Automatic Transmission Controller Gear Shift Dynamics
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Solution Overview
Problem
Conventional multi-stage automatic transmissions experience excessive work loss and increased hydraulic oil temperature due to rotational differences in engagement mechanisms, which affect vehicle acceleration and fuel efficiency, and lack flexibility in gear shifting to achieve quick and smooth operations across multiple gear stages.
Innovation Solution
A control apparatus for automatic transmission that includes a vehicle speed detector and a controller to select appropriate engagement combinations of planetary gear mechanisms, allowing for multiple gear change stages with different transmission ratios by adjusting the engagement state of clutches and brakes, enabling quick and smooth gear changes, including skip gear changes, to optimize vehicle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a predetermined gear change stage is selected in conventional automatic transmissions, then the transmission can achieve multiple gear stages, but excessive work loss occurs due to rotational difference between friction members
Solution Approach 1:
The patent applies dynamics by making the engagement combination state changeable based on operating conditions. The controller dynamically selects between first and second engagement combination states to achieve the same gear change stage, allowing the transmission to adapt its internal configuration to minimize rotational difference and work loss while maintaining gear change flexibility.
Solution Approach 2:
The patent changes the engagement combination parameters (which specific engagement mechanisms are engaged) while maintaining the same gear change stage. By switching between different engagement combination states (first vs. second state), the system optimizes the rotational difference parameter to reduce work loss without sacrificing adaptability.
2Temperature
If friction members are engaged in conventional automatic transmissions, then gear change stages are achieved, but excessive rotational difference causes increased hydraulic oil temperature
Solution Approach 1:
The system dynamically adjusts the engagement combination state based on vehicle speed and acceleration requirements. At low speeds where acceleration is critical, the first engagement combination state is used. At higher speeds, the second engagement combination state is selected to reduce rotational difference and hydraulic oil temperature, thus balancing productivity and temperature control.
Solution Approach 2:
The controller changes the engagement combination parameters to optimize the balance between vehicle acceleration and hydraulic oil temperature. By selecting appropriate engagement combinations based on operating conditions, the system maintains effective torque transmission for acceleration while minimizing excessive rotational difference that would cause temperature increase.
3Adaptability or versatility
If multiple engagement mechanisms are used for gear change, then skip gear change is enabled, but selection of appropriate engagement combination becomes complex
Solution Approach 1:
The controller uses feedback from vehicle speed detection to automatically select the appropriate engagement combination state. This feedback mechanism simplifies the complexity by providing clear decision logic: based on detected vehicle speed and acceleration requirements, the controller determines whether to use the first or second engagement combination state, eliminating the need for complex manual selection while enabling skip gear change capability.
Data Source
AI summary
A control apparatus for an automatic transmission includes a vehicle speed detector and a controller. The vehicle speed detector is configured to detect a vehicle speed. The controller is configured to set one of a plurality of gear change stages according to a running condition of a vehicle and configured to select one of a plurality of engagement combination states of a plurality of engagement mechanisms to achieve, according to the vehicle speed detected by the vehicle speed detector, at least one gear change stage out of the plurality of gear change stages in a case in which the controller sets the at least one gear change stage. The at least one gear change stage has the plurality of engagement combination states to achieve the at least one gear change stage.