodiments of the proposed solution. These include:

[0050] [Figure 1] This is a schematic diagram of an electric bicycle. [Figure 2] A diagram of the drive system. [Figure 3] This is an example of a trait map. [Figure 4] This is a diagram showing the time profile of rider torque. [Modes for carrying out the invention]

[0051] Figure 1 shows a schematic diagram of an electric bicycle 1 equipped with a front wheel 10 and a rear wheel 11. The rear wheel 11 is connected to a drive motor A via a transmission element 12 (e.g., a chain), and the drive motor A is configured to transmit the driving force it generates to the rear wheel 11 via the transmission element 12. The driving force can be generated by the rider at the bottom bracket axis T by applying bicycle torque at rider pedal rotation speed. This makes it possible to achieve human-powered propulsion of the electric bicycle 1. In this case, the rider generates rider torque at the bottom bracket axis T via a crank arm K equipped with pedals P.

[0052] Figure 2 shows a schematic diagram of the drive system. On the one hand, the drive system is configured to provide driving force for human-powered propulsion of the electric bicycle 1 to the wheels, for example, the rear wheel 11. On the other hand, the drive system is configured to provide externally powered assist power in addition to the driving force by the drive motor A.

[0053] The provision of assist power here is performed according to operating parameters determined by the control unit 100. The rider pedal rotation speed, which is a first input value for determining the operating parameters, is determined by the rotation speed unit 3. This may include, for example, a magnetic sensor. A torque unit 2 is provided for determining the rider torque, which is a second input value. The control unit 100 receives the values ​​of rider torque and rider pedal rotation speed from the rotation speed unit 3 and the torque unit 2.

[0054] The control unit 100 has a filter unit 101, which is configured to filter one or more values ​​of rider torque based on rider pedal rotations in order to determine filtered rider torque 1011. Filtering may include forming an average of several values ​​of rider torque. Filtering may further include specifying the filtered rider torque such that the filtered value is closer to the average or alternatively input rider torque than a previously filtered rider torque. The filtered rider torque is stored in the memory unit 105 so that it can be made available as a previously filtered rider torque, for example, for the next filtering. In addition, in this case, the filtered rider torque is scaled by a scaling unit 104. For this purpose, a scaling factor based on at least one previously filtered rider torque is used. Thus, the scaling unit 104 receives a previously filtered value of rider torque from the memory unit 105. An alternative scaling factor not based on at least one previously filtered rider torque is also conceivable and possible.

[0055] One advantage of using the scaling unit 104 is that the assist power can be increased as needed (e.g., on inclines) or decreased to achieve a longer range, for example. The scaling factor can also be understood as the sensitivity to which the drive system responds to increases (or decreases) in rider torque and / or rider pedal rotations. The scaling unit 104 and the memory unit 105 are, in principle, optional.

[0056] In some cases, a filtered rider torque with adjusted magnitude is used by the evaluation unit 102 to determine at least one operating parameter. The determination of at least one operating parameter by the evaluation unit 102 is further based on the rider pedal rotation speed. For determining at least one operating parameter, the evaluation unit 102 uses a predetermined characteristic map. The motor current for drive motor A is calculated by the motor current calculation unit 103 from at least one operating parameter. The calculation is performed based on the current value of the rider torque, which is made available to the motor current calculation unit 103 by the torque unit 2. For example, the rider torque can be multiplied by at least one operating parameter in the form of an assist rate to obtain an assist torque proportional to the motor current.

[0057] In addition, increasing the filtered rider torque can be performed via a second processing path based on a comparison of the current rider torque with a threshold in the threshold unit 106. In this way, the filtered rider torque can be adjusted early to, for example, new driving conditions. The filtering process itself can also be performed based on a comparison of the current rider torque with a threshold. For example, if the current rider torque exceeds a threshold, the number of rider torque values ​​used as the basis for forming the average value during filtering can be reduced. Alternatively, the filtering unit 101 can be set to approach the filtered value of the rider torque more quickly or more slowly than the average value or alternatively input rider torque based on a comparison of the current rider torque with a threshold. This can be implemented, for example, by increasing the magnitude of the increment that modifies the previously filtered rider torque.

[0058] Drive motor A operates with a calculated motor current, thereby providing assist power in addition to the driving force at the wheels.

