EV Virtual Manual Shift Control for Smooth Clutch Re-Engagement

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Solution Overview

Problem

Existing battery electric vehicles that simulate manual transmission internal combustion engines experience uncomfortable shifts due to sudden increases in virtual engine rotational speed when the driver performs a shifting operation with the accelerator pedal depressed, leading to prolonged shift times.

Innovation Solution

A battery electric vehicle with a control device that includes a vehicle model simulating a virtual internal combustion engine, clutch, and manual transmission, which adjusts the relationship between vehicle speed, accelerator operation, and electric motor torque to manage shifting operations smoothly, ensuring the rotational speed difference converges within a predetermined range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the virtual clutch is disengaged during shifting operation with accelerator pedal depressed, then the shifting operation can be performed, but the virtual engine rotational speed increases suddenly causing driver discomfort

Engineering Contradiction:
Improveshifting operationVSAvoiddriver discomfort
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system temporarily increases the virtual accelerator operation amount before clutch re-engagement to pre-adjust the virtual engine rotational speed, preventing sudden speed increase when the clutch is re-engaged during shifting with accelerator pedal depressed

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the virtual clutch is disengaged during shifting, then shifting can be performed, but the rotational speed difference increases preventing clutch re-engagement and prolonging shift time

Engineering Contradiction:
Improveshifting operationVSAvoidshift time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system performs preliminary adjustment of virtual accelerator operation amount to control virtual engine rotational speed, ensuring rotational speed difference converges within predetermined range to enable timely clutch re-engagement and complete shifting

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the rotational speed difference between virtual engine and virtual input shaft, and adjusts the virtual accelerator operation amount based on this feedback to maintain the difference within a predetermined range, enabling clutch re-engagement

Inventive Principle:
Principle #23Feedback

3Reliability

If the virtual accelerator operation amount is increased temporarily, then the rotational speed difference converges enabling clutch re-engagement, but this is a temporary deviation from requested operation amount

Engineering Contradiction:
Improveclutch re-engagementVSAvoidtemporary deviation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system temporarily deviates the virtual accelerator operation amount from the requested operation amount only for the minimal necessary duration to adjust virtual engine rotational speed and enable clutch re-engagement, then immediately restores it to the requested value

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4578706A1Battery electric vehicle
Publication Date: 2025.07.02 TOYOTA JIDOSHA KK
  • EP4578706A1 patent drawingFigure 1
  • EP4578706A1 patent drawingFigure 2
  • EP4578706A1 patent drawingFigure 3

AI summary

A battery electric vehicle (100) includes an electric motor (4F, 4R) as a driving source. The battery electric vehicle (100) includes: an accelerator pedal (22); a pseudo shifter (24) imitating a shifter that is used to perform a shifting operation of a manual transmission internal combustion engine vehicle; and a control device (101) configured to change a relationship among a vehicle speed of the battery electric vehicle (100), an accelerator operation amount of the accelerator pedal (22), and torque of the electric motor (4F, 4R) in response to an operation of the pseudo shifter (24). The control device (101) includes a memory (103) storing a vehicle model that models a virtual vehicle, and a processing circuit (102) coupled to the memory (103) and configured to execute the vehicle model. The vehicle model includes an engine model (MOD11) that models a virtual internal combustion engine, a clutch model (MOD12) that models a virtual clutch, a transmission model (MOD13) that models a virtual manual transmission, and a driver model (MOD10).