Control device and method for electromechanical brake force amplifier for braking system of running vehicle
By designing an electronic mechanism in the vehicle braking system to detect and adjust the pressure-stroke characteristic curve of the electromechanical brake amplifier, the deviation between the actual pre-pressure and the rated pre-pressure is solved, improving braking comfort and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ROBERT BOSCH GMBH
- Filing Date
- 2021-08-05
- Publication Date
- 2026-05-26
Smart Images
Figure CN114056312B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a control device for at least one electromechanical brake force amplifier for a vehicle braking system. The invention also relates to an electromechanical brake force amplifier for a vehicle braking system and a vehicle braking system. Furthermore, this invention relates to a method for using an electromechanical brake force amplifier for operating a vehicle braking system. Background Technology
[0002] The following braking systems are known from the prior art, such as DE 10 2016 208 529 A1, each equipped with an electromechanical brake force amplifier arranged in front of its master brake cylinder, at least one storage chamber and at least one wheel outlet valve. Summary of the Invention
[0003] The present invention provides a control device for at least one electromechanical brake force amplifier for a vehicle braking system having the features described below, an electromechanical brake force amplifier for a vehicle braking system having the features described below, a vehicle braking system having the features described below, and a method for an electromechanical brake force amplifier for operating a vehicle braking system having the features described below.
[0004] This invention provides an improved feasible solution for responding to the deviation between the actual pre-pressure and the desired rated pre-pressure actually induced by the operation of the electromechanical brake amplifier in at least one master brake cylinder arranged behind the electromechanical brake amplifier of a vehicle's braking system. Unlike the prior art, this invention considers that the deviation between the measured actual pre-pressure and the desired rated pre-pressure can be attributed not only to the deviation between the pressure-stroke characteristic curve considered during the operation of the electromechanical brake amplifier and the actual pressure-stroke characteristic of the electromechanical brake amplifier, but also to a non-zero brake fluid volume in at least one reservoir of the braking system. This invention also considers that when there is a deviation between the measured actual pre-pressure and the desired rated pre-pressure, an advantageous strategy for inducing the desired rated pre-pressure often also depends on the presence of a non-zero brake fluid volume in at least one reservoir of the braking system, and / or whether at least one wheel outlet valve of the braking system is at least partially open. In this way, this invention enables the driver of a vehicle using the invention to achieve good braking comfort when braking their vehicle.
[0005] In an advantageous embodiment of the control device, the electronics are additionally designed and / or programmed to: query or determine whether a non-zero amount of brake fluid is temporarily stored in at least one reservoir of the braking system if the measured actual pre-pressure is less than the pre-given rated pre-pressure or is less than the pre-given rated pre-pressure by at least the pre-given minimum difference; and / or query or determine whether at least one wheel outlet valve of the braking system is open if the measured actual pre-pressure is greater than the pre-given rated pre-pressure or is greater than the pre-given rated pre-pressure by at least the pre-given minimum difference. Thus, the embodiment of the control device described herein can be designed to take into account that an excessively low measured actual pre-pressure should generally be attributed to a non-zero amount of brake fluid in at least one reservoir of the braking system. Alternatively or supplementarily, the embodiment of the control device described herein can also be designed to: correct an excessively high measured actual pre-pressure by means of brake fluid movement through at least one at least partially open wheel outlet valve of the braking system and otherwise by means of an electromechanical brake force amplifier of the braking system if at least one wheel outlet valve of the braking system is at least partially open.
[0006] In another advantageous embodiment of the control device, if the measured actual pre-pressure is less than the predetermined rated pre-pressure or less than the predetermined rated pre-pressure by at least a predetermined minimum difference, and the electronics determine or read from the queried information that there is no non-zero brake fluid volume temporarily stored in at least one reservoir of the braking system, or if the measured actual pre-pressure is greater than the predetermined rated pre-pressure or greater than the predetermined rated pre-pressure by at least a predetermined minimum difference, then the electronics are additionally designed and / or programmed to: redetermine at least one characteristic value of the predetermined pressure-stroke-characteristic curve of the electromechanical brake amplifier, at least taking into account the measured actual pre-pressure and the predetermined rated pre-pressure. Thus, the embodiment of the control device described herein is suitable for targeted identification of when the deviation between the measured actual pre-pressure and the desired rated pre-pressure is actually based on an “error” in the predetermined pressure-stroke-characteristic curve for the electromechanical brake amplifier, and, if necessary, corrects the “error” by redetermining at least one characteristic value of the predetermined pressure-stroke-characteristic curve. In this way, the reliability of the control implemented by means of the "corrected" pressure-stroke characteristic curve of the electromechanical brake amplifier can be improved.
