Dry-Type Clutch Launch Control via Speed Feedback
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Solution Overview
Problem
Launch control systems for vehicles with dry-type clutches face challenges in maintaining stable engine operation due to errors in Torque-Stroke (T-S) curve changes, leading to potential engine stuttering or stalling during launch.
Innovation Solution
A launch control method that calculates and controls a clutch actuator using a feedforward component based on target engine speed and current engine torque, a feedback component based on speed differences, and a compensation torque using estimated clutch torque, ensuring stable clutch engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a dry-type clutch is controlled using a Torque-Stroke (T-S) curve map for launch control, then the clutch engagement can be managed, but errors in the T-S curve lead to excessive clutch engagement and engine stuttering or stalling
Solution Approach 1:
The patent implements a feedback control mechanism where the actual engine speed is continuously monitored and compared with the target engine speed. The speed difference (error signal) is fed back to adjust the clutch actuator stroke in real-time, compensating for T-S curve errors and preventing engine stuttering or stalling during launch control.
Solution Approach 2:
The patent dynamically adjusts the clutch actuator stroke parameter based on the speed difference between target and actual engine speeds. By changing the stroke parameter in response to real-time conditions rather than relying solely on pre-defined T-S curve values, the system compensates for curve errors and maintains stable engine operation.
2Force
If the clutch engagement torque is increased to prevent vehicle slip during launch, then traction is improved, but engine stuttering or stalling occurs due to excessive load
Solution Approach 1:
The feedback mechanism monitors the actual engine speed and compares it with the target speed. When the engine speed deviates due to excessive torque application, the feedback signal adjusts the clutch torque downward, preventing engine stuttering or stalling while maintaining sufficient traction.
Solution Approach 2:
The patent transitions from static T-S curve-based torque control to dynamic torque control that adapts in real-time based on engine speed feedback. This dynamic adjustment allows the clutch torque to be optimized continuously, balancing traction requirements with engine protection during launch.
3Adaptability or versatility
If the T-S curve is used to control clutch stroke, then clutch characteristics can be managed, but the curve changes with temperature and operation count making compensation difficult
Solution Approach 1:
The feedback control system continuously monitors actual engine speed and adjusts the clutch actuator stroke in real-time, compensating for T-S curve changes due to temperature and operation count. This real-time adjustment maintains control accuracy despite curve variations.
Solution Approach 2:
The system calculates a target engine speed based on accelerator pedal position before clutch engagement. This preliminary target speed serves as a reference for the feedback control, enabling the system to anticipate and compensate for T-S curve changes before they cause control errors.
Data Source
AI summary
A launch control method for a vehicle with a dry-type clutch includes: determining a target engine speed corresponding to an operation amount of an accelerator pedal of the vehicle when vehicle launch is started by operation of the accelerator pedal; calculating a feedforward component which is part of the torque to control the clutch using a rate of change over time of the target engine speed and a current engine torque; calculating a feedback component which is part of the torque to control the clutch based on a difference between the target engine speed and the current engine speed; calculating a compensation torque using a current engine torque and an estimated clutch torque which is estimated to be currently transferred by the clutch; and controlling a clutch actuator to drive the clutch with a sum of the feedforward component, the feedback component, and the compensation torque.