Electric Construction Machine Auto-Idle Timing for Low Battery
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Solution Overview
Problem
In electrically driven construction machines, the transition to auto idle control occurs after a predetermined time, regardless of the remaining electric power storage amount, leading to inefficient power consumption and reduced duration of operation before needing a recharge.
Innovation Solution
A controller adjusts the time duration for transitioning to auto idle control based on the remaining electric power storage amount, setting it shorter when the power is low, thereby reducing power consumption and extending the operation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the predetermined time duration for auto idle control transition is kept constant, then the control logic is simple, but electric power consumption increases and the operation duration is reduced
Solution Approach 1:
The patent applies dynamics by making the predetermined time duration variable rather than constant. The controller dynamically adjusts the time duration based on the state of charge of the battery, shortening it when power is low and extending it when power is sufficient. This resolves the contradiction by allowing the system to adapt its behavior to current conditions, reducing power consumption during critical low-power states while maintaining operational simplicity through predefined adjustment rules.
Solution Approach 2:
The patent changes the parameter of time duration based on the battery's state of charge. By monitoring the remaining power and adjusting the predetermined time duration accordingly, the system optimizes power consumption. When the battery charge is low, the time duration is shortened to reduce power usage; when charge is sufficient, the full duration is maintained. This parameter adjustment strategy directly addresses the contradiction between simple control and power efficiency.
2Use of energy by moving object
If the predetermined time duration is shortened to reduce power consumption, then electric power consumption decreases, but the responsiveness to operator input may be delayed
Solution Approach 1:
The patent changes the time duration parameter dynamically based on power availability rather than fixing it. When the battery has sufficient charge, the full time duration is used, maintaining normal responsiveness. When charge is low, the duration is shortened to conserve power. This conditional parameter adjustment resolves the contradiction by ensuring responsiveness is maintained when power allows, while sacrificing minimal responsiveness only when power conservation is critical.
Solution Approach 2:
The system uses feedback from the battery's state of charge to adjust the time duration. The controller continuously monitors power levels and modifies the auto idle transition timing accordingly. This feedback mechanism ensures that responsiveness is optimized when power is sufficient, while automatically reducing power consumption when the battery is low, without requiring manual intervention or complex prediction.
3Use of energy by moving object
If auto idle control is activated immediately, then electric power consumption is reduced, but the machine may be unresponsive during brief pauses in operation
Solution Approach 1:
The patent makes the auto idle transition dynamic by introducing a variable time duration that adapts to battery conditions. Instead of immediately activating auto idle control, the system waits for a predetermined period that is adjusted based on power availability. This dynamic approach balances power savings with operational responsiveness, allowing brief pauses without immediate idle transition while still reducing power consumption during extended inactivity.
Solution Approach 2:
The system performs preliminary assessment of battery charge before deciding on the time duration for auto idle transition. By evaluating the state of charge in advance, the controller pre-determines whether to use a shorter or full time duration. This preliminary action ensures that power consumption is reduced only when appropriate, while maintaining operational responsiveness when the battery has sufficient capacity to support longer wait periods.
Data Source
AI summary
In an electrically driven construction machine, decrease in the remaining electric power storage amount of an electric power storage device is reduced when a transition to auto idle control takes place in case where the remaining electric power storage amount is small, and the duration over which the remaining electric power storage amount of the electric power storage device lasts is lengthened. Accordingly, a controller 31 controls the rotation speed of an electric motor 1 such that the rotation speed of the electric motor 1 is lowered from a predetermined rotation speed to an idle rotation speed Ni when none of a plurality of operation devices 20, 21, 22, 23a, 23b, and 24 is manipulated and a predetermined time duration TD has elapsed. In addition, when the remaining electric power storage amount of an electric power storage device 33 is equal to or smaller than a first threshold Ea, the controller 31 sets the predetermined time duration TD shorter than when the remaining electric power storage amount is greater than the first threshold Ea.