Abolfazl Mohebbi

Augmented online point to point trajectory planning, a new approach in catching a moving object by a manipulator

In a structured dynamic environment, due to the known variation of the environment, robot trajectory planning can be performed robots motion starts. Within an unstructured dynamic environment, environment variations are permanent, so that the surroundings information must be acquired in an online action. Likewise the data acquisition, robot trajectory planning must be executed online. In this paper a method for online trajectory planning based on adaptive prediction planning and execution (APPE) is proposed for robotic manipulators considering velocity and torque constraints. A vision-based data acquisition system is used to acquire object positions and velocities. To describe the end-effector trajectories in joint and Cartesian space a set of time polynomial function are used. Initially a primary trajectory is planned and it will be updated in definite time periods. This action will be frequently repeated until catching is occurred. Proposed method has been tested on an experimental setup and the experimental results are presented.

Design, simulation and manufacturing of a Tracked Surveillance unmanned ground vehicle

This paper describes design, Simulation and manufacturing procedures of HIRAD - a teleoperated Tracked Surveillance UGV for military, Rescue and other civilian missions in various hazardous environments. A Double Stabilizer Flipper mechanism mounted on front pulleys enables the Robot to have good performance in travelling over uneven terrains and climbing stairs. Using this Stabilizer flipper mechanism reduces energy consumption while climbing the stairs or crossing over obstacles. The locomotion system mechanical design is also described in detail. The CAD geometry 3D-model has been produced by CATIA software. To analyze the system mobility, a virtual model was developed with ADAMS Software. This simulation included different mobility maneuvers such as stair climbing, gap crossing and travelling over steep slopes. The simulations enabled us to define motor torque requirements. We performed many experiments with manufactured prototype under various terrain conditions Such as stair climbing, gap crossing and slope elevation. In experiments, HIRAD shows good overcoming ability for the tested terrain conditions.

Trends in concurrent, multi-criteria and optimal design of mechatronic systems: A review

Due to the inherent complexity and the dynamic coupling between subsystems of mechatronic systems, a systematic and multicriteria design thinking methodology is crucial to replace the traditionally used sequential design approach. In this paper we discuss the various aspects of current approaches within mechatronic system design to point out the most important challenges. Accordingly, a review on the most recent work on design and optimization methods and tools is presented and briefly discussed. A framework for concurrent and integrated design of mechatronic system based on separation of realtime and non-realtime system behaviours is also introduced and developed methods based on this model are presented.

Mechatronic Multicriteria Profile (MMP) for Conceptual Design of a Robotic Visual Servoing System

Mechatronic systems are a combination of cooperative mechanical, electronics and control components. The high number of their components, their multi-physical aspect, the couplings between the different domains involved and the interacting design objectives makes the design task very tedious ad complex. Due to this inherent complexity, a concurrent systematic and multi-objective design thinking methodology is crucial to replace the often used sequential design approach that tends to deal with the different domains separately. In this research we present a new multi-criteria profile for mechatronic system performance evaluation in conceptual design stage. The newly introduced Mechatronic Multi-criteria Profile (MMP) includes various quantitative members such as intelligence, reliability, complexity, flexibility and cost. A nonlinear fuzzy integral called 2-additive Choquet Integral will be used for the aggregation of criteria and fitting the intuitive requirements for decision-making in the presence of interacting criteria. Finally, the effectiveness of the proposed method will be validated via a case study of designing a robotic visual servoing system.Copyright

Neural network-based decision support for conceptual design of a mechatronic system using mechatronic multi-criteria profile (MMP)

A mechatronic product is a complex multi-domain system which integrates several disciplines where mechanics are combined with electronics, control and software. The task of designing mechatronic systems is understood to be very tedious and complex because of the high number of components, the multi-physics aspects, the couplings between the different domains involved and the interacting design criteria. Due to this inherent complexity, a systematic and multi-objective approach is needed to replace the traditional methods used to support the design activity and design performance evaluation. In this paper we present a Choquet integral-based neural network alongside with a new multi-criteria profile for mechatronic system performance evaluation in conceptual design stage. The newly introduced Mechatronic Multi-criteria Profile (MMP) includes various quantitative evaluation criteria such as machine intelligence, reliability, complexity, flexibility and cost. The Choquet integral-based neural network will be used for the aggregation of criteria and fitting the intuitive requirements for decision-making in the presence of interacting criteria. Finally, a case study of designing a robotic visual servoing system is presented to validate the effectiveness of the proposed method.

