Multiparameter Numerical Investigation of Two Types of Moving Interactions Between the Deep-Sea Mining Vehicle Track Plate and Seabed Soil:Digging and Rotating Motions

To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track plate.The rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed soil.In this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging condition.First,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ sampling.Subsequently,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil heterogeneity.The results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed soil.Therefore,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.

System Identification and Parameter Self-Tuning Controller on Deep-Sea Mining Vehicle

System identification is a quintessential measure for real-time analysis on kinematic characteristics for deep-sea mining vehicle, and thus to enhance the control performance and testing efficiency. In this study, the system identification algorithm, recursive least square method with instrumental variables(IV-RLS), is tailored to model ‘Pioneer I’, a deep-sea mining vehicle which recently completed a 1305-meter-deep sea trial in the Xisha area of the South China Sea in August, 2021. The algorithm operates on the sensor data collected from the trial to obtain the vehicle’s kinematic model and accordingly design the parameter self-tuning controller. The performances demonstrate the accuracy of the model, and prove its generalization capability. With this model, the optimal controller has been designed, the control parameters have been self-tuned, and the response time and robustness of the system have been optimized,which validates the high efficiency on digital modelling for precision control of deep-sea mining vehicles.

Experimental investigation of the inhibition of deep-sea mining sediment plumes by polyaluminum chloride

Deep-sea sediment disturbance may occur when collecting polymetallic nodules,resulting in the creation of plumes that could have a negative impact on the ecological environment.This study aims to investigate the potential solution of using polyaluminum chloride(PAC)in the water jet.The effects of PAC are examined through a self-designed simulation system for deep-sea polymetallic nodule collection and sediment samples from a potential deep-sea mining area.The experimental results showed that the optimal PAC dose was found to be 0.75 g/L.Compared with the test conditions without the addition of PAC,the presence of PAC leads to a reduction in volume,lower characteristic turbidity,smaller diffusion velocity,and shorter settling time of the plume.This indicates that PAC inhibits the entire development process of the plume.The addition of PAC leads to the flocculation of mm-sized particles,resulting in the formation of cm-sized flocs.The flocculation of particles decreases the rate of erosion on the seabed by around 30%.This reduction in erosion helps to decrease the formation of plumes.Additionally,when the size of suspended particles increases,it reduces the scale at which they diffuse.Furthermore,the settling velocity of flocs(around 10^(-2) m/s)is much higher that of compared to sediment particles(around 10^(-5) m/s),which effectively reduces the amount of time the plume remains in suspension.

Integrated biomarker response to assess toxic impacts of iron and manganese on deep-sea mussel Gigantidas platifrons under a deep-sea mining activity scenario

Deep-sea mining activities can potentially release metals,which pose a toxicological threat to deep-sea ecosystems.Nevertheless,due to the remoteness and inaccessibility of the deep-sea biosphere,there is insufficient knowledge about the impact of metal exposure on its inhabitants.In this study,deep-sea mussel Gigantidas platifrons,a commonly used deep-sea toxicology model organism,was exposed to manganese(100,1000μg/L)or iron(500,5000μg/L)for 7 d,respectively.Manganese and iron were chosen for their high levels of occurrence within deep-sea deposits.Metal accumulation and a battery of biochemical biomarkers related to antioxidative stress in superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA);immune function in alkaline phosphatase(AKP),acid phosphatase(ACP);and energy metabolism in pyruvate kinase(PK)and hexokinase(HK)were assessed in mussel gills.Results showed that deep-sea mussel G.platifrons exhibited a high capacity to accumulate Mn/Fe.In addition,most tested biochemical parameters were altered by metal exposure,demonstrating that metals could induce oxidative stress,suppress the immune system,and affect energy metabolism of deep-sea mussels.The integrated biomarker response(IBR)approach indicated that the exposure to Mn/Fe had a negative impact on deep-sea mussels,and Mn demonstrated a more harmful impact on deep-sea mussels than Fe.Additionally,SOD and CAT biomarkers had the greatest impact on IBR values in Mn treatments,while ACP and HK were most influential for the low-and high-dose Fe groups,respectively.This study represents the first application of the IBR approach to evaluate the toxicity of metals on deep-sea fauna and serves as a crucial framework for risk assessment of deep-sea mining-associated metal exposure.

