Braking system of a vehicle, method for operating a vehicle and two-wheeler

Abstract

The invention relates to a braking system (20) of a vehicle (10), comprising a detection device (21) designed to detect a deceleration request (80) of the vehicle in at least two ranges, and an electric machine (30) connected to a control unit (23) of the braking system (20) in such a way that a value of a braking torque (83) can be provided to the electric machine (30) by the control unit (23), wherein the control unit (23) is designed to provide the value based on the detected range of the at least two ranges of the deceleration request (80), and furthermore the electric machine (30) is coupled (42) to a drive wheel (41) of the vehicle in a torque-transmitting manner such that the provided value (83) can be transmitted to the drive wheel (41) as a braking torque (90).

Description

Prior ArtThe invention is based on a brake system of a vehicle according to the preamble of the independent claim. The present invention also relates to a two-wheeler and a method for operating such a two-wheeler.A two-wheeler, such as in particular a motorcycle, usually has two hydraulic brake circuits which are designed independently of one another. In this case, a first brake circuit of the two hydraulic brake circuits is connected to a front wheel of the two-wheeler and a second brake circuit of the two hydraulic brake circuits is connected to a rear wheel of the two-wheeler. In such a second hydraulic brake circuit, a rider of the two-wheeler can now actuate, for example, a brake lever or a brake pedal which is operatively connected to a brake of the rear wheel, and a hydraulic brake pressure is built up which presses a brake pad against a friction surface which is connected to the rear wheel and thus exerts a braking torque on the rear wheel. Furthermore, a rider of the two-wheeler can now actuate a brake lever, which is operatively connected to a brake of the front wheel, for example, and a hydraulic brake pressure is built up, which presses a brake pad against a friction surface, which is connected to the front wheel and thus exerts a braking moment on the front wheel. The two processes described can be assisted by assistance systems, such as an anti-lock brake system, which can regulate the hydraulic brake pressure at the brake lining.Furthermore, there are two-wheelers in which an internal combustion engine is supported or even completely replaced by an electric motor arranged on the drive wheel. An electric motor can also be operated in a generator mode, i.e. it can absorb mechanical power, convert it into electrical energy and store it in a battery of the two-wheeler. This is generally known as recuperation mode and likewise brings about a braking torque which can be used to brake the two-wheeler.EP 1 855 219 B1 describes a system which, when a brake lever is actuated, requests a recuperation torque of the electric motor at the rear wheel in addition to the hydraulically effected braking torque at the front wheel and thus brakes the two-wheeler.Disclosure of the InventionA brake system of a vehicle having the features of the independent claim offers the advantage that an adaptation of a braking torque to a desired deceleration request of the vehicle is possible and that such a braking torque can be transmitted directly to a drive wheel via an electric machine.For this purpose, a brake system of a vehicle, in particular of a two-wheeler, is provided. The brake system comprises a detection device which is designed to detect a deceleration request of the vehicle in at least two regions.Furthermore, an electric machine is connected to a control unit of the brake system in such a way that a value of a braking torque can be provided to the electric machine by the control unit. The control unit is furthermore designed to provide the value of this type on the basis of the detected range of the at least two ranges of the deceleration request.In this case, the electric machine is coupled to a drive wheel of the vehicle in a torque-transmitting manner, and the value of the braking torque can be transmitted to the drive wheel by the electric machine as a braking torque.The measures listed in the dependent claims allow advantageous refinements and improvements of the device specified in the independent claim.It should be noted that the electric machine can be, for example, an electric motor which is designed to drive the vehicle and which can be operated as a generator. It should be noted here that a generator operation is characterized in that the electric machine can absorb power, convert it into electrical energy and store it in the battery of the vehicle. This process is also referred to as recuperation. Furthermore, however, embodiments are also conceivable in which the electric machine can only be operated in a generator mode.A deceleration request may be understood to mean an input of a driver to reduce an instantaneous speed of the vehicle during travel or to have a braking torque act on the drive wheel. The input of a driver can be, for example, an actuation of a lever, button or rotary handle. The detection device is designed to detect this input, wherein the input of the driver can vary, for example in an actuation force or an actuation path. The detection device is designed to detect, for example, at least two forces of different magnitude or two paths of different lengths.A torque-transmitting coupling is understood to mean a physical connection between the drive wheel and the electric machine, which is designed to transmit a torque between the drive wheel and the electric machine. This can be, for example, a chain, a belt or a common axis of rotation of the two above-mentioned components.It is expedient if the control unit or the