Torque Control System for Acceleration Transitions

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Solution Overview

Problem

Traditional engine control systems fail to accurately control engine output torque, leading to undesirable acceleration feel and response delay, particularly during transitions when a driver depresses the accelerator pedal while the vehicle is coasting, resulting in bumps or kicks.

Innovation Solution

A torque control system that includes a driver torque determination module, a lash zone torque determination module, and a rate limit determination module, which work together to limit the acceleration rate in the lash zone by applying a rate limit to the torque output, improving feel and minimizing response delay.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If traditional engine control systems increase torque output when driver depresses accelerator pedal during coasting, then acceleration response is improved, but bumps and kicks occur due to lash zone transitions

Engineering Contradiction:

Improveacceleration responseVSAvoidbumps and kicks

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The control system performs preliminary detection of the lash zone condition by monitoring engine torque and comparing it with predetermined thresholds. When the engine torque is determined to be within the lash zone range, the system proactively limits the rate of torque increase before the driver can feel bumps or kicks, thereby preventing the harmful effect while maintaining acceleration readiness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the torque control strategy based on real-time operating conditions. When coasting is detected and lash zone conditions are met, the control system applies a rate limit to torque increase. This dynamic adaptation allows the system to provide smooth acceleration when needed while maintaining rapid response capability when conditions permit.

Inventive Principle:

Principle #15Dynamics

2Object-affected harmful factors

If traditional engine control systems limit torque increase rate to prevent bumps and kicks, then driver feel is improved, but acceleration response delay increases

Engineering Contradiction:

Improvedriver feelVSAvoidacceleration response delay

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The rate limiting action is applied locally and selectively only when the engine torque is within the specific lash zone range and coasting conditions are detected. When the engine operates outside this zone or when not coasting, full torque increase capability is maintained. This localized application of rate limiting eliminates unnecessary delays while preventing bumps and kicks in the critical transition region.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The control system changes the torque increase rate parameter dynamically based on the operating state. When in the lash zone during coasting, a reduced rate parameter is applied to prevent driveline shocks. When outside the lash zone or during non-coasting conditions, the full rate parameter is restored, maintaining rapid acceleration response. This parameter adaptation resolves the trade-off between smoothness and responsiveness.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If traditional engine control systems do not detect lash zone conditions, then system complexity is reduced, but torque control accuracy deteriorates

Engineering Contradiction:

Improvecontrol system complexityVSAvoidtorque control accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces complex mechanical lash detection mechanisms with an electronic control system that uses sensors and processors to detect lash zone conditions. The system monitors engine torque using existing sensors and compares readings against predetermined thresholds stored in memory, eliminating the need for additional mechanical detection devices while achieving precise torque control accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9091219B2Torque control system and method for acceleration changes

Publication Date: 2015.07.28 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A control system includes a driver torque determination module, a lash zone torque determination module, a rate limit determination module, and an immediate torque determination module. The driver torque determination module determines a driver torque request when a driver depresses an accelerator pedal while a vehicle is coasting. The lash zone torque determination module determines a lash zone torque based on a transmission gear and an engine speed. The rate limit determination module determines an adjustment rate limit based on a previous immediate torque request, the lash zone torque, and the transmission gear. The immediate torque determination module determines a present immediate torque request based on the driver torque request and selectively determines the present immediate torque request based on the adjustment rate limit.