Small Electric Vehicle Adaptive Motor Control

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Solution Overview

Problem

Small electric vehicles, such as electric wheelchairs, face challenges in operability and traveling characteristics due to the reliance on joystick operation position for speed control, making it difficult for users with low proficiency to navigate smoothly, especially at slow speeds.

Innovation Solution

The vehicle incorporates a control unit that adjusts target rotation speeds of the motors based on cumulative power consumption, allowing for gradual updates in target vehicle speed, angular velocity, acceleration, and deceleration, adapting to the user's proficiency level by reflecting cumulative power consumption in control algorithms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the speed is determined by the operation position of the joystick-type operation element, then the vehicle can respond quickly to user input, but users with low proficiency cannot operate smoothly at slow speeds

Engineering Contradiction:
Improveoperability for users with low proficiencyVSAvoidcontrol precision at slow speeds
Core Design Contradiction:
Ease of operationVSSpeed

Solution Approach 1:

The control characteristics are dynamically adjusted based on the cumulative number of travels. The system transitions from initial control characteristics (softer, more gradual response) to final control characteristics (sharper, more direct response) as the user gains proficiency. This is achieved by updating target values such as target vehicle speed, target vehicle angular velocity, and their accelerations based on cumulative travel data, making the control system adapt to the user's skill level over time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes control parameters (target vehicle speed, target vehicle angular velocity, accelerations) based on the cumulative number of travels. By dividing cumulative power consumption by a predetermined unit of control to obtain the cumulative number of travels, the system adjusts these parameters to provide appropriate control characteristics for the user's proficiency level, resolving the contradiction between ease of operation and speed control precision.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the control characteristics are fixed, then the system is simple to implement, but it cannot adapt to different user proficiency levels

Engineering Contradiction:
Improveadaptability to user proficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system uses feedback from cumulative power consumption measurements to adjust control characteristics. The battery management unit provides cumulative power consumption data, which the control unit processes to determine the cumulative number of travels. This feedback loop enables the system to automatically adapt control parameters based on actual usage patterns, providing adaptability without requiring complex manual configuration or multiple hardware variants.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system automatically adjusts its characteristics based on cumulative travel data without requiring external intervention. By using the battery management unit's cumulative power consumption data and automatically calculating the cumulative number of travels, the system serves itself by adapting to user proficiency levels through normal operation, reducing the need for complex setup procedures or multiple configuration modes.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If target values are updated frequently, then the control adapts quickly to user proficiency, but it may cause uncomfortable feelings during transition

Engineering Contradiction:
Improvespeed of adaptationVSAvoidcomfort during transition
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The control characteristics are updated periodically based on cumulative power consumption thresholds rather than continuously. By dividing cumulative power consumption by a predetermined unit of control to obtain discrete cumulative travel counts, the system updates target values at regular intervals of usage. This periodic update approach allows gradual adaptation while maintaining stable control characteristics between updates, preventing uncomfortable transitions.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4091860A1Small electric vehicle
Publication Date: 2022.11.23 SUZUKI MOTOR CORP
  • EP4091860A1 patent drawingFigure 1
  • EP4091860A1 patent drawingFigure 2
  • EP4091860A1 patent drawingFigure 3

AI summary

[Problem to be Solved] A small electric vehicle that achieves traveling characteristics according to the proficiency of a user is provided. [Solution] A small electric vehicle (1) includes: left and right motors (40L and 40R) connected so as to respectively transmit power to left and right driving wheels (4L and 4R); left and right rotation speed sensors (43); a joystick-type operation element (83); and a control unit (10), wherein it is configured to calculate target rotation speeds of the left and right motors, based on a target vehicle speed and a target vehicle angular velocity that are provided according to an operation position of the operation element, and control the left and right motors such that the actual rotation speeds of the left and right motors follow the respective target rotation speeds, and configured to update at least one target value, according to a cumulative number of travels (β) obtained by dividing, by a predetermined control unit, a cumulative total value of a cumulative power consumption obtained by the battery management unit.