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The slippage occurs between the fingers and object will result in grasp failure that badly affects the prosthetic hand’s operation. In this paper, a new slippage prevention strategy is proposed to improve the prosthetic hand’s grasp stability. The proposed method, which comprises a slipping process model, a multi-threshold detection scheme, and a force regulation policy, can have a minimal loading force intervention after stabilization. First, the slipping process is modeled with special considerations on the nonlinear and noise characteristics of the system. Then, the multiple thresholds are selected for slippage detection to reduce the influence of loading force variation and system nonlinearity. Lastly, a loading force regulation policy consisting of a serials of constant, slight force increments is applied to suppress the detected slippage and minimize the force growth. One merit of our method is that the parameters selected in the algorithm largely depend on the system characteristics of the hand system, but not the grasped object. Experimental results show that the proposed method has better detection accuracy on slippage detection and minimal loading force intervention after slippage suppression.

Based on recent advancements in natural language processing, computer vision and robotics, a growing number of researchers and traders attempt to predict future asset prices using deep learning techniques. Typically, the goal is to find a profitable and at the same time low-risk trading strategy. However, it is not straightforward to evaluate a found trading strategy. Evaluating solely on historic price data neglects important factors arising in real markets. In this paper, we analyze the impact of real-world market conditions in terms of trading fees, borrow interests, slippage and spreads on trading returns. For that, we propose a deep learning trading bot based on Temporal Convolutional Networks, which is deployed to a real cryptocurrency exchange. We compare the results obtained in the real market with simulated returns and investigate the impact of the different real-world market conditions. Our results show that besides trading fees (which have the biggest impact on returns), factors like slippage and spread also affect the returns of the trading strategy.

Mathematical and computer models of an asynchronous electric drive of an electric vehicle with a detailed mechanical part, taking into account the mechanical differential, are built to study dynamic processes with a decrease in the coefficient of friction of wheels with a road surface. Computer simulation of dynamic processes in an electric drive during a hitting and starting on a road surface with a reduced coefficient of friction has been carried out. The analysis of time diagrams showed the adequacy of transients and their compliance with physical laws. An algorithm for the slipping beginning recognizing was developed, for which the inconsistency of the speed of the slipping wheel and the reduced speed to angular speed of the electric vehicle was used, which made it possible to synthesize a system for its elimination by the appropriate control of the electric drive. A computer model of the slip prevention system was built using 9 logical processing rules. Computer simulation of the acceleration of an electric vehicle with subsequent slipping by one and two wheels has been carried out. In accordance with the identification algorithm system completely prevents excessive slipping.

An anti-trackslip path tracking algorithm for steel box girder inspection robot based on model prediction (MPC) is proposed in this paper. This algorithm is oriented to the actual needs of the automatic inspection of steel box girder of super large bridges. It solves the slippage problem of the inspection robot because of the wear of driving wheels and slippery contact. The kinematic models of longitudinal and lateral slippage were established and corrected after analyzing the robot sliding control and slippage parameter estimation methods. The robot system error dynamic model and the error model based on state extension were proposed by overall considering control constraints. The robot’s optimized objective function was constructed to convert MPC problem into quadratic programming. Finally, path tracking simulations were performed on the inspection robot under pure rolling and sliding conditions, respectively, using the improved MPC (IMPC) algorithm and the front-wheel feedback algorithm. The comparison showed that the IMPC algorithm exceeded the front-wheel feedback algorithm based on geometrical tracking in tracking precision, proving the effectiveness of the proposed IMPC in anti-trackslip path tracking.

This paper explores the problem of how to grasp an object, and then control a robot arm so as to stabilise that object, under conditions where: i) there is significant slippage between the object and the robot’s fingers; and ii) the object is perturbed by external forces. For an n degrees of freedom (dof) robot, we treat the robot plus grasped object as an (n+1) dof system, where the grasped object can rotate between the robot’s fingers via slippage. Firstly, we propose an optimisation-based algorithm that selects the best grasping location from a set of given candidates. The best grasp is one that will yield the minimum effort for the arm to keep the object in equilibrium against external perturbations. Secondly, we propose a controller which brings the (n+1) dof system to a task configuration, and then maintains that configuration robustly against matched and unmatched disturbances. To minimise slippage between gripper and grasped object, a sufficient criterion for selecting the control coefficients is proposed by adopting a set of inequalities, which are obtained solving a nonlinear minimisation problem, dependant on the static friction estimation. We demonstrate our approach on a simulated (2+1) planar robot, comprising two joints of the robot arm, plus the additional passive joint which is formed by the slippage between the object and the robot’s fingers. We also present an experiment with a real robot arm, grasping a flat object between the fingers of a parallel jaw gripper.

