Method for controlling hydraulic volume and system for controlling hydraulic volume - Patents.com

Abstract

The present invention relates to a method for controlling hydraulic volume in a system (1) comprising a non-human brake (10) and a vehicle dynamics control (14), wherein the non-human brake (10) is hydraulically coupled to the vehicle dynamics control (14). The method, in this case, includes generating (A) a control signal by a vehicle dynamics control (14) to provide a hydraulic volume for the vehicle dynamics control (14), and providing the control signal for the non-powered brake (10). The method further includes implementing (D) the vehicle dynamics control, and guiding (E) the hydraulic volume from the vehicle dynamics control (14) back to a reservoir (50) after termination of the vehicle dynamics control via a pre-opened circuit cut-off valve (38, 42) connectable to the reservoir (50). Additionally, the method includes the step of closing (G) the circuit cut-off valves (38, 42) and controlling (H) the brake pressure in the vehicle dynamics control (14) by a non-human-operated piston (54) disposed in a non-human-operated cylinder (52) for cases in which an active braking maneuver is introduced before or during the return guide (E) of the hydraulic volume.

Description

[Technical Field]

[0001] The present invention relates to a method for controlling hydraulic volume in a system of non-human brakes and vehicle dynamics control, and more particularly to a system for controlling hydraulic volume. [Background technology]

[0002] In addition to stabilizing functions, for example in the form of conventional ESP / ABS functions, modern vehicle braking systems increasingly also include extended functions, such as driver assistance or the application of force to the brake pedal during braking by means of an eBKV (electromechanical brake force booster), or assist or partial assist functions by means of units that actively adjust the hydraulic brake pressure without active driver involvement (e.g. ESP, eBKV, boost units, etc.).

[0003] Driver assistance systems, at various stages of development, are becoming increasingly common in today's automobiles. They may be partially automated or automated, intervening in the vehicle's drive, controls (e.g., steering), or signaling devices, or they may warn the driver of impending or ongoing dangerous situations via a suitable human-machine interface. Typically, a braking system comprises an electronic brake force booster (eBKV) and an ESP system. In this combination, most of the braking system functions can be realized by the ESP system, and the brake force booster is used as an external regulator to create dynamic pressure.

[0004] In this case, the brake system can operate with a closed hydraulic system, i.e., the reservoir containing the hydraulic fluid of the brake system is used only for leakage compensation and temperature compensation, and thus the available hydraulic volume is constant. Examples for this are conventional brake systems, such as vacuum brake force boosters, electromechanical brake force boosters, such as iBooster, or Decoupled Power Brakes (DPB) combined with ESP systems. Alternatively, the brake system can operate with an open hydraulic system (e.g., an IPB system (IPB: Integrated Power Brake)). In this case, the reservoir containing the hydraulic fluid can be used to store hydraulic volume during normal driving. As a result, the available hydraulic volume of the brake system can change during braking. Each brake system has different drawbacks, for example, systems with a closed hydraulic circuit have the problem that, depending on the operation, the intake of the ESP system contains a larger hydraulic volume in the relevant area of ​​the brake system, i.e., from the main brake cylinder down to the brake cylinders on the wheels, than should be present during normal operation. Summary of the Invention

[0005] The problem underlying the present invention is to provide a method for controlling hydraulic volumes in a system consisting of non-powered brakes and vehicle dynamics control, in which no pressure remains in the brake system when the brakes are released, despite the non-powered cylinders having no compensation connections.

[0006] The above problem is solved by a method for controlling a hydraulic volume, which comprises the features of claim 1. Furthermore, the invention proposes a system with the features of claim 9. The respective dependent claims show advantageous developments of the invention.

[0007] The present invention provides a method for controlling a hydraulic volume in a system consisting of a non-powered brake and a vehicle dynamics control, the non-powered brake being hydraulically connected to the vehicle dynamics control, the method comprising the steps of generating a control signal by the vehicle dynamics control to provide a hydraulic volume for the vehicle dynamics control, providing the control signal for the non-powered brake, and implementing the control of the vehicle dynamics. A further step includes directing the hydraulic volume from the vehicle dynamics control back to a reservoir after termination of the control of the vehicle dynamics via a previously opened circuit cut-off valve connectable to the reservoir.

