System and method for sensing pedal rod to piston rod clearance in master cylinder brake assist system
阅读说明:本技术 用于感测主缸制动助力辅助系统中踏板杆到活塞杆的间隙的系统和方法 (System and method for sensing pedal rod to piston rod clearance in master cylinder brake assist system ) 是由 柯特·M·罗伯茨 苏阿特·阿里·奥兹索鲁 于 2018-06-25 设计创作,主要内容包括:一种与机动车辆制动系统的主缸一起使用的制动助力辅助系统包括感应式感测系统。该感应式感测系统具有承载在输入构件和输出构件上的感测装置,其中输入构件和输出构件联接到制动助力辅助系统的输入杆和输出杆中的相应者。输入构件和输出构件相对于彼此并且相对于定位在制动助力辅助系统内的感应式感测系统的固定元件的运动使得能够精确地估计将输入杆的面和输出杆的面分开的踏板间隙的距离。踏板间隙距离的精确估计使得能够更精确地确定在制动动作期间由车辆的操作者输入的任何给定踏板行程所需的制动力。(A brake assist system for use with a master cylinder of a motor vehicle braking system includes an inductive sensing system. The inductive sensing system has sensing devices carried on an input member and an output member, wherein the input member and the output member are coupled to respective ones of an input rod and an output rod of the brake assist system. Movement of the input member and the output member relative to each other and relative to a fixed element of an inductive sensing system positioned within the brake assist system enables accurate estimation of the distance of the pedal gap separating the face of the input rod and the face of the output rod. An accurate estimate of the pedal clearance distance enables a more accurate determination of the braking force required for any given pedal stroke input by the operator of the vehicle during a braking action.)
1. A brake assist system for use with a master cylinder of a motor vehicle braking system, the brake assist system comprising:
an inductive sensing system, the inductive sensing system comprising:
a stationary sensing component fixedly disposed within the brake assist system;
an axially movable input member operatively associated with an input rod, which in turn is associated with a brake pedal of the vehicle, the input member being movable in response to movement of the input rod and further movable about the stationary sensing component, the axially movable input member including a first sensing device;
an output member substantially axially aligned with and adapted to be axially moved by the input member, the output member being operatively associated with an output rod of the brake assist system and including a second sensing arrangement;
the first and second sensing devices are arranged to simulate an axial pedal gap separating a face of the input rod and a face of the output rod; and is
Wherein the inductive sensing system is responsive to movement of at least one of the input member and the output member relative to the other to provide an output signal indicative of a distance indicative of the axial pedal clearance during brake pedal travel.
2. The system of claim 1, wherein the first sensing device comprises an input member coil carried by the input member.
3. The system of claim 2, wherein the second sensing device comprises an output member coil carried by the output member.
4. The system of claim 1, wherein the stationary sensing component comprises a first coil and a second coil fixedly mounted within the brake assist system, the first coil defining the second coil.
5. The system of claim 4, wherein the first coil and the second coil are mounted on an interior wall portion of a housing of the brake assist system.
6. The system of claim 1, wherein the first and second sensing devices are further disposed on the input member and the output member, respectively, to overlap during a portion of axial movement of one of the input member and the output member relative to the other.
7. The system of claim 6, wherein the first sensing device comprises an input member coil and the second sensing device comprises an output member coil, and further wherein the stationary sensing component comprises a first stationary mounted coil and a second stationary mounted coil fixedly mounted within the brake assist system, the first stationary mounted coil defining the second stationary mounted coil; and is
Wherein a degree of overlap of the input member coil and the output member coil controls a degree of magnetic flux coupling between the first fixedly mounted coil and the second fixedly mounted coil to provide the output signal indicative of the distance indicative of the axial pedal gap.
8. The system of claim 1, wherein one of the first and second sensing devices comprises a metallic member secured to one of the input member or the output member, and wherein the stationary sensing component comprises a coil fixedly secured to an inner wall of a housing of the brake assist system.
9. The system of claim 8, wherein the other of the first and second sensing devices comprises a pair of metallic elements fixed to the other of the input member and the output member, and wherein the pair of metallic elements define a fixed gap therebetween, and wherein the metallic member is longitudinally aligned with the pair of metallic elements such that the gap between the pair of metallic elements is at least partially covered when the input member is moved relative to the output member.