Turning traction force of tracked mining vehicle based on rheological property of deep-sea sediment

Based on main physical and mechanical properties of deep-sea sediment from C-C poly-metallic nodule mining area in the Pacific Ocean, the best sediment simulant was successfully prepared by mixing bentonite with a certain content of water. Compression-shear coupling rheological constitutive model of the sediment simulant was established by endochronic theory and the coupling rheological parameters were obtained by compressive and compression-shear creep tests. A new calculation formula of turning traction force of the tracked mining vehicle was first derived based on the coupling rheological model and consideration of pushing resistance and sinkage of the tracked mining vehicle. Effects of the turning velocity, crawler spacing and contacting length of crawler with deep-sea sediment on the turning traction force were analyzed. Research results can provide theoretical foundation for operation safety and optimal design of the tracked mining vehicle.

Predicting the sinkage of a moving tracked mining vehicle using a new rheological formulation for soft deep-sea sediment

The sinkage of a moving tracked mining vehicle is greatly af fected by the combined compression-shear rheological properties of soft deep-sea sediments. For test purposes, the best sediment simulant is prepared based on soft deep-sea sediment from a C-C poly-metallic nodule mining area in the Pacific Ocean. Compressive creep tests and shear creep tests are combined to obtain compressive and shear rheological parameters to establish a combined compressive-shear rheological constitutive model and a compression-sinkage rheological constitutive model. The combined compression-shear rheological sinkage of the tracked mining vehicle at dif ferent speeds is calculated using the Recur Dyn software with a selfprogrammed subroutine to implement the combined compression-shear rheological constitutive model. The model results are compared with shear rheological sinkage and ordinary sinkage(without consideration of rheological properties). These results show that the combined compression-shear rheological constitutive model must be taken into account when calculating the sinkage of a tracked mining vehicle. The combined compression-shear rheological sinkage decrease with vehicle speed and is the largest among the three types of sinkage. The developed subroutine in the Recur Dyn software can be used to study the performance and structural optimization of moving tracked mining vehicles.

Fire behavior of mining vehicles in underground hard rock mines

The results from a number of investigations and fire experiments are presented and analyzed in order to characterize the fire behavior of mining vehicles in underground hard rock mines. The analysis also includes fire safety and fire protection measures with respect to the mining vehicle fire behavior.Earlier studies on fires in underground hard rock mines have shown that vehicles or mobile equipment are the dominant sources of fire. A better knowledge about the fire behavior of vehicles in underground hard rock mines is therefore needed. During the analysis the direction and flow rate of the ventilation in a drift was found to have a significant impact on the fire behavior, causing for example flame tilt with rapid fire spread. The shielded sections of a vehicle will be less affected by the ventilation flow resulting in for example a decreased flame spread. It was also found that spray fires may result in considerable heat release rate but are generally of shorter duration and will not make any significant contributions to the overall heat release rate of the fully developed vehicle fire. The fire duration of a loader tire from a full-scale fire experiment was found to be at least 200 min and will largely determine the total fire duration of the vehicle. A different scenario with different conditions with for example a slower flame spread resulted in an even longer fire duration. The radiative and convective fraction will be a key factor when determining the heat transfer mechanisms involved in a fire and will vary from material to material.Calculations show that the radiative fraction of the tire fires on two mining vehicles is significantly lower than found in earlier experiments. The design and construction of the mining vehicle will have an important impact on the fire behavior and could possibly mitigate the consequences of a fire and allow fire personnel to extinguish a fire that otherwise would have had a too high heat release rate.