[0008] For cases where an active braking maneuver is introduced before or during return guidance of the hydraulic volume, the circuit cut-off valve is closed and the brake pressure in the vehicle dynamics control is controlled by a non-human-powered piston located in a non-human-powered cylinder.

[0009] After the circuit cutoff valve is closed, hydraulic volume cannot be extracted due to the absence of a compensation connection at the non-manual cylinder. Unlike the prior art, the non-manual cylinder does not introduce additional hydraulic volume, and brake pressure in the vehicle dynamics control is controlled via the non-manual piston. The non-manual piston is advanced or retracted for control, so that hydraulic volume can be introduced or withdrawn accordingly in the vehicle dynamics control. To release the brakes, the hydraulic volume in the vehicle dynamics control is correspondingly reduced by retracting the non-manual piston. This allows the brakes to be released even without a compensation connection at the non-manual cylinder and with the circuit cutoff valve closed. Accordingly, no piping between the compensation connection and the reservoir is required, thereby saving material and therefore costs. Additionally, the construction space for such a system can be reduced.

[0010] In a preferred embodiment of the present invention, the circuit cut-off valves are opened after the vehicle dynamics control has ended. The circuit cut-off valves are thus opened only after the vehicle dynamics control has ended and if no active braking maneuver is implemented, thereby allowing the hydraulic volume to be guided back into the reservoir. During the vehicle dynamics control, the circuit cut-off valves are thus closed. If an active braking maneuver must be implemented during the vehicle dynamics control, the valves do not have to be closed first, thereby reducing the braking time. Additionally, since a failure of the valves to close in the event of an error can be detected even before the active braking maneuver is implemented, an early reaction to this error can be achieved. This additionally improves safety.

[0011] In another preferred embodiment of the invention, the circuit cut-off valve is opened before the vehicle dynamics control is performed, so that the circuit cut-off valve is already opened during the vehicle dynamics control, allowing the hydraulic volume to be quickly discharged into the reservoir after the vehicle dynamics control has been performed.

[0012] Preferably, the non-human piston is moved forward by a desired stroke amount before the vehicle dynamics control is implemented. This allows the vehicle dynamics control to be supplied with additional hydraulic volume from the non-human cylinder. This allows the vehicle dynamics control to be provided with the required hydraulic volume quickly. Additionally, it is ensured that sufficient hydraulic volume can be absorbed from the vehicle dynamics control back into the non-human cylinder, so that pressure can be released there, possibly to release the brakes.

[0013] In one advantageous development, the non-manufactured piston is moved rearward by a desired stroke amount after the hydraulic volume has been returned, preferably to a rearward end position. By moving the piston rearward, the hydraulic braking volume in the non-manufactured cylinder is enlarged. After carrying out this method, a sufficient braking volume is provided, which allows reliable active braking.

[0014] Advantageously, the hydraulic volume is controlled by a non-powered cylinder without a compensation connection, characterized in that the non-powered cylinder does not have a compensation connection connecting the vehicle dynamics control to a reservoir for returning the hydraulic volume even when the circuit cut-off valve is closed.

[0015] In another advantageous embodiment, the vehicle dynamics control transmits information about the required hydraulic volume together with the control signal. Preferably, the stroke of the non-manual piston to its forward position is set according to the required hydraulic volume. This information allows for better control of the pressure in the vehicle dynamics control. The non-manual piston can be controlled accordingly to ensure that this volume can be absorbed again by the non-manual cylinder after active braking. This allows the brakes to be released again.

[0016] The problem underlying the present invention is additionally solved by a system for controlling a hydraulic volume in a system consisting of a non-human brake and a vehicle dynamics control. The system in this case comprises a non-human brake, a vehicle dynamics control hydraulically connected to the non-human brake, and a control device for controlling the vehicle dynamics control, the non-human brake being connected to the vehicle dynamics control by a signal, and the system is configured to perform the method according to the present invention. Such a system substantially has the advantages listed above relative to the method.

[0017] According to another expedient embodiment, the non-powered brake has a non-powered cylinder without a compensating connection, which achieves the aforementioned advantages.

