Maximum Payload Capacity Research Articles

A piezoelectric driven amphibious microrobot capable of fast and controllable movement

Abstract Due to its excellent adaptability to the environment and flexibility in narrow spaces, amphibious microrobots have become an important research direction recently. This study proposes an amphibious microrobot driven by piezoelectric actuators with a body length of 4.5 cm and a mass of 1.4 g. The microrobot consists of two active front legs, two passive rear legs, two caudal fins, and a support frame. Each front leg and each caudal fin are designed as structures integrated with their respective piezoelectric actuators. The microrobot has a tilted body, and the ground exerts an oblique upward impact force that makes it jump forward when its front legs swing backwards. The opposite swing of the two caudal fins generates propulsion for swimming. The components of the microrobot are manufactured based on the monolithic laminate process. The monolithic front actuator-leg and monolithic actuator-fin both emerge from a multi-layer material laminate. The support frame is designed and fabricated as a monolithic structure to improve assembly accuracy and reduce redundant assembly steps. The manufactured microrobot demonstrates its flexible and fast amphibious movements. Its maximum land walking speed reaches 15.3 cm/s and its turning speed reaches 48.2 degrees per second. The microrobot has a maximum payload capacity of 5 g moving on land. When the front legs and caudal fins work simultaneously, its underwater swimming speed reaches 9.1 cm/s, and the maximum turning speed is 20.5 degrees per second. The microrobot also confirms a maximum payload of 3 g during its underwater movement.

Development Of Agriculture Spraying Drone

The primary objective of the AGRICULTURE SPRAYING DRONE is to enhance the efficiency of agricultural spraying through the utilisation of unmanned aerial vehicles (UAVs) and also to minimise waste and adverse effects on the environment while optimising conventional agricultural spraying techniques. With the help of a 22000 mAh battery, the system combines cutting-edge parts, including the Hobby wing X6plus motors, K++ V2 flight controller, Sky Droid T12 receiver and transmitter, Hobby wing pump, flowmeter, Can hub, obstacle avoidance system, and PMU. The drone, with a total weight of 29 kg and a maximum payload capacity of 12 kg, guarantees accurate and productive spraying operations across large agricultural areas. Key characteristics include adaptive spraying patterns tailored to specific field conditions, targeted pesticide application, and real-time crop health monitoring. An additional mobile application enhances the system by offering farmers the ability to remotely operate, schedule spraying, and examine field data. In order to show how the suggested drone system may be implemented practically and its effectiveness assessed in actual agricultural settings, the article describes the system architecture and provides a use-case scenario. By enabling more effective and sustainable agricultural methods, this research advances precision agriculture technologies. Key Words: Agriculture Spraying Drone, Precision Spraying, Sustainability.

Deployment of Dynamic Wireless Power Transfer Considering Loading Capacity of Electric Trucks

Electric vehicles (EVs) are gradually being introduced in the transportation sector to reduce greenhouse gas emissions. However, short range and inadequate recharging facilities have hindered the widespread use of EVs. The tradeoff between the battery capacity and maximum load capacity makes it difficult to achieve the same range as that of a gasoline-powered vehicle. The EV range can be extended through dynamic wireless power transfer (DWPT), in which power is transferred from a device containing power transmission coils laid on the road. In this system, the EVs can be powered without stopping, and the actual range relative to the battery capacity can be significantly extended, which in turn increases the maximum load capacity. Therefore, this study aims to develop an optimal DWPT deployment model for last-mile freight transport, explicitly considering the loading capacity of electric trucks, and discusses the relationship between DWPT placement and maximum payload capacity. A total cost minimization problem was formulated, which includes the operational and DWPT deployment costs for actual last-one-mile transportation networks in Tokyo. The results were compared with the total cost and required battery capacity without using DWPT systems. Subsequently, the effects of reducing the total cost and increasing the maximum load capacity were calculated. The results clearly reflect the tradeoff between the number of DWPT installations, battery capacity, and maximum load capacity. Moreover, the purchasing cost and DWPT system installation per location presented a greater influence on the optimal solution and cost structure compared to the battery cost per kWh.

