Maximum Payload Research Articles

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%.

Coating with cationic inulin enhances the drug release profile and in vitro anticancer activity of lecithin-based nano drug delivery systems

Core-shell structured lipidic nanoparticles (LNPs) were developed using lecithin sodium acetate (Lec-OAc) ionic complex as a core unit and quaternized inulin (QIn) as the shell part. Inulin (In) was modified using glycidyl trimethyl ammonium chloride (GTMAC) as a positively charged shell part and used for coating the negatively surface charged Lec-OAc. The critical micelle concentration (CMC) of the core was determined as 1.047 × 10−4 M, which is expected to provide high stability in blood circulation as a drug-carrying compartment. The amounts of curcumin (Cur) and paclitaxel (Ptx) loaded to LNPs (CurPtx-LNPs), and quaternized inulin-coated LNPs (Cur-Ptx-QIn-LNPs) were optimized to obtain mono-dispersed particles with maximum payload. The total amount of 2.0 mg of the drug mixture (1 mg Cur and 1 mg Ptx) was the optimized quantity for QIn-LNPs and CurPtx-QIn-LNPs due to the favorable physicochemical properties determined by dynamic light scattering (DLS) studies. This inference was confirmed by differential scanning calorimeter (DSC), and Fourier-transform infrared (FT-IR). SEM and TEM images clearly revealed the spherical shapes of LNPs and QIn-LNPs, and QIn covered the LNPs completely. The cumulative release measurements of Cur and Ptx from CurPtx-QIn-LNPs, along with the kinetic studies, showed a significant decrease in the release period of drug molecules with the effect of the coating. At the same time, Korsmeyer-Peppas was the best diffusion-controlled release model. Coating of the LNPs with QIn increased the cell-internalization of NPs to the MDA-MB-231 breast cancer cell lines, resulting in a better toxicity profile than the empty LNPs.

Conceptual design and aerodynamic analysis of a Mars octocopter for sample collection

Mars sampling is of great significance for the comprehensive study of Martian geological evolution. The successful demonstration of the Ingenuity Helicopter reveals the potential of rotorcraft for sampling tasks on Mars. However, the Ingenuity Helicopter cannot carry samplers, and large helicopters face difficulties in folding automatically. Thus, a multi-axis rotorcraft may be more suitable for Mars sampling tasks. This paper proposes an octocopter named MarsBird-V with a foldable rotor system and wheels for moving agilely. The design method for the structure and control system of MarsBird-V is illustrated, followed by the mass and power estimation approach. On the basis of the blade element momentum theory, the criterion is proposed for the aerodynamic performance evaluation of the coaxial rotors. The aerodynamic data of the coaxial rotors are obtained by the computational fluid dynamics method, which is applied to determine parameters. The propulsion capacity is calculated in the rotational speed range limited by the Mach number of the blade tip. As estimated, the minimum gross mass of the MarsBird-V is 6 kg. The proportion of payload in the gross mass increases as the power increases. The MarsBird-V achieves maximum durability of 420 s at a power of 1017 W and obtains a maximum payload efficiency of 0.43 g/W at a power of 2362 W. This paper also presents the deployment process and mission analysis. The MarsBird-V can perform sampling tasks in a cycle time of 2 to 5 days.

WheTLHLoc: Small-Scale Hybrid Locomotion Robot With Stair Climbing Capability

AbstractThis paper discusses the theoretical analysis and the experimental validation of the step and stair climbing capability of wheel-track-leg hybrid locomotion (WheTLHLoc), a small-scale hybrid locomotion robot with overall size of 450 × 350 × 130 mm and maximum payload of 0.5 kg. The architecture of this robot combines two tracks, two rotating legs, two actuated wheels, and two passive omni wheels. The robot is capable of performing different locomotion modes: wheeled locomotion on flat and compact grounds with maximum speed of 0.9 m/s, tracked locomotion on soft and yielding terrains with maximum speed of 0.1 m/s, mixed use of tracks, legs, and wheels to overcome obstacles. In particular, the process of step and stair climbing is analyzed considering static stability and non-slipping conditions. The experimental campaign on the first prototype has confirmed the effectiveness of the proposed climbing maneuver for steps up to 165 mm and the operative flexibility of the WheTLHLoc robot.

