WP5 Auxiliary Supporting Equipment & Software
Here, equipment and software that will be used in conjunction with the technologies developed in WP1 – WP4 will be developed. First, a vehicle processing hub will be developed to transport the small unmanned exploratory vehicles to the point of deployment, to control them, and to collect data from them. Second, a remotely-operated vehicle for carrying mechanical equipment such as drilling rigs and roof supports to the affected area of the mine will be developed. Third, a means of simulating evacuation will be developed, using advanced new techniques, to provide guidance on the most likely location of any missing miners. Finally, a means will be developed of using computational fluid dynamics (CFD) to predict temperatures and environmental variables following an incident and to assess the risk posed to miners, rescue personnel and exploratory vehicles.
The work is divided into the following tasks:
T5.1 – Vehicle Processing Hub
The vehicle processing hub serves the purpose of a control centre for the unmanned exploratory vehicles developed in WP4 and a means of easily carrying several such vehicles to the area where they will be deployed. As such it takes the form of a vehicle, but a much smaller vehicle than the one to be developed in T5.2, which is an essential characteristic given that it is an aim, wherever possible, to be able to deploy the exploratory vehicles at a very early stage in an incident response in order to obtain key data to help further plan the response.
The vehicle processing hub will be based on a commercial wheeled platform with at least six wheels and the first job is to analyse the available products and make a selection. Next it will be adapted to carry sufficient equipment to fulfil the communication and processing missions as well as transporting the exploratory vehicles. Work will also be carried out into the development of a deployment mechanism (pulleys, lift, etc.). Once finished, the vehicle will be tested on the surface, in conjunction with the exploratory vehicles, in order to adjust their commanding and manoeuvring capability.
The hardware architecture, and hence the development programme, will be divided in three parts: (1) descent system with power electronics, (2) exploratory vehicle deployment system with magazine-like mechanism, (3) navigation system, and (4) communication and processing system. The number of on-board computers will be optimised for robust functioning as follows: one basic CPU for parts (1) and (2), one embedded CPU for navigation, including some sensor interfacing, and one high computational power CPU with a secure data saving capability for part (4).
The software architecture of the vehicle will be centralised and based on the ROS (Robot Operating System) standard and on the YARP middleware. While the exploratory vehicles, in distributed manner, will also use ROS-YARP, the vehicle processing hub software will guarantee quasi plug-and-play connectivity and fast Human Machine Interface (HMI) development.
T5.2 –Electrically Powered Vehicle for Transporting Mechanical Aids
The main purpose of this vehicle is to aid the transportation of a large amount of mechanical equipment and materials – including the drilling rigs and props developed in this project – into the area affected by a major incident, where other means of transportation are unavailable or cannot be used. This will allow the most suitable equipment to be used more rapidly in rescue operations, depending on the type of rescue. Additionally, the rescuers’ effort will be shifted from transportation activities, possibly shortening the rescue operation, with beneficial effects on the welfare of any affected miners. The platform will be battery powered and controlled by a remote controller.
To achieve this, while minimizing development time, an existing mobile inspection platform will be adapted to better suit the needs of a rescue operation. This electrically powered robot (MPI) has been developed by EMAG for monitoring environmental conditions in mines and is described in [Kasprzyczak, Leszek; Szwejkowski, Pawel and Cader, Maciej (2016): Robotics in Mining Exemplified by Mobile Inspection Platform (Mining – Informatics, Automation and Electrical Engineering 2/2016)].
Firstly, the functional requirement for the transportation platform will be defined. As part of this job, a list of potential equipment and materials to be transported will be prepared and additional requirements determined using preliminary information on the size and dimensions of the drilling rig and props being developed in WP4. In addition, Other requirements of such a vehicle from the perspective of the rescuer will also be considered.
The necessary modifications to the chassis, propulsion and other equipment will be specified to decrease the weight and increase mobility. Next, the defined changes will be implemented. The platform chassis will be designed to incorporate adequate propulsion systems, and an adequate power supply will be designed for use in a coal mine environment. Then the control and safety equipment will be developed.
Finally a prototype will be built and subjected to initial tests under laboratory conditions prior to eventual field trials in WP6.
T5.3 – Simulation of Effects of Incidents on Environment & Infrastructure
In this project, the equipment and techniques developed will be capable of addressing several types of serious incident including rock falls, increased levels of carbon monoxide or other toxic elements, fires and explosions. The environment, following the incident, will make rescue work difficult, especially through sections where temperatures are high. In particular, information is needed on the conditions in the mine before permitting access to rescuers and, in the case of the most extreme cases such as when very high temperatures are likely, before deploying unmanned exploratory vehicles into the affected areas. While the resilient sensors developed in WP2 will be capable of providing some of this information, because these will not necessarily be able to provide the full spectrum capability of standard sensors, Computation Fluid Dynamics (CFD) simulation will also be developed to augment the live data by assessing the likely environmental conditions in an affected area of a mine before committing personnel or deploying the small unmanned vehicles developed in WP3.