NuBot: A Magnetic Adhesion Robot with Passive Suspension to Inspect the Steel Lining

The steel lining of huge facilities is a significant structure, which experiences extreme environments and needs to be inspected periodically after manufacture. However, due to the complexity (crisscross welds, curved surface, etc.) of their inside environments, high demands for stable adhesion and curvature adaptability are put forward. This paper presents a novel wheeled magnetic adhesion robot with passive suspension applied in nuclear power containment called NuBot, and mainly focuses on the following aspects: (1) proposing the wheeled locomotion suspension to adapt the robot to the uneven surface; (2) implementing the parameter optimization of NuBot. A comprehensive optimization model is established, and global optimal dimensions are properly chosen from performance atlases; (3) determining the normalization factor and actual dimensional parameters by constraints of the steel lining environment; (4) structure design of the overall robot and the magnetic wheels are completed. Experiments show that the robot can achieve precise locomotion on both strong and weak magnetic walls with various inclination angles, and can stably cross the 5 mm weld seam. Besides, its maximum payload capacity reaches 3.6 kg. Results show that the NuBot designed by the proposed systematic method has good comprehensive capabilities of surface-adaptability, adhesion stability, and payload. Besides, the robot can be applied in more ferromagnetic environments and the design method offers guidance for similar wheeled robots with passive suspension.

Real-time measurement-driven reinforcement learning control approach for uncertain nonlinear systems

The paper introduces an interactive machine learning mechanism to process the measurements of an uncertain, nonlinear dynamic process and hence advise an actuation strategy in real-time. For concept demonstration, a trajectory-following optimization problem of a Kinova robotic arm is solved using an integral reinforcement learning approach with guaranteed stability for slowly varying dynamics. The solution is implemented using a model-free value iteration process to solve the integral temporal difference equations of the problem. The performance of the proposed technique is benchmarked against that of another model-free high-order approach and is validated for dynamic payload and disturbances. Unlike its benchmark, the proposed adaptive strategy is capable of handling extreme process variations. This is experimentally demonstrated by introducing static and time-varying payloads close to the rated maximum payload capacity of the manipulator arm. The comparison algorithm exhibited up to a seven-fold percent overshoot compared to the proposed integral reinforcement learning solution. The robustness of the algorithm is further validated by disturbing the real-time adapted strategy gains with a white noise of a standard deviation as high as 5%.

Steganlysis on data embedded medical image

Cybercrime around the world is increasing day by day abruptly. Stego attack is one of the popular methods of transferring the message secretly through the cover medium. Most of the sources are using this process for covert communication. The paper discusses the importance and analysis of data hiding theft and covert communication process through steganalysis where it talks about the ”covered writing” in such a way that the mutation of an image is not discernible. The main motive of this paper is to attack and analyze the Digital Imaging and Communications in Medicine (DICOM) file format. The file format DICOM discussed in this research is mostly supported in the medical field. CT Scans and MRI Scans are widely used in hospitals to view the human body. The random pixels is chosen to hide the text on the DICOM formats and the performance is measured using different metrics. The proposed approach produces 100% recovery of the hidden text inside an image with maximum payload capacity.

Chemical Rocket Motors for Space Launch Applications: Parametric Approach

Hybridrocket motors are widely used in heavy launch vehicles with maximum payload capacity. The main reason for the study in this field is that the hybrid rocket motor is very easy to handle and has a simple design. In this paper, we have studied the parameters involved in designing and optimizing the hybrid rockets which provides in achieving maximum performance value. The several parameters considered for parameters involve are- burn rate, specific fuel consumption, specific impulse, efficiency. The design constraints will be responsible in achieving a high thrust level through the nozzle. The study also highlights the propellants being used in hybrid rocket motor. The collaborative research will aid in briefing the design and the working of the hybrid motors that is frequently being utilized in the industry.

