Electric bicycle drive unit and control method for asymmetrically applying assist torque generated by external force operation

Abstract

The proposed solution relates in particular to a drive unit for an electric bicycle (1), which is actuated by muscle power and generates a drive torque (M L , M R ), a bottom bracket shaft (T) with two shaft ends that generates a driving torque (M L , M R ) and to the output member, and control electronics (SE) for controlling the level of the assist torque, through which the user can separately specify the level of assist torque for the left leg and the right leg.

Description

[Technical Field]

[0001] The proposed solution relates to a drive unit for an electric bicycle and a method for controlling the drive unit. [Background technology]

[0002] Conventionally, electric bicycle drive devices equipped with at least one motor for applying an assist torque generated by an external force operation have been widely known. In addition to the drive torque generated by muscle operation, the assist torque applied by the external force operation via the motor can be transmitted to the output member of the drive device. This reduces the amount of effort required for the electric bicycle user to ride the electric bicycle, as the electric bicycle is not driven solely by the drive torque applied to the pedal shaft by muscle operation. The amount of assist torque is specified by control electronics of the drive device. These control electronics can, for example, adjust the amount of assist torque at different assist levels depending on the amount of drive torque generated by muscle operation.

[0003] Furthermore, Patent Document 1 below shows that the driving torque applied by a user to the shaft end of a pedal shaft can vary, particularly depending on which leg acts on the corresponding shaft end. For example, a user may apply a greater force with one leg to the pedal connected to the shaft end than with the other leg on the opposite side of the pedal shaft. Against this background, Patent Document 1 proposes automatically varying the assist torque generated by the motor so that a constant output (rotational) torque is continuously applied to the output member of the driving device, even if the user's pedaling force and the resulting driving torque vary. Therefore, the solution for controlling a driving device for an electric bicycle proposed in Patent Document 1 aims to control at least one motor of the driving device so as to obtain a constant (total) output torque over one complete rotation (360°) of the pedal shaft, the output torque being composed of the driving torque generated by muscle operation and the assist torque generated by external force operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] German Patent No. 10 2009 029 655 Summary of the Invention [Problem to be solved by the invention]

[0005] However, despite the solution proposed in Patent Document 1, there is still a need for a drive device for an electric bicycle that allows the user to variably adjust the assist torque according to their own physical condition. The proposed solution here provides a solution to that need.

[0006] In particular, a drive unit for an electric bicycle is proposed, which comprises: Pedal axles that can generate driving torque at both ends using the muscle strength of the electric bicycle user's left and right legs. Output member for driving the wheels of electric bicycles At least one motor that applies an assist torque generated by an external force operation that can be transmitted to an output member in addition to the drive torque generated by muscle force operation. Control electronics that control the amount of assist torque and allow the user to set different amounts of assist torque for the left and right legs.

[0007] The proposed drive system can apply asymmetric assist torque to both legs of a user, allowing different load intensities to be applied to the legs depending on the user's settings while riding an electric bicycle equipped with the drive system. Thus, the user can set the degree of motor assistance to one leg or the other via the control electronics. The degree of motor assistance depends on the leg receiving assistance and is determined by which end of the pedal shaft (i.e., which rotational position of the pedal shaft) is currently applying drive torque through muscle operation or whether drive torque can be applied by one leg or the other. Depending on which pedal, i.e., which end of the pedal shaft, the user is operating with one leg or the other, the drive system applies different amounts of assist torque depending on the user's settings. The proposed drive system allows the user to specifically set one leg to receive more motor assistance and a lower load while riding an electric bicycle. A user of an electric bicycle with the proposed drive unit can, for example, if he has a physical condition, in particular if he has injured or operated on the knee of one leg, ensure that the load on this leg is less than the load on the other leg while riding the electric bicycle.

[0008] For example, according to one embodiment, the user can set the amount of assist torque for one leg to be higher than for the other leg via the control electronics, so that while riding an electric bicycle, the drive torque applied to the pedal shaft by muscle operation of one leg can be smaller than that of the other leg.