This paper proposes a tracking control method that suppresses slippage by using the driving force of a tracked vehicle. First, the velocity of the tracked vehicle including slippage is estimated using a disturbance observer and machine learning technique. This estimated velocity is utilized to design an observer that can estimate the driving force of the crawler. By distributing and controlling the driving force, tracking control with reduced slippage can be realized. The experimental results demonstrate the tracking performance of the proposed control system.

For realizing practical robot applications, in this paper surface covering and active sensing with 2.73 × 2.73mm2 size MEMS-CMOS integrated 3-axis tactile sensor devices are proposed. For detecting slippage of objects, we developed surface covering structure considering force concentration to the sensor diaphragm and the diaphragm protection from overload. The fabricated sensor device successfully showed the slippage prediction, slipping, sliding and falling of the various type's objects. Next, for recognizing the object textures, the sensing surface of the fabricated tactile sensor device moved along object surfaces. With applying force, initially 6N, depending on the object textures unique time series sensing data appeared and can be used for recognition.

Planetary gear transmission has the characteristics of an immense power-to-weight ratio, compact structure. It has been widely used in various industrial fields. Due to the complex load conditions, bearings are easily damaged during the operation process. However, in real applications, vibration characteristics of the defect bearings in gearboxes are too weak that it is challenging to extract useful information. This paper presents a dynamic model for an inner-race defect sun gear bearing in a planetary gearbox, from which the simulation results are validated using our planetary gearbox test bench and can be implemented in feature extraction in vibration signals. Specifically, time-varying stiffness during gear meshing and the slippage between raceways and balls are considered. Simulation results show dominant ball passing frequencies of inner-race defect, which are validated by the experimental results. Besides, the capability of our model to extract bearing defect frequencies from strong gear vibrations is proved by the envelope analysis.

In the case of assuming that the debonding interface layer was a thin fluid layer and taking the structural boundary conditions into consideration, we derived the expressions of ultrasonic reflection/transmission coefficients in a thick adhesive layer composite structure with debonding and slip defects under water immersion conditions based on the global matrix method. In addition, the finite element method was used to calculate the ultrasonic reflection/transmission coefficients when the bonding interface is debonded and slipped in the bonding structure. The theoretical calculation and simulation results are in complete agreement. The influences of the position of the interface defects (upper or lower interface of the adhesive layer) and defect types (slippage, debonding) on the ultrasonic reflection characteristics were also studied. The results show that if the incident angle and frequency of the sound wave are set appropriately, the perfected bonding, slippage and debonding interfaces can be distinguished.

The wheeled mobile robot (WMR) is widely employed in many industrial fields, and more new control difficulties appear when the WMR works on soft terrains (e.g., Lunar exploration), one of which is induced by wheel slippage. In this paper, a new approach for the haptic teleoperation of a differential WMR coupling with wheel slippage on soft terrains is proposed. In the proposed teleoperator, the linear/angular velocities of the slave WMR are directly mapped with the master robot’s positions. The command-tracking errors and the non-passivity at the slave WMR site induced by the wheel slippage are compensated by the proposed feedforward controllers for each wheel based on the online estimated slippage. The stability of the teleoperation system is guaranteed by the passivity theory while the environment termination is proved to be passive with the proposed feedforward controllers. The experiments validate that the proposed teleoperator is stable while the command-tracking performance of the slave WMR is obviously improved on soft terrains.

The paper introduces a novel design for an in-pipe climbing robot with a flexible body, along with the successful simulation of the proposed mechanism. The presented Three-Module pipe climber can traverse a complex network of pipes and bends at various angles. It has bidirectional motion capabilities and is orientation independent. It can also negotiate the ‘Singularity Region’ encountered while turning through the Tjunction. The pipe climber has three modules which are arranged symmetrically $120^{\mathrm{o}}$ apart from each other. These modules mount the tracks which provide the necessary traction for the robot to avoid slippage on the pipe’s surface. The modules, independently, have the ability to compress asymmetrically allowing the robot to bend in any direction. The taper in the front of the design and additional body flexibility due to passive spring compliance aid the motion at turns. The design of the robot is done on SOLIDWORKS and its motion is studied using MSC ADAMS. While simulating the proposed mechanism, differential speed was provided to the tracks for negotiating turns.

