Background: MANET is a self-organized wireless network with no infrastructure. Especially data transfer from one system to another system needs to be done in a secure way. In order to provide data integrity, authentication plays an important role in data communication. RSA and ECC are widely used algorithms in the real world, but authentication using these algorithms is time-consuming. Towards this, various algorithms came into existence with different security primitives. However, it is important to design an effective key agreement process with reduced computational cost among these security mechanisms. We have designed an effective mechanism to mitigate packet dropping attacks to secure end-to-end communication in MANET. Objective: The proposed light weight authentication method is based on chaotic maps that uses Chebyshev polynomials as primitive operation. Methods: The methodology includes semi group property of Chebyshev polynomials and also the discrete logarithmic problem based chaotic maps that takes less time than these existing algorithms and evaluates with respect to attack Resilience, packet deliverya fraction, delay, throughput, and overhead. Results: Simulation produces the result of the proposed mechanism and give better performance in terms of packet delivery ratio, overhead and computational cost. Conclusion: Authentication based on developed mechanism consumes less time as shown in statistical analysis and mitigates packet dropping attacks effectively than that of traditional methods like RSA and ECC with respect to key generation mechanism.

Background: As a component of the motor’s electromechanical energy conversion, the winding is very important. When the winding design is improper, the harmonic content is increased, which leads to an increase in the motor loss and torque ripple. Therefore, winding design is very important for motor design. Objective: The effect of winding forms on the induction motor is analysed in this paper. The variation in performance parameters of different winding forms is invesitgated. Methods: This paper takes an 11 kW, 1500 r/min induction motor as the research object; the two- dimensional transient field finite element model has been established to calculate the basic parameters, which are then compared with the experimental data to verify the correctness of the model. Finally, the magnetizing reactance, starting performance, stator leakage reactance, various losses, and efficiency under different winding forms are calculated and compared. Results: When the motor adopts double-layer winding, the magnetizing reactance, stator slot leakage reactance, and harmonic leakage reactance are less than those of the motor with single-layer winding by 13.47%, 25.37% and 20.97%, respectively, while the end-leakage reactance, starting torque, and starting current rotor copper loss are higher than those of the motor with single-layer winding by 7.14%, 9.52%, 18.54%, and 15.23%, respectively. The core loss and stator copper loss of motors with different winding forms are almost unchanged. The efficiency of the motor with single-layer winding is higher than that of the motor with double-layer winding by 1.22%. Conclusion: When the winding form is different, the magnetizing reactance, stator slot leakage reactance, harmonic leakage reactance, and end-leakage reactance are different. Leakage reactance is the main factor that causes a difference in starting torque and starting current between the two winding forms. The core loss and stator copper loss of motor with different winding forms are almost unchanged, while the difference in the rotor copper loss is obvious. In addition, the efficiency of the motor with single-layer winding is higher than that of the motor with double-layer winding.

Background: Traditional rigid robots are difficult to adapt to complex unstructured environments due to their limited degree of freedom and lack of flexibility. Therefore, soft crawling robots are concerned widely by their powerful deformation ability, infinite number of degrees of freedom, and effective interaction with humans. Objective: This paper aims to report the recent progress of soft crawling robots and provide a reference for readers in this field. Methods: By reading and summarizing the patents and papers related to soft crawling robots in recent years, they are divided into three categories according to different driving methods. The structure, motion mechanism, characteristics, and applications of each class of robots are compared and analyzed. Results: The advantages and disadvantages of each driving method are analyzed, and the key issues in soft crawling robots are pointed out. Based on this, the future development direction of this research field is predicted. Conclusion: The study shows that according to the driving method, soft crawling robots are classified as pressure driven, motor-wire driven, and soft active material driven. In addition, the characteristics of each drive are summarized. In the future, soft crawling robots will have more potential applications in biomedicine, outdoor survey, rescue search, and inspection and maintenance of equipment.

Abstract:Perception-based navigation systems have become more popular in robotic applications such as autonomous moving vehicles in hospitals, logistics, packing and forwarding, mines, military, defense, consumer robots, building surveillance, rescuing and carrying a child or physically challenged people, and so on, due to the need, advanced development, and large influence. To improve positioning, localization, and path planning on obstacle-free trajectories, several navigation designs have been developed. In this study, we attempt to analyze various navigation methods and technologies applied by mobile robots in various applications. On paths without obstacles, a number of navigation designs have been created to enhance positioning, localization, and path planning. An overview of many navigation technologies is given in this article. The paper focuses on Measurand-based navigation of mobile robot applications in a diverse environment by taking into account previous research works. Additionally, there is a comparison of technologies, methodologies, applications, algorithms for error reduction, and different kinds of perception systems, in addition to metrics like accuracy and usability. This limited study focuses on the integration of an antenna with an IMU-based navigation system that is suited for all environments, as well as some future trends to detect to aid in the profound-implication of navigation system enhancement in robotic applications.