detection device is designed to assign a first delay request to a first region of the at least two regions and to assign a second delay request to a second region of the at least two regions. In this case, the first deceleration request is smaller in terms of amount than the second deceleration request. Furthermore, the control unit is designed to assign a first value of a first braking torque to the first range and to assign a second value of a second braking torque to the second range. In this case, the first value is smaller in terms of amount than the second value.This offers the advantage overall that deceleration requests which differ from one another in their magnitude, i.e. which accordingly differ, can be assigned different braking torques. For example, the driver may make a deceleration request in a first braking operation at a first speed that is greater in magnitude than another deceleration request in a second braking operation at a second speed. By way of example, a driver will make a smaller deceleration request when there is a deceleration from 110 km / h to 100 km / h, which should take place within 5 seconds, than when there is a deceleration from 110 km / h to 0 km / h, which should likewise take place within 5 seconds.It is advantageous if a further wheel of the vehicle is operatively connected to a brake of the vehicle, wherein the brake is designed to decelerate the further wheel. In this case, the control unit is designed to provide a third value of a braking torque when a deceleration request is detected in a third range. This third value can be transmitted to the further wheel as a further braking torque by means of the brake. This has the advantage that a higher braking force can be transmitted by two wheels than by one wheel.By way of example, this can be done in that the control unit causes the brake to build up a hydraulic pressure, wherein the brake is in particular designed to form such a hydraulic pressure. In another embodiment, the hydraulic pressure could be provided by an anti-lock brake system. Embodiments are also conceivable in which the brake is operated electrically and is controlled electrically by the control unit. The deceleration of a vehicle is limited by a frictional force which can be transmitted to a substrate by means of tires. In this embodiment, a braking effect which is higher in total could be achieved by braking the further wheel of the vehicle than if only the drive wheel is braked by means of the electric machine, since now two wheels transmit the frictional force. This can be advantageous in particular also in the case of a dynamically changing driving situation if the transmittable frictional force changes, for example in the case of a change from straight-ahead driving to cornering.In particular, it would be advantageous if the control unit is designed in such a way that it provides the third value as the difference between a fifth value and a fourth value. The fourth value is selected as a certain value of the braking torque at the drive wheel. The control unit or the detection device is configured to assign a third deceleration request to the third range and the control unit is further configured to assign the fifth value of a fifth braking torque to the third range. This fifth value is greater in terms of amount than the fourth value.This allows the vehicle to be braked, for example, even if the driver incorrectly estimates the transmittable frictional force on the wheel which is driven by the electric machine and does not actively actuate the brake. In this case, a total deceleration is implemented by a braking torque at the rear wheel and a braking torque at the front wheel even if the driver makes the deceleration request only by the rear wheel detection unit. Further exemplary applications could be that the braking torques are distributed to both wheels in a manner adapted to the road surface if the braking force that can be transmitted to the road surface is reduced by its properties, such as wetness, smoothness or soiling.It can furthermore be expedient here if the fourth value of the braking torque at the drive wheel is selected as at least 60% of the maximum braking power of the electric machine, preferably selected as at least 80%, and in particular the maximum braking power of the electric machine is selected. In this configuration, the brake would transmit a braking torque even if the maximum transmittable braking torque by the electric machine is not yet transmitted. Thus, a safety margin would be available and the rear wheel could be braked further if the driver made a further deceleration request.It can be expedient if the brake is designed as a hydraulic, mechanical or electrical brake. The embodiment described above allows an embodiment of the brake which is independent of the embodiment by means of the electric machine. This can be economically advantageous, and a second brake independent of the first brake also offers greater traffic safety.Furthermore, the brake can be designed as a further electric machine which is designed to transmit a braking torque to the further wheel. This can be advantageous if a further electric machine is provided for the further wheel anyway. A control strategy for the electric machine according to claim 1 can be transmitted to the further electric machine and a hydraulic brake can be omitted. This simplifies the system and would also be advantageous from an economic point of view.It would be expedient if the detection device is designed as a pressure sensor, displacement sensor or angle sensor which is designed to detect a pressure, displacement or angle in at least two regions and the detection device comprises a lever, pedal or knob. This would allow a reasonable and ergonomically favorable embodiment