This paper presents a vision-based method for estimating the joint torques and motion of a 10 link passive pendulum. Torque estimation in these systems is challenging owing to the lack of direct torque sensors and the complex dynamics of multi-degree-of-freedom systems. To address this, a high-speed camera was employed to capture the joint angles, and an Extended Kalman Filter was used to estimate the angular velocities and torques online. Unlike traditional methods, this approach non-intrusively extracts dynamic information from high-degree-of-freedom systems. The proposed approach was validated through simulations and physical experiments, achieving a maximum normalized root mean square error of 0.84% across all joints. These results show that accurate torque estimation is possible with minimal sensor data, which is beneficial when sensor placement is restricted.

This paper presents a robust and fast Model Predictive Control (MPC) method for maintaining balance and performing trajectory planning in dynamic obstacle scenarios during humanoid robot locomotion. The balance conditions and motion equations of the robot are expressed within a single objective function, and constrained optimization is solved using Sequential Quadratic Programming (SQP). This approach facilitates both maintaining balance and performing obstacle avoidance maneuvers in dynamically changing environments. The method has been performance-tested using Augmented Lagrangian (ALM) and Trust Region Constrained (TRC) Methods, and it has been observed to provide faster responses on hardware with limited computational power. The study was simulated in the Gazebo simulation environment using the Robotis-OP3 humanoid robot, demonstrating that the proposed optimization-based approach provides fast and stable control results.

In this paper, a novel optimization algorithm was developed that plans collision-free, singularity-free and time-optimal trajectories with constrained position, velocity, acceleration, and jerk in the case of various operations of industrial and collaborative robots sharing a common workspace. The structure of the optimization algorithm used here includes Batch Belief Tree (BBT), Artificial Potential Field (APF), and A*. The proposed algorithm is tested on challenging trajectories. The performance of the proposed algorithm is compared with RRT*, RRT, BIT and Kinodynamic RRT algorithms. In the performance tests, seven industrial, collaborative, and redundant collaborative robots were simulated on RoboDK. The results indicate that the algorithm surpasses all compared tree-based algorithms in terms of success rate per trial (e.g., achieving a solution in 29 out of 30 attempts). Additionally, it consistently delivers reliable outputs while ensuring both jerk and time optimality.

This paper presents a novel consensus-based adaptive genetic-optimized auction (CAGA) algorithm to solve the dynamic task allocation (DTA) problem for a fleet of autonomous vehicles. The algorithm employs an auction routine for task assignment and a genetic algorithm (GA) to optimize task prices subject to the price update rule. The proposed algorithm is devised to achieve superior solutions in real-world applications. Hence, uncertainty theory was adopted to model uncertainties in task positions to create a realistic environment. In addition, Monte Carlo (MC) simulations are performed to effectively determine the degree of uncertainty. Several test scenarios have been carried out using other market-based methods, and the results illustrate the effectiveness of the algorithm.

Gimbal mechanism can be mostly preferable as a camera steering system in air vehicle imaging systems. Gimbal mechanism should be designed in ways that gimbal is not affected by the motion of the platform on which the gimbal is mounted on and by flight of operations without any problem. The effect of the platform motion may cause undesirable blur problems that occur on the image. The velocity limits can be determined to eliminate the image blurring. If actual velocity values of the related gimbal axes are under this limit, the blurring can be ignored otherwise it can be a major problem for the imaging system. In this study, definition of blur is given and the velocity limit is determined. Aside from theoretical calculations and definitions, blur ratio is analyzed with respect to four random generated flight scenarios for different gimbal configurations. This work is especially important for determination of gimbal configuration with respect to flight operational concept. At the end of this study, some methods are recommended for elimination of blur in imaging systems.

Twin Rotor Aero-dynamical System (TRAS) include non-negligible nonlinearities due to frictions in the joints. In this study, joint frictions of the 2 DOF Double Dual Twin Rotor Aero-dynamical System (TDDTRAS) were estimated based on experimental data and simulation dynamic responses. Three different friction estimation models such as Non-Conservative, Linear, and a Non-linear friction models were compared to estimate the joint frictions of the (TDDTRAS) developed in our laboratory. Based on comparative experimental friction analysis, the joint frictions of the (TDDTRAS) are estimated better using Non-Linear friction model (NLFM). The mathematical model with NLFM is developed for simulation and controller. A robust dynamics model was obtained by the NLFM which will be used in the inverse dynamic model for the PID controller. PID controllers designed based on the mathematical model with nonlinear friction model. Accurate inverse model and the joint friction compensation improved PID controller performance for the TDDTRAS.