Life Cycle Assessment of the Cellulosic Jet Fuel Derived from Agriculture Residue

The purpose of this paper is to discover the impacts of contradictory factors in the application of agricultural residue with sustainable biofuel benefits. Based on the Life cycle assessment (LCA) approach, the quantitative LCA assessment model and approach have been established, coupling upstream cultivation and downstream jet biofuel product, which would benefit agriculture residue choice. The LCA model investigated the effects of interaction factors on energy consumption, including land release and agriculture residue use change. The computational framework of the LCA model is classified into three sub-models, including the cultivation and harvesting model, the refining process and distribution model, and the flight model. According to uncertainty analysis by the LCA model, the positive energy gains have been conducted at a wide range of hydrogen production and methanol production. The application model is represented by six types of typical aircraft widely used in China, including the LTO cycle module, actual cruising distance and maximum cruising distance module, actual payload, and maximum payload module. In the whole life cycle assessment, GHGs of agriculture residue is 17.9 gCO2e/MJ while petroleum-based jet fuel is 90.2 gCO2e/MJ. The order of GHGs in WTW (well to wheel) is agriculture residue < corn stover < beanstalk < wheat straw < rice straw. The land release conducted obviously to the total GHGs emission for rice straw, which indicated that land release should involve in the LCA.

UAV Propeller Rotational Speed Measurement through FMCW Radars

The growing number of civil applications in which Unmanned Aerial Vehicles (UAVs) are involved can create many concerns for airspace security and surveillance. Gathering as much information as possible about a drone can be crucial to apply proper countermeasures if a potentially dangerous situation is detected. Of course, the presence of a UAV can be detected by radar, but it is possible to extend the system capabilities to obtain additional information. For example, in the case in which the UAV is equipped with propellers, the radar-measured rotational speed could be important information to classify the type of UAV or to reveal if it is carrying some possibly harmful payload. In addition, the rotational speed measured through radar could be used for different purposes, such as to detect a drone manumission, to estimate its maximum payload, or for predictive maintenance of the drone. Measuring the propellers’ rotational speed with radar systems is a critical task, as the Doppler generated by the rotation can be very high, and it is very difficult to find commercial radar systems in the market able to handle such a high Doppler. Another problem is caused by the typically very small Radar Cross-Section (RCS) of the propellers, which makes their detection even more difficult. In the literature, common detection techniques are based on the measurement of the Doppler effect produced by the propellers to derive their rotational speed, but due to the very limited capabilities of commercial sensors, this approach can be applied only at very low values of the rotational speed. In this work, a different approach based on a Frequency-Modulated Continuous Wave (FMCW) radar is proposed, which exploits the vibration of the UAV generated by the rotation of the propellers. The phenomenon and how the sensor can detect it will be presented, which is joined with a performance analysis comparing different estimation techniques for the indirect measurement of the propellers’ speed to evaluate the potential benefits of the proposed approach.

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.

Finite Element Analysis of a Novel Robotic Gripper:Grabo

Robotic grippers, with several design variations in its jaws, are gaining popularity in commercial market worldwide in recent past. In fact, these customized robotic grippers are widely used for diverse end-applications in various arenas. We have aimed to optimize the mechanical design of such customized robotic grippers having two fingers (jaws), as those grippers are the most prevalent variants in industrial robots. In this study, a niche contigutive robotic gripper for direct adhesion contactis developed, to meet the technical trials of force-closure of grasp. The prime focus of our research is reduction of the tareweight of the prototype gripper keeping its strength unaltered under the threshold of grasping maximum payload. Through Finite Element Analysis and optimization thereof, material retention percentage is defined for the prototype gripper so as to improve its overall envelope.