10. The system of claim 9, further comprising an inductance-capacitance (LC) circuit for applying an alternating current signal to the coil.
11. The system of claim 10, wherein a change in position of the metallic member relative to the pair of metallic elements causes a change in frequency of the output signal from the LC circuit, the change in frequency being indicative of a change in distance representative of the axial pedal gap.
12. The system of claim 11, wherein the metal member overlaps the gap to a greater or lesser extent during movement of the input member relative to the output member, which affects the frequency of the output signal from the LC circuit.
13. The system of claim 8, wherein the metal member comprises a rectangular shaped metal member.
14. A brake assist system for use with a master cylinder of a motor vehicle braking system, the brake assist system comprising:
an inductive sensing system for detecting an axial pedal gap between a face of an input rod and a face of an output rod of the brake assist system, the inductive sensing system comprising:
an AC input signal source for generating an AC input signal;
a first fixedly mounted coil disposed within the brake assist system;
a second fixedly mounted coil disposed within the brake assist system and bounded by the first fixedly mounted coil, one of the first and second fixedly mounted coils receiving the AC input signal;
an axially movable input member operatively associated with the input rod, which in turn is associated with a brake pedal of the vehicle, and wherein the input member is movable in response to movement of the input rod and is further movable adjacent the first and second fixedly mounted coils, the axially movable input member comprising an input member coil;
an output member substantially axially aligned with the input member and adapted to be axially moved by the input member, the output member being operatively associated with the output rod of the brake assist system and including an input member coil;
the input member coil and the output member coil are further arranged to at least partially overlap each other during movement of the input rod and the output rod;
the degree of overlap of the input member coil and the output member coil affects the inductive coupling between the first fixedly mounted coil and the second fixedly mounted coil during movement of at least one of the input rod and the output rod; and is
One of the first and second fixedly mounted coils that does not receive the AC input signal provides an output signal indicative of the axial pedal lash during brake pedal travel.
15. The system of claim 14, wherein the first and second fixedly mounted coils are mounted to an inner wall of a housing of the brake assist system.
16. A brake assist system for use with a master cylinder of a motor vehicle braking system, the brake assist system comprising:
an inductive sensing system for detecting an axial pedal gap between a face of an input rod and a face of an output rod of the brake assist system, the inductive sensing system comprising:
an LC oscillator circuit;
a coil fixedly disposed within the brake assist system, the coil receiving an AC signal from the LC oscillator circuit;
an axially movable input member operatively associated with the input rod, which in turn is associated with a brake pedal of the vehicle, and wherein the input member is movable in response to movement of the input rod and is further movable in proximity to the coil;
an output member substantially axially aligned with the input member and adapted to be axially moved by the input member, the output member being operatively associated with an output rod of the brake assist system;
one of the input member and the output member comprises a metallic sensing member and the other comprises spaced apart fixed metallic sensing elements;
the metal sensing member and the metal sensing element are further arranged to simulate the axial pedal gap separating a face of the input rod and a face of the output rod; and is
The inductive sensing system is responsive to movement of at least one of the input member and the output member relative to the other, the movement changing a degree of overlap of the metallic sensing member relative to the metallic sensing element, the change in the degree of overlap resulting in a change in a frequency of an output signal from the LC oscillator circuit, the output signal being indicative of a distance indicative of the axial pedal lash during brake pedal travel.
17. The system of claim 16, wherein the metal sensing element comprises a pair of spaced apart fixed metal elements arranged along a longitudinal axis of motion of the metal sensing member, the spaced apart fixed metal sensing elements defining a gap therebetween.
18. The system of claim 17, wherein the metal sensing member is arranged to at least partially overlap a gap between the pair of spaced apart fixed metal sensing elements during movement of one of the input member or the output member.
