Systems engineering
Underground Electric Loader — Ep. 2 “Strategy Development”
A story of optimum concept development of autonomous electric loader. Episode 2 covers the operational analysis and strategy development.
Underground Electric Loader — This article is part of a series.
Episode 2: Strategy Development
Previously on “Underground Electric Loader”
In the previous pilot episode, we introduced the project, studied the current mining industry, and listed reasons for electrification of mining equipment.
In this episode, we touch upon the model-based systems engineering, present the operational analysis of our system, and develop the strategy by identifying opportunities, brainstorming strategies and formalising the development goal.
Table of Contents:
- Model-Based Systems Engineering
- Operational Analysis
- Strategy Development
1. Opportunity Identification
2. Strategy Generation and Selection
3. Mission Statement - Conclusion
Model-Based Systems Engineering
We are going to start with operation analysis of the system to be designed. But first, let’s briefly introduce the model-baed systems engineering.
Products are becoming increasing complex, especially due to more software content and automation of systems. This leads to the need of describing, simulating, and verifying the product as a system that encompasses software, hardware and human actors, while at the same time cutting down design costs, preventing costly corrections at late design stages, and achieving faster time-to-market. Here comes MBSE!
Model-based systems engineering (MBSE) approach promises to address these challenges by
- ensuring that the requirements are well-defined, traceable, and testable;
- allowing engineers to evaluate trade-offs among functional and non-functional requirements;
- running what-if scenarios early;
- defining the interfaces and interactions between the system components and to analyse the safety and reliability;
- enabling collaboration between design teams and suppliers along the system’s development journey;
- enabling the reuse of existing system elements and digital twins from previous products;
- shifting left the decision making and verification of the product design.
MBSE system modelling can be integrated into or connected to a PLM software to make use of the defined product architecture in downstream development tasks.
Our system is going to benefit from the MBSE practices because of its high complexity including the loader and the infrastructure that enables autonomous and remote operation, and its high reliance of software.
We use the Arcadia method which is similar to SysML in this project.
Operational Analysis
The first step is performing operational analysis which defines high-level interactions among actors/entities and the system capabilities they require. In essence, it answers the question “What the users of the system need to accomplish?”
Our operational architecture simply illustrates the underground mining process which aims for maximum economic recovery of minerals held in the bedrock. We omit the discussion of underground mining methods, as the system we are developing — the load-haul-dump (LHD) loader — is used in all methods, be they for steep or flat orebodies.
In the operation architecture above, we have chosen to define the scope of the operation broadly from an underground mine all the way to a mineral processing plant. In the later stages of the MBSE modelling, the last entity — mineral processing plant won’t be considered as the system we are designing doesn’t directly interact with the plant.
Now, when we understand the context of our system, it’s time for the next step — strategy development.
Strategy Development
In strategy development stage, we generate and screen strategies to create a technological mean of moving blasted rocks at drawpoint onto the trucks in a manner that is more efficient and effective than conventional diesel underground LHD loader. We start with an open-source “reconnaissance” of opportunities.
1. Opportunity Identification
The identified raw opportunities are presented below (main sources are the State of Play 2022, Dassault Systemes 2021, Sandvik 2022) :
- Develop emission-free products to meet investors’ rising environmental expectations.
- Replace depleted revenue streams from spare parts and maintenance (20 moving parts for electric machine instead of 20 000 for diesel engine) with new-electric-specific revenue streams.
- Shift focus to overall lifecycle expenses rather than just initial costs, making a compelling case for electric mining vehicles through substantial cost and emission savings, as demonstrated by Sandvik’s data from 2021 in Australia: over a 7-year equipment fleet cycle of ~30 heavy vehicles, switching to electric resulted in the fuel cost savings of around US$17 million and a 59-kiloton reduction in CO2 emissions.
- Address the challenge of consistent and reliable power supply for mining operations in remote locations by offering hybrid electricity generation facilities alongside electric vehicles, since remoteness of many mine sites results in a reliance on fossil fuels.
- Enhance workforce skills through virtual reality training, strengthening the competitive edge of mining machinery OEMs.
- Implementing automated data-driven mines which lead to improved operational efficiency.
