Electric brake system for vehicle

Abstract

The invention provides an electric brake system (100) for a vehicle (200), which comprises a brake value encoder (210), at least one first axle (220) with at least two wheels (221, 222), and a second axle (230) with at least two wheels (231, 232). A first axle modulator (120) is assigned to the first axle (220). A second axle modulator (130) is assigned to the second axle (230). In addition, a single central control unit (110) is provided, which generates and outputs a first brake signal (111) for the first axle modulator (120) and a second brake signal (112) for the second axle modulator (130) depending on a brake signal (211) from the brake value encoder (210) or depending on another brake request (400). The first and second axle modulators (120, 130) are respectively configured to decelerate the wheels (221, 222, 231, 232) of the first and second axles (220, 230) in dependence on first and second brake signals (111, 112) from a central control unit (110).

Description

Technical Field

[0001] The invention relates to an electric brake system for a vehicle and a method for controlling a brake system of a vehicle. Background Art

[0002] Braking systems for vehicles are well known. DE 10 2004 099 469 A1 describes an electronically controlled electromechanical brake control system for a commercial vehicle. The vehicle has a front axle with two wheels, a rear axle with two wheels and a service brake for braking the wheels. Each of the four wheels is equipped with a brake assembly for braking operation. The brake assembly can be electrically controlled. In addition, a first central control device is provided for controlling the brake unit. In addition, a second central control device is provided as a redundant control device for the first control device. Each axle is equipped with an axle modulator, which, depending on the axle braking command from the central control unit, determines the wheel braking command for each wheel on the axle equipped with the axle modulator. The braking command is dynamically adjusted in the central control unit for vehicle stabilization.

[0003] To improve vehicle braking systems, a braking system having reduced complexity is desired. Summary of the invention

[0004] It is therefore an object of the present invention to provide an electric brake system for a vehicle having reduced complexity. In particular, it is an object of the present invention to provide an electric brake system for a vehicle having reduced costs.

[0005] This object is achieved by an electric vehicle brake system according to an electric brake system for a vehicle and by a method for controlling an electric vehicle brake system for a vehicle according to the invention as follows.

[0006] The electric brake system for a vehicle according to the present invention is provided with a brake value encoder, at least one first axle with at least two wheels, and a second axle with at least two wheels, and the electric brake system has:

[0007] a first axle modulator assigned to the first axle and at least one second axle modulator assigned to the second axle,

[0008] a single central control unit which is designed to generate and output a first brake signal for the first axle modulator and a second brake signal for the second axle modulator as a function of the brake signal from the brake value encoder,

[0009] wherein the first and second axle modulators are respectively configured to decelerate the wheels of the first and second axles via brake modulator signals in dependence on the first and second brake signals from the central control unit,

[0010] in,

[0011] The axle modulator receives a brake signal from the brake value encoder as an input signal in addition to the first or second brake signal from the central control unit, and the axle modulator is respectively constructed to use the brake signal from the brake value encoder as an input signal to generate the brake modulator signal when a fault occurs in the central control unit or on the central control unit.

[0012] The method according to the invention for controlling an electric brake system for a vehicle according to the invention has the following steps:

[0013] generating a first brake signal for a first axle modulator and a second brake signal for a second axle modulator by a single central control unit as a function of a brake signal from a brake value encoder, wherein the brake signal from the brake value encoder is used as an input signal in or on the central control unit in the event of a fault, and

[0014] The wheels of the first and second axles are decelerated in dependence on the first and second brake signals from the central control unit or in dependence on the brake signal of the brake value encoder.

[0015] Therefore, an electric brake system for a vehicle is provided, which has a brake value encoder, at least one first axle with at least two wheels, and a second axle with at least two wheels. A first axle modulator is assigned to the first axle. A second axle modulator is assigned to the second axle. In addition, a single central control unit is provided, which generates and outputs a first brake signal for the first axle modulator and a second brake signal for the second axle modulator as a function of a brake signal from the brake value encoder or as a function of another brake request transmitted to the central control unit via a data connection (e.g. from a driver assistance system). The first axle modulator and the second axle modulator are each designed to decelerate the wheels of the first axle and the second axle as a function of the first brake signal and the second brake signal from the central control unit.

[0016] Thus, an electric vehicle brake system or a brake system for a vehicle is provided which has only one central control unit (central module). Each axle of the vehicle is equipped with an axle modulator which receives a brake signal from the central control unit and initiates a corresponding deceleration at the wheels of the respective axle. The axle modulator has at least one brake modulator for each of the wheels connected to the axle. The brake modulator acts on the brake actuator so that the wheel is braked.

