Automatic Transmission Control Logic for Driver Gear Selection
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Solution Overview
Problem
Existing arrangements for controlling automatically shifting transmissions in motor vehicles do not effectively enhance driver influence over gear changes, particularly in transitioning between automatic and manual modes, leading to suboptimal driver control and comfort.
Innovation Solution
An electronic control unit is configured to manage the automatically shifting transmission by requiring a specified minimum duration of actuation for the second selecting device and recognizing simultaneous or successive opposite commands to determine when to return to automatic gear change control, allowing for immediate upshifting or downshifting and maintaining gear selection until the actuation is terminated or opposite commands are given.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the second selecting device is actuated to trigger immediate upshifting or downshifting from automatic mode, then driver control over gear changes is improved, but the system complexity and control logic complexity increase
Solution Approach 1:
The control unit is pre-programmed with specific actuation duration thresholds and command recognition patterns. When the second selecting device is actuated, the system automatically compares the actuation duration against predefined minimum durations and evaluates whether opposite commands are present, enabling immediate determination of whether to return to automatic mode without complex real-time deliberation
Solution Approach 2:
The system continuously monitors the state of the second selecting device, detecting both the duration of actuation and the presence of opposite commands (upshift vs downshift). This feedback mechanism allows the control unit to automatically recognize when conditions warrant returning to automatic mode, creating a closed-loop control system that responds dynamically to driver input patterns
2Extent of automation
If the transmission returns to automatic mode after a predefined time period, then the system automatically recovers from manual mode, but driver performance intentions may be lost before the intended gear change is complete
Solution Approach 1:
The control unit is configured to evaluate multiple conditions simultaneously before initiating the return to automatic mode: it checks whether the actuation duration has reached the minimum threshold, whether opposite commands are present, and whether the actuation has been terminated. This preliminary evaluation ensures that the system only returns to automatic mode when the driver's intent is clearly established
Solution Approach 2:
The system implements continuous monitoring of the second selecting device state, tracking both the duration of actuation and the sequence of commands. This feedback allows the control unit to distinguish between tentative driver inputs (brief actuations without opposite commands) and deliberate gear change intentions (sustained actuations or sequences with opposite commands), ensuring reliable interpretation of driver performance intentions
3Speed
If brief actuation of the second selecting device triggers immediate gear change, then responsiveness to driver input is improved, but accidental or unintended gear changes may occur
Solution Approach 1:
The control unit is configured to prevent immediate gear change in cases of brief actuation by requiring that the actuation duration reach a minimum threshold before the gear change is executed. This preliminary anti-action counteracts the potential harm of accidental gear changes while preserving the ability to respond quickly to deliberate driver inputs that meet the duration criterion
Solution Approach 2:
The system dynamically adjusts its response based on the actual duration of actuation. For actuations that meet or exceed the minimum duration, the system executes immediate gear change for responsiveness. For actuations below the threshold, the system maintains the current gear or requires additional conditions (such as presence of opposite commands) before allowing gear change, thereby adapting the responsiveness level to the certainty of driver intent
Data Source
AI summary
In an arrangement for controlling an automatically shifting transmission, as a result of a corresponding programming of an electric control device, when actuating a second selecting device, starting from the automatic mode, first an immediate upshifting or downshifting can be prompted and is permitted unless prevented by a specified condition. In the case of a brief actuation, a first or further immediate upshifting and/or downshifting can be prompted and the current or thereby reached gear will be maintained until, first, the duration of the actuation has reached the specific minimum duration and, second, the actuation of the selecting device was terminated. When the second selecting device has a first operating element for the manual triggering of an upshift command and a second operating element for the manual triggering of a downshift command, the event controlling the return to the automatic mode may be the recognition of the simultaneously present commands downshifting and upshifting. After a first actuation of the second selecting device for the purpose of a manually prompted immediate up- or downshifting, a transition may immediately take place to the automatic gear change control according to the automatic mode, if subsequently thereto, an actuation of the second selecting device for the purpose of a gear change in a direction opposite thereto takes place within a comparatively brief time window.