[0009] Alternatively or additionally, various modes can be selected via the control electronics to set the amount of assist torque asymmetrically or symmetrically. For example, the following can be selectively set: - Applying a higher assist torque to one leg (either leg) than the other leg Applying a lower assist torque to one leg than the other -Apply the same support elements to both legs

[0010] In this embodiment, for example, the drive unit allows for selection between asymmetric and symmetric assist modes. In asymmetric assist mode, different amounts of assist torque are applied to the user's legs. In symmetric assist mode, the same assist torque (i.e., the same in both its progression and maximum value) is applied to both legs. In asymmetric assist mode, it is also possible to select whether one leg (left or right) is to be applied with a higher assist torque or a lower assist force.

[0011] The drive device allows the degree of difference in the assist torque applied to the user's left and right legs to be configured in various ways. For example, in one embodiment, the control electronics can set the percentage by which the assist torque for one leg is higher or lower than the assist torque for the other leg. This can be done, for example, via a virtual or physical slider displayed or configured on the drive device's operating unit or on a mobile terminal device connected to the drive device.

[0012] Essentially, the control electronics can be connected to an operating unit of the drive, on which the user can set the assist torque, and the operating unit is equipped, for example, with a display, which visually informs the user of the electric bicycle of the current setting of the drive.

[0013] Alternatively or additionally, the drive unit may include an interface for wireless communication with a mobile terminal. In this case, the drive unit is configured to receive data via the interface and, based on the data, set the amount of assist torque for the left and / or right leg. The interface for wireless communication with the mobile terminal, e.g., a mobile device such as a smartphone, handheld device, or laptop, may be provided in the control electronics or in an operating unit of the drive unit connected to the control electronics. User input may thus be wirelessly transmitted via the mobile terminal to the drive unit to set the asymmetrical application of the assist torque generated by the motor for riding the e-bike.

[0014] In a new development, the settings made by the mobile terminal can also be visually indicated on the display of the operating unit. If necessary, a user confirmation can be requested on the operating unit of the drive device in order for the settings made by the mobile terminal to be executed by the control electronics of the drive device. This prevents user inputs made on the mobile device from accidentally changing the settings of the drive device of the electric bicycle.

[0015] In one embodiment, the control electronics can be configured to set different amounts of assist torque for the user's left and right legs based on at least one sensor value from at least one sensor device of the drive device. The at least one sensor value indicates, for example, the drive torque input to the pedal shaft through muscle manipulation and / or the rotational position of the pedal shaft. The drive torque detected by the sensor, particularly the curve of the drive torque detected by the sensor, and the rotational position of the pedal shaft (e.g., the position of the pedal shaft rotatable about an axis relative to a fixed zero position) are used to adjust the appropriate curve of the assist torque so that the amount of assist torque varies depending on whether drive torque is currently being introduced, or at least can be introduced, into the pedal shaft through muscle manipulation by one leg or the other, respectively. The determined or measured drive torque and / or the measured rotational position of the pedal shaft can be used to determine when and how much assist torque to provide in order to set the individual load of the user's desired leg. For example, when the user presses the pedals connected to the respective shaft ends with maximum force with one leg or the other, the respective assist forces reach their maximums every 180° (with different maximum values ​​for each leg). Therefore, the assist torque setting can be controlled in a timely manner using at least one sensor value.

[0016] Alternatively or additionally, at least one sensor device of the drive device can be used to detect whether the drive torque input by muscle force manipulation at one end of the pedal shaft provided for one leg differs (is higher or lower) by at least a tolerance threshold value from the drive torque input by muscle force manipulation at the end of the pedal shaft provided for the other leg. The corresponding sensor value indicates, for example, the drive torque input to the pedal shaft by muscle force manipulation. For example, a sensor device for this purpose may include a torque sensor on the pedal shaft. Thus, if it is determined that the difference between the pedal force applied to the end of the pedal shaft and the resulting drive torque input to the right and left pedal shafts of the drive device is greater than a value defined by the tolerance threshold, the user is suggested to apply assist torque asymmetrically. For example, the control electronics may be configured to generate a warning signal to notify the user when a drive torque input (single or repeated) from one end of a pedal shaft for one leg differs from a drive torque input from the other end of a pedal shaft for the other leg by at least a tolerance threshold. "Differing by at least a tolerance threshold" may refer to, for example, a percentage deviation or difference between the maximum or average drive torque input to each side or each end. In this case, for example, the degree to which the drive torque input to one side or one end differs from the other side may be evaluated for each revolution of the pedal shaft about its axis, and a determination may be made as to whether to issue a warning to the user.