[0017] The central control unit receives a brake signal from a brake value encoder or from a vehicle system authorized for this purpose. The central control unit converts the received brake signal into a brake signal for the first and second axle modulators in order to be able to decelerate or brake the vehicle. The axle modulators receive the respective brake signals from the central control unit and convert the brake signals into signals for the brake actuators via the brake modulators.

[0018] According to a preferred embodiment, each axle modulator has an axle control unit and at least two brake modulators, which each generate a brake modulator signal for controlling a brake actuator and output the brake modulator signal to the brake actuators arranged directly on the respective wheels.

[0019] According to a preferred embodiment, the axle modulator receives as input a brake signal from a brake value encoder in addition to the first or second brake signal from the central control unit. In the event of a fault in or on the central control unit, the axle modulator uses the brake signal from the brake value encoder as input signal to generate the brake modulator signal.

[0020] Therefore, the brake signal of the brake value encoder is output not only to the central control unit but also to each axle modulator. By having the axle modulator receive the brake signal from the brake value encoder, the axle modulator achieves redundant braking even when a failure occurs in the central control unit or in the line between the central control unit and the respective axle modulator. In this way, the safety of the brake system according to the present invention can be guaranteed even when the complexity of the brake system is reduced and the costs associated therewith are reduced.

[0021] According to a further preferred embodiment, at least one axle modulator signal line is provided between at least two axle modulators. The axle modulator signal line is used for communication between the axle modulators, in particular in the event of a fault in or on the central control unit. This allows axle braking forces to be compensated, which can improve vehicle stability and braking performance even in the event of a fault in the central control unit.

[0022] The invention also relates to a vehicle, in particular a commercial vehicle, having a brake value encoder, at least one first axle with at least two wheels, a second axle with at least two wheels, and at least one electric brake system as described above.

[0023] According to one embodiment, the mass of the vehicle is substantially evenly distributed on the first and second axles. As its alternative, the mass of the vehicle also can be unevenly distributed on the axles.

[0024] The invention also relates to a method for controlling an electric brake system of a vehicle, the vehicle having a brake value encoder, at least one first axle with at least two wheels and a second axle with at least two wheels. A first axle modulator is assigned to the first axle and at least one second axle modulator is assigned to the second axle. A first brake signal for the first axle modulator and a second brake signal for the second axle modulator are generated by a single central control unit in dependence on a brake signal from the brake value encoder. The central control unit brakes the wheels of the first and second axles in dependence on the first and second brake signals.

[0025] In the prior art, two control units are provided in the form of central modules of the braking system: a central control unit and a redundant central control unit, while the braking system according to the invention uses only a single central control unit. The central control unit works as a central module of the braking system and is used to control and monitor the electrically controlled braking system. The target deceleration of the vehicle is known from the signal of the brake value encoder. For example, the target deceleration can be used as an input signal for the electronic control together with the respective wheel speeds of the vehicle wheels. In the case of an electronically controlled pneumatic braking system, the control knows the pressure setpoints of the braking system on the front and rear axles. For electric braking systems, the control knows the electrical setpoints for driving the electric brake actuators. The setpoints are compared with the actual values, and any differences can be corrected. The central control unit is connected to the axle modules and exchanges data, and in particular exchanges the respective brake signals for the respective axle modulators.

[0026] According to one aspect of the invention, an axle modulator is provided for each axle. The axle modulator forms an axle control unit. The axle modulator can optionally have a pneumatic pressure control channel.

[0027] The axle modulator may have additional connections for a redundant pneumatic brake circuit.

[0028] The axle modulator can have a control unit or a control module which enables an anti-lock braking system ABS control of the wheels connected to the axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Advantages and embodiments of the present invention are explained in detail below with reference to the accompanying drawings.

[0030] Figure 1 shows a schematic diagram of a brake system according to a first embodiment, and

[0031] Figure 2 A schematic illustration of a brake system according to a second exemplary embodiment is shown. DETAILED DESCRIPTION

[0032] Figure 1A schematic diagram of a braking system according to a first embodiment is shown. A vehicle 200 (particularly a commercial vehicle) has a braking system 100. The vehicle 200 has a brake value encoder 210 and at least two axles 220, 230, each of which has at least two wheels 221, 222, 231, 232. Wheels 221, 222, 231, 232 can be drive wheels or non-drive wheels. The braking system 100 according to the first embodiment is designed as an electronically controlled braking system EBS for a vehicle, particularly a commercial vehicle. This commercial vehicle or vehicle preferably has similar mass distribution M1, M2 on the front axle and the rear axle. The mass M of the vehicle is therefore not substantially unevenly distributed. Such a commercial vehicle 200 can be a touring bus or a truck with a loading area or a box structure.

