Electric Brake Pad Contact Detection via Sensor Feedback
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Solution Overview
Problem
Existing electric brake systems for vehicles face challenges in accurately detecting contact between a brake pad and rotor with minimal braking force, as this contact position changes due to wear and thermal expansion, affecting braking force consistency.
Innovation Solution
An electric brake system with a movable motor portion and sensors that utilize the Mahalanobis Taguchi System to analyze motor and wheel data, adjusting the minimal contact position based on sensed conditions to maintain optimal braking force, including motor current, acceleration, voltage, speed, and temperature, ensuring consistent braking performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the brake pad is pressed against the brake rotor to generate braking force, then braking force is generated, but the contact position changes due to wear and thermal expansion, causing inconsistency in braking force
Solution Approach 1:
The system dynamically adjusts the minimal contact position over time based on sensor feedback. The controller receives data from sensors monitoring brake pad wear, thermal expansion, and rotor runout, then recalculates and updates the minimal contact position to maintain consistent braking force despite changing physical conditions
Solution Approach 2:
The system implements a closed-loop feedback mechanism where sensors continuously monitor brake system parameters (pad wear, temperature, rotor runout) and communicate this data to the controller. The controller uses this feedback to detect when the brake pad contacts the rotor and adjusts the minimal contact position accordingly, ensuring consistent braking force application
2Reliability
If sensors are added to detect brake pad contact and adjust minimal contact position, then braking force consistency is improved, but device complexity increases
Solution Approach 1:
The system uses existing sensors in the brake system for multiple purposes. Sensors originally designed to monitor general brake conditions are also utilized to detect minimal contact position and track brake pad wear, thermal expansion, and rotor runout. This multi-functionality approach avoids adding dedicated sensors solely for contact detection, thereby reducing overall system complexity
Data Source
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AI summary
The invention provides an electric brake system (10) and method. The electric brake system (10) includes an electric motor (12) having a portion (14) moveable along a path (16) between a plurality of positions for moving a brake pad (18) and applying a selectable amount of braking force on a brake rotor (20). One of the plurality of positions is a minimal contact position. The minimal contact position is operable to change among the plurality of positions over time. The electric brake system (10) also includes an electric controller (22) for controlling the electric motor (12) to move the portion (14) along the path (16) between the minimal contact position and at least one other of the plurality of positions for moving the brake pad (18) and for selecting the amount of braking force. The electric brake system (10) also includes at least one sensor (24, 26, 28, 30, 32) for sensing at least one of motor current, motor acceleration, controller voltage, motor speed, motor voltage, and motor temperature, and communicating a sensed condition to the controller (22). The controller (22) is operable to change the minimal contact position in response to the condition sensed and communicated by the at least one sensor.