Open Cut » Overburden Removal
The Issues
Productivity of operators
Operators are the key to dragline productivity. Performance of existing operators varies somewhere in the range 10-35%, so approaches to raising skills to uniform levels should be investigated.
Productivity loss in training new operators
A dragline is a significant production asset and it makes poor economic sense to use it as a training tool, as is current practice.
Perpetuation of poor operating practices
The current approach of using experienced operators as instructors for training new operators can lead to poor operating practices being perpetuated.
Dragline damage and ongoing maintenance
Training novices on simulators, rather than draglines, minimises the risk of accidental damage to the dragline. Operators can also be trained in operational techniques that minimise stresses on the machine which leads to reduced maintenance cost.
Project Objectives
1. Analyse the training needs of dragline operators
Gather information from interviews with, and observation of dragline operators, to determine the required skills. Analyse the data to determine those skill areas which have the potential to be enhanced through the use of simulators.
2. Develop a mathematical model of a dragline to be used in a simulator
Evaluate relevant dragline research and computer graphic technologies in order to determine the costs, time scale and risks involved in building a computer based dragline training simulator.
3. Create a conceptual design for a computer based dragline simulator
Having identified the relevant technologies, evaluate their necessity, risk and cost. Create a conceptual design for a simulator and provide costing and a timetable for construction and commissioning.
Conclusions
Benefits of simulators for training
A simulator offers considerable advantages for training new and experienced operators in practical skills. The advantages include productivity gains, a safe learning environment, and consistency of standards.
Feasibility of implementation
Construction of a simulator could commence today. A prototype could be completed in 24 months for a total project cost of $2.39M. The major risks have been identified and are manageable, and the cost benefits exceed the minimum rate of return on capital.
The state of dragline research has not progressed quite as far as required for an interactive training simulator. Much of the modelling has either been at a superficial, mine-planning level with not enough detail for operator feedback, or the models are too detailed and thereby unsuitable for a real-time simulator
There are a number of groups in Australia however, that could provide the necessary pieces to the model. This will be most important in the areas of bucket dynamics and bucket-ground interaction. If this research is to progress, direction must be given to it. Models suitable for operator training will not be developed as a matter of course.
The technology and justification exist for the development of a dragline training simulator. What is required is the appropriate focus for the application of the required technologies.
The study has shown that it will be necessary to develop mathematical models of a number of processes to suit this real-time simulator environment.
The most challenging area is that of bucket-ground interaction. The productivity of operators is influenced significantly by their ability to fill the bucket efficiently. In addition, much of the feedback is visual, so a model which represents this process is needed to create both realistic hoist, swing and drag dynamics during filling and to provide a base for realistic visuals.
Other areas in which existing models will have to be extended, or new models created are:
- bucket, rope and jewellery swing dynamics
- spoil heap growth
The remaining models and technology can be imported from other simulator applications.
As part of the study a prototype vision system was developed. This provided an objective basis for judging the suitability of computer generated vision for simulator training. It also provided a means of estimating the effectiveness.
The final result of the study is positive. A 'virtual' dragline simulator will satisfy a range for training needs. It is justifiable and there is technology available to enable its development to proceed with reasonable expectations of success.
It is the primary conclusion of this report that with the aid of existing data, models and tools, a dragline simulator is technically feasible and economically justifiable.
Recommendations
- A prototype dragline simulator should be constructed which meets the needs of basic operator training identified in this report.
- As part of the project to construct the simulator, enough training courseware should be generated to ensure a positive and productive introduction into the industry.
- The project should include sufficient technical assistance during the first year to ensure smooth operation.
- There should be a follow on project to expand the simulator's capabilities to meet more advanced training needs. The details of these enhancements should be developed on the basis of experience with the prototype machine.