High Capacity Image Steganography System based on Multi-layer Security and LSB Exchanging Method

Data security is becoming an important issue because of the vast use of the Internet and data transfer from one place to another. Security of these data is essential, especially when these data represent critical information. There are several techniques used to hide these data, such as encryption. Steganography can be utilised as an alternative to encryption because encryption is susceptible to data modification during transmission. Steganography is the hiding data on a cover multimedia such as images, audio, and video. The technique allows security for data transmission so unwanted third parties cannot notice the hidden data. The challenge of steganography is the trade-off between the hidden data's payload capacity and the system's imperceptibility and robustness. If the hidden data increases, the imperceptibility and the robustness will be decreased. This case is a big challenge in this digital world where social media, Internet, and data transfer are used hugely. Because of this, this paper proposes using a modified Least Significant Bit (LSB) method for the embedding process called Multi-Layer Least Significant Bit Exchange Method (MLLSBEM). This proposed algorithm uses the AES encryption method to encrypt the secret text and then uses Huffman coding to compress the encrypted message as pre-processing data. The proposed study seeks to strike a compromise between important issues, provide maximum payload capacity, and retain high security, imperceptibility, and reliability for secret communication Using image processing and steganography techniques. Simulation findings demonstrate that the suggested method is superior for existing PSNR, SSIM, NCC, and payload capacity investigations. The proposed method is immune to the histogram, chi-square, and HVS attacks.

Genuine Reversible Data Hiding Technique for H.264 Bitstream Using Multi-Dimensional Histogram Shifting Technology on QDCT Coefficients

Video has become the most important medium for communication among people. Video has become the most important medium for communication among people. Therefore, reversible data hiding technologies for video have been developed so that information can be hidden in the video without damaging the original video in order to be used in the copyright protection and distribution field of video. This paper proposes a practical and genuine reversible data hiding method by using a multi-dimensional histogram shifting scheme on QDCT coefficients in the H.264/AVC bitstream. The proposed method defines the vacant histogram bins as a set of n-dimensional vectors and finds the optimal vector space, which gives the best performance, in a 4 × 4 QDCT block. In addition, the secret message is mapped to the optimal vector space, which is equivalent to embedding the information into the QDCT block. The simulation results show that the data hiding efficiency is the highest among the compared five existing methods. In addition, the image distortion and maximum payload capacity are measured quite high.

Trajectory Planning of Quadrotor UAV with Maximum Payload and Minimum Oscillation of Suspended Load Using Optimal Control

This paper focuses on the problem of transporting a cable-suspended load by a quadrotor UAV for safer flight and more efficiency. The dynamic model of a quadrotor coupled to the suspended load is derived using the Euler-Lagrange formulation. The optimal trajectory for carrying the maximum payload and minimum oscillation of swinging load will be obtained. The optimal cable length to increase the maximum payload capacity and reduce the maximum oscillation angle of swinging load is obtained. Also, the effect of load mass on the maximum oscillation angle of swinging load is studied. In this paper, the optimization procedure is based on the solution of the optimal control problem from the class of open loop with an indirect method. The application Pontryagin’s Minimum Principle lead to deriving the optimality conditions and subsequently a two-point boundary value problem (TPBVP) which is solved by a numerical method. An appropriate algorithm is presented for calculating the maximum payload to move between two specified points. The main superiority of this method is that it can solve a wide range of optimal maneuvers for arbitrary initial and final configurations relevant to every considered cost function. Generating various optimal paths with different maximum payloads and oscillation angles by modifying the values of the penalty matrices. In order to verify the efficiency of the proposed method and the presented algorithm, a simulation study is performed for a quadrotor with a suspended load in maneuver between two specified points and various object function.