[0033] According to one aspect of the invention, however, the central control unit can also take into account an uneven axle load distribution. However, a failure of the central control unit means that a dynamic axle load-dependent braking force distribution can no longer be ensured. However, in the case of vehicles with a typical uniform axle load distribution, a failure of the dynamic axle load-dependent braking force distribution 470 can be tolerated. For other vehicles with an uneven load distribution, an axle modulator signal line 115 may be required, by which the braking force distribution can be ensured.

[0034] The brake system 100 has a (single) central control unit 110. The central control unit 110 corresponds, for example, to a central module in an electronic brake system EBS. The brake system 100 has a first and a second axle modulator 120, 130. The axle modulators 120, 130, 140 are preferably provided for each axle 220, 230, 240 of the vehicle 200. The central control unit 110 obtains a brake signal 211 from a brake value encoder 210 of the vehicle 200. Optionally, the brake signal 211 is also directly supplied to at least one of the first and second axle modulators 120, 130. In a preferred embodiment, the brake signal is provided by the brake value encoder via a plurality of signal lines, wherein each signal line is connected to an axle modulator respectively. In addition, all signal lines are also connected together to the central control unit.

[0035] The axle modulators 120 , 130 each have an axle control unit 121 , 131 and a brake modulator 122 , 132 for each wheel situated on the axle.

[0036] The first axle modulator 120 receives a first brake signal 111 from the central control unit 110 via a line 110 a , while the second axle modulator 130 receives a second brake signal 112 from the central control unit 110 via a line 110 b .

[0037] In or on each wheel 221 , 222 , 231 , 232 of the vehicle is provided a brake actuator 123a , 123b , 133a , 133b which is controlled by a respective brake modulator 122 , 132 .

[0038] For an electronically controlled brake system EBS, the central control unit 110 detects the deceleration based on a brake signal 211 from a brake value encoder 210 and based on a vehicle stability program and / or a driver assistance system. The vehicle stability program and / or the driver assistance system can be implemented in the central control unit 110 or can be connected to the central control unit 110. The central control unit 110 then generates a brake signal 111, 112 for each axle modulator 120, 130. The axle modulators 120, 130 convert this brake information into signals for the individual brake actuators 123a, 123b, 133a, 133b via brake modulators 122, 132.

[0039] The axle modulators 120, 130 optionally receive not only the first and second brake signals 111, 112 from the central control unit 110, but also the brake signal 211 directly from the brake value encoder 210. This provides safety redundancy, especially for the case where the central control unit or the signal lines 110a, 110b are disturbed. If this happens, the axle modulators 120, 130 can drive the respective brake actuators 123a, 123b, 133a, 133b based on the brake signal 211 directly received from the brake value encoder 210 through the brake modulators 122, 132 to achieve the braking of the vehicle.

[0040] Brake actuators can be driven or operated hydraulically, pneumatically or electrically.

[0041] If, in the event of a fault, central control unit 110 and / or signal lines 110 a , 110 b are faulty, the axle modulator can initiate a deceleration of the vehicle based on brake signal 211 and optionally by taking into account braking force distribution parameters.

[0042] In the event of a fault (defect in the central control unit 110 or the signal lines 110a, 110b), the axle modulator can lead to a deceleration of the vehicle even without the central control unit 110. However, this also means that the vehicle stability program 410 and / or the driver assistance system 420 implemented by the central control unit 110 or taken into account cannot be taken into account.

[0043] Each axle modulator 120, 130 is assigned to an axle 220, 230 of the vehicle 200. The axle modulators 120, 130 are preferably arranged in, on or near the respective axle 220, 230. Each axle modulator 120, 130 has an axle control unit 121, 131, two brake modulators 122, 132 and an electromechanical brake actuator 123a, 123b, 133a, 133b. The brake modulator optionally has an electrical or electronic switching unit for controlling the electromechanical brake actuator and transmitting power to the electromechanical brake actuator.

[0044] According to one aspect of the invention, the third signal line 115 is optionally provided between the first axle modulator 120 and the second axle modulator 130. In the event of a fault 430 (failure of the central control unit 110), the axle modulators 120, 130 can thus communicate with one another in order to be able to achieve the desired deceleration of the vehicle. In this case, not only can the braking force distribution parameters be taken into account, but the braking force distribution 470 can also be carried out in a situation-dependent manner, with the goal of the best possible vehicle deceleration and the best possible driving stability. This is particularly advantageous in vehicles with an uneven mass distribution M1, M2. In the event of such a fault 430, the driving assistance system 410 and the vehicle stability system 420 cannot be taken into account, because these are only processed or taken into account by the central control unit 110.

