Papers by Keyword: Robot Manipulator

Abstract: This paper considers synthesis method of fault detection system for actuators of robot manipulators based on using of signals fusion from stereo camera, angles sensors of joints and desired values of joint variables. The vision system is used for determining the position of three markers rigidly connected with working tool in the coordinate system associated with the manipulator. The advantage of proposed fault detection system is the simplicity of implementation and precision of detection of typical faults without knowledge about non-linear dynamic of robot and actuators. The results of mathematical simulation on the example of the PUMA-type manipulator using its kinematic model, position and orientation data of markers placed on working tool of manipulator, obtained from vision system fully confirm the efficiency of the proposed fault detection system.

Abstract: The subject of this work is to develop a control system for the two degree of freedom robot manipulator. Manipulators play an increasingly important role not only in flexible automation production systems but also in medicine and rehabilitation process [3]. High-speed and high-precision trajectory tracking are indispensable capabilities for versatile applications of manipulators. Even in well-known industrial applications manipulators are characterized by structural and / or unstructured uncertainty. Through structural uncertainty we miss a situation in which we have a dynamic model of the object, but because of the uncertainty unknown parameters such as load, inaccuracies in constant torque actuators etc. to create a properly working control system is a difficult issue. In contrast, unstructured uncertainty is related to the unknown of the dynamic model, which may be due to many reasons such as the presence of high-frequency modes of the manipulator, neglected time-delays, nonlinear friction etc. In this case, when the dynamic model of the system is not known a priori (or not available), the system must first be identified, then the control law is developed based on the estimated model [5, [6[7].These problems cause that it is very difficult to find good control system but simple. In this case, the different algorithms for control system of the manipulator was proposed. The first classical PD controller was tested. Next the system design for PD controller with compensation of gravitational forces.

Abstract: To make sure the feasibility of the three-point arc interpolation in any space after the MATLAB simulation, we applied it in FPGA (Field Programmable Gate Array, FPGA), finished the PCB board design, and used the arc interpolation controller to control the robot mechanical in this article. By analyzing the actual path, we found the results match the design requirements. The space controller guarantees the real-time and accuracy requirements of arc interpolation, and will have excellent practical value.

Abstract: Robot manipulator position and posture control is a popular topic in the field of uncalibrated visual servoing, this paper presents a kalman filter-based robot manipulator five-degrees of freedom uncalibrated vision positioning method. In the case of the fixed binocular cameras and manipulator parameters are unknown; firstly, the specific point and angle image features information in the camera image space were selected in order to describe the relative pose relationship between robot manipulator ends and goals. Then, the kalman filter online estimation algorithm was applied to calculate image Jacobian matrix which is mapping relationship between image space to cartesian mission space, and vision controller was designed in the image plane realized robot manipulator five-degrees of freedom uncalibrated vision positioning control. Finally, Six-degrees of freedom robot manipulator’s five-degrees of freedom uncalibrated visual positioning Simulink model established in the Matlab environment, and the simulation result show that kalman filter online estimation method made the robot manipulator rapid convergence to the desired position and posture with high accuracy.

Abstract: Hyper-redundant robot (HRR) manipulators are useful at navigating convoluted paths, but conventionally complicated to control. The control of a hyper-redundant manipulator is complex due to its redundancy. In this paper, a simple but effective control algorithm for obstacle avoidance is proposed. The algorithm derives a collision free path around known obstacles so that the end-effector of a variable length hyper redundant robot (VHRR) is able to reach the target location following the path without hitting the obstacles. The algorithm can be grouped into two tasks to drive the end-effector along the collision free trajectories: first, solve the inverse kinematics without disregarding the existence of obstacles in the system; and second, fit the manipulator to the respective prescribe trajectories. This method has the capability to allow VHRR maneuver within its workspace without penetrating to the neighboring obstruction. Further, this method is very effective in the sense that it forms a nice coil profile avoiding zig-zag configuration, and thus eliminates sharp turn on the robot. The performance of a VHRR was tested through simulation to demonstrate the effectiveness of the proposed method. The approach succeeded in delivering the path that avoids obstacle.

Abstract: This paper proposes a novel design method of the compliance controller for robot manipulators. The neurofuzzy compliance controller (NFCC) proposed herein is an algorithm designed to automatically determine the suitable compliance for a given task or environment. The scheme dose not require any priori knowledge on a robot manipulator dynamics, a manipulator controller and an environment, and thus, it can be easily applied to the control of any robot manipulator systems. Through a series of experiments, effectiveness of the algorithm has been verified.

Abstract: A fuzzy sliding control for the motion of the robot manipulator is proposed. The quasi-sliding mode control (QSMC) was added to the fuzzy control. Therefore the system inputs and fuzzy rules can be reduced in fuzzy sliding control. Then the system will be a Single Input Single Output (SISO) system and it has only five fuzzy rules. This makes design process much more simple. The simulation results show that by employing proposed controller to the position control of a three-axis robot manipulator, the overshoot was drastically reduced. Also fast rising time and a small extent of steady-state error can be obtained.

Abstract: Robots are required to operate in different environmental conditions facing varieties of end-effector to perform the workspace interactions. This paper deals with integrated CAD/CAE/CAM system for SCORBOT-ER Vu plus Industrial robot manipulator. The DH (DenavitHartenberg) coordinate transformation method was used to perform the robot position analysis. The robot manipulator parametric solid models were constructed using Pro/ENGINEER (Pro/E). Pro/Mechanica was used to simulate the dynamic simulation and working space, CATIA was used to implement the cutting simulation, and the prototype was manufactured using a CNC milling machine. Finally, a CAD/CAE/CAM integrated system for a robot manipulator was developed. This integrated system not only promotes automation capabilities for robot manipulator production, but also simplifies the CAD/CAE/CAM process for a robot manipulator.

Abstract: This paper presents an efficient force position control scheme for high precision drilling on soft surfaces using industrial robot. The control problem is divided into two parts; the gross motion control problem and the drilling control problem. In the gross motion stage the robot motion is controlled using computed torque technique. The drilling process is controlled using hybrid force position control that maintains the desired force and trajectory profiles. The soft surface is represented by single degree of freedom mass-spring-damper system. The performance of the system is tested using 6-dof PUMA 560 robot model.

Abstract: In order to obtain accurate dynamics parameters, a two-step method for robot dynamics parameters calibration is presented. In the first step a multidimensional matrix is constituted through transforming the configurations of robot manipulators and the product of quality and centroid coordinate about links is solved by using the least square method. In the second step decoupling dynamic equation of robot is deduced based on Newton-Euler algorithm, and through planning specific joint movement, the inertia tensor and centroid coordinate of robot links are calibrated making use of the pseudo inverse method. By the above two steps, the entire calibration of robot dynamic parameters is achieved. The correctness and feasibility of the presented calibration method is manifested by simulations and experiments.