Vehicle Launch Acceleration Control Using Two-Stage Target Acceleration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle acceleration control systems fail to promptly increase vehicle acceleration to a recognizable level at the start of acceleration, leading to poor acceleration response and potential driver discomfort due to excessive jerk.
Innovation Solution
A vehicle control system that includes a control device to set a first target acceleration based on accelerator opening degree, and a second target acceleration with increased jerk within a predetermined range to improve acceleration response, while minimizing discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the target acceleration is set to increase the jerk of the vehicle to improve acceleration response, then the acceleration response is improved, but the driver may feel discomfort due to excessive jerk
Solution Approach 1:
The control device changes the parameter of target acceleration from a conventional increase pattern to a second pattern with greater rate of change, specifically designed to increase jerk within a predetermined range. This parameter change enables the acceleration to reach a recognizable level more quickly while constraining jerk to avoid driver discomfort.
Solution Approach 2:
The system dynamically adjusts the target acceleration setting based on the accelerator opening degree and its rate of change. When the rate of change of accelerator opening degree increases by a predetermined value or more, the system switches to the second target acceleration pattern, making the control characteristics adaptable to the driving situation.
2Object-affected harmful factors
If the target acceleration increases slowly in accordance with accelerator opening degree, then the driver discomfort is reduced, but the acceleration response is poor and the driver cannot recognize the start of acceleration
Solution Approach 1:
The target acceleration control is segmented into two distinct patterns: a first pattern for normal conditions and a second pattern for when rapid acceleration response is needed. The control device selects the appropriate pattern based on the rate of change of accelerator opening degree, enabling differentiated control strategies.
Solution Approach 2:
The system performs preliminary action by setting the target acceleration to increase at a greater rate before the driver can recognize the acceleration. This preliminary increase in acceleration rate ensures that the acceleration reaches the recognizable threshold quickly, addressing the problem of poor acceleration response at the start.
Data Source
AI summary
A vehicle control system includes a drive source, an accelerator opening degree sensor that detects an accelerator opening degree, and a control device that controls the drive source, and the control device includes a first control that sets a first target acceleration that increases in accordance with an increase in the accelerator opening degree and controls a torque of the drive source based on the first target acceleration, and a second control that sets a second target acceleration that increases at a rate of change greater than the first target acceleration applied in the first control, and first performs the second control when a rate of change of the accelerator opening degree increases by a predetermined value or more in a state in which the vehicle is not accelerating, and performs the first control after the second target acceleration set in the second control reaches a predetermined acceleration.