[0017] The output of the warning or the generation of the warning signal may involve, for example, informing the user that the amount of assist torque for the left and right legs can be changed in the drive devices used. Alternatively or additionally, an operating unit of the drive device and / or a mobile terminal device connected to the control electronics may automatically be provided with an operating element via which the amount of assist torque for at least one leg can be set. If the sensor detects an asymmetry in the curve of the drive torque that exceeds a value defined by a tolerance threshold, the user may automatically be offered a user input option that allows the user to set a higher or lower assist torque generated by the motor for one leg in order to correct the detected asymmetry in the drive torque.

[0018] Part of the proposed solution also includes an electric bicycle equipped with an embodiment of the proposed drive device.

[0019] The proposed solution also includes a method for controlling a drive unit of an electric bicycle, the method comprising: The driving torque can be generated by the left and right legs of the electric bicycle user operating the two ends of the pedal shaft of the driving device with muscle force. The assist torque generated by the external force operation of at least one motor of the drive device is transmitted to an output member provided to drive the wheels of the electric bicycle in addition to the drive torque generated by the muscle force operation. The amount of assist torque is electronically controlled, with different amounts of assist torque for the left and right legs set by user input.

[0020] An embodiment of the proposed control method can be implemented in particular using an embodiment of the proposed drive device, and therefore advantages and features of embodiments of the proposed drive device described above and below also apply to embodiments of the proposed control method, and vice versa.

[0021] For example, in one embodiment of the proposed control method, a user input can be provided to set the amount of assist torque for one leg higher than the other leg, so that while riding the e-bike, muscle input from one leg applies a smaller drive torque to the pedal axle than the other leg.

[0022] According to the various assistance modes described above in connection with one embodiment of the proposed drive device, one embodiment of the proposed control method allows, for example, by user input: - Applying a higher assist torque to one leg (either leg) than the other leg Applying a lower assist torque to one leg than the other -Applies the same assist element to both legs

[0023] Essentially, in one embodiment of the proposed control method, the user input can be made at an operating unit of the drive device and / or at a mobile terminal device in wireless communication with the drive device.

[0024] In one embodiment, it is detected whether the drive torque input by muscle force operation at one end of the pedal shaft provided for one leg is different (higher or lower) from the drive torque input by muscle force operation at the end of the pedal shaft provided for the other leg by at least a tolerance threshold, and in response to such detection, a warning signal is generated to notify the user.

[0025] For example, a warning signal visually informs the user that different amounts of assist torque can be set for the left and right legs. The user is thus not only notified that asymmetric pedal forces or resulting drive torques have been detected, but is also immediately informed of possible corrective measures, and in particular that the amount of assist torque can be set separately for each leg, i.e., for each side of the pedal axle.

[0026] Alternatively or additionally, an operating element can be provided on the operating unit of the drive device and / or on a mobile terminal device connected to the drive device, along with a warning signal, which allows the amount of assist torque for at least one leg to be set individually. If it is detected (either once or repeatedly) that the asymmetry between the applied pedal force and the resulting drive torque exceeds an acceptable threshold, the user is automatically given the option to adjust the assist force for each leg individually via the operating element. [Brief explanation of the drawings]

[0027] The accompanying drawings show examples of possible implementations of the proposed solution. [Figure 1] Schematic diagram of an electric bicycle equipped with an embodiment of the proposed drive unit, which is capable of wireless communication with a mobile terminal device in the form of a mobile device and is capable of setting the assist force asymmetrically according to the user's specifications via at least one electric motor. [Figure 2] FIG. 10 is a diagram showing the transition of the driving torque generated by the left and right legs on the pedal shaft of the driving device over two rotations of the pedal shaft, with the assist torque generated by the motor being applied symmetrically. [Figure 3] FIG. 1 shows the progression of drive torque over two revolutions of the pedal shaft with asymmetric motor-generated assist torque applied, with a larger motor-assisted torque applied to one side to reduce the drive torque applied by muscle manipulation. [Figure 4] FIG. 1 is a diagram showing the procedure of one embodiment of the proposed control method. DETAILED DESCRIPTION OF THE INVENTION