depending on the vehicle type.It may further be advantageous if the control unit is connected to a further control unit in such a way that the deceleration request is provided by a control unit of the control unit. A further control unit could be, for example, a further assistance system, autopilot, distance system or traffic sign recognition with automatic speed regulation. This further control unit can then make deceleration requests independent of the driver and thus increase the traffic safety of the two-wheeler, or support the driver in driving situations which were incorrectly estimated by the latter.A practical embodiment would be to integrate the brake system into a two-wheeler, with a control unit which is integrated into a further system of the two-wheeler, such as an anti-lock brake system. This embodiment allows to utilize the functionality of the anti-lock brake system to build up brake pressure at the wheel that is not braked by the electric machine. Furthermore, the control logic of the anti-lock brake system can be used to divide the braking torques between the two wheels in a manner appropriate to the driving situation and thus to ensure reliable braking. A two-wheeler can be a motorcycle, for example.Brief Description of the DrawingsExemplary embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. FIG. 1 shows an embodiment of a vehicle according to the invention. FIG. 2 shows a description according to the invention of a functional sequence.FIG. 1 schematically shows a vehicle 10 embodied as a two-wheel 11 having a brake system 20, an electric machine 30, a rear wheel 40 and a front wheel 50. The electric machine 30 is connected to the rear wheel 40 in a torque-transmitting manner to the control device 23, for example via a chain 421, a belt 422 or directly to the axis of rotation of the engine. The rear wheel 40 is thus designed as a drive wheel 41. If the detection device 21 is actuated, this is detected as a deceleration request and forwarded from the control unit 23 to the electric machine 30 as a value of a braking torque. If the braking torque is not completely transmittable to rear wheel 40, this is detected by control unit 23 via connection 24, and a third value of a braking torque is provided by control unit 23. This value is transmitted via the connection 25 to a brake 70. The detection device can be, for example, a lever 211, a button 212 or a pedal 213.Further, FIG. 1 shows a front wheel 50 operatively connected to a brake 70 and a brake lever 71 connected to the brake 70 via a brake line 72. The brake 70 can be a hydraulic brake 701, wherein the brake line 72 is then a hydraulic line 721. Furthermore, it can also be a mechanical brake 702, wherein the brake line 72 is then a cable pull 722, or an electrical brake 703, wherein the brake line 72 is then an electrical connection 723. In the described embodiments, the brake 70 can be a friction brake, which means that a friction lining 730 is pressed against a friction surface 731, for example a brake disc 732 on the front wheel 50.Furthermore, in FIG. 1, a further control unit 60 is shown, which is connected to the first control unit 23. Furthermore, the control unit 23 is connected to the electric machine 30 independently of the detection device 21. The brake 70 is connected to the control unit 23 independently of the brake lever 17. Control unit 60 is designed to provide a deceleration request to control unit 23, which may be the case, for example, if control unit 60 is part of a distance control system 601 and / or a cruise control 602 and / or an autopilot 603.Alternatively, brake 70 may also be an electric machine, which is not shown in the figures. Brake lever 71 is then another sensing element having the same functionality as sensing element 21.FIG. 2 schematically illustrates a possible sequence of a method according to the invention.A deceleration request 80 or 801 detected by the detector 21 is provided to the control unit 23. A value of a braking torque 83 is provided to the electric machine 30 by the control unit 23. The electric machine 30 transmits this braking torque 90 to the rear wheel 40 A value of transmittable torque is provided to the control unit 23 by the electric machine 84. This value 84 indicates how great the braking torque is that can be transmitted by the electric machine to the rear wheel 40. If, for example, the value of a braking torque 83 is now greater than the value of the transmittable torque 84, this difference can be provided to the brake 70 as the value of a further braking torque 85. This value is then transmitted from the brake 70 as the braking torque 91 to the front wheel 50.Furthermore, the value of the braking torque 85 can also be provided by the control unit 23, for example in order to shorten a braking distance or to improve an overall braking action, should for example the road surface be designed such that the overall value of the braking torque 83 cannot be transmitted completely to the rear wheel 40 by the electric machine 30 for safety reasons. This can be the case in the case of wetness and / or smoothness and / or soiling, which ensure that only a reduced braking torque 90 can be transmitted to the rear wheel.Control unit 23 is thus designed to split a deceleration request 80 and / or 82 into a value of a braking torque 83 and / or 85.Furthermore, a deceleration request 82 can be transmittable to the control unit 23, which is provided by the control unit 60. This deceleration request 82 can also be divided by the control unit 23 into values of a braking torque 83 and / or 85.Furthermore, the deceleration requests 80 and 82 may also be added and divided into braking torque values 83 and / or 85 by the control unit 23.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 1 855 219 B1