In order to realize the early prediction of belt conveyor faults and improve work efficiency, this paper proposes a fault prediction method based on gray least squares support vector machine. First, analyze the working status of the belt conveyor and study the cause of its failure. Then, select the characteristic parameters to establish a least squares support vector machine prediction model to determine the deviation and slippage that may occur during the operation of the belt conveyor. The longitudinal tearing failure is analyzed to realize the judgment of the failure prediction trend of the belt conveyor. In this way, not only the efficient work of the belt conveyor is ensured, but also the inconvenience caused by the inspection to the staff is reduced.

These days, crypto-currency is getting popular in society. Many people around the globe are using these coins for transactions. This world of crypto-currency works on the principle of exchange between different cryptocurrencies. It is observed that while exchanging currencies, we often get less amount of money compared to what we hope for, as exchange rates are volatile, and they increase if a considerable amount is exchanged. This phenomenon of the exchange rate dropping, when the exchange amount increases is called slippage. To solve this problem, we propose a novel application/API - Slipswap. In this work, we propose a web application “SlipSwap” that takes the input value of one currency and gives an optimal way to exchange so that the user loses the least amount of money. There is no such tool available, which helps users save a significant amount of money. Further, the proposed tool can be used as an API and can be integrated with different platforms.

Processes of braking system operations of the ground wheeled vehicle are complex nonlinear dynamic processes. When a problem of modeling vehicle braking process is setting it is considered rational to set the one in a form of the antagonistic differential game and to represent one of the antagonists - the road surface - in a form of unknown disturbance. It is considered rational to choose an artificial neural network (ANN) as a control element and flexible approximator that has properties of self-learning.

The object of research is an omnidirectional mobile platform equipped with four mecanum wheels. The movement of the system on a horizontal plane is considered. The aim of the research is to study the dynamics of the omnidirectional platform, taking into account the design of mecanum wheels: the shape of the rollers and their finite number. The equations of motion of the onmidirectional mobile platform are derived taking into account the real design of the mecanum wheels, their slippage, and the forces of multicomponent contact friction. A comparative analysis of the results of numerical modeling for various models of contact friction is performed.

Electric locking screw tools are often used in factory production. This tool uses a motor to drive the screwdriver head clamped by the fixture to rotate to achieve screw locking. Some of this electric locking screw tool looks like a thousand-hand drill, which is manually used by workers, and some is installed at the end of the manipulator as an automated tool. Whether it is manual or automated, companies have found a pain point in the process of using this tool to assemble screws, sometimes there will be slippage, and it is difficult to find such slippage during the installation process, if not handled in time, this slippage will cause poor assembly, which will seriously affect product quality. Therefore, this paper proposes a sliding wire detection system and method for electric lock screw tools based on the characteristics of the motor, which realizes the real-time detection and alarm of the sliding wire, and has the advantages of simplicity and low cost.

Grippers are the devices that mimic human hands in both function and form. Most of the grippers; however lack sensing abilities. The ones integrated with feedback and sensors are quite expensive. Safe and reliable grasping also demands a systematic and computationally viable algorithm. This paper presents the development of a low-cost sensor-based adaptive gripper with three fingers controlled by a motor. For efficient grasping of an unknown object, the paper presents a novel algorithm. Experiments show that the developed underactuated gripper is able to grasp irregular objects without damaging them. Sensing abilities, and the application of the proposed algorithm enable the detection and prevention of the slippage of the grasped object.

The rationality of friction model affects the accuracy of rail temperature calculation. A temperature-dependent coefficient of friction (COF) was adopted to develop a 3-D FE model for calculating the rail temperature. A comparison of the results between the models using the temperature-dependent and constant COF was conducted. The peak temperature is 524.73 °C at the slippage of -50% from the temperature-dependent COF, while that is 727.88°C from the constant COF. The temperature rises linearly in the model with the temperature-dependent COF, while the temperature goes up slowly gradually before reaching the peak in the model with the constant COF. The temperature gradient in the model with the constant COF are larger than that with the temperature-dependent COF.