[0045] The brake modulators 122 , 132 output brake modulation signals 122 a , 132 a to the brake actuators 123 a , 123 b , 133 a , 133 b , which cause the brake actuators 123 , 133 to perform desired deceleration or desired braking.

[0046] According to one aspect of the invention, the brake actuators 123a, 123b, 133a, 133b can be electrically controlled. This is advantageous because no further or additional intelligence needs to be present in the brake actuator or brake modulator. This is particularly advantageous in terms of the reliability of the brake modulator and the brake actuator. In particular, they have a lower susceptibility to vibrations and weather influences and temperature influences.

[0047] According to one aspect of the invention, each axle modulator 120, 130 optionally has all the electronics required to determine the respective brake signal and actuate the brake actuator. Because the axle modulators 120, 130 are located in, on, or near the axles 220, 230, the axle modulators 120, 130 are less susceptible to weather effects than electronics integrated in or on the wheels.

[0048] The brake system 100 also has an energy supply unit 150. This energy supply can be connected to the energy supply of the vehicle and has a predetermined storage capacity so that in the event of a fault, the brake system can still be supplied with energy. In particular, the energy supply unit 150 can have a plurality of rechargeable batteries 151.

[0049] Axle modulators 120 , 130 and in particular axle control units 121 , 131 are optionally suitable for carrying out an anti-lock braking system ABS control independently of central control unit 110 .

[0050] The brake system 100 can optionally have a redundant brake unit 300 (e.g. a pneumatic brake circuit) which operates independently of the central control unit 110 and, for example, enables at least emergency braking in the event of a fault in or on the central control unit 110. For this purpose, the brake unit 300 can be connected to the axle modulator 120, 130, 140 via lines 301, 302, 303. The axle modulator can therefore have an additional connection for the redundant pneumatic brake circuit. As an alternative to the connection, the brake unit 300 can also be directly connected to the brake modulator or brake actuator.

[0051] Figure 2 A schematic illustration of a braking system according to a second embodiment is shown. The braking system according to the second embodiment corresponds essentially to the braking system according to the first embodiment, wherein the vehicle has three axles 220, 230, 240. The braking system according to the second embodiment therefore has three axle modulators 120, 130, 140. The structure of the respective axle modulators according to the second embodiment corresponds to the structure of the axle modulators according to the first embodiment. Each axle modulator therefore receives a braking signal 111, 112, 113 from a central control unit 110 and a braking signal 211 of a brake value encoder 210. Optionally, a signal line 115 can extend between adjacent axle modulators 120, 130, 140, so that the axle modulators can communicate with each other via the third signal line 115, in particular in the event of a fault.

