Method for controlling a drive unit, drive unit and vehicle

Abstract

A method for controlling a drive unit is provided for a vehicle that can be propelled, at least temporarily, by muscle power. The drive unit comprises an electric drive, an energy storage device, and a mechanical drive that can be operated by muscle power. The electric drive can be powered by energy from the energy storage device to assist the mechanical drive with an adjustable power output. The method includes detecting (I) a switch-on condition, setting (II) a high-power operation of the electric drive upon detection of the switch-on condition, whereby the power of the electric drive is set to a power output that is above a rated power of the electric drive, and switching off (III) the high-power operation upon detection of a switch-off condition.

Description

[0001] The present invention relates to a method for controlling a drive unit for a vehicle that can be operated at least temporarily by muscle power, a control device for carrying out a method, a drive unit for a vehicle and a vehicle.

[0002] Methods for controlling a drive unit for an e-bike are known. The e-bike can have both an electric and a mechanical drive. The level of support provided by the electric drive to assist the mechanical drive can be adjusted depending on the rider's pedaling power. DE 10 2013 214 169 A1 discloses a method for controlling an electric drive of an electrically powered two-wheeler. This method provides for a boost mode in which the torque of a drive is briefly increased. Further methods for controlling an electric drive are disclosed in D2 DE 10 2018 217 825 A1 and D3 WO 2020 / 048 786 A1.

[0003] The object of the present invention is to provide a method for controlling a drive unit for a vehicle that can be operated at least temporarily by muscle power, with which a high level of driving comfort is achieved.

[0004] The problem is solved by a method that has the features of claim 1. Advantageous further developments are the subject of the dependent claims.

[0005] A method for controlling a drive unit is provided for a vehicle that can be propelled, at least intermittently, by muscle power. The vehicle can be an e-bike or a pedelec. The drive unit comprises an electric drive, an energy storage device, and a mechanical drive powered by muscle power. The electric drive can be provided by an electric motor. The energy storage device can be a battery or a hydrogen storage system with a fuel cell. The mechanical drive can be provided by a pedal crank unit. The electric drive can be powered by energy from the energy storage device to assist the mechanical drive with adjustable power.

[0006] The electric drive and the mechanical drive can be mechanically coupled, for example, via a summing gearbox. The total drive power of the drive unit can be calculated as the sum of the drive power of the electric drive and the drive power of the mechanical drive. The level of assistance can be determined by the ratio of the drive power of the electric drive to the drive power of the mechanical drive.

[0007] If two elements are mechanically connected, they are coupled to each other directly or indirectly in such a way that a movement of one element causes a reaction of the other. For example, a mechanical connection can be provided by a positive-locking or friction-locking connection. The mechanical connection can correspond to the meshing of corresponding gear teeth on the two elements. Further elements, such as one or more spur gear stages, can be provided between the elements.

[0008] The procedure involves detecting a power-on condition. The user interface can be provided by an input unit. The input unit can include at least one element, such as a bicycle computer, a touchscreen, a button, a switch, a push button, or a lever, configured for user input.

[0009] The activation condition can be met when an actual operating state, such as the vehicle's inclination or pedal force, exceeds a limit. The system can detect an overload situation based on the parameters of the actual operating state. This allows the system to operate in an automatic mode. This relieves the driver in an overload situation and results in a high level of driving comfort.

[0010] The activation condition can be met when a user input occurs, for example, pressing the button. This allows the process to be operated in manual mode.

[0011] The method can further include capturing a user preset of parameters for high-performance operation. A parameter of the user preset can be generated by activating the automatic mode. The method can be designed such that the activation condition can only be met if the automatic mode is set in a user preset. The method can be designed such that the activation condition can only be met if the manual mode is set in a user preset. For example, capturing the user preset can include capturing a setting of a preset acceleration power as a parameter for high-performance operation. The method can include capturing the user preset of parameters for acceleration operation via the user interface.

[0012] One of the parameters of the current operating state can be derived from at least one of the following: current gear ratio, current battery state, current wheel speed, current speed, current cadence, current pedal force, current crank torque, current vehicle acceleration (e.g., longitudinal or lateral acceleration), and current vehicle inclination. The method can include acquiring at least one of the parameters of the current operating state.

[0013] The procedure further includes setting a high-performance mode for the electric drive upon detection of the activation condition. In high-performance mode, the electric drive's power is set to a level greater than the rated power permitted for continuous operation and permissible for intermittent operation. In high-performance mode, the electric drive's power can be set to a preset acceleration power. This preset acceleration power can be the power output used to accelerate the vehicle. The preset acceleration power can be limited to a power output above the rated power and permissible for intermittent operation.For example, the preset acceleration power can be set to a maximum of 120% or 110% of the rated power. Temporary operation is possible for a permissible overload duration, for example, a few seconds, such as 20 or 30 seconds. This allows the user to have increased power from the electric drive to support the mechanical drive when needed, thus improving driving comfort.

