Predictive Transmission Shifting for Upcoming Road Grade Changes
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Solution Overview
Problem
Existing transmission systems lack the ability to predictively adjust gear shifts based on future road grade changes, leading to suboptimal drivability and fuel economy, especially when encountering hills.
Innovation Solution
A predictive shift system that utilizes road grade data to classify future road sections and communicate shift recommendations to a transmission controller, triggering or inhibiting gear shifts to maintain vehicle speed within a performance threshold, thereby enhancing shift decisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional transmission systems use standard shift patterns based on current speed and acceleration, then the transmission control is simple and responsive, but the drivability and fuel economy deteriorate when encountering future road grade changes like hills
Solution Approach 1:
The system performs preliminary actions by receiving future road grade data and predicting speed changes before the vehicle actually encounters the hill. The processor identifies upcoming uphill or downhill sections and determines optimal shift recommendations in advance, allowing the transmission to be pre-positioned for better fuel economy without waiting for the grade change to occur
Solution Approach 2:
The system implements feedback by continuously monitoring current vehicle speed, acceleration, and future road grade conditions, then using this information to dynamically adjust shift recommendations. The controller receives feedback from the processor about predicted speed deviations and modifies transmission shifting accordingly to maintain optimal performance
2Ease of operation
If the transmission shifts gears based on predicted speed changes, then drivability and fuel economy improve, but the complexity of the transmission control system increases
Solution Approach 1:
The system determines shift recommendations in advance by analyzing future road grade data before the vehicle reaches the grade change. This preliminary analysis allows the transmission to be optimally positioned for upcoming hills or descents, improving drivability without requiring complex real-time adjustments when the grade change occurs
Solution Approach 2:
The processor acts as an intermediary between the road grade data and the transmission controller. It receives future road grade information, processes it to predict speed changes, and generates shift recommendations that are then communicated to the controller, simplifying the overall system architecture while enabling intelligent predictive shifting
3Speed
If the system triggers downshifts in advance of uphill sections, then vehicle speed is maintained within performance threshold, but the frequency of gear shifts increases
Solution Approach 1:
The system triggers downshifts in advance of uphill sections by analyzing future road grade data and predicting speed changes before the vehicle encounters the hill. This allows the transmission to be pre-positioned in the appropriate gear, maintaining vehicle speed within the performance threshold without requiring multiple corrective shifts during the actual climb
Data Source
AI summary
A vehicle transmission can perform predictive shifting. Road grade and vehicle path data can be employed to identify a future change in road grade such as a hill. A change in speed relative to a vehicle cruise speed can be estimated or predicted in view of the change in road grade and a current gear. If the change of speed is determined to be outside a performance bound, shift recommendation can be determined to maintain vehicle cruise speed within the performance bound. A controller can alter default gear selection of the transmission in response to receipt of the shift recommendation.