[0007] As an advantageous improvement to the control device, if the measured actual pre-pressure deviates from or differs from the pre-given rated pre-pressure by at least a pre-given minimum difference, and if the electronics determine, or read from the queried information, that there is no non-zero brake fluid volume temporarily stored in at least one reservoir of the braking system and / or the wheel outlet valves of the braking system are not open, then the electronics can also be designed and / or programmed to: redetermine the at least one rated parameter, at least taking into account the measured actual pre-pressure and the pre-given rated pre-pressure, and to reoperate the electromechanical brake force amplifier, taking into account the at least one re-determined rated parameter. Preferably, the at least one rated parameter is redetermined in addition to taking into account a “corrected” pressure-stroke-characteristic curve with at least one re-determined characteristic value. As will become clear from the following description, such operation of correcting / adjusting the actual pre-pressure to the desired rated pre-pressure can be implemented while maintaining good braking comfort for the driver.
[0008] The advantages described above are also guaranteed in the electromechanical brake force amplifier used in the braking system of a vehicle, which can be placed in front of or be placed in front of the master brake cylinder of the braking system and is equipped with a corresponding control device.
[0009] A braking system for a vehicle also ensures the above advantages, having a corresponding control device and the aforementioned electromechanical brake amplifier or such electromechanical brake amplifier, a master brake cylinder and having at least one storage chamber and / or at least one wheel outlet valve, wherein the corresponding electromechanical brake amplifier is prepositioned in front of the master brake cylinder.
[0010] Furthermore, the implementation of a corresponding method for an electromechanical brake amplifier for a braking system of a vehicle also provides the advantages described above. It should be clearly noted that the method for an electromechanical brake amplifier for a braking system of a vehicle can be improved according to the embodiments of the control device, the electromechanical brake amplifier, and / or the braking system explained above. Attached Figure Description
[0011] Other features and advantages of the invention will now be explained with reference to the accompanying drawings.
[0012] in:
[0013] Figures 1a to 1f A flowchart, a schematic partial illustration of the vehicle's braking system, and a coordinate system are shown to explain one embodiment of the method for using an electromechanical brake force amplifier for a braking system of a vehicle; and
[0014] Figure 2 A schematic diagram of one embodiment of the control device, or braking system equipped with the control device, is shown. Detailed Implementation
[0015] Figures 1a to 1f A flowchart, a schematic partial illustration of the vehicle's braking system, and a coordinate system are shown to explain one embodiment of the method for an electromechanical brake force amplifier for a braking system used in operating a vehicle.
[0016] It should be noted that the feasibility of the method described below is not limited to specific vehicle types / motor vehicle types equipped with the braking system. The braking system in... Figures 1b to 1d The schematic diagrams shown are intended to be interpreted illustratively only. The method described below can be implemented with (almost) every type of braking system equipped with a master brake cylinder 10, an electromechanical brake force amplifier 12 (with a motor) pre-positioned on the master brake cylinder 10, and at least one reservoir 14 and / or at least one wheel outlet valve 16a and 16b, wherein at least one wheel brake cylinder 20a and 20b can be applied to / connected to the master brake cylinder 10 of the respective braking system. The at least one reservoir 14 does not refer to a brake fluid container 18 (preferably with an injection connector) connected to the master brake cylinder 10 through at least one snorting port. "The at least one wheel outlet valve 16a and 16b" should each refer to a valve through which the at least one associated wheel brake cylinder 20a and 20b are connected to the at least one connected storage chamber 14 in such a way that brake fluid can be transferred from the at least one associated wheel brake cylinder 20a and 20b to the at least one connected storage chamber 14 through the wheel outlet valves 16a and 16b, which are respectively in at least a partially open state.
[0017] The braking system shows the first braking circuit in... Figures 1b to 1d The equipment described is optional. The first braking circuit includes at least one wheel inlet valve 22a and 22b, a switching valve 24, a high-pressure shift valve 26, at least one pump 28 with a pump motor 30, a throttle mechanism 32, a preload sensor 34, and a check valve 36. The second braking circuit (not shown) of the braking system can optionally be configured corresponding to or different from the first braking circuit.
[0018] In method step S1, at least taking into account the pre-given rated preload p of the electromechanical braking force amplifier 12... target and the pre-given pressure-stroke-characteristic curve k standardIn this case, at least one rated parameter is determined regarding the rated operating mode of the electromechanical brake amplifier 12. As one of the at least one rated parameter, in method step S1, for example, the rated current intensity and / or rated energizing duration to be supplied to the motor of the electromechanical brake amplifier 12 can be determined.
