The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The communication channel delay can adversely affect performance and stability of bilateral teleoperation systems. This paper proposes a discrete-time linear quadratic Gaussian (LQG) controller that delivers a transparent stable response in the presence of constant communication latency. Different controllers are designed for each phase of operation, i.e. free motion and contact with rigid environments...
This paper presents a physical model of a spark ignition (SI) engine valve actuated by a voice coil actuator (VCA) and proposes a novel control strategy that achieves fast transitions and low seating velocities with high precision position control. The control strategy is based on applying two different pulse width modulated (PWM) voltages for transient and steady state performance. This novel switching...
This paper presents the implementation of a two degree-of-freedom, high-precision, magnetic-levitation-based positioning system. The apparatus employs one permanent magnet linear synchronous motor and is constructed by Quanser Inc. The paper focuses on the design and testing of a nonlinear controller required for actuating the positioning system. The controller is based on feedback linearization and...
This paper presents the development of an experimental testbed for multiple vehicles formation control. This four 3-DOF helicopter-testbed in the Flight Systems and Control (FSC) Laboratory of University of Toronto can be applied to validate the effectiveness of formation flight and cooperative (coordination) control strategy. Each helicopter has three degrees of freedom, in elevation, pitch and travel...
In this paper a motion planner capable of laying a trajectory for a robot operating in a complex, stationary, unknown environment based on the sensory data it acquires online from its finite range sensors is suggested. The planner utilizes concepts from the area of mechanics of solids to generate the navigation field. A new setting for the biharmonic potential field approach to planning (K. Hashimoto...
This paper addresses the design and implementation of a digital tracking controller for a fast tool servo to drive the cutting tool to machine workpieces with noncircular cross section in a lathe. The main idea of the controller lies in its actively rejecting disturbance while maintaining the simplicity and intuitiveness of existing PID approach. The proposed active disturbance rejection controller...
The paper develops a nonlinear backstepping design scheme for the balancing control of the Furuta pendulum which is an underactuated rotational inverted pendulum system. The control objective is not only to swing up the pendulum from downward position to upright, but also to drive the actuating arm to return to its starting point. The linearized Furuta pendulum system is investigated in advance in...
In this paper, a planar waypoint guidance synthesis for missiles or unmanned aerial vehicles using the optimal impact-angle-control laws is proposed. The energy optimal trajectory optimization problem with waypoint constraints can be converted to an unconstrained optimization problem of finding the optimal waypoint pass angles for the energy impact-angle-control laws. These optimal waypoint pass angles...
This paper focuses on the problem of global stabilization of a two-wheeled mobile robot. We propose a global exponentially stabilizing controller for a two-wheel mobile robot based on the discontinuous finite-time homogeneous controller for chained systems. Moreover, we demonstrate the effectiveness of proposed method through an experiment using a "Khepera 2" mobile robot
In this paper, the problem of combined target model and relative pose estimation for position-based visual servoing is addressed. The target object is assumed to be stationary with at least 3 distinguishable feature points. The midpoint triangulation method and a rough estimation method are developed for initial estimation of the target model and relative pose of target in current robot end-effector...
In this paper, an adaptive motion/force controller is developed for bilateral teleoperation systems. Design of an output feedback model reference adaptive controller (MRAC) at the remote site improves the position/velocity response with stability guarantee and a similar controller at the master site enhances the force tracking as the transmission time delay varies
In this paper we build on previous work by the authors on spacecraft formation motion design for fuel-image optimality by Hussein, Scheeres and Hyland (2005). Previous results indicate a tradeoff between image quality and fuel expenditure by I. I. Hussein et al. (2005). In this paper we state results relating image quality to the trajectory of a sparse system of TV telescopes. This relationship is...
This work deals with feedforward control of a New England Affiliated Technologies (NEAT) four-axis positioning system which is designed for single mode optical fiber alignment applications. Due to the presence of a velocity deadzone with variable boundaries, a model reference feedforward control is implemented to improve the transient response. The algorithm is efficient in execution while robust...
This paper presents a nonlinear control approach to the position tracking for a hydraulic actuation system, which consists mostly of a servovalve and an asymmetric single-rode cylinder. The proposed control approach is derived using a sliding mode control strategy. The tracking performance and the robustness against considerable parametric uncertainties (uncertain fluid compressibility, load variations,...
We discuss a vision based control approach applied to a mobile robot with a hand-eye system. Car-like mobile robots require switchback motion to change the posture. However, a camera mounted on the robot may lose sight of the target object because of this motion. In this paper, we propose a control method for nonholonomic wheeled mobile robots without changing the camera view point in a hand-eye system...
A robotic excavator must be able to operate in all three states of manipulator motion: free-space, contact and exertion of a force against an environment. A position accommodation control scheme is ideally suited for this task. The position accommodation method described in this study uses a position controller to track a pre-defined trajectory in the absence of a force at the excavator bucket. If...
A trajectory tracking control scheme for the main rotor speed in an electrically powered helicopter prototype is presented. The scheme is based on the concept of differentially flat systems which makes use of a rotor model obtained with the help of an appropriate design and implementation of sensors and actuators. Experimental results are presented where the performance of the control scheme is evaluated
Robust and real-time relative pose estimation is an integral part of a position-based visual servoing (PBVS) system. Traditionally, extended Kalman filter (EKF) has been used to solve for the nonlinear relative end-effector to object pose equations from a set of 2D-3D point correspondences. However, the performance of the estimation filter and the convergence of the pose estimates are highly sensitive...
This paper deals with the problem of guiding an operator during the execution of a 5 degrees of freedom surgical teleoperation task. The work is focused on the feasibility of a spine surgery telerobotic system, made up of a haptic master, a slave robot, an optical tracking device and a main control unit. With this system, the surgeon performs a drilling operation by using a telerobotic device, being...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.