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Surgeons are using robots as a tool to increase surgery accuracy and decrease procedure times. One of the main problems in robotic assisted orthopedic surgery is the force control in manipulator robots. It always has been subject of great study and interest in the scientific community, where the most common approach is to consider it as a hybrid control problem, due to their complexity and non-linearities...
Suppression of unnecessary vibration is an important aspect in control system design. Passive, semi active, and active suspension systems are used in vehicles to suppress vibrations and theoretically active suspension systems provide superior performance than the prior two types. This paper proposes a novel method to suppress vibrations using internal motor sensing method. The proposed active vibration...
In industry, wide varieties of work process have been automated with development of motion control. Factory automation have been sustaining modern mass production in the long run. However, a paradigm shift from mass production to high-mix low-volume production is caused in recent years. In such a production system, manual procedures of craftsmen are necessary from the points of high degrees of their...
This paper studies an integrated design method of sensorless force control and current control systems. The force control gain, the estimation bandwidth and quality factor of a 1st-order disturbance observer, the proportional and integral gain of an I-P current controllers are determined analytically and numerically by Pole assignment method and Coefficient diagram method(CDM). In the case of Pole...
This paper proposes a new position controller that is suitable for the use as the internal position servo of an admittance controller with bounded actuator forces. The new position controller approximately behaves as a proportional-integral-derivative (PID) controller with an acceleration feedforward in normal situations and as a sliding mode controller when the actuator force is saturated. The admittance...
A different way of force control is presented, that is especially advantageous for position controlled robots. Instead of usual force control laws we rely on the well tuned position control loop and just use the force sensor to measure the target pose or to predict the desired trajectory. In combination with a compliant sensor we introduce an inherently stable framework of force control which almost...
Within the research field of harvesting the energy of ocean waves, fluid power has been identified as a crucial technology in the Power Take-Off (PTO) design, due to the high torque densities required in Wave Energy Converters (WECs). The PTO is the technology converting the captured wave motion into electricity. However, conventional fluid power systems are characterized by offering poor efficiencies,...
In this paper, we report our investigation on the force-induced responses of zebrafish chorion before and after being perturbed by an externally applied prescribed force. Our experimental results show that application of an external force leads to a reduction in the stiffness of the zebrafish chorion, and that variation in such a reduction is strongly influenced by the perturbation time. Our results...
In this paper, we consider leader-based shape coordination for multi-robot systems. It is shown that having knowledge about desired velocity and effective interaction among individuals can help group members to continue the path even after leader failure. Since any collective behavior emerges from interaction among individuals, we propose interactive force to maintain minimum distance among agents...
The paper is concerned with a vehicle where each front wheel is equipped with a steering equipment. Aim of the paper is to analyze the behavior of the resulting driving apparatus during the steering maneuver in order to subsequently develop a suitable control system. The analysis is carried out in two stages, termed kinematic and dynamic. The kinematic analysis describes the steering maneuver when...
In this paper, the problem of position and force control of a robotic manipulator in contact with the environment is considered. The Hybrid Impedance Control (HIC) methodology is employed to control the position of the end-effector in such a way that the robot exhibits a desired dynamic property and hence desired Impedance which in turn results in tracking the interaction force. It is assumed that...
Medical-technical robotic systems are typical examples in which external contact forces on a system play an important role in the system dynamics. Mathematical modeling of these systems is challenging due to a variety of reasons. Mathematical models for the described class of systems contain differential equations with an associate algebraic equation, which outlines constrained system dynamics. Such...
In the case of a crane that carries its payload swinging on a cable precise control of a subsystem passively connected to a directly controllable one by elastic connection is needed. Normally the connected degree of freedom has little damping and it is apt to keep swinging accordingly. Traditionally the "input shaping technology" is applied for cranes to assist the human operator responsible...
An enhanced sliding mode control method for clutch disk towing separation testing machine is proposed in this paper. The mathematical model of each part has been established and the open loop simplified mathematical model has been deduced. Based on the simplified mathematical model, the identification model of the system is established using least-squares to identify the parameters of the system;...
This paper suggests a novel reaction force control in a robot manipulator by position feedback, motivated by the analysis of human musculoskeletal system. First, we suggest an analogy between a muscle force characteristic and two-degree-of-freedom control input structure so that the complicated human muscle structure can be reflected in robot manipulator control: reaction force generated by the viscoelasticity...
In this paper, force control is proposed to connect a molecular simulator to a haptic device. Most of the works dealing with this kind of simulators use position control to manipulate the molecules, with major stability concerns. These two control modes are compared in terms of adequacy with the molecular simulator. Stability with respect to the scaling coefficients introduced to connect the macro...
When flying an aircraft, the force feel of the control column provides the pilot with important information about the state of the aircraft. In a flight simulator this force feel needs to be simulated, which is the task of the control loading system. A hydraulic Control Loading System (CLS) was developed and installed on our flight simulator earlier days, but the CLS contains instabilities for some...
A snake can traverse cluttered and irregular environments by using irregularities around its body as push-points to aid the propulsion. This characteristic feature of biological snake locomotion, denoted obstacle-aided locomotion, is investigated for snake robot locomotion purposes in this paper. The paper presents a hybrid model of the dynamics of a planar snake robot interacting with obstacles in...
Turning is one of the most important maneuvers for biological and robotic fish. In our group's prior work, an analytical framework was proposed for modeling the steady turning of fish, given asymmetric, periodic body/tail movement or deformation. However, the approach was not illustrated with simulation or validated with experiments. The contributions of the current paper are three fold. First, an...
In this paper, we consider a 3D grasping problem. In previous work, we presented the central-axis approach and proven its capability to analyze multifingered grasps. In the present paper, we extend our study by developing and analyzing modified force-closure algorithms, and giving rigorous theoretical demonstrations. Through numerical simulations, we show that the proposed approach is computationally...
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