19. A method for sensing pedal lash within a brake assist system associated with a master cylinder of a braking system of a motor vehicle, the method comprising:
arranging a fixedly mounted sensing component within the brake assist system;
coupling an axially moveable input member to an input rod of the brake assist system, the input rod in turn being associated with a brake pedal of the vehicle, and wherein the input member is moveable in response to movement of the input rod and is further moveable in proximity to the fixedly mounted sensing component, the axially moveable input member comprising a first sensing device;
coupling an output member to an output rod of the brake assist system, the output member further being substantially axially aligned with and axially movable by the input member and carrying a second sensing device;
forming an inductive circuit having the first and second sensing devices and the fixedly mounted sensing component; and
generating, with the sensing circuit, a signal indicative of a distance representing an axial pedal clearance separating a face of the input member and a face of the output member during brake pedal travel in response to movement of at least one of the first sensing device, the second sensing device, and the fixedly mounted sensing component.
20. The method of claim 19, wherein disposing the fixedly mounted sensing component comprises fixedly disposing a coil within a housing of the brake assist system.
Technical Field
The present disclosure relates to braking systems for motor vehicles such as automobiles and trucks, and more particularly to systems and methods for more accurately sensing the clearance between a pedal rod and a piston rod in a master cylinder of a braking system.
Background
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Current braking systems for motor vehicles typically utilize a pedal travel sensor that detects the length of travel of the brake pedal as the operator depresses the brake pedal during a braking action. This detected length of movement of the brake pedal is used to determine the degree of braking action (i.e., braking force) that needs to be applied to the brake caliper of the vehicle.
Fig. 1a to 1c show a conventional master cylinder in which an
This gap 7 affects the accuracy of the braking force determination when the determination is made only by observing the distance traveled by the pedal 2 during a braking action. Determining the gap 7 will enable an even more accurate determination of the pedal travel and thus the braking force required for a given braking action. The improved accuracy of the clearance sensing may also result in improved pedal "feel" for the operator applying the brakes. However, determining the clearance 7 is not straightforward, as the clearance may vary within different brake assist systems, and may further vary over time due to wear of various internal parts of the brake assist system. Furthermore, the distance of the gap 7 needs to be accurately detected in real time to maximize the accuracy of determining the stroke length of the brake pedal 2. Also, the mechanism for sensing the gap 7 needs to be operable and integrated into the master cylinder without requiring significant modifications to the design and construction of the master cylinder and without significantly increasing its cost, size or weight.
Disclosure of Invention
The present disclosure relates to a brake assist system for use with a master cylinder of a motor vehicle braking system. The brake assist system may include an inductive sensing system. The inductive sensing system may include: a stationary sensing member fixedly disposed within the brake assist system; an axially movable input member operatively associated with an input rod, which in turn is associated with a brake pedal of the vehicle, and wherein the input member is movable in response to movement of the input rod and is further movable proximate the stationary sensing component. The axially moveable input member may comprise a first sensing arrangement. An output member may be included that is substantially axially aligned with the input member and adapted to be axially moved by the input member. The output member is operatively associated with an output lever of the brake assist system and includes a second sensing arrangement. The first and second sensing devices are arranged to simulate an axial pedal gap separating a face of the input rod and a face of the output rod. An inductive sensing system is responsive to movement of at least one of the input member and the output member relative to the other to provide an output signal indicative of a distance indicative of axial pedal clearance during brake pedal travel.
In another aspect, the present disclosure is directed to a brake assist system for use with a master cylinder of a motor vehicle braking system. The brake assist system may include an inductive sensing system for detecting a pedal clearance between a face of an input rod and a face of an output rod of the brake assist system. The inductive sensing system may include an AC input signal, a first fixedly mounted coil disposed within the brake assist system, and a second fixedly mounted coil disposed within the brake assist system and bounded by the first fixedly mounted coil, one of the first fixedly mounted coil and the second fixedly mounted coil receiving the input signal. An axially moveable input member may be included that is operatively associated with an input rod, which in turn is associated with a brake pedal of the vehicle. The input member is movable in response to movement of the input rod and is further movable about the first fixedly mounted coil and the second fixedly mounted coil. The axially moveable input member may comprise an input member coil. An output member is included that is substantially axially aligned with the input member and is adapted to be axially moved by the input member. The output member is operatively associated with an output lever of the brake assist system and includes an input member coil. The input member coil and the output member coil are further arranged to at least partially overlap each other during movement of the input rod and the output rod. The degree of overlap of the input member coil and the output member coil affects the inductive coupling between the first fixedly mounted coil and the second fixedly mounted coil during movement of at least one of the input rod and the output rod. One of the first fixedly mounted coil and the second fixedly mounted coil that does not receive an input signal provides an output signal indicative of axial pedal lash during brake pedal travel.