Deep-sea rock mechanics and mining technology:State of the art and perspectives

The review covers the development and the state of the art in deep-sea mining rock mechanics,equipment and challenges.It begins by introducing the significance of deep-sea mining,the types and geographical distribution of deep-sea resources.Section 2 reviews the mechanical properties and fracture mechanism of seabed and related continental rocks,which contributes to the advancement of relevant technologies and theories.Deep-sea mining systems developed by coastal countries are presented in Section 3.Seabed mineral collection systems are critically assessed in Section 4.Subsea mining vehicle is reviewed by walking mechanism and controlling system in Section 5.In Section 6,the development of subsea lifting system is detailed by dividing it into hydraulic and pneumatic lifting modes,and some technical problems in the lifting system are described.An in-depth description of surface support systems is presented in Section 7,which includes the deep-sea mining ship,dynamic positioning system,heave compensation system,launch and retrieval system,mineral disposing system as well as the storage and transferring systems.Section 8 discusses the challenges in the deep-sea mining,in terms of natural occurrence conditions,international legal framework and cooperative mining,environmental protection and economic benefits,etc.Finally,a brief summary and some aspects of prospective research are presented in Section 9.

Vibration Performance Analysis of a Mining Vehicle with Bounce and Pitch Tuned Hydraulically Interconnected Suspension

The current investigations primarily focus on using advanced suspensions to overcome the tradeo design of ride comfort and handling performance for mining vehicles. It is generally realized by adjusting spring sti ness or damping parameters through active control methods. However, some drawbacks regarding control complexity and uncertain reliability are inevitable for these advanced suspensions. Herein, a novel passive hydraulically interconnected suspension(HIS) system is proposed to achieve an improved ride-handling compromise of mining vehicles. A lumped-mass vehicle model involved with a mechanical–hydraulic coupled system is developed by applying the free-body diagram method. The transfer matrix method is used to derive the impedance of the hydraulic system, and the impedance is integrated to form the equation of motions for a mechanical–hydraulic coupled system. The modal analysis method is employed to obtain the free vibration transmissibilities and force vibration responses under di erent road excitations. A series of frequency characteristic analyses are presented to evaluate the isolation vibration performance between the mining vehicles with the proposed HIS and the conventional suspension. The analysis results prove that the proposed HIS system can e ectively suppress the pitch motion of sprung mass to guarantee the handling performance, and favorably provide soft bounce sti ness to improve the ride comfort. The distribution of dynamic forces between the front and rear wheels is more reasonable, and the vibration decay rate of sprung mass is increased e ectively. This research proposes a new suspension design method that can achieve the enhanced cooperative control of bounce and pitch motion modes to improve the ride comfort and handling performance of mining vehicles as an e ective passive suspension system.

A Study on the Dynamic Analysis of A Tracked Vehicle for Ocean Mining on the Deep Seabed

A study is presented on the dynamic analysis of a tracked vehicle for mining on the deep seabed of very soft soil. Equations for the interaction between the track and extremely soft seabed are employed to develop a track/soil interaction module called TVAS. The vehicle is modeled as a multibody dynamic system by the use of a multibody dynamic analysis program. The module developed is cooperated with the multibody dynamic analysis program with a user-defined subroutine. The dynamic behavior and the conceptual design of the mining vehicle on the deep seabed are investigated.

Blockage of the Deep-Sea Mining Pump Transporting Large Particles with Different Sphericity

The present study aims to plumb blockage of the deep-sea mining pump transporting large particles with different shapes. A numerical work was performed through combining the computational fluid dynamics(CFD) technique and the discrete element method(DEM). Six particle shapes with sphericity ranging from 0.67 to 1.0 were selected. A velocity triangle is built with the absolute, relative, and circumferential velocities of particles. Velocity triangles with absolute velocity angles ranging from 90° to 180° prevail in the first-stage impeller. With declining sphericity, more particles follow the velocity triangle with absolute velocity angles ranging from 0° to 90°, which weakens the ability of particles to pass through the flow passage. Furthermore, the forces acting on the particles traveling in the impeller passage are analyzed. Large particles, especially non-spherical ones, suffer from high centrifugal force and therefore move along the suction surface of the impeller blades. Non-spherical particles undergo great drag force as a result of large surface area. The distribution of drag force angles is featured by two peaks, and one vanishes due to blockage.As particle sphericity declines, both magnitude and angle of the pressure gradient force decrease. Variation of the drag force and the pressure gradient force causes clockwise deflection of the centripetal force, resulting in deflection and elongation of particle trajectory, which increases the possibility of blockage.