To this end, to determine the expected temperatures and atmospheric conditions (e.g. concentrations of oxygen, CO, NOx, opacity and many other variables) in the vicinity of the accident or access galleries, a method of simulation will be developed using CFD (Computational Fluid Dynamics) technology. This will reveal information on the distribution of gases, temperatures and other physical variables that will determine the functioning of drones and rescue teams.
First, an incident scenario will be selected so that information on the location, fire characteristics, and boundary conditions are available. Then, several simulations will be carried out taking, as a starting point, data from currently operating mines, and considering the existing ventilation systems, both during normal operation and during emergency ventilation. CFD numerical simulation programs have a high computational cost so, to limit the computation time and reduce data analysis, an important aspect of this work will be to determine the zone of influence as a result of the spread of fire. This will allow the risk to miners or rescuers to be assessed, from a knowledge of the evolution of the physical variables considered as the most critical to workers.
Then in a second phase, the simulation results will be used in the development of the small unmanned vehicles in WP3 and simulations of more specific scenarios will be carried out. Fine tuning as a result of this exercise will lead to a tool that can be used by rescuers while planning the response to an incident.
Furthermore the temperature could decrease the load bearing capacity of workings support. This could be critical during underground accidents so simulations will be carried out into the effect of temperature on the behaviour of the support using numerical Finite Element Method (FEM) code. Different types of support, as well as grades of steel, will be considered. Together with detailed mine plans, the simulations will allow the identification of high vulnerability zones where the support could be damaged by high temperatures.
T5.4 – Evacuation Simulation Software
Human factor is crucial in determining whether an accident inside a mine will be resolved satisfactorily or if the consequences will be severe. For this reason, it is not only necessary to establish how the rescue teams will be used, but it is also necessary to know how miners, who have not been trapped or injured, will attempt to evacuate the mine. Because the resilient sensors being developed in this project cannot be as comprehensive or as ubiquitous as the sensors, and in some cases miner tracking equipment, that are used during normal operation of a mine, an evacuation simulation tool will be developed to augment the live data available.
Research will be conducted into a method of simulating evacuation, taking into account the geometry of the mine, as well as installed equipment, to provide results concerning several variables including evacuation times, travel speeds, and roadways used. Once analyzed, this will allow vital information to be utilised to improve the decision-making process by the rescue team including the place of deployment of unmanned exploratory vehicles and of any drilling activities.
The determination of evacuation parameters will be carried out using STEPS (Simulation of Transient Evacuation and Pedestrian movementS) as the main tool. This is a micro-simulation tool designed by Mott MacDonald for the prediction of movement patterns under both normal and emergency conditions; it has been used successfully in buildings, malls, underground stations, tunnels, and many other spaces. STEPS employs a modern agent-based approach which predicts the movement of discrete individuals through three-dimensional space. This is in contrast to the older generation of pedestrian models which treat the problem as one of continuous flow. The major advantages of agent-based models are that they give a more realistic representation of pedestrian movement and allow the elucidation of subtle but important details of movement, thereby giving much greater insight to the designer. The approach uses a principle borrowed from the theory of cellular automata which is now well-established in the modelling of pedestrian dynamics. Crowds, like many self-organizing systems made up of individual entities, display complex emergent modes of behaviour which arise from simple deterministic and non-deterministic principles followed by the individuals making up the population. The STEPS model is able to recreate this type of emergent crowd behaviour which is fundamental to effective simulation. The modelling approach has been verified and validated by comparison with internationally-accepted design codes including NFPA 130 (National Fire Protection Agency) and full-scale testing.
The first phase in this task will be to develop a means of analysing which evacuation scenario is the most likely to happen in an accident. The input to such a simulation will be parameters such as the number of miners, their location, the available emergency evacuation routes, etc.
Second, using real data from mines, evacuation simulations will be carried out and the results will be analysed by all partners in this task, considering mainly reaction times and movement times. All the results will be assessed in the light of current mining regulations.
Finally, the simulation will be enhanced to integrate data from emergency devices (for example, a manually operated emergency button or a fire sensor) into the simulation. Although those devices cannot be simulated in STEPS, it is possible to “activate” events that trigger situations where those personnel responsible for miner safety can take necessary and appropriate action.