[0018] An embodiment of the invention is illustrated in the drawings and explained in more detail in the following description. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 illustrates a system of non-powered brakes and vehicle dynamics control during vehicle dynamics control. [Figure 2] FIG. 1 illustrates an embodiment of a method for controlling hydraulic volume in a system of non-powered brakes and vehicle dynamics control. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1 shows a system 1 consisting of a non-operated brake 10 and a vehicle dynamics control 14 during vehicle dynamics control. The system 1 is configured so that the non-operated brake 10 is hydraulically connected to the vehicle dynamics control 14 by first and second connecting valves 18 and 22 of the non-operated brake and first and second connecting valves 26 and 30 of the vehicle dynamics control, thus forming a hydraulic connection. In this case, both the non-operated brake 10 and the vehicle dynamics control 14 are designed in two systems.

[0021] The main cylinder 34 can be manually operated by a pedal mechanically coupled to the main cylinder 34, which hydraulically operates the brake cylinders 46a, 46b, 46c and 46d by means of a first or second circuit cut-off valve 38 or 42, respectively, in a respective assigned circuit of the vehicle dynamics control 14, thereby achieving emergency braking. In this case, the main brake cylinder 34 is hydraulically connected to a reservoir 50 for hydraulic fluid.

[0022] During normal operation, braking action in brake cylinders 46a, 46b, 46c, and 46d may be caused by a non-human powered cylinder 52 whose non-human powered piston 54 displaces hydraulic volume into two circuits of vehicle dynamics control 14 via non-human powered brake connection valves 18, 22. Non-human powered cylinder 52 may be hydraulically connected to hydraulic reservoir 50 via a non-human powered cylinder valve 58. Non-human powered cylinder 52 may be connected to an electric motor, which allows non-human powered piston 54 to release and absorb hydraulic volume. The electric motor may be controlled by a controller connected to a sensor system 62 that measures electric motor position. Pressure in main cylinder 34 may be measured by a pressure sensor 66.

[0023] The dual-circuit main cylinder 34 can be hydraulically connected to a brake simulator 74 via a brake simulator valve 70, thereby simulating hydraulic pressure buildup for a driver operating the brake pedal. In this case, hydraulic volume is then provided to the vehicle dynamics control 14 by the non-human-operated piston 54 during normal driving, thereby achieving braking action in the brake cylinders 46a, 46b, 46c, 46d, which are hydraulically connected to the vehicle dynamics control 14. The mechanical position of the brake pedal can be measured by a pedal stroke pickup 78, which is mechanically connected to the brake pedal, thereby controlling the non-human-operated piston 54.

[0024] The pressure generated by the non-powered piston 54 is measured by a non-powered piston pressure sensor 82. First and second check valves 86, 90 allow hydraulic fluid to be replenished from the reservoir 50 to the hydraulic system comprising the non-powered brake 10 and the vehicle dynamics control 14. The vehicle dynamics control 14 is constructed in a known manner and will not be described in detail here.

[0025] FIG. 2 illustrates one embodiment of a method for controlling hydraulic volume in the system 1 shown in FIG. 1. In a first step A of the method, a control signal is generated in a controller of the vehicle dynamics control 14. This control signal is provided to the non-powered brake 10, which in turn provides hydraulic volume to the vehicle dynamics control 14. In a second step B, the previously closed circuit cutoff valves 38, 42 are opened, which allows the vehicle dynamics control 14 to draw additional hydraulic fluid from the reservoir 50 via the check valves 86, 90. In a next step C, the non-powered piston 54 is moved forward toward the outlet leading to the vehicle dynamics control 14, which allows the non-powered cylinder 52 to provide additional hydraulic fluid to the vehicle dynamics control 14.

[0026] In the following step D, vehicle dynamics control is carried out in a known manner. After vehicle dynamics control, in the next step E, hydraulic volume is discharged from the vehicle dynamics control 14 via the opened circuit cut-off valves 38, 42 through the main cylinder 34 into the reservoir 50. With the start of this return flow, it is monitored whether an active braking maneuver is initiated via the pedal. If this is not the case, after the return flow of hydraulic volume, in the following step F, the non-operated piston 54 is again moved backward, so that sufficient hydraulic fluid is provided in the hydraulic cylinder 34 for an active braking maneuver. This causes brake fluid to be transferred into the non-operated cylinder 52 via the non-operated cylinder valve 58 or via the hydraulic path of the main cylinder 34, the circuit cut-off valves 38, 42 and the non-operated brake connecting valves 18, 22.