Kriging models for payload distribution optimisation of freight trains

This paper deals with Kriging models applied to optimise braking performances for freight trains. More precisely, it is focused on mass distribution optimisation aimed at reducing the effects of in-train forces among vehicles, e.g. compression and tensile forces, in-train emergency braking. To this end, Kriging models are applied with covariance structure based on the Matérn function, introducing specific input parameters to better outline the payload distribution on the train, also evaluating the shape of the payload distribution. The different shapes, related to the payload distributions, have been implemented into a model through a Python routine, which has been used to ‘assemble’ the simulated trains. The analysed train carries 80% of its maximum payload capacity during an emergency braking from the speed of 30 km/h. Satisfactory results have been obtained considering compression forces, tensile forces and their sum, also considering residuals and diagnositc measures.

Advanced power supply of construction hoists for supertall buildings

Abstract The operational efficiency of construction hoists is increasingly important for successful project completion of supertall buildings. In supertall building construction, the traditional power supply using cable systems for construction hoists not only breaks down frequently from its own weight and wind load, but also reduces the maximum payload capacity of the hoist. This study proposes an advanced power supply system of the contact type to enhance operational efficiency and reduce the operation costs of construction hoists. In a field test, the proposed system required only one repair taking 4 h, whereas the cable systems required 21–41 repairs that caused 20–30 days of construction delay. The proposed system also reduced the total operation cost of power supply by up to 22% over the cable systems. Moreover, it could maximize the payload capacity of the hoists. It is expected that the proposed system can reduce the overall construction period with stable operation of the hoists.

A combinatorial search method for the quasi-static payload capacity of serial modular reconfigurable robots

This paper presents a new combinatorial search method for the quasi-static stiffness performance evaluation and payload capacity analysis of serial modular reconfigurable robots (MRRs). The goal in this paper is to optimize the external payload capacity to achieve a global set of satisfactory kineto-elastic performance requirements for all module configurations. This problem exhibits considerable numerical complexities since the maximum payload capacity is dependent on a large number of possible module configurations, the worst-case stiffness poses for each configuration, and multiple kineto-elastic performance requirements. Therefore, to alleviate these difficulties, the problem is decomposed into an elimination search algorithm to reduce the configuration search space, a genetic algorithm to directly search the configuration workspaces and find the worst-case stiffness poses, and a bisection method to determine the maximum payload capacity at the worst-case configurations and poses. It is demonstrated that the worst-case stiffness search method in this paper is superior in computational time and numerical accuracy compared to previous hierarchical or incremental search methods, which require searching through a pre-determined number of poses. Through case studies, the new combinatorial search method is proven to be computationally efficient and can obtain accurate results for the worst-case stiffness poses and maximum payload capacity.

Optimum dynamic design of flexible robotic manipulator

A closed form solution to Optimum Dynamic Design (ODD) of a flexible link Robotic Manipulator is derived considering the link to be the Euler–Bernoulli beam. The Finite Element Model (FEM) for dynamic equation is solved to maximize the stiffness and minimize the mass in the formulation of ODD procedure. The optimum pre-assigned parameters of link end deflections and the maximum payload capacity form the constraint inputs. The redundant progressive series formed as an objective function is solved by Optimal Interface Theory, briefed in the Appendix. The philosophy of Interface Theory lies in the observation that with the progression, the grip improves and the grasp diminishes under the loads of the physical world problems. For the theoretical analysis, the manipulator link is considered to be a revolute jointed with two degrees of freedom (DOF)—a deflection and a rotation at each node. Based on the requirements of better productivity and higher precision in high speed industrial robots, the platform for the maximization of stiffness, minimization of mass has been prepared to demonstrate the ODD procedure. In the ODD problem, the deflection, velocity and acceleration vectors act as grip coefficients and the stiffness, damping and the mass are considered as the grasp variables.