[0028] FIG. 1 shows an electric bicycle 1 equipped with a drive unit A. The electric bicycle 1 has a frame 10 to which the drive unit A is attached. Part of the drive unit A includes control electronics SE and a sensor device 15, which may be composed of a torque sensor and a position sensor, and electronically determines the torque input by muscle operation at the pedal axle T of the drive unit A. The drive member of the drive unit A is, for example, a hollow output shaft supported coaxially with the pedal axle, and is connected to the rear wheel 12 of the electric bicycle 1 via a belt or chain 13 to drive the electric bicycle 1. In this example, a wheel sensor 14 for determining the speed of the electric bicycle 1 is also provided on the rear wheel 12. Of course, the wheel sensor 14 could also be provided on the front wheel 11 of the electric bicycle 1.

[0029] Drive unit A is part of the drive device of electric bicycle 1 and also includes an operation unit 2. In FIG. 1, operation unit 2 is attached, for example, to the handlebar of electric bicycle 1 and connected to the control electronics SE of drive unit A. A user provides input via operation unit 2 to control drive unit A. For example, operation unit 2 includes at least one display for informing the user of electric bicycle 1 of the current status of drive unit A. The current status includes the currently set assist level, the charge state of the battery that supplies power to drive unit A, etc.

[0030] The operating unit 2 is provided with an interface for wireless communication with mobile devices, such as the mobile device 3. Control commands can therefore be transmitted wirelessly from the mobile device 3 to the operating unit 2.

[0031] The drive device of the electric bicycle 1, which includes the drive unit A and the operation unit 2, can set the amount of assist torque applied by the drive unit A via the electric motor for each of the user's left and right legs through user input. This allows the user to apply different intensities of load to each leg while riding the electric bicycle 1, depending on the user's settings. In other words, the user can set the amount of motor assistance for one leg and the other leg, and the degree of motor assistance is determined by the user's leg being assisted, which in turn determines which end of the pedal shaft T receives the drive torque due to muscle operation. This allows the electric bicycle 1 to provide asymmetric assistance depending on the user's physical condition, for example, whether the user wants to apply a low intensity load to an injured or operated leg, or conversely, whether the user wants to apply a high intensity load to a leg for muscle strengthening.

[0032] In this embodiment, for example, the user can switch between the symmetric assistance mode and the asymmetric assistance mode by inputting information into the mobile device 3 or the operation unit 2.

[0033] In symmetric assist mode, the user must apply identical driving torque with both legs, as shown in the driving torque-time diagram in Figure 2. Therefore, the driving torque applied by the left leg (driving torque M in Figure 2) L ) and the driving torque applied by the right leg (driving torque M R ) is the same on both sides, so that its progression and height are identical or nearly identical over half a rotation of the pedal shaft T (each of which is a 180° rotation angle), and is typically sinusoidal. Therefore, the motor-assisted torque additionally applied to the output member of the drive unit A to drive the rear wheel 13 based on the drive torque does not vary depending on which end of the pedal shaft T the user is pressing on.

[0034] When switching to asymmetric assistance mode, the amount of assist torque is set differently for each side, i.e., for each leg of the user, via the control electronics SE. This means that, while riding the electric bicycle, a higher assist torque is applied to one leg, i.e., one side of the pedal axle T, than to the other, so that the driving torque applied to the pedal axle T by the muscle operation of one leg is smaller than that applied by the other leg. Figure 3 shows the corresponding asymmetric assistance mode. For example, a larger assist force, i.e., a larger assist torque, is applied to the right driving side, i.e., the right end of the pedal axle T. Therefore, the user of the electric bicycle 1 can apply a lower driving torque M to the left leg than to the right leg. R This setting by the user is useful, for example, when reducing the load on the user's right leg when riding the electric bicycle 1 due to an injury or surgery.