[0019] The rated preload p target Preferably, the rated preload is predetermined by the vehicle's speed control device. target It can also be (indirectly) predetermined by the speed control device using the vehicle's required rated deceleration and / or by the additional power to be applied to the vehicle. In this case, the rated preload p is determined taking into account the parameters required by the speed control device. target "The speed control device" can refer to an automatic device for pre-determining at least one vehicle deceleration to be caused by the braking system. The speed control device can be, for example, a distance-adjusting speed controller (such as, in particular, an ACC (Adaptive Cruise Control) system), an emergency braking device, and / or an automatic device for automating the vehicle. When the brake actuation element 38, located at the front of the master brake cylinder 10, is in its unoperated position, the rated preload p target The braking control element is preferably requested by the speed control device, wherein the driver can move the braking control element 38 from its unoperated position by operating the braking control element 38. "The braking control element 38" can refer, for example, to the brake pedal 38.
[0020] "The pressure-stroke-characteristic curve k" standard "This can refer to a pre-defined characteristic curve for the electromechanical brake amplifier 12, from which it is assumed that the characteristic curve corresponds to the actual pressure-stroke characteristic of the electromechanical brake amplifier 12. The pressure-stroke characteristic curve k..." standard In particular, the pre-pressure estimate is a function of the adjustable stroke x of the adjustable piston of the electromechanical brake amplifier 12, which is caused (only) by the operation of the electromechanical brake amplifier 12. If in this case, the actual pressure-stroke characteristic of the electromechanical brake amplifier 12 corresponds to the pressure-stroke characteristic curve k. standard Then the rated preload p target At the rated preload p targetThe corresponding adjustment stroke x adjusts the adjustable piston of the electromechanical brake amplifier 12, which is then present at least in the master brake cylinder 10 of the braking system. "The adjustable piston of the electromechanical brake amplifier 12" can, for example, refer to the output rod.
[0021] In another method step S2, the electromechanical brake amplifier 12 is operated taking into account the at least one determined rated parameter. For example, the motor of the electromechanical brake amplifier 12 is energized with a current intensity corresponding to the determined rated current intensity for a time interval corresponding to the rated energizing duration.
[0022] In the embodiment of the method described herein, an optional method step S3 is also performed simultaneously with method step S2, wherein the method step S3 is... Figure 1b The diagram is schematically shown. To prevent braking pressure from forming in at least one wheel brake cylinder 20a and 20b of the braking system despite the brake fluid being forced out of the master brake cylinder 10 by means of the operated electromechanical brake force amplifier 12, as method step S3, the first wheel inlet valve 22a, located in front of the first wheel brake cylinder 20a in the first braking circuit, and the first wheel outlet valve 16a, located behind the first wheel brake cylinder 20a, are controlled / held in their respective open states, thereby moving the brake fluid forced out of the master brake cylinder 10 through the first wheel inlet valve 22a and the first wheel outlet valve 16a to the at least one rearward-arranged storage chamber 14. If present, the second wheel inlet valve 22b, located in front of the second wheel brake cylinder 20b in the first braking circuit, and the second wheel outlet valve 16b, located behind the second wheel brake cylinder 20b, can be controlled / held in their closed states during method step S3. (Method step S3 can also be implemented for a second brake circuit, which is not shown). By... Figure 1b The schematic depiction of the method by which brake fluid, expelled from the master brake cylinder 10, is temporarily stored in at least one storage chamber 14 enables at least one (not shown) electric motor of the vehicle to regenerate energy and brake the vehicle without over-braking it, while converting the vehicle's kinetic energy into electrical energy. In this way, pure energy recovery / regenerative braking is particularly possible, where the vehicle is braked (almost) solely by means of at least one electric motor.
[0023] Figure 1cAnother optional method step S4 is schematically shown, by which the implementation of this method step causes braking pressure to be formed in at least the second wheel brake cylinder 20b of the first braking circuit. For this purpose, while brake fluid continues to be forced out of the master brake cylinder 10 by means of the operated electromechanical brake force amplifier 12, the second wheel inlet valve 22b is controlled and kept in its open state, and the desired braking pressure in the second wheel brake cylinder 20b is additionally set by means of the opening and closing of the first wheel inlet valve 22a when the first wheel outlet valve 16a is in the open state. (Method step S4 can also be implemented for the second braking circuit, which is not shown). By means of method step S4, the unavailability of the at least one electric motor for energy recovery braking can be compensated by the braking of the vehicle's partial energy recovery / partial regeneration (over-braking without the vehicle).
[0024] During method step S4, method steps S6 to S11, which are explained in more detail below, can be performed. For better understanding, method steps S6 to S11 are described below.