The kinematic and dynamic analysis of the high-degree of freedom (dof) hybrid systems that using serial and parallel robots together on fixed or mobile platform such as legged robots and service robots, is a rather difficult and complex, time consuming problem and a topic of great interest for researchers. There are many educational and commercial toolboxes which analyze serial and parallel robots separately. With the toolbox developed here, high-dof serial, parallel and hybrid robotics systems used on both fixed and mobile platforms can be designed and studied easily. Forward and inverse kinematics, Jacobian matrix, singularities, trajectory planning, torques and forces in joint and operational space can be examined with different robot designs. Using the toolbox that proposed in this paper, robot designer, researchers, students and educators can easily develop their own robotics systems and visualize them in the virtual reality environment provided by MATLAB. Also, it helps understanding fundamentals of high-dof multi-body hybrid robotics systems through user friendly interactive simulation. The most of existing toolboxes in the literature allow only user to analyze the predefined robots in their library with limited interactive capabilities. In some of them, the user can define a new robot with limited dof. But, the user must already have a prior knowledge about designing process of robots. In the proposed toolbox, designing and defining any new robotics systems become very easy. What makes this toolbox unique compared with the existing toolboxes is that any type of robot structures with high dof can be developed, analyzed and studied in detail.

In this study, hybrid hexapod robots with 4 legs and 2 legs/arms were designed and developed. The robot with 26 dof contains 4 actuators in the 4 standard legs and 5 actuators in the 2 reconfigurable legs/arms. In order to obtain a more stable movement in the rough terrain, each leg/arm in robot structure has one prismatic actuation. Two customized legs in this robot structure can be used as arms which may reach and hold objects. The gripper on the customized arm of the robot can carry a load of approximately 350 gr. For the control of this robot, gait analysis, trajectory planning, kinematic modelling, dynamic modeling and quantic polynomial equation were studied. The developed robot was tested in different scenarios and accomplished the desired tasks successfully.

A new graphical simulation package, which is capable of interoperability with other extensive programs, is proposed. A built-in LISP interpreter based on COMMON LISP allows a user to model and manipulate the robot while the result is displayed on a three-dimension graphical display. Other programming languages that are compatible with the component object model (COM) interface can also be applied to the modeling and simulation. The simulation package provides many useful features such as collision detection, inverse kinematics, matrix transformation operations, and several graphical user interfaces. The simulation objects are built based on a triangle strip model to form primitive objects such as a box, cone, sphere, etc. These primitive objects are combined to construct the robot that may contain several serial or parallel links so that many possible types of robots can be modeled.

The paper describes an adaptive genetic algorithm used to achieve multi-objectives such as minimizing the territory losses and maximizing enemy air losses by finding the optimum distribution of aircraft fighting in a war scenario simulated by the THUNDER software. The adaptive genetic algorithm changes the mutation and crossover adaptively to provide fast convergence to the optimum possible solutions. According to the population of the fitness values obtained for each generation, three distribution properties (the mean, the variance and the best fitness value) are determined and used as input to a fuzzy-logic system for modifying the mutation and crossover rates to obtain the individuals of the next generation. This enables fast and smooth convergence to the best possible solutions.

A model has been developed correlating the anode temperature profile with the dynamic melting rate in gas metal arc welding. Components of this model are identified as the electrode melting rate, temperature-dependent resistivity of electrode and arc voltage. The differential equations describing the dynamic behavior of the electrode extension were derived from mass continuity and energy relations. The temperature of the electrode extension was determined by convective heat transfer and joule heating. One-dimensional solutions of temperature and heat content were used to obtain the dynamic melting rate equation. The purpose of the present paper is to provide quantitative analyses, concentrating on the thermal behavior and the electrical characteristics of the arc welding system, to aid in a fundamental understanding of the process, and to develop a dynamic model that may be used in adaptive control. The model is tested by comparing simulations to experimental results.