GPS/GIS based vehicle dispatching for opencast mines

An integrated GPS and GIS based vehicle dispatching system was presented. The system uses GIS technology for the development of digital mine map database and GPS for vehicle positioning. The system consists of five modules: position module incorporated GPS and dead reckoning (DR); a map database structure for displaying and guidance purposes; a routing module based on the map database is able to give out the best route for the vehicles; map matching and route guidance module put the vehicle position to its exact location on the road despite of errors in positioning and map data; and the client-server module allows client exchange information between driver and control centre. The system can be operated in client-server level in which users can request routing and guidance with devices such as hand phone and PDA by communicating their current positions to the server or runs in autonomous mode when users cannot reach the server.

Obstacle performance of cobalt-enriching crust wheeled mining vehicle

A cobalt-enriching crust mining vehicle with four independent driven wheels was proposed. The influence of center-of-gravity position of mining vehicle on obstacle performance was studied. The results show that the mining vehicle has optimal obstacle performance with center-of-gravity position in the middle of suspension. A virtual prototype based on ADAMS software was built and its obstacle performance was simulated. Simulation results show that the mining vehicle with four independent driven wheels has excellent obstacle performance, the maximum climbing capacity is no less than 30°, the maximal ditch width and shoulder height are no less than wheel radius of mining vehicle. Thus wheeled mining vehicle is feasible for cobalt-enriching crust commercial mining.

Long-term economic sensitivity analysis of light duty underground mining vehicles by power source

LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incremental and sensitivity analysis to determine whether it is feasible to incorporate current battery technology into these machines. When revenue was taken into account, decreasing the amount of haulage in battery operated equipment by 5% or 200 kg per h amounts to a $4.0 × 10~4 loss of profit per year. On average it was found that using battery operated equipment generated $9.5 × 10~4 more in income annually, reducing the payback period from seven to two years to pay back the additional $1.0 × 10~5 investment of buying battery powered equipment over cheaper diesel equipment. Due to the estimated 5% increase in capital, it was observed that electric vehicles must possess a lifetime that is a minimum of one year longer than that of diesel equipment.

A Predictive Energy Management Strategies for Mining Dump Trucks

The plug-in hybrid vehicles(PHEV)technology can effectively address the issues of poor dynamics and higher energy consumption commonly found in traditional mining dump trucks.Meanwhile,plug-in hybrid electric trucks can achieve excellent fuel economy through efficient energy management strategies(EMS).Therefore,a series hybrid system is constructed based on a 100-ton mining dump truck in this paper.And inspired by the dynamic programming(DP)algorithm,a predictive equivalent consumption minimization strategy(P-ECMS)based on the DP optimization result is proposed.Based on the optimal control manifold and the SOC reference trajectory obtained by the DP algorithm,the P-ECMS strategy performs real-time stage parameter optimization to obtain the optimal equivalent factor(EF).Finally,applying the equivalent consumption minimization strategy(ECMS)realizes real-time control.The simulation results show that the equivalent fuel consumption of the P-ECMS strategy under the experimentally collected mining cycle conditions is 150.8 L/100 km,which is 10.9%less than that of the common CDCS strategy(169.3 L/100 km),and achieves 99.47%of the fuel saving effect of the DP strategy(150 L/100 km).

