Hybrid Construction Machine Speed Reduction Feedback
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Solution Overview
Problem
In hybrid construction machines, operators struggle to understand the relationship between the state of the electricity storage device and the need for reduced movement speed to prevent degradation, leading to potential misinterpretation of speed reductions and unclear future movement states.
Innovation Solution
A hybrid construction machine with a controller and monitor device that detects the state of the electricity storage device, executes a low speed mode when thresholds are surpassed, calculates and displays the speed reduction degree, and provides visual feedback to the operator through a monitor, clearly indicating the speed reduction and its implications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the output of the motor-generator is increased to enhance fuel consumption reduction, then the fuel efficiency is improved, but the electricity storage device may not be able to supply sufficient electric power due to its discharge capability limitations, capacity, and temperature constraints
Solution Approach 1:
The patent implements dynamic adjustment of motor-generator output based on real-time monitoring of electricity storage device state (SOC, temperature, discharge capability). The control unit dynamically modifies the power demand from the electricity storage device to match its current supply capability, preventing overload while maximizing fuel efficiency benefits.
Solution Approach 2:
The system changes operational parameters of the electricity storage device based on its state. When temperature rises or SOC decreases, the control unit adjusts discharge current limits and power output thresholds to maintain reliable operation within safe boundaries, thereby balancing fuel efficiency with reliability.
2Reliability
If the movement speed is lowered to prevent degradation acceleration of the electricity storage device, then the degradation is prevented, but the operator may not understand the reason for speed reduction and may perceive it as a failure
Solution Approach 1:
The monitor provides continuous feedback to the operator about the electricity storage device state (SOC, temperature, degradation risk level) and the relationship between these parameters and speed adjustments. This feedback loop helps the operator understand that speed reduction is a protective measure based on measurable device conditions, not a system failure.
Solution Approach 2:
The monitor uses color-coded indicators to represent different states of the electricity storage device and corresponding speed recommendations. Visual color changes provide intuitive information about device health and required speed adjustments, making the relationship between device state and speed control immediately apparent to the operator.
3Measurement precision
If multiple parameters indicative of degradation are monitored, then the monitoring precision is improved, but it becomes difficult to simultaneously monitor and display all parameters clearly
Solution Approach 1:
The monitoring system segments multiple degradation parameters (SOC, temperature, discharge capability, cycle count) into distinct monitoring modules, each tracking specific aspects of device health. This segmentation allows precise monitoring of each parameter while organizing information for systematic processing and selective display.
Solution Approach 2:
The monitor integrates multiple functions into a single display interface, showing SOC, temperature, degradation risk assessment, and speed recommendations simultaneously. The system universally handles different parameter types through a unified display paradigm, reducing overall system complexity while maintaining comprehensive monitoring precision.
Data Source
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AI summary
An output command calculating section (40) of an HCU (36) restricts a battery discharge power from an electricity storage device (31) based upon a battery electricity storage rate (SOC) and a current square integrating rate (Risc) of the electricity storage device (31). Thereby, the HCU (36) transfers from a normal mode (NMODE) to a low speed mode (LSMODE) to lower a movement speed of a hydraulic actuator. A monitor display amount calculating section (50) of the HCU (36) calculates a maximum speed reduction rate (DRs) based upon a battery discharge power limit value (Plim0) and an engine output upper limit value (Pemax) from the output command calculating section (40). A monitor device (39) displays a reduction rate of the movement speed of the hydraulic actuator in the low speed mode (LSMODE) based on the maximum speed reduction rate (DRs).