Abstract: In this paper, a planar snake-like robot travelling in serpentine locomotion is considered. A method is presented where structural and gait control parameters are used to obtain the minimum snake-robot positional error, geometrical error. Two structural parameters, length and mass of each link as well as two control parameters, initial winding angle (α0) and arc length (s) are considered. Each of the four input parameters is examined at five different levels. The method uses Taguchi experimental techniques and analyzes effects of uncertainties by means of adding noise to the robot parameters. Significance of the input parameters is also determined using Analysis of Variance.
Abstract: In this paper, virtual prototype modeling, simulation and optimization of a 3 DOF SCARA robot as an example of robot manipulators, based on using software packages are presented. The softwares, Solidworks, Matlab and specially its module, Simmechanics, are used for robot modeling and thenMulti-Variable control process is performed with PID controller for controlling the robot. After modeling error RMS is defined as optimization objective function and the controller is optimized by Genetic algorithm. In this way, online kinematics solution in Simmechanics is introduced to avoid mathematical modeling of inverse kinematics problem. The strong point of this work is to facilitate modeling of complex mechatronical systems for engineers and virtual motion visualization of the mechanisms helps the engineers to have better understanding of systems behavior. Using exact numeric prototype of the robot in optimization problem, make it possible to use optimized controller for the actual robot.
Abstract: This paper proposes a technology to automate the book deposition process in a generic Library layout. It includes usage of autonomous vehicle in the library that is guided by an assembly of lasers. To prove the practicability of this proposal a physical prototype of an autonomous robot has been developed. The robot acts as an external storage unit for books and is capable of delivering them from the initial pre-defined point to the desired final destination.
Abstract: A new gripping principle, based on Coanda effect was applied successfully in designing and developing a non contact robot gripper to curb the gripping challenges faced in the food industries. Two designs of the non contact grippers/ejectors which are working on Coanda effect are presented in this paper. The first design was made with one suction head while the second design was made with multiple suction heads. Experiments were carried out on both ejectors to observe their holding force on food materials as a function of mainly the pressure, flow of the primary air and other parameters. Tangible results were derived from the experiments, tabulated and shown in graphical forms; from which relationships between the parameters were derived. When tested on thick bark/packed food materials, they left no suction marks on them.
Abstract: In this paper we discuss a Case-Based Reasoning (CBR) method which is an on-line learning mechanism for dynamic selection and modification of behavior assemblages for collision avoidance of multi-robot system. The CBR module is designed as an additional reactive control system which provide flexible performance in novel environments without extensive high-level reasoning that would slow the system down. The results by robot simulation software MissionLab show that the CBR are effective for making decisions to avoid the collision with static obstacles as well as moving robots in multi-robot system.
Abstract: This paper presents a team performance optimisation system for multiple mobile robots in search-and-rescue operations, in which refugees are first discovered and subsequently robots are dispatched to transport themto shelters. Coordination of mobile robots involves two fundamental issues, namely task allocation and motion planning. While task allocation assigns jobs to robots, motion planning generates routes for robots to execute the assigned jobs. Task allocation and motion planning together play a pivotal role in optimisation of the robot team performance. These two issues become more challenging in dynamic search-and-rescue environments, where the refugees are unpredictably discovered at different locations and the traffic conditions of rescue zones keep changing. Weaddress these two issues by proposing an auction-based closed-loop module for task allocation and a bio-inspired intelligent module for motion planning. The task allocation module is characterised with a closed-loop bid adjustment mechanism to improve the bid accuracy even in light of stochastic rescue requests. The motion planning module is bio-inspired intelligent in that it features detection of imminent neighbours and responsiveness of virtual force navigation in dynamic traffic conditions. Simulations show that the proposed system is a practical tool to optimise the dynamic operations of search-and-rescue by a team of mobilerobots.
Abstract: This paper mainly discusses that in mobile robot vision navigation system, by using the improved Hough transform, we can improve the accuracy of line extraction and therefore avoid the image quality reduction caused by noise points. Considering the limitations of the standard Hough transform, we come up with a method with which we will accumulates the H (ρ, θ) through distributing the increment value, set a global threshold to shun the pointless measurements, eliminate the false lines by comparing θ difference between tow arbitrary lines, find the peaks by using rectangle window, and set a local threshold to eliminate false peaks. In this way, we can gain a method superior to the standard Hough transform which works better in extracting lines in application. The experiments show that this method can not only extract line features of geometric figure effectively in brief background, but also eliminate the iterative lines efficiently.
Abstract: In this paper, kinematic relationships for a 3-PRR planar parallel robot are first presented. The robot dynamics equations are formulated using Lagrange equations of first kind. The derived equations are a mixed set of differential and algebraic constraint equations, DAE, which must be satisfied simultaneously. In order to solve the robot dynamic equations, a new method is presented in which the dynamics equation is first partitioned into two parts. The constraint equations and the dependent coordinates are next eliminated. This reduces the dynamic equations to a set of differential equations as a function of three independent coordinates. Finally, a trajectory for the robot end-effector is specified and PD controller which follows the desired trajectory is implemented. The proposed method significantly simplifies the solution of the dynamics equations.
Abstract: This study investigated a mathematical model which was built for a simulation loading system based on secondary regulation. Because the loading system was complicated in structure and some other factors, the control performance was not ideal. Therefore, a dynamic robust compensating controller was designed for the system. The robust compensator could improve the control system by adding the return-to-zero factor and low pass filter on the basis of PID control. This study used MATLAB to simulate the general PID control and the robust compensation control. The results of simulation showed that when the equivalent rotary inertia and damping coefficient changed, the control performance decreased. When using the dynamic robust compensation control, the influences caused by parameter variations were reduced greatly, the system robustness and control accuracy are improved.
Abstract: The present work deals with a homogenization procedure (HP), which is developed to reduce the problem of geometrically nonlinear free vibrations of functionally graded beams (FGB) resting on elastic nonlinear foundation with immovable ends to that of isotropic homogeneous beams with effective bending stiffness and axial stiffness parameters. The material properties of the functionally graded composites examined are assumed to be graded in the thickness direction and estimated through the rule of mixture. The theoretical model is based on the Euler-Bernouilli beam theory and the Von Kármán geometrical nonlinearity assumptions. Hamilton’s principle is applied and a multimode approach is derived to calculate the fundamental nonlinear frequency parameters, which are found to be in a good agreement with the published results.