Electric Parking Brake Interface Current Timing for Reliable Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for operating electric parking brakes lack reliable detection of driver requests and are prone to electromagnetic interference, with inefficient power consumption and fault determination.
Innovation Solution
A method involving a timing sequence of current changes fed to terminals of an interface for an operator control element, with current measurements to determine driver requests, reducing electromagnetic interference and power consumption, and enabling adaptive operation across different control units, including fault detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous current is fed to the operator control element terminals, then reliable driver request detection is achieved, but power consumption increases
Solution Approach 1:
The patent implements periodic current feeding through timing sequences instead of continuous current supply. The control device feeds current in defined time sequences to the operator control element terminals, enabling reliable detection while reducing overall power consumption by eliminating continuous current flow.
2Object-generated harmful factors
If signal levels are reduced at the interface terminals, then electromagnetic interference decreases, but signal detection reliability may be compromised
Solution Approach 1:
By using periodic timing sequences with defined current feeding intervals, the patent reduces average signal levels at the interface terminals, thereby decreasing electromagnetic interference while maintaining sufficient signal strength during active measurement periods to ensure reliable detection.
Solution Approach 2:
The operator control element is designed to trigger its own reading process through the timing sequences. The control device feeds current and measures current in a self-sustaining cycle, where the measurement process itself enables the next measurement cycle without requiring continuous high-level signals.
3Adaptability or versatility
If the control unit directly determines actuator commands without functional decoupling, then response time is reduced, but adaptability to different operator control units decreases
Solution Approach 1:
The control device is segmented into a separate input unit that handles operator control element interfacing and current measurements, distinct from the control unit that determines actuator commands. This functional decoupling allows the input unit to be adapted to different operator control unit types while the control unit maintains its command determination logic.
Solution Approach 2:
The input unit acts as an intermediary between the operator control element and the control unit. It receives the operator's input, performs current measurements, determines the driver's request, and communicates this to the control unit, which then determines the actuator command. This intermediary enables adaptability without complicating the core control logic.
4Measurement precision
If current measurements are continuously performed, then driver request detection accuracy is improved, but power loss increases
Solution Approach 1:
Current measurements are performed periodically according to defined timing sequences rather than continuously. The control device feeds current and measures at specific intervals, achieving sufficient measurement precision for driver request detection while minimizing power loss during intervals when measurements are not active.
Data Source
AI summary
A method for operating an electric parking brake includes feeding a timing sequence of changes in current to terminals of an interface for an operator control element for the parking brake. The method further includes performing at least one current measurement at at least one terminal of the interface during the feeding of one of the changes in current. The method further includes determining a driver's request as a function of the at least one current measurement. The method further includes operating the electric parking brake as a function of the determined driver's request.