Automated Parking Brake Force Overlay and Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing automated parking brake systems rely solely on hydraulic pressure, which may not ensure effective brake pressure application on the rear axle, leading to safety concerns and inefficiencies.
Innovation Solution
A method that overlays hydraulic and electromechanical force components to achieve a total clamping force for parking brake processes, with distinct pressure levels set and maintained by a hydraulic actuator, ensuring precise pressure control and validation, even in the absence of direct sensors in the brake piston.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If hydraulic pressure is built up before applying the brake electromechanically, then the brake force is increased, but the pressure may not be effectively applied on the rear axle
Solution Approach 1:
The hydraulic pressure is built up in advance before the electromechanical brake application, so that when the brake is applied, the hydraulic pressure is already present and ready to provide additional braking force. This preliminary action ensures that the total clamping force is the sum of both hydraulic and electromechanical forces, improving the overall brake force while maintaining reliability through proper timing of the pressure build-up phase.
2Ease of manufacture
If a pressure sensor is placed at the brake master cylinder, then the pressure measurement is simple, but it cannot ensure the pressure is effective on the rear axle
Solution Approach 1:
The control unit acts as an intermediary that receives pressure data from the master cylinder sensor and uses this information to control the electromechanical actuator. By coordinating the electromechanical brake application based on the hydraulic pressure measurements, the system ensures effective pressure application on the rear axle even though the sensor itself remains at the master cylinder location.
3Device complexity
If only hydraulic pressure is used for automated parking brake, then the system is simpler, but the stopping efficiency is insufficient
Solution Approach 1:
The system merges hydraulic braking and electromechanical braking into a unified automated parking brake system. The hydraulic actuator provides initial pressure build-up while the electromechanical actuator applies the brake, creating a combined system that achieves superior stopping efficiency compared to hydraulic pressure alone, while maintaining reasonable system complexity through integrated control.
4Manufacturing precision
If the hydraulic pressure is held constant until the second condition, then the pressure control is precise, but the system response time is extended
Solution Approach 1:
The hydraulic pressure is held constant at a predetermined level during the intermediate phase between detecting the parking brake request and activating the electromechanical actuator. This preliminary maintenance of pressure ensures that when the brake is applied, the hydraulic force is already optimized, improving pressure control precision while the overall time loss is minimized through efficient transition to the braking phase.
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
This approach allows for safe and efficient vehicle stopping and parking by ensuring the correct build-up of clamping force, balancing different system speeds, and reducing the risk of pressure loss, while also adapting to environmental conditions like road inclines, thus enhancing safety and comfort.
Implementation Method 1
a hydraulic actuator (10) for generating a hydraulic force component
Implementation Method 2
an electromechanical actuator (2) for generating an electromechanical force component
Implementation Method 3
the hydraulic force component and the electromechanical force component are overlaid to achieve a total clamping force
Data Source
AI summary
A method for operating an automated parking brake in a motor vehicle with a hydraulic actuator for generating a hydraulic force component and an electromechanical actuator for generating an electromechanical force component, includes overlaying the hydraulic force component and the electromechanical force component to achieve a total clamping force for a parking brake process. The method further includes setting, on occurrence of a first condition, a first hydraulic pressure level, and setting, on occurrence of a second condition, a second hydraulic pressure level. The method also includes holding substantially constant the set first hydraulic pressure level with the hydraulic actuator until the occurrence of the second condition.