Crane Hydraulic Control Sequencing to Cut Pressure Mismatch Losses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing crane systems with automatic functions suffer from significant energy waste due to the concurrent operation of hydraulic components with mismatched working pressures and flows, leading to increased energy consumption and reduced operational time in electrically powered cranes.
Innovation Solution
A software-based solution where a crane controller estimates and compares the pressure and flow levels of hydraulic actuators to identify high and low pressure functions, generating driving instructions that activate only the necessary actuators at specific times to minimize waste energy, without requiring additional sensors or hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple hydraulic actuators are operated concurrently to move crane components, then the crane can reach the target position, but waste energy increases due to mismatched working pressures and flows
Solution Approach 1:
The patent segments the concurrent operation of multiple hydraulic actuators into sequential phases. The controller divides the movement task into separate time periods, activating only one actuator at a time based on its pressure and flow requirements. This segmentation eliminates the energy waste caused by simultaneous high-pressure and low-pressure operations, while still achieving the overall crane movement to the target position.
Solution Approach 2:
The patent implements dynamic control of actuator activation by continuously monitoring the crane's current position and comparing it with the target position. The controller dynamically determines which actuator should be activated at each moment based on real-time conditions, optimizing the sequence of operations to minimize energy waste while ensuring the crane reaches its destination.
2Power
If high working pressure is maintained in the hydraulic system, then powerful movements can be achieved, but energy consumption increases
Solution Approach 1:
The patent applies periodic action by alternating between different pressure levels based on the operational phase. During low-pressure phases, only low-pressure actuators are activated for movements that don't require high force. High-pressure actuators are activated only during specific time periods when powerful movements are necessary. This periodic switching between pressure levels maintains the required movement power while significantly reducing overall energy consumption.
3Adaptability or versatility
If the crane uses an electric power source with battery, then operational flexibility is improved, but operational time is limited by battery capacity
Solution Approach 1:
The patent converts the limitation of battery capacity into a benefit by optimizing energy usage. The controller identifies and eliminates waste energy from concurrent actuator operations, effectively extending the usable energy from the battery. By transforming the harmful effect of limited battery capacity into an opportunity for energy optimization, the system achieves longer operational time while maintaining the flexibility of electric power sources.
Data Source
AI summary
A crane includes a control interface to receive an operating instruction defining a target position, and a controller to determine movements of crane components and to generate driving instructions to be applied to a system of hydraulic actuators. The controller estimates a pressure level of a required working pressure of a hydraulic pump of each of the hydraulic actuators for the determined movements, and compares the estimated pressure levels and identifies the hydraulic actuators as a high pressure function, or as a low pressure function, based on the comparisons. The controller determines a time period during a movement from a current position to a target position, in which only the hydraulic actuators identified as a high pressure function or as a low pressure function is/are activated, and generates driving instructions for the hydraulic actuators to perform the determined movements, including activation of the determined hydraulic actuators during the time period.