In yet another aspect, the present disclosure is directed to a method for sensing pedal lash within a brake assist system associated with a master cylinder of a braking system of a motor vehicle. The method may include disposing a fixedly mounted sensing component within a brake assist system, and coupling an axially moveable input member to an input rod of the brake assist system. The input rod may in turn be associated with a brake pedal of a vehicle, and wherein the input member is movable in response to movement of the input rod and is further movable in proximity to the fixedly mounted sensing component, and wherein the axially movable input member may comprise a first sensing device. The method may further include coupling an output member to an output rod of the brake assist system, the output member further being substantially axially aligned with and axially movable by the input member and carrying a second sensing device. The method may further include forming an inductive circuit having a first sensing device and a second sensing device and a fixedly mounted sensing component. The method may further include generating, with the sensing circuit, a signal indicative of a distance indicative of an axial pedal gap separating a face of the input member and a face of the output member during brake pedal travel in response to movement of at least one of the first sensing device, the second sensing device, and the fixedly mounted sensing component.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Drawings
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
FIG. 1a is a simplified side view of a master cylinder and brake assist system of the prior art, showing various internal components, particularly an input rod, an output rod and a reaction plate housed within the brake assist system;
FIG. 1b is a highly enlarged side view of a region within the prior art brake assist system of FIG. 1a where the input rod, output rod and reaction plate are located and better illustrating the clearance that exists between the face of the reaction plate and the face of the output rod;
FIG. 1c is a highly enlarged side view of a region within the prior art brake assist system of FIG. 1a showing different ways of defining pedal clearance;
FIG. 2 is a simplified block diagram of an inductive sensing system according to the present teachings that may be incorporated into the brake assist system shown in FIG. 1a to sense pedal lash in real time, the inductive sensing system having a first coil and a second coil for forming a variable coupling transformer that provides an electrical signal indicative of the degree of pedal lash present, the coils shown aligned to indicate that no pedal lash is present;
FIG. 3 illustrates the inductive sensing system of FIG. 2, but instead illustrates the first and second coils being misaligned to indicate the presence of a pedal gap;
FIG. 4 illustrates another inductive sensing system for sensing pedal lash using an LC oscillator circuit and a plurality of metal elements mounted on an output member with a gap therebetween and a rectangular metal member fixedly mounted on an input rod of a brake assist system in accordance with the present teachings;
FIG. 5 shows the inductive sensing system of FIG. 4, but with the input member partially extended toward the output member, which causes the frequency of the system's LC oscillator circuit to change, and thus indicates a change in the pedal gap distance;
FIG. 6 shows the inductive sensing system of FIG. 4, but with the input member fully extended over the output member, which produces the greatest change in frequency of the signal produced by the LC oscillator circuit;
FIG. 7 illustrates one example of how the inductive sensing of FIG. 4 may be implemented into portions of a brake assist system; and is
FIG. 8 illustrates the various components of FIG. 7 integrated into a brake assist system.
Detailed Description
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Referring to FIG. 2, one embodiment of a
The
One central feature of the
During construction of the
In operation, when a pedal gap is present, such as shown in FIG. 3, the inductive coupling (i.e., flux coupling) between the
An important advantage of the
Referring now to fig. 4, a
In FIG. 4, it can be seen that the
It has been described that the
During operation, when the
As the position of the
In fig. 6, the
The
Referring briefly to FIG. 7, a
The
The
It will be appreciated that both
Various embodiments of the present disclosure presented herein may be implemented with a limited number of additional components without significantly increasing the complexity, cost, or weight of the master cylinder system of the vehicle. It is expected that various embodiments will significantly improve the accuracy of determining brake pedal travel.
While various embodiments have been described, those skilled in the art will recognize modifications or variations that may be made without departing from the present disclosure. These examples illustrate various embodiments and are not intended to limit the disclosure. Accordingly, the specification and claims should be interpreted liberally with only such limitation as is necessary in the pertinent art.