Uzamsal Alanda Bir Kripto-Stegano Hibrit Uygulama

The need for data security in communication is increasing with the developing
 technology. The best way to ensure data security is cryptography. Humanity has
 proposed many cryptography methods for hundreds of years. Today, there are
 complex cryptography algorithms, which are quite secure but require high processing
 power. Cryptography techniques used in the past are less secure but require less
 processing power. This article proposes an extended version of the Vigenère cipher,
 which is an ancient encryption method. Extended Vigenère cipher is able to encrypt
 upper and lower case letters, numeric characters, and punctuation marks. In addition,
 the method can use upper and lower case letters, numeric characters and punctuation
 marks as encryption key, and there is no key length limit. The cipher text generated
 with the extended Vigenère cipher is also hidden in an image to keep it safe in the
 transmission medium. Hiding is performed with LSB steganography, which is
 another data security method. Thus, both the readability and detectability of
 confidential data are reduced. The cryptological security of the proposed method is
 measured by the Avalanche effect. Steganographic safety is evaluated with SSIM
 and PSNR measurements. A user graphical interface has been developed and the
 maximum payload of the carrier image is measured before encryption. Proposed
 method applied on some test images with different specifications. 1 bit key
 modification avalanche effect results of proposed method with random plain texts
 between 1000-10000 characters with a key length of 8 and 16 characters is close to
 50%. Also, SSIM value calculated over 0.99 each time while maximum
 steganographic payload of the test images reached.

The multi-visit drone routing problem for pickup and delivery services

Unmanned aerial vehicles, commonly known as drones, have gained wide attention in recent years due to their potential of revolutionizing logistics and transportation. In this paper, we consider a variant of the combined truck-drone routing problem, which allows drones to serve multiple customers and provide both pickup and delivery services in each flight. The problem concerns the deployment and routing of a fleet of trucks, each equipped with a supporting drone, to serve all the pickup and delivery demands of a set of customers with minimal total cost. We explicitly model the energy consumption of drones by their travel distance, curb weight and the carrying weight of parcels, develop a mixed-integer linear programming model (MILP) with problem-customized inequalities, and show a sufficient condition for the benefit of the combined truck-drone mode over the truck-only mode. Considering the complexity of the MILP model, we propose a novel two-stage heuristic algorithm in which a maximum payload method is developed to construct the initial solutions, followed by an improved simulated annealing algorithm with problem-specific neighborhood operators and tailored acceleration strategies. Furthermore, two methods are developed to test the feasibility for both trucks and drones in each solution. The proposed algorithm outperforms two benchmark heuristics in our numerical experiments, which also demonstrate the considerable benefit of allowing multiple visits and both pickup and delivery operations in each drone flight.

Conventional and Asphaltic Underlayment Track Performance Subjected to Argo Jati Passenger Trains

Abstract This study performed the 2-dimensional modeling of Indonesia’s conventional track and the asphaltic underlayment track according to four different cyclic loading conditions by varying the train speeds and bogie load of Indonesia’s Argo Jati passenger trains set. Three different mechanical responses were considered, i.e., horizontal strains, vertical stress, and deformation, to investigate and compare the performance of Indonesia’s conventional track and the asphaltic underlayment track and to seek the possibility of Indonesia’s passenger trains to travel with higher speed and heavier axle load in the future. The numerical simulation results conclude that the asphaltic underlayment track capable of serving Argo Jati passenger trains set with the medium speed, 240 km/h, or 100 % higher than the existing operating speed. In addition, the application of a 20 cm asphalt layer below ballast will allow each passenger coach to carry the maximum payload up to 30 tons, or 50 % higher than the existing maximum payload. Furthermore, asphaltic underlayment track utilization in Indonesia’s railway systems could be beneficial for the optimization of the life cycle cost of the rail track since it could reduce the structure’s height, minimize the maintenance needs, and decrease track deterioration especially the mud pumping and deformation.

