Adaptive Engine Speed Control for Binary Clutch Shifts

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Solution Overview

Problem

Binary clutch assemblies in vehicle transmissions face challenges in smooth engine braking shifts due to high initial slip levels, which can lead to noise, vibration, and potential damage when transitioning between gear states, as they can only be in fully-applied or fully-released states, lacking intermediate control.

Innovation Solution

A controller system that detects requested engine braking shifts, actively controls engine speed to reach a target slip level of zero or near-zero RPM, and adapts the target engine speed to ensure smooth application of the binary clutch assembly, minimizing noise and vibration by periodically adjusting the target speed based on slip levels and engine braking state requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a binary clutch assembly is applied directly during engine braking shift, then the transmission can quickly transition to the desired gear state, but high initial slip levels cause noise, vibration, and potential damage to torque holding elements

Engineering Contradiction:

Improveshift transition speedVSAvoidnoise and vibration

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary engine speed adjustment before applying the binary clutch assembly. The controller ramps engine speed to a target value that pre-calculates to achieve zero or near-zero slip at the moment of clutch application, eliminating harmful noise and vibration while maintaining quick transition

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The controller continuously monitors actual engine speed and calculates real-time slip levels across the binary clutch assembly. Based on this feedback, the controller dynamically adjusts engine speed control to ensure slip reaches the target level (zero or near-zero) precisely when the clutch is applied, preventing damage and noise

Inventive Principle:

Principle #23Feedback

2Productivity

Engineering Contradiction:

Improveshift transition speedVSAvoidclutch element durability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The controller performs preliminary engine speed adjustment to pre-calculate and achieve the optimal target speed before clutch application. This ensures that when the binary clutch assembly is applied, slip is already at the target level (zero or near-zero), preventing damage to torque holding elements while maintaining quick transition

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors actual engine speed and calculates real-time slip levels. The controller uses this feedback to dynamically adjust engine speed control, ensuring slip reaches the target level precisely when the clutch is applied, thereby protecting torque holding elements from damage

Inventive Principle:

Principle #23Feedback

3Productivity

If the target engine speed is set too high, then the binary clutch assembly can be applied faster, but slip levels remain high causing noise, vibration, and harshness

Engineering Contradiction:

Improveclutch application speedVSAvoidnoise and vibration

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The controller continuously monitors actual engine speed and calculates real-time slip levels. Based on this feedback, the controller dynamically adjusts the target engine speed to ensure that when the binary clutch assembly is applied, slip reaches the target level (zero or near-zero), eliminating noise and vibration while maintaining efficient application

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the target engine speed parameter based on calculated slip levels and actual engine speed feedback. This parameter optimization ensures the clutch is applied at the precise moment when slip is minimized, eliminating harmful noise and vibration while maintaining quick transition

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8849526B2Adaptive speed-based control of a binary clutch assembly

Publication Date: 2014.09.30 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A vehicle includes an engine and a transmission, the latter of which includes a controller which executes an adaptive speed-based control method. The transmission includes gear sets each having multiple nodes, an input member continuously connected to the engine and to one of the gear sets, and a binary clutch assembly connected to the same gear set as the input member. The controller is programmed to detect a requested transmission shift into an engine braking state while the vehicle is coasting. The controller also commands an increase in engine speed to a target engine speed in response to the requested shift, and applied the binary clutch assembly when the engine output speed reaches the target engine speed. The controller calculates slip across the binary clutch assembly and adjusts the target engine speed as needed over time until the target slip is achieved at the target engine speed.