Hybrid Vehicle Control Device for Gear Upshift Driving Force Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles experience a reduction in driving force output to the driveshaft during gear upshifts, leading to deterioration in driver feel due to the upper limit driving force becoming smaller than the required driving force.
Innovation Solution
The hybrid vehicle employs a control device that sets a target driving force based on the relationship between the required driving force and the upper limit driving force, using power storage device compensation to ensure a consistent driving force output by charging or discharging power based on the difference, thereby maintaining a larger driving force during gear upshifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the upper limit power of the engine is set based on target rotation speed during gear upshift, then the engine operates at appropriate rotation speeds, but the upper limit driving force decreases and becomes smaller than the required driving force
Solution Approach 1:
The power storage device acts as an intermediary between the engine and the driveshaft. When the upper limit driving force decreases during gear upshift, the power storage device compensates by providing additional driving force through discharge, ensuring the total driving force meets the required level while the engine operates at appropriate rotation speeds.
Solution Approach 2:
The system dynamically adjusts the upper limit driving force parameter based on the charging state of the power storage device. When the power storage device is in a discharged state during gear upshift, the control device increases the upper limit driving force to compensate for the reduction, maintaining adequate driving force output.
2Speed
If the gear ratio is changed during upshift, then the vehicle speed control is improved, but the driving force output to the driveshaft is reduced
Solution Approach 1:
The control device predicts the reduction in upper limit driving force that will occur during gear upshift and takes preliminary action by increasing the upper limit driving force in advance when the power storage device is in a discharged state. This prevents the driving force from becoming insufficient during the upshift transition.
Solution Approach 2:
The control device continuously monitors the charging state of the power storage device and the gear ratio changes, and adjusts the upper limit driving force accordingly. When detecting that the power storage device is discharged and gear upshift is occurring, the system provides feedback to increase the upper limit driving force to maintain adequate output.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively suppresses the reduction in driving force output during gear upshifts, enhancing the driver's feel by ensuring a consistent and adequate driving force is maintained, thus improving drivability.
Implementation Method 1
a power storage device configured to transmit electric power to and from the first motor and the second motor
Data Source
AI summary
In a hybrid vehicle, when a required driving force is equal to or smaller than a first upper limit driving force, a control device sets a target driving force to the required driving force. When the required driving force is larger than the first upper limit driving force, the control device sets a target compensation power of a power storage device, based on a difference between the required driving force and the first upper limit driving force. The control device sets a second upper limit driving force of a driveshaft when an upper limit power is output from an engine and the power storage device is charged or discharged with a power based on the target compensation power. The control device sets a target driving force to the smaller between the required driving force and the second upper limit driving force. This configuration suppresses deterioration of the driver's drive feeling.