Powertrain Torque Control for Transient Speed Events

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Solution Overview

Problem

Powertrain transitions can result in temporary reductions in output torque capability, leading to operator perception of hesitation or failure to meet torque requests, and inefficient torque use due to fluctuating torque delivery during gear state changes or hybrid drive configuration shifts.

Innovation Solution

Determining an incipient transient speed event and limiting output torque to the minimum value of the estimated maximum output torque capability profile until the event is concluded, ensuring stable torque delivery and reducing transition time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If gear state transitions are performed to change powertrain configuration, then adaptability and versatility are improved, but output torque capability is temporarily reduced

Engineering Contradiction:

Improvepowertrain configuration flexibilityVSAvoidoutput torque capability

Core Design Contradiction:

Adaptability or versatilityVSPower

Solution Approach 1:

The system proactively reduces output torque before the transient speed event occurs during gear transitions. By anticipating the upcoming torque capability reduction and preemptively adjusting torque delivery, the system prevents torque fluctuations and maintains smooth powertrain operation throughout the configuration change.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If clutch engagement/disengagement is used to transition between gear states, then adaptability is improved, but torque delivery stability deteriorates

Engineering Contradiction:

Improvegear state transition capabilityVSAvoidtorque delivery stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system applies a counteracting torque reduction before the clutch transition-induced torque fluctuation occurs. This preliminary anti-action compensates for the expected torque instability during clutch engagement or disengagement, thereby maintaining overall torque delivery stability throughout the gear state transition.

Inventive Principle:

Principle #9Preliminary anti-action

3Power

If maximum output torque is maintained during transitions, then power is improved, but transition time increases due to torque fluctuations

Engineering Contradiction:

Improveoutput torqueVSAvoidgear shift transition time

Core Design Contradiction:

PowerVSLoss of time

Solution Approach 1:

By proactively reducing torque before the transient event, the system eliminates torque fluctuations that would otherwise cause hesitation or delays during the transition. This allows the gear shift to complete more quickly and efficiently, reducing the overall transition time while maintaining controlled power delivery.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8948942B2Pre-emptive output torque reduction for a transient speed event and prioritization of inertia

Publication Date: 2015.02.03 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method to control an output torque of a powertrain in response to an incipient transient speed event within the powertrain includes determining an incipient transient speed event, determining a maximum output torque capability profile based upon the incipient transient speed event, determining a minimum value of the maximum output torque capability profile, and limiting the output torque to not greater than the minimum value of the maximum output torque capability profile until the incipient transient speed event is concluded.