A Continuous Multivariable Finite-Time Super-Twisting Attitude and Rate Controller for Improved Rotorcraft Handling

This paper synthesizes a continuous, multivariable, finite-time-convergent, super-twisting attitude and rate controller for rotorcraft with the objective of providing desired handling qualities and robustness characteristics. A sliding manifold is defined in the system state space to represent ideal attitude and rate command response dynamics of relative degree one with respect to the command input. Subsequently, robust command tracking is achieved via the synthesis of a multivariable super-twisting flight controller, which renders the plant states convergent on to the defined sliding manifold in finite-time and in the presence of matched external disturbance input. To validate the efficacy of the controller, simulation results are presented based on a nonlinear, higher-order rotorcraft model operating in turbulence. True system convergence to the sliding manifold from an untrimmed state is shown to lie within the theoretically predicted finite-time convergence bound. Furthermore, simulations with a linear quadratic flight controller are also presented for performance comparison with the proposed super-twisting flight controller.

A Novel Guidance Law for Intercepting a Highly Maneuvering Target

Given the resolution of the guidance for intercepting highly maneuvering targets, a novel finite-time convergent guidance law is proposed, which takes the following conditions into consideration, including the impact angle constraint, the guidance command input saturation constraint, and the autopilot second-order dynamic characteristics. Firstly, based on the nonsingular terminal sliding mode control theory, a finite-time convergent nonsingular terminal sliding mode surface is designed. On the back of the backstepping control method, the virtual control law appears. A nonlinear first-order filter is constructed so as to address the “differential expansion” problem in traditional backstepping control. By designing an adaptive auxiliary system, the guidance command input saturation problem is dealt with. The RBF neural network disturbance observer is used for estimating the unknown boundary external disturbances of the guidance system caused by the target acceleration. The parameters of the RBF neural network are adjusted online in real time, for the purpose of improving the estimation accuracy of the RBF neural network disturbance observer and accelerating its convergence characteristics. At the same time, an adaptive law is designed to compensate the estimation error of the RBF neural network disturbance observer. Then, the Lyapunov stability theory is used to prove the finite-time stability of the guidance law. Finally, numerical simulations verify the effectiveness and superiority of the proposed guidance law.

Payload oscillation control of tower crane using smooth command input

This paper presents a smooth command (SC) input shaper for suppressing payload oscillations in rest-to-rest simultaneous radial and tangential motions of a tower crane. The radial and tangential acceleration profiles of the compound motions are represented by multi-sine wave functions with independent and variable maneuvering time. The proposed SC is designed using a nonlinear mathematical model of the tower crane while the parameters of the acceleration profiles and maneuvering times were optimized using a particle swarm algorithm (PSO). The simulated results were verified experimentally on a laboratory scale tower crane. The results confirm that the proposed SC input effectively canceled residual vibrations of the payload compound motions with a time length comparable to zero vibrations (ZV) shaper. Moreover, sensitivity analysis to variations in cable length reveals that the proposed command input is robust over a wide range of cable lengths.

Automation Design of Kentongan Sound for The Feeding Process of Vaname Shrimp Farming in Pond

Feeding on vanamei shrimp culture in pondsis carried out on average 4 to 5 times a day. In aquaculture activities with a large number of ponds, the sound of kentongan becomes a time reference for the operator in providing feed. The purpose of this article was to describe the process required to turn the kentongan sound into a command input for an automatic feeder. The sound of kentongan will be used as input data (commands) for the microcontroller is translated as a command for the feeder to carry out its activities of feeding. The methodology used the following points: first, field observations of the use of kentongan sounds as a sign of the feeding process for feed operators; second, literature study covering sound frequency and sensor system; third, the creation of a chart in the form of step by step logic from input in the form of kentongan sounds to the process of feeding using an automatic feeding device; fourth, the design of the hardware that will be used and the creation of the software in the form of a command flow chart. The result was realized in the form of a chart from input in the form of kentongan sounds to the process of feeding using an automatic feeder. This includes hardware and software design. There were two important things in automation design. The identification process of kentongan sounds becomes a function of frequency against time, where this frequency had certain characteristics which were expressed by graphs that have certain equation values. This kentongan sound with a certain frequency will be the input for the microcontroller to carry out its task of giving orders to the feeding device to provide feed for vanamei shrimp in ponds.