[0035] The asymmetric assistance mode can be selected, for example, by entering a customized user profile into the mobile device 3. This allows a corresponding software application on the mobile device 3 to provide a suggestion on how much to increase or decrease the assist torque for the "weaker" leg. The suggestion can take into account, for example, the (average) drive torque of the other leg determined during at least one previous ride of the electric bicycle. Alternatively or additionally, the user can individually set the assist torque for the weaker leg or its maximum value on the mobile device 3. For this purpose, a virtual operating element, for example in the form of a slider, is displayed on the touchscreen of the mobile device 3. When the user inputs the asymmetric setting of the assist torque into the mobile device 3, the relevant data is wirelessly transmitted to the operating unit 2, which stores the corresponding setting via the control electronics SE. Essentially, the assistance can be divided into several ranges of speed, torque, and cadence. In other words, different, and in particular significantly different, assist torques can be set for both drive sides, i.e., both legs, for different speed, torque, and / or cadence ranges.

[0036] For example, the drive unit A can use the sensor device 15, in particular a position sensor (for example in the form of an absolute value sensor or a double Hall sensor) of the sensor device 15, to detect the rotational position of the pedal shaft T. This allows the control electronics SE to apply the appropriate amount of torque generated by the motor depending on which shaft end of the pedal shaft is currently being applied with a drive torque by the user's muscle force.

[0037] Alternatively or additionally, the current drive torque is measured via a torque sensor in the sensor device 15. The torque sensor (or other sensor technology for detecting drive torque) can inform the user that asymmetric forces are being applied to the pedals and that asymmetric motor-generated assist torques are desirable. The control electronics SE electronically determines, for example, how much the drive torques applied to the pedal shaft T by muscle inputs on the left and right sides differ, e.g., whether they exceed a stored tolerance threshold. Here, the stored tolerance threshold can be the difference between the drive torques defined for both sides. If the corresponding tolerance threshold is exceeded once or repeatedly within a defined period (e.g., within a defined number of pedal shaft rotations), especially if it is exceeded for every rotation, a warning signal is generated to inform the user of the corresponding exceedance. This information can be visually output to the user, for example, via a display on the operating unit 2.

[0038] In response to the warning signal, the user can instantly set different assist torques for both drive sides, i.e. both legs, via the operating unit 2 and / or the mobile device 3 .

[0039] 4 shows the steps of the proposed control method for applying asymmetric assist torques to the drive unit of the electric bicycle 1. In a first step 40, the user inputs a user profile via the mobile device 3, setting a higher or lower assist force, i.e., a higher or lower assist torque, for one leg. This setting made on the mobile device 3 is wirelessly transmitted to the operating unit 2 in step 41, and the corresponding assistance is set in the control electronics SE of the drive unit A. In the following step 42, the assist force applied by the at least one electric motor of the drive unit A is controlled according to the user's wishes, so that when pedaling (on the left or right side of the drive unit A), a different assist torque (with a different maximum value and therefore a different profile) is applied to the opposite drive side, i.e., the other leg of the user of the electric bicycle 1.

[0040] The proposed solution allows for a simple and convenient setting of asymmetric assist forces depending on the user's physical condition, especially in cases where only one leg is impaired. [Explanation of symbols]

[0041] 1. Electric bicycle 10 frames 11 Front wheel 12 rear wheels 13 Chains / Belts (power transmission components) 14 Wheel Sensor 15 Sensor Device 2 Operation unit 3. Mobile devices A Drive Unit SE Control Electronic Devices T Pedal shaft

Claims

1. The electric bicycle (1) has two shaft ends, and a driving torque (M Ｌ , M Ｒ ) and a pedal shaft (T) that generates an output member for driving the wheels (12) of the electric bicycle (1); The driving torque generated by muscle manipulation (M Ｌ , M Ｒ At least one motor that applies an assist torque generated by an external force operation and that can be transmitted to the output member in addition to the above-mentioned motor; and a control electronics (SE) for controlling the amount of the assist torque, The user can set different amounts of the assist torque for the left leg and the right leg via a control electronics (SE). A drive unit for an electric bicycle (1).

2. 2. The drive device according to claim 1, wherein the user can set the amount of assist torque applied to one leg higher than the amount applied to the other leg via the control electronic device (SE), thereby making the drive torque applied to the pedal shaft (T) by muscle operation from one leg smaller than the drive torque applied from the other leg while riding the electric bicycle (1).

