Electronic Brake Caliper Pressure Modulation for Creep Groan Reduction
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Solution Overview
Problem
Existing vehicle brake systems fail to effectively reduce brake noise, such as creep groan, which occurs during transitions from static to sliding friction, affecting driver experience and vehicle operation.
Innovation Solution
A vehicle electronic brake system with a master cylinder, an electrically controllable pressure generating device, and a control unit that modulates caliper pressure through a network of valves to selectively manage brake pressure, reducing noise while ensuring adequate braking, by determining conditions conducive to noise occurrence and adjusting pressure accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional brake systems are used, then braking function is provided, but brake noise such as creep groan occurs during transitions from static to sliding friction
Solution Approach 1:
The patent replaces the purely mechanical brake system with an electronically controlled system. A control unit with processor circuit receives signals from noise detection sensors and actively modulates caliper pressure using electrically controllable valves and a pressure generating device to prevent brake noise, transforming a passive mechanical system into an active electronically controlled system.
Solution Approach 2:
The patent implements a feedback control mechanism where sensors detect brake noise conditions and transmit signals to the control unit. The control unit processes this information and adjusts caliper pressure in real-time through the pressure generating device and control valves, creating a closed-loop system that continuously monitors and corrects brake noise.
2Object-affected harmful factors
If caliper pressure is modulated to reduce brake noise, then brake noise is reduced, but braking performance may be compromised
Solution Approach 1:
The patent employs dynamic pressure modulation rather than static pressure control. The pressure generating device and control valves adjust caliper pressure in real-time based on actual brake noise conditions, vehicle speed, and braking demand, allowing the system to maintain optimal braking performance while actively suppressing noise during specific operating conditions.
Solution Approach 2:
The patent changes the pressure parameter dynamically by supplying or releasing pressure to specific calipers based on detected noise conditions. The control unit modulates pressure levels selectively during noise-prone conditions while maintaining normal pressure during non-noisy operation, ensuring braking performance is preserved across different operating scenarios.
3Object-affected harmful factors
If electronic control components are added to reduce brake noise, then brake noise reduction capability is improved, but device complexity increases
Solution Approach 1:
The control unit with processor circuit serves multiple functions: it receives noise detection signals, processes the information to determine noise conditions, controls the pressure generating device, and manages the control valves. This multi-functional integration reduces the need for separate dedicated components for each function, thereby limiting the increase in overall system complexity.
Solution Approach 2:
The pressure generating device acts as an intermediary component between the electronic control system and the hydraulic brake system. It translates electronic control signals into precise hydraulic pressure adjustments at the calipers, serving as a bridge that enables noise control without requiring direct electronic actuation of each brake component.
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 system effectively reduces brake noise like creep groan by dynamically managing caliper pressure, ensuring quiet operation and maintaining braking performance, even in conditions where noise is likely to occur, such as at static rotors or low speeds.
Implementation Method 1
an electrically controllable pressure generating device constructed and arranged to deliver a brake system pressure
Implementation Method 2
A plurality of valves is fluidly coupled between the calipers and the master cylinder
Implementation Method 3
creep groan is thought to be caused by the brake lining and rotor transitioning from static to sliding friction
Data Source
AI summary
A vehicle brake system has front and rear wheel brakes with each brake including a caliper associated with a rotor. A master cylinder is activated by a brake pedal to which the wheel brakes are connected. An electrically controllable pressure generating device delivers a brake system pressure. A plurality of valves is fluidly coupled between the calipers and the master cylinder. A control unit has a processor circuit to determine if the vehicle is operating under a condition where brake noise can occur and if so, the control unit controls the pressure generating device and certain of the valves to selectively control caliper pressure by supplying pressure or releasing pressure to certain ones of the calipers to reduce the brake noise, while ensuring adequate braking of the vehicle.