[0059] Figure 3 illustrates the characteristic map 1020. The characteristic map 1020 is shown here, for example, as a grid of assist rate values ​​between 0 and 1. An assist rate of 1 here means that the assist power is equal in magnitude to the driving force. When the filtered rider torque is low, the assist rate is similarly low. When the filtered rider torque is high, the assist power also increases with rider pedal rotation speed. In this case, different sections of the filtered rider torque provide different gradients of the assist rate with respect to rider pedal rotation speed. The highest values ​​of the assist rate are provided at high filtered rider torque and high rider pedal rotation speed. The two quantities input into the characteristic map 1020 (filtered rider torque, and rider pedal rotation speed, which may be adjusted in magnitude) typically result in an increase in the assist rate when they increase. For example, at a constant filtered rider torque, an increase in rider pedal rotation speed may lead to an increase in assist power. Overall, both quantities of rider pedal rotation speed and filtered rider torque simultaneously affect the assist power according to the support values ​​in the characteristic map 1020.

[0060] Figure 4 illustrates the temporal profile of rider torque. The rider torque values ​​therein form a graph of a trigonometric function, particularly a sinusoidal function such as |sin(x)|, with the average rider torques positioned between the minimum and maximum values ​​of the graph. Each arc 20 of the graph represents a rotational interval in the form of a half-turn of the pedal crank axis. The graph is shown as an example only; it is conceivable and possible for the graph to have any desired shape. The average rider torque is determined in a first mathematical operation by a filter unit over all rider torque values ​​recorded within a half-turn, and as a result, a value is available for each rotational interval.

[0061] This yields a series of average ridider torque over time. This series has 12 members. The average ridider torque is constant in the first section of the series (the first four members). In the second section of the series (the next four members), the average ridider torque increases stepwise compared to the first section (first step). From the second section to the third section (the last four members), the average ridider torque decreases stepwise (second step).

[0062] The dashed line 1011 represents possible profiles of the filtered rider torque. In this case, each filtered rider torque 1011 is determined based on the averaged value of the rider torques 1010. Each average rider torque 1010 in this case forms a predetermined value on which the filter unit performs a second mathematical operation. This predetermined value is specified by a first sampling rate, which can be twice as large, for example, if the average rider torque 1010 is determined from a quarter turn of the pedal crank axle.

[0063] A second mathematical operation generates a filtered lidar torque that is closer to a predetermined value than the previously filtered lidar torque. For example, the second mathematical operation may involve a stepwise increase or decrease of the previously filtered lidar torque in the direction of the predetermined value. The filtered lidar torque can be determined by a second sampling rate, which can be greater than the first sampling rate. This could, for example, correspond to the sampling rate of the motor current.

[0064] The filtering process is shaped to reproduce the increase in the first step more strongly than the decrease in the second step. This can be achieved, for example, by specifying in the second mathematical operation an increment of the filtered ridider torque that depends on the desired direction of change of the filtered ridider torque relative to the previously filtered ridider torque. Thus, in the first step, the decrease of the filtered ridider torque relative to the average ridider torque is provided over fewer (two) intervals than in the second step, while in the second step, the (decreasing) increase of the filtered ridider torque relative to the average ridider torque is provided over three or more intervals. Therefore, to the user, the assist power resulting from the positive / negative difference in change between the previously filtered ridider torque and a predetermined value of the (target) ridider torque appears, for example, to act rapidly (increase: "rapid rise") and the assist force to decrease slowly (decrease: "gradual decay").

[0065] The increase (decrease) in filtered lidar torque is delayed by one arc length relative to the increase (decrease) in lidar torque because, in each case, the average lidar torque is determined first (first mathematical operation). Subsequently, the filter unit determines the filtered lidar torque based on a predetermined value in the form of the average lidar torque (second mathematical operation).

[0066] A simple algorithm for determining filtered rider torque is reproduced below as an example. The following increments are used. Filterwert_UP indicates the increment. Filterwert_DOWN indicates the decrease in increment.

[0067] For each sampling step:

[0068] If (previously filtered ridor torque < average ridor torque) is satisfied, Filtered rider torque = Previously filtered rider torque + Filterwert_UP.

[0069] If (previously filtered rider torque > average rider torque) is satisfied, Filtered Rider Torque = Previously Filtered Rider Torque - Filterwert_DOWN.

