Electronic Brake Diagnostics Using Test Current During Driving
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Solution Overview
Problem
Existing diagnostic methods for electronic vehicle brake systems fail to accurately determine the effectiveness of brake actions while the vehicle is in motion, leading to potential safety risks due to undetected malfunctions.
Innovation Solution
A method that generates a test current value, compares it to an expected brake effect value, and uses sensors to measure the actual brake effect while the vehicle is driven, providing a diagnostic result by assessing the difference between expected and actual brake performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing diagnostic methods measure brake force when the vehicle is standing still, then the brake force can be measured and compared to an expected value, but the method cannot determine whether the effect of the brake action corresponds to an expected effect while the vehicle is driving
Solution Approach 1:
The diagnostic method transitions from static vehicle conditions (standing still) to dynamic vehicle conditions (driving). The system performs brake diagnostics while the vehicle is in motion, allowing measurement of brake effects under realistic operating conditions. This enables accurate determination of whether the actual brake effect corresponds to the expected brake effect during vehicle operation.
Solution Approach 2:
The system implements a feedback mechanism by comparing the measured brake effect (obtained from sensor data during vehicle operation) with the expected brake effect (calculated from test current values and vehicle characteristics). This feedback loop enables continuous monitoring and diagnosis of brake system performance while the vehicle is driving, resolving the contradiction between measurement accuracy and operational applicability.
2Reliability
If the vehicle is stopped for brake diagnosis, then the brake force can be measured, but the diagnosis does not reflect actual brake performance during driving
Solution Approach 1:
The system performs preliminary actions by continuously collecting sensor data and calculating expected brake effects during normal vehicle operation. When a diagnostic test is initiated, the system already has accumulated data and can immediately compare measured brake effects with expected values, enabling rapid diagnosis without requiring vehicle stoppage. This eliminates the need to lose operational time while maintaining high diagnostic reliability.
Solution Approach 2:
The diagnostic system operates continuously during vehicle driving rather than requiring intermittent stoppages. The sensor continuously measures brake effects, and the system continuously compares actual performance with expected performance based on test current values. This continuous operation maintains both high diagnostic reliability and maximizes vehicle operational time by eliminating diagnostic stoppages.
3Measurement precision
If a test current is supplied to the electric brake motor during vehicle operation, then the actual brake effect can be measured and compared to expected values, but this may disrupt vehicle operation
Solution Approach 1:
The system applies partial action by supplying test current values that are sufficient to generate measurable brake effects but are optimized to minimize disruption to normal vehicle operation. The test current is carefully controlled to achieve the minimum necessary brake effect for accurate measurement and comparison with expected values, thereby reducing harmful disruptions while maintaining measurement precision.
Solution Approach 2:
The system changes parameters by dynamically adjusting the test current values supplied to the electric brake motor based on vehicle operating conditions. The test current magnitude and duration are optimized to generate measurable brake effects without significantly disrupting vehicle performance. This parameter optimization allows accurate brake effect measurement during operation while minimizing harmful disruptions to the driving experience.
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
Enables accurate diagnosis of brake system performance during vehicle operation, allowing for timely detection of potential issues and minimizing disruption to the vehicle's operation.
Implementation Method 1
The forcing of the brake pad against the brake disc causes friction between the brake pad and the brake disc, and therewith a brake force is generated
Data Source
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AI summary
The invention pertains to a method for diagnosing an electronic vehicle brake system, a vehicle comprising such an electronic vehicle brake system, a controller configured to for diagnose an electronic vehicle brake system and a computer program for diagnosing an electronic vehicle brake system. The method comprises the steps of generating a test current value and an expected brake effect value, instructing a brake power source of the electronic brake system to supply a test current to an electric brake motor of the electronic brake system, receiving a brake effect measurement value from a sensor of the vehicle, and obtaining a diagnostic result by comparing the brake effect measurement value with the expected brake effect value. Optionally, the brake effect comprises an increase in power supplied from a wheel motor power source to an electric wheel motor, such as an in-wheel motor, of the vehicle.