[0014] The procedure may include an output of a notification to the user that the user preset is inadmissible if the user preset exceeds a restriction of the parameters for acceleration operation, for example, if the user sets a preset acceleration power of more than 120% of the rated power.

[0015] The procedure further includes deactivating high-performance operation upon detection of a shutdown condition. The shutdown condition can be met if a parameter of an actual operating state of the vehicle reaches or exceeds a limit value, for example, for a target operating state, such as when the vehicle's actual speed reaches a target maximum speed. The shutdown condition can also be met if a parameter of an actual operating state reaches a value corresponding to a target operating or normal operating state, for example, when the vehicle's inclination reaches a value within a normal operating inclination range. Finally, the shutdown condition can be met if the user terminates user input, for example, when the user releases the button.The shutdown condition can be met if the electrical machine has been operated in high-performance mode until the permissible overload operating time has elapsed.

[0016] A parameter of a target operating state can be defined by at least one of the following: a target gear ratio, a target battery state, a target wheel speed, a target maximum speed, a rider cadence range with a maximum and minimum cadence, a pedal force range with a maximum and minimum pedal force, a pedal torque range with a maximum and minimum pedal torque, a maximum vehicle acceleration (e.g., maximum longitudinal or lateral acceleration), a maximum vehicle inclination, and a level of assistance. The target operating state can represent normal operation.

[0017] In one embodiment, the activation condition can be fulfilled upon user input via a user interface. The activation condition can be detected taking into account the user input via the user interface.

[0018] The activation condition can be met when the user performs a user input, such as pressing a button or activating high-performance operation via a touchscreen. Capturing a user input can include simply pressing a button.

[0019] In one embodiment, the existence of the switch-on condition can be determined by comparing at least one parameter of an actual operating state with a parameter of a target operating state. The existence of the switch-on condition can then be recognized.

[0020] The activation condition can be met when an actual operating state, such as the vehicle's incline, cadence, pedal force, crank torque, or a combination thereof, exceeds a limit value, for example, for normal operation. This can indicate a steep incline on the surface the vehicle is traveling on or a strong headwind. It can also indicate an overload situation where the rated power of the electric drive is insufficient to comfortably support the mechanical drive. For example, this can provide increased assistance when starting on a slope.

[0021] In one embodiment, at least one parameter of the target operating state can be set via the user interface. For example, a value range for the actual inclination for normal operation can be set via the user interface. Similarly, a value range for the actual pedal force for normal operation can be set via the user interface.

[0022] In one embodiment, the shutdown condition can be met when a permissible overload operating time has elapsed after the high-power operation has been discontinued. The permissible overload operating time can be a few seconds, for example, 20 to 30 seconds. This protects the electrical machine from overheating.

[0023] In one embodiment, the existence of the shutdown condition can be determined by comparing at least one parameter of the actual operating state with at least one parameter of the target operating state. The existence of the shutdown condition can then be identified. For example, the shutdown condition may be present or fulfilled if the actual inclination of the vehicle reaches a value within a range of the target inclination for normal operation. For example, the shutdown condition may be fulfilled if the actual battery state falls below a limit, for example, if the battery is discharged. For example, the shutdown condition may be fulfilled if the actual pedal force reaches a value within a range of the target pedal force for normal operation. For example, the shutdown condition may be fulfilled if the actual lateral acceleration of the vehicle exceeds a limit for normal operation.A vehicle rollover can then be identified as a malfunction. The procedure can include the detection of a malfunction. For example, the shutdown condition can be met if the vehicle's actual speed exceeds a limit, such as the target maximum speed, for normal operation.

[0024] In one aspect, a control device is configured to execute a method according to one of the preceding embodiments. The control device has at least one user interface for inputting information into the control device and an output interface for outputting signals to control a drive unit. The user interface can be formed by an input unit. The control device can have a processing unit. The processing unit can be configured to execute a method according to one of the preceding embodiments. The control device can have a data storage device. The control device can have a location determination unit, for example, a GPS module. The control device can have a data transmission unit, for example, a Bluetooth, WLAN, or cellular network module.

[0025] In one aspect, a drive unit comprises an electric drive, an energy storage device, a muscle-powered mechanical drive, and a control device according to one of the preceding aspects and embodiments. The electric drive can be powered by energy from the energy storage device. The control device is configured to set an acceleration mode in which the electric drive assists the mechanical drive. The electric drive can be provided by an electric motor. The energy storage device can be a battery or a hydrogen storage device with a fuel cell. The mechanical drive can be provided by a pedal crank unit. The electric drive and the mechanical drive can be mechanically coupled, for example, via a summing gear.