Effect of the infill density on the performance of a 3D-printed compliant finger

Recent advances in additive manufacturing and soft robotics have enabled the production of compliant fingers and grippers using 3D printing techniques. For instance, the fused deposition modeling (FDM) method allows users to print flexible filaments with pre-specified infill densities. In order to investigate the effect of the infill density on the performance of a 3D-printed compliant finger, this study performs experimental and numerical investigations in order to develop empirical equations for estimating the output force, the output displacement, and the input force corresponding to given values of the input displacement and infill density of the compliant finger. A commercially available thermoplastic elastomer (TPE) filament, Filastic™, manufactured by BotFeeder is used in this study. Prototypes of four compliant fingers with infill densities of 40%, 60%, 80%, and 100% are produced. A two-fingered gripper is also developed and the relationship between the infill density and the maximum payload is investigated. In addition, a finite element model taking into consideration the hyperelasticity of the TPE is developed to analyze the behavior of compliant fingers with different infill densities. The numerical results show good agreement with the experimental data and with the curves for the empirical equations.

The Structural Design and Aerodynamics Analysis for a Hybrid VTOL Fixed-Wing Drone for Parcel Delivery Applications

A number of companies are experimenting with multicopter drones to deliver items to clients. Because electric planes have a restricted range, their flight range is usually limited. However, if propelled by gasoline, electric multicopter drones can only travel a short distance because of high power consumption and noise difficulties. Despite their lower aerodynamic efficiency than fixed-wing aircraft, multicopters' ability to perform vertical take-off and landing (VTOL) makes them an ideal delivery vehicles. A hybrid fixed-wing VTOL system with a tilting system that alters the flight mode could be an upgradeto the current design of hybrid fixed wing VTOL. The goal is to effectively manufacture a fixed-wing drone with an appropriate structural design and a functional tilting mechanism that can take off vertically. SolidWorks and SIMNET aero were the two approaches used throughout the design software. The drone's aerodynamic qualities were investigated in order to better understand its behaviour, such as range of flight at a given altitude, stall speed, and maximum lift created, in order to determine the maximum parcel weight the drone can carry. The drone was built using SolidWorks 3D-Solid modelling and SIMNET aero design software. The tilting mechanism is 3D printed with Polylactic Acid (PLA) material since it is both light and strong. The structural strength can also be altered by changing the in-fill. After the drone was manufactured,numerous test flights were made to examine the drone's actual behaviour and enhance its functionality. The drone's theoretical stall speed was determined to be 12.74 m/s with a maximum payload of 500g and 11.43 m/s at no load. The maximum glide distance was estimated to be 1.2 kilometres. The drone yaws to the left during test flights at a rate of 63.43 degrees per second and 4.879 degrees per second at 50% throttle. It slanted to the front, nose down, with a weight of 516 g while support was given at the tip of the left wing. The pitch rate was 2.5 degrees per second without a payload and 3.12 degrees per second with the 516g payload. With further design and calibration advancements, experimental findings that are comparable to theoretical outcomes might be possible.

PUF-Based Post-Quantum CAN-FD Framework for Vehicular Security

The Controller Area Network (CAN) is a bus protocol widely used in Electronic control Units (ECUs) to communicate between various subsystems in vehicles. Insecure CAN networks can allow attackers to control information between vital vehicular subsystems. As vehicles can have lifespans of multiple decades, post-quantum cryptosystems are essential for protecting the vehicle communication systems from quantum attacks. However, standard CAN’s efficiency and payload sizes are too small for post-quantum cryptography. The Controller Area Network Flexible Data-Rate (CAN-FD) is an updated protocol for CAN that increases transmission speeds and maximum payload size. With CAN-FD, higher security standards, such as post-quantum, can be utilized without severely impacting performance. In this paper, we propose PUF-Based Post-Quantum Cryptographic CAN-FD Framework, or PUF-PQC-CANFD. Our framework provides post-quantum security to the CAN network while transmitting and storing less information than other existing pre-quantum and post-quantum CAN frameworks. Our proposal protects against most cryptographic-based attacks while transmitting (at up to 100 ECUs) 25–94% less messages than existing pre-quantum frameworks and 99% less messages than existing post-quantum frameworks. PUF-PQC-CANFD is optimized for smaller post-quantum key sizes, storage requirements, and transmitted information to minimize the impact on resource-restricted ECUs.