Maximum load-carrying capacity of autonomous mobile manipulator in an environment with obstacle considering tip over stability

In order to increase the efficiency of wheeled mobile manipulators (WMM), it is preferred to carry the maximum payload, but in the case of a small-sized platform, which is desirable in applications, it may cause dangerous tip over, especially in the presence of obstacles. So, it is necessary to consider stability constraint in the determination of robot motion planning. This paper presents a novel approach for the determination of the maximum payload-carrying capacity of a coordinated mobile manipulator in an environment with presence of obstacle, based on stability. The proposed method considers the tip over stability on zero moment point criterion, which must be considered when the path of the end-effector is predefined but the position of the mobile platform is free, because tipping over in this condition is probable. Hence, the full dynamic model of WMM (including the coordinating vehicle and manipulator) is used, the obstacle avoidance scheme is implied based on potential functions, and the maximum payload path for a specified payload is generated using the optimal control approach. Then, an iterative method based on the stability criterion and motor restriction, including torque and jerk, was implied to calculate the maximum payload capacity. To the best of our knowledge, this is the first paper reporting on some simulation results as well as successful experiments of implementing the algorithm. The proposed approach has been implemented and tested on a nonholonomic WMM consisting of a differential-drive mobile base and a robotic arm to demonstrate the efficiency and effectiveness of the proposed approach.

High-grip Stair Climber with Powder-filled Belts

It is desirable to have a mobile robot that can move and perform various tasks over irregular terrain. However, conventional systems are not reliable or sufficiently adaptable for practical application. A traditional method for climbing stairs is to use grouser-attached tires or tracks that can grip the edges of the stairs. However, with this method, usually only one grouser on each side of the vehicle grips the stairs because the spacing between the grousers does not necessarily coincide with the distance between the steps. In the present paper, a new stair-climbing crawler with high gripping force on the stairs is developed. Powder-filled blocks are attached to the face of the tracks so that the belt can change shape to match the edge of the steps. A large friction force is therefore obtained due to the soft deformation of the blocks at every point along the belt. The results from these stair-climbing experiments prove that the newly developed crawler with powder-filled belts is more reliable than other experimental crawlers when ascending and descending stairs. The current crawler, with powder-filled belts, can carry heavy loads. The maximum payload capacity is approximately 60 kg when ascending stairs at an angle of 30°. Furthermore, the proposed crawler can change direction when climbing stairs or obstacles, which improves the turning efficiency of the crawler.

Air Travel and Cardiovascular Disease

J Travel Med 2004; 11:243–250. Almost two billion passengers undertake international and domestic air travel each year.1,2 As the population ages and our ability to care for patients with cardiac disease improves, an increasing number of people with cardiovascular disease will be traveling long distances.Many such travelers have had pacemakers or automatic defibrillators implanted,have had recent revascularization,or have had surgery which might predispose to deep venous thrombosis (DVT). Recent data drawn from several major US carriers between 1996 and 1997 show 15 deaths among approximately 1.4 million passengers.3 Cardiac events account for the greatest percentage of flight diversions and appear to represent the major cause of in-flight death.3,4 As more patients with severe cardiovascular disease travel, on-board cardiac events might be expected to increase. A general overview with contraindications to air travel and recommendations for the patient with cardiovascular disease is presented in Tables 1 and 2. We will review the pathophysiology and delineate the risk for patients with cardiovascular disease of sudden death, DVT, and ischemia/infarction when they travel by air. On 12 June 2001,the Federal Aviation Administration (FAA) issued a final ruling mandating that passengercarrying aircraft of more than 7,500-lb maximum payload capacity with at least one flight attendant carry at least one automated external defibrillator (AED) and an enhanced emergency medical kit (Table 3).All flight attendants will be required to receive initial and recurrent training on AED usage and in cardiopulmonary resuscitation (CPR). The rule becomes effective on 12 April 2004. Page et al. extrapolated from the data accumulated regarding AED use by one major US airline, and suggested that the widespread availability of AEDs on commercial airlines might prevent up to 93 in-flight deaths from ventricular fibrillation each year worldwide.5 Longterm survival rates in such patients range from 26% to 40%,which compares favorably with the 2% to 5% longterm survival rates often quoted for out-of-hospital arrests.6,7