[0025] If braking for partial energy recovery of the vehicle can no longer be initiated by means of the at least one electric motor itself, for example because at least one energy storage unit of the vehicle is fully charged and / or the current speed of the vehicle does not exceed the minimum speed necessary for the usability of braking for partial energy recovery by the at least one electric motor, then it is possible to implement... Figure 1d The optional method step S5 is schematically shown. As method step S5, at least one wheel inlet valve 22a and 22b of at least the first brake circuit is controlled / held in its open state, while simultaneously at least one wheel outlet valve 16a and 16b of at least the first brake circuit is controlled / held in its closed state. Brake fluid is simultaneously pumped from at least one connected reservoir 14 to at least one wheel brake cylinder 20a and 20b of at least the first brake circuit by means of at least one pump 28 of at least the first brake circuit. (Method step S5 can also be implemented for a second brake circuit, not shown.) Method step S5 is continued until it can be believed that the brake fluid expelled from the master brake cylinder 10 has at least partially been pumped from at least one connected reservoir 14 to at least one wheel brake cylinder 20a and 20b of at least the first brake circuit by means of at least one pump 28 of the first brake circuit. (Unnecessarily, the brake fluid expelled from the master brake cylinder 10 is completely pumped back.)
[0026] No later than after performing the method steps S1 to S5, the actual pre-pressure p is measured as method step S6. measuredIt is present at least in the master brake cylinder 10 of the braking system. Then, in method step S7, the measured actual preload p is... measured With the pre-given rated preload p target Compare them. If the measured actual preload p measured and the pre-given rated preload p target If they are (basically) consistent, then the method ends.
[0027] If the actual preload p is measured measured With the pre-given rated preload p target If there is a deviation or a difference of at least a predetermined minimum, it is necessary to ascertain whether a non-zero amount of brake fluid is temporarily stored in at least one reservoir 14 of the braking system and / or whether at least one wheel outlet valve 16a and 16b of the braking system is open. ("Open wheel outlet valves 16a and 16b" can mean not only partially open but also fully open wheel outlet valves 16a and 16b.) As will become clear by means of the following description, the measured actual preload p can be reliably ascertained in this way. measured With the pre-given rated preload p target The determined deviation is based on the pressure-stroke-characteristic curve k used to implement method step S1. standard The inadequacy of the actual pressure-stroke characteristics of the electromechanical brake force amplifier 12 is (essentially) due to other causes of failure. Therefore, the method described herein is able to identify the measured actual pre-pressure p. measured With the pre-given rated preload p target After the deviation is identified, reliable fault diagnosis can be achieved.
[0028] In the embodiments described herein, if the measured actual preload p measured Less than the pre-given rated preload p target Or more than the pre-given rated preload p target If the difference is less than at least a predetermined minimum, then method step S8 is performed. Method step S8 determines whether a non-zero amount of brake fluid is temporarily stored in at least one reservoir 14 of the braking system. In this way, the measured actual pre-pressure p can be distinguished. measured With the pre-given rated preload p target The deviation is due to inaccuracy in pressure adjustment during steps S3 to S5 of the preceding method, or due to the pressure-stroke-characteristic curve k used in step S1 of the method. standardIt is triggered due to insufficient consistency with the actual pressure-stroke characteristics of the electromechanical braking amplifier 12.
[0029] To identify whether a non-zero amount of brake fluid still exists in at least one reservoir 14 of the braking system, the actual amount of brake fluid present in the at least one reservoir 14 of the braking system can be estimated. Alternatively or supplementarily, a measurement curve relating to the pressure increase over time, recorded for example, to implement step S5 of the method described above, can be evaluated, taking into account the corresponding pump speed of at least one pump 28 of the braking system and the simultaneous operation of the electromechanical brake force amplifier 12. If, by means of the measurement curve, the pressure increase over time is identified as (significantly) lower than expected, taking into account the corresponding pump speed and the simultaneous operation of the brake actuation element 38, then it can be reliably concluded that a non-zero amount of brake fluid exists in at least one reservoir 14 of the braking system.
[0030] If, in method step S8, it is determined (with high probability) that a non-zero amount of brake fluid still exists in at least one reservoir 14 of the braking system, then it can be reliably assumed that the measured actual pre-pressure p is accurate. measured With the pre-given rated preload p target The determined deviation is (substantially) not based on the pressure-stroke-characteristic curve k used to implement step S1 of the method. standard This is inconsistent with the actual pressure-stroke characteristics of the electromechanical brake force amplifier 12. Therefore, in method step S8, if a non-zero brake fluid volume is determined in at least one reservoir 14 of the braking system, as a subsequent method step S9, at least one pump 28 of at least the first brake circuit is reactivated / continued. The measured actual pre-pressure p measured With the desired rated preload p target The deviation can thus be eliminated by purging (Leerpumpen) of the at least one storage chamber 14 by means of at least one pump 28 of at least a first braking circuit. After implementing method step S9, method step S7 can optionally be implemented again, although for better clarity... Figure 1a The loop process is not shown in the document.
