Anti-rebounding Control for Hybrid Excavator Swing Motors
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Solution Overview
Problem
Hybrid and electric excavators lack an effective anti-rebounding control system for electric motor swing operations, which is crucial for smooth stopping of swing structures without rebounding, similar to existing hydraulic systems.
Innovation Solution
An anti-rebounding control method and apparatus that utilizes an anti-rebounding control algorithm in a controller to manage the electric motor inverter, setting torque limit values to '0' or maximum based on speed feedback thresholds to control power supply, ensuring smooth stops without rebounding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an electric motor system is used for swing operations in hybrid excavators, then the system can be simplified and control precision is improved, but anti-rebounding control capability is lost causing oscillations during stopping
Solution Approach 1:
The patent replaces the mechanical hydraulic anti-rebounding system with an electrical control system. The electric motor system uses controller-based torque regulation and power interception/re-suppression mechanisms to achieve anti-rebounding control, eliminating the need for complex hydraulic circuits while maintaining or improving control precision and anti-rebounding performance
Solution Approach 2:
The patent dynamically changes control parameters (torque limits, power supply states) based on swing speed feedback. The controller adjusts torque commands and power supply interception timing according to real-time motor speed measurements, enabling adaptive anti-rebounding control that maintains reliability across varying operating conditions
2Ease of operation
If the electric motor speed is reduced to stop the swing structure, then the stopping process is simple, but rebounding and oscillations occur due to lack of anti-rebounding control
Solution Approach 1:
The patent applies preliminary action by intercepting power supply to the electric motor before the swing structure comes to a complete stop. The controller detects when motor speed enters a threshold range indicating impending stop, and proactively intercepts power supply to prevent rebounding, maintaining stability during the stopping process
Solution Approach 2:
The patent implements feedback control by continuously monitoring electric motor speed and using this information to regulate torque commands and power supply states. The controller adjusts control actions based on real-time speed feedback, ensuring stable stopping without oscillations while maintaining operational simplicity
Data Source
Figure 1~3
Figure 4A~4B
AI summary
An anti-rebounding control apparatus is provided, which includes an anti-rebounding controller outputting a first command for setting a torque limit value to "0" if an electric motor speed value is equal to or smaller than an upper threshold value and equal to or larger than a lower threshold value in the case where a speed command value of "0" is input and outputting a second command for setting the torque limit value to a maximum value if the electric motor speed value is smaller than the lower threshold value, a torque regulator setting the torque limit value to "0" when the first command is input and setting the torque limit value to the maximum value when the second command is input, and an electric motor inverter intercepting a power that is supplied to an electric motor if the torque limit value is set to "0" and re-supplying the power to the electric motor if the torque limit value is set to the maximum value. Accordingly, the same performance as an anti-rebounding system that is used in a swing system of an existing hydraulic excavator can be implemented even in a system that performs a swing operation using an electric motor such as a hybrid (or electric) excavator.