[0052] Reference numerals list

[0053] 100 Braking system

[0054] 110 Central Control Unit

[0055] 111 First brake signal

[0056] 112 Second brake signal

[0057] 110a First signal line

[0058] 110b Second signal line

[0059] 110c Third signal line

[0060] 115 Axle modulator signal line

[0061] 120 First Axle Modulator

[0062] 121 Axle control unit

[0063] 122 Brake modulator

[0064] 122a Brake modulator signal

[0065] 123a Brake actuator

[0066] 123b Brake Actuator

[0067] 130 Second axle modulator

[0068] 131 Axle control unit

[0069] 132 Brake modulator

[0070] 132a Brake modulator signal

[0071] 133a Brake actuator

[0072] 133b Brake actuator

[0073] 140 Third axle modulator

[0074] 141 Axle control unit

[0075] 142 Brake modulator

[0076] 142a Brake modulator signal

[0077] 143a Brake actuator

[0078] 143b Brake actuator

[0079] 150 Energy Supply Unit

[0080] 151 Rechargeable batteries

[0081] 200 vehicles

[0082] 210 Braking value encoder

[0083] 211 Brake signal

[0084] 220 First Axle

[0085] 221 Wheel

[0086] 222 Wheel

[0087] 230 Second Axle

[0088] 231 Wheel

[0089] 232 Wheel

[0090] 240 Third Axle

[0091] 241 Wheel

[0092] 242 Wheel

[0093] 300 Braking unit

[0094] 400 Additional brake request

[0095] 410 Driving stability program

[0096] 420 Driving assistance program

[0097] 430 Failure

[0098] 440 Braking force distribution

[0099] 450 Emergency Braking Request

[0100] 460 Braking force distribution parameters

[0101] 470 Braking force distribution

[0102] M Mass

[0103] M1, M2 mass distribution

[0104] ABS Anti-lock Braking System

Claims

1. An electric brake system (100) for a vehicle (200), the electric brake system comprising a brake value encoder (210), at least one first axle (220) with at least two wheels (221, 222) and a second axle (230) with at least two wheels (231, 232), the electric brake system (100) comprising: a first axle modulator (120) assigned to the first axle (220) and at least one second axle modulator (130) assigned to the second axle (230), a single central control unit (110) which is configured to generate and output a first braking signal (111) for the first axle modulator (120) and a second braking signal (112) for the second axle modulator (130) in dependence on a braking signal (211) from the braking value encoder (210), in, The first and second axle modulators (120, 130) are respectively configured to decelerate the wheels (221, 222; 231, 232) of the first and second axles (220, 230) via brake modulator signals (122a, 132a, 142a) in dependence on the first and second brake signals (111, 112) from the central control unit (110), It is characterized in that The axle modulators (120, 130, 140) receive a brake signal (211) from the brake value encoder (210) as an input signal in addition to the first or second brake signal (111, 112, 113) from the central control unit (110), and are each configured to use the brake signal (211) from the brake value encoder (210) as an input signal to generate the brake modulator signal (122a, 132a, 142a) when a fault (430) occurs in or on the central control unit (110).

2. The electric brake system (100) for a vehicle (200) according to claim 1, wherein: Each axle modulator (120, 130, 140) has an axle control unit (121, 131, 141) and at least two brake modulators (122, 132, 142), The brake modulators (122, 132, 142) respectively generate brake modulator signals (122a, 132a, 142a) for controlling brake actuators (123, 133, 143) and output the brake modulator signals to the brake actuators (123, 133, 143).

3. The electric brake system (100) for a vehicle (200) according to claim 1 or 2, further comprising: at least one axle modulator signal line (115) between at least two axle modulators (120, 130, 140), in, The at least one axle modulator signal line (115) is used for communication between axle modulators (120, 130, 140).

4. The electric brake system (100) for a vehicle (200) according to claim 3, wherein: The at least one axle modulator signal line (115) is used for communication between axle modulators (120, 130, 140) in the event of a fault (430) in or on the central control unit (110).

5. The electric brake system (100) for a vehicle (200) according to claim 1 or 2, wherein: The central control unit (110) is designed to simultaneously take into account a further braking request in the form of a vehicle stabilization program (410) and / or a driver assistance program (420) when generating the first and second brake signals (111, 112).

6. The electric brake system (100) for a vehicle (200) according to claim 1 or 2, wherein: The axle modulators (120, 130, 140) are each configured to perform an anti-lock brake control (ABS).

7. The electric brake system (100) for a vehicle (200) according to claim 1 or 2, wherein: The central control unit is designed to generate and output the first brake signal (111) and the second brake signal (112) also as a function of a further brake request (400) in the form of an emergency brake request (450).

8. The electric brake system (100) for a vehicle (200) according to claim 1 or 2, wherein: The central control unit (110) is integrated into one of the axle modulators (120, 130, 140).

9. A vehicle (200), comprising: Braking value encoder (210), at least one first axle (220) with at least two wheels (221, 222), a second axle (230) with at least two wheels (231, 232), and At least one electric brake system (100) according to any one of claims 1 to 8.

10. The vehicle (200) according to claim 9, wherein: The vehicle (200) is a commercial vehicle.

11. The vehicle (200) according to claim 9 or 10, wherein: The mass distribution (M1, M2) of the mass (M) of the vehicle (200) to the first and second axles (120, 130) is substantially uniform.

12. The vehicle (200) according to claim 9 or 10, wherein: The braking force distribution (470) can be set via a braking force distribution parameter (460) and as a function of an uneven mass distribution (M1, M2) of the mass (M) of the vehicle (200) to the first and second axles (120, 130), or the braking force distribution (470) can be set between at least the first and second axle modulators (120, 130, 140) as appropriate via an axle modulation signal line (115).

13. A method for controlling an electric brake system (100) for a vehicle (200) according to any one of claims 1 to 8, the method comprising the following steps: A first braking signal (111) for a first axle modulator (120) and a second braking signal (112) for a second axle modulator (130) are generated by a single central control unit (110) as a function of a braking signal (211) from a braking value encoder (210), wherein: using a brake signal (211) from the brake value encoder (210) as an input signal when a fault (430) occurs in or on the central control unit (110), and The wheels (221, 222; 231, 232) of the first and second axles (220, 230) are decelerated depending on the first and second brake signals (111, 112) from the central control unit (110) or depending on the brake signal (211) of the brake value encoder (210).

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