Hybrid Vehicle Torque Control Using Predicted Engine Response

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Solution Overview

Problem

Conventional hybrid vehicles experience drivability issues due to torque response delays and deviations from target torque caused by synchronizing engine and motor torque increases, leading to delayed driver accelerator operations.

Innovation Solution

A control system that predicts engine torque changes and adjusts motor torque to supplement the engine's response delay, estimating future engine torque based on throttle valve and intake air changes to synchronize with motor torque, thereby achieving the target vehicle torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the motor torque increase timing is delayed to synchronize with engine torque increase, then the torque deviation from target is reduced, but the torque response delay to driver accelerator operation increases

Engineering Contradiction:
Improvetorque accuracyVSAvoidtorque response delay
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The controller performs preliminary action by predicting future engine torque based on current engine state and accelerator operation, then adjusts motor torque in advance to compensate for the expected engine torque delay. This allows the motor to proactively make up for the engine's slow response while maintaining accurate total torque control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The controller continuously monitors actual engine torque, accelerator operation amount, and engine state, then uses this feedback to dynamically adjust motor torque. The feedback loop enables real-time correction of torque deviations by comparing predicted engine torque with actual measurements and adjusting motor contribution accordingly.

Inventive Principle:
Principle #23Feedback

2Speed

If the motor torque is increased to compensate for engine torque delay, then the torque response to accelerator operation is improved, but the torque deviation from target increases

Engineering Contradiction:
Improvetorque response speedVSAvoidtorque accuracy
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The controller dynamically changes motor torque parameters based on predicted engine torque and actual engine state. By adjusting motor torque as a variable parameter rather than a fixed value, the system can optimize both response speed and torque accuracy, making the motor contribute more during transient phases and less during steady state.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system transitions from a static torque distribution approach to a dynamic one where motor torque continuously adapts based on real-time engine performance and driver input. This dynamic adjustment allows the motor to flexibly compensate for engine response variations while maintaining precise total torque control throughout transient and steady-state operations.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If the engine and motor torque distribution is optimized for energy efficiency, then the overall vehicle efficiency is improved, but the torque response uniformity between engine and motor deteriorates

Engineering Contradiction:
Improveenergy efficiencyVSAvoidtorque response uniformity
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The controller acts as an intermediary that coordinates between the engine's energy-efficient operation and the motor's rapid torque response. By predicting engine torque and adjusting motor contribution as a mediating factor, the system maintains energy-efficient engine operation while using the motor to bridge response timing gaps, thus preserving both efficiency and response uniformity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4275937B1Vehicle driving force control device, and vehicle
Publication Date: 2025.10.15 MAZDA MOTOR CORP
  • EP4275937B1 patent drawingFigure 1
  • EP4275937B1 patent drawingFigure 2
  • EP4275937B1 patent drawingFigure 3

AI summary

A driving force control device for a vehicle is provided, which includes a motor, an engine, and a controller. The controller sets a target torque of the vehicle corresponding to accelerator operation, and distributes a target engine torque according to a distribution rule defined beforehand, based on the target torque of the vehicle, and outputs a control signal corresponding to the target engine torque to the engine. The controller estimates an amount of intake air into a cylinder in the future based on the target engine torque, and estimates a torque of the engine in the future based on the estimated amount of intake air. The controller sets a target motor torque based on the estimated torque of the engine so that the target torque of the vehicle is achieved in the future, and outputs a control signal corresponding to the target motor torque to the motor.