Electrified Tractor Battery Power Control via Dynamic Charging Rate

Solution Overview

Problem

Electrified tractors face inefficiencies and potential work interruptions due to battery output restrictions, leading to prolonged work times or incomplete tasks in farm fields, as existing technologies fail to effectively manage battery charging rates and temperatures during operations.

Innovation Solution

The electrified tractor incorporates a control device that manages battery input-output power by restricting it within set ranges based on charging rates and temperatures, calculates estimated charging rates and temperatures for specific work conditions, and adjusts power usage to prevent over-discharge or overheat, including forced stop processes and notification systems to ensure efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the output of the battery is restricted to protect against over-discharge, then the battery reliability is improved, but the working efficiency and productivity of the electrified tractor deteriorate

Engineering Contradiction:

Improvebattery reliabilityVSAvoidworking efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the battery output restriction conditions changeable based on real-time charging rate calculations. The control device dynamically adjusts whether to restrict battery output by evaluating the calculated charging rate against predetermined thresholds, allowing the restriction conditions to adapt to actual working conditions rather than maintaining fixed restrictions throughout operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies preliminary action by calculating the charging rate in advance based on battery capacity, current charge level, and estimated remaining work time. This preliminary calculation allows the system to predict whether restricting battery output would prevent the charging rate from falling below a predetermined threshold, enabling proactive decision-making about when to apply or relax restrictions before the situation arises

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the battery output is restricted within a prescribed range, then the battery is protected from over-discharge, but the working efficiency of the electrified tractor becomes low and work completion time increases

Engineering Contradiction:

Improvebattery protectionVSAvoidwork completion time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the battery output restriction conditions changeable based on real-time charging rate calculations. The control device dynamically adjusts whether to restrict battery output by evaluating the calculated charging rate against predetermined thresholds, allowing the restriction conditions to adapt to actual working conditions rather than maintaining fixed restrictions throughout operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies feedback by using the calculated charging rate as a feedback signal to determine whether to maintain or relax battery output restrictions. The control device continuously monitors the charging rate and adjusts restriction status accordingly, creating a closed-loop control system that responds to actual battery state and work progress

Inventive Principle:

Principle #23Feedback

3Productivity

If the charging rate is maintained high to complete work quickly, then the productivity is improved, but the battery temperature rises and over-discharge risk increases

Engineering Contradiction:

Improvework completion speedVSAvoidbattery temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent applies feedback by using the calculated charging rate as a feedback signal to determine whether to maintain or relax battery output restrictions. The control device continuously monitors the charging rate and adjusts restriction status accordingly, creating a closed-loop control system that responds to actual battery state and work progress

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies parameter changes by adjusting the battery output restriction status based on the calculated charging rate. When the charging rate indicates safe conditions, the system relaxes restrictions to allow higher power output; when the charging rate approaches dangerous levels, the system tightens restrictions, thereby dynamically changing operational parameters to balance productivity and safety

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11690307B2Electrified tractor

Publication Date: 2023.07.04 TOYOTA JIDOSHA KK

AI summary

An electrified tractor includes a vehicle body, a working machine, an electric motor, a battery, an inverter that controls input-output electric power of the battery. The electrified tractor includes a control device that controls the inverter. The control device executes a restriction process, a charging rate calculation process and a relaxation process. In the restriction process, the control device controls the inverter such that the input and output of the battery is restricted within a prescribed electric power range, when a state of the battery satisfies a restriction condition. In the charging rate calculation process, the control device calculates a charging rate of the battery when it is assumed that a work is finished in a farming field, as an estimated charging rate. In the relaxation process, the control device expands the prescribed electric power range, when the estimated charging rate is higher than a first prescribed charging rate.