In real-world grasping tasks, unstable grasping will lead to sliding between the object and the robotic nd-effectors. When the target object owns special properties (e.g. glasses, etc.), sliding may cause damage to both the object and the grasping environment, so it is necessary to predict and classify whether sliding occurs at the moment of grasping. Aiming at predicting sliding, this paper proposes a sliding prediction solution for time series tactile data obtained by crude sensor Xela and designs a novel neural network: the force motion tracking network. It predicts the variation trend of the frictional force at the moment of contact, and then concatenate the collected and predicted friction force data as the input of the LSTM network to classify the contact state (whether there is slippage). In this paper, 660 sets of tactile time series data are collected, and we process high dimensional tactile time series data into video data. This data processing method can be applied to other similar tactile sensors. Meanwhile, we also verify the proposed model, the mean square error of our force tracking network is much smaller than ConvLSTM, and the prediction accuracy of our network can reach to 93.5%,which is higher than other methods.

Helical gear is one of the parts of a machine which undergoes mechanical operation with some loading condition acting upon it. Helical gear deals with high contact and friction which reduces the slippage compared to spur gears. The load may cause damage to the gears generally to the tooth surface and breakage of gear tooth and other damages to the gear that may include deterioration of plastic material and the rim or web breakages. When the gears are used in assemblies are named as gear train. The leading factor of gear failures are the stress and surface strength of a gear tooth. So, it has been interesting in the research area to minimise the stress acted on the gear and optimal design of gear. In this paper the design of gear train at specific parameter is done in Solidworks and the aluminium alloy material is considered. The further analysis is done in ansys 18.0 where some loading condition is applied for the analysis. Two types of analysis is done to the simulation which is vibration and stress analysis. It is 500 N-m of moment is applied at gear train and the stress in the tooth and shafts are determined that whether the result analysis obtained is within the yield tensile limit of the used material.

Filament winding is an emerging field in order to transfer filament from one spool to another spool according to having the desired length and pattern. Filament materials that are commonly wound in the industry include threads, yarns, synthetic fiber, and wire. Currently, winding machines are available in textile industry for threads or yarns, however such machines are not suitable for fiber optic winding with high precision in winding pattern. In comparison to thread or yarns, optical fiber is more fragile and cannot be subjected to high stresses and extreme bends. In nature optical fiber has very low surface friction as a result slippage phenomenon exist between layers during filament winding. In addition, fiber optic winding density and pattern stability is not well addressed. This research presents application of fuzzy logic-based control technique on newly developed precision fiber optic winding machine.

In this paper, the trajectory tracking control problem of a mobile robot with four omni wheels is considered. The robot moves on a horizontal surface when the wheels slip. A dynamic model of the robot is constructed taking into account wheel slippage during braking. The movement of the wheeled robot is controlled by four independent direct current (DC) motors. Moreover, the torques developed by the engines are linear with respect to the voltage supplied to the engine and the angular velocity of the rotor. Based on the Lyapunov function method, a nonlinear control law is constructed that solves the trajectory tracking problem. Theorem on the asymptotic stability of the set of the closed-loop system equilibrium positions is proved.

Performance of a rigid wheel on deformable soils has been studied extensively, however little research had focused on inflatable soft wheels. In this project, we have designed and constructed a pneumatic actuated compliance tuning wheel. Unlike traditional rigid rim wheels, the proposed design embeds air bladders between the wheel grousers. Inflated air bladders provide additional traction by increasing the wheel’s contact area with the ground. The wheel was tested for slippage on deformable sandy terrain, rough obstacles and smooth metal surfaces. Reduced slippage was observed with bladder inflation in both a sandy terrain test and obstacle test. A smoother forward motion was observed in all test conditions with inflated bladders. The wheel’s capability of climbing was also evaluated qualitatively on a smooth metal-surface slope. As the slope angle increased, the bladder inflation proved to be necessary in order to successfully climb. Overall, the mobility of the wheel was improved on various terrains by the addition of inflatable soft air bladders.

The HP3 instrument measures the thermal flux through the Martian crust using a penetration probe. Launched on the InSight mission in 2018, HP3 was deployed for penetration activities in the beginning of 2019. This paper shortly introduces the HP3 instrument and shows the design and analysis process of the feet pattern and of each foot. The pattern of the feet is driven by the accommodation of the instrument on the lander and the need to ensure stability of the instrument on the surface. A four-feet design was chosen as it can be fitted very good into the available volume. During operation, the instrument is vulnerable to tipping as the landing site can be tilted and partially covered with rocks and depressions. Therefore it is shown analytically, that the instrument is stable, although it might be partially located on rocks or depression in combination with a tilted landing site. The new design of the feet is introduced and compared to a flat-plate foot. The capability of each design to produce slippage resistance is estimated analytically. The analytical estimations show, that the chosen flight-design generates more slippage resistance than the flat-plate approach. Even though the analytical estimations do not cover all effects generating slippage resistance.

