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The aim of this paper is to design a torque sensorless controller for a human-electric hybrid bicycle. The human input torque is estimated using the disturbance observer to design the controller for electric motor to assist the cyclist based on the requirement. The closed loop stability is ensured for various assist condition as per the standard. Simulation results are presented to validate the proposed...
In this paper we propose to track online computed force trajectories to control the energy of various types of pendulum-like objects. The considered pendulum-like objects can be controlled by multiple agents and swing in different oscillation degrees of freedom. Our goal is to excite one specific oscillation, the intended oscillation, while damping all other disturbance oscillations. By approximating...
A self optimizing control algorithm is applied to the ABS control problem where the algorithm accomplishes to maximize friction potential of the tires during braking in unknown road conditions. Simulation studies are conducted to show effectiveness of the controller. The algorithm is also tested in an experimental setup. In order to control a real electromechanical braking system, necessary observers...
Managed Pressure Drilling (MPD) in oil-gas industry remains a challenge problem. As the annulus is completely clogged, upstream choke pressure measurement can be used to control the well downhole pressure. To reinforce the tunnel face, MPD becomes difficult as the annulus is totally open. In this paper, we propose a finite dimensional model to all fluid phenomena between the main pump till the fluid...
In this paper, a distributed approach for the estimation of kinematic and inertial parameters of an unknown rigid body is presented. The body is manipulated by a pool of ground mobile manipulators. Each robot retrieves a noisy measurement of its velocity and the contact forces applied to the body. Kinematics and dynamics arguments are used to distributively estimate the relative positions of the contact...
We describe an on-line observer that allows to monitor the soil-tire contact longitudinal stiffness of off-road vehicles equipped with low cost sensors. The knowledge of such a value is a milestone in the development of active security devices, or at least a mean to inform the driver about the longitudinal stability of his vehicle. Indeed, these vehicles are frequently subject to ground changes and...
A sensorless control method of a tubular linear permanent magnet motor is presented. The sensorless algorithm is based on back-EMF estimation and consists of two observer stages. First, the back-EMF vector is estimated using a modified disturbance observer. Next, a Phased Locked Loop (PLL) tracking observer is implemented to extract the position from the back-EMF vector. The algorithm does not require...
The paper deals with the problem of controlling the impact between a mechanical system, having n degrees of freedom, and a body possibly subject to elastic/plastic. deformations. Goal of the proposed control scheme is the regulation of the impact force to a desired vaine, while imposing a prescribed configuration to the system, even in presence of possible plastic deformations of the body. The behaviour...
A hydraulic parallel link servomechanism which has hydraulic cylinders as variable-length links, is applied to a motion control system with three degrees of freedom. Preview control is applied to a profile tracing system. A disturbance observer and H∞ control are applied to the system to improve the accuracy and achieve robust stability. The effectiveness of these. control methods is experimentally...
Large space structures often consist of truss elements which are connected by bolted joints. The dry friction energy dissipation in these junctions turns out to be a major source of damping. For vibration suppression, the joints are designed such that the normal force to a frictional interface is controlled which improves damping performance. The use of active control to vary the normal contact force...
The aim of this paper is to study the force/position tracking problem of robot manipulators using the well-known hybrid/position control approach. It is shown that the robot system is closed-loop stable and that the desired force can always be reached. A systematic procedure of control synthesis is presented and stability conditions for the control parameters are derived. No velocity measurements...
In this paper we present a design procedure for semiactive suspensions of road vehicles, where the shock absorber (damper) uses magneto-rheological fluid instead of oil. We first derive a target active control law that minimizes a quadratic performance index and takes the form of a feedback control law. Then, we approximate the target law by controlling the damper coefficient f of the semiactive suspension...
This paper considers H2 controllers implemented using an explicit observer for systems subjected to input magnitude saturation. It is stressed that the approach of only focusing on controller windup, by using fundamental observer anti-windup technique where the observer is fed by the saturated control signal, could imply severely deteriorated closed-loop characteristics and even sustained oscillations.
Pneumatic muscles are interesting in their use as actuators in robotics, because they have a high power/weight ratio, a high tension force and a long durability. However, their physical model is highly nonlinear. In this paper a nonlinear control strategy is presented. The main objective is to control a trolley, which is driven by an artificial muscle to follow a reference path. The cascaded control,...
Simultaneous position and force tracking are two critical factors in teleportation systems to achieve transparency. In this paper, a new control scheme is proposed to guarantee asymptotic position and force tracking in teleportation systems with disturbances. To this end, two sliding mode controllers are designed for the master and the slave robots respectively and are incorporated into the 4-channel...
The skill preservation of an expert has been a serious problem for countries with aging population because decrease of the number of successors. The concepts of haptic database and force sensor recorder which have been developed recently suggests solutions of using third multimedia type of haptic communication. Haptic information is a bilateral information of the law of action and reaction. The reaction...
This paper proposes an enhanced force limiting gripper to avoid object deformation when it is in contact with the slave due to excessive forces imposed by the master operator in bilateral control. The force lock protects the gripped object on the slave and the attainment of the force limit is notified to the master operator via a small vibration. Master operator is expected to experience a spring...
Trains get electric power from power supplier through power collectors. Typical examples of this structure are trolley wire and pantographs, or third rail and collector shoes. Contact force is generated when a power collector contacts power supplier in both systems. Sometimes there are some wave form reductions on the surface of power supplier, and it causes fluctuation of contact force. This force...
This paper proposes a power assist control methodology based on an operation force observer for a nursing lift, where operation force of nurse applying to the nursing lift is estimated using an operation force observer. In order to improve estimation performance for the operation force, a position information based disturbance observer is applied, in which no differentiators are needed to calculate...
This paper analyzes the stability of acceleration-based bilateral control (ABC) using a disturbance observer (DOB) and a reaction force observer (RFOB) by considering the effect of environmental impedance and modeling error. ABC is one of the control method to enable highly precise transmission of haptic sensation between master and slave robots. Conventionally, ABC is analyzed by using slave side...
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