Since the authors are not responding to the editor’s requests to fulfill the editorial requirement, therefore, the article has been withdrawn. Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php. BENTHAM SCIENCE DISCLAIMER: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

Background: Based on the high-speed operation of the spindle, the influence of the rotation accuracy of the spindle on the system will increase with the increase of the rotation speed. Therefore, how to predict rotation accuracy becomes very important for mechanical equipment based on the spindle. Objective: To summarize the classification and characteristics of the spindle rotation accuracy detection device to predict future development. Methods: The current status of various representative patents related to spindle rotation accuracy testing equipment is analyzed. According to the characteristics of testing equipment, the development level of existing testing equipment in error separation and high-speed detection of the spindle is analyzed, and the latest patented technology is expounded and compared. Results: The structure of the spindle rotation accuracy detection device is analyzed and compared, and the typical characteristics are summarized. The problems existing in the detection of spindle rotation accuracy are analyzed, and their development trend is prospected. Conclusion: It is obtained that the contact-type rotary accuracy testing equipment is generally suitable for static measurement, the single-probe and multi-probe testing equipment can be basically satisfied with the measurement, and the optical testing equipment can be widely used in the measurement under the high-speed rotation of the spindle. There is room for further development in the dynamic load detection of the spindle.

Background: The dynamic viscosity - temperature characteristics of lubricants are the main factors used to determine the oil film thickness and carrying capacity. There are few studies on the factors affecting the dynamic viscosity-temperature characteristics of lubricating oils and the dynamic viscosity-temperature model. Objective: This research aims to analyse the influences of lubricating oil type and initial kinematic viscosity on dynamic viscosity - temperature characteristics and present a new dynamic viscosity - temperature model. Methods: The characteristic curves of dynamic viscosity versus temperature of polyol ester oil, paraffinic mineral oil, and five types of PAO (poly a-olefin) oils with different initial viscosities were obtained by using a kinematic viscosity test device and a density test device. The influences of lubricating oil type and lubricating oil viscosity on dynamic viscosity - temperature characteristics were analysed. Based on our patent technology and repeated verification, a new dynamic viscosity - temperature model was presented. Results: Viscosity - temperature curves of three different types of lubricating oils and viscosity - temperature curves of PAO oils with different initial kinematic viscosities were obtained. A new dynamic viscosity - temperature model η=A×e^(((-T)/n) )⁡+ η_0 was proposed. Conclusion: The dynamic viscosity - temperature characteristics of lubricating oils are not only determined by the type of oils but also determined by the initial kinematic viscosity.The variation of dynamic viscosity of lubricating oils with temperature in the scope of -40~110℃ can be described by the following viscosity temperature model : , which can be used in wider temperature range than the existing models.

Background:: Visual tracking is a crucial component of computer vision systems. Objective:: To deal with the problems of occlusion, pose variation, and illumination in long-time tracking, we propose a new kernel-based multiple instances learning tracker. objective: visual tracking Method:: The tracker captures five positive bags, including the occlusion bag, pose bag, illumination bag, scale bag, and object bag, to deal with the appearance changes of an object in a complex environment. A Gaussian kernel function is used to compute the inner product for selecting the powerful weak classifiers, which further improves the efficiency of the tracker. Moreover, the tracking situation is determined by using these five classifiers, and the correlating classifiers are updated. Results:: The experimental results show that the proposed algorithm is robust in terms of occlusion and various appearance changes. Conclusion:: The proposed algorithm preforms well in complex situations. conclusion: And it preforms well in complex situation.

Background: The Operational amplifier (op-amp) is the building block of linear integrated electronics, therefore proposing newer design models with improved parameters is an essential landmark in the electronics industry in the hunt for a faster and more efficient design. Objective: To attain high speed and low power supply, the authors designed an op-amp using three different techniques. Initially compensating network was designed and simulated but the resultant output voltage saturates in inverting and non-inverting modes. Methods: Voltage feedback op-amp (VFOA) and current feedback op-amp (CFOA) were proposed to achieve the target. The authors have successfully designed the circuit, but the power dissipated is less and Common Mode Rejection Ratio (CMRR) is high in CFOA in comparison to VFOA. Results: The results are simulated for three different configurations and inverting configuration results in remarkable results in comparison to a non-inverting and differential amplifier. Inverting configuration using VFOA results in 91.22dB, and 0.0131W CMRR and power dissipation, respectively, while that of CFOA results in 97.34dB, and 0.0129W CMRR, and power dissipation, respectively. Conclusion: 1.6% improvement in CMRR and a 26.8% improvement in power dissipated for the proposed CMOS CFOA in comparison to the proposed VFOA. All the validations are done by plotting the bode plot and Nyquist plot.

Background: To reduce environmental pollution and improve resource utilization, lightweight equipment has become an important development trend of manufacturing. Therefore, thin-walled parts are being widely used in automobiles, aerospace, etc. due to their lightweight and high specific strength. However, they usually deform during machining due to poor stiffness. Objective: To reduce the machining deformation, the finite element method has been used to analyze the deformation law of thin-walled parts. Method: A 3D milling model of Al7050-T7451 thin-walled parts was established. Then, the influence of hole structure, rib, and auxiliary support on the deformation was investigated under the condition of optimized parameters. Moreover, some related patents on the research of machining deformation of thin-walled parts were also consulted. Results: The results showed that the established 3D model could accurately predict the machining deformation of thin-walled parts. The machining deformation on the edges is more severe due to holes that weaken the stiffness of thin-walled parts. Besides, ribbed slab and auxiliary support can shorten machining deformation by 71.9% and 65.2%, respectively.