A planetary rover experiences mobility problems, such as excessive slippage and entrapment, on loose terrain known as regolith. To prevent such situations, understanding wheel-soil interaction mechanics is necessary. Thus, this study focuses on the soil deformation beneath a grouser wheel and the wheel traction performance. The soil deformation is analyzed by using particle image velocimetry (PIV) technique, and the wheel traction is measured by a force-torque (FT) sensor. The experimental results present that the soil around a grouser moves to the directions on the front and rear of the wheel when the grouser enters into the soil. After that, the soil flow describes an arc-shaped flow from the front of the wheel towards the rear-end of the wheel caused by the grouser. These results indicate that the grouser wheel causes a different flow of soil than a wheel without grousers. Therefore, a model for the grouser wheel that takes into account the soil deformation must be developed in the future. We also investigate the effects of the normal load of the wheel on the soil deformation. The normal load of the wheel affects the thickness of the soil deformation area rather than the shape of the boundary line of the soil deformation area. In addition, the maximum thickness of the soil deformation area and the velocity of the soil particles increase with an increase of the normal load of the wheel. As for the wheel performance, the increase of the normal load causes an increase of wheel sinkage and traveling traction. From these results, it can be deduced that an increase in the thickness of the soil deformation area leads to an increase in the traction performance of the grouser wheel. In conclusion, this work contributes further to the understanding of wheel-soil interaction and the relationship between wheel performance and soil deformation.

Automation of bridge inspection by multi-copters is expected to reduce cost and to increase the efficiency of maintenance of infrastructures. To realize stable flights of multicopters under strong winds is one of the crucial problems of image-based inspection of concrete structures. This paper introduces a multi-copter with an outer frame which is optimized to move on the concrete surfaces. The frame enables a multi-copter to fly by contacting to wall surface continuously and realizes stable flights with a certain distance from a wall in order to capture the image without any blurs which can be applied to the image processing for inspection. The proposed frame is cube shape, contacts and pushes a wall with 4 points, and keeps the same distance from a wall which is most important to measure defects such as cracks. Our system with frame consists of wind sensors to measure the wind strength and control thrust force and pitch angle to prevent slippage on a wall induced by a gust of wind. We developed a multi-copter system with a cube shape outer with wind sensors and control theory. This paper validated the effectiveness of the proposed method through experiments on a real concrete surface.

This study aimed to propose a flexible tracked vehicle, dual-body flexible crawler (d-FlexCraw), that can fit in the surface profile, reduce slippage against the ground, and absorb turning over. A prototype of d-FlexCraw is developed to verify the validity of the proposed concept. We conducts some fundamental performance tests and evaluate fundamental mobility.

Recently there have been many efforts to study the predictability of financial market trend using various machine learning approaches. In this paper we explore the idea of using deep neural networks to analyze and predict futures market movements. Our approach adopts deep long short term memory (LSTM) as the main model architecture and predicts futures market movement using augmented market trading data. Training and testing of our model is performed in a rolling fashion to ensure the validity and reliability of the prediction. We discuss the design trade-off of several configurations and variations of our model, and evaluate the impact of various parameter choices as well as how model and backtesting perform under different parameter settings. We further design and implement a complete trading platform to evaluate our approach. Backtesting and live paper trading of our model on this platform achieves promising returns. Moreover, a total return of 58.69% is obtained with live paper trading for a twelve-month period when taking into account of slippage and commissions, which demonstrates the effectiveness of our proposed approach.

We are reporting the first silicon electron device for the realization of detection in slip of grasping by laparoscopic forceps under very low friction condition. Even under "zero-level" friction, slip of grasping object is detectable with the original algorithm inspired from our finger’s sense of slip. At present, the surgeons of laparoscopic surgery or robotic surgery can able to get through monitor visual information only. It is one of the essential reasons why endoscopic surgeries requires much higher skills than conventional open surgery. Since organ surface is very slippery by blood and body fluid, very low friction around the organs is an essential issue especially in the case of laparoscopic surgery. Fabricated silicon slip sensing imager can visualize the grasping force distribution on the slippery organ surface, and the slippage of the organ is digitized by calculation of the center of load distribution. This is the first demonstration of slip detection at sub-mm spatial resolution under a very low friction condition on the tip of laparoscopic forceps, which is not only applicable to the medical treatment but also industrial robotics applications.

