Vehicle Drive Transfer Control Device Torque Fluctuation Suppression
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Solution Overview
Problem
Existing vehicle drive transfer devices experience fluctuations in output torque during speed changes due to inadequate control of engagement pressure for engagement devices, which is not addressed in existing technologies.
Innovation Solution
A control device that includes an electronic control unit to manage engagement pressures for engagement and disengagement devices, varying the engagement pressure for the engagement-side device at a constant or higher variation rate to control input torque and stabilize output torque during shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If speed change control is performed by varying rotational speed during shifting, then shift speed switching is achieved, but output torque fluctuations occur due to inadequate engagement pressure control
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the engagement pressure of the engagement-side engagement device during the shifting process. Specifically, the engagement pressure is increased at a controlled rate during the inertia phase to match the varying torque transfer requirements, thereby suppressing output torque fluctuations while enabling smooth shift speed transitions.
2Stability of the object's composition
If engagement pressure for engagement-side device is increased to suppress torque fluctuations, then output torque stability improves, but engagement pressure control complexity increases
Solution Approach 1:
The patent implements feedback control by continuously monitoring the shifting state and adjusting the engagement pressure accordingly. The control system detects the inertia phase and engages/disengages phases, and based on this feedback, dynamically modifies the engagement pressure command to suppress torque fluctuations. This feedback mechanism enables stable output torque without requiring overly complex control systems.
3Productivity
If torque transfer distribution is varied between engagement devices, then shifting performance improves, but torque transfer control difficulty increases
Solution Approach 1:
The patent applies preliminary action by pre-planning the engagement pressure variation pattern before the shifting occurs. The control system determines in advance the rate of engagement pressure increase and the timing for transitioning between engage and disengage phases. This preliminary planning simplifies the real-time control difficulty by providing a predetermined torque transfer distribution strategy that optimizes shifting performance.
Data Source
AI summary
A control device that controls a vehicle drive transfer device in which a speed change device that includes a plurality of engagement devices and that selectively establishes one of a plurality of shift speeds with different speed ratios in accordance with a state of engagement of the plurality of engagement devices is provided in a power transfer path that connects between a drive force source and wheels.