- Focus on electric equipment as they can load faster and drive up to 10% faster up and down a ramp. They are also smaller per capacity: a 50-ton capacity electric truck can be the size of a 40-ton traditional truck.
- Offer electric machines, as they usually generate approximately 90% less heat. Such machines support the trend of going deeper and deeper underground, which increases the requirements for ventilation and cooling, as the operating temperatures increase with depth.
- Leverage powerful electric motors while addressing their cooling requirements, as the size of electric drives underground isn’t limited by ventilation compared to diesel motors.
- Foster collaboration among mining companies, OEMs, suppliers, capital, and government to achieve emission reduction goals, promoting standardised solutions (e.g. battery charger) and fostering alliances across the supply chain.
- Lower the customisation engineering effort and cost by increased part reuse and common design approaches to drive down production cost.
- Incorporate advanced technologies from larger and better funded automotive industry to reduce complexity, reduce cost and improve reliability.
Next, we generate strategies to take advantage of identified opportunities.
2. Strategy Generation and Selection
Strategies do not necessarily originate from raw opportunities above, yet, they are connected to them. We brainstorm the strategies without self-censorship. Hence, most strategies are nonsensical.
- Strategy #1: Underground load-haul-dump loader that works in cooperation with underground drill rig and underground truck and enables zero-emission and data-driven mines
- Strategy #2: A lot of local miners with hand-held baskets to load the blasted rock on to the dumper truck (shared value creation)
- Strategy #3: Robot colony that load the blasted rock on to the dumper truck
- Strategy #4: Explode an underground mine with a hundreds-kiloton explosive to create an extra-deep open mine and transport all rocks up to the surface and detect ore rocks with AI-based machine vision conveyor system to lower dilution
- Strategy #5: Smart trampoline next to the mine wall to be blasted; immediately after the controlled blast, rocks drop to the smart trampoline because of their potential energy; the smart trampoline converts that potential energy of rocks into a kinetic energy of projectile flight to direct the rocks to the basket of the rugged dumper truck standing next to the smart trampoline
- Strategy #6: Blasting explosive inserted into the drilled holes are connected via high-strength wires to basket of the rugged dumper truck; during the blasting, the blasting explosives are quickly pulled towards the dumper truck to give ore rocks a horizontal speed towards the basket of the dumper truck, so that the rocks land on the basket.
- Strategy #7: Mobile pressurised suction chamber
- Strategy #8: Mobile conveyor belt
- Strategy #9: Using loader bucket or excavator mounted to the back of the dumper truck
- Strategy #10: Using a pneumatic or hydraulic mattress that is inserted below rocks same way as the conveyor belt. Then starting to fill the mattress so that the section that is in the back of the tunnel starts to fill up first and then move to fill the rest of the mattress. This creates a wave like effect that pushes the rock forward. Then using is a conveyor ramp at the back of the dumper truck that lifts the forward rolling rocks to the truck bed.
- Strategy #11: Covering the blasted rock with magnetic fluid, then moving the rocks by controlling the fluid with electromagnets mounted to the tunnel walls, ceiling, and floor. The fluid is then moved over a strainer which lets the fluid flow trough but leaves the rocks on top. When the fluid is removed, the rocks are dropped to the truck bed.
Screening and selecting the strategies based on the market need and technological feasibility has resulted in highlighting strategies #1, #3 and #9 as promising.
We compared our estimation of the promising strategies’ performance concerning the existence of a real market and a real product, and worthwhileness of effort.
The first strategy, namely the underground loader, has been found to be the most promising strategy, and hence we prioritise it in the subsequent stages of concept development. A wide popularity of underground loaders in mines globally is a solid validation of soundness of the selected strategy.
3. Mission Statement
Finally, The mission statement formulation concludes the strategy development.
The mission statement is based on the selected strategy and serves as a light torch for further product development.
Now, it’s time to wrap up this episode.
Conclusion
To finish up, in this episode, we have explored the notion of model-based systems engineering, demonstrated the operational analysis of our system, and devise the strategy for its advancement by recognising opportunities, generating strategies, and setting clear development objectives.
In the next episode, we begin the concept development. We look into customer needs identification, target requirements and system analysis.