[0031] However, if determined in method step S8, although the measured actual prepressure p measured Less than the pre-given rated preload p target Or more than the pre-given rated preload p targetIf the measured pre-pressure p is less than at least a predetermined minimum difference, but there is no non-zero brake fluid volume temporarily stored in at least one reservoir 14 of the braking system, then it indicates that the measured actual pre-pressure p measured With the rated preload p target The deviation is based on the pre-given pressure-stroke-characteristic curve k standard The inadequacy of the actual pressure-stroke characteristics of the electromechanical brake force amplifier 12. If it is reliably confirmed by means of the method step S8 that there is no non-zero brake fluid volume temporarily stored in at least one reservoir 14 of the braking system, then at least one of the method steps S10 and S11 is performed.
[0032] As a method step S10, at least considering the measured actual prepressure p measured and the pre-given rated preload p target Under these circumstances, the pre-given pressure-stroke-characteristic curve k of the electromechanical braking force amplifier 12 should be redefined. standard At least one eigenvalue. This is achieved by means of Figure 1e The coordinate system is shown exemplarily.
[0033] exist Figure 1e In the coordinate system, the horizontal axis represents the adjustment stroke x (in millimeters) of the adjustable piston of the electromechanical brake amplifier 12 as it moves away from its initial position, while the vertical axis shows the pressure value p (in bar).
[0034] In addition to the pre-given pressure-stroke-characteristic curve k standard In addition, the selection set of the selectable characteristic curve k will also be plotted into... Figure 1e In the coordinate system. Using Figure 1e As can be seen from the coordinate system, the pre-given rated preload p can be used to... target and the measured actual preload p measured To determine one of the selectable characteristic curves, k1, which most reliably reflects the current pressure-stroke characteristics of the electromechanical brake amplifier 12. The correctly selected characteristic curve k1 can be identified, for example, by the actual pre-pressure p measured for the current adjustment stroke x1 of the adjustable piston of the electromechanical brake amplifier 12. measured-1 (Almost) on the selected characteristic curve k1 (p measured-1 =k1(x1)). In contrast, the rated preload p is given only for the current adjustment stroke x1 of the adjustable piston of the electromechanical braking force amplifier 12. target-1 Under the pre-defined pressure-stroke-characteristic curve k standardAbove. In particular, the selected characteristic curve k1 can then be determined as the new pressure-stroke characteristic curve k. standard And it is stored on the storage unit.
[0035] As a supplement or alternative to the method step S10, method step S11 can also take into account at least the measured actual pre-pressure p. measured and the pre-given rated preload p target In this case, the at least one rated parameter is re-determined, and then the electromechanical brake force amplifier 12 can be operated again taking into account the at least one re-determined rated parameter. In this way, it can be ensured that, even though at least one empty reservoir 14 of the braking system (or, as will become clear from the following description, even when wheel brake cylinders 20a and 20b are closed), sufficient brake fluid is transferred from (or into) the master brake cylinder 10 by means of the operation of the electromechanical brake force amplifier 12 caused by method step S11, so as to ensure the desired rated preload p is maintained at least in a portion of the braking system space. target This is thanks to Figure 1e Arrow 40 in the coordinate system is depicted graphically.
[0036] Preferably, in implementing method step S11, the "corrected" characteristic curve k1 of the electromechanical brake amplifier 12, obtained by means of the previously concluded method step S10, is used to redetermine at least one rated parameter. Because the "corrected" characteristic curve k1 in this case (almost) corresponds to the actual pressure-stroke characteristics of the electromechanical brake amplifier 12, optimized operation of the electromechanical brake amplifier 12 is ensured when implementing method step S11. The driver, when braking as necessary, does not / almost feels the increase in the adjustment stroke x1 of the adjustable piston of the electromechanical brake amplifier 12 from position x1 to a new position x1+δ1.
[0037] Furthermore, in the embodiment of the method described here, if the measured actual preload p measured Greater than the predetermined rated preload p target Or more than the pre-given rated preload p targetIf the difference exceeds at least a predetermined minimum, then in method step S12, it is determined whether at least one wheel outlet valve 16a and 16b of the braking system is open. If, in method step S12, it is determined that at least one of the wheel outlet valves 16a and 16b of the braking system is at least partially open, then it can be reliably considered that the measured actual preload p is... measured With the desired rated preload p target The deviation can be corrected even without re-running the electromechanical brake amplifier 12. For this purpose, as a method step S13, the measured actual pre-pressure p is compared with... measured and the desired rated preload p target The amount of brake fluid corresponding to the deviation is transferred to the storage chamber 14 located at the rear through at least one partially open wheel outlet valve 16a and 16b.
