Crane Capacity Calculation at Locked Counterweight
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Crane operators face limitations with variable position counterweights, requiring numerous capacity charts for various boom combinations and counterweight positions, leading to increased data storage, calculations, and reduced flexibility when operating in confined spaces.
Innovation Solution
A method and system for determining crane capacity at intermediate counterweight positions, allowing for a large number of available positions while minimizing paper charts, data storage, and calculations, by calculating the load on the hook and comparing it with the maximum capacity to output the lower value, and a crane control system that adjusts the counterweight position based on sensor inputs and load charts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If capacity charts are generated for a large number of discrete counterweight positions, then the flexibility and accuracy of crane capacity determination is improved, but the amount of paper charts, data storage, and calculations required increases substantially
Solution Approach 1:
The patent implements a dynamic counterweight position system where the counterweight can be moved to various positions along the boom, and the control system automatically calculates capacity charts for any intermediate position based on the maximum capacity chart. This eliminates the need to pre-generate and store multiple static capacity charts for each discrete position, while still providing the flexibility of operating at any counterweight position.
Solution Approach 2:
The patent uses the maximum capacity chart (generated at the maximum counterweight position) as a template or copy, and derives capacity charts for intermediate positions by proportional scaling. Instead of creating entirely new capacity charts for each position, the system copies the structure and methodology of the maximum capacity chart and adjusts the values based on the ratio of counterweight positions, significantly reducing computational and storage requirements.
2Productivity
If the variable position counterweight is moved to its furthest extent to maximize crane capacity, then the crane capacity is improved, but the operator may contact obstacles such as walls or the tailswing may increase
Solution Approach 1:
The patent implements a dynamically adjustable counterweight position system that allows the operator to move the counterweight to any position along the boom based on real-time operational requirements. The control system calculates the appropriate capacity chart for the current counterweight position, enabling the operator to reduce the counterweight position (and thus reduce tailswing and avoid obstacles) while still maintaining accurate capacity information for the reduced position.
Solution Approach 2:
The patent changes the parameter of counterweight position from a fixed maximum value to a variable parameter that can be adjusted continuously. By changing this parameter, the system adapts the crane's capacity characteristics to match the operational environment, allowing the operator to trade some capacity for reduced tailswing or obstacle clearance when necessary.
3Device complexity
If a limited number of discrete counterweight positions are selected for capacity chart generation, then the data storage and calculations are reduced, but the crane capacity may be substantially less than available when operating in confined spaces
Solution Approach 1:
The patent transitions from a static system with a limited number of discrete counterweight positions to a dynamic system where the counterweight can be positioned continuously along the boom. The control system automatically generates or retrieves the appropriate capacity chart for any intermediate position, eliminating the need to pre-select and store capacity charts for only a few discrete positions while maximizing crane capacity utilization.
Solution Approach 2:
The patent treats the counterweight position as a continuous parameter rather than a discrete parameter with limited values. By changing the nature of this parameter from discrete to continuous, the system enables the operator to utilize the full range of available crane capacity in confined spaces while the control system handles the computational complexity of generating capacity charts for any position on demand.
Data Source
AI summary
A method for calculating a crane capacity for a crane having a variable position counterweight at a locked position includes determining a boom combination and determining a maximum capacity at a hook position for the boom combination. A maximum target value for an operating condition dependent on a balance of the crane is determined. An indication of the locked counterweight position is received. At least one new target value for the operating condition dependent on the balance of the crane between the variable position counterweight at the locked counterweight position is established. A new capacity of the crane is calculated by decrementing the maximum capacity of the crane proportionally to a difference in the maximum target value and the at least one new target value. Cranes and crane control systems may employ this method.