[0070] For clarity, overflow is ignored in this example. The sampling step is repeated here at a second sampling rate. [Explanation of Symbols]

[0071] 1. Electric bicycle 10 Front Wheel 100 control units 101 Filter Unit 1010 Average Rider Torque 1011 Filtered Rider Torque 102 evaluation units 1020 Trait Map 103 Motor current calculation unit 104 Scaling Unit 105 memory units 106 threshold units 11 Rear wheels 12 Communication elements 2 Torque Units 20 arcs 3 rotation speed unit A Drive motor K Crank P pedal T Bottom Bracket Axle

Claims

1. A drive system for an electric bicycle (1), A bottom bracket shaft (T) for applying rider torque at rider pedal rotation speed to generate driving force for propelling the electric bicycle (1) by human power, Depending on at least one operating parameter, at least one drive motor (A) provides externally powered assist power in addition to the driving force, A rotation speed unit (3) for determining the rotation speed of the rider pedal, A torque unit (2) for determining the rider torque, It has, The system includes an electronic control unit (100) for determining the at least one operating parameter based at least on the rider pedal rotation speed and the rider torque, The aforementioned electronic control unit (100) A filter unit (101) is configured to perform filtering of one or more values ​​of the rider torque based on the rider pedal rotation speed in order to determine the filtered rider torque (1011), An evaluation unit (102) is configured to determine at least one operating parameter from a predetermined characteristic map (1020) which is at least two-dimensional, based at least on the filtered rider torque and the rider pedal rotation speed. A drive system characterized by including

2. The drive system according to claim 1, characterized in that the at least one operating parameter is a motor current, motor torque, motor output, or assist rate, which forms the basis for determining the assist power from the driving force.

3. The drive system according to claim 1 or 2, characterized in that the filtering process includes averaging of a plurality of values ​​of the ridor torque.

4. The drive system according to any one of claims 1 to 3, characterized in that the filter unit (101) is configured to determine at least one of the time interval and rotation interval of the bottom bracket shaft (T) from the rider pedal rotation speed, and to base the filtering process on at least one value of the rider torque within the range of at least one of the time interval and rotation interval.

5. The drive system according to any one of claims 1 to 4, characterized in that the filter unit (101) is configured to perform filtering of the rider torque by a predetermined number of values.

6. The drive system according to any one of claims 1 to 5, characterized in that the predetermined characteristic map (1020) includes a plurality of combinations of input values, each of which is assigned an output value of at least one operating parameter.

7. The drive system according to claim 6, characterized in that the evaluation unit (102) is configured to determine an output value from at least one output value closest to a particular combination of input values ​​if no output value is assigned to that combination.

8. The evaluation unit (102) is A set of characteristic maps configured for different driving conditions and specified for determining the at least one operating parameter, and The drive system according to any one of claims 1 to 7, characterized by having at least one of a set of modifications for the characteristic map (1020) that are configured for different driving conditions and applicable to the characteristic map (1020).

9. The evaluation unit (102) is Based on the road gradient, navigation information, the charge level of the electronic energy storage device, the service life of the electronic energy storage device, at least one of the biometric parameters of the driver of the electric bicycle (1), and at least one of the setting parameters, The drive system according to any one of claims 1 to 8, characterized in that it is configured to further determine the at least one operating parameter.

10. The drive system according to any one of claims 1 to 9, characterized in that the electronic control unit (100) is configured to continuously determine the at least one operating parameter.

11. The filtered rider torque for use by the evaluation unit (102) is A scaling factor based on at least one of the previously filtered rider torque, the current rider torque, and the rider pedal rotation speed, The drive system according to any one of claims 1 to 10, characterized by having a scaling unit (104) configured to increase or decrease.

12. The drive system according to any one of claims 1 to 11, characterized in that the filter unit (101) is configured to process the averaged ridor torque in such a manner that, in a series of intervals in which the averaged ridor torque changes in steps, the steps are more strongly reproduced when they represent an increase than when they represent a decrease in the averaged ridor torque.

13. The drive system according to any one of claims 1 to 12, characterized in that the electronic control unit (100) is configured to further increase the filtered ridor torque when the ridor torque exceeds a threshold.

14. A method for determining at least one operating parameter for at least one drive motor (A) of an electric bicycle (1), The driving force for human-powered propulsion of the electric bicycle (1) is generated by applying rider torque at the rider pedal rotation speed to the bottom bracket shaft (T) of at least one drive motor (A), To determine the rider pedal rotation speed and the rider torque, In order to determine the filtered rider torque (1011), filter (101) one or more values ​​of the rider torque based on the rider pedal rotation speed. Based at least the filtered rider torque and the rider pedal rotation speed, the at least one operating parameter is determined from a predetermined characteristic map (1020), and In addition to the aforementioned driving force, the at least one drive motor (A) provides an externally powered assist power according to the at least one operating parameter. A method that includes this.

15. A computer program product having an instruction that causes the at least one processor of an electronic control unit (100) for the drive system of an electric bicycle (1) to perform the method according to claim 14 when executed by the at least one processor.

16. An electric bicycle (1) having the drive system according to any one of claims 1 to 13.

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