Experimental research on grouser traction of deep-sea mining machine

The traction characteristics of the grouser, cutting the simulative soil of deepsea sediment, with different tooth widths, tooth heights, and ground pressures are studied with traction characteristic test apparatus. A traction-displacement model is obtained by combining the analysis of the cutting mechanism. The results show that the tractiondisplacement curves of grousers with different tooth widths, tooth heights, and ground pressures have the same changing trend, which matches the Wong traction model. Their sensitivity coefficient and shear modulus are slightly fluctuated. Therefore, the average values can be used as the traction model parameters. The maximum traction of the grouser with a two-side edge and a 10 mm tooth width increment changing with the tooth height and ground pressure can be determined according to the grousers with different tooth widths. By combining the traction model parameters, the traction-displacement curve of the grouser with a certain group values of tooth width, tooth height, and ground pressure can be predicted. Therefore, the slip of the mining machine can be prevented to improve the mining efficiency.

Theoretical analysis of effect of solid phase on cavitation performance of deep-sea mining pump

In view of the present situation of low cavitation performance of deep-sea mining slurry pump, the effect of solid phase on the cavitation performance of deep-sea mining pump is analyzed theoretically. The relationship between gas and liquid phases are established by cavitation nucleon theory and mass energy equation as well as solid phase and liquid phase, and then we explored the relationship between gas phase and solid phase. The results show that the critical bubble radius and solid-phase concentration flow rate during the cavitation can be related to the liquid pressure. Eq.(19) show that the larger the solid particle concentration and the solid phase flow, the earlier the cavitation will occur, and pump anti-cavitation performance will decline.

Review of Nodule Mineral Image Segmentation Algorithms for Deep-Sea Mineral Resource Assessment

A large number of nodule minerals exist in the deep sea.Based on the factors of difficulty in shooting,high economic cost and high accuracy of resource assessment,large-scale planned commercial mining has not yet been conducted.Only experimental mining has been carried out in areas with high mineral density and obvious benefits after mineral resource assessment.As an efficient method for deep-sea mineral resource assessment,the deep towing system is equipped with a visual system for mineral resource analysis using collected images and videos,which has become a key component of resource assessment.Therefore,high accuracy in deep-sea mineral image segmentation is the primary goal of the segmentation algorithm.In this paper,the existing deep-sea nodule mineral image segmentation algorithms are studied in depth and divided into traditional and deep learning-based segmentation methods,and the advantages and disadvantages of each are compared and summarized.The deep learning methods show great advantages in deep-sea mineral image segmentation,and there is a great improvement in segmentation accuracy and efficiency compared with the traditional methods.Then,the mineral image dataset and segmentation evaluation metrics are listed.Finally,possible future research topics and improvement measures are discussed for the reference of other researchers.

Influence on the Solid−Liquid Two-Phase Flow from Cross-Section Area of Slurry Pumps for Deep-Sea Mining

To explore the mechanism of solid-liquid two-phase flow in deep-sea mining pumps,this paper investigates the influences of the impeller cross-section area on the multi-phase flow in the slurry pump.Experimental and numerical results are presented for two-phase flow in four impellers with different cross-section areas.They show that the degree of vortex strength and the passing capacity of particles increase as the cross-section area of the impeller.In addition,the correlations between the two-phase flow and cross-section area have been revealed by a mathematical model taking the force of the flow field into account.The simulation results confirm the theoretical analysis,while the experimental pump performances validate the numerical calculation.The influence of the cross-section area on two-phase flow and pump performance could provide theoretical support for the design of high-performance deep-sea mining slurry pumps.

Trace Interpolation Algorithm Based on Intersection Vehicle Movement Modeling

Real vehicle tracking data play an important role in the research of routing in vehicle sensor networks. Most of the vehicle tracking data, however, were collected periodically and could not meet the requirements of real-time by many applications. Most of the existing trace interpolation algorithms use uniform interpolation methods and have low accuracy problem. From our observation, intersection vehicle status is critical to the vehicle movement. In this paper, we proposed a novel trace interpolation algorithm. Our algorithm used intersection vehicle movement modeling (IVMM) and velocity data mining (VDM) to assist the interpolation process. The algorithm is evaluated with real vehicle GPS data. Results show that our algorithm has much higher accuracy than traditional trace interpolation algorithms.