Engine Torque Control via Clutch Slip Index
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional engine torque control methods for vehicles fail to accurately sense the engagement state of a clutch, leading to engine flare due to inappropriate engine operation when the clutch is open, as the Engine Control Unit (ECU) lacks clear information about the transmission state.
Innovation Solution
An engine torque control method that senses the engagement state of the clutch and calculates a slip index based on engine torque, engine RPM, clutch torque, and clutch RPM, allowing for filter-control of engine torque to prevent engine flare by adjusting the torque slope according to the clutch's engagement state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the ECU controls engine torque based on engine state information only, then the control is simple, but engine flare occurs due to lack of accurate transmission state information
Solution Approach 1:
The TCU acts as an intermediary between the transmission system and ECU. It receives clutch state information from the transmission system, calculates the slip index, and transmits this processed information to the ECU, enabling the ECU to make informed torque control decisions without directly accessing complex transmission sensors
Solution Approach 2:
A feedback loop is established where the TCU continuously monitors clutch engagement state and slip index, then provides this information to the ECU for real-time engine torque adjustment. This feedback mechanism allows the system to respond dynamically to changing transmission conditions and prevent engine flare
2Reliability
If the clutch is rapidly disengaged to protect the vehicle, then vehicle protection is improved, but engine stall may occur due to excessive torque reduction
Solution Approach 1:
The ECU receives advance notification from the TCU about upcoming clutch disengagement events and pre-adjusts engine torque accordingly. This preliminary action allows the engine to prepare for torque changes, preventing sudden stalls while still enabling rapid clutch disengagement for vehicle protection
Solution Approach 2:
The system applies cushioning by gradually reducing engine torque in anticipation of clutch disengagement. The TCU calculates the slip index and provides early warning signals to the ECU, which then smoothly reduces torque to cushion against the sudden load change that would otherwise cause engine stall
3Device complexity
If the ECU cannot receive accurate transmission state information, then the communication system is simple, but inappropriate engine operation occurs when clutch is open
Solution Approach 1:
The TCU serves as an intermediary information processing unit that receives raw clutch state data from the transmission system, calculates the slip index using engine and clutch parameters, and transmits the processed engagement state information to the ECU. This intermediary approach enables accurate clutch state detection without requiring direct complex communication between the ECU and transmission sensors
Solution Approach 2:
The TCU creates a simplified copy of the complex transmission state by calculating the slip index, which represents the clutch engagement state in a form that the ECU can easily process and act upon, avoiding the need for the ECU to directly handle multiple raw sensor signals
Data Source
AI summary
An engine torque control method for a vehicle according to the present disclosure includes: sensing an engagement state of a clutch of the vehicle; calculating a slip index according to engine torque, engine revolutions per minute (RPM), clutch torque, and clutch RPM; and filter-controlling the engine torque based on the calculated slip index and the sensed engagement state of the clutch.