[0038] However, if it is determined in method step S12 that the wheel outlet valves 16a and 16b of the braking system are not open, then method step S11, which has been described above, is performed.
[0039] In addition to method step S11, it is also possible to measure the actual pre-pressure p measured Greater than the predetermined rated preload p target Or more than the pre-given rated preload p target If the difference exceeds at least a pre-given minimum, then method step S10 is performed. Therefore, method step S10 can be performed together with method step S11 or together with method step S13. This is in... Figure 1f It is shown schematically in the diagram.
[0040] exist Figure 1f In the coordinate system, the horizontal axis represents the adjustment stroke x (in millimeters) of the adjustable piston of the electromechanical brake amplifier 12 as it moves away from its initial position, while the vertical axis shows the pressure value p (in bar).
[0041] Also, the pre-given pressure-stroke-characteristic curve k standard The set of selectable characteristic curves k is plotted into... Figure 1f In the coordinate system. Figure 1f In the coordinate system, by means of the pre-given rated preload p target and the measured actual preload p measuredAdditionally, the selection of one of the selectable characteristic curves, k2, is shown, which most reliably reflects the current pressure-stroke characteristics of the electromechanical brake amplifier 12. The correctly selected characteristic curve k2 is particularly evident at this point: the measured actual pre-pressure p for the current adjustment stroke x2 of the adjustable piston of the electromechanical brake amplifier 12. measured-2 It is (almost) on the selected characteristic curve k2 (p measured-2 =k2(x2)). In contrast, the rated preload p is given only for the current adjustment stroke x2 of the adjustable piston of the electromechanical braking force amplifier 12. target-2 Under the pre-defined pressure-stroke-characteristic curve k standard Above. Subsequently, the selected characteristic curve k2 can be determined as the new pressure-stroke characteristic curve k. standard And it is stored in the storage unit. Thus, through the implementation of method step S10, the actual pressure-stroke characteristics of the electromechanical brake amplifier 12 can be "learned" or the pressure-stroke characteristics of the electromechanical brake amplifier 12 can be "relearned", thereby enabling the correction of manufacturing tolerances and / or aging effects on the electromechanical brake amplifier 12 and other components of the braking system equipped thereon.
[0042] With the help of arrow 40, it is also Figure 1f Method step S11 is illustrated graphically in a coordinate system. By means of method step S11, brake fluid is transferred to the master brake cylinder 10 by the operation caused by the electromechanical brake force amplifier 12. Preferably, method step S11 is used to reduce the pre-pressure until the desired rated pre-pressure p is achieved. target Preferably, when implementing step S11 of the method, the measured actual pre-pressure p is taken into account. measured The pre-given rated preload p target The at least one rated parameter of the electromechanical brake amplifier 12 is redefined using the "corrected" characteristic curve k2 obtained from the previously concluded method step S10. In this case, the driver will not notice the decrease in the adjustment stroke x of the adjustable piston of the electromechanical brake amplifier from position x2 to the new position x2-δ2. It should also be noted that the method step S11 can always be implemented relatively quietly, thereby ensuring good NVH (Noise, Vibration, Harshness) compatibility.
[0043] As an improvement to the method described herein, the stiffness factor S of the braking system can also be learned using the method described herein. F The stiffness coefficient S F Defined according to equation (Gl.1), where:
[0044] (Equation 1)
[0045] To determine the stiffness factor S F It is possible to use equation (Gl.2), where:
[0046] (Equation 2)
[0047] Figure 2 A schematic diagram of one embodiment of the control device or a braking system equipped with the control device is shown.
[0048] The usability of the control device 42 described below is not limited to a specific type of braking system, nor is it limited to a specific type of vehicle / motor vehicle equipped with the control device 42. Therefore, in Figure 2 The braking system shown is to be interpreted only as an example.
[0049] The control device 42 has a storage unit 44, on which the pressure-stroke-characteristic curve k of the electromechanical braking force amplifier, which can be controlled by the control device 42, is stored. standard Furthermore, the control device 42 has an electronic mechanism 46, which is designed and / or programmed to: at least in consideration of the electromechanical braking force amplifier 12, a rated pre-given pressure p is given to the electronic mechanism 46. target And the pressure-stroke-characteristic curve k standard In this case, at least one rated parameter related to the rated operating mode of the electromechanical brake amplifier 12 is determined, and the electromechanical brake amplifier 12 is operated by means of at least one control signal 12s, taking into account at least one determined rated parameter. Examples for the at least one rated parameter have been mentioned above. The rated preload p target For example, it can also be determined by another sub-unit 48 of the control device 42, which is configured as a speed control device 48. Examples of such speed control devices have been mentioned above. However, as an alternative, the control device 42 / its electronics 46 can also be designed to work in conjunction with a separately configured speed control device.