Designing a Firing Control System on S-60 57mm Cannon

The firing system on the S-60 57mm cannon uses the foot of the cannon crew, which is very dangerous with the position of the crew on top of the cannon when firing. So, a firing system that can be remotely controlled by a computer is required. The design of the S-60 57mm gun firing control system uses a personal computer (PC) as the firing command input, with data communication using WiFi received by the Atmega8535 microcontroller as a voltage regulator for solenoids. The solenoid has a tensile force to drive the hydraulic system where the actuator functions to drive the firing cylinder. Accelero sensor MMA7361, as a variable controller in firing, provides input data simulating the tilt position of the cannon, the position of the 0g sensor is simulated by the cannon in a balanced position. From the test results, there is a difference in sensor designation data with arc angles i.e., angle X by 2.83 degrees and angle Y by 1.86 degrees. The magnetic field produced by the solenoid 0.53 T can attract a maximum load of 20 kg. By changing the distance ratio of mechanical lever to 39.11 cm and 8.89 cm, the solenoid can drive an 88-kg firing cylinder.

Haptic User Interface of a Cable-Driven Input Device to Control the End Effector of a Surgical Telemanipulation System

In robotic telemanipulation for minimally-invasive surgery, lack of haptic sensation and non-congruent movement of input device and manipulator are major drawbacks. Input devices based on cable-driven parallel mechanisms have the potential to be a stiff alternative to input devices based on rigid parallel or serial kinematics by offering low inertia and a scalable workspace. In this paper, the haptic user interface of a cable-driven input device and its technical specifications are presented and assessed. The haptic user interface allows to intuitively control the gripping movement of the manipulator’s end effector by providing a two-finger precision grasp. By design, the interface allows to command input angles between 0° and 45°. Furthermore, interaction forces from the manipulator’s end effector can be displayed to the user’s twofinger grasp in a range from 0 N to 6 N with a frequency bandwidth of 17 Hz.

A smooth optimized input shaping method for two-dimensional crane systems using Bezier curves

Conventional input shaping commands have been successfully employed to suppress residual vibration in the payload rest-to-rest transportation process. Most of these methods introduce an impractical large and sudden variation on the acceleration profile. This paper presents a new smooth command input with adjustable time length and limited jerks. The command input is generated from the trolley displacement using a Bezier curve function by adjusting the position of the control points, which were divided into boundary and intermedium points. The boundary control points are selected to accurately move the trolley to its desired position with zero velocity and acceleration at the closing motion. The positions of the intermedium points were optimized using a particle swarm scheme for reducing maneuvering time while suppressing the payload oscillations at the end of the process and satisfying physical system constraints. Several cases were discussed for fixed cable length, variable cable involving single and multi-hoisting mechanisms, and different maneuver times. Simulated results were validated experimentally on a laboratory size crane. The results demonstrated that the proposed input Bezier-curve shaper provides an effective, reliable, and practical technique to be used for the payload transportation process. Moreover, the proposed method can generate asymmetrical acceleration and deceleration motions, which cannot be achieved using existing smoother commands.

Low-cost pick and place anthropomorphic robotic arm for the disabled and humanoid applications

This paper presents the design and development of a new low-cost pick and place anthropomorphic robotic arm for the disabled and humanoid applications. Anthropomorphic robotic arms are weapons similar in scale, appearance, and functionality to humans, and functionality. The developed robotic arm was simple, lightweight, and has four degrees of freedom (DOF) at the hand, shoulder, and elbow joints. The measurement of the link was made close to the length of the human arm. The anthropomorphic robotic arm was actuated by four DC servo motors and controlled using an Arduino UNO microcontroller board. The voice recognition unit drove the command input for the targeted object. The forward and inverse kinematics of the proposed new robotic arm has been analysed and used to program the low cost anthropomorphic robotic arm prototype to reach the desired position in the pick and place operation. This paper’s contribution is in developing the low cost, light, and straightforward weight anthropomorphic arm that can be easily attached to other applications such as a wheelchair and the kinematic study of the specific robot. The low-cost robotic arm’s capability has been tested, and the experimental results show that it can perform basic pick place tasks for the disabled and humanoid applications.

A Review Paper on Big Data Analytics in Process Industry

Today, in modern large-scale industrial processes, each step-in manufacturing produces a bulk of variables, which are highly precise in nature. However, great challenges are faced under different real-time operating conditions when using just the basic data-driven methods. One of the sultriest research points for convoluted process control is the usage of big data analytics. The aim of big data analytics is to take full advantages of the large amounts of obtained process data and mine helpful details present within. Compared to the well-developed model-based approaches, usage of big data analytics provides productive elective answers for various modern issues under different working conditions. Majority of the modelling in process control in a closed loop system is based on varying the command input to obtain desired controlled output. However, modelling of the process control in a closed loop system based on the disturbance using conventional methods is time consuming since disturbance data is too big and too complex. Utilization of advanced big data analytical methods to mine the disturbance data can lead towards more informed decisions to model the process control in the system. Thus, relevant solutions can be obtained to some of the challenges in the modeling of process control using big data analytics.