Brake Pedal Simulator With Two-Stage Restoring Force Feedback
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Solution Overview
Problem
Current pedal simulation devices in automotive braking systems provide limited and unreliable haptic feedback to drivers, failing to effectively mimic the hydraulic pressure and braking effect in brake-by-wire systems.
Innovation Solution
A pedal simulation device with a restoring device comprising a first elastically deformable restoring element with a non-linear spring characteristic and a second elastically deformable restoring element with a linear spring characteristic, along with a coupling unit and intermediate coupling unit, which provide distinct phases of piston displacement to simulate the braking process, ensuring precise and consistent haptic feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single restoring element is used in the pedal simulation device, then the device structure is simple, but the haptic feedback is limited and unreliable
Solution Approach 1:
The restoring device is segmented into multiple restoring elements (first restoring element with non-linear spring characteristic and second restoring element with linear spring characteristic) that operate in distinct phases. This segmentation allows each element to contribute differently to the haptic feedback, improving reliability while maintaining manageable structural complexity through functional division.
Solution Approach 2:
Different restoring elements are assigned different local qualities (non-linear vs. linear spring characteristics) to provide varied haptic feedback during different actuation phases. The first restoring element provides non-linear feedback for initial pedal travel, while the second provides linear feedback for subsequent travel, creating reliable and nuanced haptic feedback without requiring a completely complex device structure.
2Measurement precision
If multiple restoring elements with different spring characteristics are used, then precise haptic feedback is achieved, but the device complexity increases
Solution Approach 1:
The restoring device is divided into distinct restoring elements (first and second restoring elements) with different spring characteristics that operate in sequential phases. This segmentation enables precise control over haptic feedback characteristics during different stages of pedal actuation, achieving measurement precision through functional decomposition rather than monolithic complexity.
Solution Approach 2:
The restoring device employs dynamic phase transitions between different restoring elements. During the first actuation phase, the first restoring element with non-linear spring characteristic is predominantly deformed; during the second actuation phase, the second restoring element with linear spring characteristic is predominantly deformed. This dynamic switching enables precise haptic feedback adaptation without requiring all elements to be simultaneously active, managing device complexity.
3Manufacturing precision
If a single phase of piston displacement is used, then the actuation process is simple, but the pedal feel is unnatural and imprecise
Solution Approach 1:
The piston actuation process is segmented into distinct phases (first actuation phase and second actuation phase) with different restoring element deformations. This segmentation enables precise control over pedal feel characteristics during different stages of actuation, achieving manufacturing precision through phased operation rather than uniform single-phase actuation.
Solution Approach 2:
The restoring device operates through periodic phase transitions during piston actuation. The first restoring element is predominantly deformed during the first actuation phase, then the second restoring element is predominantly deformed during the second actuation phase. This periodic switching between phases creates a natural and precise pedal feel that mimics real brake system behavior without requiring continuously complex actuation mechanisms.
4Ease of operation
If restoring elements are deformed simultaneously, then the restoring force is consistent, but the pedal feel lacks natural variation
Solution Approach 1:
The restoring device dynamically transitions between different deformation phases rather than maintaining simultaneous deformation. During the first actuation phase, the first restoring element is predominantly deformed; during the second actuation phase, the second restoring element is predominantly deformed. This dynamic phase-based approach creates natural pedal feel variation while maintaining haptic feedback consistency through controlled transitions, resolving the contradiction between naturalness and reliability.
Solution Approach 2:
The restoring elements operate through periodic phase transitions rather than simultaneous deformation. The first restoring element is activated during the first actuation phase, then the second restoring element is activated during the second actuation phase. This periodic action pattern creates natural pedal feel variation that mimics real braking behavior while ensuring consistent haptic feedback through structured phase transitions, achieving both ease of operation and reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device delivers a natural and precise pedal feel by varying restoring forces through different phases of actuation, enhancing driver feedback and operational consistency over long periods.
Implementation Method 1
a first elastically deformable restoring element (54), which has a substantially non-linear spring characteristic
Implementation Method 2
a second elastically deformable restoring element (56), which has a substantially linear spring characteristic
Data Source
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AI summary
The invention relates to a pedal simulation device (10), comprising: a housing (36); a stop region (64), which is coupled substantially rigidly to the housing (36); a piston (44), which is accommodated in the housing (36) in such a way that the piston can be moved in an actuation direction (B), the piston thus passing through consecutive first and second actuation phases (B, C - Figure 5); a restoring device (46), which is designed to apply a restoring force to the piston (44), which restoring force acts against the displacement of the piston occurring in the actuation direction (B); the restoring device (46) comprising the following: a first elastically deformable restoring element (54), which has a substantially nonlinear spring characteristic curve, a second elastically deformable restoring element (56), which has a substantially linear spring characteristic curve, and a coupling unit (58), the first and second restoring elements (54, 56) being designed to be supported against each other by means of the coupling unit (58) at least as a result of a brake pedal actuation, the coupling unit (58) being displaceable during the first actuation phase (B - Figure 5) of the piston (44) in such a way that predominantly or substantially exclusively the first restoring element (54) is deformed, the coupling unit (58) being designed, after the first actuation phase (B - Figure 5) has been passed through, to be supported on the stop region (64) in such a way that further displacement in the actuation direction (B) is prevented, and the piston (44), during the second actuation phase (C), being designed to be displaced further in the actuation direction (B) in such a way that predominantly or substantially exclusively the second restoring element (56) is deformed.