A Comparative Study of Eye-In-Hand Image-Based Visual Servoing: Stereo vs. Mono

Visual control of manipulators provides significant advantages when working with targets with unknown positions. Among all visual servoing categories, the stereo visual servoing has shown to be very effective when dealing with unstructured environments. In this paper a comparative study of eye-in-hand image-based visual servoing (IBVS) for two approaches of stereo and mono vision is presented and various cases of control schemes, and tracking and prediction algorithms are studied. In this study the vision systems are considered to be mounted on the end-effector of a 6 degrees of freedom (DOF) manipulator robot. Additionally, a method for position prediction and trajectory estimation of the moving target in order to use in a real-time catching task is proposed and developed using Kalman Filter and Extended Kalman Filter (EKF) as the trajectory estimators. Using the proposed estimation methods, the quality of the visual servoing in a catching procedure using a 6-DOF manipulator robot is compared for mono and stereo visual servoing systems. Finally, by applying the newly introduced acceleration command-based controller (AIBVS) to the visual servoing system, the results for both cases are presented to compare the effects on the quality of servoing tasks. The aforementioned scenarios of visual servoing are simulated and implemented based on a 6-DOF DENSO 6242G robot.

FUZZY DECISION MAKING FOR CONCEPTUAL DESIGN OF A VISUAL SERVOING SYSTEM USING MECHATRONIC MULTI-CRITERIA PROFILE (MMP)

Mechatronic systems are of increased importance in engineering and their relevance goes hand in hand with the increasing complexity of the tasks they perform. Due to the inherent complexity of mechatronic systems, a concurrent systematic and multi-objective design thinking methodology is crucial to replace the often used sequential design approach that tends to deal with the different domains separately. In this research we present a new multi-criteria profile (MMP) for mechatronic system performance evaluation in the stage of conceptual design. Based on the assessed MMP for each of generated design concepts and using a method of aggregation for interacting criteria, a global performance index will be calculated. Best mechatronic configurations are determined by maximizing this performance index. In the presented paper two nonlinear fuzzy integrals called 2-additive Choquet and Sugeno will be used for the aggregation of criteria and fitting the intuitive requirements for decision-making in the presence of interacting criteria. Finally, the effectiveness of the proposed design method alongside each of the decision making models will be validated via a case study of designing a robotic visual servoing system. The comparative simulation results for the overall system performance will also be presented for both cases of using Choquet and Sugeno integrals.© 2014 ASME

An Acceleration Command Approach to Robotic Stereo Image-based Visual Servoing

Abstract This paper presents a new stereo image-based visual servoing (IBVS) controller for a six degrees of freedom (DOF) robot manipulator based on acceleration command. An eye-in-hand stereo vision system is utilized to capture the images of the object and to estimate the depth of the object. A proportional derivative (PD) controller is developed considering the acceleration command. The augmented image-based visual servoing (AIBVS) controller helps the system achieve smoother and more linear image feature trajectories and decrease the risk that the features leave the field of view (FOV). The developed control method also enhances the stability characteristics of the system and the robots end-effector 3D behaviour. Both simulation and experimental results on a 6 DOF DENSO 6242G robot validate the effectiveness of the proposed stereo AIBVS controller. The comparison with IBVS with monocular vision system demonstrates the improved performance of the proposed system.

Wavelet-Based linearization for single-degree-of-freedom nonlinear systems

This paper introduces a wavelet-based linearization method to estimate the single-degree-of-freedom (SDOF) nonlinear system response based on the traditional equivalent linearization technique. The mechanism by which the signal is decomposed and reconstructed using the wavelet transform is investigated. Since the wavelet analysis can capture temporal variations in the time and frequency content, a nonlinear system can be approximated as a time dependent linear system by combining the wavelet analysis technique with well-known traditional equivalent linearization method. Two nonlinear systems, bilinear hysteretic system and Duffing oscillator system, are used as examples to verify the effectiveness of the proposed wavelet-based linearization method.