SpringWorm: A Soft Crawling Robot with a Large-Range Omnidirectional Deformable Rectangular Spring for Control Rod Drive Mechanism Inspection.

In this article, a cable-driven elastic backbone worm-like robot (named "SpringWorm") of decimeter-level size is designed, which has high adaptability in crack inspection of the weld between reactor pressure vessel (RPV) and control rod drive mechanisms. The robot consists of a body that adopts a rectangular helix spring backbone driven by four cables and the flexible claws embedded with distributed electromagnets. Combining the omnidirectional deformation of the backbone and the passive deformation adsorption of the claws, the robot can achieve a variety of gaits. Based on the approaches of geometric analysis and transformation matrices of the coordinate frame, a kinematic model of the cable-driven backbone has been established. Moreover, a mechanical model considering the friction between the cable and the backbone has also been established. The top position and the bending angle of the backbone obtained by the theory, simulation, and experiment are in good agreement. In addition, the errors of the driving force between simulation and experimental results are also small. SpringWorm is 670 g, measures 206 × 65 × 75 mm, has a maximum speed of 8.9 mm/s, and has a maximum payload of 1 kg. The robot can climb over 2-cm-tall steps and 4-cm-deep ditches, and climb and turn on the vertical wall, on the pipe with a radius of 31 cm, and on the spherical surface of RPV.

Low-fidelity design optimization and development of a VTOL swarm UAV with an open-source framework

Hybrid configurations in aircraft design are highly favorable as they can achieve the appropriate trade-offs required to develop a generalized unmanned aerial system (UAS). Rapid prototyping of such systems at the student level is challenging because commercial software is expensive and difficult to interlink with other tools for creating a multi-disciplinary design. We address this challenge by conceptualizing an aircraft design framework made entirely of open-source software, libraries, and in-house code. We then use this framework to design an all-electric unmanned aerial system with transitioning Vertical Take-off and Landing (VTOL) and Fixed-Wing (FW) modes. The UAV is capable of long-range surveillance up to 100 Kilometers and carrying a maximum relief payload of 1 kg while operating in an ad-hoc wi-fi network with a swarm of similar UAVs. A low fidelity particle swarm optimization algorithm (PSO) and a comprehensive propulsion architecture is also incorporated and validated against commercial software. To validate the design, a prototype is fabricated from glass-fiber and XPS foam, integrated with appropriate sensors and tuned using ArduPilot software. The results show that low-fidelity design is a safe starting point for prototyping under constrained timelines. The study is concluded by discussing the technical challenges of using free software, and some practical considerations while flight testing a UAV with a hybrid configuration.

Conceptual Design of a Reusable Submunition Dispenser for Unmanned Aerial Vehicles

The paper describes a concept for developing a dedicated combat asset for performing effective fragmentation attack on surface targets and having dimensions and weight suited to being carried by an unmanned aerial vehicle (UAV) with a maximum payload of 150 kg. The designed combat asset, i.e. cluster bomblets ejected from a reusable submunition dispenser, will be intended for destroying enemy personnel, unarmoured ground targets, lightly armoured equipment, ground support equipment, and aircraft and field ammunition depots. The introduction of the paper analyzed the existing submunition dispenser and cluster bomblet solutions. The key aspects of the paper include the calculation of the effective blast radius of the designed cluster bomblet and the analysis of the trajectory of a bomb dropped from horizontal flight. A bombing analysis was carried out, taking into account the influence of the atmosphere and drop control conditions on bombing accuracy and proper fragment coverage of the bombed area. A preliminary concept of the airdrop control system was developed, which could enable effective bombing with a series of cluster bomblets. As part of the work, element models and CAD assembly models of the dispenser and cluster bomblet structures were fabricated.