Vision and proprioception are traditional sources of information for robotic grasping, but they are insufficient to achieve a stable grasp without slippage or without applying an excessive force on the object. Tactile sensors can aid in this problem by providing spatial and temporal data on the contact between fingertips and object. In this work, tactile fingertip sensors are used to detect slippage through two separate methods: the first, using principles inspired by human tactile sensing, and the second, by using a convolutional neural network trained with suitably labeled test samples. To perform a fair comparison of the methods, two evaluations are performed using a test bench and a pick-and-place robotic application. Results show promising use of the model-based method to avoid translational slippage, as it was able to consistently keep objects from slipping without overloading the grasp. Limitations of both model- and learning-based approaches are identified and discussed.

The motivation firstly occurred when executive at Mahindra told about all the mishaps that happened during assembly of machine. Majority of them was because of slippage of hoist or due to heavy weight. Something must be done in this matter. Also wearing of the machine parts happen due to strain put on the machine, this strain comes from lifting heavy loads more than the limit of the machine and reduces its life. Due to this wearing of liner and brakes of the hoist crane the lifting chain slips on the gear and may lead to damage to property and life. Any of such accidents results in loss to the company. Thus, we made a device that would determine the load lifted using a S-Type load cell which is designed to lift or carry weights up to 1000 kgs. For linear movement of the load a high torque less RPM motor is used. If while lifting heavy objects anytime the load increases the maximum capacity (which can be set by the knob) this device automatically stops the upward movement of lifting process and indicate that the weight being lifted by the hoist crane is exceeding the safety limit of the machine. Results were very fascinating as workers found it very easy to notice heavy lifting and this prevented any further wearing of liner, brakes and gear which in turn increased the usage period of the machine, reduce the maintenance cost of the company. It can be further improvised by introduction of IOT in present working system.

A nonlinear reduced-order mathematical tire model has been created. The model takes into account the radial and torsional stiffness of the tire, as well as the effect of radial deformation on torsional rigidity and, conversely, the effect of torsional deformation on radial rigidity. It will be used to study the conditions for the occurrence of undesirable oscillations of vehicle wheels. Results of numerical simulation are presented.

The safety and comfort of a vehicle is very important when driving. One of the security and convenience that can be achieved is to maintain the stable condition of the vehicle when it turns. For this reason a prototype was designed with a control method to control the condition of turning a vehicle. In this paper electronic device system is designed to control turn conditions using the fuzzy logic method, where fuzzy logic processes data error yaw rates and turning angles obtained from the IMU sensor. The system was applied to a three-wheeled vehicle model with a two-wheeled steering system. Based on testing with variations in turning angles and a fixed speed of 20 km / h, the largest yaw rate occurs at a 30 degree turning angle which is 0.2355 rad / s and after being given control of the yaw rate value to 0.03901 rad / s a yaw rate value reduction of 1 , 5943 rad / s. Testing with variations in vehicle speed and fixed turn angle of 10 degrees produces a yaw rate of 0.1314 rad / s and after the control is given to 0.03892 rad / s, a reduction of 0.09248 rad / s occurs. From these tests fuzzy logic is capable of improve vehicle response by minimizing slippage that occurs when the vehicle makes a turn movement so that the three-wheeled vehicle is maintained stability and security.

Railway traction vehicles are equipped by slip controllers to avoid wheels slippage occurrence during the train operation and simultaneously enables to maximise the force transfer from wheels to rails. Many types of slip controllers were developed during the last decades, and their development is not sill finished. The paper proposes a novel slip controller principle that is based on a calculation of power dissipation in a wheel-rail contact area. The presented approach enables better adhesion utilisation than conventional slip controllers based on the adhesion coefficient value estimation. The dissipation power is calculated from the estimated adhesion force and train velocity. The estimation of the adhesion force is made by an extended Kalman filter. The slip controller principle is verified on measured data that were obtained on a freight train hauled by an electric locomotive.

