Transmission Range Selector Monitoring for Fault Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current powertrain systems lack effective monitoring mechanisms to ensure accurate transmission range selection and prevent unintended propulsion or direction changes, which can lead to safety hazards if the target transmission range is not achieved within specified time limits or if there are incorrect direction or unintended propulsion metrics.
Innovation Solution
A method for monitoring the transmission range selector that includes detecting changes in the target range, checking for incorrect direction and unintended propulsion metrics, and executing default actions when predefined time limits or metrics are exceeded, ensuring the transmission operates as intended and preventing safety hazards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transmission range selection is monitored with multiple metrics and time limits, then safety and reliability are improved, but device complexity increases
Solution Approach 1:
The monitoring system is segmented into distinct functional modules: a target range detector that identifies desired transmission ranges, an on-board sensor that monitors actual transmission position, a time limit monitor that tracks duration metrics, and a fault detector that analyzes multiple parameters including incorrect direction metrics and unintended propulsion metrics. Each module performs a specific function, making the overall complex system manageable and maintainable while ensuring comprehensive safety monitoring
Solution Approach 2:
The system implements continuous feedback loops where the on-board sensor provides real-time position feedback to the controller, which compares actual transmission range against the target range. The time limit monitor provides feedback on how long the transmission has been in each range, and the fault detector provides feedback when any metric exceeds safe thresholds. This multi-layered feedback mechanism ensures reliable detection and response to transmission anomalies
2Object-affected harmful factors
If the system monitors multiple metrics including incorrect direction and unintended propulsion, then safety is improved, but measurement precision requirements increase
Solution Approach 1:
The monitoring system applies different precision requirements to different metrics based on their safety criticality. The incorrect direction metric monitors transmission output shaft rotation direction with high precision to detect reverse vs. forward motion errors. The unintended propulsion metric monitors engine torque and transmission clutch engagement with appropriate precision thresholds. The time limit metric uses coarser precision for duration measurement. This localized precision approach ensures safety-critical parameters are measured accurately while reducing overall system complexity
Solution Approach 2:
The system dynamically adjusts monitoring parameters and thresholds based on operating conditions. The incorrect direction metric threshold changes based on vehicle speed and load conditions. The unintended propulsion metric uses variable thresholds that account for engine torque variations and transmission gear state. This adaptive parameter approach maintains high safety standards while accommodating normal measurement variations in different operating scenarios
Data Source
AI summary
A method for monitoring a transmission range selector connected to a transmission of a powertrain system is described. The transmission range selector indicates one of a plurality of ranges including Park, Reverse, Neutral, and Drive. The method includes, upon detecting a change in a target transmission range, monitoring whether a signal output from an on-board sensor indicates an achieved range position of the transmission. When the signal output from the on-board sensor does not indicate that the target transmission range has been achieved, monitoring a transmission incorrect direction metric, monitoring a transmission unintended propulsion metric, and monitoring a metric associated with achieving the target transmission range. A fault is detected when any one of the transmission incorrect direction metric, the transmission unintended propulsion metric and the target range achievement elapsed time metric is exceeded.