Farhad Aghili

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This paper presents a unified approach for inverse and direct dynamics of constrained multibody systems that can serve as a basis for analysis, simulation, and control. The main advantage of the dynamics formulation is that it does not require the constraint equations to be linearly independent. Thus, a simulation may proceed even in the presence of(More)
This paper describes the design and development of a mechatronic testbed facility which allows high-fidelity and low-cost testing of the joint prototypes of a manipulator in a highly flexible environment. The testbed system consists of a set of load motors whose shafts are connected to those of the joint prototypes through a set of torque transducers. A(More)
Most studies on adaptive coordination of multi-robot systems assume exact knowledge of system kinematics and deal only with dynamic uncertainties. However, many industrial applications involve tasks in which a multi-robot system interacts with geometrically unknown environments. In this paper, we consider a multi-robot system grasping a rigid object in(More)
This paper describes the design and control of an integrated direct-drive joint suitable for applications that require a high-precision motion control system. The joint integrates a directdrive synchronous motor with axial air gap, a torque sensor, and a high-resolution position sensor. The key design aspects of the integrated joint, like the motor’s(More)
This paper is focused on an adaptive vision system for the guidance of a robot to intercept a non-cooperative target satellite with unknown dynamics parameters. A Kalman filter is developed to reliably estimate the states of the object as well as all of its inertial parameters - namely, the moment-of-inertia ratios, the center-of-mass location, and the(More)
In this paper, we present a methodology for emulation of a target robot operating in a complex environment by using an actual robot. The emulation scheme aims to replicate the dynamical behavior of the target robot interacting with an environment, without dealing with a complex calculation of the contact dynamics. This method forms a basis for the task(More)
The application of joint-torque sensory feedback (JTF) in robot control has been proposed in the past that, unlike the model-based controllers, does not require the dynamic model of the robot links. JTF, however, assumes precise measurement of joint torque and accurate friction model of the joints. This paper presents an adaptive JTF control algorithm that(More)
A new torque control strategy for brushless motors is presented, which results in minimum torque ripple and copper losses. The motor model assumes linear magnetics, but contains a current limit which can delimit the onset of magnetic saturation, or be the motor amplifier current limit, whichever is reached first. The control problem is formulated and solved(More)