Mining Shovel Crowd Force Control System
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Solution Overview
Problem
Mining shovels face challenges in controlling and managing the severe forces and stresses during material excavation, which can lead to mechanical damage and 'boom jacking' due to incorrect angle strikes, necessitating improved control systems to assist operators.
Innovation Solution
A control system for mining machines that includes a crowd system with a crowd motor and actuator, an electronic controller to calculate a calculated crowd force based on motor torque and speed, and an impact detection function to modify torque output, helping determine if the dipper assembly has struck a surface and adjust forces accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dipper assembly strikes the bank at high speed with sufficient force, then digging productivity is improved, but severe reactionary forces cause mechanical damage and boom jacking
Solution Approach 1:
The control system performs preliminary detection of impact conditions by monitoring crowd motor torque and speed parameters before the actual impact occurs. When impact is detected, the system proactively modifies crowd motor torque output to prevent excessive reactionary forces from damaging the mining shovel structure.
Solution Approach 2:
The control system continuously monitors operational parameters (crowd motor torque, crowd speed) and uses this feedback to detect impact conditions. Based on this feedback, the system dynamically adjusts crowd motor torque output to mitigate harmful reactionary forces while maintaining digging effectiveness.
2Force
If the crowd motor outputs high torque to penetrate the bank, then digging force is improved, but impact detection becomes difficult without proper monitoring
Solution Approach 1:
The system replaces direct mechanical impact sensing with electronic monitoring of motor parameters. By monitoring crowd motor torque and speed electronically, the control system detects impact conditions without requiring additional mechanical sensors or complex impact measurement mechanisms.
Solution Approach 2:
The control system uses crowd motor torque and speed as intermediary parameters to indirectly detect impact conditions. These motor parameters serve as mediators that translate physical impact events into measurable electrical signals, making impact detection straightforward and reliable.
3Reliability
If the control system continuously monitors and modifies torque output, then operational safety is improved, but device complexity increases
Solution Approach 1:
The control system performs multiple functions using a unified approach: it monitors crowd motor torque and speed for both normal operation control and impact detection, modifies torque output for both speed regulation and impact mitigation. This multi-functionality reduces overall system complexity by consolidating control and detection functions.
Solution Approach 2:
The control system uses the existing crowd motor's own operational parameters (torque and speed) as the monitoring basis for impact detection. This self-service approach eliminates the need for separate, dedicated impact sensors, reducing system complexity while maintaining reliable safety monitoring.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively reduces the impact of reactionary forces on the mining shovel, preventing damage and improving operational control by detecting impacts and modifying torque output, thus enhancing digging efficiency and safety.
Implementation Method 1
The electronic controller is configured to receive a crowd speed and a crowd motor torque
Implementation Method 2
calculate a calculated crowd force based in part on the crowd speed and the crowd motor torque
Implementation Method 3
an actuator-operatively associated with the crowd motor and arranged to slide the dipper arm with respect to the boom
Data Source
AI summary
A mining machine such as a mining shovel includes a digging assembly having an upward extending boom and a dipper assembly generally horizontally supported by the boom and configured to crowd toward and retract from a vertical bank at a mine site. To determine if the dipper assembly strikes the bank, an electronic controller can calculate a calculated crowd force based in part on a crowd motor torque associated with a crowd motor, a crowd speed of the dipper assembly, and an inertia parameter. If the calculated crowd force exceeds a predetermined first crowd threshold, the electronic controller can register an impact event. In further aspects, the electronic controller can execute a force modification function to modify the crowding forces and a speed reduction function to reduce the crowd speed.