Mobile Crane Boom Control for Safe Wire Payout During Auto Extension
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Solution Overview
Problem
Existing boom control systems for truck cranes are designed for specific types of boom devices, requiring manual adjustment and lacking universal safety and automation in extending and retracting operations.
Innovation Solution
A controller that calculates and maintains a safe payout length of the wire based on boom angle, length, and hook member position, using actuators to automatically extend and retract the boom, ensuring the wire is not too slack or too tight, and stopping operations if unsafe conditions occur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a boom device for a mobile crane is controlled by a conventional control system, then the control system is simple in structure, but the booms cannot be controlled to move at predetermined positions accurately and the control precision is low
Solution Approach 1:
The control system incorporates sensors that detect the actual positions of booms 2 and 3, and this detected information is fed back to the controller. The controller compares the detected positions with predetermined target positions and automatically adjusts the hydraulic cylinders to eliminate position deviations, thereby achieving precise control without requiring complex manual operation.
Solution Approach 2:
The patent replaces conventional mechanical control linkages with an electronic control system that uses sensors, a microprocessor-based controller, and electronic signal processing. This substitution enables precise digital control of boom positions while maintaining relatively simple system architecture through software-based control algorithms.
2Ease of operation
If the booms are controlled manually or by conventional systems, then the control system is simple, but it is difficult to operate the booms at night or in environments with poor visibility
Solution Approach 1:
The control system operates autonomously by automatically detecting boom positions through sensors, comparing them with predetermined positions stored in memory, and making automatic adjustments without requiring continuous manual input from the operator. This self-service capability enables operation in poor visibility conditions while keeping the control system architecture relatively simple.
Solution Approach 2:
The system continuously monitors boom positions through feedback from sensors and automatically corrects deviations from target positions. This closed-loop feedback mechanism eliminates the need for constant manual adjustment, making operation easier in challenging environmental conditions while maintaining simple system structure.
3Manufacturing precision
If the booms are controlled to move accurately to predetermined positions, then the control precision is improved, but the control system becomes complex
Solution Approach 1:
The controller receives continuous feedback from sensors regarding actual boom positions and automatically generates correction signals to achieve precise positioning. This feedback mechanism enables accurate control without requiring complex mechanical positioning mechanisms, as the precision is achieved through electronic control and comparison with predetermined positions stored in memory.
Solution Approach 2:
The patent replaces complex mechanical positioning mechanisms with an electronic control system that uses sensors, digital memory for storing predetermined positions, and microprocessor-based control algorithms. This substitution achieves high positioning precision through software-based control while maintaining relatively simple hardware architecture.
Data Source
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AI summary
[Problem] To provide a controller capable of preventing occurrence of an irregular winding and a damage of a hook hardware in an automatic extension and an automatic retraction of a boom. [Solution] A controller calculates a theoretical payout length X1(θ) of a wire in a posture in which a hook block is raised, a theoretical payout length X2(θ) of the wire in a posture in which the hook block is lying, dX1(θ)/dt, and dX2(θ)/dt, using a length L of the boom, A and B (first specified values) indicating coordinates of a hook hardware, a length K (second specified value) being a sum of a length of the hook block and a length of a hook hardware, and a derricking angle θ of the boom (S14, S21). The controller makes the boom stand and lie at a constant speed of F = dθ/dt (S23), and makes a winch drive at a wind-up speed of J × {dX1(θ)/Dt + dX2(θ)/Dt} / 2 taking J × {X1(θ) + X2(θ)} / 2 as a target value (S24).