[0050] The electronic mechanism 46 is additionally designed and / or programmed to: utilize the measured and supplied electronic mechanism 46 actual pre-pressure p present at least in the master brake cylinder 10 of the braking system, located behind the electromechanical brake force amplifier 12. measured To identify: the actual preload p measured measured Is it consistent with the pre-given rated preload p? target There is a deviation or difference of at least a pre-given minimum difference. If necessary, the electronic mechanism 46 is also designed and / or programmed to: query or determine whether a non-zero amount of brake fluid is temporarily stored in at least one reservoir 14 of the braking system, and / or query or determine whether at least one wheel outlet valve 16a and 16b of the braking system is open. (“Open wheel outlet valves 16a and 16b” can refer not only to partially open but also to fully open wheel outlet valves 16a and 16b.) Thus, the control device 42 described herein also produces the advantages already listed above.
[0051] The control device 42 is particularly designed to implement the methods described above. A restatement of the method steps is omitted here. The control device 42 can be a subunit of the electromechanical brake amplifier 12, or, if separate from the electromechanical brake amplifier, can be mounted on the braking system.
Claims
1. A control device (42) for at least one electromechanical brake force amplifier (12) for a vehicle braking system, comprising: Storage unit (44) storing the pressure-stroke-characteristic curve (k) of the electromechanical braking force amplifier (12). standard ); Electronic mechanism (46), which is designed and / or programmed to: at least in consideration of the electromechanical braking force amplifier (12), provide a pre-given rated pre-pressure (p) for electronic mechanism (46). target ) and pressure-stroke-characteristic curve (k standard In the case of determining at least one rated parameter for the rated operating mode of the electromechanical braking amplifier (12), and operating the electromechanical braking amplifier (12) in consideration of the determined at least one rated parameter. Its features are, The electronic mechanism (46) is additionally designed and / or programmed to: based on the measured and supplied actual pre-pressure (p) present in the master brake cylinder (10) of the braking system located behind the electromechanical brake force amplifier (12), at least in the braking system. measured To identify the actual preload (p) measured. measured Whether it is related to the pre-given rated preload (p) target If there is a deviation, and in the event of a deviation, check or ascertain whether a non-zero amount of brake fluid is temporarily stored in at least one storage chamber (14) of the braking system, and / or check or ascertain whether at least one wheel outlet valve (16a, 16b) of the braking system is open. And, based on the results of the query or investigation, at least taking into account the measured actual pre-pressure (p measured ) and the pre-given rated preload (p) target In the case of ), the pre-given pressure-stroke-characteristic curve (k) of the electromechanical braking force amplifier (12) is redefined. standard The electromechanical braking amplifier (12) is operated again with regard to at least one characteristic value of the at least one rated parameter and / or the at least one rated parameter is re-determined.
2. The control device (42) according to claim 1, wherein, The measured actual preload (p) measured ) and the pre-given rated preload (p) target The deviation between them is at least a pre-given minimum difference.
3. The control device (42) according to claim 1 or 2, wherein the electronic mechanism (46) is additionally designed and / or programmed to: if the measured actual pre-pressure (p) measured The pressure is less than the pre-given rated preload (p). target Then, query or ascertain whether a non-zero amount of brake fluid is temporarily stored in at least one reservoir (14) of the braking system, and / or, if the measured actual pre-pressure (p measured The pressure is greater than the pre-given rated preload (p). target If so, then check or determine whether at least one wheel outlet valve (16a, 16b) of the braking system is open.
4. The control device (42) according to claim 1 or 2, wherein, If the actual preload measured (p) measured The pressure is less than the pre-given rated preload (p). target And the electronic mechanism (46) determines or reads from the retrieved information that there is no non-zero brake fluid quantity temporarily stored in at least one reservoir (14) of the braking system, or if the measured actual pre-pressure (p measured The pressure is greater than the pre-given rated preload (p). target Then the electronic mechanism (46) is additionally designed and / or programmed to at least take into account the measured actual pre-pressure (p measured ) and the pre-given rated preload (p) target In the case of re-determining the pre-given pressure-stroke-characteristic curve (k) of the electromechanical braking force amplifier (12), the following conditions are met: standard At least one characteristic value of ).