[0026] In one aspect, a vehicle has at least one drive wheel and a drive unit according to one of the preceding aspects and embodiments. The vehicle can be propelled temporarily by muscle power. The vehicle can be powered by an e-bike or a pedelec. The drive wheel is mechanically connected to the drive unit in such a way that the drive unit can propel the vehicle. The vehicle may have other devices such as a braking system or a steering system.

[0027] In one embodiment, the vehicle can have a user interface for user input. The user interface can be formed by an input unit. For example, the input unit can include at least one element, such as a bicycle computer, a touchscreen, a button, a switch, a push button, or a lever. The user interface can also be formed by a smartphone. The smartphone can be connected to the control unit via a wired or wireless interface.

[0028] In one embodiment, the user interface can include a push button. The push button can be designed as a knob. The push button can be mounted or attached to the vehicle. The push button can be mounted on the user interface. The push button can be mounted on the handlebars of the vehicle. The push button can be mounted next to a grip on the handlebars. The push button can be mounted on the lower side of the handlebars (in the direction of gravity). The push button can be mounted so that it can be operated by the user with their thumb.

[0029] If two elements are attached to each other, they are directly or indirectly coupled in such a way that a movement of one element causes a reaction of the other element. For example, a connection can be provided by a positive-locking or force-locking connection. Further elements can be provided between the elements. Fig. Figure 1 shows a flowchart of an embodiment of a method for controlling a drive unit of a vehicle. Fig. Figure 2 shows a flowchart of an embodiment of the method for controlling the vehicle's drive unit. Fig. Figure 3 shows a flowchart of another embodiment of the method for controlling the vehicle's drive unit.

[0030] Fig. Figure 1 shows a flowchart of an embodiment of a method for controlling a vehicle's drive unit. The vehicle, in this case an e-bike, has a drive unit, a control unit, and a user interface. The drive unit can be operated manually by muscle power. The drive unit comprises an electric drive, an energy storage device (in this case a battery), and a mechanical drive (in this case, a pedal crank unit with a pedal crank). The electric drive can be powered by energy from the energy storage device to assist the mechanical drive with an adjustable power output that is greater than the rated power of the electric drive.

[0031] The process comprises, in a first step, the detection (I) of a switch-on condition. In a further step, the process comprises (II) the activation of high-power operation of the electric drive upon detection of the switch-on condition. In a further step, the process comprises (III) the deactivation of high-power operation upon detection of a switch-off condition. This ensures that, in an overload situation where the rated power of the electric drive is insufficient for comfortable vehicle operation, the electric drive is temporarily operated at a power level higher than its rated power.

[0032] Further details of the procedure and the vehicle are described below.

[0033] The vehicle is equipped with a pressure sensor to determine the actual pedal force. It is also equipped with a speed sensor to determine the actual wheel speed. The vehicle's actual speed is determined from the wheel speed. Furthermore, the vehicle's acceleration is determined from the acceleration, which is used to calculate the vehicle's current inclination, for example, when driving uphill or downhill. Finally, the actual longitudinal acceleration, such as acceleration during acceleration or braking, and the actual lateral acceleration, for example, when cornering, are also determined from the acceleration. The actual speed, pedal force, acceleration, and inclination are parameters of the vehicle's current operating state, which are continuously monitored by the control unit during operation.If a parameter, such as the actual incline or pedal force, exceeds a limit for normal operation, the control unit detects the overload situation. The control unit then automatically switches the electric drive to high-performance operation. This automatic overload detection relieves the driver and results in a high level of driving comfort.

[0034] Parameters for high-performance and normal operation can be set via the user interface. A rider cadence range with minimum and maximum cadence, a pedal force range with minimum and maximum pedal force, and a support level are parameters for normal operation. In normal operation, the control unit adjusts the power output of the electric drive based on these normal operation parameters. In one embodiment, the control unit adjusts the power output of the electric drive to support the mechanical drive, depending on the set support level and taking into account the rider cadence and pedal force ranges.

[0035] Acceleration power is a parameter for high-performance operation. The user can set the acceleration power for the electric drive via the user interface, which can exceed the manufacturer's specified rated power for continuous operation. In this case, the user can set an acceleration power of up to 120% of the rated power.

[0036] In this system, the user activates the acceleration mode by pressing a button-like switch on the user interface. The switch is positioned on the vehicle's handlebars so that the user can operate it with their thumb. When the switch is pressed, the control unit activates the high-performance mode of the electric drive. High-performance mode is when the electric drive operates at its maximum acceleration power. When the user releases the switch, the control unit ends high-performance mode and returns the electric drive to normal operation. This constitutes a manual mode of the system.