3. Through said control electronics (SE), the user Applying a higher assist torque to one leg than the other, or Applying a lower assist torque to one leg than the other, or Applying the same assist torque to both legs It is characterized in that it can be selectively set 3. A drive device according to claim 1 or 2.

4. 4. A drive unit according to claim 2 or 3, characterized in that it is possible to set, via the control electronics (SE), how much higher or lower the assist torque to one leg should be than the assist torque to the other leg.

5. 5. The drive system according to claim 1, wherein the control electronics (SE) can be connected to an operating unit (2) of the drive system, and the user can set the assist torque on the operating unit (2).

6. 6. The drive unit according to claim 1, wherein the drive unit has an interface for wireless communication with a mobile terminal device (3), and receives data via the interface to set the amount of assist torque for the left leg and / or the right leg.

7. the control electronics (SE) sets different amounts of assist torque for the left leg and the right leg of the user based on at least one sensor value of at least one sensor device (15) of the drive device; 7. The drive device according to claim 1, wherein the at least one sensor value indicates a drive torque input to the pedal shaft (T) by muscle operation and / or a rotational position of the pedal shaft (T).

8. the drive device has at least one sensor device that generates at least one sensor value indicative of a drive torque input to the pedal shaft (T) by muscle operation, A drive device as described in any one of claims 1 to 7, characterized in that the control electronic device (SE) detects, based on the sensor value, whether the drive torque input by muscle force operation to one shaft end of the pedal shaft (T) provided for one leg differs from the drive torque input by muscle force operation to the other shaft end of the pedal shaft (T) provided for the other leg by at least an allowable threshold value.

9. The drive device according to claim 8, wherein the control electronic device (SE) generates a warning signal and outputs a warning to the user when the drive torque input by muscle force operation to one shaft end of the pedal shaft (T) provided for one leg differs from the drive torque input by muscle force operation to the other shaft end of the pedal shaft (T) provided for the other leg by at least an allowable threshold value.

10. The warning signal may be sent to the user: The assist torque can be set to different amounts for the left and right legs, and / or the amount of the assist torque for at least one leg can be set via an operating element provided on an operating unit (2) of the drive device connected to the control electronics (SE) and / or on a mobile terminal (3) connected to the control electronics (SE), 10. The drive device according to claim 9, wherein the drive device notifies the driver of the following:

11. An electric bicycle comprising the drive unit according to any one of claims 1 to 10.

12. Driving torque (M Ｌ , M Ｒ ) can be generated at the two shaft ends of the pedal shaft (T) of the drive unit by the muscle operation of the left and right legs of the user of the electric bicycle (1), The assist torque is generated by an external force operation using at least one motor of the drive device, and is a drive torque (M Ｌ , M Ｒ ) and is transmitted to an output member for driving the wheel (12) of the electric bicycle (1), The amount of assist torque is electronically controlled; A method for controlling a drive unit of an electric bicycle (1), characterized in that different amounts of the assist torque are set for the left leg and the right leg by user input.

13. The method described in claim 12, characterized in that the user input can set the amount of assist torque for one leg higher than the amount for the other leg, so that the driving torque applied to the pedal shaft (T) by muscle force operation from one leg while riding the electric bicycle (1) can be made smaller than the driving torque applied from the other leg.

14. The user input Applying a higher assist torque to one leg than the other, or Applying a lower assist torque to one leg than the other, or Applying the same assist torque to both legs 14. The method according to claim 12, wherein either one of the following is selected:

15. 15. The method according to any one of claims 12 to 14, characterized in that the user input is made on an operating unit (2) of the drive device and / or on a mobile terminal (3) that is in wireless communication with the drive device.

16. 16. The method according to claim 1, further comprising detecting whether a driving torque input by muscle operation to one shaft end of the pedal shaft (T) provided for one leg differs from a driving torque input by muscle operation to the other shaft end of the pedal shaft (T) provided for the other leg by at least a tolerance threshold, and generating a warning signal to output a warning to the user in response to the detection.

17. The warning signal notifies the user: The assist torque can be set to different amounts for the left and right legs, and / or the amount of the assist torque for at least one leg can be set individually via an operating element provided on the operating unit (2) of the drive device and / or on a mobile terminal (3); 17. The method of claim 16, further comprising:

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