The aim of this paper is to compare neural networks and decision trees in the ability to trade financial futures. Emphasis is made on correctness of comparison from practitioner's point of view. Contrary to other papers, we implemented actual trading strategy simulation with slippage and commission fees. Many research papers do not pay attention to correctness of experiments from practical point of view. Predictions are incorporated into trading algorithm and trading profits and Sharpe ratio are calculated. Experiments using 30 technical indicators and 45 different futures is repeated 16,895 times and evaluation is made using out of sample data. Results show that both methods have comparable accuracy and perform similarly.

This paper presents an omnidirectional mobile robot (OMR) with longitudinal MY-wheels, and because of the switching effect of the contact radius which is the distance between the robot center and the contact point with the ground, the real model of this OMR is a discontinuous model. In order to study the influence of different approximate continuous models on the performance of the OMR, a parameterized model based on the cycloidal curve is established. A solving method of the reaction force from the ground using the movement state of the OMR is proposed, and with the solved reaction force and the force-angle stability measurement (FASM) the slippage and tip-over stability of the OMR can be evaluated. Finally, the simulation is performed, and the influence of different models on the slippage and tip-over stability of the OMR is analyzed.

Wheeled rover which is a lightweight wheeled robot is used for navigating over challenging terrain such as a steep soft sand incline. To improve the performance of the wheels on soft surfaces, the wheels are usually equipped with fixed grousers (lugs) on its wheels. However, even with the grousers the wheels tend to experience high slippage and sinks into the soft sand surface, which is caused by the rotating motion of the grousers which excavates the sand underneath the wheel towards the back of the wheel. A solution has been proposed by previous research which reduces sand movement and subsequent sinkage by using a prototype angle adjustable grouser mechanism and proven to improve the rover performance on steep inclines. The purpose of this study is to investigate the effect of grouser angle of attack when moving under the sand surface, towards the interaction between the grouser and sand particle. For the simulation process, Discrete Element Method (DEM) is used to simulate the particle-particle and particle-grouser interaction. The result shows that maintaining a constant angle using the adjustable grouser is able to reduce the amount of sand being excavated from under the wheel towards the back of the wheel as tests in high slipping conditions shows less displacement of sand particles from under the wheel towards the surface of the wheel. The result will be used to assist in analyzing the optimal parameters for wheel grouser design for use on soft sand.

The work presented in this paper shows the idea of extended factitious force method for control of skid-steering mobile platforms and the approach of non-ideal velocity constraints. The same model for both methods is presented and compared. It is shown that the both methods are different in origin but are a mechanism of overcomming a problem of underactuation on dynamic level. Extended factitious force introduces new virtual inputs to the system while the non-ideal velocity constraints method allows a small disturbance which bends the constraints imposed on the system. The methods are compared in terms of an estimation of slippage where the newly introduced terms are linear combination of the other method.

Dynamic bipedal robot locomotion has achieved remarkable success due in part to recent advances in trajectory generation and nonlinear control for stabilization. A key assumption utilized in both theory and experiments is that the robot's stance foot always makes no-slip contact with the ground, including at impacts. This assumption breaks down on slippery low-friction surfaces, as commonly encountered in outdoor terrains, leading to failure and loss of stability. In this work, we extend the theoretical analysis and trajectory optimization to account for stick-slip transitions at point foot contact using Coulomb's friction law. Using AMBER-3M planar biped robot as an experimental platform, we demonstrate for the first time a slippery walking gait which can be stabilized successfully both on a lubricated surface and on a rough no-slip surface. We also study the influence of foot slippage on reducing the mechanical cost of transport, and compare energy efficiency in both numerical simulations and experimental measurements., Comment: 7 pages, 8 figures, submitted to 2019 International Conference on Robotics and Automation (ICRA)

Motion control of skid-steered tracked mobile robot with slippage is still of interest for many specialists and researchers. Skid-steering with slippage causes complex track terrain interactions which make the modeling and control of such systems very challenging. In this paper, various control schemes are explored and tested on the tracked robot to investigate the dynamical performance under different operating conditions. First, a PID (Proportional-Integral-Derivative) controller is implemented and then compared with a FLC (Fuzzy Logic Controller). The main challenge in controlling the tracked mobile robot is the presence of highly nonlinear quantities due to slippage and soil shearing. Preliminary simulation results are introduced to verify the robustness of the proposed controllers under different operation conditions.