[0027] Active braking maneuver B before or during the hydraulic volume return step E SIf an active braking maneuver is to be initiated, then in a next step G, the circuit cut-off valves 38, 42 are closed. This is followed in a next step H by control of the brake pressure in the vehicle dynamics control by the non-human-powered piston 54. After the end of the active braking maneuver, the non-human-powered piston 54 is moved rearward, so that the hydraulic volume of the vehicle dynamics control 14 is absorbed in the non-human-powered cylinder 52. This makes it possible to release the brake cylinders 46a, 46b, 46c, 46d after the end of the active braking maneuver without brake pressure remaining in the vehicle dynamics control 14. [Explanation of symbols]

[0028] 1 System 10 Non-human brakes 14 Vehicle Dynamics Control 18 Non-powered brake coupling valve 22 Non-human brake coupling valve 26 Vehicle Dynamics Control Linkage Valve 30 Vehicle Dynamics Control Linkage Valve 34 Main cylinder 38 Circuit cutoff valve 42 Circuit cutoff valve 46a, 46b, 46c, 46d Brake cylinders 50 reservoir 52 Non-human-powered cylinder 54 Non-human Piston 58 Non-operated cylinder valve 62 Sensor system for measuring electric motor position 66 Pressure Sensor 70 Brake simulator valve 74 Brake Simulator 78 Pedal Stroke Pickup 82 Non-human piston pressure sensor 86 Check valve 90 Check valve Step A B Step C Step D Step E Step F Step G Step H Step B S Active braking maneuver

Claims

1. A method of controlling hydraulic volume in a system (1) comprising a non-human brake (10) and a vehicle dynamics control (14), the non-human brake (10) being hydraulically coupled to the vehicle dynamics control (14), generating (A) a control signal by the vehicle dynamics control (14) to provide a hydraulic volume for the vehicle dynamics control (14), and providing a control signal for the non-powered brake (10); (D) implementing control of the vehicle dynamics; conducting (E) the hydraulic volume back from the vehicle dynamics control (14) to a reservoir (50) after termination of the control of the vehicle dynamics via a pre-opened circuit cut-off valve (38, 42) connectable to the reservoir (50); for cases in which an active braking maneuver is introduced before or during the return guide (E) of the hydraulic pressure volume, closing (G) the circuit cut-off valves (38, 42) and controlling (H) the brake pressure in the vehicle dynamics control (14) by a non-human-operated piston (54) arranged in a non-human-operated cylinder (52); A method for controlling hydraulic volume in a system (1) consisting of a non-powered brake (10) and a vehicle dynamics control (14), comprising:

2. 2. A method according to claim 1, characterized in that the circuit cut-off valves (38, 42) are opened after the control (H) of the vehicle dynamics has ended.

3. 2. The method of claim 1, wherein the circuit cut-off valve (38, 42) is opened (B) before the implementation (D) of the control of the vehicle dynamics.

4. 4. The method of claim 1, further comprising moving the non-human-powered piston (54) forward (C) by a desired stroke amount prior to the implementation (D) of the control of the vehicle dynamics.

5. 5. A method according to any one of claims 1 to 4, characterized in that the non-powered piston (54) is moved backward (F) by a given stroke amount after guiding the hydraulic volume back.

6. 6. A method according to any one of claims 1 to 5, characterized in that the hydraulic volume is controlled by a non-human-powered cylinder (52) without a compensating connection.

7. 7. A method according to any one of claims 1 to 6, characterized in that the vehicle dynamics control (14) transmits information about the hydraulic volume required together with the control signal.

8. 8. A method according to any one of claims 1 to 7, characterized in that the stroke of the non-powered piston (54) to its forward position is set according to the required hydraulic pressure volume.

9. A system (1) for controlling hydraulic pressure volume in a system consisting of a non-human brake (10) and a vehicle dynamics control (14), comprising: A non-human brake (10); a vehicle dynamics control (14) hydraulically coupled to the non-human brake (10); a control device that controls the vehicle dynamics control (14); Equipped with the non-powered brake (10) is signal-coupled to the vehicle dynamics control (14); and The system is configured to perform the method according to any one of claims 1 to 8. A system (1) for controlling hydraulic pressure volume within a system consisting of non-human brakes (10) and vehicle dynamics control (14).

10. 10. The system (1) according to claim 9, characterized in that the non-powered brake (10) has a non-powered cylinder (52) without a compensation connection.

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