EV Torque Control for Simulated Manual Stall Sensation

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Solution Overview

Problem

Electric vehicles lack the driving sensation of an engine stall, which is a key experience for drivers accustomed to manual transmission vehicles, as existing torque control techniques cannot simulate the driver's manual shifting operation effectively, leading to discomfort.

Innovation Solution

An electric vehicle equipped with an accelerator pedal, pseudo-clutch pedal, pseudo-shifter, and a controller that simulates the torque characteristics of a manual transmission vehicle, allowing the driver to experience an engine stall by controlling the motor torque and notifying the driver of the stall production process, while avoiding it in specific situations detected by external sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If torque fluctuation control is performed to simulate shifting operation in EVs, then the discomfort for drivers accustomed to MT vehicles is suppressed, but the driver cannot experience the authentic driving sensation of engine stall

Engineering Contradiction:
Improvedriving comfortVSAvoiddriving sensation authenticity
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent creates a virtual copy of an internal combustion engine's torque characteristics through software control. The controller simulates engine torque curves, including the stall phenomenon, by calculating and applying appropriate torque reduction when virtual engine speed drops below idle speed. This allows drivers to experience authentic MT vehicle sensations without a physical engine.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the physical mechanical engine system with an electrical motor controlled by software algorithms. Instead of using an actual internal combustion engine that can physically stall, the system uses electronic torque control to simulate stall conditions, substituting mechanical complexity with computational control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the electric motor controls torque to simulate MT vehicle characteristics, then pseudo-shifting operation is achieved, but the driver experiences discomfort due to inability to voluntarily determine shifting timing

Engineering Contradiction:
Improvetorque characteristic simulationVSAvoiddriver control autonomy
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent implements dynamic torque control that continuously adjusts motor torque based on simulated engine parameters, vehicle speed, accelerator pedal position, and virtual gear stage. The system dynamically calculates torque reduction amounts and timing to simulate realistic engine behavior, including voluntary shifting initiated by driver input through the pseudo-shifter.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent incorporates feedback mechanisms where the controller monitors simulated engine speed, vehicle operating conditions, and driver inputs through the pseudo-shifter and pseudo-clutch pedal. This feedback loop allows the system to adjust torque output in real-time to match desired engine characteristics and respond to driver-initiated shifting operations.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If pseudo-shifter and pseudo-clutch pedal are added to EVs, then MT vehicle operation experience is provided, but the driving feeling of actual engine stall cannot be experienced

Engineering Contradiction:
ImproveMT vehicle operation simulationVSAvoidsense of discomfort
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent creates a virtual copy of an internal combustion engine's torque characteristics through software control. The controller simulates engine torque curves, including the stall phenomenon, by calculating and applying appropriate torque reduction when virtual engine speed drops below idle speed. This allows drivers to experience authentic MT vehicle sensations without a physical engine.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3950406B1Electric vehicle
Publication Date: 2023.12.20 TOYOTA JIDOSHA KK
  • EP3950406B1 patent drawingFigure 1
  • EP3950406B1 patent drawingFigure 2
  • EP3950406B1 patent drawingFigure 3

AI summary

The controller (50) of the electric vehicle (10) is configured to control the torque of the electric motor (2) using the MT vehicle model (530) based on the operation amount of the accelerator pedal (22), the operation amount of the pseudo-clutch pedal (28), and the shift position of the pseudo-shifter (26). Further, the controller is configured to execute the stall production process for changing the engine output torque used for calculation of the driving wheel torque to zero when the calculated virtual engine speed using the MT vehicle model becomes lower than the prescribed stall engine speed.