5. The control device (42) according to claim 1 or 2, wherein, If the actual preload measured (p) measured ) and the pre-given rated preload (p) target If there is a deviation, and if the electronic mechanism (46) determines or reads from the retrieved information that there is no non-zero brake fluid volume temporarily stored in at least one reservoir (14) of the braking system and / or the wheel outlet valves (16a, 16b) of the braking system are not open, then the electronic mechanism (46) is additionally designed and / or programmed to: at least taking into account the measured actual pre-pressure (p measured ) and the pre-given rated preload (p) target In the case of re-determining the at least one rated parameter, and taking into account the re-determined at least one rated parameter, the electromechanical braking amplifier (12) is operated again.
6. An electromechanical brake amplifier (12) for a vehicle braking system, the electromechanical brake amplifier being arranged or being able to be arranged before the master brake cylinder (10) of the braking system, the electromechanical brake amplifier having a control device (42) according to any one of claims 1 to 5.
7. A braking system for vehicles, having: The control device (42) according to any one of claims 1 to 5 and the electromechanical brake amplifier (12) working together, or the electromechanical brake amplifier (12) according to claim 6. The master brake cylinder (10) and the corresponding electromechanical brake force amplifier (12) are arranged before the master brake cylinder; and It has at least one storage chamber (14) and / or at least one wheel outlet valve (16a, 16b).
8. A method for an electromechanical brake force amplifier (12) for a braking system of a vehicle, comprising the following steps: At least taking into account the pre-given rated preload (p) of the electromechanical braking force amplifier (12). target ) and a pre-defined pressure-stroke-characteristic curve (k standard In the case of ), determine at least one rated parameter (S1) for the rated operating mode of the electromechanical braking amplifier (12). The electromechanical braking amplifier (12) (S2) is operated taking into account the determined at least one rated parameter; and Measure the actual preload (p) measured The actual pre-pressure is present at least in the master brake cylinder (10) located behind the electromechanical brake amplifier (12) of the braking system (S6). Its features are, If the actual preload measured (p) measured ) and the pre-given rated preload (p) target If there is a deviation, it is necessary to check or ascertain whether a non-zero amount of brake fluid is temporarily stored in at least one storage chamber (14) of the braking system (S8), and / or check or ascertain whether at least one wheel outlet valve (16a, 16b) of the braking system is open (S12). And, based on the results of the query or investigation, at least taking into account the measured actual pre-pressure (p measured ) and the pre-given rated preload (p) target In the case of ), the pre-given pressure-stroke-characteristic curve (k) of the electromechanical braking force amplifier (12) is redefined. standard The electromechanical braking amplifier (12) is operated again with regard to at least one characteristic value of the at least one rated parameter and / or the at least one rated parameter is re-determined.
9. The method according to claim 8, wherein, The measured actual preload (p) measured ) and the pre-given rated preload (p) target The deviation between them is at least a pre-given minimum difference.
10. The method according to claim 8 or 9, wherein, If the actual preload measured (p) measured The pressure is less than the pre-given rated preload (p). target If so, it is necessary to check or ascertain whether a non-zero amount of brake fluid is temporarily stored in at least one storage chamber (14) of the braking system (S8).
11. The method according to claim 8 or 9, wherein, If the actual preload measured (p) measured The pressure is greater than the pre-given rated preload (p). target If so, then it is necessary to check or ascertain whether at least one wheel outlet valve (16a, 16b) of the braking system is open (S12).
12. The method according to claim 8 or 9, wherein, If the actual preload measured (p) measured The pressure is less than the pre-given rated preload (p). target And query or ascertain that there is no non-zero brake fluid volume temporarily stored in at least one reservoir (14) of the braking system, or if the measured actual pre-pressure (p measured The pressure is greater than the pre-given rated preload (p). target ), then at least considering the measured actual pre-pressure (p) measured ) and the pre-given rated preload (p) target In the case of re-determining the pre-given pressure-stroke-characteristic curve (k) of the electromechanical braking force amplifier (12), the following conditions are met: standard (S10) at least one characteristic value of ).
13. The method according to claim 8 or 9, wherein, If the actual preload measured (p) measured ) and the pre-given rated preload (p) target If there is a deviation, and if it is found that there is no brake fluid volume not equal to zero temporarily stored in at least one reservoir (14) of the braking system, and / or it is found that the wheel outlet valves (16a, 16b) of the braking system are not open, then at least taking into account the measured actual pre-pressure (p measured ) and the pre-given rated preload (p) target In the case of re-determining the at least one rated parameter and operating the electromechanical braking amplifier (12) again in consideration of the re-determined at least one rated parameter (S11).