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Controlled hovering of motor driven flapping wing micro aerial vehicles (FWMAVs) is challenging due to its limited control authority, large inertia, vibration produced by wing strokes, and limited components accuracy due to fabrication methods. In this work, we present a hummingbird inspired FWMAV with 12 grams of weight and 20 grams of maximum lift. We present its full non-linear dynamic model including...
Finding the Time-Optimal Parameterization of a Path (TOPP) subject to second-order constraints (e.g. acceleration, torque, contact stability, etc.) is an important and well-studied problem in robotics. In comparison, TOPP subject to third-order constraints (e.g. jerk, torque rate, etc.) has received far less attention and remains largely open. In this paper, we investigate the structure of the TOPP...
There has been consistent trials to make a hydraulic actuator to be effective in interactive robot applications that require high power and durability. However, conventional strategies to obtain this goal, such as force/torque servo control or adding elastic components, suffer from complexity, sensor problems, and reduced system robustness. In this paper, we show that introducing backdrivability to...
This paper presents that the joint torque control capability can be enhanced by adding physical damper to a series elastic actuator (SEA). Joint torque tracking of standard SEA has known limitations that the torque dynamics has an relative order of two, and, as a consequence, the torque controller often requires acceleration feedback when the desired torque is defined by a function of velocity (for...
In this paper, a lightweight central pattern generator(CPG) model is designed for a snake-like robot, to achieve smooth transition of body shape and locomotion speed. First, based on the convergence behavior of the gradient system, a lightweight CPG model with fast computing time is designed and compared with other widely adopted CPG models. Then, the body shape and locomotion speed transitions in...
In this paper the concept of a unified torque/impedance controller is applied to a pneumatically actuated, antagonistic robot joint. The investigated control algorithm consists of a cascaded structure in which the outer torque/impedance controller commands a desired torque to two cylinder-based force controllers. The torque-/impedance controller is equipped with a virtual tank that ensures passivity...
Despite the growing focus on the design of compliant mechanisms for robotics actuators that manifest several advantages in terms of robustness and interaction-related characteristics, the incorporation of elasticity in the actuation drive renders under-damped vibration modes and reduces the bandwidth of the system. The addition of damping principles into compliant systems can address such impediments...
Actuators for human-interactive robot systems require transparency and guaranteed safety. An actuation system is called transparent, when it is able to generate an actuation force as desired without any actuator dynamics. The requirements for the transparent actuation include high precision and large frequency bandwidth in actuation force generation, zero mechanical impedance, and so on. In this paper,...
Hand rehabilitation and training systems generally utilize either robot hands or robotic gloves [1–3]. These devices generate the repetitive gripping motion of fingers. The configuration of robot hands, which consist of electrical motors, wires, gears, etc., is complex, making them difficult to wear. To avoid these problems, many researchers have been developing soft robotic gloves that utilize flexible...
Motor control in ball and beam system consists of a beam structure which can be constructed with server electric motor to simulate the Underactuated mechanism system of robot. It can be contacted with a control theory and robot operation in balance behavior. It is well-known that robot structure in 1-D space with a motor to control system balance, which a simple ball and beam system to observe open-loop...
Teleoperating Cyber-Physical System (TCPS) is referred as a promising technology to extend human actions and intelligences to remote locations. The task of how to collaborate master operator and slaves to keep a desired formation is largely unexplored. This paper is concerned with a formation control problem for multi-slave TCPS, subjected to time-varying delay in cyber channels and actuator saturation...
In this paper, a practical control approach is suggested for series elastic actuators(SEAs) to generate the desired torque. Firstly, based on the analysis of a nonlinear SEA, the generic dynamics for a class of SEAs is summarized. Then the dynamic equations are transformed into a novel state-space form which is convenient for controller design. Finally, based on the recently developed finite-time...
This paper proposes an Inchworm Boring Robot(IBR) which is a type of wireline robot for planetary subsurface exploration. The IBR has two key tools-excavating auger and discharging auger which are directly interacted with the planetary regolith in the drilling process. For obtaining the drilling load characteristics of IBR, an inchworm-type drilling test-bed was developed for the drilling test of...
Sit to stand (STS) is an important daily activity that requires high joint torques and neuromuscular coordination. Robotics-based assistive devices have a great potential to increase independence and quality of life for elderly and disabled people. Comparison between motion kinematic of unassisted and assisted STS transfer shows that commercial lifters result in an abnormal pattern of motion. Therefore,...
In this paper, an integral sliding-mode control(ISMC) approach for the SEA torque control is presented. The controller is efficient even in the presence of external disturbances. In particular, the general dynamics of SEA system is described and some model transformation operations are performed, and then an integral sliding-mode controller is designed, on the basis of which some theoretical analysis...
In this paper, a Cartesian admittance controller with on-line gravity and friction observer compensation based on passivity theory for elastic joint robots is proposed. For this study, a compliance and position controller for joint and Cartesian level has been described with dual loop construction: an outer-loop admittance control, and an inner-loop motor side position with torque feedback control...
A robot may be at the risk of falling from a high place when it works in an unknown complex environment, so the attitude control ability of the robot in the air should be considered to reduce the damage caused by the wrong dropping posture. When a cat drops in the upside-down posture with zero angular momentum, it can always right itself and land on its feet safely. Inspired by this biological phenomenon,...
In this study, we aimed to develop a dragonfly-like flapping robot with four wings and achieve advanced flight such as hovering and sudden turn. We developed a two-wings-flapping-robot that links the flapping motion moving the wing up and down and feathering motion twisting the wing and perform at the same time. Next, we investigated the performance of the developed robot whether it's possible to...
The purpose of this paper is to propose a method for simulation of a manipulator robot with six degrees of freedom. This method is oriented to solve the problem of absence of real robots which will operate it in validation of mathematical modeling and control of the nonlinear systems. It described in the first part the geometry of the robot manipulator, then the method is used to create this simulator...
In this paper, a novel robust adaptive controller is proposed to simultaneously cope with the unknown nonlinear backlash, friction and dynamic uncertainties in the 3-DOF robotic head system. Inverse backlash compensation with on-line backlash parameter estimation and model-based friction compensation with off-line Stribeck friction identification are incorporated into this robust adaptive scheme....
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