Closed cycle 4 K nanowatt meter for hectogram payloads

Superconducting computing research is motivated by fast energy-efficient computing, which creates the challenge of developing components with low-power dissipation requirements. In support of this research, we demonstrate a system that measures heat dissipated by electrical and absorbed optical power in packaged cryogenic devices at a temperature of 4 K. In our system, the device under test resides on a stage that is maintained at a constant 4 K using a feedback heater circuit. The sample stage is cooled via a passive weak thermal link to a stabilized 3 K bath of a closed-cycle pulsed-tube refrigerator. With a maximum device payload of 300 g and a weak thermal link of 13 800 K/W, the empirically determined minimum measurable dissipated power is 300 pW. With a very strong thermal link of 53 K/W, the maximum measurable dissipated power is 30 mW.

ANALYSIS ON ANTI-OVERTURNING STABILITY OF A TRUCK CRANE BASED ON ZERO MOMENT POINT THEORY

Truck crane stability has been a hot research issue. It is a conventional method used to calculate the moments equilibrium when analyzing stability. However, errors can occur because of the lack of dynamic simulation in conventional methods. Hence, to minimize errors, this study utilized the zero moment point (ZMP) theory to calculate the maximum lifting capacity of the truck crane considering the dynamic load, and proposed an anti-overturning detection method based on the theory. First, the model of the truck crane was established and the solution formula of ZMP was obtained. From the Lagrange equation, the dynamic model of payload oscillations was analyzed during crane operations. Second, the ZMP theory was used to analyze the stability of the truck crane and derive the maximum payload. Next, the experiment was conducted to measure the pressure of the four outriggers and their center of pressure (CoP) during hoisting, luffing, and slewing operations were calculated. Compared to stable movement, the CoP would vibrate irregularly, consequently reducing the lifting capacity of unstable motion. Finally, the anti-overturning detection method is proposed based on ZMP and CoP. Results demonstrate that the reduction of lifting capacity is caused by the dynamic load. The payload swing has a larger effect on the maximum lifting capacity than hoisting, luffing, and slewing motions. The maximum payload can decrease with the increase of the swing angle. The proposed method provides a correct judgment on the stability of the truck crane, which can accurately predict the overturning state of the crane and reduce the risk in the operation. Keywords: truck crane, overturning, zero moment point, center of pressure, stability

Topology Optimization Design and Experiment of a Soft Pneumatic Bending Actuator for Grasping Applications

Soft pneumatic bending actuators are commonly used in robotic grasping applications and can be applied for handling both delicate and irregularlyshaped objects. Because these soft pneumatic actuators are typically embedded with multiple air chambers inside soft, thin structures, their maximum payloads are usually low compared to rigid designs of similar size. This article presents a soft pneumatic bending actuator design using a topology optimization procedure that can maximize the bending capability and thus increase the allowable payload of soft grippers that consist of multiple pneumatic bending actuators. After an optimum design is obtained, multiple identical actuators are prototyped through a molding process using a silicone rubber material. Both two-fingered and three-fingered soft grippers are developed using the topology-optimized pneumatic bending actuators. Experiments, including a bending angle test, an output force test, and a payload test, are conducted in this study,and the results are compared against the test results of the commercial SRT soft pneumatic actuator. The experimental results show that the bending angle for the developed bending actuator is 111 degrees on average of 10 tests at an input pressure of 50 kPa. The output force is 9.45 N at an input pressure of 80 kPa, while the maximum payloads of the two-fingered and three-fingered grippers are 2.66 kg and 5.12 kg, respectively.