[0037] In an alternative embodiment, the shutdown condition is met when a permissible overload operating time, in this case 20 seconds, has elapsed after the high-performance operation has been switched off.

[0038] In an alternative embodiment, the user can activate an automatic mode via the user interface. When automatic mode is activated, the control unit automatically operates the electric drive at maximum acceleration power upon detecting an overload situation. During high-performance operation, the control unit monitors the vehicle's current inclination and pedal force as parameters of its current operating state. The shutdown condition is met when either the current inclination or pedal force reaches a normal operating value. After reaching this condition, the control unit switches the electric drive to normal operation.

[0039] In an alternative embodiment, the shutdown condition is met when lateral acceleration exceeds a limit value for the normal state. The control unit then detects that the vehicle is about to roll over.

[0040] The method can be formed by a combination of the features of the preceding embodiments.

[0041] Fig. Figure 2 shows a flowchart of an embodiment of the method for controlling the vehicle's drive unit. The method includes all steps of at least one of the preceding embodiments. The method is started when the vehicle is operated. In a first step, the control unit checks whether a switch-on condition exists, in this case, pressing the button. If the control unit detects user input, it operates the electric drive in high-performance mode. The control unit operates the electric drive in high-performance mode until the permissible overload operating time is reached. If the control unit detects that the permissible overload operating time has been reached, it terminates high-performance mode and operates the electric drive in normal mode.

[0042] Fig. Figure 3 shows a flowchart of another embodiment of the method for controlling the vehicle's drive unit. The method includes all steps of at least one of the embodiments described in Figure 3. Fig.The embodiments described in section 1 are used. The method is started when the vehicle is operated. In a first step, the control unit checks whether the activation condition is met, in this case, whether a parameter of the current operating state exceeds a limit value, for example, whether there is a steep incline, and checks whether an overload situation is detectable. If the overload situation is detected, the control unit checks in a further step whether the automatic mode is activated. If the automatic mode is activated, the control unit automatically operates the electric drive in high-performance mode until the permissible overload operating time is reached. If the control unit detects that the permissible overload operating time has been reached, it ends the high-performance operation and operates the electric drive in normal mode. Reference sign I. Capturing a switch-on condition II Setting up high-performance operation of the electric drive upon detection of the switch-on condition III. Shutting down high-power operation upon detection of a shutdown condition

Claims

[1] Method for controlling a drive unit for a vehicle that can be operated at least temporarily by muscle power, comprising an electric drive, an energy storage device and a mechanical drive that can be operated by muscle power, wherein The electric drive can be operated with energy from the energy storage system to support the mechanical drive with adjustable power, and the procedure includes - Detection (I) of a switch-on condition, - Setting (II) to high-power operation of the electric drive upon detection of the switch-on condition, wherein the power of the electric drive is set to a power that is greater than a rated power of the electric drive permitted for continuous operation and that is permissible for intermittent operation of the electric drive, and - Shutdown (III) of high-power operation upon detection of a shutdown condition. [2] Method according to claim 1, characterized by that the activation condition is met upon user input via a user interface. [3] Method according to any one of the preceding claims, characterized by , that the existence of the switch-on condition is determined by taking into account a comparison of at least one parameter of an actual operating state with a corresponding parameter of a target operating state. [4] Method according to any one of the preceding claims, characterized by , that at least one parameter of the desired operating state can be set via the user interface. [5] Method according to any one of the preceding claims, characterized by , that the shutdown condition is met when a permissible overload operating time has elapsed after setting (II) to high-performance operation. [6] Method according to any one of the preceding claims, characterized by, that the existence of the shutdown condition is determined by taking into account a comparison of at least one parameter of the actual operating state with at least one parameter of the target operating state. [7] Control device configured to perform a method according to any of the preceding claims, wherein the control device has at least one input interface for inputting information into the control device and one output interface for outputting signals for controlling a drive unit. [8] Drive unit comprising an electric drive, an energy storage device, a muscle-powered mechanical drive and a control device according to claim 7, wherein the electric drive can be powered by energy from the energy storage device and the control device is configured to set a high-performance operation in which the electric drive assists the mechanical drive. [9] Vehicle with at least one drive wheel and a drive unit according to claim 8, wherein the vehicle can be operated temporarily using muscle power, the drive wheel is mechanically connected to the drive unit in such a way that the drive unit can move the vehicle. [10] Vehicle according to claim 9, characterized by that the vehicle has a user interface for user input. [11] Vehicle according to claim 10, characterized by that the user interface has a button.

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