Cruise Control Gear Shift Stage Fixed Mode
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Solution Overview
Problem
Conventional cruise control devices for vehicles with multistep automatic transmissions experience delays and operation feeling issues due to frequent gear shifts and potential overshooting during acceleration control, as they change gear stages step-by-step to reach target acceleration.
Innovation Solution
The cruise control device employs a target gear shift stage fixed mode, where the gear shift stage is changed directly to the required stage for achieving target driving force, and then maintains that stage to prevent further shifts during acceleration control, reducing the number of gear shifts and shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If gradient restriction is applied to increase acceleration at a controlled rate, then operation feeling is improved, but the number of gear shifts increases and target acceleration is delayed
Solution Approach 1:
The control unit determines a target gear shift stage in advance based on the current state and required acceleration, then controls the transmission to shift to this predetermined stage, enabling the vehicle to reach target acceleration more quickly while maintaining smooth operation feeling through gradient restriction
2Object-affected harmful factors
If gear shift stage is changed step-by-step to reach target acceleration, then gear shift shocks are reduced, but the number of gear shifts increases and acceleration response is delayed
Solution Approach 1:
The control unit calculates and determines a target gear shift stage in advance based on current vehicle state and acceleration requirements, then directs the transmission to shift to this predetermined stage, reducing the number of intermediate shifts while maintaining shock reduction through controlled transition
Solution Approach 2:
The system dynamically adjusts the gear shift strategy by switching between normal control mode and target gear shift stage fixed mode based on acceleration requirements, allowing optimal balance between shock reduction and acceleration response under different driving conditions
3Ease of operation
If gradient restriction is applied during acceleration control, then operation feeling is improved, but gear shift stage changes frequently
Solution Approach 1:
The control unit determines a target gear shift stage in advance based on current state and acceleration requirements, then maintains this stage during acceleration control, reducing frequent gear shift changes while preserving the smooth acceleration characteristic provided by gradient restriction
Data Source
AI summary
A cruise control device of a vehicle including an engine and a multistep automatic transmission, includes an acceleration operation part, a driving-force operation part, and a control part that carries out acceleration control in which a driving force is brought close to a target driving force by changing a throttle-valve opening of the engine at least to bring the driving force close to a demand driving force. The control part carries out the acceleration control in a target gear shift stage fixed mode that is a control mode in which the acceleration control is carried out in a state where change of a gear shift stage is forbidden after changing the gear shift stage from a current gear shift stage that is a gear shift stage at present to a target gear shift stage that is a gear shift stage required for obtaining the target driving force at a stretch.