[0004]

Claims

Brake system (20) of a vehicle (10), in particular of a two-wheeler (11), having a detection device (21) which is designed to detect a deceleration request (80) of the vehicle in at least two regions, and an electric machine (30) which is connected to a control unit (23) of the brake system (20) in such a way that a value of a braking torque (83) can be provided to the electric machine (30) by the control unit (23), wherein the control unit (23) is designed to provide the value on the basis of the detected region of the at least two regions of the deceleration request (80), and furthermore the electric machine (30) is coupled (42) in a torque-transmitting manner to a drive wheel (41) of the vehicle in such a way that the provided value (83) can be transmitted to the drive wheel (41) as a braking torque (90).Brake system according to Claim 1, characterized in that the control unit (23) or the detection device (21) is designed to assign a first deceleration request (80) to a first region of the at least two regions and to assign a second deceleration request (801) to a second region of the at least two regions, the first deceleration request (80) being smaller in terms of amount than the second deceleration request (801), and the control unit (23) is furthermore designed to assign a first value of a first braking torque (83) to the first region and to assign a second value of a second braking torque (831) to the second region, the first value being smaller in terms of amount than the second value.Brake system according to Claim 1 or 2, characterized in that a further wheel (51) of the vehicle is operatively connected to a brake (70) of the vehicle, wherein the brake (70) is designed to decelerate the further wheel, wherein the control unit (23) is designed to provide a third value of a braking torque (85) on detection of a deceleration request in a third region (802), and the provided third value (85) can be transmitted to the further wheel (51) by means of the brake as a further braking torque (91).Brake system according to Claim 3, wherein the control unit (23) is designed in such a way that it provides the third value (85) as a difference between a fifth value and a fourth value, wherein the fourth value is selected as a specific value of the braking torque (90) at the drive wheel (50), and wherein the control unit (23) or the detection device (21) is designed to assign a third deceleration request (802) to the third range, and the control unit (23) is furthermore designed to assign the fifth value of a fifth braking torque to the third range, wherein the fifth value is greater in terms of amount than the fourth value.Brake system according to the preceding claim 4, characterized in that the fourth value is selected as the specific value of the braking torque at the drive wheel (41) as at least 60% of the maximum braking power of the electric machine, preferably selected as at least 80%, and in particular the maximum braking power of the electric machine (30).Brake system according to Claims 3 to 5, wherein the brake (70) is designed as a hydraulic brake (701), mechanical brake (702) or electrical brake (703).Brake system according to Claims 3 to 5, according to which the brake (70) is designed as a further electric machine which is designed to transmit a braking torque to the further wheel.Brake system according to Claims 1 to 7, wherein the detection device (21) is designed as a pressure sensor, displacement sensor or angle sensor, wherein the pressure sensor is designed to detect a pressure in at least two regions, the displacement sensor to detect a displacement in at least two regions and the angle sensor to detect an angle in at least two regions.A braking system according to any one of claims 1 to 8, wherein the detecting means comprises a lever (211), a button (212) or a pedal (213).Brake system according to Claims 1 to 9, wherein the control unit (23) is connected to a further control unit (60) in such a way that a further deceleration request (82) can be provided by the further control unit (60) to the control unit (23).Method for operating a vehicle (10), in particular a two-wheeler (11), having a detection device (21) which detects a deceleration request (80) of the vehicle in at least two regions, and an electric machine (30) which is connected to a control unit (23) of the brake system (20) in such a way that the control unit (23) provides a value of a braking torque (83) to the electric machine (30), wherein the control unit (23) provides the value on the basis of the detected deceleration request (80), and furthermore, the electric machine (30) is coupled to a drive wheel (41) of the vehicle in such a way that the provided value (83) is transmitted to the drive wheel (41) as a braking torque (90).Two-wheeler (11) with a brake system according to one of the preceding claims 1 to 10.Two-wheeler according to claim 12, wherein the control unit (23) is integrated into an anti-lock braking system (231).

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