Vehicle Drive Control Torque Shock Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle drive control systems experience torque shock when starting movement in creeping mode due to excessive output of motor generator driving force during engine restart, caused by peak rotation load torque and friction torque variations.
Innovation Solution
A vehicle drive control system that controls the motor to output a preliminarily set initial driving torque until the engine rotation speed reaches a predetermined speed, and then adjusts the driving torque through rotation speed feedback control to minimize torque shock and ensure smooth engine restart.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If ordinary feedback control is applied to the motor generator with a target rotation speed of idle rotation speed, then the engine rotation speed can be raised to idle rotation speed, but the integration value of rotation-speed deviations becomes abnormally large before engine start, causing excessive output of driving force and large torque shock when vehicle starts moving
Solution Approach 1:
The control method applies preliminary action by detecting whether the engine rotation speed is below a predetermined threshold and, if so, setting the driving force output to a predetermined value before the engine starts rotating. This preliminary control prevents the integration value of rotation-speed deviations from becoming abnormally large, thereby avoiding excessive driving force output and torque shock when the vehicle starts moving.
Solution Approach 2:
The control system dynamically adjusts the driving force output based on the engine rotation speed condition. When the engine rotation speed is below the predetermined value, the driving force is set to a predetermined value; when the engine rotation speed reaches or exceeds the predetermined value, feedback control is applied. This dynamic adjustment resolves the contradiction between raising engine speed and preventing torque shock.
2Reliability
If fuel supply is resumed when engine cranking is started to restart the engine, then the engine can be smoothly restarted, but the vehicle starts moving with large torque shock due to excessive motor generator driving force
Solution Approach 1:
The control method implements preliminary action by setting the driving force output to a predetermined value before the engine starts rotating (when rotation speed is below the threshold). This preliminary control ensures that when fuel supply is resumed and the engine restarts smoothly, the motor generator does not output excessive driving force, thereby preventing torque shock during vehicle start-up.
Solution Approach 2:
The control system uses feedback control to monitor engine rotation speed and adjust driving force output accordingly. When the engine rotation speed reaches or exceeds the predetermined value, feedback control is applied to maintain appropriate driving force levels, ensuring both smooth engine restart and prevention of torque shock.
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
The system effectively suppresses torque shock during vehicle start-up in creeping mode by managing driving torque based on engine rotation speed and feedback control, ensuring rapid responsiveness and smooth transition to engine-driven motion.
Implementation Method 1
a motor generator (30) coupled with a crankshaft (25) of the engine (20)
Data Source
AI summary
A vehicle drive control system includes a motor coupled with the driving shaft of an internal combustion engine so that torque can be transmitted to the drive wheels when fuel supply to the engine is cut off. The vehicle travels in a creeping mode in this state while motoring of the engine is performed through driving force of the motor. When accelerator depression is detected, fuel injection into a cylinder waiting for the intake stroke of the engine is begun and the engine is started. The crank angle position at a time when fuel injection is started is utilized as a reference position. When the crankshaft of the engine rotates from the reference crank angle position to a predetermined crank angle position, driving by the motor is stopped and the vehicle is then driven by the engine.