Electric Brake Recognition-Error Detection and Control
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Solution Overview
Problem
Existing electric-brake systems face challenges in accurately detecting recognition errors in rotation-angle obtainers, leading to potential malfunctions and excessive backward movement of the pressing member, which can cause contact with other components without a stopper, resulting in brake malfunctions.
Innovation Solution
A recognition-error detector is implemented to detect errors based on the absolute and relative rotation angles obtained by the rotation-angle obtainer, utilizing specific error patterns and change patterns to identify recognition errors, and an electric-brake controller adjusts the control of the electric motor to prevent excessive backward movement by using positions determined from modified and actual change patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the rotation-angle obtainer uses calculated absolute rotation angle based on relative rotation angle, then the system can determine pressing member position, but recognition errors occur when data processor misrecognizes sensor values
Solution Approach 1:
The system continuously monitors the changing state of absolute rotation angle and compares it against expected patterns. When the rotation angle changes in an abnormal pattern (such as decreasing when it should increase), the system detects the recognition error and triggers corrective action by resetting the initial position, thereby preventing excessive backward movement of the pressing member.
Solution Approach 2:
The system performs preliminary detection of recognition errors by analyzing the changing state of rotation angle before excessive backward movement occurs. By detecting abnormal patterns in the rotation angle changes in advance, the system can reset the initial position proactively, preventing the pressing member from moving backward too far and potentially contacting other components.
2Device complexity
If the pressing member is allowed to move backward freely without stopper, then the brake system has simpler structure, but excessive backward movement can cause contact with other components leading to malfunction
Solution Approach 1:
The system replaces the mechanical stopper with an electronic control mechanism. Instead of using a physical stopper to prevent excessive backward movement, the system uses a recognition-error detector and controller that monitor rotation angle changes and electronically control the electric motor to reset the initial position when errors are detected, thereby eliminating the need for mechanical stoppers while maintaining reliability.
Solution Approach 2:
The brake system has the ability to self-diagnose and self-correct recognition errors without external intervention. When the detector identifies abnormal rotation angle patterns, the controller automatically resets the initial position, allowing the system to service itself and prevent malfunctions without requiring mechanical constraints like stoppers.
3Reliability
If the system resets initial position frequently to prevent recognition errors, then reliability improves, but operation time and response delay increase
Solution Approach 1:
The system performs initial position reset only when recognition errors are detected through abnormal rotation angle patterns, rather than resetting continuously or preventively. This partial action approach maintains reliability by correcting errors when they occur while minimizing unnecessary resets that would waste time and reduce operational efficiency.
Data Source
AI summary
An electric-brake controller controls an electric brake operable by an electric motor. The electric-brake controller includes: a rotation-angle obtainer including (i) a relative-rotation-angle obtaining unit that obtains a relative rotation angle of the electric motor for a set time, based on values output and received from a rotation-angle sensor at intervals of the set time, and (ii) an absolute-rotation-angle obtaining unit that calculates the obtained relative rotation angle with consideration of an orientation of the relative rotation angle to obtain an absolute rotation angle that is a rotation angle of the electric motor from a start of its operation; a recognition-error detector that detects a recognition error in the rotation-angle obtainer based on the obtained absolute rotation angle or a changing state of the absolute rotation angle; and a motor controller that controls the electric motor based on a result of detection performed by the recognition-error detector.